Suggest `await` in more situations where infer types are involved
Currently we use `TyS::same_type` in diagnostics that suggest adding `.await` to opaque future types.
This change makes the suggestion slightly more general, when we're comparing types like `Result<T, E>` and `Result<_, _>` which happens sometimes in places like `match` patterns or `let` statements with partially-elaborated types.
----
Question:
1. Is this change worthwhile? Totally fine if it doesn't make sense adding.
2. Should `same_type_modulo_infer` live in `rustc_infer::infer::error_reporting` or alongside the other method in `rustc_middle::ty::util`?
3. Should we generalize this change? I wanted to change all usages, but I don't want erroneous suggestions when adding `.field_name`...
Elaborate `Future::Output` when printing opaque `impl Future` type
I would love to see the `Output =` type when printing type errors involving opaque `impl Future`.
[Test code](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=a800b481edd31575fbcaf5771a9c3678)
Before (cut relevant part of output):
```
note: while checking the return type of the `async fn`
--> /home/michael/test.rs:5:19
|
5 | async fn bar() -> usize {
| ^^^^^ checked the `Output` of this `async fn`, found opaque type
= note: expected type `usize`
found opaque type `impl Future`
```
After:
```
note: while checking the return type of the `async fn`
--> /home/michael/test.rs:5:19
|
5 | async fn bar() -> usize {
| ^^^^^ checked the `Output` of this `async fn`, found opaque type
= note: expected type `usize`
found opaque type `impl Future<Output = usize>`
```
Note the "found opaque type `impl Future<Output = usize>`" in the new output.
----
Questions:
1. We skip printing the output type when it's a projection, since I have been seeing some types like `impl Future<Output = <[static generator@/home/michael/test.rs:2:11: 2:21] as Generator<ResumeTy>>::Return>` which are not particularly helpful and leak implementation detail.
* Am I able to normalize this type within `rustc_middle::ty::print::pretty`? Alternatively, can we normalize it when creating the diagnostic? Otherwise, I'm fine with skipping it and falling back to the old output.
* Should I suppress any other types? I didn't encounter anything other than this generator projection type.
2. Not sure what the formatting of this should be. Do I include spaces in `Output = `?
Fix `non-constant value` ICE (#90878)
This also fixes the same suggestion, which was kind of broken, because it just searched for the last occurence of `const` to replace with a `let`. This works great in some cases, but when there is no const and a leading space to the file, it doesn't work and panic with overflow because it thought that it had found a const.
I also changed the suggestion to only trigger if the `const` and the non-constant value are on the same line, because if they aren't, the suggestion is very likely to be wrong.
Also don't trigger the suggestion if the found `const` is on line 0, because that triggers the ICE.
Asking Esteban to review since he was the last one to change the relevant code.
r? ``@estebank``
Fixes#90878
Clarify error messages caused by re-exporting `pub(crate)` visibility to outside
This PR clarifies error messages and suggestions caused by re-exporting pub(crate) visibility outside the crate.
Here is a small example ([Rust Playground](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=e2cd0bd4422d4f20e6522dcbad167d3b)):
```rust
mod m {
pub(crate) enum E {}
}
pub use m::E;
fn main() {}
```
This code is compiled to:
```
error[E0365]: `E` is private, and cannot be re-exported
--> prog.rs:4:9
|
4 | pub use m::E;
| ^^^^ re-export of private `E`
|
= note: consider declaring type or module `E` with `pub`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0365`.
```
However, enum `E` is actually public to the crate, not private totally—nevertheless, rustc treats `pub(crate)` and private visibility as the same on the error messages. They are not clear and should be segmented distinctly.
By applying changes in this PR, the error message below will be the following message that would be clearer:
```
error[E0365]: `E` is only public to inside of the crate, and cannot be re-exported outside
--> prog.rs:4:9
|
4 | pub use m::E;
| ^^^^ re-export of crate public `E`
|
= note: consider declaring type or module `E` with `pub`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0365`.
```
rustdoc doctest: detect `fn main` after an unexpected semicolon
Fixes#91014
The basic problem with this is that rustdoc, when hunting for `fn main`, will stop parsing after it reaches a fatal error. This unexpected semicolon was a fatal error, so in `src/test/rustdoc-ui/failed-doctest-extra-semicolon-on-item.rs`, it would wrap the doctest in an implied main function, turning it into this:
fn main() {
struct S {};
fn main() {
assert_eq!(0, 1);
}
}
This, as it turns out, is totally valid, and it executes no assertions, so *it passes,* even though the user wanted it to execute the assertion.
The Rust parser already has the ability to recover from these unexpected semicolons, but to do so, it needs to use the `parse_mod` function, so this PR changes it to do that.
fix CTFE/Miri simd_insert/extract on array-style repr(simd) types
The changed test would previously fail since `place_index` would just return the only field of `f32x4`, i.e., the array -- rather than *indexing into* the array which is what we have to do.
