diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs index 36af5394015..dbae8bfb542 100644 --- a/compiler/rustc_hir_typeck/src/closure.rs +++ b/compiler/rustc_hir_typeck/src/closure.rs @@ -227,11 +227,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { kind: TypeVariableOriginKind::ClosureSynthetic, span: expr_span, }); - let closure_kind_ty = self.next_ty_var(TypeVariableOrigin { - // FIXME(eddyb) distinguish closure kind inference variables from the rest. - kind: TypeVariableOriginKind::ClosureSynthetic, - span: expr_span, - }); + + let closure_kind_ty = match expected_kind { + Some(kind) => Ty::from_closure_kind(tcx, kind), + + // Create a type variable (for now) to represent the closure kind. + // It will be unified during the upvar inference phase (`upvar.rs`) + None => self.next_ty_var(TypeVariableOrigin { + kind: TypeVariableOriginKind::ClosureSynthetic, + span: expr_span, + }), + }; + let coroutine_captures_by_ref_ty = self.next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::ClosureSynthetic, span: expr_span, @@ -262,10 +269,17 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { }, ); - let coroutine_kind_ty = self.next_ty_var(TypeVariableOrigin { - kind: TypeVariableOriginKind::ClosureSynthetic, - span: expr_span, - }); + let coroutine_kind_ty = match expected_kind { + Some(kind) => Ty::from_coroutine_closure_kind(tcx, kind), + + // Create a type variable (for now) to represent the closure kind. + // It will be unified during the upvar inference phase (`upvar.rs`) + None => self.next_ty_var(TypeVariableOrigin { + kind: TypeVariableOriginKind::ClosureSynthetic, + span: expr_span, + }), + }; + let coroutine_upvars_ty = self.next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::ClosureSynthetic, span: expr_span, diff --git a/compiler/rustc_hir_typeck/src/upvar.rs b/compiler/rustc_hir_typeck/src/upvar.rs index 72e5b1ed95b..947fff67919 100644 --- a/compiler/rustc_hir_typeck/src/upvar.rs +++ b/compiler/rustc_hir_typeck/src/upvar.rs @@ -399,16 +399,22 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ); // Additionally, we can now constrain the coroutine's kind type. - let ty::Coroutine(_, coroutine_args) = - *self.typeck_results.borrow().expr_ty(body.value).kind() - else { - bug!(); - }; - self.demand_eqtype( - span, - coroutine_args.as_coroutine().kind_ty(), - Ty::from_coroutine_closure_kind(self.tcx, closure_kind), - ); + // + // We only do this if `infer_kind`, because if we have constrained + // the kind from closure signature inference, the kind inferred + // for the inner coroutine may actually be more restrictive. + if infer_kind { + let ty::Coroutine(_, coroutine_args) = + *self.typeck_results.borrow().expr_ty(body.value).kind() + else { + bug!(); + }; + self.demand_eqtype( + span, + coroutine_args.as_coroutine().kind_ty(), + Ty::from_coroutine_closure_kind(self.tcx, closure_kind), + ); + } } self.log_closure_min_capture_info(closure_def_id, span); diff --git a/src/tools/miri/tests/pass/async-closure-captures.rs b/src/tools/miri/tests/pass/async-closure-captures.rs index 3e33de32efb..cac26bfe146 100644 --- a/src/tools/miri/tests/pass/async-closure-captures.rs +++ b/src/tools/miri/tests/pass/async-closure-captures.rs @@ -88,4 +88,38 @@ async fn async_main() { }; call_once(c).await; } + + fn force_fnonce(f: impl async FnOnce() -> T) -> impl async FnOnce() -> T { + f + } + + // Capture something with `move`, but infer to `AsyncFnOnce` + { + let x = Hello(6); + let c = force_fnonce(async move || { + println!("{x:?}"); + }); + call_once(c).await; + + let x = &Hello(7); + let c = force_fnonce(async move || { + println!("{x:?}"); + }); + call_once(c).await; + } + + // Capture something by-ref, but infer to `AsyncFnOnce` + { + let x = Hello(8); + let c = force_fnonce(async || { + println!