Optimize allow_unwrap_types evaluation to eliminate performance regression#16652
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Sorry for the late reply, I was (and sm) at a hackathon. From my profiling in bumpalo, the performance regression is completely gone. So I'll give this a +1 if there isn't anything else to bring up. Also we should totally backport this to beta. |
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@sengmonkham Seems that CI is failing, could you look into that? |
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I have fixed all CI issues, and all checks now pass. |
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Could you please squash your commits? It would make it easier to backport to beta if we do so. |
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…gression (rust-lang#16652) Fixes rust-lang/rust-clippy#16605 This PR addresses the 6.2% compilation performance regression introduced by the original `allow_unwrap_types` implementation (which natively allocated AST strings on every `unwrap` call via `bumpalo`). The implementation has been refactored to pre-resolve types securely without a performance penalty: **Pre-Resolution Cache via `LateLintPass`**: Instead of executing `ty.to_string()` and `lookup_path_str` inside the immediate `unwrap_expect_used` hot check for every method call encountered, `allow-unwrap-types` configuration strings are now parsed exactly *once* per crate compilation during the `LateLintPass::check_crate` hook in `clippy_lints/src/methods/mod.rs`. **`DefId` Native Storage**: The parsed `DefId` representations are stored in-memory using highly efficient caching maps directly on the main `Methods` struct: - `unwrap_allowed_ids: FxHashSet<DefId>`: Allows instant O(1) lookups for standard types. - `unwrap_allowed_aliases: Vec<DefId>`: Tracks type aliases requiring signature substitution checking later. **Execution Relief**: Inside `unwrap_expect_used::check()`, string manipulation is completely removed and `ty::Adt` checking uses lightning-fast `.contains(&adt.did())` operations to categorically avoid regression allocation loops. This implementation strongly parallels the pre-resolution type-routing logic in `clippy_config::types::create_disallowed_map` without altering the core `clippy.toml` config requirements. <!-- TRIAGEBOT_START --> <!-- TRIAGEBOT_SUMMARY_START --> ### Summary Notes - [Beta-nomination](rust-lang/rust-clippy#16652 (comment)) by [samueltardieu](https://github.com/samueltardieu) *Managed by `@rustbot`—see [help](https://forge.rust-lang.org/triagebot/note.html) for details* <!-- TRIAGEBOT_SUMMARY_END --> <!-- TRIAGEBOT_END --> changelog: none
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[beta] reverts and backports This reverts two `dbg!` changes to avoid regressions[^1][^2] in the upcoming 1.95 release: - std: avoid tearing `dbg!` prints #149869 - don't drop arguments' temporaries in `dbg!` #154074 - ... which was previously backported in #154725 This also reverts a stabilization over a late issue[^3] of semantics: - Stabilize `assert_matches` #137487 And a few other backport/reverts from `main`: - Revert performing basic const checks in typeck on stable #154930 / #155033 - Revert "`-Znext-solver` Remove the forced ambiguity hack from search graph" #154712 - Clarify that core::range ranges do not have special syntax #155002 Clippy is backporting 2 ICE fixes and 1 perf regression (via #155051): - rust-lang/rust-clippy#16685 already backported in #154211 to stable. This makes sure that it doesn't regress again in beta/next stable - rust-lang/rust-clippy#16659 The ICE that is being fixed here was introduced in the 1.95 release cycle - rust-lang/rust-clippy#16652 Perf regression introduced in the 1.95 release cycle. [^1]: #153850 [^2]: #154988 [^3]: #154406
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Fixes #16605
This PR addresses the 6.2% compilation performance regression introduced by the original
allow_unwrap_typesimplementation (which natively allocated AST strings on everyunwrapcall viabumpalo).The implementation has been refactored to pre-resolve types securely without a performance penalty:
Pre-Resolution Cache via
LateLintPass: Instead of executingty.to_string()andlookup_path_strinside the immediateunwrap_expect_usedhot check for every method call encountered,allow-unwrap-typesconfiguration strings are now parsed exactly once per crate compilation during theLateLintPass::check_cratehook inclippy_lints/src/methods/mod.rs.DefIdNative Storage: The parsedDefIdrepresentations are stored in-memory using highly efficient caching maps directly on the mainMethodsstruct:unwrap_allowed_ids: FxHashSet<DefId>: Allows instant O(1) lookups for standard types.unwrap_allowed_aliases: Vec<DefId>: Tracks type aliases requiring signature substitution checking later.Execution Relief: Inside
unwrap_expect_used::check(), string manipulation is completely removed andty::Adtchecking uses lightning-fast.contains(&adt.did())operations to categorically avoid regression allocation loops. This implementation strongly parallels the pre-resolution type-routing logic inclippy_config::types::create_disallowed_mapwithout altering the coreclippy.tomlconfig requirements.Summary Notes
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@rustbot—see help for detailschangelog: none