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-rw-r--r--src/test/ui/hygiene/hygienic-labels.rs60
1 files changed, 60 insertions, 0 deletions
diff --git a/src/test/ui/hygiene/hygienic-labels.rs b/src/test/ui/hygiene/hygienic-labels.rs
new file mode 100644
index 000000000..6a7d81f04
--- /dev/null
+++ b/src/test/ui/hygiene/hygienic-labels.rs
@@ -0,0 +1,60 @@
+// run-pass
+#![allow(unreachable_code)]
+#![allow(unused_labels)]
+// Test that labels injected by macros do not break hygiene.
+
+// Issue #24278: The label/lifetime shadowing checker from #24162
+// conservatively ignores hygiene, and thus issues warnings that are
+// both true- and false-positives for this test.
+
+macro_rules! loop_x {
+ ($e: expr) => {
+ // $e shouldn't be able to interact with this 'x
+ 'x: loop {
+ $e
+ }
+ };
+}
+
+macro_rules! run_once {
+ ($e: expr) => {
+ // ditto
+ 'x: for _ in 0..1 {
+ $e
+ }
+ };
+}
+
+macro_rules! while_x {
+ ($e: expr) => {
+ // ditto
+ 'x: while 1 + 1 == 2 {
+ $e
+ }
+ };
+}
+
+pub fn main() {
+ 'x: for _ in 0..1 {
+ // this 'x should refer to the outer loop, lexically
+ loop_x!(break 'x);
+ panic!("break doesn't act hygienically inside for loop");
+ }
+
+ 'x: loop {
+ // ditto
+ loop_x!(break 'x);
+ panic!("break doesn't act hygienically inside infinite loop");
+ }
+
+ 'x: while 1 + 1 == 2 {
+ while_x!(break 'x);
+ panic!("break doesn't act hygienically inside infinite while loop");
+ }
+
+ 'x: for _ in 0..1 {
+ // ditto
+ run_once!(continue 'x);
+ panic!("continue doesn't act hygienically inside for loop");
+ }
+}