Version 4.8.1
Copyright © 2001 - 2024 The SCons Foundation
Released Tue, 03 Sep 2024 17:46:32 -0700
SCons is an extensible open source build system that orchestrates the construction of software (and other tangible products such as documentation files) by determining which component pieces must be built or rebuilt and invoking the necessary commands to build them. SCons offers many features to improve developer productivity such as parallel builds, caching of build artifacts, automatic dependency scanning, and a database of information about previous builds so details do not have to be recalculated each run.
scons requires Python 3.6 or later to run; there should be no other dependencies or requirements, unless the experimental Ninja tool is used (requires the ninja package).
Changed in version 4.3.0: support for Python 3.5 is removed. The CPython project retired 3.5 in Sept 2020: https://peps.python.org/pep-0478.
Changed in version 4.8.0: support for Python 3.6 is deprecated and will be removed in a future SCons release. The CPython project retired 3.6 in Sept 2021: https://peps.python.org/pep-0494.
You set up an SCons build by writing a script that describes things to build (targets), and, if necessary, the rules to build those files (actions). SCons comes with a collection of Builder methods which supply premade Actions for building many common software components such as executable programs, object files and libraries, so that for many software projects, only the targets and input files (sources) need be specified in a call to a builder.
SCons operates at a level of abstraction above that of pure filenames.
For example if you specify a shared library target named "foo",
SCons keeps track of the actual operating system dependent filename
(such as libfoo.so on a GNU/Linux system
and foo.dll on Windows),
and gives you a handle to refer to that target in other steps,
so you don't have to use system-specific strings yourself.
SCons can also scan automatically for dependency information,
such as header files included by source code files
(for example, #include
preprocessor directives in C or C++ files),
so these implicit dependencies do not
have to be specified manually.
SCons supports the ability to define new scanners
to support additional input file types.
Information about files involved in the build,
including a cryptographic hash of the contents of source files,
is cached for later reuse.
By default this hash (the content signature)
is used to decide if a file has changed since the last build,
although other algorithms can be used by selecting an appropriate
Decider function.
Implicit dependency files are also part of out-of-date computation.
The scanned implicit dependency information can optionally be
cached and used to speed up future builds.
A hash of each executed build action (the build signature)
is also cached, so that changes to build instructions (changing flags, etc.)
or to the build tools themselves (e.g. a compiler upgrade)
can also trigger a rebuild.
SCons supports separated source and build
directories (also called "out-of-tree builds")
through the definition of
variant directories
Using a separated build directory helps keep
the source directory clean of artifacts when doing searches,
allows setting up differing builds ("variants") without conflicts,
and allows resetting the build by just removing the build directory
(note that SCons does have a "clean" mode as well).
See the VariantDir description for more details.
When invoked, scons
looks for a file describing the build configuration
in the current directory and reads that in.
The file is by default named SConstruct,
although some variants of that,
or a developer-chosen name, are also accepted
(see the section called “SConscript Files”).
If found, the currrent directory
is set as the project top directory.
Certain command-line options specify alternate
places to look for SConstruct
(see
-C,
-D,
-u and
-U),
which will set the project top directory to the path found.
A path to the build configuration can also be
specified with the
-f option,
which leaves the current directory as the project top directory.
The build configuration may be split into multiple files:
the SConstruct file can specify additional
configuration files by calling the
SConscript function,
and any file thus invoked may
include further files in the same way.
By convention,
these subsidiary files are named
SConscript,
although any name may be used.
As a result of this naming convention,
the term SConscript files
is used to refer
generically to the complete set of
configuration files for a project
(including the SConstruct file),
regardless of the actual file names or number of such files.
A hierarchical build is not recursive - all of
the SConscript files are processed in a single pass
so that scons has a picture of the complete
dependency tree when it begins considering what needs building.
Each SConscript file is processed in a separate context
so settings made in one script do not leak into another;
information can however be shared explicitly between scripts.
Before reading the SConscript files,
scons
looks for a site directory -
a directory named site_scons
is searched for in various system directories and in the
project top directory, or if the
--site-dir
option is given, checks only for that directory.
Found site directories are prepended
to the Python module search path (sys.path),
thus allowing modules in such directories to be imported in
the normal Python way in SConscript files.
For each found site directory,
(1) if it contains a file site_init.py
that file is evaluated,
and (2) if it contains a directory
site_tools the path to that directory
is prepended to the default toolpath.
See the
--site-dir
and
--no-site-dir
options for details on default paths and
controlling the site directories.
SConscript files are written in the
Python programming language.
For many tasks, the simple syntax can be understood from examples,
so it is normally not necessary to be a Python
programmer to use SCons effectively.
SConscript files are executed in a context that makes
the facilities described in this manual page directly
available (that is, no need to import).
Standard Python scripting capabilities
such as flow control, data manipulation, and imported Python modules
are available to use in more complicated build configurations.
Other Python files can be made a part of the build system,
but they do not automatically have the SCons context and
need to import it if they need access (described later).
SCons reads and executes all of the included SConscript files
before
it begins building any targets.
Progress messages show this behavior
(the state change lines - those
beginning with the scons: tag -
may be suppressed using the
-Q option):
$ scons foo.out
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
cp foo.in foo.out
scons: done building targets.
$
To assure reproducible builds,
SCons
uses a restricted execution environment
for running external commands used to build targets,
rather then propagating the full environment
in effect at the time scons was called.
This helps avoid problems like picking up accidental
or malicious settings,
temporary debug values that are no longer needed,
or a developer having different settings than another
(or than the CI pipeline).
Environment variables needed for the proper
operation of such commands must be set in the
execution environment explicitly,
either by assigning the desired values,
or by picking those values individually or collectively
out of environment variables exposed by the Python
os.environ dictionary
(as external program inputs they should be validate
before use).
The execution environment for a given construction environment
is its $ENV value.
A small number of environment variables are picked up automatically
by scons itself (see the section called “ENVIRONMENT”).
In particular, if a compiler or other external command
needed to build a target file
is not in scons' idea of a standard system location,
it will not be found at runtime unless
you explicitly add the location into the
execution environment's PATH element.
This is a particular consideration on Windows platforms,
where it is common for a command to install into an app-specific
location and depend on setting
PATH in order for them to be found,
which does not automatically work for SCons.
One example approach is to
extract the entire PATH
environment variable and set that into the
execution environment:
import os
env = Environment(ENV={'PATH': os.environ['PATH']})
Similarly, if the commands use specific external environment variables that scons does not recognize, they can be propagated into the execution environment:
import os
env = Environment(
ENV={
'PATH': os.environ['PATH'],
'MODULEPATH': os.environ['MODULEPATH'],
'PKG_CONFIG_PATH': os.environ['PKG_CONFIG_PATH'],
}
)
Or you can explicitly propagate the invoking user's complete external environment:
import os env = Environment(ENV=os.environ.copy())
This comes at the expense of making your build dependent on the user's environment being set correctly, but it may be more convenient for some configurations. It should not cause problems if done in a build setup which tightly controls how the environment is set up before invoking scons, as in many continuous integration setups.
The above fragments are intended to illustrate a concept.
It is normally not a good idea to wipe out the entire
default value of the execution environment
(env["ENV"]),
as it may carry important information for the
execution of build commands.
scons
is normally executed in a top-level directory containing an
SConstruct file (the project top directory).
When scons is invoked,
the command line (including the contents of the
SCONSFLAGS
environment variable, if set) is processed.
Command-line options (see the section called “OPTIONS”) are consumed.
Any variable argument assignments are collected, and
remaining arguments are taken as targets to build.
Values of variables to be passed to the SConscript files
may be specified on the command line:
scons debug=1
These variables are available through the
ARGUMENTS dictionary,
and can be used in the SConscript files to modify
the build in any way:
if ARGUMENTS.get("debug", ""):
env = Environment(CCFLAGS="-g")
else:
env = Environment()
The command-line variable arguments are also available
in the ARGLIST list,
indexed by their order on the command line.
This allows you to process them in order rather than by name,
if necessary. Each ARGLIST entry is a tuple consisting
of the name and the value.
See the section called “Command-Line Construction Variables” for more information.
scons
can maintain a cache of target (derived) files that can
be shared between multiple builds. When derived-file caching is enabled in an
SConscript file, any target files built by
scons
will be copied
to the cache. If an up-to-date target file is found in the cache, it
will be retrieved from the cache instead of being rebuilt locally.
Caching behavior may be disabled and controlled in other ways by the
--cache-force,
--cache-disable,
--cache-readonly,
and
--cache-show
command-line options. The
--random
option is useful to prevent multiple builds
from trying to update the cache simultaneously.
By default,
scons
searches for known programming tools
on various systems and initializes itself based on what is found.
On Windows systems which identify as win32,
scons
searches in order for the
Microsoft Visual C++ tools,
the MinGW tool chain,
the Intel compiler tools,
and the PharLap ETS compiler.
On Windows system which identify as cygwin
(that is, if scons is invoked from a cygwin shell),
the order changes to prefer the GCC toolchain over the MSVC tools.
On OS/2 systems,
scons
searches in order for the
OS/2 compiler,
the GCC tool chain,
and the Microsoft Visual C++ tools,
On SGI IRIX, IBM AIX, Hewlett Packard HP-UX, and Oracle Solaris systems,
scons
searches for the native compiler tools
(MIPSpro, Visual Age, aCC, and Forte tools respectively)
and the GCC tool chain.
On all other platforms,
including POSIX (Linux and UNIX) and macOS platforms,
scons
searches in order
for the GCC tool chain,
and the Intel compiler tools.
The defaul tool selection can be pre-empted
through the use of the tools
argument to construction environment creation methods,
explcitly calling the Tool loader,
the through the setting of various setting of construction variables.
SCons acts on the selected targets, whether the requested operation is build, no-exec or clean. Targets are selected as follows:
Targets specified on the command line.
These may be files, directories,
or phony targets defined using the Alias function.
Directory targets are scanned by scons for any targets
that may be found with a destination in or under that directory.
The targets listed on the command line are made available in the
COMMAND_LINE_TARGETS list.
If no targets are specified on the command line,
scons will select those targets
specified in the SConscript files via calls
to the Default function. These are
known as the default targets,
and are made available in the
DEFAULT_TARGETS list.
If no targets are selected by the previous steps,
scons selects the current directory for scanning,
unless command-line options which affect the directory
for target scanning are present
(-C,
-D,
-u,
-U).
Since targets thus selected were not the result of
user instructions, this target list is not made available
for direct inspection; use the
--debug=explain
option if they need to be examined.
scons always adds to the selected targets any intermediate targets which are necessary to build the specified ones. For example, if constructing a shared library or dll from C source files, scons will also build the object files which will make up the library.
To ignore the default targets specified
through calls to Default and instead build all
target files in or below the current directory
specify the current directory (.)
as a command-line target:
scons .
To build all target files, including any files outside of the current directory, supply a command-line target of the root directory (on POSIX systems):
scons /
or the path name(s) of the volume(s) in which all the targets should be built (on Windows systems):
scons C:\ D:\
A subset of a hierarchical tree may be built by remaining at the project top directory and specifying the subdirectory as the target to build:
scons src/subdir
or by changing directory and invoking scons with the
-u
option, which traverses up the directory
hierarchy until it finds the
SConstruct
file, and then builds
targets relatively to the current subdirectory (see
also the related
-D
and
-U
options):
cd src/subdirscons -u .
In all cases, more files may be built than are requested, as scons needs to make sure any dependent files are built.
Specifying "cleanup" targets in SConscript files is
usually not necessary.
The
-c
flag removes all selected targets:
scons -c .
to remove all target files in or under the current directory, or:
scons -c build export
to remove target files under build
and export.
Additional files or directories to remove can be specified using the
Clean function in the SConscript files.
Conversely, targets that would normally be removed by the
-c
invocation can be retained by calling the
NoClean function with those targets.
scons
supports building multiple targets in parallel via a
-j
option that takes, as its argument, the number
of simultaneous tasks that may be spawned:
scons -j 4
builds four targets in parallel, for example.
In general, scons supports the same command-line options as GNU Make and many of those supported by cons.
-b
Ignored for compatibility with non-GNU versions of Make
-c,
--clean,
--remove
Set clean mode.
Clean up by removing the selected targets,
well as any files or directories associated
with a selected target through calls to the Clean function.
Will not remove any targets which are marked for
preservation through calls to the NoClean function.
While clean mode removes targets rather than building them,
work which is done directly in Python code in SConscript files
will still be carried out. If it is important to avoid some
such work from taking place in clean mode, it should be protected.
An SConscript file can determine which mode
is active by querying GetOption, as in the call
if GetOption("clean"):
--cache-debug=file
Write debug information about
derived-file caching to the specified
file.
If
file
is a hyphen
(-),
the debug information is printed to the standard output.
The printed messages describe what signature-file names
are being looked for in, retrieved from, or written to the
derived-file cache specified by CacheDir.
--cache-disable,
--no-cache
Disable derived-file caching. scons will neither retrieve files from the cache nor copy files to the cache. This option can be used to temporarily disable the cache without modifying the build scripts.
--cache-force,
--cache-populate
When using CacheDir,
populate a derived-file cache by copying any already-existing,
up-to-date derived files to the cache,
in addition to files built by this invocation.
This is useful to populate a new cache with
all the current derived files,
or to add to the cache any derived files
recently built with caching disabled via the
--cache-disable
option.
--cache-readonly
Use the derived-file cache, if enabled, to retrieve files, but do not not update the cache with any files actually built during this invocation.
--cache-show
When using a derived-file cache show the command
that would have been executed to build the file
(or the corresponding *COMSTR
contents if set)
even if the file is retrieved from cache.
Without this option, scons shows a cache retrieval message
if the file is fetched from cache.
This allows producing consistent output for build logs,
regardless of whether a target
file was rebuilt or retrieved from the cache.
--config=mode
Control how the Configure
call should use or generate the
results of configuration tests.
mode should be one of
the following choices:
SCons will use its normal dependency mechanisms to decide if a test must be rebuilt or not. This saves time by not running the same configuration tests every time you invoke scons, but will overlook changes in system header files or external commands (such as compilers) if you don't specify those dependecies explicitly. This is the default behavior.
If this mode is specified, all configuration tests will be re-run regardless of whether the cached results are out of date. This can be used to explicitly force the configuration tests to be updated in response to an otherwise unconfigured change in a system header file or compiler.
If this mode is specified,
no configuration tests will be rerun
and all results will be taken from cache.
scons will report an error
if --config=cache is specified
and a necessary test does not
have any results in the cache.
-C directory,
--directory=directory
Run as if scons was started in
directory
instead of the current working directory.
That is, change directory before searching for the
SConstruct,
Sconstruct,
sconstruct,
SConstruct.py,
Sconstruct.py
or
sconstruct.py
file or doing anything else.
When multiple
-C
options are given, each subsequent non-absolute
-C directory
is interpreted relative to the preceding one.
See also options
-u,
-U
and
-D
to change the SConstruct search behavior when this option is used.
-D
Works exactly the same way as the
-u
option except for the way default targets are handled.
When this option is used and no targets are specified on the command line,
all default targets are built, whether or not they are below the current
directory.
--debug=type[,type...]
Debug the build process.
type
specifies the kind of debugging info to emit.
Multiple types may be specified, separated by commas.
The following types are recognized:
Prints additional time profiling information. For
each command, shows the absolute start and end times.
This may be useful in debugging parallel builds.
Implies the --debug=time option.
New in version 3.1.
Print how many objects are created
of the various classes used internally by SCons
before and after reading the SConscript files
and before and after building targets.
This is not supported when SCons is executed with the Python
-O
(optimized) option
or when the SCons modules
have been compiled with optimization
(that is, when executing from
*.pyo
files).
Print a line for each unlink/relink (or copy) of a file in a variant directory from its source file. Includes debugging info for unlinking stale variant directory files, as well as unlinking old targets before building them.
Print an explanation of why scons is deciding to (re-)build the targets it selects for building.
Instruct the scanner that searches for libraries to print a message about each potential library name it is searching for, and about the actual libraries it finds.
Print the include tree after each top-level target is built. This is generally used to find out what files are included by the sources of a given derived file:
$ scons --debug=includes foo.o
Write info to a JSON file for any of the following debug options if they are enabled: memory, count, time, action-timestamps
The default output file is scons_stats.json
The file name/path can be modified by using DebugOptions for example DebugOptions(json='path/to/file.json')
$ scons --debug=memory,json foo.o
Prints a summary of hits and misses using the Memoizer, an internal subsystem that counts how often SCons uses cached values in memory instead of recomputing them each time they're needed.
Prints how much memory SCons uses
before and after reading the SConscript files
and before and after building targets.
Prints a list of the various objects of the various classes used internally by SCons.
Run scons under control of the
pdb
Python debugger.
$ scons --debug=pdb
> /usr/lib/python3.11/site-packages/SCons/Script/Main.py(869)_main()
-> options = parser.values
(Pdb)
pdb will stop at the
beginning of the scons main routine on startup.
The search path (sys.path)
at that point will include the location of the running scons,
but not of the project itself.
If you need to set breakpoints in your project files,
you will either need to add to the path,
or use absolute pathnames when referring to project files.
A .pdbrc file in the project root
can be used to add the current directory to the search path
to avoid having to enter it by hand,
along these lines:
sys.path.append('.')
Due to the implementation of the
pdb module,
the break,
tbreak
and clear
commands only understand references to filenames
which have a .py extension.
(although the suffix itself can be omitted),
except if you use an absolute path.
As a special exception to that rule, the names
SConstruct and SConscript are recognized without
needing the .py extension.
Changed in version 4.6.0:
The names SConstruct and SConscript are now
recognized without requiring
.py suffix.
Changed in version 4.8.0:
The name SCsub is now recognized
without requiring .py suffix.
Print a line each time any target (internal or external)
is prepared for building.
scons
prints this for each target it considers, even if that
target is up to date (see also --debug=explain).
This can help debug problems with targets that aren't being
built; it shows whether
scons
is at least considering them or not.
Print the raw command line used to build each target before the construction environment variables are substituted. Also shows which targets are being built by this command. Output looks something like this:
$ scons --debug=presub
Building myprog.o with action(s):
$SHCC $SHCFLAGS $SHCCFLAGS $CPPFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
...
Prints an internal Python stack trace when encountering an otherwise unexplained error.
Prints various time profiling information:
The time spent executing each individual build command
The total build time (time SCons ran from beginning to end)
The total time spent reading and executing SConscript files
The total time SCons itself spent running
(that is, not counting reading and executing SConscript files)
The total time spent executing all build commands
The elapsed wall-clock time spent executing those build commands
The time spent processing each file passed to the SConscript function
(When
scons
is executed without the
-j
option,
the elapsed wall-clock time will typically
be slightly longer than the total time spent
executing all the build commands,
due to the SCons processing that takes place
in between executing each command.
When
scons
is executed
with
the
-j
option,
and your build configuration allows good parallelization,
the elapsed wall-clock time should
be significantly smaller than the
total time spent executing all the build commands,
since multiple build commands and
intervening SCons processing
should take place in parallel.)
Enables output indicating entering and exiting each SConscript file.
--diskcheck=type
Enable specific checks for
whether or not there is a file on disk
where the SCons configuration expects a directory
(or vice versa)
when searching for source and include files.
type
can be an available diskcheck type or
the special tokens all or none.
A comma-separated string can be used to select multiple checks.
The default setting is all.
Current available checks are:
to check that files and directories on disk match SCons' expected configuration.
Disabling some or all of these checks can provide a performance boost for large configurations, or when the configuration will check for files and/or directories across networked or shared file systems, at the slight increased risk of an incorrect build or of not handling errors gracefully.
--duplicate=ORDER
There are three ways to duplicate files in a build tree: hard links,
soft (symbolic) links and copies. The default policy is to
prefer hard links to soft links to copies. You can specify a
different policy with this option.
ORDER
must be one of
hard-soft-copy
(the default),
soft-hard-copy,
hard-copy,
soft-copy
or
copy.
SCons will attempt to duplicate files using
the mechanisms in the specified order.
--enable-virtualenv
Import virtualenv-related variables to SCons.
--experimental=feature
Enable experimental features and/or tools.
feature can be an available feature name or
the special tokens all or none.
A comma-separated string can be used to select multiple features.
The default setting is none.
Current available features are:
ninja (New in version 4.2),
legacy_sched (New in version 4.6.0).
No Support offered for any features or tools enabled by this flag.
New in version 4.2 (experimental).
-f file,
--file=file,
--makefile=file,
--sconstruct=file
Use
file
as the initial SConscript file.
Multiple
-f
options may be specified,
in which case
scons
will read all of the specified files.
-h,
--help
Print a local help message for this project,
if one is defined in the SConscript files
(see the Help function),
plus a line that refers to the standard SCons help message.
If no local help message is defined,
prints the standard SCons help message
(as for the -H option)
plus help for any local options defined through AddOption.
Exits after displaying the appropriate message.
Note that use of this option requires SCons to process
the SConscript files, so syntax errors may cause
the help message not to be displayed.
--hash-chunksize=KILOBYTES
Set the block size used when computing content signatures to
KILOBYTES.
This value determines the size of the chunks which are read in at once when
computing signature hashes. Files below that size are fully stored in memory
before performing the signature computation while bigger files are read in
block-by-block. A huge block-size leads to high memory consumption while a very
small block-size slows down the build considerably.
The default value is to use a chunk size of 64 kilobytes, which should be appropriate for most uses.
New in version 4.1.
--hash-format=ALGORITHM
Set the hashing algorithm used by SCons to
ALGORITHM.
This value determines the hashing algorithm used in generating
content signatures, build signatures and CacheDir keys.
The supported list of values are:
md5,
sha1
and sha256.
However, the Python interpreter used to run scons must have the corresponding
support available in the hashlib module
to use the specified algorithm.
If this option is omitted, the first supported hash format found is selected. Typically this is MD5, however, on a FIPS-compliant system using a version of Python older than 3.9, SHA1 or SHA256 is chosen as the default. Python 3.9 and onwards clients always default to MD5, even in FIPS mode.
Specifying this option changes the name of the SConsign database.
The default database is .sconsign.dblite.
In the presence of this option,
ALGORITHM is
included in the name to indicate the difference,
even if the argument is md5.
For example, --hash-format=sha256 uses a SConsign
database named .sconsign_sha256.dblite.
New in version 4.1.
-H,
--help-options
Print the standard help message about SCons command-line options and exit.
-i,
--ignore-errors
Ignore all errors from commands executed to rebuild files.
-I directory,
--include-dir=directory
Specifies a
directory
to search for
imported Python modules. If several
-I
options
are used, the directories are searched in the order specified.
--ignore-virtualenv
Suppress importing virtualenv-related variables to SCons.
--implicit-cache
Cache implicit dependencies. This causes scons to use the implicit (scanned) dependencies from the last time it was run instead of scanning the files for implicit dependencies. This can significantly speed up SCons, but with the following limitations:
scons
will not detect changes to implicit dependency search paths
(e.g. $CPPPATH, $LIBPATH)
that would ordinarily
cause different versions of same-named files to be used.
scons
will miss changes in the implicit dependencies
in cases where a new implicit
dependency is added earlier in the implicit dependency search path
(e.g. $CPPPATH, $LIBPATH)
than a current implicit dependency with the same name.
--implicit-deps-changed
Forces SCons to ignore the cached implicit dependencies. This causes the
implicit dependencies to be rescanned and recached. This implies
--implicit-cache.
--implicit-deps-unchanged
Force SCons to ignore changes in the implicit dependencies.
This causes cached implicit dependencies to always be used.
This implies
--implicit-cache.
--install-sandbox=sandbox_path
When using the Install builders, prepend
sandbox_path
to the installation paths such that all installed files will be placed
under that directory. This option is unavailable if
one of Install, InstallAs or
InstallVersionedLib is not used in the SConscript files.
--interactive
Starts SCons in interactive mode.
The SConscript files are read once and a
scons>>>
prompt is printed.
Targets may now be rebuilt by typing commands at interactive prompt
without having to re-read the SConscript files
and re-initialize the dependency graph from scratch.
SCons interactive mode supports the following commands:
build [OPTIONS] [TARGETS] ...
Builds the specified
TARGETS
(and their dependencies)
with the specified
SCons command-line
OPTIONS.
b
and
scons
are synonyms for
build.
The following SCons command-line options affect the build command:
--cache-debug=FILE --cache-disable, --no-cache --cache-force, --cache-populate --cache-readonly --cache-show --debug=TYPE -i, --ignore-errors -j N, --jobs=N -k, --keep-going -n, --no-exec, --just-print, --dry-run, --recon -Q -s, --silent, --quiet --taskmastertrace=FILE --tree=OPTIONS
Any other SCons command-line options that are specified
do not cause errors
but have no effect on the
build
command
(mainly because they affect how the SConscript files are read,
which only happens once at the beginning of interactive mode).
clean [OPTIONS] [TARGETS] ...
Cleans the specified
TARGETS
(and their dependencies)
with the specified
OPTIONS.
c
is a synonym.
This command is itself a synonym for
build --clean
exit
Exits SCons interactive mode. You can also exit by terminating input (Ctrl+D UNIX or Linux systems, (Ctrl+Z on Windows systems).
help [COMMAND]
Provides a help message about the commands available in SCons interactive mode. If COMMAND is specified, h and ? are synonyms.
shell [COMMANDLINE]
Executes the specified
COMMANDLINE
in a subshell.
If no
COMMANDLINE
is specified,
executes the interactive command interpreter
specified in the
SHELL
environment variable
(on UNIX and Linux systems)
or the
COMSPEC
environment variable
(on Windows systems).
sh
and
!
are synonyms.
version
Prints SCons version information.
An empty line repeats the last typed command. Command-line editing can be used if the readline module is available.
$ scons --interactive
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons>>> build -n prog
scons>>> exit
-j N,
--jobs=N
Specifies the maximum number of comcurrent jobs (commands) to run.
If there is more than one
-j
option, the last one is effective.
-k,
--keep-going
Continue as much as possible after an error. The target that failed and those that depend on it will not be remade, but other targets specified on the command line will still be processed.
-m
Ignored for compatibility with non-GNU versions of Make.
--max-drift=SECONDS
Set the maximum expected drift in the modification time of files to
SECONDS.
This value determines how long a file must be unmodified
before its cached content signature
will be used instead of
calculating a new content signature (hash)
of the file's contents.
The default value is 2 days, which means a file must have a
modification time of at least two days ago in order to have its
cached content signature used.
A negative value means to never cache the
content signature and to ignore the cached value if there already is one.
A value of 0 means to always use the cached signature,
no matter how old the file is.
--md5-chunksize=KILOBYTES
A deprecated synonym for
--hash-chunksize.
Changed in version 4.2: deprecated.
-n,
--no-exec,
--just-print,
--dry-run,
--recon
Set no-exec mode. Print the commands that would be executed to build any out-of-date targets, but do not execute those commands.
Only target building is suppressed - any work in the build
system that is done directly (in regular Python code)
will still be carried out. You can add guards around
code which should not be executed in no-exec mode by
checking the value of the option at run time with GetOption:
if not GetOption("no_exec"):
# run regular instructions
The output is a best effort, as SCons cannot always precisely determine what would be built. For example, if a file generated by a builder action is also used as a source in the build, that file is not available to scan for dependencies at all in an unbuilt tree, and may contain out of date information in a previously built tree.
SCons cannot perform Configure checks in no-exec mode,
as they would make changes to the filesystem
(see $CONFIGUREDIR and $CONFIGURELOG).
It can use stored information from a previous build,
if it is not out of date,
so a "priming" build may make subsequent no-exec runs
more useful.
--no-site-dir
Do not read site directories.
Neither the standard site directories
(site_scons)
nor the path specified via a previous
--site-dir option are
added to the module search path sys.path,
searched for a site_init.py file,
or have their site_tools
directory included in the tool search path.
Can be overridden by a subequent
--site-dir option.
--package-type=type
The type
of package to create when using the Package builder.
Multiple types can be specified by using a comma-separated string,
in which case SCons will try to build for all of those package types.
Note this option is only available if the packaging tool
has been enabled.
--profile=file
Run SCons under the Python profiler
and save the results to file.
The results may be analyzed using the Python
pstats module.
-q,
--question
Do not run any commands, or print anything. Just return an exit status that is zero if the specified targets are already up to date, non-zero otherwise.
-Q
Suppress status messages about
reading SConscript files,
building targets
and entering directories.
Commands that are executed
to rebuild target files are still printed.
--random
Build dependencies in a random order. This is useful when building multiple trees simultaneously with caching enabled, to prevent multiple builds from simultaneously trying to build or retrieve the same target files.
-s,
--silent,
--quiet
Silent. Do not print commands that are executed to rebuild target files. Also suppresses SCons status messages.
-S,
--no-keep-going,
--stop
Ignored for compatibility with GNU Make
--site-dir=path
Use path as the site directory
rather than searching the list of default site directories.
This directory will be prepended to
sys.path,
the module
path/site_init.pypath/site_toolspath wins.
The default set of site directories searched when
--site-dir
is not specified depends on the system platform, as follows.
Users or system administrators can tune site-specific or
project-specific SCons behavior by setting up a
site directory in one or more of these locations.
Directories are examined in the order given, from most
generic ("system" directories) to most specific (in the current project),
so the last-executed site_init.py file is
the most specific one, giving it the chance to override
everything else), and the directories are prepended to the paths, again so
the last directory examined comes first in the resulting path.
%ALLUSERSPROFILE%/scons/site_scons %LOCALAPPDATA%/scons/site_scons %APPDATA%/scons/site_scons %USERPROFILE%/.scons/site_scons ./site_scons
Note earlier versions of the documentation listed a different path for the "system" site directory, this path is still checked but its use is discouraged:
%ALLUSERSPROFILE%/Application Data/scons/site_scons
/Library/Application Support/SCons/site_scons /opt/local/share/scons/site_scons (for MacPorts) /sw/share/scons/site_scons (for Fink) $HOME/Library/Application Support/SCons/site_scons $HOME/.scons/site_scons ./site_scons
/opt/sfw/scons/site_scons /usr/share/scons/site_scons $HOME/.scons/site_scons ./site_scons
/usr/share/scons/site_scons $HOME/.scons/site_scons ./site_scons
--stack-size=KILOBYTES
Set the size stack used to run threads to
KILOBYTES.
This value determines the stack size of the threads used to run jobs.
These threads execute the actions of the builders for the
nodes that are out-of-date.
This option has no effect unless the number of concurrent
build jobs is larger than one (as set by -j N or
--jobs=N on the command line or SetOption in a script).
Using a stack size that is too small may cause stack overflow errors. This usually shows up as segmentation faults that cause scons to abort before building anything. Using a stack size that is too large will cause scons to use more memory than required and may slow down the entire build process. The default value is to use a stack size of 256 kilobytes, which should be appropriate for most uses. You should not need to increase this value unless you encounter stack overflow errors.
-t,
--touch
Ignored for compatibility with GNU Make. (Touching a file to make it appear up-to-date is unnecessary when using scons.)
--taskmastertrace=file
Prints trace information to the specified
file
about how the internal Taskmaster object
evaluates and controls the order in which Nodes are built.
A file name of
-
may be used to specify the standard output.
--tree=type[,type...]
Prints a tree of the dependencies
after each top-level target is built.
This prints out some or all of the tree,
in various formats,
depending on the
type
specified:
Print the entire dependency tree after each top-level target is built. This prints out the complete dependency tree, including implicit dependencies and ignored dependencies.
Restricts the tree output to only derived (target) files, not source files.
Draw the tree output using Unicode line-drawing characters
instead of plain ASCII text. This option acts as a modifier
to the selected type(s). If
specified alone, without any type,
it behaves as if all
had been specified.
New in version 4.0.
Prints status information for each displayed node.
Prunes the tree to avoid repeating dependency information for nodes that have already been displayed. Any node that has already been displayed will have its name printed in [square brackets], as an indication that the dependencies for that node can be found by searching for the relevant output higher up in the tree.
Multiple type
choices may be specified, separated by commas:
# Prints only derived files, with status information:scons --tree=derived,status# Prints all dependencies of target, with status information # and pruning dependencies of already-visited Nodes:scons --tree=all,prune,status target
-u,
--up,
--search-up
Walks up the directory structure until an
SConstruct, Sconstruct, sconstruct, SConstruct.py,
Sconstruct.py or sconstruct.py
file is found, and uses that
as the project top directory.
If no targets are specified on the command line,
only targets at or below the
current directory will be built.
-U
Works exactly the same way as the
-u
option except for the way default targets are handled.
When this option is used and no targets are specified on the command line,
all default targets that are defined in the SConscript file(s) in the current
directory are built, regardless of what directory the resultant targets end
up in.
-v,
--version
Print the scons version, copyright information, list of authors, and any other relevant information. Then exit.
-w,
--print-directory
Print a message containing the working directory before and after other processing.
--no-print-directory
Turn off -w, even if it was turned on implicitly.
--warn=type,
--warn=no-type
Enable or disable (with the prefix "no-") warnings
(--warning is a synonym).
type
specifies the type of warnings to be enabled or disabled:
All warnings.
Warnings about the derived-file cache directory
specified by CacheDir not using
the latest configuration information.
These warnings are enabled by default.
Warnings about errors trying to
write a copy of a built file to a specified
derived-file cache specified by CacheDir.
These warnings are disabled by default.
Warnings about errors when a file retrieved from the derived-file cache could not be removed.
Warnings about unfamiliar signature data in
.sconsign
files.
These warnings are enabled by default.
Warnings about dependencies. These warnings are disabled by default.
Warnings about use of
currently deprecated features.
These warnings are enabled by default.
Not all deprecation warnings can be disabled with the
--warn=no-deprecated option as some
deprecated features which are late in the deprecation
cycle may have been designated as mandatory warnings,
and these will still display.
Warnings for certain deprecated features
may also be enabled or disabled individually;
see below.
Warnings about attempts to specify a build of a target with two different construction environments that use the same action. These warnings are enabled by default.
Warnings about linking Fortran and C++ object files in a single executable, which can yield unpredictable behavior with some compilers.
Warnings about construction variables which are currently allowed, but will become reserved variables in a future release.
Warnings about features that will be deprecated in the future. Such warnings are disabled by default. Enabling future deprecation warnings is recommended for projects that redistribute SCons configurations for other users to build, so that the project can be warned as soon as possible about to-be-deprecated features that may require changes to the configuration.
Warnings about link steps.
Warnings about the use of two commonly
misspelled keywords
targets
and
sources
to Builder calls. The correct spelling is the
singular form, even though
target
and
source
can themselves refer to lists of names or nodes.
Warnings about the qt tool being deprecated.
These warnings are disabled by default for the first
phase of deprecation. Enable to be reminded about use
of this tool module.
New in version 4.3.
Warnings about the
--debug=object
feature not working when
scons
is run with the Python
-O
option or from optimized Python (.pyo) modules.
Note the "no-" prefix is part of the name of this warning. Add an additional "-no" to disable.
Warnings about the version of Python
not being able to support parallel builds when the
-j
option is used.
These warnings are enabled by default.
Note the "no-" prefix is part of the name of this warning. Add an additional "-no" to disable.
Warnings about running SCons using a version of Python that has been deprecated. These warnings are enabled by default.
Warnings about attempts to set the
reserved construction variable names
$CHANGED_SOURCES,
$CHANGED_TARGETS,
$TARGET,
$TARGETS,
$SOURCE,
$SOURCES,
$UNCHANGED_SOURCES
or
$UNCHANGED_TARGETS.
These warnings are disabled by default.
Warnings about requests to set the stack size that could not be honored. These warnings are enabled by default.
Warnings about a build rule not building the expected targets. These warnings are disabled by default.
-Y repository,
--repository=repository,
--srcdir=repository
Search the specified repository
for any input and target
files not found in the local directory hierarchy. Multiple
-Y
options may be specified, in which case the
repositories are searched in the order specified.
The build configuration is described by one or more files,
known as SConscript files.
There must be at least one file for a valid build
(scons will quit if it does not find one).
scons by default looks for this file by the name
SConstruct
in the directory from which you run scons,
though if necessary, also looks for alternative file names
Sconstruct, sconstruct, SConstruct.py, Sconstruct.py
and sconstruct.py in that order.
A different file name (which can include a pathname part)
may be specified via the -f option.
Except for the SConstruct file,
these files are not searched for automatically;
you add additional configuration files to the build
by calling the SConscript function.
This allows parts of the build to be conditionally
included or excluded at run-time depending on how scons is invoked.
Each SConscript file in a build configuration is invoked
independently in a separate context.
This provides necessary isolation so that different parts of
the build don't accidentally step on each other.
You have to be explicit about sharing information,
by using the Export function or the exports argument
to the SConscript function, as well as the Return function
in a called SConscript file, and comsume shared information by using the
Import function.
The following sections describe the various SCons facilities
that can be used in SConscript files. Quick links:
| Construction Environments |
| Tools |
| Builder Methods |
| Functions and Environment Methods |
| SConscript Variables |
| Construction Variables |
| Configure Contexts |
| Command-Line Construction Variables |
| Node Objects |
A Construction Environment is the basic means by which
you communicate build information to
SCons.
A new construction environment is created using the
Environment
function:
env = Environment()
Construction environment attributes called Construction Variables may be set either by specifying them as keyword arguments when the object is created or by assigning them a value after the object is created. These two are nominally equivalent:
env = Environment(FOO='foo') env['FOO'] = 'foo'
Note that certain settings which affect tool detection are
referenced only when the tools are initializided,
so you either need either to supply them as part of the call to
Environment, or defer tool initialization.
For example, initializing the Microsoft Visual C++ version you wish to use:
# initializes msvc to v14.1
env = Environment(MSVC_VERSION="14.1")
env = Environment()
# msvc tool was initialized to default, does not reinitialize
env['MSVC_VERSION'] = "14.1"
env = Environment(tools=[])
env['MSVC_VERSION'] = "14.1"
# msvc tool initialization was deferred, so will pick up new value
env.Tool('default')
As a convenience,
construction variables may also be set or modified by the
parse_flags
keyword argument during object creation,
which has the effect of the
env.MergeFlags
method being applied to the argument value
after all other processing is completed.
This is useful either if the exact content of the flags is unknown
(for example, read from a control file)
or if the flags need to be distributed to a number of construction variables.
env.ParseFlags describes how these arguments
are distributed to construction variables.
env = Environment(parse_flags='-Iinclude -DEBUG -lm')
This example adds 'include' to
the $CPPPATH construction variable,
'EBUG' to
$CPPDEFINES,
and 'm' to
$LIBS.
An existing construction environment can be duplicated by calling the env.Clone
method. Without arguments, it will be a copy with the same
settings. Otherwise, env.Clone takes the same arguments as
Environment, and uses the arguments to create a modified copy.
SCons provides a special construction environment called the
Default Environment.
The default environment is used only for global functions, that is,
construction activities called without the context of a regular construction environment.
See DefaultEnvironment for more information.
By default, a new construction environment is
initialized with a set of builder methods
and construction variables that are appropriate
for the current platform.
The optional platform keyword argument may be
used to specify that the construction environment should
be initialized for a different platform:
env = Environment(platform='cygwin')
Specifying a platform initializes the appropriate construction variables in the environment to use and generate file names with prefixes and suffixes appropriate for that platform.
Note that the
win32
platform adds the
SystemDrive
and
SystemRoot
variables from the user's external environment
to the construction environment's
ENV
dictionary.
This is so that any executed commands
that use sockets to connect with other systems
will work on Windows systems.
The platform argument may be
a string value representing
one of the pre-defined platforms
(aix,
cygwin,
darwin,
hpux,
irix,
os2,
posix,
sunos or
win32),
or it may be be a callable platform object
returned by a call to Platform
selecting a pre-defined platform,
or it may be a user-supplied callable,
in which case the Environment method
will call it to update
the new construction environment:
def my_platform(env):
env['VAR'] = 'xyzzy'
env = Environment(platform=my_platform)
Note that supplying a non-default platform or custom
fuction for initialization
may bypass settings that should happen for the host system
and should be used with care.
It is most useful in the case where the platform is an alternative for
the one that would be auto-detected,
such as platform="cygwin"
on a system which would otherwise
identify as win32.
The optional tools and toolpath
keyword arguments affect the way tools available to the environment are initialized.
See the section called “Tools” for details.
The optional variables keyword argument
allows passing a Variables object which will be used in the
initialization of the construction environment
See the section called “Command-Line Construction Variables” for details.
SCons has many included tool modules (more properly, tool specification modules) which are used to help initialize the construction environment prior to building, and more can be written to suit a particular purpose, or added from external sources (a repository of constributed tools is available). More information on writing custom tools can be found in the Extending SCons section and specifically Tool Modules.
An SCons tool is only responsible for setup.
For example, if an SConscript file declares
the need to construct an object file from
a C-language source file by calling the
Object builder, then a tool module representing
an available C compiler needs to have run first,
to set up that builder and all the construction variables
it needs in the associated construction environment.
The tool itself is not called in the process of the build.
Tool setup happens when a construction environment is constructed,
and in the basic case needs no intervention -
platform-specific lists of default tools are used
to examine the specific capabilities of that platform and
configure the environment,
skipping those tools which are not applicable.
If necessary, a specific set of tools to
initialize in an environment during creation
may be specified using the optional keyword argument
tools.
tools must be a list,
even if there are one (or zero) tools.
This is useful to override the defaults,
to specify non-default built-in tools,
and to cause added tools to be called:
env = Environment(tools=['msvc', 'lex'])
The tools argument overrides
the default tool list, it does not add to it, so be
sure to include all the tools you need.
For example, if you are building a c/c++ program,
you must specify a tool for at least a compiler and a linker,
as in tools=['clang', 'link'].
If the tools argument is omitted,
or if tools includes
the reserved name 'default',
then SCons will auto-detect usable tools,
using the search path from the execution environment
(that is, env['ENV']['PATH']PATH from the external environment
os.environ is not used.
Changing the PATH in the execution environment
after the construction environment is constructed will not cause the tools to
be re-detected.
Tools can also be directly called by using the Tool
method (see below).
SCons supports the following tool specifications out of the box:
Sets construction variables for the 386ASM assembler for the Phar Lap ETS embedded operating system.
Sets: $AS, $ASCOM, $ASFLAGS, $ASPPCOM, $ASPPFLAGS.
Uses: $CC, $CPPFLAGS, $_CPPDEFFLAGS, $_CPPINCFLAGS.
Sets construction variables for the IMB xlc / Visual Age C++ compiler.
Sets: $CXX, $CXXVERSION, $SHCXX, $SHOBJSUFFIX.
Sets construction variables for the IBM xlc / Visual Age C compiler.
Sets: $CC, $CCVERSION, $SHCC.
Sets construction variables for the IBM Visual Age f77 Fortran compiler.
Sets construction variables for the IBM Visual Age linker.
Sets: $LINKFLAGS, $SHLIBSUFFIX, $SHLINKFLAGS.
Sets construction variables for the Apple linker (similar to the GNU linker).
Sets: $APPLELINK_COMPATIBILITY_VERSION, $APPLELINK_CURRENT_VERSION, $APPLELINK_NO_COMPATIBILITY_VERSION, $APPLELINK_NO_CURRENT_VERSION, $FRAMEWORKPATHPREFIX, $LDMODULECOM, $LDMODULEFLAGS, $LDMODULEPREFIX, $LDMODULESUFFIX, $LINKCOM, $SHLINKCOM, $SHLINKFLAGS, $_APPLELINK_COMPATIBILITY_VERSION, $_APPLELINK_CURRENT_VERSION, $_FRAMEWORKPATH, $_FRAMEWORKS.
Uses: $FRAMEWORKSFLAGS.
Sets construction variables for the ar library archiver.
Sets: $AR, $ARCOM, $ARFLAGS, $LIBPREFIX, $LIBSUFFIX, $RANLIB, $RANLIBCOM, $RANLIBFLAGS.
Sets construction variables for the as assembler.
Sets: $AS, $ASCOM, $ASFLAGS, $ASPPCOM, $ASPPFLAGS.
Uses: $CC, $CPPFLAGS, $_CPPDEFFLAGS, $_CPPINCFLAGS.
Sets construction variables for the bcc32 compiler.
Sets: $CC, $CCCOM, $CCFLAGS, $CFILESUFFIX, $CFLAGS, $CPPDEFPREFIX, $CPPDEFSUFFIX, $INCPREFIX, $INCSUFFIX, $SHCC, $SHCCCOM, $SHCCFLAGS, $SHCFLAGS, $SHOBJSUFFIX.
Uses: $_CPPDEFFLAGS, $_CPPINCFLAGS.
Sets construction variables for generic POSIX C compilers.
Sets: $CC, $CCCOM, $CCDEPFLAGS, $CCFLAGS, $CFILESUFFIX, $CFLAGS, $CPPDEFPREFIX, $CPPDEFSUFFIX, $FRAMEWORKPATH, $FRAMEWORKS, $INCPREFIX, $INCSUFFIX, $SHCC, $SHCCCOM, $SHCCFLAGS, $SHCFLAGS, $SHOBJSUFFIX.
Uses: $CCCOMSTR, $PLATFORM, $SHCCCOMSTR.
Set construction variables for the Clang C compiler.
Sets: $CC, $CCDEPFLAGS, $CCVERSION, $SHCCFLAGS.
Set construction variables for the Clang C++ compiler.
Sets: $CXX, $CXXVERSION, $SHCXXFLAGS, $SHOBJSUFFIX, $STATIC_AND_SHARED_OBJECTS_ARE_THE_SAME.
Sets up CompilationDatabase builder which generates a clang tooling compatible compilation database.
Sets: $COMPILATIONDB_COMSTR, $COMPILATIONDB_PATH_FILTER, $COMPILATIONDB_USE_ABSPATH.
Sets construction variables for the Compaq Visual Fortran compiler.
Sets: $FORTRAN, $FORTRANCOM, $FORTRANMODDIR, $FORTRANMODDIRPREFIX, $FORTRANMODDIRSUFFIX, $FORTRANPPCOM, $OBJSUFFIX, $SHFORTRANCOM, $SHFORTRANPPCOM.
Uses: $CPPFLAGS, $FORTRANFLAGS, $SHFORTRANFLAGS, $_CPPDEFFLAGS, $_FORTRANINCFLAGS, $_FORTRANMODFLAG.
Sets construction variables for generic POSIX C++ compilers.
Sets: $CPPDEFPREFIX, $CPPDEFSUFFIX, $CXX, $CXXCOM, $CXXFILESUFFIX, $CXXFLAGS, $INCPREFIX, $INCSUFFIX, $OBJSUFFIX, $SHCXX, $SHCXXCOM, $SHCXXFLAGS, $SHOBJSUFFIX.
Uses: $CXXCOMSTR, $SHCXXCOMSTR.
Set construction variables for cygwin linker/loader.
Sets: $IMPLIBPREFIX, $IMPLIBSUFFIX, $LDMODULEVERSIONFLAGS, $LINKFLAGS, $RPATHPREFIX, $RPATHSUFFIX, $SHLIBPREFIX, $SHLIBSUFFIX, $SHLIBVERSIONFLAGS, $SHLINKCOM, $SHLINKFLAGS, $_LDMODULEVERSIONFLAGS, $_SHLIBVERSIONFLAGS.
Sets construction variables for a default list of Tool modules.
Use default
in the tools list to retain the original defaults,
since the tools parameter
is treated as a literal statement of the tools
to be made available in that construction environment, not an addition.
The list of tools selected by default is not static,
but is dependent both on
the platform and on the software installed on the platform.
Some tools will not initialize if an underlying command is
not found, and some tools are selected from a list of choices
on a first-found basis. The finished tool list can be
examined by inspecting the $TOOLS construction variable
in the construction environment.
On all platforms, the tools from the following list
are selected if their respective conditions are met:
filesystem;,
wix,
lex, yacc,
rpcgen, swig,
jar, javac, javah, rmic,
dvipdf, dvips, gs,
tex, latex, pdflatex, pdftex,
tar, zip, textfile.
On Linux systems, the default tools list selects
(first-found): a C compiler from
gcc, intelc, icc, cc;
a C++ compiler from
g++, intelc, icc, cXX;
an assembler from
gas, nasm, masm;
a linker from
gnulink, ilink;
a Fortran compiler from
gfortran, g77, ifort, ifl,
f95, f90, f77;
and a static archiver ar.
It also selects all found from the list
m4
rpm.
On Windows systems, the default tools list selects
(first-found): a C compiler from
msvc, mingw, gcc, intelc,
icl, icc, cc, bcc32;
a C++ compiler from
msvc, intelc, icc, g++,
cXX, bcc32;
an assembler from
masm, nasm, gas, 386asm;
a linker from
mslink, gnulink, ilink,
linkloc, ilink32;
a Fortran compiler from
gfortran, g77, ifl, cvf,
f95, f90, fortran;
and a static archiver from
mslib, ar, tlib;
It also selects all found from the list
msvs, midl.
On MacOS systems, the default tools list selects
(first-found): a C compiler from
gcc, cc;
a C++ compiler from
g++, cXX;
an assembler as;
a linker from
applelink, gnulink;
a Fortran compiler from
gfortran, f95, f90, g77;
and a static archiver ar.
It also selects all found from the list
m4,
rpm.
Default lists for other platforms can be found by
examining the scons
source code (see
SCons/Tool/__init__.py).
Sets construction variables for D language compiler DMD.
Sets: $DC, $DCOM, $DDEBUG, $DDEBUGPREFIX, $DDEBUGSUFFIX, $DFILESUFFIX, $DFLAGPREFIX, $DFLAGS, $DFLAGSUFFIX, $DINCPREFIX, $DINCSUFFIX, $DLIB, $DLIBCOM, $DLIBDIRPREFIX, $DLIBDIRSUFFIX, $DLIBFLAGPREFIX, $DLIBFLAGSUFFIX, $DLIBLINKPREFIX, $DLIBLINKSUFFIX, $DLINK, $DLINKCOM, $DLINKFLAGPREFIX, $DLINKFLAGS, $DLINKFLAGSUFFIX, $DPATH, $DRPATHPREFIX, $DRPATHSUFFIX, $DVERPREFIX, $DVERSIONS, $DVERSUFFIX, $SHDC, $SHDCOM, $SHDLIBVERSIONFLAGS, $SHDLINK, $SHDLINKCOM, $SHDLINKFLAGS.
This tool tries to make working with Docbook in SCons a little easier. It provides several toolchains for creating different output formats, like HTML or PDF. Contained in the package is a distribution of the Docbook XSL stylesheets as of version 1.76.1. As long as you don't specify your own stylesheets for customization, these official versions are picked as default...which should reduce the inevitable setup hassles for you.
Implicit dependencies to images and XIncludes are detected automatically
if you meet the HTML requirements. The additional
stylesheet utils/xmldepend.xsl by Paul DuBois is used for this purpose.
Note, that there is no support for XML catalog resolving offered! This tool calls the XSLT processors and PDF renderers with the stylesheets you specified, that's it. The rest lies in your hands and you still have to know what you're doing when resolving names via a catalog.
For activating the tool "docbook", you have to add its name to the Environment constructor, like this
env = Environment(tools=['docbook'])
On its startup, the docbook tool tries to find a required xsltproc processor, and
a PDF renderer, e.g. fop. So make sure that these are added to your system's environment
PATH and can be called directly without specifying their full path.
For the most basic processing of Docbook to HTML, you need to have installed
the Python lxml
binding to libxml2, or
a standalone XSLT processor, currently detected are xsltproc, saxon, saxon-xslt and xalan.
Rendering to PDF requires you to have one of the applications fop or xep installed.
Creating a HTML or PDF document is very simple and straightforward. Say
env = Environment(tools=['docbook'])
env.DocbookHtml('manual.html', 'manual.xml')
env.DocbookPdf('manual.pdf', 'manual.xml')
to get both outputs from your XML source manual.xml. As a shortcut, you can
give the stem of the filenames alone, like this:
env = Environment(tools=['docbook'])
env.DocbookHtml('manual')
env.DocbookPdf('manual')
and get the same result. Target and source lists are also supported:
env = Environment(tools=['docbook']) env.DocbookHtml(['manual.html','reference.html'], ['manual.xml','reference.xml'])
or even
env = Environment(tools=['docbook']) env.DocbookHtml(['manual','reference'])
Whenever you leave out the list of sources, you may not specify a file extension! The Tool uses the given names as file stems, and adds the suffixes for target and source files accordingly.
The rules given above are valid for the Builders DocbookHtml,
DocbookPdf, DocbookEpub, DocbookSlidesPdf and DocbookXInclude. For the
DocbookMan transformation you
can specify a target name, but the actual output names are automatically
set from the refname entries in your XML source.
The Builders DocbookHtmlChunked, DocbookHtmlhelp and
DocbookSlidesHtml are special, in that:
they create a large set of files, where the exact names and their number depend on the content of the source file, and
the main target is always named index.html, i.e. the output name for the
XSL transformation is not picked up by the stylesheets.
As a result, there is simply no use in specifying a target HTML name. So the basic syntax for these builders is always:
env = Environment(tools=['docbook'])
env.DocbookHtmlhelp('manual')
If you want to use a specific XSL file, you can set the
additional xsl parameter to your
Builder call as follows:
env.DocbookHtml('other.html', 'manual.xml', xsl='html.xsl')
Since this may get tedious if you always use the same local naming for your customized XSL files,
e.g. html.xsl for HTML and pdf.xsl for PDF output, a set of
variables for setting the default XSL name is provided. These are:
DOCBOOK_DEFAULT_XSL_HTML DOCBOOK_DEFAULT_XSL_HTMLCHUNKED DOCBOOK_DEFAULT_XSL_HTMLHELP DOCBOOK_DEFAULT_XSL_PDF DOCBOOK_DEFAULT_XSL_EPUB DOCBOOK_DEFAULT_XSL_MAN DOCBOOK_DEFAULT_XSL_SLIDESPDF DOCBOOK_DEFAULT_XSL_SLIDESHTML
and you can set them when constructing your environment:
env = Environment(
tools=['docbook'],
DOCBOOK_DEFAULT_XSL_HTML='html.xsl',
DOCBOOK_DEFAULT_XSL_PDF='pdf.xsl',
)
env.DocbookHtml('manual') # now uses html.xsl
Sets: $DOCBOOK_DEFAULT_XSL_EPUB, $DOCBOOK_DEFAULT_XSL_HTML, $DOCBOOK_DEFAULT_XSL_HTMLCHUNKED, $DOCBOOK_DEFAULT_XSL_HTMLHELP, $DOCBOOK_DEFAULT_XSL_MAN, $DOCBOOK_DEFAULT_XSL_PDF, $DOCBOOK_DEFAULT_XSL_SLIDESHTML, $DOCBOOK_DEFAULT_XSL_SLIDESPDF, $DOCBOOK_FOP, $DOCBOOK_FOPCOM, $DOCBOOK_FOPFLAGS, $DOCBOOK_XMLLINT, $DOCBOOK_XMLLINTCOM, $DOCBOOK_XMLLINTFLAGS, $DOCBOOK_XSLTPROC, $DOCBOOK_XSLTPROCCOM, $DOCBOOK_XSLTPROCFLAGS, $DOCBOOK_XSLTPROCPARAMS.
Uses: $DOCBOOK_FOPCOMSTR, $DOCBOOK_XMLLINTCOMSTR, $DOCBOOK_XSLTPROCCOMSTR.
Attaches the DVI builder to the
construction environment.
Sets construction variables for the dvipdf utility.
Sets: $DVIPDF, $DVIPDFCOM, $DVIPDFFLAGS.
Uses: $DVIPDFCOMSTR.
Sets construction variables for the dvips utility.
Sets: $DVIPS, $DVIPSFLAGS, $PSCOM, $PSPREFIX, $PSSUFFIX.
Uses: $PSCOMSTR.
Set construction variables for generic POSIX Fortran 03 compilers.
Sets: $F03, $F03COM, $F03FLAGS, $F03PPCOM, $SHF03, $SHF03COM, $SHF03FLAGS, $SHF03PPCOM, $_F03INCFLAGS.
Uses: $F03COMSTR, $F03PPCOMSTR, $FORTRANCOMMONFLAGS, $SHF03COMSTR, $SHF03PPCOMSTR.
Set construction variables for generic POSIX Fortran 08 compilers.
Sets: $F08, $F08COM, $F08FLAGS, $F08PPCOM, $SHF08, $SHF08COM, $SHF08FLAGS, $SHF08PPCOM, $_F08INCFLAGS.
Uses: $F08COMSTR, $F08PPCOMSTR, $FORTRANCOMMONFLAGS, $SHF08COMSTR, $SHF08PPCOMSTR.
Set construction variables for generic POSIX Fortran 77 compilers.
Sets: $F77, $F77COM, $F77FILESUFFIXES, $F77FLAGS, $F77PPCOM, $F77PPFILESUFFIXES, $FORTRAN, $FORTRANCOM, $FORTRANFLAGS, $SHF77, $SHF77COM, $SHF77FLAGS, $SHF77PPCOM, $SHFORTRAN, $SHFORTRANCOM, $SHFORTRANFLAGS, $SHFORTRANPPCOM, $_F77INCFLAGS.
Uses: $F77COMSTR, $F77PPCOMSTR, $FORTRANCOMMONFLAGS, $FORTRANCOMSTR, $FORTRANFLAGS, $FORTRANPPCOMSTR, $SHF77COMSTR, $SHF77PPCOMSTR, $SHFORTRANCOMSTR, $SHFORTRANFLAGS, $SHFORTRANPPCOMSTR.
Set construction variables for generic POSIX Fortran 90 compilers.
Sets: $F90, $F90COM, $F90FLAGS, $F90PPCOM, $SHF90, $SHF90COM, $SHF90FLAGS, $SHF90PPCOM, $_F90INCFLAGS.
Uses: $F90COMSTR, $F90PPCOMSTR, $FORTRANCOMMONFLAGS, $SHF90COMSTR, $SHF90PPCOMSTR.
Set construction variables for generic POSIX Fortran 95 compilers.
Sets: $F95, $F95COM, $F95FLAGS, $F95PPCOM, $SHF95, $SHF95COM, $SHF95FLAGS, $SHF95PPCOM, $_F95INCFLAGS.
Uses: $F95COMSTR, $F95PPCOMSTR, $FORTRANCOMMONFLAGS, $SHF95COMSTR, $SHF95PPCOMSTR.
Set construction variables for generic POSIX Fortran compilers.
Sets: $FORTRAN, $FORTRANCOM, $FORTRANFLAGS, $SHFORTRAN, $SHFORTRANCOM, $SHFORTRANFLAGS, $SHFORTRANPPCOM.
Uses: $CPPFLAGS, $FORTRANCOMSTR, $FORTRANPPCOMSTR, $SHFORTRANCOMSTR, $SHFORTRANPPCOMSTR, $_CPPDEFFLAGS.
Set construction variables for the g++ C++ compiler.
Sets: $CXX, $CXXVERSION, $SHCXXFLAGS, $SHOBJSUFFIX.
Set construction variables for the g77 Fortran compiler.
Sets: $F77, $F77COM, $F77FILESUFFIXES, $F77PPCOM, $F77PPFILESUFFIXES, $FORTRAN, $FORTRANCOM, $FORTRANPPCOM, $SHF77, $SHF77COM, $SHF77FLAGS, $SHF77PPCOM, $SHFORTRAN, $SHFORTRANCOM, $SHFORTRANFLAGS, $SHFORTRANPPCOM.
Uses: $F77FLAGS, $FORTRANCOMMONFLAGS, $FORTRANFLAGS.
Sets construction variables for the gas assembler.
Calls the as tool.
Sets: $AS.
Set construction variables for the gcc C compiler.
Sets: $CC, $CCDEPFLAGS, $CCVERSION, $SHCCFLAGS.
Sets construction variables for the D language compiler GDC.
Sets: $DC, $DCOM, $DDEBUG, $DDEBUGPREFIX, $DDEBUGSUFFIX, $DFILESUFFIX, $DFLAGPREFIX, $DFLAGS, $DFLAGSUFFIX, $DINCPREFIX, $DINCSUFFIX, $DLIB, $DLIBCOM, $DLIBDIRPREFIX, $DLIBDIRSUFFIX, $DLIBFLAGPREFIX, $DLIBFLAGSUFFIX, $DLIBLINKPREFIX, $DLIBLINKSUFFIX, $DLINK, $DLINKCOM, $DLINKFLAGPREFIX, $DLINKFLAGS, $DLINKFLAGSUFFIX, $DPATH, $DRPATHPREFIX, $DRPATHSUFFIX, $DVERPREFIX, $DVERSIONS, $DVERSUFFIX, $SHDC, $SHDCOM, $SHDLIBVERSIONFLAGS, $SHDLINK, $SHDLINKCOM, $SHDLINKFLAGS.
This is actually a toolset, which supports internationalization and localization of software being constructed with SCons. The toolset loads following tools:
When you enable gettext, it internally loads all abovementioned tools,
so you're encouraged to see their individual documentation.
Each of the above tools provides its own builder(s) which may be used to
perform particular activities related to software internationalization. You
may be however interested in top-level
Translate builder.
To use gettext tools add 'gettext' tool to your
environment:
env = Environment( tools = ['default', 'gettext'] )
Sets construction variables for the GNU Fortran compiler.
Calls the fortran Tool module to set variables.
Sets: $F77, $F90, $F95, $FORTRAN, $SHF77, $SHF77FLAGS, $SHF90, $SHF90FLAGS, $SHF95, $SHF95FLAGS, $SHFORTRAN, $SHFORTRANFLAGS.
Set construction variables for GNU linker/loader.
Sets: $LDMODULEVERSIONFLAGS, $RPATHPREFIX, $RPATHSUFFIX, $SHLIBVERSIONFLAGS, $SHLINKFLAGS, $_LDMODULESONAME, $_SHLIBSONAME.
This Tool sets the required construction variables for working with
the Ghostscript software. It also registers an appropriate Action
with the PDF Builder, such that the conversion from
PS/EPS to PDF happens automatically for the TeX/LaTeX toolchain.
Finally, it adds an explicit Gs Builder for Ghostscript
to the environment.
Uses: $GSCOMSTR.
Set construction variables for the compilers aCC on HP/UX systems.
Set construction variables for
aCC compilers on HP/UX systems.
Calls the cXX tool for additional variables.
Sets: $CXX, $CXXVERSION, $SHCXXFLAGS.
Sets construction variables for the linker on HP/UX systems.
Sets: $LINKFLAGS, $SHLIBSUFFIX, $SHLINKFLAGS.
Sets construction variables for the icc compiler on OS/2 systems.
Sets: $CC, $CCCOM, $CFILESUFFIX, $CPPDEFPREFIX, $CPPDEFSUFFIX, $CXXCOM, $CXXFILESUFFIX, $INCPREFIX, $INCSUFFIX.
Uses: $CCFLAGS, $CFLAGS, $CPPFLAGS, $_CPPDEFFLAGS, $_CPPINCFLAGS.
Sets construction variables for the Intel C/C++ compiler.
Calls the intelc Tool module to set its variables.
Sets construction variables for the Intel Fortran compiler.
Sets: $FORTRAN, $FORTRANCOM, $FORTRANPPCOM, $SHFORTRANCOM, $SHFORTRANPPCOM.
Uses: $CPPFLAGS, $FORTRANFLAGS, $_CPPDEFFLAGS, $_FORTRANINCFLAGS.
Sets construction variables for newer versions of the Intel Fortran compiler for Linux.
Sets: $F77, $F90, $F95, $FORTRAN, $SHF77, $SHF77FLAGS, $SHF90, $SHF90FLAGS, $SHF95, $SHF95FLAGS, $SHFORTRAN, $SHFORTRANFLAGS.
Sets construction variables for the ilink linker on OS/2 systems.
Sets: $LIBDIRPREFIX, $LIBDIRSUFFIX, $LIBLINKPREFIX, $LIBLINKSUFFIX, $LINK, $LINKCOM, $LINKFLAGS.
Sets construction variables for the Borland ilink32 linker.
Sets: $LIBDIRPREFIX, $LIBDIRSUFFIX, $LIBLINKPREFIX, $LIBLINKSUFFIX, $LINK, $LINKCOM, $LINKFLAGS.
Sets construction variables for file and directory installation.
Sets: $INSTALL, $INSTALLSTR.
Sets construction variables for the Intel C/C++ compiler
(Linux and Windows, version 7 and later).
Calls the gcc or msvc
(on Linux and Windows, respectively)
tool to set underlying variables.
