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      1 #!/usr/bin/env python
      2 #
      3 # Copyright 2006, Google Inc.
      4 # All rights reserved.
      5 #
      6 # Redistribution and use in source and binary forms, with or without
      7 # modification, are permitted provided that the following conditions are
      8 # met:
      9 #
     10 #     * Redistributions of source code must retain the above copyright
     11 # notice, this list of conditions and the following disclaimer.
     12 #     * Redistributions in binary form must reproduce the above
     13 # copyright notice, this list of conditions and the following disclaimer
     14 # in the documentation and/or other materials provided with the
     15 # distribution.
     16 #     * Neither the name of Google Inc. nor the names of its
     17 # contributors may be used to endorse or promote products derived from
     18 # this software without specific prior written permission.
     19 #
     20 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     21 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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     23 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     24 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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     30 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31 
     32 """Unit test utilities for Google C++ Testing Framework."""
     33 
     34 __author__ = 'wan (at] google.com (Zhanyong Wan)'
     35 
     36 import atexit
     37 import os
     38 import shutil
     39 import sys
     40 import tempfile
     41 import unittest
     42 _test_module = unittest
     43 
     44 # Suppresses the 'Import not at the top of the file' lint complaint.
     45 # pylint: disable-msg=C6204
     46 try:
     47   import subprocess
     48   _SUBPROCESS_MODULE_AVAILABLE = True
     49 except:
     50   import popen2
     51   _SUBPROCESS_MODULE_AVAILABLE = False
     52 # pylint: enable-msg=C6204
     53 
     54 GTEST_OUTPUT_VAR_NAME = 'GTEST_OUTPUT'
     55 
     56 IS_WINDOWS = os.name == 'nt'
     57 IS_CYGWIN = os.name == 'posix' and 'CYGWIN' in os.uname()[0]
     58 
     59 # Here we expose a class from a particular module, depending on the
     60 # environment. The comment suppresses the 'Invalid variable name' lint
     61 # complaint.
     62 TestCase = _test_module.TestCase  # pylint: disable-msg=C6409
     63 
     64 # Initially maps a flag to its default value. After
     65 # _ParseAndStripGTestFlags() is called, maps a flag to its actual value.
     66 _flag_map = {'gtest_source_dir': os.path.dirname(sys.argv[0]),
     67              'gtest_build_dir': os.path.dirname(sys.argv[0])}
     68 _gtest_flags_are_parsed = False
     69 
     70 
     71 def _ParseAndStripGTestFlags(argv):
     72   """Parses and strips Google Test flags from argv.  This is idempotent."""
     73 
     74   # Suppresses the lint complaint about a global variable since we need it
     75   # here to maintain module-wide state.
     76   global _gtest_flags_are_parsed  # pylint: disable-msg=W0603
     77   if _gtest_flags_are_parsed:
     78     return
     79 
     80   _gtest_flags_are_parsed = True
     81   for flag in _flag_map:
     82     # The environment variable overrides the default value.
     83     if flag.upper() in os.environ:
     84       _flag_map[flag] = os.environ[flag.upper()]
     85 
     86     # The command line flag overrides the environment variable.
     87     i = 1  # Skips the program name.
     88     while i < len(argv):
     89       prefix = '--' + flag + '='
     90       if argv[i].startswith(prefix):
     91         _flag_map[flag] = argv[i][len(prefix):]
     92         del argv[i]
     93         break
     94       else:
     95         # We don't increment i in case we just found a --gtest_* flag
     96         # and removed it from argv.
     97         i += 1
     98 
     99 
    100 def GetFlag(flag):
    101   """Returns the value of the given flag."""
    102 
    103   # In case GetFlag() is called before Main(), we always call
    104   # _ParseAndStripGTestFlags() here to make sure the --gtest_* flags
    105   # are parsed.
    106   _ParseAndStripGTestFlags(sys.argv)
    107 
    108   return _flag_map[flag]
    109 
    110 
    111 def GetSourceDir():
    112   """Returns the absolute path of the directory where the .py files are."""
    113 
    114   return os.path.abspath(GetFlag('gtest_source_dir'))
    115 
    116 
    117 def GetBuildDir():
    118   """Returns the absolute path of the directory where the test binaries are."""
    119 
    120   return os.path.abspath(GetFlag('gtest_build_dir'))
    121 
    122 
    123 _temp_dir = None
    124 
    125 def _RemoveTempDir():
    126   if _temp_dir:
    127     shutil.rmtree(_temp_dir, ignore_errors=True)
    128 
    129 atexit.register(_RemoveTempDir)
    130 
    131 
    132 def GetTempDir():
    133   """Returns a directory for temporary files."""
    134 
    135   global _temp_dir
    136   if not _temp_dir:
    137     _temp_dir = tempfile.mkdtemp()
    138   return _temp_dir
    139 
    140 
    141 def GetTestExecutablePath(executable_name, build_dir=None):
    142   """Returns the absolute path of the test binary given its name.
    143 
    144   The function will print a message and abort the program if the resulting file
    145   doesn't exist.
    146 
    147   Args:
    148     executable_name: name of the test binary that the test script runs.
    149     build_dir:       directory where to look for executables, by default
    150                      the result of GetBuildDir().
    151 
    152   Returns:
    153     The absolute path of the test binary.
    154   """
    155 
    156   path = os.path.abspath(os.path.join(build_dir or GetBuildDir(),
    157                                       executable_name))
    158   if (IS_WINDOWS or IS_CYGWIN) and not path.endswith('.exe'):
    159     path += '.exe'
    160 
    161   if not os.path.exists(path):
    162     message = (
    163         'Unable to find the test binary. Please make sure to provide path\n'
    164         'to the binary via the --gtest_build_dir flag or the GTEST_BUILD_DIR\n'
    165         'environment variable. For convenient use, invoke this script via\n'
    166         'mk_test.py.\n'
    167         # TODO(vladl (at] google.com): change mk_test.py to test.py after renaming
    168         # the file.
