jmpbuf-unwind.h

glibc 库, 不仅可以学习使用库函数,还可以学习函数的具体实现,是提高功力的好资料

/* Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Jakub Jelinek <[e-mail]>, 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 <setjmp.h>
#include <jmpbuf-offsets.h>
#include <stdint.h>
#include <unwind.h>
#include <sysdep.h>

/* Test if longjmp to JMPBUF would unwind the frame
   containing a local variable at ADDRESS.  */
#define _JMPBUF_UNWINDS(jmpbuf, address, demangle) \
  ((int) (address) < demangle ((jmpbuf)[JB_SP]))

#define _JMPBUF_CFA_UNWINDS_ADJ(_jmpbuf, _context, _adj) \
  _JMPBUF_UNWINDS_ADJ (_jmpbuf, (void *) _Unwind_GetCFA (_context), _adj)

static inline uintptr_t __attribute__ ((unused))
_jmpbuf_sp (__jmp_buf regs)
{
  uintptr_t sp = regs[JB_SP];
#ifdef PTR_DEMANGLE
  PTR_DEMANGLE (sp);
#endif
  return sp;
}

#define _JMPBUF_UNWINDS_ADJ(_jmpbuf, _address, _adj) \
  ((uintptr_t) (_address) - (_adj) < _jmpbuf_sp (_jmpbuf) - (_adj))

/* We use the normal lobngjmp for unwinding.  */
#define __libc_unwind_longjmp(buf, val) __libc_longjmp (buf, val)