The new helper methods will also be needed for https://github.com/rust-lang/miri/issues/1912.
r? ``````@oli-obk``````
Rollup of 8 pull requests
Successful merges:
- #89258 (Make char conversion functions unstably const)
- #90578 (add const generics test)
- #90633 (Refactor single variant `Candidate` enum into a struct)
- #90800 (bootstap: create .cargo/config only if not present)
- #90942 (windows: Return the "Not Found" error when a path is empty)
- #90947 (Move some tests to more reasonable directories - 9.5)
- #90961 (Suggest removal of arguments for unit variant, not replacement)
- #90990 (Arenas cleanup)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Try all stable method candidates first before trying unstable ones
Currently we try methods in this order in each step:
* Stable by value
* Unstable by value
* Stable autoref
* Unstable autoref
* ...
This PR changes it to first try pick methods without any unstable candidates, and if none is found, try again to pick unstable ones.
Fix#90320
CC #88971, hopefully would allow us to rename the "unstable_*" methods for integer impls back.
`@rustbot` label T-compiler T-libs-api
The basic problem with this is that rustdoc, when hunting for `fn main`, will stop
parsing after it reaches a fatal error. This unexpected semicolon was a fatal error,
so in `src/test/rustdoc-ui/failed-doctest-extra-semicolon-on-item.rs`, it would wrap
the doctest in an implied main function, turning it into this:
fn main() {
struct S {};
fn main() {
assert_eq!(0, 1);
}
}
This, as it turns out, is totally valid, and it executes no assertions, so *it passes,*
even though the user wanted it to execute the assertion.
The Rust parser already has the ability to recover from these unexpected semicolons,
but to do so, it needs to use the `parse_mod` function, so this commit changes it to do that.
Rollup of 8 pull requests
Successful merges:
- #90386 (Add `-Zassert-incr-state` to assert state of incremental cache)
- #90438 (Clean up mess for --show-coverage documentation)
- #90480 (Mention `Vec::remove` in `Vec::swap_remove`'s docs)
- #90607 (Make slice->str conversion and related functions `const`)
- #90750 (rustdoc: Replace where-bounded Clean impl with simple function)
- #90895 (require full validity when determining the discriminant of a value)
- #90989 (Avoid suggesting literal formatting that turns into member access)
- #91002 (rustc: Remove `#[rustc_synthetic]`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
std: Get the standard library compiling for wasm64
This commit goes through and updates various `#[cfg]` as appropriate to
get the wasm64-unknown-unknown target behaving similarly to the
wasm32-unknown-unknown target. Most of this is just updating various
conditions for `target_arch = "wasm32"` to also account for `target_arch
= "wasm64"` where appropriate. This commit also lists `wasm64` as an
allow-listed architecture to not have the `restricted_std` feature
enabled, enabling experimentation with `-Z build-std` externally.
The main goal of this commit is to enable playing around with
`wasm64-unknown-unknown` externally via `-Z build-std` in a way that's
similar to the `wasm32-unknown-unknown` target. These targets are
effectively the same and only differ in their pointer size, but wasm64
is much newer and has much less ecosystem/library support so it'll still
take time to get wasm64 fully-fledged.
This function parameter attribute was introduced in https://github.com/rust-lang/rust/pull/44866 as an intermediate step in implementing `impl Trait`, it's not necessary or used anywhere by itself.
Improve ManuallyDrop suggestion
closes https://github.com/rust-lang/rust/issues/90585
* Fixes the recommended change to use ManuallyDrop as per the issue
* Changes the note to a help
* improves the span so it only points at the type.
Fix span for non-satisfied trivial trait bounds
The spans for "trait bound not satisfied" errors in trivial trait bounds referenced the entire item (fn, impl, struct) before.
Now they only reference the obligation itself (`String: Copy`)
Address #90869
Print escaped string if char literal has multiple characters, but only one printable character
Fixes#90857
I'm not sure about the error message here, it could get rather long and *maybe* using the names of characters would be better? That wouldn't help the length any, though.
Permit const panics in stable const contexts in stdlib
Without this change, it is not possible to use `panic!` and similar (including `assert!`) in stable const contexts inside of stdlib. See #89542 for a real-world case that currently fails for this reason. This does _not_ affect any user code.
For example, this snippet currently fails to compile:
```rust
#[stable(feature = "foo", since = "1.0.0")]
#[rustc_const_stable(feature = "foo", since = "1.0.0")]
const fn foo() {
assert!(false);
assert!(false, "foo");
}
```
With the addition of `#[rustc_const_unstable]` to `core::panicking::panic`, the error no longer occurs. This snippet has been added verbatim in this PR as a UI test.
To avoid needing to add `#![feature(core_panic)]` to libcore, the two instances of direct calls to `core::panicking::panic` have been switched to use the `panic!` macro.
I am requesting prioritization because this is holding up other stabilizations such as #89542 (which is otherwise ready to merge and succeeds with this change)
Improve diagnostics when a static lifetime is expected
Makes progress towards https://github.com/rust-lang/rust/issues/90600
The diagnostics here were previously entirely removed due to giving a misleading suggestion but if we instead provide an informative label in that same location it should better help the user understand the situation.
I included the example from the issue as it demonstrates an area where the diagnostics are still lacking.
Happy to remove that if its just adding noise atm.
warn on must_use use on async fn's
As referenced in #78149
This only works on `async` fn's for now, I can also look into if I can get `Box<dyn Future>` and `impl Future` working at this level (hir)
