glibc/nptl/pt-longjmp.c

/* ABI compatibility for 'longjmp' and 'siglongjmp' symbols in libpthread ABI.
   Copyright (C) 2002-2015 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   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, see
   <http://www.gnu.org/licenses/>.  */

#include <setjmp.h>
#include <shlib-compat.h>

/* libpthread once had its own longjmp (and siglongjmp alias), though there
   was no apparent reason for it.  There is no use in having a separate
   symbol in libpthread, but the historical ABI requires it.  For static
   linking, there is no need to provide anything here--the libc version
   will be linked in.  For shared library ABI compatibility, there must be
   longjmp and siglongjmp symbols in libpthread.so; so we define them using
   IFUNC to redirect to the libc function.  */

#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)

# if HAVE_IFUNC

static __typeof (longjmp) *
__attribute__ ((used))
longjmp_resolve (void)
{
  return &__libc_longjmp;
}

#  ifdef HAVE_ASM_SET_DIRECTIVE
#   define DEFINE_LONGJMP(name) \
  asm (".set " #name ", longjmp_resolve\n" \
       ".globl " #name "\n" \
       ".type " #name ", %gnu_indirect_function");
#  else
#   define DEFINE_LONGJMP(name) \
  asm (#name " = longjmp_resolve\n" \
       ".globl " #name "\n" \
       ".type " #name ", %gnu_indirect_function");
#  endif

# else  /* !HAVE_IFUNC */

static void __attribute__ ((noreturn, used))
longjmp_compat (jmp_buf env, int val)
{
  __libc_longjmp (env, val);
}

# define DEFINE_LONGJMP(name) strong_alias (longjmp_compat, name)

# endif  /* HAVE_IFUNC */

DEFINE_LONGJMP (longjmp_ifunc)
compat_symbol (libpthread, longjmp_ifunc, longjmp, GLIBC_2_0);

DEFINE_LONGJMP (siglongjmp_ifunc)
compat_symbol (libpthread, siglongjmp_ifunc, siglongjmp, GLIBC_2_0);

#endif