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1 // Copyright 2005, Google Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 //     * Redistributions of source code must retain the above copyright
9 // notice, this list of conditions and the following disclaimer.
10 //     * Redistributions in binary form must reproduce the above
11 // copyright notice, this list of conditions and the following disclaimer
12 // in the documentation and/or other materials provided with the
13 // distribution.
14 //     * Neither the name of Google Inc. nor the names of its
15 // contributors may be used to endorse or promote products derived from
16 // this software without specific prior written permission.
17 //
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 //
30 // Author: wan@google.com (Zhanyong Wan), vladl@google.com (Vlad Losev)
31 //
32 // This file implements death tests.
33 
34 #include "gtest/gtest-death-test.h"
35 #include "gtest/internal/gtest-port.h"
36 
37 #if GTEST_HAS_DEATH_TEST
38 
39 # if GTEST_OS_MAC
40 #  include <crt_externs.h>
41 # endif  // GTEST_OS_MAC
42 
43 # include <errno.h>
44 # include <fcntl.h>
45 # include <limits.h>
46 
47 # if GTEST_OS_LINUX
48 #  include <signal.h>
49 # endif  // GTEST_OS_LINUX
50 
51 # include <stdarg.h>
52 
53 # if GTEST_OS_WINDOWS
54 #  include <windows.h>
55 # else
56 #  include <sys/mman.h>
57 #  include <sys/wait.h>
58 # endif  // GTEST_OS_WINDOWS
59 
60 # if GTEST_OS_QNX
61 #  include <spawn.h>
62 # endif  // GTEST_OS_QNX
63 
64 #endif  // GTEST_HAS_DEATH_TEST
65 
66 #include "gtest/gtest-message.h"
67 #include "gtest/internal/gtest-string.h"
68 
69 // Indicates that this translation unit is part of Google Test's
70 // implementation.  It must come before gtest-internal-inl.h is
71 // included, or there will be a compiler error.  This trick is to
72 // prevent a user from accidentally including gtest-internal-inl.h in
73 // his code.
74 #define GTEST_IMPLEMENTATION_ 1
75 #include "src/gtest-internal-inl.h"
76 #undef GTEST_IMPLEMENTATION_
77 
78 namespace testing {
79 
80 // Constants.
81 
82 // The default death test style.
83 static const char kDefaultDeathTestStyle[] = "fast";
84 
85 GTEST_DEFINE_string_(
86     death_test_style,
87     internal::StringFromGTestEnv("death_test_style", kDefaultDeathTestStyle),
88     "Indicates how to run a death test in a forked child process: "
89     "\"threadsafe\" (child process re-executes the test binary "
90     "from the beginning, running only the specific death test) or "
91     "\"fast\" (child process runs the death test immediately "
92     "after forking).");
93 
94 GTEST_DEFINE_bool_(
95     death_test_use_fork,
96     internal::BoolFromGTestEnv("death_test_use_fork", false),
97     "Instructs to use fork()/_exit() instead of clone() in death tests. "
98     "Ignored and always uses fork() on POSIX systems where clone() is not "
99     "implemented. Useful when running under valgrind or similar tools if "
100     "those do not support clone(). Valgrind 3.3.1 will just fail if "
101     "it sees an unsupported combination of clone() flags. "
102     "It is not recommended to use this flag w/o valgrind though it will "
103     "work in 99% of the cases. Once valgrind is fixed, this flag will "
104     "most likely be removed.");
105 
106 namespace internal {
107 GTEST_DEFINE_string_(
108     internal_run_death_test, "",
109     "Indicates the file, line number, temporal index of "
110     "the single death test to run, and a file descriptor to "
111     "which a success code may be sent, all separated by "
112     "the '|' characters.  This flag is specified if and only if the current "
113     "process is a sub-process launched for running a thread-safe "
114     "death test.  FOR INTERNAL USE ONLY.");
115 }  // namespace internal
116 
117 #if GTEST_HAS_DEATH_TEST
118 
119 namespace internal {
120 
121 // Valid only for fast death tests. Indicates the code is running in the
122 // child process of a fast style death test.
123 static bool g_in_fast_death_test_child = false;
124 
125 // Returns a Boolean value indicating whether the caller is currently
126 // executing in the context of the death test child process.  Tools such as
127 // Valgrind heap checkers may need this to modify their behavior in death
128 // tests.  IMPORTANT: This is an internal utility.  Using it may break the
129 // implementation of death tests.  User code MUST NOT use it.
InDeathTestChild()130 bool InDeathTestChild() {
131 # if GTEST_OS_WINDOWS
132 
133   // On Windows, death tests are thread-safe regardless of the value of the
134   // death_test_style flag.
135   return !GTEST_FLAG(internal_run_death_test).empty();
136 
137 # else
138 
139   if (GTEST_FLAG(death_test_style) == "threadsafe")
140     return !GTEST_FLAG(internal_run_death_test).empty();
141   else
142     return g_in_fast_death_test_child;
143 #endif
144 }
145 
146 }  // namespace internal
147 
148 // ExitedWithCode constructor.
ExitedWithCode(int exit_code)149 ExitedWithCode::ExitedWithCode(int exit_code) : exit_code_(exit_code) {
150 }
151 
152 // ExitedWithCode function-call operator.
operator ()(int exit_status) const153 bool ExitedWithCode::operator()(int exit_status) const {
154 # if GTEST_OS_WINDOWS
155 
156   return exit_status == exit_code_;
157 
158 # else
159 
160   return WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == exit_code_;
161 
162 # endif  // GTEST_OS_WINDOWS
163 }
164 
165 # if !GTEST_OS_WINDOWS
166 // KilledBySignal constructor.
KilledBySignal(int signum)167 KilledBySignal::KilledBySignal(int signum) : signum_(signum) {
168 }
169 
170 // KilledBySignal function-call operator.
operator ()(int exit_status) const171 bool KilledBySignal::operator()(int exit_status) const {
172   return WIFSIGNALED(exit_status) && WTERMSIG(exit_status) == signum_;
173 }
174 # endif  // !GTEST_OS_WINDOWS
175 
176 namespace internal {
177 
178 // Utilities needed for death tests.
179 
180 // Generates a textual description of a given exit code, in the format
181 // specified by wait(2).
ExitSummary(int exit_code)182 static String ExitSummary(int exit_code) {
183   Message m;
184 
185 # if GTEST_OS_WINDOWS
186 
187   m << "Exited with exit status " << exit_code;
188 
189 # else
190 
191   if (WIFEXITED(exit_code)) {
192     m << "Exited with exit status " << WEXITSTATUS(exit_code);
193   } else if (WIFSIGNALED(exit_code)) {
194     m << "Terminated by signal " << WTERMSIG(exit_code);
195   }
196 #  ifdef WCOREDUMP
197   if (WCOREDUMP(exit_code)) {
198     m << " (core dumped)";
199   }
200 #  endif
201 # endif  // GTEST_OS_WINDOWS
202 
203   return m.GetString();
204 }
205 
206 // Returns true if exit_status describes a process that was terminated
207 // by a signal, or exited normally with a nonzero exit code.
