forbid `dyn Trait` in patterns
Do not allow `&dyn Trait` as a generic const parameters.
This also changes dyn trait in pattern from ICE to error.
closes#63322closes#70972
r? @eddyb
On type mismatch involving associated type, suggest constraint
When an associated type is found when a specific type was expected, if
possible provide a structured suggestion constraining the associated
type in a bound.
```
error[E0271]: type mismatch resolving `<T as Foo>::Y == i32`
--> $DIR/associated-types-multiple-types-one-trait.rs:13:5
|
LL | want_y(t);
| ^^^^^^ expected `i32`, found associated type
...
LL | fn want_y<T:Foo<Y=i32>>(t: &T) { }
| ----- required by this bound in `want_y`
|
= note: expected type `i32`
found associated type `<T as Foo>::Y`
help: consider constraining the associated type `<T as Foo>::Y` to `i32`
|
LL | fn have_x_want_y<T:Foo<X=u32, Y = i32>>(t: &T)
| ^^^^^^^^^
```
```
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction.rs:12:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<impl Trait as Trait>::A`
help: consider constraining the associated type `<impl Trait as Trait>::A` to `usize`
|
LL | fn foo(x: impl Trait<A = usize>) {
| ^^^^^^^^^^
```
Fix#71035. Related to #70908.
Implement RFC 2523, `#[cfg(version(..))]`
Hi! This is my first contribution to rust, I hope I didn't miss anything. I tried to implement this feature so that `#[cfg(version(1.44.0))]` works but the parser was printing an error that I wasn't sure how to fix so I just opted for implementing `#[cfg(version("1.44.0"))]` (note the quotes).
Tracking issue: #64796
Associated types with a default type in a trait can't be relied upon to
remain of that default type when in use, so literals of that type can't
be used in the trait's items. Point at the associated type and state
that information.
Reduce verbosity for associated consts of the wrong type.
Rollup of 6 pull requests
Successful merges:
- #71712 (Miri: port error backtraces to std::backtrace)
- #71736 (bootstrap: also apply unused-attributes hack without deny_warnings)
- #71738 (remove AllocId generalization of Pointer)
- #71739 (remove obsolete comment)
- #71781 (Uncomment test code for failure to use `Box::pin`)
- #71782 (Use a non-existent test path instead of clobbering /dev/null)
Failed merges:
r? @ghost
wf: handle "livelock" checking before reaching `WfPredicates::compute`.
For `wf::obligations`'s "livelock" handling, this PR shouldn't cause any behavioral changes, as the check moved to it should be equivalent to the old one in `WfPredicates::compute`.
However, it fixes#70168 by making *other* users of `WfPredicates::compute` (that is, `wf::predicate_obligations` and `compute`'s own upvar handling) correct for `ty::Infer`, in that they now get a `WellFormed(ty::Infer(_))` obligation instead of silently ignoring the type.
r? @nikomatsakis
Have the per-query caches store the results on arenas
This PR leverages the cache for each query to serve as storage area for the query results.
It introduces a new cache `ArenaCache`, which moves the result to an arena,
and only stores the reference in the hash map.
This allows to remove a sizeable part of the usage of the global `TyCtxt` arena.
I only migrated queries that already used arenas before.
Move `{Free,}RegionRelations` and `FreeRegionMap` to `rustc_infer`
...and out of `rustc_middle`. This is to further #65031, albeit in a very minor way
r? @Mark-Simulacrum
Detect mistyped associated consts in `Instance::resolve`.
*Based on #71049 to prevent redundant/misleading downstream errors.*
Fixes#70942 by refusing to resolve an associated `const` if it doesn't have the same type in the `impl` that it does in the `trait` (which we assume had errored, and `delay_span_bug` guards against bugs).
Suggest `-> impl Trait` and `-> Box<dyn Trait>` on fn that doesn't return
During development, a function could have a return type set that is a
bare trait object by accident. We already suggest using either a boxed
trait object or `impl Trait` if the return paths will allow it. We now
do so too when there are *no* return paths or they all resolve to `!`.
We still don't handle cases where the trait object is *not* the entirety
of the return type gracefully.
Closes#38376.
Check that main/start is not async
* Add new error code E0752
* Add span to hir::IsAsync::Yes
* Emit an error if main or the start function is marked as async
* Add two regression tests
This PR fixes#68523.
When the return type is `!Sized` we look for all the returned
expressions in the body to fetch their types and provide a reasonable
suggestion. The tail expression of the body is normally evaluated after
checking whether the return type is `Sized`. Changing the order of the
evaluation produces undesirable knock down effects, so we detect the
specific case that newcomers are likely to encounter ,returning a single
bare trait object, and only in that case we evaluate the tail
expression's type so that the suggestion will be accurate.
During development, a function could have a return type set that is a
bare trait object by accident. We already suggest using either a boxed
trait object or `impl Trait` if the return paths will allow it. We now
do so too when there are *no* return paths or they all resolve to `!`.
We still don't handle cases where the trait object is *not* the entirety
of the return type gracefully.
* Add new error code E0752
* Add span to hir::IsAsync::Yes
* Emit an error if main or the start function is marked as async
* Add two regression tests
Fix formatting errors and bless test outputs
* move tests to ui/async-await
fix test error text
remove span from IsAsync
Maintain chain of derived obligations
When evaluating the derived obligations from super traits, maintain a
reference to the original obligation in order to give more actionable
context in the output.
Continuation (and built on) #69745, subset of #69709.
r? @eddyb
When evaluating the derived obligations from super traits, maintain a
reference to the original obligation in order to give more actionable
context in the output.
Markus Westerlind