summaryrefslogtreecommitdiffstats
path: root/googletest/src/gtest-death-test.cc
blob: 76b87a11fc9fa1e5e5941c1802cb8e13e692a8cb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
// Copyright 2005, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

//
// This file implements death tests.

#include "gtest/gtest-death-test.h"

#include <utility>

#include "gtest/internal/gtest-port.h"
#include "gtest/internal/custom/gtest.h"

#if GTEST_HAS_DEATH_TEST

# if GTEST_OS_MAC
#  include <crt_externs.h>
# endif  // GTEST_OS_MAC

# include <errno.h>
# include <fcntl.h>
# include <limits.h>

# if GTEST_OS_LINUX
#  include <signal.h>
# endif  // GTEST_OS_LINUX

# include <stdarg.h>

# if GTEST_OS_WINDOWS
#  include <windows.h>
# else
#  include <sys/mman.h>
#  include <sys/wait.h>
# endif  // GTEST_OS_WINDOWS

# if GTEST_OS_QNX
#  include <spawn.h>
# endif  // GTEST_OS_QNX

# if GTEST_OS_FUCHSIA
#  include <lib/fdio/fd.h>
#  include <lib/fdio/io.h>
#  include <lib/fdio/spawn.h>
#  include <lib/zx/port.h>
#  include <lib/zx/process.h>
#  include <lib/zx/socket.h>
#  include <zircon/processargs.h>
#  include <zircon/syscalls.h>
#  include <zircon/syscalls/policy.h>
#  include <zircon/syscalls/port.h>
# endif  // GTEST_OS_FUCHSIA

#endif  // GTEST_HAS_DEATH_TEST

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

namespace testing {

// Constants.

// The default death test style.
//
// This is defined in internal/gtest-port.h as "fast", but can be overridden by
// a definition in internal/custom/gtest-port.h. The recommended value, which is
// used internally at Google, is "threadsafe".
static const char kDefaultDeathTestStyle[] = GTEST_DEFAULT_DEATH_TEST_STYLE;

GTEST_DEFINE_string_(
    death_test_style,
    internal::StringFromGTestEnv("death_test_style", kDefaultDeathTestStyle),
    "Indicates how to run a death test in a forked child process: "
    "\"threadsafe\" (child process re-executes the test binary "
    "from the beginning, running only the specific death test) or "
    "\"fast\" (child process runs the death test immediately "
    "after forking).");

GTEST_DEFINE_bool_(
    death_test_use_fork,
    internal::BoolFromGTestEnv("death_test_use_fork", false),
    "Instructs to use fork()/_exit() instead of clone() in death tests. "
    "Ignored and always uses fork() on POSIX systems where clone() is not "
    "implemented. Useful when running under valgrind or similar tools if "
    "those do not support clone(). Valgrind 3.3.1 will just fail if "
    "it sees an unsupported combination of clone() flags. "
    "It is not recommended to use this flag w/o valgrind though it will "
    "work in 99% of the cases. Once valgrind is fixed, this flag will "
    "most likely be removed.");

namespace internal {
GTEST_DEFINE_string_(
    internal_run_death_test, "",
    "Indicates the file, line number, temporal index of "
    "the single death test to run, and a file descriptor to "
    "which a success code may be sent, all separated by "
    "the '|' characters.  This flag is specified if and only if the current "
    "process is a sub-process launched for running a thread-safe "
    "death test.  FOR INTERNAL USE ONLY.");
}  // namespace internal

#if GTEST_HAS_DEATH_TEST

namespace internal {

// Valid only for fast death tests. Indicates the code is running in the
// child process of a fast style death test.
# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
static bool g_in_fast_death_test_child = false;
# endif

// Returns a Boolean value indicating whether the caller is currently
// executing in the context of the death test child process.  Tools such as
// Valgrind heap checkers may need this to modify their behavior in death
// tests.  IMPORTANT: This is an internal utility.  Using it may break the
// implementation of death tests.  User code MUST NOT use it.
bool InDeathTestChild() {
# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA

  // On Windows and Fuchsia, death tests are thread-safe regardless of the value
  // of the death_test_style flag.
  return !GTEST_FLAG(internal_run_death_test).empty();

# else

  if (GTEST_FLAG(death_test_style) == "threadsafe")
    return !GTEST_FLAG(internal_run_death_test).empty();
  else
    return g_in_fast_death_test_child;
#endif
}

}  // namespace internal

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

// ExitedWithCode function-call operator.
bool ExitedWithCode::operator()(int exit_status) const {
# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA

  return exit_status == exit_code_;

# else

  return WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == exit_code_;

# endif  // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
}

# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
// KilledBySignal constructor.
KilledBySignal::KilledBySignal(int signum) : signum_(signum) {
}

// KilledBySignal function-call operator.
bool KilledBySignal::operator()(int exit_status) const {
#  if defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
  {
    bool result;
    if (GTEST_KILLED_BY_SIGNAL_OVERRIDE_(signum_, exit_status, &result)) {
      return result;
    }
  }
#  endif  // defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
  return WIFSIGNALED(exit_status) && WTERMSIG(exit_status) == signum_;
}
# endif  // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA

namespace internal {

// Utilities needed for death tests.

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

# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA

  m << "Exited with exit status " << exit_code;

# else

  if (WIFEXITED(exit_code)) {
    m << "Exited with exit status " << WEXITSTATUS(exit_code);
  } else if (WIFSIGNALED(exit_code)) {
    m << "Terminated by signal " << WTERMSIG(exit_code);
  }
#  ifdef WCOREDUMP
  if (WCOREDUMP(exit_code)) {
    m << " (core dumped)";
  }
#  endif
# endif  // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA

  return m.GetString();
}

// Returns true if exit_status describes a process that was terminated
// by a signal, or exited normally with a nonzero exit code.
bool ExitedUnsuccessfully(int exit_status) {
  return !ExitedWithCode(0)(exit_status);
}

# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
// Generates a textual failure message when a death test finds more than
// one thread running, or cannot determine the number of threads, prior
// to executing the given statement.  It is the responsibility of the
// caller not to pass a thread_count of 1.
static std::string DeathTestThreadWarning(size_t thread_count) {
  Message msg;
  msg << "Death tests use fork(), which is unsafe particularly"
      << " in a threaded context. For this test, " << GTEST_NAME_ << " ";
  if (thread_count == 0) {
    msg << "couldn't detect the number of threads.";
  } else {
    msg << "detected " << thread_count << " threads.";
  }
  msg << " See "
         "https://github.com/google/googletest/blob/master/googletest/docs/"
         "advanced.md#death-tests-and-threads"
      << " for more explanation and suggested solutions, especially if"
      << " this is the last message you see before your test times out.";
  return msg.GetString();
}
# endif  // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA

// Flag characters for reporting a death test that did not die.
static const char kDeathTestLived = 'L';
static const char kDeathTestReturned = 'R';
static const char kDeathTestThrew = 'T';
static const char kDeathTestInternalError = 'I';

#if GTEST_OS_FUCHSIA

// File descriptor used for the pipe in the child process.
static const int kFuchsiaReadPipeFd = 3;

