Skip pointing out ambiguous impls in alloc/std crates too in inference errors
This generalizes the logic in `annotate_source_of_ambiguity` to skip printing ambiguity errors traits in `alloc` and `std` as well, not just `core`.
While this does spot-fix the issue mentioned below, it would be nicer to generalize this logic, for example to detect when the trait predicate's `self_ty` has any numerical inference variables. Is it worthwhile to scrap this solution for one like that?
Fixes#93450
r? `@estebank`
feel free to reassign
Remove `Session::one_time_diagnostic`
This is untracked mutable state, which modified the behaviour of queries.
It was used for 2 things: some full-blown errors, but mostly for lint declaration notes ("the lint level is defined here" notes).
It is replaced by the diagnostic deduplication infra which already exists in the diagnostic emitter.
A new diagnostic level `OnceNote` is introduced specifically for lint notes, to deduplicate subdiagnostics.
As a drive-by, diagnostic emission takes a `&mut` to allow dropping the `SubDiagnostic`s.
resolve: Do not build expensive suggestions if they are not actually used
And remove a bunch of (conditionally) unused parameters from path resolution functions.
This helps with performance issues in https://github.com/rust-lang/rust/pull/94857, and should be helpful in general even without that.
Rollup of 5 pull requests
Successful merges:
- #94391 (Fix ice when error reporting recursion errors)
- #94655 (Clarify which kinds of MIR are allowed during which phases.)
- #95179 (Try to evaluate in try unify and postpone resolution of constants that contain inference variables)
- #95270 (debuginfo: Fix debuginfo for Box<T> where T is unsized.)
- #95276 (add diagnostic items for clippy's `trim_split_whitespace`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
debuginfo: Fix debuginfo for Box<T> where T is unsized.
Before this fix, the debuginfo for the fields was generated from the struct defintion of Box<T>, but (at least at the moment) the compiler pretends that Box<T> is just a (fat) pointer, so the fields need to be `pointer` and `vtable` instead of `__0: Unique<T>` and `__1: Allocator`.
This is meant as a temporary mitigation until we can make sure that simply treating Box as a regular struct in debuginfo does not cause too much breakage in the ecosystem.
r? ````@wesleywiser````
Also remove a redundant parameter from `fn resolve_path(_with_ribs)`, `crate_lint: CrateLint` is a more detailed version of `record_used: bool` with `CrateLint::No` meaning `false` and anything else meaning `true`.
Separate const prop lints from optimizations
r? `@oli-obk`
Separates lints and optimizations during const prop by moving the lints into their own file and checking them during post borrowck cleanup.
Thanks to `@oli-obk` for mentoring me.
Change Thir to lazily create constants
To allow `AbstractConst`s to work with the previous thir changes we made and those we want to make, i.e. to avoid problems due to `ValTree` and `ConstValue` conversions, we instead switch to a thir representation for constants that allows us to lazily create constants.
r? `@oli-obk`
Properly track `ImplObligations`
Instead of probing for all possible `impl`s that could have caused an
`ImplObligation`, keep track of its `DefId` and obligation spans for
accurate error reporting.
Follow to #89580. Addresses #89418.
Before this fix, the debuginfo for the fields was generated from the
struct defintion of Box<T>, but (at least at the moment) the compiler
pretends that Box<T> is just a (fat) pointer, so the fields need to be
`pointer` and `vtable` instead of `__0: Unique<T>` and `__1: Allocator`.
This is meant as a temporary mitigation until we can make sure that
simply treating Box as a regular struct in debuginfo does not cause too
much breakage in the ecosystem.
Instead of probing for all possible impls that could have caused an
`ImplObligation`, keep track of its `DefId` and obligation spans for
accurate error reporting.
Follow up to #89580. Addresses #89418.
Remove some unnecessary clones.
Tweak output for auto trait impl obligations.
Rollup of 5 pull requests
Successful merges:
- #94249 (Better errors when a Copy impl on a Struct is not self-consistent)
- #95069 (Fix auto traits in rustdoc)
- #95221 (interpret/memory: simplify check_and_deref_ptr)
- #95225 (remove `[async output]` from `impl Future` pretty-printing)
- #95238 (Stop emitting E0026 for struct enums with underscores)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
interpret/memory: simplify check_and_deref_ptr
*Finally* I saw a way to make this code simpler. The odd preprocessing in `let ptr_or_addr =` has bothered me since forever, but it actually became unnecessary in the last provenance refactoring. :)
This also leads to slightly more explicit error messages as a nice side-effect. 🎉
r? `@oli-obk`
Better errors when a Copy impl on a Struct is not self-consistent
As discovered in a Zulip thread with `@nnethercote` and `@Mark-Simulacrum,` it's not immediately obvious why a field on an ADT doesn't implement `Copy`. This PR attempts to give slightly more detailed information by spinning up a fulfillment context to try to dig down and discover transitive fulfillment errors that cause `is_copy_modulo_regions` to fail on a ADT field.
The error message still kinda sucks, but should only show up in the case that an existing error message was totally missing... so I think it's a good compromise for now?
diagnostics: do not suggest `fn foo({ <body> }`
Instead of suggesting that the body always replace the last character on the line, presuming it must be a semicolon, the parser should instead check what the last character is, and append the body if it is anything else.
Fixes#83104
