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Register even erroneous impls
Otherwise the specialization graph fails to pick it up, even though other code assumes that all impl blocks have an entry in the specialization graph.
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4 files changed

+138
-5
lines changed

4 files changed

+138
-5
lines changed

‎compiler/rustc_middle/src/ty/fast_reject.rs

+3-1
Original file line numberDiff line numberDiff line change
@@ -32,6 +32,7 @@ pub enum SimplifiedType {
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CoroutineWitness(DefId),
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Function(usize),
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Placeholder,
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Error,
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}
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/// Generic parameters are pretty much just bound variables, e.g.
@@ -153,7 +154,8 @@ pub fn simplify_type<'tcx>(
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TreatParams::ForLookup | TreatParams::AsCandidateKey => None,
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},
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ty::Foreign(def_id) => Some(SimplifiedType::Foreign(def_id)),
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ty::Bound(..) | ty::Infer(_) | ty::Error(_) => None,
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ty::Error(_) => Some(SimplifiedType::Error),
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ty::Bound(..) | ty::Infer(_) => None,
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}
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}
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‎compiler/rustc_middle/src/ty/trait_def.rs

-4
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,5 @@
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use crate::traits::specialization_graph;
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use crate::ty::fast_reject::{self, SimplifiedType, TreatParams, TreatProjections};
3-
use crate::ty::visit::TypeVisitableExt;
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use crate::ty::{Ident, Ty, TyCtxt};
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use hir::def_id::LOCAL_CRATE;
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use rustc_hir as hir;
@@ -241,9 +240,6 @@ pub(super) fn trait_impls_of_provider(tcx: TyCtxt<'_>, trait_id: DefId) -> Trait
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let impl_def_id = impl_def_id.to_def_id();
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let impl_self_ty = tcx.type_of(impl_def_id).instantiate_identity();
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if impl_self_ty.references_error() {
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continue;
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}
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if let Some(simplified_self_ty) =
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fast_reject::simplify_type(tcx, impl_self_ty, TreatParams::AsCandidateKey)

‎tests/ui/generic-associated-types/unknown-lifetime-ice-119827.rs

+16
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,16 @@
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trait Foo {
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type Context<'c>
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where
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Self: 'c;
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}
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impl Foo for Box<dyn Foo> {}
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//~^ ERROR `Foo` cannot be made into an object
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//~| ERROR `Foo` cannot be made into an object
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//~| ERROR cycle detected
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//~| ERROR cycle detected
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//~| ERROR cycle detected
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//~| ERROR the trait bound `Box<(dyn Foo + 'static)>: Foo` is not satisfied
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//~| ERROR not all trait items implemented
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fn main() {}

