--- /dev/null
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test control flow to follow label_break_value semantics
+fn label_break(a: bool, b: bool) -> u32 {
+ let mut v = 0;
+ 'b: {
+ v = 1;
+ if a {
+ break 'b;
+ }
+ v = 2;
+ if b {
+ break 'b;
+ }
+ v = 3;
+ }
+ return v;
+}
+
+// Test that values can be returned
+fn break_value(a: bool, b: bool) -> u32 {
+ let result = 'block: {
+ if a { break 'block 1; }
+ if b { break 'block 2; }
+ 3
+ };
+ result
+}
+
+// Test nesting of labeled blocks
+// here we only check that it compiles
+fn label_break_nested() {
+ 'b: {
+ println!("hi");
+ if false {
+ break 'b;
+ }
+ 'c: {
+ if false {
+ break 'b;
+ }
+ break 'c;
+ }
+ println!("hello");
+ if true {
+ break 'b;
+ }
+ }
+}
+
+// Tests for mixing labeled blocks with loop constructs
+// This function should be the identity function
+fn label_break_mixed(v: u32) -> u32 {
+ let mut r = 0;
+ 'b: {
+ // Unlabeled break still works
+ // (only crossing boundaries is an error)
+ loop {
+ break;
+ }
+ if v == 0 {
+ break 'b;
+ }
+ // Labeled breaking an inner loop still works
+ 'c: loop {
+ if r == 1 {
+ break 'c;
+ }
+ r += 1;
+ }
+ assert_eq!(r, 1);
+ if v == 1 {
+ break 'b;
+ }
+ // Labeled breaking an outer loop still works
+ 'd: loop {
+ 'e: {
+ if v == r {
+ break 'b;
+ }
+ if r == 5 {
+ break 'd;
+ }
+ r += 1;
+ }
+ }
+ assert_eq!(r, 5);
+ assert!(v > r);
+ // Here we test return from inside a labeled block
+ return v;
+ }
+ r
+}
+
+pub fn main() {
+ assert_eq!(label_break(true, false), 1);
+ assert_eq!(label_break(false, true), 2);
+ assert_eq!(label_break(false, false), 3);
+
+ assert_eq!(break_value(true, false), 1);
+ assert_eq!(break_value(false, true), 2);
+ assert_eq!(break_value(false, false), 3);
+
+ assert_eq!(label_break_mixed(0), 0);
+ assert_eq!(label_break_mixed(1), 1);
+ assert_eq!(label_break_mixed(2), 2);
+ assert_eq!(label_break_mixed(3), 3);
+ assert_eq!(label_break_mixed(4), 4);
+ assert_eq!(label_break_mixed(5), 5);
+ assert_eq!(label_break_mixed(6), 6);
+
+ // FIXME: ensure that labeled blocks work if produced by macros and in match arms
+}