Document, fix, and test GTEST_FLAGFILE. Fixes #2726.

googletest/docs/advanced.md

@@ -2062,6 +2062,10 @@ with the `--help` flag. You can also use `-h`, `-?`, or `/?` for short.
 If an option is specified both by an environment variable and by a flag, the
 latter takes precedence.
 
+If you set the `GTEST_FLAGFILE` environment variable or the `--gtest_flagfile`
+flag to a filename, googletest will read more options from that file.
+(This can be handy when running a test harness you'd rather not edit.)
+
 ### Selecting Tests
 
 #### Listing Test Names

googletest/src/gtest.cc

@@ -6172,6 +6172,11 @@ static void LoadFlagsFromFile(const std::string& path) {
 // instantiated to either char or wchar_t.
 template <typename CharType>
 void ParseGoogleTestFlagsOnlyImpl(int* argc, CharType** argv) {
+
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+  bool flagfile_used = false;
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+
   for (int i = 1; i < *argc; i++) {
     const std::string arg_string = StreamableToString(argv[i]);
     const char* const arg = arg_string.c_str();
@@ -6187,6 +6192,7 @@ void ParseGoogleTestFlagsOnlyImpl(int* argc, CharType** argv) {
     } else if (ParseStringFlag(arg, kFlagfileFlag, &GTEST_FLAG(flagfile))) {
       LoadFlagsFromFile(GTEST_FLAG(flagfile));
       remove_flag = true;
+      flagfile_used = true;
 #endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
     } else if (arg_string == "--help" || arg_string == "-h" ||
                arg_string == "-?" || arg_string == "/?" ||
@@ -6214,6 +6220,13 @@ void ParseGoogleTestFlagsOnlyImpl(int* argc, CharType** argv) {
     }
   }
 
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+  // If --gtest_flagfile not given, obey GTEST_FLAGFILE if set
+  if (!g_help_flag && !flagfile_used && GTEST_FLAG(flagfile) != "") {
+      LoadFlagsFromFile(GTEST_FLAG(flagfile));
+  }
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+
   if (g_help_flag) {
     // We print the help here instead of in RUN_ALL_TESTS(), as the
     // latter may not be called at all if the user is using Google

googletest/test/googletest-env-var-test.py

@@ -77,6 +77,18 @@ def TestFlag(flag, test_val, default_val):
   SetEnvVar(env_var, None)
   AssertEq(default_val, GetFlag(flag))
 
+def TestFlagfileEnv(flag, test_val, default_val):
+  """Verifies that the given flag is affected by the GTEST_FLAGFILE env var."""
+
+  file_path = os.path.join(gtest_test_utils.GetTempDir(),
+                             'flagfile.tmp')
+  with open(file_path, 'wb') as f:
+    f.write('--gtest_%s=%s\n' % (flag, test_val))
+  env_var = 'GTEST_FLAGFILE'
+  SetEnvVar(env_var, file_path)
+  AssertEq(test_val, GetFlag(flag))
+  SetEnvVar(env_var, None)
+  AssertEq(default_val, GetFlag(flag))
 
 class GTestEnvVarTest(gtest_test_utils.TestCase):
 
@@ -98,6 +110,19 @@ class GTestEnvVarTest(gtest_test_utils.TestCase):
       TestFlag('death_test_use_fork', '1', '0')
       TestFlag('stack_trace_depth', '0', '100')
 
+  def testFlagfileEnvAffectsFlag(self):
+    """Tests that flagfile environment variable should affect the corresponding flag."""
+
+    TestFlagfileEnv('break_on_failure', '1', '0')
+    TestFlagfileEnv('color', 'yes', 'auto')
+    TestFlagfileEnv('filter', 'FooTest.Bar', '*')
+    SetEnvVar('XML_OUTPUT_FILE', None)  # For 'output' test
+    TestFlagfileEnv('output', 'xml:tmp/foo.xml', '')
+    TestFlagfileEnv('print_time', '0', '1')
+    TestFlagfileEnv('repeat', '999', '1')
+    TestFlagfileEnv('throw_on_failure', '1', '0')
+    TestFlagfileEnv('death_test_style', 'threadsafe', 'fast')
+    TestFlagfileEnv('catch_exceptions', '0', '1')
 
   def testXmlOutputFile(self):
     """Tests that $XML_OUTPUT_FILE affects the output flag."""