[Sanitizer] Make StackTrace a lightweight reference to array of PCs, and

introduce a BufferedStackTrace class, which owns this array.

Summary:
This change splits __sanitizer::StackTrace class into a lightweight
__sanitizer::StackTrace, which doesn't own array of PCs, and BufferedStackTrace,
which owns it. This would allow us to simplify the interface of StackDepot,
and eventually merge __sanitizer::StackTrace with __tsan::StackTrace.

Test Plan: regression test suite.

Reviewers: kcc, dvyukov

Reviewed By: dvyukov

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5985

llvm-svn: 220635

26 files changed, 241 insertions, 272 deletions

diff --git a/compiler-rt/lib/asan/asan_allocator.h b/compiler-rt/lib/asan/asan_allocator.h
index d4e3daa4e7b5..6d3a99282a4a 100644
--- a/compiler-rt/lib/asan/asan_allocator.h
+++ b/compiler-rt/lib/asan/asan_allocator.h
@@ -45,8 +45,8 @@ class AsanChunkView {
   uptr AllocTid();
   uptr FreeTid();
   bool Eq(const AsanChunkView &c) const { return chunk_ == c.chunk_; }
-  void GetAllocStack(StackTrace *stack);
-  void GetFreeStack(StackTrace *stack);
+  StackTrace GetAllocStack();
+  StackTrace GetFreeStack();
   bool AddrIsInside(uptr addr, uptr access_size, sptr *offset) {
     if (addr >= Beg() && (addr + access_size) <= End()) {
       *offset = addr - Beg();
@@ -139,20 +139,20 @@ struct AsanThreadLocalMallocStorage {
   AsanThreadLocalMallocStorage() {}
 };
 
-void *asan_memalign(uptr alignment, uptr size, StackTrace *stack,
+void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
                     AllocType alloc_type);
-void asan_free(void *ptr, StackTrace *stack, AllocType alloc_type);
-void asan_sized_free(void *ptr, uptr size, StackTrace *stack,
+void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type);
+void asan_sized_free(void *ptr, uptr size, BufferedStackTrace *stack,
                      AllocType alloc_type);
 
-void *asan_malloc(uptr size, StackTrace *stack);
-void *asan_calloc(uptr nmemb, uptr size, StackTrace *stack);
-void *asan_realloc(void *p, uptr size, StackTrace *stack);
-void *asan_valloc(uptr size, StackTrace *stack);
-void *asan_pvalloc(uptr size, StackTrace *stack);
+void *asan_malloc(uptr size, BufferedStackTrace *stack);
+void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack);
+void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack);
+void *asan_valloc(uptr size, BufferedStackTrace *stack);
+void *asan_pvalloc(uptr size, BufferedStackTrace *stack);
 
 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
-                          StackTrace *stack);
+                        BufferedStackTrace *stack);
 uptr asan_malloc_usable_size(void *ptr, uptr pc, uptr bp);
 
 uptr asan_mz_size(const void *ptr);
diff --git a/compiler-rt/lib/asan/asan_allocator2.cc b/compiler-rt/lib/asan/asan_allocator2.cc
index 27c25cfa5476..687d5ba3fc98 100644
--- a/compiler-rt/lib/asan/asan_allocator2.cc
+++ b/compiler-rt/lib/asan/asan_allocator2.cc
@@ -182,20 +182,19 @@ uptr AsanChunkView::UsedSize() { return chunk_->UsedSize(); }
 uptr AsanChunkView::AllocTid() { return chunk_->alloc_tid; }
 uptr AsanChunkView::FreeTid() { return chunk_->free_tid; }
 
-static void GetStackTraceFromId(u32 id, StackTrace *stack) {
+static StackTrace GetStackTraceFromId(u32 id) {
   CHECK(id);
-  uptr size = 0;
-  const uptr *trace = StackDepotGet(id, &size);
-  CHECK(trace);
-  stack->CopyFrom(trace, size);
+  StackTrace res = StackDepotGet(id);
+  CHECK(res.trace);
+  return res;
 }
 
-void AsanChunkView::GetAllocStack(StackTrace *stack) {
-  GetStackTraceFromId(chunk_->alloc_context_id, stack);
+StackTrace AsanChunkView::GetAllocStack() {
+  return GetStackTraceFromId(chunk_->alloc_context_id);
 }
 
-void AsanChunkView::GetFreeStack(StackTrace *stack) {
-  GetStackTraceFromId(chunk_->free_context_id, stack);
+StackTrace AsanChunkView::GetFreeStack() {
+  return GetStackTraceFromId(chunk_->free_context_id);
 }
 
 struct QuarantineCallback;
@@ -263,7 +262,7 @@ void ReInitializeAllocator() {
   quarantine.Init((uptr)flags()->quarantine_size, kMaxThreadLocalQuarantine);
 }
 
-static void *Allocate(uptr size, uptr alignment, StackTrace *stack,
+static void *Allocate(uptr size, uptr alignment, BufferedStackTrace *stack,
                       AllocType alloc_type, bool can_fill) {
   if (UNLIKELY(!asan_inited))
     AsanInitFromRtl();
@@ -391,15 +390,16 @@ static void *Allocate(uptr size, uptr alignment, StackTrace *stack,
   return res;
 }
 
-static void ReportInvalidFree(void *ptr, u8 chunk_state, StackTrace *stack) {
+static void ReportInvalidFree(void *ptr, u8 chunk_state,
+                              BufferedStackTrace *stack) {
   if (chunk_state == CHUNK_QUARANTINE)
     ReportDoubleFree((uptr)ptr, stack);
   else
     ReportFreeNotMalloced((uptr)ptr, stack);
 }
 
-static void AtomicallySetQuarantineFlag(AsanChunk *m,
-                                        void *ptr, StackTrace *stack) {
+static void AtomicallySetQuarantineFlag(AsanChunk *m, void *ptr,
+                                        BufferedStackTrace *stack) {
   u8 old_chunk_state = CHUNK_ALLOCATED;
   // Flip the chunk_state atomically to avoid race on double-free.
   if (!atomic_compare_exchange_strong((atomic_uint8_t*)m, &old_chunk_state,
@@ -410,8 +410,8 @@ static void AtomicallySetQuarantineFlag(AsanChunk *m,
 
 // Expects the chunk to already be marked as quarantined by using
 // AtomicallySetQuarantineFlag.
-static void QuarantineChunk(AsanChunk *m, void *ptr,
-                            StackTrace *stack, AllocType alloc_type) {
+static void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack,
+                            AllocType alloc_type) {
   CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE);
 
   if (m->alloc_type != alloc_type && flags()->alloc_dealloc_mismatch)
@@ -447,7 +447,7 @@ static void QuarantineChunk(AsanChunk *m, void *ptr,
   }
 }
 
-static void Deallocate(void *ptr, uptr delete_size, StackTrace *stack,
+static void Deallocate(void *ptr, uptr delete_size, BufferedStackTrace *stack,
                        AllocType alloc_type) {
   uptr p = reinterpret_cast<uptr>(ptr);
   if (p == 0) return;
@@ -464,7 +464,8 @@ static void Deallocate(void *ptr, uptr delete_size, StackTrace *stack,
   QuarantineChunk(m, ptr, stack, alloc_type);
 }
 
-static void *Reallocate(void *old_ptr, uptr new_size, StackTrace *stack) {
+static void *Reallocate(void *old_ptr, uptr new_size,
+                        BufferedStackTrace *stack) {
   CHECK(old_ptr && new_size);
   uptr p = reinterpret_cast<uptr>(old_ptr);
   uptr chunk_beg = p - kChunkHeaderSize;
@@ -577,25 +578,25 @@ void PrintInternalAllocatorStats() {
   allocator.PrintStats();
 }
 
-void *asan_memalign(uptr alignment, uptr size, StackTrace *stack,
+void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
                     AllocType alloc_type) {
   return Allocate(size, alignment, stack, alloc_type, true);
 }
 
