Implemented const casts of raw pointers #92657
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Updates src/tools/cargo. cc @ehuss Some changes occured to the Miri submodule cc @rust-lang/miri |
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r? @scottmcm (rust-highfive has picked a reviewer for you, use r? to override) |
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Sorry for the noise accidentally adding submodules, fixed it. r? @RalfJung I think you're the right person to review? |
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It's a bit unfortunate that |
Hm, no, not really... this is @rust-lang/libs-api territory. |
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This looks good to me. Can you open a tracking issue? Thanks! |
Let's make sure we track this in the tracking issue and answer that question before stabilizing. |
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This adds `as_mut()` method for `*const T` and `as_const()` for `*mut T` which are intended to make casting of consts safer. This was discussed in the [internals discussion][discussion]. [discussion]: https://internals.rust-lang.org/t/casting-constness-can-be-risky-heres-a-simple-fix/15933
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Done. Was confused about that question at first so I reworded it to hopefully avoid confusion of others. Also filled the issue number in the PR. |
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@bors r+ |
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📌 Commit 1a96623 has been approved by |
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…askrgr Rollup of 8 pull requests Successful merges: - rust-lang#92055 (Add release notes for 1.58) - rust-lang#92490 (Move crate drop-down to search results page) - rust-lang#92510 (Don't resolve blocks in foreign functions) - rust-lang#92573 (expand: Refactor InvocationCollector visitor for better code reuse) - rust-lang#92608 (rustdoc: Introduce a resolver cache for sharing data between early doc link resolution and later passes) - rust-lang#92657 (Implemented const casts of raw pointers) - rust-lang#92671 (Make `Atomic*::from_mut` return `&mut Atomic*`) - rust-lang#92673 (Remove useless collapse toggle on "all items" page) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
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I grepped the codebase for `as \*` and found a few places where we were doing explicit pointer casts but we could've been using std methods. The methods are safer because they don't allow changing mutability (unless we use cast_const or cast_mut, which don't allow changing the type). There are a few instances remaining where we cast to pointers to unsized types. These are actually fat raw pointers and they don't have std methods. Now they stand out because of the use of `as *`. This commit might require a bit of thought to review, and it turns out it has nothing to do with the MSRV bump (which gave us cast_const and cast_mut, but actually we don't use those, thankfully..). As a bit of trivia, though, the new cast_mut and cast_const methods were originally proposed and implemented by our own Kixunil: rust-lang/rust#92657
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I grepped the codebase for `as \*` and found a few places where we were doing explicit pointer casts but we could've been using std methods. The methods are safer because they don't allow changing mutability (unless we use cast_const or cast_mut, which don't allow changing the type). There are a few instances remaining where we cast to pointers to unsized types. These are actually fat raw pointers and they don't have std methods. Now they stand out because of the use of `as *`. This commit might require a bit of thought to review, and it turns out it has nothing to do with the MSRV bump (which gave us cast_const and cast_mut, but actually we don't use those, thankfully..). As a bit of trivia, though, the new cast_mut and cast_const methods were originally proposed and implemented by our own Kixunil: rust-lang/rust#92657
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This adds
as_mut()method for*const Tandas_const()for*mut Twhich are intended to make casting of consts safer. This was discussed
in the internals discussion.
Given that this is a simple change and multiple people agreed to it including @RalfJung I decided to go ahead and open the PR.