sysdeps/unix/sysv/linux/ia64/sys/ucontext.h

   1 /* Copyright (C) 1998, 2000, 2001, 2002, 2004 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef _SYS_UCONTEXT_H
  20 #define _SYS_UCONTEXT_H 1
  21
  22 #include <features.h>
  23 #include <signal.h>
  24
  25 #include <bits/sigcontext.h>
  26
  27 /*
  28  * These are here mostly for backwards compatibility with older Unices.
  29  * IA-64 Linux does not distinguish between "struct sigcontext" and
  30  * "ucontext_t" as all the necessary info is inside the former.
  31  */
  32
  33 typedef struct sigcontext mcontext_t;
  34
  35 #if defined __cplusplus && __GNUC_PREREQ (3, 5)
  36 # define _SC_GR0_OFFSET \
  37         __builtin_offsetof (struct sigcontext, sc_gr[0])
  38 #elif defined __GNUC__
  39 # define _SC_GR0_OFFSET \
  40         (((char *) &((struct sigcontext *) 0)->sc_gr[0]) - (char *) 0)
  41 #else
  42 # define _SC_GR0_OFFSET 0xc8    /* pray that this is correct... */
  43 #endif
  44
  45 typedef struct ucontext
  46   {
  47     union
  48       {
  49         mcontext_t _mc;
  50         struct
  51           {
  52             unsigned long _pad[_SC_GR0_OFFSET/8];
  53             struct ucontext *_link;     /* this should overlay sc_gr[0] */
  54           }
  55         _uc;
  56       }
  57     _u;
  58   }
  59 ucontext_t;
  60
  61 #define uc_mcontext     _u._mc
  62 #define uc_sigmask      _u._mc.sc_mask
  63 #define uc_stack        _u._mc.sc_stack
  64 #define uc_link         _u._uc._link
  65
  66 #endif /* sys/ucontext.h */