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Tests for shadowing between lifetimes and loop labels within function bodies.
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‎src/test/compile-fail/loops-reject-duplicate-labels-2.rs

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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// ignore-tidy-linelength
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// Issue #21633: reject duplicate loop labels in function bodies.
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//
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// This is testing the generalization (to the whole function body)
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// discussed here:
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// http://internals.rust-lang.org/t/psa-rejecting-duplicate-loop-labels/1833
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fn main() {
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{ 'fl: for _ in 0..10 { break; } } //~ NOTE shadowed label `'fl` declared here
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{ 'fl: loop { break; } } //~ ERROR label name `'fl` shadows a label name that is already in scope
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{ 'lf: loop { break; } } //~ NOTE shadowed label `'lf` declared here
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{ 'lf: for _ in 0..10 { break; } } //~ ERROR label name `'lf` shadows a label name that is already in scope
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{ 'wl: while 2 > 1 { break; } } //~ NOTE shadowed label `'wl` declared here
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{ 'wl: loop { break; } } //~ ERROR label name `'wl` shadows a label name that is already in scope
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{ 'lw: loop { break; } } //~ NOTE shadowed label `'lw` declared here
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{ 'lw: while 2 > 1 { break; } } //~ ERROR label name `'lw` shadows a label name that is already in scope
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{ 'fw: for _ in 0..10 { break; } } //~ NOTE shadowed label `'fw` declared here
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{ 'fw: while 2 > 1 { break; } } //~ ERROR label name `'fw` shadows a label name that is already in scope
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{ 'wf: while 2 > 1 { break; } } //~ NOTE shadowed label `'wf` declared here
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{ 'wf: for _ in 0..10 { break; } } //~ ERROR label name `'wf` shadows a label name that is already in scope
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{ 'tl: while let Some(_) = None::<i32> { break; } } //~ NOTE shadowed label `'tl` declared here
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{ 'tl: loop { break; } } //~ ERROR label name `'tl` shadows a label name that is already in scope
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{ 'lt: loop { break; } } //~ NOTE shadowed label `'lt` declared here
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{ 'lt: while let Some(_) = None::<i32> { break; } }
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//~^ ERROR label name `'lt` shadows a label name that is already in scope
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}

‎src/test/compile-fail/loops-reject-duplicate-labels.rs

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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// ignore-tidy-linelength
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// Issue #21633: reject duplicate loop labels in function bodies.
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// This is testing the exact cases that are in the issue description.
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fn main() {
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'fl: for _ in 0..10 { break; } //~ NOTE shadowed label `'fl` declared here
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'fl: loop { break; } //~ ERROR label name `'fl` shadows a label name that is already in scope
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'lf: loop { break; } //~ NOTE shadowed label `'lf` declared here
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'lf: for _ in 0..10 { break; } //~ ERROR label name `'lf` shadows a label name that is already in scope
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'wl: while 2 > 1 { break; } //~ NOTE shadowed label `'wl` declared here
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'wl: loop { break; } //~ ERROR label name `'wl` shadows a label name that is already in scope
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'lw: loop { break; } //~ NOTE shadowed label `'lw` declared here
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'lw: while 2 > 1 { break; } //~ ERROR label name `'lw` shadows a label name that is already in scope
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'fw: for _ in 0..10 { break; } //~ NOTE shadowed label `'fw` declared here
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'fw: while 2 > 1 { break; } //~ ERROR label name `'fw` shadows a label name that is already in scope
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'wf: while 2 > 1 { break; } //~ NOTE shadowed label `'wf` declared here
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'wf: for _ in 0..10 { break; } //~ ERROR label name `'wf` shadows a label name that is already in scope
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'tl: while let Some(_) = None::<i32> { break; } //~ NOTE shadowed label `'tl` declared here
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'tl: loop { break; } //~ ERROR label name `'tl` shadows a label name that is already in scope
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'lt: loop { break; } //~ NOTE shadowed label `'lt` declared here
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'lt: while let Some(_) = None::<i32> { break; }
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//~^ ERROR label name `'lt` shadows a label name that is already in scope
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}
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// Note however that it is okay for the same label to be reuse in
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// different methods of one impl, as illustrated here.
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struct S;
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impl S {
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fn m1(&self) { 'okay: loop { break 'okay; } }
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fn m2(&self) { 'okay: loop { break 'okay; } }
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}

