base/debug/stack_trace.h

   1 // Copyright (c) 2012 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
   8 #include <iosfwd>
   9 #include <string>
  10
  11 #include "base/base_export.h"
  12 #include "build/build_config.h"
  13
  14 #if defined(OS_POSIX)
  15 #include <unistd.h>
  16 #endif
  17
  18 #if defined(OS_WIN)
  19 struct _EXCEPTION_POINTERS;
  20 #endif
  21
  22 namespace base {
  23 namespace debug {
  24
  25 // Enables stack dump to console output on exception and signals.
  26 // When enabled, the process will quit immediately. This is meant to be used in
  27 // unit_tests only! This is not thread-safe: only call from main thread.
  28 BASE_EXPORT bool EnableInProcessStackDumping();
  29
  30 // A stacktrace can be helpful in debugging. For example, you can include a
  31 // stacktrace member in a object (probably around #ifndef NDEBUG) so that you
  32 // can later see where the given object was created from.
  33 class BASE_EXPORT StackTrace {
  34  public:
  35   // Creates a stacktrace from the current location.
  36   StackTrace();
  37
  38   // Creates a stacktrace from an existing array of instruction
  39   // pointers (such as returned by Addresses()).  |count| will be
  40   // trimmed to |kMaxTraces|.
  41   StackTrace(const void* const* trace, size_t count);
  42
  43 #if defined(OS_WIN)
  44   // Creates a stacktrace for an exception.
  45   // Note: this function will throw an import not found (StackWalk64) exception
  46   // on system without dbghelp 5.1.
  47   StackTrace(_EXCEPTION_POINTERS* exception_pointers);
  48 #endif
  49
  50   // Copying and assignment are allowed with the default functions.
  51
  52   ~StackTrace();
  53
  54   // Gets an array of instruction pointer values. |*count| will be set to the
  55   // number of elements in the returned array.
  56   const void* const* Addresses(size_t* count) const;
  57
  58   // Prints a backtrace to stderr
  59   void PrintBacktrace() const;
  60
  61   // Resolves backtrace to symbols and write to stream.
  62   void OutputToStream(std::ostream* os) const;
  63
  64   // Resolves backtrace to symbols and returns as string.
  65   std::string ToString() const;
  66
  67  private:
  68   // From http://msdn.microsoft.com/en-us/library/bb204633.aspx,
  69   // the sum of FramesToSkip and FramesToCapture must be less than 63,
  70   // so set it to 62. Even if on POSIX it could be a larger value, it usually
  71   // doesn't give much more information.
  72   static const int kMaxTraces = 62;
  73
  74   void* trace_[kMaxTraces];
  75
  76   // The number of valid frames in |trace_|.
  77   size_t count_;
  78 };
  79
  80 namespace internal {
  81
  82 #if defined(OS_POSIX) && !defined(OS_ANDROID)
  83 // POSIX doesn't define any async-signal safe function for converting
  84 // an integer to ASCII. We'll have to define our own version.
  85 // itoa_r() converts a (signed) integer to ASCII. It returns "buf", if the
  86 // conversion was successful or NULL otherwise. It never writes more than "sz"
  87 // bytes. Output will be truncated as needed, and a NUL character is always
  88 // appended.
  89 BASE_EXPORT char *itoa_r(intptr_t i,
  90                          char *buf,
  91                          size_t sz,
  92                          int base,
  93                          size_t padding);
  94 #endif  // defined(OS_POSIX) && !defined(OS_ANDROID)
  95
  96 }  // namespace internal
  97
  98 }  // namespace debug
  99 }  // namespace base
 100
 101 #endif  // BASE_DEBUG_STACK_TRACE_H_