    169         'Please run mk_test.py -h for help.')
    170     print >> sys.stderr, message
    171     sys.exit(1)
    172 
    173   return path
    174 
    175 
    176 def GetExitStatus(exit_code):
    177   """Returns the argument to exit(), or -1 if exit() wasn't called.
    178 
    179   Args:
    180     exit_code: the result value of os.system(command).
    181   """
    182 
    183   if os.name == 'nt':
    184     # On Windows, os.WEXITSTATUS() doesn't work and os.system() returns
    185     # the argument to exit() directly.
    186     return exit_code
    187   else:
    188     # On Unix, os.WEXITSTATUS() must be used to extract the exit status
    189     # from the result of os.system().
    190     if os.WIFEXITED(exit_code):
    191       return os.WEXITSTATUS(exit_code)
    192     else:
    193       return -1
    194 
    195 
    196 class Subprocess:
    197   def __init__(self, command, working_dir=None, capture_stderr=True, env=None):
    198     """Changes into a specified directory, if provided, and executes a command.
    199 
    200     Restores the old directory afterwards.
    201 
    202     Args:
    203       command:        The command to run, in the form of sys.argv.
    204       working_dir:    The directory to change into.
    205       capture_stderr: Determines whether to capture stderr in the output member
    206                       or to discard it.
    207       env:            Dictionary with environment to pass to the subprocess.
    208 
    209     Returns:
    210       An object that represents outcome of the executed process. It has the
    211       following attributes:
    212         terminated_by_signal   True iff the child process has been terminated
    213                                by a signal.
    214         signal                 Sygnal that terminated the child process.
    215         exited                 True iff the child process exited normally.
    216         exit_code              The code with which the child process exited.
    217         output                 Child process's stdout and stderr output
    218                                combined in a string.
    219     """
    220 
    221     # The subprocess module is the preferrable way of running programs
    222     # since it is available and behaves consistently on all platforms,
    223     # including Windows. But it is only available starting in python 2.4.
    224     # In earlier python versions, we revert to the popen2 module, which is
    225     # available in python 2.0 and later but doesn't provide required
    226     # functionality (Popen4) under Windows. This allows us to support Mac
    227     # OS X 10.4 Tiger, which has python 2.3 installed.
    228     if _SUBPROCESS_MODULE_AVAILABLE:
    229       if capture_stderr:
    230         stderr = subprocess.STDOUT
    231       else:
    232         stderr = subprocess.PIPE
    233 
    234       p = subprocess.Popen(command,
    235                            stdout=subprocess.PIPE, stderr=stderr,
    236                            cwd=working_dir, universal_newlines=True, env=env)
    237       # communicate returns a tuple with the file obect for the child's
    238       # output.
    239       self.output = p.communicate()[0]
    240       self._return_code = p.returncode
    241     else:
    242       old_dir = os.getcwd()
    243 
    244       def _ReplaceEnvDict(dest, src):
    245         # Changes made by os.environ.clear are not inheritable by child
    246         # processes until Python 2.6. To produce inheritable changes we have
    247         # to delete environment items with the del statement.
    248         for key in dest:
    249           del dest[key]
    250         dest.update(src)
    251 
    252       # When 'env' is not None, backup the environment variables and replace
    253       # them with the passed 'env'. When 'env' is None, we simply use the
    254       # current 'os.environ' for compatibility with the subprocess.Popen
    255       # semantics used above.
    256       if env is not None:
    257         old_environ = os.environ.copy()
    258         _ReplaceEnvDict(os.environ, env)
    259 
    260       try:
    261         if working_dir is not None:
    262           os.chdir(working_dir)
    263         if capture_stderr:
    264           p = popen2.Popen4(command)
    265         else:
    266           p = popen2.Popen3(command)
    267         p.tochild.close()
    268         self.output = p.fromchild.read()
    269         ret_code = p.wait()
    270       finally:
    271         os.chdir(old_dir)
    272 
    273         # Restore the old environment variables
    274         # if they were replaced.
    275         if env is not None:
    276           _ReplaceEnvDict(os.environ, old_environ)
    277 
    278       # Converts ret_code to match the semantics of
    279       # subprocess.Popen.returncode.
    280       if os.WIFSIGNALED(ret_code):
    281         self._return_code = -os.WTERMSIG(ret_code)
    282       else:  # os.WIFEXITED(ret_code) should return True here.
    283         self._return_code = os.WEXITSTATUS(ret_code)
    284 
    285     if self._return_code < 0:
    286       self.terminated_by_signal = True
    287       self.exited = False
    288       self.signal = -self._return_code
    289     else:
    290       self.terminated_by_signal = False
    291       self.exited = True
    292       self.exit_code = self._return_code
    293 
    294 
    295 def Main():
    296   """Runs the unit test."""
    297 
    298   # We must call _ParseAndStripGTestFlags() before calling
    299   # unittest.main().  Otherwise the latter will be confused by the
    300   # --gtest_* flags.
    301   _ParseAndStripGTestFlags(sys.argv)
    302   # The tested binaries should not be writing XML output files unless the
    303   # script explicitly instructs them to.
    304   # TODO(vladl (at] google.com): Move this into Subprocess when we implement
    305   # passing environment into it as a parameter.
    306   if GTEST_OUTPUT_VAR_NAME in os.environ:
    307     del os.environ[GTEST_OUTPUT_VAR_NAME]
    308 
    309   _test_module.main()
    310