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Auto merge of #118457 - eholk:genfn, r=compiler-errors

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Add support for `gen fn`

This builds on #116447 to add support for `gen fn` functions. For the most part we follow the same approach as desugaring `async fn`, but replacing `Future` with `Iterator` and `async {}` with `gen {}` for the body.

The version implemented here uses the return type of a `gen fn` as the yield type. For example:

```rust
gen fn count_to_three() -> i32 {
    yield 1;
    yield 2;
    yield 3;
}
```

In the future, I think we should experiment with a syntax like `gen fn count_to_three() yield i32 { ... }`, but that can go in another PR.

cc `@oli-obk` `@compiler-errors`
This commit is contained in:
bors 2023-12-05 18:37:15 +00:00
commit 56278a6e28
36 changed files with 417 additions and 234 deletions
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55
compiler/rustc_ast/src/ast.rs
View File

@ -1311,7 +1311,7 @@ pub struct Closure {
pub binder: ClosureBinder,
pub capture_clause: CaptureBy,
pub constness: Const,
pub asyncness: Async,
pub coro_kind: Option<CoroutineKind>,
pub movability: Movability,
pub fn_decl: P<FnDecl>,
pub body: P<Expr>,
@ -2406,28 +2406,34 @@ pub enum Unsafe {
No,
}
/// Describes what kind of coroutine markers, if any, a function has.
///
/// Coroutine markers are things that cause the function to generate a coroutine, such as `async`,
/// which makes the function return `impl Future`, or `gen`, which makes the function return `impl
/// Iterator`.
#[derive(Copy, Clone, Encodable, Decodable, Debug)]
pub enum Async {
Yes { span: Span, closure_id: NodeId, return_impl_trait_id: NodeId },
No,
pub enum CoroutineKind {
/// `async`, which evaluates to `impl Future`
Async { span: Span, closure_id: NodeId, return_impl_trait_id: NodeId },
/// `gen`, which evaluates to `impl Iterator`
Gen { span: Span, closure_id: NodeId, return_impl_trait_id: NodeId },
}
#[derive(Copy, Clone, Encodable, Decodable, Debug)]
pub enum Gen {
Yes { span: Span, closure_id: NodeId, return_impl_trait_id: NodeId },
No,
}
impl Async {
impl CoroutineKind {
pub fn is_async(self) -> bool {
matches!(self, Async::Yes { .. })
matches!(self, CoroutineKind::Async { .. })
}
/// In this case this is an `async` return, the `NodeId` for the generated `impl Trait` item.
pub fn opt_return_id(self) -> Option<(NodeId, Span)> {
pub fn is_gen(self) -> bool {
matches!(self, CoroutineKind::Gen { .. })
}
/// In this case this is an `async` or `gen` return, the `NodeId` for the generated `impl Trait`
/// item.
pub fn return_id(self) -> (NodeId, Span) {
match self {
Async::Yes { return_impl_trait_id, span, .. } => Some((return_impl_trait_id, span)),
Async::No => None,
CoroutineKind::Async { return_impl_trait_id, span, .. }
| CoroutineKind::Gen { return_impl_trait_id, span, .. } => (return_impl_trait_id, span),
}
}
}
@ -2831,8 +2837,8 @@ impl Extern {
pub struct FnHeader {
/// The `unsafe` keyword, if any
pub unsafety: Unsafe,
/// The `async` keyword, if any
pub asyncness: Async,
/// Whether this is `async`, `gen`, or nothing.
pub coro_kind: Option<CoroutineKind>,
/// The `const` keyword, if any
pub constness: Const,
/// The `extern` keyword and corresponding ABI string, if any
@ -2842,9 +2848,9 @@ pub struct FnHeader {
impl FnHeader {
/// Does this function header have any qualifiers or is it empty?
pub fn has_qualifiers(&self) -> bool {
let Self { unsafety, asyncness, constness, ext } = self;
let Self { unsafety, coro_kind, constness, ext } = self;
matches!(unsafety, Unsafe::Yes(_))
|| asyncness.is_async()
|| coro_kind.is_some()
|| matches!(constness, Const::Yes(_))
|| !matches!(ext, Extern::None)
}
@ -2852,12 +2858,7 @@ impl FnHeader {
impl Default for FnHeader {
fn default() -> FnHeader {
FnHeader {
unsafety: Unsafe::No,
asyncness: Async::No,
constness: Const::No,
ext: Extern::None,
}
FnHeader { unsafety: Unsafe::No, coro_kind: None, constness: Const::No, ext: Extern::None }
}
}
@ -3177,7 +3178,7 @@ mod size_asserts {
static_assert_size!(Block, 32);
static_assert_size!(Expr, 72);
static_assert_size!(ExprKind, 40);
static_assert_size!(Fn, 152);
static_assert_size!(Fn, 160);
static_assert_size!(ForeignItem, 96);
static_assert_size!(ForeignItemKind, 24);
static_assert_size!(GenericArg, 24);

21
compiler/rustc_ast/src/mut_visit.rs
View File

@ -121,8 +121,8 @@ pub trait MutVisitor: Sized {
noop_visit_fn_decl(d, self);
}
fn visit_asyncness(&mut self, a: &mut Async) {
noop_visit_asyncness(a, self);
fn visit_coro_kind(&mut self, a: &mut CoroutineKind) {
noop_visit_coro_kind(a, self);
}
fn visit_closure_binder(&mut self, b: &mut ClosureBinder) {
@ -871,13 +871,14 @@ pub fn noop_visit_closure_binder<T: MutVisitor>(binder: &mut ClosureBinder, vis:
}
}
pub fn noop_visit_asyncness<T: MutVisitor>(asyncness: &mut Async, vis: &mut T) {
match asyncness {
Async::Yes { span: _, closure_id, return_impl_trait_id } => {
pub fn noop_visit_coro_kind<T: MutVisitor>(coro_kind: &mut CoroutineKind, vis: &mut T) {
match coro_kind {
CoroutineKind::Async { span, closure_id, return_impl_trait_id }
| CoroutineKind::Gen { span, closure_id, return_impl_trait_id } => {
vis.visit_span(span);
vis.visit_id(closure_id);
vis.visit_id(return_impl_trait_id);
}
Async::No => {}
}
}
@ -1170,9 +1171,9 @@ fn visit_const_item<T: MutVisitor>(
}
pub fn noop_visit_fn_header<T: MutVisitor>(header: &mut FnHeader, vis: &mut T) {
let FnHeader { unsafety, asyncness, constness, ext: _ } = header;
let FnHeader { unsafety, coro_kind, constness, ext: _ } = header;
visit_constness(constness, vis);
vis.visit_asyncness(asyncness);
coro_kind.as_mut().map(|coro_kind| vis.visit_coro_kind(coro_kind));
visit_unsafety(unsafety, vis);
}
@ -1406,7 +1407,7 @@ pub fn noop_visit_expr<T: MutVisitor>(
binder,
capture_clause,
constness,
asyncness,
coro_kind,
movability: _,
fn_decl,
body,
@ -1415,7 +1416,7 @@ pub fn noop_visit_expr<T: MutVisitor>(
}) => {
vis.visit_closure_binder(binder);
visit_constness(constness, vis);
vis.visit_asyncness(asyncness);
coro_kind.as_mut().map(|coro_kind| vis.visit_coro_kind(coro_kind));
vis.visit_capture_by(capture_clause);
vis.visit_fn_decl(fn_decl);
vis.visit_expr(body);

