1//===-- tsan_rtl.cc -------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is a part of ThreadSanitizer (TSan), a race detector.
11//
12// Main file (entry points) for the TSan run-time.
13//===----------------------------------------------------------------------===//
14
15#include "sanitizer_common/sanitizer_atomic.h"
16#include "sanitizer_common/sanitizer_common.h"
17#include "sanitizer_common/sanitizer_libc.h"
18#include "sanitizer_common/sanitizer_stackdepot.h"
19#include "sanitizer_common/sanitizer_placement_new.h"
20#include "sanitizer_common/sanitizer_symbolizer.h"
21#include "tsan_defs.h"
22#include "tsan_platform.h"
23#include "tsan_rtl.h"
24#include "tsan_mman.h"
25#include "tsan_suppressions.h"
26
27volatile int __tsan_resumed = 0;
28
29extern "C" void __tsan_resume() {
30  __tsan_resumed = 1;
31}
32
33namespace __tsan {
34
35#ifndef TSAN_GO
36THREADLOCAL char cur_thread_placeholder[sizeof(ThreadState)] ALIGNED(64);
37#endif
38static char ctx_placeholder[sizeof(Context)] ALIGNED(64);
39
40// Can be overriden by a front-end.
41bool CPP_WEAK OnFinalize(bool failed) {
42  return failed;
43}
44
45static Context *ctx;
46Context *CTX() {
47  return ctx;
48}
49
50static char thread_registry_placeholder[sizeof(ThreadRegistry)];
51
52static ThreadContextBase *CreateThreadContext(u32 tid) {
53  // Map thread trace when context is created.
54  MapThreadTrace(GetThreadTrace(tid), TraceSize() * sizeof(Event));
55  void *mem = MmapOrDie(sizeof(ThreadContext), "ThreadContext");
56  return new(mem) ThreadContext(tid);
57}
58
59#ifndef TSAN_GO
60static const u32 kThreadQuarantineSize = 16;
61#else
62static const u32 kThreadQuarantineSize = 64;
63#endif
64
65Context::Context()
66  : initialized()
67  , report_mtx(MutexTypeReport, StatMtxReport)
68  , nreported()
69  , nmissed_expected()
70  , thread_registry(new(thread_registry_placeholder) ThreadRegistry(
71      CreateThreadContext, kMaxTid, kThreadQuarantineSize))
72  , racy_stacks(MBlockRacyStacks)
73  , racy_addresses(MBlockRacyAddresses)
74  , fired_suppressions(MBlockRacyAddresses) {
75}
76
77// The objects are allocated in TLS, so one may rely on zero-initialization.
78ThreadState::ThreadState(Context *ctx, int tid, int unique_id, u64 epoch,
79                         uptr stk_addr, uptr stk_size,
80                         uptr tls_addr, uptr tls_size)
81  : fast_state(tid, epoch)
82  // Do not touch these, rely on zero initialization,
83  // they may be accessed before the ctor.
84  // , fast_ignore_reads()
85  // , fast_ignore_writes()
86  // , in_rtl()
87  , shadow_stack_pos(&shadow_stack[0])
88  , tid(tid)
89  , unique_id(unique_id)
90  , stk_addr(stk_addr)
91  , stk_size(stk_size)
92  , tls_addr(tls_addr)
93  , tls_size(tls_size) {
94}
95
96static void MemoryProfileThread(void *arg) {
97  ScopedInRtl in_rtl;
98  fd_t fd = (fd_t)(uptr)arg;
99  Context *ctx = CTX();
100  for (int i = 0; ; i++) {
101    InternalScopedBuffer<char> buf(4096);
102    uptr n_threads;
103    uptr n_running_threads;
104    ctx->thread_registry->GetNumberOfThreads(&n_threads, &n_running_threads);
105    internal_snprintf(buf.data(), buf.size(), "%d: nthr=%d nlive=%d\n",
106        i, n_threads, n_running_threads);
107    internal_write(fd, buf.data(), internal_strlen(buf.data()));
108    WriteMemoryProfile(buf.data(), buf.size());
109    internal_write(fd, buf.data(), internal_strlen(buf.data()));
110    SleepForSeconds(1);
111  }
112}
113
