Rollup of 5 pull requests #107636
Closed
Rollup of 5 pull requests #107636
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
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.
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.
This makes it clear they return token trees, and makes for a nice comparison against `TokenCursor` which returns tokens.
Autotrait bounds on dyn-safe trait methods This PR is a successor to rust-lang#106604 implementing the approach encouraged by rust-lang#106604 (comment). **I propose making it legal to use autotraits as trait bounds on the `Self` type of trait methods in a trait object.** rust-lang#51443 (comment) 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 rust-lang#51443 <rust-lang#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 rust-lang#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 dtolnay/async-trait#228. r? `@lcnr`
…=compiler-errors Add candidates for DiscriminantKind builtin Part of rust-lang#107379
…dex, r=lcnr Emit warnings on unused parens in index expressions Fixes: rust-lang#96606. I am not sure what the best term for "index expression" is. Is there a better term we could use?
…=petrochenkov Improve `TokenCursor`. Some small improvements, for things that were bugging me. Best reviewed one commit at a time. r? `@petrochenkov`
…, r=Nilstrieb Fix suggestion for coercing Option<&String> to Option<&str> Fixes rust-lang#107604 This also makes the diagnostic `MachineApplicable`, and runs `rustfix` to check we're not producing incorrect code. `@rustbot` label +A-diagnostics
rustbot
added
A-translation
bors
added
S-waiting-on-author
|
@bors r+ rollup=never p=5 |
|
oops... |
|
The job Click to see the possible cause of the failure (guessed by this bot) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Successful merges:
TokenCursor. #107544 (ImproveTokenCursor.)Failed merges:
r? @ghost
@rustbot modify labels: rollup
Create a similar rollup