]> ncurses.scripts.mit.edu Git - ncurses.git/blobdiff - aclocal.m4
ncurses 5.9 - patch 20130323
[ncurses.git] / aclocal.m4
index d7b8ffc9c23067742264faebf94df450f8bcd949..f9d8914bc41b1a2a77d2b753373d3bb8498d3c58 100644 (file)
@@ -1,5 +1,5 @@
 dnl***************************************************************************
-dnl Copyright (c) 1998-2011,2012 Free Software Foundation, Inc.              *
+dnl Copyright (c) 1998-2012,2013 Free Software Foundation, Inc.              *
 dnl                                                                          *
 dnl Permission is hereby granted, free of charge, to any person obtaining a  *
 dnl copy of this software and associated documentation files (the            *
@@ -28,7 +28,7 @@ dnl***************************************************************************
 dnl
 dnl Author: Thomas E. Dickey 1995-on
 dnl
-dnl $Id: aclocal.m4,v 1.640 2012/11/03 19:39:23 tom Exp $
+dnl $Id: aclocal.m4,v 1.660 2013/03/23 22:34:35 tom Exp $
 dnl Macros used in NCURSES auto-configuration script.
 dnl
 dnl These macros are maintained separately from NCURSES.  The copyright on
@@ -62,7 +62,7 @@ AC_DEFUN([AM_LANGINFO_CODESET],
   fi
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_ACVERSION_CHECK version: 3 updated: 2012/10/03 18:39:53
+dnl CF_ACVERSION_CHECK version: 4 updated: 2013/03/04 19:52:56
 dnl ------------------
 dnl Conditionally generate script according to whether we're using a given autoconf.
 dnl
@@ -71,6 +71,7 @@ dnl $2 = code to use if AC_ACVERSION is at least as high as $1.
 dnl $3 = code to use if AC_ACVERSION is older than $1.
 define([CF_ACVERSION_CHECK],
 [
+ifdef([AC_ACVERSION], ,[m4_copy([m4_PACKAGE_VERSION],[AC_ACVERSION])])dnl
 ifdef([m4_version_compare],
 [m4_if(m4_version_compare(m4_defn([AC_ACVERSION]), [$1]), -1, [$3], [$2])],
 [CF_ACVERSION_COMPARE(
@@ -1306,7 +1307,7 @@ AC_ARG_ENABLE(rpath,
 AC_MSG_RESULT($cf_cv_enable_rpath)
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_ENABLE_STRING_HACKS version: 2 updated: 2012/10/06 17:56:13
+dnl CF_ENABLE_STRING_HACKS version: 3 updated: 2013/01/26 16:26:12
 dnl ----------------------
 dnl On a few platforms, the compiler and/or loader nags with untruthful
 dnl comments stating that "most" uses of strcat/strcpy/sprintf are incorrect,
@@ -1325,7 +1326,7 @@ AC_DEFUN([CF_ENABLE_STRING_HACKS],
 [
 AC_MSG_CHECKING(if you want to work around bogus compiler/loader warnings)
 AC_ARG_ENABLE(string-hacks,
-       [  --enable-string-hacks  work around bogus compiler/loader warnings],
+       [  --enable-string-hacks   work around bogus compiler/loader warnings],
        [with_string_hacks=$enableval],
        [with_string_hacks=no])
 AC_MSG_RESULT($with_string_hacks)
@@ -1565,6 +1566,37 @@ else
 fi
 ])
 dnl ---------------------------------------------------------------------------
+dnl CF_FUNC_MEMMOVE version: 8 updated: 2012/10/04 20:12:20
+dnl ---------------
+dnl Check for memmove, or a bcopy that can handle overlapping copy.  If neither
+dnl is found, add our own version of memmove to the list of objects.
