Mark`feature(return_position_impl_trait_in_trait)` and`feature(async_fn_in_trait)` as not incomplete
I think they've graduated, since as far as I'm aware, they don't cause compiler crashes or unsoundness anymore.
Fix elaboration with associated type bounds
When computing a trait's supertrait predicates, do not add any associated type *trait* bounds to that list of supertrait predicates. This is because supertrait predicates are expected to have the same `Self` type as the trait.
For example, given:
```rust
trait Foo: Bar<Assoc: Send>
```
Before, we would compute that the supertrait predicates of `T: Foo` are `T: Bar` and `<T as Bar>::Assoc: Send`. However, the last bound is a trait predicate for a totally different type than `T`, and existing code that uses supertrait bounds such as vtable construction, closure fn signature deduction, etc. all rely on the invariant that we have a list of predicates for self type `T`.
Fixes#76593
The reason for all the extra diagnostic noise is that we're recomputing predicates with a different filter now. These diagnostics should be deduplicated for any end-user though.
---
This does bring up an interesting question -- is the predicate `<T as Bar>::Assoc: Send` an implied bound of `T: Foo`? Because currently the only bounds implied by a (non-alias) trait are its supertraits. I guess I could fix this too, but it would require even more changes, and I'm inclined to punt this question along.
Stabilize debugger_visualizer
This stabilizes the `debugger_visualizer` attribute (#95939).
* Marks the `debugger_visualizer` feature as `accepted`.
* Marks the `debugger_visualizer` attribute as `ungated`.
* Deletes feature gate test, removes feature gate from other tests.
Closes#95939
Add `ConstParamTy` trait
This is a bit sketch, but idk.
r? `@BoxyUwU`
Yet to be done:
- [x] ~~Figure out if it's okay to implement `StructuralEq` for primitives / possibly remove their special casing~~ (it should be okay, but maybe not in this PR...)
- [ ] Maybe refactor the code a little bit
- [x] Use a macro to make impls a bit nicer
Future work:
- [ ] Actually™ use the trait when checking if a `const` generic type is allowed
- [ ] _Really_ refactor the surrounding code
- [ ] Refactor `marker.rs` into multiple modules for each "theme" of markers
Leave promoteds untainted by errors when borrowck fails
Previously, when borrowck failed it would taint all promoteds within the MIR body. An attempt to evaluated the promoteds would subsequently fail with spurious "note: erroneous constant used". For example:
```console
...
note: erroneous constant used
--> tests/ui/borrowck/tainted-promoteds.rs:7:9
|
7 | a = &0 * &1 * &2 * &3;
| ^^
note: erroneous constant used
--> tests/ui/borrowck/tainted-promoteds.rs:7:14
|
7 | a = &0 * &1 * &2 * &3;
| ^^
note: erroneous constant used
--> tests/ui/borrowck/tainted-promoteds.rs:7:19
|
7 | a = &0 * &1 * &2 * &3;
| ^^
note: erroneous constant used
--> tests/ui/borrowck/tainted-promoteds.rs:7:24
|
7 | a = &0 * &1 * &2 * &3;
| ^^
```
Borrowck failure doesn't indicate that there is anything wrong with promoteds. Leave them untainted.
Fixes#110856.
My type ascription
Oh rip it out
Ah
If you think we live too much then
You can sacrifice diagnostics
Don't mix your garbage
Into my syntax
So many weird hacks keep diagnostics alive
Yet I don't even step outside
So many bad diagnostics keep tyasc alive
Yet tyasc doesn't even bother to survive!
Test precise capture with a multi-variant enum and exhaustive patterns
Add test checking that it is possible to capture fields of a multi-variant enum, when remaining variants are visibly uninhabited (under the `exhaustive_patterns` feature gate).
Remove wrong assertion in match checking.
This assertions is completely misguided, introduced by https://github.com/rust-lang/rust/pull/108504. The responsible PR is on beta, nominating for backport.
Instead of checking that this is not a `&&`, it would make sense to check that neither arms of that `&&` is a `let`. This seems like a lot of code for unclear benefit.
r? `@saethlin`
Tweak await span to not contain dot
Fixes a discrepancy between method calls and await expressions where the latter are desugared to have a span that *contains* the dot (i.e. `.await`) but method call identifiers don't contain the dot. This leads to weird suggestions suggestions in borrowck -- see linked issue.
Fixes#110761
This mostly touches a bunch of tests to tighten their `await` span.
Previously, when borrowck failed it would taint all promoteds within the MIR
body. An attempt to evaluated the promoteds would subsequently fail with
spurious "note: erroneous constant used". For example:
```console
...
note: erroneous constant used
--> tests/ui/borrowck/tainted-promoteds.rs:7:9
|
7 | a = &0 * &1 * &2 * &3;
| ^^
note: erroneous constant used
--> tests/ui/borrowck/tainted-promoteds.rs:7:14
|
7 | a = &0 * &1 * &2 * &3;
| ^^
note: erroneous constant used
--> tests/ui/borrowck/tainted-promoteds.rs:7:19
|
7 | a = &0 * &1 * &2 * &3;
| ^^
note: erroneous constant used
--> tests/ui/borrowck/tainted-promoteds.rs:7:24
|
7 | a = &0 * &1 * &2 * &3;
| ^^
```
Borrowck failure doesn't indicate that there is anything wrong with
promoteds. Leave them untainted.
Add test checking that it is possible to capture fields of a
multi-variant enum, when remaining variants are visibly uninhabited
(under the `exhaustive_patterns` feature gate).
Fix Unreadable non-UTF-8 output on localized MSVC
Fixes#35785 by converting non UTF-8 linker output to Unicode using the OEM code page.