ExitedUnsuccessfully(int exit_status)208 bool ExitedUnsuccessfully(int exit_status) {
209   return !ExitedWithCode(0)(exit_status);
210 }
211 
212 # if !GTEST_OS_WINDOWS
213 // Generates a textual failure message when a death test finds more than
214 // one thread running, or cannot determine the number of threads, prior
215 // to executing the given statement.  It is the responsibility of the
216 // caller not to pass a thread_count of 1.
DeathTestThreadWarning(size_t thread_count)217 static String DeathTestThreadWarning(size_t thread_count) {
218   Message msg;
219   msg << "Death tests use fork(), which is unsafe particularly"
220       << " in a threaded context. For this test, " << GTEST_NAME_ << " ";
221   if (thread_count == 0)
222     msg << "couldn't detect the number of threads.";
223   else
224     msg << "detected " << thread_count << " threads.";
225   return msg.GetString();
226 }
227 # endif  // !GTEST_OS_WINDOWS
228 
229 // Flag characters for reporting a death test that did not die.
230 static const char kDeathTestLived = 'L';
231 static const char kDeathTestReturned = 'R';
232 static const char kDeathTestThrew = 'T';
233 static const char kDeathTestInternalError = 'I';
234 
235 // An enumeration describing all of the possible ways that a death test can
236 // conclude.  DIED means that the process died while executing the test
237 // code; LIVED means that process lived beyond the end of the test code;
238 // RETURNED means that the test statement attempted to execute a return
239 // statement, which is not allowed; THREW means that the test statement
240 // returned control by throwing an exception.  IN_PROGRESS means the test
241 // has not yet concluded.
242 // TODO(vladl@google.com): Unify names and possibly values for
243 // AbortReason, DeathTestOutcome, and flag characters above.
244 enum DeathTestOutcome { IN_PROGRESS, DIED, LIVED, RETURNED, THREW };
245 
246 // Routine for aborting the program which is safe to call from an
247 // exec-style death test child process, in which case the error
248 // message is propagated back to the parent process.  Otherwise, the
249 // message is simply printed to stderr.  In either case, the program
250 // then exits with status 1.
DeathTestAbort(const String & message)251 void DeathTestAbort(const String& message) {
252   // On a POSIX system, this function may be called from a threadsafe-style
253   // death test child process, which operates on a very small stack.  Use
254   // the heap for any additional non-minuscule memory requirements.
255   const InternalRunDeathTestFlag* const flag =
256       GetUnitTestImpl()->internal_run_death_test_flag();
257   if (flag != NULL) {
258     FILE* parent = posix::FDOpen(flag->write_fd(), "w");
259     fputc(kDeathTestInternalError, parent);
260     fprintf(parent, "%s", message.c_str());
261     fflush(parent);
262     _exit(1);
263   } else {
264     fprintf(stderr, "%s", message.c_str());
265     fflush(stderr);
266     posix::Abort();
267   }
268 }
269 
270 // A replacement for CHECK that calls DeathTestAbort if the assertion
271 // fails.
272 # define GTEST_DEATH_TEST_CHECK_(expression) \
273   do { \
274     if (!::testing::internal::IsTrue(expression)) { \
275       DeathTestAbort(::testing::internal::String::Format( \
276           "CHECK failed: File %s, line %d: %s", \
277           __FILE__, __LINE__, #expression)); \
278     } \
279   } while (::testing::internal::AlwaysFalse())
280 
281 // This macro is similar to GTEST_DEATH_TEST_CHECK_, but it is meant for
282 // evaluating any system call that fulfills two conditions: it must return
283 // -1 on failure, and set errno to EINTR when it is interrupted and
284 // should be tried again.  The macro expands to a loop that repeatedly
285 // evaluates the expression as long as it evaluates to -1 and sets
286 // errno to EINTR.  If the expression evaluates to -1 but errno is
287 // something other than EINTR, DeathTestAbort is called.
288 # define GTEST_DEATH_TEST_CHECK_SYSCALL_(expression) \
289   do { \
290     int gtest_retval; \
291     do { \
292       gtest_retval = (expression); \
293     } while (gtest_retval == -1 && errno == EINTR); \
294     if (gtest_retval == -1) { \
295       DeathTestAbort(::testing::internal::String::Format( \
296           "CHECK failed: File %s, line %d: %s != -1", \
297           __FILE__, __LINE__, #expression)); \
298     } \
299   } while (::testing::internal::AlwaysFalse())
300 
301 // Returns the message describing the last system error in errno.
GetLastErrnoDescription()302 String GetLastErrnoDescription() {
303     return String(errno == 0 ? "" : posix::StrError(errno));
304 }
305 
306 // This is called from a death test parent process to read a failure
307 // message from the death test child process and log it with the FATAL
308 // severity. On Windows, the message is read from a pipe handle. On other
309 // platforms, it is read from a file descriptor.
FailFromInternalError(int fd)310 static void FailFromInternalError(int fd) {
311   Message error;
312   char buffer[256];
313   int num_read;
314 
315   do {
316     while ((num_read = posix::Read(fd, buffer, 255)) > 0) {
317       buffer[num_read] = '\0';
318       error << buffer;
319     }
320   } while (num_read == -1 && errno == EINTR);
321 
322   if (num_read == 0) {
323     GTEST_LOG_(FATAL) << error.GetString();
324   } else {
325     const int last_error = errno;
326     GTEST_LOG_(FATAL) << "Error while reading death test internal: "
327                       << GetLastErrnoDescription() << " [" << last_error << "]";
328   }
329 }
330 
331 // Death test constructor.  Increments the running death test count
332 // for the current test.
DeathTest()333 DeathTest::DeathTest() {
334   TestInfo* const info = GetUnitTestImpl()->current_test_info();
335   if (info == NULL) {
336     DeathTestAbort("Cannot run a death test outside of a TEST or "
337                    "TEST_F construct");
338   }
339 }
340 
341 // Creates and returns a death test by dispatching to the current
342 // death test factory.
Create(const char * statement,const RE * regex,const char * file,int line,DeathTest ** test)343 bool DeathTest::Create(const char* statement, const RE* regex,
344                        const char* file, int line, DeathTest** test) {
345   return GetUnitTestImpl()->death_test_factory()->Create(
346       statement, regex, file, line, test);
347 }
348 
LastMessage()349 const char* DeathTest::LastMessage() {
350   return last_death_test_message_.c_str();
351 }
352 
set_last_death_test_message(const String & message)353 void DeathTest::set_last_death_test_message(const String& message) {
354   last_death_test_message_ = message;
355 }
356 
357 String DeathTest::last_death_test_message_;
358 
359 // Provides cross platform implementation for some death functionality.
360 class DeathTestImpl : public DeathTest {
361  protected:
DeathTestImpl(const char * a_statement,const RE * a_regex)362   DeathTestImpl(const char* a_statement, const RE* a_regex)
363       : statement_(a_statement),
364         regex_(a_regex),
365         spawned_(false),
366         status_(-1),
367         outcome_(IN_PROGRESS),
368         read_fd_(-1),
369         write_fd_(-1) {}
370 
371   // read_fd_ is expected to be closed and cleared by a derived class.
