summaryrefslogtreecommitdiffstats
path: root/googletest/src/gtest-port.cc
blob: 989778cf507089e08769e60190359dae5cb60cd9 (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
// Copyright 2008, 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.


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

#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fstream>
#include <memory>

#if GTEST_OS_WINDOWS
# include <windows.h>
# include <io.h>
# include <sys/stat.h>
# include <map>  // Used in ThreadLocal.
# ifdef _MSC_VER
#  include <crtdbg.h>
# endif  // _MSC_VER
#else
# include <unistd.h>
#endif  // GTEST_OS_WINDOWS

#if GTEST_OS_MAC
# include <mach/mach_init.h>
# include <mach/task.h>
# include <mach/vm_map.h>
#endif  // GTEST_OS_MAC

#if GTEST_OS_QNX
# include <devctl.h>
# include <fcntl.h>
# include <sys/procfs.h>
#endif  // GTEST_OS_QNX

#if GTEST_OS_AIX
# include <procinfo.h>
# include <sys/types.h>
#endif  // GTEST_OS_AIX

#if GTEST_OS_FUCHSIA
# include <zircon/process.h>
# include <zircon/syscalls.h>
#endif  // GTEST_OS_FUCHSIA

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

namespace testing {
namespace internal {

#if defined(_MSC_VER) || defined(__BORLANDC__)
// MSVC and C++Builder do not provide a definition of STDERR_FILENO.
const int kStdOutFileno = 1;
const int kStdErrFileno = 2;
#else
const int kStdOutFileno = STDOUT_FILENO;
const int kStdErrFileno = STDERR_FILENO;
#endif  // _MSC_VER

#if GTEST_OS_LINUX

namespace {
template <typename T>
T ReadProcFileField(const std::string& filename, int field) {
  std::string dummy;
  std::ifstream file(filename.c_str());
  while (field-- > 0) {
    file >> dummy;
  }
  T output = 0;
  file >> output;
  return output;
}
}  // namespace

// Returns the number of active threads, or 0 when there is an error.
size_t GetThreadCount() {
  const std::string filename =
      (Message() << "/proc/" << getpid() << "/stat").GetString();
  return ReadProcFileField<int>(filename, 19);
}

#elif GTEST_OS_MAC

size_t GetThreadCount() {
  const task_t task = mach_task_self();
  mach_msg_type_number_t thread_count;
  thread_act_array_t thread_list;
  const kern_return_t status = task_threads(task, &thread_list, &thread_count);
  if (status == KERN_SUCCESS) {
    // task_threads allocates resources in thread_list and we need to free them
    // to avoid leaks.
    vm_deallocate(task,
                  reinterpret_cast<vm_address_t>(thread_list),
                  sizeof(thread_t) * thread_count);
    return static_cast<size_t>(thread_count);
  } else {
    return 0;
  }
}

#elif GTEST_OS_QNX

// Returns the number of threads running in the process, or 0 to indicate that
// we cannot detect it.
size_t GetThreadCount() {
  const int fd = open("/proc/self/as", O_RDONLY);
  if (fd < 0) {
    return 0;
  }
  procfs_info process_info;
  const int status =
      devctl(fd, DCMD_PROC_INFO, &process_info, sizeof(process_info), nullptr);
  close(fd);
  if (status == EOK) {
    return static_cast<size_t>(process_info.num_threads);
  } else {
    return 0;
  }
}

#elif GTEST_OS_AIX

size_t GetThreadCount() {
  struct procentry64 entry;
  pid_t pid = getpid();
  int status = getprocs64(&entry, sizeof(entry), nullptr, 0, &pid, 1);
  if (status == 1) {
    return entry.pi_thcount;
  } else {
    return 0;
  }
}

#elif GTEST_OS_FUCHSIA

size_t GetThreadCount() {
  int dummy_buffer;
  size_t avail;
  zx_status_t status = zx_object_get_info(
      zx_process_self(),
      ZX_INFO_PROCESS_THREADS,
      &dummy_buffer,
      0,
      nullptr,
      &avail);
  if (status == ZX_OK) {
    return avail;
  } else {
    return 0;
  }
}

#else

size_t GetThreadCount() {
  // There's no portable way to detect the number of threads, so we just
  // return 0 to indicate that we cannot detect it.
  return 0;
}

#endif  // GTEST_OS_LINUX

#if GTEST_IS_THREADSAFE && GTEST_OS_WINDOWS

void SleepMilliseconds(int n) {
  ::Sleep(n);
}

AutoHandle::AutoHandle()
    : handle_(INVALID_HANDLE_VALUE) {}

AutoHandle::AutoHandle(Handle handle)
    : handle_(handle) {}

AutoHandle::~AutoHandle() {
  Reset();
}

AutoHandle::Handle AutoHandle::Get() const {
  return handle_;
}

void AutoHandle::Reset() {
  Reset(INVALID_HANDLE_VALUE);
}

void AutoHandle::Reset(HANDLE handle) {
  // Resetting with the same handle we already own is invalid.
  if (handle_ != handle) {
    if (IsCloseable()) {
      ::CloseHandle(handle_);
    }
    handle_ = handle;
  } else {
    GTEST_CHECK_(!IsCloseable())
        << "Resetting a valid handle to itself is likely a programmer error "
            "and thus not allowed.";
  }
}

bool AutoHandle::IsCloseable() const {
  // Different Windows APIs may use either of these values to represent an
  // invalid handle.
  return handle_ != nullptr && handle_ != INVALID_HANDLE_VALUE;
}

