[compiler-rt] r223145 - Simplify Symbolizer::SymbolizePC() interface.

Alexey Samsonov vonosmas at gmail.com
Tue Feb 10 16:39:34 PST 2015


Hi,

On Fri, Feb 6, 2015 at 2:44 PM, Filipe Cabecinhas <filcab at gmail.com> wrote:

> Hi Alexey,
>
> On Fri, Feb 6, 2015 at 1:17 PM, Alexey Samsonov <vonosmas at gmail.com>
> wrote:
>
>> Hi Filipe,
>>
>> First of all, did you notice it by code inspection, or actually observed
>> noticable memory leak in your program?
>>
> It was reported to us after we shipped UBSan for testing. Programs just
> crash.
> This makes sense if you take into account that you might have errors in
> each frame of a game, which runs at 60fps. Memory usage grows rapidly :-)
>

Right, I meant that ideally we should call leaky getCallerLocation() /
getFunctionLocation() only once per each error report we print, and we try
to deduplicate
reports based on their source locations (file/line/column of invalid
operation). I took a closer look, and it turned out to not be the case:
I've submitted r228732 and
r228772 to improve the situtation here. The remaining important case is
float-cast-overflow, for which we don't provide the source locations now.


>
> I remember this problem, and it wasn't fixed until now, because this
>> memory leak happens during error reporting, and can only be noticed if your
>> program has a significant
>> number of different UBSan error reports. That said, we should of course
>> fix it :)
>>
> That was the idea I had after seeing the code :-)
>
> I don't really understand your suggestion, though. Location destructor
>> already calls destructor for MemoryLocation. The problem is
>> ModuleLocation::ModuleName (and, similar SourceLocation::Filename):
>>
> Yes. The “clear the objects” would be the freeing of whatever we could,
> which is what's missing (ModuleName and Filename).
>
>
>> they can point to either constant string literals, or global data, or
>> dynamically allocated strings (e.g. via internal_strdup). We should only
>> call InternalFree() on these string buffers in the latter case.
>>
> Ah, I forgot about the string literal case.
> I wonder if it's more worth it to make the SourceLocation (and friends)
> class manage their strings a bit better, or if it would be worth it to have
> the StackFrames objects not fully free each of the module's names (We're
> leaking because we generate a FallbackLoc with the module name).
>
> Any clues on where it would be better to start? You know much more about
> what you need for location info outside of ubsan.
>

I hope to refactor this code and plug the memory leaks this week. Thanks
for bringing this issue to attention!


>
> Thank you,
>
>   Filipe
>
>
> On Thu, Feb 5, 2015 at 7:02 PM, Filipe Cabecinhas <filcab at gmail.com>
>> wrote:
>>
>>> Hi Alexey!
>>>
>>> This still has a memory leak: (ubsan_diag.cc)
>>> +  if (!Info.file) {
>>> +    ModuleLocation MLoc(internal_strdup(Info.module),
>>> Info.module_offset);
>>> +    Frames->ClearAll();
>>> +    return MLoc;
>>> +  }
>>> ^^ You're doing an strdup, but later the ModuleLocation only gets used
>>> to feed a Location, which is only used when Diag calls renderLocation.
>>> After that, it gets leaked away.
>>>
>>> One could fix this by making SourceLoc, ModuleLoc, and MemoryLoc, inside
>>> class Location (ubsan_diag.h) pointers, and clear the objects in the
>>> Location destructor.
>>> If you're ok with this let me know and I can submit the patch,
>>> otherwise, can you fix it?
>>> (I'm not sure about the uses in tsan and other sanitizers, so I don't
>>> know if they also leak)
>>>
>>> Thanks,
>>>
>>>   Filipe
>>>
>>> On Tue, Dec 2, 2014 at 11:48 AM, Alexey Samsonov <vonosmas at gmail.com>
>>> wrote:
>>>
>>>> Author: samsonov
>>>> Date: Tue Dec  2 13:48:40 2014
>>>> New Revision: 223145
>>>>
>>>> URL: http://llvm.org/viewvc/llvm-project?rev=223145&view=rev
>>>> Log:
>>>> Simplify Symbolizer::SymbolizePC() interface.
>>>>
>>>> Return a linked list of AddressInfo objects, instead of using an array
>>>> of
>>>> these objects as an output parameter. This simplifies the code in
>>>> callers
>>>> of this function (especially TSan).
>>>>
>>>> Fix a few memory leaks from internal allocator, when the returned
>>>> AddressInfo objects were not properly cleared.
>>>>
>>>> Modified:
>>>>     compiler-rt/trunk/lib/lsan/lsan_common.cc
>>>>     compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_libcdep.cc
>>>>
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
>>>>     compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.cc
>>>>     compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.h
>>>>
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
>>>>
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.h
>>>>
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
>>>>     compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_win.cc
>>>>     compiler-rt/trunk/lib/tsan/go/buildgo.sh
>>>>     compiler-rt/trunk/lib/tsan/go/tsan_go.cc
>>>>     compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc
>>>>     compiler-rt/trunk/lib/tsan/rtl/tsan_report.h
>>>>     compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h
>>>>     compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc
>>>>     compiler-rt/trunk/lib/tsan/rtl/tsan_suppressions.cc
>>>>     compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc
>>>>     compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.h
>>>>     compiler-rt/trunk/lib/ubsan/ubsan_diag.cc
>>>>
>>>> Modified: compiler-rt/trunk/lib/lsan/lsan_common.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/lsan/lsan_common.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/lsan/lsan_common.cc (original)
>>>> +++ compiler-rt/trunk/lib/lsan/lsan_common.cc Tue Dec  2 13:48:40 2014
>>>> @@ -457,30 +457,27 @@ void DoLeakCheck() {
>>>>  }
>>>>
>>>>  static Suppression *GetSuppressionForAddr(uptr addr) {
>>>> -  Suppression *s;
>>>> +  Suppression *s = nullptr;
>>>>
>>>>    // Suppress by module name.
>>>>    const char *module_name;
>>>>    uptr module_offset;
>>>> -  if (Symbolizer::GetOrInit()
>>>> -          ->GetModuleNameAndOffsetForPC(addr, &module_name,
>>>> &module_offset) &&
>>>> +  if (Symbolizer::GetOrInit()->GetModuleNameAndOffsetForPC(addr,
>>>> &module_name,
>>>> +
>>>>  &module_offset) &&
>>>>        SuppressionContext::Get()->Match(module_name, SuppressionLeak,
>>>> &s))
>>>>      return s;
>>>>
>>>>    // Suppress by file or function name.
