1# setenv.m4 serial 4
2dnl Copyright (C) 2001-2003 Free Software Foundation, Inc.
3dnl This file is free software, distributed under the terms of the GNU
4dnl General Public License.  As a special exception to the GNU General
5dnl Public License, this file may be distributed as part of a program
6dnl that contains a configuration script generated by Autoconf, under
7dnl the same distribution terms as the rest of that program.
8
9AC_DEFUN([gt_FUNC_SETENV],
10[
11  AC_REPLACE_FUNCS(setenv unsetenv)
12  if test $ac_cv_func_setenv = no; then
13    gl_PREREQ_SETENV
14  fi
15  if test $ac_cv_func_unsetenv = no; then
16    gl_PREREQ_UNSETENV
17  fi
18])
19
20# Check if a variable is properly declared.
21# gt_CHECK_VAR_DECL(includes,variable)
22AC_DEFUN([gt_CHECK_VAR_DECL],
23[
24  define([gt_cv_var], [gt_cv_var_]$2[_declaration])
25  AC_MSG_CHECKING([if $2 is properly declared])
26  AC_CACHE_VAL(gt_cv_var, [
27    AC_TRY_COMPILE([$1
28      extern struct { int foo; } $2;],
29      [$2.foo = 1;],
30      gt_cv_var=no,
31      gt_cv_var=yes)])
32  AC_MSG_RESULT($gt_cv_var)
33  if test $gt_cv_var = yes; then
34    AC_DEFINE([HAVE_]translit($2, [a-z], [A-Z])[_DECL], 1,
35              [Define if you have the declaration of $2.])
36  fi
37])
38
39# Prerequisites of lib/setenv.c.
40AC_DEFUN([gl_PREREQ_SETENV],
41[
42  AC_REQUIRE([gl_ALLOCSA])
43  AC_CHECK_HEADERS_ONCE(stdlib.h string.h unistd.h)
44  AC_CHECK_HEADERS(search.h)
45  AC_CHECK_FUNCS(tsearch)
46  gt_CHECK_VAR_DECL([#include <errno.h>], errno)
47  gt_CHECK_VAR_DECL([#include <unistd.h>], environ)
48])
49
50# Prerequisites of lib/unsetenv.c.
51AC_DEFUN([gl_PREREQ_UNSETENV],
52[
53  AC_CHECK_HEADERS_ONCE(stdlib.h string.h unistd.h)
54  gt_CHECK_VAR_DECL([#include <errno.h>], errno)
55  gt_CHECK_VAR_DECL([#include <unistd.h>], environ)
56])
57