multi-language support

[Daiki Ueno]

I'm using GNU libtool 1.4b.

Although the section "New in 1.4b" in NEWS file shows that both C++
and GCJ supports are merged from multi-language-branch, I found at
least three problem about multi-language support.

First, AC_LIBTOOL_PROG_COMPILER_PIC adds the flag "-DPIC" to
$lt_prog_compiler_pic_TAGNAME regardless of TAGNAME.  Thanks to this,
the GCJ compiler is always believed to be just as if it cannot produce
PIC.

Second, AC_LIBTOOL_COMPILER_OPTION only takes account of $CFLAGS.  When
the current language is set to C++, the compilation command held in
$ac_compile is expanded to:

  $CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&AS_MESSAGE_LOG_FD

This means that concerning C++ such a tests will bring the meaningless
result.

Third, even worse, because autoconf doesn't support GCJ at all,
AC_LIBTOOL_LANG_GCJ_CONFIG uses the C language setting as default.
At this time $ac_compile doesn't contains $GCJFLAGS,
AC_LIBTOOL_PROG_CC_C_O fails because it depends on $GCJFLAGS.

I've just begun to write a sample GCJ application using autotools.
I'm not sure about the status of multi-language support in autotools,
but still should I work on with multi-language-branch of Libtool?

Regards,
-- 
Daiki Ueno