3 This encapsulates information about executing any sort of action that
4 can build one or more target Nodes (typically files) from one or more
5 source Nodes (also typically files) given a specific Environment.
7 The base class here is ActionBase. The base class supplies just a few
8 OO utility methods and some generic methods for displaying information
9 about an Action in response to the various commands that control printing.
11 The heavy lifting is handled by subclasses for the different types of
12 actions we might execute:
15 CommandGeneratorAction
19 The subclasses supply the following public interface methods used by
23 THE public interface, "calling" an Action object executes the
24 command or Python function. This also takes care of printing
25 a pre-substitution command for debugging purposes.
28 Fetches the "contents" of an Action for signature calculation.
29 This is what the Sig/*.py subsystem uses to decide if a target
30 needs to be rebuilt because its action changed.
33 Returns a string representation of the Action *without* command
34 substitution, but allows a CommandGeneratorAction to generate
35 the right action based on the specified target, source and env.
36 This is used by the Signature subsystem (through the Executor)
37 to compare the actions used to build a target last time and
40 Subclasses also supply the following methods for internal use within
44 Returns a string representation of the Action *without* command
45 substitution. This is used by the __call__() methods to display
46 the pre-substitution command whenever the --debug=presub option
50 Returns a substituted string representation of the Action.
51 This is used by the ActionBase.show() command to display the
52 command/function that will be executed to generate the target(s).
55 The internal method that really, truly, actually handles the
56 execution of a command or Python function. This is used so
57 that the __call__() methods can take care of displaying any
58 pre-substitution representations, and *then* execute an action
59 without worrying about the specific Actions involved.
61 There is a related independent ActionCaller class that looks like a
62 regular Action, and which serves as a wrapper for arbitrary functions
63 that we want to let the user specify the arguments to now, but actually
64 execute later (when an out-of-date check determines that it's needed to
65 be executed, for example). Objects of this class are returned by an
66 ActionFactory class that provides a __call__() method as a convenient
67 way for wrapping up the functions.
74 # Permission is hereby granted, free of charge, to any person obtaining
75 # a copy of this software and associated documentation files (the
76 # "Software"), to deal in the Software without restriction, including
77 # without limitation the rights to use, copy, modify, merge, publish,
78 # distribute, sublicense, and/or sell copies of the Software, and to
79 # permit persons to whom the Software is furnished to do so, subject to
80 # the following conditions:
82 # The above copyright notice and this permission notice shall be included
83 # in all copies or substantial portions of the Software.
85 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
86 # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
87 # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
88 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
89 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
90 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
91 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
94 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
102 from SCons.Debug import logInstanceCreation
113 print_actions_presub = 0
120 except AttributeError:
123 def _actionAppend(act1, act2):
124 # This function knows how to slap two actions together.
125 # Mainly, it handles ListActions by concatenating into
126 # a single ListAction.
129 if a1 is None or a2 is None:
130 raise TypeError, "Cannot append %s to %s" % (type(act1), type(act2))
131 if isinstance(a1, ListAction):
132 if isinstance(a2, ListAction):
133 return ListAction(a1.list + a2.list)
135 return ListAction(a1.list + [ a2 ])
137 if isinstance(a2, ListAction):
138 return ListAction([ a1 ] + a2.list)
140 return ListAction([ a1, a2 ])
142 class CommandGenerator:
144 Wraps a command generator function so the Action() factory
145 function can tell a generator function from a function action.
147 def __init__(self, generator):
148 self.generator = generator
150 def __add__(self, other):
151 return _actionAppend(self, other)
153 def __radd__(self, other):
154 return _actionAppend(other, self)
156 def _do_create_action(act, *args, **kw):
157 """This is the actual "implementation" for the
158 Action factory method, below. This handles the
159 fact that passing lists to Action() itself has
160 different semantics than passing lists as elements
163 The former will create a ListAction, the latter
164 will create a CommandAction by converting the inner
165 list elements to strings."""
167 if isinstance(act, ActionBase):
169 if SCons.Util.is_List(act):
170 return apply(CommandAction, (act,)+args, kw)
171 if isinstance(act, CommandGenerator):
172 return apply(CommandGeneratorAction, (act.generator,)+args, kw)
174 return apply(FunctionAction, (act,)+args, kw)
175 if SCons.Util.is_String(act):
176 var=SCons.Util.get_environment_var(act)
178 # This looks like a string that is purely an Environment
179 # variable reference, like "$FOO" or "${FOO}". We do
180 # something special here...we lazily evaluate the contents
181 # of that Environment variable, so a user could put something
182 # like a function or a CommandGenerator in that variable
183 # instead of a string.
