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Resolve vars before emitting coerce error
1 parent c62a8ea commit 1f463ac

11 files changed

+102
-12
lines changed

‎compiler/rustc_typeck/src/check/coercion.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -1478,6 +1478,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
14781478
// type)
14791479
(self.final_ty.unwrap_or(self.expected_ty), expression_ty)
14801480
};
1481+
let (expected, found) = fcx.resolve_vars_if_possible((expected, found));
14811482

14821483
let mut err;
14831484
let mut unsized_return = false;
@@ -1663,7 +1664,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
16631664
sp,
16641665
&format!(
16651666
"return type inferred to be `{}` here",
1666-
fcx.resolve_vars_if_possible(expected)
1667+
expected
16671668
),
16681669
);
16691670
}

‎src/test/ui/expr/if/if-branch-types.stderr

+5
Original file line numberDiff line numberDiff line change
@@ -5,6 +5,11 @@ LL | let x = if true { 10i32 } else { 10u32 };
55
| ----- ^^^^^ expected `i32`, found `u32`
66
| |
77
| expected because of this
8+
|
9+
help: change the type of the numeric literal from `u32` to `i32`
10+
|
11+
LL | let x = if true { 10i32 } else { 10i32 };
12+
| ~~~
813

914
error: aborting due to previous error
1015

‎src/test/ui/expr/if/if-else-type-mismatch.stderr

+10
Original file line numberDiff line numberDiff line change
@@ -10,6 +10,11 @@ LL | | 2u32
1010
| | ^^^^ expected `i32`, found `u32`
1111
LL | | };
1212
| |_____- `if` and `else` have incompatible types
13+
|
14+
help: change the type of the numeric literal from `u32` to `i32`
15+
|
16+
LL | 2i32
17+
| ~~~
1318

1419
error[E0308]: `if` and `else` have incompatible types
1520
--> $DIR/if-else-type-mismatch.rs:8:38
@@ -18,6 +23,11 @@ LL | let _ = if true { 42i32 } else { 42u32 };
1823
| ----- ^^^^^ expected `i32`, found `u32`
1924
| |
2025
| expected because of this
26+
|
27+
help: change the type of the numeric literal from `u32` to `i32`
28+
|
29+
LL | let _ = if true { 42i32 } else { 42i32 };
30+
| ~~~
2131

2232
error[E0308]: `if` and `else` have incompatible types
2333
--> $DIR/if-else-type-mismatch.rs:13:9

‎src/test/ui/generator/type-mismatch-signature-deduction.stderr

+6
Original file line numberDiff line numberDiff line change
@@ -11,6 +11,12 @@ note: return type inferred to be `Result<{integer}, _>` here
1111
|
1212
LL | return Ok(6);
1313
| ^^^^^
14+
help: try wrapping the expression in a variant of `Result`
15+
|
16+
LL | Ok(5)
17+
| +++ +
18+
LL | Err(5)
19+
| ++++ +
1420

1521
error[E0271]: type mismatch resolving `<[generator@$DIR/type-mismatch-signature-deduction.rs:7:5: 7:7] as Generator>::Return == i32`
1622
--> $DIR/type-mismatch-signature-deduction.rs:5:13

‎src/test/ui/impl-trait/equality.stderr

+6-1
Original file line numberDiff line numberDiff line change
@@ -12,10 +12,15 @@ error[E0308]: mismatched types
1212
--> $DIR/equality.rs:15:5
1313
|
1414
LL | fn two(x: bool) -> impl Foo {
15-
| -------- expected `_` because of return type
15+
| -------- expected `i32` because of return type
1616
...
1717
LL | 0_u32
1818
| ^^^^^ expected `i32`, found `u32`
19+
|
20+
help: change the type of the numeric literal from `u32` to `i32`
21+
|
22+
LL | 0_i32
23+
| ~~~
1924

2025
error[E0277]: cannot add `impl Foo` to `u32`
2126
--> $DIR/equality.rs:24:11

