Stream: git-wasmtime

Topic: wasmtime / PR #13847 [gc_fuzz]: Extend everything we have...

Wasmtime GitHub notifications bot (Jul 08 2026 at 21:52):

khagankhan requested alexcrichton for a review on PR #13847.

Wasmtime GitHub notifications bot (Jul 08 2026 at 21:52):

khagankhan opened PR #13847 from khagankhan:array to bytecodealliance:main:

• types.rs: CompositeType::Array with a reused StructField element. Full array-to-array subtyping (element covariance/invariance, forced element-compatibility in fixup). Cross-kind supertype edges (struct<->array) are cleared. StackType::Array wired into operand satisfaction, eqref upcast, and cast repair.
• ops.rs: a full mirror of the struct op family for arrays, plus array-specific ArrayNew (fixed-length array.new_default), ArrayGet/ArraySet, and ArrayLen. Accesses are null-guarded and use index % (array_length + 1) so out-of-bounds traps are exercised but rare. A same-kind index remap keeps struct ops off array types (and vice versa) now that both share one type-index space.
• mutator.rs: array generation, element mutation, and generic rec-group duplication.
• oracles.rs: take_array + typed take_array_N imports, and Trap::ArrayOutOfBounds added to the accepted-trap allowlist.
• limits.rs: a fuzzable array_length knob (1..=16, default 5).
• config.rs: Config::to_store() could panic in Engine::new() for pooling + GC configs. The GC-heap backing memory rounds its minimum size up to a 64 KiB wasm page, but the harness clamped gc_heap_initial_size to max_memory_size in raw bytes — so a non-page-aligned max_memory_size let the rounded-up minimum overshoot the pool's per-memory limit, and Engine::new (correctly) rejected the config, which to_store().unwrap() turned into a crash. Fixed by clamping the initial size to max_memory_size rounded down to a page.

+cc @fitzgen @eeide

Wasmtime GitHub notifications bot (Jul 08 2026 at 21:52):

khagankhan requested wasmtime-fuzz-reviewers for a review on PR #13847.

Wasmtime GitHub notifications bot (Jul 08 2026 at 22:20):

alexcrichton unassigned alexcrichton from PR #13847 [gc_fuzz]: Extend everything we have done so far to array types.

Wasmtime GitHub notifications bot (Jul 08 2026 at 22:20):

alexcrichton requested fitzgen for a review on PR #13847.

Wasmtime GitHub notifications bot (Jul 09 2026 at 00:04):

github-actions[bot] added the label fuzzing on PR #13847.

Wasmtime GitHub notifications bot (Jul 09 2026 at 00:05):

github-actions[bot] commented on PR #13847:

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Wasmtime GitHub notifications bot (Jul 20 2026 at 19:07):

:thumbs_up: fitzgen submitted PR review:

Thanks! LGTM, just needs a rebase

Wasmtime GitHub notifications bot (Jul 21 2026 at 19:32):

khagankhan updated PR #13847.

Wasmtime GitHub notifications bot (Jul 21 2026 at 19:49):

khagankhan commented on PR #13847:

@fitzgen Thanks! I rebased it and considering this PR solved the bug in config.rs I resolved the conflict accordingly.

Wasmtime GitHub notifications bot (Jul 21 2026 at 20:39):

:thumbs_up: fitzgen submitted PR review:

Thanks!

Wasmtime GitHub notifications bot (Jul 21 2026 at 20:39):

fitzgen added PR #13847 [gc_fuzz]: Extend everything we have done so far to array types to the merge queue.

Wasmtime GitHub notifications bot (Jul 21 2026 at 21:02):

:check: fitzgen merged PR #13847.

Wasmtime GitHub notifications bot (Jul 21 2026 at 21:02):

fitzgen removed PR #13847 [gc_fuzz]: Extend everything we have done so far to array types from the merge queue.

Last updated: Jul 29 2026 at 05:03 UTC