# MIT License
#
# Copyright The SCons Foundation
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
"""The Scanner package for the SCons software construction utility."""
import re
import SCons.Node.FS
import SCons.PathList
import SCons.Util
# This is used instead of None as a default argument value so None can be
# used as an actual argument value.
_null = _Null
[docs]
def Scanner(function, *args, **kwargs):
"""Factory function to create a Scanner Object.
Creates the appropriate Scanner based on the type of "function".
TODO: Deprecate this some day. We've moved the functionality
inside the ScannerBase class and really don't need this factory function
any more. It was, however, used by some of our Tool modules, so
the call probably ended up in various people's custom modules
patterned on SCons code.
"""
if SCons.Util.is_Dict(function):
return Selector(function, *args, **kwargs)
return ScannerBase(function, *args, **kwargs)
[docs]
class FindPathDirs:
"""Class to bind a specific E{*}PATH variable name to a function that
will return all of the E{*}path directories.
"""
def __init__(self, variable) -> None:
self.variable = variable
def __call__(self, env, dir=None, target=None, source=None, argument=None):
try:
path = env[self.variable]
except KeyError:
return ()
dir = dir or env.fs._cwd
path = SCons.PathList.PathList(path).subst_path(env, target, source)
return tuple(dir.Rfindalldirs(path))
[docs]
class ScannerBase:
"""Base class for dependency scanners.
Implements straightforward, single-pass scanning of a single file.
A Scanner is usually set up with a scanner function (and optionally
a path function), but can also be a kind of dispatcher which
passes control to other Scanners.
A scanner function takes three arguments: a Node to scan for
dependecies, the construction environment to use, and an optional
tuple of paths (as generated by the optional path function).
It must return a list containing the Nodes for all the direct
dependencies of the file.
The optional path function is called to return paths that can be
searched for implicit dependency files. It takes five arguments:
a construction environment, a Node for the directory containing
the SConscript file that defined the primary target, a list of
target nodes, a list of source nodes, and the optional argument
for this instance.
Examples::
s = Scanner(my_scanner_function)
s = Scanner(function=my_scanner_function)
s = Scanner(function=my_scanner_function, argument='foo')
Args:
function: either a scanner function taking two or three arguments
and returning a list of File Nodes; or a mapping of keys to
other Scanner objects.
name: an optional name for identifying this scanner object
(defaults to "NONE").
argument: an optional argument that will be passed to both
*function* and *path_function*.
skeys: an optional list argument that can be used
to determine if this scanner can be used for a given Node.
In the case of File nodes, for example, the *skeys*
would be file suffixes.
path_function: an optional function which returns a tuple
of the directories that can be searched for implicit
dependency files. May also return a callable which
is called with no args and returns the tuple (supporting
Bindable class).
node_class: optional class of Nodes which this scan will return.
If not specified, defaults to :class:`SCons.Node.FS.Base`.
If *node_class* is ``None``, then this scanner will not enforce
any Node conversion and will return the raw results from *function*.
node_factory: optional factory function to be called to
translate the raw results returned by *function*
into the expected *node_class* objects.
scan_check: optional function to be called to first check whether
this node really needs to be scanned.
recursive: optional specifier of whether this scanner should be
invoked recursively on all of the implicit dependencies it returns
(for example `#include` lines in C source files, which may refer
to header files which should themselves be scanned).
May be a callable, which will be called to filter
the list of nodes found to select a subset for recursive
scanning (the canonical example being only recursively
scanning subdirectories within a directory). The default
is to not do recursive scanning.
"""
def __init__(
self,
function,
name: str="NONE",
argument=_null,
skeys=_null,
path_function=None,
# Node.FS.Base so that, by default, it's okay for a
# scanner to return a Dir, File or Entry.
node_class=SCons.Node.FS.Base,
node_factory=None,
scan_check=None,
recursive=None,
) -> None:
"""Construct a new scanner object given a scanner function."""
# Note: this class could easily work with scanner functions that take
# something other than a filename as an argument (e.g. a database
# node) and a dependencies list that aren't file names. All that
# would need to be changed is the documentation.
self.function = function
self.path_function = path_function
self.name = name
self.argument = argument
if skeys is _null:
if SCons.Util.is_Dict(function):
skeys = list(function.keys())
else:
skeys = []
self.skeys = skeys
self.node_class = node_class
self.node_factory = node_factory
self.scan_check = scan_check
if callable(recursive):
self.recurse_nodes = recursive
elif recursive:
self.recurse_nodes = self._recurse_all_nodes
else:
self.recurse_nodes = self._recurse_no_nodes
[docs]
def path(self, env, dir=None, target=None, source=None):
if not self.path_function:
return ()
if self.argument is not _null:
return self.path_function(env, dir, target, source, self.argument)
return self.path_function(env, dir, target, source)
[docs]
def __call__(self, node, env, path=()) -> list:
"""Scans a single object.
Args:
node: the node that will be passed to the scanner function
env: the environment that will be passed to the scanner function.
path: tuple of paths from the `path_function`
Returns:
A list of direct dependency nodes for the specified node.
