1# onceonly_2_57.m4 serial 3 2dnl Copyright (C) 2002-2003, 2005 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 9dnl This file defines some "once only" variants of standard autoconf macros. 10dnl AC_CHECK_HEADERS_ONCE like AC_CHECK_HEADERS 11dnl AC_CHECK_FUNCS_ONCE like AC_CHECK_FUNCS 12dnl AC_CHECK_DECLS_ONCE like AC_CHECK_DECLS 13dnl AC_REQUIRE([AC_HEADER_STDC]) like AC_HEADER_STDC 14dnl The advantage is that the check for each of the headers/functions/decls 15dnl will be put only once into the 'configure' file. It keeps the size of 16dnl the 'configure' file down, and avoids redundant output when 'configure' 17dnl is run. 18dnl The drawback is that the checks cannot be conditionalized. If you write 19dnl if some_condition; then gl_CHECK_HEADERS(stdlib.h); fi 20dnl inside an AC_DEFUNed function, the gl_CHECK_HEADERS macro call expands to 21dnl empty, and the check will be inserted before the body of the AC_DEFUNed 22dnl function. 23 24dnl This is like onceonly.m4, except that it uses diversions to named sections 25dnl DEFAULTS and INIT_PREPARE in order to check all requested headers at once, 26dnl thus reducing the size of 'configure'. Works with autoconf-2.57. The 27dnl size reduction is ca. 9%. 28 29dnl Autoconf version 2.57 or newer is recommended. 30AC_PREREQ(2.57) 31 32# AC_CHECK_HEADERS_ONCE(HEADER1 HEADER2 ...) is a once-only variant of 33# AC_CHECK_HEADERS(HEADER1 HEADER2 ...). 34AC_DEFUN([AC_CHECK_HEADERS_ONCE], [ 35 : 36 AC_FOREACH([gl_HEADER_NAME], [$1], [ 37 AC_DEFUN([gl_CHECK_HEADER_]m4_quote(translit(gl_HEADER_NAME, 38 [./-], [___])), [ 39 m4_divert_text([INIT_PREPARE], 40 [gl_header_list="$gl_header_list gl_HEADER_NAME"]) 41 gl_HEADERS_EXPANSION 42 AH_TEMPLATE(AS_TR_CPP([HAVE_]m4_defn([gl_HEADER_NAME])), 43 [Define to 1 if you have the <]m4_defn([gl_HEADER_NAME])[> header file.]) 44 ]) 45 AC_REQUIRE([gl_CHECK_HEADER_]m4_quote(translit(gl_HEADER_NAME, 46 [./-], [___]))) 47 ]) 48]) 49m4_define([gl_HEADERS_EXPANSION], [ 50 m4_divert_text([DEFAULTS], [gl_header_list=]) 51 AC_CHECK_HEADERS([$gl_header_list]) 52 m4_define([gl_HEADERS_EXPANSION], []) 53]) 54 55# AC_CHECK_FUNCS_ONCE(FUNC1 FUNC2 ...) is a once-only variant of 56# AC_CHECK_FUNCS(FUNC1 FUNC2 ...). 57AC_DEFUN([AC_CHECK_FUNCS_ONCE], [ 58 : 59 AC_FOREACH([gl_FUNC_NAME], [$1], [ 60 AC_DEFUN([gl_CHECK_FUNC_]m4_defn([gl_FUNC_NAME]), [ 61 m4_divert_text([INIT_PREPARE], 62 [gl_func_list="$gl_func_list gl_FUNC_NAME"]) 63 gl_FUNCS_EXPANSION 64 AH_TEMPLATE(AS_TR_CPP([HAVE_]m4_defn([gl_FUNC_NAME])), 65 [Define to 1 if you have the `]m4_defn([gl_FUNC_NAME])[' function.]) 66 ]) 67 AC_REQUIRE([gl_CHECK_FUNC_]m4_defn([gl_FUNC_NAME])) 68 ]) 69]) 70m4_define([gl_FUNCS_EXPANSION], [ 71 m4_divert_text([DEFAULTS], [gl_func_list=]) 72 AC_CHECK_FUNCS([$gl_func_list]) 73 m4_define([gl_FUNCS_EXPANSION], []) 74]) 75 76# AC_CHECK_DECLS_ONCE(DECL1 DECL2 ...) is a once-only variant of 77# AC_CHECK_DECLS(DECL1, DECL2, ...). 78AC_DEFUN([AC_CHECK_DECLS_ONCE], [ 79 : 80 AC_FOREACH([gl_DECL_NAME], [$1], [ 81 AC_DEFUN([gl_CHECK_DECL_]m4_defn([gl_DECL_NAME]), [ 82 AC_CHECK_DECLS(m4_defn([gl_DECL_NAME])) 83 ]) 84 AC_REQUIRE([gl_CHECK_DECL_]m4_defn([gl_DECL_NAME])) 85 ]) 86]) 87