path: root/utils/unittest/googletest/gtest-death-test.cc

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// Author: wan@google.com (Zhanyong Wan)
//
// This file implements death tests.

#include <gtest/gtest-death-test.h>
#include <gtest/internal/gtest-port.h>

#ifdef GTEST_HAS_DEATH_TEST
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#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
#include "gtest/internal/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).");

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 "
    "colons.  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

#ifdef GTEST_HAS_DEATH_TEST

// ExitedWithCode constructor.
ExitedWithCode::ExitedWithCode(int exit_code) : exit_code_(exit_code) {
}

// ExitedWithCode function-call operator.
bool ExitedWithCode::operator()(int exit_status) const {
  return WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == exit_code_;
}

// 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_;
}

namespace internal {

// Utilities needed for death tests.

// Generates a textual description of a given exit code, in the format
// specified by wait(2).
static String ExitSummary(int exit_code) {
  Message m;
  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
  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);
}

// 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 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();
}

// Static string containing a description of the outcome of the
// last death test.
static String last_death_test_message;

// Flag characters for reporting a death test that did not die.
static const char kDeathTestLived = 'L';
static const char kDeathTestReturned = 'R';
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; and RETURNED means that the test statement attempted a "return,"
// which is not allowed.  IN_PROGRESS means the test has not yet
// concluded.
enum DeathTestOutcome { IN_PROGRESS, DIED, LIVED, RETURNED };

// Routine for aborting the program which is safe to call from an
// exec-style death test child process, in which case the 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 char* format, ...) {
  // 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-miniscule memory requirements.
  const InternalRunDeathTestFlag* const flag =
      GetUnitTestImpl()->internal_run_death_test_flag();
  va_list args;
  va_start(args, format);

  if (flag != NULL) {
    FILE* parent = fdopen(flag->status_fd, "w");
    fputc(kDeathTestInternalError, parent);
    vfprintf(parent, format, args);
    fclose(parent);
    va_end(args);
    _exit(1);
  } else {
    vfprintf(stderr, format, args);
    va_end(args);
    abort();
  }
}

// A replacement for CHECK that calls DeathTestAbort if the assertion
// fails.
#define GTEST_DEATH_TEST_CHECK_(expression) \
  do { \
    if (!(expression)) { \
      DeathTestAbort("CHECK failed: File %s, line %d: %s", \
                     __FILE__, __LINE__, #expression); \
    } \
  } while (0)

// 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 retval; \
    do { \
      retval = (expression); \
    } while (retval == -1 && errno == EINTR); \
    if (retval == -1) { \
      DeathTestAbort("CHECK failed: File %s, line %d: %s != -1", \
                     __FILE__, __LINE__, #expression); \
    } \
  } while (0)

// 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();
}

// ForkingDeathTest provides implementations for most of the abstract
// methods of the DeathTest interface.  Only the