Re: Shared HDF5 in Octave?

[Michael Goffioul]

On 9/12/07, Scott Wegner <address@hidden> wrote:
> My name is Scott Wegner, and I am responsible for HDF maintenance and
> packaging for Windows.  We provide documentation and support for
> building HDF5 static libraries on cygwin and Mingw.  However, we don't
> support building shared DLL's from cygwin.  Recently, a user brought it
> to our attention that he was able to link his cygwin application with
> the Octave DLL, which provides HDF5 internally.
>
> Is anyone aware if the Octave library is using a cygwin HDF5 dll?  If
> so, could you describe the steps needed to build HDF5 shared libraries
> in cygwin?  We would like to eventually support for cygwin shared
> libraries, so any tips are helpful.

I think it's Tatsuro. IIRC, what happened is that he linked a static version
of HDF5 into octave DLL. As all DLL symbols are exported by default with
cygwin gcc, this means the octave DLL also provides the HDF5 symbols.
He then could link another oct file, which uses some HDF5 functions,
against the octave DLL, without specifying the HDF5 lib on the link
command, because HDF5 is already part of octave DLL (actually, you
then can't specify HDF5 lib on the link command, otherwise you get
duplicated symbols).

Is it the story you're talking about?

Michael.