1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef BASE_DEBUG_STACK_TRACE_H_
6#define BASE_DEBUG_STACK_TRACE_H_
7#pragma once
8
9#include <iosfwd>
10
11#include "base/base_api.h"
12#include "build/build_config.h"
13
14#if defined(OS_WIN)
15struct _EXCEPTION_POINTERS;
16#endif
17
18namespace base {
19namespace debug {
20
21// A stacktrace can be helpful in debugging. For example, you can include a
22// stacktrace member in a object (probably around #ifndef NDEBUG) so that you
23// can later see where the given object was created from.
24class BASE_API StackTrace {
25 public:
26  // Creates a stacktrace from the current location.
27  StackTrace();
28
29#if defined(OS_WIN)
30  // Creates a stacktrace for an exception.
31  // Note: this function will throw an import not found (StackWalk64) exception
32  // on system without dbghelp 5.1.
33  StackTrace(_EXCEPTION_POINTERS* exception_pointers);
34#endif
35
36  // Copying and assignment are allowed with the default functions.
37
38  ~StackTrace();
39
40  // Gets an array of instruction pointer values. |*count| will be set to the
41  // number of elements in the returned array.
42  const void* const* Addresses(size_t* count) const;
43
44  // Prints a backtrace to stderr
45  void PrintBacktrace() const;
46
47  // Resolves backtrace to symbols and write to stream.
48  void OutputToStream(std::ostream* os) const;
49
50 private:
51  // From http://msdn.microsoft.com/en-us/library/bb204633.aspx,
52  // the sum of FramesToSkip and FramesToCapture must be less than 63,
53  // so set it to 62. Even if on POSIX it could be a larger value, it usually
54  // doesn't give much more information.
55  static const int kMaxTraces = 62;
56
57  void* trace_[kMaxTraces];
58  int count_;
59};
60
61}  // namespace debug
62}  // namespace base
63
64#endif  // BASE_DEBUG_STACK_TRACE_H_
65