Address #85991
Suggest the `impl Trait` return type syntax if the user tried to return a generic parameter and we get a type mismatch
The suggestion is not emitted if the param appears in the function parameters, and only get the bounds that actually involve `T: ` directly
It also checks whether the generic param is contained in any where bound (where it isn't the self type), and if one is found (like `Option<T>: Send`), it is not suggested.
This also adds `TyS::contains`, which recursively vistits the type and looks if the other type is contained anywhere
Rollup of 6 pull requests
Successful merges:
- #92683 (Suggest copying trait associated type bounds on lifetime error)
- #92933 (Deny mixing bin crate type with lib crate types)
- #92959 (Add more info and suggestions to use of #[test] on invalid items)
- #93024 (Do not ICE when inlining a function with un-satisfiable bounds)
- #93613 (Move `{core,std}::stream::Stream` to `{core,std}::async_iter::AsyncIterator`)
- #93634 (compiler: clippy::complexity fixes)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Do not ICE when inlining a function with un-satisfiable bounds
Fixes#93008
This is kinda a hack... but it's the fix I thought had the least blast-radius.
We use `normalize_param_env_or_error` to verify that the predicates in the param env are self-consistent, since with RevealAll, a bad predicate like `<&'static () as Clone>` will be evaluated with an empty ParamEnv (since it references no generics), and we'll raise an error for it.
Add more info and suggestions to use of #[test] on invalid items
This pr changes the diagnostics for using `#[test]` on an item that can't be used as a test to explain that the attribute has no meaningful effect on non-functions and suggests the use of `#[cfg(test)]` for conditional compilation instead.
Example change:
```rs
#[test]
mod test {}
```
previously output
```
error: only functions may be used as tests
--> src/lib.rs:2:1
|
2 | mod test {}
| ^^^^^^^^^^^
```
now outputs
```
error: the `#[test]` attribute may only be used on a non-associated function
--> $DIR/test-on-not-fn.rs:3:1
|
LL | #[test]
| ^^^^^^^
LL | mod test {}
| ----------- expected a non-associated function, found a module
|
= note: the `#[test]` macro causes a a function to be run on a test and has no effect on non-functions
help: replace with conditional compilation to make the item only exist when tests are being run
|
LL | #[cfg(test)]
| ~~~~~~~~~~~~
```
Deny mixing bin crate type with lib crate types
The produced library would get a main shim too which conflicts with the
main shim of the executable linking the library.
```
$ cat > main1.rs <<EOF
fn main() {}
pub fn bar() {}
EOF
$ cat > main2.rs <<EOF
extern crate main1;
fn main() {
main1::bar();
}
EOF
$ rustc --crate-type bin --crate-type lib main1.rs
$ rustc -L. main2.rs
error: linking with `cc` failed: exit status: 1
[...]
= note: /usr/bin/ld: /tmp/crate_bin_lib/libmain1.rlib(main1.main1.707747aa-cgu.0.rcgu.o): in function `main':
main1.707747aa-cgu.0:(.text.main+0x0): multiple definition of `main'; main2.main2.02a148fe-cgu.0.rcgu.o:main2.02a148fe-cgu.0:(.text.main+0x0): first defined here
collect2: error: ld returned 1 exit status
```
Suggest copying trait associated type bounds on lifetime error
Closes#92033
Kind of the most simple suggestion to make - we don't try to be fancy. Turns out, it's still pretty useful (the couple existing tests that trigger this error end up fixed - for this error - upon applying the fix).
r? ``@estebank``
cc ``@nikomatsakis``
The `uninhabited_enum_branch` miropt now also checks whether the fallthrough
case is inhabited, and if not will ensure that it points to an unreachable
block.
rustdoc: Collect traits in scope for lang items
Inherent impls on primitive types are not included in the list of all inherent impls in the crate (`inherent_impls_in_crate_untracked`), they are taken from the list of lang items instead, but such impls can also be inlined by rustdoc, e.g. if something derefs to a primitive type.
r? `@camelid`
Fixes https://github.com/rust-lang/rust/issues/93698
Fix documentation for is_X_feature_detected!
These are now properly documented for all architectures and the
stability attributes in the docs are now correctly displayed.
This addresses this comment by `@ehuss:` https://github.com/rust-lang/rust/pull/90271#issuecomment-1038400916
cc `@adamgemmell`
Clippy: Don't lint `needless_borrow` in method receiver positions
r? `@Manishearth`
cc `@camsteffen` `@Jarcho`
cc rust-lang/rust-clippy#8441
Let's get this fix in before the beta branching tomorrow.
