Add name mangling for expr .* expr. Fixes PR9983 / <rdar://problem/9486332>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@132659 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/ItaniumMangle.cpp

@@ -2039,6 +2039,7 @@ void CXXNameMangler::mangleExpression(const Expr *E, unsigned Arity) {
   //              ::= <function-param>
   //              ::= sr <type> <unqualified-name>                   # dependent name
   //              ::= sr <type> <unqualified-name> <template-args>   # dependent template-id
+  //              ::= ds <expression> <expression>                   # expr.*expr
   //              ::= sZ <template-param>                            # size of a parameter pack
   //              ::= sZ <function-param>    # size of a function parameter pack
   //              ::= <expr-primary>
@@ -2317,8 +2318,11 @@ void CXXNameMangler::mangleExpression(const Expr *E, unsigned Arity) {
   case Expr::CompoundAssignOperatorClass: // fallthrough
   case Expr::BinaryOperatorClass: {
     const BinaryOperator *BO = cast<BinaryOperator>(E);
-    mangleOperatorName(BinaryOperator::getOverloadedOperator(BO->getOpcode()),
-                       /*Arity=*/2);
+    if (BO->getOpcode() == BO_PtrMemD)
+      Out << "ds";
+    else
+      mangleOperatorName(BinaryOperator::getOverloadedOperator(BO->getOpcode()),
+                         /*Arity=*/2);
     mangleExpression(BO->getLHS());
     mangleExpression(BO->getRHS());
     break;

test/CodeGenCXX/mangle-exprs.cpp

@@ -109,3 +109,19 @@ namespace test2 {
 
   // CHECK: store float {{.*}}, float* @_ZZN5test21gIPFfvEEEvT_DTclfL0p_EEE8variable,
 }
+
+namespace test3 {
+  template <class T, class U> void a(T x, U y, decltype(x.*y) z) {}  
+
+  struct X {
+    int *member;
+  };
+
+  // CHECK: define void @_ZN5test311instantiateEv
+  void instantiate() {
+    X x;
+    int *ip;
+    // CHECK: call void @_ZN5test31aINS_1XEMS1_PiEEvT_T0_DTdsfL0p_fL0p0_E
+    a(x, &X::member, ip);
+  }
+}