Show source of ambiguity in a few more places

compiler-errors · compiler-errors · commit ca0105ba4e3c · 2022-07-01T17:38:34.000Z
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -2020,7 +2020,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
                     subst,
                     impl_candidates,
                     ErrorCode::E0283,
-                    false,
+                    true,
                 );
 
                 let obligation = Obligation::new(
@@ -2132,7 +2132,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
                     a.into(),
                     vec![],
                     ErrorCode::E0282,
-                    false,
+                    true,
                 )
             }
             ty::PredicateKind::Projection(data) => {
@@ -2149,7 +2149,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
                         self_ty.into(),
                         vec![],
                         ErrorCode::E0284,
-                        false,
+                        true,
                     );
                     err.note(&format!("cannot satisfy `{}`", predicate));
                     err
diff --git a/src/test/ui/const-generics/generic_arg_infer/issue-91614.stderr b/src/test/ui/const-generics/generic_arg_infer/issue-91614.stderr
@@ -2,7 +2,7 @@ error[E0283]: type annotations needed for `Mask<_, LANES>`
   --> $DIR/issue-91614.rs:6:9
    |
 LL |     let y = Mask::<_, _>::splat(false);
-   |         ^
+   |         ^   ------------------- type must be known at this point
    |
    = note: cannot satisfy `_: MaskElement`
 note: required by a bound in `Mask::<T, LANES>::splat`
diff --git a/src/test/ui/inference/cannot-infer-partial-try-return.stderr b/src/test/ui/inference/cannot-infer-partial-try-return.stderr
@@ -3,6 +3,9 @@ error[E0282]: type annotations needed for `Result<(), QualifiedError<_>>`
    |
 LL |     let x = || -> Result<_, QualifiedError<_>> {
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |
+LL |         infallible()?;
+   |         ------------- type must be known at this point
    |
 help: try giving this closure an explicit return type
    |
diff --git a/src/test/ui/inference/erase-type-params-in-label.stderr b/src/test/ui/inference/erase-type-params-in-label.stderr
@@ -2,7 +2,7 @@ error[E0283]: type annotations needed for `Foo<i32, &str, W, Z>`
   --> $DIR/erase-type-params-in-label.rs:2:9
    |
 LL |     let foo = foo(1, "");
-   |         ^^^
+   |         ^^^   --- type must be known at this point
    |
    = note: cannot satisfy `_: Default`
 note: required by a bound in `foo`
@@ -23,7 +23,7 @@ error[E0283]: type annotations needed for `Bar<i32, &str, Z>`
   --> $DIR/erase-type-params-in-label.rs:5:9
    |
 LL |     let bar = bar(1, "");
-   |         ^^^
+   |         ^^^   --- type must be known at this point
    |
    = note: cannot satisfy `_: Default`
 note: required by a bound in `bar`
diff --git a/src/test/ui/inference/issue-72616.stderr b/src/test/ui/inference/issue-72616.stderr
@@ -2,7 +2,9 @@ error[E0283]: type annotations needed
   --> $DIR/issue-72616.rs:20:37
    |
 LL |         if String::from("a") == "a".try_into().unwrap() {}
-   |                                     ^^^^^^^^
+   |                              --     ^^^^^^^^
+   |                              |
+   |                              type must be known at this point
    |
    = note: multiple `impl`s satisfying `String: PartialEq<_>` found in the `alloc` crate:
            - impl PartialEq for String;
diff --git a/src/test/ui/inference/issue-72690.stderr b/src/test/ui/inference/issue-72690.stderr
@@ -55,7 +55,7 @@ error[E0283]: type annotations needed for `&T`
   --> $DIR/issue-72690.rs:17:9
    |
 LL |     let _ = "x".as_ref();
-   |         ^
+   |         ^       ------ type must be known at this point
    |
    = note: multiple `impl`s satisfying `str: AsRef<_>` found in the following crates: `core`, `std`:
            - impl AsRef<OsStr> for str;
diff --git a/src/test/ui/inference/issue-86162-1.stderr b/src/test/ui/inference/issue-86162-1.stderr
@@ -2,7 +2,9 @@ error[E0283]: type annotations needed
   --> $DIR/issue-86162-1.rs:7:9
    |
 LL |     foo(gen()); //<- Do not suggest `foo::<impl Clone>()`!