#endif

// An enumeration describing all of the possible ways that a death test can
// conclude.  DIED means that the process died while executing the test
// code; LIVED means that process lived beyond the end of the test code;
// RETURNED means that the test statement attempted to execute a return
// statement, which is not allowed; THREW means that the test statement
// returned control by throwing an exception.  IN_PROGRESS means the test
// has not yet concluded.
enum DeathTestOutcome { IN_PROGRESS, DIED, LIVED, RETURNED, THREW };

// Routine for aborting the program which is safe to call from an
// exec-style death test child process, in which case the error
// message is propagated back to the parent process.  Otherwise, the
// message is simply printed to stderr.  In either case, the program
// then exits with status 1.
static void DeathTestAbort(const std::string& message) {
  // On a POSIX system, this function may be called from a threadsafe-style
  // death test child process, which operates on a very small stack.  Use
  // the heap for any additional non-minuscule memory requirements.
  const InternalRunDeathTestFlag* const flag =
      GetUnitTestImpl()->internal_run_death_test_flag();
  if (flag != nullptr) {
    FILE* parent = posix::FDOpen(flag->write_fd(), "w");
    fputc(kDeathTestInternalError, parent);
    fprintf(parent, "%s", message.c_str());
    fflush(parent);
    _exit(1);
  } else {
    fprintf(stderr, "%s", message.c_str());
    fflush(stderr);
    posix::Abort();
  }
}

// A replacement for CHECK that calls DeathTestAbort if the assertion
// fails.
# define GTEST_DEATH_TEST_CHECK_(expression) \
  do { \
    if (!::testing::internal::IsTrue(expression)) { \
      DeathTestAbort( \
          ::std::string("CHECK failed: File ") + __FILE__ +  ", line " \
          + ::testing::internal::StreamableToString(__LINE__) + ": " \
          + #expression); \
    } \
  } while (::testing::internal::AlwaysFalse())

// This macro is similar to GTEST_DEATH_TEST_CHECK_, but it is meant for
// evaluating any system call that fulfills two conditions: it must return
// -1 on failure, and set errno to EINTR when it is interrupted and
// should be tried again.  The macro expands to a loop that repeatedly
// evaluates the expression as long as it evaluates to -1 and sets
// errno to EINTR.  If the expression evaluates to -1 but errno is
// something other than EINTR, DeathTestAbort is called.
# define GTEST_DEATH_TEST_CHECK_SYSCALL_(expression) \
  do { \
    int gtest_retval; \
    do { \
      gtest_retval = (expression); \
    } while (gtest_retval == -1 && errno == EINTR); \
    if (gtest_retval == -1) { \
      DeathTestAbort( \
          ::std::string("CHECK failed: File ") + __FILE__ + ", line " \
          + ::testing::internal::StreamableToString(__LINE__) + ": " \
          + #expression + " != -1"); \
    } \
  } while (::testing::internal::AlwaysFalse())

// Returns the message describing the last system error in errno.
std::string GetLastErrnoDescription() {
    return errno == 0 ? "" : posix::StrError(errno);
}

// This is called from a death test parent process to read a failure
// message from the death test child process and log it with the FATAL
// severity. On Windows, the message is read from a pipe handle. On other
// platforms, it is read from a file descriptor.
static void FailFromInternalError(int fd) {
  Message error;
  char buffer[256];
  int num_read;

  do {
    while ((num_read = posix::Read(fd, buffer, 255)) > 0) {
      buffer[num_read] = '\0';
      error << buffer;
    }
  } while (num_read == -1 && errno == EINTR);

  if (num_read == 0) {
    GTEST_LOG_(FATAL) << error.GetString();
  } else {
    const int last_error = errno;
    GTEST_LOG_(FATAL) << "Error while reading death test internal: "
                      << GetLastErrnoDescription() << " [" << last_error << "]";
  }
}

// Death test constructor.  Increments the running death test count
// for the current test.
DeathTest::DeathTest() {
  TestInfo* const info = GetUnitTestImpl()->current_test_info();
  if (info == nullptr) {
    DeathTestAbort("Cannot run a death test outside of a TEST or "
                   "TEST_F construct");
  }
}

// Creates and returns a death test by dispatching to the current
// death test factory.
bool DeathTest::Create(const char* statement,
                       Matcher<const std::string&> matcher, const char* file,
                       int line, DeathTest** test) {
  return GetUnitTestImpl()->death_test_factory()->Create(
      statement, std::move(matcher), file, line, test);
}

const char* DeathTest::LastMessage() {
  return last_death_test_message_.c_str();
}

void DeathTest::set_last_death_test_message(const std::string& message) {
  last_death_test_message_ = message;
}

std::string DeathTest::last_death_test_message_;

// Provides cross platform implementation for some death functionality.
class DeathTestImpl : public DeathTest {
 protected:
  DeathTestImpl(const char* a_statement, Matcher<const std::string&> matcher)
      : statement_(a_statement),
        matcher_(std::move(matcher)),
        spawned_(false),
        status_(-1),
        outcome_(IN_PROGRESS),
        read_fd_(-1),
        write_fd_(-1) {}

  // read_fd_ is expected to be closed and cleared by a derived class.
  ~DeathTestImpl() override { GTEST_DEATH_TEST_CHECK_(read_fd_ == -1); }

  void Abort(AbortReason reason) override;
  bool Passed(bool status_ok) override;

  const char* statement() const { return statement_; }
  bool spawned() const { return spawned_; }
  void set_spawned(bool is_spawned) { spawned_ = is_spawned; }
  int status() const { return status_; }
  void set_status(int a_status) { status_ = a_status; }
  DeathTestOutcome outcome() const { return outcome_; }
  void set_outcome(DeathTestOutcome an_outcome) { outcome_ = an_outcome; }
  int read_fd() const { return read_fd_; }
  void set_read_fd(int fd) { read_fd_ = fd; }
  int write_fd() const { return write_fd_; }
  void set_write_fd(int fd) { write_fd_ = fd; }

  // Called in the parent process only. Reads the result code of the death
  // test child process via a pipe, interprets it to set the outcome_
  // member, and closes read_fd_.  Outputs diagnostics and terminates in
  // case of unexpected codes.
  void ReadAndInterpretStatusByte();

  // Returns stderr output from the child process.
  virtual std::string GetErrorLogs();

 private:
  // The textual content of the code this object is testing.  This class
  // doesn't own this string and should not attempt to delete it.
  const char* const statement_;
  // A matcher that's expected to match the stderr output by the child process.
  Matcher<const std::string&> matcher_;
  // True if the death test child process has been successfully spawned.
  bool spawned_;
  // The exit status of the child process.
  int status_;
  // How the death test concluded.
  DeathTestOutcome outcome_;
  // Descriptor to the read end of the pipe to the child process.  It is
  // always -1 in the child process.  The child keeps its write end of the
  // pipe in write_fd_.
  int read_fd_;
  // Descriptor to the child's write end of the pipe to the parent process.
  // It is always -1 in the parent process.  The parent keeps its end of the
  // pipe in read_fd_.
  int write_fd_;
};

// Called in the parent process only. Reads the result code of the death
// test child process via a pipe, interprets it to set the outcome_
// member, and closes read_fd_.  Outputs diagnostics and terminates in
// case of unexpected codes.
void DeathTestImpl::ReadAndInterpretStatusByte() {
  char flag;
  int bytes_read;