>>>> -  static const uptr kMaxAddrFrames = 16;
>>>> -  InternalScopedBuffer<AddressInfo> addr_frames(kMaxAddrFrames);
>>>> -  for (uptr i = 0; i < kMaxAddrFrames; i++) new (&addr_frames[i])
>>>> AddressInfo();
>>>> -  uptr addr_frames_num = Symbolizer::GetOrInit()->SymbolizePC(
>>>> -      addr, addr_frames.data(), kMaxAddrFrames);
>>>> -  for (uptr i = 0; i < addr_frames_num; i++) {
>>>> -    if (SuppressionContext::Get()->Match(addr_frames[i].function,
>>>> -                                         SuppressionLeak, &s) ||
>>>> -        SuppressionContext::Get()->Match(addr_frames[i].file,
>>>> SuppressionLeak,
>>>> -                                         &s))
>>>> -      return s;
>>>> +  SymbolizedStack *frames = Symbolizer::GetOrInit()->SymbolizePC(addr);
>>>> +  for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
>>>> +    if (SuppressionContext::Get()->Match(cur->info.function,
>>>> SuppressionLeak,
>>>> +                                         &s) ||
>>>> +        SuppressionContext::Get()->Match(cur->info.file,
>>>> SuppressionLeak, &s)) {
>>>> +      break;
>>>> +    }
>>>>    }
>>>> -  return 0;
>>>> +  frames->ClearAll();
>>>> +  return s;
>>>>  }
>>>>
>>>>  static Suppression *GetSuppressionForStack(u32 stack_trace_id) {
>>>>
>>>> Modified:
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_libcdep.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_libcdep.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_libcdep.cc
>>>> (original)
>>>> +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_libcdep.cc
>>>> Tue Dec  2 13:48:40 2014
>>>> @@ -52,16 +52,20 @@ void SetSandboxingCallback(void (*f)())
>>>>  void ReportErrorSummary(const char *error_type, StackTrace *stack) {
>>>>    if (!common_flags()->print_summary)
>>>>      return;
>>>> -  AddressInfo ai;
>>>>  #if !SANITIZER_GO
>>>>    if (stack->size > 0 &&
>>>> Symbolizer::GetOrInit()->CanReturnFileLineInfo()) {
>>>>      // Currently, we include the first stack frame into the report
>>>> summary.
>>>>      // Maybe sometimes we need to choose another frame (e.g. skip
>>>> memcpy/etc).
>>>>      uptr pc = StackTrace::GetPreviousInstructionPc(stack->trace[0]);
>>>> -    Symbolizer::GetOrInit()->SymbolizePC(pc, &ai, 1);
>>>> +    SymbolizedStack *frame = Symbolizer::GetOrInit()->SymbolizePC(pc);
>>>> +    const AddressInfo &ai = frame->info;
>>>> +    ReportErrorSummary(error_type, ai.file, ai.line, ai.function);
>>>> +    frame->ClearAll();
>>>>    }
>>>> -#endif
>>>> +#else
>>>> +  AddressInfo ai;
>>>>    ReportErrorSummary(error_type, ai.file, ai.line, ai.function);
>>>> +#endif
>>>>  }
>>>>
>>>>  }  // namespace __sanitizer
>>>>
>>>> Modified:
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> ---
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
>>>> (original)
>>>> +++
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc Tue
>>>> Dec  2 13:48:40 2014
>>>> @@ -24,30 +24,21 @@ void StackTrace::Print() const {
>>>>      Printf("    <empty stack>\n\n");
>>>>      return;
>>>>    }
>>>> -  const int kMaxAddrFrames = 64;
>>>> -  InternalScopedBuffer<AddressInfo> addr_frames(kMaxAddrFrames);
>>>> -  for (uptr i = 0; i < kMaxAddrFrames; i++)
>>>> -    new(&addr_frames[i]) AddressInfo();
>>>>    InternalScopedString frame_desc(GetPageSizeCached() * 2);
>>>>    uptr frame_num = 0;
>>>>    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(trace[i]);
>>>> -    uptr addr_frames_num = Symbolizer::GetOrInit()->SymbolizePC(
>>>> -        pc, addr_frames.data(), kMaxAddrFrames);
>>>> -    if (addr_frames_num == 0) {
>>>> -      addr_frames[0].address = pc;
>>>> -      addr_frames_num = 1;
>>>> -    }
>>>> -    for (uptr j = 0; j < addr_frames_num; j++) {
>>>> -      AddressInfo &info = addr_frames[j];
>>>> +    SymbolizedStack *frames = Symbolizer::GetOrInit()->SymbolizePC(pc);
>>>> +    CHECK(frames);
>>>> +    for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
>>>>        frame_desc.clear();
>>>>        RenderFrame(&frame_desc, common_flags()->stack_trace_format,
>>>> frame_num++,
>>>> -                  info, common_flags()->strip_path_prefix);
>>>> +                  cur->info, common_flags()->strip_path_prefix);
>>>>        Printf("%s\n", frame_desc.data());
>>>> -      info.Clear();
>>>>      }
>>>> +    frames->ClearAll();
>>>>    }
>>>>    // Always print a trailing empty line after stack trace.
>>>>    Printf("\n");
>>>>
>>>> Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.cc
>>>> (original)
>>>> +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.cc Tue
>>>> Dec  2 13:48:40 2014
>>>> @@ -11,13 +11,61 @@
>>>>  // run-time libraries.
>>>>
>>>>  //===----------------------------------------------------------------------===//
>>>>
>>>> +#include "sanitizer_allocator_internal.h"
>>>>  #include "sanitizer_platform.h"
>>>>  #include "sanitizer_internal_defs.h"
>>>> +#include "sanitizer_libc.h"
>>>>  #include "sanitizer_placement_new.h"
>>>>  #include "sanitizer_symbolizer.h"
>>>>
>>>>  namespace __sanitizer {
>>>>
>>>> +AddressInfo::AddressInfo() {
>>>> +  internal_memset(this, 0, sizeof(AddressInfo));
>>>> +  function_offset = kUnknown;
>>>> +}
>>>> +
>>>> +void AddressInfo::Clear() {
>>>> +  InternalFree(module);
>>>> +  InternalFree(function);
>>>> +  InternalFree(file);
>>>> +  internal_memset(this, 0, sizeof(AddressInfo));
>>>> +  function_offset = kUnknown;
>>>> +}
>>>> +
>>>> +void AddressInfo::FillAddressAndModuleInfo(uptr addr, const char
>>>> *mod_name,
>>>> +                                           uptr mod_offset) {
>>>> +  address = addr;
>>>> +  module = internal_strdup(mod_name);
>>>> +  module_offset = mod_offset;
>>>> +}
>>>> +
>>>> +SymbolizedStack::SymbolizedStack() : next(nullptr), info() {}
>>>> +
>>>> +SymbolizedStack *SymbolizedStack::New(uptr addr) {
>>>> +  void *mem = InternalAlloc(sizeof(SymbolizedStack));
>>>> +  SymbolizedStack *res = new(mem) SymbolizedStack();
>>>> +  res->info.address = addr;
>>>> +  return res;
>>>> +}
>>>> +
>>>> +void SymbolizedStack::ClearAll() {
>>>> +  info.Clear();
>>>> +  if (next)
>>>> +    next->ClearAll();
>>>> +  InternalFree(this);
>>>> +}
>>>> +
>>>> +DataInfo::DataInfo() {
>>>> +  internal_memset(this, 0, sizeof(DataInfo));
>>>> +}
>>>> +
>>>> +void DataInfo::Clear() {
>>>> +  InternalFree(module);
>>>> +  InternalFree(name);
>>>> +  internal_memset(this, 0, sizeof(DataInfo));
>>>> +}
>>>> +
>>>>  Symbolizer *Symbolizer::symbolizer_;
>>>>  StaticSpinMutex Symbolizer::init_mu_;
>>>>  LowLevelAllocator Symbolizer::symbolizer_allocator_;
>>>>
>>>> Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.h
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.h?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.h
>>>> (original)
>>>> +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer.h Tue
>>>> Dec  2 13:48:40 2014
>>>> @@ -19,13 +19,14 @@
>>>>  #ifndef SANITIZER_SYMBOLIZER_H
>>>>  #define SANITIZER_SYMBOLIZER_H
>>>>
>>>> -#include "sanitizer_allocator_internal.h"
>>>> -#include "sanitizer_internal_defs.h"
>>>> -#include "sanitizer_libc.h"
>>>> +#include "sanitizer_common.h"
>>>> +#include "sanitizer_mutex.h"
>>>>
>>>>  namespace __sanitizer {
>>>>
>>>>  struct AddressInfo {
>>>> +  // Owns all the string members. Storage for them is
>>>> +  // (de)allocated using sanitizer internal allocator.
