"""SCons.Executor A module for executing actions with specific lists of target and source Nodes. """ # # 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/Executor.py 4043 2009/02/23 09:06:45 scons" import string import UserList from SCons.Debug import logInstanceCreation import SCons.Errors import SCons.Memoize class Batch: """Remembers exact association between targets and sources of executor.""" def __init__(self, targets=[], sources=[]): self.targets = targets self.sources = sources class TSList(UserList.UserList): """A class that implements $TARGETS or $SOURCES expansions by wrapping an executor Method. This class is used in the Executor.lvars() to delay creation of NodeList objects until they're needed. Note that we subclass UserList.UserList purely so that the is_Sequence() function will identify an object of this class as a list during variable expansion. We're not really using any UserList.UserList methods in practice. """ def __init__(self, func): self.func = func def __getattr__(self, attr): nl = self.func() return getattr(nl, attr) def __getitem__(self, i): nl = self.func() return nl[i] def __getslice__(self, i, j): nl = self.func() i = max(i, 0); j = max(j, 0) return nl[i:j] def __str__(self): nl = self.func() return str(nl) def __repr__(self): nl = self.func() return repr(nl) class TSObject: """A class that implements $TARGET or $SOURCE expansions by wrapping an Executor method. """ def __init__(self, func): self.func = func def __getattr__(self, attr): n = self.func() return getattr(n, attr) def __str__(self): n = self.func() if n: return str(n) return '' def __repr__(self): n = self.func() if n: return repr(n) return '' def rfile(node): """ A function to return the results of a Node's rfile() method, if it exists, and the Node itself otherwise (if it's a Value Node, e.g.). """ try: rfile = node.rfile except AttributeError: return node else: return rfile() class Executor: """A class for controlling instances of executing an action. This largely exists to hold a single association of an action, environment, list of environment override dictionaries, targets and sources for later processing as needed. """ if SCons.Memoize.use_memoizer: __metaclass__ = SCons.Memoize.Memoized_Metaclass memoizer_counters = [] def __init__(self, action, env=None, overridelist=[{}], targets=[], sources=[], builder_kw={}): if __debug__: logInstanceCreation(self, 'Executor.Executor') self.set_action_list(action) self.pre_actions = [] self.post_actions = [] self.env = env self.overridelist = overridelist if targets or sources: self.batches = [Batch(targets[:], sources[:])] else: self.batches = [] self.builder_kw = builder_kw self._memo = {} def get_lvars(self): try: return self.lvars except AttributeError: self.lvars = { 'CHANGED_SOURCES' : TSList(self._get_changed_sources), 'CHANGED_TARGETS' : TSList(self._get_changed_targets), 'SOURCE' : TSObject(self._get_source), 'SOURCES' : TSList(self._get_sources), 'TARGET' : TSObject(self._get_target), 'TARGETS' : TSList(self._get_targets), 'UNCHANGED_SOURCES' : TSList(self._get_unchanged_sources), 'UNCHANGED_TARGETS' : TSList(self._get_unchanged_targets), } return self.lvars def _get_changes(self): cs = [] ct = [] us = [] ut = [] for b in self.batches: if b.targets[0].is_up_to_date(): us.extend(map(rfile, b.sources)) ut.extend(b.targets) else: cs.extend(map(rfile, b.sources)) ct.extend(b.targets) self._changed_sources_list = SCons.Util.NodeList(cs) self._changed_targets_list = SCons.Util.NodeList(ct) self._unchanged_sources_list = SCons.Util.NodeList(us) self._unchanged_targets_list = SCons.Util.NodeList(ut) def _get_changed_sources(self, *args, **kw): try: return self._changed_sources_list except AttributeError: self._get_changes() return self._changed_sources_list def _get_changed_targets(self, *args, **kw): try: return self._changed_targets_list except AttributeError: self._get_changes() return self._changed_targets_list def _get_source(self, *args, **kw): #return SCons.Util.NodeList([rfile(self.batches[0].sources[0]).get_subst_proxy()]) return rfile(self.batches[0].sources[0]).get_subst_proxy() def _get_sources(self, *args, **kw): return SCons.Util.NodeList(map(lambda n: rfile(n).get_subst_proxy(), self.get_all_sources())) def _get_target(self, *args, **kw): #return SCons.Util.NodeList([self.batches[0].targets[0].get_subst_proxy()]) return self.batches[0].targets[0].get_subst_proxy() def _get_targets(self, *args, **kw): return SCons.Util.NodeList(map(lambda n: n.get_subst_proxy(), self.get_all_targets())) def _get_unchanged_sources(self, *args, **kw): try: return self._unchanged_sources_list except AttributeError: self._get_changes() return self._unchanged_sources_list def _get_unchanged_targets(self, *args, **kw): try: return self._unchanged_targets_list except AttributeError: self._get_changes() return self._unchanged_targets_list def get_action_targets(self): if not self.action_list: return [] targets_string = self.action_list[0].get_targets(self.env, self) if targets_string[0] == '$': targets_string = targets_string[1:] return self.get_lvars()[targets_string] def set_action_list(self, action): import SCons.Util if not SCons.Util.is_List(action): if not action: import SCons.Errors raise SCons.Errors.UserError, "Executor must have an action." action = [action] self.action_list = action def get_action_list(self): return self.pre_actions + self.action_list + self.post_actions def get_all_targets(self): """Returns all targets for all batches of this Executor.""" result = [] for batch in self.batches: # TODO(1.5): remove the list() cast result.extend(list(batch.targets)) return result def get_all_sources(self): """Returns all sources for all batches of this Executor.""" result = [] for batch in self.batches: # TODO(1.5): remove the list() cast result.extend(list(batch.sources)) return result def get_all_children(self): """Returns all unique children (dependencies) for all batches of this Executor. The Taskmaster can recognize when it's already evaluated a Node, so we don't have to make this list unique for its intended canonical use case, but we expect there to be a lot of redundancy (long lists of batched .cc files #including the same .h files over and over), so removing the duplicates once up front should save the Taskmaster a lot of work. """ result = SCons.Util.UniqueList([]) for target in self.get_all_targets(): result.extend(target.children()) return result def get_all_prerequisites(self): """Returns all unique (order-only) prerequisites for all batches of this Executor. """ result = SCons.Util.UniqueList([]) for target in self.get_all_targets(): # TODO(1.5): remove the list() cast result.extend(list(target.prerequisites)) return result def get_action_side_effects(self): """Returns all side effects for all batches of this Executor used by the underlying Action. """ result = SCons.Util.UniqueList([]) for target in self.get_action_targets(): result.extend(target.side_effects) return result memoizer_counters.append(SCons.Memoize.CountValue('get_build_env')) def get_build_env(self): """Fetch or create the appropriate build Environment for this Executor. """ try: return self._memo['get_build_env'] except KeyError: pass # Create the build environment instance with appropriate # overrides. These get evaluated against the current # environment's construction variables so that users can # add to existing values by referencing the variable in # the expansion. overrides = {} for odict in self.overridelist: overrides.update(odict) import SCons.Defaults env = self.env or SCons.Defaults.DefaultEnvironment() build_env = env.Override(overrides) self._memo['get_build_env'] = build_env return build_env def get_build_scanner_path(self, scanner): """Fetch the scanner path for this executor's targets and sources. """ env = self.get_build_env() try: cwd = self.batches[0].targets[0].cwd except (IndexError, AttributeError): cwd = None return scanner.path(env, cwd, self.get_all_targets(), self.get_all_sources()) def get_kw(self, kw={}): result = self.builder_kw.copy() result.update(kw) result['executor'] = self return result def do_nothing(self, target, kw): return 0 def do_execute(self, target, kw): """Actually execute the action list.""" env = self.get_build_env() kw = self.get_kw(kw) status = 0 for act in self.get_action_list(): #args = (self.get_all_targets(), self.get_all_sources(), env) args = ([], [], env) status = apply(act, args, kw) if isinstance(status, SCons.Errors.BuildError): status.executor = self raise status elif status: msg = "Error %s" % status raise SCons.Errors.BuildError( errstr=msg, node=self.batches[0].targets, executor=self, action=act) return status # use extra indirection because with new-style objects (Python 2.2 # and above) we can't override special methods, and nullify() needs # to be able to do this. def __call__(self, target, **kw): return self.do_execute(target, kw) def cleanup(self): self._memo = {} def add_sources(self, sources): """Add source files to this Executor's list. This is necessary for "multi" Builders that can be called repeatedly to build up a source file list for a given target.""" # TODO(batch): extend to multiple batches assert (len(self.batches) == 1) # TODO(batch): remove duplicates? sources = filter(lambda x, s=self.batches[0].sources: x not in s, sources) self.batches[0].sources.extend(sources) def get_sources(self): return self.batches[0].sources def add_batch(self, targets, sources): """Add pair of associated target and source to this Executor's list. This is necessary for "batch" Builders that can be called repeatedly to build up a list of matching target and source files that will be used in order to update multiple target files at once from multiple corresponding source files, for tools like MSVC that support it.""" self.batches.append(Batch(targets, sources)) def prepare(self): """ Preparatory checks for whether this Executor can go ahead and (try to) build its targets. """ for s in self.get_all_sources(): if s.missing(): msg = "Source `%s' not found, needed by target `%s'." raise SCons.Errors.StopError, msg % (s, self.batches[0].targets[0]) def add_pre_action(self, action): self.pre_actions.append(action) def add_post_action(self, action): self.post_actions.append(action) # another extra indirection for new-style objects and nullify... def my_str(self): env = self.get_build_env() get = lambda action, t=self.get_all_targets(), s=self.get_all_sources(), e=env: \ action.genstring(t, s, e) return string.join(map(get, self.get_action_list()), "\n") def __str__(self): return self.my_str() def