Class Node

x.__init__(...) initializes x; see x.__class__.__doc__ for signature

Overrides: object.__init__

(inherited documentation)

Returns the number of nodes added to our waiting parents list:
1 if we add a unique waiting parent, 0 if not.  (Note that the
returned values are intended to be used to increment a reference
count, so don't think you can "clean up" this function by using
True and False instead...)

Actually build the node.

This is called by the Taskmaster after it's decided that the
Node is out-of-date and must be rebuilt, and after the prepare()
method has gotten everything, uh, prepared.

This method is called from multiple threads in a parallel build,
so only do thread safe stuff here. Do thread unsafe stuff
in built().

Returns if the node is up-to-date with respect to the BuildInfo
stored last time it was built.  The default behavior is to compare
it against our own previously stored BuildInfo, but the stored
BuildInfo from another Node (typically one in a Repository)
can be used instead.

Note that we now *always* check every dependency.  We used to
short-circuit the check by returning as soon as we detected
any difference, but we now rely on checking every dependency
to make sure that any necessary Node information (for example,
the content signature of an #included .h file) is updated.

Must be overridden in a specific subclass to return True if this
Node (a dependency) has changed since the last time it was used
to build the specified target.  prev_ni is this Node's state (for
example, its file timestamp, length, maybe content signature)
as of the last time the target was built.

Note that this method is called through the dependency, not the
target, because a dependency Node must be able to use its own
logic to decide if it changed.  For example, File Nodes need to
obey if we're configured to use timestamps, but Python Value Nodes
never use timestamps and always use the content.  If this method
were called through the target, then each Node's implementation
of this method would have to have more complicated logic to
handle all the different Node types on which it might depend.

Alternate check for whether the Node is current:  If all of
our children were up-to-date, then this Node was up-to-date, too.

The SCons.Node.Alias and SCons.Node.Python.Value subclasses
rebind their current() method to this method.

Return a string representation of the Node that will always
be the same for this particular Node, no matter what.  This
is by contrast to the __str__() method, which might, for
instance, return a relative path for a file Node.  The purpose
of this method is to generate a value to be used in signature
calculation for the command line used to build a target, and
we use this method instead of str() to avoid unnecessary
rebuilds.  This method does not need to return something that
would actually work in a command line; it can return any kind of
nonsense, so long as it does not change.

Return an absolute path to the Node.  This will return simply
str(Node) by default, but for Node types that have a concept of
relative path, this might return something different.

Fetch a node's build information.

node - the node whose sources will be collected
cache - alternate node to use for the signature cache
returns - the build signature

This no longer handles the recursive descent of the
node's children's signatures.  We expect that they're
already built and updated by someone else, if that's
what's wanted.

Fetch the action executor for this node.  Create one if
there isn't already one, and requested to do so.

Return the scanned include lines (implicit dependencies)
found in this node.

The default is no implicit dependencies.  We expect this method
to be overridden by any subclass that can be scanned for
implicit dependencies.

Return a list of implicit dependencies for this node.

This method exists to handle recursive invocation of the scanner
on the implicit dependencies returned by the scanner, if the
scanner's recursive flag says that we should.

Fetch the source scanner for the specified node

NOTE:  "self" is the target being built, "node" is
the source file for which we want to fetch the scanner.

Implies self.has_builder() is true; again, expect to only be
called from locations where this is already verified.

This function may be called very often; it attempts to cache
the scanner found to improve performance.

This is a convenience function designed primarily to be
used in command generators (i.e., CommandGeneratorActions or
Environment variables that are callable), which are called
with a for_signature argument that is nonzero if the command
generator is being called to generate a signature for the
command line, which determines if we should rebuild or not.

Such command generators should use this method in preference
to str(Node) when converting a Node to a string, passing
in the for_signature parameter, such that we will call
Node.for_signature() or str(Node) properly, depending on whether
we are calculating a signature or actually constructing a
command line.

This method is expected to return an object that will function
exactly like this Node, except that it implements any additional
special features that we would like to be in effect for
Environment variable substitution.  The principle use is that
some Nodes would like to implement a __getattr__() method,
but putting that in the Node type itself has a tendency to kill
performance.  We instead put it in a proxy and return it from
this method.  It is legal for this method to return self
if no new functionality is needed for Environment substitution.

Return whether this Node has a builder or not.

In Boolean tests, this turns out to be a *lot* more efficient
than simply examining the builder attribute directly ("if
node.builder: ..."). When the builder attribute is examined
directly, it ends up calling __getattr__ for both the __len__
and __nonzero__ attributes on instances of our Builder Proxy
class(es), generating a bazillion extra calls and slowing
things down immensely.

Returns true iff this node is derived (i.e. built).

This should return true only for nodes whose path should be in
the variant directory when duplicate=0 and should contribute their build
signatures when they are used as source files to other derived files. For
example: source with source builders are not derived in this sense,
and hence should not return true.

Get a Node ready for evaluation.

This is called before the Taskmaster decides if the Node is
up-to-date or not.  Overriding this method allows for a Node
subclass to be disambiguated if necessary, or for an implicit
source builder to be attached.

Return whether this Node has a builder or not.

In Boolean tests, this turns out to be a *lot* more efficient
than simply examining the builder attribute directly ("if
node.builder: ..."). When the builder attribute is examined
directly, it ends up calling __getattr__ for both the __len__
and __nonzero__ attributes on instances of our Builder Proxy
class(es), generating a bazillion extra calls and slowing
things down immensely.

Prepare for this Node to be built.

This is called after the Taskmaster has decided that the Node
is out-of-date and must be rebuilt, but before actually calling
the method to build the Node.

This default implementation checks that explicit or implicit
dependencies either exist or are derived, and initializes the
BuildInfo structure that will hold the information about how
this node is, uh, built.

(The existence of source files is checked separately by the
Executor, which aggregates checks for all of the targets built
by a specific action.)

Overriding this method allows for for a Node subclass to remove
the underlying file from the file system.  Note that subclass
methods should call this base class method to get the child
check and the BuildInfo structure.

Try to push a node into a cache
        

Try to retrieve the node's content from a cache

This method is called from multiple threads in a parallel build,
so only do thread safe stuff here. Do thread unsafe stuff in
built().

Returns true iff the node was successfully retrieved.

Selects a scanner for this Node.

This is a separate method so it can be overridden by Node
subclasses (specifically, Node.FS.Dir) that *must* use their
own Scanner and don't select one the Scanner.Selector that's
configured for the target.

memoizer_counters

Value:

[]