AC_LIBTOOL_WIN32_DLL for libgfortran

[FX Coudert]

Hi all,

I've been trying to use tweak the libgfortran build machinery to get  
it generate a libgfortran.dll on windows systems, but I have no luck.  
I tried adding AC_LIBTOOL_WIN32_DLL to configure.ac (just before  
AM_PROG_LIBTOOL) and -no-undefined to libgfortran_la_LDFLAGS, as is  
indicated in the autobook and other online resources. but configure  
(on a cross-compiler from i686-linux to i386-pc-mingw32) still says:

> checking if libtool supports shared libraries... yes
> checking if package supports dlls... no
> checking whether to build shared libraries... no

Is there another thing needed to get this support? I admit I'm a bit  
lost in the gigantic GCC build system, but I thought the target  
libraries were actually rather... standalone, autoconf-ly speaking. I  
bet I was wrong.

Thanks for any help or hint,
FX