supports a protocol for catching tests that prematurely exit

CHANGES

@@ -2,6 +2,10 @@ Changes for 1.7.0:
 
 * New feature: death tests are supported on OpenBSD and in iOS
   simulator now.
+* New feature: Google Test now implements a protocol to allow
+  a test runner to detect that a test program has exited
+  prematurely and report it as a failure (before it would be
+  falsely reported as a success if the exit code is 0).
 * New feature: Test::RecordProperty() can now be used outside of the
   lifespan of a test method, in which case it will be attributed to
   the current test case or the test program in the XML report.

CMakeLists.txt

@@ -124,6 +124,8 @@ if (gtest_build_tests)
     test/gtest-param-test2_test.cc)
   cxx_test(gtest-port_test gtest_main)
   cxx_test(gtest_pred_impl_unittest gtest_main)
+  cxx_test(gtest_premature_exit_test gtest
+    test/gtest_premature_exit_test.cc)
   cxx_test(gtest-printers_test gtest_main)
   cxx_test(gtest_prod_test gtest_main
     test/production.cc)

Makefile.am

@@ -58,6 +58,7 @@ EXTRA_DIST += \
   test/gtest-param-test_test.cc \
   test/gtest-param-test_test.h \
   test/gtest-port_test.cc \
+  test/gtest_premature_exit_test.cc \
   test/gtest-printers_test.cc \
   test/gtest-test-part_test.cc \
   test/gtest-tuple_test.cc \

src/gtest.cc

@@ -3523,6 +3523,35 @@ const char* const
 OsStackTraceGetter::kElidedFramesMarker =
     "... " GTEST_NAME_ " internal frames ...";
 
+// A helper class that creates the premature-exit file in its
+// constructor and deletes the file in its destructor.
+class ScopedPrematureExitFile {
+ public:
+  explicit ScopedPrematureExitFile(const char* premature_exit_filepath)
+      : premature_exit_filepath_(premature_exit_filepath) {
+    // If a path to the premature-exit file is specified...
+    if (premature_exit_filepath != NULL && *premature_exit_filepath != '\0') {
+      // create the file with a single "0" character in it.  I/O
+      // errors are ignored as there's nothing better we can do and we
+      // don't want to fail the test because of this.
+      FILE* pfile = posix::FOpen(premature_exit_filepath, "w");
+      fwrite("0", 1, 1, pfile);
+      fclose(pfile);
+    }
+  }
+
+  ~ScopedPrematureExitFile() {
+    if (premature_exit_filepath_ != NULL && *premature_exit_filepath_ != '\0') {
+      remove(premature_exit_filepath_);
+    }
+  }
+
+ private:
+  const char* const premature_exit_filepath_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ScopedPrematureExitFile);
+};
+
 }  // namespace internal
 
 // class TestEventListeners
@@ -3823,14 +3852,39 @@ void UnitTest::RecordProperty(const std::string& key,
 // We don't protect this under mutex_, as we only support calling it
 // from the main thread.
 int UnitTest::Run() {
+  const bool in_death_test_child_process =
+      internal::GTEST_FLAG(internal_run_death_test).length() > 0;
+
+  // Google Test implements this protocol for catching that a test
+  // program exits before returning control to Google Test:
+  //
+  //   1. Upon start, Google Test creates a file whose absolute path
+  //      is specified by the environment variable
+  //      TEST_PREMATURE_EXIT_FILE.
+  //   2. When Google Test has finished its work, it deletes the file.
+  //
+  // This allows a test runner to set TEST_PREMATURE_EXIT_FILE before
+  // running a Google-Test-based test program and check the existence
+  // of the file at the end of the test execution to see if it has
+  // exited prematurely.
+
+  // If we are in the child process of a death test, don't
+  // create/delete the premature exit file, as doing so is unnecessary
+  // and will confuse the parent process.  Otherwise, create/delete
+  // the file upon entering/leaving this function.  If the program
+  // somehow exits before this function has a chance to return, the
+  // premature-exit file will be left undeleted, causing a test runner
+  // that understands the premature-exit-file protocol to report the
+  // test as having failed.
+  const internal::ScopedPrematureExitFile premature_exit_file(
+      in_death_test_child_process ?
+      NULL : internal::posix::GetEnv("TEST_PREMATURE_EXIT_FILE"));
+
   // Captures the value of GTEST_FLAG(catch_exceptions).  This value will be
   // used for the duration of the program.
   impl()->set_catch_exceptions(GTEST_FLAG(catch_exceptions));
 
