Using an array as a slice causes a compiler error
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bug
- Dominant language
- Rust
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Description
I'm surprised I haven't hit this earlier, but it's not possible to pass an array as a slice. Is this a known limitation? Is there an easy workaround?
Expected Behaviour
I would expect to be able to pass an array like [u32; 3] as a parameter to a function that takes a slice.
Example & Steps To Reproduce
Here is a minimal reproducible example:
#![no_std]
#![allow(unexpected_cfgs)]
fn do_work(data: &[u32], slab: &mut [u32]) {
slab[0] = data[0];
slab[1] = data[1];
slab[2] = data[2];
}
#[spirv(compute(threads(16)))]
pub fn compute_shader(
#[spirv(storage_buffer, descriptor_set = 0, binding = 0)] slab: &mut [u32],
#[spirv(global_invocation_id)] global_id: glam::UVec3,
) {
let data = [global_id.x, global_id.y, global_id.z];
do_work(&data, slab);
}
System Info
- Rustc version:
1.90 - spirv-std: from the latest
main,b3eda4df9814b6176d3c0844eb67f70a22ebb378as of this writing - SPIR-V version:
❯ spirv-val --version SPIRV-Tools v2025.3 unknown hash, 2025-06-23T19:59:33+00:00 Targets: SPIR-V 1.0 SPIR-V 1.1 SPIR-V 1.2 SPIR-V 1.3 SPIR-V 1.4 SPIR-V 1.5 SPIR-V 1.6 SPIR-V 1.2 (under OpenCL 2.2 Full Profile semantics) SPIR-V 1.0 (under Vulkan 1.0 semantics) SPIR-V 1.3 (under Vulkan 1.1 semantics) SPIR-V 1.4 (under Vulkan 1.1 semantics) SPIR-V 1.5 (under Vulkan 1.2 semantics) SPIR-V 1.6 (under Vulkan 1.3 semantics) SPIR-V 1.6 (under Vulkan 1.4 semantics)
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by compiling the minimal Rust example in the issue, focusing on the do_work call that passes &data to a &[u32] parameter. Trace the compiler's handling of the array-to-slice conversion and verify the example compiles successfully with the compute shader entry point.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 38/100