Sets: $AR, $CC, $CXX, $INTEL_C_COMPILER_VERSION, $LINK.
Sets construction variables for the jar utility.
Sets: $JAR, $JARCOM, $JARFLAGS, $JARSUFFIX.
Uses: $JARCOMSTR.
Sets construction variables for the javac compiler.
Sets: $JAVABOOTCLASSPATH, $JAVAC, $JAVACCOM, $JAVACFLAGS, $JAVACLASSPATH, $JAVACLASSSUFFIX, $JAVAINCLUDES, $JAVASOURCEPATH, $JAVASUFFIX.
Uses: $JAVACCOMSTR.
Sets construction variables for the javah tool.
Sets: $JAVACLASSSUFFIX, $JAVAH, $JAVAHCOM, $JAVAHFLAGS.
Uses: $JAVACLASSPATH, $JAVAHCOMSTR.
Sets construction variables for the latex utility.
Sets: $LATEX, $LATEXCOM, $LATEXFLAGS.
Uses: $LATEXCOMSTR.
Sets construction variables for the D language compiler LDC2.
Sets: $DC, $DCOM, $DDEBUG, $DDEBUGPREFIX, $DDEBUGSUFFIX, $DFILESUFFIX, $DFLAGPREFIX, $DFLAGS, $DFLAGSUFFIX, $DINCPREFIX, $DINCSUFFIX, $DLIB, $DLIBCOM, $DLIBDIRPREFIX, $DLIBDIRSUFFIX, $DLIBFLAGPREFIX, $DLIBFLAGSUFFIX, $DLIBLINKPREFIX, $DLIBLINKSUFFIX, $DLINK, $DLINKCOM, $DLINKFLAGPREFIX, $DLINKFLAGS, $DLINKFLAGSUFFIX, $DPATH, $DRPATHPREFIX, $DRPATHSUFFIX, $DVERPREFIX, $DVERSIONS, $DVERSUFFIX, $SHDC, $SHDCOM, $SHDLIBVERSIONFLAGS, $SHDLINK, $SHDLINKCOM, $SHDLINKFLAGS.
Sets construction variables for the lex lexical analyser.
Sets: $LEX, $LEXCOM, $LEXFLAGS, $LEXUNISTD.
Uses: $LEXCOMSTR, $LEXFLAGS, $LEX_HEADER_FILE, $LEX_TABLES_FILE.
Sets construction variables for generic POSIX linkers. This is a "smart" linker tool which selects a compiler to complete the linking based on the types of source files.
Sets: $LDMODULE, $LDMODULECOM, $LDMODULEFLAGS, $LDMODULENOVERSIONSYMLINKS, $LDMODULEPREFIX, $LDMODULESUFFIX, $LDMODULEVERSION, $LDMODULEVERSIONFLAGS, $LIBDIRPREFIX, $LIBDIRSUFFIX, $LIBLINKPREFIX, $LIBLINKSUFFIX, $LINK, $LINKCOM, $LINKFLAGS, $SHLIBSUFFIX, $SHLINK, $SHLINKCOM, $SHLINKFLAGS, $__LDMODULEVERSIONFLAGS, $__SHLIBVERSIONFLAGS.
Uses: $LDMODULECOMSTR, $LINKCOMSTR, $SHLINKCOMSTR.
Sets construction variables for the LinkLoc linker for the Phar Lap ETS embedded operating system.
Sets: $LIBDIRPREFIX, $LIBDIRSUFFIX, $LIBLINKPREFIX, $LIBLINKSUFFIX, $LINK, $LINKCOM, $LINKFLAGS, $SHLINK, $SHLINKCOM, $SHLINKFLAGS.
Uses: $LINKCOMSTR, $SHLINKCOMSTR.
Sets construction variables for the m4 macro processor.
Uses: $M4COMSTR.
Sets construction variables for the Microsoft assembler.
Sets: $AS, $ASCOM, $ASFLAGS, $ASPPCOM, $ASPPFLAGS.
Uses: $ASCOMSTR, $ASPPCOMSTR, $CPPFLAGS, $_CPPDEFFLAGS, $_CPPINCFLAGS.
Sets construction variables for the Microsoft IDL compiler.
Sets: $MIDL, $MIDLCOM, $MIDLFLAGS.
Uses: $MIDLCOMSTR.
Sets construction variables for MinGW (Minimal Gnu on Windows).
Sets: $AS, $CC, $CXX, $LDMODULECOM, $LIBPREFIX, $LIBSUFFIX, $OBJSUFFIX, $RC, $RCCOM, $RCFLAGS, $RCINCFLAGS, $RCINCPREFIX, $RCINCSUFFIX, $SHCCFLAGS, $SHCXXFLAGS, $SHLINKCOM, $SHLINKFLAGS, $SHOBJSUFFIX, $WINDOWSDEFPREFIX, $WINDOWSDEFSUFFIX.
Uses: $RCCOMSTR, $SHLINKCOMSTR.
This scons tool is a part of scons gettext toolset. It provides scons
interface to msgfmt(1) command, which generates binary
message catalog (MO) from a textual translation description
(PO).
Sets: $MOSUFFIX, $MSGFMT, $MSGFMTCOM, $MSGFMTCOMSTR, $MSGFMTFLAGS, $POSUFFIX.
Uses: $LINGUAS_FILE.
This scons tool is a part of scons gettext toolset. It provides
scons interface to msginit(1) program, which creates new
PO file, initializing the meta information with values from
user's environment (or options).
Sets: $MSGINIT, $MSGINITCOM, $MSGINITCOMSTR, $MSGINITFLAGS, $POAUTOINIT, $POCREATE_ALIAS, $POSUFFIX, $POTSUFFIX, $_MSGINITLOCALE.
Uses: $LINGUAS_FILE, $POAUTOINIT, $POTDOMAIN.
This scons tool is a part of scons gettext toolset. It provides
scons interface to msgmerge(1) command, which merges two
Uniform style .po files together.
Sets: $MSGMERGE, $MSGMERGECOM, $MSGMERGECOMSTR, $MSGMERGEFLAGS, $POSUFFIX, $POTSUFFIX, $POUPDATE_ALIAS.
Uses: $LINGUAS_FILE, $POAUTOINIT, $POTDOMAIN.
Sets construction variables for the Microsoft mslib library archiver.
Sets: $AR, $ARCOM, $ARFLAGS, $LIBPREFIX, $LIBSUFFIX.
Uses: $ARCOMSTR.
Sets construction variables for the Microsoft linker.
Sets: $LDMODULE, $LDMODULECOM, $LDMODULEFLAGS, $LDMODULEPREFIX, $LDMODULESUFFIX, $LIBDIRPREFIX, $LIBDIRSUFFIX, $LIBLINKPREFIX, $LIBLINKSUFFIX, $LINK, $LINKCOM, $LINKFLAGS, $REGSVR, $REGSVRCOM, $REGSVRFLAGS, $SHLINK, $SHLINKCOM, $SHLINKFLAGS, $WINDOWSDEFPREFIX, $WINDOWSDEFSUFFIX, $WINDOWSEXPPREFIX, $WINDOWSEXPSUFFIX, $WINDOWSPROGMANIFESTPREFIX, $WINDOWSPROGMANIFESTSUFFIX, $WINDOWSSHLIBMANIFESTPREFIX, $WINDOWSSHLIBMANIFESTSUFFIX, $WINDOWS_INSERT_DEF.
Uses: $LDMODULECOMSTR, $LINKCOMSTR, $REGSVRCOMSTR, $SHLINKCOMSTR.
Sets variables for Microsoft Platform SDK and/or Windows SDK.
Note that unlike most other Tool modules,
mssdk does not set construction variables,
but sets the environment variables
in the environment SCons uses to execute
the Microsoft toolchain:
%INCLUDE%,
%LIB%,
%LIBPATH% and
%PATH%.
Uses: $MSSDK_DIR, $MSSDK_VERSION, $MSVS_VERSION.
Sets construction variables for the Microsoft Visual C++ compiler.
Sets: $BUILDERS, $CC, $CCCOM, $CCDEPFLAGS, $CCFLAGS, $CCPCHFLAGS, $CCPDBFLAGS, $CFILESUFFIX, $CFLAGS, $CPPDEFPREFIX, $CPPDEFSUFFIX, $CXX, $CXXCOM, $CXXFILESUFFIX, $CXXFLAGS, $INCPREFIX, $INCSUFFIX, $OBJPREFIX, $OBJSUFFIX, $PCHCOM, $PCHPDBFLAGS, $RC, $RCCOM, $RCFLAGS, $SHCC, $SHCCCOM, $SHCCFLAGS, $SHCFLAGS, $SHCXX, $SHCXXCOM, $SHCXXFLAGS, $SHOBJPREFIX, $SHOBJSUFFIX.
Uses: $CCCOMSTR, $CXXCOMSTR, $MSVC_NOTFOUND_POLICY, $MSVC_SCRIPTERROR_POLICY, $MSVC_SCRIPT_ARGS, $MSVC_SDK_VERSION, $MSVC_SPECTRE_LIBS, $MSVC_TOOLSET_VERSION, $MSVC_USE_SCRIPT, $MSVC_USE_SCRIPT_ARGS, $MSVC_USE_SETTINGS, $MSVC_VERSION, $PCH, $PCHSTOP, $PDB, $SHCCCOMSTR, $SHCXXCOMSTR.
Sets construction variables for Microsoft Visual Studio.
Sets: $MSVSBUILDCOM, $MSVSCLEANCOM, $MSVSENCODING, $MSVSPROJECTCOM, $MSVSREBUILDCOM, $MSVSSCONS, $MSVSSCONSCOM, $MSVSSCONSCRIPT, $MSVSSCONSFLAGS, $MSVSSOLUTIONCOM.
Sets construction variables for the Metrowerks CodeWarrior compiler.
Sets: $CC, $CCCOM, $CFILESUFFIX, $CPPDEFPREFIX, $CPPDEFSUFFIX, $CXX, $CXXCOM, $CXXFILESUFFIX, $INCPREFIX, $INCSUFFIX, $MWCW_VERSION, $MWCW_VERSIONS, $SHCC, $SHCCCOM, $SHCCFLAGS, $SHCFLAGS, $SHCXX, $SHCXXCOM, $SHCXXFLAGS.
Uses: $CCCOMSTR, $CXXCOMSTR, $SHCCCOMSTR, $SHCXXCOMSTR.
Sets construction variables for the Metrowerks CodeWarrior linker.
Sets: $AR, $ARCOM, $LIBDIRPREFIX, $LIBDIRSUFFIX, $LIBLINKPREFIX, $LIBLINKSUFFIX, $LINK, $LINKCOM, $SHLINK, $SHLINKCOM, $SHLINKFLAGS.
Sets construction variables for the nasm Netwide Assembler.
Sets: $AS, $ASCOM, $ASFLAGS, $ASPPCOM, $ASPPFLAGS.
Uses: $ASCOMSTR, $ASPPCOMSTR.
Sets up the Ninja builder, which generates a ninja build file, and then optionally runs ninja.
This is an experimental feature. This functionality is subject to change and/or removal without a deprecation cycle.
Sets: $IMPLICIT_COMMAND_DEPENDENCIES, $NINJA_ALIAS_NAME, $NINJA_CMD_ARGS, $NINJA_COMPDB_EXPAND, $NINJA_DEPFILE_PARSE_FORMAT, $NINJA_DIR, $NINJA_DISABLE_AUTO_RUN, $NINJA_ENV_VAR_CACHE, $NINJA_FILE_NAME, $NINJA_FORCE_SCONS_BUILD, $NINJA_GENERATED_SOURCE_ALIAS_NAME, $NINJA_GENERATED_SOURCE_SUFFIXES, $NINJA_MSVC_DEPS_PREFIX, $NINJA_POOL, $NINJA_REGENERATE_DEPS, $NINJA_SCONS_DAEMON_KEEP_ALIVE, $NINJA_SCONS_DAEMON_PORT, $NINJA_SYNTAX, $_NINJA_REGENERATE_DEPS_FUNC.
Uses: $AR, $ARCOM, $ARFLAGS, $CC, $CCCOM, $CCDEPFLAGS, $CCFLAGS, $CXX, $CXXCOM, $ESCAPE, $LINK, $LINKCOM, $PLATFORM, $PRINT_CMD_LINE_FUNC, $PROGSUFFIX, $RANLIB, $RANLIBCOM, $SHCCCOM, $SHCXXCOM, $SHLINK, $SHLINKCOM.
Sets construction variables for the Package Builder.
If this tool is enabled, the --package-type
command-line option is also enabled.
Sets construction variables for the Portable Document Format builder.
Sets: $PDFPREFIX, $PDFSUFFIX.
Sets construction variables for the pdflatex utility.
Sets: $LATEXRETRIES, $PDFLATEX, $PDFLATEXCOM, $PDFLATEXFLAGS.
Uses: $PDFLATEXCOMSTR.
Sets construction variables for the pdftex utility.
Sets: $LATEXRETRIES, $PDFLATEX, $PDFLATEXCOM, $PDFLATEXFLAGS, $PDFTEX, $PDFTEXCOM, $PDFTEXFLAGS.
Uses: $PDFLATEXCOMSTR, $PDFTEXCOMSTR.
Loads the Python source scanner into the invoking environment. When loaded, the scanner will attempt to find implicit dependencies for any Python source files in the list of sources provided to an Action that uses this environment.
Available since scons 4.0..
Placeholder tool to alert anyone still using qt tools to switch to qt3 or newer tool.
Sets construction variables for building Qt3 applications.
This tool is only suitable for building targeted to Qt3, which is obsolete (the tool is deprecated since 4.3, and was renamed to qt3 in 4.5.0. ). There are contributed tools for Qt4 and Qt5, see https://github.com/SCons/scons-contrib. Qt4 has also passed end of life for standard support (in Dec 2015).
Note paths for these construction variables are assembled
using the os.path.join method
so they will have the appropriate separator at runtime,
but are listed here in the various
entries only with the '/' separator
for simplicity.
In addition, the construction variables
$CPPPATH,
$LIBPATH and
$LIBS may be modified
and the variables
$PROGEMITTER, $SHLIBEMITTER and $LIBEMITTER
are modified. Because the build-performance is affected when using this tool,
you have to explicitly specify it at Environment creation:
Environment(tools=['default','qt3'])
The qt3 tool supports the following operations:
Automatic moc file generation from header files.
You do not have to specify moc files explicitly, the tool does it for you.
However, there are a few preconditions to do so: Your header file must have
the same filebase as your implementation file and must stay in the same
directory. It must have one of the suffixes
.h,
.hpp,
.H,
.hxx,
.hh.
You can turn off automatic moc file generation by setting
$QT3_AUTOSCAN to False.
See also the corresponding
Moc Builder.
Automatic moc file generation from C++ files.
As described in the Qt documentation, include the moc file at the end of
the C++ file. Note that you have to include the file, which is generated
by the transformation
${QT3_MOCCXXPREFIX}<basename>${QT3_MOCCXXSUFFIX}, by default
<basename>.mo. A warning is generated after building the moc file if you
do not include the correct file. If you are using VariantDir, you may
need to specify duplicate=True.
You can turn off automatic moc file generation by setting $QT3_AUTOSCAN to
False. See also the corresponding
Moc Builder.
Automatic handling of .ui files.
The implementation files generated from .ui
files are handled much the same as yacc or lex files.
Each .ui file given as a source of Program,
Library or SharedLibrary
will generate three files: the declaration file, the
implementation file and a moc file. Because there are also generated headers,
you may need to specify duplicate=True in calls to
VariantDir.
See also the corresponding
Uic Builder.
Sets: $QT3DIR, $QT3_AUTOSCAN, $QT3_BINPATH, $QT3_CPPPATH, $QT3_LIB, $QT3_LIBPATH, $QT3_MOC, $QT3_MOCCXXPREFIX, $QT3_MOCCXXSUFFIX, $QT3_MOCFROMCXXCOM, $QT3_MOCFROMCXXFLAGS, $QT3_MOCFROMHCOM, $QT3_MOCFROMHFLAGS, $QT3_MOCHPREFIX, $QT3_MOCHSUFFIX, $QT3_UIC, $QT3_UICCOM, $QT3_UICDECLFLAGS, $QT3_UICDECLPREFIX, $QT3_UICDECLSUFFIX, $QT3_UICIMPLFLAGS, $QT3_UICIMPLPREFIX, $QT3_UICIMPLSUFFIX, $QT3_UISUFFIX.
Uses: $QT3DIR.
Sets construction variables for the rmic utility.
Sets: $JAVACLASSSUFFIX, $RMIC, $RMICCOM, $RMICFLAGS.
Uses: $RMICCOMSTR.
Sets construction variables for building with RPCGEN.
Sets: $RPCGEN, $RPCGENCLIENTFLAGS, $RPCGENFLAGS, $RPCGENHEADERFLAGS, $RPCGENSERVICEFLAGS, $RPCGENXDRFLAGS.
Sets construction variables for the SGI library archiver.
Sets: $AR, $ARCOMSTR, $ARFLAGS, $LIBPREFIX, $LIBSUFFIX, $SHLINK, $SHLINKFLAGS.
Uses: $ARCOMSTR, $SHLINKCOMSTR.
Sets construction variables for the SGI C++ compiler.
Sets: $CXX, $CXXFLAGS, $SHCXX, $SHOBJSUFFIX.
Sets construction variables for the SGI C compiler.
Sets: $CXX, $SHOBJSUFFIX.
Sets construction variables for the SGI linker.
Sets: $LINK, $RPATHPREFIX, $RPATHSUFFIX, $SHLINKFLAGS.
Sets construction variables for the Sun library archiver.
Sets: $AR, $ARCOM, $ARFLAGS, $LIBPREFIX, $LIBSUFFIX.
Uses: $ARCOMSTR.
Sets construction variables for the Sun C++ compiler.
Sets: $CXX, $CXXVERSION, $SHCXX, $SHCXXFLAGS, $SHOBJPREFIX, $SHOBJSUFFIX.
Sets construction variables for the Sun C compiler.
Sets: $CXX, $SHCCFLAGS, $SHOBJPREFIX, $SHOBJSUFFIX.
Set construction variables for the Sun f77 Fortran compiler.
Sets: $F77, $FORTRAN, $SHF77, $SHF77FLAGS, $SHFORTRAN, $SHFORTRANFLAGS.
Set construction variables for the Sun f90 Fortran compiler.
Sets: $F90, $FORTRAN, $SHF90, $SHF90FLAGS, $SHFORTRAN, $SHFORTRANFLAGS.
Set construction variables for the Sun f95 Fortran compiler.
Sets: $F95, $FORTRAN, $SHF95, $SHF95FLAGS, $SHFORTRAN, $SHFORTRANFLAGS.
Sets construction variables for the Sun linker.
Sets: $RPATHPREFIX, $RPATHSUFFIX, $SHLINKFLAGS.
Sets construction variables for the SWIG interface compiler.
Sets: $SWIG, $SWIGCFILESUFFIX, $SWIGCOM, $SWIGCXXFILESUFFIX, $SWIGDIRECTORSUFFIX, $SWIGFLAGS, $SWIGINCPREFIX, $SWIGINCSUFFIX, $SWIGPATH, $SWIGVERSION, $_SWIGINCFLAGS.
Uses: $SWIGCOMSTR.
Sets construction variables for the tar archiver.
Sets: $TAR, $TARCOM, $TARFLAGS, $TARSUFFIX.
Uses: $TARCOMSTR.
Sets construction variables for the TeX formatter and typesetter.
Sets: $BIBTEX, $BIBTEXCOM, $BIBTEXFLAGS, $LATEX, $LATEXCOM, $LATEXFLAGS, $MAKEINDEX, $MAKEINDEXCOM, $MAKEINDEXFLAGS, $TEX, $TEXCOM, $TEXFLAGS.
Uses: $BIBTEXCOMSTR, $LATEXCOMSTR, $MAKEINDEXCOMSTR, $TEXCOMSTR.
Set construction variables for the Textfile and Substfile builders.
Sets: $FILE_ENCODING, $LINESEPARATOR, $SUBSTFILEPREFIX, $SUBSTFILESUFFIX, $TEXTFILEPREFIX, $TEXTFILESUFFIX.
Uses: $SUBST_DICT.
Sets construction variables for the Borlan tib library archiver.
Sets: $AR, $ARCOM, $ARFLAGS, $LIBPREFIX, $LIBSUFFIX.
Uses: $ARCOMSTR.
This scons tool is a part of scons gettext toolset. It provides
scons interface to xgettext(1)
program, which extracts internationalized messages from source code. The tool
provides POTUpdate builder to make PO
Template files.
Sets: $POTSUFFIX, $POTUPDATE_ALIAS, $XGETTEXTCOM, $XGETTEXTCOMSTR, $XGETTEXTFLAGS, $XGETTEXTFROM, $XGETTEXTFROMPREFIX, $XGETTEXTFROMSUFFIX, $XGETTEXTPATH, $XGETTEXTPATHPREFIX, $XGETTEXTPATHSUFFIX, $_XGETTEXTDOMAIN, $_XGETTEXTFROMFLAGS, $_XGETTEXTPATHFLAGS.
Uses: $POTDOMAIN.
Sets construction variables for the yacc parser generator.
Sets: $YACC, $YACCCOM, $YACCFLAGS, $YACCHFILESUFFIX, $YACCHXXFILESUFFIX, $YACCVCGFILESUFFIX, $YACC_GRAPH_FILE_SUFFIX.
Uses: $YACCCOMSTR, $YACCFLAGS, $YACC_GRAPH_FILE, $YACC_HEADER_FILE.
Sets construction variables for the zip archiver.
Sets: $ZIP, $ZIPCOM, $ZIPCOMPRESSION, $ZIPFLAGS, $ZIPSUFFIX.
Uses: $ZIPCOMSTR.
You tell SCons what to build
by calling Builders,
functions which take particular action(s)
to produce target(s) of a particular type
(conventionally hinted at by the builder name, e.g. Program)
from the specified source files.
A builder call is a declaration: SCons enters the
specified relationship into its internal dependency node graph,
and only later makes the decision on whether anything is actually built,
since this depends on command-line options,
target selection rules, and whether the target(s) are
out of date with respect to the sources.
SCons
provides a number of builders, and you can also write your own
(see Builder Objects).
Builders are created dynamically at run-time,
often (though not always) by tools which determine
whether the external dependencies for the builder are satisfied,
and which perform the necessary setup
(see Tools).
Builders are attached to a construction environment as methods.
The available builder methods are registered as
key-value pairs in the
$BUILDERS attribute of the construction environment,
so the available builders can be examined.
This example displays them for debugging purposes:
env = Environment()
print("Builders:", list(env['BUILDERS']))
Builder methods take two required arguments:
target
and
source.
The target and
source arguments
can be specified either as positional arguments,
in which case target comes first, or as
keyword arguments, using target=
and source=.
Although both arguments are nominally required,
if there is a single source and the target can be inferred
the target argument can be omitted (see below).
Builder methods also take a variety of
keyword arguments, described below.
Because long lists of file names
can lead to a lot of quoting in a builder call,
SCons
supplies a Split
global function
and a same-named environment method
that splits a single string
into a list, using
strings of white-space characters as the delimiter
(similar to the Python string split
method, but succeeds even if the input isn't a string).
The following are equivalent examples of calling the
Program builder method:
env.Program('bar', ['bar.c', 'foo.c'])
env.Program('bar', Split('bar.c foo.c'))
env.Program('bar', env.Split('bar.c foo.c'))
env.Program(source=['bar.c', 'foo.c'], target='bar')
env.Program(target='bar', source=Split('bar.c foo.c'))
env.Program(target='bar', source=env.Split('bar.c foo.c'))
env.Program('bar', source='bar.c foo.c'.split())
Sources and targets can be specified as a scalar or as a list,
composed of either strings or nodes (more on nodes below).
When specifying path strings,
Python follows the POSIX pathname convention:
if a string begins with the operating system pathname separator
(on Windows both the slash and backslash separator are accepted,
and any leading drive specifier is ignored for
the determination) it is considered an absolute path,
otherwise it is a relative path.
If the path string contains no separator characters,
it is searched for as a file in the current directory. If it
contains separator characters, the search follows down
from the starting point, which is the top of the directory tree for
an absolute path and the current directory for a relative path.
The "current directory" in this context is the directory
of the SConscript file currently being processed.
SCons also recognizes a third way to specify path strings: if the string begins with the # character it is top-relative - it works like a relative path but the search follows down from the project top directory rather than from the current directory. The # can optionally be followed by a pathname separator, which is ignored if found in that position. Top-relative paths only work in places where scons will interpret the path (see some examples below). To be used in other contexts the string will need to be converted to a relative or absolute path first.
Examples:
# The comments describing the targets that will be built
# assume these calls are in a SConscript file in the
# a subdirectory named "subdir".
# Builds the program "subdir/foo" from "subdir/foo.c":
env.Program('foo', 'foo.c')
# Builds the program "/tmp/bar" from "subdir/bar.c":
env.Program('/tmp/bar', 'bar.c')
# An initial '#' or '#/' are equivalent; the following
# calls build the programs "foo" and "bar" (in the
# top-level SConstruct directory) from "subdir/foo.c" and
# "subdir/bar.c", respectively:
env.Program('#foo', 'foo.c')
env.Program('#/bar', 'bar.c')
# Builds the program "other/foo" (relative to the top-level
# SConstruct directory) from "subdir/foo.c":
env.Program('#other/foo', 'foo.c')
# This will not work, only SCons interfaces understand '#',
# os.path.exists is pure Python:
if os.path.exists('#inc/foo.h'):
env.Append(CPPPATH='#inc')
When the target shares the same base name
as the source and only the suffix varies,
and if the builder method has a suffix defined for the target file type,
then the target argument may be omitted completely,
and
scons
will deduce the target file name from
the source file name.
The following examples all build the
executable program
bar
(on POSIX systems)
or
bar.exe
(on Windows systems)
from the bar.c source file:
env.Program(target='bar', source='bar.c')
env.Program('bar', source='bar.c')
env.Program(source='bar.c')
env.Program('bar.c')
The optional
srcdir
keyword argument specifies that
all source file strings that are not absolute paths
or top-relative paths
shall be interpreted relative to the specified
srcdir.
The following example will build the
build/prog
(or
build/prog.exe
on Windows)
program from the files
src/f1.c
and
src/f2.c:
env.Program('build/prog', ['f1.c', 'f2.c'], srcdir='src')
The optional
parse_flags
keyword argument causes behavior similar to the
env.MergeFlags method, where the argument value is
broken into individual settings and merged into the appropriate construction variables.
env.Program('hello', 'hello.c', parse_flags='-Iinclude -DEBUG -lm')
This example adds 'include' to
the $CPPPATH construction variable,
'EBUG' to
$CPPDEFINES,
and 'm' to
$LIBS.
The optional
chdir
keyword argument
specifies that the Builder's action(s)
should be executed
after changing directory.
If the
chdir
argument is
a path string or a directory Node,
scons will change to the specified directory.
If the
chdir
is not a string or Node
and evaluates true,
then scons will change to the
target file's directory.
Python only keeps one current directory
location even if there are multiple threads.
This means that use of the
chdir
argument
will
not
work with the SCons
-j
option,
because individual worker threads spawned
by SCons interfere with each other
when they start changing directory.
# scons will change to the "sub" subdirectory
# before executing the "cp" command.
env.Command(
target='sub/dir/foo.out',
source='sub/dir/foo.in',
action="cp dir/foo.in dir/foo.out",
chdir='sub',
)
# Because chdir is not a string, scons will change to the
# target's directory ("sub/dir") before executing the
# "cp" command.
env.Command('sub/dir/foo.out', 'sub/dir/foo.in', "cp foo.in foo.out", chdir=True)
Note that SCons will
not
automatically modify
its expansion of
construction variables like $TARGET
and $SOURCE
when using the chdir
keyword argument--that is,
the expanded file names
will still be relative to
the project top directory,
and consequently incorrect
relative to the chdir directory.
If you use the chdir keyword argument,
you will typically need to supply a different
command line using
expansions like
${TARGET.file}
and
${SOURCE.file}
to use just the filename portion of the
target and source.
Keyword arguments that are not specifically recognized are treated as construction variable overrides, which replace or add those variables on a limited basis. These overrides will only be in effect when building the target of the builder call, and will not affect other parts of the build. For example, if you want to specify some libraries needed by just one program:
env.Program('hello', 'hello.c', LIBS=['gl', 'glut'])
or generate a shared library with a non-standard suffix:
env.SharedLibrary(
target='word',
source='word.cpp',
SHLIBSUFFIX='.ocx',
LIBSUFFIXES=['.ocx'],
)
Note that both the $SHLIBSUFFIX
and $LIBSUFFIXES
construction variables must be set if you want scons to search automatically
for dependencies on the non-standard library names;
see the descriptions of these variables for more information.
Although the builder methods defined by scons are, in fact, methods of a construction environment object, many may also be called without an explicit environment:
Program('hello', 'hello.c')
SharedLibrary('word', 'word.cpp')
If called this way, the builder will internally use the Default Environment that consists of the tools and values that scons has determined are appropriate for the local system.
Builder methods that can be called without an explicit
environment (indicated in the listing of builders below
without a leading env.)
may be called from custom Python modules that you
import into an SConscript file by adding the following
to the Python module:
from SCons.Script import *
A builder may add additional targets
beyond those requested
if an attached Emitter chooses to do so
(see the section called “Builder Objects” for more information.
$PROGEMITTER is an example).
For example, the GNU linker takes a command-line argument
-Map=,
which causes it to produce a linker map file in addition
to the executable file actually being linked.
If the mapfileProgram builder's emitter is configured
to add this mapfile if the option is set,
then two targets will be returned when you only provided for one.
For this reason,
builder methods always return a NodeList,
a list-like object whose elements are Nodes.
Nodes are the internal representation of build targets or sources
(see the section called “Node Objects” for more information).
The returned NodeList object
can be passed to other builder methods as source(s)
or to other SCons functions or methods
where a path string would normally be accepted.
For example, to add a specific preprocessor define when compiling one specific object file but not the others:
bar_obj_list = env.StaticObject('bar.c', CPPDEFINES='-DBAR')
env.Program("prog", ['foo.c', bar_obj_list, 'main.c'])
Using a Node as in this example
makes for a more portable build
by avoiding having to specify
a platform-specific object suffix
when calling the Program builder method.
The NodeList object
is also convenient to pass to the Default function,
for the same reason of avoiding a platform-specific name:
tgt = env.Program("prog", ["foo.c", "bar.c", "main.c"])
Default(tgt)
Builder calls will automatically "flatten"
lists passed as source and target, so they are free to
contain elements which are themselves lists, such as
bar_obj_list
returned by the StaticObject call.
If you need to manipulate a list of lists returned by builders
directly in Python code,
you can either build a new list by hand:
foo = Object('foo.c')
bar = Object('bar.c')
objects = ['begin.o'] + foo + ['middle.o'] + bar + ['end.o']
for obj in objects:
print(str(obj))
Or you can use the Flatten
function supplied by SCons
to create a list containing just the Nodes,
which may be more convenient:
foo = Object('foo.c')
bar = Object('bar.c')
objects = Flatten(['begin.o', foo, 'middle.o', bar, 'end.o'])
for obj in objects:
print(str(obj))
Since builder calls return
a list-like object, not an actual Python list,
it is not appropriate to use the Python add
operator (+ or +=)
to append builder results to a Python list.
Because the list and the object are different types,
Python will not update the original list in place,
but will instead create a new NodeList object
containing the concatenation of the list
elements and the builder results.
This will cause problems for any other Python variables
in your SCons configuration
that still hold on to a reference to the original list.
Instead, use the Python list
extend
method to make sure the list is updated in-place.
Example:
object_files = []
# Do NOT use += here:
# object_files += Object('bar.c')
#
# It will not update the object_files list in place.
#
# Instead, use the list extend method:
object_files.extend(Object('bar.c'))
The path name for a Node's file may be used
by passing the Node to Python's builtin
str
function:
bar_obj_list = env.StaticObject('bar.c', CPPDEFINES='-DBAR')
print("The path to bar_obj is:", str(bar_obj_list[0]))
Note that because the Builder call returns a
NodeList,
you have to access the first element in the list
(bar_obj_list[0] in the example)
to get at the Node that actually represents
the object file.
When trying to handle errors that may occur in a builder method,
consider that the corresponding Action is executed at a different
time than the SConscript file statement calling the builder.
It is not useful to wrap a builder call in a
try block,
since success in the builder call is not the same as
the builder itself succeeding.
If necessary, a Builder's Action should be coded to exit with
a useful exception message indicating the problem in the SConscript files -
programmatically recovering from build errors is rarely useful.
The following builder methods are predefined in the SCons core software distribution. Depending on the setup of a particular construction environment and on the type and software installation status of the underlying system, not all builders may be available in that construction environment. Since the function calling signature is the same for all builders:
Buildername(target, source, [key=val, ...])
it is omitted in this listing for brevity.
CFile()env.CFile()
Builds a C source file given a lex (.l)
or yacc (.y) input file.
The suffix specified by the $CFILESUFFIX construction variable
(.c by default)
is automatically added to the target
if it is not already present.
Example:
# builds foo.c env.CFile(target='foo.c', source='foo.l') # builds bar.c env.CFile(target='bar', source='bar.y')
Command()env.Command()
There is actually no Builder named Command,
rather the term "Command Builder" refers to
a function which, on each call, creates and calls
an anonymous Builder.
This is useful for "one-off" builds
where a full Builder is not needed.
Since the anonymous Builder is never hooked
into the standard Builder framework,
an Action must always be specfied.
See the Command function description
for the calling syntax and details.
CompilationDatabase()env.CompilationDatabase()
CompilationDatabase is a special builder which
adds a target to create a JSON formatted
compilation database compatible with
clang tooling
(see the
LLVM specification).
This database is suitable for consumption by various
tools and editors who can use it to obtain build and
dependency information which otherwise would be
internal to SCons.
The builder does not require any source files to be specified,
rather it arranges to emit information about all
of the C, C++ and assembler source/output pairs
identified in the build that are not excluded by the
optional filter $COMPILATIONDB_PATH_FILTER.
The target is subject to the usual SCons target
selection rules.
If called with no arguments,
the builder will default to a target name of
compile_commands.json.
If called with a single positional argument, scons will "deduce" the target name from that source argument, giving it the same name, and then ignore the source. This is the usual way to call the builder if a non-default target name is wanted.
If called with either the target=
or source= keyword arguments,
the value of the argument is taken as the target name.
If called with both, the target=
value is used and source= is ignored.
If called with multiple sources,
the source list will be ignored,
since there is no way to deduce what the intent was;
in this case the default target name will be used.
You must load the compilation_db tool prior to specifying
any part of your build or some source/output
files will not show up in the compilation database.
Available since scons 4.0.
CXXFile()env.CXXFile()
Builds a C++ source file given a lex (.ll)
or yacc (.yy)
input file.
The suffix specified by the $CXXFILESUFFIX construction variable
(.cc by default)
is automatically added to the target
if it is not already present.
Example:
# builds foo.cc env.CXXFile(target='foo.cc', source='foo.ll') # builds bar.cc env.CXXFile(target='bar', source='bar.yy')
DocbookEpub()env.DocbookEpub()
A pseudo-Builder, providing a Docbook toolchain for EPUB output.
env = Environment(tools=['docbook'])
env.DocbookEpub('manual.epub', 'manual.xml')
or simply
env = Environment(tools=['docbook'])
env.DocbookEpub('manual')
DocbookHtml()env.DocbookHtml()
A pseudo-Builder, providing a Docbook toolchain for HTML output.
env = Environment(tools=['docbook'])
env.DocbookHtml('manual.html', 'manual.xml')
or simply
env = Environment(tools=['docbook'])
env.DocbookHtml('manual')
DocbookHtmlChunked()env.DocbookHtmlChunked()
A pseudo-Builder providing a Docbook toolchain for chunked HTML output.
It supports the base.dir parameter. The
chunkfast.xsl file (requires "EXSLT") is used as the
default stylesheet. Basic syntax:
env = Environment(tools=['docbook'])
env.DocbookHtmlChunked('manual')
where manual.xml is the input file.
If you use the root.filename
parameter in your own stylesheets you have to specify the new target name.
This ensures that the dependencies get correct, especially for the cleanup via “scons -c”:
env = Environment(tools=['docbook'])
env.DocbookHtmlChunked('mymanual.html', 'manual', xsl='htmlchunk.xsl')
Some basic support for the base.dir parameter
is provided. You can add the base_dir keyword to
your Builder call, and the given prefix gets prepended to all the
created filenames:
env = Environment(tools=['docbook'])
env.DocbookHtmlChunked('manual', xsl='htmlchunk.xsl', base_dir='output/')
Make sure that you don't forget the trailing slash for the base folder, else your files get renamed only!
DocbookHtmlhelp()env.DocbookHtmlhelp()
A pseudo-Builder, providing a Docbook toolchain for HTMLHELP output. Its basic syntax is:
env = Environment(tools=['docbook'])
env.DocbookHtmlhelp('manual')
where manual.xml is the input file.
If you use the root.filename
parameter in your own stylesheets you have to specify the new target name.
This ensures that the dependencies get correct, especially for the cleanup via “scons -c”:
env = Environment(tools=['docbook'])
env.DocbookHtmlhelp('mymanual.html', 'manual', xsl='htmlhelp.xsl')
Some basic support for the base.dir parameter
is provided. You can add the base_dir keyword to
your Builder call, and the given prefix gets prepended to all the
created filenames:
env = Environment(tools=['docbook'])
env.DocbookHtmlhelp('manual', xsl='htmlhelp.xsl', base_dir='output/')
Make sure that you don't forget the trailing slash for the base folder, else your files get renamed only!
DocbookMan()env.DocbookMan()
A pseudo-Builder, providing a Docbook toolchain for Man page output. Its basic syntax is:
env = Environment(tools=['docbook'])
env.DocbookMan('manual')
where manual.xml is the input file. Note, that
you can specify a target name, but the actual output names are automatically
set from the refname entries in your XML source.
DocbookPdf()env.DocbookPdf()
A pseudo-Builder, providing a Docbook toolchain for PDF output.
env = Environment(tools=['docbook'])
env.DocbookPdf('manual.pdf', 'manual.xml')
or simply
env = Environment(tools=['docbook'])
env.DocbookPdf('manual')
DocbookSlidesHtml()env.DocbookSlidesHtml()
A pseudo-Builder, providing a Docbook toolchain for HTML slides output.
env = Environment(tools=['docbook'])
env.DocbookSlidesHtml('manual')
If you use the titlefoil.html parameter in
your own stylesheets you have to give the new target name. This ensures
that the dependencies get correct, especially for the cleanup via
“scons -c”:
env = Environment(tools=['docbook'])
env.DocbookSlidesHtml('mymanual.html','manual', xsl='slideshtml.xsl')
Some basic support for the base.dir parameter
is provided. You
can add the base_dir keyword to your Builder
call, and the given prefix gets prepended to all the created filenames:
env = Environment(tools=['docbook'])
env.DocbookSlidesHtml('manual', xsl='slideshtml.xsl', base_dir='output/')
Make sure that you don't forget the trailing slash for the base folder, else your files get renamed only!
DocbookSlidesPdf()env.DocbookSlidesPdf()
A pseudo-Builder, providing a Docbook toolchain for PDF slides output.
env = Environment(tools=['docbook'])
env.DocbookSlidesPdf('manual.pdf', 'manual.xml')
or simply
env = Environment(tools=['docbook'])
env.DocbookSlidesPdf('manual')
DocbookXInclude()env.DocbookXInclude()
A pseudo-Builder, for resolving XIncludes in a separate processing step.
env = Environment(tools=['docbook'])
env.DocbookXInclude('manual_xincluded.xml', 'manual.xml')
DocbookXslt()env.DocbookXslt()
A pseudo-Builder, applying a given XSL transformation to the input file.
env = Environment(tools=['docbook'])
env.DocbookXslt('manual_transformed.xml', 'manual.xml', xsl='transform.xslt')
Note, that this builder requires the xsl parameter
to be set.
DVI()env.DVI()
Builds a .dvi file
from a .tex,
.ltx or .latex input file.
If the source file suffix is .tex,
scons
will examine the contents of the file;
if the string
\documentclass
or
\documentstyle
is found, the file is assumed to be a LaTeX file and
the target is built by invoking the $LATEXCOM command line;
otherwise, the $TEXCOM command line is used.
If the file is a LaTeX file,
the
DVI
builder method will also examine the contents
of the
.aux
file and invoke the $BIBTEX command line
if the string
bibdata
is found,
start $MAKEINDEX to generate an index if a
.ind
file is found
and will examine the contents
.log
file and re-run the $LATEXCOM command
if the log file says it is necessary.
The suffix .dvi
(hard-coded within TeX itself)
is automatically added to the target
if it is not already present.
Examples:
# builds from aaa.tex env.DVI(target = 'aaa.dvi', source = 'aaa.tex') # builds bbb.dvi env.DVI(target = 'bbb', source = 'bbb.ltx') # builds from ccc.latex env.DVI(target = 'ccc.dvi', source = 'ccc.latex')
Gs()env.Gs()
A Builder for explicitly calling the gs executable. Depending on the underlying OS, the different names gs, gsos2 and gswin32c are tried.
env = Environment(tools=['gs'])
env.Gs(
'cover.jpg',
'scons-scons.pdf',
GSFLAGS='-dNOPAUSE -dBATCH -sDEVICE=jpeg -dFirstPage=1 -dLastPage=1 -q',
)
Install()env.Install()
Installs one or more source files or directories in the specified target, which must be a directory. The names of the specified source files or directories remain the same within the destination directory. The sources may be given as a string or as a node returned by a builder.
env.Install(target='/usr/local/bin', source=['foo', 'bar'])
Note that if target paths chosen for the
Install builder (and the related InstallAs and
InstallVersionedLib builders) are outside the
project tree, such as in the example above,
they may not be selected for "building" by default,
since in the absence of other instructions
scons builds targets that are underneath the top directory
(the directory that contains the SConstruct file,
usually the current directory).
Use command line targets or the Default function
in this case.
If the --install-sandbox command line
option is given, the target directory will be prefixed
by the directory path specified.
This is useful to test installs without installing to
a "live" location in the system.
See also FindInstalledFiles.
For more thoughts on installation, see the User Guide
(particularly the section on Command-Line Targets
and the chapters on Installing Files and on Alias Targets).
InstallAs()env.InstallAs()
Installs one or more source files or directories to specific names, allowing changing a file or directory name as part of the installation. It is an error if the target and source arguments list different numbers of files or directories.
env.InstallAs(target='/usr/local/bin/foo',
source='foo_debug')
env.InstallAs(target=['../lib/libfoo.a', '../lib/libbar.a'],
source=['libFOO.a', 'libBAR.a'])
See the note under Install.
InstallVersionedLib()env.InstallVersionedLib()
Installs a versioned shared library. The symlinks appropriate to the architecture will be generated based on symlinks of the source library.
env.InstallVersionedLib(target='/usr/local/bin/foo',
source='libxyz.1.5.2.so')
See the note under Install.
Jar()env.Jar()
Builds a Java archive (.jar) file
from the specified list of sources.
Any directories in the source list
will be searched for .class files).
Any .java files in the source list
will be compiled to .class files
by calling the Java Builder.
If the $JARCHDIR value is set, the
jar
command will change to the specified directory using the
-C
option.
If $JARCHDIR is not set explicitly,
SCons will use the top of any subdirectory tree
in which Java .class
were built by the Java Builder.
If the contents any of the source files begin with the string
Manifest-Version,
the file is assumed to be a manifest
and is passed to the
jar
command with the
m
option set.
env.Jar(target = 'foo.jar', source = 'classes')
env.Jar(target = 'bar.jar',
source = ['bar1.java', 'bar2.java'])
Java()env.Java()
Builds one or more Java class files.
The sources may be any combination of explicit
.java
files,
or directory trees which will be scanned
for .java files.
SCons will parse each source .java file
to find the classes
(including inner classes)
defined within that file,
and from that figure out the
target .class files that will be created.
The class files will be placed underneath
the specified target directory.
SCons will also search each Java file
for the Java package name,
which it assumes can be found on a line
beginning with the string
package
in the first column;
the resulting .class files
will be placed in a directory reflecting
the specified package name.
For example,
the file
Foo.java
defining a single public
Foo
class and
containing a package name of
sub.dir
will generate a corresponding
sub/dir/Foo.class
class file.
Examples:
env.Java(target='classes', source='src')
env.Java(target='classes', source=['src1', 'src2'])
env.Java(target='classes', source=['File1.java', 'File2.java'])
Java source files can use the native encoding for the underlying OS.
Since SCons compiles in simple ASCII mode by default,
the compiler will generate warnings about unmappable characters,
which may lead to errors as the file is processed further.
In this case, the user must specify the
LANG
environment variable to tell the compiler what encoding is used.
For portibility, it's best if the encoding is hard-coded
so that the compile will work if it is done on a system
with a different encoding.
env = Environment()
env['ENV']['LANG'] = 'en_GB.UTF-8'
JavaH()env.JavaH()
Builds C header and source files for
implementing Java native methods.
The target can be either a directory
in which the header files will be written,
or a header file name which
will contain all of the definitions.
The source can be the names of .class files,
the names of .java files
to be compiled into .class files
by calling the Java builder method,
or the objects returned from the
Java
builder method.
If the construction variable
$JAVACLASSDIR
is set, either in the environment
or in the call to the
JavaH
builder method itself,
then the value of the variable
will be stripped from the
beginning of any .class file names.
Examples:
# builds java_native.h
classes = env.Java(target="classdir", source="src")
env.JavaH(target="java_native.h", source=classes)
# builds include/package_foo.h and include/package_bar.h
env.JavaH(target="include", source=["package/foo.class", "package/bar.class"])
# builds export/foo.h and export/bar.h
env.JavaH(
target="export",
source=["classes/foo.class", "classes/bar.class"],
JAVACLASSDIR="classes",
)
Java versions starting with 10.0 no longer use the
javah command for generating JNI
headers/sources, and indeed have removed the command entirely
(see Java Enhancement Proposal
JEP 313),
making this tool harder to use for that purpose.
SCons may autodiscover a javah
belonging to an older release if there are multiple Java
versions on the system, which will lead to incorrect results.
To use with a newer Java, override the default values of $JAVAH
(to contain the path to the javac)
and $JAVAHFLAGS (to contain at least a -h
flag) and note that generating headers with
javac requires supplying source
.java files only,
not .class files.
Library()env.Library()
A synonym for the
StaticLibrary
builder method.
LoadableModule()env.LoadableModule()
On most systems,
this is the same as
SharedLibrary.
On Mac OS X (Darwin) platforms,
this creates a loadable module bundle.
M4()env.M4()
Builds an output file from an M4 input file.
This uses a default $M4FLAGS value of
-E,
which considers all warnings to be fatal
and stops on the first warning
when using the GNU version of m4.
Example:
env.M4(target = 'foo.c', source = 'foo.c.m4')
Moc()env.Moc()
Builds an output file from a moc input file.
moc input files are either header files or C++ files.
This builder is only available after using the
tool qt3. See the $QT3DIR variable for more information.
Example:
env.Moc('foo.h') # generates moc_foo.cc
env.Moc('foo.cpp') # generates foo.moc
MOFiles()env.MOFiles()
This builder belongs to msgfmt tool. The builder compiles
PO files to MO files.
Example 1.
Create pl.mo and en.mo by compiling
pl.po and en.po:
# ... env.MOFiles(['pl', 'en'])
Example 2.
Compile files for languages defined in LINGUAS file:
# ... env.MOFiles(LINGUAS_FILE = 1)
Example 3.
Create pl.mo and en.mo by compiling
pl.po and en.po plus files for
languages defined in LINGUAS file:
# ... env.MOFiles(['pl', 'en'], LINGUAS_FILE = 1)
Example 4.
Compile files for languages defined in LINGUAS file
(another version):
# ... env['LINGUAS_FILE'] = 1 env.MOFiles()
MSVSProject()env.MSVSProject()
Build a Microsoft Visual C++ project file and solution file.
Builds a Microsoft Visual C++ project file based on the
version of Visual Studio (or to be more precise, of
MSBuild)
that is configured: either the latest installed version,
or the version specified by
$MSVC_VERSION in the current construction environment.
For Visual Studio 6.0 a .dsp file is generated.
For Visual Studio versions 2002-2008,
a .vcproj file is generated.
For Visual Studio 2010 and later a .vcxproj
file is generated.
Note there are multiple versioning schemes involved in
the Microsoft compilation environment -
see the description of $MSVC_VERSION for equivalences.
Note SCons does not know how to construct project files for
other languages (e.g. .csproj for C#,
.vbproj for Visual Basic or
.pyproject for Python).
For the .vcxproj file, the underlying
format is the MSBuild XML Schema, and the details conform to:
https://learn.microsoft.com/en-us/cpp/build/reference/vcxproj-file-structure.
The generated solution file enables Visual Studio to
understand the project structure, and allows building it
using MSBuild to call back to SCons.
The project file encodes a toolset version that has been
selected by SCons as described above. Since recent Visual
Studio versions support multiple concurrent toolsets,
use $MSVC_VERSION to select the desired one if
it does not match the SCons default.
The project file also includes entries which describe
how to call SCons to build the project from within Visual Studio
(or from an MSBuild command line).
In some situations SCons may generate this incorrectly -
notably when using the scons-local
distribution, which is not installed in a way that that
matches the default invocation line.
If so, the $SCONS_HOME construction variable can be used to describe
the right way to locate the SCons code so that it can be imported.
By default, a matching solution file for the project is also generated.
This behavior may be disabled by
specifying auto_build_solution=0
to the MSVSProject builder.
The solution file can also be independently
generated by calling the MSVSSolution builder,
such as in the case where a solution should describe
multiple projects.
See the MSVSSolution description for further information.
The MSVSProject builder accepts several keyword arguments
describing lists of filenames to be placed into the project file.
Currently,
srcs,
incs,
localincs,
resources,
and misc
are recognized.
The names are intended to be self-explanatory, but note that the
filenames need to be specified as strings, not
as SCons File Nodes
(for example if you generate files for inclusion by using the
Glob function, the results should be converted to
a list of strings before passing them to MSVSProject).
This is because Visual Studio and
MSBuild know nothing about SCons
Node types.
Each of the filename lists are individually optional, but at
least one list must be specified for the resulting project file to
be non-empty.
In addition to the above lists of values, the following values may be specified as keyword arguments:
target
The name of the target .dsp
or .vcproj file.
The correct suffix for the version of Visual Studio
must be used, but the $MSVSPROJECTSUFFIX
construction variable will be defined to the correct
value (see example below).
variant
The name of this particular variant. Except for Visual Studio 6
projects, this can also be a list of variant names. These
are typically things like "Debug" or "Release", but
really can be anything you want. For Visual Studio
7 projects, they may also specify a target platform
separated from the variant name by a |
(vertical pipe) character: Debug|Xbox.
The default target platform is Win32. Multiple calls
to MSVSProject with different variants are allowed;
all variants will be added to the project file with
their appropriate build targets and sources.
cmdargs
Additional command line arguments
for the different variants. The number of
cmdargs entries must match the number
of variant entries, or be empty (not
specified). If you give only one, it will automatically
be propagated to all variants.
cppdefines
Preprocessor definitions for the different variants.
The number of cppdefines entries
must match the number of variant
entries, or be empty (not specified). If you give
only one, it will automatically be propagated to all
variants. If you don't give this parameter, SCons
will use the invoking environment's
$CPPDEFINES entry for all variants.
cppflags
Compiler flags for the different variants.
If a /std:c++ flag is found then
/Zc:__cplusplus is appended to the
flags if not already found, this ensures that Intellisense
uses the /std:c++ switch.
The number of cppflags entries
must match the number of variant
entries, or be empty (not specified). If you give
only one, it will automatically be propagated to all
variants. If you don't give this parameter, SCons
will combine the invoking environment's
$CCFLAGS, $CXXFLAGS,
$CPPFLAGS entries for all variants.
cpppaths
Compiler include paths for the different variants.
The number of cpppaths entries
must match the number of variant
entries, or be empty (not specified). If you give
only one, it will automatically be propagated to all
variants. If you don't give this parameter, SCons
will use the invoking environment's
$CPPPATH entry for all variants.
buildtarget
An optional string, node, or list of strings
or nodes (one per build variant), to tell
the Visual Studio debugger what output target
to use in what build variant. The number of
buildtarget entries must match the
number of variant entries.
runfile
The name of the file that Visual Studio 7 and
later will run and debug. This appears as the
value of the Output field in the
resulting Microsoft Visual C++ project file. If this is not
specified, the default is the same as the specified
buildtarget value.
SCons and Microsoft Visual Studio understand projects in different ways, and the mapping is sometimes imperfect:
Because SCons always executes its build commands
from the directory in which the SConstruct file is located,
if you generate a project file in a different directory
than the directory of the SConstruct file, users will not be able to
double-click on the file name in compilation error messages
displayed in the Visual Studio console output window. This can
be remedied by adding the Microsoft Visual C++ /FC
compiler option to the $CCFLAGS variable so that
the compiler will print the full path name of any files that
cause compilation errors.
If the project file is only used to teach the Visual Studio project browser about the file layout there should be no issues, However, Visual Studio should not be used to make changes to the project structure, build options, etc. as these will (a) not feed back to the SCons description of the project and (b) be lost if SCons regenerates the project file. The SConscript files should remain the definitive description of the build.
If the project file is used to drive
MSBuild (such as selecting
"build" from the Visual Studio interface) you lose the direct
control of target selection and command-line options you would
have if launching the build directly from SCons,
because these will be hardcoded in the project file to the
values specified in the MSVSProject call.
You can regain some of this control by defining multiple variants,
using multiple MSVSProject calls to arrange different build
targets, arguments, defines, flags and paths for different variants.
If the build is divided into a solution with multiple
MSBuild
projects the mapping is further strained. In this case,
it is important not to set Visual Studio to do parallel builds,
as it will then launch the separate project builds in parallel,
and SCons does not work well if called that way.
Instead you can set up the SCons build for parallel building -
see the SetOption function for how to do this with
num_jobs.
Example usage:
barsrcs = ['bar.cpp']
barincs = ['bar.h']
barlocalincs = ['StdAfx.h']
barresources = ['bar.rc', 'resource.h']
barmisc = ['bar_readme.txt']
dll = env.SharedLibrary(target='bar.dll', source=barsrcs)
buildtarget = [s for s in dll if str(s).endswith('dll')]
env.MSVSProject(
target='Bar' + env['MSVSPROJECTSUFFIX'],
srcs=barsrcs,
incs=barincs,
localincs=barlocalincs,
resources=barresources,
misc=barmisc,
buildtarget=buildtarget,
variant='Release',
)
DebugSettings
A dictionary of debug settings that get written
to the .vcproj.user or the
.vcxproj.user file, depending on the
version installed. As for cmdargs,
you can specify a DebugSettings
dictionary per variant. If you give only one, it will
be propagated to all variants.
Changed in version 2.4:
Added the optional DebugSettings parameter.
Currently, only Visual Studio v9.0 and Visual Studio
version v11 are implemented, for other versions no file
is generated. To generate the user file, you just need to
add a DebugSettings dictionary to the
environment with the right parameters for your MSVS version. If
the dictionary is empty, or does not contain any good value,
no file will be generated.
Following is a more contrived example, involving the setup of a project for variants and DebugSettings:
# Assuming you store your defaults in a file
vars = Variables('variables.py')
msvcver = vars.args.get('vc', '9')
# Check command args to force one Microsoft Visual Studio version
if msvcver == '9' or msvcver == '11':
env = Environment(MSVC_VERSION=msvcver + '.0', MSVC_BATCH=False)
else:
env = Environment()
AddOption(
'--userfile',
action='store_true',
dest='userfile',
default=False,
help="Create Visual C++ project file",
)
#
# 1. Configure your Debug Setting dictionary with options you want in the list
# of allowed options, for instance if you want to create a user file to launch
# a specific application for testing your dll with Microsoft Visual Studio 2008 (v9):
#
V9DebugSettings = {
'Command': 'c:\\myapp\\using\\thisdll.exe',
'WorkingDirectory': 'c:\\myapp\\using\\',
'CommandArguments': '-p password',
# 'Attach':'false',
# 'DebuggerType':'3',
# 'Remote':'1',
# 'RemoteMachine': None,
# 'RemoteCommand': None,
# 'HttpUrl': None,
# 'PDBPath': None,
# 'SQLDebugging': None,
# 'Environment': '',
# 'EnvironmentMerge':'true',
# 'DebuggerFlavor': None,
# 'MPIRunCommand': None,
# 'MPIRunArguments': None,
# 'MPIRunWorkingDirectory': None,
# 'ApplicationCommand': None,
# 'ApplicationArguments': None,
# 'ShimCommand': None,
# 'MPIAcceptMode': None,
# 'MPIAcceptFilter': None,
}
#
# 2. Because there are a lot of different options depending on the Microsoft
# Visual Studio version, if you use more than one version you have to
# define a dictionary per version, for instance if you want to create a user
# file to launch a specific application for testing your dll with Microsoft
# Visual Studio 2012 (v11):
#
V10DebugSettings = {
'LocalDebuggerCommand': 'c:\\myapp\\using\\thisdll.exe',
'LocalDebuggerWorkingDirectory': 'c:\\myapp\\using\\',
'LocalDebuggerCommandArguments': '-p password',
# 'LocalDebuggerEnvironment': None,
# 'DebuggerFlavor': 'WindowsLocalDebugger',
# 'LocalDebuggerAttach': None,
# 'LocalDebuggerDebuggerType': None,
# 'LocalDebuggerMergeEnvironment': None,
# 'LocalDebuggerSQLDebugging': None,
# 'RemoteDebuggerCommand': None,
# 'RemoteDebuggerCommandArguments': None,
# 'RemoteDebuggerWorkingDirectory': None,
# 'RemoteDebuggerServerName': None,
# 'RemoteDebuggerConnection': None,
# 'RemoteDebuggerDebuggerType': None,
# 'RemoteDebuggerAttach': None,
# 'RemoteDebuggerSQLDebugging': None,
# 'DeploymentDirectory': None,
# 'AdditionalFiles': None,
# 'RemoteDebuggerDeployDebugCppRuntime': None,
# 'WebBrowserDebuggerHttpUrl': None,
# 'WebBrowserDebuggerDebuggerType': None,
# 'WebServiceDebuggerHttpUrl': None,
# 'WebServiceDebuggerDebuggerType': None,
# 'WebServiceDebuggerSQLDebugging': None,
}
#
# 3. Select the dictionary you want depending on the version of visual Studio
# Files you want to generate.
#
if not env.GetOption('userfile'):
dbgSettings = None
elif env.get('MSVC_VERSION', None) == '9.0':
dbgSettings = V9DebugSettings
elif env.get('MSVC_VERSION', None) == '11.0':
dbgSettings = V10DebugSettings
else:
dbgSettings = None
#
# 4. Add the dictionary to the DebugSettings keyword.
#
barsrcs = ['bar.cpp', 'dllmain.cpp', 'stdafx.cpp']
barincs = ['targetver.h']
barlocalincs = ['StdAfx.h']
barresources = ['bar.rc', 'resource.h']
barmisc = ['ReadMe.txt']
dll = env.SharedLibrary(target='bar.dll', source=barsrcs)
env.MSVSProject(
target='Bar' + env['MSVSPROJECTSUFFIX'],
srcs=barsrcs,
incs=barincs,
localincs=barlocalincs,
resources=barresources,
misc=barmisc,
buildtarget=[dll[0]] * 2,
variant=('Debug|Win32', 'Release|Win32'),
cmdargs=f'vc={msvcver}',
DebugSettings=(dbgSettings, {}),
)
MSVSSolution()env.MSVSSolution()
Build a Microsoft Visual Studio Solution file.
Builds a Visual Studio solution file based on the
version of Visual Studio that is configured: either the
latest installed version, or the version specified by
$MSVC_VERSION in the construction environment. For
Visual Studio 6, a .dsw file is generated.
For Visual Studio .NET 2002 and later,
it will generate a .sln file.
Note there are multiple versioning schemes involved in
the Microsoft compilation environment -
see the description of $MSVC_VERSION for equivalences.
The solution file is a container for one or more projects, and follows the format described at https://learn.microsoft.com/en-us/visualstudio/extensibility/internals/solution-dot-sln-file.
The following values must be specified:
target
The name of the target .dsw or
.sln file. The correct
suffix for the version of Visual Studio must be used,
but the value $MSVSSOLUTIONSUFFIX will be
defined to the correct value (see example below).
variant
The name of this particular variant, or a list of
variant names (the latter is only supported for MSVS
7 solutions). These are typically things like "Debug"
or "Release", but really can be anything you want. For
MSVS 7 they may also specify target platform, like this
"Debug|Xbox". Default platform is Win32.
projects
A list of project file names, or Project nodes returned
by calls to the MSVSProject Builder, to be placed
into the solution file.
Note that these filenames need to be specified as strings,
NOT as SCons File Nodes.
This is because the solution file will be interpreted by
MSBuild
and by Visual Studio, which know nothing about SCons Node types.
Example Usage:
env.MSVSSolution(
target="Bar" + env["MSVSSOLUTIONSUFFIX"],
projects=["bar" + env["MSVSPROJECTSUFFIX"]],
variant="Release",
)
Ninja()env.Ninja()
A special builder which adds a target to create a Ninja build file. The builder does not require any source files to be specified.
This is an experimental feature. To enable it you must use one of the following methods
# On the command line
--experimental=ninja
# Or in your SConstruct
SetOption('experimental', 'ninja')
This functionality is subject to change and/or removal without deprecation cycle.
To use this tool you need to install the Python ninja package,
as the tool by default depends on being able to do an
import of the package
This can be done via:
python -m pip install ninja
If called with no arguments,
the builder will default to a target name of
ninja.build.
If called with a single positional argument, scons will "deduce" the target name from that source argument, giving it the same name, and then ignore the source. This is the usual way to call the builder if a non-default target name is wanted.
If called with either the
target=
or source= keyword arguments,
the value of the argument is taken as the target name.
If called with both, the
target=
value is used and source= is ignored.
If called with multiple sources,
the source list will be ignored,
since there is no way to deduce what the intent was;
in this case the default target name will be used.
Available since scons 4.2.
Object()env.Object()
A synonym for the
StaticObject
builder method.
Package()env.Package()
Builds software distribution packages.
A package is a container format which
includes files to install along with metadata.
Packaging is optional, and must be enabled by specifying
the packaging tool. For example:
env = Environment(tools=['default', 'packaging'])
SCons can build packages in a number of well known packaging formats.
The target package type may be selected with the
the $PACKAGETYPE construction variable
or the --package-type command line option.
The package type may be a list, in which case SCons will attempt
to build packages for each type in the list. Example:
env.Package(PACKAGETYPE=['src_zip', 'src_targz'], ...other args...)
The currently supported packagers are:
msi
|
Microsoft Installer package |
rpm
|
RPM Package Manger package |
ipkg
|
Itsy Package Management package |
tarbz2
|
bzip2-compressed tar file |
targz
|
gzip-compressed tar file |
tarxz
|
xz-compressed tar file |
zip
|
zip file |
src_tarbz2
|
bzip2-compressed tar file suitable as source to another packager |
src_targz
|
gzip-compressed tar file suitable as source to another packager |
src_tarxz
|
xz-compressed tar file suitable as source to another packager |
src_zip
|
zip file suitable as source to another packager |
The file list to include in the package may be specified with
the source keyword argument. If omitted,
the FindInstalledFiles function is called behind the scenes
to select all files that have an Install, InstallAs
or InstallVersionedLib Builder attached.
If the target keyword argument is omitted, the target name(s)
will be deduced from the package type(s).
The metadata comes partly from attributes of the files to be packaged,
and partly from packaging tags.
Tags can be passed as keyword arguments
to the Package builder call,
and may also be attached to files
(or more accurately, Nodes representing files)
with the Tag function.
Some package-level tags are mandatory, and will lead to errors if omitted.
The mandatory tags vary depending on the package type.
While packaging, the builder uses a temporary location named
by the value of the $PACKAGEROOT variable -
the package sources are copied there before packaging.
