feat: emit warnings for invalid pure annotations by Kyujenius · Pull Request #9381 · rolldown/rolldown

Kyujenius · 2026-05-13T07:45:45Z

Surfaces /* #__PURE__ */ / /* @__PURE__ */ annotations that the parser cannot apply, using Rollup's INVALID_ANNOTATION log code. The parser metadata comes from oxc-project/oxc#20687 (in oxc@0.130.0, already a dependency).

PreProcessEcmaAst::build iterates program.comments after the semantic-warnings block and pushes one diagnostic per PureNotApplied comment. No AST mutation; codegen and tree-shaking unchanged.

Five positive fixtures + one negative (a valid annotation that must produce zero warnings, guarding against false positives) cover the three contexts oxc marks plus the @__PURE__ variant and a mixed valid/invalid case. Two existing snapshots (remove_unused_pure_comment_calls, property_read_side_effects) gained the warning because their inputs already contained misplaced annotations — their # Assets output is unchanged.

One open question: Rollup also strips invalid annotations from output (per its log text "The comment will be removed to avoid issues"). I left that out to avoid a behavior change during the RC phase; happy to follow up in a separate PR if desired.

Fixes #8898.

codspeed-hq · 2026-05-13T08:15:10Z

Merging this PR will not alter performance

✅ 4 untouched benchmarks
⏩ 10 skipped benchmarks¹

_{Comparing Kyujenius:feat/warn-invalid-pure-annotations (226daaa) with main (fe43e8a)²}

10 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩
No successful run was found on main (990b38f) during the generation of this report, so fe43e8a was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

h-a-n-a · 2026-05-13T13:24:57Z

Can you resolve the conflicts please?

Kyujenius · 2026-05-13T13:26:01Z

Can you resolve the conflicts please?

Already on it 😄 rebasing onto the latest main and resolving conflicts now. Will push the updated branch shortly.

…nnotations

…otation emit

Follow-up to #9381 — addresses the review feedback about the `@__PURE__` docs being incomplete. The existing section only covered function calls. This expands it to: - Mention that `new` expressions also receive the annotation - Note the annotation's required position (immediately before the call/new expression) - List common invalid placements in a warning admonition — the same patterns that #9381's new `INVALID_ANNOTATION` warning now surfaces

Surfaces `/* #__PURE__ */` / `/* @__PURE__ */` annotations that the parser cannot apply, using Rollup's `INVALID_ANNOTATION` log code. The parser metadata comes from oxc-project/oxc#20687 (in `oxc@0.130.0`, already a dependency). `PreProcessEcmaAst::build` iterates `program.comments` after the semantic-warnings block and pushes one diagnostic per `PureNotApplied` comment. No AST mutation; codegen and tree-shaking unchanged. Five positive fixtures + one negative (a valid annotation that must produce zero warnings, guarding against false positives) cover the three contexts oxc marks plus the `@__PURE__` variant and a mixed valid/invalid case. Two existing snapshots (`remove_unused_pure_comment_calls`, `property_read_side_effects`) gained the warning because their inputs already contained misplaced annotations — their `# Assets` output is unchanged. One open question: Rollup also _strips_ invalid annotations from output (per its log text "The comment will be removed to avoid issues"). I left that out to avoid a behavior change during the RC phase; happy to follow up in a separate PR if desired. Fixes #8898.

Follow-up to #9381 — addresses the review feedback about the `@__PURE__` docs being incomplete. The existing section only covered function calls. This expands it to: - Mention that `new` expressions also receive the annotation - Note the annotation's required position (immediately before the call/new expression) - List common invalid placements in a warning admonition — the same patterns that #9381's new `INVALID_ANNOTATION` warning now surfaces

`/* #__PURE__ */ test().a.b.c` was marked as `PureNotApplied` because `set_pure_on_call_or_new_expr` only checked the top-level AST node. For member-access chains rooted at a call/new, the top-level node is a `MemberExpression`, which fell through to the `_ => false` arm. Rollup and esbuild apply PURE to the innermost call/new in this shape (member-access side effects are handled separately by `propertyReadSideEffects` in Rollup). Aligning here fixes false-positive warnings in downstream consumers that forward `PureNotApplied` to users (e.g. rolldown/rolldown#9381). Recurse through `StaticMemberExpression`, `ComputedMemberExpression`, `PrivateFieldExpression`, and the matching `ChainElement` variants (plus `TSNonNullExpression` in chains) to reach the underlying call. Fixes #22394 AI disclosure: implemented with Claude Code, reviewed manually.

