1dnl A placeholder for POSIX 2008 <stddef.h>, for platforms that have issues.
2# stddef_h.m4 serial 1
3dnl Copyright (C) 2009 Free Software Foundation, Inc.
4dnl This file is free software; the Free Software Foundation
5dnl gives unlimited permission to copy and/or distribute it,
6dnl with or without modifications, as long as this notice is preserved.
7
8AC_DEFUN([gl_STDDEF_H],
9[
10  AC_REQUIRE([gl_STDDEF_H_DEFAULTS])
11  AC_REQUIRE([gt_TYPE_WCHAR_T])
12  if test $gt_cv_c_wchar_t = no; then
13    HAVE_WCHAR_T=0
14    STDDEF_H=stddef.h
15  fi
16  AC_CACHE_CHECK([whether NULL can be used in arbitrary expressions],
17    [gl_cv_decl_null_works],
18    [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stddef.h>
19      int test[2 * (sizeof NULL == sizeof (void *)) -1];
20]])],
21      [gl_cv_decl_null_works=yes],
22      [gl_cv_decl_null_works=no])])
23  if test $gl_cv_decl_null_works = no; then
24    REPLACE_NULL=1
25    STDDEF_H=stddef.h
26  fi
27  if test -n "$STDDEF_H"; then
28    gl_CHECK_NEXT_HEADERS([stddef.h])
29  fi
30])
31
32AC_DEFUN([gl_STDDEF_MODULE_INDICATOR],
33[
34  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
35  AC_REQUIRE([gl_STDDEF_H_DEFAULTS])
36  GNULIB_[]m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./-],[ABCDEFGHIJKLMNOPQRSTUVWXYZ___])=1
37])
38
39AC_DEFUN([gl_STDDEF_H_DEFAULTS],
40[
41  dnl Assume proper GNU behavior unless another module says otherwise.
42  REPLACE_NULL=0;                AC_SUBST([REPLACE_NULL])
43  HAVE_WCHAR_T=1;                AC_SUBST([HAVE_WCHAR_T])
44  STDDEF_H='';                   AC_SUBST([STDDEF_H])
45])
46