| Age | Commit message (Collapse) | Author | Lines |
|---|
|
Add support for `for await` loops
This adds support for `for await` loops. This includes parsing, desugaring in AST->HIR lowering, and adding some support functions to the library.
Given a loop like:
```rust
for await i in iter {
...
}
```
this is desugared to something like:
```rust
let mut iter = iter.into_async_iter();
while let Some(i) = loop {
match core::pin::Pin::new(&mut iter).poll_next(cx) {
Poll::Ready(i) => break i,
Poll::Pending => yield,
}
} {
...
}
```
This PR also adds a basic `IntoAsyncIterator` trait. This is partly for symmetry with the way `Iterator` and `IntoIterator` work. The other reason is that for async iterators it's helpful to have a place apart from the data structure being iterated over to store state. `IntoAsyncIterator` gives us a good place to do this.
I've gated this feature behind `async_for_loop` and opened #118898 as the feature tracking issue.
r? `@compiler-errors`
|
|
|
|
|
|
|
|
|
|
Support bare unit structs in destructuring assignments
We should be allowed to use destructuring assignments on *bare* unit structs, not just unit structs that are located within other pattern constructors.
Fixes #118753
r? petrochenkov since you reviewed #95380, reassign if you're busy or don't want to review this.
|
|
|
|
detects redundant imports that can be eliminated.
for #117772 :
In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.
|
|
|
|
|
|
Introduce support for `async gen` blocks
I'm delighted to demonstrate that `async gen` block are not very difficult to support. They're simply coroutines that yield `Poll<Option<T>>` and return `()`.
**This PR is WIP and in draft mode for now** -- I'm mostly putting it up to show folks that it's possible. This PR needs a lang-team experiment associated with it or possible an RFC, since I don't think it falls under the jurisdiction of the `gen` RFC that was recently authored by oli (https://github.com/rust-lang/rfcs/pull/3513, https://github.com/rust-lang/rust/issues/117078).
### Technical note on the pre-generator-transform yield type:
The reason that the underlying coroutines yield `Poll<Option<T>>` and not `Poll<T>` (which would make more sense, IMO, for the pre-transformed coroutine), is because the `TransformVisitor` that is used to turn coroutines into built-in state machine functions would have to destructure and reconstruct the latter into the former, which requires at least inserting a new basic block (for a `switchInt` terminator, to match on the `Poll` discriminant).
This does mean that the desugaring (at the `rustc_ast_lowering` level) of `async gen` blocks is a bit more involved. However, since we already need to intercept both `.await` and `yield` operators, I don't consider it much of a technical burden.
r? `@ghost`
|
|
|
|
|
|
|
|
never_patterns: Parse match arms with no body
Never patterns are meant to signal unreachable cases, and thus don't take bodies:
```rust
let ptr: *const Option<!> = ...;
match *ptr {
None => { foo(); }
Some(!),
}
```
This PR makes rustc accept the above, and enforces that an arm has a body xor is a never pattern. This affects parsing of match arms even with the feature off, so this is delicate. (Plus this is my first non-trivial change to the parser).
~~The last commit is optional; it introduces a bit of churn to allow the new suggestions to be machine-applicable. There may be a better solution? I'm not sure.~~ EDIT: I removed that commit
r? `@compiler-errors`
|
|
|
|
|
|
`DefPathData::(ClosureExpr,ImplTrait)` are renamed to match `DefKind::(Closure,OpaqueTy)`.
`DefPathData::ImplTraitAssocTy` is replaced with `DefPathData::TypeNS(kw::Empty)` because both correspond to `DefKind::AssocTy`.
It's possible that introducing `(DefKind,DefPathData)::AssocOpaqueTy` could be a better solution, but that would be a much more invasive change.
Const generic parameters introduced for effects are moved from `DefPathData::TypeNS` to `DefPathData::ValueNS`, because constants are values.