+AC_DEFUN([CF_FUNC_MEMMOVE],
+[
+AC_CHECK_FUNC(memmove,,[
+AC_CHECK_FUNC(bcopy,[
+       AC_CACHE_CHECK(if bcopy does overlapping moves,cf_cv_good_bcopy,[
+               AC_TRY_RUN([
+int main() {
+       static char data[] = "abcdefghijklmnopqrstuwwxyz";
+       char temp[40];
+       bcopy(data, temp, sizeof(data));
+       bcopy(temp+10, temp, 15);
+       bcopy(temp+5, temp+15, 10);
+       ${cf_cv_main_return:-return} (strcmp(temp, "klmnopqrstuwwxypqrstuwwxyz"));
+}
+               ],
+               [cf_cv_good_bcopy=yes],
+               [cf_cv_good_bcopy=no],
+               [cf_cv_good_bcopy=unknown])
+               ])
+       ],[cf_cv_good_bcopy=no])
+       if test "$cf_cv_good_bcopy" = yes ; then
+               AC_DEFINE(USE_OK_BCOPY,1,[Define to 1 to use bcopy when memmove is unavailable])
+       else
+               AC_DEFINE(USE_MY_MEMMOVE,1,[Define to 1 to use replacement function when memmove is unavailable])
+       fi
+])])dnl
+dnl ---------------------------------------------------------------------------
 dnl CF_FUNC_NANOSLEEP version: 4 updated: 2012/10/06 17:56:13
 dnl -----------------
 dnl Check for existence of workable nanosleep() function.  Some systems, e.g.,
@@ -2716,7 +2748,7 @@ AC_DEFUN([CF_HELP_MESSAGE],
 [AC_DIVERT_HELP([$1])dnl
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_INCLUDE_DIRS version: 6 updated: 2009/01/06 19:37:40
+dnl CF_INCLUDE_DIRS version: 7 updated: 2012/11/10 19:15:05
 dnl ---------------
 dnl Construct the list of include-options according to whether we're building
 dnl in the source directory or using '--srcdir=DIR' option.  If we're building
@@ -2724,25 +2756,25 @@ dnl with gcc, don't append the includedir if it happens to be /usr/include,
 dnl since that usually breaks gcc's shadow-includes.
 AC_DEFUN([CF_INCLUDE_DIRS],
 [
-CPPFLAGS="$CPPFLAGS -I. -I../include"
-if test "$srcdir" != "."; then
-       CPPFLAGS="$CPPFLAGS -I\${srcdir}/../include"
-fi
 if test "$GCC" != yes; then
-       CPPFLAGS="$CPPFLAGS -I\${includedir}"
+       CPPFLAGS="-I\${includedir} $CPPFLAGS"
 elif test "$includedir" != "/usr/include"; then
        if test "$includedir" = '${prefix}/include' ; then
                if test $prefix != /usr ; then
-                       CPPFLAGS="$CPPFLAGS -I\${includedir}"
+                       CPPFLAGS="-I\${includedir} $CPPFLAGS"
                fi
        else
-               CPPFLAGS="$CPPFLAGS -I\${includedir}"
+               CPPFLAGS="-I\${includedir} $CPPFLAGS"
        fi
 fi
+if test "$srcdir" != "."; then
+       CPPFLAGS="-I\${srcdir}/../include $CPPFLAGS"
+fi
+CPPFLAGS="-I. -I../include $CPPFLAGS"
 AC_SUBST(CPPFLAGS)
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_INTEL_COMPILER version: 4 updated: 2010/05/26 05:38:42
+dnl CF_INTEL_COMPILER version: 5 updated: 2013/02/10 10:41:05
 dnl -----------------
 dnl Check if the given compiler is really the Intel compiler for Linux.  It
 dnl tries to imitate gcc, but does not return an error when it finds a mismatch
@@ -2756,6 +2788,7 @@ dnl $1 = GCC (default) or GXX
 dnl $2 = INTEL_COMPILER (default) or INTEL_CPLUSPLUS
 dnl $3 = CFLAGS (default) or CXXFLAGS
 AC_DEFUN([CF_INTEL_COMPILER],[
+AC_REQUIRE([AC_CANONICAL_HOST])
 ifelse([$2],,INTEL_COMPILER,[$2])=no
 
 if test "$ifelse([$1],,[$1],GCC)" = yes ; then
@@ -3035,7 +3068,7 @@ ifelse($1,,,[$1=$LIB_PREFIX])
        AC_SUBST(LIB_PREFIX)
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_LIB_RULES version: 67 updated: 2012/10/06 13:36:35
+dnl CF_LIB_RULES version: 70 updated: 2013/03/23 17:00:30
 dnl ------------
 dnl Append definitions and rules for the given models to the subdirectory
 dnl Makefiles, and the recursion rule for the top-level Makefile.  If the
@@ -3090,76 +3123,63 @@ do
                for cf_item in $cf_LIST_MODELS
                do
                        CF_LIB_SUFFIX($cf_item,cf_suffix,cf_depsuf)
+                       cf_libname=$cf_dir
+                       test "$cf_dir" = c++ && cf_libname=ncurses++
                        if test $cf_item = shared ; then
-                       if test "$cf_cv_do_symlinks" = yes ; then
-                               case "$cf_cv_shlib_version" in #(vi
-                               rel) #(vi
-                                       case "$cf_cv_system_name" in #(vi
-                                       darwin*)
-                                       case .${LIB_SUFFIX} in
-                                       .tw*)
-                                               cf_suffix=`echo $cf_suffix | sed 's/^tw//'`
-                                               cf_suffix=tw'.${REL_VERSION}'"$cf_suffix"
-                                               ;;
-                                       .t*)
-                                               cf_suffix=`echo $cf_suffix | sed 's/^t//'`
-                                               cf_suffix=t'.${REL_VERSION}'"$cf_suffix"
+                               if test -n "${LIB_SUFFIX}"
+                               then
+                                       cf_shared_suffix=`echo "$cf_suffix" | sed 's/^'"${LIB_SUFFIX}"'//'`
+                               else
+                                       cf_shared_suffix="$cf_suffix"
+                               fi