-void asan_free(void *ptr, StackTrace *stack, AllocType alloc_type) {
+void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
   Deallocate(ptr, 0, stack, alloc_type);
 }
 
-void asan_sized_free(void *ptr, uptr size, StackTrace *stack,
+void asan_sized_free(void *ptr, uptr size, BufferedStackTrace *stack,
                      AllocType alloc_type) {
   Deallocate(ptr, size, stack, alloc_type);
 }
 
-void *asan_malloc(uptr size, StackTrace *stack) {
+void *asan_malloc(uptr size, BufferedStackTrace *stack) {
   return Allocate(size, 8, stack, FROM_MALLOC, true);
 }
 
-void *asan_calloc(uptr nmemb, uptr size, StackTrace *stack) {
+void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
   if (CallocShouldReturnNullDueToOverflow(size, nmemb))
     return AllocatorReturnNull();
   void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false);
@@ -606,7 +607,7 @@ void *asan_calloc(uptr nmemb, uptr size, StackTrace *stack) {
   return ptr;
 }
 
-void *asan_realloc(void *p, uptr size, StackTrace *stack) {
+void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
   if (p == 0)
     return Allocate(size, 8, stack, FROM_MALLOC, true);
   if (size == 0) {
@@ -616,11 +617,11 @@ void *asan_realloc(void *p, uptr size, StackTrace *stack) {
   return Reallocate(p, size, stack);
 }
 
-void *asan_valloc(uptr size, StackTrace *stack) {
+void *asan_valloc(uptr size, BufferedStackTrace *stack) {
   return Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true);
 }
 
-void *asan_pvalloc(uptr size, StackTrace *stack) {
+void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
   uptr PageSize = GetPageSizeCached();
   size = RoundUpTo(size, PageSize);
   if (size == 0) {
@@ -631,7 +632,7 @@ void *asan_pvalloc(uptr size, StackTrace *stack) {
 }
 
 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
-                        StackTrace *stack) {
+                        BufferedStackTrace *stack) {
   void *ptr = Allocate(size, alignment, stack, FROM_MALLOC, true);
   CHECK(IsAligned((uptr)ptr, alignment));
   *memptr = ptr;
diff --git a/compiler-rt/lib/asan/asan_debugging.cc b/compiler-rt/lib/asan/asan_debugging.cc
index ca5fa1f759fe..2b66dd5265fc 100644
--- a/compiler-rt/lib/asan/asan_debugging.cc
+++ b/compiler-rt/lib/asan/asan_debugging.cc
@@ -86,22 +86,19 @@ uptr AsanGetStack(uptr addr, uptr *trace, uptr size, u32 *thread_id,
   AsanChunkView chunk = FindHeapChunkByAddress(addr);
   if (!chunk.IsValid()) return 0;
 
-  StackTrace stack;
+  StackTrace stack(nullptr, 0);
   if (alloc_stack) {
     if (chunk.AllocTid() == kInvalidTid) return 0;
-    chunk.GetAllocStack(&stack);
+    stack = chunk.GetAllocStack();
     if (thread_id) *thread_id = chunk.AllocTid();
   } else {
     if (chunk.FreeTid() == kInvalidTid) return 0;
-    chunk.GetFreeStack(&stack);
+    stack = chunk.GetFreeStack();
     if (thread_id) *thread_id = chunk.FreeTid();
   }
 
   if (trace && size) {
-    if (size > kStackTraceMax)
-      size = kStackTraceMax;
-    if (size > stack.size)
-      size = stack.size;
+    size = Min(size, Min(stack.size, kStackTraceMax));
     for (uptr i = 0; i < size; i++)
       trace[i] = StackTrace::GetPreviousInstructionPc(stack.trace[i]);
 
diff --git a/compiler-rt/lib/asan/asan_report.cc b/compiler-rt/lib/asan/asan_report.cc
index b42d9bc5cc8e..2ca11a31411f 100644
--- a/compiler-rt/lib/asan/asan_report.cc
+++ b/compiler-rt/lib/asan/asan_report.cc
@@ -440,16 +440,15 @@ bool DescribeAddressIfStack(uptr addr, uptr access_size) {
   // previously. That's unfortunate, but I have no better solution,
   // especially given that the alloca may be from entirely different place
   // (e.g. use-after-scope, or different thread's stack).
-  StackTrace alloca_stack;
 #if defined(__powerpc64__) && defined(__BIG_ENDIAN__)
   // On PowerPC64 ELFv1, the address of a function actually points to a
   // three-doubleword data structure with the first field containing
   // the address of the function's code.
   access.frame_pc = *reinterpret_cast<uptr *>(access.frame_pc);
 #endif
-  alloca_stack.trace[0] = access.frame_pc + 16;
-  alloca_stack.size = 1;
+  access.frame_pc += 16;
   Printf("%s", d.EndLocation());
+  StackTrace alloca_stack(&access.frame_pc, 1);
   alloca_stack.Print();
 
   InternalMmapVector<StackVarDescr> vars(16);
@@ -519,8 +518,7 @@ void DescribeHeapAddress(uptr addr, uptr access_size) {
   asanThreadRegistry().CheckLocked();
   AsanThreadContext *alloc_thread =
       GetThreadContextByTidLocked(chunk.AllocTid());
-  StackTrace alloc_stack;
-  chunk.GetAllocStack(&alloc_stack);
+  StackTrace alloc_stack = chunk.GetAllocStack();
   char tname[128];
   Decorator d;
   AsanThreadContext *free_thread = 0;
@@ -530,8 +528,7 @@ void DescribeHeapAddress(uptr addr, uptr access_size) {
            free_thread->tid,
            ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
            d.EndAllocation());
-    StackTrace free_stack;
-    chunk.GetFreeStack(&free_stack);
+    StackTrace free_stack = chunk.GetFreeStack();
     free_stack.Print();
     Printf("%spreviously allocated by thread T%d%s here:%s\n",
            d.Allocation(), alloc_thread->tid,
@@ -581,9 +578,7 @@ void DescribeThread(AsanThreadContext *context) {
       " created by T%d%s here:\n", context->parent_tid,
       ThreadNameWithParenthesis(context->parent_tid, tname, sizeof(tname)));
   Printf("%s", str.data());
-  uptr stack_size;
-  const uptr *stack_trace = StackDepotGet(context->stack_id, &stack_size);
-  StackTrace::PrintStack(stack_trace, stack_size);
+  StackDepotGet(context->stack_id).Print();
   // Recursively described parent thread if needed.
   if (flags()->print_full_thread_history) {
     AsanThreadContext *parent_context =
@@ -684,7 +679,7 @@ void ReportSIGSEGV(const char *description, uptr pc, uptr sp, uptr bp,
   ReportErrorSummary("SEGV", &stack);
 }
 
-void ReportDoubleFree(uptr addr, StackTrace *free_stack) {
+void ReportDoubleFree(uptr addr, BufferedStackTrace *free_stack) {
   ScopedInErrorReport in_report;
   Decorator d;
   Printf("%s", d.Warning());
@@ -703,7 +698,7 @@ void ReportDoubleFree(uptr addr, StackTrace *free_stack) {
 }
 
 void ReportNewDeleteSizeMismatch(uptr addr, uptr delete_size,
-                                 StackTrace *free_stack) {
+                                 BufferedStackTrace *free_stack) {
   ScopedInErrorReport in_report;
   Decorator d;
   Printf("%s", d.Warning());
@@ -726,7 +721,7 @@ void ReportNewDeleteSizeMismatch(uptr addr, uptr delete_size,
          "ASAN_OPTIONS=new_delete_type_mismatch=0\n");
 }
 
-void ReportFreeNotMalloced(uptr addr, StackTrace *free_stack) {
+void ReportFreeNotMalloced(uptr addr, BufferedStackTrace *free_stack) {
   ScopedInErrorReport in_report;
   Decorator d;
   Printf("%s", d.Warning());
@@ -743,7 +738,7 @@ void ReportFreeNotMalloced(uptr addr, StackTrace *free_stack) {
   ReportErrorSummary("bad-free", &stack);
 }
 
