This mainly aids in error recovery but also makes it a bit easier to handle lifetime resolution.
While doing so it also came apparent that we were not actually lowering lifetime outlives relationships within lifetime parameter declaration bounds, so this fixes that.
Revert #133817
This reverts commit 0585134e70, reversing changes made to 5530869e0f.
#133817 unfortunately only converted the `println!` instances to `eprintln!`, meaning that some test output (via compiletest/bootstrap) was messed up because stdout/stderr output interleaved improperly when some `println!` instances were converted to `eprintln!` instances, while some `print!` instances remain unchanged. This made reading test output annoying for contributors cc #133879.
Closes#133879 by reverting.
#133817 can be relanded in the future when `print!` instances are also matched with `println!` instances.
cc `@clubby789`
This is a clean revert so I'm going to self-approve this PR.
Rename `core_pattern_type` and `core_pattern_types` lib feature gates to `pattern_type_macro`
That's what the gates are actually gating, and the single char difference in naming was not helpful either
fixes#128987
Add context to "const in pattern" errors
*Each commit addresses specific diagnostics.*
- Add primary span labels
- Point at `const` item, and `const` generic param definition
- Reword messages and notes
- Point at generic param through which an associated `const` is being referenced
- Silence const in pattern with evaluation errors when they come from `const` items that already emit a diagnostic
- On non-structural type in const used as pattern, point at the type that should derive `PartialEq`
Add lint against function pointer comparisons
This is kind of a follow-up to https://github.com/rust-lang/rust/pull/117758 where we added a lint against wide pointer comparisons for being ambiguous and unreliable; well function pointer comparisons are also unreliable. We should IMO follow a similar logic and warn people about it.
-----
## `unpredictable_function_pointer_comparisons`
*warn-by-default*
The `unpredictable_function_pointer_comparisons` lint checks comparison of function pointer as the operands.
### Example
```rust
fn foo() {}
let a = foo as fn();
let _ = a == foo;
```
### Explanation
Function pointers comparisons do not produce meaningful result since they are never guaranteed to be unique and could vary between different code generation units. Furthermore different function could have the same address after being merged together.
----
This PR also uplift the very similar `clippy::fn_address_comparisons` lint, which only linted on if one of the operand was an `ty::FnDef` while this PR lints proposes to lint on all `ty::FnPtr` and `ty::FnDef`.
```@rustbot``` labels +I-lang-nominated
~~Edit: Blocked on https://github.com/rust-lang/libs-team/issues/323 being accepted and it's follow-up pr~~
This reverts commit 0585134e70, reversing
changes made to 5530869e0f.
The PR unfortunately only converted the `ln!` instances, meaning that
test output was messed up because stdout/stderr output interleaved when
some `println!` instances were converted to `eprintln!` instances, while
some `println!` instances remain unchanged.
This commit supplies a real fix, which makes retags more complicated, at the benefit of
making accesses more performant.
Co-authored-by: Ralf Jung <post@ralfj.de>
Implement diagnostics in all places left: generics (predicates, defaults, const params' types), fields, and type aliases.
Unfortunately this results in a 20mb addition in `analysis-stats .` due to many type methods returning an addition diagnostics result now (even if it's `None` in most cases). I'm not sure if this can be improved.
An alternative strategy that can prevent the memory usage growth is to never produce diagnostics in hir-ty methods. Instead, lower all types in the hir crate when computing diagnostics from scratch (with diagnostics this time). But this has two serious disadvantages:
1. This can cause code duplication (although it can probably be not that bad, it will still mean a lot more code).
2. I believe we eventually want to compute diagnostics for the *entire* workspace (either on-type or on-save or something alike), so users can know when they have diagnostics even in inactive files. Choosing this approach will mean we lose all precomputed salsa queries. For one file this is fine, for the whole workspace this will be very slow.
The diagnostic implemented is a simple one (E0109). It serves as a test for the new foundation.
This commit only implements diagnostics for type in bodies and body-carrying signatures; the next commit will include diagnostics in the rest of the things.
Also fix one weird bug that was detected when implementing this that caused `Fn::(A, B) -> C` (which is a valid, if bizarre, alternative syntax to `Fn(A, B) -> C` to lower incorrectly.
And also fix a maybe-bug where parentheses were sneaked into a code string needlessly; this was not detected until now because the parentheses were removed (by the make-AST family API), but with a change in this commit they are now inserted. So fix that too.
Most paths are types and therefore already are in the source map, but the trait in impl trait and in bounds are not.
We do this by storing them basically as `TypeRef`s. For convenience, I created a wrapper around `TypeRefId` called `PathId` that always stores a path, and implemented indexing from the types map to it.
Fortunately, this change impacts memory usage negligibly (adds 2mb to `analysis-stats .`, but that could be just fluff). Probably because there aren't that many trait bounds and impl traits, and this also shrinks `TypeBound` by 8 bytes.
I also added an accessor to `TypesSourceMap` to get the source code, which will be needed for diagnostics.