Packaging example:
env = Environment(tools=["default", "packaging"])
env.Install("/bin/", "my_program")
env.Package(
NAME="foo",
VERSION="1.2.3",
PACKAGEVERSION=0,
PACKAGETYPE="rpm",
LICENSE="gpl",
SUMMARY="balalalalal",
DESCRIPTION="this should be really really long",
X_RPM_GROUP="Application/fu",
SOURCE_URL="https://foo.org/foo-1.2.3.tar.gz",
)
In this example, the target /bin/my_program
created by the Install call would not be built by default
since it is not under the project top directory.
However, since no source
is specified to the Package builder,
it is selected for packaging by the default sources rule.
Since packaging is done using $PACKAGEROOT, no write is
actually done to the system's /bin directory,
and the target will be selected since
after rebasing to underneath $PACKAGEROOT it is now under
the top directory of the project.
PCH()env.PCH()
Builds a Microsoft Visual C++ precompiled header.
Calling this builder
returns a list of two target nodes: the PCH as the first element,
and the object file as the second element.
Normally the object file is ignored.
The PCH builder is generally used in
conjunction with the $PCH construction variable to force object files to use
the precompiled header:
env['PCH'] = env.PCH('StdAfx.cpp')[0]
This builder is specific to the PCH implementation in Microsoft Visual C++.
Other compiler chains also implement precompiled header support,
but PCH does not work with them at this time.
As a result, the builder is only generated into the
construction environment when
Microsoft Visual C++ is being used as the compiler.
The builder only works correctly in a C++ project. The Microsoft implementation distinguishes between precompiled headers from C and C++. Use of the builder will cause the PCH generation to happen with a flag that tells cl.exe all of the files are C++ files; if that PCH file is then supplied when compiling a C source file, cl.exe will fail the build with a compatibility violation.
If possible, arrange the project so that a
C++ source file passed to the PCH builder
is not also included in the list of sources
to be otherwise compiled in the project.
SCons will correctly track that file in the dependency tree
as a result of the PCH call,
and (for MSVC 11.0 and greater) automatically add the
corresponding object file to the link line.
If the source list is automatically generated,
for example using the Glob function,
it may be necessary to remove that file from the list.
PDF()env.PDF()
Builds a .pdf file
from a .dvi input file
(or, by extension, a .tex,
.ltx,
or
.latex input file).
The suffix specified by the $PDFSUFFIX construction variable
(.pdf by default)
is added automatically to the target
if it is not already present. Example:
# builds from aaa.tex env.PDF(target = 'aaa.pdf', source = 'aaa.tex') # builds bbb.pdf from bbb.dvi env.PDF(target = 'bbb', source = 'bbb.dvi')
POInit()env.POInit()
This builder belongs to msginit tool. The builder initializes missing
PO file(s) if $POAUTOINIT is set. If
$POAUTOINIT is not set (default), POInit prints instruction for
user (that is supposed to be a translator), telling how the
PO file should be initialized. In normal projects
you should not use POInit and use POUpdate
instead. POUpdate chooses intelligently between
msgmerge(1) and msginit(1). POInit
always uses msginit(1) and should be regarded as builder for
special purposes or for temporary use (e.g. for quick, one time initialization
of a bunch of PO files) or for tests.
Target nodes defined through POInit are not built by default (they're
Ignored from '.' node) but are added to
special Alias ('po-create' by default).
The alias name may be changed through the $POCREATE_ALIAS
construction variable. All PO files defined through
POInit may be easily initialized by scons po-create.
Example 1.
Initialize en.po and pl.po from
messages.pot:
# ... env.POInit(['en', 'pl']) # messages.pot --> [en.po, pl.po]
Example 2.
Initialize en.po and pl.po from
foo.pot:
# ... env.POInit(['en', 'pl'], ['foo']) # foo.pot --> [en.po, pl.po]
Example 3.
Initialize en.po and pl.po from
foo.pot but using $POTDOMAIN construction
variable:
# ... env.POInit(['en', 'pl'], POTDOMAIN='foo') # foo.pot --> [en.po, pl.po]
Example 4.
Initialize PO files for languages defined in
LINGUAS file. The files will be initialized from template
messages.pot:
# ... env.POInit(LINGUAS_FILE = 1) # needs 'LINGUAS' file
Example 5.
Initialize en.po and pl.pl
PO files plus files for languages defined in
LINGUAS file. The files will be initialized from template
messages.pot:
# ... env.POInit(['en', 'pl'], LINGUAS_FILE = 1)
Example 6.
You may preconfigure your environment first, and then initialize
PO files:
# ... env['POAUTOINIT'] = 1 env['LINGUAS_FILE'] = 1 env['POTDOMAIN'] = 'foo' env.POInit()
which has same efect as:
# ... env.POInit(POAUTOINIT = 1, LINGUAS_FILE = 1, POTDOMAIN = 'foo')
PostScript()env.PostScript()
Builds a .ps file
from a .dvi input file
(or, by extension, a .tex,
.ltx,
or
.latex input file).
The suffix specified by the $PSSUFFIX construction variable
(.ps by default)
is added automatically to the target
if it is not already present. Example:
# builds from aaa.tex env.PostScript(target = 'aaa.ps', source = 'aaa.tex') # builds bbb.ps from bbb.dvi env.PostScript(target = 'bbb', source = 'bbb.dvi')
POTUpdate()env.POTUpdate()
The builder belongs to xgettext tool. The builder updates target
POT file if exists or creates one if it doesn't. The node is
not built by default (i.e. it is Ignored from
'.'), but only on demand (i.e. when given
POT file is required or when special alias is invoked). This
builder adds its targe node (messages.pot, say) to a
special alias (pot-update by default, see
$POTUPDATE_ALIAS) so you can update/create them easily with
scons pot-update. The file is not written until there is no
real change in internationalized messages (or in comments that enter
POT file).
You may see xgettext(1) being invoked by the
xgettext tool even if there is no real change in internationalized
messages (so the POT file is not being updated). This
happens every time a source file has changed. In such case we invoke
xgettext(1) and compare its output with the content of
POT file to decide whether the file should be updated or
not.
Example 1.
Let's create po/ directory and place following
SConstruct script there:
# SConstruct in 'po/' subdir env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(['foo'], ['../a.cpp', '../b.cpp']) env.POTUpdate(['bar'], ['../c.cpp', '../d.cpp'])
Then invoke scons few times:
user@host:$ scons # Does not create foo.pot nor bar.pot user@host:$ scons foo.pot # Updates or creates foo.pot user@host:$ scons pot-update # Updates or creates foo.pot and bar.pot user@host:$ scons -c # Does not clean foo.pot nor bar.pot.
the results shall be as the comments above say.
Example 2.
The POTUpdate builder may be used with no target specified, in which
case default target messages.pot will be used. The
default target may also be overridden by setting $POTDOMAIN construction
variable or providing it as an override to POTUpdate builder:
# SConstruct script env = Environment( tools = ['default', 'xgettext'] ) env['POTDOMAIN'] = "foo" env.POTUpdate(source = ["a.cpp", "b.cpp"]) # Creates foo.pot ... env.POTUpdate(POTDOMAIN = "bar", source = ["c.cpp", "d.cpp"]) # and bar.pot
Example 3.
The sources may be specified within separate file, for example
POTFILES.in:
# POTFILES.in in 'po/' subdirectory ../a.cpp ../b.cpp # end of file
The name of the file (POTFILES.in) containing the list of
sources is provided via $XGETTEXTFROM:
# SConstruct file in 'po/' subdirectory env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(XGETTEXTFROM = 'POTFILES.in')
Example 4.
You may use $XGETTEXTPATH to define source search path. Assume, for
example, that you have files a.cpp,
b.cpp, po/SConstruct,
po/POTFILES.in. Then your POT-related
files could look as below:
# POTFILES.in in 'po/' subdirectory a.cpp b.cpp # end of file
# SConstruct file in 'po/' subdirectory env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(XGETTEXTFROM = 'POTFILES.in', XGETTEXTPATH='../')
Example 5.
Multiple search directories may be defined within a list, i.e.
XGETTEXTPATH = ['dir1', 'dir2', ...]. The order in the list
determines the search order of source files. The path to the first file found
is used.
Let's create 0/1/po/SConstruct script:
# SConstruct file in '0/1/po/' subdirectory env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(XGETTEXTFROM = 'POTFILES.in', XGETTEXTPATH=['../', '../../'])
and 0/1/po/POTFILES.in:
# POTFILES.in in '0/1/po/' subdirectory a.cpp # end of file
Write two *.cpp files, the first one is
0/a.cpp:
/* 0/a.cpp */
gettext("Hello from ../../a.cpp")
and the second is 0/1/a.cpp:
/* 0/1/a.cpp */
gettext("Hello from ../a.cpp")
then run scons. You'll obtain 0/1/po/messages.pot with the
message "Hello from ../a.cpp". When you reverse order in
$XGETTEXTFOM, i.e. when you write SConscript as
# SConstruct file in '0/1/po/' subdirectory env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(XGETTEXTFROM = 'POTFILES.in', XGETTEXTPATH=['../../', '../'])
then the messages.pot will contain
msgid "Hello from ../../a.cpp" line and not
msgid "Hello from ../a.cpp".
POUpdate()env.POUpdate()
The builder belongs to msgmerge tool. The builder updates
PO files with msgmerge(1), or initializes
missing PO files as described in documentation of
msginit tool and POInit builder (see also
$POAUTOINIT). Note, that POUpdate does not add its
targets to po-create alias as POInit
does.
Target nodes defined through POUpdate are not built by default
(they're Ignored from '.' node). Instead,
they are added automatically to special Alias
('po-update' by default). The alias name may be changed
through the $POUPDATE_ALIAS construction variable. You can easily
update PO files in your project by scons
po-update.
Example 1.
Update en.po and pl.po from
messages.pot template (see also $POTDOMAIN),
assuming that the later one exists or there is rule to build it (see
POTUpdate):
# ... env.POUpdate(['en','pl']) # messages.pot --> [en.po, pl.po]
Example 2.
Update en.po and pl.po from
foo.pot template:
# ... env.POUpdate(['en', 'pl'], ['foo']) # foo.pot --> [en.po, pl.pl]
Example 3.
Update en.po and pl.po from
foo.pot (another version):
# ... env.POUpdate(['en', 'pl'], POTDOMAIN='foo') # foo.pot -- > [en.po, pl.pl]
Example 4.
Update files for languages defined in LINGUAS file. The
files are updated from messages.pot template:
# ... env.POUpdate(LINGUAS_FILE = 1) # needs 'LINGUAS' file
Example 5.
Same as above, but update from foo.pot template:
# ... env.POUpdate(LINGUAS_FILE = 1, source = ['foo'])
Example 6.
Update en.po and pl.po plus files for
languages defined in LINGUAS file. The files are updated
from messages.pot template:
# produce 'en.po', 'pl.po' + files defined in 'LINGUAS': env.POUpdate(['en', 'pl' ], LINGUAS_FILE = 1)
Example 7.
Use $POAUTOINIT to automatically initialize PO file
if it doesn't exist:
# ... env.POUpdate(LINGUAS_FILE = 1, POAUTOINIT = 1)
Example 8.
Update PO files for languages defined in
LINGUAS file. The files are updated from
foo.pot template. All necessary settings are
pre-configured via environment.
# ... env['POAUTOINIT'] = 1 env['LINGUAS_FILE'] = 1 env['POTDOMAIN'] = 'foo' env.POUpdate()
Program()env.Program()
Builds an executable given one or more object files
or C, C++, D, or Fortran source files.
If any C, C++, D or Fortran source files are specified,
then they will be automatically
compiled to object files using the
Object
builder method;
see that builder method's description for
a list of legal source file suffixes
and how they are interpreted.
The target executable file prefix,
specified by the $PROGPREFIX construction variable
(nothing by default),
and suffix,
specified by the $PROGSUFFIX construction variable
(by default, .exe on Windows systems,
nothing on POSIX systems),
are automatically added to the target if not already present.
Example:
env.Program(target='foo', source=['foo.o', 'bar.c', 'baz.f'])
ProgramAllAtOnce()env.ProgramAllAtOnce()
Builds an executable from D sources without first creating individual objects for each file.
D sources can be compiled file-by-file as C and C++ source are, and D is integrated into the scons Object and Program builders for this model of build. D codes can though do whole source meta-programming (some of the testing frameworks do this). For this it is imperative that all sources are compiled and linked in a single call to the D compiler. This builder serves that purpose.
env.ProgramAllAtOnce('executable', ['mod_a.d, mod_b.d', 'mod_c.d'])
This command will compile the modules mod_a, mod_b, and mod_c in a single compilation process without first creating object files for the modules. Some of the D compilers will create executable.o others will not.
RES()env.RES()
Builds a Microsoft Visual C++ resource file.
This builder method is only provided
when Microsoft Visual C++ or MinGW is being used as the compiler. The
.res
(or
.o
for MinGW) suffix is added to the target name if no other suffix is given.
The source
file is scanned for implicit dependencies as though it were a C file.
Example:
env.RES('resource.rc')
RMIC()env.RMIC()
Builds stub and skeleton class files
for remote objects
from Java .class files.
The target is a directory
relative to which the stub
and skeleton class files will be written.
The source can be the names of .class files,
or the objects return from the
Java
builder method.
If the construction variable
$JAVACLASSDIR
is set, either in the environment
or in the call to the
RMIC
builder method itself,
then the value of the variable
will be stripped from the
beginning of any .class
file names.
classes = env.Java(target='classdir', source='src')
env.RMIC(target='outdir1', source=classes)
env.RMIC(
target='outdir2',
source=['package/foo.class', 'package/bar.class'],
)
env.RMIC(
target='outdir3',
source=['classes/foo.class', 'classes/bar.class'],
JAVACLASSDIR='classes',
)
RPCGenClient()env.RPCGenClient()
Generates an RPC client stub (_clnt.c) file
from a specified RPC (.x) source file.
Because rpcgen only builds output files
in the local directory,
the command will be executed
in the source file's directory by default.
# Builds src/rpcif_clnt.c
env.RPCGenClient('src/rpcif.x')
RPCGenHeader()env.RPCGenHeader()
Generates an RPC header (.h) file
from a specified RPC (.x) source file.
Because rpcgen only builds output files
in the local directory,
the command will be executed
in the source file's directory by default.
# Builds src/rpcif.h
env.RPCGenHeader('src/rpcif.x')
RPCGenService()env.RPCGenService()
Generates an RPC server-skeleton (_svc.c) file
from a specified RPC (.x) source file.
Because rpcgen only builds output files
in the local directory,
the command will be executed
in the source file's directory by default.
# Builds src/rpcif_svc.c
env.RPCGenClient('src/rpcif.x')
RPCGenXDR()env.RPCGenXDR()
Generates an RPC XDR routine (_xdr.c) file
from a specified RPC (.x) source file.
Because rpcgen only builds output files
in the local directory,
the command will be executed
in the source file's directory by default.
# Builds src/rpcif_xdr.c
env.RPCGenClient('src/rpcif.x')
SharedLibrary()env.SharedLibrary()
Builds a shared library
given one or more object files
and/or C, C++, D or Fortran source files.
Any source files listed in the
source parameter
will be automatically
compiled to object files suitable
for use in a shared library.
Any object files listed in the
source parameter
must have been built for a shared library
(that is, using the
SharedObject
builder method).
scons
will raise an error if there is any mismatch.
The target library file prefix,
specified by the $SHLIBPREFIX construction variable
(by default, lib on POSIX systems,
nothing on Windows systems),
and suffix,
specified by the $SHLIBSUFFIX construction variable
(by default, .dll on Windows systems,
.so on POSIX systems),
are automatically added (if not already present)
to the target name to make up the library filename.
On a POSIX system, if the $SHLIBVERSION construction variable is set,
it is appended (following a period) to the resulting library name.
Example:
env.SharedLibrary(target='bar', source=['bar.c', 'foo.o'])
On Windows systems, the
SharedLibrary
builder method will always build an import library
(.lib)
in addition to the shared library (.dll),
adding a .lib library with the same basename
if there is not already a .lib file explicitly
listed in the targets.
On Cygwin systems, the
SharedLibrary
builder method will always build an import library
(.dll.a)
in addition to the shared library (.dll),
adding a .dll.a library with the same basename
if there is not already a .dll.a file explicitly
listed in the targets.
On some platforms, there is a distinction between a shared library
(loaded automatically by the system to resolve external references)
and a loadable module (explicitly loaded by user action).
For maximum portability, use the LoadableModule builder for the latter.
If $SHLIBVERSION is defined, a versioned
shared library is created. This modifies $SHLINKFLAGS as required,
adds the version number to the library name, and creates any
symbolic links that are needed.
env.SharedLibrary(target='bar', source=['bar.c', 'foo.o'], SHLIBVERSION='1.5.2')
On a POSIX system, supplying a simple version string (no dots)
creates exactly one symbolic link: SHLIBVERSION="1"
would create (for example) library libbar.so.1
and symbolic link libbar.so.
Supplying a dotted version string will create two symbolic links
(irrespective of the number of segments in the version):
SHLIBVERSION="1.5.2" for the same library
would create library libbar.so.1.5.2
and symbolic links libbar.so and
libbar.so.1. A Darwin (OSX)
system creates one symlink in either case,
for the second example the library would be
libbar.1.5.2.dylib
and the link would be libbar.dylib.
On Windows systems, specifying the
register=1 keyword argument
will cause the .dll to be
registered after it is built.
The command that is run is determined by the $REGSVR construction variable
(regsvr32 by default),
and the flags passed are determined by $REGSVRFLAGS. By
default, $REGSVRFLAGS includes the /s option,
to prevent dialogs from popping
up and requiring user attention when it is run. If you change
$REGSVRFLAGS, be sure to include the /s option.
For example,
env.SharedLibrary(target='bar', source=['bar.cxx', 'foo.obj'], register=1)
will register bar.dll as a COM object
when it is done linking it.
SharedObject()env.SharedObject()
Builds an object file intended for
inclusion in a shared library.
Source files must have one of the same set of extensions
specified above for the
StaticObject
builder method.
On some platforms building a shared object requires additional
compiler option
(e.g. -fPIC for gcc)
in addition to those needed to build a
normal (static) object, but on some platforms there is no difference between a
shared object and a normal (static) one. When there is a difference, SCons
will only allow shared objects to be linked into a shared library, and will
use a different suffix for shared objects. On platforms where there is no
difference, SCons will allow both normal (static)
and shared objects to be linked into a
shared library, and will use the same suffix for shared and normal
(static) objects.
The target object file prefix,
specified by the $SHOBJPREFIX construction variable
(by default, the same as $OBJPREFIX),
and suffix,
specified by the $SHOBJSUFFIX construction variable,
are automatically added to the target if not already present.
Examples:
env.SharedObject(target='ddd', source='ddd.c') env.SharedObject(target='eee.o', source='eee.cpp') env.SharedObject(target='fff.obj', source='fff.for')
Note that the source files will be scanned
according to the suffix mappings in the
SourceFileScanner
object.
See the manpage section "Scanner Objects"
for more information.
StaticLibrary()env.StaticLibrary()
Builds a static library given one or more object files
or C, C++, D or Fortran source files.
If any source files are given,
then they will be automatically
compiled to object files.
The static library file prefix,
specified by the $LIBPREFIX construction variable
(by default, lib on POSIX systems,
nothing on Windows systems),
and suffix,
specified by the $LIBSUFFIX construction variable
(by default, .lib on Windows systems,
.a on POSIX systems),
are automatically added to the target if not already present.
Example:
env.StaticLibrary(target='bar', source=['bar.c', 'foo.o'])
Any object files listed in the
source
must have been built for a static library
(that is, using the
StaticObject
builder method).
scons
will raise an error if there is any mismatch.
StaticObject()env.StaticObject()
Builds a static object file from one or more C, C++, D, or Fortran source files. Source files must have one of the following extensions:
.asm assembly language file
.ASM assembly language file
.c C file
.C Windows: C file
POSIX: C++ file
.cc C++ file
.cpp C++ file
.cxx C++ file
.cxx C++ file
.c++ C++ file
.C++ C++ file
.d D file
.f Fortran file
.F Windows: Fortran file
POSIX: Fortran file + C pre-processor
.for Fortran file
.FOR Fortran file
.fpp Fortran file + C pre-processor
.FPP Fortran file + C pre-processor
.m Object C file
.mm Object C++ file
.s assembly language file
.S Windows: assembly language file
ARM: CodeSourcery Sourcery Lite
.sx assembly language file + C pre-processor
POSIX: assembly language file + C pre-processor
.spp assembly language file + C pre-processor
.SPP assembly language file + C pre-processor
The target object file prefix,
specified by the $OBJPREFIX construction variable
(nothing by default),
and suffix,
specified by the $OBJSUFFIX construction variable
(.obj on Windows systems,
.o on POSIX systems),
are automatically added to the target if not already present.
Examples:
env.StaticObject(target='aaa', source='aaa.c') env.StaticObject(target='bbb.o', source='bbb.c++') env.StaticObject(target='ccc.obj', source='ccc.f')
Note that the source files will be scanned
according to the suffix mappings in the
SourceFileScanner
object.
See the manpage section "Scanner Objects"
for more information.
Substfile()env.Substfile()
The Substfile builder creates a single text file from
a template consisting of a file or set of files (or nodes),
replacing text using the $SUBST_DICT construction variable (if set).
If a set, they are concatenated into the target file
using the value of the
$LINESEPARATOR construction variable as a separator between contents;
the separator is not emitted after the contents of the last file.
Nested lists of source files
are flattened. See also Textfile.
By default the target file encoding is "utf-8" and can be changed by $FILE_ENCODING
Examples:
If a single source file name is specified and has a .in suffix,
the suffix is stripped and the remainder of the name is used as the default target name.
The prefix and suffix specified by the $SUBSTFILEPREFIX
and $SUBSTFILESUFFIX construction variables
(an empty string by default in both cases)
are automatically added to the target if they are not already present.
If a construction variable named $SUBST_DICT is present,
it may be either a Python dictionary or a sequence of
(key, value) tuples.
If it is a dictionary it is converted into a list of tuples
with unspecified order,
so if one key is a prefix of another key
or if one substitution could be further expanded by another subsitition,
it is unpredictable whether the expansion will occur.
Any occurrences of a key in the source are replaced by the corresponding value, which may be a Python callable function or a string. If the value is a callable, it is called with no arguments to get a string. Strings are subst-expanded and the result replaces the key.
env = Environment(tools=['default'])
env['prefix'] = '/usr/bin'
script_dict = {'@prefix@': '/bin', '@exec_prefix@': '$prefix'}
env.Substfile('script.in', SUBST_DICT=script_dict)
conf_dict = {'%VERSION%': '1.2.3', '%BASE%': 'MyProg'}
env.Substfile('config.h.in', conf_dict, SUBST_DICT=conf_dict)
# UNPREDICTABLE - one key is a prefix of another
bad_foo = {'$foo': '$foo', '$foobar': '$foobar'}
env.Substfile('foo.in', SUBST_DICT=bad_foo)
# PREDICTABLE - keys are applied longest first
good_foo = [('$foobar', '$foobar'), ('$foo', '$foo')]
env.Substfile('foo.in', SUBST_DICT=good_foo)
# UNPREDICTABLE - one substitution could be futher expanded
bad_bar = {'@bar@': '@soap@', '@soap@': 'lye'}
env.Substfile('bar.in', SUBST_DICT=bad_bar)
# PREDICTABLE - substitutions are expanded in order
good_bar = (('@bar@', '@soap@'), ('@soap@', 'lye'))
env.Substfile('bar.in', SUBST_DICT=good_bar)
# the SUBST_DICT may be in common (and not an override)
substutions = {}
subst = Environment(tools=['textfile'], SUBST_DICT=substitutions)
substitutions['@foo@'] = 'foo'
subst['SUBST_DICT']['@bar@'] = 'bar'
subst.Substfile(
'pgm1.c',
[Value('#include "@foo@.h"'), Value('#include "@bar@.h"'), "common.in", "pgm1.in"],
)
subst.Substfile(
'pgm2.c',
[Value('#include "@foo@.h"'), Value('#include "@bar@.h"'), "common.in", "pgm2.in"],
)
Tar()env.Tar()
Builds a tar archive of the specified files
and/or directories.
Unlike most builder methods,
the
Tar
builder method may be called multiple times
for a given target;
each additional call
adds to the list of entries
that will be built into the archive.
Any source directories will
be scanned for changes to
any on-disk files,
regardless of whether or not
scons
knows about them from other Builder or function calls.
env.Tar('src.tar', 'src')
# Create the stuff.tar file.
env.Tar('stuff', ['subdir1', 'subdir2'])
# Also add "another" to the stuff.tar file.
env.Tar('stuff', 'another')
# Set TARFLAGS to create a gzip-filtered archive.
env = Environment(TARFLAGS = '-c -z')
env.Tar('foo.tar.gz', 'foo')
# Also set the suffix to .tgz.
env = Environment(TARFLAGS = '-c -z',
TARSUFFIX = '.tgz')
env.Tar('foo')
Textfile()env.Textfile()
The Textfile builder generates a single text file from
a template consisting of a list of strings, replacing text
using the $SUBST_DICT construction variable (if set) -
see Substfile for a description of replacement.
The strings will be separated in the target file using the
value of the
$LINESEPARATOR construction variable;
the line separator is not emitted after the last string.
Nested lists of source strings
are flattened.
Source strings need not literally be Python strings:
they can be Nodes or Python objects that convert cleanly
to Value nodes.
The prefix and suffix specified by the $TEXTFILEPREFIX
and $TEXTFILESUFFIX construction variables
(by default an empty string and .txt, respectively)
are automatically added to the target if they are not already present.
By default the target file encoding is "utf-8" and can be changed by $FILE_ENCODING
Examples:
# builds/writes foo.txt
env.Textfile(target='foo.txt', source=['Goethe', 42, 'Schiller'])
# builds/writes bar.txt
env.Textfile(target='bar', source=['lalala', 'tanteratei'], LINESEPARATOR='|*')
# nested lists are flattened automatically
env.Textfile(target='blob', source=['lalala', ['Goethe', 42, 'Schiller'], 'tanteratei'])
# files may be used as input by wraping them in File()
env.Textfile(
target='concat', # concatenate files with a marker between
source=[File('concat1'), File('concat2')],
LINESEPARATOR='====================\n',
)
Results:
foo.txt
Goethe 42 Schiller
bar.txt
lalala|*tanteratei
blob.txt
lalala Goethe 42 Schiller tanteratei
Translate()env.Translate()
This pseudo-builder belongs to gettext toolset. The builder extracts
internationalized messages from source files, updates POT
template (if necessary) and then updates PO translations (if
necessary). If $POAUTOINIT is set, missing PO files
will be automatically created (i.e. without translator person intervention).
The variables $LINGUAS_FILE and $POTDOMAIN are taken into
acount too. All other construction variables used by POTUpdate, and
POUpdate work here too.
Example 1.
The simplest way is to specify input files and output languages inline in
a SCons script when invoking Translate
# SConscript in 'po/' directory env = Environment( tools = ["default", "gettext"] ) env['POAUTOINIT'] = 1 env.Translate(['en','pl'], ['../a.cpp','../b.cpp'])
Example 2.
If you wish, you may also stick to conventional style known from
autotools, i.e. using
POTFILES.in and LINGUAS files
# LINGUAS en pl #end
# POTFILES.in a.cpp b.cpp # end
# SConscript env = Environment( tools = ["default", "gettext"] ) env['POAUTOINIT'] = 1 env['XGETTEXTPATH'] = ['../'] env.Translate(LINGUAS_FILE = 1, XGETTEXTFROM = 'POTFILES.in')
The last approach is perhaps the recommended one. It allows easily split
internationalization/localization onto separate SCons scripts, where a script
in source tree is responsible for translations (from sources to
PO files) and script(s) under variant directories are
responsible for compilation of PO to MO
files to and for installation of MO files. The "gluing
factor" synchronizing these two scripts is then the content of
LINGUAS file. Note, that the updated
POT and PO files are usually going to be
committed back to the repository, so they must be updated within the source
directory (and not in variant directories). Additionaly, the file listing of
po/ directory contains LINGUAS file,
so the source tree looks familiar to translators, and they may work with the
project in their usual way.
Example 3. Let's prepare a development tree as below
project/
+ SConstruct
+ build/
+ src/
+ po/
+ SConscript
+ SConscript.i18n
+ POTFILES.in
+ LINGUAS
with build being variant directory. Write the top-level
SConstruct script as follows
# SConstruct
env = Environment( tools = ["default", "gettext"] )
VariantDir('build', 'src', duplicate = 0)
env['POAUTOINIT'] = 1
SConscript('src/po/SConscript.i18n', exports = 'env')
SConscript('build/po/SConscript', exports = 'env')
the src/po/SConscript.i18n as
# src/po/SConscript.i18n
Import('env')
env.Translate(LINGUAS_FILE=1, XGETTEXTFROM='POTFILES.in', XGETTEXTPATH=['../'])
and the src/po/SConscript
# src/po/SConscript
Import('env')
env.MOFiles(LINGUAS_FILE = 1)
Such setup produces POT and PO files
under source tree in src/po/ and binary
MO files under variant tree in
build/po/. This way the POT and
PO files are separated from other output files, which must
not be committed back to source repositories (e.g. MO
files).
In above example, the PO files are not updated,
nor created automatically when you issue scons '.' command.
The files must be updated (created) by hand via scons
po-update and then MO files can be compiled by
running scons '.'.
TypeLibrary()env.TypeLibrary()
Builds a Windows type library (.tlb)
file from an input IDL file (.idl).
In addition, it will build the associated interface stub and
proxy source files,
naming them according to the base name of the .idl file.
For example,
env.TypeLibrary(source="foo.idl")
Will create foo.tlb,
foo.h,
foo_i.c,
foo_p.c
and
foo_data.c
files.
Uic()env.Uic()
Builds a header file, an implementation file and a moc file from an ui file.
and returns the corresponding nodes in the that order.
This builder is only available after using the tool qt3.
Note: you can specify .ui files directly as source
files to the Program,
Library and SharedLibrary builders
without using this builder. Using this builder lets you override the standard
naming conventions (be careful: prefixes are always prepended to names of
built files; if you don't want prefixes, you may set them to ``).
See the $QT3DIR variable for more information.
Example:
env.Uic('foo.ui') # -> ['foo.h', 'uic_foo.cc', 'moc_foo.cc']
env.Uic(
target=Split('include/foo.h gen/uicfoo.cc gen/mocfoo.cc'),
source='foo.ui'
) # -> ['include/foo.h', 'gen/uicfoo.cc', 'gen/mocfoo.cc']
Zip()env.Zip()
Builds a zip archive of the specified files
and/or directories.
Unlike most builder methods,
the
Zip
builder method may be called multiple times
for a given target;
each additional call
adds to the list of entries
that will be built into the archive.
Any source directories will
be scanned for changes to
any on-disk files,
regardless of whether or not
scons
knows about them from other Builder or function calls.
env.Zip('src.zip', 'src')
# Create the stuff.zip file.
env.Zip('stuff', ['subdir1', 'subdir2'])
# Also add "another" to the stuff.tar file.
env.Zip('stuff', 'another')
All
targets of builder methods automatically depend on their sources.
An explicit dependency can
be specified using the
env.Depends
method of a construction environment (see below).
In addition,
scons
automatically scans
source files for various programming languages,
so the dependencies do not need to be specified explicitly.
By default, SCons can
C source files,
C++ source files,
Fortran source files with
.F
(POSIX systems only),
.fpp,
or
.FPP
file extensions,
and assembly language files with
.S
(POSIX systems only),
.spp,
or
.SPP
files extensions
for C preprocessor dependencies.
SCons also has default support
for scanning D source files,
You can also write your own Scanners
to add support for additional source file types.
These can be added to the default
Scanner object used by the
Object, StaticObject and SharedObject
Builders by adding them
to the
SourceFileScanner
object.
See the section called “Scanner Objects”
for more information about
defining your own Scanner objects
and using the
SourceFileScanner
object.
SCons provides a variety of construction environment methods and global functions to manipulate the build configuration. Often, a construction environment method and a global function with the same name exist for convenience. In this section, both forms are shown if the function can be called in either way. The documentation style for these is as follows:
Function(arguments, [optional arguments, ...]) # Global functionenv.Function(arguments, [optional arguments, ...]) # Environment method
In these function signatures,
arguments in brackets ([]) are optional,
and ellipses (...) indicate possible repetition.
Positional vs. keyword arguments are usually detailed
in the following text, not in the signature itself.
The Python positional-only (/)
and keyword-only (*) markers are not used.
When the Python keyword=value style is shown,
it can have two meanings.
If the keyword argument is known to the function,
the value is the default for that argument if it is omitted.
If the keyword is unknown to the function,
some methods treat it as a construction variable assignment;
otherwise an exception is raised for an unknown argument.
A global function and a same-named construction environment method have the same base functionality, with two key differences:
Construction environment methods that change the environment act on the environment instance from which they are called, while the corresponding global function acts on a special “hidden” construction environment called the Default Environment. In some cases, the global function may take an initial argument giving the object to operate on.
String-valued arguments
(including strings in list-valued arguments)
are subject to construction variable expansion
by the environment method form;
variable expansion is not immediately performed in the global function.
For example, Default('$MYTARGET')
adds '$MYTARGET' to the
list of default targets,
while if the value in env of
MYTARGET is 'mine',
env.Default('$MYTARGET' adds
'mine'
to the default targets.
For more details on construction variable expansion, see the
Construction variables section.
Global functions are automatically in scope inside SConscript files.
If your project adds Python modules that you include
via the Python import statement
from an SConscript file,
such code will need to add the functions
to that module’s global scope explicitly.
You can do that by adding the following import to the Python module:
from SCons.Script import *.
SCons provides the following construction environment methods and global functions.
The list can be augmented on a project basis using AddMethod
Action(action, [output, [var, ...]] [key=value, ...])env.Action(action, [output, [var, ...]] [key=value, ...])
A factory function to create an Action object for
the specified
action.
See the manpage section "Action Objects"
for a complete explanation of the arguments and behavior.
Note that the env.Action
form of the invocation will expand
construction variables in any argument strings,
including the
action
argument, at the time it is called
using the construction variables in the
env
construction environment through which
env.Action was called.
The Action global function
form delays all variable expansion
until the Action object is actually used.
AddMethod(object, function, [name])env.AddMethod(function, [name])
Adds function to an object as a method.
function will be called with an instance
object as the first argument as for other methods.
If name is given, it is used as
the name of the new method, else the name of
function is used.
When the global function AddMethod is called,
the object to add the method to must be passed as the first argument;
typically this will be Environment,
in order to create a method which applies to all construction environments
subsequently constructed.
When called using the env.AddMethod form,
the method is added to the specified construction environment only.
Added methods propagate through env.Clone calls.
More examples:
# Function to add must accept an instance argument.
# The Python convention is to call this 'self'.
def my_method(self, arg):
print("my_method() got", arg)
# Use the global function to add a method to the Environment class:
AddMethod(Environment, my_method)
env = Environment()
env.my_method('arg')
# Use the optional name argument to set the name of the method:
env.AddMethod(my_method, 'other_method_name')
env.other_method_name('another arg')
AddOption(opt_str, ..., attr=value, ...)
Adds a local (project-specific) command-line option.
One or more opt_str values are
the strings representing how the option can be called,
while the keyword arguments define attributes of the option.
For the most part these are the same as for the
OptionParser.add_option
method in the standard Python library module
optparse,
but with a few additional capabilities noted below.
See the
optparse documentation
for a thorough discussion of its option-processing capabities.
All options added through AddOption are placed
in a special "Local Options" option group.
In addition to the arguments and values supported by the
optparse
add_option
method, AddOption
allows setting the
nargs
keyword value to
a string '?' (question mark)
to indicate that the option argument for
that option string may be omitted.
If the option string is present on the
command line but has no matching option
argument, the value of the
const
keyword argument is produced as the value
of the option.
If the option string is omitted from
the command line, the value of the
default
keyword argument is produced, as usual;
if there is no
default
keyword argument in the AddOption call,
None is produced.
optparse recognizes
abbreviations of long option names,
as long as they can be unambiguously resolved.
For example, if
add_option is called to
define a --devicename option,
it will recognize --device,
--dev
and so forth as long as there is no other option
which could also match to the same abbreviation.
Options added via
AddOption do not support
the automatic recognition of abbreviations.
Instead, to allow specific abbreviations,
include them as synonyms in the AddOption call itself.
Once a new command-line option has been added with
AddOption,
the option value may be accessed using
GetOption
or
env.GetOption.
If the settable=True argument
was supplied in the AddOption call,
the value may also be set later using
SetOption
or
env.SetOption,
if conditions in an
SConscript file
require overriding any default value.
Note however that a
value specified on the command line will
always
override a value set in an SConscript file.
Changed in 4.8.0: added the
settable keyword argument
to enable an added option to be settable via SetOption.
Help text for an option is a combination
of the string supplied in the
help keyword
argument to AddOption and information
collected from the other keyword arguments.
Such help is displayed if the
-h command line option
is used (but not with -H).
Help for all local options is displayed
under the separate heading
Local Options.
The options are unsorted - they will appear
in the help text in the order in which the
AddOption
calls occur.
Example:
AddOption(
'--prefix',
dest='prefix',
nargs=1,
type='string',
action='store',
metavar='DIR',
help='installation prefix',
)
env = Environment(PREFIX=GetOption('prefix'))
For that example, the following help text would be produced:
Local Options: --prefix=DIR installation prefix
Help text for local options may be unavailable if
the Help function has been called,
see the Help documentation for details.
As an artifact of the internal implementation,
the behavior of options added by AddOption
which take option arguments is undefined
if whitespace
(rather than an = sign) is used as
the separator on the command line.
Users should avoid such usage; it is recommended
to add a note to this effect to project documentation
if the situation is likely to arise.
In addition, if the nargs
keyword is used to specify more than one following
option argument (that is, with a value of 2
or greater), such arguments would necessarily
be whitespace separated, triggering the issue.
Developers should not use AddOption this way.
Future versions of SCons will likely forbid such usage.
AddPostAction(target, action)env.AddPostAction(target, action)
Arranges for the specified
action
to be performed
after the specified
target
has been built.
action may be
an Action object, or anything that
can be converted into an Action object.
See the manpage section "Action Objects"
for a complete explanation.
When multiple targets are supplied, the action may be called multiple times, once after each action that generates one or more targets in the list.
foo = Program('foo.c')
# remove execute permission from binary:
AddPostAction(foo, Chmod('$TARGET', "a-x"))
AddPreAction(target, action)env.AddPreAction(target, action)
Arranges for the specified
action
to be performed
before the specified
target
is built.
action may be
an Action object, or anything that
can be converted into an Action object.
See the manpage section "Action Objects"
for a complete explanation.
When multiple targets are specified, the action(s) may be called multiple times, once before each action that generates one or more targets in the list.
Note that if any of the targets are built in multiple steps,
the action will be invoked just
before the "final" action that specifically
generates the specified target(s).
For example, when building an executable program
from a specified source
.c
file via an intermediate object file:
foo = Program('foo.c')
AddPreAction(foo, 'pre_action')
The specified
pre_action
would be executed before
scons
calls the link command that actually
generates the executable program binary
foo,
not before compiling the
foo.c
file into an object file.
Alias(alias, [source, [action]])env.Alias(alias, [source, [action]])
Creates an alias target that
can be used as a reference to zero or more other targets,
specified by the optional source parameter.
Aliases provide a way to give a shorter or more descriptive
name to specific targets,
and to group multiple targets under a single name.
The alias name, or an Alias Node object,
may be used as a dependency of any other target,
including another alias.
alias and source
may each be a string or Node object,
or a list of strings or Node objects;
if Nodes are used for
alias
they must be Alias nodes.
If source is omitted,
the alias is created but has no reference;
if selected for building this will result in a
“Nothing to be done.” message.
An empty alias can be used to define the alias
in a visible place in the project;
it can later be appended to in a subsidiary SConscript file
with the actual target(s) to refer to.
The optional
action
parameter specifies an action or list of actions
that will be executed
whenever the any of the alias targets are out-of-date.
Alias can be called for an existing alias,
which appends the alias
and/or action arguments
to the existing lists for that alias.
Returns a list of Alias Node objects representing the alias(es), which exist outside of any physical file system. The alias name space is separate from the name space for tangible targets; to avoid confusion do not reuse target names as alias names.
Examples:
Alias('install')
Alias('install', '/usr/bin')
Alias(['install', 'install-lib'], '/usr/local/lib')
env.Alias('install', ['/usr/local/bin', '/usr/local/lib'])
env.Alias('install', ['/usr/local/man'])
env.Alias('update', ['file1', 'file2'], "update_database $SOURCES")
AllowSubstExceptions([exception, ...])
Specifies the exceptions that will be allowed
when expanding construction variables.
By default,
any construction variable expansions that generate a
NameError
or
IndexError
exception will expand to a
''
(an empty string) and not cause scons to fail.
All exceptions not in the specified list
will generate an error message
and terminate processing.
If
AllowSubstExceptions
is called multiple times,
each call completely overwrites the previous list
of allowed exceptions.
Example:
# Requires that all construction variable names exist.
# (You may wish to do this if you want to enforce strictly
# that all construction variables must be defined before use.)
AllowSubstExceptions()
# Also allow a string containing a zero-division expansion
# like '${1 / 0}' to evalute to ''.
AllowSubstExceptions(IndexError, NameError, ZeroDivisionError)
AlwaysBuild(target, ...)env.AlwaysBuild(target, ...)
Marks each given
target
so that it is always assumed to be out of date,
and will always be rebuilt if needed.
Note, however, that
AlwaysBuild
does not add its target(s) to the default target list,
so the targets will only be built
if they are specified on the command line,
or are a dependent of a target specified on the command line--but
they will
always
be built if so specified.
Multiple targets can be passed in to a single call to
AlwaysBuild.
env.Append(key=val, [...])
Appends value(s) intelligently to construction variables in
env.
The construction variables and values to add to them are passed as
key=val pairs (Python keyword arguments).
env.Append is designed to allow adding values
without having to think about the data type of an existing construction variable.
Regular Python syntax can also be used to manipulate the construction variable,
but for that you may need to know the types involved,
for example pure Python lets you directly "add" two lists of strings,
but adding a string to a list or a list to a string requires
different syntax - things Append takes care of.
Some pre-defined construction variables do have type expectations
based on how SCons will use them:
for example $CPPDEFINES is often a string or a list of strings,
but can also be a list of tuples or a dictionary;
while $LIBEMITTER
is expected to be a callable or list of callables,
and $BUILDERS is expected to be a dictionary.
Consult the documentation for the various construction variables for more details.
The following descriptions apply to both the Append
and Prepend methods, as well as their
Unique variants,
with the differences being the insertion point of the added values
and whether duplication is allowed.
val can be almost any type.
If env does not have a construction variable
named key,
then key is simply
stored with a value of val.
Otherwise, val is
combinined with the existing value,
possibly converting into an appropriate type
which can hold the expanded contents.
There are a few special cases to be aware of.
Normally, when two strings are combined,
the result is a new string containing their concatenation
(and you are responsible for supplying any needed separation);
however, the contents of $CPPDEFINES will
will be postprocessed by adding a prefix and/or suffix
to each entry when the command line is produced,
so SCons keeps them separate -
appending a string will result in a separate string entry,
not a combined string.
For $CPPDEFINES. as well as
$LIBS, and the various *PATH variables,
SCons will amend the variable by supplying the compiler-specific
syntax (e.g. prepending a -D or /D
prefix for $CPPDEFINES), so you should omit this syntax when
adding values to these variables.
Examples (gcc syntax shown in the expansion of CPPDEFINES):
env = Environment(CXXFLAGS="-std=c11", CPPDEFINES="RELEASE")
print(f"CXXFLAGS = {env['CXXFLAGS']}, CPPDEFINES = {env['CPPDEFINES']}")
# notice including a leading space in CXXFLAGS addition
env.Append(CXXFLAGS=" -O", CPPDEFINES="EXTRA")
print(f"CXXFLAGS = {env['CXXFLAGS']}, CPPDEFINES = {env['CPPDEFINES']}")
print("CPPDEFINES will expand to", env.subst('$_CPPDEFFLAGS'))
$ scons -Q CXXFLAGS = -std=c11, CPPDEFINES = RELEASE CXXFLAGS = -std=c11 -O, CPPDEFINES = deque(['RELEASE', 'EXTRA']) CPPDEFINES will expand to -DRELEASE -DEXTRA scons: `.' is up to date.
Because $CPPDEFINES is intended for command-line
specification of C/C++ preprocessor macros,
additional syntax is accepted when adding to it.
The preprocessor accepts arguments to predefine a macro name by itself
(-DFOO for most compilers,
/DFOO for Microsoft C++),
which gives it an implicit value of 1,
or can be given with a replacement value
(-DBAR=TEXT).
SCons follows these rules when adding to $CPPDEFINES:
A string is split on spaces,
giving an easy way to enter multiple macros in one addition.
Use an = to specify a valued macro.
A tuple is treated as a valued macro.
Use the value None if the macro should not have a value.
It is an error to supply more than two elements in such a tuple.
A list is processed in order, adding each item without further interpretation. In this case, space-separated strings are not split.
A dictionary is processed in order,
adding each key-value pair as a valued macro.
Use the value None if the macro should not have a value.
Examples:
env = Environment(CPPDEFINES="FOO")
print("CPPDEFINES =", env['CPPDEFINES'])
env.Append(CPPDEFINES="BAR=1")
print("CPPDEFINES =", env['CPPDEFINES'])
env.Append(CPPDEFINES=[("OTHER", 2)])
print("CPPDEFINES =", env['CPPDEFINES'])
env.Append(CPPDEFINES={"EXTRA": "arg"})
print("CPPDEFINES =", env['CPPDEFINES'])
print("CPPDEFINES will expand to", env.subst('$_CPPDEFFLAGS'))
$ scons -Q
CPPDEFINES = FOO
CPPDEFINES = deque(['FOO', 'BAR=1'])
CPPDEFINES = deque(['FOO', 'BAR=1', ('OTHER', 2)])
CPPDEFINES = deque(['FOO', 'BAR=1', ('OTHER', 2), ('EXTRA', 'arg')])
CPPDEFINES will expand to -DFOO -DBAR=1 -DOTHER=2 -DEXTRA=arg
scons: `.' is up to date.
Examples of adding multiple macros:
env = Environment()
env.Append(CPPDEFINES=[("ONE", 1), "TWO", ("THREE", )])
print("CPPDEFINES =", env['CPPDEFINES'])
env.Append(CPPDEFINES={"FOUR": 4, "FIVE": None})
print("CPPDEFINES =", env['CPPDEFINES'])
print("CPPDEFINES will expand to", env.subst('$_CPPDEFFLAGS'))
$ scons -Q
CPPDEFINES = [('ONE', 1), 'TWO', ('THREE',)]
CPPDEFINES = deque([('ONE', 1), 'TWO', ('THREE',), ('FOUR', 4), ('FIVE', None)])
CPPDEFINES will expand to -DONE=1 -DTWO -DTHREE -DFOUR=4 -DFIVE
scons: `.' is up to date.
Changed in version 4.5: clarifined the use of tuples vs. other types, handling is now consistent across the four functions.
env = Environment()
env.Append(CPPDEFINES=("MACRO1", "MACRO2"))
print("CPPDEFINES =", env['CPPDEFINES'])
env.Append(CPPDEFINES=[("MACRO3", "MACRO4")])
print("CPPDEFINES =", env['CPPDEFINES'])
print("CPPDEFINES will expand to", env.subst('$_CPPDEFFLAGS'))
$ scons -Q
CPPDEFINES = ('MACRO1', 'MACRO2')
CPPDEFINES = deque(['MACRO1', 'MACRO2', ('MACRO3', 'MACRO4')])
CPPDEFINES will expand to -DMACRO1 -DMACRO2 -DMACRO3=MACRO4
scons: `.' is up to date.
See $CPPDEFINES for more details.
Appending a string val
to a dictonary-typed construction variable enters
val as the key in the dictionary,
and None as its value.
Using a tuple type to supply a key-value pair
only works for the special case of $CPPDEFINES
described above.
Although most combinations of types work without needing to know the details, some combinations do not make sense and Python raises an exception.
When using env.Append to modify construction variables
which are path specifications (conventionally,
the names of such end in PATH),
it is recommended to add the values as a list of strings,
even if you are only adding a single string.
The same goes for adding library names to $LIBS.
env.Append(CPPPATH=["#/include"])
See also env.AppendUnique,
env.Prepend and env.PrependUnique.
env.AppendENVPath(name, newpath, [envname, sep, delete_existing=False])
Append path elements specified by newpath
to the given search path string or list name
in mapping envname in the construction environment.
Supplying envname is optional:
the default is the execution environment $ENV.
Optional sep is used as the search path separator,
the default is the platform's separator (os.pathsep).
A path element will only appear once.
Any duplicates in newpath are dropped,
keeping the last appearing (to preserve path order).
If delete_existing
is False (the default)
any addition duplicating an existing path element is ignored;
if delete_existing
is True the existing value will
be dropped and the path element will be added at the end.
To help maintain uniqueness all paths are normalized (using
os.path.normpath
and
os.path.normcase).
Example:
print('before:', env['ENV']['INCLUDE'])
include_path = '/foo/bar:/foo'
env.AppendENVPath('INCLUDE', include_path)
print('after:', env['ENV']['INCLUDE'])
Yields:
before: /foo:/biz after: /biz:/foo/bar:/foo
See also env.PrependENVPath.
env.AppendUnique(key=val, [...], [delete_existing=False])
Append values to construction variables in the current construction environment,
maintaining uniqueness.
Works like env.Append,
except that values that would become duplicates
are not added.
If delete_existing
is set to a true value, then for any duplicate,
the existing instance of val is first removed,
then val is appended,
having the effect of moving it to the end.
Example:
env.AppendUnique(CCFLAGS='-g', FOO=['foo.yyy'])
See also env.Append,
env.Prepend
and env.PrependUnique.
Builder(action, [arguments])env.Builder(action, [arguments])
Creates a Builder object for
the specified
action.
See the manpage section "Builder Objects"
for a complete explanation of the arguments and behavior.
Note that the
env.Builder()
form of the invocation will expand
construction variables in any arguments strings,
including the
action
argument,
at the time it is called
using the construction variables in the
env
construction environment through which
env.Builder was called.
The
Builder
form delays all variable expansion
until after the Builder object is actually called.
CacheDir(cache_dir, custom_class=None)env.CacheDir(cache_dir, custom_class=None)
Direct
scons
to maintain a derived-file cache in
cache_dir.
The derived files in the cache will be shared
among all the builds specifying the same
cache_dir.
Specifying a
cache_dir
of
None
disables derived file caching.
Calling the environment method
env.CacheDir
limits the effect to targets built
through the specified construction environment.
Calling the global function
CacheDir
sets a global default
that will be used by all targets built
through construction environments
that do not set up environment-specific
caching by calling env.CacheDir.
Caching behavior can be configured by passing a specialized cache
class as the optional custom_class parameter.
This class must be a subclass of
SCons.CacheDir.CacheDir.
SCons will internally invoke the custom class for performing
caching operations.
If the parameter is omitted or set to
None, SCons will use the default
SCons.CacheDir.CacheDir class.
When derived-file caching
is being used and
scons
finds a derived file that needs to be rebuilt,
it will first look in the cache to see if a
file with matching build signature exists
(indicating the input file(s) and build action(s)
were identical to those for the current target),
and if so, will retrieve the file from the cache.
scons
will report
Retrieved `file' from cache
instead of the normal build message.
If the derived file is not present in the cache,
scons
will build it and
then place a copy of the built file in the cache,
identified by its build signature, for future use.
The
Retrieved `file' from cache
messages are useful for human consumption,
but less useful when comparing log files between
scons runs which will show differences that are
noisy and not actually significant.
To disable,
use the --cache-show option.
With this option, scons changes printing
to always show the action that would
have been used to build the file without caching.
Derived-file caching
may be disabled for any invocation
of scons by giving the
--cache-disable
command line option;
cache updating may be disabled, leaving cache
fetching enabled, by giving the
--cache-readonly option.
If the
--cache-force
option is used,
scons
will place a copy of
all
derived files into the cache,
even if they already existed
and were not built by this invocation.
This is useful to populate a cache
the first time a
cache_dir
is used for a build,
or to bring a cache up to date after
a build with cache updating disabled
(--cache-disable
or --cache-readonly)
has been done.
The
NoCache
method can be used to disable caching of specific files. This can be
useful if inputs and/or outputs of some tool are impossible to
predict or prohibitively large.
Note that (at this time) SCons provides no facilities for managing the derived-file cache. It is up to the developer to arrange for cache pruning, expiry, access control, etc. if needed.
Clean(targets, files_or_dirs)env.Clean(targets, files_or_dirs)
This specifies a list of files or directories which should be removed
whenever the targets are specified with the
-c
command line option.
The specified targets may be a list
or an individual target.
Multiple calls to
Clean
are legal,
and create new targets or add files and directories to the
clean list for the specified targets.
Multiple files or directories should be specified
either as separate arguments to the
Clean
method, or as a list.
Clean
will also accept the return value of any of the construction environment
Builder methods.
Examples:
The related
NoClean
function overrides calling
Clean
for the same target,
and any targets passed to both functions will
not
be removed by the
-c
option.
Examples:
Clean('foo', ['bar', 'baz'])
Clean('dist', env.Program('hello', 'hello.c'))
Clean(['foo', 'bar'], 'something_else_to_clean')
In this example, installing the project creates a subdirectory for the documentation. This statement causes the subdirectory to be removed if the project is deinstalled.
Clean(docdir, os.path.join(docdir, projectname))
env.Clone([key=val, ...])
Returns an independent copy of a construction environment. If there are any unrecognized keyword arguments specified, they are added as construction variables in the copy, overwriting any existing values for those keywords. See the manpage section "Construction Environments" for more details.
Example:
env2 = env.Clone() env3 = env.Clone(CCFLAGS='-g')
A list of tools
and a toolpath may be specified,
as in the Environment constructor:
def MyTool(env):
env['FOO'] = 'bar'
env4 = env.Clone(tools=['msvc', MyTool])
The
parse_flags
keyword argument is also recognized, to allow merging command-line
style arguments into the appropriate construction
variables (see env.MergeFlags).
# create an environment for compiling programs that use wxWidgets wx_env = env.Clone(parse_flags='!wx-config --cflags --cxxflags')
The variables
keyword argument is also recognized, to allow (re)initializing
construction variables from a Variables object.
Changed in version 4.8.0:
the variables parameter was added.
Command(target, source, action, [key=val, ...])env.Command(target, source, action, [key=val, ...])
Creates an anonymous builder and calls it,
thus recording action
to build target
from source
into the dependency tree.
This can be more convenient for a single special-case build
than having to define and add a new named Builder.
The
Command function accepts the
source_scanner and
target_scanner
keyword arguments which are used to specify
custom scanners for the specified sources or targets.
The value must be a Scanner object.
For example, the global
DirScanner
object can be used
if any of the sources will be directories
that must be scanned on-disk for
changes to files that aren't
already specified in other Builder or function calls.
The
Command function also accepts the
source_factory and
target_factory
keyword arguments which are used to specify
factory functions to create SCons Nodes
from any sources or targets specified as strings.
If any sources or targets are already Node objects,
they are not further transformed even if
a factory is specified for them.
The default for each is the Entry factory.
These four arguments, if given, are used in the creation of the Builder. Other Builder-specific keyword arguments are not recognized as such. See the manpage section "Builder Objects" for more information about how these arguments work in a Builder.
Any remaining keyword arguments are passed on to the generated builder when it is called, and behave as described in the manpage section "Builder Methods", in short: recognized arguments have their specified meanings, while the rest are used to override any same-named existing construction variables from the construction environment.
action can be an external command,
specified as a string,
or a callable Python object;
see the manpage section "Action Objects"
for more complete information.
Also note that a string specifying an external command
may be preceded by an at-sign
(@)
to suppress printing the command in question,
or by a hyphen
(-)
to ignore the exit status of the external command.
Examples:
env.Command(
target='foo.out',
source='foo.in',
action="$FOO_BUILD < $SOURCES > $TARGET"
)
env.Command(
target='bar.out',
source='bar.in',
action=["rm -f $TARGET", "$BAR_BUILD < $SOURCES > $TARGET"],
ENV={'PATH': '/usr/local/bin/'},
)
import os
def rename(env, target, source):
os.rename('.tmp', str(target[0]))
env.Command(
target='baz.out',
source='baz.in',
action=["$BAZ_BUILD < $SOURCES > .tmp", rename],
)
Note that the
Command
function will usually assume, by default,
that the specified targets and/or sources are Files,
if no other part of the configuration
identifies what type of entries they are.
If necessary, you can explicitly specify
that targets or source nodes should
be treated as directories
by using the
Dir
or
env.Dir
functions.
Examples:
env.Command('ddd.list', Dir('ddd'), 'ls -l $SOURCE > $TARGET')
env['DISTDIR'] = 'destination/directory'
env.Command(env.Dir('$DISTDIR')), None, make_distdir)
Also note that SCons will usually automatically create any directory necessary to hold a target file, so you normally don't need to create directories by hand.
Configure(env, [custom_tests, conf_dir, log_file, config_h])env.Configure([custom_tests, conf_dir, log_file, config_h])
Creates a Configure object for integrated
functionality similar to GNU autoconf.
See the manpage section "Configure Contexts"
for a complete explanation of the arguments and behavior.
DebugOptions([json])
Allows setting options for SCons debug options. Currently the only supported value is
json which sets the path to the json file created when
--debug=json is set.
DebugOptions(json='#/build/output/scons_stats.json')
New in version 4.6.0.
Decider(function)env.Decider(function)
Specifies that all up-to-date decisions for
targets built through this construction environment
will be handled by the specified
function.
function can be the name of
a function or one of the following strings
that specify the predefined decision function
that will be applied:
"content"
Specifies that a target shall be considered out of date and rebuilt
if the dependency's content has changed since the last time
the target was built,
as determined by performing a checksum
on the dependency's contents using the selected hash function,
and comparing it to the checksum recorded the
last time the target was built.
content is the default decider.
Changed in version 4.1:
The decider was renamed to content
since the hash function is now selectable.
The former name, MD5,
can still be used as a synonym, but is deprecated.
"content-timestamp"
Specifies that a target shall be considered out of date and rebuilt
if the dependency's content has changed since the last time
the target was built,
except that dependencies with a timestamp that matches
the last time the target was rebuilt will be
assumed to be up-to-date and
not
rebuilt.
This provides behavior very similar
to the
content
behavior of always checksumming file contents,
with an optimization of not checking
the contents of files whose timestamps haven't changed.
The drawback is that SCons will
not
detect if a file's content has changed
but its timestamp is the same,
as might happen in an automated script
that runs a build,
updates a file,
and runs the build again,
all within a single second.
Changed in version 4.1:
The decider was renamed to content-timestamp
since the hash function is now selectable.
The former name, MD5-timestamp,
can still be used as a synonym, but is deprecated.
"timestamp-newer"
Specifies that a target shall be considered out of date and rebuilt
if the dependency's timestamp is newer than the target file's timestamp.
This is the behavior of the classic Make utility,
and
make
can be used a synonym for
timestamp-newer.
"timestamp-match"
Specifies that a target shall be considered out of date and rebuilt if the dependency's timestamp is different than the timestamp recorded the last time the target was built. This provides behavior very similar to the classic Make utility (in particular, files are not opened up so that their contents can be checksummed) except that the target will also be rebuilt if a dependency file has been restored to a version with an earlier timestamp, such as can happen when restoring files from backup archives.
Examples:
# Use exact timestamp matches by default.
Decider('timestamp-match')
# Use hash content signatures for any targets built
# with the attached construction environment.
env.Decider('content')
In addition to the above already-available functions, the
function
argument may be a Python function you supply.
Such a function must accept the following four arguments:
dependency
The Node (file) which
should cause the
target
to be rebuilt
if it has "changed" since the last tme
target
was built.
target
The Node (file) being built.
In the normal case,
this is what should get rebuilt
if the
dependency
has "changed."
prev_ni
Stored information about the state of the
dependency
the last time the
target
was built.
This can be consulted to match various
file characteristics
such as the timestamp,
size, or content signature.
repo_node
If set, use this Node instead of the one specified by
dependency
to determine if the dependency has changed.
This argument is optional so should be written
as a default argument (typically it would be
written as repo_node=None).
A caller will normally only set this if the
target only exists in a Repository.
The
function
should return a value which evaluates
True
if the
dependency
has "changed" since the last time
the
target
was built
(indicating that the target
should
be rebuilt),
and a value which evaluates
False
otherwise
(indicating that the target should
not
be rebuilt).
Note that the decision can be made
using whatever criteria are appopriate.
Ignoring some or all of the function arguments
is perfectly normal.
Example:
def my_decider(dependency, target, prev_ni, repo_node=None):
return not os.path.exists(str(target))
env.Decider(my_decider)
Default(target[, ...])env.Default(target[, ...])
Specify default targets to the SCons target selection mechanism.
Any call to Default will cause SCons to use the
defined default target list instead of
its built-in algorithm for determining default targets
(see the manpage section "Target Selection").
target may be one or more strings,
a list of strings,
a NodeList as returned by a Builder,
or None.
A string target may be the name of
a file or directory, or a target previously defined by a call to
Alias (defining the alias later will still create
the alias, but it will not be recognized as a default).
Calls to Default are additive.
A target of
None
will clear any existing default target list;
subsequent calls to
Default
will add to the (now empty) default target list
like normal.
Both forms of this call affect the same global list of default targets; the construction environment method applies construction variable expansion to the targets.
The current list of targets added using
Default is available in the
DEFAULT_TARGETS list (see below).
Examples:
Default('foo', 'bar', 'baz')
env.Default(['a', 'b', 'c'])
hello = env.Program('hello', 'hello.c')
env.Default(hello)
DefaultEnvironment([key=value, ...])
Instantiates and returns the global construction environment object. The Default Environment is used internally by SCons when executing a global function or the global form of a Builder method that requires access to a construction environment.
On the first call,
arguments are interpreted as for the Environment function.
The Default Environment is a singleton;
subsequent calls to DefaultEnvironment return
the already-constructed object,
and any keyword arguments are silently ignored.
The Default Environment can be modified after instantiation, similar to other construction environments, although some construction environment methods may be unavailable. Modifying the Default Environment has no effect on any other construction environment, either existing or newly constructed.
It is not necessary to explicitly call DefaultEnvironment.
SCons instantiates the default environment automatically when the
build phase begins, if has not already been done.
However, calling it explicitly provides the opportunity to
affect and examine its contents.
Instantiation occurs even if nothing in the build system
appars to use it, due to internal uses.
If the project SConscript files do not use global functions or Builders,
a small performance gain may be achieved by calling
DefaultEnvironment with an empty tools list
(DefaultEnvironment(tools=[])).
This avoids the tool initialization cost for the Default Environment,
which is mainly of interest in the test suite
where scons is launched repeatedly in a short time period.
Depends(target, dependency)env.Depends(target, dependency)
Specifies an explicit dependency;
the
target
will be rebuilt
whenever the
dependency
has changed.
Both the specified
target
and
dependency
can be a string
(usually the path name of a file or directory)
or Node objects,
or a list of strings or Node objects
(such as returned by a Builder call).
This should only be necessary
for cases where the dependency
is not caught by a Scanner
for the file.
Example:
env.Depends('foo', 'other-input-file-for-foo')
mylib = env.Library('mylib.c')
installed_lib = env.Install('lib', mylib)
bar = env.Program('bar.c')
# Arrange for the library to be copied into the installation
# directory before trying to build the "bar" program.
# (Note that this is for example only. A "real" library
# dependency would normally be configured through the $LIBS
# and $LIBPATH variables, not using an env.Depends() call.)
env.Depends(bar, installed_lib)
env.Detect(progs)
Find an executable from one or more choices:
progs may be a string or a list of strings.
Returns the first value from progs
that was found, or None.
Executable is searched by checking the paths in the execution environment
(env['ENV']['PATH']).
On Windows systems, additionally applies the filename suffixes found in
the execution environment
(env['ENV']['PATHEXT'])
but will not include any such extension in the return value.
env.Detect is a wrapper around env.WhereIs.
env.Dictionary([vars])
Returns a dictionary object containing the construction variables in the construction environment. If there are any arguments specified, the values of the specified construction variables are returned as a string (if one argument) or as a list of strings.
