SCons :: Node :: Node :: Class Node
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Class Node

source code

Known Subclasses:
Alias.Alias, FS.Base, Python.Value

The base Node class, for entities that we know how to
build, or use to build other Nodes.



Nested Classes [hide private]
  Attrs
  BuildInfo
The generic base class for build information for a Node.
  NodeInfo
The generic base class for signature information for a Node.
Instance Methods [hide private]
 
Decider(self, function) source code
 
__init__(self) source code
 
_add_child(self, collection, set, child)
Adds 'child' to 'collection', first checking 'set' to see if it's already present.
source code
 
_children_get(self) source code
 
_children_reset(self) source code
 
add_dependency(self, depend)
Adds dependencies.
source code
 
add_ignore(self, depend)
Adds dependencies to ignore.
source code
 
add_prerequisite(self, prerequisite)
Adds prerequisites
source code
 
add_source(self, source)
Adds sources.
source code
 
add_to_implicit(self, deps) source code
 
add_to_waiting_parents(self, node)
Returns the number of nodes added to our waiting parents list: 1 if we add a unique waiting parent, 0 if not.
source code
 
add_to_waiting_s_e(self, node) source code
 
add_wkid(self, wkid)
Add a node to the list of kids waiting to be evaluated
source code
 
all_children(self, scan=False)
Return a list of all the node's direct children.
source code
 
alter_targets(self)
Return a list of alternate targets for this Node.
source code
 
build(self, **kw)
Actually build the node.
source code
 
builder_set(self, builder) source code
 
built(self)
Called just after this node is successfully built.
source code
 
changed(self, node=False)
Returns if the node is up-to-date with respect to the BuildInfo stored last time it was built.
source code
 
changed_since_last_build(self, target, prev_ni)
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.
source code
 
children(self, scan=False)
Return a list of the node's direct children, minus those that are ignored by this node.
source code
 
children_are_up_to_date(self)
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.
source code
 
clear(self)
Completely clear a Node of all its cached state (so that it can be re-evaluated by interfaces that do continuous integration builds).
source code
 
clear_memoized_values(self) source code
 
del_binfo(self)
Delete the build info from this node.
source code
 
disambiguate(self, must_exist=False) source code
 
do_not_store_info(self) source code
 
env_set(self, env, safe=0) source code
 
executor_cleanup(self)
Let the executor clean up any cached information.
source code
 
exists(self)
Does this node exists?
source code
 
explain(self) source code
 
for_signature(self)
Return a string representation of the Node that will always be the same for this particular Node, no matter what.
source code
 
get_abspath(self)
Return an absolute path to the Node.
source code
 
get_binfo(self)
Fetch a node's build information.
source code
 
get_build_env(self)
Fetch the appropriate Environment to build this node.
source code
 
get_build_scanner_path(self, scanner)
Fetch the appropriate scanner path for this node.
source code
 
get_builder(self, default_builder=False)
Return the set builder, or a specified default value
source code
 
get_cachedir_csig(self) source code
 
get_csig(self) source code
 
get_env(self) source code
 
get_env_scanner(self, env, kw={}) source code
 
get_executor(self, create=False)
Fetch the action executor for this node.
source code
 
get_found_includes(self, env, scanner, path)
Return the scanned include lines (implicit dependencies) found in this node.
source code
 
get_implicit_deps(self, env, scanner, path)
Return a list of implicit dependencies for this node.
source code
 
get_ninfo(self) source code
 
get_source_scanner(self, node)
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.
source code
 
get_state(self) source code
 
get_stored_implicit(self)
Fetch the stored implicit dependencies
source code
 
get_stored_info(self) source code
 
get_string(self, for_signature)
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.
source code
 
get_subst_proxy(self)
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.
source code
 
get_suffix(self) source code
 
get_target_scanner(self) source code
 
has_builder(self)
Return whether this Node has a builder or not.
source code
 
has_explicit_builder(self)
Return whether this Node has an explicit builder This allows an internal Builder created by SCons to be marked non-explicit, so that it can be overridden by an explicit builder that the user supplies (the canonical example being directories).
source code
 
is_derived(self)
Returns true iff this node is derived (i.e.
source code
 
is_literal(self)
Always pass the string representation of a Node to the command interpreter literally.
source code
 
is_up_to_date(self)
Default check for whether the Node is current: unknown Node subtypes are always out of date, so they will always get built.
source code
 
make_ready(self)
Get a Node ready for evaluation.
source code
 
missing(self) source code
 
multiple_side_effect_has_builder(self)
Return whether this Node has a builder or not.
source code
 
new_binfo(self) source code
 
new_ninfo(self) source code
 
postprocess(self)
Clean up anything we don't need to hang onto after we've been built.
source code
 
prepare(self)
Prepare for this Node to be built.
source code
 
push_to_cache(self)
Try to push a node into a cache...
source code
 
remove(self)
Remove this Node: no-op by default.
source code
 
render_include_tree(self)
Return a text representation, suitable for displaying to the user, of the include tree for the sources of this node.
source code
 
reset_executor(self)
Remove cached executor; forces recompute when needed.
source code
 
retrieve_from_cache(self)
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.
source code
 
rexists(self)
Does this node exist locally or in a repositiory?
source code
 
scan(self)
Scan this node's dependents for implicit dependencies.
source code
 
scanner_key(self) source code
 
select_scanner(self, scanner)
Selects a scanner for this Node.
source code
 
set_always_build(self, always_build=False)
Set the Node's always_build value.
source code
 
set_executor(self, executor)
Set the action executor for this node.
source code
 
set_explicit(self, is_explicit) source code
 
set_nocache(self, nocache=False)
Set the Node's nocache value.
source code
 
set_noclean(self, noclean=False)
Set the Node's noclean value.
source code
 
set_precious(self, precious=False)
Set the Node's precious value.
source code
 
set_specific_source(self, source) source code
 
set_state(self, state) source code
 
state_has_changed(self, target, prev_ni) source code
 
store_info(self)
Make the build signature permanent (that is, store it in the .sconsign file or equivalent).
source code
 
visited(self)
Called just after this node has been visited (with or without a build).
source code
Class Variables [hide private]
  __metaclass__ = SCons.Memoize.Memoized_Metaclass
  memoizer_counters = [<SCons.Memoize.CountValue instance at 0x8...
Method Details [hide private]

add_to_waiting_parents(self, node)

source code 

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...)

build(self, **kw)

source code 
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().

changed(self, node=False)

source code 

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.

changed_since_last_build(self, target, prev_ni)

source code 


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.

children_are_up_to_date(self)

source code 
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.

for_signature(self)

source code 

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.

get_abspath(self)

source code 

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.

get_binfo(self)

source code 

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.

get_executor(self, create=False)

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

get_found_includes(self, env, scanner, path)

source code 
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.

get_implicit_deps(self, env, scanner, path)

source code 
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.

get_source_scanner(self, node)

source code 
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.

get_string(self, for_signature)

source code 
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.

get_subst_proxy(self)

source code 

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.

has_builder(self)

source code 
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.

is_derived(self)

source code 

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.

make_ready(self)

source code 
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.

multiple_side_effect_has_builder(self)

source code 
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(self)

source code 
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.

push_to_cache(self)

source code 
Try to push a node into a cache
        

retrieve_from_cache(self)

source code 
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.

select_scanner(self, scanner)

source code 
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.


Class Variable Details [hide private]

memoizer_counters

Value:
[]