+                               if test "$cf_cv_do_symlinks" = yes ; then
+                                       cf_version_name=
+
+                                       case "$cf_cv_shlib_version" in #(vi
+                                       rel) #(vi
+                                               cf_version_name=REL_VERSION
                                                ;;
-                                       .w*)
-                                               cf_suffix=`echo $cf_suffix | sed 's/^w//'`
-                                               cf_suffix=w'.${REL_VERSION}'"$cf_suffix"
+                                       abi)
+                                               cf_version_name=ABI_VERSION
                                                ;;
-                                       *)
-                                               cf_suffix='.${REL_VERSION}'"$cf_suffix"
-                                               ;;
-                                       esac
-                                       ;; #(vi
-                                       *) cf_suffix="$cf_suffix"'.${REL_VERSION}' ;;
                                        esac
+
+                                       if test -n "$cf_version_name"
+                                       then
+                                               case "$cf_cv_system_name" in #(vi
+                                               darwin*)
+                                                       # "w", etc?
+                                                       cf_suffix="${LIB_SUFFIX}"'.${'$cf_version_name'}'"$cf_shared_suffix"
+                                                       ;; #(vi
+                                               *)
+                                                       cf_suffix="$cf_suffix"'.${'$cf_version_name'}'
+                                                       ;;
+                                               esac
+                                       fi
+                                       if test -n "${LIB_SUFFIX}"
+                                       then
+                                               cf_shared_suffix=`echo "$cf_suffix" | sed 's/^'"${LIB_SUFFIX}"'//'`
+                                       else
+                                               cf_shared_suffix="$cf_suffix"
+                                       fi
+                               fi
+                               # cygwin needs import library, and has unique naming convention
+                               # use autodetected ${cf_prefix} for import lib and static lib, but
+                               # use 'cyg' prefix for shared lib.
+                               case $cf_cv_shlib_version in #(vi
+                               cygdll) #(vi
+                                       cf_cygsuf=`echo "$cf_suffix" | sed -e 's/\.dll/\${ABI_VERSION}.dll/'`
+                                       Libs_To_Make="$Libs_To_Make ../lib/cyg${cf_libname}${cf_cygsuf}"
+                                       continue
                                        ;;
-                               abi)
-                                       case "$cf_cv_system_name" in #(vi
-                                       darwin*)
-                                       case .${LIB_SUFFIX} in
-                                       .tw*)
-                                               cf_suffix=`echo $cf_suffix | sed 's/^tw//'`
-                                               cf_suffix=tw'.${ABI_VERSION}'"$cf_suffix"
-                                               ;;
-                                       .t*)
-                                               cf_suffix=`echo $cf_suffix | sed 's/^t//'`
-                                               cf_suffix=t'.${ABI_VERSION}'"$cf_suffix"
-                                               ;;
-                                       .w*)
-                                               cf_suffix=`echo $cf_suffix | sed 's/^w//'`
-                                               cf_suffix=w'.${ABI_VERSION}'"$cf_suffix"
-                                               ;;
-                                       *)
-                                               cf_suffix='.${ABI_VERSION}'"$cf_suffix"
-                                               ;;
-                                       esac
-                                       ;; #(vi
-                                       *) cf_suffix="$cf_suffix"'.${ABI_VERSION}' ;;
-                                       esac
+                               mingw)
+                                       cf_cygsuf=`echo "$cf_suffix" | sed -e 's/\.dll/\${ABI_VERSION}.dll/'`
+                                       Libs_To_Make="$Libs_To_Make ../lib/lib${cf_libname}${cf_cygsuf}"
+                                       continue
                                        ;;
                                esac
                        fi
-                       # cygwin needs import library, and has unique naming convention
-                       # use autodetected ${cf_prefix} for import lib and static lib, but
-                       # use 'cyg' prefix for shared lib.