  // The read() here blocks until data is available (signifying the
  // failure of the death test) or until the pipe is closed (signifying
  // its success), so it's okay to call this in the parent before
  // the child process has exited.
  do {
    bytes_read = posix::Read(read_fd(), &flag, 1);
  } while (bytes_read == -1 && errno == EINTR);

  if (bytes_read == 0) {
    set_outcome(DIED);
  } else if (bytes_read == 1) {
    switch (flag) {
      case kDeathTestReturned:
        set_outcome(RETURNED);
        break;
      case kDeathTestThrew:
        set_outcome(THREW);
        break;
      case kDeathTestLived:
        set_outcome(LIVED);
        break;
      case kDeathTestInternalError:
        FailFromInternalError(read_fd());  // Does not return.
        break;
      default:
        GTEST_LOG_(FATAL) << "Death test child process reported "
                          << "unexpected status byte ("
                          << static_cast<unsigned int>(flag) << ")";
    }
  } else {
    GTEST_LOG_(FATAL) << "Read from death test child process failed: "
                      << GetLastErrnoDescription();
  }
  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Close(read_fd()));
  set_read_fd(-1);
}

std::string DeathTestImpl::GetErrorLogs() {
  return GetCapturedStderr();
}

// Signals that the death test code which should have exited, didn't.
// Should be called only in a death test child process.
// Writes a status byte to the child's status file descriptor, then
// calls _exit(1).
void DeathTestImpl::Abort(AbortReason reason) {
  // The parent process considers the death test to be a failure if
  // it finds any data in our pipe.  So, here we write a single flag byte
  // to the pipe, then exit.
  const char status_ch =
      reason == TEST_DID_NOT_DIE ? kDeathTestLived :
      reason == TEST_THREW_EXCEPTION ? kDeathTestThrew : kDeathTestReturned;

  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Write(write_fd(), &status_ch, 1));
  // We are leaking the descriptor here because on some platforms (i.e.,
  // when built as Windows DLL), destructors of global objects will still
  // run after calling _exit(). On such systems, write_fd_ will be
  // indirectly closed from the destructor of UnitTestImpl, causing double
  // close if it is also closed here. On debug configurations, double close
  // may assert. As there are no in-process buffers to flush here, we are
  // relying on the OS to close the descriptor after the process terminates
  // when the destructors are not run.
  _exit(1);  // Exits w/o any normal exit hooks (we were supposed to crash)
}

// Returns an indented copy of stderr output for a death test.
// This makes distinguishing death test output lines from regular log lines
// much easier.
static ::std::string FormatDeathTestOutput(const ::std::string& output) {
  ::std::string ret;
  for (size_t at = 0; ; ) {
    const size_t line_end = output.find('\n', at);
    ret += "[  DEATH   ] ";
    if (line_end == ::std::string::npos) {
      ret += output.substr(at);
      break;
    }
    ret += output.substr(at, line_end + 1 - at);
    at = line_end + 1;
  }
  return ret;
}

// Assesses the success or failure of a death test, using both private
// members which have previously been set, and one argument:
//
// Private data members:
//   outcome:  An enumeration describing how the death test
//             concluded: DIED, LIVED, THREW, or RETURNED.  The death test
//             fails in the latter three cases.
//   status:   The exit status of the child process. On *nix, it is in the
//             in the format specified by wait(2). On Windows, this is the
//             value supplied to the ExitProcess() API or a numeric code
//             of the exception that terminated the program.
//   matcher_: A matcher that's expected to match the stderr output by the child
//             process.
//
// Argument:
//   status_ok: true if exit_status is acceptable in the context of
//              this particular death test, which fails if it is false
//
// Returns true iff all of the above conditions are met.  Otherwise, the
// first failing condition, in the order given above, is the one that is
// reported. Also sets the last death test message string.
bool DeathTestImpl::Passed(bool status_ok) {
  if (!spawned())
    return false;

  const std::string error_message = GetErrorLogs();

  bool success = false;
  Message buffer;

  buffer << "Death test: " << statement() << "\n";
  switch (outcome()) {
    case LIVED:
      buffer << "    Result: failed to die.\n"
             << " Error msg:\n" << FormatDeathTestOutput(error_message);
      break;
    case THREW:
      buffer << "    Result: threw an exception.\n"
             << " Error msg:\n" << FormatDeathTestOutput(error_message);
      break;
    case RETURNED:
      buffer << "    Result: illegal return in test statement.\n"
             << " Error msg:\n" << FormatDeathTestOutput(error_message);
      break;
    case DIED:
      if (status_ok) {
        if (matcher_.Matches(error_message)) {
          success = true;
        } else {
          std::ostringstream stream;
          matcher_.DescribeTo(&stream);
          buffer << "    Result: died but not with expected error.\n"
                 << "  Expected: " << stream.str() << "\n"
                 << "Actual msg:\n"
                 << FormatDeathTestOutput(error_message);
        }
      } else {
        buffer << "    Result: died but not with expected exit code:\n"
               << "            " << ExitSummary(status()) << "\n"
               << "Actual msg:\n" << FormatDeathTestOutput(error_message);
      }
      break;
    case IN_PROGRESS:
    default:
      GTEST_LOG_(FATAL)
          << "DeathTest::Passed somehow called before conclusion of test";
  }

  DeathTest::set_last_death_test_message(buffer.GetString());
  return success;
}

# if GTEST_OS_WINDOWS
// WindowsDeathTest implements death tests on Windows. Due to the
// specifics of starting new processes on Windows, death tests there are
// always threadsafe, and Google Test considers the
// --gtest_death_test_style=fast setting to be equivalent to
// --gtest_death_test_style=threadsafe there.
//
// A few implementation notes:  Like the Linux version, the Windows
// implementation uses pipes for child-to-parent communication. But due to
// the specifics of pipes on Windows, some extra steps are required:
//
// 1. The parent creates a communication pipe and stores handles to both
//    ends of it.
// 2. The parent starts the child and provides it with the information
//    necessary to acquire the handle to the write end of the pipe.
// 3. The child acquires the write end of the pipe and signals the parent
//    using a Windows event.
// 4. Now the parent can release the write end of the pipe on its side. If
//    this is done before step 3, the object's reference count goes down to
//    0 and it is destroyed, preventing the child from acquiring it. The
//    parent now has to release it, or read operations on the read end of
//    the pipe will not return when the child terminates.
// 5. The parent reads child's output through the pipe (outcome code and
//    any possible error messages) from the pipe, and its stderr and then
//    determines whether to fail the test.
//
// Note: to distinguish Win32 API calls from the local method and function
// calls, the former are explicitly resolved in the global namespace.
//
class WindowsDeathTest : public DeathTestImpl {
 public:
  WindowsDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
                   const char* file, int line)
      : DeathTestImpl(a_statement, std::move(matcher)),
        file_(file),
        line_(line) {}

