gl/stddef.in.h

   1 /* A substitute for POSIX 2008 <stddef.h>, for platforms that have issues.
   2
   3    Copyright (C) 2009-2012 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, see <http://www.gnu.org/licenses/>.  */
  17
  18 /* Written by Eric Blake.  */
  19
  20 /*
  21  * POSIX 2008 <stddef.h> for platforms that have issues.
  22  * <http://www.opengroup.org/susv3xbd/stddef.h.html>
  23  */
  24
  25 #if __GNUC__ >= 3
  26 @PRAGMA_SYSTEM_HEADER@
  27 #endif
  28 @PRAGMA_COLUMNS@
  29
  30 #if defined __need_wchar_t || defined __need_size_t  \
  31   || defined __need_ptrdiff_t || defined __need_NULL \
  32   || defined __need_wint_t
  33 /* Special invocation convention inside gcc header files.  In
  34    particular, gcc provides a version of <stddef.h> that blindly
  35    redefines NULL even when __need_wint_t was defined, even though
  36    wint_t is not normally provided by <stddef.h>.  Hence, we must
  37    remember if special invocation has ever been used to obtain wint_t,
  38    in which case we need to clean up NULL yet again.  */
  39
  40 # if !(defined _@GUARD_PREFIX@_STDDEF_H && defined _GL_STDDEF_WINT_T)
  41 #  ifdef __need_wint_t
  42 #   undef _@GUARD_PREFIX@_STDDEF_H
  43 #   define _GL_STDDEF_WINT_T
  44 #  endif
  45 #  @INCLUDE_NEXT@ @NEXT_STDDEF_H@
  46 # endif
  47
  48 #else
  49 /* Normal invocation convention.  */
  50
  51 # ifndef _@GUARD_PREFIX@_STDDEF_H
  52
  53 /* The include_next requires a split double-inclusion guard.  */
  54
  55 #  @INCLUDE_NEXT@ @NEXT_STDDEF_H@
  56
  57 #  ifndef _@GUARD_PREFIX@_STDDEF_H
  58 #   define _@GUARD_PREFIX@_STDDEF_H
  59
  60 /* On NetBSD 5.0, the definition of NULL lacks proper parentheses.  */
  61 #if @REPLACE_NULL@
  62 # undef NULL
  63 # ifdef __cplusplus
  64    /* ISO C++ says that the macro NULL must expand to an integer constant
  65       expression, hence '((void *) 0)' is not allowed in C++.  */
  66 #  if __GNUG__ >= 3
  67     /* GNU C++ has a __null macro that behaves like an integer ('int' or
  68        'long') but has the same size as a pointer.  Use that, to avoid
  69        warnings.  */
  70 #   define NULL __null
  71 #  else
  72 #   define NULL 0L
  73 #  endif
  74 # else
  75 #  define NULL ((void *) 0)
  76 # endif
  77 #endif
  78
  79 /* Some platforms lack wchar_t.  */
  80 #if !@HAVE_WCHAR_T@
  81 # define wchar_t int
  82 #endif
  83
  84 #  endif /* _@GUARD_PREFIX@_STDDEF_H */
  85 # endif /* _@GUARD_PREFIX@_STDDEF_H */
  86 #endif /* __need_XXX */