[Vm-dev] Official VM missing MPEGPlugin

[David T. Lewis]

On Sat, Jan 15, 2011 at 10:11:25AM -0800, Eliot Miranda wrote:
>  
> On Sat, Jan 15, 2011 at 9:14 AM, David T. Lewis <lewis at mail.msen.com> wrote:
> 
> >
> > On Fri, Jan 14, 2011 at 11:59:47AM -0500, Matthew Fulmer wrote:
> > >
> > > Cog VM includes the MPEGPlugin, but the interpreter VM from
> > > http://ftp.squeak.org/4.1/
> > > does not. It's needed by Cobalt.
> >
> > Well I'm stumped. The plugin exists and is installed in the normal
> > place. But it is not being loaded when called from #primFileValidMPEG:.
> > There are no errors (e.g. unresolved symbols etc) and no problems
> > compiling, we are just not finding the plugin at runtime.
> >
> > I'm sure I'm missing something obvious, but I can't spot it.
> >
> 
> I suspect it's not obvious and I'd be willing to bet there /is/ an undefined
> symbol in the plugin.  It won't show on the compiler command line unless you
> compile carefully, since the compiler does allow undefined symbols, a
> side-efeft of the default global namespace.  If the program into which a
> shared library is loaded has already loaded some other shared library that
> defines undefined in that first shared library the first shared library will
> get its definition from the other.  So remake the plugin, capturing the link
> step, and then manually repeat the link step supplying
> "-Wl,--warn-unresolved-symbols -Wl,--no-allow-shlib-undefined" and hopefully
> you'll be informed of the undefined symbols.

Thanks Eliot,

It's definitely a missing symbol issue, which is what might be expected
if the entire Mpeg3Plugin.c file was being omitted from the build ;)

This is a CMake configuration problem, so I'll see if I can fumble my
way through to a find a fix.

Thanks,
Dave