  // All of these virtual functions are inherited from DeathTest.
  virtual int Wait();
  virtual TestRole AssumeRole();

 private:
  // The name of the file in which the death test is located.
  const char* const file_;
  // The line number on which the death test is located.
  const int line_;
  // Handle to the write end of the pipe to the child process.
  AutoHandle write_handle_;
  // Child process handle.
  AutoHandle child_handle_;
  // Event the child process uses to signal the parent that it has
  // acquired the handle to the write end of the pipe. After seeing this
  // event the parent can release its own handles to make sure its
  // ReadFile() calls return when the child terminates.
  AutoHandle event_handle_;
};

// Waits for the child in a death test to exit, returning its exit
// status, or 0 if no child process exists.  As a side effect, sets the
// outcome data member.
int WindowsDeathTest::Wait() {
  if (!spawned())
    return 0;

  // Wait until the child either signals that it has acquired the write end
  // of the pipe or it dies.
  const HANDLE wait_handles[2] = { child_handle_.Get(), event_handle_.Get() };
  switch (::WaitForMultipleObjects(2,
                                   wait_handles,
                                   FALSE,  // Waits for any of the handles.
                                   INFINITE)) {
    case WAIT_OBJECT_0:
    case WAIT_OBJECT_0 + 1:
      break;
    default:
      GTEST_DEATH_TEST_CHECK_(false);  // Should not get here.
  }

  // The child has acquired the write end of the pipe or exited.
  // We release the handle on our side and continue.
  write_handle_.Reset();
  event_handle_.Reset();

  ReadAndInterpretStatusByte();

  // Waits for the child process to exit if it haven't already. This
  // returns immediately if the child has already exited, regardless of
  // whether previous calls to WaitForMultipleObjects synchronized on this
  // handle or not.
  GTEST_DEATH_TEST_CHECK_(
      WAIT_OBJECT_0 == ::WaitForSingleObject(child_handle_.Get(),
                                             INFINITE));
  DWORD status_code;
  GTEST_DEATH_TEST_CHECK_(
      ::GetExitCodeProcess(child_handle_.Get(), &status_code) != FALSE);
  child_handle_.Reset();
  set_status(static_cast<int>(status_code));
  return status();
}

// The AssumeRole process for a Windows death test.  It creates a child
// process with the same executable as the current process to run the
// death test.  The child process is given the --gtest_filter and
// --gtest_internal_run_death_test flags such that it knows to run the
// current death test only.
DeathTest::TestRole WindowsDeathTest::AssumeRole() {
  const UnitTestImpl* const impl = GetUnitTestImpl();
  const InternalRunDeathTestFlag* const flag =
      impl->internal_run_death_test_flag();
  const TestInfo* const info = impl->current_test_info();
  const int death_test_index = info->result()->death_test_count();

  if (flag != nullptr) {
    // ParseInternalRunDeathTestFlag() has performed all the necessary
    // processing.
    set_write_fd(flag->write_fd());
    return EXECUTE_TEST;
  }

  // WindowsDeathTest uses an anonymous pipe to communicate results of
  // a death test.
  SECURITY_ATTRIBUTES handles_are_inheritable = {sizeof(SECURITY_ATTRIBUTES),
                                                 nullptr, TRUE};
  HANDLE read_handle, write_handle;
  GTEST_DEATH_TEST_CHECK_(
      ::CreatePipe(&read_handle, &write_handle, &handles_are_inheritable,
                   0)  // Default buffer size.
      != FALSE);
  set_read_fd(::_open_osfhandle(reinterpret_cast<intptr_t>(read_handle),
                                O_RDONLY));
  write_handle_.Reset(write_handle);
  event_handle_.Reset(::CreateEvent(
      &handles_are_inheritable,
      TRUE,       // The event will automatically reset to non-signaled state.
      FALSE,      // The initial state is non-signalled.
      nullptr));  // The even is unnamed.
  GTEST_DEATH_TEST_CHECK_(event_handle_.Get() != nullptr);
  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
                                  kFilterFlag + "=" + info->test_suite_name() +
                                  "." + info->name();
  const std::string internal_flag =
      std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag +
      "=" + file_ + "|" + StreamableToString(line_) + "|" +
      StreamableToString(death_test_index) + "|" +
      StreamableToString(static_cast<unsigned int>(::GetCurrentProcessId())) +
      // size_t has the same width as pointers on both 32-bit and 64-bit
      // Windows platforms.
      // See http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx.
      "|" + StreamableToString(reinterpret_cast<size_t>(write_handle)) +
      "|" + StreamableToString(reinterpret_cast<size_t>(event_handle_.Get()));

  char executable_path[_MAX_PATH + 1];  // NOLINT
  GTEST_DEATH_TEST_CHECK_(_MAX_PATH + 1 != ::GetModuleFileNameA(nullptr,
                                                                executable_path,
                                                                _MAX_PATH));

  std::string command_line =
      std::string(::GetCommandLineA()) + " " + filter_flag + " \"" +
      internal_flag + "\"";

  DeathTest::set_last_death_test_message("");

  CaptureStderr();
  // Flush the log buffers since the log streams are shared with the child.
  FlushInfoLog();

  // The child process will share the standard handles with the parent.
  STARTUPINFOA startup_info;
  memset(&startup_info, 0, sizeof(STARTUPINFO));
  startup_info.dwFlags = STARTF_USESTDHANDLES;
  startup_info.hStdInput = ::GetStdHandle(STD_INPUT_HANDLE);
  startup_info.hStdOutput = ::GetStdHandle(STD_OUTPUT_HANDLE);
  startup_info.hStdError = ::GetStdHandle(STD_ERROR_HANDLE);

  PROCESS_INFORMATION process_info;
  GTEST_DEATH_TEST_CHECK_(
      ::CreateProcessA(
          executable_path, const_cast<char*>(command_line.c_str()),
          nullptr,  // Retuned process handle is not inheritable.
          nullptr,  // Retuned thread handle is not inheritable.
          TRUE,  // Child inherits all inheritable handles (for write_handle_).
          0x0,   // Default creation flags.
          nullptr,  // Inherit the parent's environment.
          UnitTest::GetInstance()->original_working_dir(), &startup_info,
          &process_info) != FALSE);
  child_handle_.Reset(process_info.hProcess);
  ::CloseHandle(process_info.hThread);
  set_spawned(true);
  return OVERSEE_TEST;
}

# elif GTEST_OS_FUCHSIA

class FuchsiaDeathTest : public DeathTestImpl {
 public:
  FuchsiaDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
                   const char* file, int line)
      : DeathTestImpl(a_statement, std::move(matcher)),
        file_(file),
        line_(line) {}

  // All of these virtual functions are inherited from DeathTest.
  int Wait() override;
  TestRole AssumeRole() override;
  std::string GetErrorLogs() override;

 private:
  // The name of the file in which the death test is located.
  const char* const file_;
  // The line number on which the death test is located.
  const int line_;
  // The stderr data captured by the child process.
  std::string captured_stderr_;

  zx::process child_process_;
  zx::port port_;
  zx::socket stderr_socket_;
};

// Utility class for accumulating command-line arguments.
class Arguments {
 public:
  Arguments() { args_.push_back(nullptr); }