2
compiler/rustc_ast/src/visit.rs
View File

@ -861,7 +861,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
ExprKind::Closure(box Closure {
binder,
capture_clause,
asyncness: _,
coro_kind: _,
constness: _,
movability: _,
fn_decl,

56
compiler/rustc_ast_lowering/src/expr.rs
View File

@ -195,39 +195,39 @@ impl<'hir> LoweringContext<'_, 'hir> {
binder,
capture_clause,
constness,
asyncness,
coro_kind,
movability,
fn_decl,
body,
fn_decl_span,
fn_arg_span,
}) => {
if let Async::Yes { closure_id, .. } = asyncness {
self.lower_expr_async_closure(
binder,
*capture_clause,
e.id,
hir_id,
*closure_id,
fn_decl,
body,
*fn_decl_span,
*fn_arg_span,
)
} else {
self.lower_expr_closure(
binder,
*capture_clause,
e.id,
*constness,
*movability,
fn_decl,
body,
*fn_decl_span,
*fn_arg_span,
)
}
}
}) => match coro_kind {
Some(
CoroutineKind::Async { closure_id, .. }
| CoroutineKind::Gen { closure_id, .. },
) => self.lower_expr_async_closure(
binder,
*capture_clause,
e.id,
hir_id,
*closure_id,
fn_decl,
body,
*fn_decl_span,
*fn_arg_span,
),
None => self.lower_expr_closure(
binder,
*capture_clause,
e.id,
*constness,
*movability,
fn_decl,
body,
*fn_decl_span,
*fn_arg_span,
),
},
ExprKind::Block(blk, opt_label) => {
let opt_label = self.lower_label(*opt_label);
hir::ExprKind::Block(self.lower_block(blk, opt_label.is_some()), opt_label)

144
compiler/rustc_ast_lowering/src/item.rs
View File

@ -206,15 +206,19 @@ impl<'hir> LoweringContext<'_, 'hir> {
// `impl Future<Output = T>` here because lower_body
// only cares about the input argument patterns in the function
// declaration (decl), not the return types.
let asyncness = header.asyncness;
let body_id =
this.lower_maybe_async_body(span, hir_id, decl, asyncness, body.as_deref());
let coro_kind = header.coro_kind;
let body_id = this.lower_maybe_coroutine_body(
span,
hir_id,
decl,
coro_kind,
body.as_deref(),
);
let itctx = ImplTraitContext::Universal;
let (generics, decl) =
this.lower_generics(generics, header.constness, id, &itctx, |this| {
let ret_id = asyncness.opt_return_id();
this.lower_fn_decl(decl, id, *fn_sig_span, FnDeclKind::Fn, ret_id)
this.lower_fn_decl(decl, id, *fn_sig_span, FnDeclKind::Fn, coro_kind)
});
let sig = hir::FnSig {
decl,
@ -725,27 +729,30 @@ impl<'hir> LoweringContext<'_, 'hir> {
(generics, kind, expr.is_some())
}
AssocItemKind::Fn(box Fn { sig, generics, body: None, .. }) => {
let asyncness = sig.header.asyncness;
let names = self.lower_fn_params_to_names(&sig.decl);
let (generics, sig) = self.lower_method_sig(
generics,
sig,
i.id,
FnDeclKind::Trait,
asyncness.opt_return_id(),
sig.header.coro_kind,
);
(generics, hir::TraitItemKind::Fn(sig, hir::TraitFn::Required(names)), false)
}
AssocItemKind::Fn(box Fn { sig, generics, body: Some(body), .. }) => {
let asyncness = sig.header.asyncness;
let body_id =
self.lower_maybe_async_body(i.span, hir_id, &sig.decl, asyncness, Some(body));
let body_id = self.lower_maybe_coroutine_body(
i.span,
hir_id,
&sig.decl,
sig.header.coro_kind,
Some(body),
);
let (generics, sig) = self.lower_method_sig(
generics,
sig,
i.id,
FnDeclKind::Trait,
asyncness.opt_return_id(),
sig.header.coro_kind,
);
(generics, hir::TraitItemKind::Fn(sig, hir::TraitFn::Provided(body_id)), true)
}
@ -834,12 +841,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
},
),
AssocItemKind::Fn(box Fn { sig, generics, body, .. }) => {
let asyncness = sig.header.asyncness;
let body_id = self.lower_maybe_async_body(
let body_id = self.lower_maybe_coroutine_body(
i.span,
hir_id,
&sig.decl,
asyncness,
sig.header.coro_kind,
body.as_deref(),
);
let (generics, sig) = self.lower_method_sig(
@ -847,7 +853,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
sig,
i.id,
if self.is_in_trait_impl { FnDeclKind::Impl } else { FnDeclKind::Inherent },
asyncness.opt_return_id(),
sig.header.coro_kind,
);
(generics, hir::ImplItemKind::Fn(sig, body_id))
@ -1011,17 +1017,23 @@ impl<'hir> LoweringContext<'_, 'hir> {
})
}
fn lower_maybe_async_body(
/// Takes what may be the body of an `async fn` or a `gen fn` and wraps it in an `async {}` or
/// `gen {}` block as appropriate.
fn lower_maybe_coroutine_body(
&mut self,
span: Span,
fn_id: hir::HirId,
decl: &FnDecl,
asyncness: Async,
coro_kind: Option<CoroutineKind>,
body: Option<&Block>,
) -> hir::BodyId {
let (closure_id, body) = match (asyncness, body) {
(Async::Yes { closure_id, .. }, Some(body)) => (closure_id, body),
_ => return self.lower_fn_body_block(span, decl, body),
let (Some(coro_kind), Some(body)) = (coro_kind, body) else {
return self.lower_fn_body_block(span, decl, body);
};
let closure_id = match coro_kind {
CoroutineKind::Async { closure_id, .. } | CoroutineKind::Gen { closure_id, .. } => {
closure_id
}
};
self.lower_body(|this| {
@ -1163,44 +1175,54 @@ impl<'hir> LoweringContext<'_, 'hir> {
parameters.push(new_parameter);
}
let async_expr = this.make_async_expr(
CaptureBy::Value { move_kw: rustc_span::DUMMY_SP },
closure_id,
None,
body.span,
hir::CoroutineSource::Fn,
|this| {
// Create a block from the user's function body:
let user_body = this.lower_block_expr(body);
let mkbody = |this: &mut LoweringContext<'_, 'hir>| {
// Create a block from the user's function body:
let user_body = this.lower_block_expr(body);
// Transform into `drop-temps { <user-body> }`, an expression:
let desugared_span =
this.mark_span_with_reason(DesugaringKind::Async, user_body.span, None);
let user_body =
this.expr_drop_temps(desugared_span, this.arena.alloc(user_body));
// Transform into `drop-temps { <user-body> }`, an expression:
let desugared_span =
this.mark_span_with_reason(DesugaringKind::Async, user_body.span, None);
let user_body = this.expr_drop_temps(desugared_span, this.arena.alloc(user_body));
// As noted above, create the final block like
//
// ```
// {
// let $param_pattern = $raw_param;
// ...
// drop-temps { <user-body> }
// }
// ```
let body = this.block_all(
desugared_span,
this.arena.alloc_from_iter(statements),
Some(user_body),
);
// As noted above, create the final block like
//
// ```
// {
// let $param_pattern = $raw_param;
// ...
// drop-temps { <user-body> }
// }
// ```
let body = this.block_all(
desugared_span,
this.arena.alloc_from_iter(statements),
Some(user_body),
);
this.expr_block(body)
},
);
this.expr_block(body)
};
let coroutine_expr = match coro_kind {
CoroutineKind::Async { .. } => this.make_async_expr(
CaptureBy::Value { move_kw: rustc_span::DUMMY_SP },
closure_id,
None,
body.span,
hir::CoroutineSource::Fn,
mkbody,
),
CoroutineKind::Gen { .. } => this.make_gen_expr(
CaptureBy::Value { move_kw: rustc_span::DUMMY_SP },
closure_id,
None,
body.span,
hir::CoroutineSource::Fn,
mkbody,
),
};
let hir_id = this.lower_node_id(closure_id);
this.maybe_forward_track_caller(body.span, fn_id, hir_id);
let expr = hir::Expr { hir_id, kind: async_expr, span: this.lower_span(body.span) };
let expr = hir::Expr { hir_id, kind: coroutine_expr, span: this.lower_span(body.span) };
(this.arena.alloc_from_iter(parameters), expr)
})
@ -1212,21 +1234,26 @@ impl<'hir> LoweringContext<'_, 'hir> {
sig: &FnSig,
id: NodeId,
kind: FnDeclKind,
is_async: Option<(NodeId, Span)>,
coro_kind: Option<CoroutineKind>,
) -> (&'hir hir::Generics<'hir>, hir::FnSig<'hir>) {
let header = self.lower_fn_header(sig.header);
let itctx = ImplTraitContext::Universal;
let (generics, decl) =
self.lower_generics(generics, sig.header.constness, id, &itctx, |this| {
this.lower_fn_decl(&sig.decl, id, sig.span, kind, is_async)
this.lower_fn_decl(&sig.decl, id, sig.span, kind, coro_kind)
});
(generics, hir::FnSig { header, decl, span: self.lower_span(sig.span) })
}
fn lower_fn_header(&mut self, h: FnHeader) -> hir::FnHeader {
let asyncness = if let Some(CoroutineKind::Async { span, .. }) = h.coro_kind {
hir::IsAsync::Async(span)
} else {
hir::IsAsync::NotAsync
};
hir::FnHeader {
unsafety: self.lower_unsafety(h.unsafety),
asyncness: self.lower_asyncness(h.asyncness),
asyncness: asyncness,
constness: self.lower_constness(h.constness),
abi: self.lower_extern(h.ext),
}
@ -1268,13 +1295,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
});
}
fn lower_asyncness(&mut self, a: Async) -> hir::IsAsync {
match a {
Async::Yes { span, .. } => hir::IsAsync::Async(span),
Async::No => hir::IsAsync::NotAsync,
}
}
pub(super) fn lower_constness(&mut self, c: Const) -> hir::Constness {
match c {
Const::Yes(_) => hir::Constness::Const,

