Bug 528846 - Handle id-expression that instantiates to pseudo-destructor name of built-in type

The pseudo-destructor is represented as a CPPImplicitFunction, computed
lazily and stored by CPPBasicType.

This commit also adds support for alias templates to
CPPTemplates.getTemplateName().

Change-Id: I6774556b2493cb68d32c3007d6ce48c7805595f4

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

@@ -10525,4 +10525,16 @@ public class AST2TemplateTests extends AST2CPPTestBase {
 		BindingAssertionHelper helper = getAssertionHelper();
 		helper.assertProblem("generate<400>", "generate<400>");
 	}
+	
+	//	template <typename T> T declval();
+	//
+	//	template <class T>
+	//	using destructor_expr_t = decltype(declval<T>().~T());
+	//
+	//	typedef destructor_expr_t<int> Waldo;
+	public void testDestructorExpressionType_528846() throws Exception {
+		BindingAssertionHelper helper = getAssertionHelper();
+		IType waldo = helper.assertNonProblem("Waldo");
+		assertSameType(CommonCPPTypes.void_, waldo);
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPBasicType.java

@@ -46,4 +46,12 @@ public interface ICPPBasicType extends IBasicType {
 	 */
 	@Deprecated
 	public static final int t_wchar_t = ICPPASTSimpleDeclSpecifier.t_wchar_t;
+
+	/**
+	 * Get the built-in type's pseudo-destructor.
+	 * The pseudo-destructor is the function named by e.g. an id-expression
+	 * of the form "T().~T" when instantiated with T mapped to a built-in type.
+	 * @since 6.5
+	 */
+	public ICPPFunction getPseudoDestructor();
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPBasicType.java

@@ -12,19 +12,24 @@
  *******************************************************************************/
 package org.eclipse.cdt.internal.core.dom.parser.cpp;
 
+import static org.eclipse.cdt.core.dom.ast.cpp.ICPPParameter.EMPTY_CPPPARAMETER_ARRAY;
+
 import org.eclipse.cdt.core.dom.ast.ASTTypeUtil;
 import org.eclipse.cdt.core.dom.ast.IASTExpression;
 import org.eclipse.cdt.core.dom.ast.IASTLiteralExpression;
 import org.eclipse.cdt.core.dom.ast.IASTSimpleDeclSpecifier;
 import org.eclipse.cdt.core.dom.ast.IBasicType;
+import org.eclipse.cdt.core.dom.ast.IScope;
 import org.eclipse.cdt.core.dom.ast.IType;
 import org.eclipse.cdt.core.dom.ast.ITypedef;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTInitializerClause;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTSimpleDeclSpecifier;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPBasicType;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPFunction;
 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.ValueFactory;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPSemantics;
 import org.eclipse.core.runtime.CoreException;
 
 /**
@@ -52,6 +57,7 @@ public class CPPBasicType implements ICPPBasicType, ISerializableType {
 	private final Kind fKind;
 	private final int fModifiers;
 	private Long fAssociatedValue;
+	private ICPPFunction fPseudoDestructor;
 
 	public CPPBasicType(Kind kind, int qualifiers, IASTExpression expression) {
 		if (kind == Kind.eUnspecified) {
@@ -321,4 +327,15 @@ public class CPPBasicType implements ICPPBasicType, ISerializableType {
 	public IASTExpression getValue() {
 		return null;
 	}
+
+	@Override
+	public ICPPFunction getPseudoDestructor() {
+		if (fPseudoDestructor == null) {
+			char[] dtorName = ("~" + toString()).toCharArray(); //$NON-NLS-1$
+			IScope globalScope = CPPSemantics.getCurrentLookupPoint().getTranslationUnit().getScope();
+			fPseudoDestructor = new CPPImplicitFunction(dtorName, globalScope, 
+					CPPClassScope.DESTRUCTOR_FUNCTION_TYPE, EMPTY_CPPPARAMETER_ARRAY, true, false);
+		}
+		return fPseudoDestructor;
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClassScope.java

@@ -19,7 +19,7 @@ import static org.eclipse.cdt.core.dom.ast.cpp.ICPPParameter.EMPTY_CPPPARAMETER_
 import static org.eclipse.cdt.core.parser.util.ArrayUtil.addAll;
 import static org.eclipse.cdt.core.parser.util.ArrayUtil.appendAt;
 import static org.eclipse.cdt.core.parser.util.ArrayUtil.trim;
-import static org.eclipse.cdt.internal.core.dom.parser.cpp.CPPBasicType.UNSPECIFIED_TYPE;
+import static org.eclipse.cdt.internal.core.dom.parser.cpp.CPPBasicType.VOID;
 import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUtil.TDEF;
 
 import java.util.Arrays;
@@ -69,8 +69,10 @@ import org.eclipse.core.runtime.IStatus;
  * Base implementation for C++ scopes.
  */
 public class CPPClassScope extends CPPScope implements ICPPClassScope {
-    private static final ICPPFunctionType DESTRUCTOR_FUNCTION_TYPE =
+	// Destructors don't have a return type, but the type of a destructor call expression
-    		CPPVisitor.createImplicitFunctionType(UNSPECIFIED_TYPE, EMPTY_CPPPARAMETER_ARRAY, false, false);
+	// is void, so it's simpler to model them as having a void return type.
+    public static final ICPPFunctionType DESTRUCTOR_FUNCTION_TYPE =
+    		CPPVisitor.createImplicitFunctionType(VOID, EMPTY_CPPPARAMETER_ARRAY, false, false);
 
 	private ICPPMethod[] implicits;
 

