add_retag: ensure box-to-raw-ptr casts are preserved for Miri #122647
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Some changes occurred to MIR optimizations cc @rust-lang/wg-mir-opt The Miri subtree was changed cc @rust-lang/miri |
RalfJung
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Mar 17, 2024
| &elaborate_box_derefs::ElaborateBoxDerefs, | ||
| &coroutine::StateTransform, | ||
| &add_retag::AddRetag, | ||
| &Lint(known_panics_lint::KnownPanicsLint), |
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I was not sure what to do with the pass order here. AddRetag needs to be before ElaborateBoxDerefs removes all traces of primitive Box derefs. Whether they should be before or after StateTransform, I don't know. I decided to use the order which doesn't change anything on stable (where AddRetag is a NOP).
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@bors r+ rollup thanks for the thorough explanations |
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add_retag: ensure box-to-raw-ptr casts are preserved for Miri In rust-lang#122233 I added `retag_box_to_raw` not realizing that we can already do `addr_of_mut!(*bx)` to turn a box into a raw pointer without an intermediate reference. We just need to ensure this information is preserved past the ElaborateBoxDerefs pass. r? `@oli-obk`
This was referenced Mar 18, 2024
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…iaskrgr Rollup of 8 pull requests Successful merges: - rust-lang#122480 (Avoid various uses of `Option<Span>` in favor of using `DUMMY_SP` in the few cases that used `None`) - rust-lang#122567 (Remove fixme about LLVM basic block naming) - rust-lang#122588 (less useless filter calls in imported_source_file) - rust-lang#122647 (add_retag: ensure box-to-raw-ptr casts are preserved for Miri) - rust-lang#122649 (Update the minimum external LLVM to 17) - rust-lang#122680 (Do not eat nested expressions' results in `MayContainYieldPoint` format args visitor) - rust-lang#122683 (add missing test: expected paren or brace in macro) - rust-lang#122689 (Add missing `try_visit` calls in visitors.) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup merge of rust-lang#122647 - RalfJung:box-to-raw-retag, r=oli-obk add_retag: ensure box-to-raw-ptr casts are preserved for Miri In rust-lang#122233 I added `retag_box_to_raw` not realizing that we can already do `addr_of_mut!(*bx)` to turn a box into a raw pointer without an intermediate reference. We just need to ensure this information is preserved past the ElaborateBoxDerefs pass. r? ``@oli-obk``
This was referenced Apr 16, 2024
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Box::into_raw: make Miri understand that this is a box-to-raw cast Turns out rust-lang#122647 went a bit too far in cleaning up `Box`... we still need a hack in `Box::into_raw`. The nicer fix would be to make Stacked Borrows not care about reference-to-raw-pointer casts, but it's unclear whether that will ever be possible without going to full Tree Borrows. Fixes rust-lang/miri#3473.
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Rollup merge of rust-lang#124013 - RalfJung:box-to-raw, r=oli-obk Box::into_raw: make Miri understand that this is a box-to-raw cast Turns out rust-lang#122647 went a bit too far in cleaning up `Box`... we still need a hack in `Box::into_raw`. The nicer fix would be to make Stacked Borrows not care about reference-to-raw-pointer casts, but it's unclear whether that will ever be possible without going to full Tree Borrows. Fixes rust-lang/miri#3473.
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Box::into_raw: make Miri understand that this is a box-to-raw cast Turns out rust-lang/rust#122647 went a bit too far in cleaning up `Box`... we still need a hack in `Box::into_raw`. The nicer fix would be to make Stacked Borrows not care about reference-to-raw-pointer casts, but it's unclear whether that will ever be possible without going to full Tree Borrows. Fixes #3473.
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In #122233 I added
retag_box_to_rawnot realizing that we can already doaddr_of_mut!(*bx)to turn a box into a raw pointer without an intermediate reference. We just need to ensure this information is preserved past the ElaborateBoxDerefs pass.r? @oli-obk