114static void InitializeMemoryProfile() {
115  if (flags()->profile_memory == 0 || flags()->profile_memory[0] == 0)
116    return;
117  InternalScopedBuffer<char> filename(4096);
118  internal_snprintf(filename.data(), filename.size(), "%s.%d",
119      flags()->profile_memory, GetPid());
120  fd_t fd = OpenFile(filename.data(), true);
121  if (fd == kInvalidFd) {
122    Printf("Failed to open memory profile file '%s'\n", &filename[0]);
123    Die();
124  }
125  internal_start_thread(&MemoryProfileThread, (void*)(uptr)fd);
126}
127
128void DontNeedShadowFor(uptr addr, uptr size) {
129  uptr shadow_beg = MemToShadow(addr);
130  uptr shadow_end = MemToShadow(addr + size);
131  FlushUnneededShadowMemory(shadow_beg, shadow_end - shadow_beg);
132}
133
134static void MemoryFlushThread(void *arg) {
135  ScopedInRtl in_rtl;
136  for (int i = 0; ; i++) {
137    SleepForMillis(flags()->flush_memory_ms);
138    FlushShadowMemory();
139  }
140}
141
142static void InitializeMemoryFlush() {
143  if (flags()->flush_memory_ms == 0)
144    return;
145  if (flags()->flush_memory_ms < 100)
146    flags()->flush_memory_ms = 100;
147  internal_start_thread(&MemoryFlushThread, 0);
148}
149
150void MapShadow(uptr addr, uptr size) {
151  MmapFixedNoReserve(MemToShadow(addr), size * kShadowMultiplier);
152}
153
154void MapThreadTrace(uptr addr, uptr size) {
155  DPrintf("#0: Mapping trace at %p-%p(0x%zx)\n", addr, addr + size, size);
156  CHECK_GE(addr, kTraceMemBegin);
157  CHECK_LE(addr + size, kTraceMemBegin + kTraceMemSize);
158  if (addr != (uptr)MmapFixedNoReserve(addr, size)) {
159    Printf("FATAL: ThreadSanitizer can not mmap thread trace\n");
160    Die();
161  }
162}
163
164void Initialize(ThreadState *thr) {
165  // Thread safe because done before all threads exist.
166  static bool is_initialized = false;
167  if (is_initialized)
168    return;
169  is_initialized = true;
170  SanitizerToolName = "ThreadSanitizer";
171  // Install tool-specific callbacks in sanitizer_common.
172  SetCheckFailedCallback(TsanCheckFailed);
173
174  ScopedInRtl in_rtl;
175#ifndef TSAN_GO
176  InitializeAllocator();
177#endif
178  InitializeInterceptors();
179  const char *env = InitializePlatform();
180  InitializeMutex();
181  InitializeDynamicAnnotations();
182  ctx = new(ctx_placeholder) Context;
183#ifndef TSAN_GO
184  InitializeShadowMemory();
185#endif
186  InitializeFlags(&ctx->flags, env);
187  // Setup correct file descriptor for error reports.
188  if (internal_strcmp(flags()->log_path, "stdout") == 0)
189    __sanitizer_set_report_fd(kStdoutFd);
190  else if (internal_strcmp(flags()->log_path, "stderr") == 0)
191    __sanitizer_set_report_fd(kStderrFd);
192  else
193    __sanitizer_set_report_path(flags()->log_path);
194  InitializeSuppressions();
195#ifndef TSAN_GO
196  // Initialize external symbolizer before internal threads are started.
197  const char *external_symbolizer = flags()->external_symbolizer_path;
198  if (external_symbolizer != 0 && external_symbolizer[0] != '\0') {
199    if (!InitializeExternalSymbolizer(external_symbolizer)) {
200      Printf("Failed to start external symbolizer: '%s'\n",
201             external_symbolizer);
202      Die();
203    }
204  }
205#endif
206  InitializeMemoryProfile();
207  InitializeMemoryFlush();
208
209  if (ctx->flags.verbosity)
210    Printf("***** Running under ThreadSanitizer v2 (pid %d) *****\n",
211               GetPid());
212
213  // Initialize thread 0.