("{x:?}"); + }); + call_once(c).await; + + let x = &Hello(9); + let c = force_fnonce(async || { + println!("{x:?}"); + }); + call_once(c).await; + } } diff --git a/src/tools/miri/tests/pass/async-closure-captures.stderr b/src/tools/miri/tests/pass/async-closure-captures.stderr new file mode 100644 index 00000000000..f1548aadefa --- /dev/null +++ b/src/tools/miri/tests/pass/async-closure-captures.stderr @@ -0,0 +1,31 @@ +error[E0597]: `x` does not live long enough + --> $DIR/async-closure-captures.rs:LL:CC + | +LL | let c = force_fnonce(async move || { + | ____________________________________________- +LL | | println!("{x:?}"); + | | ^ borrowed value does not live long enough +LL | | }); + | | -- + | | || + | | |`x` dropped here while still borrowed + | |_________|borrow later used here + | value captured here by coroutine + +error[E0597]: `x` does not live long enough + --> $DIR/async-closure-captures.rs:LL:CC + | +LL | let c = force_fnonce(async move || { + | ____________________________________________- +LL | | println!("{x:?}"); + | | ^ borrowed value does not live long enough +LL | | }); + | | -- + | | || + | | |`x` dropped here while still borrowed + | |_________|borrow later used here + | value captured here by coroutine + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0597`. diff --git a/src/tools/miri/tests/pass/async-closure-captures.stdout b/src/tools/miri/tests/pass/async-closure-captures.stdout deleted file mode 100644 index a0db6d236fe..00000000000 --- a/src/tools/miri/tests/pass/async-closure-captures.stdout +++ /dev/null @@ -1,10 +0,0 @@ -Hello(0) -Hello(0) -Hello(1) -Hello(1) -Hello(2) -Hello(3) -Hello(3) -Hello(4) -Hello(4) -Hello(5) diff --git a/tests/ui/async-await/async-closures/captures.rs b/tests/ui/async-await/async-closures/captures.rs index e3ab8713709..6011292b645 100644 --- a/tests/ui/async-await/async-closures/captures.rs +++ b/tests/ui/async-await/async-closures/captures.rs @@ -1,7 +1,7 @@ //@ aux-build:block-on.rs //@ edition:2021 -//@ run-pass -//@ check-run-results + + // Same as miri's `tests/pass/async-closure-captures.rs`, keep in sync @@ -79,4 +79,40 @@ async fn async_main() { }; call_once(c).await; } + + fn force_fnonce(f: impl async FnOnce() -> T) -> impl async FnOnce() -> T { + f + } + + // Capture something with `move`, but infer to `AsyncFnOnce` + { + let x = Hello(6); + let c = force_fnonce(async move || { + println!("{x:?}"); + }); + call_once(c).await; + + let x = &Hello(7); + let c = force_fnonce(async move || { + println!("{x:?}"); + }); + call_once(c).await; + } + + // Capture something by-ref, but infer to `AsyncFnOnce` + { + let x = Hello(8); + let c = force_fnonce(async || { + println!("{x:?}"); + //~^ ERROR `x` does not live long enough + }); + call_once(c).await; + + let x = &Hello(9); + let c = force_fnonce(async || { + println!("{x:?}"); + //~^ ERROR `x` does not live long enough + }); + call_once(c).await; + } } diff --git a/tests/ui/async-await/async-closures/captures.stderr b/tests/ui/async-await/async-closures/captures.stderr new file mode 100644 index 00000000000..5893854e57a --- /dev/null +++ b/tests/ui/async-await/async-closures/captures.stderr @@ -0,0 +1,31 @@ +error[E0597]: `x` does not live long enough + --> $DIR/captures.rs:89:24 + | +LL | let c = force_fnonce(async move || { + | ____________________________________________- +LL | | println!("{x:?}"); + | | ^ borrowed value does not live long enough +LL | | }); + | | -- + | | || + | | |`x` dropped here while still borrowed + | |_________|borrow later used here + | value captured here by coroutine + +error[E0597]: `x` does not live long enough + --> $DIR/captures.rs:95:24 + | +LL | let c = force_fnonce(async move || { + | ____________________________________________- +LL | | println!