Much like there are specialized variants of `mk_ty`. This will enable
some optimization in the next commit.
Also rename the existing `re_error*` functions as `mk_re_error*`, for
consistency.
Remove needless supertrait constraints from Interner projections
These associated types are already all constrained to implement `Ord`, so specifically requiring its supertraits `Eq`, `PartialEq` and `PartialOrd` is superfluous.
Suggest fix for misplaced generic params on fn item #103366fixes#103366
This still has some work to go, but works for 2/3 of the initial base cases described in #1033366
simple fn:
```
error: expected identifier, found `<`
--> shreys/test_1.rs:1:3
|
1 | fn<T> id(x: T) -> T { x }
| ^ expected identifier
|
help: help: place the generic parameter list after the function name:
|
1 | fn id<T>(x: T) -> T { x }
| ~~~~
```
Complicated bounds
```
error: expected identifier, found `<`
--> spanishpear/test_2.rs:1:3
|
1 | fn<'a, B: 'a + std::ops::Add<Output = u32>> f(_x: B) { }
| ^ expected identifier
|
help: help: place the generic parameter list after the function name:
|
1 | fn f<'a, B: 'a + std::ops::Add<Output = u32>>(_x: B) { }
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
Opening a draft PR for comments on approach, particularly I have the following questions:
- [x] Is it okay to be using `err.span_suggestion` over struct derives? I struggled to get the initial implementation (particularly the correct suggestion message) on struct derives, although I think given what I've learned since starting, I could attempt re-doing it with that approach.
- [x] in the case where the snippet cannot be obtained from a span, is the `help` but no suggestion okay? I think yes (also, when does this case occur?)
- [x] are there any red flags for the generalisation of this work for relevant item kinds (i.e. `struct`, `enum`, `trait`, and `union`). My basic testing indicates it does work for those types except the help tip is currently hardcoded to `after the function name` - which should change dependent on the item.
- [x] I am planning to not show the suggestion if there is already a `<` after the item identifier, (i.e. if there are already generics, as after a function name per the original issue). Any major objections?
- [x] Is the style of error okay? I wasn't sure if there was a way to make it display nicer, or if thats handled by span_suggestion
These aren't blocking questions, and I will keep working on:
- check if there is a `<` after the ident (and if so, not showing the suggestion)
- generalize the help message
- figuring out how to write/run/etc ui tests (including reading the docs for them)
- logic cleanups
fix: improve the suggestion on future not awaited
Considering the following code
```rust
fn foo() -> u8 {
async fn async_fn() -> u8 { 22 }
async_fn()
}
fn main() {}
```
the error generated before this commit from the compiler is
```
➜ rust git:(macros/async_fn_suggestion) ✗ rustc test.rs --edition 2021
error[E0308]: mismatched types
--> test.rs:4:5
|
1 | fn foo() -> u8 {
| -- expected `u8` because of return type
...
4 | async_fn()
| ^^^^^^^^^^ expected `u8`, found opaque type
|
= note: expected type `u8`
found opaque type `impl Future<Output = u8>`
help: consider `await`ing on the `Future`
|
4 | async_fn().await
| ++++++
error: aborting due to previous error
```
In this case the error is nor perfect, and can confuse the user that do not know that the opaque type is the future.
So this commit will propose (and conclude the work start in https://github.com/rust-lang/rust/issues/80658)
to change the string `opaque type` to `future` when applicable and also remove the Expected vs Received note by adding a more specific one regarding the async function that return a future type.
So the new error emitted by the compiler is
```
error[E0308]: mismatched types
--> test.rs:4:5
|
1 | fn foo() -> u8 {
| -- expected `u8` because of return type
...
4 | async_fn()
| ^^^^^^^^^^ expected `u8`, found future
|
note: calling an async function returns a future
--> test.rs:4:5
|
4 | async_fn()
| ^^^^^^^^^^
help: consider `await`ing on the `Future`
|
4 | async_fn().await
| ++++++
error: aborting due to previous error
```
Fixes https://github.com/rust-lang/rust/issues/80658
It remains to rework the case described in the following issue https://github.com/rust-lang/rust/issues/107899 but I think this deserves its own PR after we discuss a little bit how to handle these kinds of cases.
r? `@eholk`
`@rustbot` label +I-async-nominated
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Move folding & visiting traits into type library
This is a rework of #107712, following feedback on that PR.
In particular, this version uses trait aliases to reduce the API churn for trait consumers. Doing so requires a workaround for #107747 until its fix in #107803 is merged into the stage0 compiler; this workaround, which uses conditional compilation based on the `bootstrap` configuration predicate, sits in dedicated commit b409329c for ease of reversion.