-   |         ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
+   |     --- ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
+   |     |
+   |     type must be known at this point
    |
    = note: cannot satisfy `_: Clone`
 note: required by a bound in `foo`
diff --git a/src/test/ui/inference/issue-86162-2.stderr b/src/test/ui/inference/issue-86162-2.stderr
@@ -2,7 +2,9 @@ error[E0283]: type annotations needed
   --> $DIR/issue-86162-2.rs:12:14
    |
 LL |     Foo::bar(gen()); //<- Do not suggest `Foo::bar::<impl Clone>()`!
-   |              ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
+   |     -------- ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
+   |     |
+   |     type must be known at this point
    |
    = note: cannot satisfy `_: Clone`
 note: required by a bound in `Foo::bar`
diff --git a/src/test/ui/issues/issue-69455.stderr b/src/test/ui/issues/issue-69455.stderr
@@ -14,7 +14,9 @@ error[E0283]: type annotations needed
   --> $DIR/issue-69455.rs:29:41
    |
 LL |     println!("{}", 23u64.test(xs.iter().sum()));
-   |                                         ^^^ cannot infer type of the type parameter `S` declared on the associated function `sum`
+   |                          ----           ^^^ cannot infer type of the type parameter `S` declared on the associated function `sum`
+   |                          |
+   |                          type must be known at this point
    |
 note: multiple `impl`s satisfying `u64: Test<_>` found
   --> $DIR/issue-69455.rs:11:1
diff --git a/src/test/ui/issues/issue-7813.stderr b/src/test/ui/issues/issue-7813.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed for `&[_; 0]`
   --> $DIR/issue-7813.rs:2:9
    |
 LL |     let v = &[];
-   |         ^
+   |         ^   --- type must be known at this point
    |
 help: consider giving `v` an explicit type, where the placeholders `_` are specified
    |
diff --git a/src/test/ui/suggestions/suggest-closure-return-type-1.stderr b/src/test/ui/suggestions/suggest-closure-return-type-1.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed for `[_; 0]`
   --> $DIR/suggest-closure-return-type-1.rs:4:18
    |
 LL |     unbound_drop(|| -> _ { [] });
-   |                  ^^^^^^^
+   |                  ^^^^^^^   -- type must be known at this point
    |
 help: try giving this closure an explicit return type
    |
diff --git a/src/test/ui/suggestions/suggest-closure-return-type-2.stderr b/src/test/ui/suggestions/suggest-closure-return-type-2.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed for `[_; 0]`
   --> $DIR/suggest-closure-return-type-2.rs:4:18
    |
 LL |     unbound_drop(|| { [] })
-   |                  ^^
+   |                  ^^   -- type must be known at this point
    |
 help: try giving this closure an explicit return type
    |
diff --git a/src/test/ui/suggestions/suggest-closure-return-type-3.stderr b/src/test/ui/suggestions/suggest-closure-return-type-3.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed for `[_; 0]`
   --> $DIR/suggest-closure-return-type-3.rs:4:18
    |
 LL |     unbound_drop(|| []);
-   |                  ^^
+   |                  ^^ -- type must be known at this point
    |
 help: try giving this closure an explicit return type
    |
diff --git a/src/test/ui/traits/issue-77982.stderr b/src/test/ui/traits/issue-77982.stderr
@@ -26,7 +26,9 @@ error[E0283]: type annotations needed
   --> $DIR/issue-77982.rs:8:10
    |
 LL |     opts.get(opt.as_ref());
-   |          ^^^ cannot infer type of the type parameter `Q` declared on the associated function `get`
