Re: [PATCH v4 2/3] mesa-libclc: New recipe for forking libclc for Rusticl purposes in Mesa

[Quentin Schulz <quentin.schulz@cherry.de>]

Hi Zoltán,

On 8/7/26 7:44 AM, Zoltán Böszörményi wrote:
> See the reasoning and discussion at
> https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/43020
> which was merged and backported to 26.2.0.
> 
> TL;DR: LLVM constantly introduces breaking changes that cause
> regressions for running OpenCL CTS with Rusticl and finally
> Karol Herbst had enough.
> 
> This fork is from the LLVM 22 version of libclc and contains the
> necessary fixes to make Rusticl pass OpenCL CTS.
> 
> Signed-off-by: Zoltán Böszörményi <zboszor@gmail.com>
> ---
>   meta/conf/distro/include/maintainers.inc      |  1 +
>   .../mesa/mesa-libclc_22.1.8.3.bb              | 26 +++++++++++++++++++
>   2 files changed, 27 insertions(+)
>   create mode 100644 meta/recipes-graphics/mesa/mesa-libclc_22.1.8.3.bb
> 
> diff --git a/meta/conf/distro/include/maintainers.inc b/meta/conf/distro/include/maintainers.inc
> index c5b701c244..feccf29ce4 100644
> --- a/meta/conf/distro/include/maintainers.inc
> +++ b/meta/conf/distro/include/maintainers.inc
> @@ -524,6 +524,7 @@ RECIPE_MAINTAINER:pn-menu-cache = "Ross Burton <ross.burton@arm.com>"
>   RECIPE_MAINTAINER:pn-mesa = "Unassigned <unassigned@yoctoproject.org>"
>   RECIPE_MAINTAINER:pn-mesa-demos = "Unassigned <unassigned@yoctoproject.org>"
>   RECIPE_MAINTAINER:pn-mesa-gl = "Unassigned <unassigned@yoctoproject.org>"
> +RECIPE_MAINTAINER:pn-mesa-libclc = "Zoltán Böszörményi <zboszor@gmail.com>"
>   RECIPE_MAINTAINER:pn-mesa-tools-native = "Unassigned <unassigned@yoctoproject.org>"
>   RECIPE_MAINTAINER:pn-meson = "Trevor Gamblin <tgamblin@baylibre.com>"
>   RECIPE_MAINTAINER:pn-meta-environment-${MACHINE} = "Richard Purdie <richard.purdie@linuxfoundation.org>"
> diff --git a/meta/recipes-graphics/mesa/mesa-libclc_22.1.8.3.bb b/meta/recipes-graphics/mesa/mesa-libclc_22.1.8.3.bb
> new file mode 100644
> index 0000000000..c93b5b9d9d
> --- /dev/null
> +++ b/meta/recipes-graphics/mesa/mesa-libclc_22.1.8.3.bb
> @@ -0,0 +1,26 @@
> +SUMMARY = "Mesa fork of libclc: Implementation of the library requirements of the OpenCL C programming language."
> +HOMEPAGE = "https://gitlab.freedesktop.org/karolherbst/mesa-libclc/"

Sorry for the mangled link. Sad that they still keep this in Karol's 
namespace. It however matches what they use in their CI (via the GitLab 
Project ID), see .gitlab-ci/container/build-libclc.sh.

> +SECTION = "devel"
> +LICENSE = "Apache-2.0-with-LLVM-exception"
> +LIC_FILES_CHKSUM = "file://LICENSE.TXT;md5=7cc795f6cbb2d801d84336b83c8017db"
> +
> +SRC_URI = "git://gitlab.freedesktop.org/karolherbst/mesa-libclc.git;protocol=https;branch=llvm_22"
> +
> +SRCREV = "87f66007242ff10e9e84bf32be84f9057f6abc75"

How do we make sure we use the mesa-libclc blessed by mesa for a given 
release?

It seems like we should use the tag as specified in 
MESA_LIBCLC_VERSION=22.1.8.3 in .gitlab-ci/container/build-libclc.sh. 
Can you add a comment in mesa-libclc and mesa.inc that mesa-libclc 
should only be bumped with mesa.inc, and that a bump in mesa.inc should 
REEEEEEALLLLLLY check we use the expected mesa-libclc version (put it 
next to SRCREV so it appears in the git context when someone sends a patch).

I've only barely looked at the changes made between 26.1.0 and 26.2.0 
but we should be able to drastically relax the libclc requirement for 
anything but opencl (rusticl). c.f. 20b40644b7ae ("clc: make libclc 
optional for configs not needing it")

Someone will need to start looking into what they're doing with 
panfrost, c.f. the new panfrost-rust option. There's a bunch of 
additional dependencies in src/panfrost/compiler/kraid/meson.build we'll 
need. Oh well, something for later (but probably very soon, like next 
release).

Cheers,
Quentin