waflib/Context.py

   1 #!/usr/bin/env python
   2 # encoding: utf-8
   3 # Thomas Nagy, 2010-2018 (ita)
   4
   5 """
   6 Classes and functions enabling the command system
   7 """
   8
   9 import os, re, imp, sys
  10 from waflib import Utils, Errors, Logs
  11 import waflib.Node
  12
  13 # the following 3 constants are updated on each new release (do not touch)
  14 HEXVERSION=0x2000c00
  15 """Constant updated on new releases"""
  16
  17 WAFVERSION="2.0.12"
  18 """Constant updated on new releases"""
  19
  20 WAFREVISION="54841218840ffa34fddf834680a5a17db69caa12"
  21 """Git revision when the waf version is updated"""
  22
  23 ABI = 20
  24 """Version of the build data cache file format (used in :py:const:`waflib.Context.DBFILE`)"""
  25
  26 DBFILE = '.wafpickle-%s-%d-%d' % (sys.platform, sys.hexversion, ABI)
  27 """Name of the pickle file for storing the build data"""
  28
  29 APPNAME = 'APPNAME'
  30 """Default application name (used by ``waf dist``)"""
  31
  32 VERSION = 'VERSION'
  33 """Default application version (used by ``waf dist``)"""
  34
  35 TOP  = 'top'
  36 """The variable name for the top-level directory in wscript files"""
  37
  38 OUT  = 'out'
  39 """The variable name for the output directory in wscript files"""
  40
  41 WSCRIPT_FILE = 'wscript'
  42 """Name of the waf script files"""
  43
  44 launch_dir = ''
  45 """Directory from which waf has been called"""
  46 run_dir = ''
  47 """Location of the wscript file to use as the entry point"""
  48 top_dir = ''
  49 """Location of the project directory (top), if the project was configured"""
  50 out_dir = ''
  51 """Location of the build directory (out), if the project was configured"""
  52 waf_dir = ''
  53 """Directory containing the waf modules"""
  54
  55 default_encoding = Utils.console_encoding()
  56 """Encoding to use when reading outputs from other processes"""
  57
  58 g_module = None
  59 """
  60 Module representing the top-level wscript file (see :py:const:`waflib.Context.run_dir`)
  61 """
  62
  63 STDOUT = 1
  64 STDERR = -1
  65 BOTH   = 0
  66
  67 classes = []
  68 """
  69 List of :py:class:`waflib.Context.Context` subclasses that can be used as waf commands. The classes
  70 are added automatically by a metaclass.
  71 """
  72
  73 def create_context(cmd_name, *k, **kw):
  74         """
  75         Returns a new :py:class:`waflib.Context.Context` instance corresponding to the given command.
  76         Used in particular by :py:func:`waflib.Scripting.run_command`
  77
  78         :param cmd_name: command name
  79         :type cmd_name: string
  80         :param k: arguments to give to the context class initializer
  81         :type k: list
  82         :param k: keyword arguments to give to the context class initializer
  83         :type k: dict
  84         :return: Context object
  85         :rtype: :py:class:`waflib.Context.Context`
  86         """
  87         for x in classes:
  88                 if x.cmd == cmd_name:
  89                         return x(*k, **kw)
  90         ctx = Context(*k, **kw)
  91         ctx.fun = cmd_name
  92         return ctx
  93
  94 class store_context(type):
  95         """
  96         Metaclass that registers command classes into the list :py:const:`waflib.Context.classes`
  97         Context classes must provide an attribute 'cmd' representing the command name, and a function
  98         attribute 'fun' representing the function name that the command uses.
