diff --git a/compiler/rustc_const_eval/src/check_consts/qualifs.rs b/compiler/rustc_const_eval/src/check_consts/qualifs.rs
index 9fd7219499b27..d5d3f7767b133 100644
--- a/compiler/rustc_const_eval/src/check_consts/qualifs.rs
+++ b/compiler/rustc_const_eval/src/check_consts/qualifs.rs
@@ -100,7 +100,33 @@ impl Qualif for HasMutInterior {
}
fn in_any_value_of_ty<'tcx>(cx: &ConstCx<'_, 'tcx>, ty: Ty<'tcx>) -> bool {
- !ty.is_freeze(cx.tcx, cx.param_env)
+ // Avoid selecting for simple cases, such as builtin types.
+ if ty.is_trivially_freeze() {
+ return false;
+ }
+
+ // We do not use `ty.is_freeze` here, because that requires revealing opaque types, which
+ // requires borrowck, which in turn will invoke mir_const_qualifs again, causing a cycle error.
+ // Instead we invoke an obligation context manually, and provide the opaque type inference settings
+ // that allow the trait solver to just error out instead of cycling.
+ let freeze_def_id = cx.tcx.require_lang_item(LangItem::Freeze, Some(cx.body.span));
+
+ let obligation = Obligation::new(
+ cx.tcx,
+ ObligationCause::dummy_with_span(cx.body.span),
+ cx.param_env,
+ ty::TraitRef::new(cx.tcx, freeze_def_id, [ty::GenericArg::from(ty)]),
+ );
+
+ let infcx = cx
+ .tcx
+ .infer_ctxt()
+ .with_opaque_type_inference(cx.body.source.def_id().expect_local())
+ .build();
+ let ocx = ObligationCtxt::new(&infcx);
+ ocx.register_obligation(obligation);
+ let errors = ocx.select_all_or_error();
+ !errors.is_empty()
}
fn in_adt_inherently<'tcx>(
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 9307e38068128..4335d96737aaf 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -1268,7 +1268,7 @@ impl<'tcx> Ty<'tcx> {
///
/// Returning true means the type is known to be `Freeze`. Returning
/// `false` means nothing -- could be `Freeze`, might not be.
- fn is_trivially_freeze(self) -> bool {
+ pub fn is_trivially_freeze(self) -> bool {
match self.kind() {
ty::Int(_)
| ty::Uint(_)
diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
index 4c3d833b0f90f..06b79ea63ca47 100644
--- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
@@ -772,7 +772,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
);
}
- ty::Alias(ty::Opaque, _) => {
+ ty::Alias(ty::Opaque, alias) => {
if candidates.vec.iter().any(|c| matches!(c, ProjectionCandidate(_))) {
// We do not generate an auto impl candidate for `impl Trait`s which already
// reference our auto trait.
@@ -787,6 +787,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// We do not emit auto trait candidates for opaque types in coherence.
// Doing so can result in weird dependency cycles.
candidates.ambiguous = true;
+ } else if self.infcx.can_define_opaque_ty(alias.def_id) {
+ // We do not emit auto trait candidates for opaque types in their defining scope, as
+ // we need to know the hidden type first, which we can't reliably know within the defining
+ // scope.
+ candidates.ambiguous = true;
} else {
candidates.vec.push(AutoImplCandidate)
}
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 02ad361f9f59f..c007cd5314a86 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -2386,13 +2386,17 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
}
ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => {
- // We can resolve the `impl Trait` to its concrete type,
- // which enforces a DAG between the functions requiring
- // the auto trait bounds in question.
- match self.tcx().type_of_opaque(def_id) {
- Ok(ty) => t.rebind(vec![ty.instantiate(self.tcx(), args)]),
- Err(_) => {
- return Err(SelectionError::OpaqueTypeAutoTraitLeakageUnknown(def_id));
+ if self.infcx.can_define_opaque_ty(def_id) {
+ unreachable!()
+ } else {
+ // We can resolve the `impl Trait` to its concrete type,
+ // which enforces a DAG between the functions requiring
+ // the auto trait bounds in question.
+ match self.tcx().type_of_opaque(def_id) {
+ Ok(ty) => t.rebind(vec![ty.instantiate(self.tcx(), args)]),
+ Err(_) => {
+ return Err(SelectionError::OpaqueTypeAutoTraitLeakageUnknown(def_id));
+ }
}
}
}
diff --git a/tests/ui/const-generics/opaque_types.stderr b/tests/ui/const-generics/opaque_types.stderr
index 2c7384984c694..3947d645fcbe2 100644
--- a/tests/ui/const-generics/opaque_types.stderr
+++ b/tests/ui/const-generics/opaque_types.stderr
@@ -122,8 +122,6 @@ note: ...which requires const checking `main::{constant#0}`...
|
LL | foo::<42>();
| ^^
- = note: ...which requires computing whether `Foo` is freeze...
- = note: ...which requires evaluating trait selection obligation `Foo: core::marker::Freeze`...
= note: ...which again requires computing type of opaque `Foo::{opaque#0}`, completing the cycle
note: cycle used when computing type of `Foo::{opaque#0}`
--> $DIR/opaque_types.rs:3:12
diff --git a/tests/ui/consts/const-fn-cycle.rs b/tests/ui/consts/const-fn-cycle.rs
index 5175296a53e5b..2879e3049c0d9 100644
--- a/tests/ui/consts/const-fn-cycle.rs
+++ b/tests/ui/consts/const-fn-cycle.rs
@@ -7,6 +7,8 @@
/// to end up revealing opaque types (the RPIT in `many`'s return type),
/// which can quickly lead to cycles.
