Use per-parent disambiguators everywhere
This PR addressing the following concerns about per-parent disambiguators (rust-lang/rust#153955):
- DisambiguatorState is removed, PerParentDisambiguatorState is now used everywhere,
- Steals were removed from every per-parent disambiguator in resolver,
- It adds `parent` field in `PerParentDisambiguatorState` in `#[cfg(debug_assertions)]` for asserting that per-parent disambiguator corresponds to the same `LocalDefId` which is passed into `create_def`,
- ~Removes `Disambiguator` trait replacing it with `Disambiguator` enum, with this change we no longer expose `next` method (as trait should be public otherwise the warning will be emitted). It may affect perf in a negative way though.~
~Those changes should not fix perf issues that were [reported](https://github.com/rust-lang/rust/pull/153955#issuecomment-4269223191), perf run that was attempted [before](https://github.com/rust-lang/rust/pull/153955#issuecomment-4214516698) showed much better results. Performance can be probably fixed by removing per-parent disambiguators replacing them with a single one as it was before, then it will be passed to AST -> HIR lowering and modified. For delayed owners we can store ~followup disambiguators as it was in the beginning of the rust-lang/rust#153955~ per-parent disambiguators. This solution should save achievements from rust-lang/rust#153955 (removed `DefPathData` variants).
However, I would prefer to keep per-parent disambiguators as it seems a better architectural solution for me.~
r? @petrochenkov
cc @oli-obk
Remove duplicated `Flags` methods.
The `Flags` trait has two methods: `flags` and `outer_exclusive_binder`. Multiple types impl this trait and then also have duplicate inherent methods with the same names; these are all marked with "Think about removing this" comments. This is left over from things being moved into `rustc_type_ir`.
This commit removes those inherent methods. This requires adding `use Flags` to a number of files.
r? @lcnr
Fix incorrect `let` to `const` suggestion for pattern bindings
When a variable from a pattern binding was referenced inside a `const {}` block, the compiler incorrectly suggested replacing `let` with `const`. This was reported in rust-lang/rust#152831 for `if let`, but also applies to `while let` and `let ... else`.
Improve E0308 error message for `impl Trait` return mismatches
When a function returns `impl Trait`, all branches must return the same concrete type. Previously, the compiler showed:
expected `First` because of return type
This was misleading, as it suggested the return type was `First`, rather than any single type implementing the trait.
Update the diagnostic to:
expected a single type implementing `Value` because of return type
Also highlight the first return expression to make it clearer why subsequent returns do not match.
Rollup of 4 pull requests
Successful merges:
- rust-lang/rust#152611 (Modify error message of importing inherent associated items when `#[feature(import_trait_associated_functions)]` is enabled)
- rust-lang/rust#155359 (Improperctypes refactor2.2)
- rust-lang/rust#155036 (Store a PathBuf rather than SerializedModule for cached modules)
- rust-lang/rust#155554 (add warning message when using x fix)
Store a PathBuf rather than SerializedModule for cached modules
In cg_gcc `ModuleBuffer` already only contains a path anyway. And for moving LTO into `-Zlink-only` we will need to serialize `MaybeLtoModules`. By storing a path cached modules we avoid writing them to the disk a second time during serialization of `MaybeLtoModules`.
Some further improvements will require changes to cg_gcc that I would prefer landing in the cg_gcc repo to actually test the LTO changes in CI.
Part of https://github.com/rust-lang/compiler-team/issues/908
Improperctypes refactor2.2
This is "part 2/3 of 2/3 of 1/2" of the original pull request https://github.com/rust-lang/rust/pull/134697 (refactor plus overhaul of the ImproperCTypes family of lints)
(all pulls of this series of pulls are supersets of the previous pulls.)
previous pull: https://github.com/rust-lang/rust/pull/155358
next pull: https://github.com/rust-lang/rust/pull/146273
This commit splits the lint's `visit_type` function into multiple functions that focus on specific things:
- visit_indirection (references, boxes, raw pointers)
- visit_variant_fields (the list of fields of a struct, enum variant, or union)
- visit_enum
- visit_struct_or_union
- visit_type (most "easy" decisions such as labeling `char` unsafe are here)
since, during these visits, we often move from an "outer type" to an "inner type" (structs, arrays, pointers, etc...),
two structs have been added to track the current state of a visit:
- VisitorState tracks the state related to the "original type" being checked (function argument/return, static variable)
- OuterTyData tracks the data related to the type "immediately outer to the current visited type"
r? petrochenkov (because you asked me to)
Modify error message of importing inherent associated items when `#[feature(import_trait_associated_functions)]` is enabled
Fixesrust-lang/rust#148009
This PR improves the diagnostic for importing inherent associated items from a struct or union when
`#[feature(import_trait_associated_functions)]` (rust-lang/rust#134691) is enabled.
Previously, this would result in a "not a module" error. This change provides a more specific error message clarifying that only trait associated items can be imported, while inherent associated items remain ineligible for import.
Enums are currently excluded from this change because their variants are valid import targets and require distinct handling.
Another interal change that shouldn't impact rustc users.
Code called outside of `visit_type` (and callees) is moved inside, by
adding new types to properly track the state of a type visitation.
- OuterTyKind tracks the knowledge of the type "directly outside of" the
one being visited (if we are visiting a struct's field, an array's
element, etc)
- RootUseFlags tracks the knowledge of how the "original type being
visited" is used: static variable, function argument/return, etc.