-                       case $cf_cv_shlib_version in #(vi
-                       cygdll) #(vi
-                               cf_cygsuf=`echo "$cf_suffix" | sed -e 's/\.dll/\${ABI_VERSION}.dll/'`
-                               Libs_To_Make="$Libs_To_Make ../lib/cyg${cf_dir}${cf_cygsuf}"
-                               continue
-                               ;;
-                       mingw)
-                               cf_cygsuf=`echo "$cf_suffix" | sed -e 's/\.dll/\${ABI_VERSION}.dll/'`
-                               Libs_To_Make="$Libs_To_Make ../lib/lib${cf_dir}${cf_cygsuf}"
-                               continue
-                               ;;
-                       esac
-                       fi
-                       Libs_To_Make="$Libs_To_Make ../lib/${cf_prefix}${cf_dir}${cf_suffix}"
+                       Libs_To_Make="$Libs_To_Make ../lib/${cf_prefix}${cf_libname}${cf_suffix}"
                done
 
                if test $cf_dir = ncurses ; then
@@ -3195,6 +3215,33 @@ do
                        cf_subsets=`echo "$LIB_SUBSETS" | sed -e 's/^termlib.* //'`
                fi
 
+               if test $cf_dir = c++; then
+                       if test "x$with_shared_cxx" != xyes; then
+                               cf_list=
+                               for cf_item in $Libs_To_Make
+                               do
+                                       case $cf_item in
+                                       *.a)
+                                               ;;
+                                       *)
+                                               cf_item=`echo "$cf_item" | sed -e "s,"$cf_shared_suffix",.a,"`
+                                               ;;
+                                       esac
+                                       for cf_test in $cf_list
+                                       do
+                                               if test "$cf_test" = "$cf_item"
+                                               then
+                                                       cf_LIST_MODELS=`echo "$cf_LIST_MODELS" | sed -e 's/normal//'`
+                                                       cf_item=
+                                                       break
+                                               fi
+                                       done
+                                       test -n "$cf_item" && cf_list="$cf_list $cf_item"
+                               done
+                               Libs_To_Make="$cf_list"
+                       fi
+               fi
+
                sed -e "s%@Libs_To_Make@%$Libs_To_Make%" \
                    -e "s%@SHARED_LIB@%$SHARED_LIB%" \
                        $cf_dir/Makefile >$cf_dir/Makefile.out
@@ -3209,8 +3256,23 @@ do
                        cf_subdirs=
                        for cf_item in $cf_LIST_MODELS
                        do
+
                        echo "Appending rules for ${cf_item} model (${cf_dir}: ${cf_subset})"
                        CF_UPPER(cf_ITEM,$cf_item)
+
+                       CXX_MODEL=$cf_ITEM
+                       if test "$CXX_MODEL" = SHARED; then
+                               case $cf_cv_shlib_version in #(vi
+                               cygdll|mingw) #(vi
+                                       test "x$with_shared_cxx" = xno && CF_VERBOSE(overriding CXX_MODEL to SHARED)
+                                       with_shared_cxx=yes
+                                       ;;
+                               *)
+                                       test "x$with_shared_cxx" = xno && CXX_MODEL=NORMAL