+//@ check-pass
+
pub struct Parser<H>(H);
impl<H, T> Parser<H>
@@ -18,7 +20,6 @@ where
}
pub const fn many<'s>(&'s self) -> Parser<impl for<'a> Fn(&'a str) -> Vec<T> + 's> {
- //~^ ERROR: cycle detected
Parser::new(|_| unimplemented!())
}
}
diff --git a/tests/ui/consts/const-fn-cycle.stderr b/tests/ui/consts/const-fn-cycle.stderr
deleted file mode 100644
index c851f7342be9c..0000000000000
--- a/tests/ui/consts/const-fn-cycle.stderr
+++ /dev/null
@@ -1,34 +0,0 @@
-error[E0391]: cycle detected when computing type of opaque `<impl at $DIR/const-fn-cycle.rs:12:1: 14:33>::many::{opaque#0}`
- --> $DIR/const-fn-cycle.rs:20:47
- |
-LL | pub const fn many<'s>(&'s self) -> Parser<impl for<'a> Fn(&'a str) -> Vec<T> + 's> {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- |
-note: ...which requires borrow-checking `<impl at $DIR/const-fn-cycle.rs:12:1: 14:33>::many`...
- --> $DIR/const-fn-cycle.rs:20:5
- |
-LL | pub const fn many<'s>(&'s self) -> Parser<impl for<'a> Fn(&'a str) -> Vec<T> + 's> {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires promoting constants in MIR for `<impl at $DIR/const-fn-cycle.rs:12:1: 14:33>::many`...
- --> $DIR/const-fn-cycle.rs:20:5
- |
-LL | pub const fn many<'s>(&'s self) -> Parser<impl for<'a> Fn(&'a str) -> Vec<T> + 's> {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires const checking `<impl at $DIR/const-fn-cycle.rs:12:1: 14:33>::many`...
- --> $DIR/const-fn-cycle.rs:20:5
- |
-LL | pub const fn many<'s>(&'s self) -> Parser<impl for<'a> Fn(&'a str) -> Vec<T> + 's> {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- = note: ...which requires computing whether `Parser<<impl at $DIR/const-fn-cycle.rs:12:1: 14:33>::many::{opaque#0}>` is freeze...
- = note: ...which requires evaluating trait selection obligation `Parser<<impl at $DIR/const-fn-cycle.rs:12:1: 14:33>::many::{opaque#0}>: core::marker::Freeze`...
- = note: ...which again requires computing type of opaque `<impl at $DIR/const-fn-cycle.rs:12:1: 14:33>::many::{opaque#0}`, completing the cycle
-note: cycle used when computing type of `<impl at $DIR/const-fn-cycle.rs:12:1: 14:33>::many::{opaque#0}`
- --> $DIR/const-fn-cycle.rs:20:47
- |
-LL | pub const fn many<'s>(&'s self) -> Parser<impl for<'a> Fn(&'a str) -> Vec<T> + 's> {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0391`.
diff --git a/tests/ui/consts/const-promoted-opaque.atomic.stderr b/tests/ui/consts/const-promoted-opaque.atomic.stderr
index a0459f4040ec6..1f2a7753ff543 100644
--- a/tests/ui/consts/const-promoted-opaque.atomic.stderr
+++ b/tests/ui/consts/const-promoted-opaque.atomic.stderr
@@ -1,5 +1,5 @@
error[E0658]: cannot borrow here, since the borrowed element may contain interior mutability
- --> $DIR/const-promoted-opaque.rs:29:25
+ --> $DIR/const-promoted-opaque.rs:28:25
|
LL | let _: &'static _ = &FOO;
| ^^^^
@@ -9,7 +9,7 @@ LL | let _: &'static _ = &FOO;
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
error[E0493]: destructor of `helper::Foo` cannot be evaluated at compile-time
- --> $DIR/const-promoted-opaque.rs:29:26
+ --> $DIR/const-promoted-opaque.rs:28:26
|
LL | let _: &'static _ = &FOO;
| ^^^ the destructor for this type cannot be evaluated in constants
@@ -18,13 +18,13 @@ LL | };
| - value is dropped here
error[E0492]: constants cannot refer to interior mutable data
- --> $DIR/const-promoted-opaque.rs:34:19
+ --> $DIR/const-promoted-opaque.rs:33:19
|
LL | const BAZ: &Foo = &FOO;
| ^^^^ this borrow of an interior mutable value may end up in the final value
error[E0716]: temporary value dropped while borrowed
- --> $DIR/const-promoted-opaque.rs:38:26
+ --> $DIR/const-promoted-opaque.rs:37:26
|
LL | let _: &'static _ = &FOO;
| ---------- ^^^ creates a temporary value which is freed while still in use
@@ -34,38 +34,7 @@ LL |
LL | }
| - temporary value is freed at the end of this statement
-error[E0391]: cycle detected when computing type of opaque `helper::Foo::{opaque#0}`
- --> $DIR/const-promoted-opaque.rs:14:20
- |
-LL | pub type Foo = impl Sized;
- | ^^^^^^^^^^
- |
-note: ...which requires borrow-checking `helper::FOO`...
- --> $DIR/const-promoted-opaque.rs:21:5
- |
-LL | pub const FOO: Foo = std::sync::atomic::AtomicU8::new(42);
- | ^^^^^^^^^^^^^^^^^^
-note: ...which requires promoting constants in MIR for `helper::FOO`...
