Re: uchar C++ tests: Fix build error on FreeBSD 12

[Bruno Haible]

> I've reported it as an autoconf bug 
> <https://savannah.gnu.org/support/?110294>.
> Here is the workaround.

This is not the only hassle I'm seeing. In a testdir produced with
  ./gnulib-tool --create-testdir --dir=../testdir --single-configure 
--with-c++-tests uchar
the gl_ANSI_CXX macro is expanded too late.

I don't know which code I cannot trust: the gl_ANSI_CXX macro, the Autoconf
AC_REQUIRE mechanism, or the Autoconf AC_LANG_PUSH/AC_LANG_POP macros.

Anyway, this workaround seems to help:


2020-08-19  Bruno Haible  <bruno@clisp.org>

        ansi-c++-opt: Work around an autoconf macro reordering problem.
        * modules/ansi-c++-opt: Require gl_ANSI_CXX already in the early
        section.

diff --git a/modules/ansi-c++-opt b/modules/ansi-c++-opt
index 176f174..ebf3c46 100644
--- a/modules/ansi-c++-opt
+++ b/modules/ansi-c++-opt
@@ -6,9 +6,11 @@ m4/ansi-c++.m4
 
 Depends-on:
 
-configure.ac:
+configure.ac-early:
 AC_REQUIRE([gl_ANSI_CXX])
 
+configure.ac:
+
 Makefile.am:
 
 Include: