Bug 415198 - [false positive] Semantic error for decltype(func())::name

in dependent context

Change-Id: I12d41dd88fb5fd5e501907bc709efdabc44f3d17
Signed-off-by: Nathan Ridge <zeratul976@hotmail.com>
Reviewed-on: https://git.eclipse.org/r/15569
Reviewed-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>
IP-Clean: Sergey Prigogin <eclipse.sprigogin@gmail.com>
Tested-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>

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

@@ -8039,4 +8039,25 @@ public class AST2TemplateTests extends AST2TestBase {
 	public void testOutOfLineMethodOfPartialSpecialization_401152() throws Exception {
 		parseAndCheckBindings();
 	}
+
+	//	template <typename T>
+	//	T foo(T);
+	//
+	//	template <typename T>
+	//	struct U {
+	//	    typedef typename decltype(foo(T()))::type type;    
+	//	};
+	//	
+	//	struct S {
+	//		typedef int type;
+	//	};
+	//
+	//	int main() {
+	//		U<S>::type x;
+	//	}
+	public void testDependentDecltypeInNameQualifier_415198() throws Exception {
+		BindingAssertionHelper helper = getAssertionHelper();
+		helper.assertNonProblem("decltype(foo(T()))::type");
+		assertSameType((ITypedef) helper.assertNonProblem("U<S>::type"), CommonTypes.int_);
+	}
 }

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

@@ -1266,12 +1266,19 @@ public class CPPTemplates {
 			}
 
 			if (type instanceof ICPPUnknownBinding) {
+				if (type instanceof TypeOfDependentExpression) {
+					ICPPEvaluation eval = ((TypeOfDependentExpression) type).getEvaluation();
+					ICPPEvaluation instantiated = eval.instantiate(tpMap, packOffset, within, Value.MAX_RECURSION_DEPTH, point);
+					if (instantiated != eval)
+						return instantiated.getTypeOrFunctionSet(point);
+				} else {
 					IBinding binding= resolveUnknown((ICPPUnknownBinding) type, tpMap, packOffset, within, point);
 					if (binding instanceof IType)
 						return (IType) binding;
 	
 					return type;
 				}
+			}
 
 			if (within != null && type instanceof IBinding) {
 				IType unwound= getNestedType(type, TDEF);
@@ -1348,13 +1355,6 @@ public class CPPTemplates {
 				return typeContainer;
 			}
 
-			if (type instanceof TypeOfDependentExpression) {
-				ICPPEvaluation eval = ((TypeOfDependentExpression) type).getEvaluation();
-				ICPPEvaluation instantiated = eval.instantiate(tpMap, packOffset, within, Value.MAX_RECURSION_DEPTH, point);
-				if (instantiated != eval)
-					return instantiated.getTypeOrFunctionSet(point);
-			}
-
 			return type;
 		} catch (DOMException e) {
 			return e.getProblem();
@@ -2646,6 +2646,11 @@ public class CPPTemplates {
         	if (type instanceof IBinding)
         		return (IBinding) type;
         }
+        if (unknown instanceof TypeOfDependentExpression) {
+        	IType type= instantiateType((IType) unknown, tpMap, packOffset, within, point);
+        	if (type instanceof IBinding)
+        		return (IBinding) type;
+        }
         return unknown;
 	}
 

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

@@ -12,11 +12,13 @@
 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.ISerializableEvaluation;
 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.ProblemType;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPUnknownBinding;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.ICPPEvaluation;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.ICPPUnknownType;
 import org.eclipse.core.runtime.CoreException;
@@ -24,10 +26,11 @@ import org.eclipse.core.runtime.CoreException;
 /**
  * Represents the type of a dependent expression.
  */
-public class TypeOfDependentExpression implements ICPPUnknownType, ISerializableType {
+public class TypeOfDependentExpression extends CPPUnknownBinding implements ICPPUnknownType, ISerializableType {
 	private final ICPPEvaluation fEvaluation;
 
 	public TypeOfDependentExpression(ICPPEvaluation evaluation) {
+		super(evaluation.getSignature());
 		fEvaluation= evaluation;
 	}
 	
@@ -42,12 +45,8 @@ public class TypeOfDependentExpression implements ICPPUnknownType, ISerializable
 	}
 	
 	@Override
-	public Object clone() {
+	public TypeOfDependentExpression clone() {
-		try {
+		return (TypeOfDependentExpression) super.clone();
-			return super.clone();
-		} catch (CloneNotSupportedException e) {
-			return null;
-		}
 	}
 
 	public char[] getSignature() {
@@ -73,4 +72,10 @@ public class TypeOfDependentExpression implements ICPPUnknownType, ISerializable
 			return new TypeOfDependentExpression((ICPPEvaluation) eval);
 		return ProblemType.UNKNOWN_FOR_EXPRESSION;
 	}
+
+	@Override
+	public IBinding getOwner() {
+		// We won't know until instantiation.
+		return null;
+	}
 }