setjmp/setjmp.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 /*
  20  *      ANSI Standard: 4.6 NON-LOCAL JUMPS <setjmp.h>
  21  */
  22
  23 #ifndef _SETJMP_H
  24
  25 #define _SETJMP_H       1
  26 #include <features.h>
  27
  28 __BEGIN_DECLS
  29
  30 /* Get the machine-dependent definition of `__jmp_buf'.  */
  31 #include <jmp_buf.h>
  32 #include <sigset.h>             /* Get `__sigset_t'.  */
  33
  34 /* Calling environment, plus possibly a saved signal mask.  */
  35 typedef struct __jmp_buf_tag    /* C++ doesn't like tagless structs.  */
  36   {
  37     /* NOTE: The machine-dependent definitions of `__sigsetjmp'
  38        assume that a `jmp_buf' begins with a `__jmp_buf'.
  39        Do not move this member or add others before it.  */
  40     __jmp_buf __jmpbuf;         /* Calling environment.  */
  41     int __mask_was_saved;       /* Saved the signal mask?  */
  42     __sigset_t __saved_mask;    /* Saved signal mask.  */
  43   } jmp_buf[1];
  44
  45
  46 /* Store the calling environment in ENV, also saving the
  47    signal mask if SAVEMASK is nonzero.  Return 0.
  48    This is the internal name for `sigsetjmp'.  */
  49 extern int __sigsetjmp __P ((jmp_buf __env, int __savemask));
  50
  51 #ifndef __FAVOR_BSD
  52 /* Set ENV to the current position and return 0, not saving the signal mask.
  53    This is just like `sigsetjmp (ENV, 0)'.
  54    The ANSI C standard says `setjmp' is a macro.  */
  55 #define setjmp(env)     __sigsetjmp ((env), 0)
  56 #else
  57 /* We are in 4.3 BSD-compatibility mode in which `setjmp'
  58    saves the signal mask like `sigsetjmp (ENV, 1)'.  */
  59 #define setjmp(env)     __sigsetjmp ((env), 1)
  60 #endif /* Favor BSD.  */
  61
  62 #ifdef __USE_BSD
  63 /* Set ENV to the current position and return 0, not saving the signal mask.
  64    This is the 4.3 BSD name for ANSI `setjmp'.  */
  65 #define _setjmp(env)    __sigsetjmp ((env), 0)
  66 #endif
  67
  68
  69 /* Jump to the environment saved in ENV, making the
  70    `setjmp' call there return VAL, or 1 if VAL is 0.  */
  71 extern void longjmp __P ((jmp_buf __env, int __val))
  72      __attribute__ ((__noreturn__));
  73 #ifdef  __USE_BSD
  74 /* Same.  Usually `_longjmp' is used with `_setjmp', which does not save
  75    the signal mask.  But it is how ENV was saved that determines whether
  76    `longjmp' restores the mask; `_longjmp' is just an alias.  */
  77 extern void _longjmp __P ((jmp_buf __env, int __val))
  78      __attribute__ ((__noreturn__));
  79 #endif /* Use BSD.  */
  80
  81 /* Internal machine-dependent function to restore context sans signal mask.  */
  82 extern void __longjmp __P ((__jmp_buf __env, int __val))
  83      __attribute__ ((__noreturn__));
  84
  85 /* Internal function to possibly save the current mask of blocked signals
  86    in ENV, and always set the flag saying whether or not it was saved.
  87    This is used by the machine-dependent definition of `__sigsetjmp'.
  88    Always returns zero, for convenience.  */
  89 extern int __sigjmp_save __P ((jmp_buf __env, int __savemask));
  90
  91
  92 #ifdef  __USE_POSIX
  93 /* Use the same type for `jmp_buf' and `sigjmp_buf'.
  94    The `__mask_was_saved' flag determines whether
  95    or not `longjmp' will restore the signal mask.  */
  96 typedef jmp_buf sigjmp_buf;
  97
  98 /* Store the calling environment in ENV, also saving the
  99    signal mask if SAVEMASK is nonzero.  Return 0.  */
 100 #define sigsetjmp(env, savemask)        __sigsetjmp ((env), (savemask))
 101
 102 /* Jump to the environment saved in ENV, making the
 103    sigsetjmp call there return VAL, or 1 if VAL is 0.
 104    Restore the signal mask if that sigsetjmp call saved it.
 105    This is just an alias `longjmp'.  */
 106 extern void siglongjmp __P ((sigjmp_buf __env, int __val))
 107      __attribute__ ((__noreturn__));
 108 #endif /* Use POSIX.  */
 109
 110 __END_DECLS
 111
 112 #endif /* setjmp.h  */