@IWANABETHATGUY

## [1.0.2] - 2026-05-20 ### 🚀 Features - devtools: emit package size in PackageGraphReady (#9434) by @IWANABETHATGUY - devtools: classify package dependency types (#9427) by @IWANABETHATGUY - devtools: map packages to modules and chunks (#9426) by @IWANABETHATGUY - devtools: mark used packages (#9423) by @IWANABETHATGUY - devtools: make duplicate packages discoverable (#9422) by @IWANABETHATGUY - devtools: emit package metadata (#9421) by @IWANABETHATGUY - update oxc to 0.132.0 (#9449) by @shulaoda - update oxc to 0.131.0 (#9424) by @shulaoda - allow checks.* to escalate emissions to hard errors (#9388) by @IWANABETHATGUY - dev: support watcher options `include` and `exclude` (#9395) by @h-a-n-a - emit warnings for invalid pure annotations (#9381) by @Kyujenius ### 🐛 Bug Fixes - hash: keep chunk file names stable when an unrelated entry is added (#9444) by @hyf0 - call `codeSplitting.groups[].name` in deterministic order (#9457) by @sapphi-red - dev/lazy: make `resolve_id` idempotent when the resolved id is already a lazy entry (#9439) by @h-a-n-a - chunk-optimization: publish absorbed dynamic-entry namespace cross-chunk (#9448) by @IWANABETHATGUY - treeshake: propagate pure annotation through compound exprs (#9431) by @Dunqing - finalizer: skip redundant init call when barrel executes in same chunk (#9354) by @IWANABETHATGUY - linking: initialize wrapped ESM re-export owners (#9353) by @IWANABETHATGUY - do not inherit __toESM across chunks for named-only external imports (#9333) (#9415) by @IWANABETHATGUY - watcher: don't write output or emit events after close() (#9328) by @situ2001 - chunk-optimization: avoid unsafe dynamic-only merges (#9398) by @IWANABETHATGUY - cjs: rename CJS-wrapped locals that would shadow chunk-scope names (#9392) by @hyf0 - dev/lazy: watch lazy modules added in rebuilds (#9391) by @h-a-n-a ### 🚜 Refactor - rolldown_dev: move dev example to break publish cycle (#9465) by @Boshen - binding: drop unsafe napi string helper, hoist transform ArcStr (#9456) by @hyf0 - ecmascript_utils: split rewrite_ident_reference off JsxExt trait (#9417) by @IWANABETHATGUY - use `ThreadsafeFunction::call_async_catch` (#9390) by @sapphi-red ### 📚 Documentation - devtools: document @rolldown/debug usage and package graph consumption (#9435) by @IWANABETHATGUY - replace `Inter` with system font stack in OG template SVG (#9240) by @yvbopeng - remove `output.comments` warning as all issues have been resolved (#9393) by @sapphi-red - in-depth: clarify @__PURE__ scope and document positions (#9389) by @Kyujenius - readme: remove release candidate notice (#9387) by @shulaoda ### ⚡ Performance - vite-resolve: cache importer existence checks (#9443) by @Brooooooklyn - binding: reduce plugin string clones (#9436) by @Brooooooklyn ### 🧪 Testing - enable `legal_comments_inline` test (#9394) by @sapphi-red ### ⚙️ Miscellaneous Tasks - bump pnpm to v11.1.2 (#9447) by @Boshen - deps: update rust crates (#9461) by @renovate[bot] - deps: update rollup submodule for tests to v4.60.4 (#9453) by @rolldown-guard[bot] - deps: update test262 submodule for tests (#9454) by @rolldown-guard[bot] - deps: update npm packages (#9430) by @renovate[bot] - deps: update github actions (#9429) by @renovate[bot] - deps: update dependency rolldown-plugin-dts to v0.25.1 (#9452) by @renovate[bot] - deps: update rust crates (#9428) by @renovate[bot] - revert allow checks.* to escalate emissions to hard errors (#9388) (#9438) by @IWANABETHATGUY - update mimalloc-safe to 0.1.61 (#9413) by @shulaoda - deny `todo`, `unimplemented`, and `print_stderr` clippy lints (#9412) by @Boshen - deps: update mimalloc-safe to 0.1.60 (#9410) by @shulaoda - remove `pip install setuptools` workaround for node-gyp on macOS (#9370) by @sapphi-red - renovate: disable automerge to require manual approval (#9386) by @shulaoda - deps: update napi (#9385) by @renovate[bot] ### ❤️ New Contributors * @yvbopeng made their first contribution in [#9240](#9240) Co-authored-by: shulaoda <165626830+shulaoda@users.noreply.github.com>

