text: // Copyright 2005, 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), vladl@google.com (Vlad Losev)
  //
  // This file implements death tests.
  
  #include "gtest/gtest-death-test.h"
  #include "gtest/internal/gtest-port.h"
  #include "gtest/internal/custom/gtest.h"
  
  #if GTEST_HAS_DEATH_TEST
  
  # if GTEST_OS_MAC
  #  include <crt_externs.h>
  # endif  // GTEST_OS_MAC
  
  # include <errno.h>
  # include <fcntl.h>
  # include <limits.h>
  
  # if GTEST_OS_LINUX
  #  include <signal.h>
  # endif  // GTEST_OS_LINUX
  
  # include <stdarg.h>
  
  # if GTEST_OS_WINDOWS
  #  include <windows.h>
  # else
  #  include <sys/mman.h>
  #  include <sys/wait.h>
  # endif  // GTEST_OS_WINDOWS
  
  # if GTEST_OS_QNX
  #  include <spawn.h>
  # endif  // GTEST_OS_QNX
  
  #endif  // GTEST_HAS_DEATH_TEST
  
  #include "gtest/gtest-message.h"
  #include "gtest/internal/gtest-string.h"
  #include "gtest-internal-inl.h"
  
  namespace testing {
  
  // Constants.
  
  // The default death test style.
  static const char kDefaultDeathTestStyle[] = "fast";
  
  GTEST_DEFINE_string_(
      death_test_style,
      internal::StringFromGTestEnv("death_test_style", kDefaultDeathTestStyle),
      "Indicates how to run a death test in a forked child process: "
      "\"threadsafe\" (child process re-executes the test binary "
      "from the beginning, running only the specific death test) or "
      "\"fast\" (child process runs the death test immediately "
      "after forking).");
  
  GTEST_DEFINE_bool_(
      death_test_use_fork,
      internal::BoolFromGTestEnv("death_test_use_fork", false),
      "Instructs to use fork()/_exit() instead of clone() in death tests. "
      "Ignored and always uses fork() on POSIX systems where clone() is not "
      "implemented. Useful when running under valgrind or similar tools if "
      "those do not support clone(). Valgrind 3.3.1 will just fail if "
      "it sees an unsupported combination of clone() flags. "
      "It is not recommended to use this flag w/o valgrind though it will "
      "work in 99% of the cases. Once valgrind is fixed, this flag will "
      "most likely be removed.");
  
  namespace internal {
  GTEST_DEFINE_string_(
      internal_run_death_test, "",
      "Indicates the file, line number, temporal index of "
      "the single death test to run, and a file descriptor to "
      "which a success code may be sent, all separated by "
      "the '|' characters.  This flag is specified if and only if the current "
      "process is a sub-process launched for running a thread-safe "
      "death test.  FOR INTERNAL USE ONLY.");
  }  // namespace internal
  
  #if GTEST_HAS_DEATH_TEST
  
  namespace internal {
  
  // Valid only for fast death tests. Indicates the code is running in the
  // child process of a fast style death test.
  # if !GTEST_OS_WINDOWS
  static bool g_in_fast_death_test_child = false;
  # endif
  
  // Returns a Boolean value indicating whether the caller is currently
  // executing in the context of the death test child process.  Tools such as
  // Valgrind heap checkers may need this to modify their behavior in death
  // tests.  IMPORTANT: This is an internal utility.  Using it may break the
  // implementation of death tests.  User code MUST NOT use it.
  bool InDeathTestChild() {
  # if GTEST_OS_WINDOWS
  
    // On Windows, death tests are thread-safe regardless of the value of the
    // death_test_style flag.
    return !GTEST_FLAG(internal_run_death_test).empty();
  
  # else
  
    if (GTEST_FLAG(death_test_style) == "threadsafe")
      return !GTEST_FLAG(internal_run_death_test).empty();
    else
      return g_in_fast_death_test_child;
  #endif
  }
  
  }  // namespace internal
  
  // ExitedWithCode constructor.
  ExitedWithCode::ExitedWithCode(int exit_code) : exit_code_(exit_code) {
  }
  
  // ExitedWithCode function-call operator.
  bool ExitedWithCode::operator()(int exit_status) const {
  # if GTEST_OS_WINDOWS
  
    return exit_status == exit_code_;
  
  # else
  
    return WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == exit_code_;
  
  # endif  // GTEST_OS_WINDOWS
  }
  
  # if !GTEST_OS_WINDOWS
  // KilledBySignal constructor.
  KilledBySignal::KilledBySignal(int signum) : signum_(signum) {
  }
  
  // KilledBySignal function-call operator.
  bool KilledBySignal::operator()(int exit_status) const {
  #  if defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
    {
      bool result;
      if (GTEST_KILLED_BY_SIGNAL_OVERRIDE_(signum_, exit_status, &result)) {
        return result;
      }
    }
  #  endif  // defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
    return WIFSIGNALED(exit_status) && WTERMSIG(exit_status) == signum_;
  }
  # endif  // !GTEST_OS_WINDOWS
  
  namespace internal {
  
  // Utilities needed for death tests.
  
  // Generates a textual description of a given exit code, in the format
  // specified by wait(2).
  static std::string ExitSummary(int exit_code) {
    Message m;
  
  # if GTEST_OS_WINDOWS
  
    m << "Exited with exit status " << exit_code;
  
  # else
  
    if (WIFEXITED(exit_code)) {
      m << "Exited with exit status " << WEXITSTATUS(exit_code);
    } else if (WIFSIGNALED(exit_code)) {
      m << "Terminated by signal " << WTERMSIG(exit_code);
    }
  #  ifdef WCOREDUMP
    if (WCOREDUMP(exit_code)) {
      m << " (core dumped)";
    }
  #  endif
  # endif  // GTEST_OS_WINDOWS
  
    return m.GetString();
  }
  
  // Returns true if exit_status describes a process that was terminated
  // by a signal, or exited normally with a nonzero exit code.
  bool ExitedUnsuccessfully(int exit_status) {
    return !ExitedWithCode(0)(exit_status);
  }
  
