SCons.Action

1 """SCons.Action 2 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. 6 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. 10 11 A second-level base class is _ActionAction. This extends ActionBase 12 by providing the methods that can be used to show and perform an 13 action. True Action objects will subclass _ActionAction; Action 14 factory class objects will subclass ActionBase. 15 16 The heavy lifting is handled by subclasses for the different types of 17 actions we might execute: 18 19 CommandAction 20 CommandGeneratorAction 21 FunctionAction 22 ListAction 23 24 The subclasses supply the following public interface methods used by 25 other modules: 26 27 __call__() 28 THE public interface, "calling" an Action object executes the 29 command or Python function. This also takes care of printing 30 a pre-substitution command for debugging purposes. 31 32 get_contents() 33 Fetches the "contents" of an Action for signature calculation 34 plus the varlist. This is what gets MD5 checksummed to decide 35 if a target needs to be rebuilt because its action changed. 36 37 genstring() 38 Returns a string representation of the Action *without* 39 command substitution, but allows a CommandGeneratorAction to 40 generate the right action based on the specified target, 41 source and env. This is used by the Signature subsystem 42 (through the Executor) to obtain an (imprecise) representation 43 of the Action operation for informative purposes. 44 45 46 Subclasses also supply the following methods for internal use within 47 this module: 48 49 __str__() 50 Returns a string approximation of the Action; no variable 51 substitution is performed. 52 53 execute() 54 The internal method that really, truly, actually handles the 55 execution of a command or Python function. This is used so 56 that the __call__() methods can take care of displaying any 57 pre-substitution representations, and *then* execute an action 58 without worrying about the specific Actions involved. 59 60 get_presig() 61 Fetches the "contents" of a subclass for signature calculation. 62 The varlist is added to this to produce the Action's contents. 63 64 strfunction() 65 Returns a substituted string representation of the Action. 66 This is used by the _ActionAction.show() command to display the 67 command/function that will be executed to generate the target(s). 68 69 There is a related independent ActionCaller class that looks like a 70 regular Action, and which serves as a wrapper for arbitrary functions 71 that we want to let the user specify the arguments to now, but actually 72 execute later (when an out-of-date check determines that it's needed to 73 be executed, for example). Objects of this class are returned by an 74 ActionFactory class that provides a __call__() method as a convenient 75 way for wrapping up the functions. 76 77 """ 78 79 # Copyright (c) 2001 - 2014 The SCons Foundation 80 # 81 # Permission is hereby granted, free of charge, to any person obtaining 82 # a copy of this software and associated documentation files (the 83 # "Software"), to deal in the Software without restriction, including 84 # without limitation the rights to use, copy, modify, merge, publish, 85 # distribute, sublicense, and/or sell copies of the Software, and to 86 # permit persons to whom the Software is furnished to do so, subject to 87 # the following conditions: 88 # 89 # The above copyright notice and this permission notice shall be included 90 # in all copies or substantial portions of the Software. 91 # 92 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY 93 # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE 94 # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 95 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 96 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 97 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 98 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 99 100 __revision__ = "src/engine/SCons/Action.py 2014/09/27 12:51:43 garyo" 101 102 import SCons.compat 103 104 import dis 105 import os 106 # compat layer imports "cPickle" for us if it's available. 107 import pickle 108 import re 109 import sys 110 import subprocess 111 112 import SCons.Debug 113 from SCons.Debug import logInstanceCreation 114 import SCons.Errors 115 import SCons.Executor 116 import SCons.Util 117 import SCons.Subst 118 119 # we use these a lot, so try to optimize them 120 is_String = SCons.Util.is_String 121 is_List = SCons.Util.is_List 122

123 -class _null(object):

124 pass

125 126 print_actions = 1 127 execute_actions = 1 128 print_actions_presub = 0 129

130 -def rfile(n):

131 try: 132 return n.rfile() 133 except AttributeError: 134 return n

135

136 -def default_exitstatfunc(s):

137 return s

138 139 try: 140 SET_LINENO = dis.SET_LINENO 141 HAVE_ARGUMENT = dis.HAVE_ARGUMENT 142 except AttributeError: 143 remove_set_lineno_codes = lambda x: x 144 else:

145 - def remove_set_lineno_codes(code):

146 result = [] 147 n = len(code) 148 i = 0 149 while i < n: 150 c = code[i] 151 op = ord(c) 152 if op >= HAVE_ARGUMENT: 153 if op != SET_LINENO: 154 result.append(code[i:i+3]) 155 i = i+3 156 else: 157 result.append(c) 158 i = i+1 159 return ''.join(result)

160 161 strip_quotes = re.compile('^[\'"](.*)[\'"]$') 162 163

164 -def _callable_contents(obj):

165 """Return the signature contents of a callable Python object. 166 """ 167 try: 168 # Test if obj is a method. 169 return _function_contents(obj.im_func) 170 171 except AttributeError: 172 try: 173 # Test if obj is a callable object. 174 return _function_contents(obj.__call__.im_func) 175 176 except AttributeError: 177 try: 178 # Test if obj is a code object. 179 return _code_contents(obj) 180 181 except AttributeError: 182 # Test if obj is a function object. 183 return _function_contents(obj)

184 185

186 -def _object_contents(obj):

