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1 // Copyright 2005, Google Inc.
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29 
30 //
31 // This file implements death tests.
32 
33 #include "gtest/gtest-death-test.h"
34 
35 #include <utility>
36 
39 
40 #if GTEST_HAS_DEATH_TEST
41 
42 # if GTEST_OS_MAC
43 # include <crt_externs.h>
44 # endif // GTEST_OS_MAC
45 
46 # include <errno.h>
47 # include <fcntl.h>
48 # include <limits.h>
49 
50 # if GTEST_OS_LINUX
51 # include <signal.h>
52 # endif // GTEST_OS_LINUX
53 
54 # include <stdarg.h>
55 
56 # if GTEST_OS_WINDOWS
57 # include <windows.h>
58 # else
59 # include <sys/mman.h>
60 # include <sys/wait.h>
61 # endif // GTEST_OS_WINDOWS
62 
63 # if GTEST_OS_QNX
64 # include <spawn.h>
65 # endif // GTEST_OS_QNX
66 
67 # if GTEST_OS_FUCHSIA
68 # include <lib/fdio/fd.h>
69 # include <lib/fdio/io.h>
70 # include <lib/fdio/spawn.h>
71 # include <lib/zx/channel.h>
72 # include <lib/zx/port.h>
73 # include <lib/zx/process.h>
74 # include <lib/zx/socket.h>
75 # include <zircon/processargs.h>
76 # include <zircon/syscalls.h>
77 # include <zircon/syscalls/policy.h>
78 # include <zircon/syscalls/port.h>
79 # endif // GTEST_OS_FUCHSIA
80 
81 #endif // GTEST_HAS_DEATH_TEST
82 
83 #include "gtest/gtest-message.h"
85 #include "src/gtest-internal-inl.h"
86 
87 namespace testing {
88 
89 // Constants.
90 
91 // The default death test style.
92 //
93 // This is defined in internal/gtest-port.h as "fast", but can be overridden by
94 // a definition in internal/custom/gtest-port.h. The recommended value, which is
95 // used internally at Google, is "threadsafe".
97 
99  death_test_style,
101  "Indicates how to run a death test in a forked child process: "
102  "\"threadsafe\" (child process re-executes the test binary "
103  "from the beginning, running only the specific death test) or "
104  "\"fast\" (child process runs the death test immediately "
105  "after forking).");
106 
108  death_test_use_fork,
109  internal::BoolFromGTestEnv("death_test_use_fork", false),
110  "Instructs to use fork()/_exit() instead of clone() in death tests. "
111  "Ignored and always uses fork() on POSIX systems where clone() is not "
112  "implemented. Useful when running under valgrind or similar tools if "
113  "those do not support clone(). Valgrind 3.3.1 will just fail if "
114  "it sees an unsupported combination of clone() flags. "
115  "It is not recommended to use this flag w/o valgrind though it will "
116  "work in 99% of the cases. Once valgrind is fixed, this flag will "
117  "most likely be removed.");
118 
119 namespace internal {
121  internal_run_death_test, "",
122  "Indicates the file, line number, temporal index of "
123  "the single death test to run, and a file descriptor to "
124  "which a success code may be sent, all separated by "
125  "the '|' characters. This flag is specified if and only if the "
126  "current process is a sub-process launched for running a thread-safe "
127  "death test. FOR INTERNAL USE ONLY.");
128 } // namespace internal
129 
130 #if GTEST_HAS_DEATH_TEST
131 
132 namespace internal {
133 
134 // Valid only for fast death tests. Indicates the code is running in the
135 // child process of a fast style death test.
136 # if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
137 static bool g_in_fast_death_test_child = false;
138 # endif
139 
140 // Returns a Boolean value indicating whether the caller is currently
141 // executing in the context of the death test child process. Tools such as
142 // Valgrind heap checkers may need this to modify their behavior in death
143 // tests. IMPORTANT: This is an internal utility. Using it may break the
144 // implementation of death tests. User code MUST NOT use it.
145 bool InDeathTestChild() {
146 # if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
147 
148  // On Windows and Fuchsia, death tests are thread-safe regardless of the value
149  // of the death_test_style flag.
150  return !GTEST_FLAG(internal_run_death_test).empty();
151 
152 # else
153 
154  if (GTEST_FLAG(death_test_style) == "threadsafe")
155  return !GTEST_FLAG(internal_run_death_test).empty();
156  else
157  return g_in_fast_death_test_child;
158 #endif
159 }
160 
161 } // namespace internal
162 
163 // ExitedWithCode constructor.
164 ExitedWithCode::ExitedWithCode(int exit_code) : exit_code_(exit_code) {
165 }
166 
167 // ExitedWithCode function-call operator.
168 bool ExitedWithCode::operator()(int exit_status) const {
169 # if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
170 
171  return exit_status == exit_code_;
172 
173 # else
174 
175  return WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == exit_code_;
176 
177 # endif // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
178 }
179 
180 # if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
181 // KilledBySignal constructor.
182 KilledBySignal::KilledBySignal(int signum) : signum_(signum) {
183 }
184 
185 // KilledBySignal function-call operator.
186 bool KilledBySignal::operator()(int exit_status) const {
187 # if defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
188  {
189  bool result;
190  if (GTEST_KILLED_BY_SIGNAL_OVERRIDE_(signum_, exit_status, &result)) {
191  return result;
192  }
193  }
194 # endif // defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
195  return WIFSIGNALED(exit_status) && WTERMSIG(exit_status) == signum_;
196 }
197 # endif // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
198 
199 namespace internal {
200 
201 // Utilities needed for death tests.
202 
203 // Generates a textual description of a given exit code, in the format
204 // specified by wait(2).
205 static std::string ExitSummary(int exit_code) {
206  Message m;
207 
208 # if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
209 
210  m << "Exited with exit status " << exit_code;
211 
212 # else
213 
214  if (WIFEXITED(exit_code)) {
215  m << "Exited with exit status " << WEXITSTATUS(exit_code);
216  } else if (WIFSIGNALED(exit_code)) {
217  m << "Terminated by signal " << WTERMSIG(exit_code);
218  }
219 # ifdef WCOREDUMP
220  if (WCOREDUMP(exit_code)) {
221  m << " (core dumped)";
222  }
223 # endif
224 # endif // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
225 
226  return m.GetString();
227 }
228 
229 // Returns true if exit_status describes a process that was terminated
230 // by a signal, or exited normally with a nonzero exit code.
231 bool ExitedUnsuccessfully(int exit_status) {
232  return !ExitedWithCode(0)(exit_status);
233 }
234 
235 # if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
236 // Generates a textual failure message when a death test finds more than
237 // one thread running, or cannot determine the number of threads, prior
238 // to executing the given statement. It is the responsibility of the
239 // caller not to pass a thread_count of 1.
240 static std::string DeathTestThreadWarning(size_t thread_count) {
241  Message msg;
242  msg << "Death tests use fork(), which is unsafe particularly"
243  << " in a threaded context. For this test, " << GTEST_NAME_ << " ";
244  if (thread_count == 0) {
245  msg << "couldn't detect the number of threads.";
246  } else {
247  msg << "detected " << thread_count << " threads.";
248  }
249  msg << " See "
250  "https://github.com/google/googletest/blob/master/googletest/docs/"
251  "advanced.md#death-tests-and-threads"
252  << " for more explanation and suggested solutions, especially if"
253  << " this is the last message you see before your test times out.";
254  return msg.GetString();
255 }
256 # endif // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
257 
258 // Flag characters for reporting a death test that did not die.
259 static const char kDeathTestLived = 'L';
260 static const char kDeathTestReturned = 'R';
261 static const char kDeathTestThrew = 'T';
262 static const char kDeathTestInternalError = 'I';
263 
264 #if GTEST_OS_FUCHSIA
265 
266 // File descriptor used for the pipe in the child process.
267 static const int kFuchsiaReadPipeFd = 3;
268 
269 #endif
270 
271 // An enumeration describing all of the possible ways that a death test can
272 // conclude. DIED means that the process died while executing the test
273 // code; LIVED means that process lived beyond the end of the test code;
274 // RETURNED means that the test statement attempted to execute a return
275 // statement, which is not allowed; THREW means that the test statement
276 // returned control by throwing an exception. IN_PROGRESS means the test
277 // has not yet concluded.
