Mesa 18.3.0, Meson, LLVM, RTTI and OpenCL

[Jakub Bogusz]

On Tue, Dec 11, 2018 at 03:37:40PM +0100, Jacek Konieczny wrote:
> Hi,
> 
> I am preparing package for Mesa 18.3.0, switching the build system to
> Meson, as autoconf/automake is deprecated.
> 
> I made it build, but without OpenCL. The problem is the Clover part of
> Mesa requires RTTI to build (uses dynamic_cast) and Mesa is build
> -fno-rtti when compiled with LLVM built without RTTI.
> 
> LLVM builds without RTTI by default, but it should be possible to build
> it with RTTI, using 'REQUIRES_RTTI=1', which we have in our llvm.spec.
> It doesn't seem to work, though:
> 
> [jajcus at jajo ~]$ llvm-config --has-rtti
> NO
> [jajcus at jajo ~]$ rpm -qf `which llvm-config`
> llvm-devel-7.0.0-1.x86_64
> 
> Should we fix it? It is disabled in LLVM for a reason, but it seems Mesa
> expects it rather enabled. Also, changing the setting now will change
> the ABI, which will force us to recompile everything compiled with
> current LLVM. And I am not sure how to fix it, anyway.

THEY just changed the way of enabling rtti (from make variable to cmake
define).
As we had rtti in previous versions of llvm and it's needed by other
packages (i.e. Mesa/pipe-*), IMO we should just keep it enabled (and
rebuild packages already built with rtti-less llvm 7, if necessary).


-- 
Jakub Bogusz    http://qboosh.pl/