  # if !GTEST_OS_WINDOWS
  // Generates a textual failure message when a death test finds more than
  // one thread running, or cannot determine the number of threads, prior
  // to executing the given statement.  It is the responsibility of the
  // caller not to pass a thread_count of 1.
  static std::string DeathTestThreadWarning(size_t thread_count) {
    Message msg;
    msg << "Death tests use fork(), which is unsafe particularly"
        << " in a threaded context. For this test, " << GTEST_NAME_ << " ";
    if (thread_count == 0)
      msg << "couldn't detect the number of threads.";
    else
      msg << "detected " << thread_count << " threads.";
    return msg.GetString();
  }
  # endif  // !GTEST_OS_WINDOWS
  
  // Flag characters for reporting a death test that did not die.
  static const char kDeathTestLived = 'L';
  static const char kDeathTestReturned = 'R';
  static const char kDeathTestThrew = 'T';
  static const char kDeathTestInternalError = 'I';
  
  // An enumeration describing all of the possible ways that a death test can
  // conclude.  DIED means that the process died while executing the test
  // code; LIVED means that process lived beyond the end of the test code;
  // RETURNED means that the test statement attempted to execute a return
  // statement, which is not allowed; THREW means that the test statement
  // returned control by throwing an exception.  IN_PROGRESS means the test
  // has not yet concluded.
  // TODO(vladl@google.com): Unify names and possibly values for
  // AbortReason, DeathTestOutcome, and flag characters above.
  enum DeathTestOutcome { IN_PROGRESS, DIED, LIVED, RETURNED, THREW };
  
  // Routine for aborting the program which is safe to call from an
  // exec-style death test child process, in which case the error
  // message is propagated back to the parent process.  Otherwise, the
  // message is simply printed to stderr.  In either case, the program
  // then exits with status 1.
  static void DeathTestAbort(const std::string& message) {
    // On a POSIX system, this function may be called from a threadsafe-style
    // death test child process, which operates on a very small stack.  Use
    // the heap for any additional non-minuscule memory requirements.
    const InternalRunDeathTestFlag* const flag =
        GetUnitTestImpl()->internal_run_death_test_flag();
    if (flag != NULL) {
      FILE* parent = posix::FDOpen(flag->write_fd(), "w");
      fputc(kDeathTestInternalError, parent);
      fprintf(parent, "%s", message.c_str());
      fflush(parent);
      _exit(1);
    } else {
      fprintf(stderr, "%s", message.c_str());
      fflush(stderr);
      posix::Abort();
    }
  }
  
  // A replacement for CHECK that calls DeathTestAbort if the assertion
  // fails.
  # define GTEST_DEATH_TEST_CHECK_(expression) \
    do { \
      if (!::testing::internal::IsTrue(expression)) { \
        DeathTestAbort( \
            ::std::string("CHECK failed: File ") + __FILE__ +  ", line " \
            + ::testing::internal::StreamableToString(__LINE__) + ": " \
            + #expression); \
      } \
    } while (::testing::internal::AlwaysFalse())
  
  // This macro is similar to GTEST_DEATH_TEST_CHECK_, but it is meant for
  // evaluating any system call that fulfills two conditions: it must return
  // -1 on failure, and set errno to EINTR when it is interrupted and
  // should be tried again.  The macro expands to a loop that repeatedly
  // evaluates the expression as long as it evaluates to -1 and sets
  // errno to EINTR.  If the expression evaluates to -1 but errno is
  // something other than EINTR, DeathTestAbort is called.
  # define GTEST_DEATH_TEST_CHECK_SYSCALL_(expression) \
    do { \
      int gtest_retval; \
      do { \
        gtest_retval = (expression); \
      } while (gtest_retval == -1 && errno == EINTR); \
      if (gtest_retval == -1) { \
        DeathTestAbort( \
            ::std::string("CHECK failed: File ") + __FILE__ + ", line " \
            + ::testing::internal::StreamableToString(__LINE__) + ": " \
            + #expression + " != -1"); \
      } \
    } while (::testing::internal::AlwaysFalse())
  
  // Returns the message describing the last system error in errno.
  std::string GetLastErrnoDescription() {
      return errno == 0 ? "" : posix::StrError(errno);
  }
  
  // This is called from a death test parent process to read a failure
  // message from the death test child process and log it with the FATAL
  // severity. On Windows, the message is read from a pipe handle. On other
  // platforms, it is read from a file descriptor.
  static void FailFromInternalError(int fd) {
    Message error;
    char buffer[256];
    int num_read;
  
    do {
      while ((num_read = posix::Read(fd, buffer, 255)) > 0) {
        buffer[num_read] = '\0';
        error << buffer;
      }
    } while (num_read == -1 && errno == EINTR);
  
    if (num_read == 0) {
      GTEST_LOG_(FATAL) << error.GetString();
    } else {
      const int last_error = errno;
      GTEST_LOG_(FATAL) << "Error while reading death test internal: "
                        << GetLastErrnoDescription() << " [" << last_error << "]";
    }
  }
  
  // Death test constructor.  Increments the running death test count
  // for the current test.
  DeathTest::DeathTest() {
    TestInfo* const info = GetUnitTestImpl()->current_test_info();
    if (info == NULL) {
      DeathTestAbort("Cannot run a death test outside of a TEST or "
                     "TEST_F construct");
    }
  }
  
  // Creates and returns a death test by dispatching to the current
  // death test factory.
  bool DeathTest::Create(const char* statement, const RE* regex,
                         const char* file, int line, DeathTest** test) {
    return GetUnitTestImpl()->death_test_factory()->Create(
        statement, regex, file, line, test);
  }
  
  const char* DeathTest::LastMessage() {
    return last_death_test_message_.c_str();
  }
  
  void DeathTest::set_last_death_test_message(const std::string& message) {
    last_death_test_message_ = message;
  }
  
  std::string DeathTest::last_death_test_message_;
  
  // Provides cross platform implementation for some death functionality.
  class DeathTestImpl : public DeathTest {
   protected:
    DeathTestImpl(const char* a_statement, const RE* a_regex)
        : statement_(a_statement),
          regex_(a_regex),
          spawned_(false),
          status_(-1),
          outcome_(IN_PROGRESS),
          read_fd_(-1),
          write_fd_(-1) {}
  
