Index: docs/ReleaseNotes.rst
===================================================================
--- docs/ReleaseNotes.rst
+++ docs/ReleaseNotes.rst
@@ -59,6 +59,9 @@
   ``-Wno-c++98-compat-extra-semi``, so if you want that diagnostic, you need
   to explicitly re-enable it (e.g. by appending ``-Wextra-semi``).
 
+- ``-Wself-assign`` and ``-Wself-assign-field`` were extended to diagnose
+  self-assignment operations using overloaded operators (i.e. classes)
+
 Non-comprehensive list of changes in this release
 -------------------------------------------------
 
Index: lib/Sema/SemaExpr.cpp
===================================================================
--- lib/Sema/SemaExpr.cpp
+++ lib/Sema/SemaExpr.cpp
@@ -11471,8 +11471,7 @@
 }
 
 /// DiagnoseSelfAssignment - Emits a warning if a value is assigned to itself.
-/// This warning is only emitted for builtin assignment operations. It is also
-/// suppressed in the event of macro expansions.
+/// This warning suppressed in the event of macro expansions.
 static void DiagnoseSelfAssignment(Sema &S, Expr *LHSExpr, Expr *RHSExpr,
                                    SourceLocation OpLoc) {
   if (S.inTemplateInstantiation())
@@ -12091,6 +12090,21 @@
 static ExprResult BuildOverloadedBinOp(Sema &S, Scope *Sc, SourceLocation OpLoc,
                                        BinaryOperatorKind Opc,
                                        Expr *LHS, Expr *RHS) {
+  switch (Opc) {
+  case BO_Assign:
+  case BO_DivAssign:
+  case BO_RemAssign:
+  case BO_SubAssign:
+  case BO_AndAssign:
+  case BO_OrAssign:
+  case BO_XorAssign:
+    DiagnoseSelfAssignment(S, LHS, RHS, OpLoc);
+    CheckIdentityFieldAssignment(LHS, RHS, OpLoc, S);
+    break;
+  default:
+    break;
+  }
+
   // Find all of the overloaded operators visible from this
   // point. We perform both an operator-name lookup from the local
   // scope and an argument-dependent lookup based on the types of
Index: test/SemaCXX/implicit-exception-spec.cpp
===================================================================
--- test/SemaCXX/implicit-exception-spec.cpp
+++ test/SemaCXX/implicit-exception-spec.cpp
@@ -119,7 +119,7 @@
   template<typename T, bool A, bool B, bool C, bool D, bool E, bool F> void check() {
     T *p = nullptr;
     T &a = *p;
-    static_assert(noexcept(a = a) == D, "");
+    static_assert(noexcept(a = a) == D, ""); // expected-warning {{explicitly assigning value of variable}}
     static_assert(noexcept(a = static_cast<T&&>(a)) == E, "");
     static_assert(noexcept(delete &a) == F, "");
 
Index: test/SemaCXX/member-init.cpp
===================================================================
--- test/SemaCXX/member-init.cpp
+++ test/SemaCXX/member-init.cpp
@@ -101,7 +101,7 @@
   struct Sprite {
     Point location = Point(0,0); // expected-error {{no matching constructor for initialization of 'rdar14084171::Point'}}
   };
-  void f(Sprite& x) { x = x; }
+  void f(Sprite& x) { x = x; } // expected-warning {{explicitly assigning value of variable}}
 }
 
 namespace PR18560 {
Index: test/SemaCXX/warn-self-assign-builtin.cpp
===================================================================
--- test/SemaCXX/warn-self-assign-builtin.cpp
+++ test/SemaCXX/warn-self-assign-builtin.cpp
@@ -8,8 +8,16 @@
   b = a = b;
   a = a = a; // expected-warning{{explicitly assigning}}
   a = b = b = a;
-  a &= a; // expected-warning{{explicitly assigning}}
-  a |= a; // expected-warning{{explicitly assigning}}
+
+  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;
 }
 
@@ -30,8 +38,8 @@
 #undef LHS
 #undef RHS
 
-  S s;
-  s = s; // Not a builtin assignment operator, no warning.
+  // A way to silence the warning.
+  a = (int &)a;
 
   // Volatile stores aren't side-effect free.
   volatile int vol_a;
@@ -40,9 +48,10 @@
   vol_a_ref = vol_a_ref;
 }
 
