[WIP] Make pointer casts work in const fn
#1968
Open
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
We already have the merge queue; running on push is redundant.
Upgrade our MSRV to 1.65 and remove version detection logic prior to that version.
* Release 0.9.0-alpha.0 Upgrade our MSRV to 1.65 and remove version detection logic prior to that version. * Enable clippy::missing_const_for_fn While we're here, remove defensive programming against bug in `Layout::from_size_align` which is no longer needed on our new MSRV.
Now that our MSRV is 1.65, we can clean up some code. Makes progress on #67
Also clean up some code for 0.9.
* Upgrade some code for MSRV 1.65 Now that our MSRV is 1.65, we can clean up some code. Makes progress on #67 * Upgrade versions of some dependencies Now that our MSRV is 1.65, it unlocks upgrading some dependencies' versions.
Bumps [github/codeql-action](https://github.com/github/codeql-action) from 3.26.12 to 3.26.13. - [Release notes](https://github.com/github/codeql-action/releases) - [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md) - [Commits](github/codeql-action@c36620d...f779452) --- updated-dependencies: - dependency-name: github/codeql-action dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Bumps [Swatinem/rust-cache](https://github.com/swatinem/rust-cache) from 2.7.3 to 2.7.5. - [Release notes](https://github.com/swatinem/rust-cache/releases) - [Changelog](https://github.com/Swatinem/rust-cache/blob/master/CHANGELOG.md) - [Commits](Swatinem/rust-cache@23bce25...82a92a6) --- updated-dependencies: - dependency-name: Swatinem/rust-cache dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Previously, we supported the `AtLeast` bound, which was used to describe a subset relationship in which `I: AtLeast<J>` implied that `I` as at least as restrictive as `J`. However, as described in #1866, this incorrectly models invariants as monotonic. In reality, invariants both provide guarantees but also *require* guarantees. This commit takes a step in the direction of resolving #1866 by removing `AtLeast`. Uses of `AtLeast<Shared>` are replaced by a new `Reference` trait, which is implemented for `Shared` and `Exclusive`. This serves two purposes: First, it makes it explicit what this bound means. Previously, `AtLeast<Shared>` had an ambiguous meaning, while `Reference` means precisely that an invariant is either `Shared` or `Exclusive` and nothing else. Second, it paves the way for #1183, in which we may add new aliasing invariants which convey ownership. In that case, it will be important for existing methods to add `Reference` bounds when those methods would not be sound in the face of ownership semantics. We also inline the items in the `invariant` module, which were previously generated by macro. The addition of the `Reference` trait did not play nicely with that macro, and we will likely need to go further from the macro in order to fix #1839 – this fix will likely require making aliasing invariants meaningfully different than other invariants, for example by adding an associated type. Makes progress on #1866
Explain why we only support concrete types so that future authors won't spuriously add support for them.
`PtrInner` carries all invariants which are not controlled by type parameters. Since `PtrInner` does not promise to uphold aliasing, alignment, or validity, we can move some utility methods to `PtrInner` which previously were responsible for maintaining invariants orthogonal to their purpose. Makes progress on #1892 (still needs to be fixed on v0.8.x) Closes #1890
This prepares us for future changes which will significantly increase the amount of code in the `invariant` module. Also merge `aliasing_safety` into this new file.
When the aliasing mode is `Any`, `Ptr<'a, T>` is invariant in `'a` and `T`. When the aliasing mode is `Shared` or `Exclusive`, `Ptr` has the same variance as `&'a T` and `&'a mut T` respectively. Makes progress on #1839
`AliasingSafe` is really about whether a pointer permits unsynchronized reads - either because the referent contains no `UnsafeCell`s or because the aliasing mode is `Exclusive`. Previously, `AliasingSafe` was not named consistent with this meaning, and was a function of a *pair* of types rather than of a single type. This commit fixes both oversights. While we're here, we also add `Read` bounds in some places, allowing us to simplify many safety comments.
For aliasing, use `Inaccessible`. For alignment and validity, use `Unknown`.
This commit adds a framework which supports encoding in the type system any `I -> I` mapping where `I` is any `Invariant` type. This permits us to make `cast_unsized`'s return value smarter, and as a result, allows us to remove a lot of `unsafe` code. Makes progress on #1122
gherrit-pr-id: I003d5360d1b7f7882a71490813eca50b39025f14
We eventually hope to make use of `#[marker]` traits once they're stable. This permits us to test to make sure the feature is as we expect and that our intended usage works. gherrit-pr-id: I3a111bf5647fdcc9805cbadf36f729ac69b28509
And allow `non_local_definitions`.
We eventually hope to make use of `#[marker]` traits once they're stable. This permits us to test to make sure the feature is as we expect and that our intended usage works. gherrit-pr-id: I3a111bf5647fdcc9805cbadf36f729ac69b28509
Co-authored-by: Joshua Liebow-Feeser <[email protected]>
Makes progress on #1931 gherrit-pr-id: If0e198c377137dd941ebd5dc68787766a593e1eb
Makes progress on #1931 gherrit-pr-id: Ib2708e8f233f624bcd1f2ec80b5dae91c7e1db46
Release 0.2.0. Makes progress on #1931 gherrit-pr-id: I7ce0c981ed1f1bc1f4ff85dffef2a74114c6e76d
Bumps [actions/dependency-review-action](https://github.com/actions/dependency-review-action) from 4.3.4 to 4.3.5. - [Release notes](https://github.com/actions/dependency-review-action/releases) - [Commits](actions/dependency-review-action@5a2ce3f...a6993e2) --- updated-dependencies: - dependency-name: actions/dependency-review-action dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Release 0.2.1. Makes progress on #1931 gherrit-pr-id: Icc9b6841e66c961989862ff6fb3b4f5140c54513
gherrit-pr-id: I3016a31a5d3c9c0461a5e7fcf3fd9bc4d0a111bc
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR is on branch const-ptr-cast.
const fn#1968