Notification::Notification()
    : event_(::CreateEvent(nullptr,     // Default security attributes.
                           TRUE,        // Do not reset automatically.
                           FALSE,       // Initially unset.
                           nullptr)) {  // Anonymous event.
  GTEST_CHECK_(event_.Get() != nullptr);
}

void Notification::Notify() {
  GTEST_CHECK_(::SetEvent(event_.Get()) != FALSE);
}

void Notification::WaitForNotification() {
  GTEST_CHECK_(
      ::WaitForSingleObject(event_.Get(), INFINITE) == WAIT_OBJECT_0);
}

Mutex::Mutex()
    : owner_thread_id_(0),
      type_(kDynamic),
      critical_section_init_phase_(0),
      critical_section_(new CRITICAL_SECTION) {
  ::InitializeCriticalSection(critical_section_);
}

Mutex::~Mutex() {
  // Static mutexes are leaked intentionally. It is not thread-safe to try
  // to clean them up.
  if (type_ == kDynamic) {
    ::DeleteCriticalSection(critical_section_);
    delete critical_section_;
    critical_section_ = nullptr;
  }
}

void Mutex::Lock() {
  ThreadSafeLazyInit();
  ::EnterCriticalSection(critical_section_);
  owner_thread_id_ = ::GetCurrentThreadId();
}

void Mutex::Unlock() {
  ThreadSafeLazyInit();
  // We don't protect writing to owner_thread_id_ here, as it's the
  // caller's responsibility to ensure that the current thread holds the
  // mutex when this is called.
  owner_thread_id_ = 0;
  ::LeaveCriticalSection(critical_section_);
}

// Does nothing if the current thread holds the mutex. Otherwise, crashes
// with high probability.
void Mutex::AssertHeld() {
  ThreadSafeLazyInit();
  GTEST_CHECK_(owner_thread_id_ == ::GetCurrentThreadId())
      << "The current thread is not holding the mutex @" << this;
}

namespace {

// Use the RAII idiom to flag mem allocs that are intentionally never
// deallocated. The motivation is to silence the false positive mem leaks
// that are reported by the debug version of MS's CRT which can only detect
// if an alloc is missing a matching deallocation.
// Example:
//    MemoryIsNotDeallocated memory_is_not_deallocated;
//    critical_section_ = new CRITICAL_SECTION;
//
class MemoryIsNotDeallocated
{
 public:
  MemoryIsNotDeallocated() : old_crtdbg_flag_(0) {
#ifdef _MSC_VER
    old_crtdbg_flag_ = _CrtSetDbgFlag(_CRTDBG_REPORT_FLAG);
    // Set heap allocation block type to _IGNORE_BLOCK so that MS debug CRT
    // doesn't report mem leak if there's no matching deallocation.
    _CrtSetDbgFlag(old_crtdbg_flag_ & ~_CRTDBG_ALLOC_MEM_DF);
#endif  //  _MSC_VER
  }

  ~MemoryIsNotDeallocated() {
#ifdef _MSC_VER
    // Restore the original _CRTDBG_ALLOC_MEM_DF flag
    _CrtSetDbgFlag(old_crtdbg_flag_);
#endif  //  _MSC_VER
  }

 private:
  int old_crtdbg_flag_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(MemoryIsNotDeallocated);
};

}  // namespace

// Initializes owner_thread_id_ and critical_section_ in static mutexes.
void Mutex::ThreadSafeLazyInit() {
  // Dynamic mutexes are initialized in the constructor.
  if (type_ == kStatic) {
    switch (
        ::InterlockedCompareExchange(&critical_section_init_phase_, 1L, 0L)) {
      case 0:
        // If critical_section_init_phase_ was 0 before the exchange, we
        // are the first to test it and need to perform the initialization.
        owner_thread_id_ = 0;
        {
          // Use RAII to flag that following mem alloc is never deallocated.
          MemoryIsNotDeallocated memory_is_not_deallocated;
          critical_section_ = new CRITICAL_SECTION;
        }
        ::InitializeCriticalSection(critical_section_);
        // Updates the critical_section_init_phase_ to 2 to signal
        // initialization complete.
        GTEST_CHECK_(::InterlockedCompareExchange(
                          &critical_section_init_phase_, 2L, 1L) ==
                      1L);
        break;
      case 1:
        // Somebody else is already initializing the mutex; spin until they
        // are done.
        while (::InterlockedCompareExchange(&critical_section_init_phase_,
                                            2L,
                                            2L) != 2L) {
          // Possibly yields the rest of the thread's time slice to other
          // threads.
          ::Sleep(0);
        }
        break;

      case 2:
        break;  // The mutex is already initialized and ready for use.

      default:
        GTEST_CHECK_(false)
            << "Unexpected value of critical_section_init_phase_ "
            << "while initializing a static mutex.";
    }
  }
}

namespace {

class ThreadWithParamSupport : public ThreadWithParamBase {
 public:
  static HANDLE CreateThread(Runnable* runnable,
                             Notification* thread_can_start) {
    ThreadMainParam* param = new ThreadMainParam(runnable, thread_can_start);
    DWORD thread_id;
    HANDLE thread_handle = ::CreateThread(
        nullptr,  // Default security.
        0,        // Default stack size.
        &ThreadWithParamSupport::ThreadMain,
        param,        // Parameter to ThreadMainStatic
        0x0,          // Default creation flags.
        &thread_id);  // Need a valid pointer for the call to work under Win98.
    GTEST_CHECK_(thread_handle != nullptr)
        << "CreateThread failed with error " << ::GetLastError() << ".";
    if (thread_handle == nullptr) {
      delete param;
    }
    return thread_handle;
  }

 private:
  struct ThreadMainParam {
    ThreadMainParam(Runnable* runnable, Notification* thread_can_start)
        : runnable_(runnable),
          thread_can_start_(thread_can_start) {
    }
    std::unique_ptr<Runnable> runnable_;
    // Does not own.
    Notification* thread_can_start_;
  };

  static DWORD WINAPI ThreadMain(void* ptr) {
    // Transfers ownership.
    std::unique_ptr<ThreadMainParam> param(static_cast<ThreadMainParam*>(ptr));
    if (param->thread_can_start_ != nullptr)
      param->thread_can_start_->WaitForNotification();
    param->runnable_->Run();
    return 0;
  }