    // read_fd_ is expected to be closed and cleared by a derived class.
    ~DeathTestImpl() { GTEST_DEATH_TEST_CHECK_(read_fd_ == -1); }
  
    void Abort(AbortReason reason);
    virtual bool Passed(bool status_ok);
  
    const char* statement() const { return statement_; }
    const RE* regex() const { return regex_; }
    bool spawned() const { return spawned_; }
    void set_spawned(bool is_spawned) { spawned_ = is_spawned; }
    int status() const { return status_; }
    void set_status(int a_status) { status_ = a_status; }
    DeathTestOutcome outcome() const { return outcome_; }
    void set_outcome(DeathTestOutcome an_outcome) { outcome_ = an_outcome; }
    int read_fd() const { return read_fd_; }
    void set_read_fd(int fd) { read_fd_ = fd; }
    int write_fd() const { return write_fd_; }
    void set_write_fd(int fd) { write_fd_ = fd; }
  
    // Called in the parent process only. Reads the result code of the death
    // test child process via a pipe, interprets it to set the outcome_
    // member, and closes read_fd_.  Outputs diagnostics and terminates in
    // case of unexpected codes.
    void ReadAndInterpretStatusByte();
  
   private:
    // The textual content of the code this object is testing.  This class
    // doesn't own this string and should not attempt to delete it.
    const char* const statement_;
    // The regular expression which test output must match.  DeathTestImpl
    // doesn't own this object and should not attempt to delete it.
    const RE* const regex_;
    // True if the death test child process has been successfully spawned.
    bool spawned_;
    // The exit status of the child process.
    int status_;
    // How the death test concluded.
    DeathTestOutcome outcome_;
    // Descriptor to the read end of the pipe to the child process.  It is
    // always -1 in the child process.  The child keeps its write end of the
    // pipe in write_fd_.
    int read_fd_;
    // Descriptor to the child's write end of the pipe to the parent process.
    // It is always -1 in the parent process.  The parent keeps its end of the
    // pipe in read_fd_.
    int write_fd_;
  };
  
  // Called in the parent process only. Reads the result code of the death
  // test child process via a pipe, interprets it to set the outcome_
  // member, and closes read_fd_.  Outputs diagnostics and terminates in
  // case of unexpected codes.
  void DeathTestImpl::ReadAndInterpretStatusByte() {
    char flag;
    int bytes_read;
  
    // The read() here blocks until data is available (signifying the
    // failure of the death test) or until the pipe is closed (signifying
    // its success), so it's okay to call this in the parent before
    // the child process has exited.
    do {
      bytes_read = posix::Read(read_fd(), &flag, 1);
    } while (bytes_read == -1 && errno == EINTR);
  
    if (bytes_read == 0) {
      set_outcome(DIED);
    } else if (bytes_read == 1) {
      switch (flag) {
        case kDeathTestReturned:
          set_outcome(RETURNED);
          break;
        case kDeathTestThrew:
          set_outcome(THREW);
          break;
        case kDeathTestLived:
          set_outcome(LIVED);
          break;
        case kDeathTestInternalError:
          FailFromInternalError(read_fd());  // Does not return.
          break;
        default:
          GTEST_LOG_(FATAL) << "Death test child process reported "
                            << "unexpected status byte ("
                            << static_cast<unsigned int>(flag) << ")";
      }
    } else {
      GTEST_LOG_(FATAL) << "Read from death test child process failed: "
                        << GetLastErrnoDescription();
    }
    GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Close(read_fd()));
    set_read_fd(-1);
  }
  
  // Signals that the death test code which should have exited, didn't.
  // Should be called only in a death test child process.
  // Writes a status byte to the child's status file descriptor, then
  // calls _exit(1).
  void DeathTestImpl::Abort(AbortReason reason) {
    // The parent process considers the death test to be a failure if
    // it finds any data in our pipe.  So, here we write a single flag byte
    // to the pipe, then exit.
    const char status_ch =
        reason == TEST_DID_NOT_DIE ? kDeathTestLived :
        reason == TEST_THREW_EXCEPTION ? kDeathTestThrew : kDeathTestReturned;
  
    GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Write(write_fd(), &status_ch, 1));
    // We are leaking the descriptor here because on some platforms (i.e.,
    // when built as Windows DLL), destructors of global objects will still
    // run after calling _exit(). On such systems, write_fd_ will be
    // indirectly closed from the destructor of UnitTestImpl, causing double
    // close if it is also closed here. On debug configurations, double close
    // may assert. As there are no in-process buffers to flush here, we are
    // relying on the OS to close the descriptor after the process terminates
    // when the destructors are not run.
    _exit(1);  // Exits w/o any normal exit hooks (we were supposed to crash)
  }
  
  // Returns an indented copy of stderr output for a death test.
  // This makes distinguishing death test output lines from regular log lines
  // much easier.
  static ::std::string FormatDeathTestOutput(const ::std::string& output) {
    ::std::string ret;
    for (size_t at = 0; ; ) {
      const size_t line_end = output.find('\n', at);
      ret += "[  DEATH   ] ";
      if (line_end == ::std::string::npos) {
        ret += output.substr(at);
        break;
      }
      ret += output.substr(at, line_end + 1 - at);
      at = line_end + 1;
    }
    return ret;
  }
  
  // Assesses the success or failure of a death test, using both private
  // members which have previously been set, and one argument:
  //
  // Private data members:
  //   outcome:  An enumeration describing how the death test
  //             concluded: DIED, LIVED, THREW, or RETURNED.  The death test
  //             fails in the latter three cases.
  //   status:   The exit status of the child process. On *nix, it is in the
  //             in the format specified by wait(2). On Windows, this is the
  //             value supplied to the ExitProcess() API or a numeric code
  //             of the exception that terminated the program.
  //   regex:    A regular expression object to be applied to
  //             the test's captured standard error output; the death test
  //             fails if it does not match.
  //
  // Argument:
  //   status_ok: true if exit_status is acceptable in the context of
  //              this particular death test, which fails if it is false
  //
  // Returns true iff all of the above conditions are met.  Otherwise, the
  // first failing condition, in the order given above, is the one that is
  // reported. Also sets the last death test message string.
  bool DeathTestImpl::Passed(bool status_ok) {
    if (!spawned())
      return false;
  
    const std::string error_message = GetCapturedStderr();
  
    bool success = false;
    Message buffer;
  