The possibility of the `rustc_middle` crate retaining its own distinct versions of each folding/visiting trait, blanket-implemented on all types that implement the respective trait in the type library, was also explored: however since this would necessitate making each `rustc_middle` trait a subtrait of the respective type library trait (so that such blanket implementations can delegate their generic methods), no benefit would be gained.
r? types
Considering the following code
```rust
fn foo() -> u8 {
async fn async_fn() -> u8 { 22 }
async_fn()
}
fn main() {}
```
the error generated before this commit from the compiler is
```
➜ rust git:(macros/async_fn_suggestion) ✗ rustc test.rs --edition 2021
error[E0308]: mismatched types
--> test.rs:4:5
|
1 | fn foo() -> u8 {
| -- expected `u8` because of return type
...
4 | async_fn()
| ^^^^^^^^^^ expected `u8`, found opaque type
|
= note: expected type `u8`
found opaque type `impl Future<Output = u8>`
help: consider `await`ing on the `Future`
|
4 | async_fn().await
| ++++++
error: aborting due to previous error
```
In this case the error is nor perfect, and can confuse the user
that do not know that the opaque type is the future.
So this commit will propose (and conclude the work start in
https://github.com/rust-lang/rust/issues/80658)
to change the string `opaque type` to `future` when applicable
and also remove the Expected vs Received note by adding a more
specific one regarding the async function that return a future type.
So the new error emitted by the compiler is
```
error[E0308]: mismatched types
--> test.rs:4:5
|
1 | fn foo() -> u8 {
| -- expected `u8` because of return type
...
4 | async_fn()
| ^^^^^^^^^^ expected `u8`, found future
|
note: calling an async function returns a future
--> test.rs:4:5
|
4 | async_fn()
| ^^^^^^^^^^
help: consider `await`ing on the `Future`
|
4 | async_fn().await
| ++++++
error: aborting due to previous error
```
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
layout: deal with placeholders, ICE on bound types
A placeholder type is the same as a param as they represent "this could be any type". A bound type represents a type inside of a `for<T>` or `exists<T>`. When entering a forall or exists `T` should be instantiated as a existential (inference var) or universal (placeholder). You should never observe a bound variable without its binder.
rustc_ast: Merge impls and reorder methods for attributes and meta items
Merge `impl` blocks for the same types, change order of methods to be more predictable and consistent between impls.
No functional changes.
Follow up to https://github.com/rust-lang/rust/pull/107569.
Introduce `-Zterminal-urls` to use OSC8 for error codes
Terminals supporting the OSC8 Hyperlink Extension can support inline anchors where the text is user defineable but clicking on it opens a browser to a specified URLs, just like `<a href="URL">` does in HTML.
https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
a placeholder type is the same as a param as they
represent "this could be any type". A bound type
represents a type inside of a `for<T>` or `exists<T>`.
When entering a forall or exists `T` should be
instantiated as a existential (inference var) or universal
(placeholder). You should never observe a bound variable
without its binder.
Create a single value cache for the () query key
Since queries using `()` as the key can only store a single value, specialize for that case.
This looks like a minor performance improvement:
<table><tr><td rowspan="2">Benchmark</td><td colspan="1"><b>Before</b></th><td colspan="2"><b>After</b></th></tr><tr><td align="right">Time</td><td align="right">Time</td><td align="right">%</th></tr><tr><td>🟣 <b>clap</b>:check</td><td align="right">1.8477s</td><td align="right">1.8415s</td><td align="right"> -0.33%</td></tr><tr><td>🟣 <b>hyper</b>:check</td><td align="right">0.2666s</td><td align="right">0.2655s</td><td align="right"> -0.40%</td></tr><tr><td>🟣 <b>syntex_syntax</b>:check</td><td align="right">6.3943s</td><td align="right">6.3686s</td><td align="right"> -0.40%</td></tr><tr><td>🟣 <b>syn</b>:check</td><td align="right">1.6413s</td><td align="right">1.6345s</td><td align="right"> -0.42%</td></tr><tr><td>🟣 <b>regex</b>:check</td><td align="right">1.0337s</td><td align="right">1.0313s</td><td align="right"> -0.24%</td></tr><tr><td>Total</td><td align="right">11.1836s</td><td align="right">11.1414s</td><td align="right"> -0.38%</td></tr><tr><td>Summary</td><td align="right">1.0000s</td><td align="right">0.9964s</td><td align="right"> -0.36%</td></tr></table>
Use associated items of `char` instead of freestanding items in `core::char`
The associated functions and constants on `char` have been stable since 1.52 and the freestanding items have soft-deprecated since 1.62 (https://github.com/rust-lang/rust/pull/95566). This PR ~~marks them as "deprecated in future", similar to the integer and floating point modules (`core::{i32, f32}` etc)~~ replaces all uses of `core::char::*` with `char::*` to prepare for future deprecation of `core::char::*`.