  // Prohibit instantiation.
  ThreadWithParamSupport();

  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParamSupport);
};

}  // namespace

ThreadWithParamBase::ThreadWithParamBase(Runnable *runnable,
                                         Notification* thread_can_start)
      : thread_(ThreadWithParamSupport::CreateThread(runnable,
                                                     thread_can_start)) {
}

ThreadWithParamBase::~ThreadWithParamBase() {
  Join();
}

void ThreadWithParamBase::Join() {
  GTEST_CHECK_(::WaitForSingleObject(thread_.Get(), INFINITE) == WAIT_OBJECT_0)
      << "Failed to join the thread with error " << ::GetLastError() << ".";
}

// Maps a thread to a set of ThreadIdToThreadLocals that have values
// instantiated on that thread and notifies them when the thread exits.  A
// ThreadLocal instance is expected to persist until all threads it has
// values on have terminated.
class ThreadLocalRegistryImpl {
 public:
  // Registers thread_local_instance as having value on the current thread.
  // Returns a value that can be used to identify the thread from other threads.
  static ThreadLocalValueHolderBase* GetValueOnCurrentThread(
      const ThreadLocalBase* thread_local_instance) {
    DWORD current_thread = ::GetCurrentThreadId();
    MutexLock lock(&mutex_);
    ThreadIdToThreadLocals* const thread_to_thread_locals =
        GetThreadLocalsMapLocked();
    ThreadIdToThreadLocals::iterator thread_local_pos =
        thread_to_thread_locals->find(current_thread);
    if (thread_local_pos == thread_to_thread_locals->end()) {
      thread_local_pos = thread_to_thread_locals->insert(
          std::make_pair(current_thread, ThreadLocalValues())).first;
      StartWatcherThreadFor(current_thread);
    }
    ThreadLocalValues& thread_local_values = thread_local_pos->second;
    ThreadLocalValues::iterator value_pos =
        thread_local_values.find(thread_local_instance);
    if (value_pos == thread_local_values.end()) {
      value_pos =
          thread_local_values
              .insert(std::make_pair(
                  thread_local_instance,
                  std::shared_ptr<ThreadLocalValueHolderBase>(
                      thread_local_instance->NewValueForCurrentThread())))
              .first;
    }
    return value_pos->second.get();
  }

  static void OnThreadLocalDestroyed(
      const ThreadLocalBase* thread_local_instance) {
    std::vector<std::shared_ptr<ThreadLocalValueHolderBase> > value_holders;
    // Clean up the ThreadLocalValues data structure while holding the lock, but
    // defer the destruction of the ThreadLocalValueHolderBases.
    {
      MutexLock lock(&mutex_);
      ThreadIdToThreadLocals* const thread_to_thread_locals =
          GetThreadLocalsMapLocked();
      for (ThreadIdToThreadLocals::iterator it =
          thread_to_thread_locals->begin();
          it != thread_to_thread_locals->end();
          ++it) {
        ThreadLocalValues& thread_local_values = it->second;
        ThreadLocalValues::iterator value_pos =
            thread_local_values.find(thread_local_instance);
        if (value_pos != thread_local_values.end()) {
          value_holders.push_back(value_pos->second);
          thread_local_values.erase(value_pos);
          // This 'if' can only be successful at most once, so theoretically we
          // could break out of the loop here, but we don't bother doing so.
        }
      }
    }
    // Outside the lock, let the destructor for 'value_holders' deallocate the
    // ThreadLocalValueHolderBases.
  }

  static void OnThreadExit(DWORD thread_id) {
    GTEST_CHECK_(thread_id != 0) << ::GetLastError();
    std::vector<std::shared_ptr<ThreadLocalValueHolderBase> > value_holders;
    // Clean up the ThreadIdToThreadLocals data structure while holding the
    // lock, but defer the destruction of the ThreadLocalValueHolderBases.
    {
      MutexLock lock(&mutex_);
      ThreadIdToThreadLocals* const thread_to_thread_locals =
          GetThreadLocalsMapLocked();
      ThreadIdToThreadLocals::iterator thread_local_pos =
          thread_to_thread_locals->find(thread_id);
      if (thread_local_pos != thread_to_thread_locals->end()) {
        ThreadLocalValues& thread_local_values = thread_local_pos->second;
        for (ThreadLocalValues::iterator value_pos =
            thread_local_values.begin();
            value_pos != thread_local_values.end();
            ++value_pos) {
          value_holders.push_back(value_pos->second);
        }
        thread_to_thread_locals->erase(thread_local_pos);
      }
    }
    // Outside the lock, let the destructor for 'value_holders' deallocate the
    // ThreadLocalValueHolderBases.
  }

 private:
  // In a particular thread, maps a ThreadLocal object to its value.
  typedef std::map<const ThreadLocalBase*,
                   std::shared_ptr<ThreadLocalValueHolderBase> >
      ThreadLocalValues;
  // Stores all ThreadIdToThreadLocals having values in a thread, indexed by
  // thread's ID.
  typedef std::map<DWORD, ThreadLocalValues> ThreadIdToThreadLocals;

