Unify validation error presentation in Naga CLI and WebGPU compilation messages

[ErichDonGubler]

Connections

• Supersedes Fold Error source chain Display output into shader errors #3731.
• One step on the path towards Consolidate diagnostic presentation logic into library error types #4494.

Description

This PR changes the format of validation errors emitted by naga CLI and the compilation message API in WebGPU. It changes the presentation of the error in this shader:

fn sdfRect(samplePosition: vec2f, halfSize: vec2f) -> f32 {
    let componentWiseEdgeDistance = abs(samplePosition) - halfSize;
    let outsideDistance = length(max(componentWiseEdgeDistance, vec2f(0)));
    let insideDistance = min(max(componentWiseEdgeDistance.x, componentWiseEdgeDistance.y), 0);
    return outsideDistance + insideDistance;
}

…which is reported like this in Naga CLI:

error:
  ┌─ in.wgsl:1:1
  │
1 │ ╭ fn sdfRect(samplePosition: vec2f, halfSize: vec2f) -> f32 {
2 │ │     let componentWiseEdgeDistance = abs(samplePosition) - halfSize;
3 │ │     let outsideDistance = length(max(componentWiseEdgeDistance, vec2f(0)));
4 │ │     let insideDistance = min(max(componentWiseEdgeDistance.x, componentWiseEdgeDistance.y), 0);
  │ │                          ^^^ naga::Expression [12]
5 │ │     return outsideDistance + insideDistance;
  │ ╰────────────────────────────────────────────^ naga::Function [0]

Function [0] 'sdfRect' is invalid:
        Expression [12] is invalid
        Argument [1] to Min as expression [11] has an invalid type.

…and, particularly badly and motivating this PR, like this in consumers of the compilation message API in WebGPU:

Shader validation error: 
  ┌─ in.wgsl:1:1
  │  
1 │ ╭ fn sdfRect(samplePosition: vec2f, halfSize: vec2f) -> f32 {
2 │ │     let componentWiseEdgeDistance = abs(samplePosition) - halfSize;
3 │ │     let outsideDistance = length(max(componentWiseEdgeDistance, vec2f(0)));
4 │ │     let insideDistance = min(max(componentWiseEdgeDistance.x, componentWiseEdgeDistance.y), 0);
  │ │                          ^^^ naga::Expression [12]
5 │ │     return outsideDistance + insideDistance;
  │ ╰────────────────────────────────────────────^ naga::Function [0]

…to this in both contexts:

error: Function [0] 'sdfRect' is invalid
  ┌─ in.wgsl:1:1
  │
1 │ ╭ fn sdfRect(samplePosition: vec2f, halfSize: vec2f) -> f32 {
2 │ │     let componentWiseEdgeDistance = abs(samplePosition) - halfSize;
3 │ │     let outsideDistance = length(max(componentWiseEdgeDistance, vec2f(0)));
4 │ │     let insideDistance = min(max(componentWiseEdgeDistance.x, componentWiseEdgeDistance.y), 0);
  │ │                          ^^^ naga::Expression [12]
5 │ │     return outsideDistance + insideDistance;
  │ ╰────────────────────────────────────────────^ naga::Function [0]
  │
  = Expression [12] is invalid
  = Argument [1] to Min as expression [11] has an invalid type.

Testing

I have validated the output of this myself, as is hopefully demonstrated. No tests appeared to need to be updated. If we want snapshot coverage for Naga CLI's output, or our WebGPU API's compilation message items, I believe we should file a follow-up issue to address it.

Checklist

• Run cargo fmt.
• Run taplo format.
• Run cargo clippy. If applicable, add:
  • --target wasm32-unknown-unknown
  • --target wasm32-unknown-emscripten
• Run cargo xtask test to run tests.
• Add change to CHANGELOG.md. See simple instructions inside file.

[teoxoy]

Great seeing code getting removed even when more functionality is added!