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 <functional>
36#include <utility>
37
38#include "gtest/internal/custom/gtest.h"
39#include "gtest/internal/gtest-port.h"
40
41#if GTEST_HAS_DEATH_TEST
42
43#if GTEST_OS_MAC
44#include <crt_externs.h>
45#endif // GTEST_OS_MAC
46
47#include <errno.h>
48#include <fcntl.h>
49#include <limits.h>
50
51#if GTEST_OS_LINUX
52#include <signal.h>
53#endif // GTEST_OS_LINUX
54
55#include <stdarg.h>
56
57#if GTEST_OS_WINDOWS
58#include <windows.h>
59#else
60#include <sys/mman.h>
61#include <sys/wait.h>
62#endif // GTEST_OS_WINDOWS
63
64#if GTEST_OS_QNX
65#include <spawn.h>
66#endif // GTEST_OS_QNX
67
68#if GTEST_OS_FUCHSIA
69#include <lib/fdio/fd.h>
70#include <lib/fdio/io.h>
71#include <lib/fdio/spawn.h>
72#include <lib/zx/channel.h>
73#include <lib/zx/port.h>
74#include <lib/zx/process.h>
75#include <lib/zx/socket.h>
76#include <zircon/processargs.h>
77#include <zircon/syscalls.h>
78#include <zircon/syscalls/policy.h>
79#include <zircon/syscalls/port.h>
80#endif // GTEST_OS_FUCHSIA
81
82#endif // GTEST_HAS_DEATH_TEST
83
84#include "gtest/gtest-message.h"
85#include "gtest/internal/gtest-string.h"
86#include "src/gtest-internal-inl.h"
87
88namespace testing {
89
90// Constants.
91
92// The default death test style.
93//
94// This is defined in internal/gtest-port.h as "fast", but can be overridden by
95// a definition in internal/custom/gtest-port.h. The recommended value, which is
96// used internally at Google, is "threadsafe".
97static const char kDefaultDeathTestStyle[] = GTEST_DEFAULT_DEATH_TEST_STYLE;
98
99} // namespace testing
100
101GTEST_DEFINE_string_(
102 death_test_style,
103 testing::internal::StringFromGTestEnv("death_test_style",
104 testing::kDefaultDeathTestStyle),
105 "Indicates how to run a death test in a forked child process: "
106 "\"threadsafe\" (child process re-executes the test binary "
107 "from the beginning, running only the specific death test) or "
108 "\"fast\" (child process runs the death test immediately "
109 "after forking).");
110
111GTEST_DEFINE_bool_(
112 death_test_use_fork,
113 testing::internal::BoolFromGTestEnv("death_test_use_fork", false),
114 "Instructs to use fork()/_exit() instead of clone() in death tests. "
115 "Ignored and always uses fork() on POSIX systems where clone() is not "
116 "implemented. Useful when running under valgrind or similar tools if "
117 "those do not support clone(). Valgrind 3.3.1 will just fail if "
118 "it sees an unsupported combination of clone() flags. "
119 "It is not recommended to use this flag w/o valgrind though it will "
120 "work in 99% of the cases. Once valgrind is fixed, this flag will "
121 "most likely be removed.");
122
123GTEST_DEFINE_string_(
124 internal_run_death_test, "",
125 "Indicates the file, line number, temporal index of "
126 "the single death test to run, and a file descriptor to "
127 "which a success code may be sent, all separated by "
128 "the '|' characters. This flag is specified if and only if the "
129 "current process is a sub-process launched for running a thread-safe "
130 "death test. FOR INTERNAL USE ONLY.");
131
132namespace testing {
133
134#if GTEST_HAS_DEATH_TEST
135
136namespace internal {
137
138// Valid only for fast death tests. Indicates the code is running in the
139// child process of a fast style death test.
140#if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
141static bool g_in_fast_death_test_child = false;
142#endif
143
144// Returns a Boolean value indicating whether the caller is currently
145// executing in the context of the death test child process. Tools such as
146// Valgrind heap checkers may need this to modify their behavior in death
147// tests. IMPORTANT: This is an internal utility. Using it may break the
148// implementation of death tests. User code MUST NOT use it.
149bool InDeathTestChild() {
150#if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
151
152 // On Windows and Fuchsia, death tests are thread-safe regardless of the value
153 // of the death_test_style flag.
154 return !GTEST_FLAG_GET(internal_run_death_test).empty();
155
156#else
157
158 if (GTEST_FLAG_GET(death_test_style) == "threadsafe")
159 return !GTEST_FLAG_GET(internal_run_death_test).empty();
160 else
161 return g_in_fast_death_test_child;
162#endif
163}
164
165} // namespace internal
166
167// ExitedWithCode constructor.
168ExitedWithCode::ExitedWithCode(int exit_code) : exit_code_(exit_code) {}
169
170// ExitedWithCode function-call operator.
171bool ExitedWithCode::operator()(int exit_status) const {
172#if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
173
174 return exit_status == exit_code_;
175
176#else
177
178 return WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == exit_code_;
179
180#endif // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
181}
182
183#if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
184// KilledBySignal constructor.
185KilledBySignal::KilledBySignal(int signum) : signum_(signum) {}
186
187// KilledBySignal function-call operator.
188bool KilledBySignal::operator()(int exit_status) const {
189#if defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
190 {
191 bool result;
192 if (GTEST_KILLED_BY_SIGNAL_OVERRIDE_(signum_, exit_status, &result)) {
193 return result;
194 }
195 }
196#endif // defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
197 return WIFSIGNALED(exit_status) && WTERMSIG(exit_status) == signum_;
198}
199#endif // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
200
201namespace internal {
202
203// Utilities needed for death tests.
204
205// Generates a textual description of a given exit code, in the format
206// specified by wait(2).
207static std::string ExitSummary(int exit_code) {
208 Message m;
209
210#if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
211
212 m << "Exited with exit status " << exit_code;
213
214#else
215
216 if (WIFEXITED(exit_code)) {
217 m << "Exited with exit status " << WEXITSTATUS(exit_code);
218 } else if (WIFSIGNALED(exit_code)) {
219 m << "Terminated by signal " << WTERMSIG(exit_code);
220 }
221#ifdef WCOREDUMP
222 if (WCOREDUMP(exit_code)) {
223 m << " (core dumped)";
224 }
225#endif
226#endif // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
227
228 return m.GetString();
229}
230
231// Returns true if exit_status describes a process that was terminated
232// by a signal, or exited normally with a nonzero exit code.
233bool ExitedUnsuccessfully(int exit_status) {
234 return !ExitedWithCode(0)(exit_status);
235}
236
237#if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
238// Generates a textual failure message when a death test finds more than
239// one thread running, or cannot determine the number of threads, prior
240// to executing the given statement. It is the responsibility of the
241// caller not to pass a thread_count of 1.
242static std::string DeathTestThreadWarning(size_t thread_count) {
243 Message msg;
244 msg << "Death tests use fork(), which is unsafe particularly"
245 << " in a threaded context. For this test, " << GTEST_NAME_ << " ";
246 if (thread_count == 0) {
247 msg << "couldn't detect the number of threads.";
248 } else {
249 msg << "detected " << thread_count << " threads.";
250 }
251 msg << " See "
252 "https://github.com/google/googletest/blob/main/docs/"
253 "advanced.md#death-tests-and-threads"
254 << " for more explanation and suggested solutions, especially if"
255 << " this is the last message you see before your test times out.";
256 return msg.GetString();
257}
258#endif // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
259
260// Flag characters for reporting a death test that did not die.