214  int tid = ThreadCreate(thr, 0, 0, true);
215  CHECK_EQ(tid, 0);
216  ThreadStart(thr, tid, GetPid());
217  CHECK_EQ(thr->in_rtl, 1);
218  ctx->initialized = true;
219
220  if (flags()->stop_on_start) {
221    Printf("ThreadSanitizer is suspended at startup (pid %d)."
222           " Call __tsan_resume().\n",
223           GetPid());
224    while (__tsan_resumed == 0) {}
225  }
226}
227
228int Finalize(ThreadState *thr) {
229  ScopedInRtl in_rtl;
230  Context *ctx = __tsan::ctx;
231  bool failed = false;
232
233  if (flags()->atexit_sleep_ms > 0 && ThreadCount(thr) > 1)
234    SleepForMillis(flags()->atexit_sleep_ms);
235
236  // Wait for pending reports.
237  ctx->report_mtx.Lock();
238  ctx->report_mtx.Unlock();
239
240#ifndef TSAN_GO
241  if (ctx->flags.verbosity)
242    AllocatorPrintStats();
243#endif
244
245  ThreadFinalize(thr);
246
247  if (ctx->nreported) {
248    failed = true;
249#ifndef TSAN_GO
250    Printf("ThreadSanitizer: reported %d warnings\n", ctx->nreported);
251#else
252    Printf("Found %d data race(s)\n", ctx->nreported);
253#endif
254  }
255
256  if (ctx->nmissed_expected) {
257    failed = true;
258    Printf("ThreadSanitizer: missed %d expected races\n",
259        ctx->nmissed_expected);
260  }
261
262  failed = OnFinalize(failed);
263
264  StatAggregate(ctx->stat, thr->stat);
265  StatOutput(ctx->stat);
266  return failed ? flags()->exitcode : 0;
267}
268
269#ifndef TSAN_GO
270u32 CurrentStackId(ThreadState *thr, uptr pc) {
271  if (thr->shadow_stack_pos == 0)  // May happen during bootstrap.
272    return 0;
273  if (pc) {
274    thr->shadow_stack_pos[0] = pc;
275    thr->shadow_stack_pos++;
276  }
277  u32 id = StackDepotPut(thr->shadow_stack,
278                         thr->shadow_stack_pos - thr->shadow_stack);
279  if (pc)
280    thr->shadow_stack_pos--;
281  return id;
282}
283#endif
284
285void TraceSwitch(ThreadState *thr) {
286  thr->nomalloc++;
287  ScopedInRtl in_rtl;
288  Lock l(&thr->trace.mtx);
289  unsigned trace = (thr->fast_state.epoch() / kTracePartSize) % TraceParts();
290  TraceHeader *hdr = &thr->trace.headers[trace];
291  hdr->epoch0 = thr->fast_state.epoch();
292  hdr->stack0.ObtainCurrent(thr, 0);
293  hdr->mset0 = thr->mset;
294  thr->nomalloc--;
295}
296
297uptr TraceTopPC(ThreadState *thr) {
298  Event *events = (Event*)GetThreadTrace(thr->tid);
299  uptr pc = events[thr->fast_state.GetTracePos()];
300  return pc;
301}
302
303uptr TraceSize() {
304  return (uptr)(1ull << (kTracePartSizeBits + flags()->history_size + 1));
305}
306
307uptr TraceParts() {
308  return TraceSize() / kTracePartSize;
309}
310
311#ifndef TSAN_GO
312extern "C" void __tsan_trace_switch() {
313  TraceSwitch(cur_thread());
314}
315
316extern "C" void __tsan_report_race() {
317  ReportRace(cur_thread());
318}
319#endif
320
321ALWAYS_INLINE
322static Shadow LoadShadow(u64 *p) {
323  u64 raw = atomic_load((atomic_uint64_t*)p, memory_order_relaxed);
324  return Shadow(raw);
325}
326
327ALWAYS_INLINE
328static void StoreShadow(u64 *sp, u64 s) {
329  atomic_store((atomic_uint64_t*)sp, s, memory_order_relaxed);
330}
331
332ALWAYS_INLINE
333static void StoreIfNotYetStored(u64 *sp, u64 *s) {
334  StoreShadow(sp, *s);
335  *s = 0;
336}
337
338static inline void HandleRace(ThreadState *thr, u64 *shadow_mem,
339                              Shadow cur, Shadow old) {
340  thr->racy_state[0] = cur.raw();
341  thr->racy_state[1] = old.raw();
342  thr->racy_shadow_addr = shadow_mem;
343#ifndef TSAN_GO
344  HACKY_CALL(__tsan_report_race);
345#else
346  ReportRace(thr);
347#endif
348}
349
350static inline bool OldIsInSameSynchEpoch(Shadow old, ThreadState *thr) {
351  return old.epoch() >= thr->fast_synch_epoch;
352}
353
354static inline bool HappensBefore(Shadow old, ThreadState *thr) {
355  return thr->clock.get(old.TidWithIgnore()) >= old.epoch();
356}
357
358ALWAYS_INLINE
359void MemoryAccessImpl(ThreadState *thr, uptr addr,
360    int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic,
361    u64 *shadow_mem, Shadow cur) {
362  StatInc(thr, StatMop);
363  StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
364  StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
365
366  // This potentially can live in an MMX/SSE scratch register.