- --> $DIR/const-promoted-opaque.rs:21:5
- |
-LL | pub const FOO: Foo = std::sync::atomic::AtomicU8::new(42);
- | ^^^^^^^^^^^^^^^^^^
-note: ...which requires const checking `helper::FOO`...
- --> $DIR/const-promoted-opaque.rs:21:5
- |
-LL | pub const FOO: Foo = std::sync::atomic::AtomicU8::new(42);
- | ^^^^^^^^^^^^^^^^^^
- = note: ...which requires computing whether `helper::Foo` is freeze...
- = note: ...which requires evaluating trait selection obligation `helper::Foo: core::marker::Freeze`...
- = note: ...which again requires computing type of opaque `helper::Foo::{opaque#0}`, completing the cycle
-note: cycle used when computing type of `helper::Foo::{opaque#0}`
- --> $DIR/const-promoted-opaque.rs:14:20
- |
-LL | pub type Foo = impl Sized;
- | ^^^^^^^^^^
- = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
-
-error: aborting due to 5 previous errors
+error: aborting due to 4 previous errors
-Some errors have detailed explanations: E0391, E0492, E0493, E0658, E0716.
-For more information about an error, try `rustc --explain E0391`.
+Some errors have detailed explanations: E0492, E0493, E0658, E0716.
+For more information about an error, try `rustc --explain E0492`.
diff --git a/tests/ui/consts/const-promoted-opaque.rs b/tests/ui/consts/const-promoted-opaque.rs
index e20823527f48b..303618df9df06 100644
--- a/tests/ui/consts/const-promoted-opaque.rs
+++ b/tests/ui/consts/const-promoted-opaque.rs
@@ -12,7 +12,6 @@
mod helper {
pub type Foo = impl Sized;
- //[string,atomic]~^ ERROR cycle detected
#[cfg(string)]
pub const FOO: Foo = String::new();
@@ -28,11 +27,11 @@ use helper::*;
const BAR: () = {
let _: &'static _ = &FOO;
//[string,atomic]~^ ERROR: destructor of `helper::Foo` cannot be evaluated at compile-time
- //[string,atomic]~| ERROR: cannot borrow here
+ //[atomic]~| ERROR: cannot borrow here
};
const BAZ: &Foo = &FOO;
-//[string,atomic]~^ ERROR: constants cannot refer to interior mutable data
+//[atomic]~^ ERROR: constants cannot refer to interior mutable data
fn main() {
let _: &'static _ = &FOO;
diff --git a/tests/ui/consts/const-promoted-opaque.string.stderr b/tests/ui/consts/const-promoted-opaque.string.stderr
index a613d517e68ef..fa1dbb05d175d 100644
--- a/tests/ui/consts/const-promoted-opaque.string.stderr
+++ b/tests/ui/consts/const-promoted-opaque.string.stderr
@@ -1,15 +1,5 @@
-error[E0658]: cannot borrow here, since the borrowed element may contain interior mutability
- --> $DIR/const-promoted-opaque.rs:29:25
- |
-LL | let _: &'static _ = &FOO;
- | ^^^^
- |
- = note: see issue #80384 <https://github.com/rust-lang/rust/issues/80384> for more information
- = help: add `#![feature(const_refs_to_cell)]` to the crate attributes to enable
- = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
error[E0493]: destructor of `helper::Foo` cannot be evaluated at compile-time
- --> $DIR/const-promoted-opaque.rs:29:26
+ --> $DIR/const-promoted-opaque.rs:28:26
|
LL | let _: &'static _ = &FOO;
| ^^^ the destructor for this type cannot be evaluated in constants
@@ -17,14 +7,8 @@ LL | let _: &'static _ = &FOO;
LL | };
| - value is dropped here
-error[E0492]: constants cannot refer to interior mutable data
- --> $DIR/const-promoted-opaque.rs:34:19
- |
-LL | const BAZ: &Foo = &FOO;
- | ^^^^ this borrow of an interior mutable value may end up in the final value
-
error[E0716]: temporary value dropped while borrowed
- --> $DIR/const-promoted-opaque.rs:38:26
+ --> $DIR/const-promoted-opaque.rs:37:26
|
LL | let _: &'static _ = &FOO;
| ---------- ^^^ creates a temporary value which is freed while still in use
@@ -34,38 +18,7 @@ LL |
LL | }
| - temporary value is freed at the end of this statement
-error[E0391]: cycle detected when computing type of opaque `helper::Foo::{opaque#0}`
- --> $DIR/const-promoted-opaque.rs:14:20
- |
-LL | pub type Foo = impl Sized;
- | ^^^^^^^^^^
- |
-note: ...which requires borrow-checking `helper::FOO`...
- --> $DIR/const-promoted-opaque.rs:18:5
- |
-LL | pub const FOO: Foo = String::new();
- | ^^^^^^^^^^^^^^^^^^
-note: ...which requires promoting constants in MIR for `helper::FOO`...
- --> $DIR/const-promoted-opaque.rs:18:5
- |
-LL | pub const FOO: Foo = String::new();
- | ^^^^^^^^^^^^^^^^^^
-note: ...which requires const checking `helper::FOO`...
- --> $DIR/const-promoted-opaque.rs:18:5
- |
-LL | pub const FOO: Foo = String::new();
- | ^^^^^^^^^^^^^^^^^^
- = note: ...which requires computing whether `helper::Foo` is freeze...