>>>>    uptr address;
>>>>
>>>>    char *module;
>>>> @@ -39,45 +40,38 @@ struct AddressInfo {
>>>>    int line;
>>>>    int column;
>>>>
>>>> -  AddressInfo() {
>>>> -    internal_memset(this, 0, sizeof(AddressInfo));
>>>> -    function_offset = kUnknown;
>>>> -  }
>>>> -
>>>> +  AddressInfo();
>>>>    // Deletes all strings and resets all fields.
>>>> -  void Clear() {
>>>> -    InternalFree(module);
>>>> -    InternalFree(function);
>>>> -    InternalFree(file);
>>>> -    internal_memset(this, 0, sizeof(AddressInfo));
>>>> -    function_offset = kUnknown;
>>>> -  }
>>>> -
>>>> +  void Clear();
>>>>    void FillAddressAndModuleInfo(uptr addr, const char *mod_name,
>>>> -                                uptr mod_offset) {
>>>> -    address = addr;
>>>> -    module = internal_strdup(mod_name);
>>>> -    module_offset = mod_offset;
>>>> -  }
>>>> +                                uptr mod_offset);
>>>> +};
>>>> +
>>>> +// Linked list of symbolized frames (each frame is described by
>>>> AddressInfo).
>>>> +struct SymbolizedStack {
>>>> +  SymbolizedStack *next;
>>>> +  AddressInfo info;
>>>> +  static SymbolizedStack *New(uptr addr);
>>>> +  // Deletes current, and all subsequent frames in the linked list.
>>>> +  // The object cannot be accessed after the call to this function.
>>>> +  void ClearAll();
>>>> +
>>>> + private:
>>>> +  SymbolizedStack();
>>>>  };
>>>>
>>>>  // For now, DataInfo is used to describe global variable.
>>>>  struct DataInfo {
>>>> +  // Owns all the string members. Storage for them is
>>>> +  // (de)allocated using sanitizer internal allocator.
>>>>    char *module;
>>>>    uptr module_offset;
>>>>    char *name;
>>>>    uptr start;
>>>>    uptr size;
>>>>
>>>> -  DataInfo() {
>>>> -    internal_memset(this, 0, sizeof(DataInfo));
>>>> -  }
>>>> -
>>>> -  void Clear() {
>>>> -    InternalFree(module);
>>>> -    InternalFree(name);
>>>> -    internal_memset(this, 0, sizeof(DataInfo));
>>>> -  }
>>>> +  DataInfo();
>>>> +  void Clear();
>>>>  };
>>>>
>>>>  class Symbolizer {
>>>> @@ -85,11 +79,10 @@ class Symbolizer {
>>>>    /// Initialize and return platform-specific implementation of
>>>> symbolizer
>>>>    /// (if it wasn't already initialized).
>>>>    static Symbolizer *GetOrInit();
>>>> -  // Fills at most "max_frames" elements of "frames" with descriptions
>>>> -  // for a given address (in all inlined functions). Returns the number
>>>> -  // of descriptions actually filled.
>>>> -  virtual uptr SymbolizePC(uptr address, AddressInfo *frames, uptr
>>>> max_frames) {
>>>> -    return 0;
>>>> +  // Returns a list of symbolized frames for a given address
>>>> (containing
>>>> +  // all inlined functions, if necessary).