~DeathTestImpl()372   ~DeathTestImpl() { GTEST_DEATH_TEST_CHECK_(read_fd_ == -1); }
373 
374   void Abort(AbortReason reason);
375   virtual bool Passed(bool status_ok);
376 
statement() const377   const char* statement() const { return statement_; }
regex() const378   const RE* regex() const { return regex_; }
spawned() const379   bool spawned() const { return spawned_; }
set_spawned(bool is_spawned)380   void set_spawned(bool is_spawned) { spawned_ = is_spawned; }
status() const381   int status() const { return status_; }
set_status(int a_status)382   void set_status(int a_status) { status_ = a_status; }
outcome() const383   DeathTestOutcome outcome() const { return outcome_; }
set_outcome(DeathTestOutcome an_outcome)384   void set_outcome(DeathTestOutcome an_outcome) { outcome_ = an_outcome; }
read_fd() const385   int read_fd() const { return read_fd_; }
set_read_fd(int fd)386   void set_read_fd(int fd) { read_fd_ = fd; }
write_fd() const387   int write_fd() const { return write_fd_; }
set_write_fd(int fd)388   void set_write_fd(int fd) { write_fd_ = fd; }
389 
390   // Called in the parent process only. Reads the result code of the death
391   // test child process via a pipe, interprets it to set the outcome_
392   // member, and closes read_fd_.  Outputs diagnostics and terminates in
393   // case of unexpected codes.
394   void ReadAndInterpretStatusByte();
395 
396  private:
397   // The textual content of the code this object is testing.  This class
398   // doesn't own this string and should not attempt to delete it.
399   const char* const statement_;
400   // The regular expression which test output must match.  DeathTestImpl
401   // doesn't own this object and should not attempt to delete it.
402   const RE* const regex_;
403   // True if the death test child process has been successfully spawned.
404   bool spawned_;
405   // The exit status of the child process.
406   int status_;
407   // How the death test concluded.
408   DeathTestOutcome outcome_;
409   // Descriptor to the read end of the pipe to the child process.  It is
410   // always -1 in the child process.  The child keeps its write end of the
411   // pipe in write_fd_.
412   int read_fd_;
413   // Descriptor to the child's write end of the pipe to the parent process.
414   // It is always -1 in the parent process.  The parent keeps its end of the
415   // pipe in read_fd_.
416   int write_fd_;
417 };
418 
419 // Called in the parent process only. Reads the result code of the death
420 // test child process via a pipe, interprets it to set the outcome_
421 // member, and closes read_fd_.  Outputs diagnostics and terminates in
422 // case of unexpected codes.
ReadAndInterpretStatusByte()423 void DeathTestImpl::ReadAndInterpretStatusByte() {
424   char flag;
425   int bytes_read;
426 
427   // The read() here blocks until data is available (signifying the
428   // failure of the death test) or until the pipe is closed (signifying
429   // its success), so it's okay to call this in the parent before
430   // the child process has exited.
431   do {
432     bytes_read = posix::Read(read_fd(), &flag, 1);
433   } while (bytes_read == -1 && errno == EINTR);
434 
435   if (bytes_read == 0) {
436     set_outcome(DIED);
437   } else if (bytes_read == 1) {
438     switch (flag) {
439       case kDeathTestReturned:
440         set_outcome(RETURNED);
441         break;
442       case kDeathTestThrew:
443         set_outcome(THREW);
444         break;
445       case kDeathTestLived:
446         set_outcome(LIVED);
447         break;
448       case kDeathTestInternalError:
449         FailFromInternalError(read_fd());  // Does not return.
450         break;
451       default:
452         GTEST_LOG_(FATAL) << "Death test child process reported "
453                           << "unexpected status byte ("
454                           << static_cast<unsigned int>(flag) << ")";
455     }
456   } else {
457     GTEST_LOG_(FATAL) << "Read from death test child process failed: "
458                       << GetLastErrnoDescription();
459   }
460   GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Close(read_fd()));
461   set_read_fd(-1);
462 }
463 
464 // Signals that the death test code which should have exited, didn't.
465 // Should be called only in a death test child process.
466 // Writes a status byte to the child's status file descriptor, then
467 // calls _exit(1).
Abort(AbortReason reason)468 void DeathTestImpl::Abort(AbortReason reason) {
469   // The parent process considers the death test to be a failure if
470   // it finds any data in our pipe.  So, here we write a single flag byte
471   // to the pipe, then exit.
472   const char status_ch =
473       reason == TEST_DID_NOT_DIE ? kDeathTestLived :
474       reason == TEST_THREW_EXCEPTION ? kDeathTestThrew : kDeathTestReturned;
475 
476   GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Write(write_fd(), &status_ch, 1));
477   // We are leaking the descriptor here because on some platforms (i.e.,
478   // when built as Windows DLL), destructors of global objects will still
479   // run after calling _exit(). On such systems, write_fd_ will be
480   // indirectly closed from the destructor of UnitTestImpl, causing double
481   // close if it is also closed here. On debug configurations, double close
482   // may assert. As there are no in-process buffers to flush here, we are
483   // relying on the OS to close the descriptor after the process terminates
484   // when the destructors are not run.
485   _exit(1);  // Exits w/o any normal exit hooks (we were supposed to crash)
486 }
487 
488 // Returns an indented copy of stderr output for a death test.
489 // This makes distinguishing death test output lines from regular log lines
490 // much easier.
FormatDeathTestOutput(const::std::string & output)491 static ::std::string FormatDeathTestOutput(const ::std::string& output) {
492   ::std::string ret;
493   for (size_t at = 0; ; ) {
494     const size_t line_end = output.find('\n', at);
495     ret += "[  DEATH   ] ";
496     if (line_end == ::std::string::npos) {
497       ret += output.substr(at);
498       break;
499     }
500     ret += output.substr(at, line_end + 1 - at);
501     at = line_end + 1;
502   }
503   return ret;
504 }
505 
506 // Assesses the success or failure of a death test, using both private
507 // members which have previously been set, and one argument:
508 //
509 // Private data members:
510 //   outcome:  An enumeration describing how the death test
511 //             concluded: DIED, LIVED, THREW, or RETURNED.  The death test
512 //             fails in the latter three cases.
513 //   status:   The exit status of the child process. On *nix, it is in the
514 //             in the format specified by wait(2). On Windows, this is the
515 //             value supplied to the ExitProcess() API or a numeric code
516 //             of the exception that terminated the program.
517 //   regex:    A regular expression object to be applied to
518 //             the test's captured standard error output; the death test
519 //             fails if it does not match.
520 //
521 // Argument:
522 //   status_ok: true if exit_status is acceptable in the context of
523 //              this particular death test, which fails if it is false
524 //
525 // Returns true iff all of the above conditions are met.  Otherwise, the
526 // first failing condition, in the order given above, is the one that is
527 // reported. Also sets the last death test message string.
