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Avoid emitting redundant "unused label" lint

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This commit is contained in:
Esteban Küber 2021-01-20 17:57:47 -08:00
parent c065234b34
commit 74ddaf000c
5 changed files with 20 additions and 64 deletions
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4
compiler/rustc_resolve/src/late/diagnostics.rs
View File

@ -545,7 +545,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
if let Some(err_code) = &err.code {
if err_code == &rustc_errors::error_code!(E0425) {
for label_rib in &self.label_ribs {
for (label_ident, _) in &label_rib.bindings {
for (label_ident, node_id) in &label_rib.bindings {
if format!("'{}", ident) == label_ident.to_string() {
err.span_label(label_ident.span, "a label with a similar name exists");
if let PathSource::Expr(Some(Expr {
@ -559,6 +559,8 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
label_ident.name.to_string(),
Applicability::MaybeIncorrect,
);
// Do not lint against unused label when we suggest them.
self.diagnostic_metadata.unused_labels.remove(node_id);
}
}
}

4
src/test/ui/label/label_misspelled.rs
View File

@ -25,22 +25,18 @@ fn main() {
fn foo() {
'LOOP: loop {
//~^ WARN unused label
break LOOP;
//~^ ERROR cannot find value `LOOP` in this scope
};
'while_loop: while true { //~ WARN denote infinite loops with
//~^ WARN unused label
break while_loop;
//~^ ERROR cannot find value `while_loop` in this scope
};
'while_let: while let Some(_) = Some(()) {
//~^ WARN unused label
break while_let;
//~^ ERROR cannot find value `while_let` in this scope
}
'for_loop: for _ in 0..3 {
//~^ WARN unused label
break for_loop;
//~^ ERROR cannot find value `for_loop` in this scope
};

54
src/test/ui/label/label_misspelled.stderr
View File

@ -35,11 +35,10 @@ LL | LOOP;
| ^^^^ not found in this scope
error[E0425]: cannot find value `LOOP` in this scope
--> $DIR/label_misspelled.rs:29:15
--> $DIR/label_misspelled.rs:28:15
|
LL | 'LOOP: loop {
| ----- a label with a similar name exists
LL |
LL | break LOOP;
| ^^^^
| |
@ -47,11 +46,10 @@ LL | break LOOP;
| help: use the similarly named label: `'LOOP`
error[E0425]: cannot find value `while_loop` in this scope
--> $DIR/label_misspelled.rs:34:15
--> $DIR/label_misspelled.rs:32:15
|
LL | 'while_loop: while true {
| ----------- a label with a similar name exists
LL |
LL | break while_loop;
| ^^^^^^^^^^
| |
@ -59,11 +57,10 @@ LL | break while_loop;
| help: use the similarly named label: `'while_loop`
error[E0425]: cannot find value `while_let` in this scope
--> $DIR/label_misspelled.rs:39:15
--> $DIR/label_misspelled.rs:36:15
|
LL | 'while_let: while let Some(_) = Some(()) {
| ---------- a label with a similar name exists
LL |
LL | break while_let;
| ^^^^^^^^^
| |
@ -71,11 +68,10 @@ LL | break while_let;
| help: use the similarly named label: `'while_let`
error[E0425]: cannot find value `for_loop` in this scope
--> $DIR/label_misspelled.rs:44:15
--> $DIR/label_misspelled.rs:40:15
|
LL | 'for_loop: for _ in 0..3 {
| --------- a label with a similar name exists
LL |
LL | break for_loop;
| ^^^^^^^^
| |
@ -120,62 +116,38 @@ warning: unused label
LL | 'LOOP: loop {
| ^^^^^
warning: unused label
--> $DIR/label_misspelled.rs:27:5
|
LL | 'LOOP: loop {
| ^^^^^
warning: unused label
--> $DIR/label_misspelled.rs:32:5
|
LL | 'while_loop: while true {
| ^^^^^^^^^^^
warning: denote infinite loops with `loop { ... }`
--> $DIR/label_misspelled.rs:32:5
--> $DIR/label_misspelled.rs:31:5
|
LL | 'while_loop: while true {
| ^^^^^^^^^^^^^^^^^^^^^^^ help: use `loop`
warning: unused label
--> $DIR/label_misspelled.rs:37:5
|
LL | 'while_let: while let Some(_) = Some(()) {
| ^^^^^^^^^^
warning: unused label
--> $DIR/label_misspelled.rs:42:5
|
LL | 'for_loop: for _ in 0..3 {
| ^^^^^^^^^
warning: unused label
--> $DIR/label_misspelled.rs:51:5
--> $DIR/label_misspelled.rs:47:5
|
LL | 'while_loop: while true {
| ^^^^^^^^^^^
warning: denote infinite loops with `loop { ... }`
--> $DIR/label_misspelled.rs:51:5
--> $DIR/label_misspelled.rs:47:5
|
LL | 'while_loop: while true {
| ^^^^^^^^^^^^^^^^^^^^^^^ help: use `loop`
warning: unused label
--> $DIR/label_misspelled.rs:56:5
--> $DIR/label_misspelled.rs:52:5
|
LL | 'while_let: while let Some(_) = Some(()) {
| ^^^^^^^^^^
warning: unused label
--> $DIR/label_misspelled.rs:61:5
--> $DIR/label_misspelled.rs:57:5
|
LL | 'for_loop: for _ in 0..3 {
| ^^^^^^^^^
error[E0571]: `break` with value from a `while` loop
--> $DIR/label_misspelled.rs:53:9
--> $DIR/label_misspelled.rs:49:9
|
LL | 'while_loop: while true {
| ----------------------- you can't `break` with a value in a `while` loop
@ -193,7 +165,7 @@ LL | break 'while_loop;
| ^^^^^^^^^^^
error[E0571]: `break` with value from a `while` loop
--> $DIR/label_misspelled.rs:58:9
--> $DIR/label_misspelled.rs:54:9
|
LL | 'while_let: while let Some(_) = Some(()) {
| ---------------------------------------- you can't `break` with a value in a `while` loop
@ -211,7 +183,7 @@ LL | break 'while_let;
| ^^^^^^^^^^
error[E0571]: `break` with value from a `for` loop
--> $DIR/label_misspelled.rs:63:9
--> $DIR/label_misspelled.rs:59:9
|
LL | 'for_loop: for _ in 0..3 {
| ------------------------ you can't `break` with a value in a `for` loop
@ -228,7 +200,7 @@ help: alternatively, you might have meant to use the available loop label
LL | break 'for_loop;
| ^^^^^^^^^
error: aborting due to 11 previous errors; 14 warnings emitted
error: aborting due to 11 previous errors; 10 warnings emitted
Some errors have detailed explanations: E0425, E0571.
For more information about an error, try `rustc --explain E0425`.