187 """Return the signature contents of any Python object. 188 189 We have to handle the case where object contains a code object 190 since it can be pickled directly. 191 """ 192 try: 193 # Test if obj is a method. 194 return _function_contents(obj.im_func) 195 196 except AttributeError: 197 try: 198 # Test if obj is a callable object. 199 return _function_contents(obj.__call__.im_func) 200 201 except AttributeError: 202 try: 203 # Test if obj is a code object. 204 return _code_contents(obj) 205 206 except AttributeError: 207 try: 208 # Test if obj is a function object. 209 return _function_contents(obj) 210 211 except AttributeError: 212 # Should be a pickable Python object. 213 try: 214 return pickle.dumps(obj) 215 except (pickle.PicklingError, TypeError): 216 # This is weird, but it seems that nested classes 217 # are unpickable. The Python docs say it should 218 # always be a PicklingError, but some Python 219 # versions seem to return TypeError. Just do 220 # the best we can. 221 return str(obj)

222 223

224 -def _code_contents(code):

225 """Return the signature contents of a code object. 226 227 By providing direct access to the code object of the 228 function, Python makes this extremely easy. Hooray! 229 230 Unfortunately, older versions of Python include line 231 number indications in the compiled byte code. Boo! 232 So we remove the line number byte codes to prevent 233 recompilations from moving a Python function. 234 """ 235 236 contents = [] 237 238 # The code contents depends on the number of local variables 239 # but not their actual names. 240 contents.append("%s,%s" % (code.co_argcount, len(code.co_varnames))) 241 try: 242 contents.append(",%s,%s" % (len(code.co_cellvars), len(code.co_freevars))) 243 except AttributeError: 244 # Older versions of Python do not support closures. 245 contents.append(",0,0") 246 247 # The code contents depends on any constants accessed by the 248 # function. Note that we have to call _object_contents on each 249 # constants because the code object of nested functions can 250 # show-up among the constants. 251 # 252 # Note that we also always ignore the first entry of co_consts 253 # which contains the function doc string. We assume that the 254 # function does not access its doc string. 255 contents.append(',(' + ','.join(map(_object_contents,code.co_consts[1:])) + ')') 256 257 # The code contents depends on the variable names used to 258 # accessed global variable, as changing the variable name changes 259 # the variable actually accessed and therefore changes the 260 # function result. 261 contents.append(',(' + ','.join(map(_object_contents,code.co_names)) + ')') 262 263 264 # The code contents depends on its actual code!!! 265 contents.append(',(' + str(remove_set_lineno_codes(code.co_code)) + ')') 266 267 return ''.join(contents)

268 269

270 -def _function_contents(func):

271 """Return the signature contents of a function.""" 272 273 contents = [_code_contents(func.func_code)] 274 275 # The function contents depends on the value of defaults arguments 276 if func.func_defaults: 277 contents.append(',(' + ','.join(map(_object_contents,func.func_defaults)) + ')') 278 else: 279 contents.append(',()') 280 281 # The function contents depends on the closure captured cell values. 282 try: 283 closure = func.func_closure or [] 284 except AttributeError: 285 # Older versions of Python do not support closures. 286 closure = [] 287 288 #xxx = [_object_contents(x.cell_contents) for x in closure] 289 try: 290 xxx = [_object_contents(x.cell_contents) for x in closure] 291 except AttributeError: 292 xxx = [] 293 contents.append(',(' + ','.join(xxx) + ')') 294 295 return ''.join(contents)

296 297

298 -def _actionAppend(act1, act2):

299 # This function knows how to slap two actions together. 300 # Mainly, it handles ListActions by concatenating into 301 # a single ListAction. 302 a1 = Action(act1) 303 a2 = Action(act2) 304 if a1 is None: 305 return a2 306 if a2 is None: 307 return a1 308 if isinstance(a1, ListAction): 309 if isinstance(a2, ListAction): 310 return ListAction(a1.list + a2.list) 311 else: 312 return ListAction(a1.list + [ a2 ]) 313 else: 314 if isinstance(a2, ListAction): 315 return ListAction([ a1 ] + a2.list) 316 else: 317 return ListAction([ a1, a2 ])

318

319 -def _do_create_keywords(args, kw):

320 """This converts any arguments after the action argument into 321 their equivalent keywords and adds them to the kw argument. 322 """ 323 v = kw.get('varlist', ()) 324 # prevent varlist="FOO" from being interpreted as ['F', 'O', 'O'] 325 if is_String(v): v = (v,) 326 kw['varlist'] = tuple(v) 327 if args: 328 # turn positional args into equivalent keywords 329 cmdstrfunc = args[0] 330 if cmdstrfunc is None or is_String(cmdstrfunc): 331 kw['cmdstr'] = cmdstrfunc 332 elif callable(cmdstrfunc): 333 kw['strfunction'] = cmdstrfunc 334 else: 335 raise SCons.Errors.UserError( 336 'Invalid command display variable type. ' 337 'You must either pass a string or a callback which ' 338 'accepts (target, source, env) as parameters.') 339 if len(args) > 1: 340 kw['varlist'] = tuple(SCons.Util.flatten(args[1:])) + kw['varlist'] 341 if kw.get('strfunction', _null) is not _null \ 342 and kw.get('cmdstr', _null) is not _null: 343 raise SCons.Errors.UserError( 344 'Cannot have both strfunction and cmdstr args to Action()')

345

346 -def _do_create_action(act, kw):

