/Unittests/googletest/test/gtest_test_utils.py

  1#!/usr/bin/env python
  2#
  3# Copyright 2006, Google Inc.
  4# All rights reserved.
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 10#     * Redistributions of source code must retain the above copyright
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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@google.com (Zhanyong Wan)'
 35
 36import atexit
 37import os
 38import shutil
 39import sys
 40import tempfile
 41import unittest
 42_test_module = unittest
 43
 44# Suppresses the 'Import not at the top of the file' lint complaint.
 45# pylint: disable-msg=C6204
 46try:
 47  import subprocess
 48  _SUBPROCESS_MODULE_AVAILABLE = True
 49except:
 50  import popen2
 51  _SUBPROCESS_MODULE_AVAILABLE = False
 52# pylint: enable-msg=C6204
 53
 54
 55IS_WINDOWS = os.name == 'nt'
 56IS_CYGWIN = os.name == 'posix' and 'CYGWIN' in os.uname()[0]
 57
 58# Here we expose a class from a particular module, depending on the
 59# environment. The comment suppresses the 'Invalid variable name' lint
 60# complaint.
 61TestCase = _test_module.TestCase  # pylint: disable-msg=C6409
 62
 63# Initially maps a flag to its default value. After
 64# _ParseAndStripGTestFlags() is called, maps a flag to its actual value.
 65_flag_map = {'gtest_source_dir': os.path.dirname(sys.argv[0]),
 66             'gtest_build_dir': os.path.dirname(sys.argv[0])}
 67_gtest_flags_are_parsed = False
 68
 69
 70def _ParseAndStripGTestFlags(argv):
 71  """Parses and strips Google Test flags from argv.  This is idempotent."""
 72
 73  # Suppresses the lint complaint about a global variable since we need it
 74  # here to maintain module-wide state.
 75  global _gtest_flags_are_parsed  # pylint: disable-msg=W0603
 76  if _gtest_flags_are_parsed:
 77    return
 78
 79  _gtest_flags_are_parsed = True
 80  for flag in _flag_map:
 81    # The environment variable overrides the default value.
 82    if flag.upper() in os.environ:
 83      _flag_map[flag] = os.environ[flag.upper()]
 84
 85    # The command line flag overrides the environment variable.
 86    i = 1  # Skips the program name.
 87    while i < len(argv):
 88      prefix = '--' + flag + '='
 89      if argv[i].startswith(prefix):
 90        _flag_map[flag] = argv[i][len(prefix):]
 91        del argv[i]
 92        break
 93      else:
 94        # We don't increment i in case we just found a --gtest_* flag
 95        # and removed it from argv.
 96        i += 1
 97
 98
 99def GetFlag(flag):
100  """Returns the value of the given flag."""
101
102  # In case GetFlag() is called before Main(), we always call
103  # _ParseAndStripGTestFlags() here to make sure the --gtest_* flags
104  # are parsed.
105  _ParseAndStripGTestFlags(sys.argv)
106
107  return _flag_map[flag]
108
109
110def GetSourceDir():
111  """Returns the absolute path of the directory where the .py files are."""
112
113  return os.path.abspath(GetFlag('gtest_source_dir'))
114
115
116def GetBuildDir():
117  """Returns the absolute path of the directory where the test binaries are."""
118
119  return os.path.abspath(GetFlag('gtest_build_dir'))
120
121
122_temp_dir = None
123
124def _RemoveTempDir():
125  if _temp_dir:
126    shutil.rmtree(_temp_dir, ignore_errors=True)
127
128atexit.register(_RemoveTempDir)
129
130
131def GetTempDir():
132  """Returns a directory for temporary files."""
133
134  global _temp_dir
135  if not _temp_dir:
136    _temp_dir = tempfile.mkdtemp()
137  return _temp_dir
138
139
140def GetTestExecutablePath(executable_name):
141  """Returns the absolute path of the test binary given its name.
142
143  The function will print a message and abort the program if the resulting file
144  doesn't exist.
145
146  Args:
147    executable_name: name of the test binary that the test script runs.
