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Rollup merge of #102708 - TaKO8Ki:improve-eqeq-suggestion, r=estebank

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Suggest `==` to wrong assign expr

Given the following code:

```rust
fn main() {
    let x = 3;
    let y = 3;
    if x == x && y = y {
        println!("{}", x);
    }
}
```

Current output is:

```
error[E0308]: mismatched types
 --> src/main.rs:4:18
  |
4 |     if x == x && y = y {
  |                  ^ expected `bool`, found integer

error[E0308]: mismatched types
 --> src/main.rs:4:8
  |
4 |     if x == x && y = y {
  |        ^^^^^^^^^^^^^^^ expected `bool`, found `()`
```

This adds a suggestion:

```diff
error[E0308]: mismatched types
 --> src/main.rs:6:18
  |
6 |     if x == x && y = y {
  |                  ^ expected `bool`, found integer

error[E0308]: mismatched types
 --> src/main.rs:6:8
  |
6 |     if x == x && y = y {
  |        ^^^^^^^^^^^^^^^ expected `bool`, found `()`
  |
+ help: you might have meant to compare for equality
+   |
+ 6 |     if x == x && y == y {
+   |                     +
```

And this fixes a part of #97469
This commit is contained in:
Matthias Krüger
2022-10-06 07:07:37 +02:00
committed by GitHub
parent a9b3441c17 b7c42c55a2
commit 0512a06186
6 changed files with 88 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
compiler/rustc_hir_analysis/src/check/expr.rs
View File

@@ -1045,6 +1045,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
let rhs_ty = self.check_expr(&rhs);
let (applicability, eq) = if self.can_coerce(rhs_ty, lhs_ty) {
(Applicability::MachineApplicable, true)
} else if let ExprKind::Binary(
Spanned { node: hir::BinOpKind::And | hir::BinOpKind::Or, .. },
_,
rhs_expr,
) = lhs.kind
{
let actual_lhs_ty = self.check_expr(&rhs_expr);
(Applicability::MaybeIncorrect, self.can_coerce(rhs_ty, actual_lhs_ty))
} else {
(Applicability::MaybeIncorrect, false)
};
@@ -1067,9 +1075,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
}
if eq {
err.span_suggestion_verbose(
span,
span.shrink_to_hi(),
"you might have meant to compare for equality",
"==",
'=',
applicability,
);
}

5
src/test/ui/expr/if/bad-if-let-suggestion.stderr
View File

@@ -62,6 +62,11 @@ error[E0308]: mismatched types
|
LL | if let x = 1 && i = 2 {}
| ^^^^^^^^^^^^^^^^^^ expected `bool`, found `()`
|
help: you might have meant to compare for equality
|
LL | if let x = 1 && i == 2 {}
| +
error: aborting due to 8 previous errors

4
src/test/ui/rfc-2497-if-let-chains/disallowed-positions.stderr
View File

@@ -1510,7 +1510,7 @@ LL | if x = let 0 = 0 {}
help: you might have meant to compare for equality
|
LL | if x == let 0 = 0 {}
| ~~
| +
error[E0308]: mismatched types
--> $DIR/disallowed-positions.rs:157:8
@@ -1704,7 +1704,7 @@ LL | while x = let 0 = 0 {}
help: you might have meant to compare for equality
|
LL | while x == let 0 = 0 {}
| ~~
| +
error[E0308]: mismatched types
--> $DIR/disallowed-positions.rs:249:11