"""
if self.scan_check and not self.scan_check(node, env):
return []
# here we may morph into a different Scanner instance:
self = self.select(node) # pylint: disable=self-cls-assignment
if self.argument is not _null:
node_list = self.function(node, env, path, self.argument)
else:
node_list = self.function(node, env, path)
kw = {}
if hasattr(node, 'dir'):
kw['directory'] = node.dir
conv = env.get_factory(self.node_factory)
cls = self.node_class
nl = [conv(n, **kw) if cls and not isinstance(n, cls) else n for n in node_list]
return nl
def __eq__(self, other):
try:
return self.__dict__ == other.__dict__
except AttributeError:
# other probably doesn't have a __dict__
return self.__dict__ == other
def __hash__(self):
return id(self)
def __str__(self) -> str:
return self.name
[docs]
def add_skey(self, skey) -> None:
"""Add a skey to the list of skeys"""
self.skeys.append(skey)
[docs]
def get_skeys(self, env=None):
if env and SCons.Util.is_String(self.skeys):
return env.subst_list(self.skeys)[0]
return self.skeys
[docs]
def select(self, node):
if SCons.Util.is_Dict(self.function):
key = node.scanner_key()
try:
return self.function[key]
except KeyError:
return None
else:
return self
[docs]
@staticmethod
def _recurse_all_nodes(nodes):
return nodes
[docs]
@staticmethod
def _recurse_no_nodes(nodes):
return []
# recurse_nodes = _recurse_no_nodes
[docs]
def add_scanner(self, skey, scanner) -> None:
self.function[skey] = scanner
self.add_skey(skey)
# keep the old name for a while in case external users are using.
# there are no more internal uses of this class by the name "Base"
Base = ScannerBase
[docs]
class Selector(ScannerBase):
"""
A class for selecting a more specific scanner based on the
:func:`scanner_key` (suffix) for a specific Node.
TODO: This functionality has been moved into the inner workings of
the ScannerBase class, and this class will be deprecated at some point.
(It was never exposed directly as part of the public interface,
although it is used by the :func:`Scanner` factory function that was
used by various Tool modules and therefore was likely a template
for custom modules that may be out there.)
"""
def __init__(self, mapping, *args, **kwargs) -> None:
super().__init__(None, *args, **kwargs)
self.mapping = mapping
self.skeys = list(mapping.keys())
def __call__(self, node, env, path=()):
return self.select(node)(node, env, path)
[docs]
def select(self, node):
try:
return self.mapping[node.scanner_key()]
except KeyError:
return None
[docs]
def add_scanner(self, skey, scanner) -> None:
self.mapping[skey] = scanner
self.add_skey(skey)
[docs]
class Current(ScannerBase):
"""
A class for scanning files that are source files (have no builder)
or are derived files and are current (which implies that they exist,
either locally or in a repository).
"""
def __init__(self, *args, **kwargs) -> None:
def current_check(node, env):
return not node.has_builder() or node.is_up_to_date()
kwargs['scan_check'] = current_check
super().__init__(*args, **kwargs)
[docs]
class Classic(Current):
"""
A Scanner subclass to contain the common logic for classic CPP-style
include scanning, but which can be customized to use different
regular expressions to find the includes.
Note that in order for this to work "out of the box" (without
overriding the :meth:`find_include` and :meth:`sort_key1` methods),
the regular expression passed to the constructor must return the
name of the include file in group 0.
"""
def __init__(self, name, suffixes, path_variable, regex, *args, **kwargs) -> None:
self.cre = re.compile(regex, re.M)
def _scan(node, _, path=(), self=self):
node = node.rfile()
if not node.exists():
return []
return self.scan(node, path)
kwargs['function'] = _scan
kwargs['path_function'] = FindPathDirs(path_variable)
# Allow recursive to propagate if child class specifies.
# In this case resource scanner needs to specify a filter on which files
# get recursively processed. Previously was hardcoded to 1 instead of
# defaulted to 1.
kwargs['recursive'] = kwargs.get('recursive', True)
kwargs['skeys'] = suffixes
kwargs['name'] = name
super().__init__(*args, **kwargs)
[docs]
@staticmethod
def find_include(include, source_dir, path):
n = SCons.Node.FS.find_file(include, (source_dir,) + tuple(path))
return n, include
[docs]
@staticmethod
def sort_key(include):
return SCons.Node.FS._my_normcase(include)
[docs]
def find_include_names(self, node):
return self.cre.findall(node.get_text_contents())
[docs]
def scan(self, node, path=()):
# cache the includes list in node so we only scan it once:
if node.includes is not None:
includes = node.includes
else:
includes = self.find_include_names(node)
# Intern the names of the include files. Saves some memory
# if the same header is included many times.
node.includes = list(map(SCons.Util.silent_intern, includes))
# This is a hand-coded DSU (decorate-sort-undecorate, or
# Schwartzian transform) pattern. The sort key is the raw name
# of the file as specifed on the #include line (including the
# " or <, since that may affect what file is found), which lets
# us keep the sort order constant regardless of whether the file
# is actually found in a Repository or locally.
nodes = []
source_dir = node.get_dir()
if callable(path):
path = path()
for include in includes:
n, i = self.find_include(include, source_dir, path)
if n is None:
SCons.Warnings.warn(
SCons.Warnings.DependencyWarning,
"No dependency generated for file: %s "
"(included from: %s) -- file not found" % (i, node),
)
else:
nodes.append((self.sort_key(include), n))
return [pair[1] for pair in sorted(nodes)]
[docs]
class ClassicCPP(Classic):
"""
A Classic Scanner subclass which takes into account the type of
bracketing used to include the file, and uses classic CPP rules
for searching for the files based on the bracketing.
Note that in order for this to work, the regular expression passed
to the constructor must return the leading bracket in group 0, and
the contained filename in group 1.
"""
[docs]
@staticmethod
def find_include(include, source_dir, path):
include = list(map(SCons.Util.to_str, include))
if include[0] == '"':
paths = (source_dir,) + tuple(path)
else:
paths = tuple(path) + (source_dir,)
n = SCons.Node.FS.find_file(include[1], paths)
i = SCons.Util.silent_intern(include[1])
return n, i
[docs]
@staticmethod
def sort_key(include):
return SCons.Node.FS._my_normcase(' '.join(include))
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