- = note: ...which requires evaluating trait selection obligation `helper::Foo: core::marker::Freeze`...
- = note: ...which again requires computing type of opaque `helper::Foo::{opaque#0}`, completing the cycle
-note: cycle used when computing type of `helper::Foo::{opaque#0}`
- --> $DIR/const-promoted-opaque.rs:14:20
- |
-LL | pub type Foo = impl Sized;
- | ^^^^^^^^^^
- = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
-
-error: aborting due to 5 previous errors
+error: aborting due to 2 previous errors
-Some errors have detailed explanations: E0391, E0492, E0493, E0658, E0716.
-For more information about an error, try `rustc --explain E0391`.
+Some errors have detailed explanations: E0493, E0716.
+For more information about an error, try `rustc --explain E0493`.
diff --git a/tests/ui/impl-trait/auto-trait-selection-freeze.next.stderr b/tests/ui/impl-trait/auto-trait-selection-freeze.next.stderr
new file mode 100644
index 0000000000000..5caf0eb2fd4e3
--- /dev/null
+++ b/tests/ui/impl-trait/auto-trait-selection-freeze.next.stderr
@@ -0,0 +1,22 @@
+error[E0283]: type annotations needed
+ --> $DIR/auto-trait-selection-freeze.rs:19:16
+ |
+LL | if false { is_trait(foo()) } else { Default::default() }
+ | ^^^^^^^^ ----- type must be known at this point
+ | |
+ | cannot infer type of the type parameter `T` declared on the function `is_trait`
+ |
+ = note: cannot satisfy `_: Trait<_>`
+note: required by a bound in `is_trait`
+ --> $DIR/auto-trait-selection-freeze.rs:11:16
+ |
+LL | fn is_trait<T: Trait<U>, U: Default>(_: T) -> U {
+ | ^^^^^^^^ required by this bound in `is_trait`
+help: consider specifying the generic arguments
+ |
+LL | if false { is_trait::<T, U>(foo()) } else { Default::default() }
+ | ++++++++
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0283`.
diff --git a/tests/ui/impl-trait/auto-trait-selection-freeze.old.stderr b/tests/ui/impl-trait/auto-trait-selection-freeze.old.stderr
new file mode 100644
index 0000000000000..b4d2229d408d2
--- /dev/null
+++ b/tests/ui/impl-trait/auto-trait-selection-freeze.old.stderr
@@ -0,0 +1,26 @@
+error[E0283]: type annotations needed
+ --> $DIR/auto-trait-selection-freeze.rs:19:16
+ |
+LL | if false { is_trait(foo()) } else { Default::default() }
+ | ^^^^^^^^ cannot infer type of the type parameter `U` declared on the function `is_trait`
+ |
+note: multiple `impl`s satisfying `impl Sized: Trait<_>` found
+ --> $DIR/auto-trait-selection-freeze.rs:16:1
+ |
+LL | impl<T: Freeze> Trait<u32> for T {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | impl<T> Trait<i32> for T {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^
+note: required by a bound in `is_trait`
+ --> $DIR/auto-trait-selection-freeze.rs:11:16
+ |
+LL | fn is_trait<T: Trait<U>, U: Default>(_: T) -> U {
+ | ^^^^^^^^ required by this bound in `is_trait`
+help: consider specifying the generic arguments
+ |
+LL | if false { is_trait::<_, U>(foo()) } else { Default::default() }
+ | ++++++++
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0283`.
diff --git a/tests/ui/impl-trait/auto-trait-selection-freeze.rs b/tests/ui/impl-trait/auto-trait-selection-freeze.rs
new file mode 100644
index 0000000000000..7306a1c41f746
--- /dev/null
+++ b/tests/ui/impl-trait/auto-trait-selection-freeze.rs
@@ -0,0 +1,23 @@
+//! This test shows how we fail selection in a way that can influence
+//! selection in a code path that succeeds.
+
+//@ revisions: next old
+//@[next] compile-flags: -Znext-solver
+
+#![feature(freeze)]
+
+use std::marker::Freeze;
+
+fn is_trait<T: Trait<U>, U: Default>(_: T) -> U {
+ Default::default()
+}
+
+trait Trait<T> {}
+impl<T: Freeze> Trait<u32> for T {}
+impl<T> Trait<i32> for T {}
+fn foo() -> impl Sized {
+ if false { is_trait(foo()) } else { Default::default() }
+ //~^ ERROR: type annotations needed
+}
+
+fn main() {}
diff --git a/tests/ui/impl-trait/auto-trait-selection.next.stderr b/tests/ui/impl-trait/auto-trait-selection.next.stderr
new file mode 100644
index 0000000000000..d34fdcc44967f
--- /dev/null
+++ b/tests/ui/impl-trait/auto-trait-selection.next.stderr
@@ -0,0 +1,22 @@
+error[E0283]: type annotations needed
+ --> $DIR/auto-trait-selection.rs:15:16
+ |
+LL | if false { is_trait(foo()) } else { Default::default() }
+ | ^^^^^^^^ ----- type must be known at this point
+ | |
+ | cannot infer type of the type parameter `T` declared on the function `is_trait`
+ |
+ = note: cannot satisfy `_: Trait<_>`
+note: required by a bound in `is_trait`
+ --> $DIR/auto-trait-selection.rs:7:16
+ |
+LL | fn is_trait<T: Trait<U>, U: Default>(_: T) -> U {
+ | ^^^^^^^^ required by this bound in `is_trait`
+help: consider specifying the generic arguments
+ |
+LL | if false { is_trait::<T, U>(foo()) } else { Default::default() }
+ | ++++++++
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0283`.
