Initial support for return type notation (RTN)
See: https://smallcultfollowing.com/babysteps/blog/2023/02/13/return-type-notation-send-bounds-part-2/
1. Only supports `T: Trait<method(): Send>` style bounds, not `<T as Trait>::method(): Send`. Checking validity and injecting an implicit binder for all of the late-bound method generics is harder to do for the latter.
* I'd add this in a follow-up.
3. ~Doesn't support RTN in general type position, i.e. no `let x: <T as Trait>::method() = ...`~
* I don't think we actually want this.
5. Doesn't add syntax for "eliding" the function args -- i.e. for now, we write `method(): Send` instead of `method(..): Send`.
* May be a hazard if we try to add it in the future. I'll probably add it in a follow-up later, with a structured suggestion to change `method()` to `method(..)` once we add it.
7. ~I'm not in love with the feature gate name 😺~
* I renamed it to `return_type_notation` ✔️
Follow-up PRs will probably add support for `where T::method(): Send` bounds. I'm not sure if we ever want to support return-type-notation in arbitrary type positions. I may also make the bounds require `..` in the args list later.
r? `@ghost`
Remove the `NodeId` of `ast::ExprKind::Async`
This is a followup to https://github.com/rust-lang/rust/pull/104833#pullrequestreview-1314537416.
In my original attempt, I was using `LoweringContext::expr`, which was not correct as it creates a fresh `DefId`.
It now uses the correct `DefId` for the wrapping `Expr`, and also makes forwarding `#[track_caller]` attributes more explicit.
Remove box expressions from HIR
After #108516, `#[rustc_box]` is used at HIR->THIR lowering and this is no longer emitted, so it can be removed.
This is based on top of #108471 to help with conflicts, so 43490488ccacd1a822e9c621f5ed6fca99959a0b is the only relevant commit (sorry for all the duplicated pings!)
````@rustbot```` label +S-blocked
After removing the `map_in_place` method, which isn't much use because
modifying every element in a collection such as a `Vec` can be done
trivially with iteration.
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.
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.
Revert "review comment: Remove AST AnonTy"
This reverts commit 020cca8d36.
Revert "Ensure macros are not affected"
This reverts commit 12d18e4031.
Revert "Emit fewer errors on patterns with possible type ascription"
This reverts commit c847a01a3b.
Revert "Teach parser to understand fake anonymous enum syntax"
This reverts commit 2d82420665.
Move format_args!() into AST (and expand it during AST lowering)
Implements https://github.com/rust-lang/compiler-team/issues/541
This moves FormatArgs from rustc_builtin_macros to rustc_ast_lowering. For now, the end result is the same. But this allows for future changes to do smarter things with format_args!(). It also allows Clippy to directly access the ast::FormatArgs, making things a lot easier.
This change turns the format args types into lang items. The builtin macro used to refer to them by their path. After this change, the path is no longer relevant, making it easier to make changes in `core`.
This updates clippy to use the new language items, but this doesn't yet make clippy use the ast::FormatArgs structure that's now available. That should be done after this is merged.
Teach parser to understand fake anonymous enum syntax
Parse `Ty | OtherTy` in function argument and return types.
Parse type ascription in top level patterns.
Minimally address #100741.