347 """This is the actual "implementation" for the 348 Action factory method, below. This handles the 349 fact that passing lists to Action() itself has 350 different semantics than passing lists as elements 351 of lists. 352 353 The former will create a ListAction, the latter 354 will create a CommandAction by converting the inner 355 list elements to strings.""" 356 357 if isinstance(act, ActionBase): 358 return act 359 360 if is_List(act): 361 return CommandAction(act, **kw) 362 363 if callable(act): 364 try: 365 gen = kw['generator'] 366 del kw['generator'] 367 except KeyError: 368 gen = 0 369 if gen: 370 action_type = CommandGeneratorAction 371 else: 372 action_type = FunctionAction 373 return action_type(act, kw) 374 375 if is_String(act): 376 var=SCons.Util.get_environment_var(act) 377 if var: 378 # This looks like a string that is purely an Environment 379 # variable reference, like "$FOO" or "${FOO}". We do 380 # something special here...we lazily evaluate the contents 381 # of that Environment variable, so a user could put something 382 # like a function or a CommandGenerator in that variable 383 # instead of a string. 384 return LazyAction(var, kw) 385 commands = str(act).split('\n') 386 if len(commands) == 1: 387 return CommandAction(commands[0], **kw) 388 # The list of string commands may include a LazyAction, so we 389 # reprocess them via _do_create_list_action. 390 return _do_create_list_action(commands, kw) 391 # Catch a common error case with a nice message: 392 if isinstance(act, int) or isinstance(act, float): 393 raise TypeError("Don't know how to create an Action from a number (%s)"%act) 394 # Else fail silently (???) 395 return None

396

397 -def _do_create_list_action(act, kw):

398 """A factory for list actions. Convert the input list into Actions 399 and then wrap them in a ListAction.""" 400 acts = [] 401 for a in act: 402 aa = _do_create_action(a, kw) 403 if aa is not None: acts.append(aa) 404 if not acts: 405 return ListAction([]) 406 elif len(acts) == 1: 407 return acts[0] 408 else: 409 return ListAction(acts)

410

411 -def Action(act, *args, **kw):

412 """A factory for action objects.""" 413 # Really simple: the _do_create_* routines do the heavy lifting. 414 _do_create_keywords(args, kw) 415 if is_List(act): 416 return _do_create_list_action(act, kw) 417 return _do_create_action(act, kw)

418

419 -class ActionBase(object):

420 """Base class for all types of action objects that can be held by 421 other objects (Builders, Executors, etc.) This provides the 422 common methods for manipulating and combining those actions.""" 423

424 - def __cmp__(self, other):

425 return cmp(self.__dict__, other)

426

427 - def no_batch_key(self, env, target, source):

428 return None

429 430 batch_key = no_batch_key 431

432 - def genstring(self, target, source, env):

433 return str(self)

434

435 - def get_contents(self, target, source, env):

436 result = [ self.get_presig(target, source, env) ] 437 # This should never happen, as the Action() factory should wrap 438 # the varlist, but just in case an action is created directly, 439 # we duplicate this check here. 440 vl = self.get_varlist(target, source, env) 441 if is_String(vl): vl = (vl,) 442 for v in vl: 443 # do the subst this way to ignore $(...$) parts: 444 result.append(env.subst_target_source('${'+v+'}', SCons.Subst.SUBST_SIG, target, source)) 445 return ''.join(result)

446

447 - def __add__(self, other):

448 return _actionAppend(self, other)

449

450 - def __radd__(self, other):

451 return _actionAppend(other, self)

452

453 - def presub_lines(self, env):

454 # CommandGeneratorAction needs a real environment 455 # in order to return the proper string here, since 456 # it may call LazyAction, which looks up a key 457 # in that env. So we temporarily remember the env here, 458 # and CommandGeneratorAction will use this env 459 # when it calls its _generate method. 460 self.presub_env = env 461 lines = str(self).split('\n') 462 self.presub_env = None # don't need this any more 463 return lines

464

465 - def get_varlist(self, target, source, env, executor=None):

466 return self.varlist

467

468 - def get_targets(self, env, executor):

469 """ 470 Returns the type of targets ($TARGETS, $CHANGED_TARGETS) used 471 by this action. 472 """ 473 return self.targets

474

475 -class _ActionAction(ActionBase):

476 """Base class for actions that create output objects."""

477 - def __init__(self, cmdstr=_null, strfunction=_null, varlist=(), 478 presub=_null, chdir=None, exitstatfunc=None, 479 batch_key=None, targets='$TARGETS', 480 **kw):

481 self.cmdstr = cmdstr 482 if strfunction is not _null: 483 if strfunction is None: 484 self.cmdstr = None 485 else: 486 self.strfunction = strfunction 487 self.varlist = varlist 488 self.presub = presub 489 self.chdir = chdir 490 if not exitstatfunc: 491 exitstatfunc = default_exitstatfunc 492 self.exitstatfunc = exitstatfunc 493 494 self.targets = targets 495 496 if batch_key: 497 if not callable(batch_key): 498 # They have set batch_key, but not to their own 499 # callable. The default behavior here will batch 500 # *all* targets+sources using this action, separated 501 # for each construction environment. 502 def default_batch_key(self, env, target, source): 503 return (id(self), id(env))

504 batch_key = default_batch_key 505 SCons.Util.AddMethod(self, batch_key, 'batch_key')

506

507 - def print_cmd_line(self, s, target, source, env):

