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Diffstat (limited to 'SCons/Action.py')
| -rw-r--r-- | SCons/Action.py | 1469 |
1 files changed, 1469 insertions, 0 deletions
diff --git a/SCons/Action.py b/SCons/Action.py new file mode 100644 index 0000000..5bc85d5 --- /dev/null +++ b/SCons/Action.py @@ -0,0 +1,1469 @@ +"""SCons.Action + +This encapsulates information about executing any sort of action that +can build one or more target Nodes (typically files) from one or more +source Nodes (also typically files) given a specific Environment. + +The base class here is ActionBase. The base class supplies just a few +OO utility methods and some generic methods for displaying information +about an Action in response to the various commands that control printing. + +A second-level base class is _ActionAction. This extends ActionBase +by providing the methods that can be used to show and perform an +action. True Action objects will subclass _ActionAction; Action +factory class objects will subclass ActionBase. + +The heavy lifting is handled by subclasses for the different types of +actions we might execute: + + CommandAction + CommandGeneratorAction + FunctionAction + ListAction + +The subclasses supply the following public interface methods used by +other modules: + + __call__() + THE public interface, "calling" an Action object executes the + command or Python function. This also takes care of printing + a pre-substitution command for debugging purposes. + + get_contents() + Fetches the "contents" of an Action for signature calculation + plus the varlist. This is what gets MD5 checksummed to decide + if a target needs to be rebuilt because its action changed. + + genstring() + Returns a string representation of the Action *without* + command substitution, but allows a CommandGeneratorAction to + generate the right action based on the specified target, + source and env. This is used by the Signature subsystem + (through the Executor) to obtain an (imprecise) representation + of the Action operation for informative purposes. + + +Subclasses also supply the following methods for internal use within +this module: + + __str__() + Returns a string approximation of the Action; no variable + substitution is performed. + + execute() + The internal method that really, truly, actually handles the + execution of a command or Python function. This is used so + that the __call__() methods can take care of displaying any + pre-substitution representations, and *then* execute an action + without worrying about the specific Actions involved. + + get_presig() + Fetches the "contents" of a subclass for signature calculation. + The varlist is added to this to produce the Action's contents. + TODO(?): Change this to always return ascii/bytes and not unicode (or py3 strings) + + strfunction() + Returns a substituted string representation of the Action. + This is used by the _ActionAction.show() command to display the + command/function that will be executed to generate the target(s). + +There is a related independent ActionCaller class that looks like a +regular Action, and which serves as a wrapper for arbitrary functions +that we want to let the user specify the arguments to now, but actually +execute later (when an out-of-date check determines that it's needed to +be executed, for example). Objects of this class are returned by an +ActionFactory class that provides a __call__() method as a convenient +way for wrapping up the functions. + +""" + +# __COPYRIGHT__ +# +# 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__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__" + +import os +import pickle +import re +import sys +import subprocess +from subprocess import DEVNULL +import itertools +import inspect +from collections import OrderedDict + +import SCons.Debug +from SCons.Debug import logInstanceCreation +import SCons.Errors +import SCons.Util +import SCons.Subst + +# we use these a lot, so try to optimize them +from SCons.Util import is_String, is_List + +class _null(object): + pass + +print_actions = 1 +execute_actions = 1 +print_actions_presub = 0 + +# Use pickle protocol 1 when pickling functions for signature +# otherwise python3 and python2 will yield different pickles +# for the same object. +# This is due to default being 1 for python 2.7, and 3 for 3.x +# TODO: We can roll this forward to 2 (if it has value), but not +# before a deprecation cycle as the sconsigns will change +ACTION_SIGNATURE_PICKLE_PROTOCOL = 1 + + +def rfile(n): + try: + return n.rfile() + except AttributeError: + return n + + +def default_exitstatfunc(s): + return s + +strip_quotes = re.compile('^[\'"](.*)[\'"]$') + + +def _callable_contents(obj): + """Return the signature contents of a callable Python object. + """ + try: + # Test if obj is a method. + return _function_contents(obj.__func__) + + except AttributeError: + try: + # Test if obj is a callable object. + return _function_contents(obj.__call__.__func__) + + except AttributeError: + try: + # Test if obj is a code object. + return _code_contents(obj) + + except AttributeError: + # Test if obj is a function object. + return _function_contents(obj) + + +def _object_contents(obj): + """Return the signature contents of any Python object. + + We have to handle the case where object contains a code object + since it can be pickled directly. + """ + try: + # Test if obj is a method. + return _function_contents(obj.__func__) + + except AttributeError: + try: + # Test if obj is a callable object. + return _function_contents(obj.__call__.