Passed(bool status_ok)528 bool DeathTestImpl::Passed(bool status_ok) {
529   if (!spawned())
530     return false;
531 
532   const String error_message = GetCapturedStderr();
533 
534   bool success = false;
535   Message buffer;
536 
537   buffer << "Death test: " << statement() << "\n";
538   switch (outcome()) {
539     case LIVED:
540       buffer << "    Result: failed to die.\n"
541              << " Error msg:\n" << FormatDeathTestOutput(error_message);
542       break;
543     case THREW:
544       buffer << "    Result: threw an exception.\n"
545              << " Error msg:\n" << FormatDeathTestOutput(error_message);
546       break;
547     case RETURNED:
548       buffer << "    Result: illegal return in test statement.\n"
549              << " Error msg:\n" << FormatDeathTestOutput(error_message);
550       break;
551     case DIED:
552       if (status_ok) {
553         const bool matched = RE::PartialMatch(error_message.c_str(), *regex());
554         if (matched) {
555           success = true;
556         } else {
557           buffer << "    Result: died but not with expected error.\n"
558                  << "  Expected: " << regex()->pattern() << "\n"
559                  << "Actual msg:\n" << FormatDeathTestOutput(error_message);
560         }
561       } else {
562         buffer << "    Result: died but not with expected exit code:\n"
563                << "            " << ExitSummary(status()) << "\n"
564                << "Actual msg:\n" << FormatDeathTestOutput(error_message);
565       }
566       break;
567     case IN_PROGRESS:
568     default:
569       GTEST_LOG_(FATAL)
570           << "DeathTest::Passed somehow called before conclusion of test";
571   }
572 
573   DeathTest::set_last_death_test_message(buffer.GetString());
574   return success;
575 }
576 
577 # if GTEST_OS_WINDOWS
578 // WindowsDeathTest implements death tests on Windows. Due to the
579 // specifics of starting new processes on Windows, death tests there are
580 // always threadsafe, and Google Test considers the
581 // --gtest_death_test_style=fast setting to be equivalent to
582 // --gtest_death_test_style=threadsafe there.
583 //
584 // A few implementation notes:  Like the Linux version, the Windows
585 // implementation uses pipes for child-to-parent communication. But due to
586 // the specifics of pipes on Windows, some extra steps are required:
587 //
588 // 1. The parent creates a communication pipe and stores handles to both
589 //    ends of it.
590 // 2. The parent starts the child and provides it with the information
591 //    necessary to acquire the handle to the write end of the pipe.
592 // 3. The child acquires the write end of the pipe and signals the parent
593 //    using a Windows event.
594 // 4. Now the parent can release the write end of the pipe on its side. If
595 //    this is done before step 3, the object's reference count goes down to
596 //    0 and it is destroyed, preventing the child from acquiring it. The
597 //    parent now has to release it, or read operations on the read end of
598 //    the pipe will not return when the child terminates.
599 // 5. The parent reads child's output through the pipe (outcome code and
600 //    any possible error messages) from the pipe, and its stderr and then
601 //    determines whether to fail the test.
602 //
603 // Note: to distinguish Win32 API calls from the local method and function
604 // calls, the former are explicitly resolved in the global namespace.
605 //
606 class WindowsDeathTest : public DeathTestImpl {
607  public:
WindowsDeathTest(const char * a_statement,const RE * a_regex,const char * file,int line)608   WindowsDeathTest(const char* a_statement,
609                    const RE* a_regex,
610                    const char* file,
611                    int line)
612       : DeathTestImpl(a_statement, a_regex), file_(file), line_(line) {}
613 
614   // All of these virtual functions are inherited from DeathTest.
615   virtual int Wait();
616   virtual TestRole AssumeRole();
617 
618  private:
619   // The name of the file in which the death test is located.
620   const char* const file_;
621   // The line number on which the death test is located.
622   const int line_;
623   // Handle to the write end of the pipe to the child process.
624   AutoHandle write_handle_;
625   // Child process handle.
626   AutoHandle child_handle_;
627   // Event the child process uses to signal the parent that it has
628   // acquired the handle to the write end of the pipe. After seeing this
629   // event the parent can release its own handles to make sure its
630   // ReadFile() calls return when the child terminates.
631   AutoHandle event_handle_;
632 };
633 
634 // Waits for the child in a death test to exit, returning its exit
635 // status, or 0 if no child process exists.  As a side effect, sets the
636 // outcome data member.
Wait()637 int WindowsDeathTest::Wait() {
638   if (!spawned())
639     return 0;
640 
641   // Wait until the child either signals that it has acquired the write end
642   // of the pipe or it dies.
643   const HANDLE wait_handles[2] = { child_handle_.Get(), event_handle_.Get() };
644   switch (::WaitForMultipleObjects(2,
645                                    wait_handles,
646                                    FALSE,  // Waits for any of the handles.
647                                    INFINITE)) {
648     case WAIT_OBJECT_0:
649     case WAIT_OBJECT_0 + 1:
650       break;
651     default:
652       GTEST_DEATH_TEST_CHECK_(false);  // Should not get here.
653   }
654 
655   // The child has acquired the write end of the pipe or exited.
656   // We release the handle on our side and continue.
657   write_handle_.Reset();
658   event_handle_.Reset();
659 
660   ReadAndInterpretStatusByte();
661 
662   // Waits for the child process to exit if it haven't already. This
663   // returns immediately if the child has already exited, regardless of
664   // whether previous calls to WaitForMultipleObjects synchronized on this
665   // handle or not.
666   GTEST_DEATH_TEST_CHECK_(
667       WAIT_OBJECT_0 == ::WaitForSingleObject(child_handle_.Get(),
668                                              INFINITE));
669   DWORD status_code;
670   GTEST_DEATH_TEST_CHECK_(
671       ::GetExitCodeProcess(child_handle_.Get(), &status_code) != FALSE);
672   child_handle_.Reset();
673   set_status(static_cast<int>(status_code));
674   return status();
675 }
676 
677 // The AssumeRole process for a Windows death test.  It creates a child
678 // process with the same executable as the current process to run the
679 // death test.  The child process is given the --gtest_filter and
680 // --gtest_internal_run_death_test flags such that it knows to run the
681 // current death test only.
AssumeRole()682 DeathTest::TestRole WindowsDeathTest::AssumeRole() {
683   const UnitTestImpl* const impl = GetUnitTestImpl();
684   const InternalRunDeathTestFlag* const flag =
685       impl->internal_run_death_test_flag();
686   const TestInfo* const info = impl->current_test_info();
687   const int death_test_index = info->result()->death_test_count();
688 
689   if (flag != NULL) {
690     // ParseInternalRunDeathTestFlag() has performed all the necessary
691     // processing.
692     set_write_fd(flag->write_fd());
693     return EXECUTE_TEST;
694   }
695 
696   // WindowsDeathTest uses an anonymous pipe to communicate results of
697   // a death test.
698   SECURITY_ATTRIBUTES handles_are_inheritable = {
699     sizeof(SECURITY_ATTRIBUTES), NULL, TRUE };
700   HANDLE read_handle, write_handle;
701   GTEST_DEATH_TEST_CHECK_(
702       ::CreatePipe(&read_handle, &write_handle, &handles_are_inheritable,
703                    0)  // Default buffer size.
