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forked from 0ad/0ad
0ad/source/lib/sysdep/os/linux/ldbg.cpp
2010-10-04 17:21:55 +00:00

130 lines
3.9 KiB
C++

/* Copyright (c) 2010 Wildfire Games
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
// Note: This used to use BFD to get more useful debugging information.
// (See SVN r8270 if you want that code.)
// That requires binutils at runtime, which hits some bugs and library versioning
// issues on some Linux distros.
// The debugging info reported by this code with BFD wasn't especially useful,
// and it's easy enough to get people to run in gdb if we want a proper backtrace.
// So we now go with the simple approach of not using BFD.
#include "precompiled.h"
#include "lib/sysdep/sysdep.h"
#include "lib/debug.h"
#include <execinfo.h>
void* debug_GetCaller(void* UNUSED(context), const wchar_t* UNUSED(lastFuncToSkip))
{
// bt[0] == this function
// bt[1] == our caller
// bt[2] == the first caller they are interested in
// HACK: we currently don't support lastFuncToSkip (would require debug information),
// instead just returning the caller of the function calling us
void *bt[3];
int bt_size = backtrace(bt, 3);
if (bt_size < 3)
return NULL;
return bt[2];
}
LibError debug_DumpStack(wchar_t* buf, size_t max_chars, void* UNUSED(context), const wchar_t* UNUSED(lastFuncToSkip))
{
static const size_t N_FRAMES = 16;
void *bt[N_FRAMES];
int bt_size = 0;
wchar_t *bufpos = buf;
wchar_t *bufend = buf + max_chars;
bt_size = backtrace(bt, ARRAY_SIZE(bt));
// Assumed max length of a single print-out
static const size_t MAX_OUT_CHARS = 1024;
for (size_t i = 0; (int)i < bt_size && bufpos+MAX_OUT_CHARS < bufend; i++)
{
wchar_t file[DBG_FILE_LEN];
wchar_t symbol[DBG_SYMBOL_LEN];
int line;
int len;
if (debug_ResolveSymbol(bt[i], symbol, file, &line) == 0)
{
if (file[0])
len = swprintf(bufpos, MAX_OUT_CHARS, L"(%p) %ls:%d %ls\n", bt[i], file, line, symbol);
else
len = swprintf(bufpos, MAX_OUT_CHARS, L"(%p) %ls\n", bt[i], symbol);
}
else
{
len = swprintf(bufpos, MAX_OUT_CHARS, L"(%p)\n", bt[i]);
}
if (len < 0)
{
// MAX_OUT_CHARS exceeded, realistically this was caused by some
// mindbogglingly long symbol name... replace the end with an
// ellipsis and a newline
memcpy(&bufpos[MAX_OUT_CHARS-6], L"...\n", 5*sizeof(wchar_t));
len = MAX_OUT_CHARS;
}
bufpos += len;
}
return INFO::OK;
}
LibError debug_ResolveSymbol(void* ptr_of_interest, wchar_t* sym_name, wchar_t* file, int* line)
{
if (sym_name)
*sym_name = 0;
if (file)
*file = 0;
if (line)
*line = 0;
char** symbols = backtrace_symbols(&ptr_of_interest, 1);
if (symbols)
{
swprintf_s(sym_name, DBG_SYMBOL_LEN, L"%s", symbols[0]);
free(symbols);
// (Note that this will usually return a pretty useless string,
// because we compile with -fvisibility=hidden and there won't be
// any exposed symbols for backtrace_symbols to report.)
return INFO::OK;
}
else
{
return ERR::FAIL;
}
}
void debug_SetThreadName(char const* UNUSED(name))
{
// Currently unimplemented
}