278 enum DeathTestOutcome { IN_PROGRESS, DIED, LIVED, RETURNED, THREW };
279 
280 // Routine for aborting the program which is safe to call from an
281 // exec-style death test child process, in which case the error
282 // message is propagated back to the parent process. Otherwise, the
283 // message is simply printed to stderr. In either case, the program
284 // then exits with status 1.
285 static void DeathTestAbort(const std::string& message) {
286  // On a POSIX system, this function may be called from a threadsafe-style
287  // death test child process, which operates on a very small stack. Use
288  // the heap for any additional non-minuscule memory requirements.
289  const InternalRunDeathTestFlag* const flag =
290  GetUnitTestImpl()->internal_run_death_test_flag();
291  if (flag != nullptr) {
292  FILE* parent = posix::FDOpen(flag->write_fd(), "w");
293  fputc(kDeathTestInternalError, parent);
294  fprintf(parent, "%s", message.c_str());
295  fflush(parent);
296  _exit(1);
297  } else {
298  fprintf(stderr, "%s", message.c_str());
299  fflush(stderr);
300  posix::Abort();
301  }
302 }
303 
304 // A replacement for CHECK that calls DeathTestAbort if the assertion
305 // fails.
306 # define GTEST_DEATH_TEST_CHECK_(expression) \
307  do { \
308  if (!::testing::internal::IsTrue(expression)) { \
309  DeathTestAbort( \
310  ::std::string("CHECK failed: File ") + __FILE__ + ", line " \
311  + ::testing::internal::StreamableToString(__LINE__) + ": " \
312  + #expression); \
313  } \
314  } while (::testing::internal::AlwaysFalse())
315 
316 // This macro is similar to GTEST_DEATH_TEST_CHECK_, but it is meant for
317 // evaluating any system call that fulfills two conditions: it must return
318 // -1 on failure, and set errno to EINTR when it is interrupted and
319 // should be tried again. The macro expands to a loop that repeatedly
320 // evaluates the expression as long as it evaluates to -1 and sets
321 // errno to EINTR. If the expression evaluates to -1 but errno is
322 // something other than EINTR, DeathTestAbort is called.
323 # define GTEST_DEATH_TEST_CHECK_SYSCALL_(expression) \
324  do { \
325  int gtest_retval; \
326  do { \
327  gtest_retval = (expression); \
328  } while (gtest_retval == -1 && errno == EINTR); \
329  if (gtest_retval == -1) { \
330  DeathTestAbort( \
331  ::std::string("CHECK failed: File ") + __FILE__ + ", line " \
332  + ::testing::internal::StreamableToString(__LINE__) + ": " \
333  + #expression + " != -1"); \
334  } \
335  } while (::testing::internal::AlwaysFalse())
336 
337 // Returns the message describing the last system error in errno.
338 std::string GetLastErrnoDescription() {
339  return errno == 0 ? "" : posix::StrError(errno);
340 }
341 
342 // This is called from a death test parent process to read a failure
343 // message from the death test child process and log it with the FATAL
344 // severity. On Windows, the message is read from a pipe handle. On other
345 // platforms, it is read from a file descriptor.
346 static void FailFromInternalError(int fd) {
347  Message error;
348  char buffer[256];
349  int num_read;
350 
351  do {
352  while ((num_read = posix::Read(fd, buffer, 255)) > 0) {
353  buffer[num_read] = '\0';
354  error << buffer;
355  }
356  } while (num_read == -1 && errno == EINTR);
357 
358  if (num_read == 0) {
359  GTEST_LOG_(FATAL) << error.GetString();
360  } else {
361  const int last_error = errno;
362  GTEST_LOG_(FATAL) << "Error while reading death test internal: "
363  << GetLastErrnoDescription() << " [" << last_error << "]";
364  }
365 }
366 
367 // Death test constructor. Increments the running death test count
368 // for the current test.
369 DeathTest::DeathTest() {
370  TestInfo* const info = GetUnitTestImpl()->current_test_info();
371  if (info == nullptr) {
372  DeathTestAbort("Cannot run a death test outside of a TEST or "
373  "TEST_F construct");
374  }
375 }
376 
377 // Creates and returns a death test by dispatching to the current
378 // death test factory.
379 bool DeathTest::Create(const char* statement,
380  Matcher<const std::string&> matcher, const char* file,
381  int line, DeathTest** test) {
382  return GetUnitTestImpl()->death_test_factory()->Create(
383  statement, std::move(matcher), file, line, test);
384 }
385 
386 const char* DeathTest::LastMessage() {
387  return last_death_test_message_.c_str();
388 }
389 
390 void DeathTest::set_last_death_test_message(const std::string& message) {
391  last_death_test_message_ = message;
392 }
393 
394 std::string DeathTest::last_death_test_message_;
395 
396 // Provides cross platform implementation for some death functionality.
397 class DeathTestImpl : public DeathTest {
398  protected:
399  DeathTestImpl(const char* a_statement, Matcher<const std::string&> matcher)
400  : statement_(a_statement),
401  matcher_(std::move(matcher)),
402  spawned_(false),
403  status_(-1),
404  outcome_(IN_PROGRESS),
405  read_fd_(-1),
406  write_fd_(-1) {}
407 
408  // read_fd_ is expected to be closed and cleared by a derived class.
409  ~DeathTestImpl() override { GTEST_DEATH_TEST_CHECK_(read_fd_ == -1); }
410 
411  void Abort(AbortReason reason) override;
412  bool Passed(bool status_ok) override;
413 
414  const char* statement() const { return statement_; }
415  bool spawned() const { return spawned_; }
416  void set_spawned(bool is_spawned) { spawned_ = is_spawned; }
417  int status() const { return status_; }
418  void set_status(int a_status) { status_ = a_status; }
419  DeathTestOutcome outcome() const { return outcome_; }
420  void set_outcome(DeathTestOutcome an_outcome) { outcome_ = an_outcome; }
421  int read_fd() const { return read_fd_; }
422  void set_read_fd(int fd) { read_fd_ = fd; }
423  int write_fd() const { return write_fd_; }
424  void set_write_fd(int fd) { write_fd_ = fd; }
425 
426  // Called in the parent process only. Reads the result code of the death
427  // test child process via a pipe, interprets it to set the outcome_
428  // member, and closes read_fd_. Outputs diagnostics and terminates in
429  // case of unexpected codes.
430  void ReadAndInterpretStatusByte();
431 
432  // Returns stderr output from the child process.
433  virtual std::string GetErrorLogs();
434 
435  private:
436  // The textual content of the code this object is testing. This class
437  // doesn't own this string and should not attempt to delete it.
438  const char* const statement_;
439  // A matcher that's expected to match the stderr output by the child process.
440  Matcher<const std::string&> matcher_;
441  // True if the death test child process has been successfully spawned.
442  bool spawned_;
443  // The exit status of the child process.
444  int status_;
445  // How the death test concluded.
446  DeathTestOutcome outcome_;
447  // Descriptor to the read end of the pipe to the child process. It is
448  // always -1 in the child process. The child keeps its write end of the
449  // pipe in write_fd_.
450  int read_fd_;
451  // Descriptor to the child's write end of the pipe to the parent process.
452  // It is always -1 in the parent process. The parent keeps its end of the
453  // pipe in read_fd_.
454  int write_fd_;
455 };
456 
457 // Called in the parent process only. Reads the result code of the death
458 // test child process via a pipe, interprets it to set the outcome_
459 // member, and closes read_fd_. Outputs diagnostics and terminates in
460 // case of unexpected codes.
461 void DeathTestImpl::ReadAndInterpretStatusByte() {
462  char flag;
463  int bytes_read;
464 
465  // The read() here blocks until data is available (signifying the
466  // failure of the death test) or until the pipe is closed (signifying
467  // its success), so it's okay to call this in the parent before
468  // the child process has exited.