diff --git a/tests/ui/impl-trait/auto-trait-selection.old.stderr b/tests/ui/impl-trait/auto-trait-selection.old.stderr
new file mode 100644
index 0000000000000..1b5fd95fdf903
--- /dev/null
+++ b/tests/ui/impl-trait/auto-trait-selection.old.stderr
@@ -0,0 +1,26 @@
+error[E0283]: type annotations needed
+ --> $DIR/auto-trait-selection.rs:15:16
+ |
+LL | if false { is_trait(foo()) } else { Default::default() }
+ | ^^^^^^^^ cannot infer type of the type parameter `U` declared on the function `is_trait`
+ |
+note: multiple `impl`s satisfying `impl Sized: Trait<_>` found
+ --> $DIR/auto-trait-selection.rs:12:1
+ |
+LL | impl<T: Send> Trait<u32> for T {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | impl<T> Trait<i32> for T {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^
+note: required by a bound in `is_trait`
+ --> $DIR/auto-trait-selection.rs:7:16
+ |
+LL | fn is_trait<T: Trait<U>, U: Default>(_: T) -> U {
+ | ^^^^^^^^ required by this bound in `is_trait`
+help: consider specifying the generic arguments
+ |
+LL | if false { is_trait::<_, U>(foo()) } else { Default::default() }
+ | ++++++++
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0283`.
diff --git a/tests/ui/impl-trait/auto-trait-selection.rs b/tests/ui/impl-trait/auto-trait-selection.rs
new file mode 100644
index 0000000000000..ee5612459c257
--- /dev/null
+++ b/tests/ui/impl-trait/auto-trait-selection.rs
@@ -0,0 +1,19 @@
+//! This test shows how we fail selection in a way that can influence
+//! selection in a code path that succeeds.
+
+//@ revisions: next old
+//@[next] compile-flags: -Znext-solver
+
+fn is_trait<T: Trait<U>, U: Default>(_: T) -> U {
+ Default::default()
+}
+
+trait Trait<T> {}
+impl<T: Send> Trait<u32> for T {}
+impl<T> Trait<i32> for T {}
+fn foo() -> impl Sized {
+ if false { is_trait(foo()) } else { Default::default() }
+ //~^ ERROR: type annotations needed
+}
+
+fn main() {}
diff --git a/tests/ui/impl-trait/call_method_on_inherent_impl_ref.current.stderr b/tests/ui/impl-trait/call_method_on_inherent_impl_ref.current.stderr
index fe6e166cb4fa1..fb51bb7b4173b 100644
--- a/tests/ui/impl-trait/call_method_on_inherent_impl_ref.current.stderr
+++ b/tests/ui/impl-trait/call_method_on_inherent_impl_ref.current.stderr
@@ -1,5 +1,5 @@
error[E0599]: no method named `my_debug` found for opaque type `impl Debug` in the current scope
- --> $DIR/call_method_on_inherent_impl_ref.rs:20:11
+ --> $DIR/call_method_on_inherent_impl_ref.rs:19:11
|
LL | fn my_debug(&self);
| -------- the method is available for `&impl Debug` here
@@ -14,27 +14,6 @@ note: `MyDebug` defines an item `my_debug`, perhaps you need to implement it
LL | trait MyDebug {
| ^^^^^^^^^^^^^
-error[E0391]: cycle detected when computing type of opaque `my_foo::{opaque#0}`
- --> $DIR/call_method_on_inherent_impl_ref.rs:15:16
- |
-LL | fn my_foo() -> impl std::fmt::Debug {
- | ^^^^^^^^^^^^^^^^^^^^
- |
-note: ...which requires type-checking `my_foo`...
- --> $DIR/call_method_on_inherent_impl_ref.rs:20:9
- |
-LL | x.my_debug();
- | ^
- = note: ...which requires evaluating trait selection obligation `my_foo::{opaque#0}: core::marker::Unpin`...
- = note: ...which again requires computing type of opaque `my_foo::{opaque#0}`, completing the cycle
-note: cycle used when computing type of `my_foo::{opaque#0}`
- --> $DIR/call_method_on_inherent_impl_ref.rs:15:16
- |
-LL | fn my_foo() -> impl std::fmt::Debug {
- | ^^^^^^^^^^^^^^^^^^^^
- = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
-
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
-Some errors have detailed explanations: E0391, E0599.
-For more information about an error, try `rustc --explain E0391`.