261static const char kDeathTestLived = 'L';
262static const char kDeathTestReturned = 'R';
263static const char kDeathTestThrew = 'T';
264static const char kDeathTestInternalError = 'I';
265
266#if GTEST_OS_FUCHSIA
267
268// File descriptor used for the pipe in the child process.
269static const int kFuchsiaReadPipeFd = 3;
270
271#endif
272
273// An enumeration describing all of the possible ways that a death test can
274// conclude. DIED means that the process died while executing the test
275// code; LIVED means that process lived beyond the end of the test code;
276// RETURNED means that the test statement attempted to execute a return
277// statement, which is not allowed; THREW means that the test statement
278// returned control by throwing an exception. IN_PROGRESS means the test
279// has not yet concluded.
280enum DeathTestOutcome { IN_PROGRESS, DIED, LIVED, RETURNED, THREW };
281
282// Routine for aborting the program which is safe to call from an
283// exec-style death test child process, in which case the error
284// message is propagated back to the parent process. Otherwise, the
285// message is simply printed to stderr. In either case, the program
286// then exits with status 1.
287[[noreturn]] static void DeathTestAbort(const std::string& message) {
288 // On a POSIX system, this function may be called from a threadsafe-style
289 // death test child process, which operates on a very small stack. Use
290 // the heap for any additional non-minuscule memory requirements.
291 const InternalRunDeathTestFlag* const flag =
292 GetUnitTestImpl()->internal_run_death_test_flag();
293 if (flag != nullptr) {
294 FILE* parent = posix::FDOpen(fd: flag->write_fd(), mode: "w");
295 fputc(c: kDeathTestInternalError, stream: parent);
296 fprintf(stream: parent, format: "%s", message.c_str());
297 fflush(stream: parent);
298 _exit(status: 1);
299 } else {
300 fprintf(stderr, format: "%s", message.c_str());
301 fflush(stderr);
302 posix::Abort();
303 }
304}
305
306// A replacement for CHECK that calls DeathTestAbort if the assertion
307// fails.
308#define GTEST_DEATH_TEST_CHECK_(expression) \
309 do { \
310 if (!::testing::internal::IsTrue(expression)) { \
311 DeathTestAbort(::std::string("CHECK failed: File ") + __FILE__ + \
312 ", line " + \
313 ::testing::internal::StreamableToString(__LINE__) + \
314 ": " + #expression); \
315 } \
316 } while (::testing::internal::AlwaysFalse())
317
318// This macro is similar to GTEST_DEATH_TEST_CHECK_, but it is meant for
319// evaluating any system call that fulfills two conditions: it must return
320// -1 on failure, and set errno to EINTR when it is interrupted and
321// should be tried again. The macro expands to a loop that repeatedly
322// evaluates the expression as long as it evaluates to -1 and sets
323// errno to EINTR. If the expression evaluates to -1 but errno is
324// something other than EINTR, DeathTestAbort is called.
325#define GTEST_DEATH_TEST_CHECK_SYSCALL_(expression) \
326 do { \
327 int gtest_retval; \
328 do { \
329 gtest_retval = (expression); \
330 } while (gtest_retval == -1 && errno == EINTR); \
331 if (gtest_retval == -1) { \
332 DeathTestAbort(::std::string("CHECK failed: File ") + __FILE__ + \
333 ", line " + \
334 ::testing::internal::StreamableToString(__LINE__) + \
335 ": " + #expression + " != -1"); \
336 } \
337 } while (::testing::internal::AlwaysFalse())
338
339// Returns the message describing the last system error in errno.
340std::string GetLastErrnoDescription() {
341 return errno == 0 ? "" : posix::StrError(errno);
342}
343
344// This is called from a death test parent process to read a failure
345// message from the death test child process and log it with the FATAL
346// severity. On Windows, the message is read from a pipe handle. On other
347// platforms, it is read from a file descriptor.
348static void FailFromInternalError(int fd) {
349 Message error;
350 char buffer[256];
351 int num_read;
352
353 do {
354 while ((num_read = posix::Read(fd, buf: buffer, count: 255)) > 0) {
355 buffer[num_read] = '\0';
356 error << buffer;
357 }
358 } while (num_read == -1 && errno == EINTR);
359
360 if (num_read == 0) {
361 GTEST_LOG_(FATAL) << error.GetString();
362 } else {
363 const int last_error = errno;
364 GTEST_LOG_(FATAL) << "Error while reading death test internal: "
365 << GetLastErrnoDescription() << " [" << last_error << "]";
366 }
367}
368
369// Death test constructor. Increments the running death test count
370// for the current test.
371DeathTest::DeathTest() {
372 TestInfo* const info = GetUnitTestImpl()->current_test_info();
373 if (info == nullptr) {
374 DeathTestAbort(
375 message: "Cannot run a death test outside of a TEST or "
376 "TEST_F construct");
377 }
378}
379
380// Creates and returns a death test by dispatching to the current
381// death test factory.
382bool DeathTest::Create(const char* statement,
383 Matcher<const std::string&> matcher, const char* file,
384 int line, DeathTest** test) {
385 return GetUnitTestImpl()->death_test_factory()->Create(
386 statement, matcher: std::move(matcher), file, line, test);
387}
388
389const char* DeathTest::LastMessage() {
390 return last_death_test_message_.c_str();
391}
392
393void DeathTest::set_last_death_test_message(const std::string& message) {
394 last_death_test_message_ = message;
395}
396
397std::string DeathTest::last_death_test_message_;
398
399// Provides cross platform implementation for some death functionality.
400class DeathTestImpl : public DeathTest {
401 protected:
402 DeathTestImpl(const char* a_statement, Matcher<const std::string&> matcher)
403 : statement_(a_statement),
404 matcher_(std::move(matcher)),
405 spawned_(false),
406 status_(-1),
407 outcome_(IN_PROGRESS),
408 read_fd_(-1),
409 write_fd_(-1) {}
410
411 // read_fd_ is expected to be closed and cleared by a derived class.
412 ~DeathTestImpl() override { GTEST_DEATH_TEST_CHECK_(read_fd_ == -1); }
413
414 void Abort(AbortReason reason) override;
415 bool Passed(bool status_ok) override;
416
417 const char* statement() const { return statement_; }
418 bool spawned() const { return spawned_; }
419 void set_spawned(bool is_spawned) { spawned_ = is_spawned; }
420 int status() const { return status_; }
421 void set_status(int a_status) { status_ = a_status; }
422 DeathTestOutcome outcome() const { return outcome_; }
423 void set_outcome(DeathTestOutcome an_outcome) { outcome_ = an_outcome; }
424 int read_fd() const { return read_fd_; }
425 void set_read_fd(int fd) { read_fd_ = fd; }
426 int write_fd() const { return write_fd_; }
427 void set_write_fd(int fd) { write_fd_ = fd; }
428
429 // Called in the parent process only. Reads the result code of the death
430 // test child process via a pipe, interprets it to set the outcome_
431 // member, and closes read_fd_. Outputs diagnostics and terminates in
432 // case of unexpected codes.
433 void ReadAndInterpretStatusByte();
434
435 // Returns stderr output from the child process.
436 virtual std::string GetErrorLogs();
437
438 private:
439 // The textual content of the code this object is testing. This class
440 // doesn't own this string and should not attempt to delete it.
441 const char* const statement_;
442 // A matcher that's expected to match the stderr output by the child process.
443 Matcher<const std::string&> matcher_;
444 // True if the death test child process has been successfully spawned.
445 bool spawned_;
446 // The exit status of the child process.
447 int status_;
448 // How the death test concluded.
449 DeathTestOutcome outcome_;
450 // Descriptor to the read end of the pipe to the child process. It is
451 // always -1 in the child process. The child keeps its write end of the
452 // pipe in write_fd_.
