Bug 525982 - Have TypeOfUnknownMember implement ICPPUnknownBinding

This ensures that name resolution can proceed when a TypeOfUnknownMember
appears on the left hand side of a scope resolution operator.

Change-Id: I2dfc22eb474b8a2f776eda09ce90c91462d7fe5b

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java

@@ -9723,6 +9723,15 @@ public class AST2TemplateTests extends AST2CPPTestBase {
 		IVariable var2 = helper.assertNonProblem("var2");
 		assertSameType(var1.getType(), var2.getType());
 	}
+	
+	//	template <typename T>
+	//	void foo() {
+	//	    typedef decltype(T::member) C;
+	//	    typedef decltype(C::member) D;
+	//	}
+	public void testScopeOfUnkownMemberType_525982() throws Exception {
+		parseAndCheckBindings();
+	}
 
 	//	template <bool>
 	//	struct integral_constant {

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java

@@ -1533,6 +1533,16 @@ public class CPPTemplates {
 							return instantiated.getType();
 						}
 					}
+				} else if (type instanceof TypeOfUnknownMember) {
+					IBinding binding = resolveUnknown(((TypeOfUnknownMember) type).getUnknownMember(), context);
+					if (binding instanceof IType) {
+						return (IType) binding;
+					} else if (binding instanceof IVariable) {
+						return ((IVariable) binding).getType();
+					} else if (binding instanceof IFunction) {
+						return ((IFunction) binding).getType();
+					}
+					return type;
 				} else {
 					IBinding binding= resolveUnknown((ICPPUnknownBinding) type, context);
 					if (binding instanceof IType)
@@ -1542,18 +1552,6 @@ public class CPPTemplates {
 				}
 			}
 			
-			if (type instanceof TypeOfUnknownMember) {
-				IBinding binding = resolveUnknown(((TypeOfUnknownMember) type).getUnknownMember(), context);
-				if (binding instanceof IType) {
-					return (IType) binding;
-				} else if (binding instanceof IVariable) {
-					return ((IVariable) binding).getType();
-				} else if (binding instanceof IFunction) {
-					return ((IFunction) binding).getType();
-				}
-				return type;
-			}
-
 			if (context.getContextTypeSpecialization() != null && type instanceof IBinding) {
 				IType unwound= getNestedType(type, TDEF);
 				ICPPClassSpecialization withinClass = context.getContextClassSpecialization();

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/TypeOfUnknownMember.java

@@ -11,9 +11,11 @@
 package org.eclipse.cdt.internal.core.dom.parser.cpp.semantics;
 
 import org.eclipse.cdt.core.CCorePlugin;
+import org.eclipse.cdt.core.dom.ast.IBinding;
 import org.eclipse.cdt.core.dom.ast.IType;
 import org.eclipse.cdt.internal.core.dom.parser.ISerializableType;
 import org.eclipse.cdt.internal.core.dom.parser.ITypeMarshalBuffer;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPUnknownBinding;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPUnknownMember;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.ICPPUnknownType;
 import org.eclipse.cdt.internal.core.index.IIndexFragment;
@@ -22,10 +24,11 @@ import org.eclipse.core.runtime.CoreException;
 /**
  * Represents the type of an unknown member.
  */
-public class TypeOfUnknownMember implements ICPPUnknownType, ISerializableType {
+public class TypeOfUnknownMember extends CPPUnknownBinding implements ICPPUnknownType, ISerializableType {
 	private final CPPUnknownMember fMember;
 
 	public TypeOfUnknownMember(CPPUnknownMember member) {
+		super(("decltype(" + member.getName() + ")").toCharArray());  //$NON-NLS-1$  //$NON-NLS-2$
 		fMember = member;
 	}
 
@@ -53,11 +56,8 @@ public class TypeOfUnknownMember implements ICPPUnknownType, ISerializableType {
 	}
 
 	@Override
-	public Object clone() {
+	public IBinding getOwner() {
-		try {
+		// We won't know until instantiation.
-			return super.clone();
+		return null;
-		} catch (CloneNotSupportedException e) {
-			return null;
-		}
 	}
 }