>>>> +  virtual SymbolizedStack *SymbolizePC(uptr address) {
>>>> +    return SymbolizedStack::New(address);
>>>>    }
>>>>    virtual bool SymbolizeData(uptr address, DataInfo *info) {
>>>>      return false;
>>>>
>>>> Modified:
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> ---
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
>>>> (original)
>>>> +++
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
>>>> Tue Dec  2 13:48:40 2014
>>>> @@ -83,44 +83,52 @@ char *CplusV3Demangle(const char *name)
>>>>  }
>>>>  # endif  // SANITIZER_CP_DEMANGLE
>>>>
>>>> -struct SymbolizeCodeData {
>>>> -  AddressInfo *frames;
>>>> -  uptr n_frames;
>>>> -  uptr max_frames;
>>>> +struct SymbolizeCodeCallbackArg {
>>>> +  SymbolizedStack *first;
>>>> +  SymbolizedStack *last;
>>>>    const char *module_name;
>>>>    uptr module_offset;
>>>> +
>>>> +  void append(SymbolizedStack *f) {
>>>> +    if (last != nullptr) {
>>>> +      last->next = f;
>>>> +      last = f;
>>>> +    } else {
>>>> +      first = f;
>>>> +      last = f;
>>>> +    }
>>>> +  }
>>>>  };
>>>>
>>>>  extern "C" {
>>>>  static int SymbolizeCodePCInfoCallback(void *vdata, uintptr_t addr,
>>>>                                         const char *filename, int
>>>> lineno,
>>>>                                         const char *function) {
>>>> -  SymbolizeCodeData *cdata = (SymbolizeCodeData *)vdata;
>>>> +  SymbolizeCodeCallbackArg *cdata = (SymbolizeCodeCallbackArg *)vdata;
>>>>    if (function) {
>>>> -    AddressInfo *info = &cdata->frames[cdata->n_frames++];
>>>> -    info->Clear();
>>>> +    SymbolizedStack *cur = SymbolizedStack::New(addr);
>>>> +    cdata->append(cur);
>>>> +    AddressInfo *info = &cur->info;
>>>>      info->FillAddressAndModuleInfo(addr, cdata->module_name,
>>>>                                     cdata->module_offset);
>>>>      info->function = LibbacktraceSymbolizer::Demangle(function, true);
>>>>      if (filename)
>>>>        info->file = internal_strdup(filename);
>>>>      info->line = lineno;
>>>> -    if (cdata->n_frames == cdata->max_frames)
>>>> -      return 1;
>>>>    }
>>>>    return 0;
>>>>  }
>>>>
>>>>  static void SymbolizeCodeCallback(void *vdata, uintptr_t addr,
>>>>                                    const char *symname, uintptr_t,
>>>> uintptr_t) {
>>>> -  SymbolizeCodeData *cdata = (SymbolizeCodeData *)vdata;
>>>> +  SymbolizeCodeCallbackArg *cdata = (SymbolizeCodeCallbackArg *)vdata;
>>>>    if (symname) {
>>>> -    AddressInfo *info = &cdata->frames[0];
>>>> -    info->Clear();
>>>> +    SymbolizedStack *cur = SymbolizedStack::New(addr);
>>>> +    cdata->append(cur);
>>>> +    AddressInfo *info = &cur->info;
>>>>      info->FillAddressAndModuleInfo(addr, cdata->module_name,
>>>>                                     cdata->module_offset);
>>>>      info->function = LibbacktraceSymbolizer::Demangle(symname, true);
>>>> -    cdata->n_frames = 1;
>>>>    }
>>>>  }
>>>>
>>>> @@ -148,23 +156,21 @@ LibbacktraceSymbolizer *LibbacktraceSymb
>>>>    return new(*alloc) LibbacktraceSymbolizer(state);
>>>>  }
>>>>
>>>> -uptr LibbacktraceSymbolizer::SymbolizeCode(uptr addr, AddressInfo
>>>> *frames,
>>>> -                                           uptr max_frames,
>>>> -                                           const char *module_name,
>>>> -                                           uptr module_offset) {
>>>> -  SymbolizeCodeData data;
>>>> -  data.frames = frames;
>>>> -  data.n_frames = 0;
>>>> -  data.max_frames = max_frames;
>>>> +SymbolizedStack *LibbacktraceSymbolizer::SymbolizeCode(uptr addr,
>>>> +                                                       const char
>>>> *module_name,
>>>> +                                                       uptr
>>>> module_offset) {
>>>> +  SymbolizeCodeCallbackArg data;
>>>> +  data.first = nullptr;
>>>> +  data.last = nullptr;
>>>>    data.module_name = module_name;
>>>>    data.module_offset = module_offset;
>>>>    backtrace_pcinfo((backtrace_state *)state_, addr,
>>>> SymbolizeCodePCInfoCallback,
>>>>                     ErrorCallback, &data);
>>>> -  if (data.n_frames)
>>>> -    return data.n_frames;
>>>> +  if (data.first)
>>>> +    return data.first;
>>>>    backtrace_syminfo((backtrace_state *)state_, addr,
>>>> SymbolizeCodeCallback,
>>>>                      ErrorCallback, &data);
>>>> -  return data.n_frames;
>>>> +  return data.first;
>>>>  }
>>>>
>>>>  bool LibbacktraceSymbolizer::SymbolizeData(DataInfo *info) {
>>>> @@ -179,12 +185,11 @@ LibbacktraceSymbolizer *LibbacktraceSymb
>>>>    return 0;
>>>>  }
>>>>
>>>> -uptr LibbacktraceSymbolizer::SymbolizeCode(uptr addr, AddressInfo
>>>> *frames,
>>>> -                                           uptr max_frames,
>>>> -                                           const char *module_name,
>>>> -                                           uptr module_offset) {
>>>> +SymbolizedStack *LibbacktraceSymbolizer::SymbolizeCode(uptr addr,
>>>> +                                                       const char
>>>> *module_name,
>>>> +                                                       uptr
>>>> module_offset) {
>>>>    (void)state_;
>>>> -  return 0;
>>>> +  return nullptr;
>>>>  }
>>>>
>>>>  bool LibbacktraceSymbolizer::SymbolizeData(DataInfo *info) {
>>>>
>>>> Modified:
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.h
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.h?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> ---
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.h
>>>> (original)
>>>> +++
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libbacktrace.h
>>>> Tue Dec  2 13:48:40 2014
>>>> @@ -32,8 +32,8 @@ class LibbacktraceSymbolizer {
>>>>   public:
>>>>    static LibbacktraceSymbolizer *get(LowLevelAllocator *alloc);
>>>>
>>>> -  uptr SymbolizeCode(uptr addr, AddressInfo *frames, uptr max_frames,
>>>> -                     const char *module_name, uptr module_offset);
>>>> +  SymbolizedStack *SymbolizeCode(uptr addr, const char *module_name,
>>>> +                                 uptr module_offset);
>>>>
>>>>    bool SymbolizeData(DataInfo *info);
>>>>
>>>>
>>>> Modified:
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> ---
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
>>>> (original)
>>>> +++
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
>>>> Tue Dec  2 13:48:40 2014
>>>> @@ -514,34 +514,32 @@ class POSIXSymbolizer : public Symbolize
>>>>          internal_symbolizer_(internal_symbolizer),
>>>>          libbacktrace_symbolizer_(libbacktrace_symbolizer) {}
>>>>
>>>> -  uptr SymbolizePC(uptr addr, AddressInfo *frames, uptr max_frames)
>>>> override {
>>>> +  SymbolizedStack *SymbolizePC(uptr addr) override {
>>>>      BlockingMutexLock l(&mu_);
>>>> -    if (max_frames == 0)
>>>> -      return 0;
>>>>      const char *module_name;
>>>>      uptr module_offset;
>>>>      if (!FindModuleNameAndOffsetForAddress(addr, &module_name,
>>>> &module_offset))
>>>> -      return 0;
>>>> +      return SymbolizedStack::New(addr);
>>>>      // First, try to use libbacktrace symbolizer (if it's available).
>>>>      if (libbacktrace_symbolizer_ != 0) {
>>>>        mu_.CheckLocked();
>>>> -      uptr res = libbacktrace_symbolizer_->SymbolizeCode(
>>>> -          addr, frames, max_frames, module_name, module_offset);
>>>> -      if (res > 0)
>>>> +      if (SymbolizedStack *res =
>>>> libbacktrace_symbolizer_->SymbolizeCode(
>>>> +              addr, module_name, module_offset))
>>>>          return res;
>>>>      }
>>>> +    // Always fill data about module name and offset.
>>>> +    SymbolizedStack *res = SymbolizedStack::New(addr);
>>>> +    res->info.FillAddressAndModuleInfo(addr, module_name,
>>>> module_offset);
>>>> +
>>>>      const char *str = SendCommand(false, module_name, module_offset);
>>>>      if (str == 0) {
>>>> -      // Symbolizer was not initialized or failed. Fill only data
>>>> -      // about module name and offset.