    buffer << "Death test: " << statement() << "\n";
    switch (outcome()) {
      case LIVED:
        buffer << "    Result: failed to die.\n"
               << " Error msg:\n" << FormatDeathTestOutput(error_message);
        break;
      case THREW:
        buffer << "    Result: threw an exception.\n"
               << " Error msg:\n" << FormatDeathTestOutput(error_message);
        break;
      case RETURNED:
        buffer << "    Result: illegal return in test statement.\n"
               << " Error msg:\n" << FormatDeathTestOutput(error_message);
        break;
      case DIED:
        if (status_ok) {
          const bool matched = RE::PartialMatch(error_message.c_str(), *regex());
          if (matched) {
            success = true;
          } else {
            buffer << "    Result: died but not with expected error.\n"
                   << "  Expected: " << regex()->pattern() << "\n"
                   << "Actual msg:\n" << FormatDeathTestOutput(error_message);
          }
        } else {
          buffer << "    Result: died but not with expected exit code:\n"
                 << "            " << ExitSummary(status()) << "\n"
                 << "Actual msg:\n" << FormatDeathTestOutput(error_message);
        }
        break;
      case IN_PROGRESS:
      default:
        GTEST_LOG_(FATAL)
            << "DeathTest::Passed somehow called before conclusion of test";
    }
  
    DeathTest::set_last_death_test_message(buffer.GetString());
    return success;
  }
  
  # if GTEST_OS_WINDOWS
  // WindowsDeathTest implements death tests on Windows. Due to the
  // specifics of starting new processes on Windows, death tests there are
  // always threadsafe, and Google Test considers the
  // --gtest_death_test_style=fast setting to be equivalent to
  // --gtest_death_test_style=threadsafe there.
  //
  // A few implementation notes:  Like the Linux version, the Windows
  // implementation uses pipes for child-to-parent communication. But due to
  // the specifics of pipes on Windows, some extra steps are required:
  //
  // 1. The parent creates a communication pipe and stores handles to both
  //    ends of it.
  // 2. The parent starts the child and provides it with the information
  //    necessary to acquire the handle to the write end of the pipe.
  // 3. The child acquires the write end of the pipe and signals the parent
  //    using a Windows event.
  // 4. Now the parent can release the write end of the pipe on its side. If
  //    this is done before step 3, the object's reference count goes down to
  //    0 and it is destroyed, preventing the child from acquiring it. The
  //    parent now has to release it, or read operations on the read end of
  //    the pipe will not return when the child terminates.
  // 5. The parent reads child's output through the pipe (outcome code and
  //    any possible error messages) from the pipe, and its stderr and then
  //    determines whether to fail the test.
  //
  // Note: to distinguish Win32 API calls from the local method and function
  // calls, the former are explicitly resolved in the global namespace.
  //
  class WindowsDeathTest : public DeathTestImpl {
   public:
    WindowsDeathTest(const char* a_statement,
                     const RE* a_regex,
                     const char* file,
                     int line)
        : DeathTestImpl(a_statement, a_regex), file_(file), line_(line) {}
  
    // All of these virtual functions are inherited from DeathTest.
    virtual int Wait();
    virtual TestRole AssumeRole();
  
   private:
    // The name of the file in which the death test is located.
    const char* const file_;
    // The line number on which the death test is located.
    const int line_;
    // Handle to the write end of the pipe to the child process.
    AutoHandle write_handle_;
    // Child process handle.
    AutoHandle child_handle_;
    // Event the child process uses to signal the parent that it has
    // acquired the handle to the write end of the pipe. After seeing this
    // event the parent can release its own handles to make sure its
    // ReadFile() calls return when the child terminates.
    AutoHandle event_handle_;
  };
  
  // Waits for the child in a death test to exit, returning its exit
  // status, or 0 if no child process exists.  As a side effect, sets the
  // outcome data member.
  int WindowsDeathTest::Wait() {
    if (!spawned())
      return 0;
  
    // Wait until the child either signals that it has acquired the write end
    // of the pipe or it dies.
    const HANDLE wait_handles[2] = { child_handle_.Get(), event_handle_.Get() };
    switch (::WaitForMultipleObjects(2,
                                     wait_handles,
                                     FALSE,  // Waits for any of the handles.
                                     INFINITE)) {
      case WAIT_OBJECT_0:
      case WAIT_OBJECT_0 + 1:
        break;
      default:
        GTEST_DEATH_TEST_CHECK_(false);  // Should not get here.
    }
  
    // The child has acquired the write end of the pipe or exited.
    // We release the handle on our side and continue.
    write_handle_.Reset();
    event_handle_.Reset();
  
    ReadAndInterpretStatusByte();
  
    // Waits for the child process to exit if it haven't already. This
    // returns immediately if the child has already exited, regardless of
    // whether previous calls to WaitForMultipleObjects synchronized on this
    // handle or not.
    GTEST_DEATH_TEST_CHECK_(
        WAIT_OBJECT_0 == ::WaitForSingleObject(child_handle_.Get(),
                                               INFINITE));
    DWORD status_code;
    GTEST_DEATH_TEST_CHECK_(
        ::GetExitCodeProcess(child_handle_.Get(), &status_code) != FALSE);
    child_handle_.Reset();
    set_status(static_cast<int>(status_code));
    return status();
  }
  
  // The AssumeRole process for a Windows death test.  It creates a child
  // process with the same executable as the current process to run the
  // death test.  The child process is given the --gtest_filter and
  // --gtest_internal_run_death_test flags such that it knows to run the
  // current death test only.
  DeathTest::TestRole WindowsDeathTest::AssumeRole() {
    const UnitTestImpl* const impl = GetUnitTestImpl();
    const InternalRunDeathTestFlag* const flag =
        impl->internal_run_death_test_flag();
    const TestInfo* const info = impl->current_test_info();
    const int death_test_index = info->result()->death_test_count();
  
    if (flag != NULL) {
      // ParseInternalRunDeathTestFlag() has performed all the necessary
      // processing.
      set_write_fd(flag->write_fd());
      return EXECUTE_TEST;
    }
  