 #if GTEST_HAS_SEH
-  const bool in_death_test_child_process =
-      internal::GTEST_FLAG(internal_run_death_test).length() > 0;
-
   // Either the user wants Google Test to catch exceptions thrown by the
   // tests or this is executing in the context of death test child
   // process. In either case the user does not want to see pop-up dialogs

test/gtest_break_on_failure_unittest.py

@@ -66,21 +66,15 @@ EXE_PATH = gtest_test_utils.GetTestExecutablePath(
     'gtest_break_on_failure_unittest_')
 
 
-# Utilities.
+environ = gtest_test_utils.environ
+SetEnvVar = gtest_test_utils.SetEnvVar
 
-
-environ = os.environ.copy()
-
-
-def SetEnvVar(env_var, value):
-  """Sets an environment variable to a given value; unsets it when the
-  given value is None.
-  """
-
-  if value is not None:
-    environ[env_var] = value
-  elif env_var in environ:
-    del environ[env_var]
+# Tests in this file run a Google-Test-based test program and expect it
+# to terminate prematurely.  Therefore they are incompatible with
+# the premature-exit-file protocol by design.  Unset the
+# premature-exit filepath to prevent Google Test from creating
+# the file.
+SetEnvVar(gtest_test_utils.PREMATURE_EXIT_FILE_ENV_VAR, None)
 
 
 def Run(command):

test/gtest_catch_exceptions_test.py

@@ -57,14 +57,27 @@ EX_EXE_PATH = gtest_test_utils.GetTestExecutablePath(
 EXE_PATH = gtest_test_utils.GetTestExecutablePath(
     'gtest_catch_exceptions_no_ex_test_')
 
-TEST_LIST = gtest_test_utils.Subprocess([EXE_PATH, LIST_TESTS_FLAG]).output
+environ = gtest_test_utils.environ
+SetEnvVar = gtest_test_utils.SetEnvVar
+
+# Tests in this file run a Google-Test-based test program and expect it
+# to terminate prematurely.  Therefore they are incompatible with
+# the premature-exit-file protocol by design.  Unset the
+# premature-exit filepath to prevent Google Test from creating
+# the file.
+SetEnvVar(gtest_test_utils.PREMATURE_EXIT_FILE_ENV_VAR, None)
+
+TEST_LIST = gtest_test_utils.Subprocess(
+    [EXE_PATH, LIST_TESTS_FLAG], env=environ).output
 
 SUPPORTS_SEH_EXCEPTIONS = 'ThrowsSehException' in TEST_LIST
 
 if SUPPORTS_SEH_EXCEPTIONS:
-  BINARY_OUTPUT = gtest_test_utils.Subprocess([EXE_PATH]).output
+  BINARY_OUTPUT = gtest_test_utils.Subprocess([EXE_PATH], env=environ).output
+
+EX_BINARY_OUTPUT = gtest_test_utils.Subprocess(
+    [EX_EXE_PATH], env=environ).output
 
-EX_BINARY_OUTPUT = gtest_test_utils.Subprocess([EX_EXE_PATH]).output
 
 # The tests.
 if SUPPORTS_SEH_EXCEPTIONS:
@@ -212,7 +225,8 @@ class CatchCxxExceptionsTest(gtest_test_utils.TestCase):
     uncaught_exceptions_ex_binary_output = gtest_test_utils.Subprocess(
         [EX_EXE_PATH,
          NO_CATCH_EXCEPTIONS_FLAG,
-         FITLER_OUT_SEH_TESTS_FLAG]).output
+         FITLER_OUT_SEH_TESTS_FLAG],
+        env=environ).output
 
     self.assert_('Unhandled C++ exception terminating the program'
                  in uncaught_exceptions_ex_binary_output)