__func__) + + except AttributeError: + try: + # Test if obj is a code object. + return _code_contents(obj) + + except AttributeError: + try: + # Test if obj is a function object. + return _function_contents(obj) + + except AttributeError as ae: + # Should be a pickle-able Python object. + try: + return _object_instance_content(obj) + # pickling an Action instance or object doesn't yield a stable + # content as instance property may be dumped in different orders + # return pickle.dumps(obj, ACTION_SIGNATURE_PICKLE_PROTOCOL) + except (pickle.PicklingError, TypeError, AttributeError) as ex: + # This is weird, but it seems that nested classes + # are unpickable. The Python docs say it should + # always be a PicklingError, but some Python + # versions seem to return TypeError. Just do + # the best we can. + return bytearray(repr(obj), 'utf-8') + + +def _code_contents(code, docstring=None): + r"""Return the signature contents of a code object. + + By providing direct access to the code object of the + function, Python makes this extremely easy. Hooray! + + Unfortunately, older versions of Python include line + number indications in the compiled byte code. Boo! + So we remove the line number byte codes to prevent + recompilations from moving a Python function. + + See: + - https://docs.python.org/2/library/inspect.html + - http://python-reference.readthedocs.io/en/latest/docs/code/index.html + + For info on what each co\_ variable provides + + The signature is as follows (should be byte/chars): + co_argcount, len(co_varnames), len(co_cellvars), len(co_freevars), + ( comma separated signature for each object in co_consts ), + ( comma separated signature for each object in co_names ), + ( The bytecode with line number bytecodes removed from co_code ) + + co_argcount - Returns the number of positional arguments (including arguments with default values). + co_varnames - Returns a tuple containing the names of the local variables (starting with the argument names). + co_cellvars - Returns a tuple containing the names of local variables that are referenced by nested functions. + co_freevars - Returns a tuple containing the names of free variables. (?) + co_consts - Returns a tuple containing the literals used by the bytecode. + co_names - Returns a tuple containing the names used by the bytecode. + co_code - Returns a string representing the sequence of bytecode instructions. + + """ + + # contents = [] + + # The code contents depends on the number of local variables + # but not their actual names. + contents = bytearray("{}, {}".format(code.co_argcount, len(code.co_varnames)), 'utf-8') + + contents.extend(b", ") + contents.extend(bytearray(str(len(code.co_cellvars)), 'utf-8')) + contents.extend(b", ") + contents.extend(bytearray(str(len(code.co_freevars)), 'utf-8')) + + # The code contents depends on any constants accessed by the + # function. Note that we have to call _object_contents on each + # constants because the code object of nested functions can + # show-up among the constants. + z = [_object_contents(cc) for cc in code.co_consts if cc != docstring] + contents.extend(b',(') + contents.extend(bytearray(',', 'utf-8').join(z)) + contents.extend(b')') + + # The code contents depends on the variable names used to + # accessed global variable, as changing the variable name changes + # the variable actually accessed and therefore changes the + # function result. + z= [bytearray(_object_contents(cc)) for cc in code.co_names] + contents.extend(b',(') + contents.extend(bytearray(',','utf-8').join(z)) + contents.extend(b')') + + # The code contents depends on its actual code!!! + contents.extend(b',(') + contents.extend(code.co_code) + contents.extend(b')') + + return contents + + +def _function_contents(func): + """ + The signature is as follows (should be byte/chars): + < _code_contents (see above) from func.__code__ > + ,( comma separated _object_contents for function argument defaults) + ,( comma separated _object_contents for any closure contents ) + + + See also: https://docs.python.org/3/reference/datamodel.html + - func.__code__ - The code object representing the compiled function body. + - func.__defaults__ - A tuple containing default argument values for those arguments that have defaults, or None if no arguments have a default value + - func.__closure__ - None or a tuple of cells that contain bindings for the function's free variables. + + :Returns: + Signature contents of a function. (in bytes) + """ + + contents = [_code_contents(func.__code__, func.__doc__)] + + # The function contents depends on the value of defaults arguments + if func.__defaults__: + + function_defaults_contents = [_object_contents(cc) for cc in func.__defaults__] + + defaults = bytearray(b',(') + defaults.extend(bytearray(b',').join(function_defaults_contents)) + defaults.extend(b')') + + contents.append(defaults) + else: + contents.append(b',()') + + # The function contents depends on the closure captured cell values. + closure = func.__closure__ or [] + + try: + closure_contents = [_object_contents(x.cell_contents) for x in closure] + except AttributeError: + closure_contents = [] + + contents.append(b',(') + contents.append(bytearray(b',').join(closure_contents)) + contents.append(b')') + + retval = bytearray(b'').join(contents) + return retval + + +def _object_instance_content(obj): + """ + Returns consistant content for a action class or an instance thereof + + :Parameters: + - `obj` Should be either and action class or an instance thereof + + :Returns: + bytearray or bytes representing the obj suitable for generating a signature from. + """ + retval = bytearray() + + if obj is None: + return b'N.' + + if isinstance(obj, SCons.Util.BaseStringTypes): + return SCons.Util.to_bytes(obj) + + inst_class = obj.__class__ + inst_class_name = bytearray(obj.__class__.__name__,'utf-8') + inst_class_module = bytearray(obj.__class__.__module__,'utf-8') + inst_class_hierarchy = bytearray(repr(inspect.getclasstree([obj.