1812128 - WasmParser.js doesn't support WebAssembly GC proposal

Status: RESOLVED FIXED

(DevTools :: Debugger, defect, P3)

Description

[bashor]

Attachment: wasm-sourcemap-wasm.wasm

Steps to reproduce:

Firefox devtools unable to decompile wasm file generated by Kotlin/Wasm

Actual results:

It shows "Error occured during wast conversion : Unknown type kind: -49"

Expected results:

Decompiled wasm binary

Comment 1

[Ryan Hunt [:rhunt]]

It looks like the issue is in WasmParser.js not supporting the new types being introduced in the WebAssembly GC proposal.

I'm not sure if WasmParser.js is maintained anymore. It may make sense to try to switch to a different library? The wasm team contributes to wasm-tools which has a Rust crate for converting bytecode to text. Maybe we could compile that crate to wasm and use that as a replacement in devtools?

Comment 2

[Yury Delendik (:yury)]

(In reply to Ryan Hunt [:rhunt] from comment #1)

It looks like the issue is in WasmParser.js not supporting the new types being introduced in the WebAssembly GC proposal.

I'm not sure if WasmParser.js is maintained anymore. It may make sense to try to switch to a different library? The wasm team contributes to wasm-tools which has a Rust crate for converting bytecode to text. Maybe we could compile that crate to wasm and use that as a replacement in devtools?

The Chrome DevTools were using wasmparser.js at some point, and it is still in their codebase.

The main requirements for the bytecode-to-text library is to support mapping of bytecode offset to text lines (for debugging). I did not check if wasm-tools have this feature.

Comment 3

[bashor]

The Chrome DevTools were using wasmparser.js at some point, and it is still in their codebase.

AFAIK (at least inside source viewer/editor) they are using decompiler based on V8 internals.

Comment 4

[Yury Delendik (:yury)]

Submitted https://github.com/wasdk/wasmparser/pull/133 with Wasm GC milestone 6 codes.

Comment 5

[Yury Delendik (:yury)]

Attachment: Bug 1812128 - Update wasmparser.js to 5.6.0. r?bomsy

Comment 6

[Yury Delendik (:yury)]

Attachment: simple-gc-m6.html (enable

Simple test that run something like:

(module
  (rec
    (type $t0  (struct (field f32)))
    (type $t1 (sub $t0 (struct (field f32) (field i32))))
  )

  (func $f0 (param (ref null $t0)) (result (ref null $t1))
    (ref.cast $t1
      (local.get 0)
    )
  )

  (func (export "main")
    (drop
      (call $f0
        (struct.new_default $t1)))
  )

)

(enable javascript.options.wasm_function_references javascript.options.wasm_gc)

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2a4fdb257953
Update wasmparser.js to 5.6.0. r=devtools-reviewers,ochameau

Comment 8

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/2a4fdb257953