Make the ".*" operator work correctly when the base is a prvalue and the field has a non-trivial copy constructor. PR13097.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158578 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/Expr.cpp

@@ -2376,6 +2376,10 @@ bool Expr::isTemporaryObject(ASTContext &C, const CXXRecordDecl *TempTy) const {
   if (isa<MemberExpr>(E))
     return false;
 
+  if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E))
+    if (BO->isPtrMemOp())
+      return false;
+
   // - opaque values (all)
   if (isa<OpaqueValueExpr>(E))
     return false;

lib/CodeGen/CGExpr.cpp

@@ -156,7 +156,11 @@ namespace {
 /// \brief An adjustment to be made to the temporary created when emitting a
 /// reference binding, which accesses a particular subobject of that temporary.
   struct SubobjectAdjustment {
-    enum { DerivedToBaseAdjustment, FieldAdjustment } Kind;
+    enum {
+      DerivedToBaseAdjustment,
+      FieldAdjustment,
+      MemberPointerAdjustment
+    } Kind;
 
     union {
       struct {
@@ -165,6 +169,11 @@ namespace {
       } DerivedToBase;
 
       FieldDecl *Field;
+
+      struct {
+        const MemberPointerType *MPT;
+        llvm::Value *Ptr;
+      } Ptr;
     };
 
     SubobjectAdjustment(const CastExpr *BasePath,
@@ -178,6 +187,12 @@ namespace {
       : Kind(FieldAdjustment) {
       this->Field = Field;
     }
+
+    SubobjectAdjustment(const MemberPointerType *MPT, llvm::Value *Ptr)
+      : Kind(MemberPointerAdjustment) {
+      this->Ptr.MPT = MPT;
+      this->Ptr.Ptr = Ptr;
+    }
   };
 }
 
@@ -345,6 +360,15 @@ EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E,
             continue;
           }
         }
+      } else if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
+        if (BO->isPtrMemOp()) {
+          assert(BO->getLHS()->isRValue());
+          E = BO->getLHS();
+          const MemberPointerType *MPT =
+              BO->getRHS()->getType()->getAs<MemberPointerType>();
+          llvm::Value *Ptr = CGF.EmitScalarExpr(BO->getRHS());
+          Adjustments.push_back(SubobjectAdjustment(MPT, Ptr));
+        }
       }
 
       if (const OpaqueValueExpr *opaque = dyn_cast<OpaqueValueExpr>(E))
@@ -417,6 +441,11 @@ EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E,
           break;
         }
 
+        case SubobjectAdjustment::MemberPointerAdjustment: {
+          Object = CGF.CGM.getCXXABI().EmitMemberDataPointerAddress(
+                        CGF, Object, Adjustment.Ptr.Ptr, Adjustment.Ptr.MPT);
+          break;
+        }
         }
       }
 

test/CodeGenCXX/pointers-to-data-members.cpp

@@ -240,3 +240,17 @@ namespace PR11487 {
   // CHECK-GLOBAL: @_ZN7PR114871xE = global %"union.PR11487::U" { i64 -1, [8 x i8] zeroinitializer }, align 8
   
 }
+
+namespace PR13097 {
+  struct X { int x; X(const X&); };
+  struct A {
+    int qq;
+      X x;
+  };
+  A f();
+  X g() { return f().*&A::x; }
+  // CHECK: define void @_ZN7PR130971gEv
+  // CHECK: call void @_ZN7PR130971fEv
+  // CHECK-NOT: memcpy
+  // CHECK: call void @_ZN7PR130971XC1ERKS0_
+}