Fix ICE when using Box<T, A> with pointer sized A
Fixes#78459
Note that using `Box<T, A>` with a more than pointer sized `A` or using a pointer sized `A` with a Box of a DST will produce a different ICE (#92054) which is not fixed by this PR.
Add a `try_collect()` helper method to `Iterator`
Implement `Iterator::try_collect()` as a helper around `Iterator::collect()` as discussed [here](https://internals.rust-lang.org/t/idea-fallible-iterator-mapping-with-try-map/15715/5?u=a.lafrance).
First time contributor so definitely open to any feedback about my implementation! Specifically wondering if I should open a tracking issue for the unstable feature I introduced.
As the main participant in the internals discussion: r? `@scottmcm`
Add MAIN_SEPARATOR_STR
Currently, if someone needs access to the path separator as a str, they need to go through this mess:
```rust
unsafe {
std::str::from_utf8_unchecked(slice::from_ref(&(MAIN_SEPARATOR as u8)))
}
```
This PR just re-exports an existing path separator str API.
Improve comments about type folding/visiting.
I have found this code confusing for years. I've always roughly
understood it, but never exactly. I just made my fourth(?) attempt and
finally cracked it.
This commit improves the comments. In particular, it explicitly
describes how you can't do a custom fold/visit of any type; there are
actually a handful of "types of interest" (e.g. `Ty`, `Predicate`,
`Region`, `Const`) that can be custom folded/visted, and all other types
just get a generic traversal. I think this was the part that eluded me
on all my prior attempts at understanding.
The commit also updates comments to account for some newer changes such
as the fallible/infallible folding distinction, does some minor
reorderings, and moves one `impl` to a better place.
r? `@BoxyUwU`
Update tracking issue numbers for inline assembly sub-features
The main tracking issue for inline assembly is [closed](https://github.com/rust-lang/rust/issues/72016#issuecomment-1022332954), further tracking of the remaining sub-features has been moved to separate tracking issues.
I have found this code confusing for years. I've always roughly
understood it, but never exactly. I just made my fourth(?) attempt and
finally cracked it.
This commit improves the comments. In particular, it explicitly
describes how you can't do a custom fold/visit of any type; there are
actually a handful of "types of interest" (e.g. `Ty`, `Predicate`,
`Region`, `Const`) that can be custom folded/visted, and all other types
just get a generic traversal. I think this was the part that eluded me
on all my prior attempts at understanding.
The commit also updates comments to account for some newer changes such
as the fallible/infallible folding distinction, does some minor
reorderings, and moves one `impl` to a better place.
Rollup of 8 pull requests
Successful merges:
- #89869 (Add documentation to more `From::from` implementations.)
- #93479 (Use `optflag` for `--report-time`)
- #93693 (Suggest deriving required supertraits)
- #93981 (Fix suggestion to slice if scurtinee is a reference to `Result` or `Option`)
- #93996 (Do not suggest "is a function" for free variables)
- #94030 (Correctly mark the span of captured arguments in `format_args!()`)
- #94031 ([diagnostics] Add mentions to `Copy` types being valid for `union` fields)
- #94064 (Update dist-x86_64-musl to Ubuntu 20.04)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Update dist-x86_64-musl to Ubuntu 20.04
This updates the dist-x86_64-musl image to use Ubuntu 20.04. The current Ubuntu 16.04 based image only works due to the Docker cache, it's not possible anymore to run it locally because of the usual certificate expiration issue.
I believe updating the OS here is relatively safe because this targets musl, so there are no concerns about raising the glibc baseline. There is some risk here in that it updates the compiler toolchain used to produce artifacts, though I'm not aware of any specific issues that could cause.
r? ``@Mark-Simulacrum``
[diagnostics] Add mentions to `Copy` types being valid for `union` fields
This came up from some user on Discord which was using a `T : PrimitiveInt` generic type, and they wanted to use in a `union`. Rather than adding a `Copy` bound, they started pondering about the `ManuallyDrop<T>` road, and how to correctly use `unsafe` to perform the drops.
<img width="648" alt="Screen Shot 2022-02-15 at 22 28 34" src="https://user-images.githubusercontent.com/9920355/154152496-8f9be74b-ad59-4724-8f9e-48b446774e06.png">
- [Discord link](https://discord.com/channels/442252698964721669/443150878111694848/943092778534072320)
So, it seemed like the error message for types with potential drop glue on `union` fields could be improved to also mention the `Copy` alternative, since in many cases where `union`s are concerned, people are dealing with PODs / `Copy` types anyways 🙂
___
``@rustbot`` modify labels: +A-diagnostics +D-terse
Correctly mark the span of captured arguments in `format_args!()`
It should not include the braces, or misspelling suggestions will be wrong.
Fixes#94010.
