dnl A placeholder for POSIX 2008 <stddef.h>, for platforms that have issues.

# stddef_h.m4 serial 2

dnl Copyright (C) 2009, 2010 Free Software Foundation, Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_STDDEF_H],

[

AC_REQUIRE([gl_STDDEF_H_DEFAULTS])

AC_REQUIRE([gt_TYPE_WCHAR_T])

if test $gt_cv_c_wchar_t = no; then

HAVE_WCHAR_T=0

STDDEF_H=stddef.h

fi

AC_CACHE_CHECK([whether NULL can be used in arbitrary expressions],

[gl_cv_decl_null_works],

[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stddef.h>

int test[2 * (sizeof NULL == sizeof (void *)) -1];

]])],

[gl_cv_decl_null_works=yes],

[gl_cv_decl_null_works=no])])

if test $gl_cv_decl_null_works = no; then

REPLACE_NULL=1

STDDEF_H=stddef.h

fi

if test -n "$STDDEF_H"; then

gl_CHECK_NEXT_HEADERS([stddef.h])

fi

])

AC_DEFUN([gl_STDDEF_MODULE_INDICATOR],

[

dnl Use AC_REQUIRE here, so that the default settings are expanded once only.

AC_REQUIRE([gl_STDDEF_H_DEFAULTS])

gl_MODULE_INDICATOR_SET_VARIABLE([$1])

])

AC_DEFUN([gl_STDDEF_H_DEFAULTS],

[

dnl Assume proper GNU behavior unless another module says otherwise.

REPLACE_NULL=0; AC_SUBST([REPLACE_NULL])

HAVE_WCHAR_T=1; AC_SUBST([HAVE_WCHAR_T])

STDDEF_H=''; AC_SUBST([STDDEF_H])

])