// Copyright 2005, Google Inc.

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//

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//

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//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

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// 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"

#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"

// Indicates that this translation unit is part of Google Test's

// implementation.  It must come before gtest-internal-inl.h is

// included, or there will be a compiler error.  This trick is to

// prevent a user from accidentally including gtest-internal-inl.h in

// his code.

#define GTEST_IMPLEMENTATION_ 1

#include "src/gtest-internal-inl.h"

#undef GTEST_IMPLEMENTATION_

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.

static bool g_in_fast_death_test_child = false;

// 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 {

  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.

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