__class__,])),'utf-8') + # print("ICH:%s : %s"%(inst_class_hierarchy, repr(obj))) + + properties = [(p, getattr(obj, p, "None")) for p in dir(obj) if not (p[:2] == '__' or inspect.ismethod(getattr(obj, p)) or inspect.isbuiltin(getattr(obj,p))) ] + properties.sort() + properties_str = ','.join(["%s=%s"%(p[0],p[1]) for p in properties]) + properties_bytes = bytearray(properties_str,'utf-8') + + methods = [p for p in dir(obj) if inspect.ismethod(getattr(obj, p))] + methods.sort() + + method_contents = [] + for m in methods: + # print("Method:%s"%m) + v = _function_contents(getattr(obj, m)) + # print("[%s->]V:%s [%s]"%(m,v,type(v))) + method_contents.append(v) + + retval = bytearray(b'{') + retval.extend(inst_class_name) + retval.extend(b":") + retval.extend(inst_class_module) + retval.extend(b'}[[') + retval.extend(inst_class_hierarchy) + retval.extend(b']]{{') + retval.extend(bytearray(b",").join(method_contents)) + retval.extend(b"}}{{{") + retval.extend(properties_bytes) + retval.extend(b'}}}') + return retval + + # print("class :%s"%inst_class) + # print("class_name :%s"%inst_class_name) + # print("class_module :%s"%inst_class_module) + # print("Class hier :\n%s"%pp.pformat(inst_class_hierarchy)) + # print("Inst Properties:\n%s"%pp.pformat(properties)) + # print("Inst Methods :\n%s"%pp.pformat(methods)) + +def _actionAppend(act1, act2): + # This function knows how to slap two actions together. + # Mainly, it handles ListActions by concatenating into + # a single ListAction. + a1 = Action(act1) + a2 = Action(act2) + if a1 is None: + return a2 + if a2 is None: + return a1 + if isinstance(a1, ListAction): + if isinstance(a2, ListAction): + return ListAction(a1.list + a2.list) + else: + return ListAction(a1.list + [ a2 ]) + else: + if isinstance(a2, ListAction): + return ListAction([ a1 ] + a2.list) + else: + return ListAction([ a1, a2 ]) + + +def _do_create_keywords(args, kw): + """This converts any arguments after the action argument into + their equivalent keywords and adds them to the kw argument. + """ + v = kw.get('varlist', ()) + # prevent varlist="FOO" from being interpreted as ['F', 'O', 'O'] + if is_String(v): v = (v,) + kw['varlist'] = tuple(v) + if args: + # turn positional args into equivalent keywords + cmdstrfunc = args[0] + if cmdstrfunc is None or is_String(cmdstrfunc): + kw['cmdstr'] = cmdstrfunc + elif callable(cmdstrfunc): + kw['strfunction'] = cmdstrfunc + else: + raise SCons.Errors.UserError( + 'Invalid command display variable type. ' + 'You must either pass a string or a callback which ' + 'accepts (target, source, env) as parameters.') + if len(args) > 1: + kw['varlist'] = tuple(SCons.Util.flatten(args[1:])) + kw['varlist'] + if kw.get('strfunction', _null) is not _null \ + and kw.get('cmdstr', _null) is not _null: + raise SCons.Errors.UserError( + 'Cannot have both strfunction and cmdstr args to Action()') + + +def _do_create_action(act, kw): + """This is the actual "implementation" for the + Action factory method, below. This handles the + fact that passing lists to Action() itself has + different semantics than passing lists as elements + of lists. + + The former will create a ListAction, the latter + will create a CommandAction by converting the inner + list elements to strings.""" + + if isinstance(act, ActionBase): + return act + + if is_String(act): + var=SCons.Util.get_environment_var(act) + if var: + # This looks like a string that is purely an Environment + # variable reference, like "$FOO" or "${FOO}". We do + # something special here...we lazily evaluate the contents + # of that Environment variable, so a user could put something + # like a function or a CommandGenerator in that variable + # instead of a string. + return LazyAction(var, kw) + commands = str(act).split('\n') + if len(commands) == 1: + return CommandAction(commands[0], **kw) + # The list of string commands may include a LazyAction, so we + # reprocess them via _do_create_list_action. + return _do_create_list_action(commands, kw) + + if is_List(act): + return CommandAction(act, **kw) + + if callable(act): + try: + gen = kw['generator'] + del kw['generator'] + except KeyError: + gen = 0 + if gen: + action_type = CommandGeneratorAction + else: + action_type = FunctionAction + return action_type(act, kw) + + # Catch a common error case with a nice message: + if isinstance(act, int) or isinstance(act, float): + raise TypeError("Don't know how to create an Action from a number (%s)"%act) + # Else fail silently (???) + return None + + +def _do_create_list_action(act, kw): + """A factory for list actions. Convert the input list into Actions + and then wrap them in a ListAction.""" + acts = [] + for a in act: + aa = _do_create_action(a, kw) + if aa is not None: acts.append(aa) + if not acts: + return ListAction([]) + elif len(acts) == 1: + return acts[0] + else: + return ListAction(acts) + + +def Action(act, *args, **kw): + """A factory for action objects.""" + # Really simple: the _do_create_* routines do the heavy lifting. + _do_create_keywords(args, kw) + if is_List(act): + return _do_create_list_action(act, kw) + return _do_create_action(act, kw) + + +class ActionBase(object): + """Base class for all types of action objects that can be held by + other objects (Builders, Executors, etc.) This provides the + common methods for manipulating and combining those actions.""" + + def __eq__(self, other): + return self.__dict__ == other + + def no_batch_key(self, env, target, source): + return None + + batch_key = no_batch_key + + def genstring(self, target, source, env): + return str(self) + + def get_contents(self, target, source, env): + result = self.get_presig(target, source, env) + + if not isinstance(result,(bytes, bytearray)): + result = bytearray(result, 'utf-8') + else: + # Make a copy and put in bytearray, without this the contents returned by get_presig + # can be changed by the logic below, appending with each call and causing very + # hard to track down issues... + result = bytearray(result) + + # At this point everything should be a bytearray + + # This should never happen, as the Action() factory should wrap + # the varlist, but just in case an action is created directly, + # we duplicate this check here. + vl = self.get_varlist(target, source, env) + if is_String(vl): vl = (vl,) + for v in vl: + # do the subst this way to ignore $(...