453 int read_fd_;
454 // Descriptor to the child's write end of the pipe to the parent process.
455 // It is always -1 in the parent process. The parent keeps its end of the
456 // pipe in read_fd_.
457 int write_fd_;
458};
459
460// Called in the parent process only. Reads the result code of the death
461// test child process via a pipe, interprets it to set the outcome_
462// member, and closes read_fd_. Outputs diagnostics and terminates in
463// case of unexpected codes.
464void DeathTestImpl::ReadAndInterpretStatusByte() {
465 char flag;
466 int bytes_read;
467
468 // The read() here blocks until data is available (signifying the
469 // failure of the death test) or until the pipe is closed (signifying
470 // its success), so it's okay to call this in the parent before
471 // the child process has exited.
472 do {
473 bytes_read = posix::Read(fd: read_fd(), buf: &flag, count: 1);
474 } while (bytes_read == -1 && errno == EINTR);
475
476 if (bytes_read == 0) {
477 set_outcome(DIED);
478 } else if (bytes_read == 1) {
479 switch (flag) {
480 case kDeathTestReturned:
481 set_outcome(RETURNED);
482 break;
483 case kDeathTestThrew:
484 set_outcome(THREW);
485 break;
486 case kDeathTestLived:
487 set_outcome(LIVED);
488 break;
489 case kDeathTestInternalError:
490 FailFromInternalError(fd: read_fd()); // Does not return.
491 break;
492 default:
493 GTEST_LOG_(FATAL) << "Death test child process reported "
494 << "unexpected status byte ("
495 << static_cast<unsigned int>(flag) << ")";
496 }
497 } else {
498 GTEST_LOG_(FATAL) << "Read from death test child process failed: "
499 << GetLastErrnoDescription();
500 }
501 GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Close(read_fd()));
502 set_read_fd(-1);
503}
504
505std::string DeathTestImpl::GetErrorLogs() { return GetCapturedStderr(); }
506
507// Signals that the death test code which should have exited, didn't.
508// Should be called only in a death test child process.
509// Writes a status byte to the child's status file descriptor, then
510// calls _exit(1).
511void DeathTestImpl::Abort(AbortReason reason) {
512 // The parent process considers the death test to be a failure if
513 // it finds any data in our pipe. So, here we write a single flag byte
514 // to the pipe, then exit.
515 const char status_ch = reason == TEST_DID_NOT_DIE ? kDeathTestLived
516 : reason == TEST_THREW_EXCEPTION ? kDeathTestThrew
517 : kDeathTestReturned;
518
519 GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Write(write_fd(), &status_ch, 1));
520 // We are leaking the descriptor here because on some platforms (i.e.,
521 // when built as Windows DLL), destructors of global objects will still
522 // run after calling _exit(). On such systems, write_fd_ will be
523 // indirectly closed from the destructor of UnitTestImpl, causing double
524 // close if it is also closed here. On debug configurations, double close
525 // may assert. As there are no in-process buffers to flush here, we are
526 // relying on the OS to close the descriptor after the process terminates
527 // when the destructors are not run.
528 _exit(status: 1); // Exits w/o any normal exit hooks (we were supposed to crash)
529}
530
531// Returns an indented copy of stderr output for a death test.
532// This makes distinguishing death test output lines from regular log lines
533// much easier.
534static ::std::string FormatDeathTestOutput(const ::std::string& output) {
535 ::std::string ret;
536 for (size_t at = 0;;) {
537 const size_t line_end = output.find(c: '\n', pos: at);
538 ret += "[ DEATH ] ";
539 if (line_end == ::std::string::npos) {
540 ret += output.substr(pos: at);
541 break;
542 }
543 ret += output.substr(pos: at, n: line_end + 1 - at);
544 at = line_end + 1;
545 }
546 return ret;
547}
548
549// Assesses the success or failure of a death test, using both private
550// members which have previously been set, and one argument:
551//
552// Private data members:
553// outcome: An enumeration describing how the death test
554// concluded: DIED, LIVED, THREW, or RETURNED. The death test
555// fails in the latter three cases.
556// status: The exit status of the child process. On *nix, it is in the
557// in the format specified by wait(2). On Windows, this is the
558// value supplied to the ExitProcess() API or a numeric code
559// of the exception that terminated the program.
560// matcher_: A matcher that's expected to match the stderr output by the child
561// process.
562//
563// Argument:
564// status_ok: true if exit_status is acceptable in the context of
565// this particular death test, which fails if it is false
566//
567// Returns true if and only if all of the above conditions are met. Otherwise,
568// the first failing condition, in the order given above, is the one that is
569// reported. Also sets the last death test message string.
570bool DeathTestImpl::Passed(bool status_ok) {
571 if (!spawned()) 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"
583 << FormatDeathTestOutput(output: error_message);
584 break;
585 case THREW:
586 buffer << " Result: threw an exception.\n"
587 << " Error msg:\n"
588 << FormatDeathTestOutput(output: error_message);
589 break;
590 case RETURNED:
591 buffer << " Result: illegal return in test statement.\n"
592 << " Error msg:\n"
593 << FormatDeathTestOutput(output: error_message);
594 break;
595 case DIED:
596 if (status_ok) {
597 if (matcher_.Matches(x: error_message)) {
598 success = true;
599 } else {
600 std::ostringstream stream;
601 matcher_.DescribeTo(os: &stream);
602 buffer << " Result: died but not with expected error.\n"
603 << " Expected: " << stream.str() << "\n"
604 << "Actual msg:\n"
605 << FormatDeathTestOutput(output: error_message);
606 }
607 } else {
608 buffer << " Result: died but not with expected exit code:\n"
609 << " " << ExitSummary(exit_code: status()) << "\n"
610 << "Actual msg:\n"
611 << FormatDeathTestOutput(output: error_message);
612 }
613 break;
614 case IN_PROGRESS:
615 default:
616 GTEST_LOG_(FATAL)
617 << "DeathTest::Passed somehow called before conclusion of test";
618 }
619
620 DeathTest::set_last_death_test_message(buffer.GetString());
621 return success;
622}
623
624#if GTEST_OS_WINDOWS
625// WindowsDeathTest implements death tests on Windows. Due to the
626// specifics of starting new processes on Windows, death tests there are
627// always threadsafe, and Google Test considers the
628// --gtest_death_test_style=fast setting to be equivalent to
629// --gtest_death_test_style=threadsafe there.
630//
631// A few implementation notes: Like the Linux version, the Windows
632// implementation uses pipes for child-to-parent communication. But due to
633// the specifics of pipes on Windows, some extra steps are required:
634//
635// 1. The parent creates a communication pipe and stores handles to both
636// ends of it.
637// 2. The parent starts the child and provides it with the information
638// necessary to acquire the handle to the write end of the pipe.
639// 3. The child acquires the write end of the pipe and signals the parent
640// using a Windows event.
641// 4. Now the parent can release the write end of the pipe on its side. If
642// this is done before step 3, the object's reference count goes down to
643// 0 and it is destroyed, preventing the child from acquiring it. The
644// parent now has to release it, or read operations on the read end of
645// the pipe will not return when the child terminates.
646// 5. The parent reads child's output through the pipe (outcome code and
647// any possible error messages) from the pipe, and its stderr and then
648// determines whether to fail the test.
649//
650// Note: to distinguish Win32 API calls from the local method and function
651// calls, the former are explicitly resolved in the global namespace.
652//
653class WindowsDeathTest : public DeathTestImpl {
654 public:
655 WindowsDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
656 const char* file, int line)
657 : DeathTestImpl(a_statement, std::move(matcher)),
658 file_(file),
659 line_(line) {}
660
661 // All of these virtual functions are inherited from DeathTest.