Example:
cvars = env.Dictionary()
cc_values = env.Dictionary('CC', 'CCFLAGS', 'CCCOM')
Dir(name, [directory])env.Dir(name, [directory])
Returns Directory Node(s).
A Directory Node is an object that represents a directory.
name
can be a relative or absolute path or a list of such paths.
directory
is an optional directory that will be used as the parent directory.
If no
directory
is specified, the current script's directory is used as the parent.
If
name
is a single pathname, the corresponding node is returned.
If
name
is a list, SCons returns a list of nodes.
Construction variables are expanded in
name.
Directory Nodes can be used anywhere you would supply a string as a directory name to a Builder method or function. Directory Nodes have attributes and methods that are useful in many situations; see manpage section "Filesystem Nodes" for more information.
env.Dump([key, ...], [format=])
Serializes construction variables from the current construction environment
to a string.
The method supports the following formats specified by
format,
which must be used a a keyword argument:
pretty
Returns a pretty-printed representation of the variables (this is the default). The variables will be presented in Python dict form.
json
Returns a JSON-formatted string representation of the variables. The variables will be presented as a JSON object literal, the JSON equivalent of a Python dict.
If no key is supplied,
all the construction variables are serialized.
If one or more keys are supplied,
only those keys and their values are serialized.
Changed in NEXT_VERSION:
More than one key can be specified.
The returned string always looks like a dict (or JSON equivalent);
previously a single key serialized only the value,
not the key with the value.
This SConstruct:
env = Environment()
print(env.Dump('CCCOM'))
print(env.Dump('CC', 'CCFLAGS', format='json'))
will print something like:
{'CCCOM': '$CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES'}
{
"CC": "gcc",
"CCFLAGS": []
}
While this SConstruct:
env = Environment() print(env.Dump())
will print something like:
{ 'AR': 'ar',
'ARCOM': '$AR $ARFLAGS $TARGET $SOURCES\n$RANLIB $RANLIBFLAGS $TARGET',
'ARFLAGS': ['r'],
'AS': 'as',
'ASCOM': '$AS $ASFLAGS -o $TARGET $SOURCES',
'ASFLAGS': [],
...
EnsurePythonVersion(major, minor)
Ensure that the Python version is at least
major.minor.
This function will
print out an error message and exit SCons with a non-zero exit code if the
actual Python version is not late enough.
Example:
EnsurePythonVersion(2,2)
EnsureSConsVersion(major, minor, [revision])
Ensure that the SCons version is at least
major.minor,
or
major.minor.revision.
if
revision
is specified.
This function will
print out an error message and exit SCons with a non-zero exit code if the
actual SCons version is not late enough.
Examples:
EnsureSConsVersion(0,14) EnsureSConsVersion(0,96,90)
Environment([key=value, ...])env.Environment([key=value, ...])
Return a new construction environment
initialized with the specified
key=value
pairs.
The keyword arguments
parse_flags,
platform,
toolpath,
tools
and variables
are specially recognized and do not lead to
construction variable creation.
See the manpage section "Construction Environments" for more details.
Execute(action, [actionargs ...])env.Execute(action, [actionargs ...])
Executes an Action.
action
may be an Action object
or it may be a command-line string,
list of commands,
or executable Python function,
each of which will first be converted
into an Action object
and then executed.
Any additional arguments to Execute
are passed on to the Action factory function
which actually creates the Action object
(see the manpage section Action Objects
for a description). Example:
Execute(Copy('file.out', 'file.in'))
Execute performs its action immediately,
as part of the SConscript-reading phase.
There are no sources or targets declared in an
Execute call, so any objects it manipulates
will not be tracked as part of the SCons dependency graph.
In the example above, neither
file.out nor
file.in will be tracked objects.
Execute returns the exit value of the command
or return value of the Python function.
scons
prints an error message if the executed
action
fails (exits with or returns a non-zero value),
however it does
not,
automatically terminate the build for such a failure.
If you want the build to stop in response to a failed
Execute
call,
you must explicitly check for a non-zero return value:
if Execute("mkdir sub/dir/ectory"):
# The mkdir failed, don't try to build.
Exit(1)
Exit([value])
This tells
scons
to exit immediately
with the specified
value.
A default exit value of
0
(zero)
is used if no value is specified.
Export([vars...], [key=value...])env.Export([vars...], [key=value...])
Exports variables for sharing with other SConscript files.
The variables are added to a global collection where
they can be imported by other SConscript files.
vars may be one or more
strings, or a list of strings. If any string
contains whitespace, it is split automatically
into individual strings. Each string must
match the name of a variable that is in scope
during evaluation of the current SConscript file,
or an exception is raised.
A vars argument
may also be a dictionary or
individual keyword arguments;
in accordance with Python syntax rules,
keyword arguments must come after any
non-keyword arguments.
The dictionary/keyword form can be used
to map the local name of a variable to
a different name to be used for imports.
See the Examples for an illustration of the syntax.
Export calls are cumulative. Specifying a previously
exported variable will replace the previous value in the collection.
Both local variables and global variables can be exported.
To use an exported variable, an SConscript must
call Import to bring it into its own scope.
Importing creates an additional reference to the object that
was originally exported, so if that object is mutable,
changes made will be visible to other users of that object.
Examples:
env = Environment()
# Make env available for all SConscript files to Import().
Export("env")
package = 'my_name'
# Make env and package available for all SConscript files:.
Export("env", "package")
# Make env and package available for all SConscript files:
Export(["env", "package"])
# Make env available using the name debug:
Export(debug=env)
# Make env available using the name debug:
Export({"debug": env})
Note that the
SConscript
function also supports an exports
argument that allows exporting one or more variables
to the SConscript files invoked by that call (only).
See the description of that function for details.
File(name, [directory])env.File(name, [directory])
Returns File Node(s).
A File Node is an object that represents a file.
name
can be a relative or absolute path or a list of such paths.
directory
is an optional directory that will be used as the parent directory.
If no
directory
is specified, the current script's directory is used as the parent.
If
name
is a single pathname, the corresponding node is returned.
If
name
is a list, SCons returns a list of nodes.
Construction variables are expanded in
name.
File Nodes can be used anywhere you would supply a string as a file name to a Builder method or function. File Nodes have attributes and methods that are useful in many situations; see manpage section "Filesystem Nodes" for more information.
FindFile(file, dirs)env.FindFile(file, dirs)
Search for
file
in the path specified by
dirs.
dirs
may be a list of directory names or a single directory name.
In addition to searching for files that exist in the filesystem,
this function also searches for derived files
that have not yet been built.
Example:
foo = env.FindFile('foo', ['dir1', 'dir2'])
FindInstalledFiles()env.FindInstalledFiles()
Returns the list of targets set up by the
Install
or
InstallAs
builders.
This function serves as a convenient method to select the contents of a binary package.
Example:
Install('/bin', ['executable_a', 'executable_b'])
# will return the file node list
# ['/bin/executable_a', '/bin/executable_b']
FindInstalledFiles()
Install('/lib', ['some_library'])
# will return the file node list
# ['/bin/executable_a', '/bin/executable_b', '/lib/some_library']
FindInstalledFiles()
FindPathDirs(variable)
Returns a function
(actually a callable Python object)
intended to be used as the
path_function
of a Scanner object.
The returned object will look up the specified
variable
in a construction environment
and treat the construction variable's value as a list of
directory paths that should be searched
(like
$CPPPATH,
$LIBPATH,
etc.).
Note that use of
FindPathDirs
is generally preferable to
writing your own
path_function
for the following reasons:
1) The returned list will contain all appropriate directories
found in source trees
(when
VariantDir
is used)
or in code repositories
(when
Repository
or the
-Y
option are used).
2) scons will identify expansions of
variable
that evaluate to the same list of directories as,
in fact, the same list,
and avoid re-scanning the directories for files,
when possible.
Example:
def my_scan(node, env, path, arg):
# Code to scan file contents goes here...
return include_files
scanner = Scanner(name = 'myscanner',
function = my_scan,
path_function = FindPathDirs('MYPATH'))
FindSourceFiles(node='"."')env.FindSourceFiles(node='"."')
Returns the list of nodes which serve as the source of the built files.
It does so by inspecting the dependency tree starting at the optional
argument
node
which defaults to the '"."'-node. It will then return all leaves of
node.
These are all children which have no further children.
This function is a convenient method to select the contents of a Source Package.
Example:
Program('src/main_a.c')
Program('src/main_b.c')
Program('main_c.c')
# returns ['main_c.c', 'src/main_a.c', 'SConstruct', 'src/main_b.c']
FindSourceFiles()
# returns ['src/main_b.c', 'src/main_a.c' ]
FindSourceFiles('src')
As you can see build support files (SConstruct in the above example) will also be returned by this function.
Flatten(sequence)env.Flatten(sequence)
Takes a sequence (that is, a Python list or tuple) that may contain nested sequences and returns a flattened list containing all of the individual elements in any sequence. This can be helpful for collecting the lists returned by calls to Builders; other Builders will automatically flatten lists specified as input, but direct Python manipulation of these lists does not.
Examples:
foo = Object('foo.c')
bar = Object('bar.c')
# Because `foo' and `bar' are lists returned by the Object() Builder,
# `objects' will be a list containing nested lists:
objects = ['f1.o', foo, 'f2.o', bar, 'f3.o']
# Passing such a list to another Builder is all right because
# the Builder will flatten the list automatically:
Program(source = objects)
# If you need to manipulate the list directly using Python, you need to
# call Flatten() yourself, or otherwise handle nested lists:
for object in Flatten(objects):
print(str(object))
GetBuildFailures()
Returns a list of exceptions for the
actions that failed while
attempting to build targets.
Each element in the returned list is a
BuildError
object
with the following attributes
that record various aspects
of the build failure:
.node
The node that was being built
when the build failure occurred.
.status
The numeric exit status
returned by the command or Python function
that failed when trying to build the
specified Node.
.errstr
The SCons error string
describing the build failure.
(This is often a generic
message like "Error 2"
to indicate that an executed
command exited with a status of 2.)
.filename
The name of the file or
directory that actually caused the failure.
This may be different from the
.node
attribute.
For example,
if an attempt to build a target named
sub/dir/target
fails because the
sub/dir
directory could not be created,
then the
.node
attribute will be
sub/dir/target
but the
.filename
attribute will be
sub/dir.
.executor
The SCons Executor object
for the target Node
being built.
This can be used to retrieve
the construction environment used
for the failed action.
.action
The actual SCons Action object that failed.
This will be one specific action
out of the possible list of
actions that would have been
executed to build the target.
.command
The actual expanded command that was executed and failed,
after expansion of
$TARGET,
$SOURCE,
and other construction variables.
Note that the
GetBuildFailures
function
will always return an empty list
until any build failure has occurred,
which means that
GetBuildFailures
will always return an empty list
while the
SConscript
files are being read.
Its primary intended use is
for functions that will be
executed before SCons exits
by passing them to the
standard Python
atexit.register()
function.
Example:
import atexit
def print_build_failures():
from SCons.Script import GetBuildFailures
for bf in GetBuildFailures():
print("%s failed: %s" % (bf.node, bf.errstr))
atexit.register(print_build_failures)
GetBuildPath(file, [...])env.GetBuildPath(file, [...])
Returns the
scons
path name (or names) for the specified
file
(or files).
The specified
file
or files
may be
scons
Nodes or strings representing path names.
GetLaunchDir()
Returns the absolute path name of the directory from which
scons
was initially invoked.
This can be useful when using the
-u,
-U
or
-D
options, which internally
change to the directory in which the
SConstruct
file is found.
GetOption(name)env.GetOption(name)
Query the value of settable options which may have been set
on the command line, via option defaults,
or by using the SetOption function.
The value of the option is returned in a type matching how the
option was declared - see the documentation of the
corresponding command line option for information about each specific
option.
name can be an entry from the following table,
which shows the corresponding command line arguments
that could affect the value.
name can be also be the destination
variable name from a project-specific option added using the
AddOption function, as long as that addition has been
processed prior to the GetOption call in the SConscript files.
| Query name | Command-line options | Notes |
|---|---|---|
cache_debug
|
--cache-debug
|
|
cache_disable
|
--cache-disable,
--no-cache
|
|
cache_force
|
--cache-force,
--cache-populate
|
|
cache_readonly
|
--cache-readonly
|
|
cache_show
|
--cache-show
|
|
clean
|
-c,
--clean,
--remove
|
|
climb_up
|
-D
-U
-u
--up
--search_up
|
|
config
|
--config
|
|
debug
|
--debug
|
|
directory
|
-C, --directory |
|
diskcheck
|
--diskcheck
|
|
duplicate
|
--duplicate
|
|
enable_virtualenv
|
--enable-virtualenv
|
|
experimental
|
--experimental
|
since 4.2 |
file
|
-f,
--file,
--makefile,
--sconstruct
|
|
hash_format
|
--hash-format
|
since 4.2 |
help
|
-h, --help |
|
ignore_errors
|
-i, --ignore-errors |
|
ignore_virtualenv
|
--ignore-virtualenv
|
|
implicit_cache
|
--implicit-cache
|
|
implicit_deps_changed
|
--implicit-deps-changed
|
|
implicit_deps_unchanged
|
--implicit-deps-unchanged
|
|
include_dir
|
-I, --include-dir |
|
install_sandbox
|
--install-sandbox
|
Available only if the install tool has been called |
keep_going
|
-k, --keep-going |
|
max_drift
|
--max-drift
|
|
md5_chunksize
|
--hash-chunksize,
--md5-chunksize
|
--hash-chunksize since 4.2
|
no_exec
|
-n,
--no-exec,
--just-print,
--dry-run,
--recon
|
|
no_progress
|
-Q
|
|
num_jobs
|
-j, --jobs |
|
package_type
|
--package-type
|
Available only if the packaging tool has been called |
profile_file
|
--profile
|
|
question
|
-q, --question |
|
random
|
--random
|
|
repository
|
-Y,
--repository,
--srcdir
|
|
silent
|
-s,
--silent,
--quiet
|
|
site_dir
|
--site-dir, --no-site-dir |
|
stack_size
|
--stack-size
|
|
taskmastertrace_file
|
--taskmastertrace
|
|
tree_printers
|
--tree
|
|
warn
|
--warn, --warning |
GetSConsVersion()
Returns the current SCons version in the form of a Tuple[int, int, int], representing the major, minor, and revision values respectively. Added in 4.8.0.
Glob(pattern, [ondisk=True, source=False, strings=False, exclude=None])env.Glob(pattern, [ondisk=True, source=False, strings=False, exclude=None])
Returns a possibly empty list of Nodes (or strings) that match
pathname specification pattern.
pattern can be absolute,
top-relative,
or (most commonly) relative to the directory of the current
SConscript file.
Glob matches both files stored on disk and Nodes
which SCons already knows about, even if any corresponding
file is not currently stored on disk.
The evironment method form (env.Glob)
performs string substition on
pattern
and returns whatever matches the resulting expanded pattern.
The results are sorted, unlike for the similar Python
glob.glob function,
to ensure build order will be stable.
pattern
can contain POSIX-style shell metacharacters for matching:
| Pattern | Meaning |
|---|---|
*
|
matches everything |
?
|
matches any single character |
[seq]
|
matches any character in seq (can be a list or a range). |
[!seq]
|
matches any character not in seq |
For a literal match, wrap the metacharacter in brackets to
escape the normal behavior.
For example, '[?]' matches the character
'?'.
Filenames starting with a dot are specially handled - they can only be matched by patterns that start with a dot (or have a dot immediately following a pathname separator character, or slash), they are not not matched by the metacharacters. Metacharacter matches also do not span directory separators.
Glob
understands repositories
(see the
Repository
function)
and source directories
(see the
VariantDir
function)
and returns a Node (or string, if so configured) match
in the local (SConscript) directory
if a matching Node is found
anywhere in a corresponding
repository or source directory.
If the optional
ondisk
argument evaluates false,
the search for matches on disk is disabled,
and only matches from
already-configured File or Dir Nodes are returned.
The default is to return Nodes for
matches on disk as well.
If the optional
source
argument evaluates true,
and the local directory is a variant directory,
then Glob returnes Nodes from
the corresponding source directory,
rather than the local directory.
If the optional
strings
argument evaluates true,
Glob
returns matches as strings, rather than Nodes.
The returned strings will be relative to
the local (SConscript) directory.
(Note that while this may make it easier to perform
arbitrary manipulation of file names,
it loses the context SCons would have in the Node,
so if the returned strings are
passed to a different
SConscript
file,
any Node translation there will be relative
to that
SConscript
directory,
not to the original
SConscript
directory.)
The optional
exclude
argument may be set to a pattern or a list of patterns
descibing files or directories
to filter out of the match list.
Elements matching a least one specified pattern will be excluded.
These patterns use the same syntax as for
pattern.
Examples:
Program("foo", Glob("*.c"))
Zip("/tmp/everything", Glob(".??*") + Glob("*"))
sources = Glob("*.cpp", exclude=["os_*_specific_*.cpp"]) \
+ Glob("os_%s_specific_*.cpp" % currentOS)
Help(text, append=False, local_only=False)env.Help(text, append=False, local_only=False)
Adds text to the help message shown when
scons is called with the
-h or --help
argument.
On the first call to Help,
if append is False
(the default), any existing help text is discarded.
The default help text is the help for the scons
command itself plus help collected from any
project-local AddOption calls.
This is the help printed if Help has never been called.
If append is True,
text is appended to
the existing help text.
If local_only is also True
(the default is False),
the project-local help from AddOption calls is preserved
in the help message but the scons command help is not.
Subsequent calls to
Help ignore the keyword arguments
append and
local_only
and always append to the existing help text.
Changed in 4.6.0: added local_only.
Ignore(target, dependency)env.Ignore(target, dependency)
Ignores dependency
when deciding if
target needs to be rebuilt.
target and
dependency
can each be a single filename or Node
or a list of filenames or Nodes.
Ignore can also be used to
remove a target from the default build
by specifying the directory the target will be built in as
target
and the file you want to skip selecting for building as
dependency.
Note that this only removes the target from
the default target selection algorithm:
if it is a dependency of another object being
built SCons still builds it normally.
See the third and forth examples below.
Examples:
env.Ignore('foo', 'foo.c')
env.Ignore('bar', ['bar1.h', 'bar2.h'])
env.Ignore('.', 'foobar.obj')
env.Ignore('bar', 'bar/foobar.obj')
Import(vars...)env.Import(vars...)
Imports variables into the scope of the current SConscript file.
vars
must be strings representing names of variables
which have been previously exported either by the
Export function or by the
exports argument to the
SConscript function.
Variables exported by the
SConscript call
take precedence.
Multiple variable names can be passed to
Import
as separate arguments, as a list of strings,
or as words in a space-separated string.
The wildcard "*" can be used to import all
available variables.
If the imported variable is mutable, changes made locally will be reflected in the object the variable is bound to. This allows subsidiary SConscript files to contribute to building up, for example, a construction environment.
Examples:
Import("env")
Import("env", "variable")
Import(["env", "variable"])
Import("*")
Literal(string)env.Literal(string)
The specified
string
will be preserved as-is
and not have construction variables expanded.
Local(targets)env.Local(targets)
The specified
targets
will have copies made in the local tree,
even if an already up-to-date copy
exists in a repository.
Returns a list of the target Node or Nodes.
env.MergeFlags(arg, [unique])
Merges values from
arg
into construction variables in env.
If arg is a dictionary,
each key-value pair represents a
construction variable name and the corresponding flags to merge.
If arg
is not a dictionary,
MergeFlags attempts to convert it to one
before the values are merged.
env.ParseFlags is used for this,
so values to be converted are subject to the
same limitations:
ParseFlags has knowledge of which construction variables certain
flags should go to, but not all;
and only for GCC and compatible compiler chains.
arg
must be a single object,
so to pass multiple strings,
enclose them in a list.
If unique is true (the default),
duplicate values are not retained.
In case of duplication,
any construction variable names that end in
PATH
keep the left-most value so the
path searcb order is not altered.
All other construction variables keep
the right-most value.
If unique is false,
values are appended even if they are duplicates.
Examples:
# Add an optimization flag to $CCFLAGS.
env.MergeFlags({'CCFLAGS': '-O3'})
# Combine the flags returned from running pkg-config with an optimization
# flag and merge the result into the construction variables.
env.MergeFlags(['!pkg-config gtk+-2.0 --cflags', '-O3'])
# Combine an optimization flag with the flags returned from running pkg-config
# for two distinct packages and merge into the construction variables.
env.MergeFlags(
[
'-O3',
'!pkg-config gtk+-2.0 --cflags --libs',
'!pkg-config libpng12 --cflags --libs',
]
)
NoCache(target, ...)env.NoCache(target, ...)
Specifies a list of files which should
not
be cached whenever the
CacheDir
method has been activated.
The specified targets may be a list
or an individual target.
Multiple files should be specified
either as separate arguments to the
NoCache
method, or as a list.
NoCache
will also accept the return value of any of the construction environment
Builder methods.
Calling
NoCache
on directories and other non-File Node types has no effect because
only File Nodes are cached.
Examples:
NoCache('foo.elf')
NoCache(env.Program('hello', 'hello.c'))
NoClean(target, ...)env.NoClean(target, ...)
Specifies a list of files or directories which should
not
be removed whenever the targets (or their dependencies)
are specified with the
-c
command line option.
The specified targets may be a list
or an individual target.
Multiple calls to
NoClean
are legal,
and prevent each specified target
from being removed by calls to the
-c
option.
Multiple files or directories should be specified
either as separate arguments to the
NoClean
method, or as a list.
NoClean
will also accept the return value of any of the construction environment
Builder methods.
Calling
NoClean
for a target overrides calling
Clean
for the same target,
and any targets passed to both functions will
not
be removed by the
-c
option.
Examples:
NoClean('foo.elf')
NoClean(env.Program('hello', 'hello.c'))
env.ParseConfig(command, [function, unique])
Updates the current construction environment with the values extracted
from the output of running external command,
by passing it to a helper function.
command may be a string
or a list of strings representing the command and
its arguments.
If function
is omitted or None,
env.MergeFlags is used.
By default,
duplicate values are not
added to any construction variables;
you can specify
unique=False
to allow duplicate values to be added.
command is executed using the
SCons execution environment (that is, the construction variable
$ENV in the current construction environment).
If command needs additional information
to operate properly, that needs to be set in the execution environment.
For example, pkg-config
may need a custom value set in the PKG_CONFIG_PATH
environment variable.
env.MergeFlags needs to understand
the output produced by command
in order to distribute it to appropriate construction variables.
env.MergeFlags uses a separate function to
do that processing -
see env.ParseFlags for the details, including a
a table of options and corresponding construction variables.
To provide alternative processing of the output of
command,
you can suppply a custom
function,
which must accept three arguments:
the construction environment to modify,
a string argument containing the output from running
command,
and the optional
unique flag.
ParseDepends(filename, [must_exist, only_one])env.ParseDepends(filename, [must_exist, only_one])
Parses the contents of filename
as a list of dependencies in the style of
Make
or
mkdep,
and explicitly establishes all of the listed dependencies.
By default,
it is not an error
if filename
does not exist.
The optional
must_exist
argument may be set to True
to have SCons
raise an exception if the file does not exist,
or is otherwise inaccessible.
The optional
only_one
argument may be set to True
to have SCons raise an exception
if the file contains dependency
information for more than one target.
This can provide a small sanity check
for files intended to be generated
by, for example, the
gcc -M
flag,
which should typically only
write dependency information for
one output file into a corresponding
.d
file.
filename
and all of the files listed therein
will be interpreted relative to
the directory of the
SConscript
file which calls the
ParseDepends
function.
env.ParseFlags(flags, ...)
Parses one or more strings containing
typical command-line flags for GCC-style tool chains
and returns a dictionary with the flag values
separated into the appropriate SCons construction variables.
Intended as a companion to the
env.MergeFlags
method, but allows for the values in the returned dictionary
to be modified, if necessary,
before merging them into the construction environment.
(Note that
env.MergeFlags
will call this method if its argument is not a dictionary,
so it is usually not necessary to call
env.ParseFlags
directly unless you want to manipulate the values.)
If the first character in any string is
an exclamation mark (!),
the rest of the string is executed as a command,
and the output from the command is
parsed as GCC tool chain command-line flags
and added to the resulting dictionary.
This can be used to call a *-config
command typical of the POSIX programming environment
(for example,
pkg-config).
Note that such a command is executed using the
SCons execution environment;
if the command needs additional information,
that information needs to be explicitly provided.
See ParseConfig for more details.
Flag values are translated according to the prefix found, and added to the following construction variables:
-arch CCFLAGS, LINKFLAGS -D CPPDEFINES -framework FRAMEWORKS -frameworkdir= FRAMEWORKPATH -fmerge-all-constants CCFLAGS, LINKFLAGS -fopenmp CCFLAGS, LINKFLAGS -fsanitize CCFLAGS, LINKFLAGS -include CCFLAGS -imacros CCFLAGS -isysroot CCFLAGS, LINKFLAGS -isystem CCFLAGS -iquote CCFLAGS -idirafter CCFLAGS -I CPPPATH -l LIBS -L LIBPATH -mno-cygwin CCFLAGS, LINKFLAGS -mwindows LINKFLAGS -openmp CCFLAGS, LINKFLAGS -pthread CCFLAGS, LINKFLAGS -std= CFLAGS -stdlib= CXXFLAGS -Wa, ASFLAGS, CCFLAGS -Wl,-rpath= RPATH -Wl,-R, RPATH -Wl,-R RPATH -Wl, LINKFLAGS -Wp, CPPFLAGS - CCFLAGS + CCFLAGS, LINKFLAGS
Any other strings not associated with options
are assumed to be the names of libraries
and added to the
$LIBS
construction variable.
Examples (all of which produce the same result):
dict = env.ParseFlags('-O2 -Dfoo -Dbar=1')
dict = env.ParseFlags('-O2', '-Dfoo', '-Dbar=1')
dict = env.ParseFlags(['-O2', '-Dfoo -Dbar=1'])
dict = env.ParseFlags('-O2', '!echo -Dfoo -Dbar=1')
Platform(plat)env.Platform(plat)
When called as a global function,
returns a callable platform object
selected by plat
(defaults to the detected platform for the
current system)
that can be used to initialize
a construction environment by passing it as the
platform keyword argument to the
Environment function.
Example:
env = Environment(platform=Platform('win32'))
When called as a method of an environment,
calls the platform object indicated by
plat
to update that environment.
env.Platform('posix')
See the manpage section "Construction Environments" for more details.
Precious(target, ...)env.Precious(target, ...)
Marks target as precious so it is not
deleted before it is rebuilt.
Normally SCons deletes a target before building it.
Multiple targets can be passed in a single call,
and may be strings and/or nodes.
Returns a list of the affected target nodes.
env.Prepend(key=val, [...])
Prepend values to construction variables in the current construction environment,
Works like env.Append (see for details),
except that values are added to the front,
rather than the end, of any existing value of the construction variable
Example:
env.Prepend(CCFLAGS='-g ', FOO=['foo.yyy'])
See also env.Append,
env.AppendUnique
and env.PrependUnique.
env.PrependENVPath(name, newpath, [envname, sep, delete_existing=True])
Prepend path elements specified by newpath
to the given search path string or list name
in mapping envname in the construction environment.
Supplying envname is optional:
the default is the execution environment $ENV.
Optional sep is used as the search path separator,
the default is the platform's separator (os.pathsep).
A path element will only appear once.
Any duplicates in newpath are dropped,
keeping the first appearing (to preserve path order).
If delete_existing
is False
any addition duplicating an existing path element is ignored;
if delete_existing
is True (the default) the existing value will
be dropped and the path element will be inserted at the beginning.
To help maintain uniqueness all paths are normalized (using
os.path.normpath
and
os.path.normcase).
Example:
print('before:', env['ENV']['INCLUDE'])
include_path = '/foo/bar:/foo'
env.PrependENVPath('INCLUDE', include_path)
print('after:', env['ENV']['INCLUDE'])
Yields:
before: /biz:/foo after: /foo/bar:/foo:/biz
See also env.AppendENVPath.
env.PrependUnique(key=val, [...], [delete_existing=False])
Prepend values to construction variables in the current construction environment,
maintaining uniqueness.
Works like env.Append,
except that values are added to the front,
rather than the end, of the construction variable,
and values that would become duplicates
are not added.
If delete_existing
is set to a true value, then for any duplicate,
the existing instance of val is first removed,
then val is inserted,
having the effect of moving it to the front.
Example:
env.PrependUnique(CCFLAGS='-g', FOO=['foo.yyy'])
See also env.Append,
env.AppendUnique
and env.Prepend.
Progress(callable, [interval])Progress(string, [interval, file, overwrite])Progress(list_of_strings, [interval, file, overwrite])
Allows SCons to show progress made during the build by displaying a string or calling a function while evaluating Nodes (e.g. files).
If the first specified argument is a Python callable
(a function or an object that has a
__call__ method),
the function will be called
once every
interval
times a Node is evaluated (default 1).
The callable will be passed the evaluated Node
as its only argument.
(For future compatibility,
it's a good idea to also add
*args
and
**kwargs
as arguments to your function or method signatures.
This will prevent the code from breaking
if SCons ever changes the interface
to call the function with additional arguments in the future.)
An example of a simple custom progress function that prints a string containing the Node name every 10 Nodes:
def my_progress_function(node, *args, **kwargs):
print('Evaluating node %s!' % node)
Progress(my_progress_function, interval=10)
A more complicated example of a custom progress display object
that prints a string containing a count
every 100 evaluated Nodes.
Note the use of
\r
(a carriage return)
at the end so that the string
will overwrite itself on a display:
import sys
class ProgressCounter(object):
count = 0
def __call__(self, node, *args, **kw):
self.count += 100
sys.stderr.write('Evaluated %s nodes\r' % self.count)
Progress(ProgressCounter(), interval=100)
If the first argument to
Progress is a string or list of strings,
it is taken as text to be displayed every
interval
evaluated Nodes.
If the first argument is a list of strings,
then each string in the list will be displayed
in rotating fashion every
interval
evaluated Nodes.
The default is to print the string on standard output.
An alternate output stream
may be specified with the
file
keyword argument, which the
caller must pass already opened.
The following will print a series of dots on the error output, one dot for every 100 evaluated Nodes:
import sys
Progress('.', interval=100, file=sys.stderr)
If the string contains the verbatim substring
$TARGET;,
it will be replaced with the Node.
Note that, for performance reasons, this is
not
a regular SCons variable substition,
so you can not use other variables
or use curly braces.
The following example will print the name of
every evaluated Node,
using a carriage return)
(\r)
to cause each line to overwritten by the next line,
and the
overwrite
keyword argument (default False)
to make sure the previously-printed
file name is overwritten with blank spaces:
import sys
Progress('$TARGET\r', overwrite=True)
A list of strings can be used to implement a "spinner" on the user's screen as follows, changing every five evaluated Nodes:
Progress(['-\r', '\\\r', '|\r', '/\r'], interval=5)
Pseudo(target, ...)env.Pseudo(target, ...)
Marks target as a pseudo target,
not representing the production of any physical target file.
If any pseudo target does exist,
SCons will abort the build with an error.
Multiple targets can be passed in a single call,
and may be strings and/or Nodes.
Returns a list of the affected target nodes.
Pseudo may be useful in conjuction with a builder
call (such as Command) which does not create a physical target,
and the behavior if the target accidentally existed would be incorrect.
This is similar in concept to the GNU make
.PHONY target.
SCons also provides a powerful target alias capability
(see Alias) which may provide more flexibility
in many situations when defining target names that are not directly built.
PyPackageDir(modulename)env.PyPackageDir(modulename)
Finds the location of modulename,
which can be a string or a sequence of strings,
each representing the name of a Python module.
Construction variables are expanded in
modulename.
Returns a Directory Node (see Dir),
or a list of Directory Nodes if
modulename is a sequence.
None is returned for any module not found.
When a Tool module which is installed as a
Python module is used, you need
to specify a toolpath argument to
Tool,
Environment
or Clone,
as tools outside the standard project locations
(site_scons/site_tools)
will not be found otherwise.
Using PyPackageDir allows this path to be
discovered at runtime instead of hardcoding the path.
Example:
env = Environment(
tools=["default", "ExampleTool"],
toolpath=[PyPackageDir("example_tool")]
)
env.Replace(key=val, [...])
Replaces construction variables in the Environment with the specified keyword arguments.
Example:
env.Replace(CCFLAGS='-g', FOO='foo.xxx')
Repository(directory)env.Repository(directory)
Specifies that
directory
is a repository to be searched for files.
Multiple calls to
Repository
are legal,
and each one adds to the list of
repositories that will be searched.
To scons, a repository is a copy of the source tree, from the top-level directory on down, which may contain both source files and derived files that can be used to build targets in the local source tree. The canonical example would be an official source tree maintained by an integrator. If the repository contains derived files, then the derived files should have been built using scons, so that the repository contains the necessary signature information to allow scons to figure out when it is appropriate to use the repository copy of a derived file, instead of building one locally.
Note that if an up-to-date derived file
already exists in a repository,
scons
will
not
make a copy in the local directory tree.
In order to guarantee that a local copy
will be made,
use the
Local
method.
Requires(target, prerequisite)env.Requires(target, prerequisite)
Specifies an order-only relationship
between target
and prerequisite.
The prerequisites
will be (re)built, if necessary,
before
the target file(s),
but the target file(s) do not actually
depend on the prerequisites
and will not be rebuilt simply because
the prerequisite file(s) change.
target and
prerequisite may each
be a string or Node, or a list of strings or Nodes.
If there are multiple
target values,
the prerequisite(s) are added to each one.
Returns a list of the affected target nodes.
Example:
env.Requires('foo', 'file-that-must-be-built-before-foo')
Return([vars..., stop=True])
Return to the calling SConscript, optionally
returning the values of variables named in
vars.
Multiple strings contaning variable names may be passed to
Return. A string containing white space
is split into individual variable names.
Returns the value if one variable is specified,
else returns a tuple of values.
Returns an empty tuple if vars
is omitted.
By default Return stops processing the current SConscript
and returns immediately.
The optional
stop
keyword argument
may be set to a false value
to continue processing the rest of the SConscript
file after the
Return
call (this was the default behavior prior to SCons 0.98.)
However, the values returned
are still the values of the variables in the named
vars
at the point
Return
was called.
Examples:
# Returns no values (evaluates False)
Return()
# Returns the value of the 'foo' Python variable.
Return("foo")
# Returns the values of the Python variables 'foo' and 'bar'.
Return("foo", "bar")
# Returns the values of Python variables 'val1' and 'val2'.
Return('val1 val2')
Scanner(function, [name, argument, skeys, path_function, node_class, node_factory, scan_check, recursive])env.Scanner(function, [name, argument, skeys, path_function, node_class, node_factory, scan_check, recursive])
Creates a Scanner object for
the specified
function.
See manpage section "Scanner Objects"
for a complete explanation of the arguments and behavior.
SConscript(scriptnames, [exports, variant_dir, duplicate, must_exist])env.SConscript(scriptnames, [exports, variant_dir, duplicate, must_exist])SConscript(dirs=subdirs, [name=scriptname, exports, variant_dir, duplicate, must_exist])env.SConscript(dirs=subdirs, [name=scriptname, exports, variant_dir, duplicate, must_exist])
Executes subsidiary SConscript (build configuration) file(s).
There are two ways to call the
SConscript function.
The first calling style is to supply
one or more SConscript file names
as the first positional argument,
which can be a string or a list of strings.
If there is a second positional argument,
it is treated as if the
exports
keyword argument had been given (see below).
Examples:
SConscript('SConscript') # run SConscript in the current directory
SConscript('src/SConscript') # run SConscript in the src directory
SConscript(['src/SConscript', 'doc/SConscript'])
SConscript(Split('src/SConscript doc/SConscript'))
config = SConscript('MyConfig.py')
The second calling style is to omit the positional argument naming
the script and instead specify directory names using the
dirs keyword argument.
The value can be a string or list of strings.
In this case,
scons
will execute a subsidiary configuration file named
SConscript (by default)
in each of the specified directories.
You may specify a name other than
SConscript
by supplying an optional
name=scriptname
keyword argument.
The first three examples below have the same effect
as the first three examples above:
SConscript(dirs='.') # run SConscript in the current directory SConscript(dirs='src') # run SConscript in the src directory SConscript(dirs=['src', 'doc']) SConscript(dirs=['sub1', 'sub2'], name='MySConscript')
The optional
exports
keyword argument specifies variables to make available
for use by the called SConscripts,
which are evaluated in an isolated context
and otherwise do not have access to local variables
from the calling SConscript.
The value may be a string or list of strings representing
variable names, or a dictionary mapping local names to
the names they can be imported by.
For the first (scriptnames) calling style,
a second positional argument will also be interpreted as
exports;
the second (directory) calling style accepts no
positional arguments and must use the keyword form.
These variables are locally exported only to the called
SConscript file(s), and take precedence over any same-named
variables in the global pool managed by the
Export
function.
The subsidiary SConscript files
must use the
Import
function to import the variables into their local scope.
Examples:
foo = SConscript('sub/SConscript', exports='env')
SConscript('dir/SConscript', exports=['env', 'variable'])
SConscript(dirs='subdir', exports='env variable')
SConscript(dirs=['one', 'two', 'three'], exports='shared_info')
If the optional
variant_dir
argument is present, it causes an effect equivalent to the
VariantDir function,
but in effect only within the scope of the SConscript call.
The variant_dir
argument is interpreted relative to the directory of the
calling SConscript file.
The source directory is the directory in which the
called SConscript
file resides and the SConscript
file is evaluated as if it were in the
variant_dir
directory. Thus:
SConscript('src/SConscript', variant_dir='build')
is equivalent to:
VariantDir('build', 'src')
SConscript('build/SConscript')
If the sources are in the same directory as the
SConstruct,
SConscript('SConscript', variant_dir='build')
is equivalent to:
VariantDir('build', '.')
SConscript('build/SConscript')
The optional
duplicate argument is
interpreted as for VariantDir.
If the variant_dir argument
is omitted, the duplicate argument is ignored.
See the description of
VariantDir
for additional details and restrictions.
If the optional
must_exist
is True (the default),
an exception is raised if a requested
SConscript file is not found.
To allow missing scripts to be silently ignored
(the default behavior prior to SCons version 3.1),
pass
must_exist=False in the SConscript call.
Changed in 4.6.0: must_exist
now defaults to True.
Here are some composite examples:
# collect the configuration information and use it to build src and doc
shared_info = SConscript('MyConfig.py')
SConscript('src/SConscript', exports='shared_info')
SConscript('doc/SConscript', exports='shared_info')
# build debugging and production versions. SConscript
# can use Dir('.').path to determine variant.
SConscript('SConscript', variant_dir='debug', duplicate=0)
SConscript('SConscript', variant_dir='prod', duplicate=0)
# build debugging and production versions. SConscript
# is passed flags to use.
opts = { 'CPPDEFINES' : ['DEBUG'], 'CCFLAGS' : '-pgdb' }
SConscript('SConscript', variant_dir='debug', duplicate=0, exports=opts)
opts = { 'CPPDEFINES' : ['NODEBUG'], 'CCFLAGS' : '-O' }
SConscript('SConscript', variant_dir='prod', duplicate=0, exports=opts)
# build common documentation and compile for different architectures
SConscript('doc/SConscript', variant_dir='build/doc', duplicate=0)
SConscript('src/SConscript', variant_dir='build/x86', duplicate=0)
SConscript('src/SConscript', variant_dir='build/ppc', duplicate=0)
SConscript returns the values of any variables
named by the executed SConscript file(s) in arguments
to the Return function.
If a single SConscript call causes multiple scripts to
be executed, the return value is a tuple containing
the returns of each of the scripts. If an executed
script does not explicitly call Return, it returns
None.
SConscriptChdir(value)
By default,
scons
changes its working directory
to the directory in which each
subsidiary SConscript file lives
while reading and processing that script.
This behavior may be disabled
by specifying an argument which
evaluates false, in which case
scons
will stay in the top-level directory
while reading all SConscript files.
(This may be necessary when building from repositories,
when all the directories in which SConscript files may be found
don't necessarily exist locally.)
You may enable and disable
this ability by calling
SConscriptChdir
multiple times.
Example:
SConscriptChdir(False)
SConscript('foo/SConscript') # will not chdir to foo
SConscriptChdir(True)
SConscript('bar/SConscript') # will chdir to bar
SConsignFile([name, dbm_module])env.SConsignFile([name, dbm_module])
Specify where to store the SCons file signature database, and which database format to use. This may be useful to specify alternate database files and/or file locations for different types of builds.
The optional name argument
is the base name of the database file(s).
If not an absolute path name,
these are placed relative to the directory containing the
top-level SConstruct file.
The default is
.sconsign.
The actual database file(s) stored on disk
may have an appropriate suffix appended
by the chosen
dbm_module
The optional dbm_module
argument specifies which
Python database module to use
for reading/writing the file.
The module must be imported first;
then the imported module name
is passed as the argument.
The default is a custom
SCons.dblite
module that uses pickled
Python data structures,
which works on all Python versions.
See documentation of the Python
dbm module
for other available types.
If called with no arguments,
the database will default to
.sconsign.dblite
in the top directory of the project,
which is also the default if
if SConsignFile is not called.
The setting is global, so the only difference
between the global function and the environment method form
is variable expansion on name.
There should only be one active call to this
function/method in a given build setup.
If
name
is set to
None,
scons
will store file signatures
in a separate
.sconsign
file in each directory,
not in a single combined database file.
This is a backwards-compatibility meaure to support
what was the default behavior
prior to SCons 0.97 (i.e. before 2008).
Use of this mode is discouraged and may be
deprecated in a future SCons release.
Examples:
# Explicitly stores signatures in ".sconsign.dblite"
# in the top-level SConstruct directory (the default behavior).
SConsignFile()
# Stores signatures in the file "etc/scons-signatures"
# relative to the top-level SConstruct directory.
# SCons will add a database suffix to this name.
SConsignFile("etc/scons-signatures")
# Stores signatures in the specified absolute file name.
# SCons will add a database suffix to this name.
SConsignFile("/home/me/SCons/signatures")
# Stores signatures in a separate .sconsign file
# in each directory.
SConsignFile(None)
# Stores signatures in a GNU dbm format .sconsign file
import dbm.gnu
SConsignFile(dbm_module=dbm.gnu)
env.SetDefault(key=val, [...])
Sets construction variables to default values specified with the keyword arguments if (and only if) the variables are not already set. The following statements are equivalent:
env.SetDefault(FOO='foo')
if 'FOO' not in env:
env['FOO'] = 'foo'
SetOption(name, value)env.SetOption(name, value)
Sets scons option variable name
to value.
These options are all also settable via
command-line options but the variable name
may differ from the command-line option name -
see the table for correspondences.
A value set via command-line option will take
precedence over one set with SetOption, which
allows setting a project default in the scripts and
temporarily overriding it via command line.
SetOption calls can also be placed in the
site_init.py file.
See the documentation in the manpage for the
corresponding command line option for information about each specific option.
The value parameter is mandatory,
for option values which are boolean in nature
(that is, the command line option does not take an argument)
use a value
which evaluates to true (e.g. True,
1) or false (e.g. False,
0).
Options which affect the reading and processing of SConscript files
are not settable using SetOption since those files must
be read in order to find the SetOption call in the first place.
For project-specific options (sometimes called
local options)
added via an AddOption call,
SetOption is available only after the
AddOption call has completed successfully,
and only if that call included the
settable=True argument.
The settable variables with their associated command-line options are:
| Settable name | Command-line options | Notes |
|---|---|---|
clean
|
-c,
--clean,
--remove
|
|
diskcheck
|
--diskcheck
|
|
duplicate
|
--duplicate
|
|
experimental
|
--experimental
|
since 4.2 |
hash_chunksize
|
--hash-chunksize
|
Actually sets md5_chunksize.
since 4.2
|
hash_format
|
--hash-format
|
since 4.2 |
help
|
-h, --help |
|
implicit_cache
|
--implicit-cache
|
|
implicit_deps_changed
|
--implicit-deps-changed
|
Also sets implicit_cache.
(settable since 4.2)
|
implicit_deps_unchanged
|
--implicit-deps-unchanged
|
Also sets implicit_cache.
(settable since 4.2)
|
max_drift
|
--max-drift
|
|
md5_chunksize
|
--md5-chunksize
|
|
no_exec
|
-n,
--no-exec,
--just-print,
--dry-run,
--recon
|
|
no_progress
|
-Q
|
See [a] |
num_jobs
|
-j, --jobs |
|
random
|
--random
|
|
silent
|
-s,
--silent,
--quiet
|
|
stack_size
|
--stack-size
|
|
warn
|
--warn
|
|
|
[a] If |
||
Example:
SetOption('max_drift', 0)
SideEffect(side_effect, target)env.SideEffect(side_effect, target)
Declares
side_effect
as a side effect of building
target.
Both
side_effect
and
target
can be a list, a file name, or a node.
A side effect is a target file that is created or updated
as a side effect of building other targets.
For example, a Windows PDB
file is created as a side effect of building the .obj
files for a static library,
and various log files are created updated
as side effects of various TeX commands.
If a target is a side effect of multiple build commands,
scons
will ensure that only one set of commands
is executed at a time.
Consequently, you only need to use this method
for side-effect targets that are built as a result of
multiple build commands.
Because multiple build commands may update
the same side effect file,
by default the
side_effect
target is
not
automatically removed
when the
target
is removed by the
-c
option.
(Note, however, that the
side_effect
might be removed as part of
cleaning the directory in which it lives.)
If you want to make sure the
side_effect
is cleaned whenever a specific
target
is cleaned,
you must specify this explicitly
with the
Clean
or
env.Clean
function.
This function returns the list of side effect Node objects that were successfully added. If the list of side effects contained any side effects that had already been added, they are not added and included in the returned list.
Split(arg)env.Split(arg)
If arg is a string,
splits on whitespace and returns a list of
strings without whitespace.
This mode is the most common case,
and can be used to split a list of filenames
(for example) rather than having to type them as a
list of individually quoted words.
If arg is a list or tuple
returns the list or tuple unchanged.
If arg is any other type of object,
returns a list containing just the object.
These non-string cases do not actually do any spliting,
but allow an argument variable to be passed to
Split without having to first check its type.
Example:
files = Split("f1.c f2.c f3.c")
files = env.Split("f4.c f5.c f6.c")
files = Split("""
f7.c
f8.c
f9.c
""")
env.subst(input, [raw, target, source, conv])
Performs construction variable interpolation
(substitution)
on input,
which can be a string or a sequence.
Substitutable elements take the form
${,
although if there is no ambiguity in recognizing the element,
the braces can be omitted.
A literal $ can be entered by
using $$.
expression}
By default,
leading or trailing white space will
be removed from the result,
and all sequences of white space
will be compressed to a single space character.
Additionally, any
$(
and
$)
character sequences will be stripped from the returned string,
The optional
raw
argument may be set to
1
if you want to preserve white space and
$(-$)
sequences.
The
raw
argument may be set to
2
if you want to additionally discard
all characters between any
$(
and
$)
pairs
(as is done for signature calculation).
If input is a sequence
(list or tuple),
the individual elements of
the sequence will be expanded,
and the results will be returned as a list.
The optional
target
and
source
keyword arguments
must be set to lists of
target and source nodes, respectively,
if you want the
$TARGET,
$TARGETS,
$SOURCE
and
$SOURCES
to be available for expansion.
This is usually necessary if you are
calling
env.subst
from within a Python function used
as an SCons action.
Returned string values or sequence elements
are converted to their string representation by default.
The optional
conv
argument
may specify a conversion function
that will be used in place of
the default.
For example, if you want Python objects
(including SCons Nodes)
to be returned as Python objects,
you can use a Python
lambda expression to pass in an unnamed function
that simply returns its unconverted argument.
Example:
print(env.subst("The C compiler is: $CC"))
def compile(target, source, env):
sourceDir = env.subst(
"${SOURCE.srcdir}",
target=target,
source=source
)
source_nodes = env.subst('$EXPAND_TO_NODELIST', conv=lambda x: x)
Tag(node, tags)
Annotates file or directory Nodes with
information about how the
Package
Builder should package those files or directories.
All Node-level tags are optional.
Examples:
# makes sure the built library will be installed with 644 file access mode
Tag(Library('lib.c'), UNIX_ATTR="0o644")
# marks file2.txt to be a documentation file
Tag('file2.txt', DOC)
Tool(name, [toolpath, key=value, ...])env.Tool(name, [toolpath, key=value, ...])
Locates the tool specification module name
and returns a callable tool object for that tool.
When the environment method (env.Tool) form is used,
the tool object is automatically called before the method returns
to update env,
and name is
appended to the $TOOLS
construction variable in that environment.
When the global function Tool form is used,
the tool object is constructed but not called,
as it lacks the context of an environment to update,
and the returned object needs to be used to arrange for the call.
The tool module is searched for in the tool search paths (see the
Tools section in the manual page
for details)
and in any paths specified by the optional
toolpath parameter,
which must be a list of strings.
If toolpath is omitted,
the toolpath
supplied when the environment was created,
if any, is used.
Any remaining keyword arguments are saved in
the tool object,
and will be passed to the tool module's
generate function
when the tool object is actually called.
The generate function
can update the construction environment with construction variables and arrange
any other initialization
needed to use the mechanisms that tool describes,
and can use these extra arguments to help
guide its actions.
Changed in version 4.2:
env.Tool now returns the tool object,
previously it did not return (i.e. returned None).
Examples:
env.Tool('gcc')
env.Tool('opengl', toolpath=['build/tools'])
The returned tool object can be passed to an
Environment or Clone call
as part of the tools keyword argument,
in which case the tool is applied to the environment being constructed,
or it can be called directly,
in which case a construction environment to update must be
passed as the argument.
Either approach will also update the
$TOOLS construction variable.
Examples:
env = Environment(tools=[Tool('msvc')])
env = Environment()
msvctool = Tool('msvc')
msvctool(env) # adds 'msvc' to the TOOLS variable
gltool = Tool('opengl', toolpath = ['tools'])
gltool(env) # adds 'opengl' to the TOOLS variable
ValidateOptions([throw_exception=False])
Check that all the options specified on the command line are either
SCons built-in options or defined via calls to AddOption.
SCons will eventually fail on unknown options anyway, but calling
this function allows the build to "fail fast" before executing
expensive logic later in the build.
This function should only be called after the last AddOption
call in your SConscript logic.
Be aware that some tools call AddOption, if you are getting
error messages for arguments that they add, you will need to ensure
that those tools are loaded before calling ValidateOptions.
If there are any unknown command line options, ValidateOptions
prints an error message and exits with an error exit status.
If the optional throw_exception argument is
True (default is False),
a SConsBadOptionError is raised,
giving an opportunity for the SConscript logic to catch that
exception and handle invalid options appropriately. Note that
this exception name needs to be imported (see the example below).
A common build problem is typos (or thinkos) - a user enters an option that is just a little off the expected value, or perhaps a different word with a similar meaning. It may be useful to abort the build before going too far down the wrong path. For example:
$ scons --compilers=mingw # the correct flag is --compiler
Here SCons could go off and run a bunch of configure steps with
the default value of --compiler, since the
incorrect command line did not actually supply a value to it,
costing developer time to track down why the configure logic
made the "wrong" choices. This example shows catching this:
from SCons.Script.SConsOptions import SConsBadOptionError
AddOption(
'--compiler',
dest='compiler',
action='store',
default='gcc',
type='string',
)
# ... other SConscript logic ...
try:
ValidateOptions(throw_exception=True)
except SConsBadOptionError as e:
print(f"ValidateOptions detects a fail: ", e.opt_str)
Exit(3)
New in version 4.5.0
Value(value, [built_value], [name])env.Value(value, [built_value], [name])
Returns a Node object representing the specified Python
value.
Value Nodes can be used as dependencies of targets.
If the string representation of the Value Node
changes between SCons runs, it is considered
out of date and any targets depending it will be rebuilt.
Since Value Nodes have no filesystem representation,
timestamps are not used; the timestamp deciders
perform the same content-based up to date check.
The optional
built_value
argument can be specified
when the Value Node is created
to indicate the Node should already be considered "built."
The optional name parameter can be provided as an
alternative name for the resulting Value node;
this is advised if the value parameter
cannot be converted to a string.
Value Nodes have a
write
method that can be used to "build" a Value Node
by setting a new value.
The corresponding
read
method returns the built value of the Node.
Changed in version 4.0:
the name parameter was added.
Examples:
env = Environment()
def create(target, source, env):
"""Action function to create a file from a Value.
Writes 'prefix=$SOURCE' into the file name given as $TARGET.
"""
with open(str(target[0]), 'wb') as f:
f.write(b'prefix=' + source[0].get_contents() + b'\n')
# Fetch the prefix= argument, if any, from the command line.
# Use /usr/local as the default.
prefix = ARGUMENTS.get('prefix', '/usr/local')
# Attach builder named Config to the construction environment
# using the 'create' action function above.
env['BUILDERS']['Config'] = Builder(action=create)
env.Config(target='package-config', source=Value(prefix))
def build_value(target, source, env):
"""Action function to "build" a Value.
Writes contents of $SOURCE into $TARGET, thus updating if it existed.
"""
target[0].write(source[0].get_contents())
output = env.Value('before')
input = env.Value('after')
# Attach a builder named UpdateValue to the construction environment
# using the 'build_value' action function above.
env['BUILDERS']['UpdateValue'] = Builder(action=build_value)
env.UpdateValue(target=Value(output), source=Value(input))
VariantDir(variant_dir, src_dir, [duplicate])env.VariantDir(variant_dir, src_dir, [duplicate])
Sets up a mapping to define a variant build directory in
variant_dir.
src_dir must not be underneath
variant_dir.
A VariantDir mapping is global, even if called using the
env.VariantDir form.
VariantDir
can be called multiple times with the same
src_dir
to set up multiple variant builds with different options.
Note if variant_dir
is not under the project top directory,
target selection rules will not pick targets in the
variant directory unless they are explicitly specified.
When files in variant_dir are referenced,
SCons backfills as needed with files from src_dir
to create a complete build directory.
By default, SCons
physically duplicates the source files, SConscript files,
and directory structure as needed into the variant directory.
Thus, a build performed in the variant directory is guaranteed to be identical
to a build performed in the source directory even if
intermediate source files are generated during the build,
or if preprocessors or other scanners search for included files
using paths relative to the source file,
or if individual compilers or other invoked tools are hard-coded
to put derived files in the same directory as source files.
Only the files SCons calculates are needed for the build are
duplicated into variant_dir.
If possible on the platform,
the duplication is performed by linking rather than copying.
This behavior is affected by the
--duplicate
command-line option.
Duplicating the source files may be disabled by setting the
duplicate
argument to
False.
This will cause
SCons
to invoke Builders using the path names of source files in
src_dir
and the path names of derived files within
variant_dir.
This is more efficient than duplicating,
and is safe for most builds;
revert to duplicate=True
if it causes problems.
VariantDir
works most naturally when used with a subsidiary SConscript file.
The subsidiary SConscript file must be called as if it were in
variant_dir,
regardless of the value of
duplicate.
When calling an SConscript file, you can use the
exports keyword argument
to pass parameters (individually or as an appropriately set up environment)
so the SConscript can pick up the right settings for that variant build.
The SConscript must Import these to use them. Example:
env1 = Environment(...settings for variant1...)
env2 = Environment(...settings for variant2...)
# run src/SConscript in two variant directories
VariantDir('build/variant1', 'src')
SConscript('build/variant1/SConscript', exports={"env": env1})
VariantDir('build/variant2', 'src')
SConscript('build/variant2/SConscript', exports={"env": env2})
See also the
SConscript function
for another way to specify a variant directory
in conjunction with calling a subsidiary SConscript file.
More examples:
# use names in the build directory, not the source directory
VariantDir('build', 'src', duplicate=0)
Program('build/prog', 'build/source.c')
# this builds both the source and docs in a separate subtree
VariantDir('build', '.', duplicate=0)
SConscript(dirs=['build/src','build/doc'])
# same as previous example, but only uses SConscript
SConscript(dirs='src', variant_dir='build/src', duplicate=0)
SConscript(dirs='doc', variant_dir='build/doc', duplicate=0)
WhereIs(program, [path, pathext, reject])env.WhereIs(program, [path, pathext, reject])
Searches for the specified executable
program,
returning the full path to the program
or None.
When called as a construction environment method,
searches the paths in the
path keyword argument,
or if None (the default)
the paths listed in the construction environment
(env['ENV']['PATH']).
The external environment's path list
(os.environ['PATH'])
is used as a fallback if the key
env['ENV']['PATH']
does not exist.
On Windows systems, searches for executable
programs with any of the file extensions listed in the
pathext keyword argument,
or if None (the default)
the pathname extensions listed in the construction environment
(env['ENV']['PATHEXT']).
The external environment's pathname extensions list
(os.environ['PATHEXT'])
is used as a fallback if the key
env['ENV']['PATHEXT']
does not exist.
When called as a global function, uses the external
environment's path
os.environ['PATH']
and path extensions
os.environ['PATHEXT'],
respectively, if
path and
pathext are
None.
Will not select any
path name or names
in the optional
reject
list.
In addition to the global functions and methods,
scons
supports a number of variables
that can be used for run-time queries in SConscript files
to affect how you want the build to be performed.
ARGLIST
A list of the variable=value build variable arguments specified on the command line. Each element in the list is a tuple consisting of the variable and its value. The separate variable and value elements of the tuple can be accessed by subscripting for elements [0] and [1] of the tuple, or, more readably, by using tuple unpacking. Examples:
print("first variable, value =", ARGLIST[0][0], ARGLIST[0][1])
print("second variable, value =", ARGLIST[1][0], ARGLIST[1][1])
var, value = ARGLIST[2]
print("third variable, value =", var, value)
for var, value in ARGLIST:
# process variable and value
The values obtained from ARGLIST
(or from ARGUMENTS)
are always strings since they originate from outside the SCons process.
As "untrusted data",
they should be validated before usage,
and may need conversion to an appropriate type.
ARGUMENTS
A dictionary of all the
variable=value
build variable arguments specified on the command line.
The dictionary is in command-line order,
so if a given variable has
more than one value assigned to it
on the command line,
the last (right-most) value is
the one saved in the ARGUMENTS
dictionary.
Example:
if ARGUMENTS.get("debug", ""):
env = Environment(CCFLAGS="-g")
else:
env = Environment()
See also ARGLIST.
BUILD_TARGETS
A list of the targets which
scons
has been asked to build.
The contents will be either those targets listed
on the command line, or, if none, those targets set
via calls to the Default function.
It does
not
contain any dependent targets that scons
selects for building as a result of making the sure the
specified targets are up to date, if those targets
did not appear on the command line.
The list is empty if neither
command line targets or Default calls are present.
The elements of this list may be strings
or
nodes, so you should run the list through the Python
str
function to make sure any Node path names
are converted to strings.
Because this list may be taken from the
list of targets specified using the
Default function,
the contents of the list may change
on each successive call to Default.
See DEFAULT_TARGETS
for additional information.
Example:
if 'foo' in BUILD_TARGETS:
print("Don't forget to test the `foo' program!")
if 'special/program' in BUILD_TARGETS:
SConscript('special')
COMMAND_LINE_TARGETS
A list of the targets explicitly specified on
the command line. If there are command line targets,
this list has the same contents as
BUILD_TARGETS.
If there are no targets specified on the command line,
the list is empty. The elements of this list are strings.
This can be used, for example,
to take specific actions only
when a certain targets is explicitly requested for building.
Example:
if 'foo' in COMMAND_LINE_TARGETS:
print("Don't forget to test the `foo' program!")
if 'special/program' in COMMAND_LINE_TARGETS:
SConscript('special')
DEFAULT_TARGETS
A list of the target
nodes
that have been specified using the
Default
function. If there are no command line
targets, this list will have the same contents as
BUILD_TARGETS.
Since the elements of the list are nodes,
you need to call the Python
str
function on them to get the path name for each Node.
Example:
print(str(DEFAULT_TARGETS[0]))
if 'foo' in [str(t) for t in DEFAULT_TARGETS]:
print("Don't forget to test the `foo' program!")
The contents of the
DEFAULT_TARGETS
list change on on each successive call to the
Default function:
print([str(t) for t in DEFAULT_TARGETS]) # originally []
Default('foo')
print([str(t) for t in DEFAULT_TARGETS]) # now a node ['foo']
Default('bar')
print([str(t) for t in DEFAULT_TARGETS]) # now a node ['foo', 'bar']
Default(None)
print([str(t) for t in DEFAULT_TARGETS]) # back to []
Consequently, be sure to use
DEFAULT_TARGETS
only after you've made all of your
Default() calls,
or else simply be careful of the order
of these statements in your SConscript files
so that you don't look for a specific
default target before it's actually been added to the list.
These variables may be accessed from custom Python modules that you
import into an SConscript file by adding the following
to the Python module:
from SCons.Script import *
Construction Variables are key-value pairs used to store information in a construction environment that is needed needed for builds using that environment. Construction variable naming must follow the same rules as Python identifier naming: the initial character must be an underscore or letter, followed by any number of underscores, letters, or digits. The convention is to use uppercase for all letters for easier visual identification.
Construction variables are used to hold many different types of information.
For example, the $CPPDEFINES variable is how to tell a C/C++
compiler about preprocessor macros you need for your build.
The tool discovery that SCons performs will cause the
$CXX variable to hold the name of the C++ compiler,
if one was detected on the system, but you can give it a different
value to force a compiler command of a different name to be used.
Some variables contain lists of filename suffixes that are recognized
by a particular compiler chain.
$BUILDERS contains a mapping of configured
Builder names (e.g. Textfile) to the actual Builder instance
to call when that Builder is used.
Construction variables may include references to other construction variables:
the same tool which set up the C/C++ compiler will also set
up an "action string", describing how to invoke that compiler,
in $CXXCOM, which contains other construction variables
using $VARIABLE syntax.
These references will be expanded and replaced on use
(see Variable Substitution).
Construction variables are referenced as if they were keys and values in a Python dictionary:
env["CC"] = "cc"
flags = env.get("CPPDEFINES", [])
Construction variables can also be retrieved and set
by using the Dictionary
method of the construction environment to create an actual
dictionary:
cvars = env.Dictionary() cvars["CC"] = "cc"
in the previous example, since cvars
is an external copy, the value of $CC in the
construction environment itself is not changed by the assignment.
Construction variables can set by passing them as keyword arguments when creating a new construction environment:
env = Environment(CC="cc")
or when copying a construction environment using the
Clone method:
env2 = env.Clone(CC="cl.exe")
Construction variables can also be supplied as keyword arguments to a builder, in which case those settings affect only the work done by that builder call, and not the construction environment as a whole. This concept is called an override:
env.Program('hello', 'hello.c', LIBS=['gl', 'glut'])
Many useful construction variables are automatically defined by SCons, tuned to the specific platform in use, and you can modify these or define any additional construction variables for use in your own Builders, Scanners and other tools. Take care not to overwrite ones which SCons is using. The following is a list of predefined construction variables. Pay attention to whether the values are ones you may be expected to set vs. ones that are set to expected values by internal tools and other initializations and probably should not be modified.
Note the actual list available
at execution time will never include all of these, as the ones
detected as not being applicable (wrong platform, necessary
external command or files not installed, etc.) will not be set up.
Correct build setups should be resilient to the possible
absence of certain construction variables before using them,
for example by using a Python dictionary
get method to retrieve the value and
taking alternative action if the return indicates the variable is unset.
The env.Dump method can be called to examine the
construction variables set in a particular environment.
__LDMODULEVERSIONFLAGS
This construction variable automatically introduces $_LDMODULEVERSIONFLAGS
if $LDMODULEVERSION is set. Othervise it evaluates to an empty string.
__SHLIBVERSIONFLAGS
This construction variable automatically introduces $_SHLIBVERSIONFLAGS
if $SHLIBVERSION is set. Othervise it evaluates to an empty string.
APPLELINK_COMPATIBILITY_VERSION
On Mac OS X this is used to set the linker flag: -compatibility_version
The value is specified as X[.Y[.Z]] where X is between 1 and 65535, Y can be omitted or between 1 and
255, Z can be omitted or between 1 and 255. This value will be derived from $SHLIBVERSION if
not
specified. The lowest digit will be dropped and replaced by a 0.
If the $APPLELINK_NO_COMPATIBILITY_VERSION is set then no -compatibility_version will be
output.
