diff options
| -rw-r--r-- | compiler/rustc_passes/src/loops.rs | 76 | ||||
| -rw-r--r-- | src/test/ui/label/label_misspelled.rs | 27 | ||||
| -rw-r--r-- | src/test/ui/label/label_misspelled.stderr | 78 | ||||
| -rw-r--r-- | src/test/ui/loops/loop-break-value-no-repeat.stderr | 4 | ||||
| -rw-r--r-- | src/test/ui/loops/loop-break-value.rs | 1 | ||||
| -rw-r--r-- | src/test/ui/loops/loop-break-value.stderr | 64 |
6 files changed, 175 insertions, 75 deletions
diff --git a/compiler/rustc_passes/src/loops.rs b/compiler/rustc_passes/src/loops.rs index ed3bfce510c..18b6b98e16a 100644 --- a/compiler/rustc_passes/src/loops.rs +++ b/compiler/rustc_passes/src/loops.rs @@ -90,47 +90,83 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> { }; if let Some(Node::Block(_)) = loop_id.and_then(|id| self.hir_map.find(id)) { - return; - } + return; } - if opt_expr.is_some() { - let loop_kind = if let Some(loop_id) = loop_id { - Some(match self.hir_map.expect_expr(loop_id).kind { - hir::ExprKind::Loop(_, _, source) => source, + if let Some(break_expr) = opt_expr { + let (head, label, loop_kind) = if let Some(loop_id) = loop_id { + match self.hir_map.expect_expr(loop_id).kind { + hir::ExprKind::Loop(_, label, source, sp) => { + (Some(sp), label, Some(source)) + } ref r => { span_bug!(e.span, "break label resolved to a non-loop: {:?}", r) } - }) + } } else { - None + (None, None, None) }; match loop_kind { None | Some(hir::LoopSource::Loop) => (), Some(kind) => { - struct_span_err!( + let mut err = struct_span_err!( self.sess, e.span, E0571, "`break` with value from a `{}` loop", kind.name() - ) - .span_label( + ); + err.span_label( e.span, - "can only break with a value inside \ - `loop` or breakable block", - ) - .span_suggestion( + "can only break with a value inside `loop` or breakable block", + ); + if let Some(head) = head { + err.span_label( + head, + &format!( + "you can't `break` with a value in a `{}` loop", + kind.name() + ), + ); + } + err.span_suggestion( e.span, &format!( - "instead, use `break` on its own \ - without a value inside this `{}` loop", - kind.name() + "use `break` on its own without a value inside this `{}` loop", + kind.name(), ), "break".to_string(), Applicability::MaybeIncorrect, - ) - .emit(); + ); + if let Some(label) = label { + match break_expr.kind { + hir::ExprKind::Path(hir::QPath::Resolved( + None, + hir::Path { + segments: [segment], + res: hir::def::Res::Err, + .. + }, + )) if label.ident.to_string() + == format!("'{}", segment.ident) => + { + // This error is redundant, we will have already emitted a + // suggestion to use the label when `segment` wasn't found + // (hence the `Res::Err` check). + err.delay_as_bug(); + } + _ => { + err.span_suggestion( + break_expr.span, + "alternatively, you might have meant to use the \ + available loop label", + label.ident.to_string(), + Applicability::MaybeIncorrect, + ); + } + } + } + err.emit(); } } } diff --git a/src/test/ui/label/label_misspelled.rs b/src/test/ui/label/label_misspelled.rs index 7a8ff0360f6..17c709768d5 100644 --- a/src/test/ui/label/label_misspelled.rs +++ b/src/test/ui/label/label_misspelled.rs @@ -1,8 +1,4 @@ fn main() { - 'LOOP: loop { - LOOP; - //~^ ERROR cannot find value `LOOP` in this scope - }; 'while_loop: while true { //~ WARN denote infinite loops with while_loop; //~^ ERROR cannot find value `while_loop` in this scope @@ -15,6 +11,10 @@ fn main() { for_loop; //~^ ERROR cannot find value `for_loop` in this scope }; + 'LOOP: loop { + LOOP; + //~^ ERROR cannot find value `LOOP` in this scope + }; } fn foo() { @@ -25,16 +25,29 @@ fn foo() { 'while_loop: while true { //~ WARN denote infinite loops with break while_loop; //~^ ERROR cannot find value `while_loop` in this scope - //~| ERROR `break` with value from a `while` loop }; 'while_let: while