setjmp/setjmp.h

   1 /* Copyright (C) 1991-2018 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/types/__sigset_t.h>
  31
  32 /* Calling environment, plus possibly a saved signal mask.  */
  33 struct __jmp_buf_tag
  34   {
  35     /* NOTE: The machine-dependent definitions of `__sigsetjmp'
  36        assume that a `jmp_buf' begins with a `__jmp_buf' and that
  37        `__mask_was_saved' follows it.  Do not move these members
  38        or add others before it.  */
  39     __jmp_buf __jmpbuf;         /* Calling environment.  */
  40     int __mask_was_saved;       /* Saved the signal mask?  */
  41     __sigset_t __saved_mask;    /* Saved signal mask.  */
  42   };
  43
  44
  45 typedef struct __jmp_buf_tag jmp_buf[1];
  46
  47 /* Store the calling environment in ENV, also saving the signal mask.
  48    Return 0.  */
  49 extern int setjmp (jmp_buf __env) __THROWNL;
  50
  51 /* Store the calling environment in ENV, also saving the
  52    signal mask if SAVEMASK is nonzero.  Return 0.
  53    This is the internal name for `sigsetjmp'.  */
  54 extern int __sigsetjmp (struct __jmp_buf_tag __env[1], int __savemask) __THROWNL;
  55
  56 /* Store the calling environment in ENV, not saving the signal mask.
  57    Return 0.  */
  58 extern int _setjmp (struct __jmp_buf_tag __env[1]) __THROWNL;
  59
  60 /* Do not save the signal mask.  This is equivalent to the `_setjmp'
  61    BSD function.  */
  62 #define setjmp(env)     _setjmp (env)
  63
  64
  65 /* Jump to the environment saved in ENV, making the
  66    `setjmp' call there return VAL, or 1 if VAL is 0.  */
  67 extern void longjmp (struct __jmp_buf_tag __env[1], int __val)
  68      __THROWNL __attribute__ ((__noreturn__));
  69
  70 #if defined __USE_MISC || defined __USE_XOPEN
  71 /* Same.  Usually `_longjmp' is used with `_setjmp', which does not save
  72    the signal mask.  But it is how ENV was saved that determines whether
  73    `longjmp' restores the mask; `_longjmp' is just an alias.  */
  74 extern void _longjmp (struct __jmp_buf_tag __env[1], int __val)
  75      __THROWNL __attribute__ ((__noreturn__));
  76 #endif
  77
  78
  79 #ifdef  __USE_POSIX
  80 /* Use the same type for `jmp_buf' and `sigjmp_buf'.
  81    The `__mask_was_saved' flag determines whether
  82    or not `longjmp' will restore the signal mask.  */
  83 typedef struct __jmp_buf_tag sigjmp_buf[1];
  84
  85 /* Store the calling environment in ENV, also saving the
  86    signal mask if SAVEMASK is nonzero.  Return 0.  */
  87 # define sigsetjmp(env, savemask)       __sigsetjmp (env, savemask)
  88
  89 /* Jump to the environment saved in ENV, making the
  90    sigsetjmp call there return VAL, or 1 if VAL is 0.
  91    Restore the signal mask if that sigsetjmp call saved it.
  92    This is just an alias `longjmp'.  */
  93 extern void siglongjmp (sigjmp_buf __env, int __val)
  94      __THROWNL __attribute__ ((__noreturn__));
  95 #endif /* Use POSIX.  */
  96
  97
  98 /* Define helper functions to catch unsafe code.  */
  99 #if __USE_FORTIFY_LEVEL > 0
 100 # include <bits/setjmp2.h>
 101 #endif
 102
 103 __END_DECLS
 104
 105 #endif /* setjmp.h  */