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Diffstat (limited to 'engine/SCons/Node/__init__.py')
| -rw-r--r-- | engine/SCons/Node/__init__.py | 1341 |
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diff --git a/engine/SCons/Node/__init__.py b/engine/SCons/Node/__init__.py new file mode 100644 index 0000000..6acc751 --- /dev/null +++ b/engine/SCons/Node/__init__.py @@ -0,0 +1,1341 @@ +"""SCons.Node + +The Node package for the SCons software construction utility. + +This is, in many ways, the heart of SCons. + +A Node is where we encapsulate all of the dependency information about +any thing that SCons can build, or about any thing which SCons can use +to build some other thing. The canonical "thing," of course, is a file, +but a Node can also represent something remote (like a web page) or +something completely abstract (like an Alias). + +Each specific type of "thing" is specifically represented by a subclass +of the Node base class: Node.FS.File for files, Node.Alias for aliases, +etc. Dependency information is kept here in the base class, and +information specific to files/aliases/etc. is in the subclass. The +goal, if we've done this correctly, is that any type of "thing" should +be able to depend on any other type of "thing." + +""" + +# +# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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. +# + +__revision__ = "src/engine/SCons/Node/__init__.py 4577 2009/12/27 19:43:56 scons" + +import copy +from itertools import chain, izip +import string +import UserList + +from SCons.Debug import logInstanceCreation +import SCons.Executor +import SCons.Memoize +import SCons.Util + +from SCons.Debug import Trace + +def classname(obj): + return string.split(str(obj.__class__), '.')[-1] + +# Node states +# +# These are in "priority" order, so that the maximum value for any +# child/dependency of a node represents the state of that node if +# it has no builder of its own. The canonical example is a file +# system directory, which is only up to date if all of its children +# were up to date. +no_state = 0 +pending = 1 +executing = 2 +up_to_date = 3 +executed = 4 +failed = 5 + +StateString = { + 0 : "no_state", + 1 : "pending", + 2 : "executing", + 3 : "up_to_date", + 4 : "executed", + 5 : "failed", +} + +# controls whether implicit dependencies are cached: +implicit_cache = 0 + +# controls whether implicit dep changes are ignored: +implicit_deps_unchanged = 0 + +# controls whether the cached implicit deps are ignored: +implicit_deps_changed = 0 + +# A variable that can be set to an interface-specific function be called +# to annotate a Node with information about its creation. +def do_nothing(node): pass + +Annotate = do_nothing + +# Classes for signature info for Nodes. + +class NodeInfoBase: + """ + The generic base class for signature information for a Node. + + Node subclasses should subclass NodeInfoBase to provide their own + logic for dealing with their own Node-specific signature information. + """ + current_version_id = 1 + def __init__(self, node): + # Create an object attribute from the class attribute so it ends up + # in the pickled data in the .sconsign file. + self._version_id = self.current_version_id + def update(self, node): + try: + field_list = self.field_list + except AttributeError: + return + for f in field_list: + try: + delattr(self, f) + except AttributeError: + pass + try: + func = getattr(node, 'get_' + f) + except AttributeError: + pass + else: + setattr(self, f, func()) + def convert(self, node, val): + pass + def merge(self, other): + self.__dict__.update(other.__dict__) + def format(self, field_list=None, names=0): + if field_list is None: + try: + field_list = self.field_list + except AttributeError: + field_list = self.__dict__.keys() + field_list.sort() + fields = [] + for field in field_list: + try: + f = getattr(self, field) + except AttributeError: + f = None + f = str(f) + if names: + f = field + ': ' + f + fields.append(f) + return fields + +class BuildInfoBase: + """ + The generic base class for build information for a Node. + + This is what gets stored in a .sconsign file for each target file. + It contains a NodeInfo instance for this node (signature information + that's specific to the type of Node) and direct attributes for the + generic build stuff we have to track: sources, explicit dependencies, + implicit dependencies, and action information. + """ + current_version_id = 1 + def __init__(self, node): + # Create an object attribute from the class attribute so it ends up + # in the pickled data in the .sconsign file. + self._version_id = self.current_version_id + self.bsourcesigs = [] + self.bdependsigs = [] + self.bimplicitsigs = [] + self.bactsig = None + def merge(self, other): + self.