60
compiler/rustc_ast_lowering/src/lib.rs
View File

@ -1778,13 +1778,15 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
}))
}
// Lowers a function declaration.
//
// `decl`: the unlowered (AST) function declaration.
// `fn_node_id`: `impl Trait` arguments are lowered into generic parameters on the given `NodeId`.
// `make_ret_async`: if `Some`, converts `-> T` into `-> impl Future<Output = T>` in the
// return type. This is used for `async fn` declarations. The `NodeId` is the ID of the
// return type `impl Trait` item, and the `Span` points to the `async` keyword.
/// Lowers a function declaration.
///
/// `decl`: the unlowered (AST) function declaration.
///
/// `fn_node_id`: `impl Trait` arguments are lowered into generic parameters on the given
/// `NodeId`.
///
/// `transform_return_type`: if `Some`, applies some conversion to the return type, such as is
/// needed for `async fn` and `gen fn`. See [`CoroutineKind`] for more details.
#[instrument(level = "debug", skip(self))]
fn lower_fn_decl(
&mut self,
@ -1792,7 +1794,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
fn_node_id: NodeId,
fn_span: Span,
kind: FnDeclKind,
make_ret_async: Option<(NodeId, Span)>,
coro: Option<CoroutineKind>,
) -> &'hir hir::FnDecl<'hir> {
let c_variadic = decl.c_variadic();
@ -1821,11 +1823,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
self.lower_ty_direct(&param.ty, &itctx)
}));
let output = if let Some((ret_id, _span)) = make_ret_async {
let fn_def_id = self.local_def_id(fn_node_id);
self.lower_async_fn_ret_ty(&decl.output, fn_def_id, ret_id, kind, fn_span)
} else {
match &decl.output {
let output = match coro {
Some(coro) => {
let fn_def_id = self.local_def_id(fn_node_id);
self.lower_coroutine_fn_ret_ty(&decl.output, fn_def_id, coro, kind, fn_span)
}
None => match &decl.output {
FnRetTy::Ty(ty) => {
let context = if kind.return_impl_trait_allowed() {
let fn_def_id = self.local_def_id(fn_node_id);
@ -1849,7 +1852,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
hir::FnRetTy::Return(self.lower_ty(ty, &context))
}
FnRetTy::Default(span) => hir::FnRetTy::DefaultReturn(self.lower_span(*span)),
}
},
};
self.arena.alloc(hir::FnDecl {
@ -1888,17 +1891,22 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
// `fn_node_id`: `NodeId` of the parent function (used to create child impl trait definition)
// `opaque_ty_node_id`: `NodeId` of the opaque `impl Trait` type that should be created
#[instrument(level = "debug", skip(self))]
fn lower_async_fn_ret_ty(
fn lower_coroutine_fn_ret_ty(
&mut self,
output: &FnRetTy,
fn_def_id: LocalDefId,
opaque_ty_node_id: NodeId,
coro: CoroutineKind,
fn_kind: FnDeclKind,
fn_span: Span,
) -> hir::FnRetTy<'hir> {
let span = self.lower_span(fn_span);
let opaque_ty_span = self.mark_span_with_reason(DesugaringKind::Async, span, None);
let opaque_ty_node_id = match coro {
CoroutineKind::Async { return_impl_trait_id, .. }
| CoroutineKind::Gen { return_impl_trait_id, .. } => return_impl_trait_id,
};
let captured_lifetimes: Vec<_> = self
.resolver
.take_extra_lifetime_params(opaque_ty_node_id)
@ -1914,15 +1922,16 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
span,
opaque_ty_span,
|this| {
let future_bound = this.lower_async_fn_output_type_to_future_bound(
let bound = this.lower_coroutine_fn_output_type_to_bound(
output,
coro,
span,
ImplTraitContext::ReturnPositionOpaqueTy {
origin: hir::OpaqueTyOrigin::FnReturn(fn_def_id),
fn_kind,
},
);
arena_vec![this; future_bound]
arena_vec![this; bound]
},
);
@ -1931,9 +1940,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
}
/// Transforms `-> T` into `Future<Output = T>`.
fn lower_async_fn_output_type_to_future_bound(
fn lower_coroutine_fn_output_type_to_bound(
&mut self,
output: &FnRetTy,
coro: CoroutineKind,
span: Span,
nested_impl_trait_context: ImplTraitContext,
) -> hir::GenericBound<'hir> {
@ -1948,17 +1958,21 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
FnRetTy::Default(ret_ty_span) => self.arena.alloc(self.ty_tup(*ret_ty_span, &[])),
};
// "<Output = T>"
// "<$assoc_ty_name = T>"
let (assoc_ty_name, trait_lang_item) = match coro {
CoroutineKind::Async { .. } => (hir::FN_OUTPUT_NAME, hir::LangItem::Future),
CoroutineKind::Gen { .. } => (hir::ITERATOR_ITEM_NAME, hir::LangItem::Iterator),
};
let future_args = self.arena.alloc(hir::GenericArgs {
args: &[],
bindings: arena_vec![self; self.output_ty_binding(span, output_ty)],
bindings: arena_vec![self; self.assoc_ty_binding(assoc_ty_name, span, output_ty)],
parenthesized: hir::GenericArgsParentheses::No,
span_ext: DUMMY_SP,
});
hir::GenericBound::LangItemTrait(
// ::std::future::Future<future_params>
hir::LangItem::Future,
trait_lang_item,
self.lower_span(span),
self.next_id(),
future_args,

