glibc/sysdeps/generic/backtrace.c
Ulrich Drepper e021cda255 Update.
1998-06-16  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/generic/backtrace.c (INNER_THAN): New definition, use it
	to compare stack addresses.
1998-06-17 10:24:52 +00:00

90 lines
2.7 KiB
C

/* Return backtrace of current program state. Generic version.
Copyright (C) 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <execinfo.h>
/* This is a global variable set at program start time. It marks the
highest used stack address. */
extern void *__libc_stack_end;
/* This implementation assumes a stack layout that matches the defaults
used by gcc's `__builtin_frame_address' and `__builtin_return_address'
(FP is the frame pointer register):
+-----------------+ +-----------------+
FP -> | previous FP --------> | previous FP ------>...
| | | |
| return address | | return address |
+-----------------+ +-----------------+
*/
/* Get some notion of the current stack. Need not be exactly the top
of the stack, just something somewhere in the current frame. */
#ifndef CURRENT_STACK_FRAME
# define CURRENT_STACK_FRAME ({ char __csf; &__csf; })
#endif
/* By default we assume that the stack grows downward. */
#ifndef INNER_THAN
# define INNER_THAN <
#endif
struct layout
{
struct layout *next;
void *return_address;
};
int
__backtrace (array, size)
void **array;
int size;
{
struct layout *current;
void *top_frame;
void *top_stack;
int cnt = 0;
top_frame = __builtin_frame_address (0);
top_stack = CURRENT_STACK_FRAME;
/* We skip the call to this function, it makes no sense to record it. */
current = (struct layout *) top_frame;
while (cnt < size)
{
if ((void *) current INNER_THAN top_stack
|| !((void *) current INNER_THAN __libc_stack_end))
/* This means the address is out of range. Note that for the
toplevel we see a frame pointer with value NULL which clearly is
out of range. */
break;
array[cnt++] = current->return_address;
current = current->next;
}
return cnt;
}
weak_alias (__backtrace, backtrace)