@IWANABETHATGUY

## [1.0.2] - 2026-05-20 ### 🚀 Features - devtools: emit package size in PackageGraphReady (rolldown#9434) by @IWANABETHATGUY - devtools: classify package dependency types (rolldown#9427) by @IWANABETHATGUY - devtools: map packages to modules and chunks (rolldown#9426) by @IWANABETHATGUY - devtools: mark used packages (rolldown#9423) by @IWANABETHATGUY - devtools: make duplicate packages discoverable (rolldown#9422) by @IWANABETHATGUY - devtools: emit package metadata (rolldown#9421) by @IWANABETHATGUY - update oxc to 0.132.0 (rolldown#9449) by @shulaoda - update oxc to 0.131.0 (rolldown#9424) by @shulaoda - allow checks.* to escalate emissions to hard errors (rolldown#9388) by @IWANABETHATGUY - dev: support watcher options `include` and `exclude` (rolldown#9395) by @h-a-n-a - emit warnings for invalid pure annotations (rolldown#9381) by @Kyujenius ### 🐛 Bug Fixes - hash: keep chunk file names stable when an unrelated entry is added (rolldown#9444) by @hyf0 - call `codeSplitting.groups[].name` in deterministic order (rolldown#9457) by @sapphi-red - dev/lazy: make `resolve_id` idempotent when the resolved id is already a lazy entry (rolldown#9439) by @h-a-n-a - chunk-optimization: publish absorbed dynamic-entry namespace cross-chunk (rolldown#9448) by @IWANABETHATGUY - treeshake: propagate pure annotation through compound exprs (rolldown#9431) by @Dunqing - finalizer: skip redundant init call when barrel executes in same chunk (rolldown#9354) by @IWANABETHATGUY - linking: initialize wrapped ESM re-export owners (rolldown#9353) by @IWANABETHATGUY - do not inherit __toESM across chunks for named-only external imports (rolldown#9333) (rolldown#9415) by @IWANABETHATGUY - watcher: don't write output or emit events after close() (rolldown#9328) by @situ2001 - chunk-optimization: avoid unsafe dynamic-only merges (rolldown#9398) by @IWANABETHATGUY - cjs: rename CJS-wrapped locals that would shadow chunk-scope names (rolldown#9392) by @hyf0 - dev/lazy: watch lazy modules added in rebuilds (rolldown#9391) by @h-a-n-a ### 🚜 Refactor - rolldown_dev: move dev example to break publish cycle (rolldown#9465) by @Boshen - binding: drop unsafe napi string helper, hoist transform ArcStr (rolldown#9456) by @hyf0 - ecmascript_utils: split rewrite_ident_reference off JsxExt trait (rolldown#9417) by @IWANABETHATGUY - use `ThreadsafeFunction::call_async_catch` (rolldown#9390) by @sapphi-red ### 📚 Documentation - devtools: document @rolldown/debug usage and package graph consumption (rolldown#9435) by @IWANABETHATGUY - replace `Inter` with system font stack in OG template SVG (rolldown#9240) by @yvbopeng - remove `output.comments` warning as all issues have been resolved (rolldown#9393) by @sapphi-red - in-depth: clarify @__PURE__ scope and document positions (rolldown#9389) by @Kyujenius - readme: remove release candidate notice (rolldown#9387) by @shulaoda ### ⚡ Performance - vite-resolve: cache importer existence checks (rolldown#9443) by @Brooooooklyn - binding: reduce plugin string clones (rolldown#9436) by @Brooooooklyn ### 🧪 Testing - enable `legal_comments_inline` test (rolldown#9394) by @sapphi-red ### ⚙️ Miscellaneous Tasks - bump pnpm to v11.1.2 (rolldown#9447) by @Boshen - deps: update rust crates (rolldown#9461) by @renovate[bot] - deps: update rollup submodule for tests to v4.60.4 (rolldown#9453) by @rolldown-guard[bot] - deps: update test262 submodule for tests (rolldown#9454) by @rolldown-guard[bot] - deps: update npm packages (rolldown#9430) by @renovate[bot] - deps: update github actions (rolldown#9429) by @renovate[bot] - deps: update dependency rolldown-plugin-dts to v0.25.1 (rolldown#9452) by @renovate[bot] - deps: update rust crates (rolldown#9428) by @renovate[bot] - revert allow checks.* to escalate emissions to hard errors (rolldown#9388) (rolldown#9438) by @IWANABETHATGUY - update mimalloc-safe to 0.1.61 (rolldown#9413) by @shulaoda - deny `todo`, `unimplemented`, and `print_stderr` clippy lints (rolldown#9412) by @Boshen - deps: update mimalloc-safe to 0.1.60 (rolldown#9410) by @shulaoda - remove `pip install setuptools` workaround for node-gyp on macOS (rolldown#9370) by @sapphi-red - renovate: disable automerge to require manual approval (rolldown#9386) by @shulaoda - deps: update napi (rolldown#9385) by @renovate[bot] ### ❤️ New Contributors * @yvbopeng made their first contribution in [rolldown#9240](rolldown#9240) Co-authored-by: shulaoda <165626830+shulaoda@users.noreply.github.com>

