NEWS: warnings with clang

[bison.git] / src / system.h

/* System-dependent definitions for Bison.

   Copyright (C) 2000-2007, 2009-2012 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef BISON_SYSTEM_H
# define BISON_SYSTEM_H

/* flex 2.5.31 gratutiously defines macros like INT8_MIN.  But this
   runs afoul of pre-C99 compilers that have <inttypes.h> or
   <stdint.h>, which are included below if available.  It also runs
   afoul of pre-C99 compilers that define these macros in <limits.h>.  */
# if ! defined __STDC_VERSION__ || __STDC_VERSION__ < 199901
#  undef INT8_MIN
#  undef INT16_MIN
#  undef INT32_MIN
#  undef INT8_MAX
#  undef INT16_MAX
#  undef UINT8_MAX
#  undef INT32_MAX
#  undef UINT16_MAX
#  undef UINT32_MAX
# endif

# include <limits.h>
# include <stddef.h>
# include <stdlib.h>
# include <string.h>
# include <unistd.h>
# include <inttypes.h>

# ifndef UINTPTR_MAX
/* This isn't perfect, but it's good enough for Bison, which needs
   only to hash pointers.  */
typedef size_t uintptr_t;
# endif

// Version mismatch.
# define EX_MISMATCH 63

/*---------.
| Gnulib.  |
`---------*/

# include <unlocked-io.h>
# include <verify.h>
# include <xalloc.h>


/*-----------------.
| GCC extensions.  |
`-----------------*/

/* Use PACIFY_CC to indicate that Code is unimportant to the logic of Bison
   but that it is necessary for suppressing compiler warnings.  For example,
   Code might be a variable initializer that's always overwritten before the
   variable is used.

   PACIFY_CC is intended to be useful only as a comment as it does not alter
   Code.  It is tempting to redefine PACIFY_CC so that it will suppress Code
   when configuring without --enable-gcc-warnings.  However, that would mean
   that, for maintainers, Bison would compile with potentially less warnings
   and safer logic than it would for users.  Due to the overhead of M4,
   suppressing Code is unlikely to offer any significant improvement in
   Bison's performance anyway.  */
# define PACIFY_CC(Code) Code

# ifndef __attribute__
/* This feature is available in gcc versions 2.5 and later.  */
#  if (! defined __GNUC__ || __GNUC__ < 2 \
       || (__GNUC__ == 2 && __GNUC_MINOR__ < 5))
#   define __attribute__(Spec) /* empty */
#  endif
# endif

/* The __-protected variants of `format' and `printf' attributes
   are accepted by gcc versions 2.6.4 (effectively 2.7) and later.  */
# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
#  define __format__ format
#  define __printf__ printf
# endif

# ifndef ATTRIBUTE_NORETURN
#  define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
# endif

# ifndef ATTRIBUTE_UNUSED
#  define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
# endif


/*------.
| NLS.  |
`------*/

# include <locale.h>

# include <gettext.h>
# define _(Msgid)  gettext (Msgid)
# define N_(Msgid) (Msgid)


/*-----------.
| Booleans.  |
`-----------*/

# include <stdbool.h>



/*-------------.
| Assertions.  |
`-------------*/

/* In the past, Bison defined aver to simply invoke abort in the case of
   a failed assertion.  The rationale was that <assert.h>'s assertions
   were too heavyweight and could be disabled too easily.  See
   discussions at
   <http://lists.gnu.org/archive/html/bison-patches/2006-01/msg00080.html>
   <http://lists.gnu.org/archive/html/bison-patches/2006-09/msg00111.html>.

   However, normal assert output can be helpful during development and
   in bug reports from users.  Moreover, it's not clear now that
   <assert.h>'s assertions are significantly heavyweight.  Finally, if
   users want to experiment with disabling assertions, it's debatable
   whether it's our responsibility to stop them.  See discussion
   starting at
   <http://lists.gnu.org/archive/html/bison-patches/2009-09/msg00013.html>.

   For now, we use assert but we call it aver throughout Bison in case
   we later wish to try another scheme.
*/
# include <assert.h>
# define aver assert


/*-----------.
| Obstacks.  |
`-----------*/

# define obstack_chunk_alloc xmalloc
# define obstack_chunk_free  free
# include <obstack.h>

# define obstack_sgrow(Obs, Str)                \
  obstack_grow (Obs, Str, strlen (Str))

/* Output Str escaped for our postprocessing (i.e., escape M4 special
   characters).

   For instance "[foo]" -> "@{foo@}", "$$" -> "$][$][". */

# define obstack_escape(Obs, Str)                       \
  do {                                                  \
    char const *p;                                      \
    for (p = Str; *p; p++)                              \
      switch (*p)                                       \
        {                                               \
        case '$': obstack_sgrow (Obs, "$]["); break;    \
        case '@': obstack_sgrow (Obs, "@@" ); break;    \
        case '[': obstack_sgrow (Obs, "@{" ); break;    \
        case ']': obstack_sgrow (Obs, "@}" ); break;    \
        default:  obstack_1grow (Obs, *p   ); break;    \
        }                                               \
  } while (0)


/* Output Str both quoted for M4 (i.e., embed in [[...]]), and escaped
   for our postprocessing (i.e., escape M4 special characters).  If
   Str is empty (or NULL), output "[]" instead of "[[]]" as it make M4
   programming easier (m4_ifval can be used).

   For instance "[foo]" -> "[[@{foo@}]]", "$$" -> "[[$][$][]]". */

# define obstack_quote(Obs, Str)                \
  do {                                          \
    char const* obstack_quote_p = Str;          \
    if (obstack_quote_p && obstack_quote_p[0])  \
      {                                         \
        obstack_sgrow (Obs, "[[");              \
        obstack_escape (Obs, obstack_quote_p);  \
        obstack_sgrow (Obs, "]]");              \
      }                                         \
    else                                        \
      obstack_sgrow (Obs, "[]");                \
  } while (0)





/*-----------------------------------------.
| Extensions to use for the output files.  |
`-----------------------------------------*/

# ifndef OUTPUT_EXT
#  define OUTPUT_EXT ".output"
# endif

# ifndef TAB_EXT
#  define TAB_EXT ".tab"
# endif



/*---------------------.
| Free a linked list.  |
`---------------------*/

# define LIST_FREE(Type, List)                  \
  do {                                          \
    Type *_node, *_next;                        \
    for (_node = List; _node; _node = _next)    \
      {                                         \
        _next = _node->next;                    \
        free (_node);                           \
      }                                         \
  } while (0)


/*---------------------------------------------.
| Debugging memory allocation (must be last).  |
`---------------------------------------------*/

# if WITH_DMALLOC
#  define DMALLOC_FUNC_CHECK
#  include <dmalloc.h>
# endif /* WITH_DMALLOC */

#endif  /* ! BISON_SYSTEM_H */