  // Holds the thread id and thread handle that we pass from
  // StartWatcherThreadFor to WatcherThreadFunc.
  typedef std::pair<DWORD, HANDLE> ThreadIdAndHandle;

  static void StartWatcherThreadFor(DWORD thread_id) {
    // The returned handle will be kept in thread_map and closed by
    // watcher_thread in WatcherThreadFunc.
    HANDLE thread = ::OpenThread(SYNCHRONIZE | THREAD_QUERY_INFORMATION,
                                 FALSE,
                                 thread_id);
    GTEST_CHECK_(thread != nullptr);
    // We need to pass a valid thread ID pointer into CreateThread for it
    // to work correctly under Win98.
    DWORD watcher_thread_id;
    HANDLE watcher_thread = ::CreateThread(
        nullptr,  // Default security.
        0,        // Default stack size
        &ThreadLocalRegistryImpl::WatcherThreadFunc,
        reinterpret_cast<LPVOID>(new ThreadIdAndHandle(thread_id, thread)),
        CREATE_SUSPENDED, &watcher_thread_id);
    GTEST_CHECK_(watcher_thread != nullptr);
    // Give the watcher thread the same priority as ours to avoid being
    // blocked by it.
    ::SetThreadPriority(watcher_thread,
                        ::GetThreadPriority(::GetCurrentThread()));
    ::ResumeThread(watcher_thread);
    ::CloseHandle(watcher_thread);
  }

  // Monitors exit from a given thread and notifies those
  // ThreadIdToThreadLocals about thread termination.
  static DWORD WINAPI WatcherThreadFunc(LPVOID param) {
    const ThreadIdAndHandle* tah =
        reinterpret_cast<const ThreadIdAndHandle*>(param);
    GTEST_CHECK_(
        ::WaitForSingleObject(tah->second, INFINITE) == WAIT_OBJECT_0);
    OnThreadExit(tah->first);
    ::CloseHandle(tah->second);
    delete tah;
    return 0;
  }

  // Returns map of thread local instances.
  static ThreadIdToThreadLocals* GetThreadLocalsMapLocked() {
    mutex_.AssertHeld();
    MemoryIsNotDeallocated memory_is_not_deallocated;
    static ThreadIdToThreadLocals* map = new ThreadIdToThreadLocals();
    return map;
  }

  // Protects access to GetThreadLocalsMapLocked() and its return value.
  static Mutex mutex_;
  // Protects access to GetThreadMapLocked() and its return value.
  static Mutex thread_map_mutex_;
};

Mutex ThreadLocalRegistryImpl::mutex_(Mutex::kStaticMutex);
Mutex ThreadLocalRegistryImpl::thread_map_mutex_(Mutex::kStaticMutex);

ThreadLocalValueHolderBase* ThreadLocalRegistry::GetValueOnCurrentThread(
      const ThreadLocalBase* thread_local_instance) {
  return ThreadLocalRegistryImpl::GetValueOnCurrentThread(
      thread_local_instance);
}

void ThreadLocalRegistry::OnThreadLocalDestroyed(
      const ThreadLocalBase* thread_local_instance) {
  ThreadLocalRegistryImpl::OnThreadLocalDestroyed(thread_local_instance);
}

#endif  // GTEST_IS_THREADSAFE && GTEST_OS_WINDOWS

#if GTEST_USES_POSIX_RE

// Implements RE.  Currently only needed for death tests.

RE::~RE() {
  if (is_valid_) {
    // regfree'ing an invalid regex might crash because the content
    // of the regex is undefined. Since the regex's are essentially
    // the same, one cannot be valid (or invalid) without the other
    // being so too.
    regfree(&partial_regex_);
    regfree(&full_regex_);
  }
  free(const_cast<char*>(pattern_));
}

// Returns true iff regular expression re matches the entire str.
bool RE::FullMatch(const char* str, const RE& re) {
  if (!re.is_valid_) return false;

  regmatch_t match;
  return regexec(&re.full_regex_, str, 1, &match, 0) == 0;
}

// Returns true iff regular expression re matches a substring of str
// (including str itself).
bool RE::PartialMatch(const char* str, const RE& re) {
  if (!re.is_valid_) return false;

  regmatch_t match;
  return regexec(&re.partial_regex_, str, 1, &match, 0) == 0;
}

// Initializes an RE from its string representation.
void RE::Init(const char* regex) {
  pattern_ = posix::StrDup(regex);

  // Reserves enough bytes to hold the regular expression used for a
  // full match.
  const size_t full_regex_len = strlen(regex) + 10;
  char* const full_pattern = new char[full_regex_len];

  snprintf(full_pattern, full_regex_len, "^(%s)$", regex);
  is_valid_ = regcomp(&full_regex_, full_pattern, REG_EXTENDED) == 0;
  // We want to call regcomp(&partial_regex_, ...) even if the
  // previous expression returns false.  Otherwise partial_regex_ may
  // not be properly initialized can may cause trouble when it's
  // freed.
  //
  // Some implementation of POSIX regex (e.g. on at least some
  // versions of Cygwin) doesn't accept the empty string as a valid
  // regex.  We change it to an equivalent form "()" to be safe.
  if (is_valid_) {
    const char* const partial_regex = (*regex == '\0') ? "()" : regex;
    is_valid_ = regcomp(&partial_regex_, partial_regex, REG_EXTENDED) == 0;
  }
  EXPECT_TRUE(is_valid_)
      << "Regular expression \"" << regex
      << "\" is not a valid POSIX Extended regular expression.";

  delete[] full_pattern;
}

#elif GTEST_USES_SIMPLE_RE

// Returns true iff ch appears anywhere in str (excluding the
// terminating '\0' character).
bool IsInSet(char ch, const char* str) {
  return ch != '\0' && strchr(str, ch) != nullptr;
}