test/gtest_premature_exit_test.cc

@@ -0,0 +1,141 @@
+// Copyright 2013, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: wan@google.com (Zhanyong Wan)
+//
+// Tests that Google Test manipulates the premature-exit-detection
+// file correctly.
+
+#include <stdio.h>
+
+#include "gtest/gtest.h"
+
+using ::testing::InitGoogleTest;
+using ::testing::Test;
+using ::testing::internal::posix::GetEnv;
+using ::testing::internal::posix::Stat;
+using ::testing::internal::posix::StatStruct;
+
+namespace {
+
+// Is the TEST_PREMATURE_EXIT_FILE environment variable expected to be
+// set?
+const bool kTestPrematureExitFileEnvVarShouldBeSet = false;
+
+class PrematureExitTest : public Test {
+ public:
+  // Returns true iff the given file exists.
+  static bool FileExists(const char* filepath) {
+    StatStruct stat;
+    return Stat(filepath, &stat) == 0;
+  }
+
+ protected:
+  PrematureExitTest() {
+    premature_exit_file_path_ = GetEnv("TEST_PREMATURE_EXIT_FILE");
+
+    // Normalize NULL to "" for ease of handling.
+    if (premature_exit_file_path_ == NULL) {
+      premature_exit_file_path_ = "";
+    }
+  }
+
+  // Returns true iff the premature-exit file exists.
+  bool PrematureExitFileExists() const {
+    return FileExists(premature_exit_file_path_);
+  }
+
+  const char* premature_exit_file_path_;
+};
+
+typedef PrematureExitTest PrematureExitDeathTest;
+
+// Tests that:
+//   - the premature-exit file exists during the execution of a
+//     death test (EXPECT_DEATH*), and
+//   - a death test doesn't interfere with the main test process's
+//     handling of the premature-exit file.
+TEST_F(PrematureExitDeathTest, FileExistsDuringExecutionOfDeathTest) {
+  if (*premature_exit_file_path_ == '\0') {
+    return;
+  }
+
+  EXPECT_DEATH_IF_SUPPORTED({
+      // If the file exists, crash the process such that the main test
+      // process will catch the (expected) crash and report a success;
+      // otherwise don't crash, which will cause the main test process
+      // to report that the death test has failed.
+      if (PrematureExitFileExists()) {
+        exit(1);
+      }
+    }, "");
+}
+
+// Tests that TEST_PREMATURE_EXIT_FILE is set where it's expected to
+// be set.
+TEST_F(PrematureExitTest, TestPrematureExitFileEnvVarIsSet) {
+  if (kTestPrematureExitFileEnvVarShouldBeSet) {
+    const char* const filepath = GetEnv("TEST_PREMATURE_EXIT_FILE");
+    ASSERT_TRUE(filepath != NULL);
+    ASSERT_NE(*filepath, '\0');
+  }
+}
+
+// Tests that the premature-exit file exists during the execution of a
+// normal (non-death) test.
+TEST_F(PrematureExitTest, PrematureExitFileExistsDuringTestExecution) {
+  if (*premature_exit_file_path_ == '\0') {
+    return;
+  }
+
+  EXPECT_TRUE(PrematureExitFileExists())
+      << " file " << premature_exit_file_path_
+      << " should exist during test execution, but doesn't.";
+}
+
+}  // namespace
+
+int main(int argc, char **argv) {
+  InitGoogleTest(&argc, argv);
+  const int exit_code = RUN_ALL_TESTS();
+
+  // Test that the premature-exit file is deleted upon return from
+  // RUN_ALL_TESTS().
+  const char* const filepath = GetEnv("TEST_PREMATURE_EXIT_FILE");
+  if (filepath != NULL && *filepath != '\0') {
+    if (PrematureExitTest::FileExists(filepath)) {
+      printf(
+          "File %s shouldn't exist after the test program finishes, but does.",
+          filepath);
+      return 1;
+    }
+  }
+
+  return exit_code;
+}

test/gtest_test_utils.py

@@ -56,6 +56,21 @@ GTEST_OUTPUT_VAR_NAME = 'GTEST_OUTPUT'
 IS_WINDOWS = os.name == 'nt'
 IS_CYGWIN = os.name == 'posix' and 'CYGWIN' in os.uname()[0]
 
+# The environment variable for specifying the path to the premature-exit file.
+PREMATURE_EXIT_FILE_ENV_VAR = 'TEST_PREMATURE_EXIT_FILE'
+
+environ = os.environ.copy()
+
+
+def SetEnvVar(env_var, value):
+  """Sets/unsets an environment variable to a given value."""
+
+  if value is not None:
+    environ[env_var] = value
+  elif env_var in environ:
+    del environ[env_var]
+
+
 # Here we expose a class from a particular module, depending on the
 # environment. The comment suppresses the 'Invalid variable name' lint
 # complaint.