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Diffstat (limited to 'engine/SCons/Executor.py')
| -rw-r--r-- | engine/SCons/Executor.py | 636 |
1 files changed, 636 insertions, 0 deletions
diff --git a/engine/SCons/Executor.py b/engine/SCons/Executor.py new file mode 100644 index 0000000..ddb8140 --- /dev/null +++ b/engine/SCons/Executor.py @@ -0,0 +1,636 @@ +"""SCons.Executor + +A module for executing actions with specific lists of target and source +Nodes. + +""" + +# +# 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/Executor.py 2014/09/27 12:51:43 garyo" + +import collections + +import SCons.Debug +from SCons.Debug import logInstanceCreation +import SCons.Errors +import SCons.Memoize + + +class Batch(object): + """Remembers exact association between targets + and sources of executor.""" + def __init__(self, targets=[], sources=[]): + self.targets = targets + self.sources = sources + + + +class TSList(collections.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 collections.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 + collections.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(object): + """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(object): + """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 SCons.Debug.track_instances: 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(list(map(rfile, b.sources))) + ut.extend(b.targets) + else: + cs.extend(list(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([rfile(n).get_subst_proxy() for n in 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([n.get_subst_proxy() for n in 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): + if self.action_list is None: + return [] + 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: + result.extend(batch.targets) + return result + + def get_all_sources(self): + """Returns all sources for all batches of this Executor.""" + result = [] + for batch in self.batches: + result.extend(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(): + if target.prerequisites is not None: + result.extend(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 = 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 = [x for x in sources if x not in self.batches[0].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() + return "\n".join([action.genstring(self.get_all_targets(), + self.get_all_sources(), + env) + for action in self.get_action_list()]) + + + def __str__(self): + return self.my_str() + + def nullify(self): + self.cleanup() + self.do_execute = self.do_nothing + self.my_str = lambda: '' + + 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() + result = "".join([action.get_contents(self.get_all_targets(), + self.get_all_sources(), + env) + for action in 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 = [s for s in sourcelist if s not in idict] + + 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 key not in _batch_executors + _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(object): + """A null Executor, with a null build Environment, that does + nothing when the rest of the methods call it. + + This might be able to disappear 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 SCons.Debug.track_instances: 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.batches[0].targets[0].children() + 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: |