1 // Copyright (c) 2006-2009 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 // This is a cross platform interface for helper functions related to debuggers. 6 // You should use this to test if you're running under a debugger, and if you 7 // would like to yield (breakpoint) into the debugger. 8 9 #ifndef BASE_DEBUG_UTIL_H_ 10 #define BASE_DEBUG_UTIL_H_ 11 12 #include <iosfwd> 13 #include <vector> 14 15 #include "base/basictypes.h" 16 17 #if defined(OS_WIN) 18 struct _EXCEPTION_POINTERS; 19 #endif 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. 24 class StackTrace { 25 public: 26 // Creates a stacktrace from the current location 27 StackTrace(); 28 29 // Note that the default copy constructor and assignment constructors 30 // are OK. 31 32 #if defined(OS_WIN) 33 // Creates a stacktrace for an exception. 34 // Note: this function will throw an import not found (StackWalk64) exception 35 // on system without dbghelp 5.1. 36 StackTrace(_EXCEPTION_POINTERS* exception_pointers); 37 #endif 38 // Gets an array of instruction pointer values. 39 // count: (output) the number of elements in the returned array 40 const void *const *Addresses(size_t* count); 41 // Prints a backtrace to stderr 42 void PrintBacktrace(); 43 44 // Resolves backtrace to symbols and write to stream. 45 void OutputToStream(std::ostream* os); 46 47 private: 48 // From http://msdn.microsoft.com/en-us/library/bb204633.aspx, 49 // the sum of FramesToSkip and FramesToCapture must be less than 63, 50 // so set it to 62. Even if on POSIX it could be a larger value, it usually 51 // doesn't give much more information. 52 static const int MAX_TRACES = 62; 53 void* trace_[MAX_TRACES]; 54 int count_; 55 }; 56 57 class DebugUtil { 58 public: 59 // Starts the registered system-wide JIT debugger to attach it to specified 60 // process. 61 static bool SpawnDebuggerOnProcess(unsigned process_id); 62 63 // Waits wait_seconds seconds for a debugger to attach to the current process. 64 // When silent is false, an exception is thrown when a debugger is detected. 65 static bool WaitForDebugger(int wait_seconds, bool silent); 66 67 // Are we running under a debugger? 68 // On OS X, the underlying mechanism doesn't work when the sandbox is enabled. 69 // To get around this, this function caches its value. 70 // WARNING: Because of this, on OS X, a call MUST be made to this function 71 // BEFORE the sandbox is enabled. 72 static bool BeingDebugged(); 73 74 // Break into the debugger, assumes a debugger is present. 75 static void BreakDebugger(); 76 77 #if defined(OS_MACOSX) 78 // On Mac OS X, it can take a really long time for the OS crash handler to 79 // process a Chrome crash when debugging symbols are available. This 80 // translates into a long wait until the process actually dies. This call 81 // disables Apple Crash Reporter entirely. 82 static void DisableOSCrashDumps(); 83 #endif // defined(OS_MACOSX) 84 }; 85 86 #endif // BASE_DEBUG_UTIL_H_ 87
