From 1d78ce681e4bf0c0259fc97e422298d68635dc4f Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Tue, 12 Dec 2023 20:08:34 +0000
Subject: [PATCH] Actually parse async gen blocks correctly
---
compiler/rustc_parse/src/parser/expr.rs | 27 ++++++++++------
tests/ui/coroutine/async-gen-deduce-yield.rs | 14 ++++++++
.../feature-gate-gen_blocks.e2024.stderr | 32 ++++++++++++++++---
.../feature-gate-gen_blocks.none.stderr | 14 +++++++-
.../feature-gates/feature-gate-gen_blocks.rs | 15 ++++++++-
5 files changed, 87 insertions(+), 15 deletions(-)
create mode 100644 tests/ui/coroutine/async-gen-deduce-yield.rs
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 3c0627526be..3606c0fa098 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -1440,21 +1440,23 @@ impl<'a> Parser<'a> {
} else if this.eat_keyword(kw::Underscore) {
Ok(this.mk_expr(this.prev_token.span, ExprKind::Underscore))
} else if this.token.uninterpolated_span().at_least_rust_2018() {
- // `Span:.at_least_rust_2018()` is somewhat expensive; don't get it repeatedly.
- if this.check_keyword(kw::Async) {
+ // `Span::at_least_rust_2018()` is somewhat expensive; don't get it repeatedly.
+ if this.token.uninterpolated_span().at_least_rust_2024()
+ // check for `gen {}` and `gen move {}`
+ // or `async gen {}` and `async gen move {}`
+ && (this.is_gen_block(kw::Gen, 0)
+ || (this.check_keyword(kw::Async) && this.is_gen_block(kw::Gen, 1)))
+ {
+ // FIXME: (async) gen closures aren't yet parsed.
+ this.parse_gen_block()
+ } else if this.check_keyword(kw::Async) {
// FIXME(gen_blocks): Parse `gen async` and suggest swap
if this.is_gen_block(kw::Async, 0) {
// Check for `async {` and `async move {`,
- // or `async gen {` and `async gen move {`.
this.parse_gen_block()
} else {
this.parse_expr_closure()
}
- } else if this.token.uninterpolated_span().at_least_rust_2024()
- && (this.is_gen_block(kw::Gen, 0)
- || (this.check_keyword(kw::Async) && this.is_gen_block(kw::Gen, 1)))
- {
- this.parse_gen_block()
} else if this.eat_keyword_noexpect(kw::Await) {
this.recover_incorrect_await_syntax(lo, this.prev_token.span)
} else {
@@ -3219,9 +3221,16 @@ impl<'a> Parser<'a> {
if self.eat_keyword(kw::Gen) { GenBlockKind::AsyncGen } else { GenBlockKind::Async }
} else {
assert!(self.eat_keyword(kw::Gen));
- self.sess.gated_spans.gate(sym::gen_blocks, lo.to(self.token.span));
GenBlockKind::Gen
};
+ match kind {
+ GenBlockKind::Async => {
+ // `async` blocks are stable
+ }
+ GenBlockKind::Gen | GenBlockKind::AsyncGen => {
+ self.sess.gated_spans.gate(sym::gen_blocks, lo.to(self.prev_token.span));
+ }
+ }
let capture_clause = self.parse_capture_clause()?;
let (attrs, body) = self.parse_inner_attrs_and_block()?;
let kind = ExprKind::Gen(capture_clause, body, kind);
diff --git a/tests/ui/coroutine/async-gen-deduce-yield.rs b/tests/ui/coroutine/async-gen-deduce-yield.rs
new file mode 100644
index 00000000000..9ccc8ee41f6
--- /dev/null
+++ b/tests/ui/coroutine/async-gen-deduce-yield.rs
@@ -0,0 +1,14 @@
+// compile-flags: --edition 2024 -Zunstable-options
+// check-pass
+
+#![feature(async_iterator, gen_blocks)]
+
+use std::async_iter::AsyncIterator;
+
+fn deduce() -> impl AsyncIterator<Item = ()> {
+ async gen {
+ yield Default::default();
+ }
+}
+
+fn main() {}
diff --git a/tests/ui/feature-gates/feature-gate-gen_blocks.e2024.stderr b/tests/ui/feature-gates/feature-gate-gen_blocks.e2024.stderr
index 1462c41e957..c582ca7ba3d 100644
--- a/tests/ui/feature-gates/feature-gate-gen_blocks.e2024.stderr
+++ b/tests/ui/feature-gates/feature-gate-gen_blocks.e2024.stderr
@@ -2,16 +2,34 @@ error[E0658]: gen blocks are experimental
--> $DIR/feature-gate-gen_blocks.rs:5:5