508 # In python 3, and in some of our tests, sys.stdout is 509 # a String io object, and it takes unicode strings only 510 # In other cases it's a regular Python 2.x file object 511 # which takes strings (bytes), and if you pass those a 512 # unicode object they try to decode with 'ascii' codec 513 # which fails if the cmd line has any hi-bit-set chars. 514 # This code assumes s is a regular string, but should 515 # work if it's unicode too. 516 try: 517 sys.stdout.write(unicode(s + "\n")) 518 except UnicodeDecodeError: 519 sys.stdout.write(s + "\n")

520

521 - def __call__(self, target, source, env, 522 exitstatfunc=_null, 523 presub=_null, 524 show=_null, 525 execute=_null, 526 chdir=_null, 527 executor=None):

528 if not is_List(target): 529 target = [target] 530 if not is_List(source): 531 source = [source] 532 533 if presub is _null: 534 presub = self.presub 535 if presub is _null: 536 presub = print_actions_presub 537 if exitstatfunc is _null: exitstatfunc = self.exitstatfunc 538 if show is _null: show = print_actions 539 if execute is _null: execute = execute_actions 540 if chdir is _null: chdir = self.chdir 541 save_cwd = None 542 if chdir: 543 save_cwd = os.getcwd() 544 try: 545 chdir = str(chdir.abspath) 546 except AttributeError: 547 if not is_String(chdir): 548 if executor: 549 chdir = str(executor.batches[0].targets[0].dir) 550 else: 551 chdir = str(target[0].dir) 552 if presub: 553 if executor: 554 target = executor.get_all_targets() 555 source = executor.get_all_sources() 556 t = ' and '.join(map(str, target)) 557 l = '\n '.join(self.presub_lines(env)) 558 out = u"Building %s with action:\n %s\n" % (t, l) 559 sys.stdout.write(out) 560 cmd = None 561 if show and self.strfunction: 562 if executor: 563 target = executor.get_all_targets() 564 source = executor.get_all_sources() 565 try: 566 cmd = self.strfunction(target, source, env, executor) 567 except TypeError: 568 cmd = self.strfunction(target, source, env) 569 if cmd: 570 if chdir: 571 cmd = ('os.chdir(%s)\n' % repr(chdir)) + cmd 572 try: 573 get = env.get 574 except AttributeError: 575 print_func = self.print_cmd_line 576 else: 577 print_func = get('PRINT_CMD_LINE_FUNC') 578 if not print_func: 579 print_func = self.print_cmd_line 580 print_func(cmd, target, source, env) 581 stat = 0 582 if execute: 583 if chdir: 584 os.chdir(chdir) 585 try: 586 stat = self.execute(target, source, env, executor=executor) 587 if isinstance(stat, SCons.Errors.BuildError): 588 s = exitstatfunc(stat.status) 589 if s: 590 stat.status = s 591 else: 592 stat = s 593 else: 594 stat = exitstatfunc(stat) 595 finally: 596 if save_cwd: 597 os.chdir(save_cwd) 598 if cmd and save_cwd: 599 print_func('os.chdir(%s)' % repr(save_cwd), target, source, env) 600 601 return stat

602 603

604 -def _string_from_cmd_list(cmd_list):

605 """Takes a list of command line arguments and returns a pretty 606 representation for printing.""" 607 cl = [] 608 for arg in map(str, cmd_list): 609 if ' ' in arg or '\t' in arg: 610 arg = '"' + arg + '"' 611 cl.append(arg) 612 return ' '.join(cl)

613 614 # A fiddlin' little function that has an 'import SCons.Environment' which 615 # can't be moved to the top level without creating an import loop. Since 616 # this import creates a local variable named 'SCons', it blocks access to 617 # the global variable, so we move it here to prevent complaints about local 618 # variables being used uninitialized. 619 default_ENV = None

620 -def get_default_ENV(env):

621 global default_ENV 622 try: 623 return env['ENV'] 624 except KeyError: 625 if not default_ENV: 626 import SCons.Environment 627 # This is a hideously expensive way to get a default shell 628 # environment. What it really should do is run the platform 629 # setup to get the default ENV. Fortunately, it's incredibly 630 # rare for an Environment not to have a shell environment, so 631 # we're not going to worry about it overmuch. 632 default_ENV = SCons.Environment.Environment()['ENV'] 633 return default_ENV

634 635 # This function is still in draft mode. We're going to need something like 636 # it in the long run as more and more places use subprocess, but I'm sure 637 # it'll have to be tweaked to get the full desired functionality. 638 # one special arg (so far?), 'error', to tell what to do with exceptions.

639 -def _subproc(scons_env, cmd, error = 'ignore', **kw):