Ensure we don't feed owners from ast lowering if we ever make that query tracked
follow-up to rust-lang/rust#153489
I don't expect this to ever really be an issue, but better safe than sorry 😆
Move diagnostic attribute target checks from check_attr
Move diagnostic attribute target checks into their targets. Part of https://github.com/rust-lang/rust/issues/131229#issuecomment-3959910413
This is much easier with `emit_dyn_lint` :) (thanks @GuillaumeGomez !)
I think there might be some opportunity to simplify all these `check_diagnostic_*` methods in `check_attr`. However there are some diagnostic attribute prs in flight and I'd like to wait for those to land first and then think about it. So that PR is not for today.
r? @JonathanBrouwer (or @GuillaumeGomez if you want)
Fix `#[expect(dead_code)]` liveness propagation
Fixes https://github.com/rust-lang/rust/issues/154324
Fixes https://github.com/rust-lang/rust/issues/152370 (cc @eggyal)
Previously, when traversing from a `ComesFromAllowExpect::Yes` item (i.e., with `#[allow(dead_code)]` or `#[expect(dead_code)]`), other `ComesFromAllowExpect::Yes` items reached during propagation would be updated to `ComesFromAllowExpect::No` and inserted into `live_symbols`. That caused `dead_code` lint couldn't be emitted correctly.
After this PR, `ComesFromAllowExpect::Yes` items no longer incorrectly update other `ComesFromAllowExpect::Yes` items during propagation or mark them live by mistake, then `dead_code` lint could behave as expected.
Rewrite `FlatMapInPlace`.
Replace the hacky macro with a generic function and a new `FlatMapInPlaceVec` trait. More verbose but more readable and typical.
LLM disclosure: I asked Claude Code to critique this file and it suggested the generic function + trait idea. I implemented the idea entirely by hand.
r? @chenyukang
tests: add whitespace tests for vertical tab behavior
This PR adds two small tests to highlight how vertical tab (\x0B)
is handled differently across Rust's whitespace definitions.
The Rust lexer treats vertical tab as whitespace (Unicode
Pattern_White_Space), while `split_ascii_whitespace` follows the
WhatWG Infra Standard and does not include vertical tab.
These tests make that difference visible and easier to understand.
See: https://github.com/rustfoundation/interop-initiative/issues/53
* tests: add whitespace tests for vertical tab behavior
Add two small tests to highlight how vertical tab is handled differently.
- vertical_tab_lexer.rs checks that the lexer treats vertical tab as whitespace
- ascii_whitespace_excludes_vertical_tab.rs shows that split_ascii_whitespace does not split on it
This helps document the difference between the Rust parser (which accepts vertical tab)
and the standard library’s ASCII whitespace handling.
See: rust-lang/rust-project-goals#53
* tests: add ignore-tidy-tab directive to whitespace tests
* tests: expand vertical tab lexer test to cover all Pattern_White_Space chars
* tests: add whitespace/ README entry explaining lexer vs stdlib mismatch
* Update ascii_whitespace_excludes_vertical_tab.rs
* Update ascii_whitespace_excludes_vertical_tab.rs
make sure tabs and spaces are well checked
* Update ascii_whitespace_excludes_vertical_tab.rs
* fix tidy: add whitespace README entry
* Update README.md with missing full stop
* Update ascii_whitespace_excludes_vertical_tab.rs
* fix tidy: use full path format for whitespace README entry
* fix tidy: README order, trailing newlines in whitespace tests
* fix: add run-pass directive and restore embedded whitespace bytes
* fix tidy: remove duplicate whitespace README entry
*
Add failing UI test for invalid whitespace (zero width space)
This adds a //@ check-fail test to ensure that disallowed whitespace
characters like ZERO WIDTH SPACE are rejected by the Rust lexer.
* git add tests/ui/whitespace/invalid_whitespace.rs
git commit -m "Fix tidy: add trailing newline"
git push
* Fix tidy: add trailing newline
* Update invalid_whitespace.rs
* Update invalid_whitespace.rs
* Clean up whitespace in invalid_whitespace.rs
Remove unnecessary blank lines in invalid_whitespace.rs
* Update invalid_whitespace.rs
* Clarify ZERO WIDTH SPACE usage in test
Update comment to clarify usage of ZERO WIDTH SPACE.
* Improve error messages for invalid whitespace
Updated error messages to clarify the issue with invisible characters.
* Modify invalid_whitespace test for clarity
Update test to check for invalid whitespace characters.
* Resolve unknown token error in invalid_whitespace.rs
Fix whitespace issue causing unknown token error.
* Remove invisible character from variable assignment
Fix invisible character issue in variable assignment.
* Improve error message for invalid whitespace
Updated error message to clarify invisible characters.
* Improve error handling for invisible characters
Updated error message for invisible characters in code.
* Document error for unknown token due to whitespace
Add error message for invalid whitespace in code
* Update error message for invalid whitespace handling
* Modify invalid_whitespace.rs for whitespace checks
Updated the test to check for invalid whitespace handling.
* Correct whitespace in variable declaration
Fix formatting issue by adding space around '=' in variable declaration.
* Update error message for invalid whitespace
* Update invalid_whitespace.stderr
* Refine error handling for invalid whitespace test
Update the error messages for invalid whitespace in the test.
* Update invalid_whitespace.rs
* Fix whitespace issues in invalid_whitespace.rs
* Update invalid_whitespace.stderr file
* Clean up whitespace in invalid_whitespace.rs
Removed unnecessary blank lines from the test file.
* Update invalid_whitespace.stderr
bors