704       != FALSE);
705   set_read_fd(::_open_osfhandle(reinterpret_cast<intptr_t>(read_handle),
706                                 O_RDONLY));
707   write_handle_.Reset(write_handle);
708   event_handle_.Reset(::CreateEvent(
709       &handles_are_inheritable,
710       TRUE,    // The event will automatically reset to non-signaled state.
711       FALSE,   // The initial state is non-signalled.
712       NULL));  // The even is unnamed.
713   GTEST_DEATH_TEST_CHECK_(event_handle_.Get() != NULL);
714   const String filter_flag = String::Format("--%s%s=%s.%s",
715                                             GTEST_FLAG_PREFIX_, kFilterFlag,
716                                             info->test_case_name(),
717                                             info->name());
718   const String internal_flag = String::Format(
719     "--%s%s=%s|%d|%d|%u|%Iu|%Iu",
720       GTEST_FLAG_PREFIX_,
721       kInternalRunDeathTestFlag,
722       file_, line_,
723       death_test_index,
724       static_cast<unsigned int>(::GetCurrentProcessId()),
725       // size_t has the same with as pointers on both 32-bit and 64-bit
726       // Windows platforms.
727       // See http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx.
728       reinterpret_cast<size_t>(write_handle),
729       reinterpret_cast<size_t>(event_handle_.Get()));
730 
731   char executable_path[_MAX_PATH + 1];  // NOLINT
732   GTEST_DEATH_TEST_CHECK_(
733       _MAX_PATH + 1 != ::GetModuleFileNameA(NULL,
734                                             executable_path,
735                                             _MAX_PATH));
736 
737   String command_line = String::Format("%s %s \"%s\"",
738                                        ::GetCommandLineA(),
739                                        filter_flag.c_str(),
740                                        internal_flag.c_str());
741 
742   DeathTest::set_last_death_test_message("");
743 
744   CaptureStderr();
745   // Flush the log buffers since the log streams are shared with the child.
746   FlushInfoLog();
747 
748   // The child process will share the standard handles with the parent.
749   STARTUPINFOA startup_info;
750   memset(&startup_info, 0, sizeof(STARTUPINFO));
751   startup_info.dwFlags = STARTF_USESTDHANDLES;
752   startup_info.hStdInput = ::GetStdHandle(STD_INPUT_HANDLE);
753   startup_info.hStdOutput = ::GetStdHandle(STD_OUTPUT_HANDLE);
754   startup_info.hStdError = ::GetStdHandle(STD_ERROR_HANDLE);
755 
756   PROCESS_INFORMATION process_info;
757   GTEST_DEATH_TEST_CHECK_(::CreateProcessA(
758       executable_path,
759       const_cast<char*>(command_line.c_str()),
760       NULL,   // Retuned process handle is not inheritable.
761       NULL,   // Retuned thread handle is not inheritable.
762       TRUE,   // Child inherits all inheritable handles (for write_handle_).
763       0x0,    // Default creation flags.
764       NULL,   // Inherit the parent's environment.
765       UnitTest::GetInstance()->original_working_dir(),
766       &startup_info,
767       &process_info) != FALSE);
768   child_handle_.Reset(process_info.hProcess);
769   ::CloseHandle(process_info.hThread);
770   set_spawned(true);
771   return OVERSEE_TEST;
772 }
773 # else  // We are not on Windows.
774 
775 // ForkingDeathTest provides implementations for most of the abstract
776 // methods of the DeathTest interface.  Only the AssumeRole method is
777 // left undefined.
778 class ForkingDeathTest : public DeathTestImpl {
779  public:
780   ForkingDeathTest(const char* statement, const RE* regex);
781 
782   // All of these virtual functions are inherited from DeathTest.
783   virtual int Wait();
784 
785  protected:
set_child_pid(pid_t child_pid)786   void set_child_pid(pid_t child_pid) { child_pid_ = child_pid; }
787 
788  private:
789   // PID of child process during death test; 0 in the child process itself.
790   pid_t child_pid_;
791 };
792 
793 // Constructs a ForkingDeathTest.
ForkingDeathTest(const char * a_statement,const RE * a_regex)794 ForkingDeathTest::ForkingDeathTest(const char* a_statement, const RE* a_regex)
795     : DeathTestImpl(a_statement, a_regex),
796       child_pid_(-1) {}
797 
798 // Waits for the child in a death test to exit, returning its exit
799 // status, or 0 if no child process exists.  As a side effect, sets the
800 // outcome data member.
Wait()801 int ForkingDeathTest::Wait() {
802   if (!spawned())
803     return 0;
804 
805   ReadAndInterpretStatusByte();
806 
807   int status_value;
808   GTEST_DEATH_TEST_CHECK_SYSCALL_(waitpid(child_pid_, &status_value, 0));
809   set_status(status_value);
810   return status_value;
811 }
812 
813 // A concrete death test class that forks, then immediately runs the test
814 // in the child process.
815 class NoExecDeathTest : public ForkingDeathTest {
816  public:
NoExecDeathTest(const char * a_statement,const RE * a_regex)817   NoExecDeathTest(const char* a_statement, const RE* a_regex) :
818       ForkingDeathTest(a_statement, a_regex) { }
819   virtual TestRole AssumeRole();
820 };
821 
822 // The AssumeRole process for a fork-and-run death test.  It implements a
823 // straightforward fork, with a simple pipe to transmit the status byte.
AssumeRole()824 DeathTest::TestRole NoExecDeathTest::AssumeRole() {
825   const size_t thread_count = GetThreadCount();
826   if (thread_count != 1) {
827     GTEST_LOG_(WARNING) << DeathTestThreadWarning(thread_count);
828   }
829 
830   int pipe_fd[2];
831   GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
832 
833   DeathTest::set_last_death_test_message("");
834   CaptureStderr();
835   // When we fork the process below, the log file buffers are copied, but the
836   // file descriptors are shared.  We flush all log files here so that closing
837   // the file descriptors in the child process doesn't throw off the
838   // synchronization between descriptors and buffers in the parent process.
839   // This is as close to the fork as possible to avoid a race condition in case
840   // there are multiple threads running before the death test, and another
841   // thread writes to the log file.
842   FlushInfoLog();
843 
844   const pid_t child_pid = fork();
845   GTEST_DEATH_TEST_CHECK_(child_pid != -1);
846   set_child_pid(child_pid);
847   if (child_pid == 0) {
848     GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[0]));
849     set_write_fd(pipe_fd[1]);
850     // Redirects all logging to stderr in the child process to prevent
851     // concurrent writes to the log files.  We capture stderr in the parent
852     // process and append the child process' output to a log.
853     LogToStderr();
854     // Event forwarding to the listeners of event listener API mush be shut
855     // down in death test subprocesses.
856     GetUnitTestImpl()->listeners()->SuppressEventForwarding();
857     g_in_fast_death_test_child = true;
858     return EXECUTE_TEST;
859   } else {
860     GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
861     set_read_fd(pipe_fd[0]);
862     set_spawned(true);
863     return OVERSEE_TEST;
864   }
865 }
866 
867 // A concrete death test class that forks and re-executes the main
868 // program from the beginning, with command-line flags set that cause
869 // only this specific death test to be run.
