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# Here we expose a class from a particular module, depending on the
60# environment. The comment suppresses the 'Invalid variable name' lint
61# complaint.
62TestCase = _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 = {'source_dir': os.path.dirname(sys.argv[0]),
67             'build_dir': os.path.dirname(sys.argv[0])}
68_gtest_flags_are_parsed = False
69
70
71def _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
100def 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
111def GetSourceDir():
112  """Returns the absolute path of the directory where the .py files are."""
113
114  return os.path.abspath(GetFlag('source_dir'))
115
116
117def GetBuildDir():
118  """Returns the absolute path of the directory where the test binaries are."""
119
120  return os.path.abspath(GetFlag('build_dir'))
121
122
123_temp_dir = None
124
125def _RemoveTempDir():
126  if _temp_dir:
127    shutil.rmtree(_temp_dir, ignore_errors=True)
128
129atexit.register(_RemoveTempDir)
130
131
132def 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
141def 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 --build_dir flag or the BUILD_DIR\n'
165        'environment variable.')
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, env=None):
194    """Changes into a specified directory, if provided, and executes a command.
195
196    Restores the old directory afterwards.
197
198    Args:
199      command:        The command to run, in the form of sys.argv.
200      working_dir:    The directory to change into.
201      capture_stderr: Determines whether to capture stderr in the output member
202                      or to discard it.
203      env:            Dictionary with environment to pass to the subprocess.
204
205    Returns:
206      An object that represents outcome of the executed process. It has the
207      following attributes:
208        terminated_by_signal   True iff the child process has been terminated
209                               by a signal.
210        signal                 Sygnal that terminated the child process.
211        exited                 True iff the child process exited normally.
212        exit_code              The code with which the child process exited.
213        output                 Child process's stdout and stderr output
214                               combined in a string.
215    """
216
217    # The subprocess module is the preferrable way of running programs
218    # since it is available and behaves consistently on all platforms,
219    # including Windows. But it is only available starting in python 2.4.
220    # In earlier python versions, we revert to the popen2 module, which is
221    # available in python 2.0 and later but doesn't provide required
222    # functionality (Popen4) under Windows. This allows us to support Mac
223    # OS X 10.4 Tiger, which has python 2.3 installed.
224    if _SUBPROCESS_MODULE_AVAILABLE:
225      if capture_stderr:
226        stderr = subprocess.STDOUT
227      else:
228        stderr = subprocess.PIPE
229
230      p = subprocess.Popen(command,
231                           stdout=subprocess.PIPE, stderr=stderr,
232                           cwd=working_dir, universal_newlines=True, env=env)
233      # communicate returns a tuple with the file obect for the child's
234      # output.
235      self.output = p.communicate()[0]
236      self._return_code = p.returncode
237    else:
238      old_dir = os.getcwd()
239
240      def _ReplaceEnvDict(dest, src):
241        # Changes made by os.environ.clear are not inheritable by child
242        # processes until Python 2.6. To produce inheritable changes we have
243        # to delete environment items with the del statement.
244        for key in dest:
245          del dest[key]
246        dest.update(src)
247
248      # When 'env' is not None, backup the environment variables and replace
249      # them with the passed 'env'. When 'env' is None, we simply use the
250      # current 'os.environ' for compatibility with the subprocess.Popen
251      # semantics used above.
252      if env is not None:
253        old_environ = os.environ.copy()
254        _ReplaceEnvDict(os.environ, env)
255
256      try:
257        if working_dir is not None:
258          os.chdir(working_dir)
259        if capture_stderr:
260          p = popen2.Popen4(command)
261        else:
262          p = popen2.Popen3(command)
263        p.tochild.close()
264        self.output = p.fromchild.read()
265        ret_code = p.wait()
266      finally:
267        os.chdir(old_dir)
268
269        # Restore the old environment variables
270        # if they were replaced.
271        if env is not None:
272          _ReplaceEnvDict(os.environ, old_environ)
273
274      # Converts ret_code to match the semantics of
275      # subprocess.Popen.returncode.
276      if os.WIFSIGNALED(ret_code):
277        self._return_code = -os.WTERMSIG(ret_code)
278      else:  # os.WIFEXITED(ret_code) should return True here.
279        self._return_code = os.WEXITSTATUS(ret_code)
280
281    if self._return_code < 0:
282      self.terminated_by_signal = True
283      self.exited = False
284      self.signal = -self._return_code
285    else:
286      self.terminated_by_signal = False
287      self.exited = True
288      self.exit_code = self._return_code
289
290
291def Main():
292  """Runs the unit test."""
293
294  # We must call _ParseAndStripGTestFlags() before calling
295  # unittest.main().  Otherwise the latter will be confused by the
296  # --gtest_* flags.
297  _ParseAndStripGTestFlags(sys.argv)
298  # The tested binaries should not be writing XML output files unless the
299  # script explicitly instructs them to.
300  # TODO(vladl@google.com): Move this into Subprocess when we implement
301  # passing environment into it as a parameter.
302  if GTEST_OUTPUT_VAR_NAME in os.environ:
303    del os.environ[GTEST_OUTPUT_VAR_NAME]
304
305  _test_module.main()
306