// Returns true iff ch belongs to the given classification.  Unlike
// similar functions in <ctype.h>, these aren't affected by the
// current locale.
bool IsAsciiDigit(char ch) { return '0' <= ch && ch <= '9'; }
bool IsAsciiPunct(char ch) {
  return IsInSet(ch, "^-!\"#$%&'()*+,./:;<=>?@[\\]_`{|}~");
}
bool IsRepeat(char ch) { return IsInSet(ch, "?*+"); }
bool IsAsciiWhiteSpace(char ch) { return IsInSet(ch, " \f\n\r\t\v"); }
bool IsAsciiWordChar(char ch) {
  return ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') ||
      ('0' <= ch && ch <= '9') || ch == '_';
}

// Returns true iff "\\c" is a supported escape sequence.
bool IsValidEscape(char c) {
  return (IsAsciiPunct(c) || IsInSet(c, "dDfnrsStvwW"));
}

// Returns true iff the given atom (specified by escaped and pattern)
// matches ch.  The result is undefined if the atom is invalid.
bool AtomMatchesChar(bool escaped, char pattern_char, char ch) {
  if (escaped) {  // "\\p" where p is pattern_char.
    switch (pattern_char) {
      case 'd': return IsAsciiDigit(ch);
      case 'D': return !IsAsciiDigit(ch);
      case 'f': return ch == '\f';
      case 'n': return ch == '\n';
      case 'r': return ch == '\r';
      case 's': return IsAsciiWhiteSpace(ch);
      case 'S': return !IsAsciiWhiteSpace(ch);
      case 't': return ch == '\t';
      case 'v': return ch == '\v';
      case 'w': return IsAsciiWordChar(ch);
      case 'W': return !IsAsciiWordChar(ch);
    }
    return IsAsciiPunct(pattern_char) && pattern_char == ch;
  }

  return (pattern_char == '.' && ch != '\n') || pattern_char == ch;
}

// Helper function used by ValidateRegex() to format error messages.
static std::string FormatRegexSyntaxError(const char* regex, int index) {
  return (Message() << "Syntax error at index " << index
          << " in simple regular expression \"" << regex << "\": ").GetString();
}

// Generates non-fatal failures and returns false if regex is invalid;
// otherwise returns true.
bool ValidateRegex(const char* regex) {
  if (regex == nullptr) {
    ADD_FAILURE() << "NULL is not a valid simple regular expression.";
    return false;
  }

  bool is_valid = true;

  // True iff ?, *, or + can follow the previous atom.
  bool prev_repeatable = false;
  for (int i = 0; regex[i]; i++) {
    if (regex[i] == '\\') {  // An escape sequence
      i++;
      if (regex[i] == '\0') {
        ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
                      << "'\\' cannot appear at the end.";
        return false;
      }

      if (!IsValidEscape(regex[i])) {
        ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
                      << "invalid escape sequence \"\\" << regex[i] << "\".";
        is_valid = false;
      }
      prev_repeatable = true;
    } else {  // Not an escape sequence.
      const char ch = regex[i];

      if (ch == '^' && i > 0) {
        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
                      << "'^' can only appear at the beginning.";
        is_valid = false;
      } else if (ch == '$' && regex[i + 1] != '\0') {
        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
                      << "'$' can only appear at the end.";
        is_valid = false;
      } else if (IsInSet(ch, "()[]{}|")) {
        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
                      << "'" << ch << "' is unsupported.";
        is_valid = false;
      } else if (IsRepeat(ch) && !prev_repeatable) {
        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
                      << "'" << ch << "' can only follow a repeatable token.";
        is_valid = false;
      }

      prev_repeatable = !IsInSet(ch, "^$?*+");
    }
  }

  return is_valid;
}

// Matches a repeated regex atom followed by a valid simple regular
// expression.  The regex atom is defined as c if escaped is false,
// or \c otherwise.  repeat is the repetition meta character (?, *,
// or +).  The behavior is undefined if str contains too many
// characters to be indexable by size_t, in which case the test will
// probably time out anyway.  We are fine with this limitation as
// std::string has it too.
bool MatchRepetitionAndRegexAtHead(
    bool escaped, char c, char repeat, const char* regex,
    const char* str) {
  const size_t min_count = (repeat == '+') ? 1 : 0;
  const size_t max_count = (repeat == '?') ? 1 :
      static_cast<size_t>(-1) - 1;
  // We cannot call numeric_limits::max() as it conflicts with the
  // max() macro on Windows.

  for (size_t i = 0; i <= max_count; ++i) {
    // We know that the atom matches each of the first i characters in str.
    if (i >= min_count && MatchRegexAtHead(regex, str + i)) {
      // We have enough matches at the head, and the tail matches too.
      // Since we only care about *whether* the pattern matches str
      // (as opposed to *how* it matches), there is no need to find a
      // greedy match.
      return true;
    }
    if (str[i] == '\0' || !AtomMatchesChar(escaped, c, str[i]))
      return false;
  }
  return false;
}

// Returns true iff regex matches a prefix of str.  regex must be a
// valid simple regular expression and not start with "^", or the
// result is undefined.
bool MatchRegexAtHead(const char* regex, const char* str) {
  if (*regex == '\0')  // An empty regex matches a prefix of anything.
    return true;

  // "$" only matches the end of a string.  Note that regex being
  // valid guarantees that there's nothing after "$" in it.
  if (*regex == '$')
    return *str == '\0';