  ~Arguments() {
    for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
         ++i) {
      free(*i);
    }
  }
  void AddArgument(const char* argument) {
    args_.insert(args_.end() - 1, posix::StrDup(argument));
  }

  template <typename Str>
  void AddArguments(const ::std::vector<Str>& arguments) {
    for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
         i != arguments.end();
         ++i) {
      args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
    }
  }
  char* const* Argv() {
    return &args_[0];
  }

  int size() {
    return args_.size() - 1;
  }

 private:
  std::vector<char*> args_;
};

// Waits for the child in a death test to exit, returning its exit
// status, or 0 if no child process exists.  As a side effect, sets the
// outcome data member.
int FuchsiaDeathTest::Wait() {
  const int kProcessKey = 0;
  const int kSocketKey = 1;

  if (!spawned())
    return 0;

  // Register to wait for the child process to terminate.
  zx_status_t status_zx;
  status_zx = child_process_.wait_async(
      port_, kProcessKey, ZX_PROCESS_TERMINATED, ZX_WAIT_ASYNC_ONCE);
  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
  // Register to wait for the socket to be readable or closed.
  status_zx = stderr_socket_.wait_async(
      port_, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED,
      ZX_WAIT_ASYNC_ONCE);
  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);

  bool process_terminated = false;
  bool socket_closed = false;
  do {
    zx_port_packet_t packet = {};
    status_zx = port_.wait(zx::time::infinite(), &packet);
    GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);

    if (packet.key == kProcessKey) {
      if (ZX_PKT_IS_EXCEPTION(packet.type)) {
        // Process encountered an exception. Kill it directly rather than
        // letting other handlers process the event. We will get a second
        // kProcessKey event when the process actually terminates.
        status_zx = child_process_.kill();
        GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
      } else {
        // Process terminated.
        GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
        GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_PROCESS_TERMINATED);
        process_terminated = true;
      }
    } else if (packet.key == kSocketKey) {
      GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
      if (packet.signal.observed & ZX_SOCKET_READABLE) {
        // Read data from the socket.
        constexpr size_t kBufferSize = 1024;
        do {
          size_t old_length = captured_stderr_.length();
          size_t bytes_read = 0;
          captured_stderr_.resize(old_length + kBufferSize);
          status_zx = stderr_socket_.read(
              0, &captured_stderr_.front() + old_length, kBufferSize,
              &bytes_read);
          captured_stderr_.resize(old_length + bytes_read);
        } while (status_zx == ZX_OK);
        if (status_zx == ZX_ERR_PEER_CLOSED) {
          socket_closed = true;
        } else {
          GTEST_DEATH_TEST_CHECK_(status_zx == ZX_ERR_SHOULD_WAIT);
          status_zx = stderr_socket_.wait_async(
              port_, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED,
              ZX_WAIT_ASYNC_ONCE);
          GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
        }
      } else {
        GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_SOCKET_PEER_CLOSED);
        socket_closed = true;
      }
    }
  } while (!process_terminated && !socket_closed);

  ReadAndInterpretStatusByte();

  zx_info_process_t buffer;
  status_zx = child_process_.get_info(
      ZX_INFO_PROCESS, &buffer, sizeof(buffer), nullptr, nullptr);
  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);

  GTEST_DEATH_TEST_CHECK_(buffer.exited);
  set_status(buffer.return_code);
  return status();
}

// The AssumeRole process for a Fuchsia death test.  It creates a child
// process with the same executable as the current process to run the
// death test.  The child process is given the --gtest_filter and
// --gtest_internal_run_death_test flags such that it knows to run the
// current death test only.
DeathTest::TestRole FuchsiaDeathTest::AssumeRole() {
  const UnitTestImpl* const impl = GetUnitTestImpl();
  const InternalRunDeathTestFlag* const flag =
      impl->internal_run_death_test_flag();
  const TestInfo* const info = impl->current_test_info();
  const int death_test_index = info->result()->death_test_count();

  if (flag != nullptr) {
    // ParseInternalRunDeathTestFlag() has performed all the necessary
    // processing.
    set_write_fd(kFuchsiaReadPipeFd);
    return EXECUTE_TEST;
  }

  // Flush the log buffers since the log streams are shared with the child.
  FlushInfoLog();

  // Build the child process command line.
  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
                                  kFilterFlag + "=" + info->test_suite_name() +
                                  "." + info->name();
  const std::string internal_flag =
      std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag + "="
      + file_ + "|"
      + StreamableToString(line_) + "|"
      + StreamableToString(death_test_index);
  Arguments args;
  args.AddArguments(GetInjectableArgvs());
  args.AddArgument(filter_flag.c_str());
  args.AddArgument(internal_flag.c_str());

  // Build the pipe for communication with the child.
  zx_status_t status;
  zx_handle_t child_pipe_handle;
  int child_pipe_fd;
  status = fdio_pipe_half2(&child_pipe_fd, &child_pipe_handle);
  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
  set_read_fd(child_pipe_fd);

  // Set the pipe handle for the child.
  fdio_spawn_action_t spawn_actions[2] = {};
  fdio_spawn_action_t* add_handle_action = &spawn_actions[0];
  add_handle_action->action = FDIO_SPAWN_ACTION_ADD_HANDLE;
  add_handle_action->h.id = PA_HND(PA_FD, kFuchsiaReadPipeFd);
  add_handle_action->h.handle = child_pipe_handle;

  // Create a socket pair will be used to receive the child process' stderr.
  zx::socket stderr_producer_socket;
  status =
      zx::socket::create(0, &stderr_producer_socket, &stderr_socket_);
  GTEST_DEATH_TEST_CHECK_(status >= 0);
  int stderr_producer_fd = -1;
  status =
      fdio_fd_create(stderr_producer_socket.release(), &stderr_producer_fd);
  GTEST_DEATH_TEST_CHECK_(status >= 0);

  // Make the stderr socket nonblocking.
  GTEST_DEATH_TEST_CHECK_(fcntl(stderr_producer_fd, F_SETFL, 0) == 0);

  fdio_spawn_action_t* add_stderr_action = &spawn_actions[1];
  add_stderr_action->action = FDIO_SPAWN_ACTION_CLONE_FD;
  add_stderr_action->fd.local_fd = stderr_producer_fd;
  add_stderr_action->fd.target_fd = STDERR_FILENO;

  // Create a child job.
  zx_handle_t child_job = ZX_HANDLE_INVALID;
  status = zx_job_create(zx_job_default(), 0, & child_job);
  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
  zx_policy_basic_t policy;
  policy.condition = ZX_POL_NEW_ANY;
  policy.policy = ZX_POL_ACTION_ALLOW;
  status = zx_job_set_policy(
      child_job, ZX_JOB_POL_RELATIVE, ZX_JOB_POL_BASIC, &policy, 1);
  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);

  // Create an exception port and attach it to the |child_job|, to allow
  // us to suppress the system default exception handler from firing.
  status = zx::port::create(0, &port_);
  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
  status = zx_task_bind_exception_port(
      child_job, port_.get(), 0 /* key */, 0 /*options */);
  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);

  // Spawn the child process.
  status = fdio_spawn_etc(
      child_job, FDIO_SPAWN_CLONE_ALL, args.Argv()[0], args.Argv(), nullptr,
      2, spawn_actions, child_process_.reset_and_get_address(), nullptr);
  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);

  set_spawned(true);
  return OVERSEE_TEST;
}

std::string FuchsiaDeathTest::GetErrorLogs() {
  return captured_stderr_;
}

#else  // We are neither on Windows, nor on Fuchsia.