1
src/test/ui/label/label_misspelled_2.rs
View File

@ -5,7 +5,6 @@ fn main() {
break 'a;
}
'b: for _ in 0..1 {
//~^ WARN unused label
break b; //~ ERROR cannot find value `b` in this scope
}
c: for _ in 0..1 { //~ ERROR expected identifier, found keyword `for`

21
src/test/ui/label/label_misspelled_2.stderr
View File

@ -1,11 +1,11 @@
error: expected identifier, found keyword `for`
--> $DIR/label_misspelled_2.rs:11:8
--> $DIR/label_misspelled_2.rs:10:8
|
LL | c: for _ in 0..1 {
| ^^^ expected identifier, found keyword
error: expected `<`, found reserved identifier `_`
--> $DIR/label_misspelled_2.rs:11:12
--> $DIR/label_misspelled_2.rs:10:12
|
LL | c: for _ in 0..1 {
| - ^ expected `<`
@ -16,29 +16,16 @@ LL | c: for _ in 0..1 {
= note: see issue #23416 <https://github.com/rust-lang/rust/issues/23416> for more information
error[E0425]: cannot find value `b` in this scope
--> $DIR/label_misspelled_2.rs:9:15
--> $DIR/label_misspelled_2.rs:8:15
|
LL | 'b: for _ in 0..1 {
| -- a label with a similar name exists
LL |
LL | break b;
| ^
| |
| not found in this scope
| help: use the similarly named label: `'b`
warning: unused label
--> $DIR/label_misspelled_2.rs:7:5
|
LL | 'b: for _ in 0..1 {
| ^^
|
note: the lint level is defined here
--> $DIR/label_misspelled_2.rs:1:9
|
LL | #![warn(unused_labels)]
| ^^^^^^^^^^^^^
error: aborting due to 3 previous errors; 1 warning emitted
error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0425`.