640 """Do common setup for a subprocess.Popen() call""" 641 # allow std{in,out,err} to be "'devnull'" 642 io = kw.get('stdin') 643 if is_String(io) and io == 'devnull': 644 kw['stdin'] = open(os.devnull) 645 io = kw.get('stdout') 646 if is_String(io) and io == 'devnull': 647 kw['stdout'] = open(os.devnull, 'w') 648 io = kw.get('stderr') 649 if is_String(io) and io == 'devnull': 650 kw['stderr'] = open(os.devnull, 'w') 651 652 # Figure out what shell environment to use 653 ENV = kw.get('env', None) 654 if ENV is None: ENV = get_default_ENV(scons_env) 655 656 # Ensure that the ENV values are all strings: 657 new_env = {} 658 for key, value in ENV.items(): 659 if is_List(value): 660 # If the value is a list, then we assume it is a path list, 661 # because that's a pretty common list-like value to stick 662 # in an environment variable: 663 value = SCons.Util.flatten_sequence(value) 664 new_env[key] = os.pathsep.join(map(str, value)) 665 else: 666 # It's either a string or something else. If it's a string, 667 # we still want to call str() because it might be a *Unicode* 668 # string, which makes subprocess.Popen() gag. If it isn't a 669 # string or a list, then we just coerce it to a string, which 670 # is the proper way to handle Dir and File instances and will 671 # produce something reasonable for just about everything else: 672 new_env[key] = str(value) 673 kw['env'] = new_env 674 675 try: 676 return subprocess.Popen(cmd, **kw) 677 except EnvironmentError, e: 678 if error == 'raise': raise 679 # return a dummy Popen instance that only returns error 680 class dummyPopen(object): 681 def __init__(self, e): self.exception = e 682 def communicate(self,input=None): return ('','') 683 def wait(self): return -self.exception.errno 684 stdin = None 685 class f(object): 686 def read(self): return '' 687 def readline(self): return '' 688 def __iter__(self): return iter(())

689 stdout = stderr = f() 690 return dummyPopen(e) 691

692 -class CommandAction(_ActionAction):

693 """Class for command-execution actions."""

694 - def __init__(self, cmd, **kw):

695 # Cmd can actually be a list or a single item; if it's a 696 # single item it should be the command string to execute; if a 697 # list then it should be the words of the command string to 698 # execute. Only a single command should be executed by this 699 # object; lists of commands should be handled by embedding 700 # these objects in a ListAction object (which the Action() 701 # factory above does). cmd will be passed to 702 # Environment.subst_list() for substituting environment 703 # variables. 704 if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.CommandAction') 705 706 _ActionAction.__init__(self, **kw) 707 if is_List(cmd): 708 if list(filter(is_List, cmd)): 709 raise TypeError("CommandAction should be given only " \ 710 "a single command") 711 self.cmd_list = cmd

712

713 - def __str__(self):

714 if is_List(self.cmd_list): 715 return ' '.join(map(str, self.cmd_list)) 716 return str(self.cmd_list)

717

718 - def process(self, target, source, env, executor=None):

719 if executor: 720 result = env.subst_list(self.cmd_list, 0, executor=executor) 721 else: 722 result = env.subst_list(self.cmd_list, 0, target, source) 723 silent = None 724 ignore = None 725 while True: 726 try: c = result[0][0][0] 727 except IndexError: c = None 728 if c == '@': silent = 1 729 elif c == '-': ignore = 1 730 else: break 731 result[0][0] = result[0][0][1:] 732 try: 733 if not result[0][0]: 734 result[0] = result[0][1:] 735 except IndexError: 736 pass 737 return result, ignore, silent

738

739 - def strfunction(self, target, source, env, executor=None):

740 if self.cmdstr is None: 741 return None 742 if self.cmdstr is not _null: 743 from SCons.Subst import SUBST_RAW 744 if executor: 745 c = env.subst(self.cmdstr, SUBST_RAW, executor=executor) 746 else: 747 c = env.subst(self.cmdstr, SUBST_RAW, target, source) 748 if c: 749 return c 750 cmd_list, ignore, silent = self.process(target, source, env, executor) 751 if silent: 752 return '' 753 return _string_from_cmd_list(cmd_list[0])

754

755 - def execute(self, target, source, env, executor=None):

756 """Execute a command action. 757 758 This will handle lists of commands as well as individual commands, 759 because construction variable substitution may turn a single 760 "command" into a list. This means that this class can actually 761 handle lists of commands, even though that's not how we use it 762 externally. 763 """ 764 escape_list = SCons.Subst.escape_list 765 flatten_sequence = SCons.Util.flatten_sequence 766 767 try: 768 shell = env['SHELL'] 769 except KeyError: 770 raise SCons.Errors.UserError('Missing SHELL construction variable.') 771 772 try: 773 spawn = env['SPAWN'] 774 except KeyError: 775 raise SCons.Errors.UserError('Missing SPAWN construction variable.') 776 else: 777 if is_String(spawn): 778 spawn = env.subst(spawn, raw=1, conv=lambda x: x) 779 780 escape = env.get('ESCAPE', lambda x: x) 781 782 ENV = get_default_ENV(env) 783 784 # Ensure that the ENV values are all strings: 785 for key, value in ENV.items(): 786 if not is_String(value): 787 if is_List(value): 788 # If the value is a list, then we assume it is a 789 # path list, because that's a pretty common list-like 790 # value to stick in an environment variable: 791 value = flatten_sequence(value) 792 ENV[key] = os.pathsep.join(map(str, value)) 793 else: 794 # If it isn't a string or a list, then we just coerce 795 # it to a string, which is the proper way to handle 796 # Dir and File instances and will produce something 797 # reasonable for just about everything else: 798 ENV[key] = str(value) 799 800 if executor: 801 target = executor.get_all_targets() 802 source = executor.get_all_sources() 803 cmd_list, ignore, silent = self.process(target, list(map(rfile, source)), env, executor) 804 805 # Use len() to filter out any "command" that's zero-length. 806 for cmd_line in filter(len, cmd_list): 807 # Escape the command line for the interpreter we are using. 808 cmd_line = escape_list(cmd_line, escape) 809 result = spawn(shell, escape, cmd_line[0], cmd_line, ENV) 810 if not ignore and result: 811 msg = "Error %s" % result 812 return SCons.Errors.BuildError(errstr=msg, 813 status=result, 814 action=self, 815 command=cmd_line) 816 return 0