+For more information about this error, try `rustc --explain E0599`.
diff --git a/tests/ui/impl-trait/call_method_on_inherent_impl_ref.next.stderr b/tests/ui/impl-trait/call_method_on_inherent_impl_ref.next.stderr
index 327f6ca3450f1..7202cb6f90a6f 100644
--- a/tests/ui/impl-trait/call_method_on_inherent_impl_ref.next.stderr
+++ b/tests/ui/impl-trait/call_method_on_inherent_impl_ref.next.stderr
@@ -1,5 +1,5 @@
error[E0282]: type annotations needed
- --> $DIR/call_method_on_inherent_impl_ref.rs:18:13
+ --> $DIR/call_method_on_inherent_impl_ref.rs:17:13
|
LL | let x = my_foo();
| ^
@@ -13,7 +13,7 @@ LL | let x: /* Type */ = my_foo();
| ++++++++++++
error[E0282]: type annotations needed for `&_`
- --> $DIR/call_method_on_inherent_impl_ref.rs:28:13
+ --> $DIR/call_method_on_inherent_impl_ref.rs:27:13
|
LL | let x = &my_bar();
| ^
diff --git a/tests/ui/impl-trait/call_method_on_inherent_impl_ref.rs b/tests/ui/impl-trait/call_method_on_inherent_impl_ref.rs
index 40ad21532a4e2..abe60e5e45a34 100644
--- a/tests/ui/impl-trait/call_method_on_inherent_impl_ref.rs
+++ b/tests/ui/impl-trait/call_method_on_inherent_impl_ref.rs
@@ -13,7 +13,6 @@ where
}
fn my_foo() -> impl std::fmt::Debug {
- //[current]~^ cycle
if false {
let x = my_foo();
//[next]~^ type annotations needed
diff --git a/tests/ui/impl-trait/rpit/const_check_false_cycle.rs b/tests/ui/impl-trait/rpit/const_check_false_cycle.rs
new file mode 100644
index 0000000000000..d4ea0e3b14785
--- /dev/null
+++ b/tests/ui/impl-trait/rpit/const_check_false_cycle.rs
@@ -0,0 +1,14 @@
+//! This test caused a cycle error when checking whether the
+//! return type is `Freeze` during const checking, even though
+//! the information is readily available.
+
+//@ revisions: current next
+//@[next] compile-flags: -Znext-solver
+//@ check-pass
+
+const fn f() -> impl Eq {
+ g()
+}
+const fn g() {}
+
+fn main() {}
diff --git a/tests/ui/impl-trait/unsized_coercion3.next.stderr b/tests/ui/impl-trait/unsized_coercion3.next.stderr
index bab8d1cd83b30..586ae07602821 100644
--- a/tests/ui/impl-trait/unsized_coercion3.next.stderr
+++ b/tests/ui/impl-trait/unsized_coercion3.next.stderr
@@ -5,7 +5,7 @@ LL | let x = hello();
| ^^^^^^^ types differ
error[E0308]: mismatched types
- --> $DIR/unsized_coercion3.rs:19:14
+ --> $DIR/unsized_coercion3.rs:18:14
|
LL | fn hello() -> Box<impl Trait + ?Sized> {
| ------------------- the expected opaque type
@@ -21,7 +21,7 @@ note: associated function defined here
--> $SRC_DIR/alloc/src/boxed.rs:LL:COL
error[E0277]: the size for values of type `impl Trait + ?Sized` cannot be known at compilation time
- --> $DIR/unsized_coercion3.rs:19:14
+ --> $DIR/unsized_coercion3.rs:18:14
|
LL | Box::new(1u32)
| -------- ^^^^ doesn't have a size known at compile-time
diff --git a/tests/ui/impl-trait/unsized_coercion3.old.stderr b/tests/ui/impl-trait/unsized_coercion3.old.stderr
index 24a302d7007ab..52a72b84a8dd6 100644
--- a/tests/ui/impl-trait/unsized_coercion3.old.stderr
+++ b/tests/ui/impl-trait/unsized_coercion3.old.stderr
@@ -1,17 +1,3 @@
-error: cannot check whether the hidden type of opaque type satisfies auto traits
- --> $DIR/unsized_coercion3.rs:15:32
- |
-LL | let y: Box<dyn Send> = x;
- | ^
- |
- = note: fetching the hidden types of an opaque inside of the defining scope is not supported. You can try moving the opaque type and the item that actually registers a hidden type into a new submodule
-note: opaque type is declared here
- --> $DIR/unsized_coercion3.rs:11:19
- |
-LL | fn hello() -> Box<impl Trait + ?Sized> {
- | ^^^^^^^^^^^^^^^^^^^
- = note: required for the cast from `Box<impl Trait + ?Sized>` to `Box<dyn Send>`
-
error[E0277]: the size for values of type `impl Trait + ?Sized` cannot be known at compilation time
--> $DIR/unsized_coercion3.rs:15:32
|
@@ -21,6 +7,6 @@ LL | let y: Box<dyn Send> = x;
= help: the trait `Sized` is not implemented for `impl Trait + ?Sized`
= note: required for the cast from `Box<impl Trait + ?Sized>` to `Box<dyn Send>`
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/impl-trait/unsized_coercion3.rs b/tests/ui/impl-trait/unsized_coercion3.rs
index 85950ac583ebc..7e862de2157d9 100644
--- a/tests/ui/impl-trait/unsized_coercion3.rs
+++ b/tests/ui/impl-trait/unsized_coercion3.rs
@@ -14,7 +14,6 @@ fn hello() -> Box<impl Trait + ?Sized> {
//[next]~^ ERROR: type mismatch resolving `impl Trait + ?Sized <: dyn Send`
let y: Box<dyn Send> = x;
//[old]~^ ERROR: the size for values of type `impl Trait + ?Sized` cannot be know
- //[old]~| ERROR: cannot check whether the hidden type of opaque type satisfies auto traits
}
Box::new(1u32)
//[next]~^ ERROR: mismatched types
diff --git a/tests/ui/impl-trait/unsized_coercion5.old.stderr b/tests/ui/impl-trait/unsized_coercion5.old.stderr
index b6437266f27dd..06ad54b1f1d8b 100644
--- a/tests/ui/impl-trait/unsized_coercion5.old.stderr
+++ b/tests/ui/impl-trait/unsized_coercion5.old.stderr
@@ -9,20 +9,6 @@ LL | let y: Box<dyn Send> = x as Box<dyn Trait + Send>;
= note: expected struct `Box<dyn Send>`
found struct `Box<dyn Trait + Send>`
-error: cannot check whether the hidden type of opaque type satisfies auto traits
- --> $DIR/unsized_coercion5.rs:16:32
- |
-LL | let y: Box<dyn Send> = x as Box<dyn Trait + Send>;
- | ^
- |
- = note: fetching the hidden types of an opaque inside of the defining scope is not supported. You can try moving the opaque type and the item that actually registers a hidden type into a new submodule
-note: opaque type is declared here
- --> $DIR/unsized_coercion5.rs:13:19
- |
-LL | fn hello() -> Box<impl Trait + ?Sized> {
- | ^^^^^^^^^^^^^^^^^^^
- = note: required for the cast from `Box<impl Trait + ?Sized>` to `Box<dyn Trait + Send>`
-
error[E0277]: the size for values of type `impl Trait + ?Sized` cannot be known at compilation time
--> $DIR/unsized_coercion5.rs:16:32
|
@@ -32,7 +18,7 @@ LL | let y: Box<dyn Send> = x as Box<dyn Trait + Send>;
= help: the trait `Sized` is not implemented for `impl Trait + ?Sized`
= note: required for the cast from `Box<impl Trait + ?Sized>` to `Box<dyn Trait + Send>`
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
Some errors have detailed explanations: E0277, E0308.
