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Diffstat (limited to 'm4/onceonly.m4')
| -rw-r--r-- | m4/onceonly.m4 | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/m4/onceonly.m4 b/m4/onceonly.m4 new file mode 100644 index 00000000..6a9c87b7 --- /dev/null +++ b/m4/onceonly.m4 @@ -0,0 +1,91 @@ +# onceonly.m4 serial 7 +dnl Copyright (C) 2002-2003, 2005-2006, 2008-2010 Free Software Foundation, +dnl Inc. +dnl This file is free software, distributed under the terms of the GNU +dnl General Public License. As a special exception to the GNU General +dnl Public License, this file may be distributed as part of a program +dnl that contains a configuration script generated by Autoconf, under +dnl the same distribution terms as the rest of that program. + +dnl This file defines some "once only" variants of standard autoconf macros. +dnl AC_CHECK_HEADERS_ONCE like AC_CHECK_HEADERS +dnl AC_CHECK_FUNCS_ONCE like AC_CHECK_FUNCS +dnl AC_CHECK_DECLS_ONCE like AC_CHECK_DECLS +dnl AC_REQUIRE([AC_FUNC_STRCOLL]) like AC_FUNC_STRCOLL +dnl The advantage is that the check for each of the headers/functions/decls +dnl will be put only once into the 'configure' file. It keeps the size of +dnl the 'configure' file down, and avoids redundant output when 'configure' +dnl is run. +dnl The drawback is that the checks cannot be conditionalized. If you write +dnl if some_condition; then gl_CHECK_HEADERS(stdlib.h); fi +dnl inside an AC_DEFUNed function, the gl_CHECK_HEADERS macro call expands to +dnl empty, and the check will be inserted before the body of the AC_DEFUNed +dnl function. + +dnl The original code implemented AC_CHECK_HEADERS_ONCE and AC_CHECK_FUNCS_ONCE +dnl in terms of AC_DEFUN and AC_REQUIRE. This implementation uses diversions to +dnl named sections DEFAULTS and INIT_PREPARE in order to check all requested +dnl headers at once, thus reducing the size of 'configure'. It is known to work +dnl with autoconf 2.57..2.62 at least . The size reduction is ca. 9%. + +dnl Autoconf version 2.59 plus gnulib is required; this file is not needed +dnl with Autoconf 2.60 or greater. But note that autoconf's implementation of +dnl AC_CHECK_DECLS_ONCE expects a comma-separated list of symbols as first +dnl argument! +AC_PREREQ([2.59]) + +# AC_CHECK_HEADERS_ONCE(HEADER1 HEADER2 ...) is a once-only variant of +# AC_CHECK_HEADERS(HEADER1 HEADER2 ...). +AC_DEFUN([AC_CHECK_HEADERS_ONCE], [ + : + m4_foreach_w([gl_HEADER_NAME], [$1], [ + AC_DEFUN([gl_CHECK_HEADER_]m4_quote(m4_translit(gl_HEADER_NAME, + [./-], [___])), [ + m4_divert_text([INIT_PREPARE], + [gl_header_list="$gl_header_list gl_HEADER_NAME"]) + gl_HEADERS_EXPANSION + AH_TEMPLATE(AS_TR_CPP([HAVE_]m4_defn([gl_HEADER_NAME])), + [Define to 1 if you have the <]m4_defn([gl_HEADER_NAME])[> header file.]) + ]) + AC_REQUIRE([gl_CHECK_HEADER_]m4_quote(m4_translit(gl_HEADER_NAME, + [./-], [___]))) + ]) +]) +m4_define([gl_HEADERS_EXPANSION], [ + m4_divert_text([DEFAULTS], [gl_header_list=]) + AC_CHECK_HEADERS([$gl_header_list]) + m4_define([gl_HEADERS_EXPANSION], []) +]) + +# AC_CHECK_FUNCS_ONCE(FUNC1 FUNC2 ...) is a once-only variant of +# AC_CHECK_FUNCS(FUNC1 FUNC2 ...). +AC_DEFUN([AC_CHECK_FUNCS_ONCE], [ + : + m4_foreach_w([gl_FUNC_NAME], [$1], [ + AC_DEFUN([gl_CHECK_FUNC_]m4_defn([gl_FUNC_NAME]), [ + m4_divert_text([INIT_PREPARE], + [gl_func_list="$gl_func_list gl_FUNC_NAME"]) + gl_FUNCS_EXPANSION + AH_TEMPLATE(AS_TR_CPP([HAVE_]m4_defn([gl_FUNC_NAME])), + [Define to 1 if you have the `]m4_defn([gl_FUNC_NAME])[' function.]) + ]) + AC_REQUIRE([gl_CHECK_FUNC_]m4_defn([gl_FUNC_NAME])) + ]) +]) +m4_define([gl_FUNCS_EXPANSION], [ + m4_divert_text([DEFAULTS], [gl_func_list=]) + AC_CHECK_FUNCS([$gl_func_list]) + m4_define([gl_FUNCS_EXPANSION], []) +]) + +# AC_CHECK_DECLS_ONCE(DECL1 DECL2 ...) is a once-only variant of +# AC_CHECK_DECLS(DECL1, DECL2, ...). +AC_DEFUN([AC_CHECK_DECLS_ONCE], [ + : + m4_foreach_w([gl_DECL_NAME], [$1], [ + AC_DEFUN([gl_CHECK_DECL_]m4_defn([gl_DECL_NAME]), [ + AC_CHECK_DECLS(m4_defn([gl_DECL_NAME])) + ]) + AC_REQUIRE([gl_CHECK_DECL_]m4_defn([gl_DECL_NAME])) + ]) +]) |