  // Is the first thing in regex an escape sequence?
  const bool escaped = *regex == '\\';
  if (escaped)
    ++regex;
  if (IsRepeat(regex[1])) {
    // MatchRepetitionAndRegexAtHead() calls MatchRegexAtHead(), so
    // here's an indirect recursion.  It terminates as the regex gets
    // shorter in each recursion.
    return MatchRepetitionAndRegexAtHead(
        escaped, regex[0], regex[1], regex + 2, str);
  } else {
    // regex isn't empty, isn't "$", and doesn't start with a
    // repetition.  We match the first atom of regex with the first
    // character of str and recurse.
    return (*str != '\0') && AtomMatchesChar(escaped, *regex, *str) &&
        MatchRegexAtHead(regex + 1, str + 1);
  }
}

// Returns true iff regex matches any substring of str.  regex must be
// a valid simple regular expression, or the result is undefined.
//
// The algorithm is recursive, but the recursion depth doesn't exceed
// the regex length, so we won't need to worry about running out of
// stack space normally.  In rare cases the time complexity can be
// exponential with respect to the regex length + the string length,
// but usually it's must faster (often close to linear).
bool MatchRegexAnywhere(const char* regex, const char* str) {
  if (regex == nullptr || str == nullptr) return false;

  if (*regex == '^')
    return MatchRegexAtHead(regex + 1, str);

  // A successful match can be anywhere in str.
  do {
    if (MatchRegexAtHead(regex, str))
      return true;
  } while (*str++ != '\0');
  return false;
}

// Implements the RE class.

RE::~RE() {
  free(const_cast<char*>(pattern_));
  free(const_cast<char*>(full_pattern_));
}

// Returns true iff regular expression re matches the entire str.
bool RE::FullMatch(const char* str, const RE& re) {
  return re.is_valid_ && MatchRegexAnywhere(re.full_pattern_, str);
}

// Returns true iff regular expression re matches a substring of str
// (including str itself).
bool RE::PartialMatch(const char* str, const RE& re) {
  return re.is_valid_ && MatchRegexAnywhere(re.pattern_, str);
}

// Initializes an RE from its string representation.
void RE::Init(const char* regex) {
  pattern_ = full_pattern_ = nullptr;
  if (regex != nullptr) {
    pattern_ = posix::StrDup(regex);
  }

  is_valid_ = ValidateRegex(regex);
  if (!is_valid_) {
    // No need to calculate the full pattern when the regex is invalid.
    return;
  }

  const size_t len = strlen(regex);
  // Reserves enough bytes to hold the regular expression used for a
  // full match: we need space to prepend a '^', append a '$', and
  // terminate the string with '\0'.
  char* buffer = static_cast<char*>(malloc(len + 3));
  full_pattern_ = buffer;

  if (*regex != '^')
    *buffer++ = '^';  // Makes sure full_pattern_ starts with '^'.

  // We don't use snprintf or strncpy, as they trigger a warning when
  // compiled with VC++ 8.0.
  memcpy(buffer, regex, len);
  buffer += len;

  if (len == 0 || regex[len - 1] != '$')
    *buffer++ = '$';  // Makes sure full_pattern_ ends with '$'.

  *buffer = '\0';
}

#endif  // GTEST_USES_POSIX_RE

const char kUnknownFile[] = "unknown file";

// Formats a source file path and a line number as they would appear
// in an error message from the compiler used to compile this code.
GTEST_API_ ::std::string FormatFileLocation(const char* file, int line) {
  const std::string file_name(file == nullptr ? kUnknownFile : file);

  if (line < 0) {
    return file_name + ":";
  }
#ifdef _MSC_VER
  return file_name + "(" + StreamableToString(line) + "):";
#else
  return file_name + ":" + StreamableToString(line) + ":";
#endif  // _MSC_VER
}

// Formats a file location for compiler-independent XML output.
// Although this function is not platform dependent, we put it next to
// FormatFileLocation in order to contrast the two functions.
// Note that FormatCompilerIndependentFileLocation() does NOT append colon
// to the file location it produces, unlike FormatFileLocation().
GTEST_API_ ::std::string FormatCompilerIndependentFileLocation(
    const char* file, int line) {
  const std::string file_name(file == nullptr ? kUnknownFile : file);

  if (line < 0)
    return file_name;
  else
    return file_name + ":" + StreamableToString(line);
}

GTestLog::GTestLog(GTestLogSeverity severity, const char* file, int line)
    : severity_(severity) {
  const char* const marker =
      severity == GTEST_INFO ?    "[  INFO ]" :
      severity == GTEST_WARNING ? "[WARNING]" :
      severity == GTEST_ERROR ?   "[ ERROR ]" : "[ FATAL ]";
  GetStream() << ::std::endl << marker << " "
              << FormatFileLocation(file, line).c_str() << ": ";
}

// Flushes the buffers and, if severity is GTEST_FATAL, aborts the program.
GTestLog::~GTestLog() {
  GetStream() << ::std::endl;
  if (severity_ == GTEST_FATAL) {
    fflush(stderr);
    posix::Abort();
  }
}

// Disable Microsoft deprecation warnings for POSIX functions called from
// this class (creat, dup, dup2, and close)
GTEST_DISABLE_MSC_DEPRECATED_PUSH_()

#if GTEST_HAS_STREAM_REDIRECTION

// Object that captures an output stream (stdout/stderr).
class CapturedStream {
 public:
  // The ctor redirects the stream to a temporary file.
  explicit CapturedStream(int fd) : fd_(fd), uncaptured_fd_(dup(fd)) {
# if GTEST_OS_WINDOWS
    char temp_dir_path[MAX_PATH + 1] = { '\0' };  // NOLINT
    char temp_file_path[MAX_PATH + 1] = { '\0' };  // NOLINT

