Code gen for pointer-to-datamember - WIP.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@84771 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index d3d1c61..2266b25 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -866,6 +866,9 @@
     llvm::Value *V = LocalDeclMap[IPD];
     assert(V && "BlockVarDecl not entered in LocalDeclMap?");
     return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
+  } else if (const QualifiedDeclRefExpr *QDRExpr = 
+             dyn_cast<QualifiedDeclRefExpr>(E)) {
+    return EmitPointerToDataMemberLValue(QDRExpr);
   }
   assert(0 && "Unimp declref");
   //an invalid LValue, but the assert will
@@ -1513,6 +1516,24 @@
 }
 
 
+LValue CodeGenFunction::EmitPointerToDataMemberLValue(
+                                              const QualifiedDeclRefExpr *E) {
+  const FieldDecl *Field = cast<FieldDecl>(E->getDecl());
+  const NestedNameSpecifier *NNSpec = E->getQualifier();
+  const Type *NNSpecType = NNSpec->getAsType();
+  QualType NNSpecTy = getContext().getCanonicalType(QualType(NNSpecType, 0));
+  NNSpecTy = getContext().getPointerType(NNSpecTy);
+  llvm::Value *V = llvm::Constant::getNullValue(ConvertType(NNSpecTy));
+  LValue MemExpLV = EmitLValueForField(V, const_cast<FieldDecl*>(Field), 
+                                       /*isUnion*/false, /*Qualifiers*/0);
+  const llvm::Type* ResultType = ConvertType(
+                                             getContext().getPointerDiffType());
+  V = Builder.CreatePtrToInt(MemExpLV.getAddress(), ResultType, 
+                             "datamember");
+  LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType()));
+  return LV;
+}
+
 RValue CodeGenFunction::EmitCall(llvm::Value *Callee, QualType CalleeType,
                                  CallExpr::const_arg_iterator ArgBeg,
                                  CallExpr::const_arg_iterator ArgEnd,
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 00b07e4..3e65e47 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -819,6 +819,7 @@
   LValue EmitConditionalOperatorLValue(const ConditionalOperator *E);
   LValue EmitCastLValue(const CastExpr *E);
   LValue EmitNullInitializationLValue(const CXXZeroInitValueExpr *E);
+  LValue EmitPointerToDataMemberLValue(const QualifiedDeclRefExpr *E);
   
   llvm::Value *EmitIvarOffset(const ObjCInterfaceDecl *Interface,
                               const ObjCIvarDecl *Ivar);