662 virtual int Wait();
663 virtual TestRole AssumeRole();
664
665 private:
666 // The name of the file in which the death test is located.
667 const char* const file_;
668 // The line number on which the death test is located.
669 const int line_;
670 // Handle to the write end of the pipe to the child process.
671 AutoHandle write_handle_;
672 // Child process handle.
673 AutoHandle child_handle_;
674 // Event the child process uses to signal the parent that it has
675 // acquired the handle to the write end of the pipe. After seeing this
676 // event the parent can release its own handles to make sure its
677 // ReadFile() calls return when the child terminates.
678 AutoHandle event_handle_;
679};
680
681// Waits for the child in a death test to exit, returning its exit
682// status, or 0 if no child process exists. As a side effect, sets the
683// outcome data member.
684int WindowsDeathTest::Wait() {
685 if (!spawned()) return 0;
686
687 // Wait until the child either signals that it has acquired the write end
688 // of the pipe or it dies.
689 const HANDLE wait_handles[2] = {child_handle_.Get(), event_handle_.Get()};
690 switch (::WaitForMultipleObjects(2, wait_handles,
691 FALSE, // Waits for any of the handles.
692 INFINITE)) {
693 case WAIT_OBJECT_0:
694 case WAIT_OBJECT_0 + 1:
695 break;
696 default:
697 GTEST_DEATH_TEST_CHECK_(false); // Should not get here.
698 }
699
700 // The child has acquired the write end of the pipe or exited.
701 // We release the handle on our side and continue.
702 write_handle_.Reset();
703 event_handle_.Reset();
704
705 ReadAndInterpretStatusByte();
706
707 // Waits for the child process to exit if it haven't already. This
708 // returns immediately if the child has already exited, regardless of
709 // whether previous calls to WaitForMultipleObjects synchronized on this
710 // handle or not.
711 GTEST_DEATH_TEST_CHECK_(WAIT_OBJECT_0 ==
712 ::WaitForSingleObject(child_handle_.Get(), INFINITE));
713 DWORD status_code;
714 GTEST_DEATH_TEST_CHECK_(
715 ::GetExitCodeProcess(child_handle_.Get(), &status_code) != FALSE);
716 child_handle_.Reset();
717 set_status(static_cast<int>(status_code));
718 return status();
719}
720
721// The AssumeRole process for a Windows death test. It creates a child
722// process with the same executable as the current process to run the
723// death test. The child process is given the --gtest_filter and
724// --gtest_internal_run_death_test flags such that it knows to run the
725// current death test only.
726DeathTest::TestRole WindowsDeathTest::AssumeRole() {
727 const UnitTestImpl* const impl = GetUnitTestImpl();
728 const InternalRunDeathTestFlag* const flag =
729 impl->internal_run_death_test_flag();
730 const TestInfo* const info = impl->current_test_info();
731 const int death_test_index = info->result()->death_test_count();
732
733 if (flag != nullptr) {
734 // ParseInternalRunDeathTestFlag() has performed all the necessary
735 // processing.
736 set_write_fd(flag->write_fd());
737 return EXECUTE_TEST;
738 }
739
740 // WindowsDeathTest uses an anonymous pipe to communicate results of
741 // a death test.
742 SECURITY_ATTRIBUTES handles_are_inheritable = {sizeof(SECURITY_ATTRIBUTES),
743 nullptr, TRUE};
744 HANDLE read_handle, write_handle;
745 GTEST_DEATH_TEST_CHECK_(::CreatePipe(&read_handle, &write_handle,
746 &handles_are_inheritable,
747 0) // Default buffer size.
748 != FALSE);
749 set_read_fd(
750 ::_open_osfhandle(reinterpret_cast<intptr_t>(read_handle), O_RDONLY));
751 write_handle_.Reset(write_handle);
752 event_handle_.Reset(::CreateEvent(
753 &handles_are_inheritable,
754 TRUE, // The event will automatically reset to non-signaled state.
755 FALSE, // The initial state is non-signalled.
756 nullptr)); // The even is unnamed.
757 GTEST_DEATH_TEST_CHECK_(event_handle_.Get() != nullptr);
758 const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
759 "filter=" + info->test_suite_name() + "." +
760 info->name();
761 const std::string internal_flag =
762 std::string("--") + GTEST_FLAG_PREFIX_ +
763 "internal_run_death_test=" + file_ + "|" + StreamableToString(line_) +
764 "|" + StreamableToString(death_test_index) + "|" +
765 StreamableToString(static_cast<unsigned int>(::GetCurrentProcessId())) +
766 // size_t has the same width as pointers on both 32-bit and 64-bit
767 // Windows platforms.
768 // See http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx.
769 "|" + StreamableToString(reinterpret_cast<size_t>(write_handle)) + "|" +
770 StreamableToString(reinterpret_cast<size_t>(event_handle_.Get()));
771
772 char executable_path[_MAX_PATH + 1]; // NOLINT
773 GTEST_DEATH_TEST_CHECK_(_MAX_PATH + 1 != ::GetModuleFileNameA(nullptr,
774 executable_path,
775 _MAX_PATH));
776
777 std::string command_line = std::string(::GetCommandLineA()) + " " +
778 filter_flag + " \"" + 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, // Returned process handle is not inheritable.
799 nullptr, // Returned 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
813class 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.
840class 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(); ++i) {
858 args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
859 }
860 }
861 char* const* Argv() { return &args_[0]; }
862
863 int size() { return static_cast<int>(args_.size()) - 1; }
864
865 private:
866 std::vector<char*> args_;
867};
868
869// Waits for the child in a death test to exit, returning its exit
870// status, or 0 if no child process exists. As a side effect, sets the
871// outcome data member.
872int FuchsiaDeathTest::Wait() {
873 const int kProcessKey = 0;
874 const int kSocketKey = 1;
875 const int kExceptionKey = 2;
876
877 if (!spawned()) return 0;
878
879 // Create a port to wait for socket/task/exception events.
880 zx_status_t status_zx;
881 zx::port port;
882 status_zx = zx::port::create(0, &port);
883 GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
884
885 // Register to wait for the child process to terminate.
886 status_zx =
887 child_process_.wait_async(port, kProcessKey, ZX_PROCESS_TERMINATED, 0);
888 GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
889
890 // Register to wait for the socket to be readable or closed.
891 status_zx = stderr_socket_.wait_async(
892 port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED, 0);
893 GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
894
895 // Register to wait for an exception.
896 status_zx = exception_channel_.wait_async(port, kExceptionKey,
897 ZX_CHANNEL_READABLE, 0);
898 GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
899
900 bool process_terminated = false;
901 bool socket_closed = false;
902 do {
903 zx_port_packet_t packet = {};
904 status_zx = port.wait(zx::time::infinite(), &packet);
905 GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
906
907 if (packet.key == kExceptionKey) {
908 // Process encountered an exception. Kill it directly rather than
909 // letting other handlers process the event. We will get a kProcessKey
910 // event when the process actually terminates.
911 status_zx = child_process_.kill();
912 GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
913 } else if (packet.key == kProcessKey) {
914 // Process terminated.
915 GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
916 GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_PROCESS_TERMINATED);
917 process_terminated = true;
918 } else if (packet.key == kSocketKey) {
919 GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
920 if (packet.signal.observed & ZX_SOCKET_READABLE) {
921 // Read data from the socket.