817

818 - def get_presig(self, target, source, env, executor=None):

819 """Return the signature contents of this action's command line. 820 821 This strips $(-$) and everything in between the string, 822 since those parts don't affect signatures. 823 """ 824 from SCons.Subst import SUBST_SIG 825 cmd = self.cmd_list 826 if is_List(cmd): 827 cmd = ' '.join(map(str, cmd)) 828 else: 829 cmd = str(cmd) 830 if executor: 831 return env.subst_target_source(cmd, SUBST_SIG, executor=executor) 832 else: 833 return env.subst_target_source(cmd, SUBST_SIG, target, source)

834

835 - def get_implicit_deps(self, target, source, env, executor=None):

836 icd = env.get('IMPLICIT_COMMAND_DEPENDENCIES', True) 837 if is_String(icd) and icd[:1] == '$': 838 icd = env.subst(icd) 839 if not icd or icd in ('0', 'None'): 840 return [] 841 from SCons.Subst import SUBST_SIG 842 if executor: 843 cmd_list = env.subst_list(self.cmd_list, SUBST_SIG, executor=executor) 844 else: 845 cmd_list = env.subst_list(self.cmd_list, SUBST_SIG, target, source) 846 res = [] 847 for cmd_line in cmd_list: 848 if cmd_line: 849 d = str(cmd_line[0]) 850 m = strip_quotes.match(d) 851 if m: 852 d = m.group(1) 853 d = env.WhereIs(d) 854 if d: 855 res.append(env.fs.File(d)) 856 return res

857

858 -class CommandGeneratorAction(ActionBase):

859 """Class for command-generator actions."""

860 - def __init__(self, generator, kw):

861 if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.CommandGeneratorAction') 862 self.generator = generator 863 self.gen_kw = kw 864 self.varlist = kw.get('varlist', ()) 865 self.targets = kw.get('targets', '$TARGETS')

866

867 - def _generate(self, target, source, env, for_signature, executor=None):

868 # ensure that target is a list, to make it easier to write 869 # generator functions: 870 if not is_List(target): 871 target = [target] 872 873 if executor: 874 target = executor.get_all_targets() 875 source = executor.get_all_sources() 876 ret = self.generator(target=target, 877 source=source, 878 env=env, 879 for_signature=for_signature) 880 gen_cmd = Action(ret, **self.gen_kw) 881 if not gen_cmd: 882 raise SCons.Errors.UserError("Object returned from command generator: %s cannot be used to create an Action." % repr(ret)) 883 return gen_cmd

884

885 - def __str__(self):

886 try: 887 env = self.presub_env 888 except AttributeError: 889 env = None 890 if env is None: 891 env = SCons.Defaults.DefaultEnvironment() 892 act = self._generate([], [], env, 1) 893 return str(act)

894

895 - def batch_key(self, env, target, source):

896 return self._generate(target, source, env, 1).batch_key(env, target, source)

897

898 - def genstring(self, target, source, env, executor=None):

899 return self._generate(target, source, env, 1, executor).genstring(target, source, env)

900

901 - def __call__(self, target, source, env, exitstatfunc=_null, presub=_null, 902 show=_null, execute=_null, chdir=_null, executor=None):

903 act = self._generate(target, source, env, 0, executor) 904 if act is None: 905 raise SCons.Errors.UserError("While building `%s': " 906 "Cannot deduce file extension from source files: %s" 907 % (repr(list(map(str, target))), repr(list(map(str, source))))) 908 return act(target, source, env, exitstatfunc, presub, 909 show, execute, chdir, executor)

910

911 - def get_presig(self, target, source, env, executor=None):

912 """Return the signature contents of this action's command line. 913 914 This strips $(-$) and everything in between the string, 915 since those parts don't affect signatures. 916 """ 917 return self._generate(target, source, env, 1, executor).get_presig(target, source, env)

918

919 - def get_implicit_deps(self, target, source, env, executor=None):

920 return self._generate(target, source, env, 1, executor).get_implicit_deps(target, source, env)

921

922 - def get_varlist(self, target, source, env, executor=None):

923 return self._generate(target, source, env, 1, executor).get_varlist(target, source, env, executor)

924

925 - def get_targets(self, env, executor):

926 return self._generate(None, None, env, 1, executor).get_targets(env, executor)

927 928 929 930 # A LazyAction is a kind of hybrid generator and command action for 931 # strings of the form "$VAR". These strings normally expand to other 932 # strings (think "$CCCOM" to "$CC -c -o $TARGET $SOURCE"), but we also 933 # want to be able to replace them with functions in the construction 934 # environment. Consequently, we want lazy evaluation and creation of 935 # an Action in the case of the function, but that's overkill in the more 936 # normal case of expansion to other strings. 937 # 938 # So we do this with a subclass that's both a generator *and* 939 # a command action. The overridden methods all do a quick check 940 # of the construction variable, and if it's a string we just call 941 # the corresponding CommandAction method to do the heavy lifting. 942 # If not, then we call the same-named CommandGeneratorAction method. 943 # The CommandGeneratorAction methods work by using the overridden 944 # _generate() method, that is, our own way of handling "generation" of 945 # an action based on what's in the construction variable. 946

947 -class LazyAction(CommandGeneratorAction, CommandAction):

948

949 - def __init__(self, var, kw):