870 class ExecDeathTest : public ForkingDeathTest {
871  public:
ExecDeathTest(const char * a_statement,const RE * a_regex,const char * file,int line)872   ExecDeathTest(const char* a_statement, const RE* a_regex,
873                 const char* file, int line) :
874       ForkingDeathTest(a_statement, a_regex), file_(file), line_(line) { }
875   virtual TestRole AssumeRole();
876  private:
877   static ::std::vector<testing::internal::string>
GetArgvsForDeathTestChildProcess()878   GetArgvsForDeathTestChildProcess() {
879     ::std::vector<testing::internal::string> args = GetInjectableArgvs();
880     return args;
881   }
882   // The name of the file in which the death test is located.
883   const char* const file_;
884   // The line number on which the death test is located.
885   const int line_;
886 };
887 
888 // Utility class for accumulating command-line arguments.
889 class Arguments {
890  public:
Arguments()891   Arguments() {
892     args_.push_back(NULL);
893   }
894 
~Arguments()895   ~Arguments() {
896     for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
897          ++i) {
898       free(*i);
899     }
900   }
AddArgument(const char * argument)901   void AddArgument(const char* argument) {
902     args_.insert(args_.end() - 1, posix::StrDup(argument));
903   }
904 
905   template <typename Str>
AddArguments(const::std::vector<Str> & arguments)906   void AddArguments(const ::std::vector<Str>& arguments) {
907     for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
908          i != arguments.end();
909          ++i) {
910       args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
911     }
912   }
Argv()913   char* const* Argv() {
914     return &args_[0];
915   }
916 
917  private:
918   std::vector<char*> args_;
919 };
920 
921 // A struct that encompasses the arguments to the child process of a
922 // threadsafe-style death test process.
923 struct ExecDeathTestArgs {
924   char* const* argv;  // Command-line arguments for the child's call to exec
925   int close_fd;       // File descriptor to close; the read end of a pipe
926 };
927 
928 #  if GTEST_OS_MAC
GetEnviron()929 inline char** GetEnviron() {
930   // When Google Test is built as a framework on MacOS X, the environ variable
931   // is unavailable. Apple's documentation (man environ) recommends using
932   // _NSGetEnviron() instead.
933   return *_NSGetEnviron();
934 }
935 #  else
936 // Some POSIX platforms expect you to declare environ. extern "C" makes
937 // it reside in the global namespace.
938 extern "C" char** environ;
GetEnviron()939 inline char** GetEnviron() { return environ; }
940 #  endif  // GTEST_OS_MAC
941 
942 #  if !GTEST_OS_QNX
943 // The main function for a threadsafe-style death test child process.
944 // This function is called in a clone()-ed process and thus must avoid
945 // any potentially unsafe operations like malloc or libc functions.
ExecDeathTestChildMain(void * child_arg)946 static int ExecDeathTestChildMain(void* child_arg) {
947   ExecDeathTestArgs* const args = static_cast<ExecDeathTestArgs*>(child_arg);
948   GTEST_DEATH_TEST_CHECK_SYSCALL_(close(args->close_fd));
949 
950   // We need to execute the test program in the same environment where
951   // it was originally invoked.  Therefore we change to the original
952   // working directory first.
953   const char* const original_dir =
954       UnitTest::GetInstance()->original_working_dir();
955   // We can safely call chdir() as it's a direct system call.
956   if (chdir(original_dir) != 0) {
957     DeathTestAbort(String::Format("chdir(\"%s\") failed: %s",
958                                   original_dir,
959                                   GetLastErrnoDescription().c_str()));
960     return EXIT_FAILURE;
961   }
962 
963   // We can safely call execve() as it's a direct system call.  We
964   // cannot use execvp() as it's a libc function and thus potentially
965   // unsafe.  Since execve() doesn't search the PATH, the user must
966   // invoke the test program via a valid path that contains at least
967   // one path separator.
968   execve(args->argv[0], args->argv, GetEnviron());
969   DeathTestAbort(String::Format("execve(%s, ...) in %s failed: %s",
970                                 args->argv[0],
971                                 original_dir,
972                                 GetLastErrnoDescription().c_str()));
973   return EXIT_FAILURE;
974 }
975 #  endif  // !GTEST_OS_QNX
976 
977 // Two utility routines that together determine the direction the stack
978 // grows.
979 // This could be accomplished more elegantly by a single recursive
980 // function, but we want to guard against the unlikely possibility of
981 // a smart compiler optimizing the recursion away.
982 //
983 // GTEST_NO_INLINE_ is required to prevent GCC 4.6 from inlining
984 // StackLowerThanAddress into StackGrowsDown, which then doesn't give
985 // correct answer.
986 void StackLowerThanAddress(const void* ptr, bool* result) GTEST_NO_INLINE_;
StackLowerThanAddress(const void * ptr,bool * result)987 void StackLowerThanAddress(const void* ptr, bool* result) {
988   int dummy;
989   *result = (&dummy < ptr);
990 }
991 
StackGrowsDown()992 bool StackGrowsDown() {
993   int dummy;
994   bool result;
995   StackLowerThanAddress(&dummy, &result);
996   return result;
997 }
998 
999 // Spawns a child process with the same executable as the current process in
1000 // a thread-safe manner and instructs it to run the death test.  The
1001 // implementation uses fork(2) + exec.  On systems where clone(2) is
1002 // available, it is used instead, being slightly more thread-safe.  On QNX,
1003 // fork supports only single-threaded environments, so this function uses
1004 // spawn(2) there instead.  The function dies with an error message if
1005 // anything goes wrong.
ExecDeathTestSpawnChild(char * const * argv,int close_fd)1006 static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
1007   ExecDeathTestArgs args = { argv, close_fd };
1008   pid_t child_pid = -1;
1009 
1010 #  if GTEST_OS_QNX
1011   // Obtains the current directory and sets it to be closed in the child
1012   // process.
1013   const int cwd_fd = open(".", O_RDONLY);
1014   GTEST_DEATH_TEST_CHECK_(cwd_fd != -1);
1015   GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(cwd_fd, F_SETFD, FD_CLOEXEC));
1016   // We need to execute the test program in the same environment where
1017   // it was originally invoked.  Therefore we change to the original
1018   // working directory first.
1019   const char* const original_dir =
1020       UnitTest::GetInstance()->original_working_dir();
1021   // We can safely call chdir() as it's a direct system call.
1022   if (chdir(original_dir) != 0) {
1023     DeathTestAbort(String::Format("chdir(\"%s\") failed: %s",
1024                                   original_dir,
1025                                   GetLastErrnoDescription().c_str()));
1026     return EXIT_FAILURE;
1027   }
1028 
1029   int fd_flags;
1030   // Set close_fd to be closed after spawn.
1031   GTEST_DEATH_TEST_CHECK_SYSCALL_(fd_flags = fcntl(close_fd, F_GETFD));
1032   GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(close_fd, F_SETFD,
1033                                         fd_flags | FD_CLOEXEC));
1034   struct inheritance inherit = {0};
1035   // spawn is a system call.