‎src/test/compile-fail/loops-reject-labels-shadowing-lifetimes.rs

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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// Issue #21633: reject duplicate loop labels in function bodies.
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// This is testing interaction between lifetime-params and labels.
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fn main() {
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fn foo<'a>() { //~ NOTE shadowed lifetime `'a` declared here
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'a: loop { break 'a; }
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//~^ ERROR label name `'a` shadows a lifetime name that is already in scope
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}
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struct Struct<'b, 'c> { _f: &'b i8, _g: &'c i8 }
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enum Enum<'d, 'e> { A(&'d i8), B(&'e i8) }
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impl<'d, 'e> Struct<'d, 'e> {
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fn meth_okay() {
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'a: loop { break 'a; }
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'b: loop { break 'b; }
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'c: loop { break 'c; }
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}
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}
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impl <'d, 'e> Enum<'d, 'e> {
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fn meth_okay() {
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'a: loop { break 'a; }
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'b: loop { break 'b; }
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'c: loop { break 'c; }
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}
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}
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impl<'bad, 'c> Struct<'bad, 'c> { //~ NOTE shadowed lifetime `'bad` declared here
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fn meth_bad(&self) {
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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}
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impl<'b, 'bad> Struct<'b, 'bad> { //~ NOTE shadowed lifetime `'bad` declared here
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fn meth_bad2(&self) {
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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}
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impl<'b, 'c> Struct<'b, 'c> {
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fn meth_bad3<'bad>(x: &'bad i8) { //~ NOTE shadowed lifetime `'bad` declared here
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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fn meth_bad4<'a,'bad>(x: &'a i8, y: &'bad i8) {
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//~^ NOTE shadowed lifetime `'bad` declared here
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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}
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impl <'bad, 'e> Enum<'bad, 'e> { //~ NOTE shadowed lifetime `'bad` declared here
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fn meth_bad(&self) {
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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}
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impl <'d, 'bad> Enum<'d, 'bad> { //~ NOTE shadowed lifetime `'bad` declared here
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fn meth_bad2(&self) {
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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}
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impl <'d, 'e> Enum<'d, 'e> {
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fn meth_bad3<'bad>(x: &'bad i8) { //~ NOTE shadowed lifetime `'bad` declared here
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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fn meth_bad4<'a,'bad>(x: &'bad i8) { //~ NOTE shadowed lifetime `'bad` declared here
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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}
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trait HasDefaultMethod1<'bad> { //~ NOTE shadowed lifetime `'bad` declared here
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fn meth_okay() {
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'c: loop { break 'c; }
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}
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fn meth_bad(&self) {
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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}
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trait HasDefaultMethod2<'a,'bad> { //~ NOTE shadowed lifetime `'bad` declared here
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fn meth_bad(&self) {
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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}
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trait HasDefaultMethod3<'a,'b> {
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fn meth_bad<'bad>(&self) { //~ NOTE shadowed lifetime `'bad` declared here
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'bad: loop { break 'bad; }
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//~^ ERROR label name `'bad` shadows a lifetime name that is already in scope
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}
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}
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}

‎src/test/compile-fail/loops-reject-lifetime-shadowing-label.rs

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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// Issue #21633: reject duplicate loop labels in function bodies.
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//
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// Test rejection of lifetimes in *expressions* that shadow loop labels.
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fn main() {
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// Reusing lifetime `'a` in function item is okay.
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fn foo<'a>(x: &'a i8) -> i8 { *x }
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// So is reusing `'a` in struct item
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struct S1<'a> { x: &'a i8 } impl<'a> S1<'a> { fn m(&self) {} }
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// and a method item
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struct S2; impl S2 { fn m<'a>(&self) {} }
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let z = 3_i8;
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'a: loop { //~ NOTE shadowed label `'a` declared here
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let b = Box::new(|x: i8| *x) as Box<for <'a> Fn(&'a i8)>;
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//~^ ERROR lifetime name `'a` shadows a label name that is already in scope
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assert_eq!((*b)(&z), z);
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break 'a;
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}
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}

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