__dict__.update(other.__dict__) + +class Node: + """The base Node class, for entities that we know how to + build, or use to build other Nodes. + """ + + if SCons.Memoize.use_memoizer: + __metaclass__ = SCons.Memoize.Memoized_Metaclass + + memoizer_counters = [] + + class Attrs: + pass + + def __init__(self): + if __debug__: logInstanceCreation(self, 'Node.Node') + # Note that we no longer explicitly initialize a self.builder + # attribute to None here. That's because the self.builder + # attribute may be created on-the-fly later by a subclass (the + # canonical example being a builder to fetch a file from a + # source code system like CVS or Subversion). + + # Each list of children that we maintain is accompanied by a + # dictionary used to look up quickly whether a node is already + # present in the list. Empirical tests showed that it was + # fastest to maintain them as side-by-side Node attributes in + # this way, instead of wrapping up each list+dictionary pair in + # a class. (Of course, we could always still do that in the + # future if we had a good reason to...). + self.sources = [] # source files used to build node + self.sources_set = set() + self._specific_sources = False + self.depends = [] # explicit dependencies (from Depends) + self.depends_set = set() + self.ignore = [] # dependencies to ignore + self.ignore_set = set() + self.prerequisites = SCons.Util.UniqueList() + self.implicit = None # implicit (scanned) dependencies (None means not scanned yet) + self.waiting_parents = set() + self.waiting_s_e = set() + self.ref_count = 0 + self.wkids = None # Kids yet to walk, when it's an array + + self.env = None + self.state = no_state + self.precious = None + self.noclean = 0 + self.nocache = 0 + self.always_build = None + self.includes = None + self.attributes = self.Attrs() # Generic place to stick information about the Node. + self.side_effect = 0 # true iff this node is a side effect + self.side_effects = [] # the side effects of building this target + self.linked = 0 # is this node linked to the variant directory? + + self.clear_memoized_values() + + # Let the interface in which the build engine is embedded + # annotate this Node with its own info (like a description of + # what line in what file created the node, for example). + Annotate(self) + + def disambiguate(self, must_exist=None): + return self + + def get_suffix(self): + return '' + + memoizer_counters.append(SCons.Memoize.CountValue('get_build_env')) + + def get_build_env(self): + """Fetch the appropriate Environment to build this node. + """ + try: + return self._memo['get_build_env'] + except KeyError: + pass + result = self.get_executor().get_build_env() + self._memo['get_build_env'] = result + return result + + def get_build_scanner_path(self, scanner): + """Fetch the appropriate scanner path for this node.""" + return self.get_executor().get_build_scanner_path(scanner) + + def set_executor(self, executor): + """Set the action executor for this node.""" + self.executor = executor + + def get_executor(self, create=1): + """Fetch the action executor for this node. Create one if + there isn't already one, and requested to do so.""" + try: + executor = self.executor + except AttributeError: + if not create: + raise + try: + act = self.builder.action + except AttributeError: + executor = SCons.Executor.Null(targets=[self]) + else: + executor = SCons.Executor.Executor(act, + self.env or self.builder.env, + [self.builder.overrides], + [self], + self.sources) + self.executor = executor + return executor + + def executor_cleanup(self): + """Let the executor clean up any cached information.""" + try: + executor = self.get_executor(create=None) + except AttributeError: + pass + else: + executor.cleanup() + + def reset_executor(self): + "Remove cached executor; forces recompute when needed." + try: + delattr(self, 'executor') + except AttributeError: + pass + + def push_to_cache(self): + """Try to push a node into a cache + """ + pass + + def 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. Do thread unsafe stuff in + built(). + + Returns true iff the node was successfully retrieved. + """ + return 0 + + # + # Taskmaster interface subsystem + # + + def make_ready(self): + """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. + """ + pass + + def prepare(self): + """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. + """ + for d in self.depends: + if d.missing(): + msg = "Explicit dependency `%s' not found, needed by target `%s'." + raise SCons.Errors.StopError, msg % (d, self) + if self.implicit is not None: + for i in self.implicit: + if i.missing(): + msg = "Implicit dependency `%s' not found, needed by target `%s'." + raise SCons.Errors.StopError, msg % (i, self) + self.binfo = self.get_binfo() + + def build(self, **kw): + """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(). + + """ + try: + apply(self.get_executor(), (self,), kw) + except SCons.Errors.BuildError, e: + e.node = self + raise + + def built(self): + """Called just after this node is successfully built.""" + + # Clear the implicit dependency caches of any Nodes + # waiting for this Node to be built. + for parent in self.waiting_parents: + parent.implicit = None + + self.clear() + + self.ninfo.update(self) + + def visited(self): + """Called just after this node has been visited (with or + without a build).""" + try: + binfo = self.binfo + except AttributeError: + # Apparently this node doesn't need build info, so + # don't bother calculating or storing it. + pass + else: + self.ninfo.update(self) + self.store_info() + + # + # + # + + def add_to_waiting_s_e(self, node): + self.waiting_s_e.add(node) + + def 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. (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...) + """ + wp = self.waiting_parents + if node in wp: + return 0 + wp.add(node) + return 1 + + def postprocess(self): + """Clean up anything we don't need to hang onto after we've + been built.""" + self.executor_cleanup() + self.waiting_parents = set() + + def 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). + """ + # The del_binfo() call here isn't necessary for normal execution, + # but is for interactive mode, where we might rebuild the same + # target and need to start from scratch. + self.del_binfo() + self.clear_memoized_values() + self.ninfo = self.new_ninfo() + self.executor_cleanup() + try: + delattr(self, '_calculated_sig') + except AttributeError: + pass + self.includes = None + + def clear_memoized_values(self): + self._memo = {} + + def builder_set(self, builder): + self.builder = builder + try: + del self.executor + except AttributeError: + pass + + def has_builder(self): + """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. + """ + try: + b = self.builder + except AttributeError: + # There was no explicit builder for this Node, so initialize + # the self.builder attribute to None now. + b = self.builder = None + return b is not None + + def set_explicit(self, is_explicit): + self.is_explicit = is_explicit + + def 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).""" + try: + return self.is_explicit + except AttributeError: + self.is_explicit = None + return self.is_explicit + + def get_builder(self, default_builder=None): + """Return the set builder, or a specified default value""" + try: + return self.builder + except AttributeError: + return default_builder + + multiple_side_effect_has_builder = has_builder + + def is_derived(self): + """ + 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. + """ + return self.has_builder() or self.side_effect + + def alter_targets(self): + """Return a list of alternate targets for this Node. + """ + return [], None + + def get_found_includes(self, env, scanner, path): + """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 [] + + def get_implicit_deps(self, env, scanner, path): + """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. + """ + if not scanner: + return [] + + # Give the scanner a chance to select a more specific scanner + # for this Node. + #scanner = scanner.select(self) + + nodes = [self] + seen = {} + seen[self] = 1 + deps = [] + while nodes: + n = nodes.pop(0) + d = filter(lambda x, seen=seen: not seen.has_key(x), + n.get_found_includes(env, scanner, path)) + if d: + deps.extend(d) + for n in d: + seen[n] = 1 + nodes.extend(scanner.recurse_nodes(d)) + + return deps + + def get_env_scanner(self, env, kw={}): + return env.get_scanner(self.scanner_key()) + + def get_target_scanner(self): + return self.builder.target_scanner + + def 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. + + 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. + """ + scanner = None + try: + scanner = self.builder.source_scanner + except AttributeError: + pass + if not scanner: + # The builder didn't have an explicit scanner, so go look up + # a scanner from env['SCANNERS'] based on the node's scanner + # key (usually the file extension). + scanner = self.get_env_scanner(self.get_build_env()) + if scanner: + scanner = scanner.select(node) + return scanner + + def add_to_implicit(self, deps): + if not hasattr(self, 'implicit') or self.implicit is None: + self.implicit = [] + self.implicit_set = set() + self._children_reset() + self._add_child(self.implicit, self.implicit_set, deps) + + def scan(self): + """Scan this node's dependents for implicit dependencies.""" + # Don't bother scanning non-derived files, because we don't + # care what their dependencies are. + # Don't scan again, if we already have scanned. + if self.implicit is not None: + return + self.implicit = [] + self.implicit_set = set() + self._children_reset() + if not self.has_builder(): + return + + build_env = self.get_build_env() + executor = self.get_executor() + + # Here's where we implement --implicit-cache. + if implicit_cache and not implicit_deps_changed: + implicit = self.get_stored_implicit() + if implicit is not None: + # We now add the implicit dependencies returned from the + # stored .sconsign entry to have already been converted + # to Nodes for us. (We used to run them through a + # source_factory function here.) + + # Update all of the targets with them. This + # essentially short-circuits an N*M scan of the + # sources for each individual target, which is a hell + # of a lot more efficient. + for tgt in executor.get_all_targets(): + tgt.add_to_implicit(implicit) + + if implicit_deps_unchanged or self.is_up_to_date(): + return + # one of this node's sources has changed, + # so we must recalculate the implicit deps: + self.implicit = [] + self.implicit_set = set() + + # Have the executor scan the sources. + executor.scan_sources(self.builder.source_scanner) + + # If there's a target scanner, have the executor scan the target + # node itself and associated targets that might be built. + scanner = self.get_target_scanner() + if scanner: + executor.scan_targets(scanner) + + def scanner_key(self): + return None + + def select_scanner(self, scanner): + """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. + """ + return scanner.select(self) + + def env_set(self, env, safe=0): + if safe and self.env: + return + self.env = env + + # + # SIGNATURE SUBSYSTEM + # + + NodeInfo = NodeInfoBase + BuildInfo = BuildInfoBase + + def new_ninfo(self): + ninfo = self.NodeInfo(self) + return ninfo + + def get_ninfo(self): + try: + return self.ninfo + except AttributeError: + self.ninfo = self.new_ninfo() + return self.ninfo + + def new_binfo(self): + binfo = self.BuildInfo(self) + return binfo + + def get_binfo(self): + """ + 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. + """ + try: + return self.binfo + except AttributeError: + pass + + binfo = self.new_binfo() + self.binfo = binfo + + executor = self.get_executor() + ignore_set = self.ignore_set + + if self.has_builder(): + binfo.bact = str(executor) + binfo.bactsig = SCons.Util.MD5signature(executor.get_contents()) + + if self._specific_sources: + sources = [] + for s in self.sources: + if s not in ignore_set: + sources.append(s) + else: + sources = executor.get_unignored_sources(self, self.ignore) + seen = set() + bsources = [] + bsourcesigs = [] + for s in sources: + if not s in seen: + seen.add(s) + bsources.append(s) + bsourcesigs.append(s.get_ninfo()) + binfo.bsources = bsources + binfo.bsourcesigs = bsourcesigs + + depends = self.depends + dependsigs = [] + for d in depends: + if d not in ignore_set: + dependsigs.append(d.get_ninfo()) + binfo.bdepends = depends + binfo.bdependsigs = dependsigs + + implicit = self.implicit or [] + implicitsigs = [] + for i in implicit: + if i not in ignore_set: + implicitsigs.append(i.get_ninfo()) + binfo.bimplicit = implicit + binfo.bimplicitsigs = implicitsigs + + return binfo + + def del_binfo(self): + """Delete the build info from this node.""" + try: + delattr(self, 'binfo') + except AttributeError: + pass + + def get_csig(self): + try: + return self.ninfo.csig + except AttributeError: + ninfo = self.get_ninfo() + ninfo.csig = SCons.Util.MD5signature(self.get_contents()) + return self.ninfo.csig + + def get_cachedir_csig(self): + return self.get_csig() + + def store_info(self): + """Make the build signature permanent (that is, store it in the + .sconsign file or equivalent).""" + pass + + def do_not_store_info(self): + pass + + def get_stored_info(self): + return None + + def get_stored_implicit(self): + """Fetch the stored implicit dependencies""" + return None + + # + # + # + + def set_precious(self, precious = 1): + """Set the Node's precious value.""" + self.precious = precious + + def set_noclean(self, noclean = 1): + """Set the Node's noclean value.""" + # Make sure noclean is an integer so the --debug=stree + # output in Util.py can use it as an index. + self.noclean = noclean and 1 or 0 + + def set_nocache(self, nocache = 1): + """Set the Node's nocache