let Some(_) = Some(()) { break while_let; //~^ ERROR cannot find value `while_let` in this scope - //~| ERROR `break` with value from a `while` loop } 'for_loop: for _ in 0..3 { break for_loop; //~^ ERROR cannot find value `for_loop` in this scope - //~| ERROR `break` with value from a `for` loop + }; +} + +fn bar() { + let foo = (); + 'while_loop: while true { //~ WARN denote infinite loops with + break foo; + //~^ ERROR `break` with value from a `while` loop + }; + 'while_let: while let Some(_) = Some(()) { + break foo; + //~^ ERROR `break` with value from a `while` loop + } + 'for_loop: for _ in 0..3 { + break foo; + //~^ ERROR `break` with value from a `for` loop }; } diff --git a/src/test/ui/label/label_misspelled.stderr b/src/test/ui/label/label_misspelled.stderr index 7cfb6e8147d..3e99b0ff979 100644 --- a/src/test/ui/label/label_misspelled.stderr +++ b/src/test/ui/label/label_misspelled.stderr @@ -1,13 +1,5 @@ -error[E0425]: cannot find value `LOOP` in this scope - --> $DIR/label_misspelled.rs:3:9 - | -LL | 'LOOP: loop { - | ----- a label with a similar name exists -LL | LOOP; - | ^^^^ not found in this scope - error[E0425]: cannot find value `while_loop` in this scope - --> $DIR/label_misspelled.rs:7:9 + --> $DIR/label_misspelled.rs:3:9 | LL | 'while_loop: while true { | ----------- a label with a similar name exists @@ -15,7 +7,7 @@ LL | while_loop; | ^^^^^^^^^^ not found in this scope error[E0425]: cannot find value `while_let` in this scope - --> $DIR/label_misspelled.rs:11:9 + --> $DIR/label_misspelled.rs:7:9 | LL | 'while_let: while let Some(_) = Some(()) { | ---------- a label with a similar name exists @@ -23,7 +15,7 @@ LL | while_let; | ^^^^^^^^^ not found in this scope error[E0425]: cannot find value `for_loop` in this scope - --> $DIR/label_misspelled.rs:15:9 + --> $DIR/label_misspelled.rs:11:9 | LL | 'for_loop: for _ in 0..3 { | --------- a label with a similar name exists @@ -31,6 +23,14 @@ LL | for_loop; | ^^^^^^^^ not found in this scope error[E0425]: cannot find value `LOOP` in this scope + --> $DIR/label_misspelled.rs:15:9 + | +LL | 'LOOP: loop { + | ----- a label with a similar name exists +LL | LOOP; + | ^^^^ not found in this scope + +error[E0425]: cannot find value `LOOP` in this scope --> $DIR/label_misspelled.rs:22:15 | LL | 'LOOP: loop { @@ -53,7 +53,7 @@ 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:31:15 + --> $DIR/label_misspelled.rs:30:15 | LL | 'while_let: while let Some(_) = Some(()) { | ---------- a label with a similar name exists @@ -64,7 +64,7 @@ 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:36:15 + --> $DIR/label_misspelled.rs:34:15 | LL | 'for_loop: for _ in 0..3 { | --------- a label with a similar name exists @@ -75,7 +75,7 @@ LL | break for_loop; | help: use the similarly named label: `'for_loop` warning: denote infinite loops with `loop { ... }` - --> $DIR/label_misspelled.rs:6:5 + --> $DIR/label_misspelled.rs:2:5 | LL | 'while_loop: while true { | ^^^^^^^^^^^^^^^^^^^^^^^ help: use `loop` @@ -88,40 +88,64 @@ warning: denote infinite loops with `loop { ... }` LL | 'while_loop: while true { | ^^^^^^^^^^^^^^^^^^^^^^^ help: use `loop` +warning: denote infinite loops with `loop { ... }` + --> $DIR/label_misspelled.rs:41:5 + | +LL | 'while_loop: while true { + | ^^^^^^^^^^^^^^^^^^^^^^^ help: use `loop` + error[E0571]: `break` with value from a `while` loop - --> $DIR/label_misspelled.rs:26:9 + --> $DIR/label_misspelled.rs:42:9 | -LL | break while_loop; - | ^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block +LL | 'while_loop: while true { + | ----------------------- you can't `break` with a value in a `while` loop +LL | break foo; + | ^^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `while` loop +help: use `break` on its own without a value inside this `while` loop | LL | break; | ^^^^^ +help: alternatively, you might have meant to use the available loop label + | +LL | break 'while_loop; + | ^^^^^^^^^^^ error[E0571]: `break` with value from a `while` loop - --> $DIR/label_misspelled.rs:31:9 + --> $DIR/label_misspelled.rs:46:9 | -LL | break while_let; - | ^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block +LL | 'while_let: while let Some(_) = Some(()) { + | ---------------------------------------- you can't `break` with a value in a `while` loop +LL | break foo; + | ^^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `while` loop +help: use `break` on its own without a value inside this `while` loop | LL | break; | ^^^^^ +help: alternatively, you might have meant to use the available loop label + | +LL | break 'while_let; + | ^^^^^^^^^^ error[E0571]: `break` with value from a `for` loop - --> $DIR/label_misspelled.rs:36:9 + --> $DIR/label_misspelled.rs:50:9 | -LL | break for_loop; - | ^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block +LL | 'for_loop: for _ in 0..3 { + | ------------------------ you can't `break` with a value in a `for` loop +LL | break foo; + | ^^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `for` loop +help: use `break` on its own without a value inside this `for` loop | LL | break; | ^^^^^ +help: alternatively, you might have meant to use the available loop label + | +LL | break 'for_loop; + | ^^^^^^^^^ -error: aborting due to 11 previous errors; 2 warnings emitted +error: aborting due to 11 previous errors; 3 warnings emitted Some errors have detailed explanations: E0425, E0571. For more information about an error, try `rustc --explain E0425`. diff --git a/src/test/ui/loops/loop-break-value-no-repeat.stderr b/src/test/ui/loops/loop-break-value-no-repeat.stderr index ff93e9220e9..1c0d39a6e5a 100644 --- a/src/test/ui/loops/loop-break-value-no-repeat.stderr +++ b/src/test/ui/loops/loop-break-value-no-repeat.stderr @@ -1,10 +1,12 @@ error[E0571]: `break` with value from a `for` loop --> $DIR/loop-break-value-no-repeat.rs:12:9 | +LL | for _ in &[1,2,3] { + | ----------------- you can't `break` with a value in a `for` loop LL | break 22 | ^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `for` loop +help: use `break` on its own without a value inside this `for` loop | LL | break | ^^^^^ diff --git a/src/test/ui/loops/loop-break-value.rs b/src/test/ui/loops/loop-break-value.rs index 8a080cfdf49..51c9a36a039 100644 --- a/src/test/ui/loops/loop-break-value.rs +++ b/src/test/ui/loops/loop-break-value.rs @@ -94,6 +94,5 @@ fn main() { 'LOOP: for _ in 0 .. 9 { break LOOP; //~^ ERROR cannot find value `LOOP` in this scope - //~| ERROR `break` with value from a `for` loop } } diff --git a/src/test/ui/loops/loop-break-value.stderr b/src/test/ui/loops/loop-break-value.stderr index 27104118a63..c7cf1017d4b 100644 --- a/src/test/ui/loops/loop-break-value.stderr +++ b/src/test/ui/loops/loop-break-value.stderr @@ -20,32 +20,48 @@ LL | 'while_loop: while true { error[E0571]: `break` with value from a `while` loop --> $DIR/loop-break-value.rs:28:9 | +LL | 'while_loop: while true { + | ----------------------- you can't `break` with a value in a `while` loop +LL | break; LL | break (); | ^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `while` loop +help: use `break` on its own without a value inside this `while` loop | LL | break; | ^^^^^ +help: alternatively, you might have meant to use the available loop label + | +LL | break 'while_loop; + | ^^^^^^^^^^^ error[E0571]: `break` with value from a `while` loop --> $DIR/loop-break-value.rs:30:13 | +LL | 'while_loop: while true { + | ----------------------- you can't `break` with a value in a `while` loop +... LL | break 'while_loop 123; | ^^^^^^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `while` loop +help: use `break` on its own without a value inside this `while` loop | LL | break; | ^^^^^ +help: alternatively, you might have meant to use the available loop label + | +LL | break 'while_loop 'while_loop; + | ^^^^^^^^^^^ error[E0571]: `break` with value from a `while` loop --> $DIR/loop-break-value.rs:38:12 | +LL | while let Some(_) = Some(()) { + | ---------------------------- you can't `break` with a value in a `while` loop LL | if break () { | ^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `while` loop +help: use `break` on its own without a value inside this `while` loop | LL | if break { | ^^^^^ @@ -53,10 +69,12 @@ LL | if break { error[E0571]: `break` with value from a `while` loop --> $DIR/loop-break-value.rs:43:9 | +LL | while let Some(_) = Some(()) { + | ---------------------------- you can't `break` with a value in a `while` loop LL | break None; | ^^^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `while` loop +help: use `break` on its own without a value inside this `while` loop | LL | break; | ^^^^^ @@ -64,21 +82,30 @@ LL | break; error[E0571]: `break` with value from a `while` loop --> $DIR/loop-break-value.rs:49:13 | +LL | 'while_let_loop: while let Some(_) = Some(()) { + | --------------------------------------------- you can't `break` with a value in a `while` loop +LL | loop { LL | break 'while_let_loop "nope"; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `while` loop +help: use `break` on its own without a value inside this `while` loop | LL | break; | ^^^^^ +help: alternatively, you might have meant to use the available loop label + | +LL | break 'while_let_loop 'while_let_loop; + | ^^^^^^^^^^^^^^^ error[E0571]: `break` with value from a `for` loop --> $DIR/loop-break-value.rs:56:9 | +LL | for _ in &[1,2,3] { + | ----------------- you can't `break` with a value in a `for` loop LL | break (); | ^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `for` loop +help: use `break` on its own without a value inside this `for` loop | LL | break; | ^^^^^ @@ -86,10 +113,13 @@ LL | break; error[E0571]: `break` with value from a `for` loop --> $DIR/loop-break-value.rs:57:9 | +LL | for _ in &[1,2,3] { + | ----------------- you can't `break` with a value in a `for` loop +LL | break (); LL | break [()]; | ^^^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `for` loop +help: use `break` on its own without a value inside this `for` loop | LL | break; | ^^^^^ @@ -97,24 +127,20 @@ LL | break; error[E0571]: `break` with value from a `for` loop --> $DIR/loop-break-value.rs:64:13 | +LL | 'for_loop: for _ in &[1,2,3] { + | ---------------------------- you can't `break` with a value in a `for` loop +... LL | break 'for_loop Some(17); | ^^^^^^^^^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block | -help: instead, use `break` on its own without a value inside this `for` loop +help: use `break` on its own without a value inside this `for` loop | LL | break; | ^^^^^ - -error[E0571]: `break` with value from a `for` loop - --> $DIR/loop-break-value.rs:95:9 - | -LL | break LOOP; - | ^^^^^^^^^^ can only break with a value inside `loop` or breakable block +help: alternatively, you might have meant to use the available loop label | -help: instead, use `break` on its own without a value inside this `for` loop - | -LL | break; - | ^^^^^ +LL | break 'for_loop 'for_loop; + | ^^^^^^^^^ error[E0308]: mismatched types --> $DIR/loop-break-value.rs:4:31 @@ -173,7 +199,7 @@ LL | break; | expected integer, found `()` | help: give it a value of the expected type: `break value` -error: aborting due to 18 previous errors; 1 warning emitted +error: aborting due to 17 previous errors; 1 warning emitted Some errors have detailed explanations: E0308, E0425, E0571. For more information about an error, try `rustc --explain E0308`. |