922 constexpr size_t kBufferSize = 1024;
923 do {
924 size_t old_length = captured_stderr_.length();
925 size_t bytes_read = 0;
926 captured_stderr_.resize(old_length + kBufferSize);
927 status_zx =
928 stderr_socket_.read(0, &captured_stderr_.front() + old_length,
929 kBufferSize, &bytes_read);
930 captured_stderr_.resize(old_length + bytes_read);
931 } while (status_zx == ZX_OK);
932 if (status_zx == ZX_ERR_PEER_CLOSED) {
933 socket_closed = true;
934 } else {
935 GTEST_DEATH_TEST_CHECK_(status_zx == ZX_ERR_SHOULD_WAIT);
936 status_zx = stderr_socket_.wait_async(
937 port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED, 0);
938 GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
939 }
940 } else {
941 GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_SOCKET_PEER_CLOSED);
942 socket_closed = true;
943 }
944 }
945 } while (!process_terminated && !socket_closed);
946
947 ReadAndInterpretStatusByte();
948
949 zx_info_process_t buffer;
950 status_zx = child_process_.get_info(ZX_INFO_PROCESS, &buffer, sizeof(buffer),
951 nullptr, nullptr);
952 GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
953
954 GTEST_DEATH_TEST_CHECK_(buffer.flags & ZX_INFO_PROCESS_FLAG_EXITED);
955 set_status(static_cast<int>(buffer.return_code));
956 return status();
957}
958
959// The AssumeRole process for a Fuchsia death test. It creates a child
960// process with the same executable as the current process to run the
961// death test. The child process is given the --gtest_filter and
962// --gtest_internal_run_death_test flags such that it knows to run the
963// current death test only.
964DeathTest::TestRole FuchsiaDeathTest::AssumeRole() {
965 const UnitTestImpl* const impl = GetUnitTestImpl();
966 const InternalRunDeathTestFlag* const flag =
967 impl->internal_run_death_test_flag();
968 const TestInfo* const info = impl->current_test_info();
969 const int death_test_index = info->result()->death_test_count();
970
971 if (flag != nullptr) {
972 // ParseInternalRunDeathTestFlag() has performed all the necessary
973 // processing.
974 set_write_fd(kFuchsiaReadPipeFd);
975 return EXECUTE_TEST;
976 }
977
978 // Flush the log buffers since the log streams are shared with the child.
979 FlushInfoLog();
980
981 // Build the child process command line.
982 const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
983 "filter=" + info->test_suite_name() + "." +
984 info->name();
985 const std::string internal_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
986 kInternalRunDeathTestFlag + "=" + file_ +
987 "|" + StreamableToString(line_) + "|" +
988 StreamableToString(death_test_index);
989 Arguments args;
990 args.AddArguments(GetInjectableArgvs());
991 args.AddArgument(filter_flag.c_str());
992 args.AddArgument(internal_flag.c_str());
993
994 // Build the pipe for communication with the child.
995 zx_status_t status;
996 zx_handle_t child_pipe_handle;
997 int child_pipe_fd;
998 status = fdio_pipe_half(&child_pipe_fd, &child_pipe_handle);
999 GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1000 set_read_fd(child_pipe_fd);
1001
1002 // Set the pipe handle for the child.
1003 fdio_spawn_action_t spawn_actions[2] = {};
1004 fdio_spawn_action_t* add_handle_action = &spawn_actions[0];
1005 add_handle_action->action = FDIO_SPAWN_ACTION_ADD_HANDLE;
1006 add_handle_action->h.id = PA_HND(PA_FD, kFuchsiaReadPipeFd);
1007 add_handle_action->h.handle = child_pipe_handle;
1008
1009 // Create a socket pair will be used to receive the child process' stderr.
1010 zx::socket stderr_producer_socket;
1011 status = zx::socket::create(0, &stderr_producer_socket, &stderr_socket_);
1012 GTEST_DEATH_TEST_CHECK_(status >= 0);
1013 int stderr_producer_fd = -1;
1014 status =
1015 fdio_fd_create(stderr_producer_socket.release(), &stderr_producer_fd);
1016 GTEST_DEATH_TEST_CHECK_(status >= 0);
1017
1018 // Make the stderr socket nonblocking.
1019 GTEST_DEATH_TEST_CHECK_(fcntl(stderr_producer_fd, F_SETFL, 0) == 0);
1020
1021 fdio_spawn_action_t* add_stderr_action = &spawn_actions[1];
1022 add_stderr_action->action = FDIO_SPAWN_ACTION_CLONE_FD;
1023 add_stderr_action->fd.local_fd = stderr_producer_fd;
1024 add_stderr_action->fd.target_fd = STDERR_FILENO;
1025
1026 // Create a child job.
1027 zx_handle_t child_job = ZX_HANDLE_INVALID;
1028 status = zx_job_create(zx_job_default(), 0, &child_job);
1029 GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1030 zx_policy_basic_t policy;
1031 policy.condition = ZX_POL_NEW_ANY;
1032 policy.policy = ZX_POL_ACTION_ALLOW;
1033 status = zx_job_set_policy(child_job, ZX_JOB_POL_RELATIVE, ZX_JOB_POL_BASIC,
1034 &policy, 1);
1035 GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1036
1037 // Create an exception channel attached to the |child_job|, to allow
1038 // us to suppress the system default exception handler from firing.
1039 status = zx_task_create_exception_channel(
1040 child_job, 0, exception_channel_.reset_and_get_address());
1041 GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1042
1043 // Spawn the child process.
1044 status = fdio_spawn_etc(child_job, FDIO_SPAWN_CLONE_ALL, args.Argv()[0],
1045 args.Argv(), nullptr, 2, spawn_actions,
1046 child_process_.reset_and_get_address(), nullptr);
1047 GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
1048
1049 set_spawned(true);
1050 return OVERSEE_TEST;
1051}
1052
1053std::string FuchsiaDeathTest::GetErrorLogs() { return captured_stderr_; }
1054
1055#else // We are neither on Windows, nor on Fuchsia.
1056
1057// ForkingDeathTest provides implementations for most of the abstract
1058// methods of the DeathTest interface. Only the AssumeRole method is
1059// left undefined.
1060class ForkingDeathTest : public DeathTestImpl {
1061 public:
1062 ForkingDeathTest(const char* statement, Matcher<const std::string&> matcher);
1063
1064 // All of these virtual functions are inherited from DeathTest.
1065 int Wait() override;
1066
1067 protected:
1068 void set_child_pid(pid_t child_pid) { child_pid_ = child_pid; }
1069
1070 private:
1071 // PID of child process during death test; 0 in the child process itself.
1072 pid_t child_pid_;
1073};
1074
1075// Constructs a ForkingDeathTest.
1076ForkingDeathTest::ForkingDeathTest(const char* a_statement,
1077 Matcher<const std::string&> matcher)
1078 : DeathTestImpl(a_statement, std::move(matcher)), child_pid_(-1) {}
1079
1080// Waits for the child in a death test to exit, returning its exit
1081// status, or 0 if no child process exists. As a side effect, sets the
1082// outcome data member.
1083int ForkingDeathTest::Wait() {
1084 if (!spawned()) return 0;
1085
1086 ReadAndInterpretStatusByte();
1087
1088 int status_value;
1089 GTEST_DEATH_TEST_CHECK_SYSCALL_(waitpid(child_pid_, &status_value, 0));
1090 set_status(status_value);
1091 return status_value;
1092}
1093
1094// A concrete death test class that forks, then immediately runs the test
1095// in the child process.
1096class NoExecDeathTest : public ForkingDeathTest {
1097 public:
1098 NoExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher)
1099 : ForkingDeathTest(a_statement, std::move(matcher)) {}
1100 TestRole AssumeRole() override;
1101};
1102
1103// The AssumeRole process for a fork-and-run death test. It implements a
1104// straightforward fork, with a simple pipe to transmit the status byte.
