ports/sysdeps/m68k/stackinfo.h

   1 /* Copyright (C) 1999-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library.  If not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 /* This file contains a bit of information about the stack allocation
  19    of the processor.  */
  20
  21 #ifndef _STACKINFO_H
  22 #define _STACKINFO_H    1
  23
  24 #include <elf.h>
  25
  26 /* On m68k the stack grows down.  */
  27 #define _STACK_GROWS_DOWN       1
  28
  29 /* Default to an executable stack.  PF_X can be overridden if PT_GNU_STACK
  30    is present, but it is presumed absent.  */
  31 #define DEFAULT_STACK_PERMS (PF_R|PF_W|PF_X)
  32
  33 /* Access to the stack pointer.  */
  34 #define stackinfo_get_sp() \
  35   ({ void *p__; asm volatile ("move.l %%sp, %0" : "=r" (p__)); p__; })
  36 #define stackinfo_sub_sp(ptr) \
  37   ({ ptrdiff_t d__;                                             \
  38      asm volatile ("sub.l %%sp, %0" : "=r" (d__) : "0" (ptr));  \
  39      d__; })
  40
  41 #endif  /* stackinfo.h */