From d5a01e8789ff46e4f35bf48273c274b5c5effd31 Mon Sep 17 00:00:00 2001
From: Oliver Schneider <git-spam-no-reply9815368754983@oli-obk.de>
Date: Mon, 14 Mar 2016 17:24:55 +0100
Subject: [PATCH] prevent cc lint from panicking on unreachable code

---
 src/cyclomatic_complexity.rs                | 4 ++++
 tests/compile-fail/cyclomatic_complexity.rs | 6 ++++++
 2 files changed, 10 insertions(+)

diff --git a/src/cyclomatic_complexity.rs b/src/cyclomatic_complexity.rs
index bc13576fe3b..a03a42f2bc0 100644
--- a/src/cyclomatic_complexity.rs
+++ b/src/cyclomatic_complexity.rs
@@ -47,6 +47,10 @@ impl CyclomaticComplexity {
         let cfg = CFG::new(cx.tcx, block);
         let n = cfg.graph.len_nodes() as u64;
         let e = cfg.graph.len_edges() as u64;
+        if e + 2 < n {
+            // the function has unreachable code, other lints should catch this
+            return;
+        }
         let cc = e + 2 - n;
         let mut helper = CCHelper {
             match_arms: 0,
diff --git a/tests/compile-fail/cyclomatic_complexity.rs b/tests/compile-fail/cyclomatic_complexity.rs
index 30a05c3f87d..f744d60440f 100644
--- a/tests/compile-fail/cyclomatic_complexity.rs
+++ b/tests/compile-fail/cyclomatic_complexity.rs
@@ -298,3 +298,9 @@ fn void(void: Void) { //~ ERROR: the function has a cyclomatic complexity of 1
         }
     }
 }
+
+#[cyclomatic_complexity = "0"]
+fn mcarton_sees_all() {
+    panic!("meh");
+    panic!("möh");
+}