950 if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.LazyAction') 951 #FUTURE CommandAction.__init__(self, '${'+var+'}', **kw) 952 CommandAction.__init__(self, '${'+var+'}', **kw) 953 self.var = SCons.Util.to_String(var) 954 self.gen_kw = kw

955

956 - def get_parent_class(self, env):

957 c = env.get(self.var) 958 if is_String(c) and not '\n' in c: 959 return CommandAction 960 return CommandGeneratorAction

961

962 - def _generate_cache(self, env):

963 if env: 964 c = env.get(self.var, '') 965 else: 966 c = '' 967 gen_cmd = Action(c, **self.gen_kw) 968 if not gen_cmd: 969 raise SCons.Errors.UserError("$%s value %s cannot be used to create an Action." % (self.var, repr(c))) 970 return gen_cmd

971

972 - def _generate(self, target, source, env, for_signature, executor=None):

973 return self._generate_cache(env)

974

975 - def __call__(self, target, source, env, *args, **kw):

976 c = self.get_parent_class(env) 977 return c.__call__(self, target, source, env, *args, **kw)

978

979 - def get_presig(self, target, source, env):

980 c = self.get_parent_class(env) 981 return c.get_presig(self, target, source, env)

982

983 - def get_varlist(self, target, source, env, executor=None):

984 c = self.get_parent_class(env) 985 return c.get_varlist(self, target, source, env, executor)

986 987

988 -class FunctionAction(_ActionAction):

989 """Class for Python function actions.""" 990

991 - def __init__(self, execfunction, kw):

992 if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.FunctionAction') 993 994 self.execfunction = execfunction 995 try: 996 self.funccontents = _callable_contents(execfunction) 997 except AttributeError: 998 try: 999 # See if execfunction will do the heavy lifting for us. 1000 self.gc = execfunction.get_contents 1001 except AttributeError: 1002 # This is weird, just do the best we can. 1003 self.funccontents = _object_contents(execfunction) 1004 1005 _ActionAction.__init__(self, **kw)

1006

1007 - def function_name(self):

1008 try: 1009 return self.execfunction.__name__ 1010 except AttributeError: 1011 try: 1012 return self.execfunction.__class__.__name__ 1013 except AttributeError: 1014 return "unknown_python_function"

1015

1016 - def strfunction(self, target, source, env, executor=None):

1017 if self.cmdstr is None: 1018 return None 1019 if self.cmdstr is not _null: 1020 from SCons.Subst import SUBST_RAW 1021 if executor: 1022 c = env.subst(self.cmdstr, SUBST_RAW, executor=executor) 1023 else: 1024 c = env.subst(self.cmdstr, SUBST_RAW, target, source) 1025 if c: 1026 return c 1027 def array(a): 1028 def quote(s): 1029 try: 1030 str_for_display = s.str_for_display 1031 except AttributeError: 1032 s = repr(s) 1033 else: 1034 s = str_for_display() 1035 return s

1036 return '[' + ", ".join(map(quote, a)) + ']'

1037 try: 1038 strfunc = self.execfunction.strfunction 1039 except AttributeError: 1040 pass 1041 else: 1042 if strfunc is None: 1043 return None 1044 if callable(strfunc): 1045 return strfunc(target, source, env) 1046 name = self.function_name() 1047 tstr = array(target) 1048 sstr = array(source) 1049 return "%s(%s, %s)" % (name, tstr, sstr) 1050

1051 - def __str__(self):

1052 name = self.function_name() 1053 if name == 'ActionCaller': 1054 return str(self.execfunction) 1055 return "%s(target, source, env)" % name

1056

1057 - def execute(self, target, source, env, executor=None):

1058 exc_info = (None,None,None) 1059 try: 1060 if executor: 1061 target = executor.get_all_targets() 1062 source = executor.get_all_sources() 1063 rsources = list(map(rfile, source)) 1064 try: 1065 result = self.execfunction(target=target, source=rsources, env=env) 1066 except KeyboardInterrupt, e: 1067 raise 1068 except SystemExit, e: 1069 raise 1070 except Exception, e: 1071 result = e 1072 exc_info = sys.exc_info() 1073 1074 if result: 1075 result = SCons.Errors.convert_to_BuildError(result, exc_info) 1076 result.node=target 1077 result.action=self 1078 try: 1079 result.command=self.strfunction(target, source, env, executor) 1080 except TypeError: 1081 result.command=self.strfunction(target, source, env) 1082 1083 # FIXME: This maintains backward compatibility with respect to 1084 # which type of exceptions were returned by raising an 1085 # exception and which ones were returned by value. It would 1086 # probably be best to always return them by value here, but 1087 # some codes do not check the return value of Actions and I do 1088 # not have the time to modify them at this point. 1089 if (exc_info[1] and 1090 not isinstance(exc_info[1],EnvironmentError)): 1091 raise result 1092 1093 return result 1094 finally: 1095 # Break the cycle between the traceback object and this 1096 # function stack frame. See the sys.exc_info() doc info for 1097 # more information about this issue. 1098 del exc_info

1099 1100

1101 - def get_presig(self, target, source, env):

1102 """Return the signature contents of this callable action.""" 1103 try: 1104 return self.gc(target, source, env) 1105 except AttributeError: 1106 return self.funccontents

1107

1108 - def get_implicit_deps(self, target, source, env):

1109 return []

1110

1111 -class ListAction(ActionBase):

1112 """Class for lists of other actions."""

