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# environ.m4 serial 8
dnl Copyright (C) 2001-2004, 2006-2023 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_ONCE([gl_ENVIRON],
[
AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
dnl Persuade glibc <unistd.h> to declare environ.
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
AC_CHECK_HEADERS_ONCE([unistd.h])
gt_CHECK_VAR_DECL(
[#if HAVE_UNISTD_H
#include <unistd.h>
#endif
/* mingw, BeOS, Haiku declare environ in <stdlib.h>, not in <unistd.h>. */
#include <stdlib.h>
],
[environ])
if test $gt_cv_var_environ_declaration != yes; then
HAVE_DECL_ENVIRON=0
fi
])
# Check if a variable is properly declared.
# gt_CHECK_VAR_DECL(includes,variable)
AC_DEFUN([gt_CHECK_VAR_DECL],
[
define([gt_cv_var], [gt_cv_var_]$2[_declaration])
AC_CACHE_CHECK([if $2 is properly declared], [gt_cv_var],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[$1
typedef struct { int foo; } foo_t;
extern foo_t $2;]],
[[$2.foo = 1;]])],
[gt_cv_var=no],
[gt_cv_var=yes])])
if test $gt_cv_var = yes; then
AC_DEFINE([HAVE_]m4_translit($2, [a-z], [A-Z])[_DECL], 1,
[Define if you have the declaration of $2.])
fi
undefine([gt_cv_var])
])
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