367  // The required intrinsics are:
368  // __m128i _mm_move_epi64(__m128i*);
369  // _mm_storel_epi64(u64*, __m128i);
370  u64 store_word = cur.raw();
371
372  // scan all the shadow values and dispatch to 4 categories:
373  // same, replace, candidate and race (see comments below).
374  // we consider only 3 cases regarding access sizes:
375  // equal, intersect and not intersect. initially I considered
376  // larger and smaller as well, it allowed to replace some
377  // 'candidates' with 'same' or 'replace', but I think
378  // it's just not worth it (performance- and complexity-wise).
379
380  Shadow old(0);
381  if (kShadowCnt == 1) {
382    int idx = 0;
383#include "tsan_update_shadow_word_inl.h"
384  } else if (kShadowCnt == 2) {
385    int idx = 0;
386#include "tsan_update_shadow_word_inl.h"
387    idx = 1;
388#include "tsan_update_shadow_word_inl.h"
389  } else if (kShadowCnt == 4) {
390    int idx = 0;
391#include "tsan_update_shadow_word_inl.h"
392    idx = 1;
393#include "tsan_update_shadow_word_inl.h"
394    idx = 2;
395#include "tsan_update_shadow_word_inl.h"
396    idx = 3;
397#include "tsan_update_shadow_word_inl.h"
398  } else if (kShadowCnt == 8) {
399    int idx = 0;
400#include "tsan_update_shadow_word_inl.h"
401    idx = 1;
402#include "tsan_update_shadow_word_inl.h"
403    idx = 2;
404#include "tsan_update_shadow_word_inl.h"
405    idx = 3;
406#include "tsan_update_shadow_word_inl.h"
407    idx = 4;
408#include "tsan_update_shadow_word_inl.h"
409    idx = 5;
410#include "tsan_update_shadow_word_inl.h"
411    idx = 6;
412#include "tsan_update_shadow_word_inl.h"
413    idx = 7;
414#include "tsan_update_shadow_word_inl.h"
415  } else {
416    CHECK(false);
417  }
418
419  // we did not find any races and had already stored
420  // the current access info, so we are done
421  if (LIKELY(store_word == 0))
422    return;
423  // choose a random candidate slot and replace it
424  StoreShadow(shadow_mem + (cur.epoch() % kShadowCnt), store_word);
425  StatInc(thr, StatShadowReplace);
426  return;
427 RACE:
428  HandleRace(thr, shadow_mem, cur, old);
429  return;
430}
431
432ALWAYS_INLINE
433void MemoryAccess(ThreadState *thr, uptr pc, uptr addr,
434    int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic) {
435  u64 *shadow_mem = (u64*)MemToShadow(addr);
436  DPrintf2("#%d: MemoryAccess: @%p %p size=%d"
437      " is_write=%d shadow_mem=%p {%zx, %zx, %zx, %zx}\n",
438      (int)thr->fast_state.tid(), (void*)pc, (void*)addr,
439      (int)(1 << kAccessSizeLog), kAccessIsWrite, shadow_mem,
440      (uptr)shadow_mem[0], (uptr)shadow_mem[1],
441      (uptr)shadow_mem[2], (uptr)shadow_mem[3]);
442#if TSAN_DEBUG
443  if (!IsAppMem(addr)) {
444    Printf("Access to non app mem %zx\n", addr);
445    DCHECK(IsAppMem(addr));
446  }
447  if (!IsShadowMem((uptr)shadow_mem)) {
448    Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
449    DCHECK(IsShadowMem((uptr)shadow_mem));
450  }
451#endif
452
453  FastState fast_state = thr->fast_state;
454  if (fast_state.GetIgnoreBit())
455    return;
456  fast_state.IncrementEpoch();
457  thr->fast_state = fast_state;
458  Shadow cur(fast_state);
459  cur.SetAddr0AndSizeLog(addr & 7, kAccessSizeLog);
460  cur.SetWrite(kAccessIsWrite);
461  cur.SetAtomic(kIsAtomic);
462
463  // We must not store to the trace if we do not store to the shadow.