469  do {
470  bytes_read = posix::Read(read_fd(), &flag, 1);
471  } while (bytes_read == -1 && errno == EINTR);
472 
473  if (bytes_read == 0) {
474  set_outcome(DIED);
475  } else if (bytes_read == 1) {
476  switch (flag) {
477  case kDeathTestReturned:
478  set_outcome(RETURNED);
479  break;
480  case kDeathTestThrew:
481  set_outcome(THREW);
482  break;
483  case kDeathTestLived:
484  set_outcome(LIVED);
485  break;
486  case kDeathTestInternalError:
487  FailFromInternalError(read_fd()); // Does not return.
488  break;
489  default:
490  GTEST_LOG_(FATAL) << "Death test child process reported "
491  << "unexpected status byte ("
492  << static_cast<unsigned int>(flag) << ")";
493  }
494  } else {
495  GTEST_LOG_(FATAL) << "Read from death test child process failed: "
496  << GetLastErrnoDescription();
497  }
498  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Close(read_fd()));
499  set_read_fd(-1);
500 }
501 
502 std::string DeathTestImpl::GetErrorLogs() {
503  return GetCapturedStderr();
504 }
505 
506 // Signals that the death test code which should have exited, didn't.
507 // Should be called only in a death test child process.
508 // Writes a status byte to the child's status file descriptor, then
509 // calls _exit(1).
510 void DeathTestImpl::Abort(AbortReason reason) {
511  // The parent process considers the death test to be a failure if
512  // it finds any data in our pipe. So, here we write a single flag byte
513  // to the pipe, then exit.
514  const char status_ch =
515  reason == TEST_DID_NOT_DIE ? kDeathTestLived :
516  reason == TEST_THREW_EXCEPTION ? kDeathTestThrew : kDeathTestReturned;
517 
518  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Write(write_fd(), &status_ch, 1));
519  // We are leaking the descriptor here because on some platforms (i.e.,
520  // when built as Windows DLL), destructors of global objects will still
521  // run after calling _exit(). On such systems, write_fd_ will be
522  // indirectly closed from the destructor of UnitTestImpl, causing double
523  // close if it is also closed here. On debug configurations, double close
524  // may assert. As there are no in-process buffers to flush here, we are
525  // relying on the OS to close the descriptor after the process terminates
526  // when the destructors are not run.
527  _exit(1); // Exits w/o any normal exit hooks (we were supposed to crash)
528 }
529 
530 // Returns an indented copy of stderr output for a death test.
531 // This makes distinguishing death test output lines from regular log lines
532 // much easier.
533 static ::std::string FormatDeathTestOutput(const ::std::string& output) {
534  ::std::string ret;
535  for (size_t at = 0; ; ) {
536  const size_t line_end = output.find('\n', at);
537  ret += "[ DEATH ] ";
538  if (line_end == ::std::string::npos) {
539  ret += output.substr(at);
540  break;
541  }
542  ret += output.substr(at, line_end + 1 - at);
543  at = line_end + 1;
544  }
545  return ret;
546 }
547 
548 // Assesses the success or failure of a death test, using both private
549 // members which have previously been set, and one argument:
550 //
551 // Private data members:
552 // outcome: An enumeration describing how the death test
553 // concluded: DIED, LIVED, THREW, or RETURNED. The death test
554 // fails in the latter three cases.
555 // status: The exit status of the child process. On *nix, it is in the
556 // in the format specified by wait(2). On Windows, this is the
557 // value supplied to the ExitProcess() API or a numeric code
558 // of the exception that terminated the program.
559 // matcher_: A matcher that's expected to match the stderr output by the child
560 // process.
561 //
562 // Argument:
563 // status_ok: true if exit_status is acceptable in the context of
564 // this particular death test, which fails if it is false
565 //
566 // Returns true if and only if all of the above conditions are met. Otherwise,
567 // the first failing condition, in the order given above, is the one that is
568 // reported. Also sets the last death test message string.
569 bool DeathTestImpl::Passed(bool status_ok) {
570  if (!spawned())
571  return false;
572 
573  const std::string error_message = GetErrorLogs();
574 
575  bool success = false;
576  Message buffer;
577 
578  buffer << "Death test: " << statement() << "\n";
579  switch (outcome()) {
580  case LIVED:
581  buffer << " Result: failed to die.\n"
582  << " Error msg:\n" << FormatDeathTestOutput(error_message);
583  break;
584  case THREW:
585  buffer << " Result: threw an exception.\n"
586  << " Error msg:\n" << FormatDeathTestOutput(error_message);
587  break;
588  case RETURNED:
589  buffer << " Result: illegal return in test statement.\n"
590  << " Error msg:\n" << FormatDeathTestOutput(error_message);
591  break;
592  case DIED:
593  if (status_ok) {
594  if (matcher_.Matches(error_message)) {
595  success = true;
596  } else {
597  std::ostringstream stream;
598  matcher_.DescribeTo(&stream);
599  buffer << " Result: died but not with expected error.\n"
600  << " Expected: " << stream.str() << "\n"
601  << "Actual msg:\n"
602  << FormatDeathTestOutput(error_message);
603  }
604  } else {
605  buffer << " Result: died but not with expected exit code:\n"
606  << " " << ExitSummary(status()) << "\n"
607  << "Actual msg:\n" << FormatDeathTestOutput(error_message);
608  }
609  break;
610  case IN_PROGRESS:
611  default:
612  GTEST_LOG_(FATAL)
613  << "DeathTest::Passed somehow called before conclusion of test";
614  }
615 
616  DeathTest::set_last_death_test_message(buffer.GetString());
617  return success;
618 }
619 
620 # if GTEST_OS_WINDOWS
621 // WindowsDeathTest implements death tests on Windows. Due to the
622 // specifics of starting new processes on Windows, death tests there are
623 // always threadsafe, and Google Test considers the
624 // --gtest_death_test_style=fast setting to be equivalent to
625 // --gtest_death_test_style=threadsafe there.
626 //
627 // A few implementation notes: Like the Linux version, the Windows
628 // implementation uses pipes for child-to-parent communication. But due to
629 // the specifics of pipes on Windows, some extra steps are required:
630 //
631 // 1. The parent creates a communication pipe and stores handles to both
632 // ends of it.
633 // 2. The parent starts the child and provides it with the information
634 // necessary to acquire the handle to the write end of the pipe.
635 // 3. The child acquires the write end of the pipe and signals the parent
636 // using a Windows event.
637 // 4. Now the parent can release the write end of the pipe on its side. If
638 // this is done before step 3, the object's reference count goes down to
639 // 0 and it is destroyed, preventing the child from acquiring it. The
640 // parent now has to release it, or read operations on the read end of
641 // the pipe will not return when the child terminates.
642 // 5. The parent reads child's output through the pipe (outcome code and
643 // any possible error messages) from the pipe, and its stderr and then
644 // determines whether to fail the test.
645 //
646 // Note: to distinguish Win32 API calls from the local method and function
647 // calls, the former are explicitly resolved in the global namespace.
648 //
649 class WindowsDeathTest : public DeathTestImpl {
650  public:
651  WindowsDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
652  const char* file, int line)
653  : DeathTestImpl(a_statement, std::move(matcher)),
654  file_(file),
655  line_(line) {}
656 
657  // All of these virtual functions are inherited from DeathTest.
658  virtual int Wait();
659  virtual TestRole AssumeRole();
660 
661  private:
662  // The name of the file in which the death test is located.
663  const char* const file_;
664  // The line number on which the death test is located.
665  const int line_;
666  // Handle to the write end of the pipe to the child process.
667  AutoHandle write_handle_;
668  // Child process handle.
669  AutoHandle child_handle_;
670  // Event the child process uses to signal the parent that it has
671  // acquired the handle to the write end of the pipe. After seeing this
672  // event the parent can release its own handles to make sure its
673  // ReadFile() calls return when the child terminates.
674  AutoHandle event_handle_;
675 };
676 
677 // Waits for the child in a death test to exit, returning its exit
678 // status, or 0 if no child process exists. As a side effect, sets the
679 // outcome data member.
680 int WindowsDeathTest::Wait() {
681  if (!spawned())
682  return 0;
683 
684  // Wait until the child either signals that it has acquired the write end
685  // of the pipe or it dies.
686  const HANDLE wait_handles[2] = { child_handle_.Get(), event_handle_.Get() };
687  switch (::WaitForMultipleObjects(2,
688  wait_handles,
689  FALSE, // Waits for any of the handles.
690  INFINITE)) {
691  case WAIT_OBJECT_0:
692  case WAIT_OBJECT_0 + 1:
693  break;
694  default:
695  GTEST_DEATH_TEST_CHECK_(false); // Should not get here.
696  }
697 
698  // The child has acquired the write end of the pipe or exited.
699  // We release the handle on our side and continue.