See MacOS's ld manpage for more details
_APPLELINK_COMPATIBILITY_VERSION
A macro (by default a generator function) used to create the linker flags to specify
apple's linker's -compatibility_version flag.
The default generator uses $APPLELINK_COMPATIBILITY_VERSION
and $APPLELINK_NO_COMPATIBILITY_VERSION and $SHLIBVERSION
to determine the correct flag.
APPLELINK_CURRENT_VERSION
On Mac OS X this is used to set the linker flag: -current_version
The value is specified as X[.Y[.Z]] where X is between 1 and 65535, Y can be omitted or between 1 and
255, Z can be omitted or between 1 and 255. This value will be set to $SHLIBVERSION if not
specified.
If the $APPLELINK_NO_CURRENT_VERSION is set then no -current_version will be
output.
See MacOS's ld manpage for more details
_APPLELINK_CURRENT_VERSION
A macro (by default a generator function) used to create the linker flags to specify apple's linker's
-current_version flag. The default generator uses $APPLELINK_CURRENT_VERSION and
$APPLELINK_NO_CURRENT_VERSION and $SHLIBVERSION to determine the correct flag.
APPLELINK_NO_COMPATIBILITY_VERSION
Set this to any True (1|True|non-empty string) value to disable adding -compatibility_version flag when generating versioned shared libraries.
This overrides $APPLELINK_COMPATIBILITY_VERSION.
APPLELINK_NO_CURRENT_VERSION
Set this to any True (1|True|non-empty string) value to disable adding -current_version flag when generating versioned shared libraries.
This overrides $APPLELINK_CURRENT_VERSION.
AR
The static library archiver.
ARCHITECTURE
Specifies the system architecture for which
the package is being built.
The default is the system architecture
of the machine on which SCons is running.
This is used to fill in the
Architecture:
field in an Ipkg
control file,
and the BuildArch: field
in the RPM .spec file,
as well as forming part of the name of a generated RPM package file.
See the Package builder.
ARCOM
The command line used to generate a static library from object files.
ARCOMSTR
The string displayed when a static library is
generated from object files.
If this is not set, then $ARCOM (the command line) is displayed.
env = Environment(ARCOMSTR = "Archiving $TARGET")
ARFLAGS
General options passed to the static library archiver.
AS
The assembler.
ASCOM
The command line used to generate an object file from an assembly-language source file.
ASCOMSTR
The string displayed when an object file
is generated from an assembly-language source file.
If this is not set, then $ASCOM (the command line) is displayed.
env = Environment(ASCOMSTR = "Assembling $TARGET")
ASFLAGS
General options passed to the assembler.
ASPPCOM
The command line used to assemble an assembly-language
source file into an object file
after first running the file through the C preprocessor.
Any options specified
in the $ASFLAGS and $CPPFLAGS construction variables
are included on this command line.
ASPPCOMSTR
The string displayed when an object file
is generated from an assembly-language source file
after first running the file through the C preprocessor.
If this is not set, then $ASPPCOM (the command line) is displayed.
env = Environment(ASPPCOMSTR = "Assembling $TARGET")
ASPPFLAGS
General options when an assembling an assembly-language
source file into an object file
after first running the file through the C preprocessor.
The default is to use the value of $ASFLAGS.
BIBTEX
The bibliography generator for the TeX formatter and typesetter and the LaTeX structured formatter and typesetter.
BIBTEXCOM
The command line used to call the bibliography generator for the TeX formatter and typesetter and the LaTeX structured formatter and typesetter.
BIBTEXCOMSTR
The string displayed when generating a bibliography
for TeX or LaTeX.
If this is not set, then $BIBTEXCOM (the command line) is displayed.
env = Environment(BIBTEXCOMSTR = "Generating bibliography $TARGET")
BIBTEXFLAGS
General options passed to the bibliography generator for the TeX formatter and typesetter and the LaTeX structured formatter and typesetter.
BUILDERS
A dictionary mapping the names of the builders available through the construction environment to underlying Builder objects. Custom builders need to be added to this to make them available.
A platform-dependent default list of builders such as
Program, Library etc. is used to
populate this construction variable when the construction environment is initialized
via the presence/absence of the tools those builders depend on.
$BUILDERS can be examined to learn which builders will
actually be available at run-time.
Note that if you initialize this construction variable through
assignment when the construction environment is created,
that value for $BUILDERS will override any defaults:
bld = Builder(action='foobuild < $SOURCE > $TARGET')
env = Environment(BUILDERS={'NewBuilder': bld})
To instead use a new Builder object in addition to the default Builders, add your new Builder object like this:
env = Environment()
env.Append(BUILDERS={'NewBuilder': bld})
or this:
env = Environment() env['BUILDERS']['NewBuilder'] = bld
CACHEDIR_CLASS
The class type that SCons should use when instantiating a
new CacheDir in this construction environment. Must be
a subclass of the SCons.CacheDir.CacheDir class.
CC
The C compiler.
CCCOM
The command line used to compile a C source file to a (static) object
file. Any options specified in the $CFLAGS, $CCFLAGS and
$CPPFLAGS construction variables are included on this command line.
See also $SHCCCOM for compiling to shared objects.
CCCOMSTR
If set, the string displayed when a C source file
is compiled to a (static) object file.
If not set, then $CCCOM (the command line) is displayed.
See also $SHCCCOMSTR for compiling to shared objects.
env = Environment(CCCOMSTR = "Compiling static object $TARGET")
CCDEPFLAGS
Options to pass to C or C++ compiler to generate list of dependency files.
This is set only by compilers which support this functionality. (gcc, clang, and msvc currently)
CCFLAGS
General options that are passed to the C and C++ compilers.
See also $SHCCFLAGS for compiling to shared objects.
CCPCHFLAGS
Options added to the compiler command line
to support building with precompiled headers.
The default value expands expands to the appropriate
Microsoft Visual C++ command-line options
when the $PCH construction variable is set.
CCPDBFLAGS
Options added to the compiler command line
to support storing debugging information in a
Microsoft Visual C++ PDB file.
The default value expands expands to appropriate
Microsoft Visual C++ command-line options
when the $PDB construction variable is set.
The Microsoft Visual C++ compiler option that SCons uses by default
to generate PDB information is /Z7.
This works correctly with parallel (-j) builds
because it embeds the debug information in the intermediate object files,
as opposed to sharing a single PDB file between multiple object files.
This is also the only way to get debug information
embedded into a static library.
Using the /Zi instead may yield improved
link-time performance,
although parallel builds will no longer work.
You can generate PDB files with the /Zi
switch by overriding the default $CCPDBFLAGS variable as follows:
env['CCPDBFLAGS'] = ['${(PDB and "/Zi /Fd%s" % File(PDB)) or ""}']
An alternative would be to use the /Zi
to put the debugging information in a separate .pdb
file for each object file by overriding
the $CCPDBFLAGS variable as follows:
env['CCPDBFLAGS'] = '/Zi /Fd${TARGET}.pdb'
CCVERSION
The version number of the C compiler. This may or may not be set, depending on the specific C compiler being used.
CFILESUFFIX
The suffix for C source files.
This is used by the internal CFile builder
when generating C files from Lex (.l) or YACC (.y) input files.
The default suffix, of course, is
.c
(lower case).
On case-insensitive systems (like Windows),
SCons also treats
.C
(upper case) files
as C files.
CFLAGS
General options that are passed to the C compiler (C only; not C++).
See also $SHCFLAGS for compiling to shared objects.
CHANGE_SPECFILE
A hook for modifying the file that controls the packaging build
(the .spec for RPM,
the control for Ipkg,
the .wxs for MSI).
If set, the function will be called
after the SCons template for the file has been written.
See the Package builder.
CHANGED_SOURCES
A reserved variable name that may not be set or used in a construction environment. (See the manpage section "Variable Substitution" for more information).
CHANGED_TARGETS
A reserved variable name that may not be set or used in a construction environment. (See the manpage section "Variable Substitution" for more information).
CHANGELOG
The name of a file containing the change log text
to be included in the package.
This is included as the
%changelog
section of the RPM
.spec file.
See the Package builder.
COMPILATIONDB_COMSTR
The string displayed when the CompilationDatabase
builder's action is run.
COMPILATIONDB_PATH_FILTER
A string which instructs CompilationDatabase to
only include entries where the output member
matches the pattern in the filter string using fnmatch, which
uses glob style wildcards.
The default value is an empty string '', which disables filtering.
COMPILATIONDB_USE_ABSPATH
A boolean flag to instruct CompilationDatabase
whether to write the file and
output members
in the compilation database using absolute or relative paths.
The default value is False (use relative paths)
_concat
A function used to produce variables like $_CPPINCFLAGS. It takes
four mandatory arguments, and up to 4 additional optional arguments:
1) a prefix to concatenate onto each element,
2) a list of elements,
3) a suffix to concatenate onto each element,
4) an environment for variable interpolation,
5) an optional function that will be called to transform the list before concatenation,
6) an optionally specified target (Can use TARGET),
7) an optionally specified source (Can use SOURCE),
8) optional affect_signature flag which will wrap non-empty returned value with $( and $) to indicate the contents
should not affect the signature of the generated command line.
env['_CPPINCFLAGS'] = '${_concat(INCPREFIX, CPPPATH, INCSUFFIX, __env__, RDirs, TARGET, SOURCE, affect_signature=False)}'
CONFIGUREDIR
The name of the directory in which
Configure context test files are written.
The default is
.sconf_temp
in the top-level directory
containing the
SConstruct
file.
If variant directories are in use,
and the configure check results should not be
shared between variants,
you can set $CONFIGUREDIR
and $CONFIGURELOG so they are
unique per variant directory.
CONFIGURELOG
The name of the Configure context log file.
The default is
config.log
in the top-level directory
containing the
SConstruct
file.
If variant directories are in use,
and the configure check results should not be
shared between variants,
you can set $CONFIGUREDIR
and $CONFIGURELOG so they are
unique per variant directory.
_CPPDEFFLAGS
An automatically-generated construction variable
containing the C preprocessor command-line options
to define values.
The value of $_CPPDEFFLAGS is created
by respectively prepending and appending
$CPPDEFPREFIX and $CPPDEFSUFFIX
to each definition in $CPPDEFINES.
CPPDEFINES
A platform independent specification of C preprocessor macro definitions.
The definitions are added to command lines
through the automatically-generated
$_CPPDEFFLAGS construction variable,
which is constructed according to
the contents of $CPPDEFINES:
If $CPPDEFINES is a string,
the values of the
$CPPDEFPREFIX and $CPPDEFSUFFIX construction variables
are respectively prepended and appended to
each definition in $CPPDEFINES,
split on whitespace.
# Adds -Dxyz to POSIX compiler command lines, # and /Dxyz to Microsoft Visual C++ command lines. env = Environment(CPPDEFINES='xyz')
If $CPPDEFINES is a list,
the values of the
$CPPDEFPREFIX and $CPPDEFSUFFIX construction variables
are respectively prepended and appended to
each element in the list.
If any element is a tuple (or list)
then the first item of the tuple is the macro name
and the second is the macro definition.
If the definition is not omitted or None,
the name and definition are combined into a single
name=definition item
before the preending/appending.
# Adds -DB=2 -DA to POSIX compiler command lines,
# and /DB=2 /DA to Microsoft Visual C++ command lines.
env = Environment(CPPDEFINES=[('B', 2), 'A'])
If $CPPDEFINES is a dictionary,
the values of the
$CPPDEFPREFIX and $CPPDEFSUFFIX construction variables
are respectively prepended and appended to
each key from the dictionary.
If the value for a key is not None,
then the key (macro name) and the value
(macros definition) are combined into a single
name=definition item
before the prepending/appending.
# Adds -DA -DB=2 to POSIX compiler command lines,
# or /DA /DB=2 to Microsoft Visual C++ command lines.
env = Environment(CPPDEFINES={'B':2, 'A':None})
Depending on how contents are added to $CPPDEFINES,
it may be transformed into a compound type,
for example a list containing strings, tuples and/or dictionaries.
SCons can correctly expand such a compound type.
Note that SCons may call the compiler via a shell. If a macro definition contains characters such as spaces that have meaning to the shell, or is intended to be a string value, you may need to use the shell's quoting syntax to avoid interpretation by the shell before the preprocessor sees it. Function-like macros are not supported via this mechanism (and some compilers do not even implement that functionality via the command lines). When quoting, note that one set of quote characters are used to define a Python string, then quotes embedded inside that would be consumed by the shell unless escaped. These examples may help illustrate:
env = Environment(CPPDEFINES=['USE_ALT_HEADER=\\"foo_alt.h\\"'])
env = Environment(CPPDEFINES=[('USE_ALT_HEADER', '\\"foo_alt.h\\"')])
:Changed in version 4.5:
SCons no longer sorts $CPPDEFINES values entered
in dictionary form. Python now preserves dictionary
keys in the order they are entered, so it is no longer
necessary to sort them to ensure a stable command line.
CPPDEFPREFIX
The prefix used to specify preprocessor macro definitions
on the C compiler command line.
This will be prepended to each definition
in the $CPPDEFINES construction variable
when the $_CPPDEFFLAGS variable is automatically generated.
CPPDEFSUFFIX
The suffix used to specify preprocessor macro definitions
on the C compiler command line.
This will be appended to each definition
in the $CPPDEFINES construction variable
when the $_CPPDEFFLAGS variable is automatically generated.
CPPFLAGS
User-specified C preprocessor options.
These will be included in any command that uses the C preprocessor,
including not just compilation of C and C++ source files
via the $CCCOM,
$SHCCCOM,
$CXXCOM and
$SHCXXCOM command lines,
but also the $FORTRANPPCOM,
$SHFORTRANPPCOM,
$F77PPCOM and
$SHF77PPCOM command lines
used to compile a Fortran source file,
and the $ASPPCOM command line
used to assemble an assembly language source file,
after first running each file through the C preprocessor.
Note that this variable does
not
contain
-I
(or similar) include search path options
that scons generates automatically from $CPPPATH.
See $_CPPINCFLAGS, below,
for the variable that expands to those options.
_CPPINCFLAGS
An automatically-generated construction variable
containing the C preprocessor command-line options
for specifying directories to be searched for include files.
The value of $_CPPINCFLAGS is created
by respectively prepending and appending
$INCPREFIX and $INCSUFFIX
to each directory in $CPPPATH.
CPPPATH
The list of directories that the C preprocessor will search for include
directories. The C/C++ implicit dependency scanner will search these
directories for include files.
In general it's not advised to put include directory directives
directly into $CCFLAGS or $CXXFLAGS
as the result will be non-portable
and the directories will not be searched by the dependency scanner.
$CPPPATH should be a list of path strings,
or a single string, not a pathname list joined by
Python's os.pathsep.
Note:
directory names in $CPPPATH
will be looked-up relative to the directory of the SConscript file
when they are used in a command.
To force scons
to look-up a directory relative to the root of the source tree use
the # prefix:
env = Environment(CPPPATH='#/include')
The directory look-up can also be forced using the
Dir
function:
include = Dir('include')
env = Environment(CPPPATH=include)
The directory list will be added to command lines
through the automatically-generated
$_CPPINCFLAGS construction variable,
which is constructed by
respectively prepending and appending the values of the
$INCPREFIX and $INCSUFFIX construction variables
to each directory in $CPPPATH.
Any command lines you define that need
the $CPPPATH directory list should
include $_CPPINCFLAGS:
env = Environment(CCCOM="my_compiler $_CPPINCFLAGS -c -o $TARGET $SOURCE")
CPPSUFFIXES
The list of suffixes of files that will be scanned for C preprocessor implicit dependencies (#include lines). The default list is:
[".c", ".C", ".cxx", ".cpp", ".c++", ".cc", ".h", ".H", ".hxx", ".hpp", ".hh", ".F", ".fpp", ".FPP", ".m", ".mm", ".S", ".spp", ".SPP"]
CXX
The C++ compiler.
See also $SHCXX for compiling to shared objects..
CXXCOM
The command line used to compile a C++ source file to an object file.
Any options specified in the $CXXFLAGS and
$CPPFLAGS construction variables
are included on this command line.
See also $SHCXXCOM for compiling to shared objects..
CXXCOMSTR
If set, the string displayed when a C++ source file
is compiled to a (static) object file.
If not set, then $CXXCOM (the command line) is displayed.
See also $SHCXXCOMSTR for compiling to shared objects..
env = Environment(CXXCOMSTR = "Compiling static object $TARGET")
CXXFILESUFFIX
The suffix for C++ source files.
This is used by the internal CXXFile builder
when generating C++ files from Lex (.ll) or YACC (.yy) input files.
The default suffix is
.cc.
SCons also treats files with the suffixes
.cpp,
.cxx,
.c++,
and
.C++
as C++ files,
and files with
.mm
suffixes as Objective C++ files.
On case-sensitive systems (Linux, UNIX, and other POSIX-alikes),
SCons also treats
.C
(upper case) files
as C++ files.
CXXFLAGS
General options that are passed to the C++ compiler.
By default, this includes the value of $CCFLAGS,
so that setting $CCFLAGS affects both C and C++ compilation.
If you want to add C++-specific flags,
you must set or override the value of $CXXFLAGS.
See also $SHCXXFLAGS for compiling to shared objects..
CXXVERSION
The version number of the C++ compiler. This may or may not be set, depending on the specific C++ compiler being used.
DC
The D compiler to use.
See also $SHDC for compiling to shared objects.
DCOM
The command line used to compile a D file to an object file.
Any options specified in the $DFLAGS construction variable
is included on this command line.
See also $SHDCOM for compiling to shared objects.
DCOMSTR
If set, the string displayed when a D source file
is compiled to a (static) object file.
If not set, then $DCOM (the command line) is displayed.
See also $SHDCOMSTR for compiling to shared objects.
DDEBUG
List of debug tags to enable when compiling.
DDEBUGPREFIX
DDEBUGPREFIX.
DDEBUGSUFFIX
DDEBUGSUFFIX.
DESCRIPTION
A long description of the project being packaged. This is included in the relevant section of the file that controls the packaging build.
See the Package builder.
DESCRIPTION_lang
A language-specific long description for
the specified lang.
This is used to populate a
%description -l
section of an RPM
.spec file.
See the Package builder.
DFILESUFFIX
DFILESUFFIX.
DFLAGPREFIX
DFLAGPREFIX.
DFLAGS
General options that are passed to the D compiler.
DFLAGSUFFIX
DFLAGSUFFIX.
DI_FILE_DIR
Path where .di files will be generated
DI_FILE_DIR_PREFIX
Prefix to send the di path argument to compiler
DI_FILE_DIR_SUFFFIX
Suffix to send the di path argument to compiler
DI_FILE_SUFFIX
Suffix of d include files default is .di
DINCPREFIX
DINCPREFIX.
DINCSUFFIX
DLIBFLAGSUFFIX.
Dir
A function that converts a string into a Dir instance relative to the target being built.
Dirs
A function that converts a list of strings into a list of Dir instances relative to the target being built.
DLIB
Name of the lib tool to use for D codes.
DLIBCOM
The command line to use when creating libraries.
DLIBDIRPREFIX
DLIBLINKPREFIX.
DLIBDIRSUFFIX
DLIBLINKSUFFIX.
DLIBFLAGPREFIX
DLIBFLAGPREFIX.
DLIBFLAGSUFFIX
DLIBFLAGSUFFIX.
DLIBLINKPREFIX
DLIBLINKPREFIX.
DLIBLINKSUFFIX
DLIBLINKSUFFIX.
DLINK
Name of the linker to use for linking systems including D sources.
See also $SHDLINK for linking shared objects.
DLINKCOM
The command line to use when linking systems including D sources.
See also $SHDLINKCOM for linking shared objects.
DLINKFLAGPREFIX
DLINKFLAGPREFIX.
DLINKFLAGS
List of linker flags.
See also $SHDLINKFLAGS for linking shared objects.
DLINKFLAGSUFFIX
DLINKFLAGSUFFIX.
DOCBOOK_DEFAULT_XSL_EPUB
The default XSLT file for the DocbookEpub builder within the
current environment, if no other XSLT gets specified via keyword.
DOCBOOK_DEFAULT_XSL_HTML
The default XSLT file for the DocbookHtml builder within the
current environment, if no other XSLT gets specified via keyword.
DOCBOOK_DEFAULT_XSL_HTMLCHUNKED
The default XSLT file for the DocbookHtmlChunked builder within the
current environment, if no other XSLT gets specified via keyword.
DOCBOOK_DEFAULT_XSL_HTMLHELP
The default XSLT file for the DocbookHtmlhelp builder within the
current environment, if no other XSLT gets specified via keyword.
DOCBOOK_DEFAULT_XSL_MAN
The default XSLT file for the DocbookMan builder within the
current environment, if no other XSLT gets specified via keyword.
DOCBOOK_DEFAULT_XSL_PDF
The default XSLT file for the DocbookPdf builder within the
current environment, if no other XSLT gets specified via keyword.
DOCBOOK_DEFAULT_XSL_SLIDESHTML
The default XSLT file for the DocbookSlidesHtml builder within the
current environment, if no other XSLT gets specified via keyword.
DOCBOOK_DEFAULT_XSL_SLIDESPDF
The default XSLT file for the DocbookSlidesPdf builder within the
current environment, if no other XSLT gets specified via keyword.
DOCBOOK_FOP
The path to the PDF renderer fop or xep,
if one of them is installed (fop gets checked first).
DOCBOOK_FOPCOM
The full command-line for the
PDF renderer fop or xep.
DOCBOOK_FOPCOMSTR
The string displayed when a renderer like fop or
xep is used to create PDF output from an XML file.
DOCBOOK_FOPFLAGS
Additonal command-line flags for the
PDF renderer fop or xep.
DOCBOOK_XMLLINT
The path to the external executable xmllint, if it's installed.
Note, that this is only used as last fallback for resolving
XIncludes, if no lxml Python binding can be imported
in the current system.
DOCBOOK_XMLLINTCOM
The full command-line for the external executable
xmllint.
DOCBOOK_XMLLINTCOMSTR
The string displayed when xmllint is used to resolve
XIncludes for a given XML file.
DOCBOOK_XMLLINTFLAGS
Additonal command-line flags for the external executable
xmllint.
DOCBOOK_XSLTPROC
The path to the external executable xsltproc
(or saxon, xalan), if one of them
is installed.
Note, that this is only used as last fallback for XSL transformations, if
no lxml Python binding can be imported in the current system.
DOCBOOK_XSLTPROCCOM
The full command-line for the external executable
xsltproc (or saxon,
xalan).
DOCBOOK_XSLTPROCCOMSTR
The string displayed when xsltproc is used to transform
an XML file via a given XSLT stylesheet.
DOCBOOK_XSLTPROCFLAGS
Additonal command-line flags for the external executable
xsltproc (or saxon,
xalan).
DOCBOOK_XSLTPROCPARAMS
Additonal parameters that are not intended for the XSLT processor executable, but
the XSL processing itself. By default, they get appended at the end of the command line
for saxon and saxon-xslt, respectively.
DPATH
List of paths to search for import modules.
DRPATHPREFIX
DRPATHPREFIX.
DRPATHSUFFIX
DRPATHSUFFIX.
DSUFFIXES
The list of suffixes of files that will be scanned
for imported D package files.
The default list is ['.d'].
DVERPREFIX
DVERPREFIX.
DVERSIONS
List of version tags to enable when compiling.
DVERSUFFIX
DVERSUFFIX.
DVIPDF
The TeX DVI file to PDF file converter.
DVIPDFCOM
The command line used to convert TeX DVI files into a PDF file.
DVIPDFCOMSTR
The string displayed when a TeX DVI file
is converted into a PDF file.
If this is not set, then $DVIPDFCOM (the command line) is displayed.
DVIPDFFLAGS
General options passed to the TeX DVI file to PDF file converter.
DVIPS
The TeX DVI file to PostScript converter.
DVIPSFLAGS
General options passed to the TeX DVI file to PostScript converter.
ENV
The execution environment -
a dictionary of environment variables
used when SCons invokes external commands
to build targets defined in this construction environment.
When $ENV is passed to a command,
all list values are assumed to be path lists and
are joined using the search path separator.
Any other non-string values are coerced to a string.
Note that by default
SCons
does
not
propagate the environment in effect when you execute
scons (the "shell environment")
to the execution environment.
This is so that builds will be guaranteed
repeatable regardless of the environment
variables set at the time
scons
is invoked.
If you want to propagate a
shell environment variable
to the commands executed
to build target files,
you must do so explicitly.
A common example is
the system PATH
environment variable,
so that
scons
will find utilities the same way
as the invoking shell (or other process):
import os
env = Environment(ENV={'PATH': os.environ['PATH']})
Although it is usually not recommended, you can propagate the entire shell environment in one go:
import os env = Environment(ENV=os.environ.copy())
ESCAPE
A function that will be called to escape shell special characters in command lines. The function should take one argument: the command line string to escape; and should return the escaped command line.
F03
The Fortran 03 compiler.
You should normally set the $FORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $F03 if you need to use a specific compiler
or compiler version for Fortran 03 files.
F03COM
The command line used to compile a Fortran 03 source file to an object file.
You only need to set $F03COM if you need to use a specific
command line for Fortran 03 files.
You should normally set the $FORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
F03COMSTR
If set, the string displayed when a Fortran 03 source file
is compiled to an object file.
If not set, then $F03COM or $FORTRANCOM
(the command line) is displayed.
F03FILESUFFIXES
The list of file extensions for which the F03 dialect will be used. By
default, this is ['.f03']
F03FLAGS
General user-specified options that are passed to the Fortran 03 compiler.
Note that this variable does
not
contain
-I
(or similar) include search path options
that scons generates automatically from $F03PATH.
See
$_F03INCFLAGS
below,
for the variable that expands to those options.
You only need to set $F03FLAGS if you need to define specific
user options for Fortran 03 files.
You should normally set the $FORTRANFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
_F03INCFLAGS
An automatically-generated construction variable
containing the Fortran 03 compiler command-line options
for specifying directories to be searched for include files.
The value of $_F03INCFLAGS is created
by appending $INCPREFIX and $INCSUFFIX
to the beginning and end
of each directory in $F03PATH.
F03PATH
The list of directories that the Fortran 03 compiler will search for include
directories. The implicit dependency scanner will search these
directories for include files. Don't explicitly put include directory
arguments in $F03FLAGS because the result will be non-portable
and the directories will not be searched by the dependency scanner. Note:
directory names in $F03PATH will be looked-up relative to the SConscript
directory when they are used in a command. To force
scons
to look-up a directory relative to the root of the source tree use #:
You only need to set $F03PATH if you need to define a specific
include path for Fortran 03 files.
You should normally set the $FORTRANPATH variable,
which specifies the include path
for the default Fortran compiler
for all Fortran versions.
env = Environment(F03PATH='#/include')
The directory look-up can also be forced using the
Dir()
function:
include = Dir('include')
env = Environment(F03PATH=include)
The directory list will be added to command lines
through the automatically-generated
$_F03INCFLAGS
construction variable,
which is constructed by
appending the values of the
$INCPREFIX and $INCSUFFIX
construction variables
to the beginning and end
of each directory in $F03PATH.
Any command lines you define that need
the F03PATH directory list should
include $_F03INCFLAGS:
env = Environment(F03COM="my_compiler $_F03INCFLAGS -c -o $TARGET $SOURCE")
F03PPCOM
The command line used to compile a Fortran 03 source file to an object file
after first running the file through the C preprocessor.
Any options specified in the $F03FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $F03PPCOM if you need to use a specific
C-preprocessor command line for Fortran 03 files.
You should normally set the $FORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
F03PPCOMSTR
If set, the string displayed when a Fortran 03 source file
is compiled to an object file
after first running the file through the C preprocessor.
If not set, then $F03PPCOM or $FORTRANPPCOM
(the command line) is displayed.
F03PPFILESUFFIXES
The list of file extensions for which the compilation + preprocessor pass for F03 dialect will be used. By default, this is empty.
F08
The Fortran 08 compiler.
You should normally set the $FORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $F08 if you need to use a specific compiler
or compiler version for Fortran 08 files.
F08COM
The command line used to compile a Fortran 08 source file to an object file.
You only need to set $F08COM if you need to use a specific
command line for Fortran 08 files.
You should normally set the $FORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
F08COMSTR
If set, the string displayed when a Fortran 08 source file
is compiled to an object file.
If not set, then $F08COM or $FORTRANCOM
(the command line) is displayed.
F08FILESUFFIXES
The list of file extensions for which the F08 dialect will be used. By
default, this is ['.f08']
F08FLAGS
General user-specified options that are passed to the Fortran 08 compiler.
Note that this variable does
not
contain
-I
(or similar) include search path options
that scons generates automatically from $F08PATH.
See
$_F08INCFLAGS
below,
for the variable that expands to those options.
You only need to set $F08FLAGS if you need to define specific
user options for Fortran 08 files.
You should normally set the $FORTRANFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
_F08INCFLAGS
An automatically-generated construction variable
containing the Fortran 08 compiler command-line options
for specifying directories to be searched for include files.
The value of $_F08INCFLAGS is created
by appending $INCPREFIX and $INCSUFFIX
to the beginning and end
of each directory in $F08PATH.
F08PATH
The list of directories that the Fortran 08 compiler will search for include
directories. The implicit dependency scanner will search these
directories for include files. Don't explicitly put include directory
arguments in $F08FLAGS because the result will be non-portable
and the directories will not be searched by the dependency scanner. Note:
directory names in $F08PATH will be looked-up relative to the SConscript
directory when they are used in a command. To force
scons
to look-up a directory relative to the root of the source tree use #:
You only need to set $F08PATH if you need to define a specific
include path for Fortran 08 files.
You should normally set the $FORTRANPATH variable,
which specifies the include path
for the default Fortran compiler
for all Fortran versions.
env = Environment(F08PATH='#/include')
The directory look-up can also be forced using the
Dir()
function:
include = Dir('include')
env = Environment(F08PATH=include)
The directory list will be added to command lines
through the automatically-generated
$_F08INCFLAGS
construction variable,
which is constructed by
appending the values of the
$INCPREFIX and $INCSUFFIX
construction variables
to the beginning and end
of each directory in $F08PATH.
Any command lines you define that need
the F08PATH directory list should
include $_F08INCFLAGS:
env = Environment(F08COM="my_compiler $_F08INCFLAGS -c -o $TARGET $SOURCE")
F08PPCOM
The command line used to compile a Fortran 08 source file to an object file
after first running the file through the C preprocessor.
Any options specified in the $F08FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $F08PPCOM if you need to use a specific
C-preprocessor command line for Fortran 08 files.
You should normally set the $FORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
F08PPCOMSTR
If set, the string displayed when a Fortran 08 source file
is compiled to an object file
after first running the file through the C preprocessor.
If not set, then $F08PPCOM or $FORTRANPPCOM
(the command line) is displayed.
F08PPFILESUFFIXES
The list of file extensions for which the compilation + preprocessor pass for F08 dialect will be used. By default, this is empty.
F77
The Fortran 77 compiler.
You should normally set the $FORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $F77 if you need to use a specific compiler
or compiler version for Fortran 77 files.
F77COM
The command line used to compile a Fortran 77 source file to an object file.
You only need to set $F77COM if you need to use a specific
command line for Fortran 77 files.
You should normally set the $FORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
F77COMSTR
If set, the string displayed when a Fortran 77 source file
is compiled to an object file.
If not set, then $F77COM or $FORTRANCOM
(the command line) is displayed.
F77FILESUFFIXES
The list of file extensions for which the F77 dialect will be used. By
default, this is ['.f77']
F77FLAGS
General user-specified options that are passed to the Fortran 77 compiler.
Note that this variable does
not
contain
-I
(or similar) include search path options
that scons generates automatically from $F77PATH.
See
$_F77INCFLAGS
below,
for the variable that expands to those options.
You only need to set $F77FLAGS if you need to define specific
user options for Fortran 77 files.
You should normally set the $FORTRANFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
_F77INCFLAGS
An automatically-generated construction variable
containing the Fortran 77 compiler command-line options
for specifying directories to be searched for include files.
The value of $_F77INCFLAGS is created
by appending $INCPREFIX and $INCSUFFIX
to the beginning and end
of each directory in $F77PATH.
F77PATH
The list of directories that the Fortran 77 compiler will search for include
directories. The implicit dependency scanner will search these
directories for include files. Don't explicitly put include directory
arguments in $F77FLAGS because the result will be non-portable
and the directories will not be searched by the dependency scanner. Note:
directory names in $F77PATH will be looked-up relative to the SConscript
directory when they are used in a command. To force
scons
to look-up a directory relative to the root of the source tree use #:
You only need to set $F77PATH if you need to define a specific
include path for Fortran 77 files.
You should normally set the $FORTRANPATH variable,
which specifies the include path
for the default Fortran compiler
for all Fortran versions.
env = Environment(F77PATH='#/include')
The directory look-up can also be forced using the
Dir()
function:
include = Dir('include')
env = Environment(F77PATH=include)
The directory list will be added to command lines
through the automatically-generated
$_F77INCFLAGS
construction variable,
which is constructed by
appending the values of the
$INCPREFIX and $INCSUFFIX
construction variables
to the beginning and end
of each directory in $F77PATH.
Any command lines you define that need
the F77PATH directory list should
include $_F77INCFLAGS:
env = Environment(F77COM="my_compiler $_F77INCFLAGS -c -o $TARGET $SOURCE")
F77PPCOM
The command line used to compile a Fortran 77 source file to an object file
after first running the file through the C preprocessor.
Any options specified in the $F77FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $F77PPCOM if you need to use a specific
C-preprocessor command line for Fortran 77 files.
You should normally set the $FORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
F77PPCOMSTR
If set, the string displayed when a Fortran 77 source file
is compiled to an object file
after first running the file through the C preprocessor.
If not set, then $F77PPCOM or $FORTRANPPCOM
(the command line) is displayed.
F77PPFILESUFFIXES
The list of file extensions for which the compilation + preprocessor pass for F77 dialect will be used. By default, this is empty.
F90
The Fortran 90 compiler.
You should normally set the $FORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $F90 if you need to use a specific compiler
or compiler version for Fortran 90 files.
F90COM
The command line used to compile a Fortran 90 source file to an object file.
You only need to set $F90COM if you need to use a specific
command line for Fortran 90 files.
You should normally set the $FORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
F90COMSTR
If set, the string displayed when a Fortran 90 source file
is compiled to an object file.
If not set, then $F90COM or $FORTRANCOM
(the command line) is displayed.
F90FILESUFFIXES
The list of file extensions for which the F90 dialect will be used. By
default, this is ['.f90']
F90FLAGS
General user-specified options that are passed to the Fortran 90 compiler.
Note that this variable does
not
contain
-I
(or similar) include search path options
that scons generates automatically from $F90PATH.
See
$_F90INCFLAGS
below,
for the variable that expands to those options.
You only need to set $F90FLAGS if you need to define specific
user options for Fortran 90 files.
You should normally set the $FORTRANFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
_F90INCFLAGS
An automatically-generated construction variable
containing the Fortran 90 compiler command-line options
for specifying directories to be searched for include files.
The value of $_F90INCFLAGS is created
by appending $INCPREFIX and $INCSUFFIX
to the beginning and end
of each directory in $F90PATH.
F90PATH
The list of directories that the Fortran 90 compiler will search for include
directories. The implicit dependency scanner will search these
directories for include files. Don't explicitly put include directory
arguments in $F90FLAGS because the result will be non-portable
and the directories will not be searched by the dependency scanner. Note:
directory names in $F90PATH will be looked-up relative to the SConscript
directory when they are used in a command. To force
scons
to look-up a directory relative to the root of the source tree use #:
You only need to set $F90PATH if you need to define a specific
include path for Fortran 90 files.
You should normally set the $FORTRANPATH variable,
which specifies the include path
for the default Fortran compiler
for all Fortran versions.
env = Environment(F90PATH='#/include')
The directory look-up can also be forced using the
Dir()
function:
include = Dir('include')
env = Environment(F90PATH=include)
The directory list will be added to command lines
through the automatically-generated
$_F90INCFLAGS
construction variable,
which is constructed by
appending the values of the
$INCPREFIX and $INCSUFFIX
construction variables
to the beginning and end
of each directory in $F90PATH.
Any command lines you define that need
the F90PATH directory list should
include $_F90INCFLAGS:
env = Environment(F90COM="my_compiler $_F90INCFLAGS -c -o $TARGET $SOURCE")
F90PPCOM
The command line used to compile a Fortran 90 source file to an object file
after first running the file through the C preprocessor.
Any options specified in the $F90FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $F90PPCOM if you need to use a specific
C-preprocessor command line for Fortran 90 files.
You should normally set the $FORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
F90PPCOMSTR
If set, the string displayed when a Fortran 90 source file
is compiled after first running the file through the C preprocessor.
If not set, then $F90PPCOM or $FORTRANPPCOM
(the command line) is displayed.
F90PPFILESUFFIXES
The list of file extensions for which the compilation + preprocessor pass for F90 dialect will be used. By default, this is empty.
F95
The Fortran 95 compiler.
You should normally set the $FORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $F95 if you need to use a specific compiler
or compiler version for Fortran 95 files.
F95COM
The command line used to compile a Fortran 95 source file to an object file.
You only need to set $F95COM if you need to use a specific
command line for Fortran 95 files.
You should normally set the $FORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
F95COMSTR
If set, the string displayed when a Fortran 95 source file
is compiled to an object file.
If not set, then $F95COM or $FORTRANCOM
(the command line) is displayed.
F95FILESUFFIXES
The list of file extensions for which the F95 dialect will be used. By
default, this is ['.f95']
F95FLAGS
General user-specified options that are passed to the Fortran 95 compiler.
Note that this variable does
not
contain
-I
(or similar) include search path options
that scons generates automatically from $F95PATH.
See
$_F95INCFLAGS
below,
for the variable that expands to those options.
You only need to set $F95FLAGS if you need to define specific
user options for Fortran 95 files.
You should normally set the $FORTRANFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
_F95INCFLAGS
An automatically-generated construction variable
containing the Fortran 95 compiler command-line options
for specifying directories to be searched for include files.
The value of $_F95INCFLAGS is created
by appending $INCPREFIX and $INCSUFFIX
to the beginning and end
of each directory in $F95PATH.
F95PATH
The list of directories that the Fortran 95 compiler will search for include
directories. The implicit dependency scanner will search these
directories for include files. Don't explicitly put include directory
arguments in $F95FLAGS because the result will be non-portable
and the directories will not be searched by the dependency scanner. Note:
directory names in $F95PATH will be looked-up relative to the SConscript
directory when they are used in a command. To force
scons
to look-up a directory relative to the root of the source tree use #:
You only need to set $F95PATH if you need to define a specific
include path for Fortran 95 files.
You should normally set the $FORTRANPATH variable,
which specifies the include path
for the default Fortran compiler
for all Fortran versions.
env = Environment(F95PATH='#/include')
The directory look-up can also be forced using the
Dir()
function:
include = Dir('include')
env = Environment(F95PATH=include)
The directory list will be added to command lines
through the automatically-generated
$_F95INCFLAGS
construction variable,
which is constructed by
appending the values of the
$INCPREFIX and $INCSUFFIX
construction variables
to the beginning and end
of each directory in $F95PATH.
Any command lines you define that need
the F95PATH directory list should
include $_F95INCFLAGS:
env = Environment(F95COM="my_compiler $_F95INCFLAGS -c -o $TARGET $SOURCE")
F95PPCOM
The command line used to compile a Fortran 95 source file to an object file
after first running the file through the C preprocessor.
Any options specified in the $F95FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $F95PPCOM if you need to use a specific
C-preprocessor command line for Fortran 95 files.
You should normally set the $FORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
F95PPCOMSTR
If set, the string displayed when a Fortran 95 source file
is compiled to an object file
after first running the file through the C preprocessor.
If not set, then $F95PPCOM or $FORTRANPPCOM
(the command line) is displayed.
F95PPFILESUFFIXES
The list of file extensions for which the compilation + preprocessor pass for F95 dialect will be used. By default, this is empty.
File
A function that converts a string into a File instance relative to the target being built.
FILE_ENCODING
File encoding used for files written by Textfile and Substfile.
Set to "utf-8" by default.
New in version 4.5.0.
FORTRAN
The default Fortran compiler for all versions of Fortran.
FORTRANCOM
The command line used to compile a Fortran source file to an object file.
By default, any options specified
in the $FORTRANFLAGS,
$_FORTRANMODFLAG, and
$_FORTRANINCFLAGS
construction variables are included on this command line.
FORTRANCOMMONFLAGS
General user-specified options that are passed to the Fortran compiler.
Similar to $FORTRANFLAGS,
but this construction variable is applied to all dialects.
New in version 4.4.
FORTRANCOMSTR
If set, the string displayed when a Fortran source file
is compiled to an object file.
If not set, then $FORTRANCOM
(the command line) is displayed.
FORTRANFILESUFFIXES
The list of file extensions for which the FORTRAN dialect will be used. By
default, this is ['.f', '.for', '.ftn']
FORTRANFLAGS
General user-specified options for the FORTRAN dialect
that are passed to the Fortran compiler.
Note that this variable does
not
contain
-I
(or similar) include or module search path options
that scons generates automatically from $FORTRANPATH.
See
$_FORTRANINCFLAGS and $_FORTRANMODFLAG
for the construction variables that expand those options.
_FORTRANINCFLAGS
An automatically-generated construction variable
containing the Fortran compiler command-line options
for specifying directories to be searched for include
files and module files.
The value of $_FORTRANINCFLAGS is created
by respectively prepending and appending
$INCPREFIX and $INCSUFFIX
to the beginning and end
of each directory in $FORTRANPATH.
FORTRANMODDIR
Directory location where the Fortran compiler should place any module files it generates. This variable is empty, by default. Some Fortran compilers will internally append this directory in the search path for module files, as well.
FORTRANMODDIRPREFIX
The prefix used to specify a module directory on the Fortran compiler command
line.
This will be prepended to the beginning of the directory
in the $FORTRANMODDIR construction variables
when the $_FORTRANMODFLAG variables is automatically generated.
FORTRANMODDIRSUFFIX
The suffix used to specify a module directory on the Fortran compiler command
line.
This will be appended to the end of the directory
in the $FORTRANMODDIR construction variables
when the $_FORTRANMODFLAG variables is automatically generated.
_FORTRANMODFLAG
An automatically-generated construction variable
containing the Fortran compiler command-line option
for specifying the directory location where the Fortran
compiler should place any module files that happen to get
generated during compilation.
The value of $_FORTRANMODFLAG is created
by respectively prepending and appending
$FORTRANMODDIRPREFIX and $FORTRANMODDIRSUFFIX
to the beginning and end of the directory in $FORTRANMODDIR.
FORTRANMODPREFIX
The module file prefix used by the Fortran compiler. SCons assumes that
the Fortran compiler follows the quasi-standard naming convention for
module files of
module_name.mod.
As a result, this variable is left empty, by default. For situations in
which the compiler does not necessarily follow the normal convention,
the user may use this variable. Its value will be appended to every
module file name as scons attempts to resolve dependencies.
FORTRANMODSUFFIX
The module file suffix used by the Fortran compiler. SCons assumes that
the Fortran compiler follows the quasi-standard naming convention for
module files of
module_name.mod.
As a result, this variable is set to ".mod", by default. For situations
in which the compiler does not necessarily follow the normal convention,
the user may use this variable. Its value will be appended to every
module file name as scons attempts to resolve dependencies.
FORTRANPATH
The list of directories that the Fortran compiler will search for include files and (for some compilers) module files. The Fortran implicit dependency scanner will search these directories for include files (but not module files since they are autogenerated and, as such, may not actually exist at the time the scan takes place). Don't explicitly put include directory arguments in FORTRANFLAGS because the result will be non-portable and the directories will not be searched by the dependency scanner. Note: directory names in FORTRANPATH will be looked-up relative to the SConscript directory when they are used in a command. To force scons to look-up a directory relative to the root of the source tree use #:
env = Environment(FORTRANPATH='#/include')
The directory look-up can also be forced using the
Dir()
function:
include = Dir('include')
env = Environment(FORTRANPATH=include)
The directory list will be added to command lines
through the automatically-generated
$_FORTRANINCFLAGS
construction variable,
which is constructed by
respectively prepending and appending the values of the
$INCPREFIX and $INCSUFFIX
construction variables
to the beginning and end
of each directory in $FORTRANPATH.
Any command lines you define that need
the FORTRANPATH directory list should
include $_FORTRANINCFLAGS:
env = Environment(FORTRANCOM="my_compiler $_FORTRANINCFLAGS -c -o $TARGET $SOURCE")
FORTRANPPCOM
The command line used to compile a Fortran source file to an object file
after first running the file through the C preprocessor.
By default, any options specified in the $FORTRANFLAGS,
$CPPFLAGS,
$_CPPDEFFLAGS,
$_FORTRANMODFLAG, and
$_FORTRANINCFLAGS
construction variables are included on this command line.
FORTRANPPCOMSTR
If set, the string displayed when a Fortran source file
is compiled to an object file
after first running the file through the C preprocessor.
If not set, then $FORTRANPPCOM
(the command line) is displayed.
FORTRANPPFILESUFFIXES
The list of file extensions for which the compilation + preprocessor pass for
FORTRAN dialect will be used. By default, this is ['.fpp', '.FPP']
FORTRANSUFFIXES
The list of suffixes of files that will be scanned for Fortran implicit dependencies (INCLUDE lines and USE statements). The default list is:
[".f", ".F", ".for", ".FOR", ".ftn", ".FTN", ".fpp", ".FPP", ".f77", ".F77", ".f90", ".F90", ".f95", ".F95"]
FRAMEWORKPATH
On Mac OS X with gcc,
a list containing the paths to search for frameworks.
Used by the compiler to find framework-style includes like
#include <Fmwk/Header.h>.
Used by the linker to find user-specified frameworks when linking (see
$FRAMEWORKS).
For example:
env.AppendUnique(FRAMEWORKPATH='#myframeworkdir')
will add
... -Fmyframeworkdir
to the compiler and linker command lines.
_FRAMEWORKPATH
On Mac OS X with gcc, an automatically-generated construction variable
containing the linker command-line options corresponding to
$FRAMEWORKPATH.
FRAMEWORKPATHPREFIX
On Mac OS X with gcc, the prefix to be used for the FRAMEWORKPATH entries.
(see $FRAMEWORKPATH).
The default value is
-F.
FRAMEWORKPREFIX
On Mac OS X with gcc,
the prefix to be used for linking in frameworks
(see $FRAMEWORKS).
The default value is
-framework.
FRAMEWORKS
On Mac OS X with gcc, a list of the framework names to be linked into a program or shared library or bundle. The default value is the empty list. For example:
env.AppendUnique(FRAMEWORKS=Split('System Cocoa SystemConfiguration'))
_FRAMEWORKS
On Mac OS X with gcc, an automatically-generated construction variable containing the linker command-line options for linking with FRAMEWORKS.
FRAMEWORKSFLAGS
On Mac OS X with gcc,
general user-supplied frameworks options to be added at
the end of a command
line building a loadable module.
(This has been largely superseded by
the $FRAMEWORKPATH, $FRAMEWORKPATHPREFIX,
$FRAMEWORKPREFIX and $FRAMEWORKS variables
described above.)
GS
The Ghostscript program used to, for example, convert PostScript to PDF files.
GSCOM
The full Ghostscript command line used for the conversion process. Its default
value is “$GS $GSFLAGS -sOutputFile=$TARGET $SOURCES”.
GSCOMSTR
The string displayed when
Ghostscript is called for the conversion process.
If this is not set (the default), then $GSCOM (the command line) is displayed.
GSFLAGS
General options passed to the Ghostscript program,
when converting PostScript to PDF files for example. Its default value
is “-dNOPAUSE -dBATCH -sDEVICE=pdfwrite”
HOST_ARCH
The name of the host hardware architecture
used to create this construction environment.
The platform code sets this when initializing
(see $PLATFORM and the
platform argument to Environment).
Note the detected name of the architecture may not be identical to
that returned by the Python
platform.machine method.
On the win32 platform,
if the Microsoft Visual C++ compiler is available,
msvc tool setup is done using
$HOST_ARCH and $TARGET_ARCH.
Changing the values at any later time will not cause
the tool to be reinitialized.
Valid host arch values are
x86 and arm
for 32-bit hosts and
amd64, arm64,
and x86_64 for 64-bit hosts.
Should be considered immutable.
$HOST_ARCH is not currently used by other platforms,
but the option is reserved to do so in future
HOST_OS
The name of the host operating system for the platform
used to create this construction environment.
The platform code sets this when initializing
(see $PLATFORM and the
platform argument to Environment).
Should be considered immutable.
$HOST_OS is not currently used by SCons,
but the option is reserved to do so in future
IDLSUFFIXES
The list of suffixes of files that will be scanned for IDL implicit dependencies (#include or import lines). The default list is:
[".idl", ".IDL"]
IMPLIBNOVERSIONSYMLINKS
Used to override $SHLIBNOVERSIONSYMLINKS/$LDMODULENOVERSIONSYMLINKS when
creating versioned import library for a shared library/loadable module. If not defined,
then $SHLIBNOVERSIONSYMLINKS/$LDMODULENOVERSIONSYMLINKS is used to determine
whether to disable symlink generation or not.
IMPLIBPREFIX
The prefix used for import library names. For example, cygwin uses import
libraries (libfoo.dll.a) in pair with dynamic libraries
(cygfoo.dll). The cyglink linker sets
$IMPLIBPREFIX to 'lib' and $SHLIBPREFIX
to 'cyg'.
IMPLIBSUFFIX
The suffix used for import library names. For example, cygwin uses import
libraries (libfoo.dll.a) in pair with dynamic libraries
(cygfoo.dll). The cyglink linker sets
$IMPLIBSUFFIX to '.dll.a' and $SHLIBSUFFIX
to '.dll'.
IMPLIBVERSION
Used to override $SHLIBVERSION/$LDMODULEVERSION when
generating versioned import library for a shared library/loadable module. If
undefined, the $SHLIBVERSION/$LDMODULEVERSION is used to
determine the version of versioned import library.
IMPLICIT_COMMAND_DEPENDENCIES
Controls whether or not SCons will add implicit dependencies for the commands executed to build targets.
By default, SCons will add to each target
an implicit dependency on the command
represented by the first argument of any
command line it executes (which is typically
the command itself). By setting such
a dependency, SCons can determine that
a target should be rebuilt if the command changes,
such as when a compiler is upgraded to a new version.
The specific file for the dependency is
found by searching the
PATH
variable in the
ENV dictionary
in the construction environment used to execute the command.
The default is the same as
setting the construction variable
$IMPLICIT_COMMAND_DEPENDENCIES
to a True-like value (“true”,
“yes”,
or “1” - but not a number
greater than one, as that has a different meaning).
Action strings can be segmented by the
use of an AND operator, &&.
In a segemented string, each segment is a separate
“command line”, these are run
sequentially until one fails or the entire
sequence has been executed. If an
action string is segmented, then the selected
behavior of $IMPLICIT_COMMAND_DEPENDENCIES
is applied to each segment.
If $IMPLICIT_COMMAND_DEPENDENCIES
is set to a False-like value
(“none”,
“false”,
“no”,
“0”,
etc.),
then the implicit dependency will
not be added to the targets
built with that construction environment.
If $IMPLICIT_COMMAND_DEPENDENCIES
is set to “2” or higher,
then that number of arguments in the command line
will be scanned for relative or absolute paths.
If any are present, they will be added as
implicit dependencies to the targets built
with that construction environment.
The first argument in the command line will be
searched for using the PATH
variable in the ENV dictionary
in the construction environment used to execute the command.
The other arguments will only be found if they
are absolute paths or valid paths relative
to the working directory.
If $IMPLICIT_COMMAND_DEPENDENCIES
is set to “all”,
then all arguments in the command line will be
scanned for relative or absolute paths.
If any are present, they will be added as
implicit dependencies to the targets built
with that construction environment.
The first argument in the command line will be
searched for using the PATH
variable in the ENV dictionary
in the construction environment used to execute the command.
The other arguments will only be found if they
are absolute paths or valid paths relative
to the working directory.
env = Environment(IMPLICIT_COMMAND_DEPENDENCIES=False)
INCPREFIX
The prefix used to specify an include directory on the C compiler command
line.
This will be prepended to each directory
in the $CPPPATH and $FORTRANPATH construction variables
when the $_CPPINCFLAGS and $_FORTRANINCFLAGS
variables are automatically generated.
INCSUFFIX
The suffix used to specify an include directory on the C compiler command
line.
This will be appended to each directory
in the $CPPPATH and $FORTRANPATH construction variables
when the $_CPPINCFLAGS and $_FORTRANINCFLAGS
variables are automatically generated.
INSTALL
A function to be called to install a file into a destination file name. The default function copies the file into the destination (and sets the destination file's mode and permission bits to match the source file's). The function takes the following arguments:
def install(dest, source, env):
dest
is the path name of the destination file.
source
is the path name of the source file.
env
is the construction environment
(a dictionary of construction values)
in force for this file installation.
INSTALLSTR
The string displayed when a file is installed into a destination file name. The default is:
Install file: "$SOURCE" as "$TARGET"
INTEL_C_COMPILER_VERSION
Set by the intelc Tool
to the major version number of the Intel C compiler
selected for use.
JAR
The Java archive tool.
JARCHDIR
The directory to which the Java archive tool should change
(using the
-C
option).
JARCOM
The command line used to call the Java archive tool.
JARCOMSTR
The string displayed when the Java archive tool
is called
If this is not set, then $JARCOM (the command line) is displayed.
env = Environment(JARCOMSTR="JARchiving $SOURCES into $TARGET")
JARFLAGS
General options passed to the Java archive tool.
By default this is set to
cf
to create the necessary
jar
file.
JARSUFFIX
The suffix for Java archives:
.jar
by default.
JAVABOOTCLASSPATH
Specifies the location of the bootstrap class files. Can be specified as a string or Node object, or as a list of strings or Node objects.
The value will be added to the JDK command lines
via the -bootclasspath option,
which requires a system-specific search path separator.
This will be supplied by SCons as needed when it
constructs the command line if $JAVABOOTCLASSPATH is
provided in list form.
If $JAVABOOTCLASSPATH is a single string containing
search path separator characters
(: for POSIX systems or
; for Windows), it will not be modified;
and so is inherently system-specific;
to supply the path in a system-independent manner,
give $JAVABOOTCLASSPATH as a list of paths instead.
Can only be used when compiling for releases prior to JDK 9.
JAVAC
The Java compiler.
JAVACCOM
The command line used to compile a directory tree containing
Java source files to
corresponding Java class files.
Any options specified in the $JAVACFLAGS construction variable
are included on this command line.
JAVACCOMSTR
The string displayed when compiling
a directory tree of Java source files to
corresponding Java class files.
If this is not set, then $JAVACCOM (the command line) is displayed.
env = Environment(JAVACCOMSTR="Compiling class files $TARGETS from $SOURCES")
JAVACFLAGS
General options that are passed to the Java compiler.
JAVACLASSDIR
The directory in which Java class files may be found.
This is stripped from the beginning of any Java
.class
file names supplied to the JavaH builder.
JAVACLASSPATH
Specifies the class search path for the JDK tools.
Can be specified as a string or Node object,
or as a list of strings or Node objects.
Class path entries may be directory names to search
for class files or packages, pathnames to archives
(.jar or .zip)
containing classes, or paths ending in a "base name wildcard"
character (*), which matches files
in that directory with a .jar suffix.
See the Java documentation for more details.
The value will be added to the JDK command lines
via the -classpath option,
which requires a system-specific search path separator.
This will be supplied by SCons as needed when it
constructs the command line if $JAVACLASSPATH is
provided in list form.
If $JAVACLASSPATH is a single string containing
search path separator characters
(: for POSIX systems or
; for Windows),
it will be split on the separator into a list of individual
paths for dependency scanning purposes.
It will not be modified for JDK command-line usage,
so such a string is inherently system-specific;
to supply the path in a system-independent manner,
give $JAVACLASSPATH as a list of paths instead.
SCons always
supplies a -sourcepath
when invoking the Java compiler javac,
regardless of the setting of $JAVASOURCEPATH,
as it passes the path(s) to the source(s) supplied
in the call to the Java builder via
-sourcepath .
From the documentation of the standard Java toolkit for javac:
“If not compiling code for modules, if the
--source-path or -sourcepath
option is not specified, then the user class path is also
searched for source files.”
Since -sourcepath is always supplied,
javac will not use the contents of the value of
$JAVACLASSPATH when searching for sources.
JAVACLASSSUFFIX
The suffix for Java class files;
.class
by default.
JAVAH
The Java generator for C header and stub files.
JAVAHCOM
The command line used to generate C header and stub files
from Java classes.
Any options specified in the $JAVAHFLAGS construction variable
are included on this command line.
JAVAHCOMSTR
The string displayed when C header and stub files
are generated from Java classes.
If this is not set, then $JAVAHCOM (the command line) is displayed.
env = Environment(JAVAHCOMSTR="Generating header/stub file(s) $TARGETS from $SOURCES")
JAVAHFLAGS
General options passed to the C header and stub file generator for Java classes.
JAVAINCLUDES
Include path for Java header files
(such as jni.h).
JAVAPROCESSORPATH
Specifies the location of the annotation processor class files. Can be specified as a string or Node object, or as a list of strings or Node objects.
The value will be added to the JDK command lines
via the -processorpath option,
which requires a system-specific search path separator.
This will be supplied by SCons as needed when it
constructs the command line if $JAVAPROCESSORPATH is
provided in list form.
If $JAVAPROCESSORPATH is a single string containing
search path separator characters
(: for POSIX systems or
; for Windows), it will not be modified;
and so is inherently system-specific;
to supply the path in a system-independent manner,
give $JAVAPROCESSORPATH as a list of paths instead.
New in version 4.5.0
JAVASOURCEPATH
Specifies the list of directories that
will be searched for input (source)
.java files.
Can be specified as a string or Node object,
or as a list of strings or Node objects.
The value will be added to the JDK command lines
via the -sourcepath option,
which requires a system-specific search path separator,
This will be supplied by SCons as needed when it
constructs the command line if $JAVASOURCEPATH is
provided in list form.
If $JAVASOURCEPATH is a single string containing
search path separator characters
(: for POSIX systems or
; for Windows), it will not be modified,
and so is inherently system-specific;
to supply the path in a system-independent manner,
give $JAVASOURCEPATH as a list of paths instead.
Note that the specified directories are only added to
the command line via the -sourcepath option.
SCons does not currently search the
$JAVASOURCEPATH directories for dependent
.java
files.
JAVASUFFIX
The suffix for Java files;
.java
by default.
JAVAVERSION
Specifies the Java version being used by the Java
builder. Set this to specify the version of Java targeted
by the javac compiler.
This is sometimes necessary because
Java 1.5 changed the file names that are created
for nested anonymous inner classes,
which can cause a mismatch with the files
that SCons expects will be generated by the javac compiler.
Setting $JAVAVERSION to a version greater than
1.4 makes SCons realize that a build
with such a compiler is actually up to date.
The default is 1.4.
While this is not primarily intended for
selecting one version of the Java compiler vs. another,
it does have that effect on the Windows platform. A
more precise approach is to set $JAVAC (and related
construction variables for related utilities) to the path to the specific
Java compiler you want, if that is not the default compiler.
On non-Windows platforms, the
alternatives system may provide a
way to adjust the default Java compiler without
having to specify explicit paths.
LATEX
The LaTeX structured formatter and typesetter.
LATEXCOM
The command line used to call the LaTeX structured formatter and typesetter.
LATEXCOMSTR
The string displayed when calling
the LaTeX structured formatter and typesetter.
If this is not set, then $LATEXCOM (the command line) is displayed.
env = Environment(LATEXCOMSTR = "Building $TARGET from LaTeX input $SOURCES")
LATEXFLAGS
General options passed to the LaTeX structured formatter and typesetter.
LATEXRETRIES
The maximum number of times that LaTeX
will be re-run if the
.log
generated by the $LATEXCOM command
indicates that there are undefined references.
The default is to try to resolve undefined references
by re-running LaTeX up to three times.
LATEXSUFFIXES
The list of suffixes of files that will be scanned
for LaTeX implicit dependencies
(\include or \import files).
The default list is:
[".tex", ".ltx", ".latex"]
LDMODULE
The linker for building loadable modules.
By default, this is the same as $SHLINK.
LDMODULECOM
The command line for building loadable modules.
On Mac OS X, this uses the $LDMODULE,
$LDMODULEFLAGS and
$FRAMEWORKSFLAGS variables.
On other systems, this is the same as $SHLINK.
LDMODULECOMSTR
If set, the string displayed when building loadable modules.
If not set, then $LDMODULECOM (the command line) is displayed.
LDMODULEEMITTER
Contains the emitter specification for the
LoadableModule builder.
The manpage section "Builder Objects" contains
general information on specifying emitters.
LDMODULEFLAGS
General user options passed to the linker for building loadable modules.
LDMODULENOVERSIONSYMLINKS
Instructs the LoadableModule builder to not automatically create symlinks
for versioned modules. Defaults to $SHLIBNOVERSIONSYMLINKS
LDMODULEPREFIX
The prefix used for loadable module file names.
On Mac OS X, this is null;
on other systems, this is
the same as $SHLIBPREFIX.
_LDMODULESONAME
A macro that automatically generates loadable module's SONAME based on $TARGET,
$LDMODULEVERSION and $LDMODULESUFFIX. Used by LoadableModule builder
when the linker tool supports SONAME (e.g. gnulink).
LDMODULESUFFIX
The suffix used for loadable module file names. On Mac OS X, this is null; on other systems, this is the same as $SHLIBSUFFIX.
LDMODULEVERSION
When this construction variable is defined, a versioned loadable module
is created by LoadableModule builder. This activates the
$_LDMODULEVERSIONFLAGS and thus modifies the $LDMODULECOM as
required, adds the version number to the library name, and creates the symlinks
that are needed. $LDMODULEVERSION versions should exist in the same
format as $SHLIBVERSION.
_LDMODULEVERSIONFLAGS
This macro automatically introduces extra flags to $LDMODULECOM when
building versioned LoadableModule (that is when
$LDMODULEVERSION is set). _LDMODULEVERSIONFLAGS
usually adds $SHLIBVERSIONFLAGS and some extra dynamically generated
options (such as -Wl,-soname=$_LDMODULESONAME). It is unused
by plain (unversioned) loadable modules.
LDMODULEVERSIONFLAGS
Extra flags added to $LDMODULECOM when building versioned
LoadableModule. These flags are only used when $LDMODULEVERSION is
set.
LEX
The lexical analyzer generator.
LEX_HEADER_FILE
If supplied, generate a C header file with the name taken from this variable.
Will be emitted as a --header-file=
command-line option. Use this in preference to including
--header-file= in $LEXFLAGS directly.
LEX_TABLES_FILE
If supplied, write the lex tables to a file with the name
taken from this variable.
Will be emitted as a --tables-file=
command-line option. Use this in preference to including
--tables-file= in $LEXFLAGS directly.
LEXCOM
The command line used to call the lexical analyzer generator to generate a source file.
LEXCOMSTR
The string displayed when generating a source file
using the lexical analyzer generator.
If this is not set, then $LEXCOM (the command line) is displayed.
env = Environment(LEXCOMSTR="Lex'ing $TARGET from $SOURCES")
LEXFLAGS
General options passed to the lexical analyzer generator.
In addition to passing the value on during invocation,
the lex tool also examines this construction variable for options
which cause additional output files to be generated,
and adds those to the target list.
Recognized for this purpose are GNU flex options
--header-file= and
--tables-file=;
the output file is named by the option argument.
Note that files specified by --header-file= and
--tables-file= may not be properly handled
by SCons in all situations. Consider using
$LEX_HEADER_FILE and $LEX_TABLES_FILE instead.
LEXUNISTD
Used only on windows environments to set a lex flag to prevent 'unistd.h' from being included. The default value is '--nounistd'.
_LIBDIRFLAGS
An automatically-generated construction variable
containing the linker command-line options
for specifying directories to be searched for library.
The value of $_LIBDIRFLAGS is created
by respectively prepending and appending $LIBDIRPREFIX
and $LIBDIRSUFFIX
to each directory in $LIBPATH.
LIBDIRPREFIX
The prefix used to specify a library directory on the linker command line.
This will be prepended to each directory
in the $LIBPATH construction variable
when the $_LIBDIRFLAGS variable is automatically generated.
