1 files changed, 60 insertions, 0 deletions
diff --git a/tests/coverage/loops_branches.rs b/tests/coverage/loops_branches.rs
new file mode 100644
index 00000000000..f3a343bcc1f
--- /dev/null
+++ b/tests/coverage/loops_branches.rs
@@ -0,0 +1,60 @@
+#![allow(unused_assignments, unused_variables, while_true)]
+
+// This test confirms that (1) unexecuted infinite loops are handled correctly by the
+// InstrumentCoverage MIR pass; and (2) Counter Expressions that subtract from zero can be dropped.
+
+struct DebugTest;
+
+impl std::fmt::Debug for DebugTest {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        if true {
+            if false {
+                while true {}
+            }
+            write!(f, "cool")?;
+        } else {
+        }
+
+        for i in 0..10 {
+            if true {
+                if false {
+                    while true {}
+                }
+                write!(f, "cool")?;
+            } else {
+            }
+        }
+        Ok(())
+    }
+}
+
+struct DisplayTest;
+
+impl std::fmt::Display for DisplayTest {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        if false {
+        } else {
+            if false {
+                while true {}
+            }
+            write!(f, "cool")?;
+        }
+        for i in 0..10 {
+            if false {
+            } else {
+                if false {
+                    while true {}
+                }
+                write!(f, "cool")?;
+            }
+        }
+        Ok(())
+    }
+}
+
+fn main() {
+    let debug_test = DebugTest;
+    println!("{:?}", debug_test);
+    let display_test = DisplayTest;
+    println!("{}", display_test);
+}