700  write_handle_.Reset();
701  event_handle_.Reset();
702 
703  ReadAndInterpretStatusByte();
704 
705  // Waits for the child process to exit if it haven't already. This
706  // returns immediately if the child has already exited, regardless of
707  // whether previous calls to WaitForMultipleObjects synchronized on this
708  // handle or not.
709  GTEST_DEATH_TEST_CHECK_(
710  WAIT_OBJECT_0 == ::WaitForSingleObject(child_handle_.Get(),
711  INFINITE));
712  DWORD status_code;
713  GTEST_DEATH_TEST_CHECK_(
714  ::GetExitCodeProcess(child_handle_.Get(), &status_code) != FALSE);
715  child_handle_.Reset();
716  set_status(static_cast<int>(status_code));
717  return status();
718 }
719 
720 // The AssumeRole process for a Windows death test. It creates a child
721 // process with the same executable as the current process to run the
722 // death test. The child process is given the --gtest_filter and
723 // --gtest_internal_run_death_test flags such that it knows to run the
724 // current death test only.
725 DeathTest::TestRole WindowsDeathTest::AssumeRole() {
726  const UnitTestImpl* const impl = GetUnitTestImpl();
727  const InternalRunDeathTestFlag* const flag =
728  impl->internal_run_death_test_flag();
729  const TestInfo* const info = impl->current_test_info();
730  const int death_test_index = info->result()->death_test_count();
731 
732  if (flag != nullptr) {
733  // ParseInternalRunDeathTestFlag() has performed all the necessary
734  // processing.
735  set_write_fd(flag->write_fd());
736  return EXECUTE_TEST;
737  }
738 
739  // WindowsDeathTest uses an anonymous pipe to communicate results of
740  // a death test.
741  SECURITY_ATTRIBUTES handles_are_inheritable = {sizeof(SECURITY_ATTRIBUTES),
742  nullptr, TRUE};
743  HANDLE read_handle, write_handle;
744  GTEST_DEATH_TEST_CHECK_(
745  ::CreatePipe(&read_handle, &write_handle, &handles_are_inheritable,
746  0) // Default buffer size.
747  != FALSE);
748  set_read_fd(::_open_osfhandle(reinterpret_cast<intptr_t>(read_handle),
749  O_RDONLY));
750  write_handle_.Reset(write_handle);
751  event_handle_.Reset(::CreateEvent(
752  &handles_are_inheritable,
753  TRUE, // The event will automatically reset to non-signaled state.
754  FALSE, // The initial state is non-signalled.
755  nullptr)); // The even is unnamed.
756  GTEST_DEATH_TEST_CHECK_(event_handle_.Get() != nullptr);
757  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
758  kFilterFlag + "=" + info->test_suite_name() +
759  "." + info->name();
760  const std::string internal_flag =
761  std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag +
762  "=" + file_ + "|" + StreamableToString(line_) + "|" +
763  StreamableToString(death_test_index) + "|" +
764  StreamableToString(static_cast<unsigned int>(::GetCurrentProcessId())) +
765  // size_t has the same width as pointers on both 32-bit and 64-bit
766  // Windows platforms.
767  // See http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx.
768  "|" + StreamableToString(reinterpret_cast<size_t>(write_handle)) +
769  "|" + StreamableToString(reinterpret_cast<size_t>(event_handle_.Get()));
770 
771  char executable_path[_MAX_PATH + 1]; // NOLINT
772  GTEST_DEATH_TEST_CHECK_(_MAX_PATH + 1 != ::GetModuleFileNameA(nullptr,
773  executable_path,
774  _MAX_PATH));
775 
776  std::string command_line =
777  std::string(::GetCommandLineA()) + " " + filter_flag + " \"" +
778  internal_flag + "\"";
779 
780  DeathTest::set_last_death_test_message("");
781 
782  CaptureStderr();
783  // Flush the log buffers since the log streams are shared with the child.
784  FlushInfoLog();
785 
786  // The child process will share the standard handles with the parent.
787  STARTUPINFOA startup_info;
788  memset(&startup_info, 0, sizeof(STARTUPINFO));
789  startup_info.dwFlags = STARTF_USESTDHANDLES;
790  startup_info.hStdInput = ::GetStdHandle(STD_INPUT_HANDLE);
791  startup_info.hStdOutput = ::GetStdHandle(STD_OUTPUT_HANDLE);
792  startup_info.hStdError = ::GetStdHandle(STD_ERROR_HANDLE);
793 
794  PROCESS_INFORMATION process_info;
795  GTEST_DEATH_TEST_CHECK_(
796  ::CreateProcessA(
797  executable_path, const_cast<char*>(command_line.c_str()),
798  nullptr, // Retuned process handle is not inheritable.
799  nullptr, // Retuned thread handle is not inheritable.
800  TRUE, // Child inherits all inheritable handles (for write_handle_).
801  0x0, // Default creation flags.
802  nullptr, // Inherit the parent's environment.
803  UnitTest::GetInstance()->original_working_dir(), &startup_info,
804  &process_info) != FALSE);
805  child_handle_.Reset(process_info.hProcess);
806  ::CloseHandle(process_info.hThread);
807  set_spawned(true);
808  return OVERSEE_TEST;
809 }
810 
811 # elif GTEST_OS_FUCHSIA
812 
813 class FuchsiaDeathTest : public DeathTestImpl {
814  public:
815  FuchsiaDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
816  const char* file, int line)
817  : DeathTestImpl(a_statement, std::move(matcher)),
818  file_(file),
819  line_(line) {}
820 
821  // All of these virtual functions are inherited from DeathTest.
822  int Wait() override;
823  TestRole AssumeRole() override;
824  std::string GetErrorLogs() override;
825 
826  private:
827  // The name of the file in which the death test is located.
828  const char* const file_;
829  // The line number on which the death test is located.
830  const int line_;
831  // The stderr data captured by the child process.
832  std::string captured_stderr_;
833 
834  zx::process child_process_;
835  zx::channel exception_channel_;
836  zx::socket stderr_socket_;
837 };
838 
839 // Utility class for accumulating command-line arguments.
840 class Arguments {
841  public:
842  Arguments() { args_.push_back(nullptr); }
843 
844  ~Arguments() {
845  for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
846  ++i) {
847  free(*i);
848  }
849  }
850  void AddArgument(const char* argument) {
851  args_.insert(args_.end() - 1, posix::StrDup(argument));
852  }
853 
854  template <typename Str>
855  void AddArguments(const ::std::vector<Str>& arguments) {
856  for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
857  i != arguments.end();
858  ++i) {
859  args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
860  }
861  }
862  char* const* Argv() {
863  return &args_[0];
864  }
865 
866  int size() {
867  return args_.size() - 1;
868  }
869 
870  private:
871  std::vector<char*> args_;
872 };
873 
874 // Waits for the child in a death test to exit, returning its exit
875 // status, or 0 if no child process exists. As a side effect, sets the
876 // outcome data member.
877 int FuchsiaDeathTest::Wait() {
878  const int kProcessKey = 0;
879  const int kSocketKey = 1;
880  const int kExceptionKey = 2;
881 
882  if (!spawned())
883  return 0;
884 
885  // Create a port to wait for socket/task/exception events.
886  zx_status_t status_zx;
887  zx::port port;
888  status_zx = zx::port::create(0, &port);
889  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
890 
891  // Register to wait for the child process to terminate.
892  status_zx = child_process_.wait_async(
893  port, kProcessKey, ZX_PROCESS_TERMINATED, ZX_WAIT_ASYNC_ONCE);
894  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
895 
896  // Register to wait for the socket to be readable or closed.
897  status_zx = stderr_socket_.wait_async(
898  port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED,
899  ZX_WAIT_ASYNC_ONCE);
900  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
901 
902  // Register to wait for an exception.
903  status_zx = exception_channel_.wait_async(
904  port, kExceptionKey, ZX_CHANNEL_READABLE, ZX_WAIT_ASYNC_ONCE);
905  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
906 
907  bool process_terminated = false;
908  bool socket_closed = false;
909  do {
910  zx_port_packet_t packet = {};
911  status_zx = port.wait(zx::time::infinite(), &packet);
912  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
913 
914  if (packet.key == kExceptionKey) {
915  // Process encountered an exception. Kill it directly rather than
916  // letting other handlers process the event. We will get a kProcessKey
917  // event when the process actually terminates.
918  status_zx = child_process_.kill();
919  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
920  } else if (packet.key == kProcessKey) {
921  // Process terminated.
