Emit warnings on unused parens in index expressions
Fixes: #96606.
I am not sure what the best term for "index expression" is. Is there a better term we could use?
Autotrait bounds on dyn-safe trait methods
This PR is a successor to #106604 implementing the approach encouraged by https://github.com/rust-lang/rust/pull/106604#issuecomment-1387353737.
**I propose making it legal to use autotraits as trait bounds on the `Self` type of trait methods in a trait object.** https://github.com/rust-lang/rust/issues/51443#issuecomment-1374847313 justifies why this use case is particularly important in the context of the async-trait crate.
```rust
#![feature(auto_traits)]
#![deny(where_clauses_object_safety)]
auto trait AutoTrait {}
trait MyTrait {
fn f(&self) where Self: AutoTrait;
}
fn main() {
let _: &dyn MyTrait;
}
```
Previously this would fail with:
```console
error: the trait `MyTrait` cannot be made into an object
--> src/main.rs:7:8
|
7 | fn f(&self) where Self: AutoTrait;
| ^
|
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #51443 <https://github.com/rust-lang/rust/issues/51443>
note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
--> src/main.rs:7:8
|
6 | trait MyTrait {
| ------- this trait cannot be made into an object...
7 | fn f(&self) where Self: AutoTrait;
| ^ ...because method `f` references the `Self` type in its `where` clause
= help: consider moving `f` to another trait
```
In order for this to be sound without hitting #50781, **I further propose that we disallow handwritten autotrait impls that apply to trait objects.** Both of the following were previously allowed (_on nightly_) and no longer allowed in my proposal:
```rust
auto trait AutoTrait {}
trait MyTrait {}
impl AutoTrait for dyn MyTrait {} // NOT ALLOWED
impl<T: ?Sized> AutoTrait for T {} // NOT ALLOWED
```
(`impl<T> AutoTrait for T {}` remains allowed.)
After this change, traits with a default impl are implemented for a trait object **if and only if** the autotrait is one of the trait object's trait bounds (or a supertrait of a bound). In other words `dyn Trait + AutoTrait` always implements AutoTrait while `dyn Trait` never implements AutoTrait.
Fixes https://github.com/dtolnay/async-trait/issues/228.
r? `@lcnr`
Don't generate unecessary `&&self.field` in deriving Debug
Since unsized fields may only be the last one in a struct, we only need to generate a double reference (`&&self.field`) for the final one.
cc `@nnethercote`
ast: Optimize list and value extraction primitives for attributes
It's not necessary to convert the whole attribute into a meta item to extract something specific.
Rollup of 6 pull requests
Successful merges:
- #106575 (Suggest `move` in nested closure when appropriate)
- #106805 (Suggest `{var:?}` when finding `{?:var}` in inline format strings)
- #107500 (Add tests to assert current behavior of large future sizes)
- #107598 (Fix benchmarks in library/core with black_box)
- #107602 (Parse and recover from type ascription in patterns)
- #107608 (Use triple rather than arch for fuchsia test-runner)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Use triple rather than arch for fuchsia test-runner
This allows the user of the test-runner script to specify a full triple rather than just an architecture which helps with the transition from the two component to three component target triples for fuchsia.
Suggest `{var:?}` when finding `{?:var}` in inline format strings
Link to issue: https://github.com/rust-lang/rust/issues/106572
This is my first PR to this project, so hopefully I can get some good pointers with me from the first PR.
Currently my idea was to test out whether or not this is the correct solution to this issue and then hopefully expand upon the idea to not only work for Debug formatting but for all of them. If this is a valid solution, I will create a new issue to give a better error message to a broader range of wrong-order formatting.
Enable Cargo's sparse protocol in CI
This enables the sparse protocol in CI in order to exercise and dogfood it. This is intended test the production server in a real-world situation.
Closes#107342
Add `rust.lto=off` to bootstrap and set as compiler/library default
Closes#107202
The issue mentions `embed-bitcode=on`, but here c8e6a9e8b6/src/bootstrap/compile.rs (L379-L381)
it appears that this is always set for std stage 1+, so I'm unsure if changes are needed here.
`@rustbot` label +A-bootstrap
The motivation here is to eliminate the `Option<(Delimiter,
DelimSpan)>`, which is `None` for the outermost token stream and `Some`
for all other token streams.
We are already treating the innermost frame specially -- this is the
`frame` vs `stack` distinction in `TokenCursor`. We can push that
further so that `frame` only contains the cursor, and `stack` elements
contain the delimiters for their children. When we are in the outermost
token stream `stack` is empty, so there are no stored delimiters, which
is what we want because the outermost token stream *has* no delimiters.
This change also shrinks `TokenCursor`, which shrinks `Parser` and
`LazyAttrTokenStreamImpl`, which is nice.
Sometimes the parser needs to desugar a doc comment into `#[doc =
r"foo"]`. Currently it does this in a hacky way: by pushing a "fake" new
frame (one without a delimiter) onto the `TokenCursor` stack.
This commit changes things so that the token stream itself is modified
in place. The nice thing about this is that it means
`TokenCursorFrame::delim_sp` is now only `None` for the outermost frame.
Rollup of 7 pull requests
Successful merges:
- #106919 (Recover `_` as `..` in field pattern)
- #107493 (Improve diagnostic for missing space in range pattern)
- #107515 (Improve pretty-printing of `HirIdValidator` errors)
- #107524 (Remove both StorageLive and StorageDead in CopyProp.)
- #107532 (Erase regions before doing uninhabited check in borrowck)
- #107559 (Rename `rust_2015` → `is_rust_2015`)
- #107577 (Reinstate the `hir-stats.rs` tests on stage 1.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Erase regions before doing uninhabited check in borrowck
~Also, fingerprint query keys/values when debug assertions are enabled. This should make it easier to check for issues like this without `-Cincremental`, and make UI tests a bit cleaner.~ edit: moving that to a separate PR
Fixes#107505
Remove both StorageLive and StorageDead in CopyProp.
Fixes https://github.com/rust-lang/rust/issues/107511https://github.com/rust-lang/rust/pull/106908 removed StorageDead without the accompanying StorageLive. In loops, execution would see repeated StorageLive, without any StorageDead, which is UB.
So when removing storage statements, we have to remove both StorageLive and StorageDead.
~I also added a MIR validation pass for StorageLive. It may be a bit overzealous.~
