[Vm-dev] FT2Plugin stops working with latest version (was: Add argvec and envec to sqVirtualMachine.[ch]? (was: FT2Plugin stops working with latest version))

[David T. Lewis]

On Wed, Oct 05, 2011 at 11:23:03PM -0400, David T. Lewis wrote:
> On Thu, Oct 06, 2011 at 05:00:12AM +0300, Igor Stasenko wrote:
> >  
> > On 6 October 2011 04:19, David T. Lewis <lewis at mail.msen.com> wrote:
> > >
> > >
> > > On Wed, Oct 05, 2011 at 05:22:40PM +0200, Igor Stasenko wrote:
> > >>
> > >> On 5 October 2011 17:18, David T. Lewis <lewis at mail.msen.com> wrote:
> > >> >
> > >> > On Wed, Oct 05, 2011 at 11:52:49AM -0300, Esteban Lorenzano wrote:
> > >> >>
> > >> >> pd: Dave, please, please... if you have 5', can you see the BytesPerWord problem?
> > >> >
> > >> > I am traveling a lot right now but I will try. I looked at it a briefly
> > >> > a couple of days ago and got myself confused :/
> > >> >
> > >> > Igor, perhaps you can confirm - when you build a Cog VM with FreeTypePlugin,
> > >> > and when the plugin source code is using BytesPerWord (defined elsewhere,
> > >> > I don't remember where at the moment), you were able to get a working
> > >> > FreeTypePlugin, right? So if the code generator is producing "BytesPerWord"
> > >> > in the plugin source, it should be working? Sorry for my confusion,
> > >> > but I did not have time to retrace my earlier steps from building a Cog
> > >> > VM to test compiling the plugin, so I can't check this right now (and
> > >> > maybe I made a mistake when I was looking at it earlier).
> > >> >
> > >>
> > >>
> > >> Everything was working before you added the change for bytesPerWord method :D
> > >> I don't know what is the problem right now, (i thought we're fixed it
> > >> after discussing few weeks ago..) because i am not working on VM
> > >> builds right now.
> > >> So, Esteban, it is your call :D
> > >>
> > >
> > > OK, back to Esteban's original question about getting FreetypePlugin working.
> > >
> > > I said earlier that I had built and tested a FreetypePlugin on Cog, but
> > > this is wrong. The plugin compiled successfully, and in loaded into my
> > > Squeak image when I tried it (based on 'Smalltalk listLoadedModules'), so
> > > I thought that it was working. However, the build process that I used was
> > > the the original unix/config/configure process, and this apparently is not
> > > working correctly for FreetypePlugin (the actual FT2Plugin.c code is not
> > > included in the build).
> > >
> > > Therefore - I cannot confirm that this works on Cog. All I can say for
> > > sure is that the code generator changes that I provided produce the
> > > "BytesPerWord" output that would normally be used in the oscog branch,
> > > which would be the same as the code that apparently originally worked
> > > when Igor built a Cog VM prior to these changes.
> > >
> > > Igor, whenever you next build some VMs, can you please check and see
> > > if the FreetypePlugin is running correctly (not just loading, but
> > > actually doing something)? If so, there must be something different
> > > in your build procedure compared to what Esteban is doing.
> > >
> > 
> > I had error reports that build is broken on jenkins server , and the
> > problem is undefined bytes-per-word thingy.
> > If you look at
> > 
> > https://ci.lille.inria.fr/pharo/view/Cog/job/Cog-Mac-Carbon/9/console
> > 
> > linking C shared library
> > /Users/hudson/jenkins/workspace/Cog-Mac-Carbon/cog/results/CogVM.app/Contents/Resources/libFT2Plugin.dylib
> > Undefined symbols:
> >   "_bytesPerWord", referenced from:
> >       _ftHandleValueFromReceiver in FT2Plugin.c.o
> >       _primitiveLoadGlyphSlotFromFace in FT2Plugin.c.o
> > ld: symbol(s) not found
> 
> This just means that the image that did the code generation did not
> have the code generator patch for BytesPerWord, so of course it will
> not work.  The "self bytesPerWord" in Smalltalk needs to be translated
> as "BytesPerWord" for Cog. But the question is whether the BytesPerWord
> macro is defined for plugins in the oscog branch. I suspect that the
> answer is no, and that is why Esteban cannot get the plugin to work.
> 
> But now I think I see the problem. The BytesPerWord macro is generated
> by CCodeGenerator>>emitCConstantsOn: which eliminates all unused constants
> before generating them as macros in the C source for FreeTypePlugin.
> When we use "self bytesPerWord", the BytesPerWord variable is not
> directly referenced by the plugin, and therefore the macro does not
> get generated in FreetypePlugin.c. So we need a way to convince
> CCodeGenerator not to treat BytesPerWord as unreferenced.
> 
> So that is the problem ... just need to think of a solution now.
> 

I just posted VMMaker-oscog-dtl.125, which contains a one-line patch
that appears to address the problem of BytesPerWord not being defined
in FreeTypePlugin.

Dave