922  GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
923  GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_PROCESS_TERMINATED);
924  process_terminated = true;
925  } else if (packet.key == kSocketKey) {
926  GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
927  if (packet.signal.observed & ZX_SOCKET_READABLE) {
928  // Read data from the socket.
929  constexpr size_t kBufferSize = 1024;
930  do {
931  size_t old_length = captured_stderr_.length();
932  size_t bytes_read = 0;
933  captured_stderr_.resize(old_length + kBufferSize);
934  status_zx = stderr_socket_.read(
935  0, &captured_stderr_.front() + old_length, kBufferSize,
936  &bytes_read);
937  captured_stderr_.resize(old_length + bytes_read);
938  } while (status_zx == ZX_OK);
939  if (status_zx == ZX_ERR_PEER_CLOSED) {
940  socket_closed = true;
941  } else {
942  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_ERR_SHOULD_WAIT);
943  status_zx = stderr_socket_.wait_async(
944  port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED,
945  ZX_WAIT_ASYNC_ONCE);
946  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
947  }
948  } else {
949  GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_SOCKET_PEER_CLOSED);
950  socket_closed = true;
951  }
952  }
953  } while (!process_terminated && !socket_closed);
954 
955  ReadAndInterpretStatusByte();
956 
957  zx_info_process_t buffer;
958  status_zx = child_process_.get_info(
959  ZX_INFO_PROCESS, &buffer, sizeof(buffer), nullptr, nullptr);
960  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
961 
962  GTEST_DEATH_TEST_CHECK_(buffer.exited);
963  set_status(buffer.return_code);
964  return status();
965 }
966 
967 // The AssumeRole process for a Fuchsia death test. It creates a child
968 // process with the same executable as the current process to run the
969 // death test. The child process is given the --gtest_filter and
970 // --gtest_internal_run_death_test flags such that it knows to run the
971 // current death test only.
972 DeathTest::TestRole FuchsiaDeathTest::AssumeRole() {
973  const UnitTestImpl* const impl = GetUnitTestImpl();
974  const InternalRunDeathTestFlag* const flag =
975  impl->internal_run_death_test_flag();
976  const TestInfo* const info = impl->current_test_info();
977  const int death_test_index = info->result()->death_test_count();
978 
979  if (flag != nullptr) {
980  // ParseInternalRunDeathTestFlag() has performed all the necessary
981  // processing.
982  set_write_fd(kFuchsiaReadPipeFd);
983  return EXECUTE_TEST;
984  }
985 
986  // Flush the log buffers since the log streams are shared with the child.
987  FlushInfoLog();
988 
989  // Build the child process command line.
990  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
991  kFilterFlag + "=" + info->test_suite_name() +
992  "." + info->name();
993  const std::string internal_flag =
994  std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag + "="
995  + file_ + "|"
996  + StreamableToString(line_) + "|"
997  + StreamableToString(death_test_index);
998  Arguments args;
999  args.AddArguments(GetInjectableArgvs());
1000  args.AddArgument(filter_flag.c_str());
1001  args.AddArgument(internal_flag.c_str());
1002 
1003  // Build the pipe for communication with the child.
1004  zx_status_t status;
1005  zx_handle_t child_pipe_handle;
1006  int child_pipe_fd;
1007  status = fdio_pipe_half(&child_pipe_fd, &child_pipe_handle);
1008  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1009  set_read_fd(child_pipe_fd);
1010 
1011  // Set the pipe handle for the child.
1012  fdio_spawn_action_t spawn_actions[2] = {};
1013  fdio_spawn_action_t* add_handle_action = &spawn_actions[0];
1014  add_handle_action->action = FDIO_SPAWN_ACTION_ADD_HANDLE;
1015  add_handle_action->h.id = PA_HND(PA_FD, kFuchsiaReadPipeFd);
1016  add_handle_action->h.handle = child_pipe_handle;
1017 
1018  // Create a socket pair will be used to receive the child process' stderr.
1019  zx::socket stderr_producer_socket;
1020  status =
1021  zx::socket::create(0, &stderr_producer_socket, &stderr_socket_);
1022  GTEST_DEATH_TEST_CHECK_(status >= 0);
1023  int stderr_producer_fd = -1;
1024  status =
1025  fdio_fd_create(stderr_producer_socket.release(), &stderr_producer_fd);
1026  GTEST_DEATH_TEST_CHECK_(status >= 0);
1027 
1028  // Make the stderr socket nonblocking.
1029  GTEST_DEATH_TEST_CHECK_(fcntl(stderr_producer_fd, F_SETFL, 0) == 0);
1030 
1031  fdio_spawn_action_t* add_stderr_action = &spawn_actions[1];
1032  add_stderr_action->action = FDIO_SPAWN_ACTION_CLONE_FD;
1033  add_stderr_action->fd.local_fd = stderr_producer_fd;
1034  add_stderr_action->fd.target_fd = STDERR_FILENO;
1035 
1036  // Create a child job.
1037  zx_handle_t child_job = ZX_HANDLE_INVALID;
1038  status = zx_job_create(zx_job_default(), 0, & child_job);
1039  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1040  zx_policy_basic_t policy;
1041  policy.condition = ZX_POL_NEW_ANY;
1042  policy.policy = ZX_POL_ACTION_ALLOW;
1043  status = zx_job_set_policy(
1044  child_job, ZX_JOB_POL_RELATIVE, ZX_JOB_POL_BASIC, &policy, 1);
1045  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1046 
1047  // Create an exception channel attached to the |child_job|, to allow
1048  // us to suppress the system default exception handler from firing.
1049  status =
1050  zx_task_create_exception_channel(
1051  child_job, 0, exception_channel_.reset_and_get_address());
1052  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1053 
1054  // Spawn the child process.
1055  status = fdio_spawn_etc(
1056  child_job, FDIO_SPAWN_CLONE_ALL, args.Argv()[0], args.Argv(), nullptr,
1057  2, spawn_actions, child_process_.reset_and_get_address(), nullptr);
1058  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1059 
1060  set_spawned(true);
1061  return OVERSEE_TEST;
1062 }
1063 
1064 std::string FuchsiaDeathTest::GetErrorLogs() {
1065  return captured_stderr_;
1066 }
1067 
1068 #else // We are neither on Windows, nor on Fuchsia.
1069 
1070 // ForkingDeathTest provides implementations for most of the abstract
1071 // methods of the DeathTest interface. Only the AssumeRole method is
1072 // left undefined.
1073 class ForkingDeathTest : public DeathTestImpl {
1074  public:
1075  ForkingDeathTest(const char* statement, Matcher<const std::string&> matcher);
1076 
1077  // All of these virtual functions are inherited from DeathTest.
1078  int Wait() override;
1079 
1080  protected:
1081  void set_child_pid(pid_t child_pid) { child_pid_ = child_pid; }
1082 
1083  private:
1084  // PID of child process during death test; 0 in the child process itself.
1085  pid_t child_pid_;
1086 };
1087 
1088 // Constructs a ForkingDeathTest.
1089 ForkingDeathTest::ForkingDeathTest(const char* a_statement,
1090  Matcher<const std::string&> matcher)
1091  : DeathTestImpl(a_statement, std::move(matcher)), child_pid_(-1) {}
1092 
1093 // Waits for the child in a death test to exit, returning its exit
1094 // status, or 0 if no child process exists. As a side effect, sets the
1095 // outcome data member.
1096 int ForkingDeathTest::Wait() {
1097  if (!spawned())
1098  return 0;
1099 
1100  ReadAndInterpretStatusByte();
1101 
1102  int status_value;
1103  GTEST_DEATH_TEST_CHECK_SYSCALL_(waitpid(child_pid_, &status_value, 0));
1104  set_status(status_value);
1105  return status_value;
1106 }
1107 
1108 // A concrete death test class that forks, then immediately runs the test
1109 // in the child process.
1110 class NoExecDeathTest : public ForkingDeathTest {
1111  public:
1112  NoExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher)
1113  : ForkingDeathTest(a_statement, std::move(matcher)) {}
1114  TestRole AssumeRole() override;
1115 };
1116 
1117 // The AssumeRole process for a fork-and-run death test. It implements a
1118 // straightforward fork, with a simple pipe to transmit the status byte.