-void ReportAllocTypeMismatch(uptr addr, StackTrace *free_stack,
+void ReportAllocTypeMismatch(uptr addr, BufferedStackTrace *free_stack,
                              AllocType alloc_type,
                              AllocType dealloc_type) {
   static const char *alloc_names[] =
@@ -766,7 +761,7 @@ void ReportAllocTypeMismatch(uptr addr, StackTrace *free_stack,
          "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
 }
 
-void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
+void ReportMallocUsableSizeNotOwned(uptr addr, BufferedStackTrace *stack) {
   ScopedInErrorReport in_report;
   Decorator d;
   Printf("%s", d.Warning());
@@ -779,7 +774,8 @@ void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
   ReportErrorSummary("bad-malloc_usable_size", stack);
 }
 
-void ReportSanitizerGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
+void ReportSanitizerGetAllocatedSizeNotOwned(uptr addr,
+                                             BufferedStackTrace *stack) {
   ScopedInErrorReport in_report;
   Decorator d;
   Printf("%s", d.Warning());
@@ -792,9 +788,10 @@ void ReportSanitizerGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
   ReportErrorSummary("bad-__sanitizer_get_allocated_size", stack);
 }
 
-void ReportStringFunctionMemoryRangesOverlap(
-    const char *function, const char *offset1, uptr length1,
-    const char *offset2, uptr length2, StackTrace *stack) {
+void ReportStringFunctionMemoryRangesOverlap(const char *function,
+                                             const char *offset1, uptr length1,
+                                             const char *offset2, uptr length2,
+                                             BufferedStackTrace *stack) {
   ScopedInErrorReport in_report;
   Decorator d;
   char bug_type[100];
@@ -811,7 +808,7 @@ void ReportStringFunctionMemoryRangesOverlap(
 }
 
 void ReportStringFunctionSizeOverflow(uptr offset, uptr size,
-                                      StackTrace *stack) {
+                                      BufferedStackTrace *stack) {
   ScopedInErrorReport in_report;
   Decorator d;
   const char *bug_type = "negative-size-param";
@@ -825,7 +822,7 @@ void ReportStringFunctionSizeOverflow(uptr offset, uptr size,
 
 void ReportBadParamsToAnnotateContiguousContainer(uptr beg, uptr end,
                                                   uptr old_mid, uptr new_mid,
-                                                  StackTrace *stack) {
+                                                  BufferedStackTrace *stack) {
   ScopedInErrorReport in_report;
   Report("ERROR: AddressSanitizer: bad parameters to "
          "__sanitizer_annotate_contiguous_container:\n"
@@ -855,12 +852,9 @@ void ReportODRViolation(const __asan_global *g1, u32 stack_id1,
   if (stack_id1 && stack_id2) {
     Printf("These globals were registered at these points:\n");
     Printf("  [1]:\n");
-    uptr stack_size;
-    const uptr *stack_trace = StackDepotGet(stack_id1, &stack_size);
-    StackTrace::PrintStack(stack_trace, stack_size);
+    StackDepotGet(stack_id1).Print();
     Printf("  [2]:\n");
-    stack_trace = StackDepotGet(stack_id2, &stack_size);
-    StackTrace::PrintStack(stack_trace, stack_size);
+    StackDepotGet(stack_id2).Print();
   }
   Report("HINT: if you don't care about these warnings you may set "
          "ASAN_OPTIONS=detect_odr_violation=0\n");
@@ -900,8 +894,8 @@ static INLINE void CheckForInvalidPointerPair(void *p1, void *p2) {
 }
 // ----------------------- Mac-specific reports ----------------- {{{1
 
-void WarnMacFreeUnallocated(
-    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
+void WarnMacFreeUnallocated(uptr addr, uptr zone_ptr, const char *zone_name,
+                            BufferedStackTrace *stack) {
   // Just print a warning here.
   Printf("free_common(%p) -- attempting to free unallocated memory.\n"
              "AddressSanitizer is ignoring this error on Mac OS now.\n",
@@ -911,8 +905,8 @@ void WarnMacFreeUnallocated(
   DescribeHeapAddress(addr, 1);
 }
 
-void ReportMacMzReallocUnknown(
-    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
+void ReportMacMzReallocUnknown(uptr addr, uptr zone_ptr, const char *zone_name,
+                               BufferedStackTrace *stack) {
   ScopedInErrorReport in_report;
   Printf("mz_realloc(%p) -- attempting to realloc unallocated memory.\n"
              "This is an unrecoverable problem, exiting now.\n",
@@ -922,8 +916,8 @@ void ReportMacMzReallocUnknown(
   DescribeHeapAddress(addr, 1);
 }
 
-void ReportMacCfReallocUnknown(
-    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
+void ReportMacCfReallocUnknown(uptr addr, uptr zone_ptr, const char *zone_name,
+                               BufferedStackTrace *stack) {
   ScopedInErrorReport in_report;
   Printf("cf_realloc(%p) -- attempting to realloc unallocated memory.\n"
              "This is an unrecoverable problem, exiting now.\n",
diff --git a/compiler-rt/lib/asan/asan_report.h b/compiler-rt/lib/asan/asan_report.h
index 48fb52987012..fd65bad95dfc 100644
--- a/compiler-rt/lib/asan/asan_report.h
+++ b/compiler-rt/lib/asan/asan_report.h
@@ -57,35 +57,41 @@ void NORETURN
 void NORETURN ReportSIGSEGV(const char *description, uptr pc, uptr sp, uptr bp,
                             void *context, uptr addr);
 void NORETURN ReportNewDeleteSizeMismatch(uptr addr, uptr delete_size,
-                                          StackTrace *free_stack);
-void NORETURN ReportDoubleFree(uptr addr, StackTrace *free_stack);
-void NORETURN ReportFreeNotMalloced(uptr addr, StackTrace *free_stack);
-void NORETURN ReportAllocTypeMismatch(uptr addr, StackTrace *free_stack,
+                                          BufferedStackTrace *free_stack);
+void NORETURN ReportDoubleFree(uptr addr, BufferedStackTrace *free_stack);
+void NORETURN ReportFreeNotMalloced(uptr addr, BufferedStackTrace *free_stack);
+void NORETURN ReportAllocTypeMismatch(uptr addr, BufferedStackTrace *free_stack,
                                       AllocType alloc_type,
                                       AllocType dealloc_type);
-void NORETURN ReportMallocUsableSizeNotOwned(uptr addr,
-                                             StackTrace *stack);
 void NORETURN
-ReportSanitizerGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack);
-void NORETURN ReportStringFunctionMemoryRangesOverlap(
-    const char *function, const char *offset1, uptr length1,
-    const char *offset2, uptr length2, StackTrace *stack);
+    ReportMallocUsableSizeNotOwned(uptr addr, BufferedStackTrace *stack);
 void NORETURN
-ReportStringFunctionSizeOverflow(uptr offset, uptr size, StackTrace *stack);
+    ReportSanitizerGetAllocatedSizeNotOwned(uptr addr,
+                                            BufferedStackTrace *stack);
 void NORETURN
-ReportBadParamsToAnnotateContiguousContainer(uptr beg, uptr end, uptr old_mid,
-                                             uptr new_mid, StackTrace *stack);
+    ReportStringFunctionMemoryRangesOverlap(const char *function,
+                                            const char *offset1, uptr length1,
+                                            const char *offset2, uptr length2,
+                                            BufferedStackTrace *stack);
+void NORETURN ReportStringFunctionSizeOverflow(uptr offset, uptr size,
+                                               BufferedStackTrace *stack);
+void NORETURN
+    ReportBadParamsToAnnotateContiguousContainer(uptr beg, uptr end,
+                                                 uptr old_mid, uptr new_mid,
+                                                 BufferedStackTrace *stack);
 
 void NORETURN
 ReportODRViolation(const __asan_global *g1, u32 stack_id1,
                    const __asan_global *g2, u32 stack_id2);
 