1105DeathTest::TestRole NoExecDeathTest::AssumeRole() {
1106 const size_t thread_count = GetThreadCount();
1107 if (thread_count != 1) {
1108 GTEST_LOG_(WARNING) << DeathTestThreadWarning(thread_count);
1109 }
1110
1111 int pipe_fd[2];
1112 GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
1113
1114 DeathTest::set_last_death_test_message("");
1115 CaptureStderr();
1116 // When we fork the process below, the log file buffers are copied, but the
1117 // file descriptors are shared. We flush all log files here so that closing
1118 // the file descriptors in the child process doesn't throw off the
1119 // synchronization between descriptors and buffers in the parent process.
1120 // This is as close to the fork as possible to avoid a race condition in case
1121 // there are multiple threads running before the death test, and another
1122 // thread writes to the log file.
1123 FlushInfoLog();
1124
1125 const pid_t child_pid = fork();
1126 GTEST_DEATH_TEST_CHECK_(child_pid != -1);
1127 set_child_pid(child_pid);
1128 if (child_pid == 0) {
1129 GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[0]));
1130 set_write_fd(pipe_fd[1]);
1131 // Redirects all logging to stderr in the child process to prevent
1132 // concurrent writes to the log files. We capture stderr in the parent
1133 // process and append the child process' output to a log.
1134 LogToStderr();
1135 // Event forwarding to the listeners of event listener API mush be shut
1136 // down in death test subprocesses.
1137 GetUnitTestImpl()->listeners()->SuppressEventForwarding();
1138 g_in_fast_death_test_child = true;
1139 return EXECUTE_TEST;
1140 } else {
1141 GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
1142 set_read_fd(pipe_fd[0]);
1143 set_spawned(true);
1144 return OVERSEE_TEST;
1145 }
1146}
1147
1148// A concrete death test class that forks and re-executes the main
1149// program from the beginning, with command-line flags set that cause
1150// only this specific death test to be run.
1151class ExecDeathTest : public ForkingDeathTest {
1152 public:
1153 ExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
1154 const char* file, int line)
1155 : ForkingDeathTest(a_statement, std::move(matcher)),
1156 file_(file),
1157 line_(line) {}
1158 TestRole AssumeRole() override;
1159
1160 private:
1161 static ::std::vector<std::string> GetArgvsForDeathTestChildProcess() {
1162 ::std::vector<std::string> args = GetInjectableArgvs();
1163#if defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
1164 ::std::vector<std::string> extra_args =
1165 GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_();
1166 args.insert(args.end(), extra_args.begin(), extra_args.end());
1167#endif // defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
1168 return args;
1169 }
1170 // The name of the file in which the death test is located.
1171 const char* const file_;
1172 // The line number on which the death test is located.
1173 const int line_;
1174};
1175
1176// Utility class for accumulating command-line arguments.
1177class Arguments {
1178 public:
1179 Arguments() { args_.push_back(x: nullptr); }
1180
1181 ~Arguments() {
1182 for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
1183 ++i) {
1184 free(ptr: *i);
1185 }
1186 }
1187 void AddArgument(const char* argument) {
1188 args_.insert(position: args_.end() - 1, x: posix::StrDup(src: argument));
1189 }
1190
1191 template <typename Str>
1192 void AddArguments(const ::std::vector<Str>& arguments) {
1193 for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
1194 i != arguments.end(); ++i) {
1195 args_.insert(args_.end() - 1, posix::StrDup(src: i->c_str()));
1196 }
1197 }
1198 char* const* Argv() { return &args_[0]; }
1199
1200 private:
1201 std::vector<char*> args_;
1202};
1203
1204// A struct that encompasses the arguments to the child process of a
1205// threadsafe-style death test process.
1206struct ExecDeathTestArgs {
1207 char* const* argv; // Command-line arguments for the child's call to exec
1208 int close_fd; // File descriptor to close; the read end of a pipe
1209};
1210
1211#if GTEST_OS_QNX
1212extern "C" char** environ;
1213#else // GTEST_OS_QNX
1214// The main function for a threadsafe-style death test child process.
1215// This function is called in a clone()-ed process and thus must avoid
1216// any potentially unsafe operations like malloc or libc functions.
1217static int ExecDeathTestChildMain(void* child_arg) {
1218 ExecDeathTestArgs* const args = static_cast<ExecDeathTestArgs*>(child_arg);
1219 GTEST_DEATH_TEST_CHECK_SYSCALL_(close(args->close_fd));
1220
1221 // We need to execute the test program in the same environment where
1222 // it was originally invoked. Therefore we change to the original
1223 // working directory first.
1224 const char* const original_dir =
1225 UnitTest::GetInstance()->original_working_dir();
1226 // We can safely call chdir() as it's a direct system call.
1227 if (chdir(path: original_dir) != 0) {
1228 DeathTestAbort(message: std::string("chdir(\"") + original_dir +
1229 "\") failed: " + GetLastErrnoDescription());
1230 return EXIT_FAILURE;
1231 }
1232
1233 // We can safely call execv() as it's almost a direct system call. We
1234 // cannot use execvp() as it's a libc function and thus potentially
1235 // unsafe. Since execv() doesn't search the PATH, the user must
1236 // invoke the test program via a valid path that contains at least
1237 // one path separator.
1238 execv(path: args->argv[0], argv: args->argv);
1239 DeathTestAbort(message: std::string("execv(") + args->argv[0] + ", ...) in " +
1240 original_dir + " failed: " + GetLastErrnoDescription());
1241 return EXIT_FAILURE;
1242}
1243#endif // GTEST_OS_QNX
1244
1245#if GTEST_HAS_CLONE
1246// Two utility routines that together determine the direction the stack
1247// grows.
1248// This could be accomplished more elegantly by a single recursive
1249// function, but we want to guard against the unlikely possibility of
1250// a smart compiler optimizing the recursion away.
1251//
1252// GTEST_NO_INLINE_ is required to prevent GCC 4.6 from inlining
1253// StackLowerThanAddress into StackGrowsDown, which then doesn't give
1254// correct answer.
1255static void StackLowerThanAddress(const void* ptr,
1256 bool* result) GTEST_NO_INLINE_;
1257// Make sure sanitizers do not tamper with the stack here.
1258// Ideally, we want to use `__builtin_frame_address` instead of a local variable
1259// address with sanitizer disabled, but it does not work when the
1260// compiler optimizes the stack frame out, which happens on PowerPC targets.
1261// HWAddressSanitizer add a random tag to the MSB of the local variable address,
1262// making comparison result unpredictable.
1263GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
1264GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
1265static void StackLowerThanAddress(const void* ptr, bool* result) {
1266 int dummy = 0;
1267 *result = std::less<const void*>()(&dummy, ptr);
1268}
1269
1270// Make sure AddressSanitizer does not tamper with the stack here.
1271GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
1272GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
1273static bool StackGrowsDown() {
1274 int dummy = 0;
1275 bool result;
1276 StackLowerThanAddress(ptr: &dummy, result: &result);
1277 return result;
1278}
1279#endif // GTEST_HAS_CLONE
1280
1281// Spawns a child process with the same executable as the current process in
1282// a thread-safe manner and instructs it to run the death test. The
1283// implementation uses fork(2) + exec. On systems where clone(2) is
1284// available, it is used instead, being slightly more thread-safe. On QNX,
1285// fork supports only single-threaded environments, so this function uses
1286// spawn(2) there instead. The function dies with an error message if
1287// anything goes wrong.
1288static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
1289 ExecDeathTestArgs args = {.argv: argv, .close_fd: close_fd};
1290 pid_t child_pid = -1;
1291
1292#if GTEST_OS_QNX
1293 // Obtains the current directory and sets it to be closed in the child
1294 // process.