    ::GetTempPathA(sizeof(temp_dir_path), temp_dir_path);
    const UINT success = ::GetTempFileNameA(temp_dir_path,
                                            "gtest_redir",
                                            0,  // Generate unique file name.
                                            temp_file_path);
    GTEST_CHECK_(success != 0)
        << "Unable to create a temporary file in " << temp_dir_path;
    const int captured_fd = creat(temp_file_path, _S_IREAD | _S_IWRITE);
    GTEST_CHECK_(captured_fd != -1) << "Unable to open temporary file "
                                    << temp_file_path;
    filename_ = temp_file_path;
# else
    // There's no guarantee that a test has write access to the current
    // directory, so we create the temporary file in the /tmp directory
    // instead. We use /tmp on most systems, and /sdcard on Android.
    // That's because Android doesn't have /tmp.
#  if GTEST_OS_LINUX_ANDROID
    // Note: Android applications are expected to call the framework's
    // Context.getExternalStorageDirectory() method through JNI to get
    // the location of the world-writable SD Card directory. However,
    // this requires a Context handle, which cannot be retrieved
    // globally from native code. Doing so also precludes running the
    // code as part of a regular standalone executable, which doesn't
    // run in a Dalvik process (e.g. when running it through 'adb shell').
    //
    // The location /sdcard is directly accessible from native code
    // and is the only location (unofficially) supported by the Android
    // team. It's generally a symlink to the real SD Card mount point
    // which can be /mnt/sdcard, /mnt/sdcard0, /system/media/sdcard, or
    // other OEM-customized locations. Never rely on these, and always
    // use /sdcard.
    char name_template[] = "/sdcard/gtest_captured_stream.XXXXXX";
#  else
    char name_template[] = "/tmp/captured_stream.XXXXXX";
#  endif  // GTEST_OS_LINUX_ANDROID
    const int captured_fd = mkstemp(name_template);
    filename_ = name_template;
# endif  // GTEST_OS_WINDOWS
    fflush(nullptr);
    dup2(captured_fd, fd_);
    close(captured_fd);
  }

  ~CapturedStream() {
    remove(filename_.c_str());
  }

  std::string GetCapturedString() {
    if (uncaptured_fd_ != -1) {
      // Restores the original stream.
      fflush(nullptr);
      dup2(uncaptured_fd_, fd_);
      close(uncaptured_fd_);
      uncaptured_fd_ = -1;
    }

    FILE* const file = posix::FOpen(filename_.c_str(), "r");
    const std::string content = ReadEntireFile(file);
    posix::FClose(file);
    return content;
  }

 private:
  const int fd_;  // A stream to capture.
  int uncaptured_fd_;
  // Name of the temporary file holding the stderr output.
  ::std::string filename_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(CapturedStream);
};

GTEST_DISABLE_MSC_DEPRECATED_POP_()

static CapturedStream* g_captured_stderr = nullptr;
static CapturedStream* g_captured_stdout = nullptr;

// Starts capturing an output stream (stdout/stderr).
static void CaptureStream(int fd, const char* stream_name,
                          CapturedStream** stream) {
  if (*stream != nullptr) {
    GTEST_LOG_(FATAL) << "Only one " << stream_name
                      << " capturer can exist at a time.";
  }
  *stream = new CapturedStream(fd);
}

// Stops capturing the output stream and returns the captured string.
static std::string GetCapturedStream(CapturedStream** captured_stream) {
  const std::string content = (*captured_stream)->GetCapturedString();

  delete *captured_stream;
  *captured_stream = nullptr;

  return content;
}

// Starts capturing stdout.
void CaptureStdout() {
  CaptureStream(kStdOutFileno, "stdout", &g_captured_stdout);
}

// Starts capturing stderr.
void CaptureStderr() {
  CaptureStream(kStdErrFileno, "stderr", &g_captured_stderr);
}

// Stops capturing stdout and returns the captured string.
std::string GetCapturedStdout() {
  return GetCapturedStream(&g_captured_stdout);
}

// Stops capturing stderr and returns the captured string.
std::string GetCapturedStderr() {
  return GetCapturedStream(&g_captured_stderr);
}

#endif  // GTEST_HAS_STREAM_REDIRECTION





size_t GetFileSize(FILE* file) {
  fseek(file, 0, SEEK_END);
  return static_cast<size_t>(ftell(file));
}

std::string ReadEntireFile(FILE* file) {
  const size_t file_size = GetFileSize(file);
  char* const buffer = new char[file_size];

  size_t bytes_last_read = 0;  // # of bytes read in the last fread()
  size_t bytes_read = 0;       // # of bytes read so far

  fseek(file, 0, SEEK_SET);

  // Keeps reading the file until we cannot read further or the
  // pre-determined file size is reached.
  do {
    bytes_last_read = fread(buffer+bytes_read, 1, file_size-bytes_read, file);
    bytes_read += bytes_last_read;
  } while (bytes_last_read > 0 && bytes_read < file_size);

  const std::string content(buffer, bytes_read);
  delete[] buffer;

  return content;
}

#if GTEST_HAS_DEATH_TEST
static const std::vector<std::string>* g_injected_test_argvs =
    nullptr;  // Owned.

std::vector<std::string> GetInjectableArgvs() {
  if (g_injected_test_argvs != nullptr) {
    return *g_injected_test_argvs;
  }
  return GetArgvs();
}

void SetInjectableArgvs(const std::vector<std::string>* new_argvs) {
  if (g_injected_test_argvs != new_argvs) delete g_injected_test_argvs;
  g_injected_test_argvs = new_argvs;
}

void SetInjectableArgvs(const std::vector<std::string>& new_argvs) {
  SetInjectableArgvs(
      new std::vector<std::string>(new_argvs.begin(), new_argvs.end()));
}