// ForkingDeathTest provides implementations for most of the abstract
// methods of the DeathTest interface.  Only the AssumeRole method is
// left undefined.
class ForkingDeathTest : public DeathTestImpl {
 public:
  ForkingDeathTest(const char* statement, Matcher<const std::string&> matcher);

  // All of these virtual functions are inherited from DeathTest.
  int Wait() override;

 protected:
  void set_child_pid(pid_t child_pid) { child_pid_ = child_pid; }

 private:
  // PID of child process during death test; 0 in the child process itself.
  pid_t child_pid_;
};

// Constructs a ForkingDeathTest.
ForkingDeathTest::ForkingDeathTest(const char* a_statement,
                                   Matcher<const std::string&> matcher)
    : DeathTestImpl(a_statement, std::move(matcher)), child_pid_(-1) {}

// Waits for the child in a death test to exit, returning its exit
// status, or 0 if no child process exists.  As a side effect, sets the
// outcome data member.
int ForkingDeathTest::Wait() {
  if (!spawned())
    return 0;

  ReadAndInterpretStatusByte();

  int status_value;
  GTEST_DEATH_TEST_CHECK_SYSCALL_(waitpid(child_pid_, &status_value, 0));
  set_status(status_value);
  return status_value;
}

// A concrete death test class that forks, then immediately runs the test
// in the child process.
class NoExecDeathTest : public ForkingDeathTest {
 public:
  NoExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher)
      : ForkingDeathTest(a_statement, std::move(matcher)) {}
  TestRole AssumeRole() override;
};

// The AssumeRole process for a fork-and-run death test.  It implements a
// straightforward fork, with a simple pipe to transmit the status byte.
DeathTest::TestRole NoExecDeathTest::AssumeRole() {
  const size_t thread_count = GetThreadCount();
  if (thread_count != 1) {
    GTEST_LOG_(WARNING) << DeathTestThreadWarning(thread_count);
  }

  int pipe_fd[2];
  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);

  DeathTest::set_last_death_test_message("");
  CaptureStderr();
  // When we fork the process below, the log file buffers are copied, but the
  // file descriptors are shared.  We flush all log files here so that closing
  // the file descriptors in the child process doesn't throw off the
  // synchronization between descriptors and buffers in the parent process.
  // This is as close to the fork as possible to avoid a race condition in case
  // there are multiple threads running before the death test, and another
  // thread writes to the log file.
  FlushInfoLog();

  const pid_t child_pid = fork();
  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
  set_child_pid(child_pid);
  if (child_pid == 0) {
    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[0]));
    set_write_fd(pipe_fd[1]);
    // Redirects all logging to stderr in the child process to prevent
    // concurrent writes to the log files.  We capture stderr in the parent
    // process and append the child process' output to a log.
    LogToStderr();
    // Event forwarding to the listeners of event listener API mush be shut
    // down in death test subprocesses.
    GetUnitTestImpl()->listeners()->SuppressEventForwarding();
    g_in_fast_death_test_child = true;
    return EXECUTE_TEST;
  } else {
    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
    set_read_fd(pipe_fd[0]);
    set_spawned(true);
    return OVERSEE_TEST;
  }
}

// A concrete death test class that forks and re-executes the main
// program from the beginning, with command-line flags set that cause
// only this specific death test to be run.
class ExecDeathTest : public ForkingDeathTest {
 public:
  ExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
                const char* file, int line)
      : ForkingDeathTest(a_statement, std::move(matcher)),
        file_(file),
        line_(line) {}
  TestRole AssumeRole() override;

 private:
  static ::std::vector<std::string> GetArgvsForDeathTestChildProcess() {
    ::std::vector<std::string> args = GetInjectableArgvs();
#  if defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
    ::std::vector<std::string> extra_args =
        GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_();
    args.insert(args.end(), extra_args.begin(), extra_args.end());
#  endif  // defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
    return args;
  }
  // The name of the file in which the death test is located.
  const char* const file_;
  // The line number on which the death test is located.
  const int line_;
};

// Utility class for accumulating command-line arguments.
class Arguments {
 public:
  Arguments() { args_.push_back(nullptr); }

  ~Arguments() {
    for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
         ++i) {
      free(*i);
    }
  }
  void AddArgument(const char* argument) {
    args_.insert(args_.end() - 1, posix::StrDup(argument));
  }

  template <typename Str>
  void AddArguments(const ::std::vector<Str>& arguments) {
    for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
         i != arguments.end();
         ++i) {
      args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
    }
  }
  char* const* Argv() {
    return &args_[0];
  }

 private:
  std::vector<char*> args_;
};

// A struct that encompasses the arguments to the child process of a
// threadsafe-style death test process.
struct ExecDeathTestArgs {
  char* const* argv;  // Command-line arguments for the child's call to exec
  int close_fd;       // File descriptor to close; the read end of a pipe
};

#  if GTEST_OS_MAC
inline char** GetEnviron() {
  // When Google Test is built as a framework on MacOS X, the environ variable
  // is unavailable. Apple's documentation (man environ) recommends using
  // _NSGetEnviron() instead.
  return *_NSGetEnviron();
}
#  else
// Some POSIX platforms expect you to declare environ. extern "C" makes
// it reside in the global namespace.
extern "C" char** environ;
inline char** GetEnviron() { return environ; }
#  endif  // GTEST_OS_MAC

#  if !GTEST_OS_QNX
// The main function for a threadsafe-style death test child process.
// This function is called in a clone()-ed process and thus must avoid
// any potentially unsafe operations like malloc or libc functions.
static int ExecDeathTestChildMain(void* child_arg) {
  ExecDeathTestArgs* const args = static_cast<ExecDeathTestArgs*>(child_arg);
  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(args->close_fd));

  // We need to execute the test program in the same environment where
  // it was originally invoked.  Therefore we change to the original
  // working directory first.
  const char* const original_dir =
      UnitTest::GetInstance()->original_working_dir();
  // We can safely call chdir() as it's a direct system call.
  if (chdir(original_dir) != 0) {
    DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
                   GetLastErrnoDescription());
    return EXIT_FAILURE;
  }

  // We can safely call execve() as it's a direct system call.  We
  // cannot use execvp() as it's a libc function and thus potentially
  // unsafe.  Since execve() doesn't search the PATH, the user must
  // invoke the test program via a valid path that contains at least
  // one path separator.
  execve(args->argv[0], args->argv, GetEnviron());
  DeathTestAbort(std::string("execve(") + args->argv[0] + ", ...) in " +
                 original_dir + " failed: " +
                 GetLastErrnoDescription());
  return EXIT_FAILURE;
}
#  endif  // !GTEST_OS_QNX

#  if GTEST_HAS_CLONE
// Two utility routines that together determine the direction the stack
// grows.
// This could be accomplished more elegantly by a single recursive
// function, but we want to guard against the unlikely possibility of
// a smart compiler optimizing the recursion away.
//
// GTEST_NO_INLINE_ is required to prevent GCC 4.6 from inlining
// StackLowerThanAddress into StackGrowsDown, which then doesn't give
// correct answer.
static void StackLowerThanAddress(const void* ptr,
                                  bool* result) GTEST_NO_INLINE_;
// HWAddressSanitizer add a random tag to the MSB of the local variable address,
// making comparison result unpredictable.
GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
static void StackLowerThanAddress(const void* ptr, bool* result) {
  int dummy;
  *result = (&dummy < ptr);
}