+   |          ^^^     ------ type must be known at this point
+   |          |
+   |          cannot infer type of the type parameter `Q` declared on the associated function `get`
    |
    = note: multiple `impl`s satisfying `String: AsRef<_>` found in the following crates: `alloc`, `std`:
            - impl AsRef<OsStr> for String;
@@ -42,7 +44,9 @@ error[E0283]: type annotations needed
   --> $DIR/issue-77982.rs:13:59
    |
 LL |     let ips: Vec<_> = (0..100_000).map(|_| u32::from(0u32.into())).collect();
-   |                                                           ^^^^
+   |                                            ---------      ^^^^
+   |                                            |
+   |                                            type must be known at this point
    |
    = note: multiple `impl`s satisfying `u32: From<_>` found in the following crates: `core`, `std`:
            - impl From<Ipv4Addr> for u32;
@@ -59,7 +63,7 @@ error[E0283]: type annotations needed for `Box<T>`
   --> $DIR/issue-77982.rs:36:9
    |
 LL |     let _ = ().foo();
-   |         ^
+   |         ^      --- type must be known at this point
    |
 note: multiple `impl`s satisfying `(): Foo<'_, _>` found
   --> $DIR/issue-77982.rs:29:1
@@ -77,7 +81,7 @@ error[E0283]: type annotations needed for `Box<T>`
   --> $DIR/issue-77982.rs:40:9
    |
 LL |     let _ = (&()).bar();
-   |         ^
+   |         ^         --- type must be known at this point
    |
 note: multiple `impl`s satisfying `&(): Bar<'_, _>` found
   --> $DIR/issue-77982.rs:32:1
diff --git a/src/test/ui/type/type-check/cannot_infer_local_or_array.stderr b/src/test/ui/type/type-check/cannot_infer_local_or_array.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed for `[_; 0]`
   --> $DIR/cannot_infer_local_or_array.rs:2:9
    |
 LL |     let x = [];
-   |         ^
+   |         ^   -- type must be known at this point
    |
 help: consider giving `x` an explicit type, where the placeholders `_` are specified
    |

Original file line number	Diff line number	Diff line change
@@ -2,7 +2,7 @@ error[E0283]: type annotations needed for `Mask<_, LANES>`
`2`	`2`	`--> $DIR/issue-91614.rs:6:9`
`3`	`3`	`\|`
`4`	`4`	`LL \| let y = Mask::<_, _>::splat(false);`
`5`		`- \| ^`
	`5`	`+ \| ^ ------------------- type must be known at this point`
`6`	`6`	`\|`
`7`	`7`	= note: cannot satisfy `_: MaskElement`
`8`	`8`	note: required by a bound in `Mask::<T, LANES>::splat`
Original file line number	Diff line number	Diff line change
@@ -3,6 +3,9 @@ error[E0282]: type annotations needed for `Result<(), QualifiedError<_>>`
`3`	`3`	`\|`
`4`	`4`	`LL \| let x = \|\| -> Result<_, QualifiedError<_>> {`
`5`	`5`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
	`6`	`+LL \|`
	`7`	`+LL \| infallible()?;`
	`8`	`+ \| ------------- type must be known at this point`
`6`	`9`	`\|`
`7`	`10`	`help: try giving this closure an explicit return type`
`8`	`11`	`\|`
Original file line number	Diff line number	Diff line change
@@ -2,7 +2,7 @@ error[E0283]: type annotations needed for `Foo<i32, &str, W, Z>`
`2`	`2`	`--> $DIR/erase-type-params-in-label.rs:2:9`
`3`	`3`	`\|`
`4`	`4`	`LL \| let foo = foo(1, "");`
`5`		`- \| ^^^`
	`5`	`+ \| ^^^ --- type must be known at this point`
`6`	`6`	`\|`
`7`	`7`	= note: cannot satisfy `_: Default`
`8`	`8`	note: required by a bound in `foo`
@@ -23,7 +23,7 @@ error[E0283]: type annotations needed for `Bar<i32, &str, Z>`
`23`	`23`	`--> $DIR/erase-type-params-in-label.rs:5:9`
`24`	`24`	`\|`
`25`	`25`	`LL \| let bar = bar(1, "");`
`26`		`- \| ^^^`
