260039 2023-08-10 13:58:01 -0700 [Wasm-GC] Module linking should take subtyping into account 2023-12-18 09:55:08 -0800 1 1 1 Unclassified WebKit WebAssembly WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 247394 1 asumu webkit-unassigned webkit-bug-importer oldest_to_newest 1970571 0 asumu 2023-08-10 13:58:01 -0700 Right now, module linking checks for exact type index equality to make sure linked functions satisfy their types. The GC proposal extends this to work with subtypes, instead of exact match, but this isn't implemented yet. For example, this test fragment is from the GC proposal repo test suite: ``` (module (type $t0 (sub (func (result (ref null func))))) (rec (type $t1 (sub $t0 (func (result (ref null $t1)))))) (rec (type $t2 (sub $t1 (func (result (ref null $t2)))))) (func (export "f0") (type $t0) (ref.null func)) (func (export "f1") (type $t1) (ref.null $t1)) (func (export "f2") (type $t2) (ref.null $t2)) ) (register "M") (module (type $t0 (sub (func (result (ref null func))))) (rec (type $t1 (sub $t0 (func (result (ref null $t1)))))) (rec (type $t2 (sub $t1 (func (result (ref null $t2)))))) (func (import "M" "f0") (type $t0)) (func (import "M" "f1") (type $t0)) (func (import "M" "f1") (type $t1)) (func (import "M" "f2") (type $t0)) (func (import "M" "f2") (type $t1)) (func (import "M" "f2") (type $t2)) ) ``` The import "f1" takes a function that has type `$t1` (subtype of `$t0`) and tries to import it under type `$t0`. This currently fails, but is supposed to succeed. It should be relatively easy to fix, by changing the index equality check to a `isSubtype` call. 1971908 1 webkit-bug-importer 2023-08-17 13:58:15 -0700 <rdar://problem/114045477> 1999976 2 asumu 2023-12-15 10:28:12 -0800 Pull request: https://github.com/WebKit/WebKit/pull/21875 2000456 3 ews-feeder 2023-12-18 09:55:06 -0800 Committed 272226@main (3015bbe0e8ab): <https://commits.webkit.org/272226@main> Reviewed commits have been landed. Closing PR #21875 and removing active labels.