Re-enable trivial bounds
cc #50825
Remove implementations from global bounds in winnowing when there is ambiguity.
This results in the reverse of #24066 happening sometimes. I'm not sure if anything can be done about that though.
cc #48214
r? @nikomatsakis
Rollup of 13 pull requests
Successful merges:
- #50143 (Add deprecation lint for duplicated `macro_export`s)
- #51099 (Fix Issue 38777)
- #51276 (Dedup auto traits in trait objects.)
- #51298 (Stabilize unit tests with non-`()` return type)
- #51360 (Suggest parentheses when a struct literal needs them)
- #51391 (Use spans pointing at the inside of a rustdoc attribute)
- #51394 (Use scope tree depths to speed up `nearest_common_ancestor`.)
- #51396 (Make the size of Option<NonZero*> a documented guarantee.)
- #51401 (Warn on `repr` without hints)
- #51412 (Avoid useless Vec clones in pending_obligations().)
- #51427 (compiletest: autoremove duplicate .nll.* files (#51204))
- #51436 (Do not require stage 2 compiler for rustdoc)
- #51437 (rustbuild: generate full list of dependencies for metadata)
Failed merges:
Suggest parentheses when a struct literal needs them
When writing a struct literal in an expression that expects a block to
be started afterwards (like an `if` statement), do not suggest using the
same struct literal:
```
did you mean `S { /* fields * /}`?
```
Instead, suggest surrounding the expression with parentheses:
```
did you mean `(S { /* fields * /})`?
```
Fix#47360, #50090. Leaving #42982 open to come back to this problem with a better solution.
Dedup auto traits in trait objects.
Fixes#47010
Note that the test file `run-pass/trait-object-auto-dedup.rs` passes before and after this change. It's the `ui` test that changed from compiling to not compiling. Which does make this a breaking change, but I cannot imagine anybody actually being broken by it.
NLL: report type moved from behind borrow of array/slice
When NLL has illegal move due to borrowed content in an array or slice, provide feedback about why the move wasn't a copy.
Drive by: While comparing the resulting `.nll.stderr` files to their old borrowck variants, I noticed that the test for borrowck-vec-pattern-nesting.rs was not signaling some errors under NLL due to the test assuming lexical lifetimes. So I fixed that too.
Fix#51190
Removes extra global bounds at the winnowing stage rather than when
normalizing the param_env. This avoids breaking inference when there is
a global bound.
Deny #[cfg] and #[cfg_attr] on generic parameters.
Fix#51279.
Attributes on generic parameters are not expanded, meaning `#[cfg]`, `#[cfg_attr]` and attribute proc macros are entirely ignored on them.
This PR makes using the first two attributes an error, because if they are correctly expanded will affect the AST and change code behavior.
I'm beta-nominating this, because generic parameter attributes are stabilizing in 1.27, and if we did not reserve their usage, we may never be able to repurpose the meaning of these attributes in the Rust 2015 edition.
Accept `..` in incorrect position to avoid further errors
We currently give a specific message when encountering a `..` anywhere
other than the end of a pattern. Modify the parser to accept it (while
still emitting the error) so that we don't also trigger "missing fields
in pattern" errors afterwards.
Add suggestions to either remove trailing `,` or moving the `..` to the
end.
Follow up to #49268.
When using `..` somewhere other than the end, parse the rest of the
pattern correctly while still emitting an error.
Add suggestions to either remove trailing `,` or moving the `..` to the
end.
We currently give a specific message when encountering a `..` anywhere
other than the end of a pattern. Modify the parser to accept it (while
still emitting the error) so that we don't also trigger "missing fields
in pattern" errors afterwards.
Check array indices in constant propagation
Previously, uses of constant weren't correctly propagated.
This fixes#48920.
r? @oli-obk because you suggested it
When writing a struct literal in an expression that expects a block to
be started afterwards (like an `if` statement), do not suggest using the
same struct literal:
```
did you mean `S { /* fields * /}`?
```
Instead, suggest surrounding the expression with parentheses:
```
did you mean `(S { /* fields * /})`?
```
Suggest not mutably borrowing a mutable reference
This PR would (hopefully) solve #45392. I deviated a bit from @estebank's instructions since the error span only included the borrowed expression (e.g. the `b` in `&mut b`). I also didn't check the mutability of the local binding, since this whole case is concerned with an immutable local.
I can see two outstanding questions:
1. `note_immutability_blame` is called in two places, but I only have one test case. I think it covers the call in `report_bckerror`, but I'm not sure how to trigger the call from `report_aliasability_violation`.
2. There is one failing test, where the local binding is `self: &mut Self`. I'm not entirely sure what the correct output should be, but I think the new message should also apply. Unfortunately, since this parameter is parsed differently, its `let_span` covers both the pattern and the type, leading to a wrong suggestion text. I'm not sure how to correctly identify this case.
Do not promote union field accesses
r? @eddyb
technically a breaking change, but the code errored on the previous stable and produces UB + a warning on the current stable. I don't think we need a crater run in that case.
