Rusticl¶

Enabling¶

In order to use Rusticl on any platform the environment variable RUSTICL_ENABLE has to be used. Rusticl does not advertise devices for any driver by default yet as doing so can impact system stability until remaining core issues are ironed out.

Building¶

To build Rusticl you need to satisfy the following build dependencies:

rustc
rustfmt (highly recommended, but only required for CI builds or when authoring patches)
bindgen
LLVM built with libclc and -DLLVM_ENABLE_DUMP=ON.
SPIRV-Tools
SPIRV-LLVM-Translator for a libLLVMSPIRVLib.so matching your version of LLVM, i.e. if you’re using LLVM 15 (libLLVM.so.15), then you need a libLLVMSPIRVLib.so.15.

The minimum versions to build Rusticl are:

Rust: 1.60
Meson: 1.2.0
Bindgen: 0.62.0
LLVM: 11.0.0 (recommended: 15.0.0)
Clang: 11.0.0 (recommended: 15.0.0) Updating clang requires a rebuilt of mesa and rusticl if and only if the value of CLANG_RESOURCE_DIR changes. It is defined through clang/Config/config.h.
SPIRV-Tools: any version (recommended: v2022.3)

Afterwards you only need to add -Dgallium-rusticl=true -Dllvm=enabled -Drust_std=2021 to your build options.

Most of the code related to Mesa’s C code lives inside /mesa, with the occasional use of enums, structs or constants through the code base.

If you need help ping karolherbst either in #dri-devel or #rusticl on OFTC.

Rust Update Policy¶

Given that for some distributions it’s not feasible to keep up with the pace of Rust, we promise to only bump the minimum required Rust version following those rules:

Only up to the Rust requirement of other major Linux desktop components, e.g.:
- Firefox ESR: Minimum Supported Rust Version:
- latest Linux Kernel Rust requirement
Only require a newer Rust version than stated by other rules if and only if it’s required to get around a bug inside rustc.

As bug fixes might run into rustc compiler bugs, a rust version bump _can_ happen on a stable branch as well.

Contributing¶

The minimum configuration you need to start developing with rust is RUSTC=clippy-driver meson configure -Dgallium-rusticl=true -Dllvm=enabled -Drust_std=2021. In addition you probably want to enable any device drivers on your platform. Some device drivers as well as some features are locked behind flags during runtime. See Rusticl environment variables for more info.

All patches that are potentially conformance breaking and also patches that add new features should be ran against the appropriate conformance tests.

Also, make sure the formatting is in order before submitting code. That can easily be done via git ls-files */{lib,app}.rs | xargs rustfmt.

When submitting Merge Requests or filing bugs related to Rusticl, make sure to add the Rusticl label so people subscribed to that Label get pinged.

Known issues¶

One issue you might come across is, that the Rust edition meson sets is not right. This is a known meson bug and in order to fix it, simply run meson configure $your_build_dir -Drust_std=2021