 // Mac-specific errors and warnings.
-void WarnMacFreeUnallocated(
-    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack);
-void NORETURN ReportMacMzReallocUnknown(
-    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack);
-void NORETURN ReportMacCfReallocUnknown(
-    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack);
+void WarnMacFreeUnallocated(uptr addr, uptr zone_ptr, const char *zone_name,
+                            BufferedStackTrace *stack);
+void NORETURN ReportMacMzReallocUnknown(uptr addr, uptr zone_ptr,
+                                        const char *zone_name,
+                                        BufferedStackTrace *stack);
+void NORETURN ReportMacCfReallocUnknown(uptr addr, uptr zone_ptr,
+                                        const char *zone_name,
+                                        BufferedStackTrace *stack);
 
 }  // namespace __asan
diff --git a/compiler-rt/lib/asan/asan_stack.h b/compiler-rt/lib/asan/asan_stack.h
index 884f0776ac05..7cee75528d2d 100644
--- a/compiler-rt/lib/asan/asan_stack.h
+++ b/compiler-rt/lib/asan/asan_stack.h
@@ -25,8 +25,9 @@ namespace __asan {
 // The pc will be in the position 0 of the resulting stack trace.
 // The bp may refer to the current frame or to the caller's frame.
 ALWAYS_INLINE
-void GetStackTraceWithPcBpAndContext(StackTrace *stack, uptr max_depth, uptr pc,
-                                     uptr bp, void *context, bool fast) {
+void GetStackTraceWithPcBpAndContext(BufferedStackTrace *stack, uptr max_depth,
+                                     uptr pc, uptr bp, void *context,
+                                     bool fast) {
 #if SANITIZER_WINDOWS
   stack->Unwind(max_depth, pc, bp, context, 0, 0, fast);
 #else
@@ -53,14 +54,14 @@ void GetStackTraceWithPcBpAndContext(StackTrace *stack, uptr max_depth, uptr pc,
 // don't want stack trace to contain functions from ASan internals.
 
 #define GET_STACK_TRACE(max_size, fast)                                        \
-  StackTrace stack;                                                            \
+  BufferedStackTrace stack;                                                    \
   if (max_size <= 2) {                                                         \
     stack.size = max_size;                                                     \
     if (max_size > 0) {                                                        \
       stack.top_frame_bp = GET_CURRENT_FRAME();                                \
-      stack.trace[0] = StackTrace::GetCurrentPc();                             \
+      stack.trace_buffer[0] = StackTrace::GetCurrentPc();                      \
       if (max_size > 1)                                                        \
-        stack.trace[1] = GET_CALLER_PC();                                      \
+        stack.trace_buffer[1] = GET_CALLER_PC();                               \
     }                                                                          \
   } else {                                                                     \
     GetStackTraceWithPcBpAndContext(&stack, max_size,                          \
@@ -69,12 +70,12 @@ void GetStackTraceWithPcBpAndContext(StackTrace *stack, uptr max_depth, uptr pc,
   }
 
 #define GET_STACK_TRACE_FATAL(pc, bp)                                          \
-  StackTrace stack;                                                            \
+  BufferedStackTrace stack;                                                    \
   GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, 0,           \
                                   common_flags()->fast_unwind_on_fatal)
 
 #define GET_STACK_TRACE_SIGNAL(pc, bp, context)                                \
-  StackTrace stack;                                                            \
+  BufferedStackTrace stack;                                                    \
   GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, context,     \
                                   common_flags()->fast_unwind_on_fatal)
 
diff --git a/compiler-rt/lib/asan/tests/asan_noinst_test.cc b/compiler-rt/lib/asan/tests/asan_noinst_test.cc
index 7fae462a774e..bb6af45bddf9 100644
--- a/compiler-rt/lib/asan/tests/asan_noinst_test.cc
+++ b/compiler-rt/lib/asan/tests/asan_noinst_test.cc
@@ -52,19 +52,19 @@ TEST(AddressSanitizer, InternalSimpleDeathTest) {
 
 static void MallocStress(size_t n) {
   u32 seed = my_rand();
-  StackTrace stack1;
-  stack1.trace[0] = 0xa123;
-  stack1.trace[1] = 0xa456;
+  BufferedStackTrace stack1;
+  stack1.trace_buffer[0] = 0xa123;
+  stack1.trace_buffer[1] = 0xa456;
   stack1.size = 2;
 
-  StackTrace stack2;
-  stack2.trace[0] = 0xb123;
-  stack2.trace[1] = 0xb456;
+  BufferedStackTrace stack2;
+  stack2.trace_buffer[0] = 0xb123;
+  stack2.trace_buffer[1] = 0xb456;
   stack2.size = 2;
 
-  StackTrace stack3;
-  stack3.trace[0] = 0xc123;
-  stack3.trace[1] = 0xc456;
+  BufferedStackTrace stack3;
+  stack3.trace_buffer[0] = 0xc123;
+  stack3.trace_buffer[1] = 0xc456;
   stack3.size = 2;
 
   std::vector<void *> vec;
@@ -140,8 +140,8 @@ TEST(AddressSanitizer, DISABLED_InternalPrintShadow) {
 }
 
 TEST(AddressSanitizer, QuarantineTest) {
-  StackTrace stack;
-  stack.trace[0] = 0x890;
+  BufferedStackTrace stack;
+  stack.trace_buffer[0] = 0x890;
   stack.size = 1;
 
   const int size = 1024;
@@ -161,8 +161,8 @@ TEST(AddressSanitizer, QuarantineTest) {
 void *ThreadedQuarantineTestWorker(void *unused) {
   (void)unused;
   u32 seed = my_rand();
-  StackTrace stack;
-  stack.trace[0] = 0x890;
+  BufferedStackTrace stack;
+  stack.trace_buffer[0] = 0x890;
   stack.size = 1;
 
   for (size_t i = 0; i < 1000; i++) {
@@ -188,8 +188,8 @@ TEST(AddressSanitizer, ThreadedQuarantineTest) {
 
 void *ThreadedOneSizeMallocStress(void *unused) {
   (void)unused;
-  StackTrace stack;
-  stack.trace[0] = 0x890;
+  BufferedStackTrace stack;
+  stack.trace_buffer[0] = 0x890;
   stack.size = 1;
   const size_t kNumMallocs = 1000;
   for (int iter = 0; iter < 1000; iter++) {
@@ -241,8 +241,8 @@ TEST(AddressSanitizer, LoadStoreCallbacks) {
   uptr buggy_ptr;
 
   __asan_test_only_reported_buggy_pointer = &buggy_ptr;
-  StackTrace stack;
-  stack.trace[0] = 0x890;
+  BufferedStackTrace stack;
+  stack.trace_buffer[0] = 0x890;
   stack.size = 1;
 
   for (uptr len = 16; len <= 32; len++) {
diff --git a/compiler-rt/lib/lsan/lsan.h b/compiler-rt/lib/lsan/lsan.h
index d9dd63ab8c57..53783cdc9c7d 100644
--- a/compiler-rt/lib/lsan/lsan.h
+++ b/compiler-rt/lib/lsan/lsan.h
@@ -15,17 +15,17 @@
 #include "sanitizer_common/sanitizer_flags.h"
 #include "sanitizer_common/sanitizer_stacktrace.h"
 