‎tests/ui/generic-associated-types/unknown-lifetime-ice-119827.stderr

+119
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,119 @@
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error[E0391]: cycle detected when computing type of `<impl at $DIR/unknown-lifetime-ice-119827.rs:7:1: 7:26>`
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--> $DIR/unknown-lifetime-ice-119827.rs:7:1
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|
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LL | impl Foo for Box<dyn Foo> {}
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| ^^^^^^^^^^^^^^^^^^^^^^^^^
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|
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note: ...which requires finding trait impls of `Foo`...
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--> $DIR/unknown-lifetime-ice-119827.rs:1:1
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|
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LL | trait Foo {
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| ^^^^^^^^^
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= note: ...which again requires computing type of `<impl at $DIR/unknown-lifetime-ice-119827.rs:7:1: 7:26>`, completing the cycle
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note: cycle used when collecting item types in top-level module
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--> $DIR/unknown-lifetime-ice-119827.rs:1:1
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|
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LL | / trait Foo {
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LL | | type Context<'c>
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LL | | where
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LL | | Self: 'c;
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... |
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LL | |
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LL | | fn main() {}
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| |____________^
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= 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
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error[E0391]: cycle detected when computing type of `<impl at $DIR/unknown-lifetime-ice-119827.rs:7:1: 7:26>`
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--> $DIR/unknown-lifetime-ice-119827.rs:7:1
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|
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LL | impl Foo for Box<dyn Foo> {}
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| ^^^^^^^^^^^^^^^^^^^^^^^^^
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|
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= note: ...which immediately requires computing type of `<impl at $DIR/unknown-lifetime-ice-119827.rs:7:1: 7:26>` again
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note: cycle used when collecting item types in top-level module
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--> $DIR/unknown-lifetime-ice-119827.rs:1:1
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|
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LL | / trait Foo {
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LL | | type Context<'c>
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LL | | where
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LL | | Self: 'c;
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... |
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LL | |
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LL | | fn main() {}
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| |____________^
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= 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
45+
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error[E0391]: cycle detected when computing type of `<impl at $DIR/unknown-lifetime-ice-119827.rs:7:1: 7:26>`
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--> $DIR/unknown-lifetime-ice-119827.rs:7:1
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|
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LL | impl Foo for Box<dyn Foo> {}
50+
| ^^^^^^^^^^^^^^^^^^^^^^^^^
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|
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= note: ...which immediately requires computing type of `<impl at $DIR/unknown-lifetime-ice-119827.rs:7:1: 7:26>` again
53+
note: cycle used when collecting item types in top-level module
54+
--> $DIR/unknown-lifetime-ice-119827.rs:1:1
55+
|
56+
LL | / trait Foo {
57+
LL | | type Context<'c>
58+
LL | | where
59+
LL | | Self: 'c;
60+
... |
61+
LL | |
62+
LL | | fn main() {}
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| |____________^
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= 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
65+
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
66+
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error[E0038]: the trait `Foo` cannot be made into an object
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--> $DIR/unknown-lifetime-ice-119827.rs:7:22
69+
|
70+
LL | impl Foo for Box<dyn Foo> {}
71+
| ^^^ `Foo` cannot be made into an object
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|
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note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
74+
--> $DIR/unknown-lifetime-ice-119827.rs:2:10
75+
|
76+
LL | trait Foo {
77+
| --- this trait cannot be made into an object...
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LL | type Context<'c>
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| ^^^^^^^ ...because it contains the generic associated type `Context`
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= help: consider moving `Context` to another trait
81+
= help: only type `{type error}` implements the trait, consider using it directly instead
82+
83+
error[E0277]: the trait bound `Box<(dyn Foo + 'static)>: Foo` is not satisfied
84+
--> $DIR/unknown-lifetime-ice-119827.rs:7:14
85+
|
86+
LL | impl Foo for Box<dyn Foo> {}
87+
| ^^^^^^^^^^^^ the trait `Foo` is not implemented for `Box<(dyn Foo + 'static)>`
88+
|
89+
= help: the trait `Foo` is implemented for `Box<(dyn Foo + 'static)>`
90+
91+
error[E0038]: the trait `Foo` cannot be made into an object
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--> $DIR/unknown-lifetime-ice-119827.rs:7:14
93+
|
94+
LL | impl Foo for Box<dyn Foo> {}
95+
| ^^^^^^^^^^^^ `Foo` cannot be made into an object
96+
|
97+
note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
98+
--> $DIR/unknown-lifetime-ice-119827.rs:2:10
99+
|
100+
LL | trait Foo {
101+
| --- this trait cannot be made into an object...
102+
LL | type Context<'c>
103+
| ^^^^^^^ ...because it contains the generic associated type `Context`
104+
= help: consider moving `Context` to another trait
105+
= help: only type `std::boxed::Box<(dyn Foo + 'static)>` implements the trait, consider using it directly instead
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error[E0046]: not all trait items implemented, missing: `Context`
108+
--> $DIR/unknown-lifetime-ice-119827.rs:7:1
109+
|
110+
LL | type Context<'c>
111+
| ---------------- `Context` from trait
112+
...
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LL | impl Foo for Box<dyn Foo> {}
114+
| ^^^^^^^^^^^^^^^^^^^^^^^^^ missing `Context` in implementation
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116+
error: aborting due to 7 previous errors
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118+
Some errors have detailed explanations: E0038, E0046, E0277, E0391.
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For more information about an error, try `rustc --explain E0038`.

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