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

   1 /* Copyright (C) 1998-2016 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 #ifndef _SYS_UCONTEXT_H
  19 #define _SYS_UCONTEXT_H 1
  20
  21 #include <features.h>
  22 #include <signal.h>
  23
  24 /* We need the signal context definitions even if they are not exposed
  25    by <signal.h>.  */
  26 #include <bits/sigcontext.h>
  27 #include <bits/sigstack.h>
  28
  29
  30 /*
  31  * These are here mostly for backwards compatibility with older Unices.
  32  * IA-64 Linux does not distinguish between "struct sigcontext" and
  33  * "ucontext_t" as all the necessary info is inside the former.
  34  */
  35
  36 typedef struct sigcontext mcontext_t;
  37
  38 #if __GNUC_PREREQ (3, 5)
  39 # define _SC_GR0_OFFSET \
  40         __builtin_offsetof (struct sigcontext, sc_gr[0])
  41 #elif defined __GNUC__
  42 # define _SC_GR0_OFFSET \
  43         (((char *) &((struct sigcontext *) 0)->sc_gr[0]) - (char *) 0)
  44 #else
  45 # define _SC_GR0_OFFSET 0xc8    /* pray that this is correct... */
  46 #endif
  47
  48 typedef struct ucontext
  49   {
  50     union
  51       {
  52         mcontext_t _mc;
  53         struct
  54           {
  55             unsigned long _pad[_SC_GR0_OFFSET/8];
  56             struct ucontext *_link;     /* this should overlay sc_gr[0] */
  57           }
  58         _uc;
  59       }
  60     _u;
  61   }
  62 ucontext_t;
  63
  64 #define uc_mcontext     _u._mc
  65 #define uc_sigmask      _u._mc.sc_mask
  66 #define uc_stack        _u._mc.sc_stack
  67 #define uc_link         _u._uc._link
  68
  69 #endif /* sys/ucontext.h */