[Mesa-dev] Can --enable-shared-glapi die?

[Matt Turner]

On Mon, Jul 23, 2012 at 3:15 PM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> On 07/23/2012 12:59 PM, Ian Romanick wrote:
>> Perhaps someone can refresh my memory as to what exactly this option
>> does?  Can we make this the default and remove the option from configure?
>
> The --enable-shared-glapi option allows programs to use both libGL.so
> and libGLESv2.so without zillions of conflicting linker symbols.  IIRC
> it basically extracts the API dispatch stuff into libglapi.so and makes
> both libraries depend on a single copy.
>
> I'm failing at email archaeology, but I know we've talked about this
> before.  I believe Chia-I said he thought it would be a good idea to
> make it the default, but essentially left the option as a chicken bit,
> in case it didn't work in all situations.
>
> It looks like Matt Turner, Jon Turney, and Homer Hsing also approved of
> the change.  Somebody had a patch but I can't find it now.
>
> The only trouble I know about is that if your libglapi gets out of sync
> with your libGL/libGLES, all hell breaks loose: glCompileShader gets
> routed to glLinkProgram and so on.  Apps fail in spectacular ways.  But
> as long as you keep them in sync (and it's not hard), then it works fine.
>
> I'm all for making shared-glapi mandatory.  People who care about GLES
> will want it (and thus distros would want it), there's no real downside,
> and reducing the number of configurations would be great.

Yeah, I think I had a patch to make this mandatory. I'm also not
remembering why it wasn't committed. It seems like there was some
configuration (xlib-glx, osmesa, etc) that didn't work with
shared-glapi.

I'll take a look and try to get this sorted out.

Matt