value.""" + # Make sure nocache is an integer so the --debug=stree + # output in Util.py can use it as an index. + self.nocache = nocache and 1 or 0 + + def set_always_build(self, always_build = 1): + """Set the Node's always_build value.""" + self.always_build = always_build + + def exists(self): + """Does this node exists?""" + # All node exist by default: + return 1 + + def rexists(self): + """Does this node exist locally or in a repositiory?""" + # There are no repositories by default: + return self.exists() + + def missing(self): + return not self.is_derived() and \ + not self.linked and \ + not self.rexists() + + def remove(self): + """Remove this Node: no-op by default.""" + return None + + def add_dependency(self, depend): + """Adds dependencies.""" + try: + self._add_child(self.depends, self.depends_set, depend) + except TypeError, e: + e = e.args[0] + if SCons.Util.is_List(e): + s = map(str, e) + else: + s = str(e) + raise SCons.Errors.UserError("attempted to add a non-Node dependency to %s:\n\t%s is a %s, not a Node" % (str(self), s, type(e))) + + def add_prerequisite(self, prerequisite): + """Adds prerequisites""" + self.prerequisites.extend(prerequisite) + self._children_reset() + + def add_ignore(self, depend): + """Adds dependencies to ignore.""" + try: + self._add_child(self.ignore, self.ignore_set, depend) + except TypeError, e: + e = e.args[0] + if SCons.Util.is_List(e): + s = map(str, e) + else: + s = str(e) + raise SCons.Errors.UserError("attempted to ignore a non-Node dependency of %s:\n\t%s is a %s, not a Node" % (str(self), s, type(e))) + + def add_source(self, source): + """Adds sources.""" + if self._specific_sources: + return + try: + self._add_child(self.sources, self.sources_set, source) + except TypeError, e: + e = e.args[0] + if SCons.Util.is_List(e): + s = map(str, e) + else: + s = str(e) + raise SCons.Errors.UserError("attempted to add a non-Node as source of %s:\n\t%s is a %s, not a Node" % (str(self), s, type(e))) + + def _add_child(self, collection, set, child): + """Adds 'child' to 'collection', first checking 'set' to see if it's + already present.""" + #if type(child) is not type([]): + # child = [child] + #for c in child: + # if not isinstance(c, Node): + # raise TypeError, c + added = None + for c in child: + if c not in set: + set.add(c) + collection.append(c) + added = 1 + if added: + self._children_reset() + + def set_specific_source(self, source): + self.add_source(source) + self._specific_sources = True + + def add_wkid(self, wkid): + """Add a node to the list of kids waiting to be evaluated""" + if self.wkids is not None: + self.wkids.append(wkid) + + def _children_reset(self): + self.clear_memoized_values() + # We need to let the Executor clear out any calculated + # build info that it's cached so we can re-calculate it. + self.executor_cleanup() + + memoizer_counters.append(SCons.Memoize.CountValue('_children_get')) + + def _children_get(self): + try: + return self._memo['children_get'] + except KeyError: + pass + + # The return list may contain duplicate Nodes, especially in + # source trees where there are a lot of repeated #includes + # of a tangle of .h files. Profiling shows, however, that + # eliminating the duplicates with a brute-force approach that + # preserves the order (that is, something like: + # + # u = [] + # for n in list: + # if n not in u: + # u.append(n)" + # + # takes more cycles than just letting the underlying methods + # hand back cached values if a Node's information is requested + # multiple times. (Other methods of removing duplicates, like + # using dictionary keys, lose the order, and the only ordered + # dictionary patterns I found all ended up using "not in" + # internally anyway...) + if self.ignore_set: + if self.implicit is None: + iter = chain(self.sources,self.depends) + else: + iter = chain(self.sources, self.depends, self.implicit) + + children = [] + for i in iter: + if i not in self.ignore_set: + children.append(i) + else: + if self.implicit is None: + children = self.sources + self.depends + else: + children = self.sources + self.depends + self.implicit + + self._memo['children_get'] = children + return children + + def all_children(self, scan=1): + """Return a list of all the node's direct children.""" + if scan: + self.scan() + + # The return list may contain duplicate Nodes, especially in + # source trees where there are a lot of repeated #includes + # of a tangle of .h files. Profiling shows, however, that + # eliminating the duplicates with a brute-force approach that + # preserves the order (that is, something like: + # + # u = [] + # for n in list: + # if n not in u: + # u.append(n)" + # + # takes more cycles than just letting the underlying methods + # hand back cached values if a Node's information is requested + # multiple times. (Other methods of removing duplicates, like + # using dictionary keys, lose the order, and the only ordered + # dictionary patterns I found all ended up using "not in" + # internally anyway...) + if self.implicit is None: + return self.sources + self.depends + else: + return self.sources + self.depends + self.implicit + + def children(self, scan=1): + """Return a list of the node's direct children, minus those + that are ignored by this node.""" + if scan: + self.scan() + return self._children_get() + + def set_state(self, state): + self.state = state + + def get_state(self): + return self.state + + def state_has_changed(self, target, prev_ni): + return (self.state != SCons.Node.up_to_date) + + def get_env(self): + env = self.env + if not env: + import SCons.Defaults + env = SCons.Defaults.DefaultEnvironment() + return env + + def 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. 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. + """ + raise NotImplementedError + + def Decider(self, function): + SCons.Util.AddMethod(self, function, 'changed_since_last_build') + + def changed(self, node=None): + """ + 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. + """ + t = 0 + if t: Trace('changed(%s [%s], %s)' % (self, classname(self), node)) + if node is None: + node = self + + result = False + + bi = node.get_stored_info().binfo + then = bi.bsourcesigs + bi.bdependsigs + bi.bimplicitsigs + children = self.children() + + diff = len(children) - len(then) + if diff: + # The old and new dependency lists are different lengths. + # This always indicates that the Node must be rebuilt. + # We also extend the old dependency list with enough None + # entries to equal the new dependency list, for the benefit + # of the loop below that updates node information. + then.extend([None] * diff) + if t: Trace(': old %s new %s' % (len(then), len(children))) + result = True + + for child, prev_ni in izip(children, then): + if child.changed_since_last_build(self, prev_ni): + if t: Trace(': %s changed' % child) + result = True + + contents = self.get_executor().get_contents() + if self.has_builder(): + import SCons.Util + newsig = SCons.Util.MD5signature(contents) + if bi.bactsig != newsig: + if t: Trace(': bactsig %s != newsig %s' % (bi.bactsig, newsig)) + result = True + + if not result: + if t: Trace(': up to date') + + if t: Trace('\n') + + return result + + def 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.""" + return None + + def 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. + + The SCons.Node.Alias and SCons.Node.Python.Value subclasses + rebind their current() method to this method.""" + # Allow the children to calculate their signatures. + self.binfo = self.get_binfo() + if self.always_build: + return None + state = 0 + for kid in self.children(None): + s = kid.get_state() + if s and (not state or s > state): + state = s + return (state == 0 or state == SCons.Node.up_to_date) + + def is_literal(self): + """Always pass the string representation of a Node to + the command interpreter literally.""" + return 1 + + def render_include_tree(self): + """ + Return a text representation, suitable for displaying to the + user, of the include tree for the sources of this node. + """ + if self.is_derived() and self.env: + env = self.get_build_env() + for s in self.sources: + scanner = self.get_source_scanner(s) + if scanner: + path = self.get_build_scanner_path(scanner) + else: + path = None + def f(node, env=env, scanner=scanner, path=path): + return node.get_found_includes(env, scanner, path) + return SCons.Util.render_tree(s, f, 1) + else: + return None + + def get_abspath(self): + """ + 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. + """ + return str(self) + + def for_signature(self): + """ + 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 str(self) + + def 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. + + 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.""" + if for_signature: + return self.for_signature() + return str(self) + + def 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. 