-#define GET_STACK_TRACE(max_size, fast)                                     \
-  StackTrace stack;                                                         \
-  {                                                                         \
-    uptr stack_top = 0, stack_bottom = 0;                                   \
-    ThreadContext *t;                                                       \
-    if (fast && (t = CurrentThreadContext())) {                             \
-      stack_top = t->stack_end();                                           \
-      stack_bottom = t->stack_begin();                                      \
-    }                                                                       \
-    stack.Unwind(max_size, StackTrace::GetCurrentPc(), GET_CURRENT_FRAME(), \
-                 /* context */ 0, stack_top, stack_bottom, fast);           \
+#define GET_STACK_TRACE(max_size, fast)                                        \
+  BufferedStackTrace stack;                                                    \
+  {                                                                            \
+    uptr stack_top = 0, stack_bottom = 0;                                      \
+    ThreadContext *t;                                                          \
+    if (fast && (t = CurrentThreadContext())) {                                \
+      stack_top = t->stack_end();                                              \
+      stack_bottom = t->stack_begin();                                         \
+    }                                                                          \
+    stack.Unwind(max_size, StackTrace::GetCurrentPc(), GET_CURRENT_FRAME(),    \
+                 /* context */ 0, stack_top, stack_bottom, fast);              \
   }
 
 #define GET_STACK_TRACE_FATAL \
diff --git a/compiler-rt/lib/lsan/lsan_common.cc b/compiler-rt/lib/lsan/lsan_common.cc
index a89462a729dd..ec518d7fd309 100644
--- a/compiler-rt/lib/lsan/lsan_common.cc
+++ b/compiler-rt/lib/lsan/lsan_common.cc
@@ -355,9 +355,7 @@ static void ClassifyAllChunks(SuspendedThreadsList const &suspended_threads) {
 
 static void PrintStackTraceById(u32 stack_trace_id) {
   CHECK(stack_trace_id);
-  uptr size = 0;
-  const uptr *trace = StackDepotGet(stack_trace_id, &size);
-  StackTrace::PrintStack(trace, size);
+  StackDepotGet(stack_trace_id).Print();
 }
 
 // ForEachChunk callback. Aggregates information about unreachable chunks into
@@ -372,10 +370,9 @@ static void CollectLeaksCb(uptr chunk, void *arg) {
     uptr resolution = flags()->resolution;
     u32 stack_trace_id = 0;
     if (resolution > 0) {
-      uptr size = 0;
-      const uptr *trace = StackDepotGet(m.stack_trace_id(), &size);
-      size = Min(size, resolution);
-      stack_trace_id = StackDepotPut(trace, size);
+      StackTrace stack = StackDepotGet(m.stack_trace_id());
+      uptr size = Min(stack.size, resolution);
+      stack_trace_id = StackDepotPut(stack.trace, size);
     } else {
       stack_trace_id = m.stack_trace_id();
     }
@@ -487,11 +484,10 @@ static Suppression *GetSuppressionForAddr(uptr addr) {
 }
 
 static Suppression *GetSuppressionForStack(u32 stack_trace_id) {
-  uptr size = 0;
-  const uptr *trace = StackDepotGet(stack_trace_id, &size);
-  for (uptr i = 0; i < size; i++) {
-    Suppression *s =
-        GetSuppressionForAddr(StackTrace::GetPreviousInstructionPc(trace[i]));
+  StackTrace stack = StackDepotGet(stack_trace_id);
+  for (uptr i = 0; i < stack.size; i++) {
+    Suppression *s = GetSuppressionForAddr(
+        StackTrace::GetPreviousInstructionPc(stack.trace[i]));
     if (s) return s;
   }
   return 0;
diff --git a/compiler-rt/lib/msan/msan.cc b/compiler-rt/lib/msan/msan.cc
index 846e884d13fe..ffd4a7521c8a 100644
--- a/compiler-rt/lib/msan/msan.cc
+++ b/compiler-rt/lib/msan/msan.cc
@@ -187,7 +187,7 @@ static void InitializeFlags(Flags *f, const char *options) {
   ParseFlagsFromString(f, options);
 }
 
-void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp,
+void GetStackTrace(BufferedStackTrace *stack, uptr max_s, uptr pc, uptr bp,
                    bool request_fast_unwind) {
   MsanThread *t = GetCurrentThread();
   if (!t || !StackTrace::WillUseFastUnwind(request_fast_unwind)) {
diff --git a/compiler-rt/lib/msan/msan.h b/compiler-rt/lib/msan/msan.h
index ad66016b91c0..892cf047ab5d 100644
--- a/compiler-rt/lib/msan/msan.h
+++ b/compiler-rt/lib/msan/msan.h
@@ -72,7 +72,7 @@ void MsanDie();
 void PrintWarning(uptr pc, uptr bp);
 void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin);
 
-void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp,
+void GetStackTrace(BufferedStackTrace *stack, uptr max_s, uptr pc, uptr bp,
                    bool request_fast_unwind);
 
 void ReportUMR(StackTrace *stack, u32 origin);
@@ -97,27 +97,24 @@ void CopyPoison(void *dst, const void *src, uptr size, StackTrace *stack);
 // the previous origin id.
 u32 ChainOrigin(u32 id, StackTrace *stack);
 
-#define GET_MALLOC_STACK_TRACE                                     \
-  StackTrace stack;                                                \
-  stack.size = 0;                                                  \
-  if (__msan_get_track_origins() && msan_inited)                   \
-    GetStackTrace(&stack, common_flags()->malloc_context_size,     \
-        StackTrace::GetCurrentPc(), GET_CURRENT_FRAME(),           \
-        common_flags()->fast_unwind_on_malloc)
-
-#define GET_STORE_STACK_TRACE_PC_BP(pc, bp)                  \
-  StackTrace stack;                                          \
-  stack.size = 0;                                            \
-  if (__msan_get_track_origins() > 1 && msan_inited)         \
-  GetStackTrace(&stack, flags()->store_context_size, pc, bp, \
+#define GET_MALLOC_STACK_TRACE                                                 \
+  BufferedStackTrace stack;                                                    \
+  if (__msan_get_track_origins() && msan_inited)                               \
+  GetStackTrace(&stack, common_flags()->malloc_context_size,                   \
+                StackTrace::GetCurrentPc(), GET_CURRENT_FRAME(),               \
                 common_flags()->fast_unwind_on_malloc)
 
-#define GET_FATAL_STACK_TRACE_PC_BP(pc, bp)       \
-  StackTrace stack;                               \
-  stack.size = 0;                                 \
-  if (msan_inited)                                \
-    GetStackTrace(&stack, kStackTraceMax, pc, bp, \
-                  common_flags()->fast_unwind_on_fatal)
+#define GET_STORE_STACK_TRACE_PC_BP(pc, bp)                                    \
+  BufferedStackTrace stack;                                                    \
+  if (__msan_get_track_origins() > 1 && msan_inited)                           \
+  GetStackTrace(&stack, flags()->store_context_size, pc, bp,                   \
+                common_flags()->fast_unwind_on_malloc)
+
+#define GET_FATAL_STACK_TRACE_PC_BP(pc, bp)                                    \
+  BufferedStackTrace stack;                                                    \
+  if (msan_inited)                                                             \
+  GetStackTrace(&stack, kStackTraceMax, pc, bp,                                \
+                common_flags()->fast_unwind_on_fatal)
 
 #define GET_STORE_STACK_TRACE \
   GET_STORE_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME())
diff --git a/compiler-rt/lib/msan/msan_report.cc b/compiler-rt/lib/msan/msan_report.cc
index 28dce8526f36..0f306375dbae 100644
--- a/compiler-rt/lib/msan/msan_report.cc
+++ b/compiler-rt/lib/msan/msan_report.cc
@@ -54,7 +54,7 @@ static void DescribeStackOrigin(const char *so, uptr pc) {
     // For some reason function address in LLVM IR is 1 less then the address
     // of the first instruction.
     pc += 1;
-    StackTrace::PrintStack(&pc, 1);
+    StackTrace(&pc, 1).Print();
   }
 }
 
