Skip to content

Commit 1007c9c

Browse files
compiler-errorscompiler-errors
committed
Always make inductive cycles as ambig during typeck
1 parent b781645 commit 1007c9c

File tree

7 files changed

+67
-135
lines changed

7 files changed

+67
-135
lines changed

‎compiler/rustc_trait_selection/src/traits/select/mod.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -231,7 +231,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
231231
freshener: infcx.freshener(),
232232
intercrate_ambiguity_causes: None,
233233
query_mode: TraitQueryMode::Standard,
234-
treat_inductive_cycle: TreatInductiveCycleAs::Recur,
234+
treat_inductive_cycle: TreatInductiveCycleAs::Ambig,
235235
}
236236
}
237237

‎tests/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.stderr

+13-1
Original file line numberDiff line numberDiff line change
@@ -1,3 +1,15 @@
1+
error[E0277]: `<Self as Case1>::C` is not an iterator
2+
--> $DIR/bad-bounds-on-assoc-in-trait.rs:26:21
3+
|
4+
LL | type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
5+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `<Self as Case1>::C` is not an iterator
6+
|
7+
= help: the trait `Iterator` is not implemented for `<Self as Case1>::C`
8+
help: consider further restricting the associated type
9+
|
10+
LL | trait Case1 where <Self as Case1>::C: Iterator {
11+
| ++++++++++++++++++++++++++++++++++
12+
113
error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be sent between threads safely
214
--> $DIR/bad-bounds-on-assoc-in-trait.rs:26:36
315
|
@@ -34,6 +46,6 @@ help: consider further restricting the associated type
3446
LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Sync {
3547
| ++++++++++++++++++++++++++++++++++++++++++++++++++
3648

37-
error: aborting due to 3 previous errors
49+
error: aborting due to 4 previous errors
3850

3951
For more information about this error, try `rustc --explain E0277`.

‎tests/ui/impl-trait/in-trait/specialization-broken.stderr

+12-25
Original file line numberDiff line numberDiff line change
@@ -1,31 +1,18 @@
1-
error[E0053]: method `bar` has an incompatible type for trait
2-
--> $DIR/specialization-broken.rs:16:22
1+
error[E0391]: cycle detected when computing whether impls specialize one another
2+
--> $DIR/specialization-broken.rs:12:1
33
|
44
LL | default impl<U> Foo for U
5-
| - this type parameter
6-
...
7-
LL | fn bar(&self) -> U {
8-
| ^
9-
| |
10-
| expected associated type, found type parameter `U`
11-
| help: change the output type to match the trait: `impl Sized`
5+
| ^^^^^^^^^^^^^^^^^^^^^^^^^
126
|
13-
note: type in trait
14-
--> $DIR/specialization-broken.rs:9:22
7+
= note: ...which requires evaluating trait selection obligation `i32: Foo`...
8+
= note: ...which again requires computing whether impls specialize one another, completing the cycle
9+
note: cycle used when building specialization graph of trait `Foo`
10+
--> $DIR/specialization-broken.rs:8:1
1511
|
16-
LL | fn bar(&self) -> impl Sized;
17-
| ^^^^^^^^^^
18-
= note: expected signature `fn(&U) -> impl Sized`
19-
found signature `fn(&U) -> U`
12+
LL | trait Foo {
13+
| ^^^^^^^^^
14+
= 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
2015

21-
error: method with return-position `impl Trait` in trait cannot be specialized
22-
--> $DIR/specialization-broken.rs:16:5
23-
|
24-
LL | fn bar(&self) -> U {
25-
| ^^^^^^^^^^^^^^^^^^
26-
|
27-
= note: specialization behaves in inconsistent and surprising ways with `#![feature(return_position_impl_trait_in_trait)]`, and for now is disallowed
28-
29-
error: aborting due to 2 previous errors
16+
error: aborting due to previous error
3017

31-
For more information about this error, try `rustc --explain E0053`.
18+
For more information about this error, try `rustc --explain E0391`.