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 self + + def explain(self): + if not self.exists(): + return "building `%s' because it doesn't exist\n" % self + + if self.always_build: + return "rebuilding `%s' because AlwaysBuild() is specified\n" % self + + old = self.get_stored_info() + if old is None: + return None + + old = old.binfo + old.prepare_dependencies() + + try: + old_bkids = old.bsources + old.bdepends + old.bimplicit + old_bkidsigs = old.bsourcesigs + old.bdependsigs + old.bimplicitsigs + except AttributeError: + return "Cannot explain why `%s' is being rebuilt: No previous build information found\n" % self + + new = self.get_binfo() + + new_bkids = new.bsources + new.bdepends + new.bimplicit + new_bkidsigs = new.bsourcesigs + new.bdependsigs + new.bimplicitsigs + + osig = dict(izip(old_bkids, old_bkidsigs)) + nsig = dict(izip(new_bkids, new_bkidsigs)) + + # The sources and dependencies we'll want to report are all stored + # as relative paths to this target's directory, but we want to + # report them relative to the top-level SConstruct directory, + # so we only print them after running them through this lambda + # to turn them into the right relative Node and then return + # its string. + def stringify( s, E=self.dir.Entry ) : + if hasattr( s, 'dir' ) : + return str(E(s)) + return str(s) + + lines = [] + + removed = filter(lambda x, nk=new_bkids: not x in nk, old_bkids) + if removed: + removed = map(stringify, removed) + fmt = "`%s' is no longer a dependency\n" + lines.extend(map(lambda s, fmt=fmt: fmt % s, removed)) + + for k in new_bkids: + if not k in old_bkids: + lines.append("`%s' is a new dependency\n" % stringify(k)) + elif k.changed_since_last_build(self, osig[k]): + lines.append("`%s' changed\n" % stringify(k)) + + if len(lines) == 0 and old_bkids != new_bkids: + lines.append("the dependency order changed:\n" + + "%sold: %s\n" % (' '*15, map(stringify, old_bkids)) + + "%snew: %s\n" % (' '*15, map(stringify, new_bkids))) + + if len(lines) == 0: + def fmt_with_title(title, strlines): + lines = string.split(strlines, '\n') + sep = '\n' + ' '*(15 + len(title)) + return ' '*15 + title + string.join(lines, sep) + '\n' + if old.bactsig != new.bactsig: + if old.bact == new.bact: + lines.append("the contents of the build action changed\n" + + fmt_with_title('action: ', new.bact)) + else: + lines.append("the build action changed:\n" + + fmt_with_title('old: ', old.bact) + + fmt_with_title('new: ', new.bact)) + + if len(lines) == 0: + return "rebuilding `%s' for unknown reasons\n" % self + + preamble = "rebuilding `%s' because" % self + if len(lines) == 1: + return "%s %s" % (preamble, lines[0]) + else: + lines = ["%s:\n" % preamble] + lines + return string.join(lines, ' '*11) + +try: + [].extend(UserList.UserList([])) +except TypeError: + # Python 1.5.2 doesn't allow a list to be extended by list-like + # objects (such as UserList instances), so just punt and use + # real lists. + def NodeList(l): + return l +else: + class NodeList(UserList.UserList): + def __str__(self): + return str(map(str, self.data)) + +def get_children(node, parent): return node.children() +def ignore_cycle(node, stack): pass +def do_nothing(node, parent): pass + +class Walker: + """An iterator for walking a Node tree. + + This is depth-first, children are visited before the parent. + The Walker object can be initialized with any node, and + returns the next node on the descent with each next() call. + 'kids_func' is an optional function that will be called to + get the children of a node instead of calling 'children'. + 'cycle_func' is an optional function that will be called + when a cycle is detected. + + This class does not get caught in node cycles caused, for example, + by C header file include loops. + """ + def __init__(self, node, kids_func=get_children, + cycle_func=ignore_cycle, + eval_func=do_nothing): + self.kids_func = kids_func + self.cycle_func = cycle_func + self.eval_func = eval_func + node.wkids = copy.copy(kids_func(node, None)) + self.stack = [node] + self.history = {} # used to efficiently detect and avoid cycles + self.history[node] = None + + def next(self): + """Return the next node for this walk of the tree. + + This function is intentionally iterative, not recursive, + to sidestep any issues of stack size limitations. + """ + + while self.stack: + if self.stack[-1].wkids: + node = self.stack[-1].wkids.pop(0) + if not self.stack[-1].wkids: + self.stack[-1].wkids = None + if self.history.has_key(node): + self.cycle_func(node, self.stack) + else: + node.wkids = copy.copy(self.kids_func(node, self.stack[-1])) + self.stack.append(node) + self.history[node] = None + else: + node = self.stack.pop() + del self.history[node] + if node: + if self.stack: + parent = self.stack[-1] + else: + parent = None + self.eval_func(node, parent) + return node + return None + + def is_done(self): + return not self.stack + + +arg2nodes_lookups = [] + +# Local Variables: +# tab-width:4 +# indent-tabs-mode:nil +# End: +# vim: set expandtab tabstop=4 shiftwidth=4: |