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

@@ -80,6 +80,7 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplateSpecialization;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplatedTypeTemplateParameter;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPAliasTemplate;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPAliasTemplateInstance;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPBasicType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassScope;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassSpecialization;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassTemplate;
@@ -2180,6 +2181,8 @@ public class CPPTemplates {
 			IASTDeclarator declarator = ((IASTFunctionDefinition) nestedDecl).getDeclarator();
 			declarator= ASTQueries.findInnermostDeclarator(declarator);
 			name = declarator.getName();
+		} else if (nestedDecl instanceof ICPPASTAliasDeclaration) {
+			name = ((ICPPASTAliasDeclaration) nestedDecl).getAlias();
 		}
 		if (name != null) {
 			if (name instanceof ICPPASTQualifiedName) {
@@ -3235,6 +3238,17 @@ public class CPPTemplates {
 		return exec;
 	}
 
+	/**
+	 * If 'name' is a destructor-name, return the name of the type (i.e. the
+	 * portion following the '~'). Otherwise return null.
+	 */
+	public static String unwrapDestructorName(char[] name) {
+		if (name == null || name.length == 0 || name[0] != '~') {
+			return null;
+		}
+		return new String(name).substring(1).trim();
+	}
+	
 	/**
 	 * Instantiate a plain name (simple-id).
 	 * Only destructor names require instantiation, e.g. the name "~T", when instantiated
@@ -3251,10 +3265,10 @@ public class CPPTemplates {
 	 *         instantiation context's parameter map, the provided name is returned unchanged. 
 	 */
 	public static char[] instantiateName(char[] name, InstantiationContext context, IBinding enclosingTemplate) {
-		if (name == null || name.length == 0 || name[0] != '~') {
+		String typename = unwrapDestructorName(name);
+		if (typename == null) {  // not a destructor-name
 			return name;
 		}
-		String typename = new String(name).substring(1);
 		ICPPTemplateParameterMap map = context.getParameterMap();
 		IBinding enclosing = enclosingTemplate;
 		while (enclosing != null) {
@@ -3267,10 +3281,17 @@ public class CPPTemplates {
 								IType argType = arg.getTypeValue();
 								argType = SemanticUtil.getNestedType(argType, CVTYPE | TDEF);
 								if (argType instanceof ICPPClassType) {
+									// Destructor for class type.
 									StringBuilder result = new StringBuilder();
 									result.append('~');
 									result.append(((ICPPClassType) argType).getName());
 									return result.toString().toCharArray();
+								} else if (argType instanceof ICPPBasicType) {
+									// Pseudo-destructor for builtin type.
+									StringBuilder result = new StringBuilder();
+									result.append('~');
+									ASTTypeUtil.appendType(argType, true, result);
+									return result.toString().toCharArray();
 								}
 							}
 						}

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

@@ -19,6 +19,7 @@ import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUti
 import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUtil.TDEF;
 import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUtil.getNestedType;
 
+import org.eclipse.cdt.core.dom.ast.ASTTypeUtil;
 import org.eclipse.cdt.core.dom.ast.DOMException;
 import org.eclipse.cdt.core.dom.ast.IASTEnumerationSpecifier.IASTEnumerator;
 import org.eclipse.cdt.core.dom.ast.IASTExpression;
@@ -39,6 +40,7 @@ import org.eclipse.cdt.core.dom.ast.IVariable;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTFunctionDefinition;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTQualifiedName;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplateId;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPBasicType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassTemplate;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPConstructor;
@@ -400,15 +402,22 @@ public class EvalID extends CPPDependentEvaluation {
 					return EvalFixed.INCOMPLETE;
 				}
 			}
-			IType fieldOwnerClassTypeCV = SemanticUtil.getNestedType(fieldOwnerType, TDEF | REF);
+			IType fieldOwnerTypeSimplifiedCV = SemanticUtil.getNestedType(fieldOwnerType, TDEF | REF);
-			IType fieldOwnerClassType = SemanticUtil.getNestedType(fieldOwnerClassTypeCV, CVTYPE);
+			IType fieldOwnerTypeSimplified = SemanticUtil.getNestedType(fieldOwnerTypeSimplifiedCV, CVTYPE);
-			if (fieldOwnerClassType instanceof ICPPClassType) {
+			if (fieldOwnerTypeSimplified instanceof ICPPClassType) {
-				ICPPEvaluation eval = resolveName(name, (ICPPClassType) fieldOwnerClassType, fieldOwner, 
+				ICPPEvaluation eval = resolveName(name, (ICPPClassType) fieldOwnerTypeSimplified, fieldOwner, 
-						templateArgs, fieldOwnerClassTypeCV);
+						templateArgs, fieldOwnerTypeSimplifiedCV);
 				if (eval != null)
 					return eval;
-				if (!CPPTemplates.isDependentType(fieldOwnerClassType)) 
+				if (!CPPTemplates.isDependentType(fieldOwnerTypeSimplified)) 
 					return EvalFixed.INCOMPLETE;
+			} else if (fieldOwnerTypeSimplified instanceof ICPPBasicType) {
+				// Handle pseudo-destructor of basic type, e.g. "T().~T" instantiated with [T = int].
+				String typename = CPPTemplates.unwrapDestructorName(name);
+				if (typename != null && typename.equals(ASTTypeUtil.getType(fieldOwnerTypeSimplified))) {
+					ICPPFunction pseudoDestructor = ((ICPPBasicType) fieldOwnerTypeSimplified).getPseudoDestructor();
+					return new EvalBinding(pseudoDestructor, null, getTemplateDefinition());
+				}
 			}
 		}