464  // That is, this call must be moved somewhere below.
465  TraceAddEvent(thr, fast_state, EventTypeMop, pc);
466
467  MemoryAccessImpl(thr, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic,
468      shadow_mem, cur);
469}
470
471static void MemoryRangeSet(ThreadState *thr, uptr pc, uptr addr, uptr size,
472                           u64 val) {
473  (void)thr;
474  (void)pc;
475  if (size == 0)
476    return;
477  // FIXME: fix me.
478  uptr offset = addr % kShadowCell;
479  if (offset) {
480    offset = kShadowCell - offset;
481    if (size <= offset)
482      return;
483    addr += offset;
484    size -= offset;
485  }
486  DCHECK_EQ(addr % 8, 0);
487  // If a user passes some insane arguments (memset(0)),
488  // let it just crash as usual.
489  if (!IsAppMem(addr) || !IsAppMem(addr + size - 1))
490    return;
491  // Don't want to touch lots of shadow memory.
492  // If a program maps 10MB stack, there is no need reset the whole range.
493  size = (size + (kShadowCell - 1)) & ~(kShadowCell - 1);
494  if (size < 64*1024) {
495    u64 *p = (u64*)MemToShadow(addr);
496    CHECK(IsShadowMem((uptr)p));
497    CHECK(IsShadowMem((uptr)(p + size * kShadowCnt / kShadowCell - 1)));
498    // FIXME: may overwrite a part outside the region
499    for (uptr i = 0; i < size / kShadowCell * kShadowCnt;) {
500      p[i++] = val;
501      for (uptr j = 1; j < kShadowCnt; j++)
502        p[i++] = 0;
503    }
504  } else {
505    // The region is big, reset only beginning and end.
506    const uptr kPageSize = 4096;
507    u64 *begin = (u64*)MemToShadow(addr);
508    u64 *end = begin + size / kShadowCell * kShadowCnt;
509    u64 *p = begin;
510    // Set at least first kPageSize/2 to page boundary.
511    while ((p < begin + kPageSize / kShadowSize / 2) || ((uptr)p % kPageSize)) {
512      *p++ = val;
513      for (uptr j = 1; j < kShadowCnt; j++)
514        *p++ = 0;
515    }
516    // Reset middle part.
517    u64 *p1 = p;
518    p = RoundDown(end, kPageSize);
519    UnmapOrDie((void*)p1, (uptr)p - (uptr)p1);
520    MmapFixedNoReserve((uptr)p1, (uptr)p - (uptr)p1);
521    // Set the ending.
522    while (p < end) {
523      *p++ = val;
524      for (uptr j = 1; j < kShadowCnt; j++)
525        *p++ = 0;
526    }
527  }
528}
529
530void MemoryResetRange(ThreadState *thr, uptr pc, uptr addr, uptr size) {
531  MemoryRangeSet(thr, pc, addr, size, 0);
532}
533
534void MemoryRangeFreed(ThreadState *thr, uptr pc, uptr addr, uptr size) {
535  // Processing more than 1k (4k of shadow) is expensive,
536  // can cause excessive memory consumption (user does not necessary touch
537  // the whole range) and most likely unnecessary.