9
compiler/rustc_ast_lowering/src/path.rs
View File

@ -389,7 +389,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
FnRetTy::Default(_) => self.arena.alloc(self.ty_tup(*span, &[])),
};
let args = smallvec![GenericArg::Type(self.arena.alloc(self.ty_tup(*inputs_span, inputs)))];
let binding = self.output_ty_binding(output_ty.span, output_ty);
let binding = self.assoc_ty_binding(hir::FN_OUTPUT_NAME, output_ty.span, output_ty);
(
GenericArgsCtor {
args,
@ -401,13 +401,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
)
}
/// An associated type binding `Output = $ty`.
pub(crate) fn output_ty_binding(
/// An associated type binding `$assoc_ty_name = $ty`.
pub(crate) fn assoc_ty_binding(
&mut self,
assoc_ty_name: rustc_span::Symbol,
span: Span,
ty: &'hir hir::Ty<'hir>,
) -> hir::TypeBinding<'hir> {
let ident = Ident::with_dummy_span(hir::FN_OUTPUT_NAME);
let ident = Ident::with_dummy_span(assoc_ty_name);
let kind = hir::TypeBindingKind::Equality { term: ty.into() };
let args = arena_vec![self;];
let bindings = arena_vec![self;];

9
compiler/rustc_ast_passes/src/ast_validation.rs
View File

@ -1268,13 +1268,18 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
self.check_c_variadic_type(fk);
// Functions cannot both be `const async`
// Functions cannot both be `const async` or `const gen`
if let Some(&FnHeader {
constness: Const::Yes(cspan),
asyncness: Async::Yes { span: aspan, .. },
coro_kind:
Some(
CoroutineKind::Async { span: aspan, .. }
| CoroutineKind::Gen { span: aspan, .. },
),
..
}) = fk.header()
{
// FIXME(gen_blocks): Report a different error for `const gen`
self.err_handler().emit_err(errors::ConstAndAsync {
spans: vec![cspan, aspan],
cspan,

13
compiler/rustc_ast_pretty/src/pprust/state.rs
View File

@ -1490,9 +1490,14 @@ impl<'a> State<'a> {
}
}
fn print_asyncness(&mut self, asyncness: ast::Async) {
if asyncness.is_async() {
self.word_nbsp("async");
fn print_coro_kind(&mut self, coro_kind: ast::CoroutineKind) {
match coro_kind {
ast::CoroutineKind::Gen { .. } => {
self.word_nbsp("gen");
}
ast::CoroutineKind::Async { .. } => {
self.word_nbsp("async");
}
}
}
@ -1685,7 +1690,7 @@ impl<'a> State<'a> {
fn print_fn_header_info(&mut self, header: ast::FnHeader) {
self.print_constness(header.constness);
self.print_asyncness(header.asyncness);
header.coro_kind.map(|coro_kind| self.print_coro_kind(coro_kind));
self.print_unsafety(header.unsafety);
match header.ext {

4
compiler/rustc_ast_pretty/src/pprust/state/expr.rs
View File

@ -413,7 +413,7 @@ impl<'a> State<'a> {
binder,
capture_clause,
constness,
asyncness,
coro_kind,
movability,
fn_decl,
body,
@ -423,7 +423,7 @@ impl<'a> State<'a> {
self.print_closure_binder(binder);
self.print_constness(*constness);
self.print_movability(*movability);
self.print_asyncness(*asyncness);
coro_kind.map(|coro_kind| self.print_coro_kind(coro_kind));
self.print_capture_clause(*capture_clause);
self.print_fn_params_and_ret(fn_decl, true);

6
compiler/rustc_builtin_macros/src/test.rs
View File

@ -541,10 +541,14 @@ fn check_test_signature(
return Err(sd.emit_err(errors::TestBadFn { span: i.span, cause: span, kind: "unsafe" }));
}
if let ast::Async::Yes { span, .. } = f.sig.header.asyncness {
if let Some(ast::CoroutineKind::Async { span, .. }) = f.sig.header.coro_kind {
return Err(sd.emit_err(errors::TestBadFn { span: i.span, cause: span, kind: "async" }));
}
if let Some(ast::CoroutineKind::Gen { span, .. }) = f.sig.header.coro_kind {
return Err(sd.emit_err(errors::TestBadFn { span: i.span, cause: span, kind: "gen" }));
}
// If the termination trait is active, the compiler will check that the output
// type implements the `Termination` trait as `libtest` enforces that.
let has_output = match &f.sig.decl.output {

2
compiler/rustc_expand/src/build.rs
View File

@ -547,7 +547,7 @@ impl<'a> ExtCtxt<'a> {
binder: ast::ClosureBinder::NotPresent,
capture_clause: ast::CaptureBy::Ref,
constness: ast::Const::No,
asyncness: ast::Async::No,
coro_kind: None,
movability: ast::Movability::Movable,
fn_decl,
body,

2
compiler/rustc_hir/src/hir.rs
View File

@ -2255,6 +2255,8 @@ pub enum ImplItemKind<'hir> {
/// The name of the associated type for `Fn` return types.
pub const FN_OUTPUT_NAME: Symbol = sym::Output;
/// The name of the associated type for `Iterator` item types.
pub const ITERATOR_ITEM_NAME: Symbol = sym::Item;
/// Bind a type to an associated type (i.e., `A = Foo`).
///