For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/impl-trait/unsized_coercion5.rs b/tests/ui/impl-trait/unsized_coercion5.rs
index b007267a0066f..85d313caa1355 100644
--- a/tests/ui/impl-trait/unsized_coercion5.rs
+++ b/tests/ui/impl-trait/unsized_coercion5.rs
@@ -15,8 +15,7 @@ fn hello() -> Box<impl Trait + ?Sized> {
let x = hello();
let y: Box<dyn Send> = x as Box<dyn Trait + Send>;
//[old]~^ ERROR: the size for values of type `impl Trait + ?Sized` cannot be know
- //[old]~| ERROR: cannot check whether the hidden type of opaque type satisfies auto traits
- //~^^^ ERROR: mismatched types
+ //~^^ ERROR: mismatched types
}
Box::new(1u32)
}
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.rs
index ab46d49073c7a..9cd18d4566da1 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.rs
@@ -9,7 +9,6 @@ impl MyTrait for i32 {
//~| ERROR functions in trait impls cannot be declared const
//~| ERROR functions cannot be both `const` and `async`
//~| ERROR method `bar` is not a member
- //~| ERROR cycle detected when computing type
main8().await;
//~^ ERROR cannot find function
}
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.stderr
index 1f309e1e85446..90771c344b51d 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.stderr
@@ -61,7 +61,7 @@ error: using `#![feature(effects)]` without enabling next trait solver globally
= help: use `-Znext-solver` to enable
error[E0425]: cannot find function `main8` in this scope
- --> $DIR/ice-120503-async-const-method.rs:13:9
+ --> $DIR/ice-120503-async-const-method.rs:12:9
|
LL | main8().await;
| ^^^^^ help: a function with a similar name exists: `main`
@@ -69,38 +69,7 @@ LL | main8().await;
LL | fn main() {}
| --------- similarly named function `main` defined here
-error[E0391]: cycle detected when computing type of opaque `<impl at $DIR/ice-120503-async-const-method.rs:6:1: 6:21>::bar::{opaque#0}`
- --> $DIR/ice-120503-async-const-method.rs:7:5
- |
-LL | async const fn bar(&self) {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^
- |
-note: ...which requires borrow-checking `<impl at $DIR/ice-120503-async-const-method.rs:6:1: 6:21>::bar`...
- --> $DIR/ice-120503-async-const-method.rs:7:5
- |
-LL | async const fn bar(&self) {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires promoting constants in MIR for `<impl at $DIR/ice-120503-async-const-method.rs:6:1: 6:21>::bar`...
- --> $DIR/ice-120503-async-const-method.rs:7:5
- |
-LL | async const fn bar(&self) {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires const checking `<impl at $DIR/ice-120503-async-const-method.rs:6:1: 6:21>::bar`...
- --> $DIR/ice-120503-async-const-method.rs:7:5
- |
-LL | async const fn bar(&self) {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^
- = note: ...which requires computing whether `<impl at $DIR/ice-120503-async-const-method.rs:6:1: 6:21>::bar::{opaque#0}` is freeze...
- = note: ...which requires evaluating trait selection obligation `<impl at $DIR/ice-120503-async-const-method.rs:6:1: 6:21>::bar::{opaque#0}: core::marker::Freeze`...
- = note: ...which again requires computing type of opaque `<impl at $DIR/ice-120503-async-const-method.rs:6:1: 6:21>::bar::{opaque#0}`, completing the cycle
-note: cycle used when computing type of `<impl at $DIR/ice-120503-async-const-method.rs:6:1: 6:21>::bar::{opaque#0}`
- --> $DIR/ice-120503-async-const-method.rs:7:5
- |
-LL | async const fn bar(&self) {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^
- = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
-
-error: aborting due to 7 previous errors; 1 warning emitted
+error: aborting due to 6 previous errors; 1 warning emitted
-Some errors have detailed explanations: E0379, E0391, E0407, E0425.
