setjmp/setjmp.h

   1 /* Copyright (C) 1991-2017 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 /*
  19  *      ISO C99 Standard: 7.13 Nonlocal jumps   <setjmp.h>
  20  */
  21
  22 #ifndef _SETJMP_H
  23 #define _SETJMP_H       1
  24
  25 #include <features.h>
  26
  27 __BEGIN_DECLS
  28
  29 #include <bits/setjmp.h>                /* Get `__jmp_buf'.  */
  30 #include <bits/sigset.h>                /* Get `__sigset_t'.  */
  31
  32
  33 /* Calling environment, plus possibly a saved signal mask.  */
  34 struct __jmp_buf_tag
  35   {
  36     /* NOTE: The machine-dependent definitions of `__sigsetjmp'
  37        assume that a `jmp_buf' begins with a `__jmp_buf' and that
  38        `__mask_was_saved' follows it.  Do not move these members
  39        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   };
  44
  45
  46 typedef struct __jmp_buf_tag jmp_buf[1];
  47
  48 /* Store the calling environment in ENV, also saving the signal mask.
  49    Return 0.  */
  50 extern int setjmp (jmp_buf __env) __THROWNL;
  51
  52 /* Store the calling environment in ENV, also saving the
  53    signal mask if SAVEMASK is nonzero.  Return 0.
  54    This is the internal name for `sigsetjmp'.  */
  55 extern int __sigsetjmp (struct __jmp_buf_tag __env[1], int __savemask) __THROWNL;
  56
  57 /* Store the calling environment in ENV, not saving the signal mask.
  58    Return 0.  */
  59 extern int _setjmp (struct __jmp_buf_tag __env[1]) __THROWNL;
  60
  61 /* Do not save the signal mask.  This is equivalent to the `_setjmp'
  62    BSD function.  */
  63 #define setjmp(env)     _setjmp (env)
  64
  65
  66 /* Jump to the environment saved in ENV, making the
  67    `setjmp' call there return VAL, or 1 if VAL is 0.  */
  68 extern void longjmp (struct __jmp_buf_tag __env[1], int __val)
  69      __THROWNL __attribute__ ((__noreturn__));
  70
  71 #if defined __USE_MISC || defined __USE_XOPEN
  72 /* Same.  Usually `_longjmp' is used with `_setjmp', which does not save
  73    the signal mask.  But it is how ENV was saved that determines whether
  74    `longjmp' restores the mask; `_longjmp' is just an alias.  */
  75 extern void _longjmp (struct __jmp_buf_tag __env[1], int __val)
  76      __THROWNL __attribute__ ((__noreturn__));
  77 #endif
  78
  79
  80 #ifdef  __USE_POSIX
  81 /* Use the same type for `jmp_buf' and `sigjmp_buf'.
  82    The `__mask_was_saved' flag determines whether
  83    or not `longjmp' will restore the signal mask.  */
  84 typedef struct __jmp_buf_tag sigjmp_buf[1];
  85
  86 /* Store the calling environment in ENV, also saving the
  87    signal mask if SAVEMASK is nonzero.  Return 0.  */
  88 # define sigsetjmp(env, savemask)       __sigsetjmp (env, savemask)
  89
  90 /* Jump to the environment saved in ENV, making the
  91    sigsetjmp call there return VAL, or 1 if VAL is 0.
  92    Restore the signal mask if that sigsetjmp call saved it.
  93    This is just an alias `longjmp'.  */
  94 extern void siglongjmp (sigjmp_buf __env, int __val)
  95      __THROWNL __attribute__ ((__noreturn__));
  96 #endif /* Use POSIX.  */
  97
  98
  99 /* Define helper functions to catch unsafe code.  */
 100 #if __USE_FORTIFY_LEVEL > 0
 101 # include <bits/setjmp2.h>
 102 #endif
 103
 104 __END_DECLS
 105
 106 #endif /* setjmp.h  */