1119 DeathTest::TestRole NoExecDeathTest::AssumeRole() {
1120  const size_t thread_count = GetThreadCount();
1121  if (thread_count != 1) {
1122  GTEST_LOG_(WARNING) << DeathTestThreadWarning(thread_count);
1123  }
1124 
1125  int pipe_fd[2];
1126  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
1127 
1128  DeathTest::set_last_death_test_message("");
1129  CaptureStderr();
1130  // When we fork the process below, the log file buffers are copied, but the
1131  // file descriptors are shared. We flush all log files here so that closing
1132  // the file descriptors in the child process doesn't throw off the
1133  // synchronization between descriptors and buffers in the parent process.
1134  // This is as close to the fork as possible to avoid a race condition in case
1135  // there are multiple threads running before the death test, and another
1136  // thread writes to the log file.
1137  FlushInfoLog();
1138 
1139  const pid_t child_pid = fork();
1140  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
1141  set_child_pid(child_pid);
1142  if (child_pid == 0) {
1143  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[0]));
1144  set_write_fd(pipe_fd[1]);
1145  // Redirects all logging to stderr in the child process to prevent
1146  // concurrent writes to the log files. We capture stderr in the parent
1147  // process and append the child process' output to a log.
1148  LogToStderr();
1149  // Event forwarding to the listeners of event listener API mush be shut
1150  // down in death test subprocesses.
1151  GetUnitTestImpl()->listeners()->SuppressEventForwarding();
1152  g_in_fast_death_test_child = true;
1153  return EXECUTE_TEST;
1154  } else {
1155  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
1156  set_read_fd(pipe_fd[0]);
1157  set_spawned(true);
1158  return OVERSEE_TEST;
1159  }
1160 }
1161 
1162 // A concrete death test class that forks and re-executes the main
1163 // program from the beginning, with command-line flags set that cause
1164 // only this specific death test to be run.
1165 class ExecDeathTest : public ForkingDeathTest {
1166  public:
1167  ExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
1168  const char* file, int line)
1169  : ForkingDeathTest(a_statement, std::move(matcher)),
1170  file_(file),
1171  line_(line) {}
1172  TestRole AssumeRole() override;
1173 
1174  private:
1175  static ::std::vector<std::string> GetArgvsForDeathTestChildProcess() {
1176  ::std::vector<std::string> args = GetInjectableArgvs();
1177 # if defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
1178  ::std::vector<std::string> extra_args =
1179  GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_();
1180  args.insert(args.end(), extra_args.begin(), extra_args.end());
1181 # endif // defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
1182  return args;
1183  }
1184  // The name of the file in which the death test is located.
1185  const char* const file_;
1186  // The line number on which the death test is located.
1187  const int line_;
1188 };
1189 
1190 // Utility class for accumulating command-line arguments.
1191 class Arguments {
1192  public:
1193  Arguments() { args_.push_back(nullptr); }
1194 
1195  ~Arguments() {
1196  for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
1197  ++i) {
1198  free(*i);
1199  }
1200  }
1201  void AddArgument(const char* argument) {
1202  args_.insert(args_.end() - 1, posix::StrDup(argument));
1203  }
1204 
1205  template <typename Str>
1206  void AddArguments(const ::std::vector<Str>& arguments) {
1207  for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
1208  i != arguments.end();
1209  ++i) {
1210  args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
1211  }
1212  }
1213  char* const* Argv() {
1214  return &args_[0];
1215  }
1216 
1217  private:
1218  std::vector<char*> args_;
1219 };
1220 
1221 // A struct that encompasses the arguments to the child process of a
1222 // threadsafe-style death test process.
1223 struct ExecDeathTestArgs {
1224  char* const* argv; // Command-line arguments for the child's call to exec
1225  int close_fd; // File descriptor to close; the read end of a pipe
1226 };
1227 
1228 # if GTEST_OS_MAC
1229 inline char** GetEnviron() {
1230  // When Google Test is built as a framework on MacOS X, the environ variable
1231  // is unavailable. Apple's documentation (man environ) recommends using
1232  // _NSGetEnviron() instead.
1233  return *_NSGetEnviron();
1234 }
1235 # else
1236 // Some POSIX platforms expect you to declare environ. extern "C" makes
1237 // it reside in the global namespace.
1238 extern "C" char** environ;
1239 inline char** GetEnviron() { return environ; }
1240 # endif // GTEST_OS_MAC
1241 
1242 # if !GTEST_OS_QNX
1243 // The main function for a threadsafe-style death test child process.
1244 // This function is called in a clone()-ed process and thus must avoid
1245 // any potentially unsafe operations like malloc or libc functions.
1246 static int ExecDeathTestChildMain(void* child_arg) {
1247  ExecDeathTestArgs* const args = static_cast<ExecDeathTestArgs*>(child_arg);
1248  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(args->close_fd));
1249 
1250  // We need to execute the test program in the same environment where
1251  // it was originally invoked. Therefore we change to the original
1252  // working directory first.
1253  const char* const original_dir =
1254  UnitTest::GetInstance()->original_working_dir();
1255  // We can safely call chdir() as it's a direct system call.
1256  if (chdir(original_dir) != 0) {
1257  DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
1258  GetLastErrnoDescription());
1259  return EXIT_FAILURE;
1260  }
1261 
1262  // We can safely call execve() as it's a direct system call. We
1263  // cannot use execvp() as it's a libc function and thus potentially
1264  // unsafe. Since execve() doesn't search the PATH, the user must
1265  // invoke the test program via a valid path that contains at least
1266  // one path separator.
1267  execve(args->argv[0], args->argv, GetEnviron());
1268  DeathTestAbort(std::string("execve(") + args->argv[0] + ", ...) in " +
1269  original_dir + " failed: " +
1270  GetLastErrnoDescription());
1271  return EXIT_FAILURE;
1272 }
1273 # endif // !GTEST_OS_QNX
1274 
1275 # if GTEST_HAS_CLONE
1276 // Two utility routines that together determine the direction the stack
1277 // grows.
1278 // This could be accomplished more elegantly by a single recursive
1279 // function, but we want to guard against the unlikely possibility of
1280 // a smart compiler optimizing the recursion away.
1281 //
1282 // GTEST_NO_INLINE_ is required to prevent GCC 4.6 from inlining
1283 // StackLowerThanAddress into StackGrowsDown, which then doesn't give
1284 // correct answer.
1285 static void StackLowerThanAddress(const void* ptr,
1286  bool* result) GTEST_NO_INLINE_;
1287 // Make sure sanitizers do not tamper with the stack here.
1288 // Ideally, we want to use `__builtin_frame_address` instead of a local variable
1289 // address with sanitizer disabled, but it does not work when the
1290 // compiler optimizes the stack frame out, which happens on PowerPC targets.
1291 // HWAddressSanitizer add a random tag to the MSB of the local variable address,
1292 // making comparison result unpredictable.
1295 static void StackLowerThanAddress(const void* ptr, bool* result) {
1296  int dummy;
1297  *result = (&dummy < ptr);
1298 }
1299 
1300 // Make sure AddressSanitizer does not tamper with the stack here.
1303 static bool StackGrowsDown() {
1304  int dummy;
1305  bool result;
1306  StackLowerThanAddress(&dummy, &result);
1307  return result;
1308 }
1309 # endif // GTEST_HAS_CLONE
1310 
1311 // Spawns a child process with the same executable as the current process in
1312 // a thread-safe manner and instructs it to run the death test. The
1313 // implementation uses fork(2) + exec. On systems where clone(2) is
1314 // available, it is used instead, being slightly more thread-safe. On QNX,
1315 // fork supports only single-threaded environments, so this function uses
1316 // spawn(2) there instead. The function dies with an error message if
1317 // anything goes wrong.
1318 static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
1319  ExecDeathTestArgs args = { argv, close_fd };
1320  pid_t child_pid = -1;
1321 
1322 # if GTEST_OS_QNX
1323  // Obtains the current directory and sets it to be closed in the child
1324  // process.
1325  const int cwd_fd = open(".", O_RDONLY);
1326  GTEST_DEATH_TEST_CHECK_(cwd_fd != -1);
1327  GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(cwd_fd, F_SETFD, FD_CLOEXEC));
1328  // We need to execute the test program in the same environment where
1329  // it was originally invoked. Therefore we change to the original
1330  // working directory first.
1331  const char* const original_dir =
1332  UnitTest::GetInstance()->original_working_dir();
1333  // We can safely call chdir() as it's a direct system call.