// Make sure AddressSanitizer does not tamper with the stack here.
GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
static bool StackGrowsDown() {
  int dummy;
  bool result;
  StackLowerThanAddress(&dummy, &result);
  return result;
}
#  endif  // GTEST_HAS_CLONE

// Spawns a child process with the same executable as the current process in
// a thread-safe manner and instructs it to run the death test.  The
// implementation uses fork(2) + exec.  On systems where clone(2) is
// available, it is used instead, being slightly more thread-safe.  On QNX,
// fork supports only single-threaded environments, so this function uses
// spawn(2) there instead.  The function dies with an error message if
// anything goes wrong.
static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
  ExecDeathTestArgs args = { argv, close_fd };
  pid_t child_pid = -1;

#  if GTEST_OS_QNX
  // Obtains the current directory and sets it to be closed in the child
  // process.
  const int cwd_fd = open(".", O_RDONLY);
  GTEST_DEATH_TEST_CHECK_(cwd_fd != -1);
  GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(cwd_fd, F_SETFD, FD_CLOEXEC));
  // We need to execute the test program in the same environment where
  // it was originally invoked.  Therefore we change to the original
  // working directory first.
  const char* const original_dir =
      UnitTest::GetInstance()->original_working_dir();
  // We can safely call chdir() as it's a direct system call.
  if (chdir(original_dir) != 0) {
    DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
                   GetLastErrnoDescription());
    return EXIT_FAILURE;
  }

  int fd_flags;
  // Set close_fd to be closed after spawn.
  GTEST_DEATH_TEST_CHECK_SYSCALL_(fd_flags = fcntl(close_fd, F_GETFD));
  GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(close_fd, F_SETFD,
                                        fd_flags | FD_CLOEXEC));
  struct inheritance inherit = {0};
  // spawn is a system call.
  child_pid =
      spawn(args.argv[0], 0, nullptr, &inherit, args.argv, GetEnviron());
  // Restores the current working directory.
  GTEST_DEATH_TEST_CHECK_(fchdir(cwd_fd) != -1);
  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(cwd_fd));

#  else   // GTEST_OS_QNX
#   if GTEST_OS_LINUX
  // When a SIGPROF signal is received while fork() or clone() are executing,
  // the process may hang. To avoid this, we ignore SIGPROF here and re-enable
  // it after the call to fork()/clone() is complete.
  struct sigaction saved_sigprof_action;
  struct sigaction ignore_sigprof_action;
  memset(&ignore_sigprof_action, 0, sizeof(ignore_sigprof_action));
  sigemptyset(&ignore_sigprof_action.sa_mask);
  ignore_sigprof_action.sa_handler = SIG_IGN;
  GTEST_DEATH_TEST_CHECK_SYSCALL_(sigaction(
      SIGPROF, &ignore_sigprof_action, &saved_sigprof_action));
#   endif  // GTEST_OS_LINUX

#   if GTEST_HAS_CLONE
  const bool use_fork = GTEST_FLAG(death_test_use_fork);

  if (!use_fork) {
    static const bool stack_grows_down = StackGrowsDown();
    const size_t stack_size = getpagesize();
    // MMAP_ANONYMOUS is not defined on Mac, so we use MAP_ANON instead.
    void* const stack = mmap(nullptr, stack_size, PROT_READ | PROT_WRITE,
                             MAP_ANON | MAP_PRIVATE, -1, 0);
    GTEST_DEATH_TEST_CHECK_(stack != MAP_FAILED);

    // Maximum stack alignment in bytes:  For a downward-growing stack, this
    // amount is subtracted from size of the stack space to get an address
    // that is within the stack space and is aligned on all systems we care
    // about.  As far as I know there is no ABI with stack alignment greater
    // than 64.  We assume stack and stack_size already have alignment of
    // kMaxStackAlignment.
    const size_t kMaxStackAlignment = 64;
    void* const stack_top =
        static_cast<char*>(stack) +
            (stack_grows_down ? stack_size - kMaxStackAlignment : 0);
    GTEST_DEATH_TEST_CHECK_(stack_size > kMaxStackAlignment &&
        reinterpret_cast<intptr_t>(stack_top) % kMaxStackAlignment == 0);

    child_pid = clone(&ExecDeathTestChildMain, stack_top, SIGCHLD, &args);

    GTEST_DEATH_TEST_CHECK_(munmap(stack, stack_size) != -1);
  }
#   else
  const bool use_fork = true;
#   endif  // GTEST_HAS_CLONE

  if (use_fork && (child_pid = fork()) == 0) {
      ExecDeathTestChildMain(&args);
      _exit(0);
  }
#  endif  // GTEST_OS_QNX
#  if GTEST_OS_LINUX
  GTEST_DEATH_TEST_CHECK_SYSCALL_(
      sigaction(SIGPROF, &saved_sigprof_action, nullptr));
#  endif  // GTEST_OS_LINUX

  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
  return child_pid;
}

// The AssumeRole process for a fork-and-exec death test.  It re-executes the
// main program from the beginning, setting the --gtest_filter
// and --gtest_internal_run_death_test flags to cause only the current
// death test to be re-run.
DeathTest::TestRole ExecDeathTest::AssumeRole() {
  const UnitTestImpl* const impl = GetUnitTestImpl();
  const InternalRunDeathTestFlag* const flag =
      impl->internal_run_death_test_flag();
  const TestInfo* const info = impl->current_test_info();
  const int death_test_index = info->result()->death_test_count();

  if (flag != nullptr) {
    set_write_fd(flag->write_fd());
    return EXECUTE_TEST;
  }

  int pipe_fd[2];
  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
  // Clear the close-on-exec flag on the write end of the pipe, lest
  // it be closed when the child process does an exec:
  GTEST_DEATH_TEST_CHECK_(fcntl(pipe_fd[1], F_SETFD, 0) != -1);

  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
                                  kFilterFlag + "=" + info->test_suite_name() +
                                  "." + info->name();
  const std::string internal_flag =
      std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag + "="
      + file_ + "|" + StreamableToString(line_) + "|"
      + StreamableToString(death_test_index) + "|"
      + StreamableToString(pipe_fd[1]);
  Arguments args;
  args.AddArguments(GetArgvsForDeathTestChildProcess());
  args.AddArgument(filter_flag.c_str());
  args.AddArgument(internal_flag.c_str());

  DeathTest::set_last_death_test_message("");

  CaptureStderr();
  // See the comment in NoExecDeathTest::AssumeRole for why the next line
  // is necessary.
  FlushInfoLog();

  const pid_t child_pid = ExecDeathTestSpawnChild(args.Argv(), pipe_fd[0]);
  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
  set_child_pid(child_pid);
  set_read_fd(pipe_fd[0]);
  set_spawned(true);
  return OVERSEE_TEST;
}

