xtask

xtask (xtask/) is the workspace's automation crate. The pattern is the standard "cargo xtask" idiom: a binary inside the workspace that contributors invoke as cargo xtask <subcommand> for repo-wide tasks that don't fit neatly into cargo itself.

A second xtask crate exists at naga/xtask/ for naga-specific automation, mainly the validate <backend> command.

Purpose

• Centralize cargo nextest invocations with the right flags and feature combinations (xtask test).
• Drive WebGPU CTS runs (xtask cts).
• Build / serve the wasm examples (xtask run-wasm).
• Audit CHANGELOG.md (xtask changelog).
• Handle Windows-only setup like installing WARP and the D3D12 Agility SDK.
• Re-vendor web-sys WebGPU bindings.
• Drive the miri test runs.

Directory layout

xtask/
├── Cargo.toml
└── src/
    ├── main.rs                 dispatch + help text
    ├── changelog.rs            ~18 KB
    ├── cts.rs                  ~16 KB
    ├── install_agility_sdk.rs
    ├── install_warp.rs
    ├── miri.rs
    ├── run_wasm.rs
    ├── test.rs
    ├── util.rs
    └── vendor_web_sys.rs       ~11 KB

Subcommands

cargo xtask --help prints the full list; xtask/src/main.rs is the source. Summary:

Subcommand	What it does
cts	Build, check out the pinned CTS, and run it via Deno.
test	Run nextest with the right feature combos and platform shims.
run-wasm	Build wasm examples and serve them locally.
changelog	Audit CHANGELOG.md. Used in CI on PRs.
miri	Run miri-compatible tests under miri.
vendor-web-sys	Regenerate the web-sys WebGPU bindings vendored under wgpu/src/backend/webgpu/web-sys-vendored/.
install-warp	Download Microsoft WARP DLL for software DX12 testing.
install-agility-sdk	Install the D3D12 Agility SDK for an up-to-date runtime.

Each subcommand has a help block in xtask/src/main.rs::HELP.

naga's xtask

naga/xtask/ is invoked from the naga/ directory:

cd naga
cargo xtask validate spv      # SPIRV-Tools required
cargo xtask validate msl      # XCode CLI tools (macOS)
cargo xtask validate glsl     # glslang
cargo xtask validate hlsl dxc # DXC
cargo xtask validate hlsl fxc # FXC (Windows)
cargo xtask validate dot      # GraphViz
cargo xtask validate wgsl

It runs the corresponding external tool against every checked-in snapshot output for that backend and reports failures. naga/README.md describes when each tool is required.

Integration points

• Above: contributors and CI workflows.
• Below: every other crate in the workspace, plus external tools (cargo nextest, Deno, SPIRV-Tools, glslang, DXC, FXC, GraphViz, miri).

Entry points for modification

• Add a subcommand — add a module under xtask/src/, route to it from main.rs, and document it in HELP. Try to make the command printable as --help's text matches the implementation.
• Add a workflow shim — for repo-wide tasks. Don't add a shim for one-off scripts — keep those in docs/ or the relevant crate.
• A naga-specific tool — naga/xtask/.