+                                       ;;
+                               esac
+                       fi
+
                        CF_LIB_SUFFIX($cf_item,cf_suffix,cf_depsuf)
                        CF_OBJ_SUBDIR($cf_item,cf_subdir)
 
@@ -3228,6 +3290,8 @@ do
                                        cf_libname=$TICS_LIB_SUFFIX
                                        ;;
                                esac
+                       elif test $cf_dir = c++ ; then
+                               cf_libname=ncurses++$LIB_SUFFIX
                        else
                                cf_libname=${cf_libname}$LIB_SUFFIX
                        fi
@@ -3279,6 +3343,7 @@ do
                                name=${cf_libname}${cf_dir_suffix} \
                                traces=$LIB_TRACING \
                                MODEL=$cf_ITEM \
+                               CXX_MODEL=$CXX_MODEL \
                                model=$cf_subdir \
                                prefix=$cf_prefix \
                                suffix=$cf_suffix \
@@ -4061,7 +4126,7 @@ AC_ARG_WITH(manpage-tbl,
 AC_MSG_RESULT($MANPAGE_TBL)
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_MAN_PAGES version: 41 updated: 2012/08/11 19:35:44
+dnl CF_MAN_PAGES version: 43 updated: 2013/02/09 12:53:45
 dnl ------------
 dnl Try to determine if the man-pages on the system are compressed, and if
 dnl so, what format is used.  Use this information to construct a script that
@@ -4179,11 +4244,12 @@ case \$i in #(vi
        if test ! -f $cf_man_alias ; then
 cat >>$cf_man_alias <<-CF_EOF2
                s,@DATADIR@,\$datadir,g
-               s,@TERMINFO@,\$TERMINFO,g
-               s,@NCURSES_MAJOR@,\$NCURSES_MAJOR,g
-               s,@NCURSES_MINOR@,\$NCURSES_MINOR,g
-               s,@NCURSES_PATCH@,\$NCURSES_PATCH,g
-               s,@NCURSES_OSPEED@,\$NCURSES_OSPEED,g
+               s,@TERMINFO@,\${TERMINFO:="no default value"},g
+               s,@TERMINFO_DIRS@,\${TERMINFO_DIRS:="no default value"},g
+               s,@NCURSES_MAJOR@,\${NCURSES_MAJOR:="no default value"},g
+               s,@NCURSES_MINOR@,\${NCURSES_MINOR:="no default value"},g
+               s,@NCURSES_PATCH@,\${NCURSES_PATCH:="no default value"},g
+               s,@NCURSES_OSPEED@,\${NCURSES_OSPEED:="no default value"},g
 CF_EOF
        ifelse($1,,,[
        for cf_name in $1
@@ -5227,7 +5293,7 @@ CF_VERBOSE(...checked $1 [$]$1)
 AC_SUBST(EXTRA_LDFLAGS)
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_SHARED_OPTS version: 70 updated: 2012/02/25 15:20:07
+dnl CF_SHARED_OPTS version: 72 updated: 2013/01/26 16:26:12
 dnl --------------
 dnl --------------
 dnl Attempt to determine the appropriate CC/LD options for creating a shared
@@ -5283,6 +5349,7 @@ AC_DEFUN([CF_SHARED_OPTS],
        AC_MSG_RESULT($cf_cv_shlib_version)
 
        cf_cv_rm_so_locs=no
+       cf_try_cflags=
 
        # Some less-capable ports of gcc support only -fpic
        CC_SHARED_OPTS=
@@ -5335,7 +5402,7 @@ CF_EOF
                chmod +x mk_shared_lib.sh
                ;;
        darwin*) #(vi
-               EXTRA_CFLAGS="-no-cpp-precomp"
+               cf_try_cflags="no-cpp-precomp"
                CC_SHARED_OPTS="-dynamic"
                MK_SHARED_LIB='${CC} ${CFLAGS} -dynamiclib -install_name ${libdir}/`basename $[@]` -compatibility_version ${ABI_VERSION} -current_version ${ABI_VERSION} -o $[@]'
                test "$cf_cv_shlib_version" = auto && cf_cv_shlib_version=abi
@@ -5349,6 +5416,14 @@ CF_EOF
                        LDFLAGS="$LDFLAGS -Wl,-search_paths_first"
                fi
