update ax_*.m4 files from upstream

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

6 files changed, 462 insertions, 1 deletions

diff --git a/m4/ax_append_compile_flags.m4 b/m4/ax_append_compile_flags.m4
new file mode 100644
index 0000000..1f8e708
--- /dev/null
+++ b/m4/ax_append_compile_flags.m4
@@ -0,0 +1,65 @@
+# ===========================================================================
+#  http://www.gnu.org/software/autoconf-archive/ax_append_compile_flags.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_APPEND_COMPILE_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS])
+#
+# DESCRIPTION
+#
+#   For every FLAG1, FLAG2 it is checked whether the compiler works with the
+#   flag.  If it does, the flag is added FLAGS-VARIABLE
+#
+#   If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
+#   CFLAGS) is used.  During the check the flag is always added to the
+#   current language's flags.
+#
+#   If EXTRA-FLAGS is defined, it is added to the current language's default
+#   flags (e.g. CFLAGS) when the check is done.  The check is thus made with
+#   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
+#   force the compiler to issue an error when a bad flag is given.
+#
+#   NOTE: This macro depends on the AX_APPEND_FLAG and
+#   AX_CHECK_COMPILE_FLAG. Please keep this macro in sync with
+#   AX_APPEND_LINK_FLAGS.
+#
+# LICENSE
+#
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 3
+
+AC_DEFUN([AX_APPEND_COMPILE_FLAGS],
+[AC_REQUIRE([AX_CHECK_COMPILE_FLAG])
+AC_REQUIRE([AX_APPEND_FLAG])
+for flag in $1; do
+  AX_CHECK_COMPILE_FLAG([$flag], [AX_APPEND_FLAG([$flag], [$2])], [], [$3])
+done
+])dnl AX_APPEND_COMPILE_FLAGS
diff --git a/m4/ax_append_link_flags.m4 b/m4/ax_append_link_flags.m4
new file mode 100644
index 0000000..48cbd4b
--- /dev/null
+++ b/m4/ax_append_link_flags.m4
@@ -0,0 +1,63 @@
+# ===========================================================================
+#   http://www.gnu.org/software/autoconf-archive/ax_append_link_flags.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_APPEND_LINK_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS])
+#
+# DESCRIPTION
+#
+#   For every FLAG1, FLAG2 it is checked whether the linker works with the
+#   flag.  If it does, the flag is added FLAGS-VARIABLE
+#
+#   If FLAGS-VARIABLE is not specified, the linker's flags (LDFLAGS) is
+#   used. During the check the flag is always added to the linker's flags.
+#
+#   If EXTRA-FLAGS is defined, it is added to the linker's default flags
+#   when the check is done.  The check is thus made with the flags: "LDFLAGS
+#   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
+#   issue an error when a bad flag is given.
+#
+#   NOTE: This macro depends on the AX_APPEND_FLAG and AX_CHECK_LINK_FLAG.
+#   Please keep this macro in sync with AX_APPEND_COMPILE_FLAGS.
+#
+# LICENSE
+#
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 3
+
+AC_DEFUN([AX_APPEND_LINK_FLAGS],
+[AC_REQUIRE([AX_CHECK_LINK_FLAG])
+AC_REQUIRE([AX_APPEND_FLAG])
+for flag in $1; do
+  AX_CHECK_LINK_FLAG([$flag], [AX_APPEND_FLAG([$flag], [m4_default([$2], [LDFLAGS])])], [], [$3])
+done
+])dnl AX_APPEND_LINK_FLAGS
diff --git a/m4/ax_cflags_force_c89.m4 b/m4/ax_cflags_force_c89.m4
new file mode 100644
index 0000000..19ada7f
--- /dev/null
+++ b/m4/ax_cflags_force_c89.m4
@@ -0,0 +1,93 @@
+# ===========================================================================
+#    http://www.gnu.org/software/autoconf-archive/ax_cflags_force_c89.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CFLAGS_FORCE_C89 [(shellvar [,default, [A/NA]])]
+#
+# DESCRIPTION
+#
+#   Try to find a compiler option that enables strict C89 mode.
+#
+#   For the GNU CC compiler it will be -ansi -pedantic.  The result is added
+#   to the shellvar being CFLAGS by default.
+#
+#   Currently this macro knows about GCC, Solaris C compiler, Digital Unix C
+#   compiler, C for AIX Compiler, HP-UX C compiler, IRIX C compiler, NEC
+#   SX-5 (Super-UX 10) C compiler, and Cray J90 (Unicos 10.0.0.8) C
+#   compiler.
