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 <stddef.h> 9 10 #include <iosfwd> 11 #include <string> 12 13 #include "base/base_export.h" 14 #include "build/build_config.h" 15 16 #if defined(OS_POSIX) 17 #include <unistd.h> 18 #endif 19 20 #if defined(OS_WIN) 21 struct _EXCEPTION_POINTERS; 22 struct _CONTEXT; 23 #endif 24 25 namespace base { 26 namespace debug { 27 28 // Enables stack dump to console output on exception and signals. 29 // When enabled, the process will quit immediately. This is meant to be used in 30 // unit_tests only! This is not thread-safe: only call from main thread. 31 // In sandboxed processes, this has to be called before the sandbox is turned 32 // on. 33 // Calling this function on Linux opens /proc/self/maps and caches its 34 // contents. In non-official builds, this function also opens the object files 35 // that are loaded in memory and caches their file descriptors (this cannot be 36 // done in official builds because it has security implications). 37 BASE_EXPORT bool EnableInProcessStackDumping(); 38 39 // A stacktrace can be helpful in debugging. For example, you can include a 40 // stacktrace member in a object (probably around #ifndef NDEBUG) so that you 41 // can later see where the given object was created from. 42 class BASE_EXPORT StackTrace { 43 public: 44 // Creates a stacktrace from the current location. 45 StackTrace(); 46 47 // Creates a stacktrace from an existing array of instruction 48 // pointers (such as returned by Addresses()). |count| will be 49 // trimmed to |kMaxTraces|. 50 StackTrace(const void* const* trace, size_t count); 51 52 #if defined(OS_WIN) 53 // Creates a stacktrace for an exception. 54 // Note: this function will throw an import not found (StackWalk64) exception 55 // on system without dbghelp 5.1. 56 StackTrace(_EXCEPTION_POINTERS* exception_pointers); 57 StackTrace(const _CONTEXT* context); 58 #endif 59 60 // Copying and assignment are allowed with the default functions. 61 62 ~StackTrace(); 63 64 // Gets an array of instruction pointer values. |*count| will be set to the 65 // number of elements in the returned array. 66 const void* const* Addresses(size_t* count) const; 67 68 // Prints the stack trace to stderr. 69 void Print() const; 70 71 #if !defined(__UCLIBC__) 72 // Resolves backtrace to symbols and write to stream. 73 void OutputToStream(std::ostream* os) const; 74 #endif 75 76 // Resolves backtrace to symbols and returns as string. 77 std::string ToString() const; 78 79 private: 80 #if defined(OS_WIN) 81 void InitTrace(const _CONTEXT* context_record); 82 #endif 83 84 // From http://msdn.microsoft.com/en-us/library/bb204633.aspx, 85 // the sum of FramesToSkip and FramesToCapture must be less than 63, 86 // so set it to 62. Even if on POSIX it could be a larger value, it usually 87 // doesn't give much more information. 88 static const int kMaxTraces = 62; 89 90 void* trace_[kMaxTraces]; 91 92 // The number of valid frames in |trace_|. 93 size_t count_; 94 }; 95 96 namespace internal { 97 98 #if defined(OS_POSIX) && !defined(OS_ANDROID) 99 // POSIX doesn't define any async-signal safe function for converting 100 // an integer to ASCII. We'll have to define our own version. 101 // itoa_r() converts a (signed) integer to ASCII. It returns "buf", if the 102 // conversion was successful or NULL otherwise. It never writes more than "sz" 103 // bytes. Output will be truncated as needed, and a NUL character is always 104 // appended. 105 BASE_EXPORT char *itoa_r(intptr_t i, 106 char *buf, 107 size_t sz, 108 int base, 109 size_t padding); 110 #endif // defined(OS_POSIX) && !defined(OS_ANDROID) 111 112 } // namespace internal 113 114 } // namespace debug 115 } // namespace base 116 117 #endif // BASE_DEBUG_STACK_TRACE_H_ 118