LIBDIRSUFFIX
The suffix used to specify a library directory on the linker command line.
This will be appended to each directory
in the $LIBPATH construction variable
when the $_LIBDIRFLAGS variable is automatically generated.
LIBEMITTER
Contains the emitter specification for the
StaticLibrary builder.
The manpage section "Builder Objects" contains
general information on specifying emitters.
_LIBFLAGS
An automatically-generated construction variable
containing the linker command-line options
for specifying libraries to be linked with the resulting target.
The value of $_LIBFLAGS is created
by respectively prepending and appending $LIBLINKPREFIX
and $LIBLINKSUFFIX
to each filename in $LIBS.
LIBLINKPREFIX
The prefix used to specify a library to link on the linker command line.
This will be prepended to each library
in the $LIBS construction variable
when the $_LIBFLAGS variable is automatically generated.
LIBLINKSUFFIX
The suffix used to specify a library to link on the linker command line.
This will be appended to each library
in the $LIBS construction variable
when the $_LIBFLAGS variable is automatically generated.
LIBLITERALPREFIX
If the linker supports command line syntax directing
that the argument specifying a library should be
searched for literally (without modification),
$LIBLITERALPREFIX can be set to that indicator.
For example, the GNU linker follows this rule:
“
-l:foo searches the library path
for a filename called foo,
without converting it to
libfoo.so or
libfoo.a.
”
If $LIBLITERALPREFIX is set,
SCons will not transform a string-valued entry in
$LIBS that starts with that string.
The entry will still be surrounded with
$LIBLINKPREFIX and $LIBLINKSUFFIX
on the command line.
This is useful, for example,
in directing that a static library
be used when both a static and dynamic library are available
and linker policy is to prefer dynamic libraries.
Compared to the example in $LIBS,
env.Append(LIBS=":libmylib.a")
will let the linker select that specific (static)
library name if found in the library search path.
This differs from using a
File object
to specify the static library,
as the latter bypasses the library search path entirely.
LIBPATH
The list of directories that will be searched for libraries
specified by the $LIBS construction variable.
$LIBPATH should be a list of path strings,
or a single string, not a pathname list joined by
Python's os.pathsep.
Do not put library search directives directly
into $LINKFLAGS or $SHLINKFLAGS
as the result will be non-portable.
Note:
directory names in $LIBPATH will be looked-up relative to the
directory of the SConscript file
when they are used in a command.
To force scons
to look-up a directory relative to the root of the source tree use
the # prefix:
env = Environment(LIBPATH='#/libs')
The directory look-up can also be forced using the
Dir function:
libs = Dir('libs')
env = Environment(LIBPATH=libs)
The directory list will be added to command lines
through the automatically-generated
$_LIBDIRFLAGS
construction variable,
which is constructed by
respectively prepending and appending the values of the
$LIBDIRPREFIX and $LIBDIRSUFFIX
construction variables
to each directory in $LIBPATH.
Any command lines you define that need
the $LIBPATH directory list should
include $_LIBDIRFLAGS:
env = Environment(LINKCOM="my_linker $_LIBDIRFLAGS $_LIBFLAGS -o $TARGET $SOURCE")
LIBPREFIX
The prefix used for (static) library file names. A default value is set for each platform (posix, win32, os2, etc.), but the value is overridden by individual tools (ar, mslib, sgiar, sunar, tlib, etc.) to reflect the names of the libraries they create.
LIBPREFIXES
A list of all legal prefixes for library file names
on the current platform.
When searching for library dependencies,
SCons will look for files with these prefixes,
the base library name,
and suffixes from the $LIBSUFFIXES list.
LIBS
The list of libraries that will be added to the link line for linking with any executable program, shared library, or loadable module created by the construction environment or override.
For portability,
a string-valued library name should include
only the base library name,
without prefixes such as lib
or suffixes such as .so or .dll.
SCons will attempt to
strip prefixes from the $LIBPREFIXES list
and suffixes from the $LIBSUFFIXES list,
but depending on that behavior will make the build
less portable:
for example, on a POSIX system,
no attempt will be made to strip a suffix like
.dll.
Library name strings in $LIBS should not include a path component:
instead use $LIBPATH to direct the compiler
to look for libraries in those paths,
plus any default paths the linker searches in.
If $LIBLITERALPREFIX is set to a non-empty string,
then a string-valued $LIBS entry
that starts with $LIBLITERALPREFIX
will cause the rest of the entry
to be searched for for unmodified,
but respecting normal library search paths
(this is an exception to the guideline above
about leaving off the prefix/suffix from the library name).
If a $LIBS entry is a Node object
(either as returned by a previous Builder call,
or as the result of an explicit call to File),
the pathname from that Node will be added to
$_LIBFLAGS,
and thus to the link line,
unmodified - without adding
$LIBLINKPREFIX
or
$LIBLINKSUFFIX.
Such entries are searched for literally
(including any path component);
the library search paths are not used.
For example:
env.Append(LIBS=File('/tmp/mylib.so'))
For each Builder call that causes linking with libraries,
SCons will add the libraries in the setting of $LIBS
in effect at that moment to the dependecy graph
as dependencies of the target being generated.
The library list will transformed to command line
arguments through the automatically-generated
$_LIBFLAGS construction variable
which is constructed by
respectively prepending and appending the values of the
$LIBLINKPREFIX and $LIBLINKSUFFIX construction variables
to each library name.
Any command lines you define yourself that need
the libraries from $LIBS should include $_LIBFLAGS
(as well as $_LIBDIRFLAGS)
rather than $LIBS.
For example:
env = Environment(LINKCOM="my_linker $_LIBDIRFLAGS $_LIBFLAGS -o $TARGET $SOURCE")
LIBSUFFIX
The suffix used for (static) library file names. A default value is set for each platform (posix, win32, os2, etc.), but the value is overridden by individual tools (ar, mslib, sgiar, sunar, tlib, etc.) to reflect the names of the libraries they create.
LIBSUFFIXES
A list of all legal suffixes for library file names.
on the current platform.
When searching for library dependencies,
SCons will look for files with prefixes from the $LIBPREFIXES list,
the base library name,
and these suffixes.
LICENSE
The abbreviated name, preferably the SPDX code, of the license under which this project is released (GPL-3.0, LGPL-2.1, BSD-2-Clause etc.). See http://www.opensource.org/licenses/alphabetical for a list of license names and SPDX codes.
See the Package builder.
LINESEPARATOR
The separator used by the Substfile and Textfile builders.
This value is used between sources when constructing the target.
It defaults to the current system line separator.
LINGUAS_FILE
The $LINGUAS_FILE defines file(s) containing list of additional linguas
to be processed by POInit, POUpdate or MOFiles
builders. It also affects Translate builder. If the variable contains
a string, it defines name of the list file. The $LINGUAS_FILE may be a
list of file names as well. If $LINGUAS_FILE is set to
True (or non-zero numeric value), the list will be read from
default file named
LINGUAS.
LINK
The linker.
See also $SHLINK for linking shared objects.
On POSIX systems (those using the link tool),
you should normally not change this value as it defaults
to a "smart" linker tool which selects a compiler
driver matching the type of source files in use.
So for example, if you set $CXX to a specific
compiler name, and are compiling C++ sources,
the smartlink function will automatically select the same compiler
for linking.
LINKCOM
The command line used to link object files into an executable.
See also $SHLINKCOM for linking shared objects.
LINKCOMSTR
If set, the string displayed when object files
are linked into an executable.
If not set, then $LINKCOM (the command line) is displayed.
See also $SHLINKCOMSTR. for linking shared objects.
env = Environment(LINKCOMSTR = "Linking $TARGET")
LINKFLAGS
General user options passed to the linker.
Note that this variable should
not
contain
-l
(or similar) options for linking with the libraries listed in $LIBS,
nor
-L
(or similar) library search path options
that scons generates automatically from $LIBPATH.
See
$_LIBFLAGS
above,
for the variable that expands to library-link options,
and
$_LIBDIRFLAGS
above,
for the variable that expands to library search path options.
See also $SHLINKFLAGS. for linking shared objects.
M4
The M4 macro preprocessor.
M4COM
The command line used to pass files through the M4 macro preprocessor.
M4COMSTR
The string displayed when
a file is passed through the M4 macro preprocessor.
If this is not set, then $M4COM (the command line) is displayed.
M4FLAGS
General options passed to the M4 macro preprocessor.
MAKEINDEX
The makeindex generator for the TeX formatter and typesetter and the LaTeX structured formatter and typesetter.
MAKEINDEXCOM
The command line used to call the makeindex generator for the TeX formatter and typesetter and the LaTeX structured formatter and typesetter.
MAKEINDEXCOMSTR
The string displayed when calling the makeindex generator for the
TeX formatter and typesetter
and the LaTeX structured formatter and typesetter.
If this is not set, then $MAKEINDEXCOM (the command line) is displayed.
MAKEINDEXFLAGS
General options passed to the makeindex generator for the TeX formatter and typesetter and the LaTeX structured formatter and typesetter.
MAXLINELENGTH
The maximum number of characters allowed on an external command line. On Win32 systems, link lines longer than this many characters are linked via a temporary file name.
MIDL
The Microsoft IDL compiler.
MIDLCOM
The command line used to pass files to the Microsoft IDL compiler.
MIDLCOMSTR
The string displayed when
the Microsoft IDL compiler is called.
If this is not set, then $MIDLCOM (the command line) is displayed.
MIDLFLAGS
General options passed to the Microsoft IDL compiler.
MOSUFFIX
Suffix used for MO files (default: '.mo').
See msgfmt tool and MOFiles builder.
MSGFMT
Absolute path to msgfmt(1) binary, found by
Detect().
See msgfmt tool and MOFiles builder.
MSGFMTCOM
Complete command line to run msgfmt(1) program.
See msgfmt tool and MOFiles builder.
MSGFMTCOMSTR
String to display when msgfmt(1) is invoked
(default: '', which means ``print $MSGFMTCOM'').
See msgfmt tool and MOFiles builder.
MSGFMTFLAGS
Additional flags to msgfmt(1).
See msgfmt tool and MOFiles builder.
MSGINIT
Path to msginit(1) program (found via
Detect()).
See msginit tool and POInit builder.
MSGINITCOM
Complete command line to run msginit(1) program.
See msginit tool and POInit builder.
MSGINITCOMSTR
String to display when msginit(1) is invoked
(default: '', which means ``print $MSGINITCOM'').
See msginit tool and POInit builder.
MSGINITFLAGS
List of additional flags to msginit(1) (default:
[]).
See msginit tool and POInit builder.
_MSGINITLOCALE
Internal ``macro''. Computes locale (language) name based on target filename
(default: '${TARGET.filebase}' ).
MSGMERGE
Absolute path to msgmerge(1) binary as found by
Detect().
See msgmerge tool and POUpdate builder.
MSGMERGECOM
Complete command line to run msgmerge(1) command.
See msgmerge tool and POUpdate builder.
MSGMERGECOMSTR
String to be displayed when msgmerge(1) is invoked
(default: '', which means ``print $MSGMERGECOM'').
See msgmerge tool and POUpdate builder.
MSGMERGEFLAGS
Additional flags to msgmerge(1) command.
See msgmerge tool and POUpdate builder.
MSSDK_DIR
The directory containing the Microsoft SDK (either Platform SDK or Windows SDK) to be used for compilation.
MSSDK_VERSION
The version string of the Microsoft SDK
(either Platform SDK or Windows SDK)
to be used for compilation.
Supported versions include
6.1,
6.0A,
6.0,
2003R2
and
2003R1.
MSVC_BATCH
When set to any true value,
specifies that SCons should batch
compilation of object files
when calling the Microsoft Visual C++ compiler.
All compilations of source files from the same source directory
that generate target files in a same output directory
and were configured in SCons using the same construction environment
will be built in a single call to the compiler.
Only source files that have changed since their
object files were built will be passed to each compiler invocation
(via the $CHANGED_SOURCES construction variable).
Any compilations where the object (target) file base name
(minus the .obj)
does not match the source file base name
will be compiled separately.
MSVC_NOTFOUND_POLICY
Specify the scons behavior when the Microsoft Visual C++ compiler is not detected.
The $MSVC_NOTFOUND_POLICY specifies the scons behavior when no msvc versions are detected or
when the requested msvc version is not detected.
The valid values for $MSVC_NOTFOUND_POLICY and the corresponding scons behavior are:
'Error' or 'Exception'
Raise an exception when no msvc versions are detected or when the requested msvc version is not detected.
'Warning' or 'Warn'
Issue a warning and continue when no msvc versions are detected or when the requested msvc version is not detected. Depending on usage, this could result in build failure(s).
'Ignore' or 'Suppress'
Take no action and continue when no msvc versions are detected or when the requested msvc version is not detected. Depending on usage, this could result in build failure(s).
Note: in addition to the camel case values shown above, lower case and upper case values are accepted as well.
The $MSVC_NOTFOUND_POLICY is applied when any of the following conditions are satisfied:
$MSVC_VERSION is specified, the default tools list is implicitly defined (i.e., the tools list is not specified),
and the default tools list contains one or more of the msvc tools.
$MSVC_VERSION is specified, the default tools list is explicitly specified (e.g., tools=['default']),
and the default tools list contains one or more of the msvc tools.
A non-default tools list is specified that contains one or more of the msvc tools (e.g., tools=['msvc', 'mslink']).
The $MSVC_NOTFOUND_POLICY is ignored when any of the following conditions are satisfied:
$MSVC_VERSION is not specified and the default tools list is implicitly defined (i.e., the tools list is not specified).
$MSVC_VERSION is not specified and the default tools list is explicitly specified (e.g., tools=['default']).
A non-default tool list is specified that does not contain any of the msvc tools (e.g., tools=['mingw']).
Important usage details:
$MSVC_NOTFOUND_POLICY must be passed as an argument to the Environment
constructor when an msvc tool (e.g., msvc, msvs, etc.) is
loaded via the default tools list or via a tools list passed to the
Environment constructor.
Otherwise, $MSVC_NOTFOUND_POLICY must be set before the first msvc tool is
loaded into the environment.
When $MSVC_NOTFOUND_POLICY is not specified, the default scons behavior is to issue a warning and continue
subject to the conditions listed above. The default scons behavior may change in the future.
New in version 4.4
MSVC_SCRIPT_ARGS
Pass user-defined arguments to the Microsoft Visual C++ batch file determined via autodetection.
$MSVC_SCRIPT_ARGS is available for msvc batch file arguments that do not have first-class support
via construction variables or when there is an issue with the appropriate construction variable validation.
When available, it is recommended to use the appropriate construction variables (e.g., $MSVC_TOOLSET_VERSION)
rather than $MSVC_SCRIPT_ARGS arguments.
The valid values for $MSVC_SCRIPT_ARGS are: None, a string,
or a list of strings.
The $MSVC_SCRIPT_ARGS value is converted to a scalar string (i.e., "flattened").
The resulting scalar string, if not empty, is passed as an argument to the msvc batch file determined
via autodetection subject to the validation conditions listed below.
$MSVC_SCRIPT_ARGS is ignored when the value is None and when the
result from argument conversion is an empty string. The validation conditions below do not apply.
An exception is raised when any of the following conditions are satisfied:
$MSVC_SCRIPT_ARGS is specified for Visual Studio 2013 and earlier.
Multiple SDK version arguments (e.g., '10.0.20348.0') are specified
in $MSVC_SCRIPT_ARGS.
$MSVC_SDK_VERSION is specified and an SDK version argument
(e.g., '10.0.20348.0') is specified in $MSVC_SCRIPT_ARGS.
Multiple SDK version declarations via $MSVC_SDK_VERSION and $MSVC_SCRIPT_ARGS
are not allowed.
Multiple toolset version arguments (e.g., '-vcvars_ver=14.29')
are specified in $MSVC_SCRIPT_ARGS.
$MSVC_TOOLSET_VERSION is specified and a toolset version argument
(e.g., '-vcvars_ver=14.29') is specified in $MSVC_SCRIPT_ARGS.
Multiple toolset version declarations via $MSVC_TOOLSET_VERSION and
$MSVC_SCRIPT_ARGS are not allowed.
Multiple spectre library arguments (e.g., '-vcvars_spectre_libs=spectre')
are specified in $MSVC_SCRIPT_ARGS.
$MSVC_SPECTRE_LIBS is enabled and a spectre library argument
(e.g., '-vcvars_spectre_libs=spectre') is specified in
$MSVC_SCRIPT_ARGS. Multiple spectre library declarations via $MSVC_SPECTRE_LIBS
and $MSVC_SCRIPT_ARGS are not allowed.
Multiple UWP arguments (e.g., uwp or store) are specified
in $MSVC_SCRIPT_ARGS.
$MSVC_UWP_APP is enabled and a UWP argument (e.g., uwp or
store) is specified in $MSVC_SCRIPT_ARGS. Multiple UWP declarations
via $MSVC_UWP_APP and $MSVC_SCRIPT_ARGS are not allowed.
Example 1 - A Visual Studio 2022 build with an SDK version and a toolset version specified with a string argument:
env = Environment(MSVC_VERSION='14.3', MSVC_SCRIPT_ARGS='10.0.20348.0 -vcvars_ver=14.29.30133')
Example 2 - A Visual Studio 2022 build with an SDK version and a toolset version specified with a list argument:
env = Environment(MSVC_VERSION='14.3', MSVC_SCRIPT_ARGS=['10.0.20348.0', '-vcvars_ver=14.29.30133'])
Important usage details:
$MSVC_SCRIPT_ARGS must be passed as an argument to the Environment
constructor when an msvc tool (e.g., msvc, msvs, etc.) is
loaded via the default tools list or via a tools list passed to the
Environment constructor.
Otherwise, $MSVC_SCRIPT_ARGS must be set before the first msvc tool is
loaded into the environment.
Other than checking for multiple declarations as described above, $MSVC_SCRIPT_ARGS arguments
are not validated.
Erroneous, inconsistent, and/or version incompatible $MSVC_SCRIPT_ARGS arguments are likely
to result in build failures for reasons that are not readily apparent and may be difficult to diagnose.
The burden is on the user to ensure that the arguments provided to the msvc batch file are valid, consistent
and compatible with the version of msvc selected.
New in version 4.4
MSVC_SCRIPTERROR_POLICY
Specify the scons behavior when Microsoft Visual C++ batch file errors are detected.
The $MSVC_SCRIPTERROR_POLICY specifies the scons behavior when msvc batch file errors are
detected.
When $MSVC_SCRIPTERROR_POLICY is not specified, the default scons behavior is to suppress
msvc batch file error messages.
The root cause of msvc build failures may be difficult to diagnose. In these situations, setting the scons behavior to issue a warning when msvc batch file errors are detected may produce additional diagnostic information.
The valid values for $MSVC_SCRIPTERROR_POLICY and the corresponding scons behavior are:
'Error' or 'Exception'
Raise an exception when msvc batch file errors are detected.
'Warning' or 'Warn'
Issue a warning when msvc batch file errors are detected.
'Ignore' or 'Suppress'
Suppress msvc batch file error messages.
New in version 4.4
Note: in addition to the camel case values shown above, lower case and upper case values are accepted as well.
Example 1 - A Visual Studio 2022 build with user-defined script arguments:
env = environment(MSVC_VERSION='14.3', MSVC_SCRIPT_ARGS=['8.1', 'store', '-vcvars_ver=14.1'])
env.Program('hello', ['hello.c'], CCFLAGS='/MD', LIBS=['kernel32', 'user32', 'runtimeobject'])
Example 1 - Output fragment:
... link /nologo /OUT:_build001\hello.exe kernel32.lib user32.lib runtimeobject.lib _build001\hello.obj LINK : fatal error LNK1104: cannot open file 'MSVCRT.lib' ...
Example 2 - A Visual Studio 2022 build with user-defined script arguments and the script error policy set to issue a warning when msvc batch file errors are detected:
env = environment(MSVC_VERSION='14.3', MSVC_SCRIPT_ARGS=['8.1', 'store', '-vcvars_ver=14.1'], MSVC_SCRIPTERROR_POLICY='warn')
env.Program('hello', ['hello.c'], CCFLAGS='/MD', LIBS=['kernel32', 'user32', 'runtimeobject'])
Example 2 - Output fragment:
...
scons: warning: vc script errors detected:
[ERROR:vcvars.bat] The UWP Application Platform requires a Windows 10 SDK.
[ERROR:vcvars.bat] WindowsSdkDir = "C:\Program Files (x86)\Windows Kits\8.1\"
[ERROR:vcvars.bat] host/target architecture is not supported : { x64 , x64 }
...
link /nologo /OUT:_build001\hello.exe kernel32.lib user32.lib runtimeobject.lib _build001\hello.obj
LINK : fatal error LNK1104: cannot open file 'MSVCRT.lib'
Important usage details:
$MSVC_SCRIPTERROR_POLICY must be passed as an argument to the Environment
constructor when an msvc tool (e.g., msvc, msvs, etc.) is
loaded via the default tools list or via a tools list passed to the
Environment constructor.
Otherwise, $MSVC_SCRIPTERROR_POLICY must be set before the first msvc tool is
loaded into the environment.
Due to scons implementation details, not all Windows system environment variables are propagated
to the environment in which the msvc batch file is executed. Depending on Visual Studio version
and installation options, non-fatal msvc batch file error messages may be generated for ancillary
tools which may not affect builds with the msvc compiler. For this reason, caution is recommended
when setting the script error policy to raise an exception (e.g., 'Error').
New in version 4.4
MSVC_SDK_VERSION
Build with a specific version of the Microsoft Software Development Kit (SDK).
The valid values for $MSVC_SDK_VERSION are: None
or a string containing the requested SDK version (e.g., '10.0.20348.0').
$MSVC_SDK_VERSION is ignored when the value is None and when
the value is an empty string. The validation conditions below do not apply.
An exception is raised when any of the following conditions are satisfied:
$MSVC_SDK_VERSION is specified for Visual Studio 2013 and earlier.
$MSVC_SDK_VERSION is specified and an SDK version argument is specified in
$MSVC_SCRIPT_ARGS. Multiple SDK version declarations via $MSVC_SDK_VERSION
and $MSVC_SCRIPT_ARGS are not allowed.
The $MSVC_SDK_VERSION specified does not match any of the supported formats:
'10.0.XXXXX.Y' [SDK 10.0]
'8.1' [SDK 8.1]
The system folder for the corresponding $MSVC_SDK_VERSION version is not found.
The requested SDK version does not appear to be installed.
The $MSVC_SDK_VERSION version does not appear to support the requested platform
type (i.e., UWP or Desktop). The requested SDK version
platform type components do not appear to be installed.
The $MSVC_SDK_VERSION version is 8.1, the platform type is
UWP, and the build tools selected are from Visual Studio 2017
and later (i.e., $MSVC_VERSION must be '14.0' or $MSVC_TOOLSET_VERSION
must be '14.0').
Example 1 - A Visual Studio 2022 build with a specific Windows SDK version:
env = Environment(MSVC_VERSION='14.3', MSVC_SDK_VERSION='10.0.20348.0')
Example 2 - A Visual Studio 2022 build with a specific SDK version for the Universal Windows Platform:
env = Environment(MSVC_VERSION='14.3', MSVC_SDK_VERSION='10.0.20348.0', MSVC_UWP_APP=True)
Important usage details:
$MSVC_SDK_VERSION must be passed as an argument to the Environment
constructor when an msvc tool (e.g., msvc, msvs, etc.) is
loaded via the default tools list or via a tools list passed to the
Environment constructor.
Otherwise, $MSVC_SDK_VERSION must be set before the first msvc tool is
loaded into the environment.
Should a SDK 10.0 version be installed that does not follow the naming scheme above, the
SDK version will need to be specified via $MSVC_SCRIPT_ARGS until the version number
validation format can be extended.
Should an exception be raised indicating that the SDK version is not found, verify that the requested SDK version is installed with the necessary platform type components.
There is a known issue with the Microsoft libraries when the target architecture is
ARM64 and a Windows 11 SDK (version '10.0.22000.0' and later) is used
with the v141 build tools and older v142 toolsets
(versions '14.28.29333' and earlier). Should build failures arise with these combinations
of settings due to unresolved symbols in the Microsoft libraries, $MSVC_SDK_VERSION may be employed to
specify a Windows 10 SDK (e.g., '10.0.20348.0') for the build.
New in version 4.4
MSVC_SPECTRE_LIBS
Build with the spectre-mitigated Microsoft Visual C++ libraries.
The valid values for $MSVC_SPECTRE_LIBS are: True,
False, or None.
When $MSVC_SPECTRE_LIBS is enabled (i.e., True),
the Microsoft Visual C++ environment will include the paths to the spectre-mitigated implementations
of the Microsoft Visual C++ libraries.
An exception is raised when any of the following conditions are satisfied:
$MSVC_SPECTRE_LIBS is enabled for Visual Studio 2015 and earlier.
$MSVC_SPECTRE_LIBS is enabled and a spectre library argument is specified in
$MSVC_SCRIPT_ARGS. Multiple spectre library declarations via $MSVC_SPECTRE_LIBS
and $MSVC_SCRIPT_ARGS are not allowed.
$MSVC_SPECTRE_LIBS is enabled and the platform type is UWP. There
are no spectre-mitigated libraries for Universal Windows Platform (UWP) applications or
components.
Example - A Visual Studio 2022 build with spectre mitigated Microsoft Visual C++ libraries:
env = Environment(MSVC_VERSION='14.3', MSVC_SPECTRE_LIBS=True)
Important usage details:
$MSVC_SPECTRE_LIBS must be passed as an argument to the Environment
constructor when an msvc tool (e.g., msvc, msvs, etc.) is
loaded via the default tools list or via a tools list passed to the
Environment constructor.
Otherwise, $MSVC_SPECTRE_LIBS must be set before the first msvc tool is
loaded into the environment.
Additional compiler switches (e.g., /Qspectre) are necessary for including
spectre mitigations when building user artifacts. Refer to the Visual Studio documentation for
details.
The existence of the spectre libraries host architecture and target architecture folders are not
verified when $MSVC_SPECTRE_LIBS is enabled which could result in build failures.
The burden is on the user to ensure the requisite libraries with spectre mitigations are installed.
New in version 4.4
MSVC_TOOLSET_VERSION
Build with a specific Microsoft Visual C++ toolset version.
Specifying $MSVC_TOOLSET_VERSION does not affect the autodetection and selection
of msvc instances. The $MSVC_TOOLSET_VERSION is applied after
an msvc instance is selected. This could be the default version of msvc if $MSVC_VERSION
is not specified.
The valid values for $MSVC_TOOLSET_VERSION are: None
or a string containing the requested toolset version (e.g., '14.29').
$MSVC_TOOLSET_VERSION is ignored when the value is None and when
the value is an empty string. The validation conditions below do not apply.
An exception is raised when any of the following conditions are satisfied:
$MSVC_TOOLSET_VERSION is specified for Visual Studio 2015 and earlier.
$MSVC_TOOLSET_VERSION is specified and a toolset version argument is specified in
$MSVC_SCRIPT_ARGS. Multiple toolset version declarations via $MSVC_TOOLSET_VERSION
and $MSVC_SCRIPT_ARGS are not allowed.
The $MSVC_TOOLSET_VERSION specified does not match any of the supported formats:
'XX.Y'
'XX.YY'
'XX.YY.ZZZZZ'
'XX.YY.Z' to 'XX.YY.ZZZZ'
[scons extension not directly supported by the msvc batch files and may be removed in the future]
'XX.YY.ZZ.N' [SxS format]
'XX.YY.ZZ.NN' [SxS format]
The major msvc version prefix (i.e., 'XX.Y') of the $MSVC_TOOLSET_VERSION specified
is for Visual Studio 2013 and earlier (e.g., '12.0').
The major msvc version prefix (i.e., 'XX.Y') of the $MSVC_TOOLSET_VERSION specified
is greater than the msvc version selected (e.g., '99.0').
A system folder for the corresponding $MSVC_TOOLSET_VERSION version is not found.
The requested toolset version does not appear to be installed.
Toolset selection details:
When $MSVC_TOOLSET_VERSION is not an SxS version number or a full toolset version number:
the first toolset version, ranked in descending order, that matches the $MSVC_TOOLSET_VERSION
prefix is selected.
When $MSVC_TOOLSET_VERSION is specified using the major msvc version prefix
(i.e., 'XX.Y') and the major msvc version is that of the latest release of
Visual Studio, the selected toolset version may not be the same as the default Microsoft Visual C++ toolset version.
In the latest release of Visual Studio, the default Microsoft Visual C++ toolset version is not necessarily the toolset with the largest version number.
Example 1 - A default Visual Studio build with a partial toolset version specified:
env = Environment(MSVC_TOOLSET_VERSION='14.2')
Example 2 - A default Visual Studio build with a partial toolset version specified:
env = Environment(MSVC_TOOLSET_VERSION='14.29')
Example 3 - A Visual Studio 2022 build with a full toolset version specified:
env = Environment(MSVC_VERSION='14.3', MSVC_TOOLSET_VERSION='14.29.30133')
Example 4 - A Visual Studio 2022 build with an SxS toolset version specified:
env = Environment(MSVC_VERSION='14.3', MSVC_TOOLSET_VERSION='14.29.16.11')
Important usage details:
$MSVC_TOOLSET_VERSION must be passed as an argument to the Environment
constructor when an msvc tool (e.g., msvc, msvs, etc.) is
loaded via the default tools list or via a tools list passed to the
Environment constructor.
Otherwise, $MSVC_TOOLSET_VERSION must be set before the first msvc tool is
loaded into the environment.
The existence of the toolset host architecture and target architecture folders are not verified
when $MSVC_TOOLSET_VERSION is specified which could result in build failures.
The burden is on the user to ensure the requisite toolset target architecture build tools are installed.
New in version 4.4
MSVC_USE_SCRIPT
Use a batch script to set up the Microsoft Visual C++ compiler.
If set to the name of a Visual Studio .bat file
(e.g. vcvars.bat),
SCons will run that batch file instead of the auto-detected one,
and extract the relevant variables from the result (typically
%INCLUDE%,
%LIB%, and
%PATH%) for supplying to the build.
This can be useful to force the use of a compiler version that
SCons does not detect.
$MSVC_USE_SCRIPT_ARGS provides arguments passed to this script.
Setting
$MSVC_USE_SCRIPT to None bypasses the
Visual Studio autodetection entirely;
use this if you are running SCons in a Visual Studio cmd
window and importing the shell's environment variables - that
is, if you are sure everything is set correctly already and
you don't want SCons to change anything.
$MSVC_USE_SCRIPT ignores $MSVC_VERSION and $TARGET_ARCH.
Changed in version 4.4:
new $MSVC_USE_SCRIPT_ARGS provides a
way to pass arguments.
MSVC_USE_SCRIPT_ARGS
Provides arguments passed to the script $MSVC_USE_SCRIPT.
New in version 4.4
MSVC_USE_SETTINGS
Use a dictionary to set up the Microsoft Visual C++ compiler.
$MSVC_USE_SETTINGS is ignored when $MSVC_USE_SCRIPT is defined
and/or when $MSVC_USE_SETTINGS is set to None.
The dictionary is used to populate the environment with the relevant variables
(typically %INCLUDE%, %LIB%, and %PATH%)
for supplying to the build. This can be useful to force the use of a compiler environment
that SCons does not configure correctly. This is an alternative to manually configuring
the environment when bypassing Visual Studio autodetection entirely by setting
$MSVC_USE_SCRIPT to None.
Here is an example of configuring a build environment using the Microsoft Visual C++ compiler included in the Microsoft SDK on a 64-bit host and building for a 64-bit architecture:
# Microsoft SDK 6.0 (MSVC 8.0): 64-bit host and 64-bit target
msvc_use_settings = {
"PATH": [
"C:\\Program Files\\Microsoft SDKs\\Windows\\v6.0\\VC\\Bin\\x64",
"C:\\Program Files\\Microsoft SDKs\\Windows\\v6.0\\Bin\\x64",
"C:\\Program Files\\Microsoft SDKs\\Windows\\v6.0\\Bin",
"C:\\Windows\\Microsoft.NET\\Framework\\v2.0.50727",
"C:\\Windows\\system32",
"C:\\Windows",
"C:\\Windows\\System32\\Wbem",
"C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\"
],
"INCLUDE": [
"C:\\Program Files\\Microsoft SDKs\\Windows\\v6.0\\VC\\Include",
"C:\\Program Files\\Microsoft SDKs\\Windows\\v6.0\\VC\\Include\\Sys",
"C:\\Program Files\\Microsoft SDKs\\Windows\\v6.0\\Include",
"C:\\Program Files\\Microsoft SDKs\\Windows\\v6.0\\Include\\gl",
],
"LIB": [
"C:\\Program Files\\Microsoft SDKs\\Windows\\v6.0\\VC\\Lib\\x64",
"C:\\Program Files\\Microsoft SDKs\\Windows\\v6.0\\Lib\\x64",
],
"LIBPATH": [],
"VSCMD_ARG_app_plat": [],
"VCINSTALLDIR": [],
"VCToolsInstallDir": []
}
# Specifying MSVC_VERSION is recommended
env = Environment(MSVC_VERSION='8.0', MSVC_USE_SETTINGS=msvc_use_settings)
Important usage details:
$MSVC_USE_SETTINGS must be passed as an argument to the Environment
constructor when an msvc tool (e.g., msvc, msvs, etc.) is
loaded via the default tools list or via a tools list passed to the
Environment constructor.
Otherwise, $MSVC_USE_SETTINGS must be set before the first msvc tool is
loaded into the environment.
The dictionary content requirements are based on the internal msvc implementation and therefore may change at any time. The burden is on the user to ensure the dictionary contents are minimally sufficient to ensure successful builds.
New in version 4.4
MSVC_UWP_APP
Build with the Universal Windows Platform (UWP) application Microsoft Visual C++ libraries.
The valid values for $MSVC_UWP_APP are: True,
'1', False, '0',
or None.
When $MSVC_UWP_APP is enabled (i.e., True or
'1'), the Microsoft Visual C++ environment will be set up to point
to the Windows Store compatible libraries and Microsoft Visual C++ runtimes. In doing so,
any libraries that are built will be able to be used in a UWP App and published
to the Windows Store.
An exception is raised when any of the following conditions are satisfied:
$MSVC_UWP_APP is enabled for Visual Studio 2013 and earlier.
$MSVC_UWP_APP is enabled and a UWP argument is specified in
$MSVC_SCRIPT_ARGS. Multiple UWP declarations via $MSVC_UWP_APP
and $MSVC_SCRIPT_ARGS are not allowed.
Example - A Visual Studio 2022 build for the Universal Windows Platform:
env = Environment(MSVC_VERSION='14.3', MSVC_UWP_APP=True)
Important usage details:
$MSVC_UWP_APP must be passed as an argument to the Environment
constructor when an msvc tool (e.g., msvc, msvs, etc.) is
loaded via the default tools list or via a tools list passed to the
Environment constructor.
Otherwise, $MSVC_UWP_APP must be set before the first msvc tool is
loaded into the environment.
The existence of the UWP libraries is not verified when $MSVC_UWP_APP is enabled
which could result in build failures.
The burden is on the user to ensure the requisite UWP libraries are installed.
MSVC_VERSION
A string to select the preferred version of Microsoft Visual C++.
If the specified version is unavailable and/or unknown to SCons,
a warning is issued showing the versions actually discovered,
and the build will eventually fail indicating a missing compiler binary.
If $MSVC_VERSION is not set, SCons will (by default) select the
latest version of Microsoft Visual C++ installed on your system
(excluding any preview versions).
In order to take effect, $MSVC_VERSION must be set before
the initial Microsoft Visual C++ compiler discovery takes place.
Discovery happens, at the latest, during the first call to the
Environment function, unless a tools
list is specified which excludes the entire Microsoft Visual C++ toolchain -
that is, omits "defaults"
and any specific tool module that refers to parts of the toolchain
(msvc, mslink, masm, midl
and msvs). In this case, detection is deferred until
any one of those tool modules is invoked manually.
The following two examples illustrate this:
# MSVC_VERSION set as Environment is created
env = Environment(MSVC_VERSION='14.2')
# Initialization deferred with empty tools, triggered manually
env = Environment(tools=[])
env['MSVC_VERSION'] = '14.2
env.Tool('msvc')
env.Tool('mslink')
env.Tool('msvs')
The valid values for $MSVC_VERSION represent major versions
of the compiler, except that versions ending in Exp
refer to "Express" or "Express for Desktop" Visual Studio editions.
Values that do not look like a valid compiler version
string are not supported.
The following table shows the correspondence
of $MSVC_VERSION values to various version indicators
('x' is used as a placeholder for
a single digit that can vary).
| SCons Key |
|
_MSVC_VER |
Visual Studio Product |
|
|---|---|---|---|---|
"14.3" |
14.3x | 193x | Visual Studio 2022 | 17.x, 17.1x |
"14.2" |
14.2x | 192x | Visual Studio 2019 | 16.x, 16.1x |
"14.1" |
14.1 or 14.1x | 191x | Visual Studio 2017 | 15.x |
"14.1Exp" |
14.1 or 14.1x | 191x | Visual Studio 2017 Express | 15.x |
"14.0" |
14.0 | 1900 | Visual Studio 2015 | 14.0 |
"14.0Exp" |
14.0 | 1900 | Visual Studio 2015 Express | 14.0 |
"12.0" |
12.0 | 1800 | Visual Studio 2013 | 12.0 |
"12.0Exp" |
12.0 | 1800 | Visual Studio 2013 Express | 12.0 |
"11.0" |
11.0 | 1700 | Visual Studio 2012 | 11.0 |
"11.0Exp" |
11.0 | 1700 | Visual Studio 2012 Express | 11.0 |
"10.0" |
10.0 | 1600 | Visual Studio 2010 | 10.0 |
"10.0Exp" |
10.0 | 1600 | Visual C++ Express 2010 | 10.0 |
"9.0" |
9.0 | 1500 | Visual Studio 2008 | 9.0 |
"9.0Exp" |
9.0 | 1500 | Visual C++ Express 2008 | 9.0 |
"8.0" |
8.0 | 1400 | Visual Studio 2005 | 8.0 |
"8.0Exp" |
8.0 | 1400 | Visual C++ Express 2005 | 8.0 |
"7.1" |
7.1 | 1300 | Visual Studio .NET 2003 | 7.1 |
"7.0" |
7.0 | 1200 | Visual Studio .NET 2002 | 7.0 |
"6.0" |
6.0 | 1100 | Visual Studio 6.0 | 6.0 |
It is not necessary to install a Visual Studio IDE
to build with SCons (for example, you can install only
Build Tools), but when a Visual Studio IDE is installed,
additional builders such as MSVSSolution and
MSVSProject become available and correspond to
the specified versions.
Versions ending in Exp refer to historical
"Express" or "Express for Desktop" Visual Studio editions,
which had feature limitations compared to the full editions.
It is only necessary to specify the Exp
suffix to select the express edition when both express and
non-express editions of the same product are installed
simulaneously. The Exp suffix is unnecessary,
but accepted, when only the express edition is installed.
The compilation environment can be further or more precisely specified through the
use of several other construction variables: see the descriptions of
$MSVC_TOOLSET_VERSION,
$MSVC_SDK_VERSION,
$MSVC_USE_SCRIPT,
$MSVC_USE_SCRIPT_ARGS,
and $MSVC_USE_SETTINGS.
MSVS
When the Microsoft Visual Studio tools are initialized, they set up this dictionary with the following keys:
the version of MSVS being used (can be set via
$MSVC_VERSION)
the available versions of MSVS installed
installed directory of Microsoft Visual C++
installed directory of Visual Studio
installed directory of the .NET framework
list of installed versions of the .NET framework, sorted latest to oldest.
latest installed version of the .NET framework
installed location of the .NET SDK.
installed location of the Platform SDK.
dictionary of installed Platform SDK modules, where the dictionary keys are keywords for the various modules, and the values are 2-tuples where the first is the release date, and the second is the version number.
If a value is not set, it was not available in the registry.
Visual Studio 2017 and later do not use the registry for
primary storage of this information, so typically for these
versions only PROJECTSUFFIX and
SOLUTIONSUFFIX will be set.
MSVS_ARCH
Sets the architecture for which the generated project(s) should build.
The default value is x86.
amd64 is also supported by SCons for
most Visual Studio versions. Since Visual Studio 2015
arm is supported, and since Visual Studio
2017 arm64 is supported.
Trying to set $MSVS_ARCH
to an architecture that's not supported for a given Visual
Studio version will generate an error.
MSVS_PROJECT_GUID
The string placed in a generated
Microsoft Visual C++ project file as the value of the
ProjectGUID attribute. There is no default
value. If not defined, a new GUID is generated.
MSVS_SCC_AUX_PATH
The path name placed in a generated
Microsoft Visual C++ project file as the value of the
SccAuxPath attribute if the
MSVS_SCC_PROVIDER construction variable is
also set. There is no default value.
MSVS_SCC_CONNECTION_ROOT
The root path of projects in your SCC workspace, i.e the
path under which all project and solution files will be
generated. It is used as a reference path from which the
relative paths of the generated Microsoft Visual C++ project
and solution files are computed. The relative project file path
is placed as the value of the SccLocalPath
attribute of the project file and as the values of the
SccProjectFilePathRelativizedFromConnection[i]
(where [i] ranges from 0 to the number of projects in the solution)
attributes of the GlobalSection(SourceCodeControl)
section of the Microsoft Visual Studio solution file. Similarly
the relative solution file path is placed as the values of the
SccLocalPath[i] (where [i] ranges from 0
to the number of projects in the solution) attributes of the
GlobalSection(SourceCodeControl) section of
the Microsoft Visual Studio solution file. This is used only if
the MSVS_SCC_PROVIDER construction variable is
also set. The default value is the current working directory.
MSVS_SCC_PROJECT_NAME
The project name placed in a generated Microsoft Visual C++
project file as the value of the
SccProjectName attribute if the
MSVS_SCC_PROVIDER construction variable
is also set. In this case the string is also placed in
the SccProjectName0 attribute of the
GlobalSection(SourceCodeControl) section
of the Microsoft Visual Studio solution file. There is no
default value.
MSVS_SCC_PROVIDER
The string placed in a generated Microsoft Visual C++
project file as the value of the
SccProvider attribute. The string is
also placed in the SccProvider0 attribute
of the GlobalSection(SourceCodeControl)
section of the Microsoft Visual Studio solution file. There
is no default value.
MSVS_VERSION
Set the preferred version of Microsoft Visual Studio to use.
If $MSVS_VERSION is not set, SCons will (by default)
select the latest version of Visual Studio installed on your
system. So, if you have version 6 and version 7 (MSVS .NET)
installed, it will prefer version 7. You can override this by
specifying the $MSVS_VERSION variable when
initializing the Environment, setting it to the appropriate
version ('6.0' or '7.0', for example). If the specified
version isn't installed, tool initialization will fail.
Deprecated since 1.3.0:
$MSVS_VERSION is deprecated in favor of $MSVC_VERSION.
As a transitional aid, if $MSVS_VERSION is set
and $MSVC_VERSION is not,
$MSVC_VERSION will be initialized to the value
of $MSVS_VERSION.
An error is raised if If both are set and have different values,
MSVSBUILDCOM
The build command line placed in a generated Microsoft Visual C++ project file. The default is to have Visual Studio invoke SCons with any specified build targets.
MSVSCLEANCOM
The clean command line placed in a generated Microsoft Visual C++
project file. The default is to have Visual Studio
invoke SCons with the -c option to remove
any specified targets.
MSVSENCODING
The encoding string placed in a generated Microsoft Visual C++
project file. The default is encoding
Windows-1252.
MSVSPROJECTCOM
The action used to generate Microsoft Visual C++ project files.
MSVSPROJECTSUFFIX
The suffix used for Microsoft Visual C++ project (DSP)
files. The default value is
.vcxproj when using Visual Studio 2010
and later, .vcproj
when using Visual Studio versions between 2002 and 2008,
and .dsp when using Visual Studio 6.0.
MSVSREBUILDCOM
The rebuild command line placed in a generated Microsoft Visual C++ project file. The default is to have Visual Studio invoke SCons with any specified rebuild targets.
MSVSSCONS
The SCons used in generated Microsoft Visual C++ project files. The default is the version of SCons being used to generate the project file.
MSVSSCONSCOM
The default SCons command used in generated Microsoft Visual C++ project files.
MSVSSCONSCRIPT
The sconscript file (that is, SConstruct or SConscript
file) that will be invoked by Microsoft Visual C++ project files
(through the $MSVSSCONSCOM variable). The default
is the same sconscript file that contains the call to
MSVSProject to build the project file.
MSVSSCONSFLAGS
The SCons flags used in generated Microsoft Visual C++ project files.
MSVSSOLUTIONCOM
The action used to generate Microsoft Visual Studio solution files.
MSVSSOLUTIONSUFFIX
The suffix used for Microsoft Visual Studio solution (DSW)
files. The default value is .sln
when using Visual Studio version 7.x (.NET 2002) and later,
and .dsw when using Visual Studio 6.0.
MT
The program used on Windows systems to embed manifests into DLLs and EXEs.
See also $WINDOWS_EMBED_MANIFEST.
MTEXECOM
The Windows command line used to embed manifests into executables.
See also $MTSHLIBCOM.
MTFLAGS
Flags passed to the $MT manifest embedding program (Windows only).
MTSHLIBCOM
The Windows command line used to embed manifests into shared libraries (DLLs).
See also $MTEXECOM.
MWCW_VERSION
The version number of the MetroWerks CodeWarrior C compiler to be used.
MWCW_VERSIONS
A list of installed versions of the MetroWerks CodeWarrior C compiler on this system.
NAME
Specfies the name of the project to package.
See the Package builder.
NINJA_ALIAS_NAME
The name of the alias target which will cause SCons to create the ninja build file,
and then (optionally) run ninja.
The default value is generate-ninja.
NINJA_CMD_ARGS
A string which will pass arguments through SCons to the ninja command when scons executes ninja.
Has no effect if $NINJA_DISABLE_AUTO_RUN is set.
This value can also be passed on the command line:
scons NINJA_CMD_ARGS=-v
or
scons NINJA_CMD_ARGS="-v -j 3"
NINJA_COMPDB_EXPAND
Boolean value to instruct ninja to expand the command line arguments normally put into
response files.
If true, prevents unexpanded lines in the compilation database like
“gcc @rsp_file” and instead yields expanded lines like
“gcc -c -o myfile.o myfile.c -Ia -DXYZ”.
Ninja's compdb tool added the -x flag in Ninja V1.9.0
NINJA_DEPFILE_PARSE_FORMAT
Determines the type of format ninja should expect when parsing header
include depfiles. Can be msvc, gcc, or clang.
The msvc option corresponds to /showIncludes format, and
gcc or clang correspond to -MMD -MF.
NINJA_DIR
The builddir value.
Propagates directly into the generated ninja build file.
From Ninja's docs:
“
A directory for some Ninja output files. ... (You can also store other build output in this
directory.)
”
The default value is .ninja.
NINJA_DISABLE_AUTO_RUN
Boolean. Default: False.
If true, SCons will not run ninja automatically after creating the ninja build file.
If not explicitly set, this will be set to True
if --disable_execute_ninja or
SetOption('disable_execute_ninja', True) is seen.
NINJA_ENV_VAR_CACHE
A string that sets the environment for any environment variables that differ between the OS environment and the SCons execution environment.
It will be compatible with the default shell of the operating system.
If not explicitly set, SCons will generate this dynamically from the
execution environment stored in the current construction environment
(e.g. env['ENV'])
where those values differ from the existing shell..
NINJA_FILE_NAME
The filename for the generated Ninja build file.
The default is ninja.build.
NINJA_FORCE_SCONS_BUILD
If true, causes the build nodes to callback to scons instead of using ninja to build them. This is intended to be passed to the environment on the builder invocation. It is useful if you have a build node which does something which is not easily translated into ninja.
NINJA_GENERATED_SOURCE_ALIAS_NAME
A string matching the name of a user defined alias which represents a list of all generated sources.
This will prevent the auto-detection of generated sources from $NINJA_GENERATED_SOURCE_SUFFIXES.
Then all other source files will be made to depend on this in the ninja build file, forcing the
generated sources to be built first.
NINJA_GENERATED_SOURCE_SUFFIXES
The list of source file suffixes which are generated by SCons build steps. All source files which match these suffixes will be added to the _generated_sources alias in the output ninja build file. Then all other source files will be made to depend on this in the ninja build file, forcing the generated sources to be built first.
NINJA_MSVC_DEPS_PREFIX
The msvc_deps_prefix string.
Propagates directly into the generated ninja build file.
From Ninja's docs:
“defines the string which should be stripped from msvc's /showIncludes output”
NINJA_POOL
Set the ninja_pool for this or all targets in scope for this env var.
NINJA_REGENERATE_DEPS
A generator function used to create a ninja depfile which includes all the files which would require SCons to be invoked if they change. Or a list of said files.
_NINJA_REGENERATE_DEPS_FUNC
Internal value used to specify the function to call with argument env to generate the list of files which if changed would require the ninja build file to be regenerated.
NINJA_SCONS_DAEMON_KEEP_ALIVE
The number of seconds for the SCons deamon launched by ninja to stay alive. (Default: 180000)
NINJA_SCONS_DAEMON_PORT
The TCP/IP port for the SCons daemon to listen on. NOTE: You cannot use a port already being listened to on your build machine. (Default: random number between 10000,60000)
NINJA_SYNTAX
The path to a custom ninja_syntax.py file which is used in generation.
The tool currently assumes you have ninja installed as a Python module and grabs the syntax file from that
installation if $NINJA_SYNTAX is not explicitly set.
no_import_lib
When set to non-zero,
suppresses creation of a corresponding Windows static import lib by the
SharedLibrary
builder when used with
MinGW, Microsoft Visual Studio or Metrowerks.
This also suppresses creation
of an export (.exp) file
when using Microsoft Visual Studio.
OBJPREFIX
The prefix used for (static) object file names.
OBJSUFFIX
The suffix used for (static) object file names.
PACKAGEROOT
Specifies the directory where all files in resulting archive will be
placed if applicable. The default value is “$NAME-$VERSION”.
See the Package builder.
PACKAGETYPE
Selects the package type to build when using the Package
builder. May be a string or list of strings. See the docuentation
for the builder for the currently supported types.
$PACKAGETYPE may be overridden with the --package-type
command line option.
See the Package builder.
PACKAGEVERSION
The version of the package (not the underlying project). This is currently only used by the rpm packager and should reflect changes in the packaging, not the underlying project code itself.
See the Package builder.
PCH
A node for the Microsoft Visual C++ precompiled header that will be used when compiling object files. This variable is ignored by tools other than Microsoft Visual C++. When this variable is defined, SCons will add options to the compiler command line to cause it to use the precompiled header, and will also set up the dependencies for the PCH file. Examples:
env['PCH'] = File('StdAfx.pch')
env['PCH'] = env.PCH('pch.cc')[0]
PCHCOM
The command line used by the
PCH
builder to generated a precompiled header.
PCHCOMSTR
The string displayed when generating a precompiled header.
If not set, then $PCHCOM (the command line) is displayed.
PCHPDBFLAGS
A construction variable that, when expanded,
adds the /yD flag to the command line
only if the $PDB construction variable is set.
PCHSTOP
This variable specifies how much of a source file is precompiled. This variable is ignored by tools other than Microsoft Visual C++, or when the PCH variable is not being used. When this variable is define it must be a string that is the name of the header that is included at the end of the precompiled portion of the source files, or the empty string if the "#pragma hrdstop" construct is being used:
env['PCHSTOP'] = 'StdAfx.h'
PDB
The Microsoft Visual C++ PDB file that will store debugging information for object files, shared libraries, and programs. This variable is ignored by tools other than Microsoft Visual C++. When this variable is defined SCons will add options to the compiler and linker command line to cause them to generate external debugging information, and will also set up the dependencies for the PDB file. Example:
env['PDB'] = 'hello.pdb'
The Microsoft Visual C++ compiler switch that SCons uses by default
to generate PDB information is /Z7.
This works correctly with parallel (-j) builds
because it embeds the debug information in the intermediate object files,
as opposed to sharing a single PDB file between multiple object files.
This is also the only way to get debug information
embedded into a static library.
Using the /Zi instead may yield improved
link-time performance,
although parallel builds will no longer work.
You can generate PDB files with the /Zi
switch by overriding the default $CCPDBFLAGS variable;
see the entry for that variable for specific examples.
PDFLATEX
The pdflatex utility.
PDFLATEXCOM
The command line used to call the pdflatex utility.
PDFLATEXCOMSTR
The string displayed when calling the pdflatex utility.
If this is not set, then $PDFLATEXCOM (the command line) is displayed.
env = Environment(PDFLATEX;COMSTR = "Building $TARGET from LaTeX input $SOURCES")
PDFLATEXFLAGS
General options passed to the pdflatex utility.
PDFPREFIX
The prefix used for PDF file names.
PDFSUFFIX
The suffix used for PDF file names.
PDFTEX
The pdftex utility.
PDFTEXCOM
The command line used to call the pdftex utility.
PDFTEXCOMSTR
The string displayed when calling the pdftex utility.
If this is not set, then $PDFTEXCOM (the command line) is displayed.
env = Environment(PDFTEXCOMSTR = "Building $TARGET from TeX input $SOURCES")
PDFTEXFLAGS
General options passed to the pdftex utility.
PKGCHK
On Solaris systems,
the package-checking program that will
be used (along with $PKGINFO)
to look for installed versions of
the Sun PRO C++ compiler.
The default is
/usr/sbin/pgkchk.
PKGINFO
On Solaris systems,
the package information program that will
be used (along with $PKGCHK)
to look for installed versions of
the Sun PRO C++ compiler.
The default is
pkginfo.
PLATFORM
The name of the platform used to create this construction environment.
SCons sets this when initializing the platform,
which by default is auto-detected
(see the platform
argument to Environment).
env = Environment(tools=[])
if env['PLATFORM'] == 'cygwin':
Tool('mingw')(env)
else:
Tool('msvc')(env)
POAUTOINIT
The $POAUTOINIT variable, if set to True (on non-zero
numeric value), let the msginit tool to automatically initialize
missing PO files with
msginit(1). This applies to both,
POInit and POUpdate builders (and others that use any of
them).
POCREATE_ALIAS
Common alias for all PO files created with POInit
builder (default: 'po-create').
See msginit tool and POInit builder.
POSUFFIX
Suffix used for PO files (default: '.po')
See msginit tool and POInit builder.
POTDOMAIN
The $POTDOMAIN defines default domain, used to generate
POT filename as $POTDOMAIN.potPOT file name is provided by the user. This applies to
POTUpdate, POInit and POUpdate builders (and
builders, that use them, e.g. Translate). Normally (if $POTDOMAIN is
not defined), the builders use messages.pot as default
POT file name.
POTSUFFIX
Suffix used for PO Template files (default: '.pot').
See xgettext tool and POTUpdate builder.
POTUPDATE_ALIAS
Name of the common phony target for all PO Templates created with
POUpdate (default: 'pot-update').
See xgettext tool and POTUpdate builder.
POUPDATE_ALIAS
Common alias for all PO files being defined with
POUpdate builder (default: 'po-update').
See msgmerge tool and POUpdate builder.
PRINT_CMD_LINE_FUNC
A Python function used to print the command lines as they are executed
(assuming command printing is not disabled by the
-q
or
-s
options or their equivalents).
The function must accept four arguments:
s,
target,
source and
env.
s
is a string showing the command being executed,
target,
is the target being built (file node, list, or string name(s)),
source,
is the source(s) used (file node, list, or string name(s)),
and env
is the environment being used.
The function must do the printing itself.
The default implementation,
used if this variable is not set or is None,
is to just print the string, as in:
def print_cmd_line(s, target, source, env):
sys.stdout.write(s + "\n")
Here is an example of a more interesting function:
def print_cmd_line(s, target, source, env):
sys.stdout.write(
"Building %s -> %s...\n"
% (
' and '.join([str(x) for x in source]),
' and '.join([str(x) for x in target]),
)
)
env = Environment(PRINT_CMD_LINE_FUNC=print_cmd_line)
env.Program('foo', ['foo.c', 'bar.c'])
This prints:
... scons: Building targets ... Building bar.c -> bar.o... Building foo.c -> foo.o... Building foo.o and bar.o -> foo... scons: done building targets.
Another example could be a function that logs the actual commands to a file.
PROGEMITTER
Contains the emitter specification for the
Program builder.
The manpage section "Builder Objects" contains
general information on specifying emitters.
PROGPREFIX
The prefix used for executable file names.
PROGSUFFIX
The suffix used for executable file names.
PSCOM
The command line used to convert TeX DVI files into a PostScript file.
PSCOMSTR
The string displayed when a TeX DVI file
is converted into a PostScript file.
If this is not set, then $PSCOM (the command line) is displayed.
PSPREFIX
The prefix used for PostScript file names.
PSSUFFIX
The prefix used for PostScript file names.
QT3_AUTOSCAN
Turn off scanning for mocable files. Use the Moc Builder to explicitly
specify files to run moc on.
Changed in 4.5.0: renamed from QT_AUTOSCAN.
QT3_BINPATH
The path where the Qt binaries are installed.
The default value is '$QT3DIR/bin'.
Changed in 4.5.0: renamed from QT_BINPATH.
QT3_CPPPATH
The path where the Qt header files are installed.
The default value is '$QT3DIR/include'.
Note: If you set this variable to None,
the tool won't change the $CPPPATH
construction variable.
Changed in 4.5.0: renamed from QT_CPPPATH.
QT3_DEBUG
Prints lots of debugging information while scanning for moc files.
Changed in 4.5.0: renamed from QT_DEBUG.
QT3_LIB
Default value is 'qt'.
You may want to set this to 'qt-mt'.
Note: If you set this variable to None,
the tool won't change the $LIBS variable.
Changed in 4.5.0: renamed from QT_LIB.
QT3_LIBPATH
The path where the Qt libraries are installed.
The default value is '$QT3DIR/lib'.
Note: If you set this variable to None,
the tool won't change the $LIBPATH
construction variable.
Changed in 4.5.0: renamed from QT_LIBPATH.
QT3_MOC
Default value is '$QT3_BINPATH/moc'.
QT3_MOCCXXPREFIX
Default value is ''.
Prefix for moc output files when source is a C++ file.
QT3_MOCCXXSUFFIX
Default value is '.moc'.
Suffix for moc output files when source is a C++ file.
Changed in 4.5.0: renamed from QT_MOCCXXSUFFIX.
QT3_MOCFROMCXXCOM
Command to generate a moc file from a C++ file.
Changed in 4.5.0: renamed from QT_MOCFROMCXXCOM.
QT3_MOCFROMCXXCOMSTR
The string displayed when generating a moc file from a C++ file.
If this is not set, then $QT3_MOCFROMCXXCOM (the command line) is displayed.
Changed in 4.5.0: renamed from QT_MOCFROMCXXCOMSTR.
QT3_MOCFROMCXXFLAGS
Default value is '-i'.
These flags are passed to moc when moccing a C++ file.
Changed in 4.5.0: renamed from QT_MOCFROMCXXFLAGS.
QT3_MOCFROMHCOM
Command to generate a moc file from a header.
Changed in 4.5.0: renamed from QT_MOCFROMSHCOM.
QT3_MOCFROMHCOMSTR
The string displayed when generating a moc file from a C++ file.
If this is not set, then $QT3_MOCFROMHCOM (the command line) is displayed.
Changed in 4.5.0: renamed from QT_MOCFROMSHCOMSTR.
QT3_MOCFROMHFLAGS
Default value is ''. These flags are passed to moc
when moccing a header file.
Changed in 4.5.0: renamed from QT_MOCFROMSHFLAGS.
QT3_MOCHPREFIX
Default value is 'moc_'.
Prefix for moc output files when source is a header.
Changed in 4.5.0: renamed from QT_MOCHPREFIX.
QT3_MOCHSUFFIX
Default value is '$CXXFILESUFFIX'.
Suffix for moc output files when source is a header.
Changed in 4.5.0: renamed from QT_MOCHSUFFIX.
QT3_UIC
Default value is '$QT3_BINPATH/uic'.
Changed in 4.5.0: renamed from QT_UIC.
QT3_UICCOM
Command to generate header files from .ui files.
Changed in 4.5.0: renamed from QT_UICCOM.
QT3_UICCOMSTR
The string displayed when generating header files from .ui files.
If this is not set, then $QT3_UICCOM (the command line) is displayed.
Changed in 4.5.0: renamed from QT_UICCOMSTR.
QT3_UICDECLFLAGS
Default value is ''. These flags are passed to uic
when creating a header file from a .ui file.
Changed in 4.5.0: renamed from QT_UICDECLFLAGS.
QT3_UICDECLPREFIX
Default value is ''.
Prefix for uic generated header files.
Changed in 4.5.0: renamed from QT_UICDECLPREFIX.
QT3_UICDECLSUFFIX
Default value is '.h'.
Suffix for uic generated header files.
Changed in 4.5.0: renamed from QT_UICDECLSUFFIX.
QT3_UICIMPLFLAGS
Default value is ''.
These flags are passed to uic when creating a C++
file from a .ui file.
Changed in 4.5.0: renamed from QT_UICIMPFLAGS.
QT3_UICIMPLPREFIX
Default value is 'uic_'.
Prefix for uic generated implementation files.
Changed in 4.5.0: renamed from QT_UICIMPLPREFIX.
QT3_UICIMPLSUFFIX
Default value is '$CXXFILESUFFIX'. Suffix for uic generated implementation
files.
Changed in 4.5.0: renamed from QT_UICIMPLSUFFIX.
QT3_UISUFFIX
Default value is '.ui'.
Suffix of designer input files.
Changed in 4.5.0: renamed from QT_UISUFFIX.
QT3DIR
The path to the Qt installation to build against.
If not already set,
qt3 tool tries to obtain this from
os.environ;
if not found there, it tries to make a guess.
Changed in 4.5.0: renamed from QTDIR.
RANLIB
The archive indexer.
RANLIBCOM
The command line used to index a static library archive.
RANLIBCOMSTR
The string displayed when a static library archive is indexed.
If this is not set, then $RANLIBCOM (the command line) is displayed.
env = Environment(RANLIBCOMSTR = "Indexing $TARGET")
RANLIBFLAGS
General options passed to the archive indexer.
RC
The resource compiler used to build a Microsoft Visual C++ resource file.
RCCOM
The command line used to build a Microsoft Visual C++ resource file.
RCCOMSTR
The string displayed when invoking the resource compiler
to build a Microsoft Visual C++ resource file.
If this is not set, then $RCCOM (the command line) is displayed.
RCFLAGS
The flags passed to the resource compiler by the RES builder.
RCINCFLAGS
An automatically-generated construction variable
containing the command-line options
for specifying directories to be searched
by the resource compiler.
The value of $RCINCFLAGS is created
by respectively prepending and appending
$RCINCPREFIX and $RCINCSUFFIX
to the beginning and end
of each directory in $CPPPATH.
RCINCPREFIX
The prefix (flag) used to specify an include directory
on the resource compiler command line.
This will be prepended to the beginning of each directory
in the $CPPPATH construction variable
when the $RCINCFLAGS variable is expanded.
RCINCSUFFIX
The suffix used to specify an include directory
on the resource compiler command line.
This will be appended to the end of each directory
in the $CPPPATH construction variable
when the $RCINCFLAGS variable is expanded.
RDirs
A function that converts a string into a list of Dir instances by searching the repositories.
REGSVR
The program used on Windows systems
to register a newly-built DLL library
whenever the SharedLibrary builder
is passed a keyword argument of register=True.
REGSVRCOM
The command line used on Windows systems
to register a newly-built DLL library
whenever the SharedLibrary builder
is passed a keyword argument of register=True.
REGSVRCOMSTR
The string displayed when registering a newly-built DLL file.
If this is not set, then $REGSVRCOM (the command line) is displayed.
REGSVRFLAGS
Flags passed to the DLL registration program
on Windows systems when a newly-built DLL library is registered.
By default,
this includes the /s
that prevents dialog boxes from popping up
and requiring user attention.
RMIC
The Java RMI stub compiler.
RMICCOM
The command line used to compile stub
and skeleton class files
from Java classes that contain RMI implementations.
Any options specified in the $RMICFLAGS construction variable
are included on this command line.