538  if (size > 1024)
539    size = 1024;
540  CHECK_EQ(thr->is_freeing, false);
541  thr->is_freeing = true;
542  MemoryAccessRange(thr, pc, addr, size, true);
543  thr->is_freeing = false;
544  Shadow s(thr->fast_state);
545  s.ClearIgnoreBit();
546  s.MarkAsFreed();
547  s.SetWrite(true);
548  s.SetAddr0AndSizeLog(0, 3);
549  MemoryRangeSet(thr, pc, addr, size, s.raw());
550}
551
552void MemoryRangeImitateWrite(ThreadState *thr, uptr pc, uptr addr, uptr size) {
553  Shadow s(thr->fast_state);
554  s.ClearIgnoreBit();
555  s.SetWrite(true);
556  s.SetAddr0AndSizeLog(0, 3);
557  MemoryRangeSet(thr, pc, addr, size, s.raw());
558}
559
560ALWAYS_INLINE
561void FuncEntry(ThreadState *thr, uptr pc) {
562  DCHECK_EQ(thr->in_rtl, 0);
563  StatInc(thr, StatFuncEnter);
564  DPrintf2("#%d: FuncEntry %p\n", (int)thr->fast_state.tid(), (void*)pc);
565  thr->fast_state.IncrementEpoch();
566  TraceAddEvent(thr, thr->fast_state, EventTypeFuncEnter, pc);
567
568  // Shadow stack maintenance can be replaced with
569  // stack unwinding during trace switch (which presumably must be faster).
570  DCHECK_GE(thr->shadow_stack_pos, &thr->shadow_stack[0]);
571#ifndef TSAN_GO
572  DCHECK_LT(thr->shadow_stack_pos, &thr->shadow_stack[kShadowStackSize]);
573#else
574  if (thr->shadow_stack_pos == thr->shadow_stack_end) {
575    const int sz = thr->shadow_stack_end - thr->shadow_stack;
576    const int newsz = 2 * sz;
577    uptr *newstack = (uptr*)internal_alloc(MBlockShadowStack,
578        newsz * sizeof(uptr));
579    internal_memcpy(newstack, thr->shadow_stack, sz * sizeof(uptr));
580    internal_free(thr->shadow_stack);
581    thr->shadow_stack = newstack;
582    thr->shadow_stack_pos = newstack + sz;
583    thr->shadow_stack_end = newstack + newsz;
584  }
585#endif
586  thr->shadow_stack_pos[0] = pc;
587  thr->shadow_stack_pos++;
588}
589
590ALWAYS_INLINE
591void FuncExit(ThreadState *thr) {
592  DCHECK_EQ(thr->in_rtl, 0);
593  StatInc(thr, StatFuncExit);
594  DPrintf2("#%d: FuncExit\n", (int)thr->fast_state.tid());
595  thr->fast_state.IncrementEpoch();
596  TraceAddEvent(thr, thr->fast_state, EventTypeFuncExit, 0);
597
598  DCHECK_GT(thr->shadow_stack_pos, &thr->shadow_stack[0]);
599#ifndef TSAN_GO
600  DCHECK_LT(thr->shadow_stack_pos, &thr->shadow_stack[kShadowStackSize]);
601#endif
602  thr->shadow_stack_pos--;
603}
604
605void IgnoreCtl(ThreadState *thr, bool write, bool begin) {
606  DPrintf("#%d: IgnoreCtl(%d, %d)\n", thr->tid, write, begin);
607  thr->ignore_reads_and_writes += begin ? 1 : -1;
608  CHECK_GE(thr->ignore_reads_and_writes, 0);
609  if (thr->ignore_reads_and_writes)
610    thr->fast_state.SetIgnoreBit();
611  else
612    thr->fast_state.ClearIgnoreBit();
613}
614
615bool MD5Hash::operator==(const MD5Hash &other) const {
616  return hash[0] == other.hash[0] && hash[1] == other.hash[1];
617}
618
619#if TSAN_DEBUG
620void build_consistency_debug() {}
621#else
622void build_consistency_release() {}
623#endif
624
625#if TSAN_COLLECT_STATS
626void build_consistency_stats() {}
627#else
628void build_consistency_nostats() {}
629#endif
630
631#if TSAN_SHADOW_COUNT == 1
632void build_consistency_shadow1() {}
633#elif TSAN_SHADOW_COUNT == 2
634void build_consistency_shadow2() {}
635#elif TSAN_SHADOW_COUNT == 4
636void build_consistency_shadow4() {}
637#else
638void build_consistency_shadow8() {}
639#endif
640
641}  // namespace __tsan
642
643#ifndef TSAN_GO
644// Must be included in this file to make sure everything is inlined.
645#include "tsan_interface_inl.h"
646#endif
647