commit 4090b7d2d2cb4f3e8ef448aeaca55c75a55b41ca
author danakj <danakj@chromium.org> Tue Oct 24 17:49:01 2023 +0000
committer Dawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Oct 24 17:49:01 2023 +0000
tree 7dbff550dcb63821c1e61fe9c5b342f798bfd021
parent 2d123d0dfdc67af1dcbabd178be8073726b67524

Add support for the Rust toolchain

To enable Rust build targets in standalone dawn:
- Add `checkout_rust: True` to the gclient `custom_vars` section. As
  it defaults to false:
    "custom_vars": {
      "checkout_rust": True,
    }
- Set `enable_rust = true` in GN args, as it also defaults to false.
- Run gclient sync

Then building `rust_build_tests` will build test targets in
//build/rust/tests, which rely on and verify the functioning of
the Rust toolchain.

Make new rust targets by using the GN templates in //build/rust.

In the chromium build, Rust build targets that use the templates
from //build/rust will just work.

------

Dependent steps that are already done:
1) The //tools/rust repo needs to be created in
   https://bugs.chromium.org/p/chromium/issues/detail?id=1494128
2) Then, we should remove the checkout_tools_rust DEPS var,
3) And update the tools/clang and tools/rust revisions so that they
   are compatible.
4) Roll the chromium //build changes that were required in from
   https://chromium-review.googlesource.com/c/chromium/src/+/4956874
   and
   https://chromium-review.googlesource.com/c/chromium/src/+/4966201
5) The clang roll causes clang-cl to warn on use of offsetof, but it
   does not define __GNUC__, which is used to remove the warning. So
   also remove the warning when __clang__ is defined.

Bug: chromium:1494118
Change-Id: I5e280090ec950a1da9f91e2e4717925ce4b2eaa6
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/157120
Reviewed-by: Austin Eng <enga@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: danakj <danakj@chromium.org>