+Some errors have detailed explanations: E0379, E0407, E0425.
For more information about an error, try `rustc --explain E0379`.
diff --git a/tests/ui/type-alias-impl-trait/in-where-clause.rs b/tests/ui/type-alias-impl-trait/in-where-clause.rs
index 7c0de39c7c91c..a089fdc907531 100644
--- a/tests/ui/type-alias-impl-trait/in-where-clause.rs
+++ b/tests/ui/type-alias-impl-trait/in-where-clause.rs
@@ -4,13 +4,13 @@
#![feature(type_alias_impl_trait)]
type Bar = impl Sized;
//~^ ERROR: cycle
-//~| ERROR: cycle
fn foo() -> Bar
where
Bar: Send,
{
[0; 1 + 2]
+ //~^ ERROR: type annotations needed: cannot satisfy `Bar: Send`
}
fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/in-where-clause.stderr b/tests/ui/type-alias-impl-trait/in-where-clause.stderr
index 9c08b8f127d27..f1361b47c56e6 100644
--- a/tests/ui/type-alias-impl-trait/in-where-clause.stderr
+++ b/tests/ui/type-alias-impl-trait/in-where-clause.stderr
@@ -10,7 +10,7 @@ note: ...which requires computing type of opaque `Bar::{opaque#0}`...
LL | type Bar = impl Sized;
| ^^^^^^^^^^
note: ...which requires type-checking `foo`...
- --> $DIR/in-where-clause.rs:9:1
+ --> $DIR/in-where-clause.rs:8:1
|
LL | / fn foo() -> Bar
LL | | where
@@ -25,26 +25,23 @@ LL | type Bar = impl Sized;
| ^^^^^^^^^^
= note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
-error[E0391]: cycle detected when computing type of opaque `Bar::{opaque#0}`
- --> $DIR/in-where-clause.rs:5:12
- |
-LL | type Bar = impl Sized;
- | ^^^^^^^^^^
- |
-note: ...which requires type-checking `foo`...
- --> $DIR/in-where-clause.rs:13:9
+error[E0283]: type annotations needed: cannot satisfy `Bar: Send`
+ --> $DIR/in-where-clause.rs:12:9
|
LL | [0; 1 + 2]
| ^^^^^
- = note: ...which requires evaluating trait selection obligation `Bar: core::marker::Send`...
- = note: ...which again requires computing type of opaque `Bar::{opaque#0}`, completing the cycle
-note: cycle used when computing type of `Bar::{opaque#0}`
- --> $DIR/in-where-clause.rs:5:12
|
-LL | type Bar = impl Sized;
- | ^^^^^^^^^^
- = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+ = note: cannot satisfy `Bar: Send`
+note: required by a bound in `foo`
+ --> $DIR/in-where-clause.rs:10:10
+ |
+LL | fn foo() -> Bar
+ | --- required by a bound in this function
+LL | where
+LL | Bar: Send,
+ | ^^^^ required by this bound in `foo`
error: aborting due to 2 previous errors
-For more information about this error, try `rustc --explain E0391`.
+Some errors have detailed explanations: E0283, E0391.
+For more information about an error, try `rustc --explain E0283`.
diff --git a/tests/ui/type-alias-impl-trait/reveal_local.rs b/tests/ui/type-alias-impl-trait/reveal_local.rs
index 07fd989b0fa78..34f3788e2341b 100644
--- a/tests/ui/type-alias-impl-trait/reveal_local.rs
+++ b/tests/ui/type-alias-impl-trait/reveal_local.rs
@@ -20,7 +20,7 @@ fn not_gooder() -> Foo {
// while we could know this from the hidden type, it would
// need extra roundabout logic to support it.
is_send::<Foo>();
- //~^ ERROR: cannot check whether the hidden type of `reveal_local[9507]::Foo::{opaque#0}` satisfies auto traits
+ //~^ ERROR: type annotations needed: cannot satisfy `Foo: Send`
x
}
diff --git a/tests/ui/type-alias-impl-trait/reveal_local.stderr b/tests/ui/type-alias-impl-trait/reveal_local.stderr
index e1b320cc38e31..9829c58cf73b7 100644
--- a/tests/ui/type-alias-impl-trait/reveal_local.stderr
+++ b/tests/ui/type-alias-impl-trait/reveal_local.stderr
@@ -16,18 +16,13 @@ note: required by a bound in `is_send`
LL | fn is_send<T: Send>() {}
| ^^^^ required by this bound in `is_send`
-error: cannot check whether the hidden type of `reveal_local[9507]::Foo::{opaque#0}` satisfies auto traits
+error[E0283]: type annotations needed: cannot satisfy `Foo: Send`
--> $DIR/reveal_local.rs:22:15
|
LL | is_send::<Foo>();
| ^^^
|
- = note: fetching the hidden types of an opaque inside of the defining scope is not supported. You can try moving the opaque type and the item that actually registers a hidden type into a new submodule
-note: opaque type is declared here
- --> $DIR/reveal_local.rs:5:12
- |
-LL | type Foo = impl Debug;
- | ^^^^^^^^^^
+ = note: cannot satisfy `Foo: Send`
note: required by a bound in `is_send`
--> $DIR/reveal_local.rs:7:15
|
@@ -36,3 +31,4 @@ LL | fn is_send<T: Send>() {}
error: aborting due to 2 previous errors
+For more information about this error, try `rustc --explain E0283`.