>>>> -      AddressInfo *info = &frames[0];
>>>> -      info->Clear();
>>>> -      info->FillAddressAndModuleInfo(addr, module_name, module_offset);
>>>> -      return 1;
>>>> +      // Symbolizer was not initialized or failed.
>>>> +      return res;
>>>>      }
>>>> -    uptr frame_id = 0;
>>>> -    for (frame_id = 0; frame_id < max_frames; frame_id++) {
>>>> -      AddressInfo *info = &frames[frame_id];
>>>> +
>>>> +    bool top_frame = true;
>>>> +    SymbolizedStack *last = res;
>>>> +    while (true) {
>>>>        char *function_name = 0;
>>>>        str = ExtractToken(str, "\n", &function_name);
>>>>        CHECK(function_name);
>>>> @@ -549,8 +547,18 @@ class POSIXSymbolizer : public Symbolize
>>>>          // There are no more frames.
>>>>          break;
>>>>        }
>>>> -      info->Clear();
>>>> -      info->FillAddressAndModuleInfo(addr, module_name, module_offset);
>>>> +      SymbolizedStack *cur;
>>>> +      if (top_frame) {
>>>> +        cur = res;
>>>> +        top_frame = false;
>>>> +      } else {
>>>> +        cur = SymbolizedStack::New(addr);
>>>> +        cur->info.FillAddressAndModuleInfo(addr, module_name,
>>>> module_offset);
>>>> +        last->next = cur;
>>>> +        last = cur;
>>>> +      }
>>>> +
>>>> +      AddressInfo *info = &cur->info;
>>>>        info->function = function_name;
>>>>        // Parse <file>:<line>:<column> buffer.
>>>>        char *file_line_info = 0;
>>>> @@ -572,14 +580,7 @@ class POSIXSymbolizer : public Symbolize
>>>>          info->file = 0;
>>>>        }
>>>>      }
>>>> -    if (frame_id == 0) {
>>>> -      // Make sure we return at least one frame.
>>>> -      AddressInfo *info = &frames[0];
>>>> -      info->Clear();
>>>> -      info->FillAddressAndModuleInfo(addr, module_name, module_offset);
>>>> -      frame_id = 1;
>>>> -    }
>>>> -    return frame_id;
>>>> +    return res;
>>>>    }
>>>>
>>>>    bool SymbolizeData(uptr addr, DataInfo *info) override {
>>>>
>>>> Modified:
>>>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_win.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_win.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_win.cc
>>>> (original)
>>>> +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_win.cc
>>>> Tue Dec  2 13:48:40 2014
>>>> @@ -26,9 +26,8 @@ class WinSymbolizer : public Symbolizer
>>>>   public:
>>>>    WinSymbolizer() : initialized_(false) {}
>>>>
>>>> -  uptr SymbolizePC(uptr addr, AddressInfo *frames, uptr max_frames)
>>>> override {
>>>> -    if (max_frames == 0)
>>>> -      return 0;
>>>> +  SymbolizedStack *SymbolizePC(uptr addr) override {
>>>> +    SymbolizedStack *frame = SymbolizedStack::New(addr);
>>>>
>>>>      BlockingMutexLock l(&dbghelp_mu_);
>>>>      if (!initialized_) {
>>>> @@ -60,29 +59,27 @@ class WinSymbolizer : public Symbolizer
>>>>      BOOL got_objname = SymFromAddr(GetCurrentProcess(),
>>>>                                     (DWORD64)addr, &offset, symbol);
>>>>      if (!got_objname)
>>>> -      return 0;
>>>> +      return frame;
>>>>
>>>>      DWORD unused;
>>>>      IMAGEHLP_LINE64 line_info;
>>>>      line_info.SizeOfStruct = sizeof(IMAGEHLP_LINE64);
>>>>      BOOL got_fileline = SymGetLineFromAddr64(GetCurrentProcess(),
>>>> (DWORD64)addr,
>>>>                                               &unused, &line_info);
>>>> -    AddressInfo *info = &frames[0];
>>>> -    info->Clear();
>>>> -    info->function = internal_strdup(symbol->Name);
>>>> -    info->function_offset = (uptr)offset;
>>>> +    frame->info.function = internal_strdup(symbol->Name);
>>>> +    frame->info.function_offset = (uptr)offset;
>>>>      if (got_fileline) {
>>>> -      info->file = internal_strdup(line_info.FileName);
>>>> -      info->line = line_info.LineNumber;
>>>> +      frame->info.file = internal_strdup(line_info.FileName);
>>>> +      frame->info.line = line_info.LineNumber;
>>>>      }
>>>>
>>>>      IMAGEHLP_MODULE64 mod_info;
>>>>      internal_memset(&mod_info, 0, sizeof(mod_info));
>>>>      mod_info.SizeOfStruct = sizeof(mod_info);
>>>>      if (SymGetModuleInfo64(GetCurrentProcess(), addr, &mod_info))
>>>> -      info->FillAddressAndModuleInfo(addr, mod_info.ImageName,
>>>> -                                     addr -
>>>> (uptr)mod_info.BaseOfImage);
>>>> -    return 1;
>>>> +      frame->info.FillAddressAndModuleInfo(addr, mod_info.ImageName,
>>>> +                                           addr -
>>>> (uptr)mod_info.BaseOfImage);
>>>> +    return frame;
>>>>    }
>>>>
>>>>    bool CanReturnFileLineInfo() override {
>>>>
>>>> Modified: compiler-rt/trunk/lib/tsan/go/buildgo.sh
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/go/buildgo.sh?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/tsan/go/buildgo.sh (original)
>>>> +++ compiler-rt/trunk/lib/tsan/go/buildgo.sh Tue Dec  2 13:48:40 2014
>>>> @@ -27,6 +27,7 @@ SRCS="
>>>>         ../../sanitizer_common/sanitizer_thread_registry.cc
>>>>         ../../sanitizer_common/sanitizer_stackdepot.cc
>>>>         ../../sanitizer_common/sanitizer_stacktrace.cc
>>>> +       ../../sanitizer_common/sanitizer_symbolizer.cc
>>>>  "
>>>>
>>>>  if [ "`uname -a | grep Linux`" != "" ]; then
>>>>
>>>> Modified: compiler-rt/trunk/lib/tsan/go/tsan_go.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/go/tsan_go.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/tsan/go/tsan_go.cc (original)
>>>> +++ compiler-rt/trunk/lib/tsan/go/tsan_go.cc Tue Dec  2 13:48:40 2014
>>>> @@ -59,18 +59,19 @@ struct SymbolizeContext {
>>>>  // Callback into Go.
