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Do not suggest adding labeled block if there are no labeled breaks

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This commit is contained in:
Maybe Waffle 2022-06-05 23:12:51 +04:00
parent f21c0a274e
commit c6e5bb32fb
5 changed files with 33 additions and 24 deletions
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23
compiler/rustc_parse/src/parser/expr.rs
View file

@ -13,6 +13,7 @@ use rustc_ast::tokenstream::Spacing;
use rustc_ast::util::classify;
use rustc_ast::util::literal::LitError;
use rustc_ast::util::parser::{prec_let_scrutinee_needs_par, AssocOp, Fixity};
use rustc_ast::visit::Visitor;
use rustc_ast::StmtKind;
use rustc_ast::{self as ast, AttrStyle, AttrVec, CaptureBy, ExprField, Lit, UnOp, DUMMY_NODE_ID};
use rustc_ast::{AnonConst, BinOp, BinOpKind, FnDecl, FnRetTy, MacCall, Param, Ty, TyKind};
@ -1556,6 +1557,28 @@ impl<'a> Parser<'a> {
// Continue as an expression in an effort to recover on `'label: non_block_expr`.
let expr = self.parse_expr().map(|expr| {
let found_labeled_breaks = {
struct FindLabeledBreaksVisitor(bool);
impl<'ast> Visitor<'ast> for FindLabeledBreaksVisitor {
fn visit_expr_post(&mut self, ex: &'ast Expr) {
if let ExprKind::Break(Some(_label), _) = ex.kind {
self.0 = true;
}
}
}
let mut vis = FindLabeledBreaksVisitor(false);
vis.visit_expr(&expr);
vis.0
};
// Suggestion involves adding a (as of time of writing this, unstable) labeled block
// so if the label is not used, just return the unmodified expression
if !found_labeled_breaks {
return expr;
}
let span = expr.span;
let sugg_msg = "consider enclosing expression in a block";
let suggestions = vec![

5
src/test/ui/parser/labeled-no-colon-expr.stderr
View file

@ -47,11 +47,6 @@ error: expected `while`, `for`, `loop` or `{` after a label
|
LL | 'l4 0;
| ^ expected `while`, `for`, `loop` or `{` after a label
|
help: consider enclosing expression in a block
|
LL | 'l4 {0};
| + +
error: labeled expression must be followed by `:`
--> $DIR/labeled-no-colon-expr.rs:8:9

5
src/test/ui/parser/recover-labeled-non-block-expr.fixed
View file

@ -1,8 +1,9 @@
// run-rustfix
#![feature(label_break_value)]
fn main() {
#[allow(unused_labels)]
'label: {1 + 1}; //~ ERROR expected `while`, `for`, `loop` or `{` after a label
// FIXME(waffle): add this back
// #[allow(unused_labels)]
// 'label: 1 + 1; // ERROR expected `while`, `for`, `loop` or `{` after a label
'label: {match () { () => break 'label, }}; //~ ERROR expected `while`, `for`, `loop` or `{` after a label

5
src/test/ui/parser/recover-labeled-non-block-expr.rs
View file

@ -1,8 +1,9 @@
// run-rustfix
#![feature(label_break_value)]
fn main() {
#[allow(unused_labels)]
'label: 1 + 1; //~ ERROR expected `while`, `for`, `loop` or `{` after a label
// FIXME(waffle): add this back
// #[allow(unused_labels)]
// 'label: 1 + 1; // ERROR expected `while`, `for`, `loop` or `{` after a label
'label: match () { () => break 'label, }; //~ ERROR expected `while`, `for`, `loop` or `{` after a label

19
src/test/ui/parser/recover-labeled-non-block-expr.stderr
View file

@ -1,16 +1,5 @@
error: expected `while`, `for`, `loop` or `{` after a label
--> $DIR/recover-labeled-non-block-expr.rs:5:13
|
LL | 'label: 1 + 1;
| ^ expected `while`, `for`, `loop` or `{` after a label
|
help: consider enclosing expression in a block
|
LL | 'label: {1 + 1};
| + +
error: expected `while`, `for`, `loop` or `{` after a label
--> $DIR/recover-labeled-non-block-expr.rs:7:13
--> $DIR/recover-labeled-non-block-expr.rs:8:13
|
LL | 'label: match () { () => break 'label, };
| ^^^^^ expected `while`, `for`, `loop` or `{` after a label
@ -21,7 +10,7 @@ LL | 'label: {match () { () => break 'label, }};
| + +
error: expected `while`, `for`, `loop` or `{` after a label
--> $DIR/recover-labeled-non-block-expr.rs:10:22
--> $DIR/recover-labeled-non-block-expr.rs:11:22
|
LL | let _i = 'label: match x {
| ^^^^^ expected `while`, `for`, `loop` or `{` after a label
@ -37,7 +26,7 @@ LL | break 'label 13
...
error: expected `while`, `for`, `loop` or `{` after a label
--> $DIR/recover-labeled-non-block-expr.rs:24:24
--> $DIR/recover-labeled-non-block-expr.rs:25:24
|
LL | let _val = 'label: (1, if other == 3 { break 'label (2, 3) } else { other });
| ^ expected `while`, `for`, `loop` or `{` after a label
@ -47,5 +36,5 @@ help: consider enclosing expression in a block
LL | let _val = 'label: {(1, if other == 3 { break 'label (2, 3) } else { other })};
| + +
error: aborting due to 4 previous errors
error: aborting due to 3 previous errors