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Diffstat (limited to 'engine/SCons/Builder.py')
| -rw-r--r-- | engine/SCons/Builder.py | 878 |
1 files changed, 878 insertions, 0 deletions
diff --git a/engine/SCons/Builder.py b/engine/SCons/Builder.py new file mode 100644 index 0000000..5bde037 --- /dev/null +++ b/engine/SCons/Builder.py @@ -0,0 +1,878 @@ +"""SCons.Builder + +Builder object subsystem. + +A Builder object is a callable that encapsulates information about how +to execute actions to create a target Node (file) from source Nodes +(files), and how to create those dependencies for tracking. + +The main entry point here is the Builder() factory method. This provides +a procedural interface that creates the right underlying Builder object +based on the keyword arguments supplied and the types of the arguments. + +The goal is for this external interface to be simple enough that the +vast majority of users can create new Builders as necessary to support +building new types of files in their configurations, without having to +dive any deeper into this subsystem. + +The base class here is BuilderBase. This is a concrete base class which +does, in fact, represent the Builder objects that we (or users) create. + +There is also a proxy that looks like a Builder: + + CompositeBuilder + + This proxies for a Builder with an action that is actually a + dictionary that knows how to map file suffixes to a specific + action. This is so that we can invoke different actions + (compilers, compile options) for different flavors of source + files. + +Builders and their proxies have the following public interface methods +used by other modules: + + __call__() + THE public interface. Calling a Builder object (with the + use of internal helper methods) sets up the target and source + dependencies, appropriate mapping to a specific action, and the + environment manipulation necessary for overridden construction + variable. This also takes care of warning about possible mistakes + in keyword arguments. + + add_emitter() + Adds an emitter for a specific file suffix, used by some Tool + modules to specify that (for example) a yacc invocation on a .y + can create a .h *and* a .c file. + + add_action() + Adds an action for a specific file suffix, heavily used by + Tool modules to add their specific action(s) for turning + a source file into an object file to the global static + and shared object file Builders. + +There are the following methods for internal use within this module: + + _execute() + The internal method that handles the heavily lifting when a + Builder is called. This is used so that the __call__() methods + can set up warning about possible mistakes in keyword-argument + overrides, and *then* execute all of the steps necessary so that + the warnings only occur once. + + get_name() + Returns the Builder's name within a specific Environment, + primarily used to try to return helpful information in error + messages. + + adjust_suffix() + get_prefix() + get_suffix() + get_src_suffix() + set_src_suffix() + Miscellaneous stuff for handling the prefix and suffix + manipulation we use in turning source file names into target + file names. + +""" + +# +# Copyright (c) 2001 - 2014 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/Builder.py 2014/09/27 12:51:43 garyo" + +import collections + +import SCons.Action +import SCons.Debug +from SCons.Debug import logInstanceCreation +from SCons.Errors import InternalError, UserError +import SCons.Executor +import SCons.Memoize +import SCons.Node +import SCons.Node.FS +import SCons.Util +import SCons.Warnings + +class _Null(object): + pass + +_null = _Null + +def match_splitext(path, suffixes = []): + if suffixes: + matchsuf = [S for S in suffixes if path[-len(S):] == S] + if matchsuf: + suf = max([(len(_f),_f) for _f in matchsuf])[1] + return [path[:-len(suf)], path[-len(suf):]] + return SCons.Util.splitext(path) + +class DictCmdGenerator(SCons.Util.Selector): + """This is a callable class that can be used as a + command generator function. It holds on to a dictionary + mapping file suffixes to Actions. It uses that dictionary + to return the proper action based on the file suffix of + the source file.""" + + def __init__(self, dict=None, source_ext_match=1): + SCons.Util.Selector.