@@ -77,20 +77,16 @@ static void DescribeOrigin(u32 id) {
       DescribeStackOrigin(so, pc);
       break;
     } else if (prev_o.isHeapRoot()) {
-      uptr size = 0;
-      const uptr *trace = StackDepotGet(stack_id, &size);
       Printf("  %sUninitialized value was created by a heap allocation%s\n",
              d.Origin(), d.End());
-      StackTrace::PrintStack(trace, size);
+      StackDepotGet(stack_id).Print();
       break;
     } else {
       // chained origin
-      uptr size = 0;
-      const uptr *trace = StackDepotGet(stack_id, &size);
       // FIXME: copied? modified? passed through? observed?
       Printf("  %sUninitialized value was stored to memory at%s\n", d.Origin(),
              d.End());
-      StackTrace::PrintStack(trace, size);
+      StackDepotGet(stack_id).Print();
       id = prev_id;
     }
   }
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cc b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cc
index d4fa214dc8e8..8652d5150e13 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cc
@@ -18,6 +18,7 @@
 
 namespace __sanitizer {
 
+// FIXME: Get rid of this class in favor of StackTrace.
 struct StackDepotDesc {
   const uptr *stack;
   uptr size;
@@ -122,10 +123,9 @@ StackDepotHandle StackDepotPut_WithHandle(const uptr *stack, uptr size) {
   return theDepot.Put(desc);
 }
 
-const uptr *StackDepotGet(u32 id, uptr *size) {
+StackTrace StackDepotGet(u32 id) {
   StackDepotDesc desc = theDepot.Get(id);
-  *size = desc.size;
-  return desc.stack;
+  return StackTrace(desc.stack, desc.size);
 }
 
 void StackDepotLockAll() {
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.h b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.h
index 10987e348286..c76c075ac4f9 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.h
@@ -15,6 +15,7 @@
 
 #include "sanitizer_common.h"
 #include "sanitizer_internal_defs.h"
+#include "sanitizer_stacktrace.h"
 
 namespace __sanitizer {
 
@@ -35,10 +36,11 @@ struct StackDepotHandle {
 const int kStackDepotMaxUseCount = 1U << 20;
 
 StackDepotStats *StackDepotGetStats();
+// FIXME: Pass StackTrace as an input argument here.
 u32 StackDepotPut(const uptr *stack, uptr size);
 StackDepotHandle StackDepotPut_WithHandle(const uptr *stack, uptr size);
 // Retrieves a stored stack trace by the id.
-const uptr *StackDepotGet(u32 id, uptr *size);
+StackTrace StackDepotGet(u32 id);
 
 void StackDepotLockAll();
 void StackDepotUnlockAll();
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cc b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cc
index 2c83185219e1..0f516a1e4fa6 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cc
@@ -65,11 +65,10 @@ static inline uhwptr *GetCanonicFrame(uptr bp,
 #endif
 }
 
-void StackTrace::FastUnwindStack(uptr pc, uptr bp,
-                                 uptr stack_top, uptr stack_bottom,
-                                 uptr max_depth) {
+void BufferedStackTrace::FastUnwindStack(uptr pc, uptr bp, uptr stack_top,
+                                         uptr stack_bottom, uptr max_depth) {
   CHECK_GE(max_depth, 2);
-  trace[0] = pc;
+  trace_buffer[0] = pc;
   size = 1;
   if (stack_top < 4096) return;  // Sanity check for stack top.
   uhwptr *frame = GetCanonicFrame(bp, stack_top, stack_bottom);
@@ -82,7 +81,7 @@ void StackTrace::FastUnwindStack(uptr pc, uptr bp,
          size < max_depth) {
     uhwptr pc1 = frame[1];
     if (pc1 != pc) {
-      trace[size++] = (uptr) pc1;
+      trace_buffer[size++] = (uptr) pc1;
     }
     bottom = (uptr)frame;
     frame = GetCanonicFrame((uptr)frame[0], stack_top, bottom);
@@ -93,15 +92,15 @@ static bool MatchPc(uptr cur_pc, uptr trace_pc, uptr threshold) {
   return cur_pc - trace_pc <= threshold || trace_pc - cur_pc <= threshold;
 }
 
-void StackTrace::PopStackFrames(uptr count) {
+void BufferedStackTrace::PopStackFrames(uptr count) {
   CHECK_LT(count, size);
   size -= count;
   for (uptr i = 0; i < size; ++i) {
-    trace[i] = trace[i + count];
+    trace_buffer[i] = trace_buffer[i + count];
   }
 }
 
-uptr StackTrace::LocatePcInTrace(uptr pc) {
+uptr BufferedStackTrace::LocatePcInTrace(uptr pc) {
   // Use threshold to find PC in stack trace, as PC we want to unwind from may
   // slightly differ from return address in the actual unwinded stack trace.
   const int kPcThreshold = 288;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h
index 75ab3a06d1c3..4ce53e494432 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h
@@ -30,25 +30,13 @@ static const uptr kStackTraceMax = 256;
 #endif
 
 struct StackTrace {
-  typedef bool (*SymbolizeCallback)(const void *pc, char *out_buffer,
-                                     int out_size);
-  uptr top_frame_bp;
+  const uptr *trace;
   uptr size;
-  uptr trace[kStackTraceMax];
 
-  // Prints a symbolized stacktrace, followed by an empty line.
-  static void PrintStack(const uptr *addr, uptr size);
-  void Print() const {
-    PrintStack(trace, size);
-  }
+  StackTrace(const uptr *trace, uptr size) : trace(trace), size(size) {}
 
-  void CopyFrom(const uptr *src, uptr src_size) {
-    top_frame_bp = 0;
-    size = src_size;
-    if (size > kStackTraceMax) size = kStackTraceMax;
-    for (uptr i = 0; i < size; i++)
-      trace[i] = src[i];
-  }
+  // Prints a symbolized stacktrace, followed by an empty line.
+  void Print() const;
 
   static bool WillUseFastUnwind(bool request_fast_unwind) {
     // Check if fast unwind is available. Fast unwind is the only option on Mac.
@@ -62,11 +50,21 @@ struct StackTrace {
     return request_fast_unwind;
   }
 
-  void Unwind(uptr max_depth, uptr pc, uptr bp, void *context, uptr stack_top,
-              uptr stack_bottom, bool request_fast_unwind);
-
   static uptr GetCurrentPc();
   static uptr GetPreviousInstructionPc(uptr pc);
+  typedef bool (*SymbolizeCallback)(const void *pc, char *out_buffer,
+                                    int out_size);
+};
+
+// StackTrace that owns the buffer used to store the addresses.
+struct BufferedStackTrace : public StackTrace {
+  uptr trace_buffer[kStackTraceMax];
+  uptr top_frame_bp;  // Optional bp of a top frame.
+
+  BufferedStackTrace() : StackTrace(trace_buffer, 0), top_frame_bp(0) {}
+
+  void Unwind(uptr max_depth, uptr pc, uptr bp, void *context, uptr stack_top,
+              uptr stack_bottom, bool request_fast_unwind);
 
  private:
   void FastUnwindStack(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom,
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
index 6daf0919c106..ccfb2d775372 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
@@ -22,18 +22,18 @@ static void PrintStackFramePrefix(InternalScopedString *buffer, uptr frame_num,
   buffer->append("    #%zu 0x%zx", frame_num, pc);
 }
 
-void StackTrace::PrintStack(const uptr *addr, uptr size) {
-  if (addr == 0 || size == 0) {
+void StackTrace::Print() const {
+  if (trace == nullptr || size == 0) {
     Printf("    <empty stack>\n\n");
     return;
   }
   InternalScopedBuffer<AddressInfo> addr_frames(64);
   InternalScopedString frame_desc(GetPageSizeCached() * 2);
   uptr frame_num = 0;
-  for (uptr i = 0; i < size && addr[i]; i++) {
+  for (uptr i = 0; i < size && trace[i]; i++) {
     // PCs in stack traces are actually the return addresses, that is,
     // addresses of the next instructions after the call.
-    uptr pc = GetPreviousInstructionPc(addr[i]);
+    uptr pc = GetPreviousInstructionPc(trace[i]);
     uptr addr_frames_num = Symbolizer::GetOrInit()->SymbolizePC(
         pc, addr_frames.data(), addr_frames.size());
     if (addr_frames_num == 0) {
@@ -68,9 +68,9 @@ void StackTrace::PrintStack(const uptr *addr, uptr size) {
   Printf("\n");
 }
 
