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Diffstat (limited to '')
| -rw-r--r-- | mozglue/misc/StackWalk.h | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/mozglue/misc/StackWalk.h b/mozglue/misc/StackWalk.h new file mode 100644 index 0000000000..250160934f --- /dev/null +++ b/mozglue/misc/StackWalk.h @@ -0,0 +1,215 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* APIs for getting a stack trace of the current thread */ + +#ifndef mozilla_StackWalk_h +#define mozilla_StackWalk_h + +#include "mozilla/Types.h" +#include <stdint.h> +#include <stdio.h> + +MOZ_BEGIN_EXTERN_C + +/** + * Returns the position of the Program Counter for the caller of the current + * function. This is meant to be used to feed the aFirstFramePC argument to + * MozStackWalk or MozWalkTheStack*, and should be used in the last function + * that should be skipped in the trace, and passed down to MozStackWalk or + * MozWalkTheStack*, through any intermediaries. + * + * THIS DOES NOT 100% RELIABLY GIVE THE CALLER PC, but marking functions + * calling this macro with MOZ_NEVER_INLINE gets us close. In cases it doesn't + * give the caller's PC, it may give the caller of the caller, or its caller, + * etc. depending on tail call optimization. + * + * Past versions of stackwalking relied on passing a constant number of frames + * to skip to MozStackWalk or MozWalkTheStack, which fell short in more cases + * (inlining of intermediaries, tail call optimization). + */ +#define CallerPC() __builtin_extract_return_addr(__builtin_return_address(0)) + +/** + * The callback for MozStackWalk and MozStackWalkThread. + * + * @param aFrameNumber The frame number (starts at 1, not 0). + * @param aPC The program counter value. + * @param aSP The best approximation possible of what the stack + * pointer will be pointing to when the execution returns + * to executing that at aPC. If no approximation can + * be made it will be nullptr. + * @param aClosure Extra data passed in from MozStackWalk() or + * MozStackWalkThread(). + */ +typedef void (*MozWalkStackCallback)(uint32_t aFrameNumber, void* aPC, + void* aSP, void* aClosure); + +/** + * Call aCallback for each stack frame on the current thread, from + * the caller of MozStackWalk to main (or above). + * + * @param aCallback Callback function, called once per frame. + * @param aFirstFramePC Position of the Program Counter where the trace + * starts from. All frames seen before reaching that + * address are skipped. Nullptr means that the first + * callback will be for the caller of MozStackWalk. + * @param aMaxFrames Maximum number of frames to trace. 0 means no limit. + * @param aClosure Caller-supplied data passed through to aCallback. + * + * May skip some stack frames due to compiler optimizations or code + * generation. + */ +MFBT_API void MozStackWalk(MozWalkStackCallback aCallback, + const void* aFirstFramePC, uint32_t aMaxFrames, + void* aClosure); + +typedef struct { + /* + * The name of the shared library or executable containing an + * address and the address's offset within that library, or empty + * string and zero if unknown. + */ + char library[256]; + ptrdiff_t loffset; + /* + * The name of the file name and line number of the code + * corresponding to the address, or empty string and zero if + * unknown. + */ + char filename[256]; + unsigned long lineno; + /* + * The name of the function containing an address and the address's + * offset within that function, or empty string and zero if unknown. + */ + char function[256]; + ptrdiff_t foffset; +} MozCodeAddressDetails; + +/** + * For a given pointer to code, fill in the pieces of information used + * when printing a stack trace. + * + * @param aPC The code address. + * @param aDetails A structure to be filled in with the result. + */ +MFBT_API bool MozDescribeCodeAddress(void* aPC, + MozCodeAddressDetails* aDetails); + +/** + * Format the information about a code address in a format suitable for + * stack traces on the current platform. When available, this string + * should contain the function name, source file, and line number. When + * these are not available, library and offset should be reported, if + * possible. + * + * Note that this output is parsed by several scripts including the fix*.py and + * make-tree.pl scripts in tools/rb/. It should only be change with care, and + * in conjunction with those scripts. + * + * @param aBuffer A string to be filled in with the description. + * The string will always be null-terminated. + * @param aBufferSize The size, in bytes, of aBuffer, including + * room for the terminating null. If the information + * to be printed would be larger than aBuffer, it + * will be truncated so that aBuffer[aBufferSize-1] + * is the terminating null. + * @param aFrameNumber The frame number. + * @param aPC The code address. + * @param aFunction The function name. Possibly null or the empty string. + * @param aLibrary The library name. Possibly null or the empty string. + * @param aLOffset The library offset. + * @param aFileName The filename. Possibly null or the empty string. + * @param aLineNo The line number. Possibly zero. + * @return The minimum number of characters necessary to format + * the frame information, without the terminating null. + * The buffer will have been truncated if the returned + * value is greater than aBufferSize-1. + */ +MFBT_API int MozFormatCodeAddress(char* aBuffer, uint32_t aBufferSize, + uint32_t aFrameNumber, const void* aPC, + const char* aFunction, const char* aLibrary, + ptrdiff_t aLOffset, const char* aFileName, + uint32_t aLineNo); + +/** + * Format the information about a code address in the same fashion as + * MozFormatCodeAddress. + * + * @param aBuffer A string to be filled in with the description. + * The string will always be null-terminated. + * @param aBufferSize The size, in bytes, of aBuffer, including + * room for the terminating null. If the information + * to be printed would be larger than aBuffer, it + * will be truncated so that aBuffer[aBufferSize-1] + * is the terminating null. + * @param aFrameNumber The frame number. + * @param aPC The code address. + * @param aDetails The value filled in by MozDescribeCodeAddress(aPC). + * @return The minimum number of characters necessary to format + * the frame information, without the terminating null. + * The buffer will have been truncated if the returned + * value is greater than aBufferSize-1. + */ +MFBT_API int MozFormatCodeAddressDetails(char* aBuffer, uint32_t aBufferSize, + uint32_t aFrameNumber, void* aPC, + const MozCodeAddressDetails* aDetails); + +#ifdef __cplusplus +# define FRAMES_DEFAULT = 0 +#else +# define FRAMES_DEFAULT +#endif +/** + * Walk the stack and print the stack trace to the given stream. + * + * @param aStream A stdio stream. + * @param aFirstFramePC Position of the Program Counter where the trace + * starts from. All frames seen before reaching that + * address are skipped. Nullptr means that the first + * callback will be for the caller of MozWalkTheStack. + * @param aMaxFrames Maximum number of frames to trace. 0 means no limit. + */ +MFBT_API void MozWalkTheStack(FILE* aStream, + const void* aFirstFramePC FRAMES_DEFAULT, + uint32_t aMaxFrames FRAMES_DEFAULT); + +/** + * Walk the stack and send each stack trace line to a callback writer. + * Each line string is null terminated but doesn't contain a '\n' character. + * + * @param aWriter The callback. + * @param aFirstFramePC Position of the Program Counter where the trace + * starts from. All frames seen before reaching that + * address are skipped. Nullptr means that the first + * callback will be for the caller of + * MozWalkTheStackWithWriter. + * @param aMaxFrames Maximum number of frames to trace. 0 means no limit. + */ +MFBT_API void MozWalkTheStackWithWriter( + void (*aWriter)(const char*), const void* aFirstFramePC FRAMES_DEFAULT, + uint32_t aMaxFrames FRAMES_DEFAULT); + +#undef FRAMES_DEFAULT + +MOZ_END_EXTERN_C + +#ifdef __cplusplus +namespace mozilla { + +MFBT_API void FramePointerStackWalk(MozWalkStackCallback aCallback, + uint32_t aMaxFrames, void* aClosure, + void** aBp, void* aStackEnd); + +# if defined(XP_LINUX) || defined(XP_FREEBSD) +MFBT_API void DemangleSymbol(const char* aSymbol, char* aBuffer, int aBufLen); +# endif + +} // namespace mozilla +#endif + +#endif |