  99         """
 100         def __init__(cls, name, bases, dct):
 101                 super(store_context, cls).__init__(name, bases, dct)
 102                 name = cls.__name__
 103
 104                 if name in ('ctx', 'Context'):
 105                         return
 106
 107                 try:
 108                         cls.cmd
 109                 except AttributeError:
 110                         raise Errors.WafError('Missing command for the context class %r (cmd)' % name)
 111
 112                 if not getattr(cls, 'fun', None):
 113                         cls.fun = cls.cmd
 114
 115                 classes.insert(0, cls)
 116
 117 ctx = store_context('ctx', (object,), {})
 118 """Base class for all :py:class:`waflib.Context.Context` classes"""
 119
 120 class Context(ctx):
 121         """
 122         Default context for waf commands, and base class for new command contexts.
 123
 124         Context objects are passed to top-level functions::
 125
 126                 def foo(ctx):
 127                         print(ctx.__class__.__name__) # waflib.Context.Context
 128
 129         Subclasses must define the class attributes 'cmd' and 'fun':
 130
 131         :param cmd: command to execute as in ``waf cmd``
 132         :type cmd: string
 133         :param fun: function name to execute when the command is called
 134         :type fun: string
 135
 136         .. inheritance-diagram:: waflib.Context.Context waflib.Build.BuildContext waflib.Build.InstallContext waflib.Build.UninstallContext waflib.Build.StepContext waflib.Build.ListContext waflib.Configure.ConfigurationContext waflib.Scripting.Dist waflib.Scripting.DistCheck waflib.Build.CleanContext
 137
 138         """
 139
 140         errors = Errors
 141         """
 142         Shortcut to :py:mod:`waflib.Errors` provided for convenience
 143         """
 144
 145         tools = {}
 146         """
 147         A module cache for wscript files; see :py:meth:`Context.Context.load`
 148         """
 149
 150         def __init__(self, **kw):
 151                 try:
 152                         rd = kw['run_dir']
 153                 except KeyError:
 154                         rd = run_dir
 155
 156                 # binds the context to the nodes in use to avoid a context singleton
 157                 self.node_class = type('Nod3', (waflib.Node.Node,), {})
 158                 self.node_class.__module__ = 'waflib.Node'
 159                 self.node_class.ctx = self
 160
 161                 self.root = self.node_class('', None)
 162                 self.cur_script = None
 163                 self.path = self.root.find_dir(rd)
 164
 165                 self.stack_path = []
 166                 self.exec_dict = {'ctx':self, 'conf':self, 'bld':self, 'opt':self}
 167                 self.logger = None
 168
 169         def finalize(self):
 170                 """
 171                 Called to free resources such as logger files
 172                 """
 173                 try:
 174                         logger = self.logger
 175                 except AttributeError:
 176                         pass
 177                 else:
 178                         Logs.free_logger(logger)
 179                         delattr(self, 'logger')
 180
 181         def load(self, tool_list, *k, **kw):
 182                 """
 183                 Loads a Waf tool as a module, and try calling the function named :py:const:`waflib.Context.Context.fun`
 184                 from it.  A ``tooldir`` argument may be provided as a list of module paths.
 185
 186                 :param tool_list: list of Waf tool names to load
 187                 :type tool_list: list of string or space-separated string
 188                 """
 189                 tools = Utils.to_list(tool_list)
 190                 path = Utils.to_list(kw.get('tooldir', ''))
 191                 with_sys_path = kw.get('with_sys_path', True)
 192
 193                 for t in tools:
 194                         module = load_tool(t, path, with_sys_path=with_sys_path)
 195                         fun = getattr(module, kw.get('name', self.fun), None)
 196                         if fun:
 197                                 fun(self)
 198
 199         def execute(self):
 200                 """
 201                 Here, it calls the function name in the top-level wscript file. Most subclasses
 202                 redefine this method to provide additional functionality.
 203                 """
 204                 self.recurse([os.path.dirname(g_module.root_path)])
 205
 206         def pre_recurse(self, node):
 207                 """
 208                 Method executed immediately before a folder is read by :py:meth:`waflib.Context.Context.recurse`.
 209                 The current script is bound as a Node object on ``self.cur_script``, and the current path
 210                 is bound to ``self.path``
 211
 212                 :param node: script
 213                 :type node: :py:class:`waflib.Node.Node`
 214                 """
 215                 self.stack_path.append(self.cur_script)
 216
 217                 self.cur_script = node
 218                 self.path = node.parent
 219
 220         def post_recurse(self, node):
 221                 """
 222                 Restores ``self.cur_script`` and ``self.path`` right after :py:meth:`waflib.Context.Context.recurse` terminates.