1295 const int cwd_fd = open(".", O_RDONLY);
1296 GTEST_DEATH_TEST_CHECK_(cwd_fd != -1);
1297 GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(cwd_fd, F_SETFD, FD_CLOEXEC));
1298 // We need to execute the test program in the same environment where
1299 // it was originally invoked. Therefore we change to the original
1300 // working directory first.
1301 const char* const original_dir =
1302 UnitTest::GetInstance()->original_working_dir();
1303 // We can safely call chdir() as it's a direct system call.
1304 if (chdir(original_dir) != 0) {
1305 DeathTestAbort(std::string("chdir(\"") + original_dir +
1306 "\") failed: " + GetLastErrnoDescription());
1307 return EXIT_FAILURE;
1308 }
1309
1310 int fd_flags;
1311 // Set close_fd to be closed after spawn.
1312 GTEST_DEATH_TEST_CHECK_SYSCALL_(fd_flags = fcntl(close_fd, F_GETFD));
1313 GTEST_DEATH_TEST_CHECK_SYSCALL_(
1314 fcntl(close_fd, F_SETFD, fd_flags | FD_CLOEXEC));
1315 struct inheritance inherit = {0};
1316 // spawn is a system call.
1317 child_pid = spawn(args.argv[0], 0, nullptr, &inherit, args.argv, environ);
1318 // Restores the current working directory.
1319 GTEST_DEATH_TEST_CHECK_(fchdir(cwd_fd) != -1);
1320 GTEST_DEATH_TEST_CHECK_SYSCALL_(close(cwd_fd));
1321
1322#else // GTEST_OS_QNX
1323#if GTEST_OS_LINUX
1324 // When a SIGPROF signal is received while fork() or clone() are executing,
1325 // the process may hang. To avoid this, we ignore SIGPROF here and re-enable
1326 // it after the call to fork()/clone() is complete.
1327 struct sigaction saved_sigprof_action;
1328 struct sigaction ignore_sigprof_action;
1329 memset(s: &ignore_sigprof_action, c: 0, n: sizeof(ignore_sigprof_action));
1330 sigemptyset(set: &ignore_sigprof_action.sa_mask);
1331 ignore_sigprof_action.sa_handler = SIG_IGN;
1332 GTEST_DEATH_TEST_CHECK_SYSCALL_(
1333 sigaction(SIGPROF, &ignore_sigprof_action, &saved_sigprof_action));
1334#endif // GTEST_OS_LINUX
1335
1336#if GTEST_HAS_CLONE
1337 const bool use_fork = GTEST_FLAG_GET(death_test_use_fork);
1338
1339 if (!use_fork) {
1340 static const bool stack_grows_down = StackGrowsDown();
1341 const auto stack_size = static_cast<size_t>(getpagesize() * 2);
1342 // MMAP_ANONYMOUS is not defined on Mac, so we use MAP_ANON instead.
1343 void* const stack = mmap(addr: nullptr, len: stack_size, PROT_READ | PROT_WRITE,
1344 MAP_ANON | MAP_PRIVATE, fd: -1, offset: 0);
1345 GTEST_DEATH_TEST_CHECK_(stack != MAP_FAILED);
1346
1347 // Maximum stack alignment in bytes: For a downward-growing stack, this
1348 // amount is subtracted from size of the stack space to get an address
1349 // that is within the stack space and is aligned on all systems we care
1350 // about. As far as I know there is no ABI with stack alignment greater
1351 // than 64. We assume stack and stack_size already have alignment of
1352 // kMaxStackAlignment.
1353 const size_t kMaxStackAlignment = 64;
1354 void* const stack_top =
1355 static_cast<char*>(stack) +
1356 (stack_grows_down ? stack_size - kMaxStackAlignment : 0);
1357 GTEST_DEATH_TEST_CHECK_(
1358 static_cast<size_t>(stack_size) > kMaxStackAlignment &&
1359 reinterpret_cast<uintptr_t>(stack_top) % kMaxStackAlignment == 0);
1360
1361 child_pid = clone(fn: &ExecDeathTestChildMain, child_stack: stack_top, SIGCHLD, arg: &args);
1362
1363 GTEST_DEATH_TEST_CHECK_(munmap(stack, stack_size) != -1);
1364 }
1365#else
1366 const bool use_fork = true;
1367#endif // GTEST_HAS_CLONE
1368
1369 if (use_fork && (child_pid = fork()) == 0) {
1370 ExecDeathTestChildMain(child_arg: &args);
1371 _exit(status: 0);
1372 }
1373#endif // GTEST_OS_QNX
1374#if GTEST_OS_LINUX
1375 GTEST_DEATH_TEST_CHECK_SYSCALL_(
1376 sigaction(SIGPROF, &saved_sigprof_action, nullptr));
1377#endif // GTEST_OS_LINUX
1378
1379 GTEST_DEATH_TEST_CHECK_(child_pid != -1);
1380 return child_pid;
1381}
1382
1383// The AssumeRole process for a fork-and-exec death test. It re-executes the
1384// main program from the beginning, setting the --gtest_filter
1385// and --gtest_internal_run_death_test flags to cause only the current
1386// death test to be re-run.
1387DeathTest::TestRole ExecDeathTest::AssumeRole() {
1388 const UnitTestImpl* const impl = GetUnitTestImpl();
1389 const InternalRunDeathTestFlag* const flag =
1390 impl->internal_run_death_test_flag();
1391 const TestInfo* const info = impl->current_test_info();
1392 const int death_test_index = info->result()->death_test_count();
1393
1394 if (flag != nullptr) {
1395 set_write_fd(flag->write_fd());
1396 return EXECUTE_TEST;
1397 }
1398
1399 int pipe_fd[2];
1400 GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
1401 // Clear the close-on-exec flag on the write end of the pipe, lest
1402 // it be closed when the child process does an exec:
1403 GTEST_DEATH_TEST_CHECK_(fcntl(pipe_fd[1], F_SETFD, 0) != -1);
1404
1405 const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
1406 "filter=" + info->test_suite_name() + "." +
1407 info->name();
1408 const std::string internal_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
1409 "internal_run_death_test=" + file_ + "|" +
1410 StreamableToString(streamable: line_) + "|" +
1411 StreamableToString(streamable: death_test_index) + "|" +
1412 StreamableToString(streamable: pipe_fd[1]);
1413 Arguments args;
1414 args.AddArguments(arguments: GetArgvsForDeathTestChildProcess());
1415 args.AddArgument(argument: filter_flag.c_str());
1416 args.AddArgument(argument: internal_flag.c_str());
1417
1418 DeathTest::set_last_death_test_message("");
1419
1420 CaptureStderr();
1421 // See the comment in NoExecDeathTest::AssumeRole for why the next line
1422 // is necessary.
1423 FlushInfoLog();
1424
1425 const pid_t child_pid = ExecDeathTestSpawnChild(argv: args.Argv(), close_fd: pipe_fd[0]);
1426 GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
1427 set_child_pid(child_pid);
1428 set_read_fd(pipe_fd[0]);
1429 set_spawned(true);
1430 return OVERSEE_TEST;
1431}
1432
1433#endif // !GTEST_OS_WINDOWS
1434
1435// Creates a concrete DeathTest-derived class that depends on the
1436// --gtest_death_test_style flag, and sets the pointer pointed to
1437// by the "test" argument to its address. If the test should be
1438// skipped, sets that pointer to NULL. Returns true, unless the
1439// flag is set to an invalid value.
