1#!/usr/bin/env python
2#
3# Copyright 2006, Google Inc.
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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
54GTEST_OUTPUT_VAR_NAME = 'GTEST_OUTPUT'
55
56IS_WINDOWS = os.name == 'nt'
57IS_CYGWIN = os.name == 'posix' and 'CYGWIN' in os.uname()[0]
58
59# The environment variable for specifying the path to the premature-exit file.
60PREMATURE_EXIT_FILE_ENV_VAR = 'TEST_PREMATURE_EXIT_FILE'
61
62environ = os.environ.copy()
63
64
65def SetEnvVar(env_var, value):
66  """Sets/unsets an environment variable to a given value."""
67
68  if value is not None:
69    environ[env_var] = value
70  elif env_var in environ:
71    del environ[env_var]
72
73
74# Here we expose a class from a particular module, depending on the
75# environment. The comment suppresses the 'Invalid variable name' lint
76# complaint.
77TestCase = _test_module.TestCase  # pylint: disable-msg=C6409
78
79# Initially maps a flag to its default value. After
80# _ParseAndStripGTestFlags() is called, maps a flag to its actual value.
81_flag_map = {'source_dir': os.path.dirname(sys.argv[0]),
82             'build_dir': os.path.dirname(sys.argv[0])}
83_gtest_flags_are_parsed = False
84
85
86def _ParseAndStripGTestFlags(argv):
87  """Parses and strips Google Test flags from argv.  This is idempotent."""
88
89  # Suppresses the lint complaint about a global variable since we need it
90  # here to maintain module-wide state.
91  global _gtest_flags_are_parsed  # pylint: disable-msg=W0603
92  if _gtest_flags_are_parsed:
93    return
94
95  _gtest_flags_are_parsed = True
96  for flag in _flag_map:
97    # The environment variable overrides the default value.
98    if flag.upper() in os.environ:
99      _flag_map[flag] = os.environ[flag.upper()]
100
101    # The command line flag overrides the environment variable.
102    i = 1  # Skips the program name.
103    while i < len(argv):
104      prefix = '--' + flag + '='
105      if argv[i].startswith(prefix):
106        _flag_map[flag] = argv[i][len(prefix):]
107        del argv[i]
108        break
109      else:
110        # We don't increment i in case we just found a --gtest_* flag
111        # and removed it from argv.
112        i += 1
113
114
115def GetFlag(flag):
116  """Returns the value of the given flag."""
117
118  # In case GetFlag() is called before Main(), we always call
119  # _ParseAndStripGTestFlags() here to make sure the --gtest_* flags
120  # are parsed.
121  _ParseAndStripGTestFlags(sys.argv)
122
123  return _flag_map[flag]
124
125
126def GetSourceDir():
127  """Returns the absolute path of the directory where the .py files are."""
128
129  return os.path.abspath(GetFlag('source_dir'))
130
131
132def GetBuildDir():
133  """Returns the absolute path of the directory where the test binaries are."""
134
135  return os.path.abspath(GetFlag('build_dir'))
136
137
138_temp_dir = None
139
140def _RemoveTempDir():
141  if _temp_dir:
142    shutil.rmtree(_temp_dir, ignore_errors=True)
143
144atexit.register(_RemoveTempDir)
145
146
147def GetTempDir():
148  """Returns a directory for temporary files."""
149
150  global _temp_dir
151  if not _temp_dir:
152    _temp_dir = tempfile.mkdtemp()
153  return _temp_dir
154
155
156def GetTestExecutablePath(executable_name, build_dir=None):
157  """Returns the absolute path of the test binary given its name.
158
159  The function will print a message and abort the program if the resulting file
160  doesn't exist.
161
162  Args:
163    executable_name: name of the test binary that the test script runs.
164    build_dir:       directory where to look for executables, by default
165                     the result of GetBuildDir().
166
167  Returns:
168    The absolute path of the test binary.
169  """
170
171  path = os.path.abspath(os.path.join(build_dir or GetBuildDir(),
172                                      executable_name))
173  if (IS_WINDOWS or IS_CYGWIN) and not path.endswith('.exe'):
174    path += '.exe'
175
176  if not os.path.exists(path):
177    message = (
178        'Unable to find the test binary "%s". Please make sure to provide\n'
179        'a path to the binary via the --build_dir flag or the BUILD_DIR\n'
180        'environment variable.' % path)
181    print >> sys.stderr, message
182    sys.exit(1)
183
184  return path
185
186
187def GetExitStatus(exit_code):
188  """Returns the argument to exit(), or -1 if exit() wasn't called.
189
190  Args:
191    exit_code: the result value of os.system(command).