 223
 224                 :param node: script
 225                 :type node: :py:class:`waflib.Node.Node`
 226                 """
 227                 self.cur_script = self.stack_path.pop()
 228                 if self.cur_script:
 229                         self.path = self.cur_script.parent
 230
 231         def recurse(self, dirs, name=None, mandatory=True, once=True, encoding=None):
 232                 """
 233                 Runs user-provided functions from the supplied list of directories.
 234                 The directories can be either absolute, or relative to the directory
 235                 of the wscript file
 236
 237                 The methods :py:meth:`waflib.Context.Context.pre_recurse` and
 238                 :py:meth:`waflib.Context.Context.post_recurse` are called immediately before
 239                 and after a script has been executed.
 240
 241                 :param dirs: List of directories to visit
 242                 :type dirs: list of string or space-separated string
 243                 :param name: Name of function to invoke from the wscript
 244                 :type  name: string
 245                 :param mandatory: whether sub wscript files are required to exist
 246                 :type  mandatory: bool
 247                 :param once: read the script file once for a particular context
 248                 :type once: bool
 249                 """
 250                 try:
 251                         cache = self.recurse_cache
 252                 except AttributeError:
 253                         cache = self.recurse_cache = {}
 254
 255                 for d in Utils.to_list(dirs):
 256
 257                         if not os.path.isabs(d):
 258                                 # absolute paths only
 259                                 d = os.path.join(self.path.abspath(), d)
 260
 261                         WSCRIPT     = os.path.join(d, WSCRIPT_FILE)
 262                         WSCRIPT_FUN = WSCRIPT + '_' + (name or self.fun)
 263
 264                         node = self.root.find_node(WSCRIPT_FUN)
 265                         if node and (not once or node not in cache):
 266                                 cache[node] = True
 267                                 self.pre_recurse(node)
 268                                 try:
 269                                         function_code = node.read('rU', encoding)
 270                                         exec(compile(function_code, node.abspath(), 'exec'), self.exec_dict)
 271                                 finally:
 272                                         self.post_recurse(node)
 273                         elif not node:
 274                                 node = self.root.find_node(WSCRIPT)
 275                                 tup = (node, name or self.fun)
 276                                 if node and (not once or tup not in cache):
 277                                         cache[tup] = True
 278                                         self.pre_recurse(node)
 279                                         try:
 280                                                 wscript_module = load_module(node.abspath(), encoding=encoding)
 281                                                 user_function = getattr(wscript_module, (name or self.fun), None)
 282                                                 if not user_function:
 283                                                         if not mandatory:
 284                                                                 continue
 285                                                         raise Errors.WafError('No function %r defined in %s' % (name or self.fun, node.abspath()))
 286                                                 user_function(self)
 287                                         finally:
 288                                                 self.post_recurse(node)
 289                                 elif not node:
 290                                         if not mandatory:
 291                                                 continue
 292                                         try:
 293                                                 os.listdir(d)
 294                                         except OSError:
 295                                                 raise Errors.WafError('Cannot read the folder %r' % d)
 296                                         raise Errors.WafError('No wscript file in directory %s' % d)
 297
 298         def log_command(self, cmd, kw):
 299                 if Logs.verbose:
 300                         fmt = os.environ.get('WAF_CMD_FORMAT')
 301                         if fmt == 'string':
 302                                 if not isinstance(cmd, str):
 303                                         cmd = Utils.shell_escape(cmd)
 304                         Logs.debug('runner: %r', cmd)
 305                         Logs.debug('runner_env: kw=%s', kw)
 306
 307         def exec_command(self, cmd, **kw):
 308                 """
 309                 Runs an external process and returns the exit status::
 310
 311                         def run(tsk):
 312                                 ret = tsk.generator.bld.exec_command('touch foo.txt')
 313                                 return ret
 314
 315                 If the context has the attribute 'log', then captures and logs the process stderr/stdout.
 316                 Unlike :py:meth:`waflib.Context.Context.cmd_and_log`, this method does not return the
 317                 stdout/stderr values captured.