>>>>  static void (*symbolize_cb)(SymbolizeContext *ctx);
>>>>
>>>> -ReportStack *SymbolizeCode(uptr addr) {
>>>> -  ReportStack *s = ReportStack::New(addr);
>>>> +SymbolizedStack *SymbolizeCode(uptr addr) {
>>>> +  SymbolizedStack *s = SymbolizedStack::New(addr);
>>>>    SymbolizeContext ctx;
>>>>    internal_memset(&ctx, 0, sizeof(ctx));
>>>>    ctx.pc = addr;
>>>>    symbolize_cb(&ctx);
>>>>    if (ctx.res) {
>>>> -    s->info.module_offset = ctx.off;
>>>> -    s->info.function = internal_strdup(ctx.func ? ctx.func : "??");
>>>> -    s->info.file = internal_strdup(ctx.file ? ctx.file : "-");
>>>> -    s->info.line = ctx.line;
>>>> -    s->info.column = 0;
>>>> +    AddressInfo &info = s->info;
>>>> +    info.module_offset = ctx.off;
>>>> +    info.function = internal_strdup(ctx.func ? ctx.func : "??");
>>>> +    info.file = internal_strdup(ctx.file ? ctx.file : "-");
>>>> +    info.line = ctx.line;
>>>> +    info.column = 0;
>>>>    }
>>>>    return s;
>>>>  }
>>>>
>>>> Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc (original)
>>>> +++ compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc Tue Dec  2 13:48:40
>>>> 2014
>>>> @@ -19,13 +19,11 @@
>>>>
>>>>  namespace __tsan {
>>>>
>>>> -ReportStack::ReportStack() : next(nullptr), info(),
>>>> suppressable(false) {}
>>>> +ReportStack::ReportStack() : frames(nullptr), suppressable(false) {}
>>>>
>>>> -ReportStack *ReportStack::New(uptr addr) {
>>>> +ReportStack *ReportStack::New() {
>>>>    void *mem = internal_alloc(MBlockReportStack, sizeof(ReportStack));
>>>> -  ReportStack *res = new(mem) ReportStack();
>>>> -  res->info.address = addr;
>>>> -  return res;
>>>> +  return new(mem) ReportStack();
>>>>  }
>>>>
>>>>  ReportLocation::ReportLocation(ReportLocationType type)
>>>> @@ -114,13 +112,14 @@ static const char *ReportTypeString(Repo
>>>>  }
>>>>
>>>>  void PrintStack(const ReportStack *ent) {
>>>> -  if (ent == 0) {
>>>> +  if (ent == 0 || ent->frames == 0) {
>>>>      Printf("    [failed to restore the stack]\n\n");
>>>>      return;
>>>>    }
>>>> -  for (int i = 0; ent && ent->info.address; ent = ent->next, i++) {
>>>> +  SymbolizedStack *frame = ent->frames;
>>>> +  for (int i = 0; frame && frame->info.address; frame = frame->next,
>>>> i++) {
>>>>      InternalScopedString res(2 * GetPageSizeCached());
>>>> -    RenderFrame(&res, common_flags()->stack_trace_format, i, ent->info,
>>>> +    RenderFrame(&res, common_flags()->stack_trace_format, i,
>>>> frame->info,
>>>>                  common_flags()->strip_path_prefix, "__interceptor_");
>>>>      Printf("%s\n", res.data());
>>>>    }
>>>> @@ -252,10 +251,20 @@ static ReportStack *ChooseSummaryStack(c
>>>>    return 0;
>>>>  }
>>>>
>>>> -ReportStack *SkipTsanInternalFrames(ReportStack *ent) {
>>>> -  while (FrameIsInternal(ent) && ent->next)
>>>> -    ent = ent->next;
>>>> -  return ent;
>>>> +static bool FrameIsInternal(const SymbolizedStack *frame) {
>>>> +  if (frame == 0)
>>>> +    return false;
>>>> +  const char *file = frame->info.file;
>>>> +  return file != 0 &&
>>>> +         (internal_strstr(file, "tsan_interceptors.cc") ||
>>>> +          internal_strstr(file, "sanitizer_common_interceptors.inc") ||
>>>> +          internal_strstr(file, "tsan_interface_"));
>>>> +}
>>>> +
>>>> +static SymbolizedStack *SkipTsanInternalFrames(SymbolizedStack
>>>> *frames) {
>>>> +  while (FrameIsInternal(frames) && frames->next)
>>>> +    frames = frames->next;
>>>> +  return frames;
>>>>  }
>>>>
>>>>  void PrintReport(const ReportDesc *rep) {
>>>> @@ -325,9 +334,11 @@ void PrintReport(const ReportDesc *rep)
>>>>    if (rep->typ == ReportTypeThreadLeak && rep->count > 1)
>>>>      Printf("  And %d more similar thread leaks.\n\n", rep->count - 1);
>>>>
>>>> -  if (ReportStack *ent =
>>>> SkipTsanInternalFrames(ChooseSummaryStack(rep))) {
>>>> -    const AddressInfo &info = ent->info;
>>>> -    ReportErrorSummary(rep_typ_str, info.file, info.line,
>>>> info.function);
>>>> +  if (ReportStack *stack = ChooseSummaryStack(rep)) {
>>>> +    if (SymbolizedStack *frame =
>>>> SkipTsanInternalFrames(stack->frames)) {
>>>> +      const AddressInfo &info = frame->info;
>>>> +      ReportErrorSummary(rep_typ_str, info.file, info.line,
>>>> info.function);
>>>> +    }
>>>>    }
>>>>
>>>>    Printf("==================\n");
>>>> @@ -338,12 +349,13 @@ void PrintReport(const ReportDesc *rep)
>>>>  const int kMainThreadId = 1;
>>>>
>>>>  void PrintStack(const ReportStack *ent) {
>>>> -  if (ent == 0) {
>>>> +  if (ent == 0 || ent->frames == 0) {
>>>>      Printf("  [failed to restore the stack]\n");
>>>>      return;
>>>>    }
>>>> -  for (int i = 0; ent; ent = ent->next, i++) {
>>>> -    const AddressInfo &info = ent->info;
>>>> +  SymbolizedStack *frame = ent->frames;
>>>> +  for (int i = 0; frame; frame = frame->next, i++) {
>>>> +    const AddressInfo &info = frame->info;
>>>>      Printf("  %s()\n      %s:%d +0x%zx\n", info.function, info.file,
>>>> info.line,
>>>>             (void *)info.module_offset);
>>>>    }
>>>>
>>>> Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_report.h
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_report.h?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/tsan/rtl/tsan_report.h (original)
>>>> +++ compiler-rt/trunk/lib/tsan/rtl/tsan_report.h Tue Dec  2 13:48:40
>>>> 2014
>>>> @@ -36,10 +36,9 @@ enum ReportType {
>>>>  };
>>>>
>>>>  struct ReportStack {
>>>> -  ReportStack *next;
>>>> -  AddressInfo info;
>>>> +  SymbolizedStack *frames;
>>>>    bool suppressable;
>>>> -  static ReportStack *New(uptr addr);
>>>> +  static ReportStack *New();
>>>>
>>>>   private:
>>>>    ReportStack();
>>>>
>>>> Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h (original)
>>>> +++ compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h Tue Dec  2 13:48:40 2014
>>>> @@ -568,8 +568,6 @@ bool IsFiredSuppression(Context *ctx, co
>>>>                          StackTrace trace);
>>>>  bool IsExpectedReport(uptr addr, uptr size);
>>>>  void PrintMatchedBenignRaces();
>>>> -bool FrameIsInternal(const ReportStack *frame);
>>>> -ReportStack *SkipTsanInternalFrames(ReportStack *ent);