‎src/test/ui/impl-trait/object-unsafe-trait-in-return-position-impl-trait.stderr

+2-2
Original file line numberDiff line numberDiff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
22
--> $DIR/object-unsafe-trait-in-return-position-impl-trait.rs:36:5
33
|
44
LL | fn can() -> impl NotObjectSafe {
5-
| ------------------ expected `_` because of return type
5+
| ------------------ expected `A` because of return type
66
...
77
LL | B
88
| ^ expected struct `A`, found struct `B`
@@ -11,7 +11,7 @@ error[E0308]: mismatched types
1111
--> $DIR/object-unsafe-trait-in-return-position-impl-trait.rs:43:5
1212
|
1313
LL | fn cat() -> impl ObjectSafe {
14-
| --------------- expected `_` because of return type
14+
| --------------- expected `A` because of return type
1515
...
1616
LL | B
1717
| ^ expected struct `A`, found struct `B`

‎src/test/ui/impl-trait/point-to-type-err-cause-on-impl-trait-return.stderr

+61-6
Original file line numberDiff line numberDiff line change
@@ -2,28 +2,43 @@ error[E0308]: mismatched types
22
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:5:5
33
|
44
LL | fn foo() -> impl std::fmt::Display {
5-
| ---------------------- expected `_` because of return type
5+
| ---------------------- expected `i32` because of return type
66
...
77
LL | 1u32
88
| ^^^^ expected `i32`, found `u32`
9+
|
10+
help: change the type of the numeric literal from `u32` to `i32`
11+
|
12+
LL | 1i32
13+
| ~~~
914

1015
error[E0308]: mismatched types
1116
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:12:16
1217
|
1318
LL | fn bar() -> impl std::fmt::Display {
14-
| ---------------------- expected `_` because of return type
19+
| ---------------------- expected `i32` because of return type
1520
...
1621
LL | return 1u32;
1722
| ^^^^ expected `i32`, found `u32`
23+
|
24+
help: change the type of the numeric literal from `u32` to `i32`
25+
|
26+
LL | return 1i32;
27+
| ~~~
1828

1929
error[E0308]: mismatched types
2030
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:20:9
2131
|
2232
LL | fn baz() -> impl std::fmt::Display {
23-
| ---------------------- expected `_` because of return type
33+
| ---------------------- expected `i32` because of return type
2434
...
2535
LL | 1u32
2636
| ^^^^ expected `i32`, found `u32`
37+
|
38+
help: you can convert a `u32` to an `i32` and panic if the converted value doesn't fit
39+
|
40+
LL | }.try_into().unwrap()
41+
| ++++++++++++++++++++
2742

2843
error[E0308]: `if` and `else` have incompatible types
2944
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:28:9
@@ -36,36 +51,56 @@ LL | | 1u32
3651
| | ^^^^ expected `i32`, found `u32`
3752
LL | | }
3853
| |_____- `if` and `else` have incompatible types
54+
|
55+
help: change the type of the numeric literal from `u32` to `i32`
56+
|
57+
LL | 1i32
58+
| ~~~
3959

4060
error[E0308]: mismatched types
4161
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:35:14
4262
|
4363
LL | fn bat() -> impl std::fmt::Display {
44-
| ---------------------- expected `_` because of return type
64+
| ---------------------- expected `i32` because of return type
4565
...
4666
LL | _ => 1u32,
4767
| ^^^^ expected `i32`, found `u32`
68+
|
69+
help: you can convert a `u32` to an `i32` and panic if the converted value doesn't fit
70+
|
71+
LL | }.try_into().unwrap()
72+
| ++++++++++++++++++++
4873

4974
error[E0308]: mismatched types
5075
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:40:5
5176
|
5277
LL | fn can() -> impl std::fmt::Display {
53-
| ---------------------- expected `_` because of return type
78+
| ---------------------- expected `i32` because of return type
5479
LL | / match 13 {
5580
LL | | 0 => return 0i32,
5681
LL | | 1 => 1u32,
5782
LL | | _ => 2u32,
5883
LL | | }
5984
| |_____^ expected `i32`, found `u32`
85+
|
86+
help: you can convert a `u32` to an `i32` and panic if the converted value doesn't fit
87+
|
88+
LL | }.try_into().unwrap()
89+
| ++++++++++++++++++++
6090

6191
error[E0308]: mismatched types
6292
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:53:13
6393
|
6494
LL | fn cat() -> impl std::fmt::Display {
65-
| ---------------------- expected `_` because of return type
95+
| ---------------------- expected `i32` because of return type
6696
...
6797
LL | 1u32
6898
| ^^^^ expected `i32`, found `u32`
99+
|
100+
help: you can convert a `u32` to an `i32` and panic if the converted value doesn't fit
101+
|
102+
LL | }.try_into().unwrap()
103+
| ++++++++++++++++++++
69104