	`26`	`+ \| ^^^ --- type must be known at this point`
`27`	`27`	`\|`
`28`	`28`	= note: cannot satisfy `_: Default`
`29`	`29`	note: required by a bound in `bar`
Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,9 @@ error[E0283]: type annotations needed`
`2`	`2`	`--> $DIR/issue-72616.rs:20:37`
`3`	`3`	`\|`
`4`	`4`	`LL \| if String::from("a") == "a".try_into().unwrap() {}`
`5`		`- \| ^^^^^^^^`
	`5`	`+ \| -- ^^^^^^^^`
	`6`	`+ \| \|`
	`7`	`+ \| type must be known at this point`
`6`	`8`	`\|`
`7`	`9`	= note: multiple `impl`s satisfying `String: PartialEq<_>` found in the `alloc` crate:
`8`	`10`	`- impl PartialEq for String;`
Original file line number	Diff line number	Diff line change
@@ -55,7 +55,7 @@ error[E0283]: type annotations needed for `&T`
`55`	`55`	`--> $DIR/issue-72690.rs:17:9`
`56`	`56`	`\|`
`57`	`57`	`LL \| let _ = "x".as_ref();`
`58`		`- \| ^`
	`58`	`+ \| ^ ------ type must be known at this point`
`59`	`59`	`\|`
`60`	`60`	= note: multiple `impl`s satisfying `str: AsRef<_>` found in the following crates: `core`, `std`:
`61`	`61`	`- impl AsRef<OsStr> for str;`
Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,9 @@ error[E0283]: type annotations needed`
`2`	`2`	`--> $DIR/issue-86162-1.rs:7:9`
`3`	`3`	`\|`
`4`	`4`	LL \| foo(gen()); //<- Do not suggest `foo::<impl Clone>()`!
`5`		- \| ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
	`5`	+ \| --- ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
	`6`	`+ \| \|`
	`7`	`+ \| type must be known at this point`
`6`	`8`	`\|`
`7`	`9`	= note: cannot satisfy `_: Clone`
`8`	`10`	note: required by a bound in `foo`
Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,9 @@ error[E0283]: type annotations needed`
`2`	`2`	`--> $DIR/issue-86162-2.rs:12:14`
`3`	`3`	`\|`
`4`	`4`	LL \| Foo::bar(gen()); //<- Do not suggest `Foo::bar::<impl Clone>()`!
`5`		- \| ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
	`5`	+ \| -------- ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
	`6`	`+ \| \|`
	`7`	`+ \| type must be known at this point`
`6`	`8`	`\|`
`7`	`9`	= note: cannot satisfy `_: Clone`
`8`	`10`	note: required by a bound in `Foo::bar`
Original file line number	Diff line number	Diff line change
`@@ -14,7 +14,9 @@ error[E0283]: type annotations needed`
`14`	`14`	`--> $DIR/issue-69455.rs:29:41`
`15`	`15`	`\|`
`16`	`16`	`LL \| println!("{}", 23u64.test(xs.iter().sum()));`
`17`		- \| ^^^ cannot infer type of the type parameter `S` declared on the associated function `sum`
	`17`	+ \| ---- ^^^ cannot infer type of the type parameter `S` declared on the associated function `sum`
	`18`	`+ \| \|`
	`19`	`+ \| type must be known at this point`
`18`	`20`	`\|`
`19`	`21`	note: multiple `impl`s satisfying `u64: Test<_>` found
`20`	`22`	`--> $DIR/issue-69455.rs:11:1`
Original file line number	Diff line number	Diff line change
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed for `&[_; 0]`
`2`	`2`	`--> $DIR/issue-7813.rs:2:9`
`3`	`3`	`\|`
`4`	`4`	`LL \| let v = &[];`
`5`		`- \| ^`
	`5`	`+ \| ^ --- type must be known at this point`
`6`	`6`	`\|`
`7`	`7`	help: consider giving `v` an explicit type, where the placeholders `_` are specified
`8`	`8`	`\|`
Original file line number	Diff line number	Diff line change
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed for `[_; 0]`
`2`	`2`	`--> $DIR/suggest-closure-return-type-1.rs:4:18`
`3`	`3`	`\|`
`4`	`4`	`LL \| unbound_drop(\|\| -> _ { [] });`
`5`		`- \| ^^^^^^^`
	`5`	`+ \| ^^^^^^^ -- type must be known at this point`
`6`	`6`	`\|`
`7`	`7`	`help: try giving this closure an explicit return type`
`8`	`8`	`\|`