-void StackTrace::Unwind(uptr max_depth, uptr pc, uptr bp, void *context,
-                        uptr stack_top, uptr stack_bottom,
-                        bool request_fast_unwind) {
+void BufferedStackTrace::Unwind(uptr max_depth, uptr pc, uptr bp, void *context,
+                                uptr stack_top, uptr stack_bottom,
+                                bool request_fast_unwind) {
   top_frame_bp = (max_depth > 0) ? bp : 0;
   // Avoid doing any work for small max_depth.
   if (max_depth == 0) {
@@ -79,7 +79,7 @@ void StackTrace::Unwind(uptr max_depth, uptr pc, uptr bp, void *context,
   }
   if (max_depth == 1) {
     size = 1;
-    trace[0] = pc;
+    trace_buffer[0] = pc;
     return;
   }
   if (!WillUseFastUnwind(request_fast_unwind)) {
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_unwind_posix_libcdep.cc b/compiler-rt/lib/sanitizer_common/sanitizer_unwind_posix_libcdep.cc
index bb4d4f57125a..4dc130940a4c 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_unwind_posix_libcdep.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_unwind_posix_libcdep.cc
@@ -95,7 +95,7 @@ uptr Unwind_GetIP(struct _Unwind_Context *ctx) {
 }
 
 struct UnwindTraceArg {
-  StackTrace *stack;
+  BufferedStackTrace *stack;
   uptr max_depth;
 };
 
@@ -103,27 +103,27 @@ _Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) {
   UnwindTraceArg *arg = (UnwindTraceArg*)param;
   CHECK_LT(arg->stack->size, arg->max_depth);
   uptr pc = Unwind_GetIP(ctx);
-  arg->stack->trace[arg->stack->size++] = pc;
+  arg->stack->trace_buffer[arg->stack->size++] = pc;
   if (arg->stack->size == arg->max_depth) return UNWIND_STOP;
   return UNWIND_CONTINUE;
 }
 
-void StackTrace::SlowUnwindStack(uptr pc, uptr max_depth) {
+void BufferedStackTrace::SlowUnwindStack(uptr pc, uptr max_depth) {
   CHECK_GE(max_depth, 2);
   size = 0;
   UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)};
   _Unwind_Backtrace(Unwind_Trace, &arg);
   // We need to pop a few frames so that pc is on top.
   uptr to_pop = LocatePcInTrace(pc);
-  // trace[0] belongs to the current function so we always pop it.
+  // trace_buffer[0] belongs to the current function so we always pop it.
   if (to_pop == 0)
     to_pop = 1;
   PopStackFrames(to_pop);
-  trace[0] = pc;
+  trace_buffer[0] = pc;
 }
 
-void StackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
-                                            uptr max_depth) {
+void BufferedStackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
+                                                    uptr max_depth) {
   CHECK_GE(max_depth, 2);
   if (!unwind_backtrace_signal_arch) {
     SlowUnwindStack(pc, max_depth);
@@ -145,7 +145,7 @@ void StackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
   // +2 compensate for libcorkscrew unwinder returning addresses of call
   // instructions instead of raw return addresses.
   for (sptr i = 0; i < res; ++i)
-    trace[size++] = frames[i].absolute_pc + 2;
+    trace_buffer[size++] = frames[i].absolute_pc + 2;
 }
 
 }  // namespace __sanitizer
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_win.cc b/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
index 4ecfe850e467..b20237cc5641 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
@@ -444,7 +444,7 @@ void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
 }
 
 #if !SANITIZER_GO
-void StackTrace::SlowUnwindStack(uptr pc, uptr max_depth) {
+void BufferedStackTrace::SlowUnwindStack(uptr pc, uptr max_depth) {
   CHECK_GE(max_depth, 2);
   // FIXME: CaptureStackBackTrace might be too slow for us.
   // FIXME: Compare with StackWalk64.
@@ -459,8 +459,8 @@ void StackTrace::SlowUnwindStack(uptr pc, uptr max_depth) {
   PopStackFrames(pc_location);
 }
 
-void StackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
-                                            uptr max_depth) {
+void BufferedStackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
+                                                    uptr max_depth) {
   CONTEXT ctx = *(CONTEXT *)context;
   STACKFRAME64 stack_frame;
   memset(&stack_frame, 0, sizeof(stack_frame));
diff --git a/compiler-rt/lib/sanitizer_common/tests/sanitizer_stackdepot_test.cc b/compiler-rt/lib/sanitizer_common/tests/sanitizer_stackdepot_test.cc
index 5c075d53ebff..5a36d15affe1 100644
--- a/compiler-rt/lib/sanitizer_common/tests/sanitizer_stackdepot_test.cc
+++ b/compiler-rt/lib/sanitizer_common/tests/sanitizer_stackdepot_test.cc
@@ -20,30 +20,26 @@ namespace __sanitizer {
 TEST(SanitizerCommon, StackDepotBasic) {
   uptr s1[] = {1, 2, 3, 4, 5};
   u32 i1 = StackDepotPut(s1, ARRAY_SIZE(s1));
-  uptr sz1 = 0;
-  const uptr *sp1 = StackDepotGet(i1, &sz1);
-  EXPECT_NE(sp1, (uptr*)0);
-  EXPECT_EQ(sz1, ARRAY_SIZE(s1));
-  EXPECT_EQ(internal_memcmp(sp1, s1, sizeof(s1)), 0);
+  StackTrace stack = StackDepotGet(i1);
+  EXPECT_NE(stack.trace, (uptr*)0);
+  EXPECT_EQ(ARRAY_SIZE(s1), stack.size);
+  EXPECT_EQ(0, internal_memcmp(stack.trace, s1, sizeof(s1)));
 }
 
 TEST(SanitizerCommon, StackDepotAbsent) {
-  uptr sz1 = 0;
-  const uptr *sp1 = StackDepotGet((1 << 30) - 1, &sz1);
-  EXPECT_EQ(sp1, (uptr*)0);
+  StackTrace stack = StackDepotGet((1 << 30) - 1);
+  EXPECT_EQ((uptr*)0, stack.trace);
 }
 
 TEST(SanitizerCommon, StackDepotEmptyStack) {
   u32 i1 = StackDepotPut(0, 0);
-  uptr sz1 = 0;
-  const uptr *sp1 = StackDepotGet(i1, &sz1);
-  EXPECT_EQ(sp1, (uptr*)0);
+  StackTrace stack = StackDepotGet(i1);
+  EXPECT_EQ((uptr*)0, stack.trace);
 }
 
 TEST(SanitizerCommon, StackDepotZeroId) {
-  uptr sz1 = 0;
-  const uptr *sp1 = StackDepotGet(0, &sz1);
-  EXPECT_EQ(sp1, (uptr*)0);
+  StackTrace stack = StackDepotGet(0);
+  EXPECT_EQ((uptr*)0, stack.trace);
 }
 
 TEST(SanitizerCommon, StackDepotSame) {
@@ -51,11 +47,10 @@ TEST(SanitizerCommon, StackDepotSame) {
   u32 i1 = StackDepotPut(s1, ARRAY_SIZE(s1));
   u32 i2 = StackDepotPut(s1, ARRAY_SIZE(s1));
   EXPECT_EQ(i1, i2);
-  uptr sz1 = 0;
-  const uptr *sp1 = StackDepotGet(i1, &sz1);
-  EXPECT_NE(sp1, (uptr*)0);
-  EXPECT_EQ(sz1, ARRAY_SIZE(s1));
-  EXPECT_EQ(internal_memcmp(sp1, s1, sizeof(s1)), 0);
+  StackTrace stack = StackDepotGet(i1);
+  EXPECT_NE(stack.trace, (uptr*)0);
+  EXPECT_EQ(ARRAY_SIZE(s1), stack.size);
+  EXPECT_EQ(0, internal_memcmp(stack.trace, s1, sizeof(s1)));
 }
 