1036   child_pid = spawn(args.argv[0], 0, NULL, &inherit, args.argv, GetEnviron());
1037   // Restores the current working directory.
1038   GTEST_DEATH_TEST_CHECK_(fchdir(cwd_fd) != -1);
1039   GTEST_DEATH_TEST_CHECK_SYSCALL_(close(cwd_fd));
1040 
1041 #  else   // GTEST_OS_QNX
1042 #   if GTEST_OS_LINUX
1043   // When a SIGPROF signal is received while fork() or clone() are executing,
1044   // the process may hang. To avoid this, we ignore SIGPROF here and re-enable
1045   // it after the call to fork()/clone() is complete.
1046   struct sigaction saved_sigprof_action;
1047   struct sigaction ignore_sigprof_action;
1048   memset(&ignore_sigprof_action, 0, sizeof(ignore_sigprof_action));
1049   sigemptyset(&ignore_sigprof_action.sa_mask);
1050   ignore_sigprof_action.sa_handler = SIG_IGN;
1051   GTEST_DEATH_TEST_CHECK_SYSCALL_(sigaction(
1052       SIGPROF, &ignore_sigprof_action, &saved_sigprof_action));
1053 #   endif  // GTEST_OS_LINUX
1054 
1055 #   if GTEST_HAS_CLONE
1056   const bool use_fork = GTEST_FLAG(death_test_use_fork);
1057 
1058   if (!use_fork) {
1059     static const bool stack_grows_down = StackGrowsDown();
1060     const size_t stack_size = getpagesize();
1061     // MMAP_ANONYMOUS is not defined on Mac, so we use MAP_ANON instead.
1062     void* const stack = mmap(NULL, stack_size, PROT_READ | PROT_WRITE,
1063                              MAP_ANON | MAP_PRIVATE, -1, 0);
1064     GTEST_DEATH_TEST_CHECK_(stack != MAP_FAILED);
1065     void* const stack_top =
1066         static_cast<char*>(stack) + (stack_grows_down ? stack_size : 0);
1067 
1068     child_pid = clone(&ExecDeathTestChildMain, stack_top, SIGCHLD, &args);
1069 
1070     GTEST_DEATH_TEST_CHECK_(munmap(stack, stack_size) != -1);
1071   }
1072 #   else
1073   const bool use_fork = true;
1074 #   endif  // GTEST_HAS_CLONE
1075 
1076   if (use_fork && (child_pid = fork()) == 0) {
1077       ExecDeathTestChildMain(&args);
1078       _exit(0);
1079   }
1080 #  endif  // GTEST_OS_QNX
1081 #  if GTEST_OS_LINUX
1082   GTEST_DEATH_TEST_CHECK_SYSCALL_(
1083       sigaction(SIGPROF, &saved_sigprof_action, NULL));
1084 #  endif  // GTEST_OS_LINUX
1085 
1086   GTEST_DEATH_TEST_CHECK_(child_pid != -1);
1087   return child_pid;
1088 }
1089 
1090 // The AssumeRole process for a fork-and-exec death test.  It re-executes the
1091 // main program from the beginning, setting the --gtest_filter
1092 // and --gtest_internal_run_death_test flags to cause only the current
1093 // death test to be re-run.
AssumeRole()1094 DeathTest::TestRole ExecDeathTest::AssumeRole() {
1095   const UnitTestImpl* const impl = GetUnitTestImpl();
1096   const InternalRunDeathTestFlag* const flag =
1097       impl->internal_run_death_test_flag();
1098   const TestInfo* const info = impl->current_test_info();
1099   const int death_test_index = info->result()->death_test_count();
1100 
1101   if (flag != NULL) {
1102     set_write_fd(flag->write_fd());
1103     return EXECUTE_TEST;
1104   }
1105 
1106   int pipe_fd[2];
1107   GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
1108   // Clear the close-on-exec flag on the write end of the pipe, lest
1109   // it be closed when the child process does an exec:
1110   GTEST_DEATH_TEST_CHECK_(fcntl(pipe_fd[1], F_SETFD, 0) != -1);
1111 
1112   const String filter_flag =
1113       String::Format("--%s%s=%s.%s",
1114                      GTEST_FLAG_PREFIX_, kFilterFlag,
1115                      info->test_case_name(), info->name());
1116   const String internal_flag =
1117       String::Format("--%s%s=%s|%d|%d|%d",
1118                      GTEST_FLAG_PREFIX_, kInternalRunDeathTestFlag,
1119                      file_, line_, death_test_index, pipe_fd[1]);
1120   Arguments args;
1121   args.AddArguments(GetArgvsForDeathTestChildProcess());
1122   args.AddArgument(filter_flag.c_str());
1123   args.AddArgument(internal_flag.c_str());
1124 
1125   DeathTest::set_last_death_test_message("");
1126 
1127   CaptureStderr();
1128   // See the comment in NoExecDeathTest::AssumeRole for why the next line
1129   // is necessary.
1130   FlushInfoLog();
1131 
1132   const pid_t child_pid = ExecDeathTestSpawnChild(args.Argv(), pipe_fd[0]);
1133   GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
1134   set_child_pid(child_pid);
1135   set_read_fd(pipe_fd[0]);
1136   set_spawned(true);
1137   return OVERSEE_TEST;
1138 }
1139 
1140 # endif  // !GTEST_OS_WINDOWS
1141 
1142 // Creates a concrete DeathTest-derived class that depends on the
1143 // --gtest_death_test_style flag, and sets the pointer pointed to
1144 // by the "test" argument to its address.  If the test should be
1145 // skipped, sets that pointer to NULL.  Returns true, unless the
1146 // flag is set to an invalid value.
Create(const char * statement,const RE * regex,const char * file,int line,DeathTest ** test)1147 bool DefaultDeathTestFactory::Create(const char* statement, const RE* regex,
1148                                      const char* file, int line,
1149                                      DeathTest** test) {
1150   UnitTestImpl* const impl = GetUnitTestImpl();
1151   const InternalRunDeathTestFlag* const flag =
1152       impl->internal_run_death_test_flag();
1153   const int death_test_index = impl->current_test_info()
1154       ->increment_death_test_count();
1155 
1156   if (flag != NULL) {
1157     if (death_test_index > flag->index()) {
1158       DeathTest::set_last_death_test_message(String::Format(
1159           "Death test count (%d) somehow exceeded expected maximum (%d)",
1160           death_test_index, flag->index()));
1161       return false;
1162     }
1163 
1164     if (!(flag->file() == file && flag->line() == line &&
1165           flag->index() == death_test_index)) {
1166       *test = NULL;
1167       return true;
1168     }
1169   }
1170 
1171 # if GTEST_OS_WINDOWS
1172 
1173   if (GTEST_FLAG(death_test_style) == "threadsafe" ||
1174       GTEST_FLAG(death_test_style) == "fast") {
1175     *test = new WindowsDeathTest(statement, regex, file, line);
1176   }
1177 
1178 # else
1179 
1180   if (GTEST_FLAG(death_test_style) == "threadsafe") {
1181     *test = new ExecDeathTest(statement, regex, file, line);
1182   } else if (GTEST_FLAG(death_test_style) == "fast") {
1183     *test = new NoExecDeathTest(statement, regex);
1184   }
1185 
1186 # endif  // GTEST_OS_WINDOWS
1187 
1188   else {  // NOLINT - this is more readable than unbalanced brackets inside #if.