    // WindowsDeathTest uses an anonymous pipe to communicate results of
    // a death test.
    SECURITY_ATTRIBUTES handles_are_inheritable = {
      sizeof(SECURITY_ATTRIBUTES), NULL, TRUE };
    HANDLE read_handle, write_handle;
    GTEST_DEATH_TEST_CHECK_(
        ::CreatePipe(&read_handle, &write_handle, &handles_are_inheritable,
                     0)  // Default buffer size.
        != FALSE);
    set_read_fd(::_open_osfhandle(reinterpret_cast<intptr_t>(read_handle),
                                  O_RDONLY));
    write_handle_.Reset(write_handle);
    event_handle_.Reset(::CreateEvent(
        &handles_are_inheritable,
        TRUE,    // The event will automatically reset to non-signaled state.
        FALSE,   // The initial state is non-signalled.
        NULL));  // The even is unnamed.
    GTEST_DEATH_TEST_CHECK_(event_handle_.Get() != NULL);
    const std::string filter_flag =
        std::string("--") + GTEST_FLAG_PREFIX_ + kFilterFlag + "=" +
        info->test_case_name() + "." + info->name();
    const std::string internal_flag =
        std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag +
        "=" + file_ + "|" + StreamableToString(line_) + "|" +
        StreamableToString(death_test_index) + "|" +
        StreamableToString(static_cast<unsigned int>(::GetCurrentProcessId())) +
        // size_t has the same width as pointers on both 32-bit and 64-bit
        // Windows platforms.
        // See http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx.
        "|" + StreamableToString(reinterpret_cast<size_t>(write_handle)) +
        "|" + StreamableToString(reinterpret_cast<size_t>(event_handle_.Get()));
  
    char executable_path[_MAX_PATH + 1];  // NOLINT
    GTEST_DEATH_TEST_CHECK_(
        _MAX_PATH + 1 != ::GetModuleFileNameA(NULL,
                                              executable_path,
                                              _MAX_PATH));
  
    std::string command_line =
        std::string(::GetCommandLineA()) + " " + filter_flag + " \"" +
        internal_flag + "\"";
  
    DeathTest::set_last_death_test_message("");
  
    CaptureStderr();
    // Flush the log buffers since the log streams are shared with the child.
    FlushInfoLog();
  
    // The child process will share the standard handles with the parent.
    STARTUPINFOA startup_info;
    memset(&startup_info, 0, sizeof(STARTUPINFO));
    startup_info.dwFlags = STARTF_USESTDHANDLES;
    startup_info.hStdInput = ::GetStdHandle(STD_INPUT_HANDLE);
    startup_info.hStdOutput = ::GetStdHandle(STD_OUTPUT_HANDLE);
    startup_info.hStdError = ::GetStdHandle(STD_ERROR_HANDLE);
  
    PROCESS_INFORMATION process_info;
    GTEST_DEATH_TEST_CHECK_(::CreateProcessA(
        executable_path,
        const_cast<char*>(command_line.c_str()),
        NULL,   // Retuned process handle is not inheritable.
        NULL,   // Retuned thread handle is not inheritable.
        TRUE,   // Child inherits all inheritable handles (for write_handle_).
        0x0,    // Default creation flags.
        NULL,   // Inherit the parent's environment.
        UnitTest::GetInstance()->original_working_dir(),
        &startup_info,
        &process_info) != FALSE);
    child_handle_.Reset(process_info.hProcess);
    ::CloseHandle(process_info.hThread);
    set_spawned(true);
    return OVERSEE_TEST;
  }
  # else  // We are not on Windows.
  
  // ForkingDeathTest provides implementations for most of the abstract
  // methods of the DeathTest interface.  Only the AssumeRole method is
  // left undefined.
  class ForkingDeathTest : public DeathTestImpl {
   public:
    ForkingDeathTest(const char* statement, const RE* regex);
  
    // All of these virtual functions are inherited from DeathTest.
    virtual int Wait();
  
   protected:
    void set_child_pid(pid_t child_pid) { child_pid_ = child_pid; }
  
   private:
    // PID of child process during death test; 0 in the child process itself.
    pid_t child_pid_;
  };
  
  // Constructs a ForkingDeathTest.
  ForkingDeathTest::ForkingDeathTest(const char* a_statement, const RE* a_regex)
      : DeathTestImpl(a_statement, a_regex),
        child_pid_(-1) {}
  
  // Waits for the child in a death test to exit, returning its exit
  // status, or 0 if no child process exists.  As a side effect, sets the
  // outcome data member.
  int ForkingDeathTest::Wait() {
    if (!spawned())
      return 0;
  
    ReadAndInterpretStatusByte();
  
    int status_value;
    GTEST_DEATH_TEST_CHECK_SYSCALL_(waitpid(child_pid_, &status_value, 0));
    set_status(status_value);
    return status_value;
  }
  
  // A concrete death test class that forks, then immediately runs the test
  // in the child process.
  class NoExecDeathTest : public ForkingDeathTest {
   public:
    NoExecDeathTest(const char* a_statement, const RE* a_regex) :
        ForkingDeathTest(a_statement, a_regex) { }
    virtual TestRole AssumeRole();
  };
  
  // The AssumeRole process for a fork-and-run death test.  It implements a
  // straightforward fork, with a simple pipe to transmit the status byte.
  DeathTest::TestRole NoExecDeathTest::AssumeRole() {
    const size_t thread_count = GetThreadCount();
    if (thread_count != 1) {
      GTEST_LOG_(WARNING) << DeathTestThreadWarning(thread_count);
    }
  
    int pipe_fd[2];
    GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
  
    DeathTest::set_last_death_test_message("");
    CaptureStderr();
    // When we fork the process below, the log file buffers are copied, but the
    // file descriptors are shared.  We flush all log files here so that closing
    // the file descriptors in the child process doesn't throw off the
    // synchronization between descriptors and buffers in the parent process.
    // This is as close to the fork as possible to avoid a race condition in case
    // there are multiple threads running before the death test, and another
    // thread writes to the log file.
    FlushInfoLog();
  
    const pid_t child_pid = fork();
    GTEST_DEATH_TEST_CHECK_(child_pid != -1);
    set_child_pid(child_pid);
    if (child_pid == 0) {
      GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[0]));
      set_write_fd(pipe_fd[1]);
      // Redirects all logging to stderr in the child process to prevent
      // concurrent writes to the log files.  We capture stderr in the parent
      // process and append the child process' output to a log.
      LogToStderr();
      // Event forwarding to the listeners of event listener API mush be shut
      // down in death test subprocesses.
      GetUnitTestImpl()->listeners()->SuppressEventForwarding();
      g_in_fast_death_test_child = true;
      return EXECUTE_TEST;
    } else {
      GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
      set_read_fd(pipe_fd[0]);
      set_spawned(true);
      return OVERSEE_TEST;
    }
  }
  