192  """
193
194  if os.name == 'nt':
195    # On Windows, os.WEXITSTATUS() doesn't work and os.system() returns
196    # the argument to exit() directly.
197    return exit_code
198  else:
199    # On Unix, os.WEXITSTATUS() must be used to extract the exit status
200    # from the result of os.system().
201    if os.WIFEXITED(exit_code):
202      return os.WEXITSTATUS(exit_code)
203    else:
204      return -1
205
206
207class Subprocess:
208  def __init__(self, command, working_dir=None, capture_stderr=True, env=None):
209    """Changes into a specified directory, if provided, and executes a command.
210
211    Restores the old directory afterwards.
212
213    Args:
214      command:        The command to run, in the form of sys.argv.
215      working_dir:    The directory to change into.
216      capture_stderr: Determines whether to capture stderr in the output member
217                      or to discard it.
218      env:            Dictionary with environment to pass to the subprocess.
219
220    Returns:
221      An object that represents outcome of the executed process. It has the
222      following attributes:
223        terminated_by_signal   True iff the child process has been terminated
224                               by a signal.
225        signal                 Sygnal that terminated the child process.
226        exited                 True iff the child process exited normally.
227        exit_code              The code with which the child process exited.
228        output                 Child process's stdout and stderr output
229                               combined in a string.
230    """
231
232    # The subprocess module is the preferrable way of running programs
233    # since it is available and behaves consistently on all platforms,
234    # including Windows. But it is only available starting in python 2.4.
235    # In earlier python versions, we revert to the popen2 module, which is
236    # available in python 2.0 and later but doesn't provide required
237    # functionality (Popen4) under Windows. This allows us to support Mac
238    # OS X 10.4 Tiger, which has python 2.3 installed.
239    if _SUBPROCESS_MODULE_AVAILABLE:
240      if capture_stderr:
241        stderr = subprocess.STDOUT
242      else:
243        stderr = subprocess.PIPE
244
245      p = subprocess.Popen(command,
246                           stdout=subprocess.PIPE, stderr=stderr,
247                           cwd=working_dir, universal_newlines=True, env=env)
248      # communicate returns a tuple with the file obect for the child's
249      # output.
250      self.output = p.communicate()[0]
251      self._return_code = p.returncode
252    else:
253      old_dir = os.getcwd()
254
255      def _ReplaceEnvDict(dest, src):
256        # Changes made by os.environ.clear are not inheritable by child
257        # processes until Python 2.6. To produce inheritable changes we have
258        # to delete environment items with the del statement.
259        for key in dest.keys():
260          del dest[key]
261        dest.update(src)
262
263      # When 'env' is not None, backup the environment variables and replace
264      # them with the passed 'env'. When 'env' is None, we simply use the
265      # current 'os.environ' for compatibility with the subprocess.Popen
266      # semantics used above.
267      if env is not None:
268        old_environ = os.environ.copy()
269        _ReplaceEnvDict(os.environ, env)
270
271      try:
272        if working_dir is not None:
273          os.chdir(working_dir)
274        if capture_stderr:
275          p = popen2.Popen4(command)
276        else:
277          p = popen2.Popen3(command)
278        p.tochild.close()
279        self.output = p.fromchild.read()
280        ret_code = p.wait()
281      finally:
282        os.chdir(old_dir)
283
284        # Restore the old environment variables
285        # if they were replaced.
286        if env is not None:
287          _ReplaceEnvDict(os.environ, old_environ)
288
289      # Converts ret_code to match the semantics of
290      # subprocess.Popen.returncode.
291      if os.WIFSIGNALED(ret_code):
292        self._return_code = -os.WTERMSIG(ret_code)
293      else:  # os.WIFEXITED(ret_code) should return True here.
294        self._return_code = os.WEXITSTATUS(ret_code)
295
296    if self._return_code < 0:
297      self.terminated_by_signal = True
298      self.exited = False
299      self.signal = -self._return_code
300    else:
301      self.terminated_by_signal = False
302      self.exited = True
303      self.exit_code = self._return_code
304
305
306def Main():
307  """Runs the unit test."""
308
309  # We must call _ParseAndStripGTestFlags() before calling
310  # unittest.main().  Otherwise the latter will be confused by the
311  # --gtest_* flags.
312  _ParseAndStripGTestFlags(sys.argv)
313  # The tested binaries should not be writing XML output files unless the
314  # script explicitly instructs them to.
315  # TODO(vladl@google.com): Move this into Subprocess when we implement
316  # passing environment into it as a parameter.
317  if GTEST_OUTPUT_VAR_NAME in os.environ:
318    del os.environ[GTEST_OUTPUT_VAR_NAME]
319
320  _test_module.main()
321