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2024-04-08Compute transmutability from `rustc_target::abi::Layout`Jack Wrenn-1/+3
In its first step of computing transmutability, `rustc_transmutability` constructs a byte-level representation of type layout (`Tree`). Previously, this representation was computed for ADTs by inspecting the ADT definition and performing our own layout computations. This process was error-prone, verbose, and limited our ability to analyze many types (particularly default-repr types). In this PR, we instead construct `Tree`s from `rustc_target::abi::Layout`s. This helps ensure that layout optimizations are reflected our analyses, and increases the kinds of types we can now analyze, including: - default repr ADTs - transparent unions - `UnsafeCell`-containing types Overall, this PR expands the expressvity of `rustc_transmutability` to be much closer to the transmutability analysis performed by miri. Future PRs will work to close the remaining gaps (e.g., support for `Box`, raw pointers, `NonZero*`, coroutines, etc.).
2024-03-18Avoid various uses of `Option<Span>` in favor of using `DUMMY_SP` in the few ↵Oli Scherer-1/+2
cases that used `None`
2024-03-15Safe Transmute: Use 'not yet supported', not 'unspecified' in errorsJack Wrenn-4/+4
We can (and will) support analyzing the transmutability of types whose layouts aren't completely specified by its repr. This change ensures that the error messages remain sensible after this support lands.
2024-03-13safe transmute: require that src referent is smaller than dstJack Wrenn-2/+9
The source referent absolutely must be smaller than the destination referent of a ref-to-ref transmute; the excess bytes referenced cannot arise from thin air, even if those bytes are uninitialized.
2024-02-27safe transmute: revise safety analysisJack Wrenn-4/+2
Migrate to a simplified safety analysis that does not use visibility. Closes https://github.com/rust-lang/project-safe-transmute/issues/15
2024-02-06Invert diagnostic lints.Nicholas Nethercote-2/+0
That is, change `diagnostic_outside_of_impl` and `untranslatable_diagnostic` from `allow` to `deny`, because more than half of the compiler has be converted to use translated diagnostics. This commit removes more `deny` attributes than it adds `allow` attributes, which proves that this change is warranted.
2024-01-25Remove unused featuresclubby789-1/+2
2023-10-06Make the comment order match variant declaration order.Nicholas Nethercote-1/+1
2023-10-06Remove an unnecessary `pub(crate)`.Nicholas Nethercote-1/+1
2023-09-13make the eval() functions on our const types return the resulting valueRalf Jung-7/+4
2023-09-06Fix error report for size overflow from transmuteyukang-0/+4
2023-07-17Safe Transmute: Fix ICE (due to UnevaluatedConst)Bryan Garza-1/+12
This patch updates the code that looks at the `Assume` type when evaluating if transmutation is possible. An ICE was being triggered in the case that the `Assume` parameter contained an unevaluated const (in this test case, due to a function with missing parameter names). Fixes #110892
2023-06-12Safe Transmute: Refactor error handling and Answer typeBryan Garza-4/+16
- Create `Answer` type that is not just a type alias of `Result` - Remove a usage of `map_layouts` to make the code easier to read - Don't hide errors related to Unknown Layout when computing transmutability
2023-05-24Safe Transmute: Update definition of Condition typeBryan Garza-3/+3
- Change `Condition` to not contain `Answer`s but instead just contain other `Condition`s directly. - Also improve error reporting for `DstHasStricterAlignment`
2023-05-24Safe Transmute: Check mutability before creating dst -> src obligationBryan Garza-1/+1
- Only create dst -> src obligation if Dst is mutable - Add some long comments to explain parts of the transmutability code that were unclear to me when reading - Update/add tests
2023-05-24Safe Transmute: Fix propagation of errorsBryan Garza-1/+1
- Make sure that the most specific Reason is the one that bubbles up when we are folding over the `Answer` tree. `Reason::DstIsBitIncompatible` is the least specific, so that should be used only when there isn't anything else available. - Small fixes where we used the wrong Reason variant. - Tiny cleanups
2023-05-24Safe Transmute: Change Answer type to ResultBryan Garza-8/+5
This patch updates the `Answer` type from `rustc_transmute` so that it just a type alias to `Result`. This makes it so that the standard methods for `Result` can be used to process the `Answer` tree, including being able to make use of the `?` operator on `Answer`s. Also, remove some unused functions