## Summary - Bump oxc Rust crates and `@oxc-project/*` / `oxc-*` npm packages from `0.132.0` to `0.133.0`. ~~Bump `oxc_resolver` / `oxc_resolver_napi` from `11.19.1` to `11.19.2`.~~ - Regenerate `embedded_helpers.rs` to point at `@oxc-project+runtime@0.133.0` (version string only — no helper-content drift). - Handle two new oxc fields surfaced by `cargo check`: - `oxc::transformer::DecoratorOptions.strict_null_checks` — hardcoded to `true` in the `From` impl (matches oxc's default). Exposing it through rolldown's wrapper would be a separate API change. - `oxc_minify_napi::CodegenOptions.legal_comments` — set to `None`. - Extend `DecoratorOptionSchema` and `CodegenOptionsSchema` in `validator.ts` to mirror the new optional fields. - Refresh 32 snapshots driven by upstream oxc PR [#22547](oxc-project/oxc#22547) ("fix(minifier): preserve IIFE structure in DCE-only mode"). In DCE-only mode (rolldown's per-module preprocess via `Compressor::dead_code_elimination_with_scoping`), oxc no longer inlines `(() => …)()` IIFEs that carry — or could carry — `/*#__PURE__*/` annotations, so downstream tree-shaking can see them. Empty-IIFE elision still fires. Side effects: `property_read_side_effects` now correctly tree-shakes `/*#__PURE__*/ test().a.b.c;` lines and drops the previously spurious `INVALID_ANNOTATION` warnings; TS class `(() => new Foo())()` patterns and `Symbol((() => Math.random() < 0.5)() ? …)` calls are preserved as the sources actually wrote them; `dce_of_iife/diff.md` divergence vs esbuild shrunk. ## Issues fixed Pulled in from upstream oxc fixes between 0.132.0 and 0.133.0: - Fixes #9437 — Pure-annotated IIFE returning an array is inlined (via oxc [#22547](oxc-project/oxc#22547)) - Fixes #9494 — Cross-module enum inlining mis-folds auto-increment member to 0 (via oxc [#22646](oxc-project/oxc#22646)) - Fixes #9408 — Rolldown drops `@preserve` from `/* #__PURE__ -- @preserve */` comments (via oxc [#22525](oxc-project/oxc#22525) "preserve verbatim text of pure/no-side-effects comments") - Partially addresses #8688 — `dce/dce_of_iife` esbuild divergence shrunk (via oxc [#22589](oxc-project/oxc#22589) "drop empty-body IIFE wrapper when called with arguments") Also relevant: oxc [#22566](oxc-project/oxc#22566) reduces false-positive `PureNotApplied` warnings (the warnings system landed in rolldown #9381) by applying PURE through member-access chains. ## Test plan - [x] `cargo check --workspace --all-targets` - [x] `just update-generated-code` - [x] `just test-update` - [x] `just ued` - [x] `just roll` — 32 Rust suites pass (0 failed), 1212 node tests pass (0 failed), TS lint+types clean on 804 files --------- Co-authored-by: shulaoda <165626830+shulaoda@users.noreply.github.com>