 TEST(SanitizerCommon, StackDepotSeveral) {
@@ -80,12 +75,12 @@ TEST(SanitizerCommon, StackDepotReverseMap) {
   StackDepotReverseMap map;
 
   for (uptr i = 0; i < 4; i++) {
-    uptr sz_depot, sz_map;
-    const uptr *sp_depot, *sp_map;
-    sp_depot = StackDepotGet(ids[i], &sz_depot);
+    uptr sz_map;
+    const uptr *sp_map;
+    StackTrace stack = StackDepotGet(ids[i]);
     sp_map = map.Get(ids[i], &sz_map);
-    EXPECT_EQ(sz_depot, sz_map);
-    EXPECT_EQ(sp_depot, sp_map);
+    EXPECT_EQ(stack.size, sz_map);
+    EXPECT_EQ(stack.trace, sp_map);
   }
 }
 
diff --git a/compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cc b/compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cc
index 2fb8fa6d98e3..ac820c25a0f8 100644
--- a/compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cc
+++ b/compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cc
@@ -35,7 +35,7 @@ class FastUnwindTest : public ::testing::Test {
   uptr start_pc;
   uptr fake_top;
   uptr fake_bottom;
-  StackTrace trace;
+  BufferedStackTrace trace;
 };
 
 static uptr PC(uptr idx) {
@@ -139,7 +139,7 @@ TEST_F(FastUnwindTest, FPBelowPrevFP) {
 TEST(SlowUnwindTest, ShortStackTrace) {
   if (StackTrace::WillUseFastUnwind(false))
     return;
-  StackTrace stack;
+  BufferedStackTrace stack;
   uptr pc = StackTrace::GetCurrentPc();
   uptr bp = GET_CURRENT_FRAME();
   stack.Unwind(0, pc, bp, 0, 0, 0, false);
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cc b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cc
index bb5f5934da1c..277bcea03582 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cc
@@ -475,12 +475,11 @@ void ReportDeadlock(ThreadState *thr, uptr pc, DDReport *r) {
   InternalScopedBuffer<StackTrace> stacks(2 * DDReport::kMaxLoopSize);
   uptr dummy_pc = 0x42;
   for (int i = 0; i < r->n; i++) {
-    uptr size;
     for (int j = 0; j < (flags()->second_deadlock_stack ? 2 : 1); j++) {
       u32 stk = r->loop[i].stk[j];
       if (stk) {
-        const uptr *trace = StackDepotGet(stk, &size);
-        stacks[i].Init(const_cast<uptr *>(trace), size);
+        __sanitizer::StackTrace stack = StackDepotGet(stk);
+        stacks[i].Init(const_cast<uptr *>(stack.trace), stack.size);
       } else {
         // Sometimes we fail to extract the stack trace (FIXME: investigate),
         // but we should still produce some stack trace in the report.
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cc b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cc
index bdffb19ba0f5..486be4b89eb8 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cc
@@ -107,12 +107,11 @@ static void StackStripMain(ReportStack *stack) {
 ReportStack *SymbolizeStackId(u32 stack_id) {
   if (stack_id == 0)
     return 0;
-  uptr ssz = 0;
-  const uptr *stack = StackDepotGet(stack_id, &ssz);
-  if (stack == 0)
+  __sanitizer::StackTrace stack = StackDepotGet(stack_id);
+  if (stack.trace == nullptr)
     return 0;
   StackTrace trace;
-  trace.Init(stack, ssz);
+  trace.Init(stack.trace, stack.size);
   return SymbolizeStack(trace);
 }
 
@@ -691,14 +690,15 @@ void PrintCurrentStack(ThreadState *thr, uptr pc) {
 
 void PrintCurrentStackSlow() {
 #ifndef TSAN_GO
-  __sanitizer::StackTrace *ptrace = new(internal_alloc(MBlockStackTrace,
-      sizeof(__sanitizer::StackTrace))) __sanitizer::StackTrace;
+  __sanitizer::BufferedStackTrace *ptrace = new(
+      internal_alloc(MBlockStackTrace, sizeof(__sanitizer::BufferedStackTrace)))
+      __sanitizer::BufferedStackTrace();
   ptrace->Unwind(kStackTraceMax, __sanitizer::StackTrace::GetCurrentPc(), 0, 0,
                  0, 0, false);
   for (uptr i = 0; i < ptrace->size / 2; i++) {
-    uptr tmp = ptrace->trace[i];
-    ptrace->trace[i] = ptrace->trace[ptrace->size - i - 1];
-    ptrace->trace[ptrace->size - i - 1] = tmp;
+    uptr tmp = ptrace->trace_buffer[i];
+    ptrace->trace_buffer[i] = ptrace->trace_buffer[ptrace->size - i - 1];
+    ptrace->trace_buffer[ptrace->size - i - 1] = tmp;
   }
   StackTrace trace;
   trace.Init(ptrace->trace, ptrace->size);
diff --git a/compiler-rt/lib/tsan/rtl/tsan_stack_trace.cc b/compiler-rt/lib/tsan/rtl/tsan_stack_trace.cc
index a8374f4285dc..bf1efd444f48 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_stack_trace.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_stack_trace.cc
@@ -10,7 +10,6 @@
 // This file is a part of ThreadSanitizer (TSan), a race detector.
 //
 //===----------------------------------------------------------------------===//
-//#include "sanitizer_common/sanitizer_placement_new.h"
 #include "tsan_stack_trace.h"
 #include "tsan_rtl.h"
 #include "tsan_mman.h"
@@ -87,11 +86,6 @@ void StackTrace::ObtainCurrent(ThreadState *thr, uptr toppc) {
   }
 }
 
-void StackTrace::CopyFrom(const StackTrace& other) {
-  Reset();
-  Init(other.Begin(), other.Size());
-}
-
 bool StackTrace::IsEmpty() const {
   return n_ == 0;
 }
diff --git a/compiler-rt/lib/tsan/rtl/tsan_stack_trace.h b/compiler-rt/lib/tsan/rtl/tsan_stack_trace.h
index fe82f6e60590..420fa67e292c 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_stack_trace.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_stack_trace.h
@@ -13,16 +13,11 @@
 #ifndef TSAN_STACK_TRACE_H
 #define TSAN_STACK_TRACE_H
 
-//#include "sanitizer_common/sanitizer_atomic.h"
-//#include "sanitizer_common/sanitizer_common.h"
-//#include "sanitizer_common/sanitizer_deadlock_detector_interface.h"
 #include "tsan_defs.h"
-//#include "tsan_clock.h"
-//#include "tsan_mutex.h"
-//#include "tsan_dense_alloc.h"
 
 namespace __tsan {
 
+// FIXME: Delete this class in favor of __sanitizer::StackTrace.
 class StackTrace {
  public:
   StackTrace();
@@ -38,7 +33,6 @@ class StackTrace {
   uptr Size() const;
   uptr Get(uptr i) const;
   const uptr *Begin() const;
-  void CopyFrom(const StackTrace& other);
 
  private:
   uptr n_;
diff --git a/compiler-rt/lib/ubsan/ubsan_diag.cc b/compiler-rt/lib/ubsan/ubsan_diag.cc
index fa235216d038..9af302a5c3ae 100644
--- a/compiler-rt/lib/ubsan/ubsan_diag.cc
+++ b/compiler-rt/lib/ubsan/ubsan_diag.cc
@@ -33,7 +33,7 @@ static void MaybePrintStackTrace(uptr pc, uptr bp) {
   // under ASan).
   if (StackTrace::WillUseFastUnwind(false))
     return;
-  StackTrace stack;
+  BufferedStackTrace stack;
   stack.Unwind(kStackTraceMax, pc, bp, 0, 0, 0, false);
   stack.Print();
 }