1440bool DefaultDeathTestFactory::Create(const char* statement,
1441 Matcher<const std::string&> matcher,
1442 const char* file, int line,
1443 DeathTest** test) {
1444 UnitTestImpl* const impl = GetUnitTestImpl();
1445 const InternalRunDeathTestFlag* const flag =
1446 impl->internal_run_death_test_flag();
1447 const int death_test_index =
1448 impl->current_test_info()->increment_death_test_count();
1449
1450 if (flag != nullptr) {
1451 if (death_test_index > flag->index()) {
1452 DeathTest::set_last_death_test_message(
1453 "Death test count (" + StreamableToString(streamable: death_test_index) +
1454 ") somehow exceeded expected maximum (" +
1455 StreamableToString(streamable: flag->index()) + ")");
1456 return false;
1457 }
1458
1459 if (!(flag->file() == file && flag->line() == line &&
1460 flag->index() == death_test_index)) {
1461 *test = nullptr;
1462 return true;
1463 }
1464 }
1465
1466#if GTEST_OS_WINDOWS
1467
1468 if (GTEST_FLAG_GET(death_test_style) == "threadsafe" ||
1469 GTEST_FLAG_GET(death_test_style) == "fast") {
1470 *test = new WindowsDeathTest(statement, std::move(matcher), file, line);
1471 }
1472
1473#elif GTEST_OS_FUCHSIA
1474
1475 if (GTEST_FLAG_GET(death_test_style) == "threadsafe" ||
1476 GTEST_FLAG_GET(death_test_style) == "fast") {
1477 *test = new FuchsiaDeathTest(statement, std::move(matcher), file, line);
1478 }
1479
1480#else
1481
1482 if (GTEST_FLAG_GET(death_test_style) == "threadsafe") {
1483 *test = new ExecDeathTest(statement, std::move(matcher), file, line);
1484 } else if (GTEST_FLAG_GET(death_test_style) == "fast") {
1485 *test = new NoExecDeathTest(statement, std::move(matcher));
1486 }
1487
1488#endif // GTEST_OS_WINDOWS
1489
1490 else { // NOLINT - this is more readable than unbalanced brackets inside #if.
1491 DeathTest::set_last_death_test_message("Unknown death test style \"" +
1492 GTEST_FLAG_GET(death_test_style) +
1493 "\" encountered");
1494 return false;
1495 }
1496
1497 return true;
1498}
1499
1500#if GTEST_OS_WINDOWS
1501// Recreates the pipe and event handles from the provided parameters,
1502// signals the event, and returns a file descriptor wrapped around the pipe
1503// handle. This function is called in the child process only.
1504static int GetStatusFileDescriptor(unsigned int parent_process_id,
1505 size_t write_handle_as_size_t,
1506 size_t event_handle_as_size_t) {
1507 AutoHandle parent_process_handle(::OpenProcess(PROCESS_DUP_HANDLE,
1508 FALSE, // Non-inheritable.
1509 parent_process_id));
1510 if (parent_process_handle.Get() == INVALID_HANDLE_VALUE) {
1511 DeathTestAbort("Unable to open parent process " +
1512 StreamableToString(parent_process_id));
1513 }
1514
1515 GTEST_CHECK_(sizeof(HANDLE) <= sizeof(size_t));
1516
1517 const HANDLE write_handle = reinterpret_cast<HANDLE>(write_handle_as_size_t);
1518 HANDLE dup_write_handle;
1519
1520 // The newly initialized handle is accessible only in the parent
1521 // process. To obtain one accessible within the child, we need to use
1522 // DuplicateHandle.
1523 if (!::DuplicateHandle(parent_process_handle.Get(), write_handle,
1524 ::GetCurrentProcess(), &dup_write_handle,
1525 0x0, // Requested privileges ignored since
1526 // DUPLICATE_SAME_ACCESS is used.
1527 FALSE, // Request non-inheritable handler.
1528 DUPLICATE_SAME_ACCESS)) {
1529 DeathTestAbort("Unable to duplicate the pipe handle " +
1530 StreamableToString(write_handle_as_size_t) +
1531 " from the parent process " +
1532 StreamableToString(parent_process_id));
1533 }
1534
1535 const HANDLE event_handle = reinterpret_cast<HANDLE>(event_handle_as_size_t);
1536 HANDLE dup_event_handle;
1537
1538 if (!::DuplicateHandle(parent_process_handle.Get(), event_handle,
1539 ::GetCurrentProcess(), &dup_event_handle, 0x0, FALSE,
1540 DUPLICATE_SAME_ACCESS)) {
1541 DeathTestAbort("Unable to duplicate the event handle " +
1542 StreamableToString(event_handle_as_size_t) +
1543 " from the parent process " +
1544 StreamableToString(parent_process_id));
1545 }
1546
1547 const int write_fd =
1548 ::_open_osfhandle(reinterpret_cast<intptr_t>(dup_write_handle), O_APPEND);
1549 if (write_fd == -1) {
1550 DeathTestAbort("Unable to convert pipe handle " +
1551 StreamableToString(write_handle_as_size_t) +
1552 " to a file descriptor");
1553 }
1554
1555 // Signals the parent that the write end of the pipe has been acquired
1556 // so the parent can release its own write end.
1557 ::SetEvent(dup_event_handle);
1558
1559 return write_fd;
1560}
1561#endif // GTEST_OS_WINDOWS
1562
1563// Returns a newly created InternalRunDeathTestFlag object with fields
1564// initialized from the GTEST_FLAG(internal_run_death_test) flag if
1565// the flag is specified; otherwise returns NULL.
1566InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag() {
1567 if (GTEST_FLAG_GET(internal_run_death_test) == "") return nullptr;
1568
1569 // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we
1570 // can use it here.
1571 int line = -1;
1572 int index = -1;
1573 ::std::vector< ::std::string> fields;
1574 SplitString(GTEST_FLAG_GET(internal_run_death_test), delimiter: '|', dest: &fields);
1575 int write_fd = -1;
1576
1577#if GTEST_OS_WINDOWS
1578
1579 unsigned int parent_process_id = 0;
1580 size_t write_handle_as_size_t = 0;
1581 size_t event_handle_as_size_t = 0;
1582
1583 if (fields.size() != 6 || !ParseNaturalNumber(fields[1], &line) ||
1584 !ParseNaturalNumber(fields[2], &index) ||
1585 !ParseNaturalNumber(fields[3], &parent_process_id) ||
1586 !ParseNaturalNumber(fields[4], &write_handle_as_size_t) ||
1587 !ParseNaturalNumber(fields[5], &event_handle_as_size_t)) {
1588 DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
1589 GTEST_FLAG_GET(internal_run_death_test));
1590 }
1591 write_fd = GetStatusFileDescriptor(parent_process_id, write_handle_as_size_t,
1592 event_handle_as_size_t);
1593
1594#elif GTEST_OS_FUCHSIA
1595
1596 if (fields.size() != 3 || !ParseNaturalNumber(fields[1], &line) ||
1597 !ParseNaturalNumber(fields[2], &index)) {
1598 DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
1599 GTEST_FLAG_GET(internal_run_death_test));
1600 }
1601
1602#else
1603
1604 if (fields.size() != 4 || !ParseNaturalNumber(str: fields[1], number: &line) ||
1605 !ParseNaturalNumber(str: fields[2], number: &index) ||
1606 !ParseNaturalNumber(str: fields[3], number: &write_fd)) {
1607 DeathTestAbort(message: "Bad --gtest_internal_run_death_test flag: " +
1608 GTEST_FLAG_GET(internal_run_death_test));
1609 }
1610
1611#endif // GTEST_OS_WINDOWS
1612
1613 return new InternalRunDeathTestFlag(fields[0], line, index, write_fd);
1614}
1615
1616} // namespace internal
1617
1618#endif // GTEST_HAS_DEATH_TEST
1619
1620} // namespace testing
1621