THIR patterns: Explicitly distinguish &pin from plain &/&mut
#151282
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Some changes occurred in match checking cc @Nadrieril Some changes occurred in exhaustiveness checking cc @Nadrieril Some changes occurred in match lowering cc @Nadrieril |
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I'll probably need to rebase this again after #151295. |
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This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed. Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers. |
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Big fan of this. The fact that this uncovered a bug is enough proof that we need this, if we needed any. @bors r+ |
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Rollup merge of #151282 - Zalathar:pin-pat, r=Nadrieril THIR patterns: Explicitly distinguish `&pin` from plain `&`/`&mut` Currently, `thir::PatKind::Deref` is used for ordinary `&`/`&mut` patterns, and also for `&pin const` and `&pin mut` patterns under `feature(pin_ergonomics)`. The only way to distinguish between them is by inspecting the `Ty` attached to the pattern node. That's non-obvious, making it easy to miss, and is also a bit confusing to read when it does occur. This PR therefore adds an explicit `pin: hir::Pinnedness` field to `thir::PatKind::Deref`, to explicitly distinguish pin-deref nodes from ordinary builtin-deref nodes. (I'm not deeply familiar with the future of pin-patterns, so I'm not sure whether that information is best carried as a field or as a separate `PatKind`, but I think this approach is at least an improvement over the status quo.) r? Nadrieril (or compiler)
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Rollup of 4 pull requests Successful merges: - rust-lang/rust#149174 (`const` blocks as a `mod` item) - rust-lang/rust#151282 (THIR patterns: Explicitly distinguish `&pin` from plain `&`/`&mut`) - rust-lang/rust#151593 (miri subtree update) - rust-lang/rust#151516 (Do not emit errors on non-metaitem diagnostic attr input) r? @ghost
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…iaskrgr Rollup of 4 pull requests Successful merges: - rust-lang#149174 (`const` blocks as a `mod` item) - rust-lang#151282 (THIR patterns: Explicitly distinguish `&pin` from plain `&`/`&mut`) - rust-lang#151593 (miri subtree update) - rust-lang#151516 (Do not emit errors on non-metaitem diagnostic attr input) r? @ghost
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Currently,
thir::PatKind::Derefis used for ordinary&/&mutpatterns, and also for&pin constand&pin mutpatterns underfeature(pin_ergonomics). The only way to distinguish between them is by inspecting theTyattached to the pattern node.That's non-obvious, making it easy to miss, and is also a bit confusing to read when it does occur.
This PR therefore adds an explicit
pin: hir::Pinnednessfield tothir::PatKind::Deref, to explicitly distinguish pin-deref nodes from ordinary builtin-deref nodes.(I'm not deeply familiar with the future of pin-patterns, so I'm not sure whether that information is best carried as a field or as a separate
PatKind, but I think this approach is at least an improvement over the status quo.)r? Nadrieril (or compiler)