Assertion when assembling `ref.cast` with a no ref type

[hgruniaux]

When using wasm-as on the following file:

(module
    (func (local $a anyref)
        (ref.cast i32 (local.get $a))))

An assertion fail in the code:

Assertion failed: isRef() (/src/src/wasm/wasm-type.cpp: getHeapType: 996)

I believe the assembler should print an error (the above wasm code is, of course, invalid) instead of crashing.

I tested the last version 117. I haven't tested the main branch, maybe the problem do not exist anymore.

[kripken]

Testing on latest main, I see

Fatal: 3:18: error: expected folded instruction

That location 3:18 is between the ref.cast and the i32. @tlively what does it mean by "folded instruction" that it expects there?

[tlively]

This does still look like a bug with the new parser. The error message should say something about expecting a reftype. The current behavior is that it incorrectly accepts that the ref.cast has no reftype immediate, then goes to parse the next instruction starting from i32 (local.get $a.... That does not start with the expected opening paren for a folded instruction, so it produces the current error message.