1 files changed, 51 insertions, 0 deletions
diff --git a/clang/test/SemaCXX/warn-unused-value.cpp b/clang/test/SemaCXX/warn-unused-value.cpp
new file mode 100644
index 0000000..1c0263c
--- /dev/null
+++ b/clang/test/SemaCXX/warn-unused-value.cpp
@@ -0,0 +1,51 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wunused-value %s
+
+// PR4806
+namespace test0 {
+  class Box {
+  public:
+    int i;
+    volatile int j;
+  };
+
+  void doit() {
+    // pointer to volatile has side effect (thus no warning)
+    Box* box = new Box;
+    box->i; // expected-warning {{expression result unused}}
+    box->j;
+  }
+}
+
+namespace test1 {
+struct Foo {
+  int i;
+  bool operator==(const Foo& rhs) {
+    return i == rhs.i;
+  }
+};
+
+#define NOP(x) (x)
+void b(Foo f1, Foo f2) {
+  NOP(f1 == f2);  // expected-warning {{expression result unused}}
+}
+#undef NOP
+}
+
+namespace test2 {
+  extern "C" {
+    namespace std {
+      template<typename T> struct basic_string {
+        struct X {};
+        void method() const {
+         X* x;
+         &x[0];  // expected-warning {{expression result unused}}
+        }  
+      };
+      typedef basic_string<char> string;
+      void func(const std::string& str) { 
+        str.method();  // expected-note {{in instantiation of member function}}
+      }
+    } 
+  }
+}
+