 318
 319                 :param cmd: command argument for subprocess.Popen
 320                 :type cmd: string or list
 321                 :param kw: keyword arguments for subprocess.Popen. The parameters input/timeout will be passed to wait/communicate.
 322                 :type kw: dict
 323                 :returns: process exit status
 324                 :rtype: integer
 325                 :raises: :py:class:`waflib.Errors.WafError` if an invalid executable is specified for a non-shell process
 326                 :raises: :py:class:`waflib.Errors.WafError` in case of execution failure
 327                 """
 328                 subprocess = Utils.subprocess
 329                 kw['shell'] = isinstance(cmd, str)
 330                 self.log_command(cmd, kw)
 331
 332                 if self.logger:
 333                         self.logger.info(cmd)
 334
 335                 if 'stdout' not in kw:
 336                         kw['stdout'] = subprocess.PIPE
 337                 if 'stderr' not in kw:
 338                         kw['stderr'] = subprocess.PIPE
 339
 340                 if Logs.verbose and not kw['shell'] and not Utils.check_exe(cmd[0]):
 341                         raise Errors.WafError('Program %s not found!' % cmd[0])
 342
 343                 cargs = {}
 344                 if 'timeout' in kw:
 345                         if sys.hexversion >= 0x3030000:
 346                                 cargs['timeout'] = kw['timeout']
 347                                 if not 'start_new_session' in kw:
 348                                         kw['start_new_session'] = True
 349                         del kw['timeout']
 350                 if 'input' in kw:
 351                         if kw['input']:
 352                                 cargs['input'] = kw['input']
 353                                 kw['stdin'] = subprocess.PIPE
 354                         del kw['input']
 355
 356                 if 'cwd' in kw:
 357                         if not isinstance(kw['cwd'], str):
 358                                 kw['cwd'] = kw['cwd'].abspath()
 359
 360                 encoding = kw.pop('decode_as', default_encoding)
 361
 362                 try:
 363                         ret, out, err = Utils.run_process(cmd, kw, cargs)
 364                 except Exception as e:
 365                         raise Errors.WafError('Execution failure: %s' % str(e), ex=e)
 366
 367                 if out:
 368                         if not isinstance(out, str):
 369                                 out = out.decode(encoding, errors='replace')
 370                         if self.logger:
 371                                 self.logger.debug('out: %s', out)
 372                         else:
 373                                 Logs.info(out, extra={'stream':sys.stdout, 'c1': ''})
 374                 if err:
 375                         if not isinstance(err, str):
 376                                 err = err.decode(encoding, errors='replace')
 377                         if self.logger:
 378                                 self.logger.error('err: %s' % err)
 379                         else:
 380                                 Logs.info(err, extra={'stream':sys.stderr, 'c1': ''})
 381
 382                 return ret
 383
 384         def cmd_and_log(self, cmd, **kw):
 385                 """
 386                 Executes a process and returns stdout/stderr if the execution is successful.
 387                 An exception is thrown when the exit status is non-0. In that case, both stderr and stdout
 388                 will be bound to the WafError object (configuration tests)::
 389
 390                         def configure(conf):
 391                                 out = conf.cmd_and_log(['echo', 'hello'], output=waflib.Context.STDOUT, quiet=waflib.Context.BOTH)
 392                                 (out, err) = conf.cmd_and_log(['echo', 'hello'], output=waflib.Context.BOTH)
 393                                 (out, err) = conf.cmd_and_log(cmd, input='\\n'.encode(), output=waflib.Context.STDOUT)
 394                                 try:
 395                                         conf.cmd_and_log(['which', 'someapp'], output=waflib.Context.BOTH)
 396                                 except Errors.WafError as e:
 397                                         print(e.stdout, e.stderr)
 398
 399                 :param cmd: args for subprocess.Popen
 400                 :type cmd: list or string
 401                 :param kw: keyword arguments for subprocess.Popen. The parameters input/timeout will be passed to wait/communicate.