  // A concrete death test class that forks and re-executes the main
  // program from the beginning, with command-line flags set that cause
  // only this specific death test to be run.
  class ExecDeathTest : public ForkingDeathTest {
   public:
    ExecDeathTest(const char* a_statement, const RE* a_regex,
                  const char* file, int line) :
        ForkingDeathTest(a_statement, a_regex), file_(file), line_(line) { }
    virtual TestRole AssumeRole();
   private:
    static ::std::vector<std::string> GetArgvsForDeathTestChildProcess() {
      ::std::vector<std::string> args = GetInjectableArgvs();
  #  if defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
      ::std::vector<std::string> extra_args =
          GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_();
      args.insert(args.end(), extra_args.begin(), extra_args.end());
  #  endif  // defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
      return args;
    }
    // The name of the file in which the death test is located.
    const char* const file_;
    // The line number on which the death test is located.
    const int line_;
  };
  
  // Utility class for accumulating command-line arguments.
  class Arguments {
   public:
    Arguments() {
      args_.push_back(NULL);
    }
  
    ~Arguments() {
      for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
           ++i) {
        free(*i);
      }
    }
    void AddArgument(const char* argument) {
      args_.insert(args_.end() - 1, posix::StrDup(argument));
    }
  
    template <typename Str>
    void AddArguments(const ::std::vector<Str>& arguments) {
      for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
           i != arguments.end();
           ++i) {
        args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
      }
    }
    char* const* Argv() {
      return &args_[0];
    }
  
   private:
    std::vector<char*> args_;
  };
  
  // A struct that encompasses the arguments to the child process of a
  // threadsafe-style death test process.
  struct ExecDeathTestArgs {
    char* const* argv;  // Command-line arguments for the child's call to exec
    int close_fd;       // File descriptor to close; the read end of a pipe
  };
  
  #  if GTEST_OS_MAC
  inline char** GetEnviron() {
    // When Google Test is built as a framework on MacOS X, the environ variable
    // is unavailable. Apple's documentation (man environ) recommends using
    // _NSGetEnviron() instead.
    return *_NSGetEnviron();
  }
  #  else
  // Some POSIX platforms expect you to declare environ. extern "C" makes
  // it reside in the global namespace.
  extern "C" char** environ;
  inline char** GetEnviron() { return environ; }
  #  endif  // GTEST_OS_MAC
  
  #  if !GTEST_OS_QNX
  // The main function for a threadsafe-style death test child process.
  // This function is called in a clone()-ed process and thus must avoid
  // any potentially unsafe operations like malloc or libc functions.
  static int ExecDeathTestChildMain(void* child_arg) {
    ExecDeathTestArgs* const args = static_cast<ExecDeathTestArgs*>(child_arg);
    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(args->close_fd));
  
    // We need to execute the test program in the same environment where
    // it was originally invoked.  Therefore we change to the original
    // working directory first.
    const char* const original_dir =
        UnitTest::GetInstance()->original_working_dir();
    // We can safely call chdir() as it's a direct system call.
    if (chdir(original_dir) != 0) {
      DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
                     GetLastErrnoDescription());
      return EXIT_FAILURE;
    }
  
    // We can safely call execve() as it's a direct system call.  We
    // cannot use execvp() as it's a libc function and thus potentially
    // unsafe.  Since execve() doesn't search the PATH, the user must
    // invoke the test program via a valid path that contains at least
    // one path separator.
    execve(args->argv[0], args->argv, GetEnviron());
    DeathTestAbort(std::string("execve(") + args->argv[0] + ", ...) in " +
                   original_dir + " failed: " +
                   GetLastErrnoDescription());
    return EXIT_FAILURE;
  }
  #  endif  // !GTEST_OS_QNX
  
  #  if GTEST_HAS_CLONE
  // Two utility routines that together determine the direction the stack
  // grows.
  // This could be accomplished more elegantly by a single recursive
  // function, but we want to guard against the unlikely possibility of
  // a smart compiler optimizing the recursion away.
  //
  // GTEST_NO_INLINE_ is required to prevent GCC 4.6 from inlining
  // StackLowerThanAddress into StackGrowsDown, which then doesn't give
  // correct answer.
  static void StackLowerThanAddress(const void* ptr,
                                    bool* result) GTEST_NO_INLINE_;
  static void StackLowerThanAddress(const void* ptr, bool* result) {
    int dummy;
    *result = (&dummy < ptr);
  }
  
  // Make sure AddressSanitizer does not tamper with the stack here.
  GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
  static bool StackGrowsDown() {
    int dummy;
    bool result;
    StackLowerThanAddress(&dummy, &result);
    return result;
  }
  #  endif  // GTEST_HAS_CLONE
  
  // Spawns a child process with the same executable as the current process in
  // a thread-safe manner and instructs it to run the death test.  The
  // implementation uses fork(2) + exec.  On systems where clone(2) is
  // available, it is used instead, being slightly more thread-safe.  On QNX,
  // fork supports only single-threaded environments, so this function uses
  // spawn(2) there instead.  The function dies with an error message if
  // anything goes wrong.
  static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
    ExecDeathTestArgs args = { argv, close_fd };
    pid_t child_pid = -1;
  
  #  if GTEST_OS_QNX
    // Obtains the current directory and sets it to be closed in the child
    // process.
    const int cwd_fd = open(".", O_RDONLY);
    GTEST_DEATH_TEST_CHECK_(cwd_fd != -1);
    GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(cwd_fd, F_SETFD, FD_CLOEXEC));
    // We need to execute the test program in the same environment where
    // it was originally invoked.  Therefore we change to the original
    // working directory first.
    const char* const original_dir =
        UnitTest::GetInstance()->original_working_dir();
    // We can safely call chdir() as it's a direct system call.
    if (chdir(original_dir) != 0) {
      DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
                     GetLastErrnoDescription());
      return EXIT_FAILURE;
    }
  
    int fd_flags;
    // Set close_fd to be closed after spawn.
    GTEST_DEATH_TEST_CHECK_SYSCALL_(fd_flags = fcntl(close_fd, F_GETFD));
    GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(close_fd, F_SETFD,
                                          fd_flags | FD_CLOEXEC));
    struct inheritance inherit = {0};
    // spawn is a system call.
    child_pid = spawn(args.argv[0], 0, NULL, &inherit, args.argv, GetEnviron());
    // Restores the current working directory.
    GTEST_DEATH_TEST_CHECK_(fchdir(cwd_fd) != -1);
    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(cwd_fd));
  