__init__(self, dict) + self.source_ext_match = source_ext_match + + def src_suffixes(self): + return list(self.keys()) + + def add_action(self, suffix, action): + """Add a suffix-action pair to the mapping. + """ + self[suffix] = action + + def __call__(self, target, source, env, for_signature): + if not source: + return [] + + if self.source_ext_match: + suffixes = self.src_suffixes() + ext = None + for src in map(str, source): + my_ext = match_splitext(src, suffixes)[1] + if ext and my_ext != ext: + raise UserError("While building `%s' from `%s': Cannot build multiple sources with different extensions: %s, %s" + % (repr(list(map(str, target))), src, ext, my_ext)) + ext = my_ext + else: + ext = match_splitext(str(source[0]), self.src_suffixes())[1] + + if not ext: + #return ext + raise UserError("While building `%s': " + "Cannot deduce file extension from source files: %s" + % (repr(list(map(str, target))), repr(list(map(str, source))))) + + try: + ret = SCons.Util.Selector.__call__(self, env, source, ext) + except KeyError, e: + raise UserError("Ambiguous suffixes after environment substitution: %s == %s == %s" % (e.args[0], e.args[1], e.args[2])) + if ret is None: + raise UserError("While building `%s' from `%s': Don't know how to build from a source file with suffix `%s'. Expected a suffix in this list: %s." % \ + (repr(list(map(str, target))), repr(list(map(str, source))), ext, repr(list(self.keys())))) + return ret + +class CallableSelector(SCons.Util.Selector): + """A callable dictionary that will, in turn, call the value it + finds if it can.""" + def __call__(self, env, source): + value = SCons.Util.Selector.__call__(self, env, source) + if callable(value): + value = value(env, source) + return value + +class DictEmitter(SCons.Util.Selector): + """A callable dictionary that maps file suffixes to emitters. + When called, it finds the right emitter in its dictionary for the + suffix of the first source file, and calls that emitter to get the + right lists of targets and sources to return. If there's no emitter + for the suffix in its dictionary, the original target and source are + returned. + """ + def __call__(self, target, source, env): + emitter = SCons.Util.Selector.__call__(self, env, source) + if emitter: + target, source = emitter(target, source, env) + return (target, source) + +class ListEmitter(collections.UserList): + """A callable list of emitters that calls each in sequence, + returning the result. + """ + def __call__(self, target, source, env): + for e in self.data: + target, source = e(target, source, env) + return (target, source) + +# These are a common errors when calling a Builder; +# they are similar to the 'target' and 'source' keyword args to builders, +# so we issue warnings when we see them. The warnings can, of course, +# be disabled. +misleading_keywords = { + 'targets' : 'target', + 'sources' : 'source', +} + +class OverrideWarner(collections.UserDict): + """A class for warning about keyword arguments that we use as + overrides in a Builder call. + + This class exists to handle the fact that a single Builder call + can actually invoke multiple builders. This class only emits the + warnings once, no matter how many Builders are invoked. + """ + def __init__(self, dict): + collections.UserDict.__init__(self, dict) + if SCons.Debug.track_instances: logInstanceCreation(self, 'Builder.OverrideWarner') + self.already_warned = None + def warn(self): + if self.already_warned: + return + for k in self.keys(): + if k in misleading_keywords: + alt = misleading_keywords[k] + msg = "Did you mean to use `%s' instead of `%s'?" % (alt, k) + SCons.Warnings.warn(SCons.Warnings.MisleadingKeywordsWarning, msg) + self.already_warned = 1 + +def Builder(**kw): + """A factory for builder objects.""" + composite = None + if 'generator' in kw: + if 'action' in kw: + raise UserError("You must not specify both an action and a generator.") + kw['action'] = SCons.Action.CommandGeneratorAction(kw['generator'], {}) + del kw['generator'] + elif 'action' in kw: + source_ext_match = kw.get('source_ext_match', 1) + if 'source_ext_match' in kw: + del kw['source_ext_match'] + if SCons.Util.is_Dict(kw['action']): + composite = DictCmdGenerator(kw['action'], source_ext_match) + kw['action'] = SCons.Action.CommandGeneratorAction(composite, {}) + kw['src_suffix'] = composite.src_suffixes() + else: + kw['action'] = SCons.Action.Action(kw['action']) + + if 'emitter' in kw: + emitter = kw['emitter'] + if SCons.Util.is_String(emitter): + # This allows users to pass in an Environment + # variable reference (like "$FOO") as an emitter. + # We will look in that Environment variable for + # a callable to use as the actual emitter. + var = SCons.Util.get_environment_var(emitter) + if not var: + raise UserError("Supplied emitter '%s' does not appear to refer to an Environment variable" % emitter) + kw['emitter'] = EmitterProxy(var) + elif SCons.Util.is_Dict(emitter): + kw['emitter'] = DictEmitter(emitter) + elif