 402                 :type kw: dict
 403                 :returns: a tuple containing the contents of stdout and stderr
 404                 :rtype: string
 405                 :raises: :py:class:`waflib.Errors.WafError` if an invalid executable is specified for a non-shell process
 406                 :raises: :py:class:`waflib.Errors.WafError` in case of execution failure; stdout/stderr/returncode are bound to the exception object
 407                 """
 408                 subprocess = Utils.subprocess
 409                 kw['shell'] = isinstance(cmd, str)
 410                 self.log_command(cmd, kw)
 411
 412                 quiet = kw.pop('quiet', None)
 413                 to_ret = kw.pop('output', STDOUT)
 414
 415                 if Logs.verbose and not kw['shell'] and not Utils.check_exe(cmd[0]):
 416                         raise Errors.WafError('Program %r not found!' % cmd[0])
 417
 418                 kw['stdout'] = kw['stderr'] = subprocess.PIPE
 419                 if quiet is None:
 420                         self.to_log(cmd)
 421
 422                 cargs = {}
 423                 if 'timeout' in kw:
 424                         if sys.hexversion >= 0x3030000:
 425                                 cargs['timeout'] = kw['timeout']
 426                                 if not 'start_new_session' in kw:
 427                                         kw['start_new_session'] = True
 428                         del kw['timeout']
 429                 if 'input' in kw:
 430                         if kw['input']:
 431                                 cargs['input'] = kw['input']
 432                                 kw['stdin'] = subprocess.PIPE
 433                         del kw['input']
 434
 435                 if 'cwd' in kw:
 436                         if not isinstance(kw['cwd'], str):
 437                                 kw['cwd'] = kw['cwd'].abspath()
 438
 439                 encoding = kw.pop('decode_as', default_encoding)
 440
 441                 try:
 442                         ret, out, err = Utils.run_process(cmd, kw, cargs)
 443                 except Exception as e:
 444                         raise Errors.WafError('Execution failure: %s' % str(e), ex=e)
 445
 446                 if not isinstance(out, str):
 447                         out = out.decode(encoding, errors='replace')
 448                 if not isinstance(err, str):
 449                         err = err.decode(encoding, errors='replace')
 450
 451                 if out and quiet != STDOUT and quiet != BOTH:
 452                         self.to_log('out: %s' % out)
 453                 if err and quiet != STDERR and quiet != BOTH:
 454                         self.to_log('err: %s' % err)
 455
 456                 if ret:
 457                         e = Errors.WafError('Command %r returned %r' % (cmd, ret))
 458                         e.returncode = ret
 459                         e.stderr = err
 460                         e.stdout = out
 461                         raise e
 462
 463                 if to_ret == BOTH:
 464                         return (out, err)
 465                 elif to_ret == STDERR:
 466                         return err
 467                 return out
 468
 469         def fatal(self, msg, ex=None):
 470                 """
 471                 Prints an error message in red and stops command execution; this is
 472                 usually used in the configuration section::
 473
 474                         def configure(conf):
 475                                 conf.fatal('a requirement is missing')
 476
 477                 :param msg: message to display
 478                 :type msg: string
 479                 :param ex: optional exception object
 480                 :type ex: exception
 481                 :raises: :py:class:`waflib.Errors.ConfigurationError`
 482                 """
 483                 if self.logger:
 484                         self.logger.info('from %s: %s' % (self.path.abspath(), msg))
 485                 try:
 486                         logfile = self.logger.handlers[0].baseFilename
 487                 except AttributeError:
 488                         pass
 489                 else:
 490                         if os.environ.get('WAF_PRINT_FAILURE_LOG'):
 491                                 # see #1930
 492                                 msg = 'Log from (%s):\n%s\n' % (logfile, Utils.readf(logfile))
 493                         else:
 494                                 msg = '%s\n(complete log in %s)' % (msg, logfile)
 495                 raise self.errors.ConfigurationError(msg, ex=ex)
 496
 497         def to_log(self, msg):
 498                 """
 499                 Logs information to the logger (if present), or to stderr.
 500                 Empty messages are not printed::
 501
 502                         def build(bld):
 503                                 bld.to_log('starting the build')