1189     DeathTest::set_last_death_test_message(String::Format(
1190         "Unknown death test style \"%s\" encountered",
1191         GTEST_FLAG(death_test_style).c_str()));
1192     return false;
1193   }
1194 
1195   return true;
1196 }
1197 
1198 // Splits a given string on a given delimiter, populating a given
1199 // vector with the fields.  GTEST_HAS_DEATH_TEST implies that we have
1200 // ::std::string, so we can use it here.
SplitString(const::std::string & str,char delimiter,::std::vector<::std::string> * dest)1201 static void SplitString(const ::std::string& str, char delimiter,
1202                         ::std::vector< ::std::string>* dest) {
1203   ::std::vector< ::std::string> parsed;
1204   ::std::string::size_type pos = 0;
1205   while (::testing::internal::AlwaysTrue()) {
1206     const ::std::string::size_type colon = str.find(delimiter, pos);
1207     if (colon == ::std::string::npos) {
1208       parsed.push_back(str.substr(pos));
1209       break;
1210     } else {
1211       parsed.push_back(str.substr(pos, colon - pos));
1212       pos = colon + 1;
1213     }
1214   }
1215   dest->swap(parsed);
1216 }
1217 
1218 # if GTEST_OS_WINDOWS
1219 // Recreates the pipe and event handles from the provided parameters,
1220 // signals the event, and returns a file descriptor wrapped around the pipe
1221 // handle. This function is called in the child process only.
GetStatusFileDescriptor(unsigned int parent_process_id,size_t write_handle_as_size_t,size_t event_handle_as_size_t)1222 int GetStatusFileDescriptor(unsigned int parent_process_id,
1223                             size_t write_handle_as_size_t,
1224                             size_t event_handle_as_size_t) {
1225   AutoHandle parent_process_handle(::OpenProcess(PROCESS_DUP_HANDLE,
1226                                                    FALSE,  // Non-inheritable.
1227                                                    parent_process_id));
1228   if (parent_process_handle.Get() == INVALID_HANDLE_VALUE) {
1229     DeathTestAbort(String::Format("Unable to open parent process %u",
1230                                   parent_process_id));
1231   }
1232 
1233   // TODO(vladl@google.com): Replace the following check with a
1234   // compile-time assertion when available.
1235   GTEST_CHECK_(sizeof(HANDLE) <= sizeof(size_t));
1236 
1237   const HANDLE write_handle =
1238       reinterpret_cast<HANDLE>(write_handle_as_size_t);
1239   HANDLE dup_write_handle;
1240 
1241   // The newly initialized handle is accessible only in in the parent
1242   // process. To obtain one accessible within the child, we need to use
1243   // DuplicateHandle.
1244   if (!::DuplicateHandle(parent_process_handle.Get(), write_handle,
1245                          ::GetCurrentProcess(), &dup_write_handle,
1246                          0x0,    // Requested privileges ignored since
1247                                  // DUPLICATE_SAME_ACCESS is used.
1248                          FALSE,  // Request non-inheritable handler.
1249                          DUPLICATE_SAME_ACCESS)) {
1250     DeathTestAbort(String::Format(
1251         "Unable to duplicate the pipe handle %Iu from the parent process %u",
1252         write_handle_as_size_t, parent_process_id));
1253   }
1254 
1255   const HANDLE event_handle = reinterpret_cast<HANDLE>(event_handle_as_size_t);
1256   HANDLE dup_event_handle;
1257 
1258   if (!::DuplicateHandle(parent_process_handle.Get(), event_handle,
1259                          ::GetCurrentProcess(), &dup_event_handle,
1260                          0x0,
1261                          FALSE,
1262                          DUPLICATE_SAME_ACCESS)) {
1263     DeathTestAbort(String::Format(
1264         "Unable to duplicate the event handle %Iu from the parent process %u",
1265         event_handle_as_size_t, parent_process_id));
1266   }
1267 
1268   const int write_fd =
1269       ::_open_osfhandle(reinterpret_cast<intptr_t>(dup_write_handle), O_APPEND);
1270   if (write_fd == -1) {
1271     DeathTestAbort(String::Format(
1272         "Unable to convert pipe handle %Iu to a file descriptor",
1273         write_handle_as_size_t));
1274   }
1275 
1276   // Signals the parent that the write end of the pipe has been acquired
1277   // so the parent can release its own write end.
1278   ::SetEvent(dup_event_handle);
1279 
1280   return write_fd;
1281 }
1282 # endif  // GTEST_OS_WINDOWS
1283 
1284 // Returns a newly created InternalRunDeathTestFlag object with fields
1285 // initialized from the GTEST_FLAG(internal_run_death_test) flag if
1286 // the flag is specified; otherwise returns NULL.
ParseInternalRunDeathTestFlag()1287 InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag() {
1288   if (GTEST_FLAG(internal_run_death_test) == "") return NULL;
1289 
1290   // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we
1291   // can use it here.
1292   int line = -1;
1293   int index = -1;
1294   ::std::vector< ::std::string> fields;
1295   SplitString(GTEST_FLAG(internal_run_death_test).c_str(), '|', &fields);
1296   int write_fd = -1;
1297 
1298 # if GTEST_OS_WINDOWS
1299 
1300   unsigned int parent_process_id = 0;
1301   size_t write_handle_as_size_t = 0;
1302   size_t event_handle_as_size_t = 0;
1303 
1304   if (fields.size() != 6
1305       || !ParseNaturalNumber(fields[1], &line)
1306       || !ParseNaturalNumber(fields[2], &index)
1307       || !ParseNaturalNumber(fields[3], &parent_process_id)
1308       || !ParseNaturalNumber(fields[4], &write_handle_as_size_t)
1309       || !ParseNaturalNumber(fields[5], &event_handle_as_size_t)) {
1310     DeathTestAbort(String::Format(
1311         "Bad --gtest_internal_run_death_test flag: %s",
1312         GTEST_FLAG(internal_run_death_test).c_str()));
1313   }
1314   write_fd = GetStatusFileDescriptor(parent_process_id,
1315                                      write_handle_as_size_t,
1316                                      event_handle_as_size_t);
1317 # else
1318 
1319   if (fields.size() != 4
1320       || !ParseNaturalNumber(fields[1], &line)
1321       || !ParseNaturalNumber(fields[2], &index)
1322       || !ParseNaturalNumber(fields[3], &write_fd)) {
1323     DeathTestAbort(String::Format(
1324         "Bad --gtest_internal_run_death_test flag: %s",
1325         GTEST_FLAG(internal_run_death_test).c_str()));
1326   }
1327 
1328 # endif  // GTEST_OS_WINDOWS
1329 
1330   return new InternalRunDeathTestFlag(fields[0], line, index, write_fd);
1331 }
1332 
1333 }  // namespace internal
1334 
1335 #endif  // GTEST_HAS_DEATH_TEST
1336 
1337 }  // namespace testing
1338