TS8032

When it fires

.length, or arrayLength(x), on an array<T> with no N that is not in storage: a uniform<array<T>>, a local, or a parameter. .length once folded to the literal 0, which made gid.x >= xs.length true for every invocation and the kernel a silent no-op in valid WGSL. A runtime-sized storage array now reads its length from the buffer as arrayLength(&x); the shapes that have no runtime length need an explicit size, which is what this says.

Example

"use typeshade"

declare const u: uniform<array<f32>>

function count(): f32 {
  return f32(u.length)
}

@fragment
export function main(@location(0) uv: vec2): vec4 {
  return vec4(uv, count(), 1.)
}

Compiled at build time against the pinned compiler, this program gets:

How to fix it

The same program, corrected. It compiles with no diagnostic.

"use typeshade"

class UData {
  items: array<f32, 3>
}

declare const u: uniform<UData>

function count(): f32 {
  return f32(u.items.length)
}

@fragment
export function main(@location(0) uv: vec2): vec4 {
  return vec4(uv, count(), 1.)
}

See also

TS8051 LAYOUT

A buffer binding's store type breaks one of WGSL's host-shareable rules (§51), which a struct hides from the type map and the backend only meets as emitted text: a bool, alone or in a vector, in a uniform or storage binding, as a field, a runtime array's element or the whole type (type 'bool' cannot be used in address space 'uniform' as it is non-host-shareable, and the same of vec3<bool>), a runtime-sized array<T> that is not its struct's last member, or a runtime-sized array in a uniform, whose type must be constructible.

• Resources
• arrayLength
• Error codes

Source

Where the compiler raises this code at commit 26de7be8, one line per file:

• src/compiler/ts/lower/expression-prop.ts:152