 504
 505                 Provide a logger on the context class or override this method if necessary.
 506
 507                 :param msg: message
 508                 :type msg: string
 509                 """
 510                 if not msg:
 511                         return
 512                 if self.logger:
 513                         self.logger.info(msg)
 514                 else:
 515                         sys.stderr.write(str(msg))
 516                         sys.stderr.flush()
 517
 518
 519         def msg(self, *k, **kw):
 520                 """
 521                 Prints a configuration message of the form ``msg: result``.
 522                 The second part of the message will be in colors. The output
 523                 can be disabled easly by setting ``in_msg`` to a positive value::
 524
 525                         def configure(conf):
 526                                 self.in_msg = 1
 527                                 conf.msg('Checking for library foo', 'ok')
 528                                 # no output
 529
 530                 :param msg: message to display to the user
 531                 :type msg: string
 532                 :param result: result to display
 533                 :type result: string or boolean
 534                 :param color: color to use, see :py:const:`waflib.Logs.colors_lst`
 535                 :type color: string
 536                 """
 537                 try:
 538                         msg = kw['msg']
 539                 except KeyError:
 540                         msg = k[0]
 541
 542                 self.start_msg(msg, **kw)
 543
 544                 try:
 545                         result = kw['result']
 546                 except KeyError:
 547                         result = k[1]
 548
 549                 color = kw.get('color')
 550                 if not isinstance(color, str):
 551                         color = result and 'GREEN' or 'YELLOW'
 552
 553                 self.end_msg(result, color, **kw)
 554
 555         def start_msg(self, *k, **kw):
 556                 """
 557                 Prints the beginning of a 'Checking for xxx' message. See :py:meth:`waflib.Context.Context.msg`
 558                 """
 559                 if kw.get('quiet'):
 560                         return
 561
 562                 msg = kw.get('msg') or k[0]
 563                 try:
 564                         if self.in_msg:
 565                                 self.in_msg += 1
 566                                 return
 567                 except AttributeError:
 568                         self.in_msg = 0
 569                 self.in_msg += 1
 570
 571                 try:
 572                         self.line_just = max(self.line_just, len(msg))
 573                 except AttributeError:
 574                         self.line_just = max(40, len(msg))
 575                 for x in (self.line_just * '-', msg):
 576                         self.to_log(x)
 577                 Logs.pprint('NORMAL', "%s :" % msg.ljust(self.line_just), sep='')
 578
 579         def end_msg(self, *k, **kw):
 580                 """Prints the end of a 'Checking for' message. See :py:meth:`waflib.Context.Context.msg`"""
 581                 if kw.get('quiet'):
 582                         return
 583                 self.in_msg -= 1
 584                 if self.in_msg:
 585                         return
 586
 587                 result = kw.get('result') or k[0]
 588
 589                 defcolor = 'GREEN'
 590                 if result is True:
 591                         msg = 'ok'
 592                 elif not result:
 593                         msg = 'not found'
 594                         defcolor = 'YELLOW'
 595                 else:
 596                         msg = str(result)
 597
 598                 self.to_log(msg)
 599                 try:
 600                         color = kw['color']
 601                 except KeyError:
 602                         if len(k) > 1 and k[1] in Logs.colors_lst:
 603                                 # compatibility waf 1.7
 604                                 color = k[1]
 605                         else:
 606                                 color = defcolor
 607                 Logs.pprint(color, msg)
 608
 609         def load_special_tools(self, var, ban=[]):
 610                 """
 611                 Loads third-party extensions modules for certain programming languages
 612                 by trying to list certain files in the extras/ directory. This method
 613                 is typically called once for a programming language group, see for
 614                 example :py:mod:`waflib.Tools.compiler_c`
 615
 616                 :param var: glob expression, for example 'cxx\_\*.py'
 617                 :type var: string
 618                 :param ban: list of exact file names to exclude
 619                 :type ban: list of string
 620                 """
 621                 if os.path.isdir(waf_dir):
 622                         lst = self.root.find_node(waf_dir).find_node('waflib/extras').ant_glob(var)
 623                         for x in lst:
 624                                 if not x.name in ban:
 625                                         load_tool(x.name.replace('.py', ''))
 626                 else:
 627                         from zipfile import PyZipFile
 628                         waflibs = PyZipFile(waf_dir)
 629                         lst = waflibs.namelist()
 630                         for x in lst:
 631                                 if not re.match('waflib/extras/%s' % var.replace('*', '.*'), var):
 632                                         continue
 633                                 f = os.path.basename(x)
 634                                 doban = False
 635                                 for b in ban:
 636                                         r = b.replace('*', '.*')
 637                                         if re.match(r, f):
 638                                                 doban = True
 639                                 if not doban:
 640                                         f = f.replace('.py', '')
 641                                         load_tool(f)
 642
 643 cache_modules = {}
 644 """
