__longjmp.c

来自「Glibc 2.3.2源代码(解压后有100多M)」· C语言 代码 · 共 44 行

/* Copyright (C) 2000, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Martin Schwidefsky ([e-mail]).

   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 <errno.h>
#include <sysdep.h>
#include <setjmp.h>
#include <bits/setjmp.h>
#include <stdlib.h>
#include <unistd.h>

/* Jump to the position specified by ENV, causing the
   setjmp call there to return VAL, or 1 if VAL is 0.  */
void
__longjmp (__jmp_buf env, int val)
{
   /* Restore registers and jump back.  */
   asm volatile ("lr   %%r2,%0\n\t"	  /* PUT val in grp 2.  */
		 "ld   %%f6,48(%1)\n\t"
		 "ld   %%f4,40(%1)\n\t"
		 "lm   %%r6,%%r15,0(%1)\n\t"
		 "br   %%r14"
		 : : "r" (val == 0 ? 1 : val),
		 "a" (env) : "2" );

  /* Avoid `volatile function does return' warnings.  */
  for (;;);
}