1 files changed, 67 insertions, 0 deletions
diff --git a/test/SemaCXX/warn-self-assign-builtin.cpp b/test/SemaCXX/warn-self-assign-builtin.cpp
new file mode 100644
index 0000000000000..212fc241e3e7e
--- /dev/null
+++ b/test/SemaCXX/warn-self-assign-builtin.cpp
@@ -0,0 +1,67 @@
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign -verify %s
+
+void f() {
+  int a = 42, b = 42;
+  a = a; // expected-warning{{explicitly assigning}}
+  b = b; // expected-warning{{explicitly assigning}}
+  a = b;
+  b = a = b;
+  a = a = a; // expected-warning{{explicitly assigning}}
+  a = b = b = a;
+
+  a *= a;
+  a /= a;
+  a %= a;
+  a += a;
+  a -= a;
+  a <<= a;
+  a >>= a;
+  a &= a; // expected-warning {{explicitly assigning}}
+  a |= a; // expected-warning {{explicitly assigning}}
+  a ^= a;
+}
+
+// Dummy type.
+struct S {};
+
+void false_positives() {
+#define OP =
+#define LHS a
+#define RHS a
+  int a = 42;
+  // These shouldn't warn due to the use of the preprocessor.
+  a OP a;
+  LHS = a;
+  a = RHS;
+  LHS OP RHS;
+#undef OP
+#undef LHS
+#undef RHS
+
+  // A way to silence the warning.
+  a = (int &)a;
+
+  // Volatile stores aren't side-effect free.
+  volatile int vol_a;
+  vol_a = vol_a;
+  volatile int &vol_a_ref = vol_a;
+  vol_a_ref = vol_a_ref;
+}
+
+// Do not diagnose self-assigment in an unevaluated context
+void false_positives_unevaluated_ctx(int a) noexcept(noexcept(a = a)) // expected-warning {{expression with side effects has no effect in an unevaluated context}}
+{
+  decltype(a = a) b = a;              // expected-warning {{expression with side effects has no effect in an unevaluated context}}
+  static_assert(noexcept(a = a), ""); // expected-warning {{expression with side effects has no effect in an unevaluated context}}
+  static_assert(sizeof(a = a), "");   // expected-warning {{expression with side effects has no effect in an unevaluated context}}
+}
+
+template <typename T>
+void g() {
+  T a;
+  a = a; // expected-warning{{explicitly assigning}}
+}
+void instantiate() {
+  g<int>();
+  g<S>();
+}