1113 - def __init__(self, actionlist):

1114 if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.ListAction') 1115 def list_of_actions(x): 1116 if isinstance(x, ActionBase): 1117 return x 1118 return Action(x)

1119 self.list = list(map(list_of_actions, actionlist)) 1120 # our children will have had any varlist 1121 # applied; we don't need to do it again 1122 self.varlist = () 1123 self.targets = '$TARGETS'

1124

1125 - def genstring(self, target, source, env):

1126 return '\n'.join([a.genstring(target, source, env) for a in self.list])

1127

1128 - def __str__(self):

1129 return '\n'.join(map(str, self.list))

1130

1131 - def presub_lines(self, env):

1132 return SCons.Util.flatten_sequence( 1133 [a.presub_lines(env) for a in self.list])

1134

1135 - def get_presig(self, target, source, env):

1136 """Return the signature contents of this action list. 1137 1138 Simple concatenation of the signatures of the elements. 1139 """ 1140 return "".join([x.get_contents(target, source, env) for x in self.list])

1141

1142 - def __call__(self, target, source, env, exitstatfunc=_null, presub=_null, 1143 show=_null, execute=_null, chdir=_null, executor=None):

1144 if executor: 1145 target = executor.get_all_targets() 1146 source = executor.get_all_sources() 1147 for act in self.list: 1148 stat = act(target, source, env, exitstatfunc, presub, 1149 show, execute, chdir, executor) 1150 if stat: 1151 return stat 1152 return 0

1153

1154 - def get_implicit_deps(self, target, source, env):

1155 result = [] 1156 for act in self.list: 1157 result.extend(act.get_implicit_deps(target, source, env)) 1158 return result

1159

1160 - def get_varlist(self, target, source, env, executor=None):

1161 result = SCons.Util.OrderedDict() 1162 for act in self.list: 1163 for var in act.get_varlist(target, source, env, executor): 1164 result[var] = True 1165 return list(result.keys())

1166

1167 -class ActionCaller(object):

1168 """A class for delaying calling an Action function with specific 1169 (positional and keyword) arguments until the Action is actually 1170 executed. 1171 1172 This class looks to the rest of the world like a normal Action object, 1173 but what it's really doing is hanging on to the arguments until we 1174 have a target, source and env to use for the expansion. 1175 """

1176 - def __init__(self, parent, args, kw):

1177 self.parent = parent 1178 self.args = args 1179 self.kw = kw

1180

1181 - def get_contents(self, target, source, env):

1182 actfunc = self.parent.actfunc 1183 try: 1184 # "self.actfunc" is a function. 1185 contents = str(actfunc.func_code.co_code) 1186 except AttributeError: 1187 # "self.actfunc" is a callable object. 1188 try: 1189 contents = str(actfunc.__call__.im_func.func_code.co_code) 1190 except AttributeError: 1191 # No __call__() method, so it might be a builtin 1192 # or something like that. Do the best we can. 1193 contents = str(actfunc) 1194 contents = remove_set_lineno_codes(contents) 1195 return contents

1196

1197 - def subst(self, s, target, source, env):

1198 # If s is a list, recursively apply subst() 1199 # to every element in the list 1200 if is_List(s): 1201 result = [] 1202 for elem in s: 1203 result.append(self.subst(elem, target, source, env)) 1204 return self.parent.convert(result) 1205 1206 # Special-case hack: Let a custom function wrapped in an 1207 # ActionCaller get at the environment through which the action 1208 # was called by using this hard-coded value as a special return. 1209 if s == '$__env__': 1210 return env 1211 elif is_String(s): 1212 return env.subst(s, 1, target, source) 1213 return self.parent.convert(s)

1214

1215 - def subst_args(self, target, source, env):

1216 return [self.subst(x, target, source, env) for x in self.args]

1217

1218 - def subst_kw(self, target, source, env):

1219 kw = {} 1220 for key in self.kw.keys(): 1221 kw[key] = self.subst(self.kw[key], target, source, env) 1222 return kw

1223

1224 - def __call__(self, target, source, env, executor=None):

1225 args = self.subst_args(target, source, env) 1226 kw = self.subst_kw(target, source, env) 1227 return self.parent.actfunc(*args, **kw)

1228

1229 - def strfunction(self, target, source, env):

1230 args = self.subst_args(target, source, env) 1231 kw = self.subst_kw(target, source, env) 1232 return self.parent.strfunc(*args, **kw)

1233

1234 - def __str__(self):

1235 return self.parent.strfunc(*self.args, **self.kw)

1236

1237 -class ActionFactory(object):

1238 """A factory class that will wrap up an arbitrary function 1239 as an SCons-executable Action object. 1240 1241 The real heavy lifting here is done by the ActionCaller class. 1242 We just collect the (positional and keyword) arguments that we're 1243 called with and give them to the ActionCaller object we create, 1244 so it can hang onto them until it needs them. 1245 """

1246 - def __init__(self, actfunc, strfunc, convert=lambda x: x):

1247 self.actfunc = actfunc 1248 self.strfunc = strfunc 1249 self.convert = convert

1250

1251 - def __call__(self, *args, **kw):

1252 ac = ActionCaller(self, args, kw) 1253 action = Action(ac, strfunction=ac.strfunction) 1254 return action

1255 1256 # Local Variables: 1257 # tab-width:4 1258 # indent-tabs-mode:nil 1259 # End: 1260 # vim: set expandtab tabstop=4 shiftwidth=4: 1261

Source Code for Module SCons.Action