Calling call_indirect with argument and with a function defined prior to type definitions will cause exception about lucet HOT 4 CLOSED

Oh! I know this one. The icall implementation is incorrect at the moment, and we fail a spec test that demonstrates this exact issue. When we expand the icall instruction, we check the type index at the call site with the type index of the callee. The problem is, multiple type indices can have the same structural type - the $early_fn type will be assigned to $fn0, which will be a different index than $fnT0 .

Full spec test compliance is important to us. I think we will achieve it within the next month or two. This issue is pretty isolated from the engineering we're doing to fix the rest of the major spec compliance issues, so I should be able to get a fix in pretty soon.

from lucet.

What commit were you on when you ran into this issue? I was somewhat surprised to find this works on master, since there are related spec tests we don't currently pass.

This:

(module $calli

  (table funcref (elem $fn0))

  (type $fnT0 (func (param i32) (result i32)))
  (type $fnT1 (func (param i32) (result i32)))

  (func $fn0 (param $arg i32) (result i32) (i32.const 0))

  (func $main0 (drop (call_indirect (type $fnT1) (i32.const 0) (i32.const 0))))

  (export "_start" (func $main0))
)

does still erroneously claim BadSignature, and that's definitely due to us not checking structural equivalence between $fnT0 and $fnT1. But it's also not the same code you reported :) I'm left wondering what's different that your example seems to run without issue when I tested it..

from lucet.

I don't have access to the system where I produced this but I checked out lucet an hour or two before I filed the bug (i.e. yesterday). If you aren't seeing it then I expect it is dependent on the wat -> wasm compiler behavior. I'm using wasm-as from binaryen and I'll have to get access to my home workstation before I can figure out what version it is.

from lucet.

lucetc can accept wat syntax directly, and translates it to wasm using the wabt package's translator (also available as the wat2wasm executable. So, its probably a difference in how those two translators work.

from lucet.