#if GTEST_HAS_GLOBAL_STRING
void SetInjectableArgvs(const std::vector< ::string>& new_argvs) {
  SetInjectableArgvs(
      new std::vector<std::string>(new_argvs.begin(), new_argvs.end()));
}
#endif  // GTEST_HAS_GLOBAL_STRING

void ClearInjectableArgvs() {
  delete g_injected_test_argvs;
  g_injected_test_argvs = nullptr;
}
#endif  // GTEST_HAS_DEATH_TEST

#if GTEST_OS_WINDOWS_MOBILE
namespace posix {
void Abort() {
  DebugBreak();
  TerminateProcess(GetCurrentProcess(), 1);
}
}  // namespace posix
#endif  // GTEST_OS_WINDOWS_MOBILE

// Returns the name of the environment variable corresponding to the
// given flag.  For example, FlagToEnvVar("foo") will return
// "GTEST_FOO" in the open-source version.
static std::string FlagToEnvVar(const char* flag) {
  const std::string full_flag =
      (Message() << GTEST_FLAG_PREFIX_ << flag).GetString();

  Message env_var;
  for (size_t i = 0; i != full_flag.length(); i++) {
    env_var << ToUpper(full_flag.c_str()[i]);
  }

  return env_var.GetString();
}

// Parses 'str' for a 32-bit signed integer.  If successful, writes
// the result to *value and returns true; otherwise leaves *value
// unchanged and returns false.
bool ParseInt32(const Message& src_text, const char* str, Int32* value) {
  // Parses the environment variable as a decimal integer.
  char* end = nullptr;
  const long long_value = strtol(str, &end, 10);  // NOLINT

  // Has strtol() consumed all characters in the string?
  if (*end != '\0') {
    // No - an invalid character was encountered.
    Message msg;
    msg << "WARNING: " << src_text
        << " is expected to be a 32-bit integer, but actually"
        << " has value \"" << str << "\".\n";
    printf("%s", msg.GetString().c_str());
    fflush(stdout);
    return false;
  }

  // Is the parsed value in the range of an Int32?
  const Int32 result = static_cast<Int32>(long_value);
  if (long_value == LONG_MAX || long_value == LONG_MIN ||
      // The parsed value overflows as a long.  (strtol() returns
      // LONG_MAX or LONG_MIN when the input overflows.)
      result != long_value
      // The parsed value overflows as an Int32.
      ) {
    Message msg;
    msg << "WARNING: " << src_text
        << " is expected to be a 32-bit integer, but actually"
        << " has value " << str << ", which overflows.\n";
    printf("%s", msg.GetString().c_str());
    fflush(stdout);
    return false;
  }

  *value = result;
  return true;
}

// Reads and returns the Boolean environment variable corresponding to
// the given flag; if it's not set, returns default_value.
//
// The value is considered true iff it's not "0".
bool BoolFromGTestEnv(const char* flag, bool default_value) {
#if defined(GTEST_GET_BOOL_FROM_ENV_)
  return GTEST_GET_BOOL_FROM_ENV_(flag, default_value);
#else
  const std::string env_var = FlagToEnvVar(flag);
  const char* const string_value = posix::GetEnv(env_var.c_str());
  return string_value == nullptr ? default_value
                                 : strcmp(string_value, "0") != 0;
#endif  // defined(GTEST_GET_BOOL_FROM_ENV_)
}

// Reads and returns a 32-bit integer stored in the environment
// variable corresponding to the given flag; if it isn't set or
// doesn't represent a valid 32-bit integer, returns default_value.
Int32 Int32FromGTestEnv(const char* flag, Int32 default_value) {
#if defined(GTEST_GET_INT32_FROM_ENV_)
  return GTEST_GET_INT32_FROM_ENV_(flag, default_value);
#else
  const std::string env_var = FlagToEnvVar(flag);
  const char* const string_value = posix::GetEnv(env_var.c_str());
  if (string_value == nullptr) {
    // The environment variable is not set.
    return default_value;
  }

  Int32 result = default_value;
  if (!ParseInt32(Message() << "Environment variable " << env_var,
                  string_value, &result)) {
    printf("The default value %s is used.\n",
           (Message() << default_value).GetString().c_str());
    fflush(stdout);
    return default_value;
  }

  return result;
#endif  // defined(GTEST_GET_INT32_FROM_ENV_)
}

// As a special case for the 'output' flag, if GTEST_OUTPUT is not
// set, we look for XML_OUTPUT_FILE, which is set by the Bazel build
// system.  The value of XML_OUTPUT_FILE is a filename without the
// "xml:" prefix of GTEST_OUTPUT.
// Note that this is meant to be called at the call site so it does
// not check that the flag is 'output'
// In essence this checks an env variable called XML_OUTPUT_FILE
// and if it is set we prepend "xml:" to its value, if it not set we return ""
std::string OutputFlagAlsoCheckEnvVar(){
  std::string default_value_for_output_flag = "";
  const char* xml_output_file_env = posix::GetEnv("XML_OUTPUT_FILE");
  if (nullptr != xml_output_file_env) {
    default_value_for_output_flag = std::string("xml:") + xml_output_file_env;
  }
  return default_value_for_output_flag;
}

// Reads and returns the string environment variable corresponding to
// the given flag; if it's not set, returns default_value.
const char* StringFromGTestEnv(const char* flag, const char* default_value) {
#if defined(GTEST_GET_STRING_FROM_ENV_)
  return GTEST_GET_STRING_FROM_ENV_(flag, default_value);
#else
  const std::string env_var = FlagToEnvVar(flag);
  const char* const value = posix::GetEnv(env_var.c_str());
  return value == nullptr ? default_value : value;
#endif  // defined(GTEST_GET_STRING_FROM_ENV_)
}

}  // namespace internal
}  // namespace testing