‎tests/ui/specialization/defaultimpl/specialization-no-default.stderr

+12-53
Original file line numberDiff line numberDiff line change
@@ -8,61 +8,20 @@ LL | #![feature(specialization)]
88
= help: consider using `min_specialization` instead, which is more stable and complete
99
= note: `#[warn(incomplete_features)]` on by default
1010

11-
error[E0520]: `foo` specializes an item from a parent `impl`, but that item is not marked `default`
12-
--> $DIR/specialization-no-default.rs:20:5
11+
error[E0391]: cycle detected when computing whether impls specialize one another
12+
--> $DIR/specialization-no-default.rs:46:1
1313
|
14-
LL | impl<T> Foo for T {
15-
| ----------------- parent `impl` is here
16-
...
17-
LL | fn foo(&self) {}
18-
| ^^^^^^^^^^^^^ cannot specialize default item `foo`
14+
LL | default impl<T> Baz for T {
15+
| ^^^^^^^^^^^^^^^^^^^^^^^^^
1916
|
20-
= note: to specialize, `foo` in the parent `impl` must be marked `default`
21-
22-
error[E0520]: `bar` specializes an item from a parent `impl`, but that item is not marked `default`
23-
--> $DIR/specialization-no-default.rs:23:5
24-
|
25-
LL | impl<T> Foo for T {
26-
| ----------------- parent `impl` is here
27-
...
28-
LL | fn bar(&self) {}
29-
| ^^^^^^^^^^^^^ cannot specialize default item `bar`
30-
|
31-
= note: to specialize, `bar` in the parent `impl` must be marked `default`
32-
33-
error[E0520]: `T` specializes an item from a parent `impl`, but that item is not marked `default`
34-
--> $DIR/specialization-no-default.rs:37:5
35-
|
36-
LL | impl<T> Bar for T {
37-
| ----------------- parent `impl` is here
38-
...
39-
LL | type T = ();
40-
| ^^^^^^ cannot specialize default item `T`
41-
|
42-
= note: to specialize, `T` in the parent `impl` must be marked `default`
43-
44-
error[E0520]: `baz` specializes an item from a parent `impl`, but that item is not marked `default`
45-
--> $DIR/specialization-no-default.rs:55:5
46-
|
47-
LL | impl<T: Clone> Baz for T {
48-
| ------------------------ parent `impl` is here
49-
...
50-
LL | fn baz(&self) {}
51-
| ^^^^^^^^^^^^^ cannot specialize default item `baz`
52-
|
53-
= note: to specialize, `baz` in the parent `impl` must be marked `default`
54-
55-
error[E0520]: `redundant` specializes an item from a parent `impl`, but that item is not marked `default`
56-
--> $DIR/specialization-no-default.rs:74:5
57-
|
58-
LL | impl<T: Clone> Redundant for T {
59-
| ------------------------------ parent `impl` is here
60-
...
61-
LL | fn redundant(&self) {}
62-
| ^^^^^^^^^^^^^^^^^^^ cannot specialize default item `redundant`
17+
= note: ...which immediately requires computing whether impls specialize one another again
18+
note: cycle used when building specialization graph of trait `Baz`
19+
--> $DIR/specialization-no-default.rs:42:1
6320
|
64-
= note: to specialize, `redundant` in the parent `impl` must be marked `default`
21+
LL | trait Baz {
22+
| ^^^^^^^^^
23+
= 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
6524

66-
error: aborting due to 5 previous errors; 1 warning emitted
25+
error: aborting due to previous error; 1 warning emitted
6726

68-
For more information about this error, try `rustc --explain E0520`.
27+
For more information about this error, try `rustc --explain E0391`.

‎tests/ui/specialization/defaultimpl/specialization-trait-item-not-implemented.stderr

+14-8
Original file line numberDiff line numberDiff line change
@@ -8,15 +8,21 @@ LL | #![feature(specialization)]
88
= help: consider using `min_specialization` instead, which is more stable and complete
99
= note: `#[warn(incomplete_features)]` on by default
1010

11-
error[E0046]: not all trait items implemented, missing: `foo_two`
12-
--> $DIR/specialization-trait-item-not-implemented.rs:18:1
11+
error[E0391]: cycle detected when computing whether impls specialize one another
12+
--> $DIR/specialization-trait-item-not-implemented.rs:12:1
1313
|
14-
LL | fn foo_two(&self) -> &'static str;
15-
| ---------------------------------- `foo_two` from trait
16-
...
17-
LL | impl Foo for MyStruct {}
18-
| ^^^^^^^^^^^^^^^^^^^^^ missing `foo_two` in implementation
14+
LL | default impl<T> Foo for T {
15+
| ^^^^^^^^^^^^^^^^^^^^^^^^^
16+
|
17+
= note: ...which requires evaluating trait selection obligation `MyStruct: Foo`...
18+
= note: ...which again requires computing whether impls specialize one another, completing the cycle
19+
note: cycle used when building specialization graph of trait `Foo`
20+
--> $DIR/specialization-trait-item-not-implemented.rs:5:1
21+
|
22+
LL | trait Foo {
23+
| ^^^^^^^^^
24+
= 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
1925

2026
error: aborting due to previous error; 1 warning emitted
2127

22-
For more information about this error, try `rustc --explain E0046`.
28+
For more information about this error, try `rustc --explain E0391`.