$) parts: + if isinstance(result, bytearray): + result.extend(SCons.Util.to_bytes(env.subst_target_source('${'+v+'}', SCons.Subst.SUBST_SIG, target, source))) + else: + raise Exception("WE SHOULD NEVER GET HERE result should be bytearray not:%s"%type(result)) + # result.append(SCons.Util.to_bytes(env.subst_target_source('${'+v+'}', SCons.Subst.SUBST_SIG, target, source))) + + + if isinstance(result, (bytes,bytearray)): + return result + else: + raise Exception("WE SHOULD NEVER GET HERE - #2 result should be bytearray not:%s" % type(result)) + # return b''.join(result) + + def __add__(self, other): + return _actionAppend(self, other) + + def __radd__(self, other): + return _actionAppend(other, self) + + def presub_lines(self, env): + # CommandGeneratorAction needs a real environment + # in order to return the proper string here, since + # it may call LazyAction, which looks up a key + # in that env. So we temporarily remember the env here, + # and CommandGeneratorAction will use this env + # when it calls its _generate method. + self.presub_env = env + lines = str(self).split('\n') + self.presub_env = None # don't need this any more + return lines + + def get_varlist(self, target, source, env, executor=None): + return self.varlist + + def get_targets(self, env, executor): + """ + Returns the type of targets ($TARGETS, $CHANGED_TARGETS) used + by this action. + """ + return self.targets + + +class _ActionAction(ActionBase): + """Base class for actions that create output objects.""" + def __init__(self, cmdstr=_null, strfunction=_null, varlist=(), + presub=_null, chdir=None, exitstatfunc=None, + batch_key=None, targets='$TARGETS', + **kw): + self.cmdstr = cmdstr + if strfunction is not _null: + if strfunction is None: + self.cmdstr = None + else: + self.strfunction = strfunction + self.varlist = varlist + self.presub = presub + self.chdir = chdir + if not exitstatfunc: + exitstatfunc = default_exitstatfunc + self.exitstatfunc = exitstatfunc + + self.targets = targets + + if batch_key: + if not callable(batch_key): + # They have set batch_key, but not to their own + # callable. The default behavior here will batch + # *all* targets+sources using this action, separated + # for each construction environment. + def default_batch_key(self, env, target, source): + return (id(self), id(env)) + batch_key = default_batch_key + SCons.Util.AddMethod(self, batch_key, 'batch_key') + + def print_cmd_line(self, s, target, source, env): + """ + In python 3, and in some of our tests, sys.stdout is + a String io object, and it takes unicode strings only + This code assumes s is a regular string. + """ + sys.stdout.write(s + "\n") + + def __call__(self, target, source, env, + exitstatfunc=_null, + presub=_null, + show=_null, + execute=_null, + chdir=_null, + executor=None): + if not is_List(target): + target = [target] + if not is_List(source): + source = [source] + + if presub is _null: + presub = self.presub + if presub is _null: + presub = print_actions_presub + if exitstatfunc is _null: exitstatfunc = self.exitstatfunc + if show is _null: show = print_actions + if execute is _null: execute = execute_actions + if chdir is _null: chdir = self.chdir + save_cwd = None + if chdir: + save_cwd = os.getcwd() + try: + chdir = str(chdir.get_abspath()) + except AttributeError: + if not is_String(chdir): + if executor: + chdir = str(executor.batches[0].targets[0].dir) + else: + chdir = str(target[0].dir) + if presub: + if executor: + target = executor.get_all_targets() + source = executor.get_all_sources() + t = ' and '.join(map(str, target)) + l = '\n '.join(self.presub_lines(env)) + out = "Building %s with action:\n %s\n" % (t, l) + sys.stdout.write(out) + cmd = None + if show and self.strfunction: + if executor: + target = executor.get_all_targets() + source = executor.get_all_sources() + try: + cmd = self.strfunction(target, source, env, executor) + except TypeError: + cmd = self.strfunction(target, source, env) + if cmd: + if chdir: + cmd = ('os.chdir(%s)\n' % repr(chdir)) + cmd + try: + get = env.get + except AttributeError: + print_func = self.print_cmd_line + else: + print_func = get('PRINT_CMD_LINE_FUNC') + if not print_func: + print_func = self.print_cmd_line + print_func(cmd, target, source, env) + stat = 0 + if execute: + if chdir: + os.chdir(chdir) + try: + stat = self.execute(target, source, env, executor=executor) + if isinstance(stat, SCons.Errors.BuildError): + s = exitstatfunc(stat.status) + if s: + stat.status = s + else: + stat = s + else: + stat = exitstatfunc(stat) + finally: + if save_cwd: + os.chdir(save_cwd) + if cmd and save_cwd: + print_func('os.chdir(%s)' % repr(save_cwd), target, source, env) + + return stat + + +def _string_from_cmd_list(cmd_list): + """Takes a list of command line arguments and returns a pretty + representation for printing.""" + cl = [] + for arg in map(str, cmd_list): + if ' ' in arg or '\t' in arg: + arg = '"' + arg + '"' + cl.append(arg) + return ' '.join(cl) + +default_ENV = None + + +def get_default_ENV(env): + """ + A fiddlin' little function that has an 'import SCons.Environment' which + can't be moved to the top level without creating an import loop. Since + this import creates a local variable named 'SCons', it blocks access to + the global variable, so we move it here to prevent complaints about local + variables being used uninitialized. + """ + global default_ENV + try: + return env['ENV'] + except KeyError: + if not default_ENV: + import SCons.Environment + # This is a hideously expensive way to get a default shell + # environment. What it really should do is run the platform + # setup to get the default ENV. Fortunately, it's incredibly + # rare for an Environment not to have a shell environment, so + # we're not going to worry about it overmuch. + default_ENV = SCons.Environment.Environment()['ENV'] + return default_ENV + + +def _subproc(scons_env, cmd, error='ignore', **kw): + """Wrapper for subprocess which pulls from construction env. + + Use for calls to subprocess which need to interpolate values from + an SCons construction environment into the environment passed to + subprocess. Adds an an error-handling argument. Adds ability + to specify std{in,out,err} with "'devnull'" tag. + """ + # TODO: just uses subprocess.DEVNULL now, we can drop the "devnull" + # string now - it is a holdover from Py2, which didn't have DEVNULL. + for stream in 'stdin', 'stdout', 'stderr': + io = kw.get(stream) + if is_String(io) and io == 'devnull': + kw[stream] = DEVNULL + + # Figure out what shell environment to use + ENV = kw.get('env', None) + if ENV is None: ENV = get_default_ENV(scons_env) + + # Ensure that the ENV values are all strings: + new_env = {} + for key, value in ENV.items(): + if is_List(value): + # If the value is a list, then we assume it is a path list, + # because that's a pretty common list-like value to stick + # in an environment variable: + value = SCons.Util.flatten_sequence(value) + new_env[key] = os.pathsep.join(map(str, value)) + else: + # It's either a string or something else. If it's a string, + # we still want to call str() because it might be a *Unicode* + # string, which makes subprocess.Popen() gag. If it isn't a + # string or a list, then we just coerce it to a string, which + # is the proper way to handle Dir and File instances and will + # produce something reasonable for just about everything else: + new_env[key] = str(value) + kw['env'] = new_env + + try: + pobj = subprocess.Popen(cmd, **kw) + except EnvironmentError as e: + if error == 'raise': raise + # return a dummy Popen instance that only returns error + class dummyPopen(object): + def __init__(self, e): self.exception = e + def communicate(self, input=None): return ('', '') + def wait(self): return -self.exception.errno + stdin = None + class f(object): + def read(self): return '' + def readline(self): return '' + def __iter__(self): return iter(()) + stdout = stderr = f() + pobj = dummyPopen(e) + finally: + # clean up open file handles stored in parent's kw + for k, v in kw.items(): + if inspect.ismethod(getattr(v, 'close', None)): + v.close() + + return pobj + + +class CommandAction(_ActionAction): + """Class for command-execution actions.""" + def __init__(self, cmd, **kw): + # Cmd can actually be a list or a single item; if it's a + # single item it should be the command string to execute; if a + # list then it should be the words of the command string to + # execute. Only a single command should be executed by this + # object; lists of commands should be handled by embedding + # these objects in a ListAction object (which the Action() + # factory above does). cmd will be passed to + # Environment.subst_list() for substituting environment + # variables. + if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.CommandAction') + + _ActionAction.__init__(self, **kw) + if is_List(cmd): + if [c for c in cmd if is_List(c)]: + raise TypeError("CommandAction should be given only " + "a single command") + self.cmd_list = cmd + + def __str__(self): + if is_List(self.cmd_list): + return ' '.join(map(str, self.cmd_list)) + return str(self.cmd_list) + + def process(self, target, source, env, executor=None): + if executor: + result = env.subst_list(self.cmd_list, 0, executor=executor) + else: + result = env.subst_list(self.cmd_list, 0, target, source) + silent = None + ignore = None + while True: + try: c = result[0][0][0] + except IndexError: c = None + if c == '@': silent = 1 + elif c == '-': ignore = 1 + else: break + result[0][0] = result[0][0][1:] + try: + if not result[0][0]: + result[0] = result[0][1:] + except IndexError: + pass + return result, ignore, silent + + def strfunction(self, target, source, env, executor=None): + if self.cmdstr is None: + return None + if self.cmdstr is not _null: + from SCons.Subst import SUBST_RAW + if executor: + c = env.subst(self.cmdstr, SUBST_RAW, executor=executor) + else: + c = env.subst(self.cmdstr, SUBST_RAW, target, source) + if c: + return c + cmd_list, ignore, silent = self.process(target, source, env, executor) + if silent: + return '' + return _string_from_cmd_list(cmd_list[0]) + + def execute(self, target, source, env, executor=None): + """Execute a command action. + + This will handle lists of commands as well as individual commands, + because construction variable substitution may turn a single + "command" into a list. This means that this class can actually + handle lists of commands, even though that's not how we use it + externally. + """ + escape_list = SCons.Subst.escape_list + flatten_sequence = SCons.Util.flatten_sequence + + try: + shell = env['SHELL'] + except KeyError: + raise SCons.Errors.UserError('Missing SHELL construction variable.') + + try: + spawn = env['SPAWN'] + except KeyError: + raise SCons.Errors.UserError('Missing SPAWN construction variable.') + else: + if is_String(spawn): + spawn = env.subst(spawn, raw=1, conv=lambda x: x) + + escape = env.get('ESCAPE', lambda x: x) + + ENV = get_default_ENV(env) + + # Ensure that the ENV values are all strings: + for key, value in ENV.items(): + if not is_String(value): + if is_List(value): + # If the value is a list, then we assume it is a + # path list, because that's a pretty common list-like + # value to stick in an environment variable: + value = flatten_sequence(value) + ENV[key] = os.pathsep.join(map(str, value)) + else: + # If it isn't a string or a list, then we just coerce + # it to a string, which is the proper way to handle + # Dir and File instances and will produce something + # reasonable for just about everything else: + ENV[key] = str(value) + + if executor: + target = executor.get_all_targets() + source = executor.get_all_sources() + cmd_list, ignore, silent = self.process(target, list(map(rfile, source)), env, executor) + + # Use len() to filter out any "command" that's zero-length. + for cmd_line in filter(len, cmd_list): + # Escape the command line for the interpreter we are using. + cmd_line = escape_list(cmd_line, escape) + result = spawn(shell, escape, cmd_line[0], cmd_line, ENV) + if not ignore and result: + msg = "Error %s" % result + return SCons.Errors.BuildError(errstr=msg, + status=result, + action=self, + command=cmd_line) + return 0 + + def get_presig(self, target, source, env, executor=None): + """Return the signature contents of this action's command line. + + This strips $(-$) and everything in between the string, + since those parts don't affect signatures. + """ + from SCons.Subst import SUBST_SIG + cmd = self.cmd_list + if is_List(cmd): + cmd = ' '.join(map(str, cmd)) + else: + cmd = str(cmd) + if executor: + return env.subst_target_source(cmd, SUBST_SIG, executor=executor) + else: + return env.subst_target_source(cmd, SUBST_SIG, target, source) + + def get_implicit_deps(self, target, source, env, executor=None): + """Return the implicit dependencies of this action's command line.""" + icd = env.get('IMPLICIT_COMMAND_DEPENDENCIES', True) + if is_String(icd) and icd[:1] == '$': + icd = env.subst(icd) + + if not icd or str(icd).lower in ('0', 'none', 'false', 'no', 'off'): + return [] + + try: + icd_int = int(icd) + except ValueError: + icd_int = None + + if (icd_int and icd_int > 1) or icd == 'all': + # An integer value greater than 1 specifies the number of entries + # to scan. "all" means to scan all. + return self._get_implicit_deps_heavyweight(target, source, env, executor, icd_int) + else: + # Everything else (usually 1 or True) means that we want + # lightweight dependency scanning. + return self._get_implicit_deps_lightweight(target, source, env, executor) + + def _get_implicit_deps_lightweight(self, target, source, env, executor): + """ + Lightweight dependency scanning involves only scanning the first entry + in an action string, even if it contains &&. + """ + from SCons.Subst import SUBST_SIG + if executor: + cmd_list = env.subst_list(self.cmd_list, SUBST_SIG, executor=executor) + else: + cmd_list = env.subst_list(self.cmd_list, SUBST_SIG, target, source) + res = [] + for cmd_line in cmd_list: + if cmd_line: + d = str(cmd_line[0]) + m = strip_quotes.match(d) + if m: + d = m.group(1) + d = env.WhereIs(d) + if d: + res.append(env.fs.File(d)) + return res + + def _get_implicit_deps_heavyweight(self, target, source, env, executor, + icd_int): + """ + Heavyweight dependency scanning involves scanning more than just the + first entry in an action string. The exact behavior depends on the + value of icd_int. Only files are taken as implicit dependencies; + directories are ignored. + + If icd_int is an integer value, it specifies the number of entries to + scan for implicit dependencies. Action strings are also scanned after + a &&. So for example, if icd_int=2 and the action string is + "cd <some_dir> && $PYTHON $SCRIPT_PATH <another_path>", the implicit + dependencies would be the path to the python binary and the path to the + script. + + If icd_int is None, all entries are scanned for implicit dependencies. + """ + + # Avoid circular and duplicate dependencies by not providing source, + # target, or executor to subst_list. This causes references to + # $SOURCES, $TARGETS, and all related variables to disappear. + from SCons.Subst import SUBST_SIG + cmd_list = env.subst_list(self.cmd_list, SUBST_SIG, conv=lambda x: x) + res = [] + + for cmd_line in cmd_list: + if cmd_line: + entry_count = 0 + for entry in cmd_line: + d = str(entry) + if ((icd_int is None or entry_count < icd_int) and + not d.startswith(('&', '-', '/') if os.name == 'nt' + else ('&', '-'))): + m = strip_quotes.match(d) + if m: + d = m.group(1) + + if d: + # Resolve the first entry in the command string using + # PATH, which env.WhereIs() looks in. + # For now, only match files, not directories. + p = os.path.abspath(d) if os.path.isfile(d) else None + if not p and entry_count == 0: + p = env.WhereIs(d) + + if p: + res.append(env.fs.File(p)) + + entry_count = entry_count + 1 + else: + entry_count = 0 if d == '&&' else entry_count + 1 + + # Despite not providing source and target to env.subst() above, we + # can still end up with sources in this list. For example, files in + # LIBS will still resolve in env.subst(). This won't result in + # circular dependencies, but it causes problems with cache signatures + # changing between full and incremental builds. + return [r for r in res if r not in target and r not in source] + + +class CommandGeneratorAction(ActionBase): + """Class for command-generator actions.""" + def __init__(self, generator, kw): + if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.CommandGeneratorAction') + self.generator = generator + self.gen_kw = kw + self.varlist = kw.get('varlist', ()) + self.targets = kw.get('targets', '$TARGETS') + + def _generate(self, target, source, env, for_signature, executor=None): + # ensure that target is a list, to make it easier to write + # generator functions: + if not is_List(target): + target = [target] + + if executor: + target = executor.get_all_targets() + source = executor.get_all_sources() + ret = self.generator(target=target, + source=source, + env=env, + for_signature=for_signature) + gen_cmd = Action(ret, **self.gen_kw) + if not gen_cmd: + raise SCons.Errors.UserError("Object returned from command generator: %s cannot be used to create an Action." % repr(ret)) + return gen_cmd + + def __str__(self): + try: + env = self.presub_env + except AttributeError: + env = None + if env is None: + env = SCons.Defaults.DefaultEnvironment() + act = self._generate([], [], env, 1) + return str(act) + + def batch_key(self, env, target, source): + return self._generate(target, source, env, 1).batch_key(env, target, source) + + def