Merge GDB 7.5.1

gdb/gnulib/m4/onceonly.m4

-# onceonly.m4 serial 6
-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], [$1], [
-    AC_DEFUN([gl_CHECK_HEADER_]m4_quote(translit(gl_HEADER_NAME,
-                                                 [./-], [___])), [
-      m4_divert_text([INIT_PREPARE],
-        [gl_header_list="$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(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]))
-  ])
-])