6
compiler/rustc_hir_typeck/src/closure.rs
View File

@ -651,9 +651,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
},
)
}
Some(hir::CoroutineKind::Gen(hir::CoroutineSource::Fn)) => {
todo!("gen closures do not exist yet")
}
// For a `gen {}` block created as a `gen fn` body, we need the return type to be
// ().
Some(hir::CoroutineKind::Gen(hir::CoroutineSource::Fn)) => self.tcx.types.unit,
_ => astconv.ty_infer(None, decl.output.span()),
},

12
compiler/rustc_lint/src/early.rs
View File

@ -162,7 +162,11 @@ impl<'a, T: EarlyLintPass> ast_visit::Visitor<'a> for EarlyContextAndPass<'a, T>
// Explicitly check for lints associated with 'closure_id', since
// it does not have a corresponding AST node
if let ast_visit::FnKind::Fn(_, _, sig, _, _, _) = fk {
if let ast::Async::Yes { closure_id, .. } = sig.header.asyncness {
if let Some(
ast::CoroutineKind::Async { closure_id, .. }
| ast::CoroutineKind::Gen { closure_id, .. },
) = sig.header.coro_kind
{
self.check_id(closure_id);
}
}
@ -223,7 +227,11 @@ impl<'a, T: EarlyLintPass> ast_visit::Visitor<'a> for EarlyContextAndPass<'a, T>
// it does not have a corresponding AST node
match e.kind {
ast::ExprKind::Closure(box ast::Closure {
asyncness: ast::Async::Yes { closure_id, .. },
coro_kind:
Some(
ast::CoroutineKind::Async { closure_id, .. }
| ast::CoroutineKind::Gen { closure_id, .. },
),
..
}) => self.check_id(closure_id),
_ => {}

2
compiler/rustc_parse/messages.ftl
View File

@ -23,6 +23,8 @@ parse_async_block_in_2015 = `async` blocks are only allowed in Rust 2018 or late
parse_async_fn_in_2015 = `async fn` is not permitted in Rust 2015
.label = to use `async fn`, switch to Rust 2018 or later
parse_async_gen_fn = `async gen` functions are not supported
parse_async_move_block_in_2015 = `async move` blocks are only allowed in Rust 2018 or later
parse_async_move_order_incorrect = the order of `move` and `async` is incorrect

7
compiler/rustc_parse/src/errors.rs
View File

@ -562,6 +562,13 @@ pub(crate) struct GenFn {
pub span: Span,
}
#[derive(Diagnostic)]
#[diag(parse_async_gen_fn)]
pub(crate) struct AsyncGenFn {
#[primary_span]
pub span: Span,
}
#[derive(Diagnostic)]
#[diag(parse_comma_after_base_struct)]
#[note]

10
compiler/rustc_parse/src/parser/expr.rs
View File

@ -10,7 +10,7 @@ use super::{
use crate::errors;
use crate::maybe_recover_from_interpolated_ty_qpath;
use ast::mut_visit::{noop_visit_expr, MutVisitor};
use ast::{GenBlockKind, Pat, Path, PathSegment};
use ast::{CoroutineKind, GenBlockKind, Pat, Path, PathSegment};
use core::mem;
use rustc_ast::ptr::P;
use rustc_ast::token::{self, Delimiter, Token, TokenKind};
@ -21,7 +21,7 @@ use rustc_ast::util::parser::{prec_let_scrutinee_needs_par, AssocOp, Fixity};
use rustc_ast::visit::Visitor;
use rustc_ast::{self as ast, AttrStyle, AttrVec, CaptureBy, ExprField, UnOp, DUMMY_NODE_ID};
use rustc_ast::{AnonConst, BinOp, BinOpKind, FnDecl, FnRetTy, MacCall, Param, Ty, TyKind};
use rustc_ast::{Arm, Async, BlockCheckMode, Expr, ExprKind, Label, Movability, RangeLimits};
use rustc_ast::{Arm, BlockCheckMode, Expr, ExprKind, Label, Movability, RangeLimits};
use rustc_ast::{ClosureBinder, MetaItemLit, StmtKind};
use rustc_ast_pretty::pprust;
use rustc_data_structures::stack::ensure_sufficient_stack;
@ -2237,7 +2237,7 @@ impl<'a> Parser<'a> {
let asyncness = if self.token.uninterpolated_span().at_least_rust_2018() {
self.parse_asyncness(Case::Sensitive)
} else {
Async::No
None
};
let capture_clause = self.parse_capture_clause()?;
@ -2261,7 +2261,7 @@ impl<'a> Parser<'a> {
}
};
if let Async::Yes { span, .. } = asyncness {
if let Some(CoroutineKind::Async { span, .. }) = asyncness {
// Feature-gate `async ||` closures.
self.sess.gated_spans.gate(sym::async_closure, span);
}
@ -2284,7 +2284,7 @@ impl<'a> Parser<'a> {
binder,
capture_clause,
constness,
asyncness,
coro_kind: asyncness,
movability,
fn_decl,
body,

41
compiler/rustc_parse/src/parser/item.rs
View File

@ -11,8 +11,8 @@ use rustc_ast::tokenstream::{DelimSpan, TokenStream, TokenTree};
use rustc_ast::util::case::Case;
use rustc_ast::MacCall;
use rustc_ast::{self as ast, AttrVec, Attribute, DUMMY_NODE_ID};
use rustc_ast::{Async, Const, Defaultness, IsAuto, Mutability, Unsafe, UseTree, UseTreeKind};
use rustc_ast::{BindingAnnotation, Block, FnDecl, FnSig, Param, SelfKind};
use rustc_ast::{Const, Defaultness, IsAuto, Mutability, Unsafe, UseTree, UseTreeKind};
use rustc_ast::{EnumDef, FieldDef, Generics, TraitRef, Ty, TyKind, Variant, VariantData};
use rustc_ast::{FnHeader, ForeignItem, Path, PathSegment, Visibility, VisibilityKind};
use rustc_ast_pretty::pprust;
@ -2401,7 +2401,7 @@ impl<'a> Parser<'a> {
let ext_start_sp = self.token.span;
let ext = self.parse_extern(case);
if let Async::Yes { span, .. } = asyncness {
if let Some(CoroutineKind::Async { span, .. }) = asyncness {
if span.is_rust_2015() {
self.sess.emit_err(errors::AsyncFnIn2015 {
span,
@ -2410,8 +2410,16 @@ impl<'a> Parser<'a> {
}
}
if let Gen::Yes { span, .. } = genness {
self.sess.emit_err(errors::GenFn { span });
if let Some(CoroutineKind::Gen { span, .. }) = genness {
self.sess.gated_spans.gate(sym::gen_blocks, span);
}
if let (
Some(CoroutineKind::Async { span: async_span, .. }),
Some(CoroutineKind::Gen { span: gen_span, .. }),
) = (asyncness, genness)
{
self.sess.emit_err(errors::AsyncGenFn { span: async_span.to(gen_span) });
}
if !self.eat_keyword_case(kw::Fn, case) {
@ -2444,13 +2452,18 @@ impl<'a> Parser<'a> {
}
} else if self.check_keyword(kw::Async) {
match asyncness {
Async::Yes { span, .. } => Some(WrongKw::Duplicated(span)),
Async::No => {
recover_asyncness = Async::Yes {
Some(CoroutineKind::Async { span, .. }) => {
Some(WrongKw::Duplicated(span))
}
Some(CoroutineKind::Gen { .. }) => {
panic!("not sure how to recover here")
}
None => {
recover_asyncness = Some(CoroutineKind::Async {
span: self.token.span,
closure_id: DUMMY_NODE_ID,
return_impl_trait_id: DUMMY_NODE_ID,
};
});
Some(WrongKw::Misplaced(unsafe_start_sp))
}
}
@ -2531,6 +2544,8 @@ impl<'a> Parser<'a> {
}
}
// FIXME(gen_blocks): add keyword recovery logic for genness
if wrong_kw.is_some()
&& self.may_recover()
&& self.look_ahead(1, |tok| tok.is_keyword_case(kw::Fn, case))
@ -2542,7 +2557,7 @@ impl<'a> Parser<'a> {
return Ok(FnHeader {
constness: recover_constness,
unsafety: recover_unsafety,
asyncness: recover_asyncness,
coro_kind: recover_asyncness,
ext,
});
}
@ -2552,7 +2567,13 @@ impl<'a> Parser<'a> {
}
}
Ok(FnHeader { constness, unsafety, asyncness, ext })
let coro_kind = match asyncness {
Some(CoroutineKind::Async { .. }) => asyncness,
Some(CoroutineKind::Gen { .. }) => unreachable!("asycness cannot be Gen"),
None => genness,
};
Ok(FnHeader { constness, unsafety, coro_kind, ext })
}
/// Parses the parameter list and result type of a function declaration.