148
149  Returns:
150    The absolute path of the test binary.
151  """
152
153  path = os.path.abspath(os.path.join(GetBuildDir(), executable_name))
154  if (IS_WINDOWS or IS_CYGWIN) and not path.endswith('.exe'):
155    path += '.exe'
156
157  if not os.path.exists(path):
158    message = (
159        'Unable to find the test binary. Please make sure to provide path\n'
160        'to the binary via the --gtest_build_dir flag or the GTEST_BUILD_DIR\n'
161        'environment variable. For convenient use, invoke this script via\n'
162        'mk_test.py.\n'
163        # TODO(vladl@google.com): change mk_test.py to test.py after renaming
164        # the file.
165        'Please run mk_test.py -h for help.')
166    print >> sys.stderr, message
167    sys.exit(1)
168
169  return path
170
171
172def GetExitStatus(exit_code):
173  """Returns the argument to exit(), or -1 if exit() wasn't called.
174
175  Args:
176    exit_code: the result value of os.system(command).
177  """
178
179  if os.name == 'nt':
180    # On Windows, os.WEXITSTATUS() doesn't work and os.system() returns
181    # the argument to exit() directly.
182    return exit_code
183  else:
184    # On Unix, os.WEXITSTATUS() must be used to extract the exit status
185    # from the result of os.system().
186    if os.WIFEXITED(exit_code):
187      return os.WEXITSTATUS(exit_code)
188    else:
189      return -1
190
191
192class Subprocess:
193  def __init__(self, command, working_dir=None, capture_stderr=True):
194    """Changes into a specified directory, if provided, and executes a command.
195    Restores the old directory afterwards. Execution results are returned
196    via the following attributes:
197      terminated_by_sygnal   True iff the child process has been terminated
198                             by a signal.
199      signal                 Sygnal that terminated the child process.
200      exited                 True iff the child process exited normally.
201      exit_code              The code with which the child proces exited.
202      output                 Child process's stdout and stderr output
203                             combined in a string.
204
205    Args:
206      command:        The command to run, in the form of sys.argv.
207      working_dir:    The directory to change into.
208      capture_stderr: Determines whether to capture stderr in the output member
209                      or to discard it.
210    """
211
212    # The subprocess module is the preferrable way of running programs
213    # since it is available and behaves consistently on all platforms,
214    # including Windows. But it is only available starting in python 2.4.
215    # In earlier python versions, we revert to the popen2 module, which is
216    # available in python 2.0 and later but doesn't provide required
217    # functionality (Popen4) under Windows. This allows us to support Mac
218    # OS X 10.4 Tiger, which has python 2.3 installed.
219    if _SUBPROCESS_MODULE_AVAILABLE:
220      if capture_stderr:
221        stderr = subprocess.STDOUT
222      else:
223        stderr = subprocess.PIPE
224
225      p = subprocess.Popen(command,
226                           stdout=subprocess.PIPE, stderr=stderr,
227                           cwd=working_dir, universal_newlines=True)
228      # communicate returns a tuple with the file obect for the child's
229      # output.
230      self.output = p.communicate()[0]
231      self._return_code = p.returncode
232    else:
233      old_dir = os.getcwd()
234      try:
235        if working_dir is not None:
236          os.chdir(working_dir)
237        if capture_stderr:
238          p = popen2.Popen4(command)
239        else:
240          p = popen2.Popen3(command)
241        p.tochild.close()
242        self.output = p.fromchild.read()
243        ret_code = p.wait()
244      finally:
245        os.chdir(old_dir)
246      # Converts ret_code to match the semantics of
247      # subprocess.Popen.returncode.
248      if os.WIFSIGNALED(ret_code):
249        self._return_code = -os.WTERMSIG(ret_code)
250      else:  # os.WIFEXITED(ret_code) should return True here.
251        self._return_code = os.WEXITSTATUS(ret_code)
252
253    if self._return_code < 0:
254      self.terminated_by_signal = True
255      self.exited = False
256      self.signal = -self._return_code
257    else:
258      self.terminated_by_signal = False
259      self.exited = True
260      self.exit_code = self._return_code
261
262
263def Main():
264  """Runs the unit test."""
265
266  # We must call _ParseAndStripGTestFlags() before calling
267  # unittest.main().  Otherwise the latter will be confused by the
268  # --gtest_* flags.
269  _ParseAndStripGTestFlags(sys.argv)
270  _test_module.main()