# endif  // !GTEST_OS_WINDOWS

// Creates a concrete DeathTest-derived class that depends on the
// --gtest_death_test_style flag, and sets the pointer pointed to
// by the "test" argument to its address.  If the test should be
// skipped, sets that pointer to NULL.  Returns true, unless the
// flag is set to an invalid value.
bool DefaultDeathTestFactory::Create(const char* statement,
                                     Matcher<const std::string&> matcher,
                                     const char* file, int line,
                                     DeathTest** test) {
  UnitTestImpl* const impl = GetUnitTestImpl();
  const InternalRunDeathTestFlag* const flag =
      impl->internal_run_death_test_flag();
  const int death_test_index = impl->current_test_info()
      ->increment_death_test_count();

  if (flag != nullptr) {
    if (death_test_index > flag->index()) {
      DeathTest::set_last_death_test_message(
          "Death test count (" + StreamableToString(death_test_index)
          + ") somehow exceeded expected maximum ("
          + StreamableToString(flag->index()) + ")");
      return false;
    }

    if (!(flag->file() == file && flag->line() == line &&
          flag->index() == death_test_index)) {
      *test = nullptr;
      return true;
    }
  }

# if GTEST_OS_WINDOWS

  if (GTEST_FLAG(death_test_style) == "threadsafe" ||
      GTEST_FLAG(death_test_style) == "fast") {
    *test = new WindowsDeathTest(statement, std::move(matcher), file, line);
  }

# elif GTEST_OS_FUCHSIA

  if (GTEST_FLAG(death_test_style) == "threadsafe" ||
      GTEST_FLAG(death_test_style) == "fast") {
    *test = new FuchsiaDeathTest(statement, std::move(matcher), file, line);
  }

# else

  if (GTEST_FLAG(death_test_style) == "threadsafe") {
    *test = new ExecDeathTest(statement, std::move(matcher), file, line);
  } else if (GTEST_FLAG(death_test_style) == "fast") {
    *test = new NoExecDeathTest(statement, std::move(matcher));
  }

# endif  // GTEST_OS_WINDOWS

  else {  // NOLINT - this is more readable than unbalanced brackets inside #if.
    DeathTest::set_last_death_test_message(
        "Unknown death test style \"" + GTEST_FLAG(death_test_style)
        + "\" encountered");
    return false;
  }

  return true;
}

# if GTEST_OS_WINDOWS
// Recreates the pipe and event handles from the provided parameters,
// signals the event, and returns a file descriptor wrapped around the pipe
// handle. This function is called in the child process only.
static int GetStatusFileDescriptor(unsigned int parent_process_id,
                            size_t write_handle_as_size_t,
                            size_t event_handle_as_size_t) {
  AutoHandle parent_process_handle(::OpenProcess(PROCESS_DUP_HANDLE,
                                                   FALSE,  // Non-inheritable.
                                                   parent_process_id));
  if (parent_process_handle.Get() == INVALID_HANDLE_VALUE) {
    DeathTestAbort("Unable to open parent process " +
                   StreamableToString(parent_process_id));
  }

  GTEST_CHECK_(sizeof(HANDLE) <= sizeof(size_t));

  const HANDLE write_handle =
      reinterpret_cast<HANDLE>(write_handle_as_size_t);
  HANDLE dup_write_handle;

  // The newly initialized handle is accessible only in the parent
  // process. To obtain one accessible within the child, we need to use
  // DuplicateHandle.
  if (!::DuplicateHandle(parent_process_handle.Get(), write_handle,
                         ::GetCurrentProcess(), &dup_write_handle,
                         0x0,    // Requested privileges ignored since
                                 // DUPLICATE_SAME_ACCESS is used.
                         FALSE,  // Request non-inheritable handler.
                         DUPLICATE_SAME_ACCESS)) {
    DeathTestAbort("Unable to duplicate the pipe handle " +
                   StreamableToString(write_handle_as_size_t) +
                   " from the parent process " +
                   StreamableToString(parent_process_id));
  }

  const HANDLE event_handle = reinterpret_cast<HANDLE>(event_handle_as_size_t);
  HANDLE dup_event_handle;

  if (!::DuplicateHandle(parent_process_handle.Get(), event_handle,
                         ::GetCurrentProcess(), &dup_event_handle,
                         0x0,
                         FALSE,
                         DUPLICATE_SAME_ACCESS)) {
    DeathTestAbort("Unable to duplicate the event handle " +
                   StreamableToString(event_handle_as_size_t) +
                   " from the parent process " +
                   StreamableToString(parent_process_id));
  }

  const int write_fd =
      ::_open_osfhandle(reinterpret_cast<intptr_t>(dup_write_handle), O_APPEND);
  if (write_fd == -1) {
    DeathTestAbort("Unable to convert pipe handle " +
                   StreamableToString(write_handle_as_size_t) +
                   " to a file descriptor");
  }

  // Signals the parent that the write end of the pipe has been acquired
  // so the parent can release its own write end.
  ::SetEvent(dup_event_handle);

  return write_fd;
}
# endif  // GTEST_OS_WINDOWS

// Returns a newly created InternalRunDeathTestFlag object with fields
// initialized from the GTEST_FLAG(internal_run_death_test) flag if
// the flag is specified; otherwise returns NULL.
InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag() {
  if (GTEST_FLAG(internal_run_death_test) == "") return nullptr;

  // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we
  // can use it here.
  int line = -1;
  int index = -1;
  ::std::vector< ::std::string> fields;
  SplitString(GTEST_FLAG(internal_run_death_test).c_str(), '|', &fields);
  int write_fd = -1;

# if GTEST_OS_WINDOWS

  unsigned int parent_process_id = 0;
  size_t write_handle_as_size_t = 0;
  size_t event_handle_as_size_t = 0;

  if (fields.size() != 6
      || !ParseNaturalNumber(fields[1], &line)
      || !ParseNaturalNumber(fields[2], &index)
      || !ParseNaturalNumber(fields[3], &parent_process_id)
      || !ParseNaturalNumber(fields[4], &write_handle_as_size_t)
      || !ParseNaturalNumber(fields[5], &event_handle_as_size_t)) {
    DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
                   GTEST_FLAG(internal_run_death_test));
  }
  write_fd = GetStatusFileDescriptor(parent_process_id,
                                     write_handle_as_size_t,
                                     event_handle_as_size_t);

# elif GTEST_OS_FUCHSIA

  if (fields.size() != 3
      || !ParseNaturalNumber(fields[1], &line)
      || !ParseNaturalNumber(fields[2], &index)) {
    DeathTestAbort("Bad --gtest_internal_run_death_test flag: "
        + GTEST_FLAG(internal_run_death_test));
  }

# else

  if (fields.size() != 4
      || !ParseNaturalNumber(fields[1], &line)
      || !ParseNaturalNumber(fields[2], &index)
      || !ParseNaturalNumber(fields[3], &write_fd)) {
    DeathTestAbort("Bad --gtest_internal_run_death_test flag: "
        + GTEST_FLAG(internal_run_death_test));
  }

# endif  // GTEST_OS_WINDOWS

  return new InternalRunDeathTestFlag(fields[0], line, index, write_fd);
}

}  // namespace internal

#endif  // GTEST_HAS_DEATH_TEST

}  // namespace testing