184 lcg = LazyCmdGenerator(var)
185 return apply(CommandGeneratorAction, (lcg,)+args, kw)
186 commands = string.split(str(act), '\n')
187 if len(commands) == 1:
188 return apply(CommandAction, (commands[0],)+args, kw)
190 listCmdActions = map(lambda x: CommandAction(x), commands)
191 return apply(ListAction, (listCmdActions,)+args, kw)
194 def Action(act, strfunction=_null, varlist=[]):
195 """A factory for action objects."""
196 if SCons.Util.is_List(act):
197 acts = map(lambda x, s=strfunction, v=varlist:
198 _do_create_action(x, strfunction=s, varlist=v),
200 acts = filter(lambda x: not x is None, acts)
204 return ListAction(acts, strfunction=strfunction, varlist=varlist)
206 return _do_create_action(act, strfunction=strfunction, varlist=varlist)
209 """Base class for actions that create output objects."""
210 def __init__(self, strfunction=_null, **kw):
211 if not strfunction is _null:
212 self.strfunction = strfunction
214 def __cmp__(self, other):
215 return cmp(self.__dict__, other.__dict__)
217 def __call__(self, target, source, env,
222 if not SCons.Util.is_List(target):
224 if not SCons.Util.is_List(source):
226 if presub is _null: presub = print_actions_presub
227 if show is _null: show = print_actions
228 if execute is _null: execute = execute_actions
230 t = string.join(map(str, target), 'and')
231 l = string.join(self.presub(env), '\n ')
232 out = "Building %s with action(s):\n %s\n" % (t, l)
233 sys.stdout.write(out)
234 if show and self.strfunction:
235 s = self.strfunction(target, source, env)
237 sys.stdout.write(s + '\n')
239 stat = self.execute(target, source, env)
246 def presub(self, env):
247 # CommandGeneratorAction needs a real environment
248 # in order to return the proper string here, since
249 # it may call LazyCmdGenerator, which looks up a key
250 # in that env. So we temporarily remember the env here,
251 # and CommandGeneratorAction will use this env
252 # when it calls its __generate method.
253 self.presub_env = env
254 lines = string.split(str(self), '\n')
255 self.presub_env = None # don't need this any more
258 def genstring(self, target, source, env):
261 def get_actions(self):
264 def __add__(self, other):
265 return _actionAppend(self, other)
267 def __radd__(self, other):
268 return _actionAppend(other, self)
270 def _string_from_cmd_list(cmd_list):
271 """Takes a list of command line arguments and returns a pretty
272 representation for printing."""
274 for arg in map(str, cmd_list):
275 if ' ' in arg or '\t' in arg:
276 arg = '"' + arg + '"'
278 return string.join(cl)
280 class CommandAction(ActionBase):
281 """Class for command-execution actions."""
282 def __init__(self, cmd, **kw):
283 # Cmd list can actually be a list or a single item...basically
284 # anything that we could pass in as the first arg to
285 # Environment.subst_list().
286 if __debug__: logInstanceCreation(self)
287 apply(ActionBase.__init__, (self,), kw)
291 return str(self.cmd_list)
293 def strfunction(self, target, source, env):
294 cmd_list = env.subst_list(self.cmd_list, 0, target, source)
295 return string.join(map(_string_from_cmd_list, cmd_list), "\n")
297 def execute(self, target, source, env):
298 """Execute a command action.
300 This will handle lists of commands as well as individual commands,
301 because construction variable substitution may turn a single
302 "command" into a list. This means that this class can actually
303 handle lists of commands, even though that's not how we use it
308 escape = env.get('ESCAPE', lambda x: x)
310 if env.has_key('SHELL'):
313 raise SCons.Errors.UserError('Missing SHELL construction variable.')
315 # for SConf support (by now): check, if we want to pipe the command
316 # output to somewhere else
317 if env.has_key('PIPE_BUILD'):
319 if env.has_key('PSPAWN'):
320 pspawn = env['PSPAWN']
322 raise SCons.Errors.UserError('Missing PSPAWN construction variable.')
323 if env.has_key('PSTDOUT'):
324 pstdout = env['PSTDOUT']
326 raise SCons.Errors.UserError('Missing PSTDOUT construction variable.')