+#
+#    - $1 shell-variable-to-add-to : CFLAGS
+#    - $2 add-value-if-not-found : nothing
+#    - $3 action-if-found : add value to shellvariable
+#    - $4 action-if-not-found : nothing
+#
+#   NOTE: These macros depend on AX_APPEND_FLAG.
+#
+# LICENSE
+#
+#   Copyright (c) 2009 Guido U. Draheim <guidod@gmx.de>
+#
+#   This program is free software; you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation; either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 8
+
+AC_DEFUN([AX_CFLAGS_FORCE_C89],[dnl
+AS_VAR_PUSHDEF([FLAGS],[CFLAGS])dnl
+AS_VAR_PUSHDEF([VAR],[ac_cv_cflags_force_c89])dnl
+AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for C89 mode],
+VAR,[VAR="no, unknown"
+ AC_LANG_SAVE
+ AC_LANG_C
+ ac_save_[]FLAGS="$[]FLAGS"
+for ac_arg dnl
+in "-pedantic  % -ansi -pedantic"             dnl GCC
+   "-xstrconst % -v -Xc"                      dnl Solaris C
+   "-std1      % -std1"                       dnl Digital Unix
+   " % -qlanglvl=ansi"                        dnl AIX
+   " % -ansi -ansiE"                          dnl IRIX
+   "+ESlit     % -Aa"                         dnl HP-UX C
+   "-Xc        % -Xc"                         dnl NEC SX-5 (Super-UX 10)
+   "-h conform % -h conform"                  dnl Cray C (Unicos)
+   #
+do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`
+   AC_TRY_COMPILE([],[return 0;],
+   [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])
+done
+ FLAGS="$ac_save_[]FLAGS"
+ AC_LANG_RESTORE
+])
+AS_VAR_POPDEF([FLAGS])dnl
+AC_REQUIRE([AX_APPEND_FLAG])
+case ".$VAR" in
+     .ok|.ok,*) m4_ifvaln($3,$3) ;;
+   .|.no|.no,*) m4_default($4,[m4_ifval($2,[AX_APPEND_FLAG([$2], [$1])])]) ;;
+   *) m4_default($3,[AX_APPEND_FLAG([$VAR], [$1])]) ;;
+esac
+AS_VAR_POPDEF([VAR])dnl
+])
diff --git a/m4/ax_cflags_no_writable_strings.m4 b/m4/ax_cflags_no_writable_strings.m4
new file mode 100644
index 0000000..2fb6f12
--- /dev/null
+++ b/m4/ax_cflags_no_writable_strings.m4
@@ -0,0 +1,121 @@
+# =================================================================================
+#  http://www.gnu.org/software/autoconf-archive/ax_cflags_no_writable_strings.html
+# =================================================================================
+#
+# SYNOPSIS
+#
+#   AX_CFLAGS_NO_WRITABLE_STRINGS [(shellvar [,default, [A/NA]])]
+#
+# DESCRIPTION
+#
+#   Try to find a compiler option that makes all string literals readonly.
+#
+#   The sanity check is done by looking at string.h which has a set of
+#   strcpy definitions that should be defined with const-modifiers to not
+#   emit a warning in all so many places.
+#
+#   For the GNU CC compiler it will be -fno-writable-strings -Wwrite-strings
+#   The result is added to the shellvar being CFLAGS by default.
+#
+#   DEFAULTS:
+#
+#    - $1 shell-variable-to-add-to : CFLAGS
+#    - $2 add-value-if-not-found : nothing
+#    - $3 action-if-found : add value to shellvariable
+#    - $4 action-if-not-found : nothing
+#
+#   NOTE: These macros depend on AX_APPEND_FLAG.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#
+#   This program is free software; you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation; either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 13
+
+AC_DEFUN([AX_FLAGS_NO_WRITABLE_STRINGS],[dnl
+AS_VAR_PUSHDEF([FLAGS],[_AC_LANG_PREFIX[]FLAGS])dnl
+AS_VAR_PUSHDEF([VAR],[ax_cv_[]_AC_LANG_ABBREV[]flags_no_writable_strings])dnl
+AC_CACHE_CHECK([m4_ifval([$1],[$1],FLAGS) making strings readonly],
+VAR,[VAR="no, unknown"
+ac_save_[]FLAGS="$[]FLAGS"
+# IRIX C compiler:
+#      -use_readonly_const is the default for IRIX C,
+#       puts them into .rodata, but they are copied later.