Kyujenius force-pushed the feat/warn-invalid-pure-annotations branch from ce6406a to 8a34e92 Compare May 13, 2026 07:59

Kyujenius marked this pull request as ready for review May 13, 2026 08:08

IWANABETHATGUY reviewed May 13, 2026

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Comment thread crates/rolldown/tests/esbuild/dce/remove_unused_pure_comment_calls/artifacts.snap

Kyujenius force-pushed the feat/warn-invalid-pure-annotations branch from 0a3c424 to 3240f98 Compare May 13, 2026 13:30

Kyujenius requested a review from h-a-n-a May 13, 2026 14:05

Kyujenius mentioned this pull request May 14, 2026

parser: PureNotApplied marks chained-call patterns that Rollup/esbuild consider valid oxc-project/oxc#22394

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Kyujenius and others added 6 commits May 14, 2026 11:40

feat(error): add InvalidAnnotation event kind and diagnostic

052d4e0

feat(rolldown): emit INVALID_ANNOTATION warnings for misplaced pure a…

b98bc3a

…nnotations

test(rolldown): cover invalid pure annotation warnings

40bceee

chore: regenerate code for InvalidAnnotation event kind

72a8cc0

perf(rolldown): avoid intermediate Vec allocation in invalid pure ann…

b28bd31

…otation emit

feat(error): link pure annotation docs in invalid annotation diagnostic

226daaa

h-a-n-a force-pushed the feat/warn-invalid-pure-annotations branch from 3240f98 to 226daaa Compare May 14, 2026 03:40

h-a-n-a enabled auto-merge (squash) May 14, 2026 03:41

h-a-n-a merged commit b204abb into rolldown:main May 14, 2026
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Kyujenius mentioned this pull request May 14, 2026

docs(in-depth): clarify @__PURE__ scope and document positions #9389

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Dunqing mentioned this pull request May 19, 2026

fix(parser): apply PURE comment through member-access chains oxc-project/oxc#22566

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rolldown-guard Bot mentioned this pull request May 20, 2026

release: v1.0.2 #9478

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TheAlexLichter mentioned this pull request May 21, 2026

PURE annotation bug #9496

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Dunqing mentioned this pull request May 26, 2026

chore(deps): upgrade oxc to 0.133.0 #9563

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feat: emit warnings for invalid pure annotations#9381

feat: emit warnings for invalid pure annotations#9381
h-a-n-a merged 6 commits into
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Kyujenius:feat/warn-invalid-pure-annotations

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