`DefPathData` is no longer passed to `create_def` functions to avoid redundancy.
|
|
|
|
|
|
Parsing now accepts a match arm without a body, so we must make sure to
only accept that if the pattern is a never pattern.
|
|
|
|
Because the corresponding `Level` is `DelayedBug` and `span_delayed_bug`
follows the pattern used everywhere else: `span_err`, `span_warning`,
etc.
|
|
Rollup of 7 pull requests
Successful merges:
- #116839 (Implement thread parking for xous)
- #118265 (remove the memcpy-on-equal-ptrs assumption)
- #118269 (Unify `TraitRefs` and `PolyTraitRefs` in `ValuePairs`)
- #118394 (Remove HIR opkinds)
- #118398 (Add proper cfgs in std)
- #118419 (Eagerly return `ExprKind::Err` on `yield`/`await` in wrong coroutine context)
- #118422 (Fix coroutine validation for mixed panic strategy)
r? `@ghost`
`@rustbot` modify labels: rollup
|
|
`rustc_ast_lowering` cleanups
Just some cleanups I found while looking through this code.
r? `@spastorino`
|
|
Eagerly return `ExprKind::Err` on `yield`/`await` in wrong coroutine context
This PR does 2 things:
1. Refuses to lower `.await` or `yield` when we are outside of the right coroutine context for the operator. Instead, we lower to `hir::ExprKind::Err`, to silence subsequent redundant errors.
2. Reworks a bit of the span tracking in `LoweringContext` to fix a bad span when we have something like `let x = [0; async_fn().await]` where the `await` is inside of an anon const. The span for the "item" still kinda sucks, since it overlaps with the `await` span, but at least it's accurate.
|
|
Remove HIR opkinds
`hir::BinOp`, `hir::BinOpKind`, and `hir::UnOp` are identical to `ast::BinOp`, `ast::BinOpKind`, and `ast::UnOp`, respectively. This seems silly, so this PR removes the HIR ones. (A re-export lets the AST ones be referred to using a `hir::` qualifier, which avoids renaming churn.)
r? `@cjgillot`
|
|
|
|
|
|
|
|
`LoweringContext::allow_{try_trait,gen_future}`.
Also remove some unnecessary slicing.
|
|
They're identical to the same-named types from `ast`. I find it silly
(and inefficient) to have all this boilerplate code to convert one type
to an identical type.
There is already a small amount of type sharing between the AST and HIR,
e.g. `Attribute`, `MacroDef`.
The commit adds a `pub use` to `rustc_hir` so that, for example,
`ast::BinOp` can also be referred to as `hir::BinOp`. This is so the
many existing `hir`-qualified mentions of these types don't need to
change.
The commit also moves a couple of operations from the (removed) HIR
types to the AST types, e.g. `is_by_value`.
|
|
|
|
`x clippy compiler -Aclippy::all -Wclippy::needless_borrow --fix`.
Then I had to remove a few unnecessary parens and muts that were exposed
now.
|
|
Use `copied` instead of manual `map`
|
|
|
|
|
|
Most notably, this commit changes the `pub use crate::*;` in that file
to `use crate::*;`. This requires a lot of `use` items in other crates
to be adjusted, because everything defined within `rustc_span::*` was
also available via `rustc_span::source_map::*`, which is bizarre.
The commit also removes `SourceMap::span_to_relative_line_string`, which
is unused.
|
|
|
|
|
|
|
|
|
|
|
|
similar to how we have `MatchSource`, it explains where the desugaring came from.
|
|
|
|
|
|
|
|
|
|
There was an incomplete version of the check in parsing and a second
version in AST validation. This meant that some, but not all, invalid
uses were allowed inside macros/disabled cfgs. It also means that later
passes have a hard time knowing when the let expression is in a valid
location, sometimes causing ICEs.
- Add a field to ExprKind::Let in AST/HIR to mark whether it's in a
valid location.
- Suppress later errors and MIR construction for invalid let
expressions.
|
|
|