>>>>
>>>>  #if defined(TSAN_DEBUG_OUTPUT) && TSAN_DEBUG_OUTPUT >= 1
>>>>  # define DPrintf Printf
>>>>
>>>> Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc (original)
>>>> +++ compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc Tue Dec  2
>>>> 13:48:40 2014
>>>> @@ -56,40 +56,43 @@ bool WEAK OnReport(const ReportDesc *rep
>>>>  }
>>>>  #endif
>>>>
>>>> -static void StackStripMain(ReportStack *stack) {
>>>> -  ReportStack *last_frame = 0;
>>>> -  ReportStack *last_frame2 = 0;
>>>> -  for (ReportStack *ent = stack; ent; ent = ent->next) {
>>>> +static void StackStripMain(SymbolizedStack *frames) {
>>>> +  SymbolizedStack *last_frame = nullptr;
>>>> +  SymbolizedStack *last_frame2 = nullptr;
>>>> +  for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
>>>>      last_frame2 = last_frame;
>>>> -    last_frame = ent;
>>>> +    last_frame = cur;
>>>>    }
>>>>
>>>>    if (last_frame2 == 0)
>>>>      return;
>>>> -  const char *last = last_frame->info.function;
>>>>  #ifndef TSAN_GO
>>>> +  const char *last = last_frame->info.function;
>>>>    const char *last2 = last_frame2->info.function;
>>>>    // Strip frame above 'main'
>>>>    if (last2 && 0 == internal_strcmp(last2, "main")) {
>>>> -    last_frame2->next = 0;
>>>> +    last_frame->ClearAll();
>>>> +    last_frame2->next = nullptr;
>>>>    // Strip our internal thread start routine.
>>>>    } else if (last && 0 == internal_strcmp(last,
>>>> "__tsan_thread_start_func")) {
>>>> -    last_frame2->next = 0;
>>>> +    last_frame->ClearAll();
>>>> +    last_frame2->next = nullptr;
>>>>    // Strip global ctors init.
>>>>    } else if (last && 0 == internal_strcmp(last,
>>>> "__do_global_ctors_aux")) {
>>>> -    last_frame2->next = 0;
>>>> +    last_frame->ClearAll();
>>>> +    last_frame2->next = nullptr;
>>>>    // If both are 0, then we probably just failed to symbolize.
>>>>    } else if (last || last2) {
>>>>      // Ensure that we recovered stack completely. Trimmed stack
>>>>      // can actually happen if we do not instrument some code,
>>>>      // so it's only a debug print. However we must try hard to not
>>>> miss it
>>>>      // due to our fault.
>>>> -    DPrintf("Bottom stack frame of stack %zx is missed\n", stack->pc);
>>>> +    DPrintf("Bottom stack frame of stack %zx is missed\n",
>>>> stack->info.address);
>>>>    }
>>>>  #else
>>>>    // The last frame always point into runtime (gosched0, goexit0,
>>>> runtime.main).
>>>> -  last_frame2->next = 0;
>>>> -  (void)last;
>>>> +  last_frame->ClearAll();
>>>> +  last_frame2->next = nullptr;
>>>>  #endif
>>>>  }
>>>>
>>>> @@ -105,12 +108,12 @@ ReportStack *SymbolizeStackId(u32 stack_
>>>>  static ReportStack *SymbolizeStack(StackTrace trace) {
>>>>    if (trace.size == 0)
>>>>      return 0;
>>>> -  ReportStack *stack = 0;
>>>> +  SymbolizedStack *top = nullptr;
>>>>    for (uptr si = 0; si < trace.size; si++) {
>>>>      const uptr pc = trace.trace[si];
>>>>  #ifndef TSAN_GO
>>>> -    // We obtain the return address, that is, address of the next
>>>> instruction,
>>>> -    // so offset it by 1 byte.
>>>> +    // We obtain the return address, but we're interested in the
>>>> previous
>>>> +    // instruction.
>>>>      const uptr pc1 = StackTrace::GetPreviousInstructionPc(pc);
>>>>  #else
>>>>      // FIXME(dvyukov): Go sometimes uses address of a function as top
>>>> pc.
>>>> @@ -118,18 +121,21 @@ static ReportStack *SymbolizeStack(Stack
>>>>      if (si != trace.size - 1)
>>>>        pc1 -= 1;
>>>>  #endif
>>>> -    ReportStack *ent = SymbolizeCode(pc1);
>>>> +    SymbolizedStack *ent = SymbolizeCode(pc1);
>>>>      CHECK_NE(ent, 0);
>>>> -    ReportStack *last = ent;
>>>> +    SymbolizedStack *last = ent;
>>>>      while (last->next) {
>>>>        last->info.address = pc;  // restore original pc for report
>>>>        last = last->next;
>>>>      }
>>>>      last->info.address = pc;  // restore original pc for report
>>>> -    last->next = stack;
>>>> -    stack = ent;
>>>> +    last->next = top;
>>>> +    top = ent;
>>>>    }
>>>> -  StackStripMain(stack);
>>>> +  StackStripMain(top);
>>>> +
>>>> +  ReportStack *stack = ReportStack::New();
>>>> +  stack->frames = top;
>>>>    return stack;
>>>>  }
>>>>
>>>> @@ -547,16 +553,6 @@ static bool IsFiredSuppression(Context *
>>>>    return false;
>>>>  }
>>>>
>>>> -bool FrameIsInternal(const ReportStack *frame) {
>>>> -  if (frame == 0)
>>>> -    return false;
>>>> -  const char *file = frame->info.file;
>>>> -  return file != 0 &&
>>>> -         (internal_strstr(file, "tsan_interceptors.cc") ||
>>>> -          internal_strstr(file, "sanitizer_common_interceptors.inc") ||
>>>> -          internal_strstr(file, "tsan_interface_"));
>>>> -}
>>>> -
>>>>  static bool RaceBetweenAtomicAndFree(ThreadState *thr) {
>>>>    Shadow s0(thr->racy_state[0]);
>>>>    Shadow s1(thr->racy_state[1]);
>>>>
>>>> Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_suppressions.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_suppressions.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/tsan/rtl/tsan_suppressions.cc (original)
>>>> +++ compiler-rt/trunk/lib/tsan/rtl/tsan_suppressions.cc Tue Dec  2
>>>> 13:48:40 2014
>>>> @@ -92,7 +92,8 @@ uptr IsSuppressed(ReportType typ, const
>>>>    if (stype == SuppressionNone)
>>>>      return 0;
>>>>    Suppression *s;
>>>> -  for (const ReportStack *frame = stack; frame; frame = frame->next) {
>>>> +  for (const SymbolizedStack *frame = stack->frames; frame;
>>>> +       frame = frame->next) {
>>>>      const AddressInfo &info = frame->info;
>>>>      if (SuppressionContext::Get()->Match(info.function, stype, &s) ||
>>>>          SuppressionContext::Get()->Match(info.file, stype, &s) ||
>>>>
>>>> Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc (original)
>>>> +++ compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc Tue Dec  2
>>>> 13:48:40 2014
>>>> @@ -55,7 +55,7 @@ bool __tsan_symbolize_external(uptr pc,
>>>>    return false;
>>>>  }
>>>>
>>>> -ReportStack *SymbolizeCode(uptr addr) {
>>>> +SymbolizedStack *SymbolizeCode(uptr addr) {
>>>>    // Check if PC comes from non-native land.
