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[CodeAnnotations] Implement function-level inlining hints#8265

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kripken merged 13 commits intoWebAssembly:mainfrom
kripken:func.annot
Feb 4, 2026
Merged

[CodeAnnotations] Implement function-level inlining hints#8265
kripken merged 13 commits intoWebAssembly:mainfrom
kripken:func.annot

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@kripken kripken commented Feb 3, 2026

This is the first function-level annotation, so this includes some
necessary fixes for that.

Diff without whitespace is smaller.

@kripken kripken requested a review from tlively February 3, 2026 22:46
auto offset = exprOffset - funcDeclarationsOffset;
// Compute the offset: it should be relative to the start of the
// function locals (i.e. the function declarations).
offset = exprOffset - funcDeclarationsOffset;
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Does this expression offset ever end up being 0 as well?

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It can't be 0 - the function has something at offset 0 (the number of locals, even if has no locals, that will take a byte for "0"). This is why we decided it was safe to use offset 0 in the spec.

Comment on lines 11 to 12
;; RUN: wasm-opt -all %s -S -o - | filecheck %s
;; RUN: wasm-opt -all --roundtrip %s -S -o - | filecheck %s
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Can we move the RUN lines to the top of the file for consistency with other tests? I was about to leave a comment asking how it was possible that there were no RUN lines here before I found them 😅

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Sure, moved.

(@metadata.code.inline "\12")
(func $func-annotation
;; The annotation here is on the function.
(drop
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Related to my question about the offsets, can we properly roundtrip an annotation on the first expression in a function?

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Yes, and we test that, see e.g.

(@metadata.code.inline "\00")

@kripken kripken merged commit d4f29b6 into WebAssembly:main Feb 4, 2026
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@kripken kripken deleted the func.annot branch February 4, 2026 19:59
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2 participants