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reborrow: Fix various ICEs related to auto reborrowing of user-space types - #163769
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r? @Walnut356 rustbot has assigned @Walnut356. Use Why was this reviewer chosen?The reviewer was selected based on:
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That makes sense, and the code changes look alright. Just in case, cc @aapoalas |
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I apologize for the delay @bors r+ |
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…uwer Rollup of 20 pull requests Successful merges: - #160404 (fd-views: AsRef<File>&Co. for BorrowedFd) - #161362 ( rustdoc: Correctly handle reexports when --document-private-items is used) - #163769 (reborrow: Fix various ICEs related to auto reborrowing of user-space types) - #164764 (Test(lib/sync): Fix `test_rwlock_max_readers` for 32bit architectures) - #164860 (std::fs: read interrupted by a signal, read_buf_exact_at reports EOF.) - #164869 (rustc_codegen_gcc subtree update) - #157123 (library: optimize truncate method) - #159916 (Optimize `str.escape_default().to_string()`) - #163510 (process: Improve the output of `Debug` for `ExitStatus` on Unix) - #164508 (ping me for layout invariant changes) - #164758 (Update dependency jinja2 to v3.1.6 [SECURITY]) - #164816 (Take the colon span into account for struct field initializers) - #164836 (Add regression test for #162109) - #164846 (Remove contradictory inequalities from overflow safety docs) - #164857 (Do not checkout Cargo for bootstrap tests) - #164868 (Fix skipping library build with `--keep-stage[-std]`) - #164872 (cg_llvm: clarify Send / Sync story for modules) - #164880 (Add context span showing item that can't be annotated) - #164881 (Add FIXME comments to `from_ascii_bytes_radix_impl`) - #164884 (Windows: bounds-check the reparse point name in `read_link`)
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…uwer Rollup of 20 pull requests Successful merges: - #160404 (fd-views: AsRef<File>&Co. for BorrowedFd) - #161362 ( rustdoc: Correctly handle reexports when --document-private-items is used) - #163769 (reborrow: Fix various ICEs related to auto reborrowing of user-space types) - #164764 (Test(lib/sync): Fix `test_rwlock_max_readers` for 32bit architectures) - #164860 (std::fs: read interrupted by a signal, read_buf_exact_at reports EOF.) - #164869 (rustc_codegen_gcc subtree update) - #157123 (library: optimize truncate method) - #159916 (Optimize `str.escape_default().to_string()`) - #163510 (process: Improve the output of `Debug` for `ExitStatus` on Unix) - #164508 (ping me for layout invariant changes) - #164758 (Update dependency jinja2 to v3.1.6 [SECURITY]) - #164816 (Take the colon span into account for struct field initializers) - #164836 (Add regression test for #162109) - #164846 (Remove contradictory inequalities from overflow safety docs) - #164857 (Do not checkout Cargo for bootstrap tests) - #164868 (Fix skipping library build with `--keep-stage[-std]`) - #164872 (cg_llvm: clarify Send / Sync story for modules) - #164880 (Add context span showing item that can't be annotated) - #164881 (Add FIXME comments to `from_ascii_bytes_radix_impl`) - #164884 (Windows: bounds-check the reparse point name in `read_link`)
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Rollup merge of #163769 - jakubadamw:fix-various-reborrow-ices, r=Walnut356 reborrow: Fix various ICEs related to auto reborrowing of user-space types I appreciate the feature is a lang experiment, but it probably won’t hurt to get rid of these ICEs if the fix is relatively striaghtforward. And so this PR fixes several ICEs with `#![feature(reborrow)]`. Most of them happen when a `Reborrow` or `CoerceShared` impl is wrong. Coherence reports an error for the impl, but typeck still lets code reborrow through it. Then borrowck (or const eval) crashes, because the implementation isn't the shape it expects. Fix: when a reborrow coercion goes through, check whether coherence had already rejected any `Reborrow`/`CoerceShared` impl. If it did, taint the body so that borrowck and const evaluation skip it. Related tracking issue: #145612 Note: invalid reborrows that only come from a `where` clause still ICE – that still needs a fix. Tests: one test per issue closed, using the code from the issues’ contents. #162108's code no longer reproduces as posted, however, so its test uses a slightly smaller version that hits the same ICE. I also moved the reborrow crashes/ tests that don't crash any more into tests/ui/reborrow. **LLM disclosure**: I used Claude Opus 5.5 to research the common denominator between the issues and come up with the solution that turns these ICEs into graceful compile-time errors. It also extracted the tests from the issues and extended them with the right error annotations, but I subsequenty verified them manually against the issues. Closes #156307. Closes #156308. Closes #156311. Closes #156315. Closes #158149. Closes #162108. Closes #162141. Closes #162142.
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I appreciate the feature is a lang experiment, but it probably won’t hurt to get rid of these ICEs if the fix is relatively striaghtforward. And so this PR fixes several ICEs with
#![feature(reborrow)]. Most of them happen when aReborroworCoerceSharedimpl is wrong. Coherence reports an error for the impl, but typeck still lets code reborrow through it. Then borrowck (or const eval) crashes, because the implementation isn't the shape it expects. Fix: when a reborrow coercion goes through, check whether coherence had already rejected anyReborrow/CoerceSharedimpl. If it did, taint the body so that borrowck and const evaluation skip it.Related tracking issue: #145612
Note: invalid reborrows that only come from a
whereclause still ICE – that still needs a fix.Tests: one test per issue closed, using the code from the issues’ contents. #162108's code no longer reproduces as posted, however, so its test uses a slightly smaller version that hits the same ICE. I also moved the reborrow crashes/ tests that don't crash any more into tests/ui/reborrow.
LLM disclosure: I used Claude Opus 5.5 to research the common denominator between the issues and come up with the solution that turns these ICEs into graceful compile-time errors. It also extracted the tests from the issues and extended them with the right error annotations, but I subsequenty verified them manually against the issues.
Closes #156307.
Closes #156308.
Closes #156311.
Closes #156315.
Closes #158149.
Closes #162108.
Closes #162141.
Closes #162142.