Stream: git-wasmtime

Topic: wasmtime / PR #12533 Clean up `gc_ops` fuzzing mutator

Wasmtime GitHub notifications bot (Feb 05 2026 at 16:32):

fitzgen opened PR #12533 from fitzgen:gc-fuzzer-clean-ups to bytecodealliance:main:

This commit cleans up a few random things about the gc_ops fuzzing mutator, notably:

• The macro to define GcOp and many of its methods is refactored to be more extensible going forward (e.g. all of GC op fixup is now macro-generated, instead of having special-cases for typed struct ops, and we could probably also move encoding into the macro as a follow up PR).
• Furthermore, the macro is also a for_each_*-style macro now, which lets us define the GC ops once and then use the macro multiple times to define different things, rather than being forced to put everything we want to generate into one macro RHS. This should make things a bit easier to read and edit and plays nicer with LSP.
• A bunch of GC op filtering that was logically part of fixing up an instruction is now actually part of GcOp::fixup. Also a redundant op.fixup() call was removed, GcOp::fixup takes &self instead of &mut self since it returns a new GcOp now instead of mutatint self in place, etc...
• A few other small things here and there.

+cc @khagankhan @eeide

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Wasmtime GitHub notifications bot (Feb 05 2026 at 16:32):

fitzgen requested wasmtime-fuzz-reviewers for a review on PR #12533.

Wasmtime GitHub notifications bot (Feb 05 2026 at 16:32):

fitzgen requested alexcrichton for a review on PR #12533.

Wasmtime GitHub notifications bot (Feb 05 2026 at 17:38):

fitzgen updated PR #12533.

Wasmtime GitHub notifications bot (Feb 05 2026 at 17:55):

khagankhan commented on PR #12533:

Thank you so much! Looks nice!

Wasmtime GitHub notifications bot (Feb 05 2026 at 18:30):

alexcrichton submitted PR review:

I'm rubber-stamping this since y'all two are the experts on this fuzzer and I figure it doesn't need super close review, but @fitzgen if you want me to take a look at anything in particular lemme know

Wasmtime GitHub notifications bot (Feb 05 2026 at 19:19):

fitzgen added PR #12533 Clean up gc_ops fuzzing mutator to the merge queue.

Wasmtime GitHub notifications bot (Feb 05 2026 at 19:44):

fitzgen merged PR #12533.

Wasmtime GitHub notifications bot (Feb 05 2026 at 19:44):

fitzgen removed PR #12533 Clean up gc_ops fuzzing mutator from the merge queue.

Last updated: Feb 24 2026 at 04:36 UTC