327 if env.has_key('PSTDERR'):
328 pstderr = env['PSTDERR']
330 raise SCons.Errors.UserError('Missing PSTDOUT construction variable.')
333 if env.has_key('SPAWN'):
336 raise SCons.Errors.UserError('Missing SPAWN construction variable.')
338 cmd_list = env.subst_list(self.cmd_list, 0, target, source)
339 for cmd_line in cmd_list:
346 import SCons.Environment
347 default_ENV = SCons.Environment.Environment()['ENV']
350 # ensure that the ENV values are all strings:
351 for key, value in ENV.items():
352 if SCons.Util.is_List(value):
353 # If the value is a list, then we assume
354 # it is a path list, because that's a pretty
355 # common list like value to stick in an environment
357 ENV[key] = string.join(map(str, value), os.pathsep)
358 elif not SCons.Util.is_String(value):
359 # If it isn't a string or a list, then
360 # we just coerce it to a string, which
361 # is proper way to handle Dir and File instances
362 # and will produce something reasonable for
363 # just about everything else:
364 ENV[key] = str(value)
366 # Escape the command line for the command
367 # interpreter we are using
368 cmd_line = SCons.Util.escape_list(cmd_line, escape)
370 ret = pspawn( shell, escape, cmd_line[0], cmd_line,
371 ENV, pstdout, pstderr )
373 ret = spawn(shell, escape, cmd_line[0], cmd_line, ENV)
378 def get_contents(self, target, source, env, dict=None):
379 """Return the signature contents of this action's command line.
381 This strips $(-$) and everything in between the string,
382 since those parts don't affect signatures.
385 if SCons.Util.is_List(cmd):
386 cmd = string.join(map(str, cmd))
389 return env.subst_target_source(cmd, SCons.Util.SUBST_SIG, target, source, dict)
391 class CommandGeneratorAction(ActionBase):
392 """Class for command-generator actions."""
393 def __init__(self, generator, **kw):
394 if __debug__: logInstanceCreation(self)
395 apply(ActionBase.__init__, (self,), kw)
396 self.generator = generator
398 def __generate(self, target, source, env, for_signature):
399 # ensure that target is a list, to make it easier to write
400 # generator functions:
401 if not SCons.Util.is_List(target):
404 ret = self.generator(target=target, source=source, env=env, for_signature=for_signature)
405 gen_cmd = Action(ret)
407 raise SCons.Errors.UserError("Object returned from command generator: %s cannot be used to create an Action." % repr(ret))
410 def strfunction(self, target, source, env):
411 if not SCons.Util.is_List(source):
413 rsources = map(rfile, source)
414 act = self.__generate(target, source, env, 0)
415 return act.strfunction(target, rsources, env)
419 env = self.presub_env or {}
420 except AttributeError:
422 act = self.__generate([], [], env, 0)
425 def genstring(self, target, source, env):
426 return str(self.__generate(target, source, env, 0))
428 def execute(self, target, source, env):
429 rsources = map(rfile, source)
430 act = self.__generate(target, source, env, 0)
431 return act.execute(target, source, env)
433 def get_contents(self, target, source, env, dict=None):
434 """Return the signature contents of this action's command line.
436 This strips $(-$) and everything in between the string,
437 since those parts don't affect signatures.
439 return self.__generate(target, source, env, 1).get_contents(target, source, env, dict=None)
441 class LazyCmdGenerator:
442 """This is not really an Action, although it kind of looks like one.
443 This is really a simple callable class that acts as a command
444 generator. It holds on to a key into an Environment dictionary,
445 then waits until execution time to see what type it is, then tries
446 to create an Action out of it."""
447 def __init__(self, var):
448 if __debug__: logInstanceCreation(self)
449 self.var = SCons.Util.to_String(var)
451 def strfunction(self, target, source, env):
455 # The variable reference substitutes to nothing.
459 return 'LazyCmdGenerator: %s'%str(self.var)
461 def __call__(self, target, source, env, for_signature):
465 # The variable reference substitutes to nothing.
468 def __cmp__(self, other):
469 return cmp(self.__dict__, other.__dict__)
471 class FunctionAction(ActionBase):
472 """Class for Python function actions."""