genstring(self, target, source, env, executor=None): + return self._generate(target, source, env, 1, executor).genstring(target, source, env) + + def __call__(self, target, source, env, exitstatfunc=_null, presub=_null, + show=_null, execute=_null, chdir=_null, executor=None): + act = self._generate(target, source, env, 0, executor) + if act is None: + raise SCons.Errors.UserError("While building `%s': " + "Cannot deduce file extension from source files: %s" + % (repr(list(map(str, target))), repr(list(map(str, source))))) + return act(target, source, env, exitstatfunc, presub, + show, execute, chdir, executor) + + def get_presig(self, target, source, env, executor=None): + """Return the signature contents of this action's command line. + + This strips $(-$) and everything in between the string, + since those parts don't affect signatures. + """ + return self._generate(target, source, env, 1, executor).get_presig(target, source, env) + + def get_implicit_deps(self, target, source, env, executor=None): + return self._generate(target, source, env, 1, executor).get_implicit_deps(target, source, env) + + def get_varlist(self, target, source, env, executor=None): + return self._generate(target, source, env, 1, executor).get_varlist(target, source, env, executor) + + def get_targets(self, env, executor): + return self._generate(None, None, env, 1, executor).get_targets(env, executor) + + +class LazyAction(CommandGeneratorAction, CommandAction): + """ + A LazyAction is a kind of hybrid generator and command action for + strings of the form "$VAR". These strings normally expand to other + strings (think "$CCCOM" to "$CC -c -o $TARGET $SOURCE"), but we also + want to be able to replace them with functions in the construction + environment. Consequently, we want lazy evaluation and creation of + an Action in the case of the function, but that's overkill in the more + normal case of expansion to other strings. + + So we do this with a subclass that's both a generator *and* + a command action. The overridden methods all do a quick check + of the construction variable, and if it's a string we just call + the corresponding CommandAction method to do the heavy lifting. + If not, then we call the same-named CommandGeneratorAction method. + The CommandGeneratorAction methods work by using the overridden + _generate() method, that is, our own way of handling "generation" of + an action based on what's in the construction variable. + """ + + def __init__(self, var, kw): + if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.LazyAction') + CommandAction.__init__(self, '${'+var+'}', **kw) + self.var = SCons.Util.to_String(var) + self.gen_kw = kw + + def get_parent_class(self, env): + c = env.get(self.var) + if is_String(c) and '\n' not in c: + return CommandAction + return CommandGeneratorAction + + def _generate_cache(self, env): + if env: + c = env.get(self.var, '') + else: + c = '' + gen_cmd = Action(c, **self.gen_kw) + if not gen_cmd: + raise SCons.Errors.UserError("$%s value %s cannot be used to create an Action." % (self.var, repr(c))) + return gen_cmd + + def _generate(self, target, source, env, for_signature, executor=None): + return self._generate_cache(env) + + def __call__(self, target, source, env, *args, **kw): + c = self.get_parent_class(env) + return c.__call__(self, target, source, env, *args, **kw) + + def get_presig(self, target, source, env): + c = self.get_parent_class(env) + return c.get_presig(self, target, source, env) + + def get_varlist(self, target, source, env, executor=None): + c = self.get_parent_class(env) + return c.get_varlist(self, target, source, env, executor) + + +class FunctionAction(_ActionAction): + """Class for Python function actions.""" + + def __init__(self, execfunction, kw): + if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.FunctionAction') + + self.execfunction = execfunction + try: + self.funccontents = _callable_contents(execfunction) + except AttributeError: + try: + # See if execfunction will do the heavy lifting for us. + self.gc = execfunction.get_contents + except AttributeError: + # This is weird, just do the best we can. + self.funccontents = _object_contents(execfunction) + + _ActionAction.__init__(self, **kw) + + def function_name(self): + try: + return self.execfunction.__name__ + except AttributeError: + try: + return self.execfunction.__class__.__name__ + except AttributeError: + return "unknown_python_function" + + def strfunction(self, target, source, env, executor=None): + if self.cmdstr is None: + return None + if self.cmdstr is not _null: + from SCons.Subst import SUBST_RAW + if executor: + c = env.subst(self.cmdstr, SUBST_RAW, executor=executor) + else: + c = env.subst(self.cmdstr, SUBST_RAW, target, source) + if c: + return c + + def array(a): + def quote(s): + try: + str_for_display = s.str_for_display + except AttributeError: + s = repr(s) + else: + s = str_for_display() + return s + return '[' + ", ".join(map(quote, a)) + ']' + try: + strfunc = self.execfunction.strfunction + except AttributeError: + pass + else: + if strfunc is None: + return None + if callable(strfunc): + return strfunc(target, source, env) + name = self.function_name() + tstr = array(target) + sstr = array(source) + return "%s(%s, %s)" % (name, tstr, sstr) + + def __str__(self): + name = self.function_name() + if name == 'ActionCaller': + return str(self.execfunction) + return "%s(target, source, env)" % name + + def execute(self, target, source, env, executor=None): + exc_info = (None,None,None) + try: + if executor: + target = executor.get_all_targets() + source = executor.get_all_sources() + rsources = list(map(rfile, source)) + try: + result = self.execfunction(target=target, source=rsources, env=env) + except KeyboardInterrupt as e: + raise + except SystemExit as e: + raise + except Exception as e: + result = e + exc_info = sys.exc_info() + + if result: + result = SCons.Errors.convert_to_BuildError(result, exc_info) + result.node=target + result.action=self + try: + result.command=self.strfunction(target, source, env, executor) + except TypeError: + result.command=self.strfunction(target, source, env) + + # FIXME: This maintains backward compatibility with respect to + # which type of exceptions were returned by raising an + # exception and which ones were returned by value. It would + # probably be best to always return them by value here, but + # some codes do not check the return value of Actions and I do + # not have the time to modify them at this point. + if (exc_info[1] and + not isinstance(exc_info[1],EnvironmentError)): + raise result + + return result + finally: + # Break the cycle between the traceback object and this + # function stack frame. See the sys.exc_info() doc info for + # more information about this issue. + del exc_info + + def get_presig(self, target, source, env): + """Return the signature contents of this callable action.""" + try: + return self.gc(target, source, env) + except AttributeError: + return self.funccontents + + def get_implicit_deps(self, target, source, env): + return [] + +class ListAction(ActionBase): + """Class for lists of other actions.""" + def __init__(self, actionlist): + if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.ListAction') + def list_of_actions(x): + if isinstance(x, ActionBase): + return x + return Action(x) + self.list = list(map(list_of_actions, actionlist)) + # our children will have had any varlist + # applied; we don't need to do it again + self.varlist = () + self.targets = '$TARGETS' + + def genstring(self, target, source, env): + return '\n'.join([a.genstring(target, source, env) for a in self.list]) + + def __str__(self): + return '\n'.join(map(str, self.list)) + + def presub_lines(self, env): + return SCons.Util.flatten_sequence( + [a.presub_lines(env) for a in self.list]) + + def get_presig(self, target, source, env): + """Return the signature contents of this action list. + + Simple concatenation of the signatures of the elements. + """ + return b"".join([bytes(x.get_contents(target, source, env)) for x in self.list]) + + def __call__(self, target, source, env, exitstatfunc=_null, presub=_null, + show=_null, execute=_null, chdir=_null, executor=None): + if executor: + target = executor.get_all_targets() + source = executor.get_all_sources() + for act in self.list: + stat = act(target, source, env, exitstatfunc, presub, + show, execute, chdir, executor) + if stat: + return stat + return 0 + + def get_implicit_deps(self, target, source, env): + result = [] + for act in self.list: + result.extend(act.get_implicit_deps(target, source, env)) + return result + + def get_varlist(self, target, source, env, executor=None): + result = OrderedDict() + for act in self.list: + for var in act.get_varlist(target, source, env, executor): + result[var] = True + return list(result.keys()) + + +class ActionCaller(object): + """A class for delaying calling an Action function with specific + (positional and keyword) arguments until the Action is actually + executed. + + This class looks to the rest of the world like a normal Action object, + but what it's really doing is hanging on to the arguments until we + have a target, source and env to use for the expansion. + """ + def __init__(self, parent, args, kw): + self.parent = parent + self.args = args + self.kw = kw + + def get_contents(self, target, source, env): + actfunc = self.parent.actfunc + try: + # "self.actfunc" is a function. + contents = actfunc.__code__.co_code + except AttributeError: + # "self.actfunc" is a callable object. + try: + contents = actfunc.__call__.__func__.__code__.co_code + except AttributeError: + # No __call__() method, so it might be a builtin + # or something like that. Do the best we can. + contents = repr(actfunc) + + return contents + + def subst(self, s, target, source, env): + # If s is a list, recursively apply subst() + # to every element in the list + if is_List(s): + result = [] + for elem in s: + result.append(self.subst(elem, target, source, env)) + return self.parent.convert(result) + + # Special-case hack: Let a custom function wrapped in an + # ActionCaller get at the environment through which the action + # was called by using this hard-coded value as a special return. + if s == '$__env__': + return env + elif is_String(s): + return env.subst(s, 1, target, source) + return self.parent.convert(s) + + def subst_args(self, target, source, env): + return [self.subst(x, target, source, env) for x in self.args] + + def subst_kw(self, target, source, env): + kw = {} + for key in list(self.kw.keys()): + kw[key] = self.subst(self.kw[key], target, source, env) + return kw + + def __call__(self, target, source, env, executor=None): + args = self.subst_args(target, source, env) + kw = self.subst_kw(target, source, env) + return self.parent.actfunc(*args, **kw) + + def strfunction(self, target, source, env): + args = self.subst_args(target, source, env) + kw = self.subst_kw(target, source, env) + return self.parent.strfunc(*args, **kw) + + def __str__(self): + return self.parent.strfunc(*self.args, **self.kw) + + +class ActionFactory(object): + """A factory class that will wrap up an arbitrary function + as an SCons-executable Action object. + + The real heavy lifting here is done by the ActionCaller class. + We just collect the (positional and keyword) arguments that we're + called with and give them to the ActionCaller object we create, + so it can hang onto them until it needs them. + """ + def __init__(self, actfunc, strfunc, convert=lambda x: x): + self.actfunc = actfunc + self.strfunc = strfunc + self.convert = convert + + def __call__(self, *args, **kw): + ac = ActionCaller(self, args, kw) + action = Action(ac, strfunction=ac.strfunction) + return action + +# Local Variables: +# tab-width:4 +# indent-tabs-mode:nil +# End: +# vim: set expandtab tabstop=4 shiftwidth=4: |