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 different version of EnableInProcessStackDumping that also works for 31 // sandboxed processes. For more details take a look at the description 32 // of EnableInProcessStackDumping. 33 // Calling this function on Linux opens /proc/self/maps and caches its 34 // contents. In DEBUG builds, this function also opens the object files that 35 // 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 EnableInProcessStackDumpingForSandbox(); 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(const _EXCEPTION_POINTERS* exception_pointers); 57 #endif 58 59 // Copying and assignment are allowed with the default functions. 60 61 ~StackTrace(); 62 63 // Gets an array of instruction pointer values. |*count| will be set to the 64 // number of elements in the returned array. 65 const void* const* Addresses(size_t* count) const; 66 67 // Prints the stack trace to stderr. 68 void Print() const; 69 70 #if !defined(__UCLIBC__) 71 // Resolves backtrace to symbols and write to stream. 72 void OutputToStream(std::ostream* os) const; 73 #endif 74 75 // Resolves backtrace to symbols and returns as string. 76 std::string ToString() const; 77 78 private: 79 // From http://msdn.microsoft.com/en-us/library/bb204633.aspx, 80 // the sum of FramesToSkip and FramesToCapture must be less than 63, 81 // so set it to 62. Even if on POSIX it could be a larger value, it usually 82 // doesn't give much more information. 83 static const int kMaxTraces = 62; 84 85 void* trace_[kMaxTraces]; 86 87 // The number of valid frames in |trace_|. 88 size_t count_; 89 }; 90 91 namespace internal { 92 93 #if defined(OS_POSIX) && !defined(OS_ANDROID) 94 // POSIX doesn't define any async-signal safe function for converting 95 // an integer to ASCII. We'll have to define our own version. 96 // itoa_r() converts a (signed) integer to ASCII. It returns "buf", if the 97 // conversion was successful or NULL otherwise. It never writes more than "sz" 98 // bytes. Output will be truncated as needed, and a NUL character is always 99 // appended. 100 BASE_EXPORT char *itoa_r(intptr_t i, 101 char *buf, 102 size_t sz, 103 int base, 104 size_t padding); 105 #endif // defined(OS_POSIX) && !defined(OS_ANDROID) 106 107 } // namespace internal 108 109 } // namespace debug 110 } // namespace base 111 112 #endif // BASE_DEBUG_STACK_TRACE_H_ 113