474 def __init__(self, execfunction, **kw):
475 if __debug__: logInstanceCreation(self)
476 self.execfunction = execfunction
477 apply(ActionBase.__init__, (self,), kw)
478 self.varlist = kw.get('varlist', [])
480 def function_name(self):
482 return self.execfunction.__name__
483 except AttributeError:
485 return self.execfunction.__class__.__name__
486 except AttributeError:
487 return "unknown_python_function"
489 def strfunction(self, target, source, env):
491 return '"' + str(s) + '"'
492 def array(a, q=quote):
493 return '[' + string.join(map(lambda x, q=q: q(x), a), ", ") + ']'
494 name = self.function_name()
495 tstr = len(target) == 1 and quote(target[0]) or array(target)
496 sstr = len(source) == 1 and quote(source[0]) or array(source)
497 return "%s(%s, %s)" % (name, tstr, sstr)
500 return "%s(env, target, source)" % self.function_name()
502 def execute(self, target, source, env):
503 rsources = map(rfile, source)
504 return self.execfunction(target=target, source=rsources, env=env)
506 def get_contents(self, target, source, env, dict=None):
507 """Return the signature contents of this callable action.
509 By providing direct access to the code object of the
510 function, Python makes this extremely easy. Hooray!
513 # "self.execfunction" is a function.
514 contents = str(self.execfunction.func_code.co_code)
515 except AttributeError:
516 # "self.execfunction" is a callable object.
518 contents = str(self.execfunction.__call__.im_func.func_code.co_code)
519 except AttributeError:
521 # See if execfunction will do the heavy lifting for us.
522 gc = self.execfunction.get_contents
523 except AttributeError:
524 # This is weird, just do the best we can.
525 contents = str(self.execfunction)
527 contents = gc(target, source, env, dict)
528 return contents + env.subst(string.join(map(lambda v: '${'+v+'}',
531 class ListAction(ActionBase):
532 """Class for lists of other actions."""
533 def __init__(self, list, **kw):
534 if __debug__: logInstanceCreation(self)
535 apply(ActionBase.__init__, (self,), kw)
536 self.list = map(lambda x: Action(x), list)
538 def get_actions(self):
545 return string.join(s, "\n")
547 def strfunction(self, target, source, env):
551 x = l.strfunction(target, source, env)
552 if not SCons.Util.is_List(x):
555 return string.join(s, "\n")
557 def execute(self, target, source, env):
559 r = l.execute(target, source, env)
564 def get_contents(self, target, source, env, dict=None):
565 """Return the signature contents of this action list.
567 Simple concatenation of the signatures of the elements.
569 dict = SCons.Util.subst_dict(target, source)
570 return string.join(map(lambda x, t=target, s=source, e=env, d=dict:
571 x.get_contents(t, s, e, d),
576 """A class for delaying calling an Action function with specific
577 (positional and keyword) arguments until the Action is actually
580 This class looks to the rest of the world like a normal Action object,
581 but what it's really doing is hanging on to the arguments until we
582 have a target, source and env to use for the expansion.
584 def __init__(self, parent, args, kw):
588 def get_contents(self, target, source, env, dict=None):
589 actfunc = self.parent.actfunc
591 # "self.actfunc" is a function.
592 contents = str(actfunc.func_code.co_code)
593 except AttributeError:
594 # "self.actfunc" is a callable object.
596 contents = str(actfunc.__call__.im_func.func_code.co_code)
597 except AttributeError:
598 # No __call__() method, so it might be a builtin
599 # or something like that. Do the best we can.
600 contents = str(actfunc)
602 def subst_args(self, target, source, env):
603 return map(lambda x, e=env, t=target, s=source:
606 def subst_kw(self, target, source, env):
608 for key in self.kw.keys():
609 kw[key] = env.subst(self.kw[key], 0, target, source)
611 def __call__(self, target, source, env):
612 args = self.subst_args(target, source, env)
613 kw = self.subst_kw(target, source, env)
614 return apply(self.parent.actfunc, args, kw)
615 def strfunction(self, target, source, env):
616 args = self.subst_args(target, source, env)
617 kw = self.subst_kw(target, source, env)
618 return apply(self.parent.strfunc, args, kw)
621 """A factory class that will wrap up an arbitrary function
622 as an SCons-executable Action object.
624 The real heavy lifting here is done by the ActionCaller class.
625 We just collect the (positional and keyword) arguments that we're
626 called with and give them to the ActionCaller object we create,
627 so it can hang onto them until it needs them.
629 def __init__(self, actfunc, strfunc):
630 self.actfunc = actfunc
631 self.strfunc = strfunc
632 def __call__(self, *args, **kw):
633 ac = ActionCaller(self, args, kw)
634 return Action(ac, strfunction=ac.strfunction)