1334  if (chdir(original_dir) != 0) {
1335  DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
1336  GetLastErrnoDescription());
1337  return EXIT_FAILURE;
1338  }
1339 
1340  int fd_flags;
1341  // Set close_fd to be closed after spawn.
1342  GTEST_DEATH_TEST_CHECK_SYSCALL_(fd_flags = fcntl(close_fd, F_GETFD));
1343  GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(close_fd, F_SETFD,
1344  fd_flags | FD_CLOEXEC));
1345  struct inheritance inherit = {0};
1346  // spawn is a system call.
1347  child_pid =
1348  spawn(args.argv[0], 0, nullptr, &inherit, args.argv, GetEnviron());
1349  // Restores the current working directory.
1350  GTEST_DEATH_TEST_CHECK_(fchdir(cwd_fd) != -1);
1351  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(cwd_fd));
1352 
1353 # else // GTEST_OS_QNX
1354 # if GTEST_OS_LINUX
1355  // When a SIGPROF signal is received while fork() or clone() are executing,
1356  // the process may hang. To avoid this, we ignore SIGPROF here and re-enable
1357  // it after the call to fork()/clone() is complete.
1358  struct sigaction saved_sigprof_action;
1359  struct sigaction ignore_sigprof_action;
1360  memset(&ignore_sigprof_action, 0, sizeof(ignore_sigprof_action));
1361  sigemptyset(&ignore_sigprof_action.sa_mask);
1362  ignore_sigprof_action.sa_handler = SIG_IGN;
1363  GTEST_DEATH_TEST_CHECK_SYSCALL_(sigaction(
1364  SIGPROF, &ignore_sigprof_action, &saved_sigprof_action));
1365 # endif // GTEST_OS_LINUX
1366 
1367 # if GTEST_HAS_CLONE
1368  const bool use_fork = GTEST_FLAG(death_test_use_fork);
1369 
1370  if (!use_fork) {
1371  static const bool stack_grows_down = StackGrowsDown();
1372  const auto stack_size = static_cast<size_t>(getpagesize() * 2);
1373  // MMAP_ANONYMOUS is not defined on Mac, so we use MAP_ANON instead.
1374  void* const stack = mmap(nullptr, stack_size, PROT_READ | PROT_WRITE,
1375  MAP_ANON | MAP_PRIVATE, -1, 0);
1376  GTEST_DEATH_TEST_CHECK_(stack != MAP_FAILED);
1377 
1378  // Maximum stack alignment in bytes: For a downward-growing stack, this
1379  // amount is subtracted from size of the stack space to get an address
1380  // that is within the stack space and is aligned on all systems we care
1381  // about. As far as I know there is no ABI with stack alignment greater
1382  // than 64. We assume stack and stack_size already have alignment of
1383  // kMaxStackAlignment.
1384  const size_t kMaxStackAlignment = 64;
1385  void* const stack_top =
1386  static_cast<char*>(stack) +
1387  (stack_grows_down ? stack_size - kMaxStackAlignment : 0);
1388  GTEST_DEATH_TEST_CHECK_(
1389  static_cast<size_t>(stack_size) > kMaxStackAlignment &&
1390  reinterpret_cast<uintptr_t>(stack_top) % kMaxStackAlignment == 0);
1391 
1392  child_pid = clone(&ExecDeathTestChildMain, stack_top, SIGCHLD, &args);
1393 
1394  GTEST_DEATH_TEST_CHECK_(munmap(stack, stack_size) != -1);
1395  }
1396 # else
1397  const bool use_fork = true;
1398 # endif // GTEST_HAS_CLONE
1399 
1400  if (use_fork && (child_pid = fork()) == 0) {
1401  ExecDeathTestChildMain(&args);
1402  _exit(0);
1403  }
1404 # endif // GTEST_OS_QNX
1405 # if GTEST_OS_LINUX
1406  GTEST_DEATH_TEST_CHECK_SYSCALL_(
1407  sigaction(SIGPROF, &saved_sigprof_action, nullptr));
1408 # endif // GTEST_OS_LINUX
1409 
1410  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
1411  return child_pid;
1412 }
1413 
1414 // The AssumeRole process for a fork-and-exec death test. It re-executes the
1415 // main program from the beginning, setting the --gtest_filter
1416 // and --gtest_internal_run_death_test flags to cause only the current
1417 // death test to be re-run.
1418 DeathTest::TestRole ExecDeathTest::AssumeRole() {
1419  const UnitTestImpl* const impl = GetUnitTestImpl();
1420  const InternalRunDeathTestFlag* const flag =
1421  impl->internal_run_death_test_flag();
1422  const TestInfo* const info = impl->current_test_info();
1423  const int death_test_index = info->result()->death_test_count();
1424 
1425  if (flag != nullptr) {
1426  set_write_fd(flag->write_fd());
1427  return EXECUTE_TEST;
1428  }
1429 
1430  int pipe_fd[2];
1431  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
1432  // Clear the close-on-exec flag on the write end of the pipe, lest
1433  // it be closed when the child process does an exec:
1434  GTEST_DEATH_TEST_CHECK_(fcntl(pipe_fd[1], F_SETFD, 0) != -1);
1435 
1436  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
1437  kFilterFlag + "=" + info->test_suite_name() +
1438  "." + info->name();
1439  const std::string internal_flag =
1440  std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag + "="
1441  + file_ + "|" + StreamableToString(line_) + "|"
1442  + StreamableToString(death_test_index) + "|"
1443  + StreamableToString(pipe_fd[1]);
1444  Arguments args;
1445  args.AddArguments(GetArgvsForDeathTestChildProcess());
1446  args.AddArgument(filter_flag.c_str());
1447  args.AddArgument(internal_flag.c_str());
1448 
1449  DeathTest::set_last_death_test_message("");
1450 
1451  CaptureStderr();
1452  // See the comment in NoExecDeathTest::AssumeRole for why the next line
1453  // is necessary.
1454  FlushInfoLog();
1455 
1456  const pid_t child_pid = ExecDeathTestSpawnChild(args.Argv(), pipe_fd[0]);
1457  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
1458  set_child_pid(child_pid);
1459  set_read_fd(pipe_fd[0]);
1460  set_spawned(true);
1461  return OVERSEE_TEST;
1462 }
1463 
1464 # endif // !GTEST_OS_WINDOWS
1465 
1466 // Creates a concrete DeathTest-derived class that depends on the
1467 // --gtest_death_test_style flag, and sets the pointer pointed to
1468 // by the "test" argument to its address. If the test should be
1469 // skipped, sets that pointer to NULL. Returns true, unless the
1470 // flag is set to an invalid value.
1471 bool DefaultDeathTestFactory::Create(const char* statement,
1472  Matcher<const std::string&> matcher,
1473  const char* file, int line,
1474  DeathTest** test) {
1475  UnitTestImpl* const impl = GetUnitTestImpl();
1476  const InternalRunDeathTestFlag* const flag =
1477  impl->internal_run_death_test_flag();
1478  const int death_test_index = impl->current_test_info()
1479  ->increment_death_test_count();
1480 
1481  if (flag != nullptr) {
1482  if (death_test_index > flag->index()) {
1483  DeathTest::set_last_death_test_message(
1484  "Death test count (" + StreamableToString(death_test_index)
1485  + ") somehow exceeded expected maximum ("
1486  + StreamableToString(flag->index()) + ")");
1487  return false;
1488  }
1489 
1490  if (!(flag->file() == file && flag->line() == line &&
1491  flag->index() == death_test_index)) {
1492  *test = nullptr;
1493  return true;
1494  }
1495  }
1496 
1497 # if GTEST_OS_WINDOWS
1498 
1499  if (GTEST_FLAG(death_test_style) == "threadsafe" ||
1500  GTEST_FLAG(death_test_style) == "fast") {
1501  *test = new WindowsDeathTest(statement, std::move(matcher), file, line);
1502  }
1503 
1504 # elif GTEST_OS_FUCHSIA
1505 
1506  if (GTEST_FLAG(death_test_style) == "threadsafe" ||
1507  GTEST_FLAG(death_test_style) == "fast") {
1508  *test = new FuchsiaDeathTest(statement, std::move(matcher), file, line);
1509  }
1510 
1511 # else
1512 
1513  if (GTEST_FLAG(death_test_style) == "threadsafe") {
1514  *test = new ExecDeathTest(statement, std::move(matcher), file, line);
1515  } else if (GTEST_FLAG(death_test_style) == "fast") {
1516  *test = new NoExecDeathTest(statement, std::move(matcher));
1517  }
1518 
1519 # endif // GTEST_OS_WINDOWS
1520 
1521  else { // NOLINT - this is more readable than unbalanced brackets inside #if.