RMICCOMSTR
The string displayed when compiling
stub and skeleton class files
from Java classes that contain RMI implementations.
If this is not set, then $RMICCOM (the command line) is displayed.
env = Environment(
RMICCOMSTR="Generating stub/skeleton class files $TARGETS from $SOURCES"
)
RMICFLAGS
General options passed to the Java RMI stub compiler.
RPATH
A list of paths to search for shared libraries when running programs. Currently only used in the GNU (gnulink), IRIX (sgilink) and Sun (sunlink) linkers. Ignored on platforms and toolchains that don't support it. Note that the paths added to RPATH are not transformed by scons in any way: if you want an absolute path, you must make it absolute yourself.
_RPATH
An automatically-generated construction variable
containing the rpath flags to be used when linking
a program with shared libraries.
The value of $_RPATH is created
by respectively prepending $RPATHPREFIX and appending $RPATHSUFFIX
to the beginning and end
of each directory in $RPATH.
RPATHPREFIX
The prefix used to specify a directory to be searched for
shared libraries when running programs.
This will be prepended to the beginning of each directory
in the $RPATH construction variable
when the $_RPATH variable is automatically generated.
RPATHSUFFIX
The suffix used to specify a directory to be searched for
shared libraries when running programs.
This will be appended to the end of each directory
in the $RPATH construction variable
when the $_RPATH variable is automatically generated.
RPCGEN
The RPC protocol compiler.
RPCGENCLIENTFLAGS
Options passed to the RPC protocol compiler
when generating client side stubs.
These are in addition to any flags specified in the
$RPCGENFLAGS
construction variable.
RPCGENFLAGS
General options passed to the RPC protocol compiler.
RPCGENHEADERFLAGS
Options passed to the RPC protocol compiler
when generating a header file.
These are in addition to any flags specified in the
$RPCGENFLAGS
construction variable.
RPCGENSERVICEFLAGS
Options passed to the RPC protocol compiler
when generating server side stubs.
These are in addition to any flags specified in the
$RPCGENFLAGS
construction variable.
RPCGENXDRFLAGS
Options passed to the RPC protocol compiler
when generating XDR routines.
These are in addition to any flags specified in the
$RPCGENFLAGS
construction variable.
SCANNERS
A list of the available implicit dependency scanners. New file scanners may be added by appending to this list, although the more flexible approach is to associate scanners with a specific Builder. See the manpage sections "Builder Objects" and "Scanner Objects" for more information.
SCONS_HOME
The (optional) path to the SCons library directory,
initialized from the external environment. If set, this is
used to construct a shorter and more efficient search path in
the $MSVSSCONS command line executed from C++
project files.
SHCC
The C compiler used for generating shared-library objects.
See also $CC for compiling to static objects.
SHCCCOM
The command line used to compile a C source file
to a shared-library object file.
Any options specified in the $SHCFLAGS,
$SHCCFLAGS and
$CPPFLAGS construction variables
are included on this command line.
See also $CCCOM for compiling to static objects.
SHCCCOMSTR
If set, the string displayed when a C source file
is compiled to a shared object file.
If not set, then $SHCCCOM (the command line) is displayed.
See also $CCCOMSTR for compiling to static objects.
env = Environment(SHCCCOMSTR = "Compiling shared object $TARGET")
SHCCFLAGS
Options that are passed to the C and C++ compilers
to generate shared-library objects.
See also $CCFLAGS for compiling to static objects.
SHCFLAGS
Options that are passed to the C compiler (only; not C++)
to generate shared-library objects.
See also $CFLAGS for compiling to static objects.
SHCXX
The C++ compiler used for generating shared-library objects.
See also $CXX for compiling to static objects.
SHCXXCOM
The command line used to compile a C++ source file
to a shared-library object file.
Any options specified in the $SHCXXFLAGS and
$CPPFLAGS construction variables
are included on this command line.
See also $CXXCOM for compiling to static objects.
SHCXXCOMSTR
If set, the string displayed when a C++ source file
is compiled to a shared object file.
If not set, then $SHCXXCOM (the command line) is displayed.
See also $CXXCOMSTR for compiling to static objects.
env = Environment(SHCXXCOMSTR = "Compiling shared object $TARGET")
SHCXXFLAGS
Options that are passed to the C++ compiler
to generate shared-library objects.
See also $CXXFLAGS for compiling to static objects.
SHDC
The name of the compiler to use when compiling D source
destined to be in a shared objects.
See also $DC for compiling to static objects.
SHDCOM
The command line to use when compiling code to be part of shared objects.
See also $DCOM for compiling to static objects.
SHDCOMSTR
If set, the string displayed when a D source file
is compiled to a (shared) object file.
If not set, then $SHDCOM (the command line) is displayed.
See also $DCOMSTR for compiling to static objects.
SHDLIBVERSIONFLAGS
Extra flags added to $SHDLINKCOM when building versioned
SharedLibrary. These flags are only used when $SHLIBVERSION is
set.
SHDLINK
The linker to use when creating shared objects for code bases
include D sources.
See also $DLINK for linking static objects.
SHDLINKCOM
The command line to use when generating shared objects.
See also $DLINKCOM for linking static objects.
SHDLINKFLAGS
The list of flags to use when generating a shared object.
See also $DLINKFLAGS for linking static objects.
SHELL
A string naming the shell program that will be passed to the
$SPAWN
function.
See the
$SPAWN
construction variable for more information.
SHELL_ENV_GENERATORS
A hook allowing the execution environment to be modified prior
to the actual execution of a command line from an action
via the spawner function defined by $SPAWN.
Allows substitution based on targets and sources,
as well as values from the construction environment,
adding extra environment variables, etc.
The value must be a list (or other iterable)
of functions which each generate or
alter the execution environment dictionary.
The first function will be passed a copy of the initial execution environment
($ENV in the current construction environment);
the dictionary returned by that function is passed to the next,
until the iterable is exhausted and the result returned
for use by the command spawner.
The original execution environment is not modified.
Each function provided in $SHELL_ENV_GENERATORS must accept four
arguments and return a dictionary:
env is the construction environment for this action;
target is the list of targets associated with this action;
source is the list of sources associated with this action;
and shell_env is the current dictionary after iterating
any previous $SHELL_ENV_GENERATORS functions
(this can be compared to the original execution environment,
which is available as env['ENV'], to detect any changes).
Example:
def custom_shell_env(env, target, source, shell_env):
"""customize shell_env if desired"""
if str(target[0]) == 'special_target':
shell_env['SPECIAL_VAR'] = env.subst('SOME_VAR', target=target, source=source)
return shell_env
env["SHELL_ENV_GENERATORS"] = [custom_shell_env]
Available since 4.4
SHF03
The Fortran 03 compiler used for generating shared-library objects.
You should normally set the $SHFORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $SHF03 if you need to use a specific compiler
or compiler version for Fortran 03 files.
SHF03COM
The command line used to compile a Fortran 03 source file
to a shared-library object file.
You only need to set $SHF03COM if you need to use a specific
command line for Fortran 03 files.
You should normally set the $SHFORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
SHF03COMSTR
If set, the string displayed when a Fortran 03 source file
is compiled to a shared-library object file.
If not set, then $SHF03COM or $SHFORTRANCOM
(the command line) is displayed.
SHF03FLAGS
Options that are passed to the Fortran 03 compiler
to generated shared-library objects.
You only need to set $SHF03FLAGS if you need to define specific
user options for Fortran 03 files.
You should normally set the $FORTRANCOMMONFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
SHF03PPCOM
The command line used to compile a Fortran 03 source file to a
shared-library object file
after first running the file through the C preprocessor.
Any options specified in the $SHF03FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $SHF03PPCOM if you need to use a specific
C-preprocessor command line for Fortran 03 files.
You should normally set the $SHFORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
SHF03PPCOMSTR
If set, the string displayed when a Fortran 03 source file
is compiled to a shared-library object file
after first running the file through the C preprocessor.
If not set, then $SHF03PPCOM or $SHFORTRANPPCOM
(the command line) is displayed.
SHF08
The Fortran 08 compiler used for generating shared-library objects.
You should normally set the $SHFORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $SHF08 if you need to use a specific compiler
or compiler version for Fortran 08 files.
SHF08COM
The command line used to compile a Fortran 08 source file
to a shared-library object file.
You only need to set $SHF08COM if you need to use a specific
command line for Fortran 08 files.
You should normally set the $SHFORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
SHF08COMSTR
If set, the string displayed when a Fortran 08 source file
is compiled to a shared-library object file.
If not set, then $SHF08COM or $SHFORTRANCOM
(the command line) is displayed.
SHF08FLAGS
Options that are passed to the Fortran 08 compiler
to generated shared-library objects.
You only need to set $SHF08FLAGS if you need to define specific
user options for Fortran 08 files.
You should normally set the $FORTRANCOMMONFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
SHF08PPCOM
The command line used to compile a Fortran 08 source file to a
shared-library object file
after first running the file through the C preprocessor.
Any options specified in the $SHF08FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $SHF08PPCOM if you need to use a specific
C-preprocessor command line for Fortran 08 files.
You should normally set the $SHFORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
SHF08PPCOMSTR
If set, the string displayed when a Fortran 08 source file
is compiled to a shared-library object file
after first running the file through the C preprocessor.
If not set, then $SHF08PPCOM or $SHFORTRANPPCOM
(the command line) is displayed.
SHF77
The Fortran 77 compiler used for generating shared-library objects.
You should normally set the $SHFORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $SHF77 if you need to use a specific compiler
or compiler version for Fortran 77 files.
SHF77COM
The command line used to compile a Fortran 77 source file
to a shared-library object file.
You only need to set $SHF77COM if you need to use a specific
command line for Fortran 77 files.
You should normally set the $SHFORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
SHF77COMSTR
If set, the string displayed when a Fortran 77 source file
is compiled to a shared-library object file.
If not set, then $SHF77COM or $SHFORTRANCOM
(the command line) is displayed.
SHF77FLAGS
Options that are passed to the Fortran 77 compiler
to generated shared-library objects.
You only need to set $SHF77FLAGS if you need to define specific
user options for Fortran 77 files.
You should normally set the $FORTRANCOMMONFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
SHF77PPCOM
The command line used to compile a Fortran 77 source file to a
shared-library object file
after first running the file through the C preprocessor.
Any options specified in the $SHF77FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $SHF77PPCOM if you need to use a specific
C-preprocessor command line for Fortran 77 files.
You should normally set the $SHFORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
SHF77PPCOMSTR
If set, the string displayed when a Fortran 77 source file
is compiled to a shared-library object file
after first running the file through the C preprocessor.
If not set, then $SHF77PPCOM or $SHFORTRANPPCOM
(the command line) is displayed.
SHF90
The Fortran 90 compiler used for generating shared-library objects.
You should normally set the $SHFORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $SHF90 if you need to use a specific compiler
or compiler version for Fortran 90 files.
SHF90COM
The command line used to compile a Fortran 90 source file
to a shared-library object file.
You only need to set $SHF90COM if you need to use a specific
command line for Fortran 90 files.
You should normally set the $SHFORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
SHF90COMSTR
If set, the string displayed when a Fortran 90 source file
is compiled to a shared-library object file.
If not set, then $SHF90COM or $SHFORTRANCOM
(the command line) is displayed.
SHF90FLAGS
Options that are passed to the Fortran 90 compiler
to generated shared-library objects.
You only need to set $SHF90FLAGS if you need to define specific
user options for Fortran 90 files.
You should normally set the $FORTRANCOMMONFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
SHF90PPCOM
The command line used to compile a Fortran 90 source file to a
shared-library object file
after first running the file through the C preprocessor.
Any options specified in the $SHF90FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $SHF90PPCOM if you need to use a specific
C-preprocessor command line for Fortran 90 files.
You should normally set the $SHFORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
SHF90PPCOMSTR
If set, the string displayed when a Fortran 90 source file
is compiled to a shared-library object file
after first running the file through the C preprocessor.
If not set, then $SHF90PPCOM or $SHFORTRANPPCOM
(the command line) is displayed.
SHF95
The Fortran 95 compiler used for generating shared-library objects.
You should normally set the $SHFORTRAN variable,
which specifies the default Fortran compiler
for all Fortran versions.
You only need to set $SHF95 if you need to use a specific compiler
or compiler version for Fortran 95 files.
SHF95COM
The command line used to compile a Fortran 95 source file
to a shared-library object file.
You only need to set $SHF95COM if you need to use a specific
command line for Fortran 95 files.
You should normally set the $SHFORTRANCOM variable,
which specifies the default command line
for all Fortran versions.
SHF95COMSTR
If set, the string displayed when a Fortran 95 source file
is compiled to a shared-library object file.
If not set, then $SHF95COM or $SHFORTRANCOM
(the command line) is displayed.
SHF95FLAGS
Options that are passed to the Fortran 95 compiler
to generated shared-library objects.
You only need to set $SHF95FLAGS if you need to define specific
user options for Fortran 95 files.
You should normally set the $FORTRANCOMMONFLAGS variable,
which specifies the user-specified options
passed to the default Fortran compiler
for all Fortran versions.
SHF95PPCOM
The command line used to compile a Fortran 95 source file to a
shared-library object file
after first running the file through the C preprocessor.
Any options specified in the $SHF95FLAGS and $CPPFLAGS construction variables
are included on this command line.
You only need to set $SHF95PPCOM if you need to use a specific
C-preprocessor command line for Fortran 95 files.
You should normally set the $SHFORTRANPPCOM variable,
which specifies the default C-preprocessor command line
for all Fortran versions.
SHF95PPCOMSTR
If set, the string displayed when a Fortran 95 source file
is compiled to a shared-library object file
after first running the file through the C preprocessor.
If not set, then $SHF95PPCOM or $SHFORTRANPPCOM
(the command line) is displayed.
SHFORTRAN
The default Fortran compiler used for generating shared-library objects.
SHFORTRANCOM
The command line used to compile a Fortran source file
to a shared-library object file.
By default, any options specified
in the $SHFORTRANFLAGS,
$_FORTRANMODFLAG, and
$_FORTRANINCFLAGS
construction variables are included on this command line.
See also $FORTRANCOM.
SHFORTRANCOMSTR
If set, the string displayed when a Fortran source file
is compiled to a shared-library object file.
If not set, then $SHFORTRANCOM
(the command line) is displayed.
SHFORTRANFLAGS
Options that are passed to the Fortran compiler to generate shared-library objects.
SHFORTRANPPCOM
The command line used to compile a Fortran source file to a
shared-library object file
after first running the file through the C preprocessor.
By default, any options specified in the $SHFORTRANFLAGS,
$CPPFLAGS,
$_CPPDEFFLAGS,
$_FORTRANMODFLAG, and
$_FORTRANINCFLAGS
construction variables are included on this command line.
See also $SHFORTRANCOM.
SHFORTRANPPCOMSTR
If set, the string displayed when a Fortran source file
is compiled to a shared-library object file
after first running the file through the C preprocessor.
If not set, then $SHFORTRANPPCOM
(the command line) is displayed.
SHLIBEMITTER
Contains the emitter specification for the
SharedLibrary builder.
The manpage section "Builder Objects" contains
general information on specifying emitters.
SHLIBNOVERSIONSYMLINKS
Instructs the SharedLibrary builder to not create symlinks for versioned
shared libraries.
SHLIBPREFIX
The prefix used for shared library file names.
_SHLIBSONAME
A macro that automatically generates shared library's SONAME based on $TARGET,
$SHLIBVERSION and $SHLIBSUFFIX. Used by SharedLibrary builder when
the linker tool supports SONAME (e.g. gnulink).
SHLIBSUFFIX
The suffix used for shared library file names.
SHLIBVERSION
When this construction variable is defined, a versioned shared library
is created by the SharedLibrary builder. This activates the
$_SHLIBVERSIONFLAGS and thus modifies the $SHLINKCOM as
required, adds the version number to the library name, and creates the symlinks
that are needed. $SHLIBVERSION versions should exist as alpha-numeric,
decimal-delimited values as defined by the regular expression "\w+[\.\w+]*".
Example $SHLIBVERSION values include '1', '1.2.3', and '1.2.gitaa412c8b'.
_SHLIBVERSIONFLAGS
This macro automatically introduces extra flags to $SHLINKCOM when
building versioned SharedLibrary (that is when $SHLIBVERSION
is set). _SHLIBVERSIONFLAGS usually adds $SHLIBVERSIONFLAGS
and some extra dynamically generated options (such as
-Wl,-soname=$_SHLIBSONAME. It is unused by "plain"
(unversioned) shared libraries.
SHLIBVERSIONFLAGS
Extra flags added to $SHLINKCOM when building versioned
SharedLibrary. These flags are only used when $SHLIBVERSION is
set.
SHLINK
The linker for programs that use shared libraries.
See also $LINK for linking static objects.
On POSIX systems (those using the link tool),
you should normally not change this value as it defaults
to a "smart" linker tool which selects a compiler
driver matching the type of source files in use.
So for example, if you set $SHCXX to a specific
compiler name, and are compiling C++ sources,
the smartlink function will automatically select the same compiler
for linking.
SHLINKCOM
The command line used to link programs using shared libraries.
See also $LINKCOM for linking static objects.
SHLINKCOMSTR
The string displayed when programs using shared libraries are linked.
If this is not set, then $SHLINKCOM (the command line) is displayed.
See also $LINKCOMSTR for linking static objects.
env = Environment(SHLINKCOMSTR = "Linking shared $TARGET")
SHLINKFLAGS
General user options passed to the linker for programs using shared libraries.
Note that this variable should
not
contain
-l
(or similar) options for linking with the libraries listed in $LIBS,
nor
-L
(or similar) include search path options
that scons generates automatically from $LIBPATH.
See
$_LIBFLAGS
above,
for the variable that expands to library-link options,
and
$_LIBDIRFLAGS
above,
for the variable that expands to library search path options.
See also $LINKFLAGS for linking static objects.
SHOBJPREFIX
The prefix used for shared object file names.
SHOBJSUFFIX
The suffix used for shared object file names.
SONAME
Variable used to hard-code SONAME for versioned shared library/loadable module.
env.SharedLibrary('test', 'test.c', SHLIBVERSION='0.1.2', SONAME='libtest.so.2')
The variable is used, for example, by gnulink linker tool.
SOURCE
A reserved variable name that may not be set or used in a construction environment. (See the manpage section "Variable Substitution" for more information).
SOURCE_URL
The URL
(web address)
of the location from which the project was retrieved.
This is used to fill in the
Source:
field in the controlling information for Ipkg and RPM packages.
See the Package builder.
SOURCES
A reserved variable name that may not be set or used in a construction environment. (See the manpage section "Variable Substitution" for more information).
SOVERSION
This will construct the SONAME using on the base library name
(test in the example below) and use specified SOVERSION
to create SONAME.
env.SharedLibrary('test', 'test.c', SHLIBVERSION='0.1.2', SOVERSION='2')
The variable is used, for example, by gnulink linker tool.
In the example above SONAME would be libtest.so.2
which would be a symlink and point to libtest.so.0.1.2
SPAWN
A command interpreter function that will be called to execute command line strings. The function must accept five arguments:
def spawn(shell, escape, cmd, args, env):
shell
is a string naming the shell program to use,
escape
is a function that can be called to escape shell special characters in
the command line,
cmd
is the path to the command to be executed,
args
holds the arguments to the command and
env
is a dictionary of environment variables
defining the execution environment in which the command should be executed.
STATIC_AND_SHARED_OBJECTS_ARE_THE_SAME
When this variable is true, static objects and shared objects are assumed to be the same; that is, SCons does not check for linking static objects into a shared library.
SUBST_DICT
The dictionary used by the Substfile or Textfile builders
for substitution values.
It can be anything acceptable to the dict() constructor,
so in addition to a dictionary,
lists of tuples are also acceptable.
SUBSTFILEPREFIX
The prefix used for Substfile file names,
an empty string by default.
SUBSTFILESUFFIX
The suffix used for Substfile file names,
an empty string by default.
SUMMARY
A short summary of what the project is about.
This is used to fill in the
Summary:
field in the controlling information for Ipkg and RPM packages,
and as the
Description:
field in MSI packages.
See the Package builder.
SWIG
The name of the SWIG compiler to use.
SWIGCFILESUFFIX
The suffix that will be used for intermediate C
source files generated by SWIG.
The default value is '_wrap$CFILESUFFIX' -
that is, the concatenation of the string
_wrap
and the current C suffix $CFILESUFFIX.
By default, this value is used whenever the
-c++
option is
not
specified as part of the
$SWIGFLAGS
construction variable.
SWIGCOM
The command line used to call SWIG.
SWIGCOMSTR
The string displayed when calling SWIG.
If this is not set, then $SWIGCOM (the command line) is displayed.
SWIGCXXFILESUFFIX
The suffix that will be used for intermediate C++
source files generated by SWIG.
The default value is '_wrap$CXXFILESUFFIX' -
that is, the concatenation of the string
_wrap
and the current C++ suffix $CXXFILESUFFIX.
By default, this value is used whenever the
-c++
option is specified as part of the
$SWIGFLAGS
construction variable.
SWIGDIRECTORSUFFIX
The suffix that will be used for intermediate C++ header
files generated by SWIG.
These are only generated for C++ code when the SWIG 'directors' feature is
turned on.
The default value is
_wrap.h.
SWIGFLAGS
General options passed to SWIG.
This is where you should set the target language
(-python,
-perl5,
-tcl, etc.)
and whatever other options you want to specify to SWIG,
such as the -c++ to generate C++ code
instead of C Code.
_SWIGINCFLAGS
An automatically-generated construction variable
containing the SWIG command-line options
for specifying directories to be searched for included files.
The value of $_SWIGINCFLAGS is created
by respectively prepending and appending
$SWIGINCPREFIX and $SWIGINCSUFFIX
to the beginning and end
of each directory in $SWIGPATH.
SWIGINCPREFIX
The prefix used to specify an include directory on the SWIG command line.
This will be prepended to the beginning of each directory
in the $SWIGPATH construction variable
when the $_SWIGINCFLAGS variable is automatically generated.
SWIGINCSUFFIX
The suffix used to specify an include directory on the SWIG command line.
This will be appended to the end of each directory
in the $SWIGPATH construction variable
when the $_SWIGINCFLAGS variable is automatically generated.
SWIGOUTDIR
Specifies the output directory in which SWIG
should place generated language-specific files.
This will be used by SCons to identify
the files that will be generated by the SWIG call,
and translated into the
swig -outdir option on the command line.
SWIGPATH
The list of directories that SWIG will search for included files. SCons' SWIG implicit dependency scanner will search these directories for include files. The default value is an empty list.
Don't explicitly put include directory
arguments in $SWIGFLAGS
the result will be non-portable
and the directories will not be searched by the dependency scanner.
Note: directory names in $SWIGPATH
will be looked-up relative to the SConscript
directory when they are used in a command.
To force
scons
to look-up a directory relative to the root of the source tree use
a top-relative path (#):
env = Environment(SWIGPATH='#/include')
The directory look-up can also be forced using the
Dir()
function:
include = Dir('include')
env = Environment(SWIGPATH=include)
The directory list will be added to command lines
through the automatically-generated
$_SWIGINCFLAGS
construction variable,
which is constructed by
respectively prepending and appending the values of the
$SWIGINCPREFIX and $SWIGINCSUFFIX
construction variables
to the beginning and end
of each directory in $SWIGPATH.
Any command lines you define that need
the SWIGPATH directory list should
include $_SWIGINCFLAGS:
env = Environment(SWIGCOM="my_swig -o $TARGET $_SWIGINCFLAGS $SOURCES")
SWIGVERSION
The detected version string of the SWIG tool.
TAR
The tar archiver.
TARCOM
The command line used to call the tar archiver.
TARCOMSTR
The string displayed when archiving files
using the tar archiver.
If this is not set, then $TARCOM (the command line) is displayed.
env = Environment(TARCOMSTR = "Archiving $TARGET")
TARFLAGS
General options passed to the tar archiver.
TARGET
A reserved variable name that may not be set or used in a construction environment. (See the manpage section "Variable Substitution" for more information).
TARGET_ARCH
The name of the hardware architecture that objects
created using this construction environment should target.
Can be set when creating a construction environment by passing as a keyword
argument in the Environment call.
On the win32 platform,
if the Microsoft Visual C++ compiler is available,
msvc tool setup is done using
$HOST_ARCH and $TARGET_ARCH.
If a value is not specified,
will be set to the same value as $HOST_ARCH.
Changing the value after the environment is initialized
will not cause the tool to be reinitialized.
Compiled objects will be in the target architecture if
the compilation system supports generating for that target.
The latest compiler which can fulfill the requirement will
be selected, unless a different version is directed by the
value of the $MSVC_VERSION construction variable.
On the win32/msvc combination, valid target arch values are
x86,
arm,
i386
for 32-bit targets and
amd64,
arm64,
x86_64
and ia64 (Itanium)
for 64-bit targets.
For example, if you want to compile 64-bit binaries, you would set
TARGET_ARCH='x86_64' when creating the construction environment.
Note that not all target architectures are
supported for all Visual Studio / MSVC versions.
Check the relevant Microsoft documentation.
$TARGET_ARCH is not currently used by other compilation tools,
but the option is reserved to do so in future
TARGET_OS
The name of the operating system that objects
created using this construction environment should target.
Can be set when creating a construction environment by passing as a keyword
argument in the Environment call;.
$TARGET_OS is not currently used by SCons
but the option is reserved to do so in future
TARGETS
A reserved variable name that may not be set or used in a construction environment. (See the manpage section "Variable Substitution" for more information).
TARSUFFIX
The suffix used for tar file names.
TEMPFILE
A callable object used to handle overly long command line strings,
since operations which call out to a shell will fail
if the line is longer than the shell can accept.
This tends to particularly impact linking.
The tempfile object stores the command line in a temporary
file in the appropriate format, and returns
an alternate command line so the invoked tool will make
use of the contents of the temporary file.
If you need to replace the default tempfile object,
the callable should take into account the settings of
$MAXLINELENGTH,
$TEMPFILEPREFIX,
$TEMPFILESUFFIX,
$TEMPFILEARGJOIN,
$TEMPFILEDIR
and
$TEMPFILEARGESCFUNC.
TEMPFILEARGESCFUNC
The default argument escape function is
SCons.Subst.quote_spaces.
If you need to apply extra operations on a command argument
(to fix Windows slashes, normalize paths, etc.)
before writing to the temporary file,
you can set the $TEMPFILEARGESCFUNC variable to a custom function.
Such a function takes a single string argument and returns
a new string with any modifications applied.
Example:
import sys
import re
from SCons.Subst import quote_spaces
WINPATHSEP_RE = re.compile(r"\\([^\"'\\]|$)")
def tempfile_arg_esc_func(arg):
arg = quote_spaces(arg)
if sys.platform != "win32":
return arg
# GCC requires double Windows slashes, let's use UNIX separator
return WINPATHSEP_RE.sub(r"/\1", arg)
env["TEMPFILEARGESCFUNC"] = tempfile_arg_esc_func
TEMPFILEARGJOIN
The string to use to join the arguments passed to
$TEMPFILE when the command line exceeds the limit set by
$MAXLINELENGTH.
The default value is a space.
However for MSVC, MSLINK the default is a line separator
as defined by os.linesep.
Note this value is used literally and not expanded by the subst logic.
TEMPFILEDIR
The directory to create the long-lines temporary file in.
TEMPFILEPREFIX
The prefix for the name of the temporary file used
to store command lines exceeding $MAXLINELENGTH.
The default prefix is '@', which works for the Microsoft Visual C++
and GNU toolchains on Windows.
Set this appropriately for other toolchains,
for example '-@' for the diab compiler
or '-via' for ARM toolchain.
TEMPFILESUFFIX
The suffix for the name of the temporary file used
to store command lines exceeding $MAXLINELENGTH.
The suffix should include the dot ('.') if one is wanted as
it will not be added automatically.
The default is .lnk.
TEX
The TeX formatter and typesetter.
TEXCOM
The command line used to call the TeX formatter and typesetter.
TEXCOMSTR
The string displayed when calling
the TeX formatter and typesetter.
If this is not set, then $TEXCOM (the command line) is displayed.
env = Environment(TEXCOMSTR = "Building $TARGET from TeX input $SOURCES")
TEXFLAGS
General options passed to the TeX formatter and typesetter.
TEXINPUTS
List of directories that the LaTeX program will search for include directories. The LaTeX implicit dependency scanner will search these directories for \include and \import files.
TEXTFILEPREFIX
The prefix used for Textfile file names,
an empty string by default.
TEXTFILESUFFIX
The suffix used for Textfile file names;
.txt by default.
TOOLS
A list of the names of the Tool specification modules that were actually initialized in the current construction environment. This may be useful as a diagnostic aid to see if a tool did (or did not) run. The value is informative and is not guaranteed to be complete.
UNCHANGED_SOURCES
A reserved variable name that may not be set or used in a construction environment. (See the manpage section "Variable Substitution" for more information).
UNCHANGED_TARGETS
A reserved variable name that may not be set or used in a construction environment. (See the manpage section "Variable Substitution" for more information).
VENDOR
The person or organization who supply the packaged software.
This is used to fill in the
Vendor:
field in the controlling information for RPM packages,
and the
Manufacturer:
field in the controlling information for MSI packages.
See the Package builder.
VERSION
The version of the project, specified as a string.
See the Package builder.
VSWHERE
Specify the location of vswhere.exe.
The vswhere.exe executable is distributed with Microsoft Visual Studio and Build Tools since the 2017 edition, but is also available as a standalone installation. It allows queries to obtain detailed information about installations of 2017 and later editions. SCons makes use of this information to determine the state of compiler support for those editions.
Setting the $VSWHERE variable to the path to a specific
vswhere.exe binary
causes SCons to use that binary.
If not set, SCons will search for one,
looking in the following locations in order,
using the first found
($VSWHERE is updated with the location):
%ProgramFiles(x86)%\Microsoft Visual Studio\Installer
|
%ProgramFiles%\Microsoft Visual Studio\Installer
|
%ChocolateyInstall%\bin
|
%LOCALAPPDATA%\Microsoft\WinGet\Links
|
%USERPROFILE%\scoop\shims
|
%SCOOP%\shims
|
In order to take effect, $VSWHERE must be set before
the initial Microsoft Visual C++ compiler discovery takes place.
Discovery happens, at the latest, during the first call to the
Environment function, unless a tools
list is specified which excludes the entire Microsoft Visual C++ toolchain -
that is, omits "defaults"
and any specific tool module that refers to parts of the toolchain
(msvc, mslink, masm, midl
and msvs). In this case, detection is deferred until
any one of those tool modules is invoked manually.
The following two examples illustrate this:
# VSWHERE set as Environment is created
env = Environment(VSWHERE='c:/my/path/to/vswhere')
# Initialization deferred with empty tools, triggered manually
env = Environment(tools=[])
env['VSWHERE'] = r'c:/my/vswhere/install/location/vswhere.exe'
env.Tool('msvc')
env.Tool('mslink')
env.Tool('msvs')
WINDOWS_EMBED_MANIFEST
Set to True to embed the
compiler-generated manifest
(normally ${TARGET}.manifest)
into all Windows executables and DLLs built with this environment,
as a resource during their link step.
This is done using $MT and $MTEXECOM and $MTSHLIBCOM.
See also $WINDOWS_INSERT_MANIFEST.
WINDOWS_INSERT_DEF
If set to true,
a library build of a Windows shared library
(.dll file)
will include a reference to the corresponding
module-definition file at the same time,
if a module-definition file
is not already listed as a build target.
The name of the module-definition file will
be constructed from the base name of the library
and the construction variables
$WINDOWSDEFSUFFIX and
$WINDOWSDEFPREFIX.
The default is to not add a module-definition file.
The module-definition file is not created by this directive,
and must be supplied by the developer.
WINDOWS_INSERT_MANIFEST
If set to true,
scons
will add the manifest file
generated by Microsoft Visual C++ 8.0 and later
to the target list so SCons will be aware they
were generated.
In the case of an executable, the manifest file name
is constructed using
$WINDOWSPROGMANIFESTSUFFIX and
$WINDOWSPROGMANIFESTPREFIX.
In the case of a shared library, the manifest file name
is constructed using
$WINDOWSSHLIBMANIFESTSUFFIX and
$WINDOWSSHLIBMANIFESTPREFIX.
See also $WINDOWS_EMBED_MANIFEST.
WINDOWSDEFPREFIX
The prefix used for a Windows linker module-definition file name. Defaults to empty.
WINDOWSDEFSUFFIX
The suffix used for a Windows linker module-definition file name.
Defaults to .def.
WINDOWSEXPPREFIX
The prefix used for Windows linker exports file names. Defaults to empty.
WINDOWSEXPSUFFIX
The suffix used for Windows linker exports file names.
Defaults to .exp.
WINDOWSPROGMANIFESTPREFIX
The prefix used for executable program manifest files generated by Microsoft Visual C++. Defaults to empty.
WINDOWSPROGMANIFESTSUFFIX
The suffix used for executable program manifest files
generated by Microsoft Visual C++.
Defaults to .manifest.
WINDOWSSHLIBMANIFESTPREFIX
The prefix used for shared library manifest files generated by Microsoft Visual C++. Defaults to empty.
WINDOWSSHLIBMANIFESTSUFFIX
The suffix used for shared library manifest files
generated by Microsoft Visual C++.
Defaults to .manifest.
X_IPK_DEPENDS
This is used to fill in the
Depends:
field in the controlling information for Ipkg packages.
See the Package builder.
X_IPK_DESCRIPTION
This is used to fill in the
Description:
field in the controlling information for Ipkg packages.
The default value is
“$SUMMARY\n$DESCRIPTION”
X_IPK_MAINTAINER
This is used to fill in the
Maintainer:
field in the controlling information for Ipkg packages.
X_IPK_PRIORITY
This is used to fill in the
Priority:
field in the controlling information for Ipkg packages.
X_IPK_SECTION
This is used to fill in the
Section:
field in the controlling information for Ipkg packages.
X_MSI_LANGUAGE
This is used to fill in the
Language:
attribute in the controlling information for MSI packages.
See the Package builder.
X_MSI_LICENSE_TEXT
The text of the software license in RTF format. Carriage return characters will be replaced with the RTF equivalent \\par.
See the Package builder.
X_MSI_UPGRADE_CODE
TODO
X_RPM_AUTOREQPROV
This is used to fill in the
AutoReqProv:
field in the RPM
.spec file.
See the Package builder.
X_RPM_BUILD
internal, but overridable
X_RPM_BUILDREQUIRES
This is used to fill in the
BuildRequires:
field in the RPM
.spec file.
Note this should only be used on a host managed by rpm as the dependencies will not be resolvable at build time otherwise.
X_RPM_BUILDROOT
internal, but overridable
X_RPM_CLEAN
internal, but overridable
X_RPM_CONFLICTS
This is used to fill in the
Conflicts:
field in the RPM
.spec file.
X_RPM_DEFATTR
This value is used as the default attributes for the files in the RPM package. The default value is “(-,root,root)”.
X_RPM_DISTRIBUTION
This is used to fill in the
Distribution:
field in the RPM
.spec file.
X_RPM_EPOCH
This is used to fill in the
Epoch:
field in the RPM
.spec file.
X_RPM_EXCLUDEARCH
This is used to fill in the
ExcludeArch:
field in the RPM
.spec file.
X_RPM_EXLUSIVEARCH
This is used to fill in the
ExclusiveArch:
field in the RPM
.spec file.
X_RPM_EXTRADEFS
A list used to supply extra defintions or flags
to be added to the RPM .spec file.
Each item is added as-is with a carriage return appended.
This is useful if some specific RPM feature not otherwise
anticipated by SCons needs to be turned on or off.
Note if this variable is omitted, SCons will by
default supply the value
'%global debug_package %{nil}'
to disable debug package generation.
To enable debug package generation, include this
variable set either to None, or to a custom
list that does not include the default line.
New in version 3.1.
env.Package(
NAME="foo",
...
X_RPM_EXTRADEFS=[
"%define _unpackaged_files_terminate_build 0"
"%define _missing_doc_files_terminate_build 0"
],
...
)
X_RPM_GROUP
This is used to fill in the
Group:
field in the RPM
.spec file.
X_RPM_GROUP_lang
This is used to fill in the
Group(lang):
field in the RPM
.spec file.
Note that
lang
is not literal
and should be replaced by
the appropriate language code.
X_RPM_ICON
This is used to fill in the
Icon:
field in the RPM
.spec file.
X_RPM_INSTALL
internal, but overridable
X_RPM_PACKAGER
This is used to fill in the
Packager:
field in the RPM
.spec file.
X_RPM_POSTINSTALL
This is used to fill in the
%post:
section in the RPM
.spec file.
X_RPM_POSTUNINSTALL
This is used to fill in the
%postun:
section in the RPM
.spec file.
X_RPM_PREFIX
This is used to fill in the
Prefix:
field in the RPM
.spec file.
X_RPM_PREINSTALL
This is used to fill in the
%pre:
section in the RPM
.spec file.
X_RPM_PREP
internal, but overridable
X_RPM_PREUNINSTALL
This is used to fill in the
%preun:
section in the RPM
.spec file.
X_RPM_PROVIDES
This is used to fill in the
Provides:
field in the RPM
.spec file.
X_RPM_REQUIRES
This is used to fill in the
Requires:
field in the RPM
.spec file.
X_RPM_SERIAL
This is used to fill in the
Serial:
field in the RPM
.spec file.
X_RPM_URL
This is used to fill in the
Url:
field in the RPM
.spec file.
XGETTEXT
Path to xgettext(1) program (found via
Detect()).
See xgettext tool and POTUpdate builder.
XGETTEXTCOM
Complete xgettext command line.
See xgettext tool and POTUpdate builder.
XGETTEXTCOMSTR
A string that is shown when xgettext(1) command is invoked
(default: '', which means "print $XGETTEXTCOM").
See xgettext tool and POTUpdate builder.
_XGETTEXTDOMAIN
Internal "macro". Generates xgettext domain name
form source and target (default: '${TARGET.filebase}').
XGETTEXTFLAGS
Additional flags to xgettext(1).
See xgettext tool and POTUpdate builder.
XGETTEXTFROM
Name of file containing list of xgettext(1)'s source
files. Autotools' users know this as POTFILES.in so they
will in most cases set XGETTEXTFROM="POTFILES.in" here.
The $XGETTEXTFROM files have same syntax and semantics as the well known
GNU POTFILES.in.
See xgettext tool and POTUpdate builder.
_XGETTEXTFROMFLAGS
Internal "macro". Genrates list of -D<dir> flags
from the $XGETTEXTPATH list.
XGETTEXTFROMPREFIX
This flag is used to add single $XGETTEXTFROM file to
xgettext(1)'s commandline (default:
'-f').
XGETTEXTFROMSUFFIX
(default: '')
XGETTEXTPATH
List of directories, there xgettext(1) will look for
source files (default: []).
This variable works only together with $XGETTEXTFROM
_XGETTEXTPATHFLAGS
Internal "macro". Generates list of -f<file> flags
from $XGETTEXTFROM.
XGETTEXTPATHPREFIX
This flag is used to add single search path to
xgettext(1)'s commandline (default:
'-D').
XGETTEXTPATHSUFFIX
(default: '')
YACC
The parser generator.
YACC_GRAPH_FILE
If supplied, write a graph of the automaton to a file with the name
taken from this variable.
Will be emitted as a --graph=
command-line option. Use this in preference to including
--graph= in $YACCFLAGS directly.
New in version 4.4.0.
YACC_GRAPH_FILE_SUFFIX
Previously specified by $YACCVCGFILESUFFIX.
The suffix of the file
containing a graph of the grammar automaton
when the -g option
(or --graph= without an option-argument)
is used in $YACCFLAGS.
Note that setting this variable informs SCons
how to construct the graph filename for tracking purposes,
it does not affect the actual generated filename.
Various yacc tools have emitted various formats
at different times.
Set this to match what your parser generator produces.
New in version 4.6.0.
YACC_HEADER_FILE
If supplied, generate a header file with the name taken from this variable.
Will be emitted as a --header=
command-line option. Use this in preference to including
--header= in $YACCFLAGS directly.
New in version 4.4.0.
YACCCOM
The command line used to call the parser generator to generate a source file.
YACCCOMSTR
The string displayed when generating a source file
using the parser generator.
If this is not set, then $YACCCOM (the command line) is displayed.
env = Environment(YACCCOMSTR="Yacc'ing $TARGET from $SOURCES")
YACCFLAGS
General options passed to the parser generator.
In addition to passing the value on during invocation,
the yacc tool also examines this construction variable for options
which cause additional output files to be generated,
and adds those to the target list.
If the -d option is present in $YACCFLAGS
scons assumes that the call will also create a header file
with the suffix defined by $YACCHFILESUFFIX
if the yacc source file ends in a .y suffix,
or a file with the suffix defined by $YACCHXXFILESUFFIX
if the yacc source file ends in a .yy suffix.
The header will have the same base name as the requested target.
This is only correct if the executable is bison
(or win_bison).
If using Berkeley yacc (byacc),
y.tab.h is always written -
avoid the -d in this case and
use $YACC_HEADER_FILE instead.
If a -g option is present,
scons assumes that the call will also create a graph file
with the suffix defined by $YACCVCGFILESUFFIX.
If a -v option is present,
scons assumes that the call will also create an output debug file
with the suffix .output.
Also recognized are GNU bison options
--header
(and its deprecated synonym --defines),
which is similar to
-d
but gives the option to explicitly name the output header file
through an option argument;
and --graph,
which is similar to
-g
but gives the option to explicitly name the output graph file
through an option argument.
The file suffixes described for
-d and -g above
are not applied if these are used in the option=argument form.
Note that files specified by --header= and
--graph= may not be properly handled
by SCons in all situations, and using those in $YACCFLAGS
should be considered legacy support only.
Consider using $YACC_HEADER_FILE
and $YACC_GRAPH_FILE instead
if the files need to be explicitly named
(new in version 4.4.0).
YACCHFILESUFFIX
The suffix of the C
header file generated by the parser generator
when the -d option
(or --header without an option-argument)
is used in $YACCFLAGS.
Note that setting this variable informs SCons
how to construct the header filename for tracking purposes,
it does not affect the actual generated filename.
Set this to match what your parser generator produces.
The default value is
.h.
YACCHXXFILESUFFIX
The suffix of the C++
header file generated by the parser generator
when the -d option
(or --header without an option-argument)
is used in $YACCFLAGS.
Note that setting this variable informs SCons
how to construct the header filename for tracking purposes,
it does not affect the actual generated filename.
Set this to match what your parser generator produces.
The default value is .hpp.
YACCVCGFILESUFFIX
Obsoleted. Use $YACC_GRAPH_FILE_SUFFIX instead.
The value is used only if $YACC_GRAPH_FILE_SUFFIX is not set.
The default value is .gv.
Changed in version 4.6.0: deprecated. The default value
changed from .vcg (bison stopped generating
.vcg output with version 2.4, in 2006).
ZIP
The zip compression and file packaging utility.
ZIP_OVERRIDE_TIMESTAMP
An optional timestamp which overrides the last modification time of the file when stored inside the Zip archive. This is a tuple of six values: Year (>= 1980) Month (one-based) Day of month (one-based) Hours (zero-based) Minutes (zero-based) Seconds (zero-based)
ZIPCOM
The command line used to call the zip utility, or the internal Python function used to create a zip archive.
ZIPCOMPRESSION
The
compression
flag
from the Python
zipfile
module used by the internal Python function
to control whether the zip archive
is compressed or not.
The default value is
zipfile.ZIP_DEFLATED,
which creates a compressed zip archive.
This value has no effect if the
zipfile
module is unavailable.
ZIPCOMSTR
The string displayed when archiving files
using the zip utility.
If this is not set, then $ZIPCOM
(the command line or internal Python function) is displayed.
env = Environment(ZIPCOMSTR = "Zipping $TARGET")
ZIPFLAGS
General options passed to the zip utility.
ZIPROOT
An optional zip root directory (default empty). The filenames stored in the zip file will be relative to this directory, if given. Otherwise the filenames are relative to the current directory of the command. For instance:
env = Environment()
env.Zip('foo.zip', 'subdir1/subdir2/file1', ZIPROOT='subdir1')
will produce a zip file foo.zip
containing a file with the name
subdir2/file1 rather than
subdir1/subdir2/file1.
ZIPSUFFIX
The suffix used for zip file names.
SCons
supports a
configure context,
an integrated mechanism similar to the
various AC_CHECK macros in GNU Autoconf
for testing the existence of external items needed
for the build, such as C header files, libraries, etc.
The mechanism is portable across platforms.
scons
does not maintain an explicit cache of the tested values
(this is different than Autoconf),
but uses its normal dependency tracking to keep the checked values
up to date. However, users may override this behaviour with the
--config
command line option.
Configure(env, [custom_tests, conf_dir, log_file, config_h, clean, help])env.Configure([custom_tests, conf_dir, log_file, config_h, clean, help])
Create a configure context, which tracks information
discovered while running tests. The context includes a local construction environment
(available as context.env)
which is used when running the tests and
which can be updated with the check results.
Only one context may be active
at a time, but a new context can be created
after the active one is completed.
For the global function form, the required env
describes the initial values for the context's local construction environment;
for the construction environment method form the instance provides the values.
Changed in version 4.0: raises an exception on an attempt to create a new context when there is an active context.
custom_tests
specifies a dictionary containing custom checks
(see details below).
The default value is None,
to indicate there are no custom checks in the configure context.
conf_dir
specifies a directory where the test cases are built.
This directory is not used for building normal targets.
The default value is
“#/.sconf_temp”.
log_file
specifies a file which collects the output from commands
that are executed to check for the existence of header files, libraries, etc.
The default is “#/config.log”.
If you are using variant directories,
you may want to place the log file for a given build
under that build's variant directory.
config_h
specifies a C header file where the results of tests
will be written. The results will consist of lines like
#define HAVE_STDIO_H,
#define HAVE_LIBM, etc.
Customarily, the name chosen is “config.h”.
The default is to not write a
config_h
file.
You can specify the same
config_h
file in multiple calls to Configure,
in which case SCons
will concatenate all results in the specified file.
Note that SCons
uses its normal dependency checking
to decide if it's necessary to rebuild
the specified
config_h
file.
This means that the file is not necessarily re-built each
time scons is run,
but is only rebuilt if its contents will have changed
and some target that depends on the
config_h
file is being built.
The clean
and
help
arguments can be used to suppress execution of the configuration
tests when the
-c/--clean
or
-H/-h/--help
options are used, respectively.
The default behavior is always to execute
configure context tests,
since the results of the tests may
affect the list of targets to be cleaned
or the help text.
If the configure tests do not affect these,
then you may add the
clean=False
or
help=False
arguments
(or both)
to avoid unnecessary test execution.
context.Finish()
This method must be called after configuration is done.
Though required, this is not enforced except
if Configure is called again while there is still an active context,
in which case an exception is raised.
Finish returns the environment as modified
during the course of running the configuration checks.
After this method is called, no further checks can be performed
with this configuration context.
However, you can create a new
configure context to perform additional checks.
Example of a typical Configure usage:
env = Environment()
conf = Configure(env)
if not conf.CheckCHeader("math.h"):
print("We really need math.h!")
Exit(1)
if conf.CheckLibWithHeader("qt", "qapp.h", "c++", "QApplication qapp(0,0);"):
# do stuff for qt - usage, e.g.
conf.env.Append(CPPDEFINES="WITH_QT")
env = conf.Finish()
A configure context
has the following predefined methods which
can be used to perform checks. Where
language is an optional parameter,
it specifies the compiler to use for the check,
currently a choice of C or C++.
The spellings accepted for
C are “C” or “c”;
for C++ the value can be
“CXX”, “cxx”, “C++”
or “c++”.
If language is omitted,
“C” is assumed.
context.CheckHeader(header, [include_quotes, language])
Checks if
header
is usable in the specified language.
header
may be a list,
in which case the last item in the list
is the header file to be checked,
and the previous list items are
header files whose
#include
lines should precede the
header line being checked for.
The optional argument
include_quotes
must be
a two character string, where the first character denotes the opening
quote and the second character denotes the closing quote.
By default, both characters are " (double quote).
Returns a boolean indicating success or failure.
context.CheckCHeader(header, [include_quotes])
Checks if
header
is usable when compiling a C language program.
header
may be a list,
in which case the last item in the list
is the header file to be checked,
and the previous list items are
header files whose
#include
lines should precede the
header line being checked for.
The optional argument
include_quotes
must be
a two character string, where the first character denotes the opening
quote and the second character denotes the closing quote.
By default, both characters are " (double quote).
Note this is a wrapper around
CheckHeader.
Returns a boolean indicating success or failure.
context.CheckCXXHeader(header, [include_quotes])
Checks if
header
is usable when compiling a C++ language program.
header
may be a list,
in which case the last item in the list
is the header file to be checked,
and the previous list items are
header files whose
#include
lines should precede the
header line being checked for.
The optional argument
include_quotes
must be
a two character string, where the first character denotes the opening
quote and the second character denotes the closing quote.
By default, both characters are " (double quote).
Note this is a wrapper around
CheckHeader.
Returns a boolean indicating success or failure.
context.CheckFunc(function_name, [header, language, funcargs])
Checks if function_name is usable
in the context's local environment, using the compiler
specified by language - that is,
can a check referencing it be compiled using the current values
of $CFLAGS, $CPPFLAGS,
$LIBS or other relevant construction variables.
The optional
header
argument is a string representing a code fragment
to place at the top of the test program
that will be compiled to check if the function exists.
If omitted, the default stanza will be
(with function_name appropriately substituted):
#ifdef __cplusplus extern "C" #endif char function_name(void);
If header is supplied, it should not include
the standard header file that declares function_name and it
should include a dummy prototype similar to the default case. If
this is not possible, the optional funcargs argument can be used
to specify a string containing an argument list with the same number and type of
arguments as the prototype. The arguments can simply be constant values of the correct
type. Modern C/C++ compilers reject implicit function declarations and may also reject
function calls whose arguments are not type compatible with the prototype.
Changed in version 4.7.0: added the funcargs.
Returns a boolean indicating success or failure.
context.CheckLib([library, symbol, header, language, autoadd=True, append=True, unique=False])
Checks if
library
provides
symbol by compiling a simple stub program
with the compiler selected by language,
and optionally adds that library to the context.
If supplied, the text of header is included at the
top of the stub.
If autoadd is true (the default),
and the library provides the specified
symbol (as defined by successfully
linking the stub program),
it is added to the $LIBS construction variable in the context.
if append is true (the default),
the library is appended, otherwise it is prepended.
If unique is true,
and the library would otherwise be added but is
already present in $LIBS in the configure context,
it will not be added again. The default is False.
library can be a list of library names,
or None (the default if the argument is omitted).
If the former, symbol is checked against
each library name in order, returning
(and reporting success) on the first
successful test; if the latter,
it is checked with the current value of $LIBS
(in this case no library name would be added).
If symbol
is omitted or None,
then CheckLib
just checks if
you can link against the specified
library,
Note though it is legal syntax, it would
not be very useful to call this method
with library
and symbol both
omitted or None -
at least one should be supplied.
Returns a boolean indicating success or failure.
Changed in version 4.5.0: added the
append and unique
parameters.
context.CheckLibWithHeader(library, header, [language, call, autoadd=True, append=True, unique=False])
Provides an alternative to the
CheckLib method
for checking for libraries usable in a build.
library
specifies a library or list of libraries to check.
header
specifies a header to include in the test program,
and language indicates the compiler to use.
header
may be a list,
in which case the last item in the list
is the header file to be checked,
and the previous list items are
header files whose
#include
lines should precede the
header line being checked for.
A code fragment
(must be a a valid expression, including a trailing semicolon)
to serve as the test can be supplied in
call;
if not supplied,
the default checks the ability to link against the specified
library.
If autoadd is true (the default),
the first library that passes the check
is added to the $LIBS construction variable in the context
and the method returns.
If append is true (the default),
the library is appended, otherwise prepended.
If unique is true,
and the library would otherwise be added but is
already present in $LIBS in the configure context,
it will not be added again. The default is False.
Returns a boolean indicating success or failure.
Changed in version 4.5.0: added the
append and unique
parameters.
context.CheckType(type_name, [includes, language])
Checks for the existence of a type defined by
typedef.
type_name
specifies the typedef name to check for.
includes
is a string containing one or more
#include
lines that will be inserted into the program
that will be run to test for the existence of the type.
Example:
sconf.CheckType('foo_type', '#include "my_types.h"', 'C++')
Returns a boolean indicating success or failure.
context.CheckTypeSize(type_name, [header, language, expect])
Checks for the size of a type defined by
typedef.
type_name
specifies the typedef name to check for.
The optional
header
argument is a string
that will be
placed at the top
of the test file
that will be compiled
to check if the type exists;
the default is empty.
If the optional
expect,
is supplied, it should be an integer size;
CheckTypeSize will fail unless
type_name is actually
that size.
Returns the size in bytes, or zero if the type was not found
(or if the size did not match optional expect).
For example,
CheckTypeSize('short', expect=2)
will return the size 2 only if short is
actually two bytes.
context.CheckCC()
Checks whether the C compiler
(as defined by the $CC construction variable) works,
by trying to compile a small source file.
This provides a more rigorous check:
by default, SCons itself only detects if there is a program
with the correct name, not if it is a functioning compiler.
Returns a boolean indicating success or failure.
The test program will be built with the
same command line as the one used by the Object builder
for C source files, so by setting relevant construction variables
it can be used to detect if particular compiler flags will
be accepted or rejected by the compiler.
Returns a boolean indicating success or failure.
context.CheckCXX()
Checks whether the C++ compiler
(as defined by the $CXX construction variable) works,
by trying to compile a small source file.
This provides a more rigorous check:
by default, SCons itself only detects if there is a program
with the correct name, not if it is a functioning compiler.
Returns a boolean indicating success or failure.
The test program will be built with the
same command line as the one used by the Object builder
for C++ source files, so by setting relevant construction variables
it can be used to detect if particular compiler flags will
be accepted or rejected by the compiler.
Returns a boolean indicating success or failure.
context.CheckSHCC()
Checks whether the shared-object C compiler (as defined by the
$SHCC construction variable) works
by trying to compile a small source file.
This provides a more rigorous check:
by default, SCons itself only detects if there is a program
with the correct name, not if it is a functioning compiler.
Returns a boolean indicating success or failure.
The test program will be built with the
same command line as the one used by the SharedObject builder
for C source files, so by setting relevant construction variables
it can be used to detect if particular compiler flags will
be accepted or rejected by the compiler.
Note this does not check whether a shared library/dll can
be created.
Returns a boolean indicating success or failure.
context.CheckSHCXX()
Checks whether the shared-object C++ compiler (as defined by the
$SHCXX construction variable)
works by trying to compile a small source file.
This provides a more rigorous check:
by default, SCons itself only detects if there is a program
with the correct name, not if it is a functioning compiler.
Returns a boolean indicating success or failure.
The test program will be built with the
same command line as the one used by the SharedObject builder
for C++ source files, so by setting relevant construction variables
it can be used to detect if particular compiler flags will
be accepted or rejected by the compiler.
Note this does not check whether a shared library/dll can
be created.
Returns a boolean indicating success or failure.
context.CheckProg(prog_name)
Checks if
prog_name
exists in the path SCons will use at build time.
(context.env['ENV']['PATH']).
Returns a string containing the path to the program,
or None on failure.
context.CheckDeclaration(symbol, [includes, language])
Checks if the specified
symbol
is declared.
includes
is a string containing one or more
#include
lines that will be inserted into the program
that will be run to test for the existence of the symbol.
Returns a boolean indicating success or failure.
context.CheckMember(aggregate_member,
[header, language])
Checks for the existence of a member of the C/C++ struct or class.
aggregate_member
specifies the struct/class and member to check for.
header
is a string containing one or more
#include
lines that will be inserted into the program
that will be run to test for the existence of the member.
Example:
sconf.CheckMember('struct tm.tm_sec', '#include <time.h>')
Returns a boolean indicating success or failure.
context.Define(symbol, [value, comment])
This method does not check for anything, but rather forces
the definition of a preprocessor macro that will be added
to the configuration header file.
name is the macro's identifier.
If value is given,
it will be be used as the macro replacement value.
If value is a string and needs to
display with quotes, the quotes need to be included,
as in '"string"'
If the optional
comment is given,
it is inserted as a comment above the macro definition
(suitable comment marks will be added automatically).
This is analogous to using AC_DEFINE in Autoconf.
Examples:
env = Environment()
conf = Configure(env)
# Puts the following line in the config header file:
# #define A_SYMBOL
conf.Define("A_SYMBOL")
# Puts the following line in the config header file:
# #define A_SYMBOL 1
conf.Define("A_SYMBOL", 1)
Examples of quoting string values:
env = Environment()
conf = Configure(env)
# Puts the following line in the config header file:
# #define A_SYMBOL YA
conf.Define("A_SYMBOL", "YA")
# Puts the following line in the config header file:
# #define A_SYMBOL "YA"
conf.Define("A_SYMBOL", '"YA"')
Example including comment:
env = Environment()
conf = Configure(env)
# Puts the following lines in the config header file:
# /* Set to 1 if you have a symbol */
# #define A_SYMBOL 1
conf.Define("A_SYMBOL", 1, "Set to 1 if you have a symbol")
You can define your own custom checks
in addition to using the predefined checks.
To enable custom checks,
pass a dictionary to the Configure function
as the custom_tests parameter.
The dictionary maps the names of the checks
to the custom check callables
(either a Python function or an instance of a class implementing a
__call__ method).
Each custom check will be called with a
a CheckContext
instance as the first parameter followed by the remaining arguments,
which must be supplied by the user of the check.
A CheckContext is not the same as
a configure context; rather it is an instance of a class
which contains a configure context
(available as chk_ctx.sconf).
A CheckContext
provides the following methods which custom checks
can make use of::
chk_ctx.Message(text)
Displays text
as an indicator of progess.
For example: Checking for library X....
Usually called before the check is started.
chk_ctx.Result(res)
Displays a result message as an indicator of progress.
If res is an integer,
displays yes
if res evaluates true
or no if false.
If res is a string,
it is displayed as-is.
Usually called after the check has completed.
chk_ctx.TryCompile(text, extension='')
Checks if a file containing text
and given the specified extension (e.g.
'.c')
can be compiled to an object file
using the environment's Object builder.
Returns a boolean indicating success or failure.
chk_ctx.TryLink(text, extension='')
Checks if a file containing text
and given the specified extension (e.g.
'.c')
can be compiled to an executable program
using the environment's Program builder.
Returns a boolean indicating success or failure.
chk_ctx.TryRun(text, extension='')
Checks if a file containing text
and given the specified extension (e.g.
'.c')
can be compiled to an excutable program
using the environment's Program builder and subsequently executed.
Execution is only attempted if the build succeeds.
If the program executes successfully
(that is, its return status is 0),
a tuple (True, outputStr)
is returned, where outputStr
is the standard output of the program.
If the program fails execution
(its return status is non-zero),
then (False, '') is returned.
chk_ctx.TryAction(action, [text, extension=''])
Checks if the specified
action
with an optional source file
(contents text,
given extension extension)
can be executed.
action
may be anything which can be converted to an
Action Object.
On success, a tuple
(True, outputStr)
is returned, where outputStr
is the content of the target file.
On failure
(False, '')
is returned.
chk_ctx.TryBuild(builder, [text, extension=''])
Low level implementation for testing specific builds;
the methods above are based on this method.
Given the Builder instance
builder
and the optional
text
of a source file with optional
extension,
returns a boolean indicating success or failure.
In addition,
chk_ctx.lastTarget
is set to the build target node if the build was successful.
Example of implementing and using custom checks:
def CheckQt(chk_ctx, qtdir):
chk_ctx.Message('Checking for qt ...')
lastLIBS = chk_ctx.env['LIBS']
lastLIBPATH = chk_ctx.env['LIBPATH']
lastCPPPATH = chk_ctx.env['CPPPATH']
chk_ctx.env.Append(LIBS='qt', LIBPATH=qtdir + '/lib', CPPPATH=qtdir + '/include')
ret = chk_ctx.TryLink(
"""\
#include <qapp.h>
int main(int argc, char **argv) {
QApplication qapp(argc, argv);
return 0;
}
"""
)
if not ret:
chkctx.env.Replace(LIBS=lastLIBS, LIBPATH=lastLIBPATH, CPPPATH=lastCPPPATH)
chkctx.Result(ret)
return ret
env = Environment()
conf = Configure(env, custom_tests={'CheckQt': CheckQt})
if not conf.CheckQt('/usr/lib/qt'):
print('We really need qt!')
Exit(1)
env = conf.Finish()
Often when building software,
specialized information needs to be conveyed at build time
to override the defaults in the build scripts.
Command-line arguments (like --implcit-cache)
and giving names of build targets are two ways to do that.
Another is to provide variable-assignment arguments
on the command line.
For the particular case where you want to specify new
values for construction variables,
SCons provides a Variables
object to simplify collecting those
and updating a construction environment with the values.
The typical calling style looks like:
scons VARIABLE=foo
Variables specified in the above way
can be manually processed by accessing the
ARGUMENTS dictionary
(or ARGLIST list),
but using a Variables object allows you to describe
anticipated variables,
convert them to a suitable type if necessary,
validate the values are within defined constraints,
and define defaults, help messages and aliases.
This is conceptually similar to the structure of options
(see AddOption).
It also allows obtaining values from a saved variables file,
or from a custom dictionary in an SConscript file.
The processed variables can then be applied to the desired construction environment.
Roughly speaking, arguments are used to convey information to the SCons program about how it should behave; variables are used to convey information to the build (although SCons does not enforce any such constraint).
To obtain an object for manipulating variables,
call the Variables factory function:
Variables([files, [args]])
If files is a filename or list of filenames,
they are considered to be Python scripts which will
be executed to set variables when the
Update
method is called -
this allows the use of Python syntax in the assignments.
A file can be the result of an earlier call to the
Save method.
If files is not specified,
or the
files
argument is
None,
then no files will be read.
Supplying None is required
if there are no files but you want to specify
args as a positional argument;
this can be omitted if using the keyword argument style.
If any of files is missing,
it is silently skipped.
Either of the following example file contents could be used to set an alternative C compiler:
CC = 'my_cc'
CC = os.environ.get('CC')
If
args
is specified, it must be a dictionary.
The key-value pairs from args
will be added to those obtained from
files, if any.
Keys from args
take precendence over same-named keys from files.
If omittted, the default is the
ARGUMENTS
dictionary that holds build variables
specified on the command line.
Using ARGUMENTS allows you to indicate that if a setting appears
on both the command line and in the file(s),
the command line setting is preferred.
However, any dictionary can be passed.
Examples:
vars = Variables('custom.py')
vars = Variables('overrides.py', ARGUMENTS)
vars = Variables(None, {FOO:'expansion', BAR:7})
vars = Variables(args={FOO:'expansion', BAR:7})
Calling Variables with no arguments is equivalent to:
vars = Variables(files=None, args=ARGUMENTS)
A Variables object serves as a container for
descriptions of variables,
which are added by calling methods of the object.
Each variable consists of a name (which will
become a construction variable), aliases for the name,
a help message, a default value,
and functions to validate and convert values.
Once the object is asked to process variables,
it matches up data from the input
sources it was given with the definitions,
and generates key-value pairs which are added
to the specified construction environment,
except that if any variable was described
to have a default of None,
it is not added to
the construction environment unless it
appears in the input sources.
Otherwise, a variable not in the
input sources is added using its default value.
Note that since the variables are eventually added as construction variables, you should choose variable names which do not unintentionally change pre-defined construction variables that your project will make use of (see the section called “Construction Variables” for a reference), since variables obtained have values overridden, not merged.
Also note there is currently no way to use the Variables
mechanism to define a variable which the user is
required to supply;
if necessary this can be implemented by accessing
ARGUMENTS directly,
although that only applies to the command line,
not to any stored-values files.
A Variables object has the following methods:
vars.Add(key, [help, default, validator, converter, subst])
Add a customizable construction variable to the Variables object.
key
is either the name of the variable,
or a sequence of strings, in which case
the first item in the sequence is taken as the variable name,
and any remaining values are considered aliases for the variable.
key is mandatory,
there is no default.
help
is the help text for the variable
(defaults to an empty string).
default
is the default value of the variable
(defaults to None).
If the optional validator argument is supplied,
it is a callback function to validate the value of the variable
when the variables are processed
(that is, when the Update
method runs).