SCons.Util.is_List(emitter): + kw['emitter'] = ListEmitter(emitter) + + result = BuilderBase(**kw) + + if not composite is None: + result = CompositeBuilder(result, composite) + + return result + +def _node_errors(builder, env, tlist, slist): + """Validate that the lists of target and source nodes are + legal for this builder and environment. Raise errors or + issue warnings as appropriate. + """ + + # First, figure out if there are any errors in the way the targets + # were specified. + for t in tlist: + if t.side_effect: + raise UserError("Multiple ways to build the same target were specified for: %s" % t) + if t.has_explicit_builder(): + if not t.env is None and not t.env is env: + action = t.builder.action + t_contents = action.get_contents(tlist, slist, t.env) + contents = action.get_contents(tlist, slist, env) + + if t_contents == contents: + msg = "Two different environments were specified for target %s,\n\tbut they appear to have the same action: %s" % (t, action.genstring(tlist, slist, t.env)) + SCons.Warnings.warn(SCons.Warnings.DuplicateEnvironmentWarning, msg) + else: + msg = "Two environments with different actions were specified for the same target: %s" % t + raise UserError(msg) + if builder.multi: + if t.builder != builder: + msg = "Two different builders (%s and %s) were specified for the same target: %s" % (t.builder.get_name(env), builder.get_name(env), t) + raise UserError(msg) + # TODO(batch): list constructed each time! + if t.get_executor().get_all_targets() != tlist: + msg = "Two different target lists have a target in common: %s (from %s and from %s)" % (t, list(map(str, t.get_executor().get_all_targets())), list(map(str, tlist))) + raise UserError(msg) + elif t.sources != slist: + msg = "Multiple ways to build the same target were specified for: %s (from %s and from %s)" % (t, list(map(str, t.sources)), list(map(str, slist))) + raise UserError(msg) + + if builder.single_source: + if len(slist) > 1: + raise UserError("More than one source given for single-source builder: targets=%s sources=%s" % (list(map(str,tlist)), list(map(str,slist)))) + +class EmitterProxy(object): + """This is a callable class that can act as a + Builder emitter. It holds on to a string that + is a key into an Environment dictionary, and will + look there at actual build time to see if it holds + a callable. If so, we will call that as the actual + emitter.""" + def __init__(self, var): + self.var = SCons.Util.to_String(var) + + def __call__(self, target, source, env): + emitter = self.var + + # Recursively substitute the variable. + # We can't use env.subst() because it deals only + # in strings. Maybe we should change that? + while SCons.Util.is_String(emitter) and emitter in env: + emitter = env[emitter] + if callable(emitter): + target, source = emitter(target, source, env) + elif SCons.Util.is_List(emitter): + for e in emitter: + target, source = e(target, source, env) + + return (target, source) + + + def __cmp__(self, other): + return cmp(self.var, other.var) + +class BuilderBase(object): + """Base class for Builders, objects that create output + nodes (files) from input nodes (files). + """ + + if SCons.Memoize.use_memoizer: + __metaclass__ = SCons.Memoize.Memoized_Metaclass + + memoizer_counters = [] + + def __init__(self, action = None, + prefix = '', + suffix = '', + src_suffix = '', + target_factory = None, + source_factory = None, + target_scanner = None, + source_scanner = None, + emitter = None, + multi = 0, + env = None, + single_source = 0, + name = None, + chdir = _null, + is_explicit = 1, + src_builder = None, + ensure_suffix = False, + **overrides): + if SCons.Debug.track_instances: logInstanceCreation(self, 'Builder.BuilderBase') + self._memo = {} + self.action = action + self.multi = multi + if SCons.Util.is_Dict(prefix): + prefix = CallableSelector(prefix) + self.prefix = prefix + if SCons.Util.is_Dict(suffix): + suffix = CallableSelector(suffix) + self.env = env + self.single_source = single_source + if 'overrides' in overrides: + SCons.Warnings.warn(SCons.Warnings.DeprecatedBuilderKeywordsWarning, + "The \"overrides\" keyword to Builder() creation has been deprecated;\n" +\ + "\tspecify the items as keyword arguments to the Builder() call instead.") + overrides.update(overrides['overrides']) + del overrides['overrides'] + if 'scanner' in overrides: + SCons.Warnings.warn(SCons.Warnings.DeprecatedBuilderKeywordsWarning, + "The \"scanner\" keyword to Builder() creation has been deprecated;\n" + "\tuse: source_scanner or target_scanner as appropriate.") + del overrides['scanner'] + self.overrides = overrides + + self.set_suffix(suffix) + self.set_src_suffix(src_suffix) + self.ensure_suffix = ensure_suffix + + self.target_factory = target_factory + self.source_factory = source_factory + self.target_scanner = target_scanner + self.source_scanner = source_scanner + + self.emitter = emitter + + # Optional Builder name should only be used for Builders + # that don't get attached to construction environments. + if name: + self.name = name + self.executor_kw = {} + if not chdir is _null: + self.executor_kw['chdir'] = chdir + self.is_explicit = is_explicit + + if src_builder is None: + src_builder = [] + elif not SCons.Util.is_List(src_builder): + src_builder = [ src_builder ] + self.src_builder = src_builder + + def __nonzero__(self): + raise InternalError("Do not test for the Node.builder attribute directly; use Node.has_builder() instead") + + def get_name(self, env): + """Attempts to get the name of the Builder. + + Look at the BUILDERS variable of env, expecting it to be a + dictionary containing this Builder, and return the key of the + dictionary. If there's no key, then return a directly-configured + name (if there is one) or the name of the class (by default).""" + + try: + index = list(env['BUILDERS'].values()).index(self) + return list(env['BUILDERS'].keys())[index] + except (AttributeError, KeyError, TypeError, ValueError): + try: + return self.name + except AttributeError: + return str(self.__class__) + + def __cmp__(self, other): + return cmp(self.__dict__, other.__dict__) + + def splitext(self, path, env=None): + if not env: + env = self.env + if env: + suffixes = self.src_suffixes(env) + else: + suffixes = [] + return match_splitext(path, suffixes) + + def _adjustixes(self, files, pre, suf, ensure_suffix=False): + if not files: + return [] + result = [] + if not SCons.Util.is_List(files): + files = [files] + + for f in files: + if SCons.Util.is_String(f): + f = SCons.Util.adjustixes(f, pre, suf, ensure_suffix) + result.append(f) + return result + + def _create_nodes(self, env, target = None, source = None): + """Create and return lists of target and source nodes. + """ + src_suf = self.get_src_suffix(env) + + target_factory = env.get_factory(self.target_factory) + source_factory = env.get_factory(self.source_factory) + + source = self._adjustixes(source, None, src_suf) + slist = env.arg2nodes(source, source_factory) + + pre = self.get_prefix(env, slist) + suf = self.get_suffix(env, slist) + + if target is None: + try: + t_from_s = slist[0].target_from_source + except AttributeError: + raise UserError("Do not know how to create a target from source `%s'" % slist[0]) + except IndexError: + tlist = [] + else: + splitext = lambda S: self.splitext(S,env) + tlist = [ t_from_s(pre, suf, splitext) ] + else: + target = self._adjustixes(target, pre, suf, self.ensure_suffix) + tlist = env.arg2nodes(target, target_factory, target=target, source=source) + + if self.emitter: + # The emitter is going to do str(node), but because we're + # being called *from* a builder invocation, the new targets + # don't yet have a builder set on them and will look like + # source files. Fool the emitter's str() calls by setting + # up a temporary builder on the new targets. + new_targets = [] + for t in tlist: + if not t.is_derived(): + t.builder_set(self) + new_targets.append(t) + + orig_tlist = tlist[:] + orig_slist = slist[:] + + target, source = self.emitter(target=tlist, source=slist, env=env) + + # Now delete the temporary builders that we attached to any + # new targets, so that _node_errors() doesn't do weird stuff + # to them because it thinks they already have builders. + for t in new_targets: + if t.builder is self: + # Only delete the temporary builder if the emitter + # didn't change it on us. + t.builder_set(None) + + # Have to call arg2nodes yet again, since it is legal for + # emitters to spit out strings as well as Node instances. + tlist = env.arg2nodes(target, target_factory, + target=orig_tlist, source=orig_slist) + slist = env.arg2nodes(source, source_factory, + target=orig_tlist, source=orig_slist) + + return tlist, slist + + def _execute(self, env, target, source, overwarn={}, executor_kw={}): + # We now assume that target and source are lists or None. + if self.src_builder: + source = self.src_builder_sources(env, source, overwarn) + + if self.single_source and len(source) > 1 and target is None: + result = [] + if target is None: target = [None]*len(source) + for tgt, src in zip(target, source): + if not tgt is None: tgt = [tgt] + if not src is None: src = [src] + result.extend(self._execute(env, tgt, src, overwarn)) + return SCons.Node.NodeList(result) + + overwarn.warn() + + tlist, slist = self._create_nodes(env, target, source) + + # Check for errors with the specified target/source lists. + _node_errors(self, env, tlist, slist) + + # The targets are fine, so find or make the appropriate Executor to + # build this particular list of targets from this particular list of + # sources. + + executor = None + key = None + + if self.multi: + try: + executor = tlist[0].get_executor(create = 0) + except (AttributeError, IndexError): + pass + else: + executor.add_sources(slist) + + if executor is None: + if not self.action: + fmt = "Builder %s must have an action to build %s." + raise UserError(fmt % (self.get_name(env or self.env), + list(map(str,tlist)))) + key = self.action.batch_key(env or self.env, tlist, slist) + if key: + try: + executor = SCons.Executor.GetBatchExecutor(key) + except KeyError: + pass + else: + executor.add_batch(tlist, slist) + + if executor is None: + executor = SCons.Executor.Executor(self.action, env, [], + tlist, slist, executor_kw) + if key: + SCons.Executor.AddBatchExecutor(key, executor) + + # Now set up the relevant information in the target Nodes themselves. + for t in tlist: + t.cwd = env.fs.getcwd() + t.builder_set(self) + t.env_set(env) + t.add_source(slist) + t.set_executor(executor) + t.set_explicit(self.is_explicit) + + return SCons.Node.NodeList(tlist) + + def __call__(self, env, target=None, source=None, chdir=_null, **kw): + # We now assume that target and source are lists or None. + # The caller (typically Environment.BuilderWrapper) is + # responsible for converting any scalar values to lists. + if chdir is _null: + ekw = self.executor_kw + else: + ekw = self.executor_kw.copy() + ekw['chdir'] = chdir + if kw: + if 'srcdir' in kw: + def prependDirIfRelative(f, srcdir=kw['srcdir']): + import os.path + if SCons.Util.is_String(f) and not os.path.isabs(f): + f = os.path.join(srcdir, f) + return f + if not SCons.Util.is_List(source): + source = [source] + source = list(map(prependDirIfRelative, source)) + del kw['srcdir'] + if self.overrides: + env_kw = self.overrides.copy() + env_kw.update(kw) + else: + env_kw = kw + else: + env_kw = self.overrides + env = env.Override(env_kw) + return self._execute(env, target, source, OverrideWarner(kw), ekw) + + def adjust_suffix(self, suff): + if suff and not suff[0] in [ '.', '_', '$' ]: + return '.' + suff + return suff + + def get_prefix(self, env, sources=[]): + prefix = self.prefix + if callable(prefix): + prefix = prefix(env, sources) + return env.subst(prefix) + + def set_suffix(self, suffix): + if not callable(suffix): + suffix = self.adjust_suffix(suffix) + self.suffix = suffix + + def get_suffix(self, env, sources=[]): + suffix = self.suffix + if callable(suffix): + suffix = suffix(env, sources) + return env.subst(suffix) + + def set_src_suffix(self, src_suffix): + if not src_suffix: + src_suffix = [] + elif not SCons.Util.is_List(src_suffix): + src_suffix = [ src_suffix ] + self.src_suffix = [callable(suf) and suf or self.adjust_suffix(suf) for suf in src_suffix] + + def get_src_suffix(self, env): + """Get the first src_suffix in the list of src_suffixes.""" + ret = self.src_suffixes(env) + if not ret: + return '' + return ret[0] + + def add_emitter(self, suffix, emitter): + """Add a suffix-emitter mapping to this Builder. + + This assumes that emitter has been initialized with an + appropriate dictionary type, and will throw a TypeError if + not, so the caller is responsible for knowing that this is an + appropriate method to call for the Builder in question. + """ + self.emitter[suffix] = emitter + + def add_src_builder(self, builder): + """ + Add a new Builder to the list of src_builders. + + This requires wiping out cached values so that the computed + lists of source suffixes get re-calculated. + """ + self._memo = {} + self.src_builder.append(builder) + + def _get_sdict(self, env): + """ + Returns a dictionary mapping all of the source suffixes of all + src_builders of this Builder to the underlying Builder that + should be called first. + + This dictionary is used for each target specified, so we save a + lot of extra computation by memoizing it for each construction + environment. + + Note that this is re-computed each time, not cached, because there + might be changes to one of our source Builders (or one of their + source Builders, and so on, and so on...) that we can't "see." + + The underlying methods we call cache their computed values, + though, so we hope repeatedly aggregating them into a dictionary + like this won't be too big a hit. We may need to look for a + better way to do this if performance data show this has turned + into a