1 files changed, 45 insertions, 0 deletions
diff --git a/test/Tooling/clang-diff-opt.cpp b/test/Tooling/clang-diff-opt.cpp
new file mode 100644
index 0000000000000..771c6abaecb52
--- /dev/null
+++ b/test/Tooling/clang-diff-opt.cpp
@@ -0,0 +1,45 @@
+// RUN: %clang_cc1 -E %s > %t.src.cpp
+// RUN: %clang_cc1 -E %s > %t.dst.cpp -DDEST
+// RUN: clang-diff -dump-matches -s=10 %t.src.cpp %t.dst.cpp -- | FileCheck %s
+//
+// Test the behaviour of the matching according to the optimal tree edit
+// distance, implemented with Zhang and Shasha's algorithm.
+// Just for testing we use a tiny value of 10 for maxsize. Subtrees bigger than
+// this size will not be processed by the optimal algorithm.
+
+#ifndef DEST
+
+void f1() { {;} {{;}} }
+
+void f2() { {;} {{;;;;;}} }
+
+void f3() { {;} {{;;;;;;}} }
+
+#else
+
+void f1() {
+// Jaccard similarity = 3 / (5 + 4 - 3) = 3 / 6 >= 0.5
+// The optimal matching algorithm should move the ; into the outer block
+// CHECK: Match CompoundStmt(2) to CompoundStmt(2)
+// CHECK-NOT: Match CompoundStmt(3)
+// CHECK-NEXT: Match NullStmt(4) to NullStmt(3)
+  ; {{;}}
+}
+
+void f2() {
+  // Jaccard similarity = 7 / (10 + 10 - 7) >= 0.5
+  // As none of the subtrees is bigger than 10 nodes, the optimal algorithm
+  // will be run.
+  // CHECK: Match NullStmt(11) to NullStmt(9)
+  ;; {{;;;;;}}
+}
+
+void f3() {
+  // Jaccard similarity = 8 / (11 + 11 - 8) >= 0.5
+  // As the subtrees are bigger than 10 nodes, the optimal algorithm will not
+  // be run.
+  // CHECK: Delete NullStmt(22)
+  ;; {{;;;;;;}}
+}
+ 
+#endif