A validator function must accept three arguments:
key,
value
and env,
and should raise an exception (with a helpful error message)
if value is invalid.
No return value is expected from the validator.
If the optional converter argument is supplied,
it is a callback function to convert the value into
one suitable for adding to the construction environment.
A converter function must accept the
value argument,
and may declare env
as a second argument if it needs access to the
construction environment while validating - the function will be called appropriately.
The converter is called before the validator;
it must return a value, which is then passed to the
validator (if any) for checking.
In general, the converter should not fail,
leaving validation checks to the validator,
although if an operation is impossible to complete
or there is no separate validator
it can raise a ValueError.
Substitution will be performed on the variable value
before the converter and validator are called,
unless the optional subst parameter
is false (default True).
Suppressing substitution may be useful if the variable value
looks like a construction variable reference (e.g. $VAR)
and the validator and/or converter should see it unexpanded.
As a special case, if key
is a sequence and is the only
argument to Add, it is unpacked into the five parameters
key,
help,
default,
validator and
converter,
with any missing members from the right filled in with
the respective default values.
This form allows it
to consume a tuple emitted by the convenience functions
BoolVariable,
EnumVariable,
ListVariable,
PackageVariable
and
PathVariable.
Examples:
vars.Add('CC', help='The C compiler')
def valid_color(key, val, env):
if not val in ['red', 'blue', 'yellow']:
raise Exception("Invalid color value '%s'" % val)
vars.Add('COLOR', validator=valid_color)
Changed in version 4.8.0:
added the subst parameter.
vars.AddVariables(args)
A convenience method that adds
one or more customizable construction variables
to a Variables object in one call;
equivalent to calling
Add
multiple times.
Each args member
must be a tuple that contains the arguments
for an individual call to the Add method
using the "special case" form;
the other calling styles (individual positional
arguments and/or keyword arguments) are not supported.
opt.AddVariables(
("debug", "", 0),
("CC", "The C compiler"),
("VALIDATE", "An option for testing validation", "notset", validator, None),
)
vars.Update(env, [args])
Process the input sources recorded
when the Variables object was initialized
and update
env
with the customized construction variables.
The names of any variables in the input sources that are not
configured in the Variables object
are recorded and may be retrieved using the
UnknownVariables
method.
If the optional
args
argument is provided, it is a dictionary of variables
to use in place of the one saved when
Variables
was called.
Normally, Update is not called directly,
but rather invoked indirectly by passing the Variables object to
the Environment function:
env = Environment(..., variables=vars)
vars.UnknownVariables()
Returns a dictionary containing any
variables that were specified in the
files and/or
args parameters
when Variables
was called, but the object was not actually configured for.
This information is not available until the
Update
method has run.
env = Environment(variables=vars)
for key, value in vars.UnknownVariables():
print("unknown variable: %s=%s" % (key, value))
vars.Save(filename, env)
Saves the currently set variables into a script file named
by filename.
This provides a way to cache particular variable settings for reuse.
Only variables that are set to non-default values are saved.
You can load these saved variables on a subsequent run
by passing filename to the
Variables function,
env = Environment()
vars = Variables(['variables.cache', 'custom.py'])
vars.Add(...)
vars.Update(env)
vars.Save('variables.cache', env)
vars.GenerateHelpText(env, [sort])
Return a formatted string with the help text collected
from all the variables configured in this Variables object.
This string is suitable for passing in to the Help function.
The generated string include an indication of the
actual value in the environment given by env.
If the optional
sort parameter is set to
a callable value, it is used as a comparison function to
determine how to sort the added variables.
This function must accept two arguments, compare them,
and return a negative integer if the first is
less-than the second, zero if equal, or a positive integer
if greater-than.
If sort is not callable,
but is set to True,
an alphabetical sort is performed.
The default is False (unsorted).
Help(vars.GenerateHelpText(env))
def cmp(a, b):
return (a > b) - (a < b)
Help(vars.GenerateHelpText(env, sort=cmp))
vars.FormatVariableHelpText(env, opt, help, default, actual)
Returns a formatted string
containing the printable help text
for the single option opt.
It is normally not called directly,
but is called by the GenerateHelpText
method to create the returned help text.
It may be overridden with your own
function that takes the arguments specified above
and returns a string of help text formatted to your liking.
Note that GenerateHelpText
will not put any blank lines or extra
characters in between the entries,
so you must add those characters to the returned
string if you want the entries separated.
def my_format(env, opt, help, default, actual):
fmt = "\n%s: default=%s actual=%s (%s)\n"
return fmt % (opt, default, actual, help)
vars.FormatVariableHelpText = my_format
To make it more convenient to describe custom variables,
SCons provides some pre-defined variable types,
acessible through factory functions that generate
a tuple appropriate for directly passing to
the Add or AddVariables method:
BoolVariable(key, help, default)
Set up a Boolean variable.
The variable will use
the specified name
key,
have a default value of
default,
and help
will form the descriptive part of the help text.
The variable will interpret the command-line values
y,
yes,
t,
true,
1,
on
and
all
as true,
and the command-line values
n,
no,
f,
false,
0,
off
and
none
as false.
EnumVariable(key, help, default, allowed_values, [map, ignorecase])
Set up a variable
whose value may only be from
a specified list ("enumeration") of values.
The variable will have the name
key,
have a default value of
default
and help
will form the descriptive part of the help text.
Any value that is not in
allowed_values
will raise an error,
except that the optional
map
argument is a dictionary
that can be used to map additional names into
a particular name in the
allowed_values list.
If the value of optional
ignore_case
is
0
(the default),
then the values are case-sensitive.
If the value of
ignore_case
is
1,
then values will be matched
case-insensitively.
If the value of
ignore_case
is
2,
then values will be matched
case-insensitively,
and all input values will be
converted to lower case.
ListVariable(key, help, default, names, [map, validator])
Set up a variable
whose value may be one or more
from a specified list of values.
The variable will have the name
key,
have a default value of
default,
and help
will form the descriptive part of the help text.
Any value that is not in
names or the special values
all or
none
will raise an error.
More than one value may be specified,
separated by commas.
default may be specified
either as a string of comma-separated value,
or as a list of values.
The optional
map
argument is a dictionary
that can be used to convert
input values into specific legal values
in the
names
list.
(Note that the additional values accepted through
the use of a map are not
reflected in the generated help message).
The optional validator argument
can be used to specify a custom validator callback function,
as described for Add.
The default is to use an internal validator routine.
New in 4.8.0: validator.
PackageVariable(key, help, default)
Set up a variable for a package,
where if the variable is specified,
the construction variable named by key
will end with a value of True,
False, or a user-specified value.
For example,
a package could be a third-party software component,
the build could use the information to
exclude the package, include the package in the standard way,
or include the package using a specified
directory path to find the package files.
The variable will have a default value
default,
and help
will form the descriptive part of the help text.
The variable supports (case-insensitive) truthy values
1,
yes,
true,
on,
enable
and
search
to indicate the package is "enabled",
and the (case-insensitive) falsy values
0,
no,
false,
off
and
disable
to indicate the package is "disabled".
The value of the variable may also be set to an arbitrary string, which is taken to be the path name to the package that is being enabled. The validator will raise an exception if this path does not exist in the filesystem.
PathVariable(key, help, default, [validator])
Set up a variable
whose value is expected to be a path name.
The construction variable named by key
will have have a default value of
default,
and help
will form the descriptive part of the help text.
An optional
validator argument
may be specified.
The validator will be called to
verify that the specified path
is acceptable.
SCons supplies the
following ready-made validators:
PathVariable.PathExists
Verify that the specified path exists
(this the default behavior if no
validator is supplied).
PathVariable.PathIsFile
Verify that the specified path exists and is a regular file.
PathVariable.PathIsDir
Verify that the specified path exists and is a directory.
PathVariable.PathIsDirCreate
Verify that the specified path exists and is a directory; if it does not exist, create the directory.
PathVariable.PathAccept
Accept the specific path name argument without validation, suitable for when you want your users to be able to specify a directory path that will be created as part of the build process, for example.
You may supply your own
validator
function,
which must accept three arguments:
key,
the name of the variable to be set;
val,
the specified value being checked;
and
env,
the construction environment,
and should raise an exception
if the specified value is not acceptable.
These functions make it
convenient to create a number
of variables with consistent behavior
in a single call to the AddVariables
method:
vars.AddVariables(
BoolVariable(
"warnings",
help="compilation with -Wall and similar",
default=True,
),
EnumVariable(
"debug",
help="debug output and symbols",
default="no",
allowed_values=("yes", "no", "full"),
map={},
ignorecase=0, # case sensitive
),
ListVariable(
"shared",
help="libraries to build as shared libraries",
default="all",
names=list_of_libs,
),
PackageVariable(
"x11",
help="use X11 installed here (yes = search some places)",
default="yes",
),
PathVariable(
"qtdir",
help="where the root of Qt is installed",
default=qtdir),
PathVariable(
"foopath",
help="where the foo library is installed",
default=foopath,
validator=PathVariable.PathIsDir,
),
)
SCons represents objects that are the sources or targets of
build operations as Nodes,
which are internal data structures.
There are a number of user-visible types of nodes:
File Nodes, Directory Nodes, Value Nodes and Alias Nodes.
Some of the node types have public attributes and methods,
described below. Each of the node types has a global function
and a matching environment method to create instances:
File, Dir, Value and Alias.
The File and Dir
functions/methods return
File Nodes and Directory Nodes, respectively.
Such Filesystem Nodes
represent build components that correspond to an entry
in the computer's filesystem,
whether or not such an entry exists at the time the Node is created.
You do not usually need to explicitly create filesystem Nodes,
since when you supply a string as a target or source of a Builder,
SCons will create the Nodes as needed to populate the
dependency graph.
Builders return the target Node(s) in the form of a list,
which you can then make use of.
However, since filesystem Nodes have some useful
public attributes and methods
that you can use in SConscript files,
it is sometimes appropriate to create them manually,
outside the regular context of a Builder call.
The following attributes provide information about a Node:
node.path
The build path of the given file or directory. This path is relative to the project top directory. The build path is the same as the source path if variant_dir is not being used.
node.abspath
The absolute build path of the given file or directory.
node.relpath
The build path of the given file or directory relative to the project top directory.
node.srcnode()
The
srcnode
method
returns another File or Directory Node
representing the source path of the given
File or Directory Node.
Examples:
# Get the current build dir's path, relative to top.
Dir('.').path
# Current dir's absolute path
Dir('.').abspath
# Current dir's path relative to the project top directory
Dir('.').relpath
# Next line is always '.', because it is the top dir's path relative to itself.
Dir('#.').path
# Source path of the given source file.
File('foo.c').srcnode().path
# Builders return lists of File objects:
foo = env.Program('foo.c')
print("foo will be built in", foo[0].path)
Filesystem Node objects have methods to create new
Filesystem Nodes relative to the original Node.
There are also times when you may need to refer to an entry
in a filesystem without knowing in advance whether it's a
file or a directory.
For those situations,
there is an Entry method of filesystem node objects,
which returns a Node that can represent either a file or a directory.
If the original Node is a Directory Node, these methods will place the new Node within the directory the original Node represents:
node.Dir(name)
Returns a directory Node
name
which is a subdirectory of
the directory represented by
node.
node.File(name)
Returns a file Node
name
in the directory represented by
node.
node.Entry(name)
Returns an unresolved Node
name
in the directory represented by
node.
If the original Node is a File Node, these methods will place the the new Node in the same directory as the one the original Node represents:
node.Dir(name)
Returns a Node
name
for a directory in the parent directory of
the file represented by
node.
node.File(name)
Returns a Node
name
for a file in the parent directory of
the file represented by
node.
node.Entry(name)
Returns an unresolved Node
name
in the parent directory of
the file represented by
node.
For example:
# Get a Node for a file within a directory
incl = Dir('include')
f = incl.File('header.h')
# Get a Node for a subdirectory within a directory
dist = Dir('project-3.2.1')
src = dist.Dir('src')
# Get a Node for a file in the same directory
cfile = File('sample.c')
hfile = cfile.File('sample.h')
# Combined example
docs = Dir('docs')
html = docs.Dir('html')
index = html.File('index.html')
css = index.File('app.css')
SCons provides two other Node types to represent object that will not have an equivalent filesystem entry. Such Nodes always need to be created explicitly.
The Alias method returns an Alias Node.
Aliases are virtual objects - they will not themselves result
in physical objects being constructed, but are entered into
the dependency graph related to their sources.
An alias is checked for up to date by checking if
its sources are up to date.
An alias is built by making sure its sources have been built,
and if any building took place,
applying any Actions that are defined as part of the alias.
An Alias call creates an entry in the alias namespace,
which is used for disambiguation.
If an alias source has a string valued name,
it will be resolved to a filesystem entry Node,
unless it is found in the alias namespace,
in which case it it resolved to the matching alias Node.
As a result, the order of Alias calls is significant.
An alias can refer to another alias, but only if the
other alias has previously been created.
The Value method returns a Value Node.
Value nodes are often used for generated data that
will not have any corresponding filesystem entry,
but will be used to determine whether a build target is out of date,
or to include as part of a build Action.
Common examples are timestamp strings,
revision control version strings
and other run-time generated strings.
A Value Node can also be the target of a builder.
SCons is designed to be extensible through provided facilities,
so changing the code of SCons itself is only rarely needed
to customize its behavior.
A number of the main operations use callable objects
which can be supplemented by writing your own.
Builders, Scanners and Tools each use a kind of plugin system,
allowing you to easily drop in new ones.
Information about creating
Builder Objects and
Scanner Objects
appear in the following sections.
The instructions SCons actually uses to
construct things are called Actions,
and it is easy to create Action Objects and hand them
to the objects that need to know about those actions
(besides Builders, see AddPostAction,
AddPreAction and Alias for some examples
of other places that take Actions).
Action Objects
are also described below.
Adding new Tool modules is described in
Tool Modules
scons
can be extended to build different types of targets
by adding new Builder objects
to a construction environment.
In general,
you should only need to add a new Builder object
when you want to build a new type of file or other external target.
For output file types scons already knows about,
you can usually modify the behavior of premade Builders
such as Program, Object or Library
by changing the construction variables they use
($CC, $LINK, etc.).
In this manner you can, for example, change the compiler to use,
which is simpler and less error-prone than writing a new builder.
The documentation for each Builder lists which
construction variables it uses.
Builder objects are created
using the
Builder
factory function.
Once created, a builder is added to an environment
by entering it in the $BUILDERS dictionary
in that environment (some of the examples
in this section illustrate this).
Doing so automatically triggers SCons to add a method
with the name of the builder to the environment.
The
Builder
function accepts the following keyword arguments:
action
The command used to build the target from the source.
action
may be a string representing a template command line to execute,
a list of strings representing the command
to execute with its arguments
(suitable for enclosing white space in an argument),
a dictionary
mapping source file name suffixes to
any combination of command line strings
(if the builder should accept multiple source file extensions),
a Python function,
an Action object
(see Action Objects)
or a list of any of the above.
An action function must accept three arguments:
source,
target and
env.
source is a list of source nodes;
target is a list of target nodes;
env is the construction environment to use for context.
The action
and generator
arguments must not both be used for the same Builder.
prefix
The prefix to prepend to the target file name.
prefix may be
a string, a function (or other callable) that takes
two arguments (a construction environment and a list of sources)
and returns a prefix string,
or a dictionary specifying a mapping from a specific source suffix
(of the first source specified)
to a corresponding target prefix string. For the dictionary form, both the source
suffix (key) and target prefix (value) specifications may use environment variable
substitution, and the target prefix
may also be a callable object. The default target prefix
may be indicated by a dictionary entry with a key of None.
b = Builder("build_it < $SOURCE > $TARGET", prefix="file-")
def gen_prefix(env, sources):
return "file-" + env['PLATFORM'] + '-'
b = Builder("build_it < $SOURCE > $TARGET", prefix=gen_prefix)
b = Builder(
"build_it < $SOURCE > $TARGET",
suffix={None: "file-", "$SRC_SFX_A": gen_prefix},
)
suffix
The suffix to append to the target file name.
Specified in the same manner as for prefix above.
If the suffix is a string, then
scons
prepends a '.' to the suffix if it's not already there.
The string returned by the callable object or obtained from the
dictionary is untouched and you need to manually prepend a '.'
if one is required.
b = Builder("build_it < $SOURCE > $TARGET", suffix="-file")
def gen_suffix(env, sources):
return "." + env['PLATFORM'] + "-file"
b = Builder("build_it < $SOURCE > $TARGET", suffix=gen_suffix)
b = Builder(
"build_it < $SOURCE > $TARGET",
suffix={None: ".sfx1", "$SRC_SFX_A": gen_suffix},
)
ensure_suffix
If set to a true value,
ensures that targets will end in
suffix.
Thus, the suffix will also be added to any target strings
that have a suffix that is not already suffix.
The default behavior (also indicated by a false value)
is to leave unchanged
any target string that looks like it already has a suffix.
b1 = Builder("build_it < $SOURCE > $TARGET", suffix=".out")
b2 = Builder(
"build_it < $SOURCE > $TARGET", suffix=".out", ensure_suffix=True
)
env = Environment()
env['BUILDERS']['B1'] = b1
env['BUILDERS']['B2'] = b2
# Builds "foo.txt" because ensure_suffix is not set.
env.B1('foo.txt', 'foo.in')
# Builds "bar.txt.out" because ensure_suffix is set.
env.B2('bar.txt', 'bar.in')
src_suffix
The expected source file name suffix.
src_suffix
may be a string or a list of strings.
target_scanner
A Scanner object that
will be invoked to find
implicit dependencies for this target file.
Use only to specify Scanner objects that find
implicit dependencies
based on the target file
and construction environment,
not
for implicit dependencies based on source files
(use source_scanner for those).
See the section called “Scanner Objects”
for information about creating your own Scanner objects.
source_scanner
A Scanner object that
will be invoked to
find implicit dependencies in
any source files
used to build this target file.
Use to specify a scanner to
find things like
#include
lines in source files.
The pre-built
DirScanner
Scanner object may be used to
indicate that this Builder
should scan directory trees
for on-disk changes to files
that
scons
does not know about from other Builder or function calls.
See the section called “Scanner Objects”
for information about creating your own Scanner objects.
target_factory
A factory function that the Builder will use
to turn any targets specified as strings into SCons Nodes.
By default,
SCons assumes that all targets are files
(that is, the default factory is File).
Other useful target_factory
values include Dir
for when a Builder creates a directory target,
and Entry
for when a Builder can create either a file
or directory target.
Example:
def my_mkdir(target, source, env):
# target[0] will be a Dir node for 'new_directory'
MakeDirectoryBuilder = Builder(action=my_mkdir, target_factory=Dir)
env = Environment()
env.Append(BUILDERS={'MakeDirectory': MakeDirectoryBuilder})
env.MakeDirectory('new_directory', [])
Note that the call to the MakeDirectory Builder
needs to specify an empty source list
to make the filename string represent the builder's target.
SCons assumes a single positional argument to a builder
is the source, and would try to deduce the target name from it,
which, in the absence of an automatically-added prefix or suffix,
would lead to a matching target and source name
and a circular dependency.
source_factory
A factory function that the Builder will use
to turn any sources specified as strings into SCons Nodes.
By default,
SCons assumes that all source are files
(that is, the default factory is File).
Other useful source_factory
values include Dir
for when a Builder uses a directory as a source,
and Entry
for when a Builder can use files
or directories (or both) as sources.
Example:
def collect(target, source, env):
# target[0] will default to a File node for 'archive' (no target_factory)
# source[0] will be a Dir node for 'directory_name'
CollectBuilder = Builder(action=collect, source_factory=Dir)
env = Environment()
env.Append(BUILDERS={'Collect': CollectBuilder})
env.Collect('archive', 'directory_name')
emitter
A function or list of functions to manipulate the target and source
lists before dependencies are established
and the target(s) are actually built.
emitter
can also be a string containing a construction variable to expand
to an emitter function or list of functions,
or a dictionary mapping source file suffixes
to emitter functions.
(Only the suffix of the first source file
is used to select the actual emitter function
from an emitter dictionary.)
A function passed as emitter
must accept three arguments:
source,
target and
env.
source is a list of source nodes,
target is a list of target nodes,
env is the construction environment to use for context.
An emitter must return a tuple containing two lists, the list of targets to be built by this builder, and the list of sources for this builder.
Example:
def e(target, source, env):
return target + ['foo.foo'], source + ['foo.src']
# Simple association of an emitter function with a Builder.
b = Builder("my_build < $TARGET > $SOURCE", emitter=e)
def e2(target, source, env):
return target + ['bar.foo'], source + ['bar.src']
# Simple association of a list of emitter functions with a Builder.
b = Builder("my_build < $TARGET > $SOURCE", emitter=[e, e2])
# Calling an emitter function through a construction variable.
env = Environment(MY_EMITTER=e)
b = Builder("my_build < $TARGET > $SOURCE", emitter='$MY_EMITTER')
# Calling a list of emitter functions through a construction variable.
env = Environment(EMITTER_LIST=[e, e2])
b = Builder("my_build < $TARGET > $SOURCE", emitter='$EMITTER_LIST')
# Associating multiple emitters with different file
# suffixes using a dictionary.
def e_suf1(target, source, env):
return target + ['another_target_file'], source
def e_suf2(target, source, env):
return target, source + ['another_source_file']
b = Builder(
action="my_build < $TARGET > $SOURCE",
emitter={'.suf1': e_suf1, '.suf2': e_suf2}
)
multi
Specifies whether this builder is allowed to be called multiple times for
the same target file(s). The default is False,
which means the builder
can not be called multiple times for the same target file(s). Calling a
builder multiple times for the same target simply adds additional source
files to the target; it is not allowed to change the environment associated
with the target, specify additional environment overrides,
or associate a different
builder with the target.
env
A construction environment that can be used to fetch source code using this Builder. (Note that this environment is not used for normal builds of normal target files, which use the environment that was used to call the Builder for the target file.)
generator
A function that returns a list of actions that will be executed to build the target(s) from the source(s). The returned action(s) may be an Action object, or anything that can be converted into an Action object (see the next section).
A function passed as generator
must accept four arguments:
source,
target,
env and
for_signature.
source is a list of source nodes,
target is a list of target nodes,
env is the construction environment to use for context,
and for_signature is
a Boolean value that tells the function
if it is being called for the purpose of generating a build signature
(as opposed to actually executing the command).
Since the build signature is used for rebuild determination,
the function should omit those elements
that do not affect whether a rebuild should be triggered
if for_signature is true.
Example:
def g(source, target, env, for_signature):
return [["gcc", "-c", "-o"] + target + source]
b = Builder(generator=g)
The generator and action arguments must not both be used for the same Builder.
src_builder
Specifies a builder to use when a source file name suffix does not match any of the suffixes of the builder. Using this argument produces a multi-stage builder.
single_source
Specifies that this builder expects exactly one source file per call. Giving
more than one source file without target files results in implicitly calling
the builder multiple times (once for each source given). Giving multiple
source files together with target files results in a
UserError exception.
source_ext_match
When the specified
action
argument is a dictionary,
the default behavior when a builder is passed
multiple source files is to make sure that the
extensions of all the source files match.
If it is legal for this builder to be
called with a list of source files with different extensions,
this check can be suppressed by setting
source_ext_match
to
False
or some other non-true value.
In this case, scons
will use the suffix of the first specified
source file to select the appropriate action from the
action
dictionary.
In the following example,
the setting of
source_ext_match
prevents
scons
from exiting with an error
due to the mismatched suffixes of
foo.in
and
foo.extra.
b = Builder(action={'.in': 'build $SOURCES > $TARGET'}, source_ext_match=False)
env = Environment(BUILDERS={'MyBuild': b})
env.MyBuild('foo.out', ['foo.in', 'foo.extra'])
env
A construction environment that can be used to fetch source code using this Builder. (Note that this environment is not used for normal builds of normal target files, which use the environment that was used to call the Builder for the target file.)
b = Builder(action="build < $SOURCE > $TARGET")
env = Environment(BUILDERS={'MyBuild' : b})
env.MyBuild('foo.out', 'foo.in', my_arg='xyzzy')
chdir
A directory from which scons
will execute the
action(s) specified
for this Builder.
If the
chdir
argument is
a string or a directory Node,
scons will change to the specified directory.
If the
chdir
is not a string or Node
and is non-zero,
then scons will change to the
target file's directory.
Note that scons will
not
automatically modify
its expansion of
construction variables like
$TARGET
and
$SOURCE
when using the chdir
keyword argument--that is,
the expanded file names
will still be relative to the project top directory,
and consequently incorrect
relative to the chdir directory.
Builders created using chdir keyword argument,
will need to use construction variable
expansions like
${TARGET.file}
and
${SOURCE.file}
to use just the filename portion of the
targets and source.
b = Builder(action="build < ${SOURCE.file} > ${TARGET.file}", chdir=True)
env = Environment(BUILDERS={'MyBuild' : b})
env.MyBuild('sub/dir/foo.out', 'sub/dir/foo.in')
Python only keeps one current directory
location even if there are multiple threads.
This means that use of the
chdir
argument
will
not
work with the SCons
-j
option,
because individual worker threads spawned
by SCons interfere with each other
when they start changing directory.
Any additional keyword arguments supplied
when a Builder object is created
(that is, when the Builder function is called)
will be set in the executing construction
environment when the Builder object is called.
The canonical example here would be
to set a construction variable to
the repository of a source code system.
Any such keyword arguments supplied
when a Builder object is called
will only be associated with the target
created by that particular Builder call
(and any other files built as a
result of the call).
These extra keyword arguments are passed to the
following functions:
command generator functions,
function Actions,
and
emitter functions.
The
Builder
factory function will turn its
action
keyword argument into an appropriate
internal Action object, as will
the Command function.
You can also explicitly create Action objects
for passing to Builder, or other functions
that take actions as arguments,
by calling the Action factory function.
This may more efficient when multiple
Builder objects need to do the same thing
rather than letting each of those Builder objects
create a separate Action object.
It also allows more flexible configuration
of an Action object. For example, to control
the message printed when the action is taken
you need to create the action object using Action.
The
Action factory function
returns an appropriate object for the action
represented by the type of the
action argument
(the first positional parameter):
If action is already an Action object,
the object is simply returned.
If action is a string,
a command-line Action is returned.
If such a string begins with @,
the command line is not printed.
If the string begins with hyphen
(-),
the exit status from the specified command
is ignored, allowing execution to continue
even if the command reports failure:
Action('$CC -c -o $TARGET $SOURCES')
# Doesn't print the line being executed.
Action('@build $TARGET $SOURCES')
# Ignores return value
Action('-build $TARGET $SOURCES')
If action is a list,
then a list of Action objects is returned.
An Action object is created as necessary
for each element in the list.
If an element within
the list is itself a list,
the embedded list is taken as the
command and arguments to be executed via
the command line.
This allows white space to be enclosed
in an argument rather than taken as a separator by defining
a command in a list within a list:
Action([['cc', '-c', '-DWHITE SPACE', '-o', '$TARGET', '$SOURCES']])
If action is a callable object,
a Function Action is returned.
The callable must accept three keyword arguments:
target,
source and
env.
target
is a Node object representing the target file,
source
is a Node object representing the source file and
env
is the construction environment used for building the target file.
The
target
and
source
arguments may be lists of Node objects if there is
more than one target file or source file.
The actual target and source file name(s) may
be retrieved from their Node objects
via the built-in Python str function:
target_file_name = str(target) source_file_names = [str(x) for x in source]
The function should return
0
or
None
to indicate a successful build of the target file(s).
The function may raise an exception
or return a non-zero exit status
to indicate an unsuccessful build.
def build_it(target=None, source=None, env=None):
# build the target from the source
return 0
a = Action(build_it)
If
action
is not one of the above types,
no action object is generated and Action
returns None.
The environment method form env.Action
will expand construction variables in any argument strings,
including
action,
at the time it is called,
using the construction variables in the construction environment through which
it was called. The global function form Action
delays variable expansion until
the Action object is actually used.
The optional second argument to Action
is used to control the output
which is printed when the Action is actually performed.
If this parameter is omitted,
or if the value is an empty string,
a default output depending on the type of the action is used.
For example, a command-line action will print the executed command.
The following argument types are accepted:
If the second argument is a string,
or if the cmdstr keyword argument is supplied,
the string defines what is printed.
Substitution is performed on the string before it is printed.
The string typically contains substitutable variables, notably
$TARGET(S) and $SOURCE(S),
or consists of just a single variable
which is optionally defined somewhere else.
SCons itself heavily uses the latter variant.
If the second argument is a function,
or if the strfunction keyword argument is supplied,
the function will be called to obtain the string
to be printed when the action is performed.
The function
must accept three keyword arguments:
target,
source and
env,
with the same interpretation as for a callable
action argument above.
The function is responsible for handling any required substitutions.
If the second argument is None,
or if cmdstr=None is supplied,
output is suppressed entirely.
The cmdstr and
strfunction
keyword arguments may not both be supplied in a single call to Action
Printing of action strings is affected by the setting of
$PRINT_CMD_LINE_FUNC.
Examples:
def build_it(target, source, env):
# build the target from the source
return 0
def string_it(target, source, env):
return "building '%s' from '%s'" % (target[0], source[0])
# Use a positional argument.
f = Action(build_it, string_it)
s = Action(build_it, "building '$TARGET' from '$SOURCE'")
# Alternatively, use a keyword argument.
f = Action(build_it, strfunction=string_it)
s = Action(build_it, cmdstr="building '$TARGET' from '$SOURCE'")
# You can provide a configurable variable.
l = Action(build_it, '$STRINGIT')
Any additional positional arguments, if present,
may either be construction variables or lists of construction variables
whose values will be included in the signature of the Action
(the build signature)
when deciding whether a target should be rebuilt because the action changed.
Such variables may also be specified using the
varlist
keyword parameter;
both positional and keyword forms may be present, and will be combined.
This is necessary whenever you want a target to be rebuilt
when a specific construction variable changes.
This is not often needed for a string action,
as the expanded variables will normally be part of the command line,
but may be needed if a Python function action uses
the value of a construction variable when generating the command line.
def build_it(target, source, env):
# build the target from the 'XXX' construction variable
with open(target[0], 'w') as f:
f.write(env['XXX'])
return 0
# Use positional arguments.
a = Action(build_it, '$STRINGIT', ['XXX'])
# Alternatively, use a keyword argument.
a = Action(build_it, varlist=['XXX'])
The Action factory function can be passed the following optional keyword arguments to modify the Action object's behavior:
chdir
If chdir is true
(the default is False),
SCons will change directories before
executing the action.
If the value of chdir
is a string or a directory Node,
SCons will change to the specified directory.
Otherwise, if chdir evaluates true,
SCons will change to the
target file's directory.
Note that SCons will
not
automatically modify
its expansion of
construction variables like
$TARGET and $SOURCE
when using the chdir
parameter - that is,
the expanded file names
will still be relative to
the project top directory,
and consequently incorrect
relative to the chdir directory.
Builders created using chdir keyword argument,
will need to use construction variable
expansions like
${TARGET.file}
and
${SOURCE.file}
to use just the filename portion of the
targets and source. Example:
a = Action("build < ${SOURCE.file} > ${TARGET.file}", chdir=True)
exitstatfunc
If provided, must be a callable which accepts a single parameter, the exit status (or return value) from the specified action, and which returns an arbitrary or modified value. This can be used, for example, to specify that an Action object's return value should be ignored under special conditions and SCons should, therefore, consider that the action always succeeds. Example:
def always_succeed(s):
# Always return 0, which indicates success.
return 0
a = Action("build < ${SOURCE.file} > ${TARGET.file}", exitstatfunc=always_succeed)
batch_key
If provided, indicates that the Action can create multiple target files
by processing multiple independent source files simultaneously.
(The canonical example is "batch compilation"
of multiple object files
by passing multiple source files
to a single invocation of a compiler
such as Microsoft Visual C++.
If the
batch_key
argument evaluates True and is not a callable object,
the configured Action object will cause
scons
to collect all targets built with the Action object
and configured with the same construction environment
into single invocations of the Action object's
command line or function.
Command lines will typically want to use the
$CHANGED_SOURCES construction variable
(and possibly $CHANGED_TARGETS as well)
to only pass to the command line those sources that
have actually changed since their targets were built.
Example:
a = Action('build $CHANGED_SOURCES', batch_key=True)
The
batch_key
argument may also be
a callable function
that returns a key that
will be used to identify different
"batches" of target files to be collected
for batch building.
A
batch_key
function must accept four parameters:
action,
env,
target and
source.
The first parameter, action,
is the active action object.
The second parameter, env,
is the construction environment configured for the target.
The target and source
parameters are the lists of targets and sources
for the configured action.
The returned key should typically
be a tuple of values derived from the arguments,
using any appropriate logic to decide
how multiple invocations should be batched.
For example, a
batch_key
function may decide to return
the value of a specific construction variable
from env
which will cause
scons
to batch-build targets
with matching values of that construction variable,
or perhaps return the
Python id()
of the entire construction environment,
in which case
scons
will batch-build
all targets configured with the same construction environment.
Returning
None
indicates that
the particular target should
not
be part of any batched build,
but instead will be built
by a separate invocation of action's
command or function.
Example:
def batch_key(action, env, target, source):
tdir = target[0].dir
if tdir.name == 'special':
# Don't batch-build any target
# in the special/ subdirectory.
return None
return (id(action), id(env), tdir)
a = Action('build $CHANGED_SOURCES', batch_key=batch_key)
SCons supplies Action functions that arrange for various common file and directory manipulations to be performed. These are similar in concept to "tasks" in the Ant build tool, although the implementation is slightly different. These functions do not actually perform the specified action at the time the function is called, but rather are factory functions which return an Action object that can be executed at the appropriate time.
There are two natural ways that these Action Functions are intended to be used.
First,
if you need
to perform the action
at the time the SConscript
file is being read,
you can use the
Execute
global function:
Execute(Touch('file'))
Second,
you can use these functions
to supply Actions in a list
for use by the env.Command method.
This can allow you to
perform more complicated
sequences of file manipulation
without relying
on platform-specific
external commands:
env = Environment(TMPBUILD='/tmp/builddir')
env.Command(
target='foo.out',
source='foo.in',
action=[
Mkdir('$TMPBUILD'),
Copy('$TMPBUILD', '${SOURCE.dir}'),
"cd $TMPBUILD && make",
Delete('$TMPBUILD'),
],
)
Chmod(dest, mode)
Returns an Action object that
changes the permissions on the specified
dest
file or directory to the specified
mode
which can be octal or string, similar to the POSIX
chmod command.
Examples:
Execute(Chmod('file', 0o755))
env.Command(
'foo.out',
'foo.in',
[Copy('$TARGET', '$SOURCE'), Chmod('$TARGET', 0o755)],
)
Execute(Chmod('file', "ugo+w"))
env.Command(
'foo.out',
'foo.in',
[Copy('$TARGET', '$SOURCE'), Chmod('$TARGET', "ugo+w")],
)
The behavior of Chmod is limited on Windows
and on WebAssembly platforms,
see the notes in the Python documentation for
os.chmod, which is the underlying function.
Copy(dest, src)
Returns an Action object
that will copy the
src
source file or directory to the
dest
destination file or directory.
If src is a list,
dest must be a directory
if it already exists.
Examples:
Execute(Copy('foo.output', 'foo.input'))
env.Command('bar.out', 'bar.in', Copy('$TARGET', '$SOURCE'))
Delete(entry, [must_exist])
Returns an Action that
deletes the specified
entry,
which may be a file or a directory tree.
If a directory is specified,
the entire directory tree
will be removed.
If the
must_exist
flag is set to a true value,
then a Python error will be raised
if the specified entry does not exist;
the default is false,
that is, the Action will silently do nothing
if the entry does not exist.
Examples:
Execute(Delete('/tmp/buildroot'))
env.Command(
'foo.out',
'foo.in',
action=[
Delete('${TARGET.dir}'),
MyBuildAction,
],
)
Execute(Delete('file_that_must_exist', must_exist=True))
Mkdir(name)
Returns an Action
that creates the directory
name
and all needed intermediate directories.
name may also be a list
of directories to create.
Examples:
Execute(Mkdir('/tmp/outputdir'))
env.Command(
'foo.out',
'foo.in',
action=[
Mkdir('/tmp/builddir'),
Copy('/tmp/builddir/foo.in', '$SOURCE'),
"cd /tmp/builddir && make",
Copy('$TARGET', '/tmp/builddir/foo.out'),
],
)
Move(dest, src)
Returns an Action
that moves the specified
src
file or directory to
the specified
dest
file or directory.
Examples:
Execute(Move('file.destination', 'file.source'))
env.Command(
'output_file',
'input_file',
action=[MyBuildAction, Move('$TARGET', 'file_created_by_MyBuildAction')],
)
Touch(file)
Returns an Action
that updates the modification time
on the specified
file.
Examples:
Execute(Touch('file_to_be_touched'))
env.Command('marker', 'input_file', action=[MyBuildAction, Touch('$TARGET')])
Before executing a command, scons
performs parameter expansion (substitution)
on the string that makes up the action part of the builder.
The format of a substitutable parameter is
${.
If expression}expression refers to a variable,
the braces in ${
can be omitted unless the variable name is
immediately followed by a character that could either be interpreted
as part of the name, or is Python syntax such as
[ (for indexing/slicing)
or . (for attribute access -
see Special Attributes below).
expression}
If expression refers to a construction variable,
it (including the $ or ${ })
is replaced with the value of that variable in the
construction environment at the time of execution.
If expression looks like
a variable name but is not defined in the construction environment
it is replaced with an empty string.
If expression refers to one of the
Special Variables
(see below) the corresponding value of the variable is substituted.
expression may also be
a Python expression to be evaluated.
See Python Code Substitution
below for a description.
SCons uses the following rules when converting construction variables into command line strings:
If the value is a string it is interpreted as space delimited command line arguments.
If the value is a list it is interpreted as a list of command line arguments. Each element of the list is converted to a string.
Anything that is not a list or string is converted to a string and interpreted as a single command line argument.
Newline characters (\n) delimit lines.
The newline parsing is done after
all other parsing, so it is not possible for arguments (e.g. file names) to
contain embedded newline characters.
For a literal $
use $$.
For example, $$FOO will be left in the
final string as $FOO.
When a build action is executed, a hash of the command line is
saved, together with other information about the target(s) built
by the action, for future use in rebuild determination.
This is called the build signature
(or build action signature).
The escape sequence
$(
subexpression
$)
may be used to indicate parts of a command line
that may change without
causing a rebuild--that is,
which are not to be included when calculating the build signature.
All text from
$(
up to and including the matching
$)
will be removed from the command line
before it is added to the build signature
while only the
$(
and
$)
will be removed before the command is executed.
For example, the command line string:
"echo Last build occurred $( $TODAY $). > $TARGET"
would execute the command:
echo Last build occurred $TODAY. > $TARGET
but the build signature added to any target files would be computed from:
echo Last build occurred . > $TARGET
While construction variables are normally directly substituted,
if a construction variable has a value which
is a callable Python object
(a function, or a class with a __call__ method),
that object is called during substitution.
The callable must accept four arguments:
target,
source,
env and
for_signature.
source is a list of source nodes,
target is a list of target nodes,
env is the construction environment to use for context,
and for_signature is
a boolean value that tells the callable
if it is being called for the purpose of generating a build signature.
Since the build signature is used for rebuild determination,
variable elements that do not affect whether
a rebuild should be triggered
should be omitted from the returned string
if for_signature is true.
See $(
and $) above
for the syntax.
SCons will insert whatever the callable returns into the expanded string:
def foo(target, source, env, for_signature):
return "bar"
# Will expand $BAR to "bar baz"
env = Environment(FOO=foo, BAR="$FOO baz")
As a reminder, substitution happens when
$BAR is actually used in a
builder action. The value of env['BAR']
will be exactly as it was set: "$FOO baz".
This can make debugging tricky,
as the substituted result is not available at the time
the SConscript files are being interpreted and
thus not available to the print function.
However, you can perform the substitution on demand
by calling the env.subst method for this purpose.
You can use this feature to pass arguments to a
callable variable by creating a callable class
that stores passed arguments in the instance,
and then uses them
(in the __call__ method)
when the instance is called.
Note that in this case,
the entire variable expansion must
be enclosed by curly braces
so that the arguments will
be associated with the
instantiation of the class:
class foo:
def __init__(self, arg):
self.arg = arg
def __call__(self, target, source, env, for_signature):
return self.arg + " bar"
# Will expand $BAR to "my argument bar baz"
env=Environment(FOO=foo, BAR="${FOO('my argument')} baz")
Besides regular construction variables, scons provides the following Special Variables for use in expanding commands:
$CHANGED_SOURCES
The file names of all sources of the build command that have changed since the target was last built.
$CHANGED_TARGETS
The file names of all targets that would be built from sources that have changed since the target was last built.
$SOURCE
The file name of the source of the build command, or the file name of the first source if multiple sources are being built.
$SOURCES
The file names of the sources of the build command.
$TARGET
The file name of the target being built, or the file name of the first target if multiple targets are being built.
$TARGETS
The file names of all targets being built.
$UNCHANGED_SOURCES
The file names of all sources of the build command that have not changed since the target was last built.
$UNCHANGED_TARGETS
The file names of all targets that would be built from sources that have not changed since the target was last built.
These names are reserved and may not be assigned to or used as construction variables. SCons computes them in a context-dependent manner and they and are not retrieved from a construction environment.
For example, the following builder call:
env = Environment(CC='cc')
env.Command(
target=['foo'],
source=['foo.c', 'bar.c'],
action='@echo $CC -c -o $TARGET $SOURCES'
)
would produce the following output:
cc -c -o foo foo.c bar.c
In the previous example, a string
${SOURCES[1]}
would expand to: bar.c.
A variable name may have the following modifiers appended within the enclosing curly braces to access properties of the interpolated string. These are known as special attributes.
base -
The base path of the file name,
including the directory path
but excluding any suffix.
|
dir - The name of the directory in which the file exists. |
file - The file name, minus any directory portion. |
filebase - Like file but minus its suffix. |
suffix - Just the file suffix. |
abspath - The absolute path name of the file. |
relpath - The path name of the file relative to the project top directory. |
posix -
The path with directories separated by forward slashes
(/).
Sometimes necessary on Windows systems
when a path references a file on other (POSIX) systems.
|
windows -
The path with directories separated by backslashes
(\\).
Sometimes necessary on POSIX-style systems
when a path references a file on other (Windows) systems.
win32 is a (deprecated) synonym for
windows.
|
srcpath -
The directory and file name to the source file linked to this file through
VariantDir().
If this file isn't linked,
it just returns the directory and filename unchanged.
|
srcdir -
The directory containing the source file linked to this file through
VariantDir().
If this file isn't linked,
it just returns the directory part of the filename.
|
rsrcpath -
The directory and file name to the source file linked to this file through
VariantDir().
If the file does not exist locally but exists in a Repository,
the path in the Repository is returned.
If this file isn't linked, it just returns the
directory and filename unchanged.
|
rsrcdir -
The Repository directory containing the source file linked to this file through
VariantDir().
If this file isn't linked,
it just returns the directory part of the filename.
|
For example, the specified target will expand as follows for the corresponding modifiers:
$TARGET => sub/dir/file.x
${TARGET.base} => sub/dir/file
${TARGET.dir} => sub/dir
${TARGET.file} => file.x
${TARGET.filebase} => file
${TARGET.suffix} => .x
${TARGET.abspath} => /top/dir/sub/dir/file.x
${TARGET.relpath} => sub/dir/file.x
$TARGET => ../dir2/file.x
${TARGET.abspath} => /top/dir2/file.x
${TARGET.relpath} => ../dir2/file.x
SConscript('src/SConscript', variant_dir='sub/dir')
$SOURCE => sub/dir/file.x
${SOURCE.srcpath} => src/file.x
${SOURCE.srcdir} => src
Repository('/usr/repository')
$SOURCE => sub/dir/file.x
${SOURCE.rsrcpath} => /usr/repository/src/file.x
${SOURCE.rsrcdir} => /usr/repository/src
Some modifiers can be combined, like
${TARGET.srcpath.base),
${TARGET.file.suffix}, etc.
If a substitutable expression using the notation
${
does not appear to match one of the other substitution patterns,
it is evaluated as a Python expression.
This uses Python's expression}eval function,
with the globals parameter set to
the current environment's set of construction variables,
and the result substituted in.
So in the following case:
env.Command(
'foo.out', 'foo.in', "echo ${COND==1 and 'FOO' or 'BAR'} > $TARGET"
)
the command executed will be either
echo FOO > foo.out
or
echo BAR > foo.out
according to the current value of env['COND']
when the command is executed.
The evaluation takes place when the target is being
built, not when the SConscript is being read. So if
env['COND'] is changed
later in the SConscript, the final value will be used.
Here's a more complete example. Note that all of
COND,
FOO,
and
BAR are construction variables,
and their values are substituted into the final command.
FOO is a list, so its elements are interpolated
separated by spaces.
env=Environment()
env['COND'] = 1
env['FOO'] = ['foo1', 'foo2']
env['BAR'] = 'barbar'
env.Command(
'foo.out', 'foo.in', "echo ${COND==1 and FOO or BAR} > $TARGET"
)
will execute:
echo foo1 foo2 > foo.out
In point of fact, Python expression evaluation is
how the special attributes are substituted:
they are simply attributes of the Python objects
that represent $TARGET, $SOURCES, etc.,
which SCons passes to eval which
returns the value.
Use of the Python eval function
is considered to have security implications, since,
depending on input sources,
arbitrary unchecked strings of code can be executed by the Python interpreter.
Although SCons makes use of it in a somewhat restricted context,
you should be aware of this issue when using the
${python-expression-for-subst} form.
Scanner objects are used
to scan specific file types for implicit dependencies,
for example embedded preprocessor/compiler directives
that cause other files to be included during processing.
SCons has a number of pre-built Scanner objects,
so it is usually only necessary to set up Scanners for new file types.
You do this by calling the Scanner factory function.
Scanner accepts the following arguments.
Only function is required;
the rest are optional:
function
A function which can process ("scan")
a given Node (usually a file)
and return a list of Nodes
representing any implicit
dependencies (usually files) which will be tracked
for the Node.
The function must accept three required arguments,
node,
env and
path,
and an optional fourth,
arg.
node is
the internal SCons node representing the file to scan,
env is the construction environment to use during
the scan, and path is a tuple
of directories that can be searched for files,
as generated by the optional scanner
path_function.
If the argument
parameter was supplied when the Scanner object was created,
it is passed as the arg parameter
to the scanner function when it is called.
Since argument is optional,
the scanner function may be
called without an arg parameter.
The scanner function can make use of
str(node)
to fetch the name of the file,
node.dir
to fetch the directory the file is in,
node.get_contents()
to fetch the contents of the file as bytes or
node.get_text_contents()
to fetch the contents of the file as text.
The scanner function should account for any directories
listed in the path parameter
when determining the existence of possible dependencies.
External tools such as the C/C++ preprocessor are given
lists of directories to search for source file inclusion directives
(e.g. #include "myheader.h").
That list is generated from the relevant path variable
(e.g. $CPPPATH for C/C++). The Scanner can be
directed to pass the same list on to the scanner function
via the path parameter so it can
search in the same places.
The Scanner is enabled to pass this list via the
path_function argument at Scanner creation time.
Instead of a scanner function, you can supply a dictionary as the
function parameter.
The dictionary must map keys (such as file suffixes)
to other Scanner objects.
A Scanner created this way serves as a dispatcher:
the Scanner's skeys parameter is
automatically populated with the dictionary's keys,
indicating that the Scanner handles Nodes which would be
selected by those keys; the mapping is then used to pass
the file on to a different Scanner that would not have been
selected to handle that Node based on its
own skeys.
Note that the file to scan is not guaranteed to exist at the time the scanner is called - it could be a generated file which has not been generated yet - so the scanner function must be tolerant of that.
While many scanner functions operate on source code files by
looking for known patterns in the code, they can really
do anything they need to.
For example, the Program Builder is assigned a
target_scanner which examines the
list of libraries supplied for the build ($LIBS)
and decides whether to add them as dependencies,
it does not look inside the built binary.
It is up to the scanner function to decide whether or not to
generate an SCons dependency for candidates identified by scanning.
Dependencies are a key part of SCons operation,
enabling both rebuild determination and correct ordering of builds.
It is particularly important that generated files which are
dependencies are added into the Node graph,
or use-before-create failures are likely.
However, not everything may need to be tracked as a dependency.
In some cases, implementation-provided header files change
infrequently but are included very widely,
so tracking them in the SCons node graph could become quite
expensive for limited benefit -
consider for example the C standard header file
string.h.
The scanner function is not passed any special information
to help make this choice, so the decision making encoded
in the scanner function must be carefully considered.
name
The name to use for the Scanner.
This is mainly used to identify the Scanner internally.
The default value is "NONE".
argument
If specified,
will be passed to the scanner function
function
and the path function
path_function
when called,
as the optional parameter each of those functions takes.
skeys
Scanner key(s) indicating the file types
this scanner is associated with.
Used internally to select an appropriate scanner.
In the usual case of scanning for file names,
this argument will be a list of suffixes
for the different file types that this
Scanner knows how to scan.
If skeys is a string,
it will be expanded into a list by the current environment.
path_function
If specified, a function to generate paths to pass to
the scanner function to search while generating dependencies.
The function must take five arguments:
a construction environment,
a Node for the directory containing
the SConscript file in which
the first target was defined,
a list of target nodes,
a list of source nodes,
and the value of argument
if it was supplied when the Scanner was created
(since argument is optional,
the function may be called without this argument,
the path_function
should be prepared for this).
Must return a tuple of directories
that can be searched for files to be returned
by this Scanner object.
The FindPathDirs
function can be called to return a ready-made
path_function
for a given construction variable name,
which is often easier than writing your own function from scratch.
For example,
path_function=FindPathDirs('CPPPATH')
means the scanner function will be called with the paths extracted
from $CPPPATH in the construction environment env,
and passed as the path parameter
to the scanner function.
node_class
The class of Node that should be returned
by this Scanner object.
Any strings or other objects returned
by the scanner function
that are not of this class
will be run through the function
supplied by the
node_factory argument.
A value of None can
be supplied to indicate no conversion;
the default is to return File nodes.
node_factory
A Python function that will take a string
or other object
and turn it into the appropriate class of Node
to be returned by this Scanner object,
as indicated by node_class.
scan_check
A Python function that takes two arguments, a Node (file) and a construction environment, and returns whether the Node should, in fact, be scanned for dependencies. This check can be used to eliminate unnecessary calls to the scanner function when, for example, the underlying file represented by a Node does not yet exist.
recursive
Specifies whether this scanner should be re-invoked
on the dependency files returned by the scanner.
If omitted, the Node subsystem will
only invoke the scanner on the file being scanned
and not recurse.
Recursion is needed when the files returned by the
scanner may themselves contain further file dependencies,
as in the case of preprocessor #include lines.
A value that evaluates true enables recursion;
recursive
may be a callable function,
in which case it will be called with a list of
Nodes found and
should return a list of Nodes
that should be scanned recursively;
this can be used to select a specific subset of
Nodes for additional scanning.
Once created, a Scanner can added to an environment
by setting it in the $SCANNERS list,
which automatically triggers SCons to also add it
to the environment as a method.
However, usually a scanner is not truly standalone, but needs to
be plugged in to the existing selection mechanism for
deciding how to scan source files based on filename extensions.
For this, SCons has a global
SourceFileScanner
object that is used by
the Object, SharedObject and StaticObject
builders to decide
which scanner should be used.
You can use the
SourceFileScanner.add_scanner()
method to add your own Scanner object
to the
SCons
infrastructure
that builds target programs or
libraries from a list of
source files of different types:
def xyz_scan(node, env, path):
contents = node.get_text_contents()
# Scan the contents and return the included files.
XYZScanner = Scanner(xyz_scan)
SourceFileScanner.add_scanner('.xyz', XYZScanner)
env.Program('my_prog', ['file1.c', 'file2.f', 'file3.xyz'])
Custom tools can be added to a project either by
placing them in the site_tools subdirectory
of a configured site directory,
or in a location specified by the
toolpath keyword argument to Environment.
You have to arrange to call a tool to put it into effect,
either as part of the list given to the tools
keyword argument at construction environment initialization,
or by calling env.Tool.
The toolpath parameter
takes a list of path strings,
and the tools parameter
takes a list of tools, which are often strings:
env = Environment(tools=['default', 'foo'], toolpath=['tools'])
This looks for a tool specification module foo
in directory tools and in the standard locations,
as well as using the ordinary default tools for the platform.
When looking up tool specification modules,
directories specified via toolpath are
considered before the existing tool path
(site_tools subdirectories
of the default or specified site directories),
which are in turn considered before built-in tools.
For example, adding
a tool specification module gcc.py to the toolpath
directory would override the built-in gcc tool.
The toolpath is saved in the environment
and will be used by subsequent calls to the env.Tool method,
as well as by env.Clone.
base = Environment(toolpath=['custom_path']) derived = base.Clone(tools=['custom_tool']) derived.CustomBuilder()
A tool specification module is a form of Python module,
looked up internally using the Python import mechanism,
so a tool can consist either
of a single Python file taking the name of the tool
(e.g. mytool.py) or a directory taking
the name of the tool (e.g. mytool/)
which contains at least an __init__.py file.
A tool specification module has two required entry points:
generate(env, **kwargs)
Modify the construction environment env
to set up necessary construction variables, Builders, Emitters, etc.,
so the facilities represented by the tool can be executed.
Take care not to overwrite construction variables which may
have been explicitly set by the user;
retain and/or append instead. For example:
def generate(env):
...
if 'MYTOOL' not in env:
env['MYTOOL'] = env.Detect("mytool")
flags = env.get('MYTOOLFLAGS', SCons.Util.CLVar())
env.AppendUnique(MYTOOLFLAGS='--myarg')
...
The generate function
may use any keyword arguments
that the user supplies via kwargs
to vary its initialization.
exists(env)
Return a truthy value if the tool can
be called in the context of env,
else return a falsy value.
Usually this means looking up one or more
known programs using the PATH from the
supplied env, but the tool can
make the exists decision in any way it chooses.
At the moment, user-added tools do not automatically have their
exists function called.
As a result, it is recommended that the generate
function be defensively coded - that is, do not rely on any
necessary existence checks already having been performed.
This is expected to be a temporary limitation,
and the exists function should still be provided.
An element of the tools list may also
be a function or other callable object
(including a Tool object returned by a previous call to
Tool) in which case the Environment function
will directly call that object
to update the new construction environment.
No tool lookup is done in this case.
def my_tool(env):
env['XYZZY'] = 'xyzzy'
env = Environment(tools=[my_tool])
An element of the tools list
may also be a two-element list or tuple of the form
(toolname, kw_dict).
SCons searches for the a tool specification module
toolname
as described above,
and passes kw_dict,
which must be a dictionary,
as keyword arguments to the tool's
generate function.
The generate
function can use those arguments to modify the tool's behavior
by setting up the environment in different ways
or otherwise changing its initialization.
# in tools/my_tool.py:
def generate(env, **kwargs):
# Sets MY_TOOL to the value of keyword 'arg1' or '1' if not supplied
env['MY_TOOL'] = kwargs.get('arg1', '1')
def exists(env):
return True
# in SConstruct:
env = Environment(
tools=['default', ('my_tool', {'arg1': 'abc'})], toolpath=['tools']
)
The tool specification (my_tool in the example)
can use the
$PLATFORM variable from
the construction environment it is passed to customize the tool for different platforms.
Tools can be "nested" - that is, they can be located within a subdirectory in the toolpath. A nested tool name uses a dot to represent a directory separator
# namespaced builder env = Environment(ENV=os.environ.copy(), tools=['SubDir1.SubDir2.SomeTool']) env.SomeTool(targets, sources) # Search Paths # SCons\Tool\SubDir1\SubDir2\SomeTool.py # SCons\Tool\SubDir1\SubDir2\SomeTool\__init__.py # .\site_scons\site_tools\SubDir1\SubDir2\SomeTool.py # .\site_scons\site_tools\SubDir1\SubDir2\SomeTool\__init__.py
scons and its configuration files are very portable, due largely to its implementation in Python. There are, however, a few portability issues waiting to trap the unwary.
scons handles the upper-case
.C
file suffix differently,
depending on the capabilities of
the underlying system.
On a case-sensitive system
such as Linux or UNIX,
scons treats a file with a
.C
suffix as a C++ source file.
On a case-insensitive system
such as Windows,
scons treats a file with a
.C
suffix as a C source file.
There are several ways source file suffixes impact the behavior of SCons when working with Fortran language code (not all are system-specific, but they are included here for completeness).
As the Fortran language has evolved through multiple
standards editions, projects might have a need to handle
files from different language generations differently.
To this end, SCons dispatches to a different compiler
dialect setup (expressed as a set of construction variables)
depending on the file suffix.
By default, all of these setups start out the same,
but individual construction variables can be modified as needed to tune a given dialect.
Each of these dialacts has a tool specification module
whose documentation describes the construction variables associated
with that dialect: .f
(as well as .for and .ftn)
in fortran; (construction variables start with FORTRAN)
.f77 in f77;
(construction variables start with F77)
.f90 in f90;
(construction variables start with F90)
.f95 in f95;
(construction variables start with F95)
.f03 in f03;
(construction variables start with F03)
.f08 in f08
(construction variables start with F08).
While SCons recognizes multiple internal dialects
based on filename suffixes,
the convention of various available Fortran compilers is
to assign an actual meaning to only two of these suffixes:
.f
(as well as .for and .ftn)
refers to the fixed-format source
code that was the only available option in FORTRAN 77 and earlier,
and .f90 refers to free-format source code
which became available as of the Fortran 90 standard.
Some compilers recognize suffixes which correspond to Fortran
specifications later then F90 as equivalent to
.f90 for this purpose,
while some do not - check the documentation for your compiler.
An occasionally suggested policy suggestion is to use only
.f and .f90
as Fortran filename suffixes.
The fixed/free form determination can usually be controlled
explicitly with compiler flags
(e.g. -ffixed-form for gfortran),
overriding any assumption that may be made based on the source file suffix.
The source file suffix does not imply conformance
with the similarly-named Fortran standard - a suffix of
.f08 does not mean you are compiling
specifically for Fortran 2008. Normally, compilers
provide command-line options for making this selection
(e.g. -std=f2008 for gfortran).
For dialects from F90 on (including the generic FORTRAN dialect),
a suffix of .mod is recognized for Fortran modules.
These files are a side effect of compiling a Fortran
source file containing module declarations,
and must be available when other code which declares
that it uses the module is processed.
SCons does not currently have integrated support for submodules,
introduced in the Fortran 2008 standard -
the invoked compiler will produce results,
but SCons will not recognize
.smod files as tracked objects.
On a case-sensitive system such as Linux or UNIX,
a file with a an upper-cased suffix from the set
.F,
.FOR,
.FTN,
.F90,
.F95,
.F03 and
.F08
is treated as a Fortran source file
which shall first be run through
the standard C preprocessor.
The lower-cased versions of these suffixes do not
trigger this behavior.
On systems which do not distinguish between uppper
and lower case in filenames,
this behavior is not available,
but files suffixed with either
.FPP
or .fpp
are always passed to the preprocessor first.
This matches the convention of gfortran
from the GNU Compiler Collection,
and also followed by certain other Fortran compilers.
For these two suffixes,
the generic FORTRAN dialect will be selected.
SCons itself does not invoke the preprocessor,
that is handled by the compiler,
but it adds construction variables which are applicable to the preprocessor run.
You can see this difference by examining
$FORTRANPPCOM and $FORTRANPPCOMSTR
which are used instead of
$FORTRANCOM and $FORTRANCOMSTR for that dialect.
Cygwin supplies a set of tools and utilities
that let users work on a
Windows system using a POSIX-like environment.
The Cygwin tools, including Cygwin Python,
do this, in part,
by sharing an ability to interpret POSIX-style path names.
For example, the Cygwin tools
will internally translate a Cygwin path name
like /cygdrive/c/mydir
to an equivalent Windows pathname
of C:/mydir (equivalent to C:\mydir).
Versions of Python
that are built for native Windows execution,
such as the python.org and ActiveState versions,
do not understand the Cygwin path name semantics.
This means that using a native Windows version of Python
to build compiled programs using Cygwin tools
(such as gcc, bison and flex)
may yield unpredictable results.
"Mixing and matching" in this way
can be made to work,
but it requires careful attention to the use of path names
in your SConscript files.
In practice, users can sidestep the issue by adopting the following guidelines: When using Cygwin's gcc for compiling, use the Cygwin-supplied Python interpreter to run scons; when using Microsoft Visual C++ (or some other "native" Windows compiler) use the python.org, Microsoft Store, ActiveState or other native version of Python to run scons.
This discussion largely applies to the msys2 environment as well (with the use of the mingw compiler toolchain), in particular the recommendation to use the msys2 version of Python if running scons from inside an msys2 shell.
scons.bat fileOn Windows, if scons is executed via a wrapper
scons.bat batch file,
there are (at least) two ramifications.
Note this is no longer the default - scons installed
via Python''s pip installer
will have an scons.exe which does
not have these limitations:
First, Windows command-line users that want to use variable assignment on the command line may have to put double quotes around the assignments, otherwise the Windows command shell will consume those as arguments to itself, not to scons:
scons "FOO=BAR" "BAZ=BLEH"
Second, the Cygwin shell does not
recognize typing scons
at the command line prompt as referring to this wrapper.
You can work around this either by executing
scons.bat
(including the extension)
from the Cygwin command line,
or by creating a wrapper shell
script named
scons which
invokes scons.bat.
The MinGW bin
directory must be in your PATH
environment variable or the
['ENV']['PATH'] construction variable for scons
to detect and use the MinGW tools. When running under the native Windows
Python interpreter, scons will prefer the MinGW tools over the Cygwin
tools, if they are both installed, regardless of the order of the bin
directories in the PATH variable.
If you have both MSVC and MinGW
installed and you want to use MinGW instead of MSVC,
then you must explicitly tell scons to use MinGW by passing
tools=['mingw']
to the Environment function, because scons will prefer the MSVC tools
over the MinGW tools.
In general, scons is not controlled by environment
variables set in the shell used to invoke it, leaving it
up to the SConscript file author to import those if desired.
However the following variables are imported by
scons itself if set:
SCONS_LIB_DIR
Specifies the directory that contains the scons
Python module directory. Normally scons can deduce this,
but in some circumstances, such as working with a source
release, it may be necessary to specify
(for example,
/home/aroach/scons-src-0.01/src/engine).
SCONSFLAGS
A string containing options that will be used by scons
in addition to those passed on the command line.
Can be used to reduce frequent retyping of common options.
The contents of SCONSFLAGS are considered
before any passed command line options,
so the command line can be used to override
SCONSFLAGS options if necessary.
SCONS_CACHE_MSVC_CONFIG
(Windows only). If set, save the shell environment variables generated when setting up the Microsoft Visual C++ compiler (and/or Build Tools) to a cache file, to give these settings persistence across scons invocations. Generating this information is relatively expensive, so using this option may aid performance where scons is run often, such as Continuous Integration setups.
If set to a True-like value ("1",
"true" or
"True") will cache to a file named
scons_msvc_cache.json in the user's home directory.
If set to a pathname, will use that pathname for the cache.
Note: this implementation may still be somewhat fragile. In case of problems, remove the cache file - recreating with fresh info normally resolves any issues. SCons ignores failures reading or writing the cache file and will silently revert to non-cached behavior in such cases.
New in 3.1 (experimental). The default cache file name was changed to its present value in 4.4, and contents were expanded.
QTDIR
If using the qt tool, this is the path to
the Qt installation to build against. SCons respects this
setting because it is a long-standing convention in the Qt world,
where multiple Qt installations are possible.
| The SCons User Guide at https://scons.org/doc/production/HTML/scons-user.html |
| The SCons Design Document (old) |
| The SCons Cookbook at https://scons-cookbook.readthedocs.io for examples of how to solve various problems with SCons. |
| SCons source code on GitHub |
| The SCons API Reference https://scons.org/doc/production/HTML/scons-api/index.html (for internal details) |
Originally: Steven Knight
<knight@baldmt.com>
and Anthony Roach <aroach@electriceyeball.com>.
Since 2010: The SCons Development Team <scons-dev@scons.org>.