24
compiler/rustc_parse/src/parser/mod.rs
View File

@ -11,7 +11,6 @@ mod stmt;
mod ty;
use crate::lexer::UnmatchedDelim;
use ast::Gen;
pub use attr_wrapper::AttrWrapper;
pub use diagnostics::AttemptLocalParseRecovery;
pub(crate) use expr::ForbiddenLetReason;
@ -25,9 +24,10 @@ use rustc_ast::tokenstream::{AttributesData, DelimSpan, Spacing};
use rustc_ast::tokenstream::{TokenStream, TokenTree, TokenTreeCursor};
use rustc_ast::util::case::Case;
use rustc_ast::AttrId;
use rustc_ast::CoroutineKind;
use rustc_ast::DUMMY_NODE_ID;
use rustc_ast::{self as ast, AnonConst, Const, DelimArgs, Extern};
use rustc_ast::{Async, AttrArgs, AttrArgsEq, Expr, ExprKind, Mutability, StrLit};
use rustc_ast::{AttrArgs, AttrArgsEq, Expr, ExprKind, Mutability, StrLit};
use rustc_ast::{HasAttrs, HasTokens, Unsafe, Visibility, VisibilityKind};
use rustc_ast_pretty::pprust;
use rustc_data_structures::fx::FxHashMap;
@ -1125,22 +1125,30 @@ impl<'a> Parser<'a> {
}
/// Parses asyncness: `async` or nothing.
fn parse_asyncness(&mut self, case: Case) -> Async {
fn parse_asyncness(&mut self, case: Case) -> Option<CoroutineKind> {
if self.eat_keyword_case(kw::Async, case) {
let span = self.prev_token.uninterpolated_span();
Async::Yes { span, closure_id: DUMMY_NODE_ID, return_impl_trait_id: DUMMY_NODE_ID }
Some(CoroutineKind::Async {
span,
closure_id: DUMMY_NODE_ID,
return_impl_trait_id: DUMMY_NODE_ID,
})
} else {
Async::No
None
}
}
/// Parses genness: `gen` or nothing.
fn parse_genness(&mut self, case: Case) -> Gen {
fn parse_genness(&mut self, case: Case) -> Option<CoroutineKind> {
if self.token.span.at_least_rust_2024() && self.eat_keyword_case(kw::Gen, case) {
let span = self.prev_token.uninterpolated_span();
Gen::Yes { span, closure_id: DUMMY_NODE_ID, return_impl_trait_id: DUMMY_NODE_ID }
Some(CoroutineKind::Gen {
span,
closure_id: DUMMY_NODE_ID,
return_impl_trait_id: DUMMY_NODE_ID,
})
} else {
Gen::No
None
}
}

5
compiler/rustc_parse/src/parser/ty.rs
View File

@ -596,7 +596,7 @@ impl<'a> Parser<'a> {
tokens: None,
};
let span_start = self.token.span;
let ast::FnHeader { ext, unsafety, constness, asyncness } =
let ast::FnHeader { ext, unsafety, constness, coro_kind } =
self.parse_fn_front_matter(&inherited_vis, Case::Sensitive)?;
if self.may_recover() && self.token.kind == TokenKind::Lt {
self.recover_fn_ptr_with_generics(lo, &mut params, param_insertion_point)?;
@ -609,9 +609,10 @@ impl<'a> Parser<'a> {
// cover it.
self.sess.emit_err(FnPointerCannotBeConst { span: whole_span, qualifier: span });
}
if let ast::Async::Yes { span, .. } = asyncness {
if let Some(ast::CoroutineKind::Async { span, .. }) = coro_kind {
self.sess.emit_err(FnPointerCannotBeAsync { span: whole_span, qualifier: span });
}
// FIXME(gen_blocks): emit a similar error for `gen fn()`
let decl_span = span_start.to(self.token.span);
Ok(TyKind::BareFn(P(BareFnTy { ext, unsafety, generic_params: params, decl, decl_span })))
}

16
compiler/rustc_resolve/src/def_collector.rs
View File

@ -156,7 +156,10 @@ impl<'a, 'b, 'tcx> visit::Visitor<'a> for DefCollector<'a, 'b, 'tcx> {
fn visit_fn(&mut self, fn_kind: FnKind<'a>, span: Span, _: NodeId) {
if let FnKind::Fn(_, _, sig, _, generics, body) = fn_kind {
if let Async::Yes { closure_id, .. } = sig.header.asyncness {
if let Some(
CoroutineKind::Async { closure_id, .. } | CoroutineKind::Gen { closure_id, .. },
) = sig.header.coro_kind
{
self.visit_generics(generics);
// For async functions, we need to create their inner defs inside of a
@ -281,11 +284,12 @@ impl<'a, 'b, 'tcx> visit::Visitor<'a> for DefCollector<'a, 'b, 'tcx> {
// Async closures desugar to closures inside of closures, so
// we must create two defs.
let closure_def = self.create_def(expr.id, kw::Empty, DefKind::Closure, expr.span);
match closure.asyncness {
Async::Yes { closure_id, .. } => {
self.create_def(closure_id, kw::Empty, DefKind::Closure, expr.span)
}
Async::No => closure_def,
match closure.coro_kind {
Some(
CoroutineKind::Async { closure_id, .. }
| CoroutineKind::Gen { closure_id, .. },
) => self.create_def(closure_id, kw::Empty, DefKind::Closure, expr.span),
None => closure_def,
}
}
ExprKind::Gen(_, _, _) => {