‎tests/ui/specialization/defaultimpl/specialization-trait-not-implemented.stderr

+3-28
Original file line numberDiff line numberDiff line change
@@ -8,37 +8,12 @@ LL | #![feature(specialization)]
88
= help: consider using `min_specialization` instead, which is more stable and complete
99
= note: `#[warn(incomplete_features)]` on by default
1010

11-
error[E0599]: the method `foo_one` exists for struct `MyStruct`, but its trait bounds were not satisfied
11+
error[E0275]: overflow evaluating the requirement `MyStruct: Foo`
1212
--> $DIR/specialization-trait-not-implemented.rs:22:29
1313
|
14-
LL | struct MyStruct;
15-
| ---------------
16-
| |
17-
| method `foo_one` not found for this struct
18-
| doesn't satisfy `MyStruct: Foo`
19-
...
2014
LL | println!("{}", MyStruct.foo_one());
21-
| ^^^^^^^ method cannot be called on `MyStruct` due to unsatisfied trait bounds
22-
|
23-
note: trait bound `MyStruct: Foo` was not satisfied
24-
--> $DIR/specialization-trait-not-implemented.rs:14:1
25-
|
26-
LL | default impl<T> Foo for T {
27-
| ^^^^^^^^^^^^^^^^---^^^^^-
28-
| |
29-
| unsatisfied trait bound introduced here
30-
note: the trait `Foo` must be implemented
31-
--> $DIR/specialization-trait-not-implemented.rs:7:1
32-
|
33-
LL | trait Foo {
34-
| ^^^^^^^^^
35-
= help: items from traits can only be used if the trait is implemented and in scope
36-
note: `Foo` defines an item `foo_one`, perhaps you need to implement it
37-
--> $DIR/specialization-trait-not-implemented.rs:7:1
38-
|
39-
LL | trait Foo {
40-
| ^^^^^^^^^
15+
| ^^^^^^^
4116

4217
error: aborting due to previous error; 1 warning emitted
4318

44-
For more information about this error, try `rustc --explain E0599`.
19+
For more information about this error, try `rustc --explain E0275`.

‎tests/ui/specialization/issue-39448.stderr

+12-19
Original file line numberDiff line numberDiff line change
@@ -8,28 +8,21 @@ LL | #![feature(specialization)]
88
= help: consider using `min_specialization` instead, which is more stable and complete
99
= note: `#[warn(incomplete_features)]` on by default
1010

11-
error[E0275]: overflow evaluating the requirement `T: FromA<U>`
12-
--> $DIR/issue-39448.rs:45:13
13-
|
14-
LL | x.foo(y.to()).to()
15-
| ^^
16-
|
17-
note: required for `T` to implement `FromA<U>`
18-
--> $DIR/issue-39448.rs:24:29
11+
error[E0391]: cycle detected when computing whether impls specialize one another
12+
--> $DIR/issue-39448.rs:24:1
1913
|
2014
LL | impl<T: A, U: A + FromA<T>> FromA<T> for U {
21-
| -------- ^^^^^^^^ ^
22-
| |
23-
| unsatisfied trait bound introduced here
24-
note: required for `U` to implement `ToA<T>`
25-
--> $DIR/issue-39448.rs:34:12
15+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
16+
|
17+
= note: ...which requires evaluating trait selection obligation `u16: FromA<u8>`...
18+
= note: ...which again requires computing whether impls specialize one another, completing the cycle
19+
note: cycle used when building specialization graph of trait `FromA`
20+
--> $DIR/issue-39448.rs:20:1
2621
|
27-
LL | impl<T, U> ToA<U> for T
28-
| ^^^^^^ ^
29-
LL | where
30-
LL | U: FromA<T>,
31-
| -------- unsatisfied trait bound introduced here
22+
LL | trait FromA<T> {
23+
| ^^^^^^^^^^^^^^
24+
= 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
3225

3326
error: aborting due to previous error; 1 warning emitted
3427

35-
For more information about this error, try `rustc --explain E0275`.
28+
For more information about this error, try `rustc --explain E0391`.

0 commit comments

Comments
 (0)