unwind_prot.h

   1 /* unwind_prot.h - Macros and functions for hacking unwind protection. */
   2
   3 /* Copyright (C) 1993 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software; you can redistribute it and/or modify it under
   8    the terms of the GNU General Public License as published by the Free
   9    Software Foundation; either version 2, or (at your option) any later
  10    version.
  11
  12    Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  13    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15    for more details.
  16
  17    You should have received a copy of the GNU General Public License along
  18    with Bash; see the file COPYING.  If not, write to the Free Software
  19    Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
  20
  21 #if !defined (_UNWIND_PROT_H)
  22 #define _UNWIND_PROT_H
  23
  24 /* Run a function without interrupts. */
  25 extern void begin_unwind_frame ();
  26 extern void discard_unwind_frame ();
  27 extern void run_unwind_frame ();
  28 extern void add_unwind_protect ();
  29 extern void remove_unwind_protect ();
  30 extern void run_unwind_protects ();
  31 extern void unwind_protect_var ();
  32 extern void clear_unwind_protect_list ();
  33
  34 /* Try to force correct alignment on machines where pointers and ints
  35    differ in size. */
  36 typedef union {
  37   char *s;
  38   int i;
  39 } UWP;
  40
  41 /* Define for people who like their code to look a certain way. */
  42 #define end_unwind_frame()
  43
  44 /* How to protect an integer. */
  45 #define unwind_protect_int(X) \
  46         do \
  47           { \
  48             UWP u; \
  49             u.i = (X); \
  50             unwind_protect_var (&(X), u.s, sizeof (int)); \
  51           } \
  52         while (0)
  53
  54 #define unwind_protect_short(X) \
  55   unwind_protect_var ((int *)&(X), (char *)&(X), sizeof (short))
  56
  57 /* How to protect a pointer to a string. */
  58 #define unwind_protect_string(X) \
  59   unwind_protect_var ((int *)&(X), \
  60                       ((sizeof (char *) == sizeof (int)) ? (char *) (X) : (char *) &(X)), \
  61                        sizeof (char *))
  62
  63 /* How to protect any old pointer. */
  64 #define unwind_protect_pointer(X) unwind_protect_string (X)
  65
  66 /* How to protect the contents of a jmp_buf. */
  67 #define unwind_protect_jmp_buf(X) \
  68   unwind_protect_var ((int *)(X), (char *)(X), sizeof (procenv_t))
  69
  70 #endif /* _UNWIND_PROT_H */