Add `rustc_deny_explicit_impl`
Also adjust `E0322` error message to be more general, since it's used for `DiscriminantKind` and `Pointee` as well.
Also add `rustc_deny_explicit_impl` on the `Tuple` and `Destruct` marker traits.
Walk types more carefully in `ProhibitOpaqueTypes` visitor
The visitor didn't account for the case where you could have `<TAIT as Trait>::Assoc` normalize to itself, in the case of a `type TAIT = impl Trait` with an unconstrained associated type. That causes the visitor to loop on the same type over and over.
Fixes#104291
Deduce closure signature from a type alias `impl Trait`'s supertraits
r? `@oli-obk`
Basically pass the TAIT's bounds through the same method that we're using to deduce a signature from infer var closure bounds.
Does this need a new FCP? I see it as a logical extension of #101834, but happy to rfcbot a new one if it does.
Visit attributes of trait impl items during AST validation
Fixes#104140.
This fix might not be backward compatible (in practice) since we now validate more attributes than before.
Should I write more tests?
`@rustbot` label A-attributes
Show note where the macro failed to match
When feeding the wrong tokens, it used to fail with a very generic error that wasn't very helpful. This change tries to help by noting where specifically the matching went wrong.
```rust
macro_rules! uwu {
(a a a b) => {};
}
uwu! { a a a c }
```
```diff
error: no rules expected the token `c`
--> macros.rs:5:14
|
1 | macro_rules! uwu {
| ---------------- when calling this macro
...
4 | uwu! { a a a c }
| ^ no rules expected this token in macro call
|
+note: while trying to match `b`
+ --> macros.rs:2:12
+ |
+2 | (a a a b) => {};
+ | ^
```
Add new MIR constant propagation based on dataflow analysis
The current constant propagation in `rustc_mir_transform/src/const_prop.rs` fails to handle many cases that would be expected from a constant propagation optimization. For example:
```rust
let x = if true { 0 } else { 0 };
```
This pull request adds a new constant propagation MIR optimization pass based on the existing dataflow analysis framework. Since most of the analysis is not unique to constant propagation, a generic framework has been extracted. It works on top of the existing framework and could be reused for other optimzations.
Closes#80038. Closes#81605.
## Todo
### Essential
- [x] [Writes to inactive enum variants](https://github.com/rust-lang/rust/pull/101168#pullrequestreview-1089493974). Resolved by rejecting the registration of places with downcast projections for now. Could be improved by flooding other variants if mutable access to a variant is observed.
- [X] Handle [`StatementKind::CopyNonOverlapping`](https://github.com/rust-lang/rust/pull/101168#discussion_r957774914). Resolved by flooding the destination.
- [x] Handle `UnsafeCell` / `!Freeze` correctly.
- [X] Overflow propagation of `CheckedBinaryOp`: Decided to not propagate if overflow flag is `true` (`false` will still be propagated)
- [x] More documentation in general.
- [x] Arguments for correctness, documentation of necessary assumptions.
- [x] Better performance, or alternatively, require `-Zmir-opt-level=3` for now.
### Extra
- [x] Add explicit unreachability, i.e. upgrading the lattice from $\mathbb{P} \to \mathbb{V}$ to $\set{\bot} \cup (\mathbb{P} \to \mathbb{V})$.
- [x] Use storage statements to improve precision.
- [ ] Consider opening issue for duplicate diagnostics: https://github.com/rust-lang/rust/pull/101168#issuecomment-1276609950
- [ ] Flood moved-from places with $\bot$ (requires some changes for places with tracked projections).
- [ ] Add downcast projections back in.
- [ ] [Algebraic simplifications](https://github.com/rust-lang/rust/pull/101168#discussion_r957967878) (possibly with a shared API; done by old const prop).
- [ ] Propagation through slices / arrays.
- [ ] Find other optimizations that are done by old `const_prop.rs`, but not by this one.
Rollup of 11 pull requests
Successful merges:
- #101967 (Move `unix_socket_abstract` feature API to `SocketAddrExt`.)
- #102470 (Stabilize const char convert)
- #104223 (Recover from function pointer types with generic parameter list)
- #104229 (Don't print full paths in overlap errors)
- #104294 (Don't ICE with inline const errors during MIR build)
- #104332 (Fixed some `_i32` notation in `maybe_uninit`’s doc)
- #104349 (fix some typos in comments)
- #104350 (Fix x finding Python on Windows)
- #104356 (interpret: make check_mplace public)
- #104364 (rustdoc: Resolve doc links in external traits having local impls)
- #104378 (Bump chalk to v0.87)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove unused symbols and diagnostic items
As the title suggests, this removes unused symbols from `sym::` and `#[rustc_diagnostic_item]` annotations that weren't mentioned anywhere.
Originally I tried to use grep, to find symbols and item names that are never mentioned via `sym::name`, however this produced a lot of false positives (?), for example clippy matching on `Symbol::as_str` or macros "implicitly" adding `sym::`. I ended up fixing all these false positives (?) by hand, but tbh I'm not sure if it was worth it...
Wrap bundled static libraries into object files
Fixes#103044 (not sure, couldn't test locally)
Bundled static libraries should be wrapped into object files as it's done for metadata file.
r? `@petrochenkov`
Don't print full paths in overlap errors
We don't print the full path in other diagnostics -- I don't think it particularly helps with the error message. I also delayed the printing until actually needing to render the error message.
r? diagnostics
Recover from function pointer types with generic parameter list
Give a more helpful error when encountering function pointer types with a generic parameter list like `fn<'a>(&'a str) -> bool` or `fn<T>(T) -> T` and suggest moving lifetime parameters to a `for<>` parameter list.
I've added a bunch of extra code to properly handle (unlikely?) corner cases like `for<'a> fn<'b>()` (where there already exists a `for<>` parameter list) correctly suggesting `for<'a, 'b> fn()` (merging the lists). If you deem this useless, I can simplify the code by suggesting nothing at all in this case.
I am quite open to suggestions regarding the wording of the diagnostic messages.
Fixes#103487.
``@rustbot`` label A-diagnostics
r? diagnostics