|
LL | gen {};
- | ^^^^^
+ | ^^^
|
= note: see issue #117078 <https://github.com/rust-lang/rust/issues/117078> for more information
= help: add `#![feature(gen_blocks)]` to the crate attributes to enable
error[E0658]: gen blocks are experimental
- --> $DIR/feature-gate-gen_blocks.rs:13:5
+ --> $DIR/feature-gate-gen_blocks.rs:12:5
+ |
+LL | async gen {};
+ | ^^^^^^^^^
+ |
+ = note: see issue #117078 <https://github.com/rust-lang/rust/issues/117078> for more information
+ = help: add `#![feature(gen_blocks)]` to the crate attributes to enable
+
+error[E0658]: gen blocks are experimental
+ --> $DIR/feature-gate-gen_blocks.rs:22:5
|
LL | gen {};
- | ^^^^^
+ | ^^^
+ |
+ = note: see issue #117078 <https://github.com/rust-lang/rust/issues/117078> for more information
+ = help: add `#![feature(gen_blocks)]` to the crate attributes to enable
+
+error[E0658]: gen blocks are experimental
+ --> $DIR/feature-gate-gen_blocks.rs:25:5
+ |
+LL | async gen {};
+ | ^^^^^^^^^
|
= note: see issue #117078 <https://github.com/rust-lang/rust/issues/117078> for more information
= help: add `#![feature(gen_blocks)]` to the crate attributes to enable
@@ -22,7 +40,13 @@ error[E0282]: type annotations needed
LL | gen {};
| ^^ cannot infer type
-error: aborting due to 3 previous errors
+error[E0282]: type annotations needed
+ --> $DIR/feature-gate-gen_blocks.rs:12:15
+ |
+LL | async gen {};
+ | ^^ cannot infer type
+
+error: aborting due to 6 previous errors
Some errors have detailed explanations: E0282, E0658.
For more information about an error, try `rustc --explain E0282`.
diff --git a/tests/ui/feature-gates/feature-gate-gen_blocks.none.stderr b/tests/ui/feature-gates/feature-gate-gen_blocks.none.stderr
index 56f8309a69f..b4b37f0e638 100644
--- a/tests/ui/feature-gates/feature-gate-gen_blocks.none.stderr
+++ b/tests/ui/feature-gates/feature-gate-gen_blocks.none.stderr
@@ -1,9 +1,21 @@
+error: expected one of `!`, `.`, `::`, `;`, `?`, `{`, `}`, or an operator, found `gen`
+ --> $DIR/feature-gate-gen_blocks.rs:12:11
+ |
+LL | async gen {};
+ | ^^^ expected one of 8 possible tokens
+
+error: expected one of `!`, `.`, `::`, `;`, `?`, `{`, `}`, or an operator, found `gen`
+ --> $DIR/feature-gate-gen_blocks.rs:25:11
+ |
+LL | async gen {};
+ | ^^^ expected one of 8 possible tokens
+
error[E0422]: cannot find struct, variant or union type `gen` in this scope
--> $DIR/feature-gate-gen_blocks.rs:5:5
|
LL | gen {};
| ^^^ not found in this scope
-error: aborting due to 1 previous error
+error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0422`.
diff --git a/tests/ui/feature-gates/feature-gate-gen_blocks.rs b/tests/ui/feature-gates/feature-gate-gen_blocks.rs
index e2e1574a36a..ff9a0b139c0 100644
--- a/tests/ui/feature-gates/feature-gate-gen_blocks.rs
+++ b/tests/ui/feature-gates/feature-gate-gen_blocks.rs
@@ -1,15 +1,28 @@
// revisions: e2024 none
//[e2024] compile-flags: --edition 2024 -Zunstable-options
-fn main() {
+fn test_gen() {
gen {};
//[none]~^ ERROR: cannot find struct, variant or union type `gen`
//[e2024]~^^ ERROR: gen blocks are experimental
//[e2024]~| ERROR: type annotations needed
}
+fn test_async_gen() {
+ async gen {};
+ //[none]~^ ERROR expected one of `!`, `.`, `::`, `;`, `?`, `{`, `}`, or an operator, found `gen`
+ //[e2024]~^^ ERROR: gen blocks are experimental
+ //[e2024]~| ERROR: type annotations needed
+}
+
+fn main() {}
+
#[cfg(FALSE)]
fn foo() {
gen {};
//[e2024]~^ ERROR: gen blocks are experimental
+
+ async gen {};
+ //[e2024]~^ ERROR: gen blocks are experimental
+ //[none]~^^ ERROR expected one of `!`, `.`, `::`, `;`, `?`, `{`, `}`, or an operator, found `gen`
}