 645 Dictionary holding already loaded modules (wscript), indexed by their absolute path.
 646 The modules are added automatically by :py:func:`waflib.Context.load_module`
 647 """
 648
 649 def load_module(path, encoding=None):
 650         """
 651         Loads a wscript file as a python module. This method caches results in :py:attr:`waflib.Context.cache_modules`
 652
 653         :param path: file path
 654         :type path: string
 655         :return: Loaded Python module
 656         :rtype: module
 657         """
 658         try:
 659                 return cache_modules[path]
 660         except KeyError:
 661                 pass
 662
 663         module = imp.new_module(WSCRIPT_FILE)
 664         try:
 665                 code = Utils.readf(path, m='rU', encoding=encoding)
 666         except EnvironmentError:
 667                 raise Errors.WafError('Could not read the file %r' % path)
 668
 669         module_dir = os.path.dirname(path)
 670         sys.path.insert(0, module_dir)
 671         try:
 672                 exec(compile(code, path, 'exec'), module.__dict__)
 673         finally:
 674                 sys.path.remove(module_dir)
 675
 676         cache_modules[path] = module
 677         return module
 678
 679 def load_tool(tool, tooldir=None, ctx=None, with_sys_path=True):
 680         """
 681         Importx a Waf tool as a python module, and stores it in the dict :py:const:`waflib.Context.Context.tools`
 682
 683         :type  tool: string
 684         :param tool: Name of the tool
 685         :type  tooldir: list
 686         :param tooldir: List of directories to search for the tool module
 687         :type  with_sys_path: boolean
 688         :param with_sys_path: whether or not to search the regular sys.path, besides waf_dir and potentially given tooldirs
 689         """
 690         if tool == 'java':
 691                 tool = 'javaw' # jython
 692         else:
 693                 tool = tool.replace('++', 'xx')
 694
 695         if not with_sys_path:
 696                 back_path = sys.path
 697                 sys.path = []
 698         try:
 699                 if tooldir:
 700                         assert isinstance(tooldir, list)
 701                         sys.path = tooldir + sys.path
 702                         try:
 703                                 __import__(tool)
 704                         except ImportError as e:
 705                                 e.waf_sys_path = list(sys.path)
 706                                 raise
 707                         finally:
 708                                 for d in tooldir:
 709                                         sys.path.remove(d)
 710                         ret = sys.modules[tool]
 711                         Context.tools[tool] = ret
 712                         return ret
 713                 else:
 714                         if not with_sys_path:
 715                                 sys.path.insert(0, waf_dir)
 716                         try:
 717                                 for x in ('waflib.Tools.%s', 'waflib.extras.%s', 'waflib.%s', '%s'):
 718                                         try:
 719                                                 __import__(x % tool)
 720                                                 break
 721                                         except ImportError:
 722                                                 x = None
 723                                 else: # raise an exception
 724                                         __import__(tool)
 725                         except ImportError as e:
 726                                 e.waf_sys_path = list(sys.path)
 727                                 raise
 728                         finally:
 729                                 if not with_sys_path:
 730                                         sys.path.remove(waf_dir)
 731                         ret = sys.modules[x % tool]
 732                         Context.tools[tool] = ret
 733                         return ret
 734         finally:
 735                 if not with_sys_path:
 736                         sys.path += back_path
 737