1522  DeathTest::set_last_death_test_message(
1523  "Unknown death test style \"" + GTEST_FLAG(death_test_style)
1524  + "\" encountered");
1525  return false;
1526  }
1527 
1528  return true;
1529 }
1530 
1531 # if GTEST_OS_WINDOWS
1532 // Recreates the pipe and event handles from the provided parameters,
1533 // signals the event, and returns a file descriptor wrapped around the pipe
1534 // handle. This function is called in the child process only.
1535 static int GetStatusFileDescriptor(unsigned int parent_process_id,
1536  size_t write_handle_as_size_t,
1537  size_t event_handle_as_size_t) {
1538  AutoHandle parent_process_handle(::OpenProcess(PROCESS_DUP_HANDLE,
1539  FALSE, // Non-inheritable.
1540  parent_process_id));
1541  if (parent_process_handle.Get() == INVALID_HANDLE_VALUE) {
1542  DeathTestAbort("Unable to open parent process " +
1543  StreamableToString(parent_process_id));
1544  }
1545 
1546  GTEST_CHECK_(sizeof(HANDLE) <= sizeof(size_t));
1547 
1548  const HANDLE write_handle =
1549  reinterpret_cast<HANDLE>(write_handle_as_size_t);
1550  HANDLE dup_write_handle;
1551 
1552  // The newly initialized handle is accessible only in the parent
1553  // process. To obtain one accessible within the child, we need to use
1554  // DuplicateHandle.
1555  if (!::DuplicateHandle(parent_process_handle.Get(), write_handle,
1556  ::GetCurrentProcess(), &dup_write_handle,
1557  0x0, // Requested privileges ignored since
1558  // DUPLICATE_SAME_ACCESS is used.
1559  FALSE, // Request non-inheritable handler.
1560  DUPLICATE_SAME_ACCESS)) {
1561  DeathTestAbort("Unable to duplicate the pipe handle " +
1562  StreamableToString(write_handle_as_size_t) +
1563  " from the parent process " +
1564  StreamableToString(parent_process_id));
1565  }
1566 
1567  const HANDLE event_handle = reinterpret_cast<HANDLE>(event_handle_as_size_t);
1568  HANDLE dup_event_handle;
1569 
1570  if (!::DuplicateHandle(parent_process_handle.Get(), event_handle,
1571  ::GetCurrentProcess(), &dup_event_handle,
1572  0x0,
1573  FALSE,
1574  DUPLICATE_SAME_ACCESS)) {
1575  DeathTestAbort("Unable to duplicate the event handle " +
1576  StreamableToString(event_handle_as_size_t) +
1577  " from the parent process " +
1578  StreamableToString(parent_process_id));
1579  }
1580 
1581  const int write_fd =
1582  ::_open_osfhandle(reinterpret_cast<intptr_t>(dup_write_handle), O_APPEND);
1583  if (write_fd == -1) {
1584  DeathTestAbort("Unable to convert pipe handle " +
1585  StreamableToString(write_handle_as_size_t) +
1586  " to a file descriptor");
1587  }
1588 
1589  // Signals the parent that the write end of the pipe has been acquired
1590  // so the parent can release its own write end.
1591  ::SetEvent(dup_event_handle);
1592 
1593  return write_fd;
1594 }
1595 # endif // GTEST_OS_WINDOWS
1596 
1597 // Returns a newly created InternalRunDeathTestFlag object with fields
1598 // initialized from the GTEST_FLAG(internal_run_death_test) flag if
1599 // the flag is specified; otherwise returns NULL.
1600 InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag() {
1601  if (GTEST_FLAG(internal_run_death_test) == "") return nullptr;
1602 
1603  // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we
1604  // can use it here.
1605  int line = -1;
1606  int index = -1;
1607  ::std::vector< ::std::string> fields;
1608  SplitString(GTEST_FLAG(internal_run_death_test).c_str(), '|', &fields);
1609  int write_fd = -1;
1610 
1611 # if GTEST_OS_WINDOWS
1612 
1613  unsigned int parent_process_id = 0;
1614  size_t write_handle_as_size_t = 0;
1615  size_t event_handle_as_size_t = 0;
1616 
1617  if (fields.size() != 6
1618  || !ParseNaturalNumber(fields[1], &line)
1619  || !ParseNaturalNumber(fields[2], &index)
1620  || !ParseNaturalNumber(fields[3], &parent_process_id)
1621  || !ParseNaturalNumber(fields[4], &write_handle_as_size_t)
1622  || !ParseNaturalNumber(fields[5], &event_handle_as_size_t)) {
1623  DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
1624  GTEST_FLAG(internal_run_death_test));
1625  }
1626  write_fd = GetStatusFileDescriptor(parent_process_id,
1627  write_handle_as_size_t,
1628  event_handle_as_size_t);
1629 
1630 # elif GTEST_OS_FUCHSIA
1631 
1632  if (fields.size() != 3
1633  || !ParseNaturalNumber(fields[1], &line)
1634  || !ParseNaturalNumber(fields[2], &index)) {
1635  DeathTestAbort("Bad --gtest_internal_run_death_test flag: "
1636  + GTEST_FLAG(internal_run_death_test));
1637  }
1638 
1639 # else
1640 
1641  if (fields.size() != 4
1642  || !ParseNaturalNumber(fields[1], &line)
1643  || !ParseNaturalNumber(fields[2], &index)
1644  || !ParseNaturalNumber(fields[3], &write_fd)) {
1645  DeathTestAbort("Bad --gtest_internal_run_death_test flag: "
1646  + GTEST_FLAG(internal_run_death_test));
1647  }
1648 
1649 # endif // GTEST_OS_WINDOWS
1650 
1651  return new InternalRunDeathTestFlag(fields[0], line, index, write_fd);
1652 }
1653 
1654 } // namespace internal
1655 
1656 #endif // GTEST_HAS_DEATH_TEST
1657 
1658 } // namespace testing
GTEST_API_ std::string GetCapturedStderr()
#define GTEST_NAME_
Definition: gtest-port.h:295
static const char kDefaultDeathTestStyle[]
void SplitString(const ::std::string &str, char delimiter, ::std::vector< ::std::string > *dest)
Definition: gtest.cc:1118
const char * StringFromGTestEnv(const char *flag, const char *default_val)
Definition: gtest-port.cc:1393
#define GTEST_LOG_(severity)
Definition: gtest-port.h:980
GTEST_API_ size_t GetThreadCount()
Definition: gtest-port.cc:273
const char kInternalRunDeathTestFlag[]
#define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
Definition: gtest-port.h:832
#define GTEST_FLAG(name)
Definition: gtest-port.h:2187
std::string StreamableToString(const T &streamable)
int Write(int fd, const void *buf, unsigned int count)
Definition: gtest-port.h:2079
GTEST_DEFINE_string_(death_test_style, internal::StringFromGTestEnv("death_test_style", kDefaultDeathTestStyle), "Indicates how to run a death test in a forked child process: " "\hreadsafe\(child process re-executes the test binary " "from the beginning, running only the specific death test) or " "\ast\(child process runs the death test immediately " "after forking).")
#define GTEST_DEFAULT_DEATH_TEST_STYLE
Definition: gtest-port.h:779
#define GTEST_CHECK_(condition)
Definition: gtest-port.h:1004
#define GTEST_NO_INLINE_
Definition: gtest-port.h:786
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.")
int Read(int fd, void *buf, unsigned int count)
Definition: gtest-port.h:2076
bool BoolFromGTestEnv(const char *flag, bool default_val)
Definition: gtest-port.cc:1336
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.")
GTEST_API_ void CaptureStderr()
void test()
#define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
Definition: gtest-port.h:820
expr expr expr bar false
FILE * FDOpen(int fd, const char *mode)
Definition: gtest-port.h:2072
char * StrDup(const char *src)
Definition: gtest-port.h:2029
const char * StrError(int errnum)
Definition: gtest-port.h:2083
#define GTEST_FLAG_PREFIX_
Definition: gtest-port.h:292