+#       need to be "-G0 -rdatashared" for strictmode but
+#       I am not sure what effect that has really.         - guidod
+for ac_arg dnl
+in "-pedantic -Werror % -fno-writable-strings -Wwrite-strings" dnl   GCC
+   "-pedantic -Werror % -fconst-strings -Wwrite-strings" dnl newer  GCC
+   "-pedantic % -fconst-strings %% no, const-strings is default" dnl newer  GCC
+   "-v -Xc    % -xstrconst" dnl Solaris C - strings go into readonly segment
+   "+w1 -Aa   % +ESlit"      dnl HP-UX C - strings go into readonly segment
+   "-w0 -std1 % -readonly_strings" dnl Digital Unix - again readonly segment
+   "-fullwarn -use_readonly_const %% ok, its the default" dnl IRIX C
+   #
+do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`
+   AC_TRY_COMPILE([],[return 0;],
+   [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])
+done
+case ".$VAR" in
+   .|.no|.no,*) ;;
+   *) # sanity check - testing strcpy() from string.h
+      cp config.log config.tmp
+      AC_TRY_COMPILE([#include <string.h>],[
+      char test[16];
+      if (strcpy (test, "test")) return 1;],
+      dnl the original did use test -n `$CC testprogram.c`
+      [if test `diff config.log config.tmp | grep -i warning | wc -l` != 0
+  then VAR="no, suppressed, string.h," ; fi],
+      [VAR="no, suppressed, string.h"])
+      rm config.tmp
+   ;;
+esac
+FLAGS="$ac_save_[]FLAGS"
+])
+AS_VAR_POPDEF([FLAGS])dnl
+AC_REQUIRE([AX_APPEND_FLAG])
+case ".$VAR" in
+     .ok|.ok,*) m4_ifvaln($3,$3) ;;
+   .|.no|.no,*) m4_default($4,[m4_ifval($2,[AX_APPEND_FLAG([$2], [$1])])]) ;;
+   *) m4_default($3,[AX_APPEND_FLAG([$VAR], [$1])]) ;;
+esac
+AS_VAR_POPDEF([VAR])dnl
+])dnl AX_FLAGS_NO_WRITABLE_STRINGS
+
+AC_DEFUN([AX_CFLAGS_NO_WRITABLE_STRINGS],[dnl
+AC_LANG_PUSH([C])
+AX_FLAGS_NO_WRITABLE_STRINGS([$1], [$2], [$3], [$4])
+AC_LANG_POP([C])
+])
+
+AC_DEFUN([AX_CXXFLAGS_NO_WRITABLE_STRINGS],[dnl
+AC_LANG_PUSH([C++])
+AX_FLAGS_NO_WRITABLE_STRINGS([$1], [$2], [$3], [$4])
+AC_LANG_POP([C++])
+])
diff --git a/m4/ax_cflags_strict_prototypes.m4 b/m4/ax_cflags_strict_prototypes.m4
new file mode 100644
index 0000000..2ac34be
--- /dev/null
+++ b/m4/ax_cflags_strict_prototypes.m4
@@ -0,0 +1,118 @@
+# ===============================================================================
+#  http://www.gnu.org/software/autoconf-archive/ax_cflags_strict_prototypes.html
+# ===============================================================================
+#
+# SYNOPSIS
+#
+#   AX_CFLAGS_STRICT_PROTOTYPES [(shellvar [,default, [A/NA]]
+#
+# DESCRIPTION
+#
+#   Try to find a compiler option that requires strict prototypes.
+#
+#   The sanity check is done by looking at sys/signal.h which has a set of
+#   macro-definitions SIG_DFL and SIG_IGN that are cast to the local
+#   signal-handler type. If that signal-handler type is not fully qualified
+#   then the system headers are not seen as strictly prototype clean.
+#
+#   For the GNU CC compiler it will be -fstrict-prototypes
+#   -Wstrict-prototypes The result is added to the shellvar being CFLAGS by
+#   default.