  #  else   // GTEST_OS_QNX
  #   if GTEST_OS_LINUX
    // When a SIGPROF signal is received while fork() or clone() are executing,
    // the process may hang. To avoid this, we ignore SIGPROF here and re-enable
    // it after the call to fork()/clone() is complete.
    struct sigaction saved_sigprof_action;
    struct sigaction ignore_sigprof_action;
    memset(&ignore_sigprof_action, 0, sizeof(ignore_sigprof_action));
    sigemptyset(&ignore_sigprof_action.sa_mask);
    ignore_sigprof_action.sa_handler = SIG_IGN;
    GTEST_DEATH_TEST_CHECK_SYSCALL_(sigaction(
        SIGPROF, &ignore_sigprof_action, &saved_sigprof_action));
  #   endif  // GTEST_OS_LINUX
  
  #   if GTEST_HAS_CLONE
    const bool use_fork = GTEST_FLAG(death_test_use_fork);
  
    if (!use_fork) {
      static const bool stack_grows_down = StackGrowsDown();
      const size_t stack_size = getpagesize();
      // MMAP_ANONYMOUS is not defined on Mac, so we use MAP_ANON instead.
      void* const stack = mmap(NULL, stack_size, PROT_READ | PROT_WRITE,
                               MAP_ANON | MAP_PRIVATE, -1, 0);
      GTEST_DEATH_TEST_CHECK_(stack != MAP_FAILED);
  
      // Maximum stack alignment in bytes:  For a downward-growing stack, this
      // amount is subtracted from size of the stack space to get an address
      // that is within the stack space and is aligned on all systems we care
      // about.  As far as I know there is no ABI with stack alignment greater
      // than 64.  We assume stack and stack_size already have alignment of
      // kMaxStackAlignment.
      const size_t kMaxStackAlignment = 64;
      void* const stack_top =
          static_cast<char*>(stack) +
              (stack_grows_down ? stack_size - kMaxStackAlignment : 0);
      GTEST_DEATH_TEST_CHECK_(stack_size > kMaxStackAlignment &&
          reinterpret_cast<intptr_t>(stack_top) % kMaxStackAlignment == 0);
  
      child_pid = clone(&ExecDeathTestChildMain, stack_top, SIGCHLD, &args);
  
      GTEST_DEATH_TEST_CHECK_(munmap(stack, stack_size) != -1);
    }
  #   else
    const bool use_fork = true;
  #   endif  // GTEST_HAS_CLONE
  
    if (use_fork && (child_pid = fork()) == 0) {
        ExecDeathTestChildMain(&args);
        _exit(0);
    }
  #  endif  // GTEST_OS_QNX
  #  if GTEST_OS_LINUX
    GTEST_DEATH_TEST_CHECK_SYSCALL_(
        sigaction(SIGPROF, &saved_sigprof_action, NULL));
  #  endif  // GTEST_OS_LINUX
  
    GTEST_DEATH_TEST_CHECK_(child_pid != -1);
    return child_pid;
  }
  
  // The AssumeRole process for a fork-and-exec death test.  It re-executes the
  // main program from the beginning, setting the --gtest_filter
  // and --gtest_internal_run_death_test flags to cause only the current
  // death test to be re-run.
  DeathTest::TestRole ExecDeathTest::AssumeRole() {
    const UnitTestImpl* const impl = GetUnitTestImpl();
    const InternalRunDeathTestFlag* const flag =
        impl->internal_run_death_test_flag();
    const TestInfo* const info = impl->current_test_info();
    const int death_test_index = info->result()->death_test_count();
  
    if (flag != NULL) {
      set_write_fd(flag->write_fd());
      return EXECUTE_TEST;
    }
  
    int pipe_fd[2];
    GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
    // Clear the close-on-exec flag on the write end of the pipe, lest
    // it be closed when the child process does an exec:
    GTEST_DEATH_TEST_CHECK_(fcntl(pipe_fd[1], F_SETFD, 0) != -1);
  
    const std::string filter_flag =
        std::string("--") + GTEST_FLAG_PREFIX_ + kFilterFlag + "="
        + info->test_case_name() + "." + info->name();
    const std::string internal_flag =
        std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag + "="
        + file_ + "|" + StreamableToString(line_) + "|"
        + StreamableToString(death_test_index) + "|"
        + StreamableToString(pipe_fd[1]);
    Arguments args;
    args.AddArguments(GetArgvsForDeathTestChildProcess());
    args.AddArgument(filter_flag.c_str());
    args.AddArgument(internal_flag.c_str());
  
    DeathTest::set_last_death_test_message("");
  
    CaptureStderr();
    // See the comment in NoExecDeathTest::AssumeRole for why the next line
    // is necessary.
    FlushInfoLog();
  
    const pid_t child_pid = ExecDeathTestSpawnChild(args.Argv(), pipe_fd[0]);
    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
    set_child_pid(child_pid);
    set_read_fd(pipe_fd[0]);
    set_spawned(true);
    return OVERSEE_TEST;
  }
  
  # endif  // !GTEST_OS_WINDOWS
  
  // Creates a concrete DeathTest-derived class that depends on the
  // --gtest_death_test_style flag, and sets the pointer pointed to
  // by the "test" argument to its address.  If the test should be
  // skipped, sets that pointer to NULL.  Returns true, unless the
  // flag is set to an invalid value.
  bool DefaultDeathTestFactory::Create(const char* statement, const RE* regex,
                                       const char* file, int line,
                                       DeathTest** test) {
    UnitTestImpl* const impl = GetUnitTestImpl();
    const InternalRunDeathTestFlag* const flag =
        impl->internal_run_death_test_flag();
    const int death_test_index = impl->current_test_info()
        ->increment_death_test_count();
  
    if (flag != NULL) {
      if (death_test_index > flag->index()) {
        DeathTest::set_last_death_test_message(
            "Death test count (" + StreamableToString(death_test_index)
            + ") somehow exceeded expected maximum ("
            + StreamableToString(flag->index()) + ")");
        return false;
      }
  
      if (!(flag->file() == file && flag->line() == line &&
            flag->index() == death_test_index)) {
        *test = NULL;
        return true;
      }
    }
  
