gl/stddef.in.h

   1 /* A substitute for POSIX 2008 <stddef.h>, for platforms that have issues.
   2
   3    Copyright (C) 2009-2011 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 /* Written by Eric Blake.  */
  20
  21 /*
  22  * POSIX 2008 <stddef.h> for platforms that have issues.
  23  * <http://www.opengroup.org/susv3xbd/stddef.h.html>
  24  */
  25
  26 #if __GNUC__ >= 3
  27 @PRAGMA_SYSTEM_HEADER@
  28 #endif
  29 @PRAGMA_COLUMNS@
  30
  31 #if defined __need_wchar_t || defined __need_size_t  \
  32   || defined __need_ptrdiff_t || defined __need_NULL \
  33   || defined __need_wint_t
  34 /* Special invocation convention inside gcc header files.  In
  35    particular, gcc provides a version of <stddef.h> that blindly
  36    redefines NULL even when __need_wint_t was defined, even though
  37    wint_t is not normally provided by <stddef.h>.  Hence, we must
  38    remember if special invocation has ever been used to obtain wint_t,
  39    in which case we need to clean up NULL yet again.  */
  40
  41 # if !(defined _GL_STDDEF_H && defined _GL_STDDEF_WINT_T)
  42 #  ifdef __need_wint_t
  43 #   undef _GL_STDDEF_H
  44 #   define _GL_STDDEF_WINT_T
  45 #  endif
  46 #  @INCLUDE_NEXT@ @NEXT_STDDEF_H@
  47 # endif
  48
  49 #else
  50 /* Normal invocation convention.  */
  51
  52 # ifndef _GL_STDDEF_H
  53
  54 /* The include_next requires a split double-inclusion guard.  */
  55
  56 #  @INCLUDE_NEXT@ @NEXT_STDDEF_H@
  57
  58 #  ifndef _GL_STDDEF_H
  59 #   define _GL_STDDEF_H
  60
  61 /* On NetBSD 5.0, the definition of NULL lacks proper parentheses.  */
  62 #if @REPLACE_NULL@
  63 # undef NULL
  64 # ifdef __cplusplus
  65    /* ISO C++ says that the macro NULL must expand to an integer constant
  66       expression, hence '((void *) 0)' is not allowed in C++.  */
  67 #  if __GNUG__ >= 3
  68     /* GNU C++ has a __null macro that behaves like an integer ('int' or
  69        'long') but has the same size as a pointer.  Use that, to avoid
  70        warnings.  */
  71 #   define NULL __null
  72 #  else
  73 #   define NULL 0L
  74 #  endif
  75 # else
  76 #  define NULL ((void *) 0)
  77 # endif
  78 #endif
  79
  80 /* Some platforms lack wchar_t.  */
  81 #if !@HAVE_WCHAR_T@
  82 # define wchar_t int
  83 #endif
  84
  85 #  endif /* _GL_STDDEF_H */
  86 # endif /* _GL_STDDEF_H */
  87 #endif /* __need_XXX */