glibc/sysdeps/i386/bsd-setjmp.S

/* BSD `setjmp' entry point to `sigsetjmp (..., 1)'.  i386 version.
   Copyright (C) 1994,1995,1996,1997,2000,2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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.  */

/* This just does a tail-call to `__sigsetjmp (ARG, 1)'.
   We cannot do it in C because it must be a tail-call, so frame-unwinding
   in setjmp doesn't clobber the state restored by longjmp.  */

#include <sysdep.h>
#define _ASM
#define _SETJMP_H
#include <bits/setjmp.h>
#include "bp-sym.h"
#include "bp-asm.h"

ENTRY (BP_SYM (setjmp))
	/* Note that we have to use a non-exported symbol in the next
	   jump since otherwise gas will emit it as a jump through the
	   PLT which is what we cannot use here.  */
	ENTER

	movl JMPBUF(%esp), %eax
	CHECK_BOUNDS_BOTH_WIDE (%eax, JMPBUF(%esp), $JB_SIZE)

     	/* Save registers.  */
	movl %ebx, (JB_BX*4)(%eax)
	movl %esi, (JB_SI*4)(%eax)
	movl %edi, (JB_DI*4)(%eax)
	leal JMPBUF(%esp), %ecx	/* Save SP as it will be after we return.  */
     	movl %ecx, (JB_SP*4)(%eax)
	movl PCOFF(%esp), %ecx	/* Save PC we are returning to now.  */
     	movl %ecx, (JB_PC*4)(%eax)
	LEAVE /* pop frame pointer to prepare for tail-call.  */
	movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer.  */

	/* Call __sigjmp_save.  */
	pushl $1
	pushl 8(%esp)
	call BP_SYM (__sigjmp_save)
	popl %ecx
	popl %edx
	ret
END (BP_SYM (setjmp))