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/* Return backtrace of current program state.
Copyright (C) 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <bits/libc-lock.h>
#include <dlfcn.h>
#include <execinfo.h>
#include <stdlib.h>
#include <unwind.h>
struct trace_arg
{
void **array;
int cnt, size;
};
static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
static void
init (void)
{
void *handle = __libc_dlopen ("libgcc_s.so.1");
if (handle == NULL)
return;
unwind_backtrace = __libc_dlsym (handle, "_Unwind_Backtrace");
unwind_getip = __libc_dlsym (handle, "_Unwind_GetIP");
if (unwind_getip == NULL)
unwind_backtrace = NULL;
}
static _Unwind_Reason_Code
backtrace_helper (struct _Unwind_Context *ctx, void *a)
{
struct trace_arg *arg = a;
/* We are first called with address in the __backtrace function.
Skip it. */
if (arg->cnt != -1)
arg->array[arg->cnt] = (void *) unwind_getip (ctx);
if (++arg->cnt == arg->size)
return _URC_END_OF_STACK;
return _URC_NO_REASON;
}
int
__backtrace (array, size)
void **array;
int size;
{
struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
__libc_once_define (static, once);
__libc_once (once, init);
if (unwind_backtrace == NULL)
return 0;
if (size >= 1)
unwind_backtrace (backtrace_helper, &arg);
/* _Unwind_Backtrace on IA-64 seems to put NULL address above
_start. Fix it up here. */
if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL)
--arg.cnt;
return arg.cnt != -1 ? arg.cnt : 0;
}
weak_alias (__backtrace, backtrace)
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