22
src/test/ui/type/type-check/assignment-expected-bool.stderr
View File

@@ -7,7 +7,7 @@ LL | let _: bool = 0 = 0;
help: you might have meant to compare for equality
|
LL | let _: bool = 0 == 0;
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:9:14
@@ -18,7 +18,7 @@ LL | 0 => 0 = 0,
help: you might have meant to compare for equality
|
LL | 0 => 0 == 0,
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:10:14
@@ -29,7 +29,7 @@ LL | _ => 0 = 0,
help: you might have meant to compare for equality
|
LL | _ => 0 == 0,
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:14:17
@@ -40,7 +40,7 @@ LL | true => 0 = 0,
help: you might have meant to compare for equality
|
LL | true => 0 == 0,
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:18:8
@@ -51,7 +51,7 @@ LL | if 0 = 0 {}
help: you might have meant to compare for equality
|
LL | if 0 == 0 {}
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:20:24
@@ -62,7 +62,7 @@ LL | let _: bool = if { 0 = 0 } {
help: you might have meant to compare for equality
|
LL | let _: bool = if { 0 == 0 } {
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:21:9
@@ -73,7 +73,7 @@ LL | 0 = 0
help: you might have meant to compare for equality
|
LL | 0 == 0
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:23:9
@@ -84,7 +84,7 @@ LL | 0 = 0
help: you might have meant to compare for equality
|
LL | 0 == 0
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:26:13
@@ -95,7 +95,7 @@ LL | let _ = (0 = 0)
help: you might have meant to compare for equality
|
LL | let _ = (0 == 0)
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:27:14
@@ -106,7 +106,7 @@ LL | && { 0 = 0 }
help: you might have meant to compare for equality
|
LL | && { 0 == 0 }
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-expected-bool.rs:28:12
@@ -117,7 +117,7 @@ LL | || (0 = 0);
help: you might have meant to compare for equality
|
LL | || (0 == 0);
| ~~
| +
error[E0070]: invalid left-hand side of assignment
--> $DIR/assignment-expected-bool.rs:31:22

13
src/test/ui/type/type-check/assignment-in-if.rs
View File

@@ -40,4 +40,17 @@ fn main() {
) {
println!("{}", x);
}
if x == x && x = x && x == x {
//~^ ERROR mismatched types
//~| ERROR mismatched types
//~| ERROR mismatched types
println!("{}", x);
}
if x == x && x == x && x = x {
//~^ ERROR mismatched types
//~| ERROR mismatched types
println!("{}", x);
}
}

54
src/test/ui/type/type-check/assignment-in-if.stderr
View File

@@ -7,7 +7,7 @@ LL | if x = x {
help: you might have meant to compare for equality
|
LL | if x == x {
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:20:8
@@ -18,7 +18,7 @@ LL | if (x = x) {
help: you might have meant to compare for equality
|
LL | if (x == x) {
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:25:8
@@ -29,7 +29,7 @@ LL | if y = (Foo { foo: x }) {
help: you might have meant to compare for equality
|
LL | if y == (Foo { foo: x }) {
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:30:8
@@ -40,7 +40,7 @@ LL | if 3 = x {
help: you might have meant to compare for equality
|
LL | if 3 == x {
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:36:13
@@ -51,7 +51,7 @@ LL | x = 4
help: you might have meant to compare for equality
|
LL | x == 4
| ~~
| +
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:38:13
@@ -62,8 +62,48 @@ LL | x = 5
help: you might have meant to compare for equality
|
LL | x == 5
| ~~
| +
error: aborting due to 6 previous errors
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:44:18
|
LL | if x == x && x = x && x == x {
| ^ expected `bool`, found `usize`
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:44:22
|
LL | if x == x && x = x && x == x {
| ^ expected `bool`, found `usize`
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:44:8
|
LL | if x == x && x = x && x == x {
| ^^^^^^^^^^^^^^^^^^^^^^^^^ expected `bool`, found `()`
|
help: you might have meant to compare for equality
|
LL | if x == x && x == x && x == x {
| +
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:51:28
|
LL | if x == x && x == x && x = x {
| ^ expected `bool`, found `usize`
error[E0308]: mismatched types
--> $DIR/assignment-in-if.rs:51:8
|
LL | if x == x && x == x && x = x {
| ^^^^^^^^^^^^^^^^^^^^^^^^^ expected `bool`, found `()`
|
help: you might have meant to compare for equality
|
LL | if x == x && x == x && x == x {
| +
error: aborting due to 11 previous errors
For more information about this error, try `rustc --explain E0308`.