+#
+#   DEFAULTS:
+#
+#    - $1 shell-variable-to-add-to : CFLAGS
+#    - $2 add-value-if-not-found : nothing
+#    - $3 action-if-found : add value to shellvariable
+#    - $4 action-if-not-found : nothing
+#
+#   NOTE: These macros depend on AX_APPEND_FLAG.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#
+#   This program is free software; you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation; either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 12
+
+AC_DEFUN([AX_FLAGS_STRICT_PROTOTYPES],[dnl
+AS_VAR_PUSHDEF([FLAGS],[_AC_LANG_PREFIX[]FLAGS])dnl
+AS_VAR_PUSHDEF([VAR],[ac_cv_[]_AC_LANG_ABBREV[]flags_strict_prototypes])dnl
+AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for strict prototypes],
+VAR,[VAR="no, unknown"
+ac_save_[]FLAGS="$[]FLAGS"
+for ac_arg dnl
+in "-pedantic -Werror % -fstrict-prototypes -Wstrict-prototypes" dnl   GCC
+   "-pedantic -Werror % -Wstrict-prototypes" dnl try to warn atleast
+   "-pedantic -Werror % -Wmissing-prototypes" dnl try to warn atleast
+   "-pedantic -Werror % -Werror-implicit-function-declaration" dnl
+   "-pedantic -Werror % -Wimplicit-function-declaration" dnl
+   "-pedantic % -Wstrict-prototypes %% no, unsupported" dnl oops
+   #
+do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`
+   AC_TRY_COMPILE([],[return 0;],
+   [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])
+done
+case ".$VAR" in
+   .|.no|.no,*) ;;
+   *) # sanity check with signal() from sys/signal.h
+    cp config.log config.tmp
+    AC_TRY_COMPILE([#include <signal.h>],[
+    if (signal (SIGINT, SIG_IGN) == SIG_DFL) return 1;
+    if (signal (SIGINT, SIG_IGN) != SIG_DFL) return 2;],
+    dnl the original did use test -n `$CC testprogram.c`
+    [if test `diff config.log config.tmp | grep -i warning | wc -l` != 0
+then if test `diff config.log config.tmp | grep -i warning | wc -l` != 1
+then VAR="no, suppressed, signal.h," ; fi ; fi],
+    [VAR="no, suppressed, signal.h"])
+    rm config.tmp
+  ;;
+esac
+FLAGS="$ac_save_[]FLAGS"
+])
+AS_VAR_POPDEF([FLAGS])dnl
+AC_REQUIRE([AX_APPEND_FLAG])
+case ".$VAR" in
+     .ok|.ok,*) m4_ifvaln($3,$3) ;;
+   .|.no|.no,*) m4_default($4,[m4_ifval($2,[AX_APPEND_FLAG([$2], [$1])])]) ;;
+   *) m4_default($3,[AX_APPEND_FLAG([$VAR], [$1])]) ;;
+esac
+AS_VAR_POPDEF([VAR])dnl
+])dnl AX_FLAGS_STRICT_PROTOTYPES
+
+AC_DEFUN([AX_CFLAGS_STRICT_PROTOTYPES],[dnl
+AC_LANG_PUSH([C])
+AX_FLAGS_STRICT_PROTOTYPES([$1], [$2], [$3], [$4])
+AC_LANG_POP([C])
+])
+
+AC_DEFUN([AX_CXXFLAGS_STRICT_PROTOTYPES],[dnl
+AC_LANG_PUSH([C++])
+AX_FLAGS_STRICT_PROTOTYPES([$1], [$2], [$3], [$4])
+AC_LANG_POP([C++])
+])
diff --git a/m4/ax_cflags_warn_all.m4 b/m4/ax_cflags_warn_all.m4
index c22e37f..0fa3e18 100644
--- a/m4/ax_cflags_warn_all.m4
+++ b/m4/ax_cflags_warn_all.m4
@@ -58,7 +58,7 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 13
+#serial 14
 
 AC_DEFUN([AX_FLAGS_WARN_ALL],[dnl
 AS_VAR_PUSHDEF([FLAGS],[_AC_LANG_PREFIX[]FLAGS])dnl
@@ -84,6 +84,7 @@ done
 FLAGS="$ac_save_[]FLAGS"
 ])
 AS_VAR_POPDEF([FLAGS])dnl
+AC_REQUIRE([AX_APPEND_FLAG])
 case ".$VAR" in
      .ok|.ok,*) m4_ifvaln($3,$3) ;;
    .|.no|.no,*) m4_default($4,[m4_ifval($2,[AX_APPEND_FLAG([$2], [$1])])]) ;;