  # if GTEST_OS_WINDOWS
  
    if (GTEST_FLAG(death_test_style) == "threadsafe" ||
        GTEST_FLAG(death_test_style) == "fast") {
      *test = new WindowsDeathTest(statement, regex, file, line);
    }
  
  # else
  
    if (GTEST_FLAG(death_test_style) == "threadsafe") {
      *test = new ExecDeathTest(statement, regex, file, line);
    } else if (GTEST_FLAG(death_test_style) == "fast") {
      *test = new NoExecDeathTest(statement, regex);
    }
  
  # endif  // GTEST_OS_WINDOWS
  
    else {  // NOLINT - this is more readable than unbalanced brackets inside #if.
      DeathTest::set_last_death_test_message(
          "Unknown death test style \"" + GTEST_FLAG(death_test_style)
          + "\" encountered");
      return false;
    }
  
    return true;
  }
  
  # if GTEST_OS_WINDOWS
  // Recreates the pipe and event handles from the provided parameters,
  // signals the event, and returns a file descriptor wrapped around the pipe
  // handle. This function is called in the child process only.
  static int GetStatusFileDescriptor(unsigned int parent_process_id,
                                     size_t write_handle_as_size_t,
                                     size_t event_handle_as_size_t) {
    AutoHandle parent_process_handle(::OpenProcess(PROCESS_DUP_HANDLE,
                                                   FALSE,  // Non-inheritable.
                                                   parent_process_id));
    if (parent_process_handle.Get() == INVALID_HANDLE_VALUE) {
      DeathTestAbort("Unable to open parent process " +
                     StreamableToString(parent_process_id));
    }
  
    // TODO(vladl@google.com): Replace the following check with a
    // compile-time assertion when available.
    GTEST_CHECK_(sizeof(HANDLE) <= sizeof(size_t));
  
    const HANDLE write_handle =
        reinterpret_cast<HANDLE>(write_handle_as_size_t);
    HANDLE dup_write_handle;
  
    // The newly initialized handle is accessible only in the parent
    // process. To obtain one accessible within the child, we need to use
    // DuplicateHandle.
    if (!::DuplicateHandle(parent_process_handle.Get(), write_handle,
                           ::GetCurrentProcess(), &dup_write_handle,
                           0x0,    // Requested privileges ignored since
                                   // DUPLICATE_SAME_ACCESS is used.
                           FALSE,  // Request non-inheritable handler.
                           DUPLICATE_SAME_ACCESS)) {
      DeathTestAbort("Unable to duplicate the pipe handle " +
                     StreamableToString(write_handle_as_size_t) +
                     " from the parent process " +
                     StreamableToString(parent_process_id));
    }
  
    const HANDLE event_handle = reinterpret_cast<HANDLE>(event_handle_as_size_t);
    HANDLE dup_event_handle;
  
    if (!::DuplicateHandle(parent_process_handle.Get(), event_handle,
                           ::GetCurrentProcess(), &dup_event_handle,
                           0x0,
                           FALSE,
                           DUPLICATE_SAME_ACCESS)) {
      DeathTestAbort("Unable to duplicate the event handle " +
                     StreamableToString(event_handle_as_size_t) +
                     " from the parent process " +
                     StreamableToString(parent_process_id));
    }
  
    const int write_fd =
        ::_open_osfhandle(reinterpret_cast<intptr_t>(dup_write_handle), O_APPEND);
    if (write_fd == -1) {
      DeathTestAbort("Unable to convert pipe handle " +
                     StreamableToString(write_handle_as_size_t) +
                     " to a file descriptor");
    }
  
    // Signals the parent that the write end of the pipe has been acquired
    // so the parent can release its own write end.
    ::SetEvent(dup_event_handle);
  
    return write_fd;
  }
  # endif  // GTEST_OS_WINDOWS
  
  // Returns a newly created InternalRunDeathTestFlag object with fields
  // initialized from the GTEST_FLAG(internal_run_death_test) flag if
  // the flag is specified; otherwise returns NULL.
  InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag() {
    if (GTEST_FLAG(internal_run_death_test) == "") return NULL;
  
    // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we
    // can use it here.
    int line = -1;
    int index = -1;
    ::std::vector< ::std::string> fields;
    SplitString(GTEST_FLAG(internal_run_death_test).c_str(), '|', &fields);
    int write_fd = -1;
  
  # if GTEST_OS_WINDOWS
  
    unsigned int parent_process_id = 0;
    size_t write_handle_as_size_t = 0;
    size_t event_handle_as_size_t = 0;
  
    if (fields.size() != 6
        || !ParseNaturalNumber(fields[1], &line)
        || !ParseNaturalNumber(fields[2], &index)
        || !ParseNaturalNumber(fields[3], &parent_process_id)
        || !ParseNaturalNumber(fields[4], &write_handle_as_size_t)
        || !ParseNaturalNumber(fields[5], &event_handle_as_size_t)) {
      DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
                     GTEST_FLAG(internal_run_death_test));
    }
    write_fd = GetStatusFileDescriptor(parent_process_id,
                                       write_handle_as_size_t,
                                       event_handle_as_size_t);
  # else
  
    if (fields.size() != 4
        || !ParseNaturalNumber(fields[1], &line)
        || !ParseNaturalNumber(fields[2], &index)
        || !ParseNaturalNumber(fields[3], &write_fd)) {
      DeathTestAbort("Bad --gtest_internal_run_death_test flag: "
          + GTEST_FLAG(internal_run_death_test));
    }
  
  # endif  // GTEST_OS_WINDOWS
  
    return new InternalRunDeathTestFlag(fields[0], line, index, write_fd);
  }
  
  }  // namespace internal
  
  #endif  // GTEST_HAS_DEATH_TEST
  
  }  // namespace testing
  