70105
error[E0308]: `match` arms have incompatible types
71106
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:61:14
@@ -78,6 +113,11 @@ LL | | 1 => 1u32,
78113
LL | | _ => 2u32,
79114
LL | | }
80115
| |_____- `match` arms have incompatible types
116+
|
117+
help: change the type of the numeric literal from `u32` to `i32`
118+
|
119+
LL | 1 => 1i32,
120+
| ~~~
81121

82122
error[E0308]: `if` and `else` have incompatible types
83123
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:97:9
@@ -90,6 +130,11 @@ LL | | 1u32
90130
| | ^^^^ expected `i32`, found `u32`
91131
LL | | }
92132
| |_____- `if` and `else` have incompatible types
133+
|
134+
help: change the type of the numeric literal from `u32` to `i32`
135+
|
136+
LL | 1i32
137+
| ~~~
93138

94139
error[E0746]: return type cannot have an unboxed trait object
95140
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:66:13
@@ -125,6 +170,11 @@ LL | | 1 => 1u32,
125170
LL | | _ => 2u32,
126171
LL | | }
127172
| |_____- `match` arms have incompatible types
173+
|
174+
help: change the type of the numeric literal from `u32` to `i32`
175+
|
176+
LL | 1 => 1i32,
177+
| ~~~
128178

129179
error[E0746]: return type cannot have an unboxed trait object
130180
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:77:13
@@ -164,6 +214,11 @@ LL | | 1u32
164214
| | ^^^^ expected `i32`, found `u32`
165215
LL | | }
166216
| |_____- `if` and `else` have incompatible types
217+
|
218+
help: change the type of the numeric literal from `u32` to `i32`
219+
|
220+
LL | 1i32
221+
| ~~~
167222

168223
error[E0746]: return type cannot have an unboxed trait object
169224
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:85:13

‎src/test/ui/mismatched_types/dont-point-return-on-E0308.stderr

+1-1
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
error[E0308]: mismatched types
2-
--> $DIR/dont-point-return-on-E0308.rs:10:11
2+
--> $DIR/dont-point-return-on-E0308.rs:11:11
33
|
44
LL | f(());
55
| - ^^

‎src/test/ui/mismatched_types/issue-84976.stderr

+5
Original file line numberDiff line numberDiff line change
@@ -3,6 +3,11 @@ error[E0308]: mismatched types
33
|
44
LL | length = { foo(&length) };
55
| ^^^^^^^^^^^^ expected `u32`, found `i32`
6+
|
7+
help: you can convert an `i32` to a `u32` and panic if the converted value doesn't fit
8+
|
9+
LL | length = { foo(&length).try_into().unwrap() };
10+
| ++++++++++++++++++++
611

712
error[E0308]: mismatched types
813
--> $DIR/issue-84976.rs:17:14

‎src/test/ui/reify-intrinsic.stderr

+3
Original file line numberDiff line numberDiff line change
@@ -23,6 +23,9 @@ LL | std::intrinsics::unlikely,
2323
|
2424
= note: expected fn item `extern "rust-intrinsic" fn(_) -> _ {likely}`
2525
found fn item `extern "rust-intrinsic" fn(_) -> _ {unlikely}`
26+
= note: different `fn` items always have unique types, even if their signatures are the same
27+
= help: change the expected type to be function pointer `extern "rust-intrinsic" fn(bool) -> bool`
28+
= help: if the expected type is due to type inference, cast the expected `fn` to a function pointer: `likely as extern "rust-intrinsic" fn(bool) -> bool`
2629

2730
error: aborting due to 3 previous errors
2831

‎src/test/ui/type-alias-impl-trait/issue-74280.stderr

+1-1
Original file line numberDiff line numberDiff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
22
--> $DIR/issue-74280.rs:9:5
33
|
44
LL | fn test() -> Test {
5-
| ---- expected `_` because of return type
5+
| ---- expected `()` because of return type
66
LL | let y = || -> Test { () };
77
LL | 7
88
| ^ expected `()`, found integer

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