Choose among AC_DEFUN_ONCE, AC_DEFUN in a way that aclocal understands.

diff --git a/gettext-runtime/m4/ChangeLog b/gettext-runtime/m4/ChangeLog
index bbb18cce71c5a984695946307d9e037470f53991..148d0d43406990a74850c17ae661e7a431a38a58 100644 (file)
--- a/gettext-runtime/m4/ChangeLog
+++ b/gettext-runtime/m4/ChangeLog
@@ -1,3 +1,10 @@
+2010-06-03  Bruno Haible  <bruno@clisp.org>
+
+       Choose among AC_DEFUN_ONCE, AC_DEFUN in a way that aclocal understands.
+       * iconv.m4 (gl_iconv_AC_DEFUN): New macro.
+       (AM_ICONV): Define it through gl_iconv_AC_DEFUN.
+       Reported by Ludovic Courtès <ludo@gnu.org>.
+
 2010-05-16  Bruno Haible  <bruno@clisp.org>
 
        Avoid autoconf warnings about AM_ICONV.

diff --git a/gettext-runtime/m4/iconv.m4 b/gettext-runtime/m4/iconv.m4
index 4c68472135e3a9fc323989f252708d9c4d30118b..e2041b9b49fb70bcb08cd65699529d9b0c3374a4 100644 (file)
--- a/gettext-runtime/m4/iconv.m4
+++ b/gettext-runtime/m4/iconv.m4
@@ -1,4 +1,4 @@
-# iconv.m4 serial 10 (gettext-0.18.1)
+# iconv.m4 serial 11 (gettext-0.18.1)
 dnl Copyright (C) 2000-2002, 2007-2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -173,7 +173,19 @@ int main ()
 dnl Define AM_ICONV using AC_DEFUN_ONCE for Autoconf >= 2.64, in order to
 dnl avoid warnings like
 dnl "warning: AC_REQUIRE: `AM_ICONV' was expanded before it was required".
-m4_version_prereq([2.64],[AC_DEFUN_ONCE],[AC_DEFUN])([AM_ICONV],
+dnl This is tricky because of the way 'aclocal' is implemented:
+dnl - It requires defining an auxiliary macro whose name ends in AC_DEFUN.
+dnl   Otherwise aclocal's initial scan pass would miss the macro definition.
+dnl - It requires a line break inside the AC_DEFUN_ONCE and AC_DEFUN expansions.
+dnl   Otherwise aclocal would emit many "Use of uninitialized value $1"
+dnl   warnings.
+m4_define([gl_iconv_AC_DEFUN],
+  m4_version_prereq([2.64],
+    [[AC_DEFUN_ONCE(
+        [$1], [$2])]],
+    [[AC_DEFUN(
+        [$1], [$2])]]))
+gl_iconv_AC_DEFUN([AM_ICONV],
 [
   AM_ICONV_LINK
   if test "$am_cv_func_iconv" = yes; then