("{x:?}"); + | | ^ borrowed value does not live long enough +LL | | }); + | | -- + | | || + | | |`x` dropped here while still borrowed + | |_________|borrow later used here + | value captured here by coroutine + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0597`. diff --git a/tests/ui/async-await/async-closures/wrong-fn-kind.rs b/tests/ui/async-await/async-closures/wrong-fn-kind.rs index 8502bb6e2d4..3d6f856874f 100644 --- a/tests/ui/async-await/async-closures/wrong-fn-kind.rs +++ b/tests/ui/async-await/async-closures/wrong-fn-kind.rs @@ -2,18 +2,22 @@ #![feature(async_closure)] -fn main() { - fn needs_async_fn(_: impl async Fn()) {} +fn needs_async_fn(_: impl async Fn()) {} +fn a() { let mut x = 1; needs_async_fn(async || { - //~^ ERROR expected a closure that implements the `async Fn` trait, but this closure only implements `async FnMut` + //~^ ERROR cannot borrow `x` as mutable, as it is a captured variable in a `Fn` closure x += 1; }); +} +fn b() { let x = String::new(); needs_async_fn(move || async move { //~^ ERROR expected a closure that implements the `async Fn` trait, but this closure only implements `async FnOnce` println!("{x}"); }); } + +fn main() {} diff --git a/tests/ui/async-await/async-closures/wrong-fn-kind.stderr b/tests/ui/async-await/async-closures/wrong-fn-kind.stderr index d0f1948e48f..e56389b3202 100644 --- a/tests/ui/async-await/async-closures/wrong-fn-kind.stderr +++ b/tests/ui/async-await/async-closures/wrong-fn-kind.stderr @@ -1,26 +1,5 @@ -error[E0525]: expected a closure that implements the `async Fn` trait, but this closure only implements `async FnMut` - --> $DIR/wrong-fn-kind.rs:9:20 - | -LL | needs_async_fn(async || { - | -------------- -^^^^^^^ - | | | - | _____|______________this closure implements `async FnMut`, not `async Fn` - | | | - | | required by a bound introduced by this call -LL | | -LL | | x += 1; - | | - closure is `async FnMut` because it mutates the variable `x` here -LL | | }); - | |_____- the requirement to implement `async Fn` derives from here - | -note: required by a bound in `needs_async_fn` - --> $DIR/wrong-fn-kind.rs:6:31 - | -LL | fn needs_async_fn(_: impl async Fn()) {} - | ^^^^^^^^^^ required by this bound in `needs_async_fn` - error[E0525]: expected a closure that implements the `async Fn` trait, but this closure only implements `async FnOnce` - --> $DIR/wrong-fn-kind.rs:15:20 + --> $DIR/wrong-fn-kind.rs:17:20 | LL | needs_async_fn(move || async move { | -------------- -^^^^^^ @@ -35,11 +14,29 @@ LL | | }); | |_____- the requirement to implement `async Fn` derives from here | note: required by a bound in `needs_async_fn` - --> $DIR/wrong-fn-kind.rs:6:31 + --> $DIR/wrong-fn-kind.rs:5:27 | -LL | fn needs_async_fn(_: impl async Fn()) {} - | ^^^^^^^^^^ required by this bound in `needs_async_fn` +LL | fn needs_async_fn(_: impl async Fn()) {} + | ^^^^^^^^^^ required by this bound in `needs_async_fn` + +error[E0596]: cannot borrow `x` as mutable, as it is a captured variable in a `Fn` closure + --> $DIR/wrong-fn-kind.rs:9:29 + | +LL | fn needs_async_fn(_: impl async Fn()) {} + | --------------- change this to accept `FnMut` instead of `Fn` +... +LL | needs_async_fn(async || { + | _____--------------_--------_^ + | | | | + | | | in this closure + | | expects `Fn` instead of `FnMut` +LL | | +LL | | x += 1; + | | - mutable borrow occurs due to use of `x` in closure +LL | | }); + | |_____^ cannot borrow as mutable error: aborting due to 2 previous errors -For more information about this error, try `rustc --explain E0525`. +Some errors have detailed explanations: E0525, E0596. +For more information about an error, try `rustc --explain E0525`.