suggest lifetime for closure parameter type when mismatch
This is a draft PR, will add test cases later and be ready for review.
This PR fixes https://github.com/rust-lang/rust/issues/105675 by adding a diagnostics suggestion. Also a partial fix to https://github.com/rust-lang/rust/issues/105528.
The following code will have a compile error now:
```
fn const_if_unit(input: bool) -> impl for<'a> FnOnce(&'a ()) -> usize {
let x = |_| 1;
x
}
```
Before this PR:
```
error[E0308]: mismatched types
--> src/lib.rs:3:5
|
3 | x
| ^ one type is more general than the other
|
= note: expected trait `for<'a> FnOnce<(&'a (),)>`
found trait `FnOnce<(&(),)>`
note: this closure does not fulfill the lifetime requirements
--> src/lib.rs:2:13
|
2 | let x = |_| 1;
| ^^^
error: implementation of `FnOnce` is not general enough
--> src/lib.rs:3:5
|
3 | x
| ^ implementation of `FnOnce` is not general enough
|
= note: closure with signature `fn(&'2 ()) -> usize` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2`
For more information about this error, try `rustc --explain E0308`.
error: could not compile `rust-test` due to 2 previous errors
```
After this PR:
```
error[E0308]: mismatched types
--> src/lib.rs:3:5
|
3 | x
| ^ one type is more general than the other
|
= note: expected trait `for<'a> FnOnce<(&'a (),)>`
found trait `FnOnce<(&(),)>`
note: this closure does not fulfill the lifetime requirements
--> src/lib.rs:2:13
|
2 | let x = |_| 1;
| ^^^
help: consider changing the type of the closure parameters
|
2 | let x = |_: &_| 1;
| ~~~~~~~
error: implementation of `FnOnce` is not general enough
--> src/lib.rs:3:5
|
3 | x
| ^ implementation of `FnOnce` is not general enough
|
= note: closure with signature `fn(&'2 ()) -> usize` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2`
For more information about this error, try `rustc --explain E0308`.
error: could not compile `rust-test` due to 2 previous errors
```
After applying the suggestion, it compiles. The suggestion might not always be correct as the generation procedure of that suggestion is quite simple...
Rollup of 8 pull requests
Successful merges:
- #110033 (Add 1.69.0 release notes)
- #110272 (fix: skip implied bounds if unconstrained lifetime exists)
- #110307 (Allow everyone to set the beta-nominated label)
- #110347 (Add intra-doc links to size_of_* functions)
- #110350 (Add a UI test for #79605)
- #110356 (Fix `x test rust-installer` when `cargo` is set to a relative path)
- #110364 (remove redundant clones)
- #110366 (fix some clippy::complexity)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fix `x test rust-installer` when `cargo` is set to a relative path
Previously, this would give an error because the shell script had a different working directory:
```
test: basic_install
$ sh /home/jyn/src/rust/src/tools/rust-installer/gen-installer.sh --image-dir=/home/jyn/src/rust/src/tools/rust-installer/test/image1 --work-dir=/home/jyn/src/rust/build/x86_64-unknown-linux-gnu/test/rust-installer/workdir --output-dir=/home/jyn/src/rust/build/x86_64-unknown-linux-gnu/test/rust-installer/outdir
/home/jyn/src/rust/src/tools/rust-installer/gen-installer.sh: 15: ../rust3/build/host/stage2-tools-bin/cargo: not found
TEST FAILED!
```
Allow everyone to set the beta-nominated label
It is allowed both in cargo and clippy's triagebot.toml, and nomination does not automatically mean that the PR will be backported.
[compiletest] Add more test ignore reasons, `needs-` validation, and improved error messages
This PR makes more improvements to the way compiletest ignoring headers are handled, following up on #108905:
* Human-readable ignore reasons have been added for the remaining ignore causes (`needs-*` directives, `*llvm*` directives, and debugger version directives). All ignored tests should now have a human-readable reason.
* The code handling `needs-*` directives has been refactored, and now invalid `needs-*` directive emit errors like `ignore-*` and `only-*`.
* All errors are now displayed at startup (with line numbers) rather than just the first error of the first file.
This PR is best reviewed commit-by-commit.
r? `@ehuss`
Temporarily disable the jobserver-error test
This test is failing randomly on CI. We don't have a handle on what might be causing it, so disable it for now to reduce disruption.
cc https://github.com/rust-lang/rust/issues/110321
Previously, this would give an error because the shell script had a
different working directory:
```
test: basic_install
$ sh /home/jyn/src/rust/src/tools/rust-installer/gen-installer.sh --image-dir=/home/jyn/src/rust/src/tools/rust-installer/test/image1 --work-dir=/home/jyn/src/rust/build/x86_64-unknown-linux-gnu/test/rust-installer/workdir --output-dir=/home/jyn/src/rust/build/x86_64-unknown-linux-gnu/test/rust-installer/outdir
/home/jyn/src/rust/src/tools/rust-installer/gen-installer.sh: 15: ../rust3/build/host/stage2-tools-bin/cargo: not found
TEST FAILED!
```
explicit `adt_dtorck_constraint` for `ManuallyDrop`
the only reason we didn't add outlives requirements when dropping `ManuallyDrop` was a fast-path in `trivial_dropck_outlives`. Explicitly acknowledge that fast-path in `adt_dtorck_constraint`
Only enable ConstProp at mir-opt-level >= 2.
That pass is not responsible for lints any more, so we can restrict it to optimized builds.
This reduces the amount of duplicated const-eval messages.
rustdoc-search: add support for nested generics
This change allows `search.js` to parse nested generics (which look `Like<This<Example>>`) and match them. It maintains the existing "bag semantics", so that the order of type parameters is ignored but the number is required to be greater than or equal to what's in the query.
For example, a function with the signature `fn read_all(&mut self: impl Read) -> Result<Vec<u8>, Error>` will match these queries:
* `Read -> Result<Vec<u8>, Error>`
* `Read -> Result<Error, Vec>`
* `Read -> Result<Vec<u8>>`
But it *does not* match `Result<Vec, u8>` or `Result<u8<Vec>>`.