-template <typename T> void g() {
+template <typename T>
+void g() {
   T a;
-  a = a; // May or may not be a builtin assignment operator, no warning.
+  a = a; // expected-warning{{explicitly assigning}}
 }
 void instantiate() {
   g<int>();
Index: test/SemaCXX/warn-self-assign-field-builtin.cpp
===================================================================
--- /dev/null
+++ test/SemaCXX/warn-self-assign-field-builtin.cpp
@@ -0,0 +1,109 @@
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -verify %s
+
+struct C {
+  int a;
+  int b;
+
+  void f() {
+    a = a; // expected-warning {{assigning field to itself}}
+    b = b; // expected-warning {{assigning field to itself}}
+    a = b;
+
+    this->a = a;       // expected-warning {{assigning field to itself}}
+    this->b = b;       // expected-warning {{assigning field to itself}}
+    a = this->a;       // expected-warning {{assigning field to itself}}
+    b = this->b;       // expected-warning {{assigning field to itself}}
+    this->a = this->a; // expected-warning {{assigning field to itself}}
+    this->b = this->b; // expected-warning {{assigning field to itself}}
+
+    a = b;
+    a = this->b;
+    this->a = b;
+    this->a = this->b;
+
+    a *= a;
+    a /= a;
+    a %= a;
+    a += a;
+    a -= a;
+    a <<= a;
+    a >>= a;
+    a &= a;
+    a |= a;
+    a ^= a;
+  }
+
+  void false_positives() {
+#define OP =
+#define LHS a
+#define RHS a
+    // These shouldn't warn due to the use of the preprocessor.
+    a OP a;     // expected-warning {{assigning field to itself}}
+    LHS = a;    // expected-warning {{assigning field to itself}}
+    a = RHS;    // expected-warning {{assigning field to itself}}
+    LHS OP RHS; // expected-warning {{assigning field to itself}}
+#undef OP
+#undef LHS
+#undef RHS
+
+    // A way to silence the warning.
+    a = (int &)a;
+  }
+
+  volatile int vol_a;
+  void vol_test() {
+    // Volatile stores aren't side-effect free.
+    vol_a = vol_a; // expected-warning {{assigning field to itself}}
+    volatile int &vol_a_ref = vol_a;
+    vol_a_ref = vol_a_ref;
+  }
+};
+
+// Dummy type.
+struct Dummy {};
+
+template <typename T>
+struct TemplateClass {
+  T var;
+  void f() {
+    var = var; // expected-warning 3 {{assigning field to itself}}
+  }
+};
+void instantiate() {
+  {
+    TemplateClass<int> c;
+    c.f(); // expected-note {{in instantiation of member function}}
+  }
+  {
+    TemplateClass<Dummy> c;
+    c.f(); // expected-note {{in instantiation of member function}}
+  }
+}
+
+// It may make sense not to warn on the rest of the tests.
+// It may be a valid use-case to self-assign to tell the compiler that
+// it is ok to vectorize the store.
+
+void f0(C *s, C *t) {
+  s->a = s->a;
+  t->a = s->a;
+}
+
+void f1(C &s, C &t) {
+  s.a = s.a;
+  t.a = s.a;
+}
+
+struct T {
+  C *s;
+};
+
+void f2(T *t, T *t2) {
+  t->s->a = t->s->a;
+  t2->s->a = t->s->a;
+}
+
+void f3(T &t, T &t2) {
+  t.s->a = t.s->a;
+  t2.s->a = t.s->a;
+}
Index: test/SemaCXX/warn-self-assign-field-overloaded.cpp
===================================================================
--- /dev/null
+++ test/SemaCXX/warn-self-assign-field-overloaded.cpp
@@ -0,0 +1,145 @@
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DDUMMY -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV0 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV1 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV2 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV3 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV4 -verify %s
+
+#ifdef DUMMY
+struct S {};
+#else
+struct S {
+#if defined(V0)
+  S() = default;
+#elif defined(V1)
+  S &operator=(const S &) = default;
+#elif defined(V2)
+  S &operator=(S &) = default;
+#elif defined(V3)
+  S &operator=(const S &);
+#elif defined(V4)
+  S &operator=(S &);
+#else
+#error Define something!
+#endif
+  S &operator*=(const S &);
+  S &operator/=(const S &);
+  S &operator%=(const S &);
+  S &operator+=(const S &);
+  S &operator-=(const S &);
+  S &operator<<=(const S &);
+  S &operator>>=(const S &);
+  S &operator&=(const S &);
+  S &operator|=(const S &);
+  S &operator^=(const S &);
+  S &operator=(const volatile S &) volatile;
+};
+#endif
+struct C {
+  S a;
+  S b;
+
+  void f() {
+    a = a; // expected-warning {{assigning field to itself}}
+    b = b; // expected-warning {{assigning field to itself}}
+    a = b;
+
+    this->a = a;       // expected-warning {{assigning field to itself}}
+    this->b = b;       // expected-warning {{assigning field to itself}}
+    a = this->a;       // expected-warning {{assigning field to itself}}