significant bottleneck. + """ + sdict = {} + for bld in self.get_src_builders(env): + for suf in bld.src_suffixes(env): + sdict[suf] = bld + return sdict + + def src_builder_sources(self, env, source, overwarn={}): + sdict = self._get_sdict(env) + + src_suffixes = self.src_suffixes(env) + + lengths = list(set(map(len, src_suffixes))) + + def match_src_suffix(name, src_suffixes=src_suffixes, lengths=lengths): + node_suffixes = [name[-l:] for l in lengths] + for suf in src_suffixes: + if suf in node_suffixes: + return suf + return None + + result = [] + for s in SCons.Util.flatten(source): + if SCons.Util.is_String(s): + match_suffix = match_src_suffix(env.subst(s)) + if not match_suffix and not '.' in s: + src_suf = self.get_src_suffix(env) + s = self._adjustixes(s, None, src_suf)[0] + else: + match_suffix = match_src_suffix(s.name) + if match_suffix: + try: + bld = sdict[match_suffix] + except KeyError: + result.append(s) + else: + tlist = bld._execute(env, None, [s], overwarn) + # If the subsidiary Builder returned more than one + # target, then filter out any sources that this + # Builder isn't capable of building. + if len(tlist) > 1: + tlist = [t for t in tlist if match_src_suffix(t.name)] + result.extend(tlist) + else: + result.append(s) + + source_factory = env.get_factory(self.source_factory) + + return env.arg2nodes(result, source_factory) + + def _get_src_builders_key(self, env): + return id(env) + + memoizer_counters.append(SCons.Memoize.CountDict('get_src_builders', _get_src_builders_key)) + + def get_src_builders(self, env): + """ + Returns the list of source Builders for this Builder. + + This exists mainly to look up Builders referenced as + strings in the 'BUILDER' variable of the construction + environment and cache the result. + """ + memo_key = id(env) + try: + memo_dict = self._memo['get_src_builders'] + except KeyError: + memo_dict = {} + self._memo['get_src_builders'] = memo_dict + else: + try: + return memo_dict[memo_key] + except KeyError: + pass + + builders = [] + for bld in self.src_builder: + if SCons.Util.is_String(bld): + try: + bld = env['BUILDERS'][bld] + except KeyError: + continue + builders.append(bld) + + memo_dict[memo_key] = builders + return builders + + def _subst_src_suffixes_key(self, env): + return id(env) + + memoizer_counters.append(SCons.Memoize.CountDict('subst_src_suffixes', _subst_src_suffixes_key)) + + def subst_src_suffixes(self, env): + """ + The suffix list may contain construction variable expansions, + so we have to evaluate the individual strings. To avoid doing + this over and over, we memoize the results for each construction + environment. + """ + memo_key = id(env) + try: + memo_dict = self._memo['subst_src_suffixes'] + except KeyError: + memo_dict = {} + self._memo['subst_src_suffixes'] = memo_dict + else: + try: + return memo_dict[memo_key] + except KeyError: + pass + suffixes = [env.subst(x) for x in self.src_suffix] + memo_dict[memo_key] = suffixes + return suffixes + + def src_suffixes(self, env): + """ + Returns the list of source suffixes for all src_builders of this + Builder. + + This is essentially a recursive descent of the src_builder "tree." + (This value isn't cached because there may be changes in a + src_builder many levels deep that we can't see.) + """ + sdict = {} + suffixes = self.subst_src_suffixes(env) + for s in suffixes: + sdict[s] = 1 + for builder in self.get_src_builders(env): + for s in builder.src_suffixes(env): + if s not in sdict: + sdict[s] = 1 + suffixes.append(s) + return suffixes + +class CompositeBuilder(SCons.Util.Proxy): + """A Builder Proxy whose main purpose is to always have + a DictCmdGenerator as its action, and to provide access + to the DictCmdGenerator's add_action() method. + """ + + def __init__(self, builder, cmdgen): + if SCons.Debug.track_instances: logInstanceCreation(self, 'Builder.CompositeBuilder') + SCons.Util.Proxy.__init__(self, builder) + + # cmdgen should always be an instance of DictCmdGenerator. + self.cmdgen = cmdgen + self.builder = builder + + __call__ = SCons.Util.Delegate('__call__') + + def add_action(self, suffix, action): + self.cmdgen.add_action(suffix, action) + self.set_src_suffix(self.cmdgen.src_suffixes()) + +def is_a_Builder(obj): + """"Returns True iff the specified obj is one of our Builder classes. + + The test is complicated a bit by the fact that CompositeBuilder + is a proxy, not a subclass of BuilderBase. + """ + return (isinstance(obj, BuilderBase) + or isinstance(obj, CompositeBuilder) + or callable(obj)) + +# Local Variables: +# tab-width:4 +# indent-tabs-mode:nil +# End: +# vim: set expandtab tabstop=4 shiftwidth=4: |