>>>>    if (addr & kExternalPCBit) {
>>>>      // Declare static to not consume too much stack space.
>>>> @@ -63,36 +63,17 @@ ReportStack *SymbolizeCode(uptr addr) {
>>>>      static char func_buf[1024];
>>>>      static char file_buf[1024];
>>>>      int line, col;
>>>> -    ReportStack *ent = ReportStack::New(addr);
>>>> -    if (!__tsan_symbolize_external(addr, func_buf, sizeof(func_buf),
>>>> -                                  file_buf, sizeof(file_buf), &line,
>>>> &col))
>>>> -      return ent;
>>>> -    ent->info.function = internal_strdup(func_buf);
>>>> -    ent->info.file = internal_strdup(file_buf);
>>>> -    ent->info.line = line;
>>>> -    ent->info.column = col;
>>>> -    return ent;
>>>> +    SymbolizedStack *frame = SymbolizedStack::New(addr);
>>>> +    if (__tsan_symbolize_external(addr, func_buf, sizeof(func_buf),
>>>> file_buf,
>>>> +                                  sizeof(file_buf), &line, &col)) {
>>>> +      frame->info.function = internal_strdup(func_buf);
>>>> +      frame->info.file = internal_strdup(file_buf);
>>>> +      frame->info.line = line;
>>>> +      frame->info.column = col;
>>>> +    }
>>>> +    return frame;
>>>>    }
>>>> -  static const uptr kMaxAddrFrames = 16;
>>>> -  InternalScopedBuffer<AddressInfo> addr_frames(kMaxAddrFrames);
>>>> -  for (uptr i = 0; i < kMaxAddrFrames; i++)
>>>> -    new(&addr_frames[i]) AddressInfo();
>>>> -  uptr addr_frames_num = Symbolizer::GetOrInit()->SymbolizePC(
>>>> -      addr, addr_frames.data(), kMaxAddrFrames);
>>>> -  if (addr_frames_num == 0)
>>>> -    return ReportStack::New(addr);
>>>> -  ReportStack *top = 0;
>>>> -  ReportStack *bottom = 0;
>>>> -  for (uptr i = 0; i < addr_frames_num; i++) {
>>>> -    ReportStack *cur_entry = ReportStack::New(addr);
>>>> -    cur_entry->info = addr_frames[i];
>>>> -    if (i == 0)
>>>> -      top = cur_entry;
>>>> -    else
>>>> -      bottom->next = cur_entry;
>>>> -    bottom = cur_entry;
>>>> -  }
>>>> -  return top;
>>>> +  return Symbolizer::GetOrInit()->SymbolizePC(addr);
>>>>  }
>>>>
>>>>  ReportLocation *SymbolizeData(uptr addr) {
>>>>
>>>> Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.h
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.h?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.h (original)
>>>> +++ compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.h Tue Dec  2 13:48:40
>>>> 2014
>>>> @@ -20,7 +20,7 @@ namespace __tsan {
>>>>
>>>>  void EnterSymbolizer();
>>>>  void ExitSymbolizer();
>>>> -ReportStack *SymbolizeCode(uptr addr);
>>>> +SymbolizedStack *SymbolizeCode(uptr addr);
>>>>  ReportLocation *SymbolizeData(uptr addr);
>>>>  void SymbolizeFlush();
>>>>
>>>>
>>>> Modified: compiler-rt/trunk/lib/ubsan/ubsan_diag.cc
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/ubsan/ubsan_diag.cc?rev=223145&r1=223144&r2=223145&view=diff
>>>>
>>>> ==============================================================================
>>>> --- compiler-rt/trunk/lib/ubsan/ubsan_diag.cc (original)
>>>> +++ compiler-rt/trunk/lib/ubsan/ubsan_diag.cc Tue Dec  2 13:48:40 2014
>>>> @@ -79,18 +79,26 @@ Location __ubsan::getFunctionLocation(up
>>>>      return Location();
>>>>    InitIfNecessary();
>>>>
>>>> -  AddressInfo Info;
>>>> -  if (!Symbolizer::GetOrInit()->SymbolizePC(Loc, &Info, 1) ||
>>>> !Info.module ||
>>>> -      !*Info.module)
>>>> +  SymbolizedStack *Frames = Symbolizer::GetOrInit()->SymbolizePC(Loc);
>>>> +  const AddressInfo &Info = Frames->info;
>>>> +
>>>> +  if (!Info.module) {
>>>> +    Frames->ClearAll();
>>>>      return Location(Loc);
>>>> +  }
>>>>
>>>>    if (FName && Info.function)
>>>> -    *FName = Info.function;
>>>> +    *FName = internal_strdup(Info.function);
>>>>
>>>> -  if (!Info.file)
>>>> -    return ModuleLocation(Info.module, Info.module_offset);
>>>> +  if (!Info.file) {
>>>> +    ModuleLocation MLoc(internal_strdup(Info.module),
>>>> Info.module_offset);
>>>> +    Frames->ClearAll();
>>>> +    return MLoc;
>>>> +  }
>>>>
>>>> -  return SourceLocation(Info.file, Info.line, Info.column);
>>>> +  SourceLocation SLoc(internal_strdup(Info.file), Info.line,
>>>> Info.column);
>>>> +  Frames->ClearAll();
>>>> +  return SLoc;
>>>>  }
>>>>
>>>>  Diag &Diag::operator<<(const TypeDescriptor &V) {
>>>>
>>>>
>>>> _______________________________________________
>>>> llvm-commits mailing list
>>>> llvm-commits at cs.uiuc.edu
>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>>>
>>>
>>>
>>>
>>> --
>>>   F
>>>
>>>
>>
>>
>> --
>> Alexey Samsonov
>> vonosmas at gmail.com
>>
>
>


-- 
Alexey Samsonov
vonosmas at gmail.com
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