nullify(self): self.cleanup() self.do_execute = self.do_nothing self.my_str = lambda S=self: '' memoizer_counters.append(SCons.Memoize.CountValue('get_contents')) def get_contents(self): """Fetch the signature contents. This is the main reason this class exists, so we can compute this once and cache it regardless of how many target or source Nodes there are. """ try: return self._memo['get_contents'] except KeyError: pass env = self.get_build_env() get = lambda action, t=self.get_all_targets(), s=self.get_all_sources(), e=env: \ action.get_contents(t, s, e) result = string.join(map(get, self.get_action_list()), "") self._memo['get_contents'] = result return result def get_timestamp(self): """Fetch a time stamp for this Executor. We don't have one, of course (only files do), but this is the interface used by the timestamp module. """ return 0 def scan_targets(self, scanner): # TODO(batch): scan by batches self.scan(scanner, self.get_all_targets()) def scan_sources(self, scanner): # TODO(batch): scan by batches if self.batches[0].sources: self.scan(scanner, self.get_all_sources()) def scan(self, scanner, node_list): """Scan a list of this Executor's files (targets or sources) for implicit dependencies and 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. """ env = self.get_build_env() # TODO(batch): scan by batches) deps = [] if scanner: for node in node_list: node.disambiguate() s = scanner.select(node) if not s: continue path = self.get_build_scanner_path(s) deps.extend(node.get_implicit_deps(env, s, path)) else: kw = self.get_kw() for node in node_list: node.disambiguate() scanner = node.get_env_scanner(env, kw) if not scanner: continue scanner = scanner.select(node) if not scanner: continue path = self.get_build_scanner_path(scanner) deps.extend(node.get_implicit_deps(env, scanner, path)) deps.extend(self.get_implicit_deps()) for tgt in self.get_all_targets(): tgt.add_to_implicit(deps) def _get_unignored_sources_key(self, node, ignore=()): return (node,) + tuple(ignore) memoizer_counters.append(SCons.Memoize.CountDict('get_unignored_sources', _get_unignored_sources_key)) def get_unignored_sources(self, node, ignore=()): key = (node,) + tuple(ignore) try: memo_dict = self._memo['get_unignored_sources'] except KeyError: memo_dict = {} self._memo['get_unignored_sources'] = memo_dict else: try: return memo_dict[key] except KeyError: pass if node: # TODO: better way to do this (it's a linear search, # but it may not be critical path)? sourcelist = [] for b in self.batches: if node in b.targets: sourcelist = b.sources break else: sourcelist = self.get_all_sources() if ignore: idict = {} for i in ignore: idict[i] = 1 sourcelist = filter(lambda s, i=idict: not i.has_key(s), sourcelist) memo_dict[key] = sourcelist return sourcelist def get_implicit_deps(self): """Return the executor's implicit dependencies, i.e. the nodes of the commands to be executed.""" result = [] build_env = self.get_build_env() for act in self.get_action_list(): deps = act.get_implicit_deps(self.get_all_targets(), self.get_all_sources(), build_env) result.extend(deps) return result _batch_executors = {} def GetBatchExecutor(key): return _batch_executors[key] def AddBatchExecutor(key, executor): assert not _batch_executors.has_key(key) _batch_executors[key] = executor nullenv = None def get_NullEnvironment(): """Use singleton pattern for Null Environments.""" global nullenv import SCons.Util class NullEnvironment(SCons.Util.Null): import SCons.CacheDir _CacheDir_path = None _CacheDir = SCons.CacheDir.CacheDir(None) def get_CacheDir(self): return self._CacheDir if not nullenv: nullenv = NullEnvironment() return nullenv class Null: """A null Executor, with a null build Environment, that does nothing when the rest of the methods call it. This might be able to disapper when we refactor things to disassociate Builders from Nodes entirely, so we're not going to worry about unit tests for this--at least for now. """ def __init__(self, *args, **kw): if __debug__: logInstanceCreation(self, 'Executor.Null') self.batches = [Batch(kw['targets'][:], [])] def get_build_env(self): return get_NullEnvironment() def get_build_scanner_path(self): return None def cleanup(self): pass def prepare(self): pass def get_unignored_sources(self, *args, **kw): return tuple(()) def get_action_targets(self): return [] def get_action_list(self): return [] def get_all_targets(self): return self.batches[0].targets def get_all_sources(self): return self.batches[0].targets[0].sources def get_all_children(self): return self.get_all_sources() def get_all_prerequisites(self): return [] def get_action_side_effects(self): return [] def __call__(self, *args, **kw): return 0 def get_contents(self): return '' def _morph(self): """Morph this Null executor to a real Executor object.""" batches = self.batches self.__class__ = Executor self.__init__([]) self.batches = batches # The following methods require morphing this Null Executor to a # real Executor object. def add_pre_action(self, action): self._morph() self.add_pre_action(action) def add_post_action(self, action): self._morph() self.add_post_action(action) def set_action_list(self, action): self._morph() self.set_action_list(action) # Local Variables: # tab-width:4 # indent-tabs-mode:nil # End: # vim: set expandtab tabstop=4 shiftwidth=4: