Adding tests for wat compatibility

[ktran]

We would like to validate that the wat output generated by the wasmparser is wat compatible for DevTools.

Would it make sense to you to include running wat2wasm's parseWat for validation? At the moment parseWat is already used in some tests in test.ts to generate the wasm binary, before disassembling it again and testing the output.

An option would be to run parseWat on the test/*out files and confirm that no error was thrown. However, in this case a few out files (4 in total, if pull request #32 is accepted) need to be excluded, as wat2wasm in some cases requires different wat format, although the format in the wasmparser is valid according to the specification (e.g. because of different naming of operators for SIMD -- i32.atomic.rmw8.add_u vs i32.atomic.rmw8_u.add, etc.). It would also be possible to adapt the output to be completely compatible with wat2wasm.

What do you think?

[bmeurer]

I'd vote for wasmparser to be 100% compatible with wabt.

[sunfishcode]

wasmparser should follow the spec, which was changed to use the i32.atomic.rmw8.add_u names. wabt also follows this spec, and is already updated for the new names, so this will be compatible.

Note that https://webassembly.github.io/threads/ still uses the i32.atomic.rmw8_u.add names; I filed WebAssembly/threads#152 for that.

[ktran]

Thanks Benedikt and Dan for the comments!

Dan, thanks for linking the updated threads spec.

Following these specs (threads, bulk-memory, and core spec) there seem to be a few things that are different in the wasmparser:

• using i32.atomic.rmw8.add_u
• table.copy arguments
• table.init arguments
• elem arguments (this might require a bigger change)

I'll have a look into these issues.

[duongnhn]

Thanks Benedikt and Dan for the comments!

Dan, thanks for linking the updated threads spec.

Following these specs (threads, bulk-memory, and core spec) there seem to be a few things that are different in the wasmparser:

• using i32.atomic.rmw8.add_u
• table.copy arguments
• table.init arguments
• elem arguments (this might require a bigger change)

I'll have a look into these issues.

@ktran What's about "elem arguments"? Could you elaborate :)

[ktran]

My comment on elem does not seem to be up to date anymore; it happened when parsing the memory_bulk.0.wasm file, which seems fine now.

[duongnhn]

My comment on elem does not seem to be up to date anymore; it happened when parsing the memory_bulk.0.wasm file, which seems fine now.

No worries. I think all the issues here are resolved now :)