[stack-switching] GC interaction - #14140
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This patch adds support for using Wasm GC when using the stack switching extension. The contents of this patch: * Trace GC roots across continuations Emit stack maps at stack-switch resume points and track GC-reference metadata for continuation payload buffers, allowing suspended stacks and bound arguments to be traced correctly. Allocate and update this metadata only for GC-capable payloads, leaving ordinary stack-switching paths largely unchanged. * Support `contref`s in GC types This patch enables storing `contref` values in GC structs and arrays. The core idea behind the implementation is the same as for `funcref`: a store-local interning table is used to map 16 bytes continuation identifiers to 4 bytes GC types. * Fixes issue 13750 Retain Wasm type information when loading continuation payloads and mark GC-reference results as requiring stack maps. This keeps references returned by `resume`, `suspend`, and `switch` alive across subsequent GC safepoints. Added the POC as a regression test. * Fixes issue 13021 Added the POC as a regression test. * Fixes issue 13022 Added the POC as a regression test.
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This patch adds support for using Wasm GC when using the stack switching extension. The noteworthy contents of this patch:
Emit stack maps at stack-switch resume points and track GC-reference metadata for continuation payload buffers, allowing suspended stacks and bound arguments to be traced correctly. Allocate and update this metadata only for GC-capable payloads, leaving ordinary stack-switching paths largely unchanged.
contrefs in GC typesThis patch enables storing
contrefvalues in GC structs and arrays. The core idea behind the implementation is the same as forfuncref: a store-local interning table is used to map 16 bytes continuation identifiers to 4 bytes GC types.Retain Wasm type information when loading continuation payloads and mark GC-reference results as requiring stack maps. This keeps references returned by
resume,suspend, andswitchalive across subsequent GC safepoints.Added the POC as a regression test.
Added the POC as a regression test.
Added the POC as a regression test.
The POC exits successfully with code 0 now. I've not added the POC as a regression test, because it is undistilled.
Resolves #12941. Resolves #13021. Resolves #13022. Resolves #13750.