Before:
```text
= note: Non-UTF-8 output: LINK : fatal error LNK1181: cannot open input file \'m\x84rchenhaft.obj\'\r\n
```
After:
```text
= note: LINK : fatal error LNK1181: cannot open input file 'märchenhaft.obj'
```
The difference is more dramatic if using a non-ascii language pack for Windows.
Update tests for libtest `--format json`
This PR makes the test work on beta and stable, and adds a test ensuring the option is not available on beta and stable. Backported these commits from https://github.com/rust-lang/rust/pull/110414.
Improve niche placement by trying two strategies and picking the better result
Fixes#104807Fixes#105371
Determining which sort order is better requires calculating the struct size (so we can calculate the niche offset). But that in turn depends on the field order, so happens after sorting. So the simple way to solve that is to run the whole thing twice and pick the better result.
1st commit is just code motion, the meat is in the later ones.
Don't duplicate anonymous lifetimes for async fn in traits
`record_lifetime_params_for_async` needs to be called outside of the scope of the function, or else it'll end up collecting anonymous lifetimes twice (those on the function and those within the `AnonymousCreateParameter` rib). This matches how `record_lifetime_params_for_async` is being used for functions with bodies below.
This fixes (partially) #110963 when the lifetimes are late-bound, but does not do so when the lifetimes are early-bound (as seen from the known-bug that I added).
Clear response values for overflow in new solver
When we have an overflow, return a trivial query response. This fixes an ICE with the code described in #110544:
```rust
trait Trait {}
struct W<T>(T);
impl<T, U> Trait for W<(W<T>, W<U>)>
where
W<T>: Trait,
W<U>: Trait,
{}
fn impls<T: Trait>() {}
fn main() {
impls::<W<_>>()
}
```
Where, while proving `W<?0>: Trait`, we overflow but still apply the query response of `?0 = (W<?1>, W<?2>)`. Then while re-processing the query to validate that our evaluation result was stable, we get a different query response that looks like `?1 = (W<?3>, W<?4>), ?2 = (W<?5>, W<?6>)`, and so we trigger the ICE.
Also, by returning a trivial query response we also avoid the infinite-loop/OOM behavior of the old solver.
r? ``@lcnr``
For start-biased layout we want to avoid overpromoting so that
the niche doesn't get pushed back.
For end-biased layout we want to avoid promoting fields that
may contain one of the niches of interest.
fix false negative for `unused_mut`
fixes https://github.com/rust-lang/rust/issues/110849
We want to avoid double diagnostics for code like this, but only if an error actually occurs:
```rust
fn main() {
let mut x: (i32, i32);
x.0 = 1;
}
```
The first commit fixes the lint and the second one removes all the unused `mut`s it found.
Provide better type hints when a type doesn't support a binary operator
For example, when checking whether `vec![A] == vec![A]` holds, we first evaluate the LHS's ty, then probe for any `PartialEq` implementations for that. If none is found, we report an error by evaluating `Vec<A>: PartialEq<?0>` for fulfillment errors, but the RHS is not yet evaluated and remains an inference variable `?0`!
To fix this, we evaluate the RHS and equate it to that RHS infer var `?0`, so that we are able to provide more detailed fulfillment errors for why `Vec<A>: PartialEq<Vec<A>>` doesn't hold (namely, the nested obligation `A: PartialEq<A>` doesn't hold).
Fixes#95285Fixes#110867
Use MIR's `Offset` for pointer `add` too
~~Status: draft while waiting for #110822 to land, since this is built atop that.~~
~~r? `@ghost~~`
Canonical Rust code has mostly moved to `add`/`sub` on pointers, which take `usize`, instead of `offset` which takes `isize`. (And, relatedly, when `sub_ptr` was added it turned out it replaced every single in-tree use of `offset_from`, because `usize` is just so much more useful than `isize` in Rust.)
Unfortunately, `intrinsics::offset` could only accept `*const` and `isize`, so there's a *huge* amount of type conversions back and forth being done. They're identity conversions in the backend, but still end up producing quite a lot of unhelpful MIR.
This PR changes `intrinsics::offset` to accept `*const` *and* `*mut` along with `isize` *and* `usize`. Conveniently, the backends and CTFE already handle this, since MIR's `BinOp::Offset` [already supports all four combinations](adaac6b166/compiler/rustc_const_eval/src/transform/validate.rs (L523-L528)).
To demonstrate the difference, I added some `mir-opt/pre-codegen/` tests around slice indexing. Here's the difference to `[T]::get_mut`, since it uses `<*mut _>::add` internally:
```diff
`@@` -79,30 +70,21 `@@` fn slice_get_mut_usize(_1: &mut [u32], _2: usize) -> Option<&mut u32> {
StorageLive(_12); // scope 3 at $SRC_DIR/core/src/slice/index.rs:LL:COL
StorageLive(_9); // scope 6 at $SRC_DIR/core/src/slice/index.rs:LL:COL
_9 = _8 as *mut u32 (PtrToPtr); // scope 11 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageLive(_13); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _13 = _2 as isize (IntToInt); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageLive(_14); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageLive(_15); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _15 = _9 as *const u32 (Pointer(MutToConstPointer)); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _14 = Offset(move _15, _13); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageDead(_15); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _7 = move _14 as *mut u32 (PtrToPtr); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageDead(_14); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageDead(_13); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
+ _7 = Offset(_9, _2); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
StorageDead(_9); // scope 6 at $SRC_DIR/core/src/slice/index.rs:LL:COL
StorageDead(_12); // scope 3 at $SRC_DIR/core/src/slice/index.rs:LL:COL
StorageDead(_11); // scope 3 at $SRC_DIR/core/src/slice/index.rs:LL:COL
```
1c1c8e442a (diff-a841b6a4538657add3f39bc895744331453d0625e7aace128b1f604f0b63c8fdR80)