17
compiler/rustc_resolve/src/late.rs
View File

@ -916,8 +916,10 @@ impl<'a: 'ast, 'ast, 'tcx> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast,
&sig.decl.output,
);
if let Some((async_node_id, _)) = sig.header.asyncness.opt_return_id() {
this.record_lifetime_params_for_impl_trait(async_node_id);
if let Some((coro_node_id, _)) =
sig.header.coro_kind.map(|coro_kind| coro_kind.return_id())
{
this.record_lifetime_params_for_impl_trait(coro_node_id);
}
},
);
@ -940,12 +942,13 @@ impl<'a: 'ast, 'ast, 'tcx> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast,
this.visit_generics(generics);
let declaration = &sig.decl;
let async_node_id = sig.header.asyncness.opt_return_id();
let coro_node_id =
sig.header.coro_kind.map(|coro_kind| coro_kind.return_id());
this.with_lifetime_rib(
LifetimeRibKind::AnonymousCreateParameter {
binder: fn_id,
report_in_path: async_node_id.is_some(),
report_in_path: coro_node_id.is_some(),
},
|this| {
this.resolve_fn_signature(
@ -958,7 +961,7 @@ impl<'a: 'ast, 'ast, 'tcx> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast,
&declaration.output,
);
if let Some((async_node_id, _)) = async_node_id {
if let Some((async_node_id, _)) = coro_node_id {
this.record_lifetime_params_for_impl_trait(async_node_id);
}
},
@ -4288,8 +4291,10 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
// `async |x| ...` gets desugared to `|x| async {...}`, so we need to
// resolve the arguments within the proper scopes so that usages of them inside the
// closure are detected as upvars rather than normal closure arg usages.
//
// Similarly, `gen |x| ...` gets desugared to `|x| gen {...}`, so we handle that too.
ExprKind::Closure(box ast::Closure {
asyncness: Async::Yes { .. },
coro_kind: Some(_),
ref fn_decl,
ref body,
..

4
src/tools/clippy/clippy_lints/src/doc/needless_doctest_main.rs
View File

@ -3,7 +3,7 @@ use std::{io, thread};
use crate::doc::{NEEDLESS_DOCTEST_MAIN, TEST_ATTR_IN_DOCTEST};
use clippy_utils::diagnostics::span_lint;
use rustc_ast::{Async, Fn, FnRetTy, Item, ItemKind};
use rustc_ast::{CoroutineKind, Fn, FnRetTy, Item, ItemKind};
use rustc_data_structures::sync::Lrc;
use rustc_errors::emitter::EmitterWriter;
use rustc_errors::Handler;
@ -69,7 +69,7 @@ pub fn check(
if !ignore {
get_test_spans(&item, &mut test_attr_spans);
}
let is_async = matches!(sig.header.asyncness, Async::Yes { .. });
let is_async = matches!(sig.header.coro_kind, Some(CoroutineKind::Async { .. }));
let returns_nothing = match &sig.decl.output {
FnRetTy::Default(..) => true,
FnRetTy::Ty(ty) if ty.kind.is_unit() => true,

17
src/tools/clippy/clippy_utils/src/ast_utils.rs
View File

@ -188,7 +188,7 @@ pub fn eq_expr(l: &Expr, r: &Expr) -> bool {
Closure(box ast::Closure {
binder: lb,
capture_clause: lc,
asyncness: la,
coro_kind: la,
movability: lm,
fn_decl: lf,
body: le,
@ -197,7 +197,7 @@ pub fn eq_expr(l: &Expr, r: &Expr) -> bool {
Closure(box ast::Closure {
binder: rb,
capture_clause: rc,
asyncness: ra,
coro_kind: ra,
movability: rm,
fn_decl: rf,
body: re,
@ -206,7 +206,7 @@ pub fn eq_expr(l: &Expr, r: &Expr) -> bool {
) => {
eq_closure_binder(lb, rb)
&& lc == rc
&& la.is_async() == ra.is_async()
&& la.map_or(false, |la| la.is_async()) == ra.map_or(false, |ra| ra.is_async())
&& lm == rm
&& eq_fn_decl(lf, rf)
&& eq_expr(le, re)
@ -563,9 +563,18 @@ pub fn eq_fn_sig(l: &FnSig, r: &FnSig) -> bool {
eq_fn_decl(&l.decl, &r.decl) && eq_fn_header(&l.header, &r.header)
}
fn eq_opt_coro_kind(l: Option<CoroutineKind>, r: Option<CoroutineKind>) -> bool {
match (l, r) {
(Some(CoroutineKind::Async { .. }), Some(CoroutineKind::Async { .. }))
| (Some(CoroutineKind::Gen { .. }), Some(CoroutineKind::Gen { .. })) => true,
(None, None) => true,
_ => false,
}
}
pub fn eq_fn_header(l: &FnHeader, r: &FnHeader) -> bool {
matches!(l.unsafety, Unsafe::No) == matches!(r.unsafety, Unsafe::No)
&& l.asyncness.is_async() == r.asyncness.is_async()
&& eq_opt_coro_kind(l.coro_kind, r.coro_kind)
&& matches!(l.constness, Const::No) == matches!(r.constness, Const::No)
&& eq_ext(&l.ext, &r.ext)
}

20
src/tools/rustfmt/src/closures.rs
View File

@ -29,7 +29,7 @@ pub(crate) fn rewrite_closure(
binder: &ast::ClosureBinder,
constness: ast::Const,
capture: ast::CaptureBy,
is_async: &ast::Async,
coro_kind: &Option<ast::CoroutineKind>,
movability: ast::Movability,
fn_decl: &ast::FnDecl,
body: &ast::Expr,
@ -40,7 +40,7 @@ pub(crate) fn rewrite_closure(
debug!("rewrite_closure {:?}", body);
let (prefix, extra_offset) = rewrite_closure_fn_decl(
binder, constness, capture, is_async, movability, fn_decl, body, span, context, shape,
binder, constness, capture, coro_kind, movability, fn_decl, body, span, context, shape,
)?;
// 1 = space between `|...|` and body.
let body_shape = shape.offset_left(extra_offset)?;
@ -233,7 +233,7 @@ fn rewrite_closure_fn_decl(
binder: &ast::ClosureBinder,
constness: ast::Const,
capture: ast::CaptureBy,
asyncness: &ast::Async,
coro_kind: &Option<ast::CoroutineKind>,
movability: ast::Movability,
fn_decl: &ast::FnDecl,
body: &ast::Expr,
@ -263,7 +263,11 @@ fn rewrite_closure_fn_decl(
} else {
""
};
let is_async = if asyncness.is_async() { "async " } else { "" };
let coro = match coro_kind {
Some(ast::CoroutineKind::Async { .. }) => "async ",
Some(ast::CoroutineKind::Gen { .. }) => "gen ",
None => "",
};
let mover = if matches!(capture, ast::CaptureBy::Value { .. }) {
"move "
} else {
@ -272,7 +276,7 @@ fn rewrite_closure_fn_decl(
// 4 = "|| {".len(), which is overconservative when the closure consists of
// a single expression.
let nested_shape = shape
.shrink_left(binder.len() + const_.len() + immovable.len() + is_async.len() + mover.len())?
.shrink_left(binder.len() + const_.len() + immovable.len() + coro.len() + mover.len())?
.sub_width(4)?;
// 1 = |
@ -310,7 +314,7 @@ fn rewrite_closure_fn_decl(
.tactic(tactic)
.preserve_newline(true);
let list_str = write_list(&item_vec, &fmt)?;
let mut prefix = format!("{binder}{const_}{immovable}{is_async}{mover}|{list_str}|");
let mut prefix = format!("{binder}{const_}{immovable}{coro}{mover}|{list_str}|");
if !ret_str.is_empty() {
if prefix.contains('\n') {
@ -339,7 +343,7 @@ pub(crate) fn rewrite_last_closure(
ref binder,
constness,
capture_clause,
ref asyncness,
ref coro_kind,
movability,
ref fn_decl,
ref body,
@ -360,7 +364,7 @@ pub(crate) fn rewrite_last_closure(
binder,
constness,
capture_clause,
asyncness,
coro_kind,
movability,
fn_decl,
body,