                ;;
+       hpux[[7-8]]*) #(vi
+               # HP-UX 8.07 ld lacks "+b" option used for libdir search-list 
+               if test "$GCC" != yes; then
+                       CC_SHARED_OPTS='+Z'
+               fi
+               MK_SHARED_LIB='${LD} -b -o $[@]'
+               INSTALL_LIB="-m 555"
+               ;;
        hpux*) #(vi
                # (tested with gcc 2.7.2 -- I don't have c89)
                if test "$GCC" = yes; then
@@ -5554,6 +5629,33 @@ CF_EOF
                ;;
        esac
 
+       if test -n "$cf_try_cflags"
+       then
+cat > conftest.$ac_ext <<EOF
+#line __oline__ "${as_me:-configure}"
+#include <stdio.h>
+int main(int argc, char *argv[[]])
+{
+       printf("hello\n");
+       return (argv[[argc-1]] == 0) ;
+}
+EOF
+               cf_save_CFLAGS="$CFLAGS"
+               for cf_opt in $cf_try_cflags
+               do
+                       CFLAGS="$cf_save_CFLAGS -$cf_opt"
+                       AC_MSG_CHECKING(if CFLAGS option -$cf_opt works)
+                       if AC_TRY_EVAL(ac_compile); then
+                               AC_MSG_RESULT(yes)
+                               cf_save_CFLAGS="$CFLAGS"
+                       else
+                               AC_MSG_RESULT(no)
+                       fi
+               done
+               CFLAGS="$cf_save_CFLAGS"
+       fi
+
+
        # RPATH_LIST is a colon-separated list of directories
        test -n "$cf_ld_rpath_opt" && MK_SHARED_LIB="$MK_SHARED_LIB $cf_ld_rpath_opt\${RPATH_LIST}"
        test -z "$RPATH_LIST" && RPATH_LIST="\${libdir}"
@@ -6878,6 +6980,26 @@ test "$cf_with_sysmouse" = yes && AC_DEFINE(USE_SYSMOUSE,1,[Define to 1 if we ca
 fi
 ])dnl
 dnl ---------------------------------------------------------------------------
+dnl CF_WITH_SYSTYPE version: 1 updated: 2013/01/26 16:26:12
+dnl ---------------
+dnl For testing, override the derived host system-type which is used to decide
+dnl things such as the linker commands used to build shared libraries.  This is
+dnl normally chosen automatically based on the type of system which you are
+dnl building on.  We use it for testing the configure script.
+dnl
+dnl This is different from the --host option: it is used only for testing parts
+dnl of the configure script which would not be reachable with --host since that
+dnl relies on the build environment being real, rather than mocked up.
+AC_DEFUN([CF_WITH_SYSTYPE],[
+CF_CHECK_CACHE([AC_CANONICAL_SYSTEM])
+AC_ARG_WITH(system-type,
+       [  --with-system-type=XXX  test: override derived host system-type],
+[AC_MSG_WARN(overriding system type to $withval)
+       cf_cv_system_name=$withval
+       host_os=$withval
+])
+])dnl
+dnl ---------------------------------------------------------------------------
 dnl CF_WITH_VALGRIND version: 1 updated: 2006/12/14 18:00:21
 dnl ----------------
 AC_DEFUN([CF_WITH_VALGRIND],[
@@ -6886,7 +7008,7 @@ CF_NO_LEAKS_OPTION(valgrind,
        [USE_VALGRIND])
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_XOPEN_SOURCE version: 42 updated: 2012/01/07 08:26:49
+dnl CF_XOPEN_SOURCE version: 43 updated: 2013/02/10 10:41:05
 dnl ---------------
 dnl Try to get _XOPEN_SOURCE defined properly that we can use POSIX functions,
 dnl or adapt to the vendor's definitions to get equivalent functionality,
@@ -6896,6 +7018,7 @@ dnl Parameters:
 dnl    $1 is the nominal value for _XOPEN_SOURCE
 dnl    $2 is the nominal value for _POSIX_C_SOURCE
 AC_DEFUN([CF_XOPEN_SOURCE],[
+AC_REQUIRE([AC_CANONICAL_HOST])
 
 cf_XOPEN_SOURCE=ifelse([$1],,500,[$1])
 cf_POSIX_C_SOURCE=ifelse([$2],,199506L,[$2])