2023-05-24Safe Transmute: Enable handling references, including recursive typesBryan Garza-5/+6
This patch enables support for references in Safe Transmute, by generating nested obligations during trait selection. Specifically, when we call `confirm_transmutability_candidate(...)`, we now recursively traverse the `rustc_transmute::Answer` tree and create obligations for all the `Answer` variants, some of which include multiple nested `Answer`s. Also, to handle recursive types, enable support for coinduction for the Safe Transmute trait (`BikeshedIntrinsicFrom`) by adding the `#[rustc_coinduction]` annotation. Also fix some small logic issues when reducing the `or` and `and` combinations in `rustc_transmute`, so that we don't end up with additional redundant `Answer`s in the tree. Co-authored-by: Jack Wrenn <jack@wrenn.fyi>
2023-04-26Remove unused `TypeFoldable`/`TypeVisitable` impls.Nicholas Nethercote-2/+2
2023-04-16Erase regions when confirming transmutability candidateMichael Goulet-6/+3
2023-04-09Some simple `clippy::perf` fixesNilstrieb-1/+1
2023-02-22Remove type-traversal trait aliasesAlan Egerton-1/+1
2023-01-18Also remove `#![feature(control_flow_enum)]` where possibleScott McMurray-1/+1
2022-11-03change error_reported to use Result instead of an optionyukang-1/+1
2022-10-07Remove TypeckResults from InferCtxtCameron Steffen-2/+2
2022-10-03check if const is ADT or notTakayuki Maeda-5/+10
2022-09-04Auto merge of #100726 - jswrenn:transmute, r=oli-obkbors-6/+56
safe transmute: use `Assume` struct to provide analysis options This task was left as a TODO in #92268; resolving it brings [`BikeshedIntrinsicFrom`](https://doc.rust-lang.org/nightly/core/mem/trait.BikeshedIntrinsicFrom.html) more in line with the API defined in [MCP411](https://github.com/rust-lang/compiler-team/issues/411). **Before:** ```rust pub unsafe trait BikeshedIntrinsicFrom< Src, Context, const ASSUME_ALIGNMENT: bool, const ASSUME_LIFETIMES: bool, const ASSUME_VALIDITY: bool, const ASSUME_VISIBILITY: bool, > where Src: ?Sized, {} ``` **After:** ```rust pub unsafe trait BikeshedIntrinsicFrom<Src, Context, const ASSUME: Assume = { Assume::NOTHING }> where Src: ?Sized, {} ``` `Assume::visibility` has also been renamed to `Assume::safety`, as library safety invariants are what's actually being assumed; visibility is just the mechanism by which it is currently checked (and that may change). r? `@oli-obk` --- Related: - https://github.com/rust-lang/compiler-team/issues/411 - https://github.com/rust-lang/rust/issues/99571
2022-08-31safe transmute: use `to_valtree` to destructure const `Assume`Jack Wrenn-7/+4
ref: https://github.com/rust-lang/rust/pull/100726#discussion_r954813220
2022-08-26Rollup merge of #100604 - dtolnay:okorerr, r=m-ou-seYuki Okushi-8/+1
Remove unstable Result::into_ok_or_err Pending FCP: https://github.com/rust-lang/rust/issues/82223#issuecomment-1214920203 ```@rustbot``` label +waiting-on-fcp
2022-08-23safe transmute: use `FxIndex{Map,Set}` instead of `FxHash{Map,Set}`Jack Wrenn-5/+1
resolves query instability issues, and probably better for performance
2022-08-22safe transmute: use `Assume` struct to provide analysis optionsJack Wrenn-1/+58
This was left as a TODO in #92268, and brings the trait more in line with what was defined in MCP411. `Assume::visibility` has been renamed to `Assume::safety`, as library safety is what's actually being assumed; visibility is just the mechanism by which it is currently checked (this may change). ref: https://github.com/rust-lang/compiler-team/issues/411 ref: https://github.com/rust-lang/rust/issues/99571
2022-08-21ADD - diagnostic lints to rustc_transmuteJhonny Bill Mena-0/+2
Module is complete because it has zero diagnostics.
2022-08-17Remove unstable Result::into_ok_or_errDavid Tolnay-8/+1
2022-07-27safe transmute: tweak tracingJack Wrenn-0/+3
ref: https://github.com/rust-lang/rust/pull/92268#discussion_r925246903 ref: https://github.com/rust-lang/rust/pull/92268#discussion_r925250811 ref: https://github.com/rust-lang/rust/pull/92268#discussion_r925255782
2022-07-27Initial (incomplete) implementation of transmutability trait.Jack Wrenn-0/+114
This initial implementation handles transmutations between types with specified layouts, except when references are involved. Co-authored-by: Igor null <m1el.2027@gmail.com>
generated by cgit-pink 1.4.1-3-g733a5 (git 2.37.1) at 2026-05-04 18:30:16 +0000