2
src/tools/rustfmt/src/expr.rs
View File

@ -212,7 +212,7 @@ pub(crate) fn format_expr(
&cl.binder,
cl.constness,
cl.capture_clause,
&cl.asyncness,
&cl.coro_kind,
cl.movability,
&cl.fn_decl,
&cl.body,

9
src/tools/rustfmt/src/items.rs
View File

@ -287,7 +287,7 @@ pub(crate) struct FnSig<'a> {
decl: &'a ast::FnDecl,
generics: &'a ast::Generics,
ext: ast::Extern,
is_async: Cow<'a, ast::Async>,
coro_kind: Cow<'a, Option<ast::CoroutineKind>>,
constness: ast::Const,
defaultness: ast::Defaultness,
unsafety: ast::Unsafe,
@ -302,7 +302,7 @@ impl<'a> FnSig<'a> {
) -> FnSig<'a> {
FnSig {
unsafety: method_sig.header.unsafety,
is_async: Cow::Borrowed(&method_sig.header.asyncness),
coro_kind: Cow::Borrowed(&method_sig.header.coro_kind),
constness: method_sig.header.constness,
defaultness: ast::Defaultness::Final,
ext: method_sig.header.ext,
@ -328,7 +328,7 @@ impl<'a> FnSig<'a> {
generics,
ext: fn_sig.header.ext,
constness: fn_sig.header.constness,
is_async: Cow::Borrowed(&fn_sig.header.asyncness),
coro_kind: Cow::Borrowed(&fn_sig.header.coro_kind),
defaultness,
unsafety: fn_sig.header.unsafety,
visibility: vis,
@ -343,7 +343,8 @@ impl<'a> FnSig<'a> {
result.push_str(&*format_visibility(context, self.visibility));
result.push_str(format_defaultness(self.defaultness));
result.push_str(format_constness(self.constness));
result.push_str(format_async(&self.is_async));
self.coro_kind
.map(|coro_kind| result.push_str(format_coro(&coro_kind)));
result.push_str(format_unsafety(self.unsafety));
result.push_str(&format_extern(
self.ext,

8
src/tools/rustfmt/src/utils.rs
View File

@ -75,10 +75,10 @@ pub(crate) fn format_visibility(
}
#[inline]
pub(crate) fn format_async(is_async: &ast::Async) -> &'static str {
match is_async {
ast::Async::Yes { .. } => "async ",
ast::Async::No => "",
pub(crate) fn format_coro(coro_kind: &ast::CoroutineKind) -> &'static str {
match coro_kind {
ast::CoroutineKind::Async { .. } => "async ",
ast::CoroutineKind::Gen { .. } => "gen ",
}
}

2
tests/ui-fulldeps/pprust-expr-roundtrip.rs
View File

@ -132,7 +132,7 @@ fn iter_exprs(depth: usize, f: &mut dyn FnMut(P<Expr>)) {
binder: ClosureBinder::NotPresent,
capture_clause: CaptureBy::Value { move_kw: DUMMY_SP },
constness: Const::No,
asyncness: Async::No,
coro_kind: None,
movability: Movability::Movable,
fn_decl: decl.clone(),
body: e,

11
tests/ui/coroutine/async_gen_fn.rs Normal file
View File

@ -0,0 +1,11 @@
// edition: 2024
// compile-flags: -Zunstable-options
#![feature(gen_blocks)]
// async generators are not yet supported, so this test makes sure they make some kind of reasonable
// error.
async gen fn foo() {}
//~^ `async gen` functions are not supported
fn main() {}

8
tests/ui/coroutine/async_gen_fn.stderr Normal file
View File

@ -0,0 +1,8 @@
error: `async gen` functions are not supported
--> $DIR/async_gen_fn.rs:8:1
|
LL | async gen fn foo() {}
| ^^^^^^^^^
error: aborting due to 1 previous error

6
tests/ui/coroutine/gen_fn.e2024.stderr
View File

@ -1,10 +1,12 @@
error: `gen` functions are not yet implemented
error[E0658]: gen blocks are experimental
--> $DIR/gen_fn.rs:4:1
|
LL | gen fn foo() {}
| ^^^
|
= help: for now you can use `gen {}` blocks and return `impl Iterator` instead
= 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: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0658`.

2
tests/ui/coroutine/gen_fn.rs
View File

@ -3,6 +3,6 @@
gen fn foo() {}
//[none]~^ ERROR: expected one of `#`, `async`, `const`, `default`, `extern`, `fn`, `pub`, `unsafe`, or `use`, found `gen`
//[e2024]~^^ ERROR: `gen` functions are not yet implemented
//[e2024]~^^ ERROR: gen blocks are experimental
fn main() {}

20
tests/ui/coroutine/gen_fn_iter.rs Normal file
View File

@ -0,0 +1,20 @@
// edition: 2024
// compile-flags: -Zunstable-options
// run-pass
#![feature(gen_blocks)]
// make sure that a ridiculously simple gen fn works as an iterator.
gen fn foo() -> i32 {
yield 1;
yield 2;
yield 3;
}
fn main() {
let mut iter = foo();
assert_eq!(iter.next(), Some(1));
assert_eq!(iter.next(), Some(2));
assert_eq!(iter.next(), Some(3));
assert_eq!(iter.next(), None);
}

19
tests/ui/coroutine/gen_fn_lifetime_capture.rs Normal file
View File

@ -0,0 +1,19 @@
// edition: 2024
// compile-flags: -Zunstable-options
// check-pass
#![feature(gen_blocks)]
// make sure gen fn captures lifetimes in its signature
gen fn foo<'a, 'b>(x: &'a i32, y: &'b i32, z: &'b i32) -> &'b i32 {
yield y;
yield z;
}
fn main() {
let z = 3;
let mut iter = foo(&1, &2, &z);
assert_eq!(iter.next(), Some(&2));
assert_eq!(iter.next(), Some(&3));
assert_eq!(iter.next(), None);
}