+    b = this->b;       // expected-warning {{assigning field to itself}}
+    this->a = this->a; // expected-warning {{assigning field to itself}}
+    this->b = this->b; // expected-warning {{assigning field to itself}}
+
+    a = b;
+    a = this->b;
+    this->a = b;
+    this->a = this->b;
+
+#ifndef DUMMY
+    a *= a;
+    a /= a; // expected-warning {{assigning field to itself}}
+    a %= a; // expected-warning {{assigning field to itself}}
+    a += a;
+    a -= a; // expected-warning {{assigning field to itself}}
+    a <<= a;
+    a >>= a;
+    a &= a; // expected-warning {{assigning field to itself}}
+    a |= a; // expected-warning {{assigning field to itself}}
+    a ^= a; // expected-warning {{assigning field to itself}}
+#endif
+  }
+
+  void false_positives() {
+#define OP =
+#define LHS a
+#define RHS a
+    // These shouldn't warn due to the use of the preprocessor.
+    a OP a;     // expected-warning {{assigning field to itself}}
+    LHS = a;    // expected-warning {{assigning field to itself}}
+    a = RHS;    // expected-warning {{assigning field to itself}}
+    LHS OP RHS; // expected-warning {{assigning field to itself}}
+#undef OP
+#undef LHS
+#undef RHS
+
+    // A way to silence the warning.
+    a = (S &)a;
+  }
+
+#ifndef DUMMY
+  volatile S vol_a;
+  void vol_test() {
+    // Volatile stores aren't side-effect free.
+    vol_a = vol_a; // expected-warning {{assigning field to itself}}
+    volatile S &vol_a_ref = vol_a;
+    vol_a_ref = vol_a_ref;
+  }
+#endif
+};
+
+template <typename T>
+struct TemplateClass {
+  T var;
+  void f() {
+    var = var; // expected-warning 3 {{assigning field to itself}}
+  }
+};
+void instantiate() {
+  {
+    TemplateClass<int> c;
+    c.f(); // expected-note {{in instantiation of member function}}
+  }
+  {
+    TemplateClass<S> c;
+    c.f(); // expected-note {{in instantiation of member function}}
+  }
+}
+
+// It may make sense not to warn on the rest of the tests.
+// It may be a valid use-case to self-assign to tell the compiler that
+// it is ok to vectorize the store.
+
+void f0(C *s, C *t) {
+  s->a = s->a;
+  t->a = s->a;
+}
+
+void f1(C &s, C &t) {
+  s.a = s.a;
+  t.a = s.a;
+}
+
+struct T {
+  C *s;
+};
+
+void f2(T *t, T *t2) {
+  t->s->a = t->s->a;
+  t2->s->a = t->s->a;
+}
+
+void f3(T &t, T &t2) {
+  t.s->a = t.s->a;
+  t2.s->a = t.s->a;
+}
Index: test/SemaCXX/warn-self-assign-overloaded.cpp
===================================================================
--- /dev/null
+++ test/SemaCXX/warn-self-assign-overloaded.cpp
@@ -0,0 +1,96 @@
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign -DDUMMY -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign -DV0 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign -DV1 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign -DV2 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign -DV3 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wself-assign -DV4 -verify %s
+
+#ifdef DUMMY
+struct S {};
+#else
+struct S {
+#if defined(V0)
+  S() = default;
+#elif defined(V1)
+  S &operator=(const S &) = default;
+#elif defined(V2)
+  S &operator=(S &) = default;
+#elif defined(V3)
+  S &operator=(const S &);
+#elif defined(V4)
+  S &operator=(S &);
+#else
+#error Define something!
+#endif
+  S &operator*=(const S &);
+  S &operator/=(const S &);
+  S &operator%=(const S &);
+  S &operator+=(const S &);
+  S &operator-=(const S &);
+  S &operator<<=(const S &);
+  S &operator>>=(const S &);
+  S &operator&=(const S &);
+  S &operator|=(const S &);
+  S &operator^=(const S &);
+  S &operator=(const volatile S &) volatile;
+};
+#endif
+
+void f() {
+  S a, b;
+  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;
+
+#ifndef DUMMY
+  a *= a;
+  a /= a; // expected-warning {{explicitly assigning}}
+  a %= a; // expected-warning {{explicitly assigning}}
+  a += a;
+  a -= a; // expected-warning {{explicitly assigning}}
+  a <<= a;
+  a >>= a;
+  a &= a; // expected-warning {{explicitly assigning}}
+  a |= a; // expected-warning {{explicitly assigning}}
+  a ^= a; // expected-warning {{explicitly assigning}}
+#endif
+}
+
+void false_positives() {
+#define OP =
+#define LHS a
+#define RHS a
+  S a;
+  // 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 = (S &)a;
+
+#ifndef DUMMY
+  // Volatile stores aren't side-effect free.
+  volatile S vol_a;
+  vol_a = vol_a;
+  volatile S &vol_a_ref = vol_a;
+  vol_a_ref = vol_a_ref;
+#endif
+}
+
+template <typename T>
+void g() {
+  T a;
+  a = a; // expected-warning{{explicitly assigning}}
+}
+void instantiate() {
+  g<int>();
+  g<S>();
+}