TypeInfoValidator.java

/*******************************************************************************
 * Copyright (c) 2010 xored software, Inc.  
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html  
 *
 * Contributors:
 *     xored software, Inc. - initial API and Implementation (Alex Panchenko)
 *******************************************************************************/
package org.eclipse.dltk.internal.javascript.validation;

import static org.eclipse.dltk.internal.javascript.ti.IReferenceAttributes.PHANTOM;
import static org.eclipse.dltk.internal.javascript.ti.IReferenceAttributes.R_METHOD;
import static org.eclipse.dltk.internal.javascript.validation.JavaScriptValidations.typeOf;
import static org.eclipse.dltk.javascript.typeinfo.RUtils.locationOf;
import static org.eclipse.osgi.util.NLS.bind;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Stack;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.dltk.annotations.NonNull;
import org.eclipse.dltk.annotations.Nullable;
import org.eclipse.dltk.ast.ASTNode;
import org.eclipse.dltk.compiler.problem.IProblemIdentifier;
import org.eclipse.dltk.compiler.problem.IValidationStatus;
import org.eclipse.dltk.compiler.problem.ValidationMultiStatus;
import org.eclipse.dltk.compiler.problem.ValidationStatus;
import org.eclipse.dltk.core.ISourceNode;
import org.eclipse.dltk.core.builder.IBuildContext;
import org.eclipse.dltk.core.builder.IBuildParticipant;
import org.eclipse.dltk.core.builder.IBuildParticipantExtension;
import org.eclipse.dltk.core.builder.IBuildParticipantExtension4;
import org.eclipse.dltk.internal.javascript.parser.JSDocValidatorFactory.TypeChecker;
import org.eclipse.dltk.internal.javascript.ti.ConstantValue;
import org.eclipse.dltk.internal.javascript.ti.IReferenceAttributes;
import org.eclipse.dltk.internal.javascript.ti.ITypeInferenceContext;
import org.eclipse.dltk.internal.javascript.ti.IValue;
import org.eclipse.dltk.internal.javascript.ti.JSMethod;
import org.eclipse.dltk.internal.javascript.ti.TypeInferencer2;
import org.eclipse.dltk.internal.javascript.ti.TypeInferencerVisitor;
import org.eclipse.dltk.javascript.ast.Argument;
import org.eclipse.dltk.javascript.ast.BinaryOperation;
import org.eclipse.dltk.javascript.ast.CallExpression;
import org.eclipse.dltk.javascript.ast.Expression;
import org.eclipse.dltk.javascript.ast.FunctionStatement;
import org.eclipse.dltk.javascript.ast.GetArrayItemExpression;
import org.eclipse.dltk.javascript.ast.Identifier;
import org.eclipse.dltk.javascript.ast.IfStatement;
import org.eclipse.dltk.javascript.ast.JSNode;
import org.eclipse.dltk.javascript.ast.NewExpression;
import org.eclipse.dltk.javascript.ast.PropertyExpression;
import org.eclipse.dltk.javascript.ast.ReturnStatement;
import org.eclipse.dltk.javascript.ast.Script;
import org.eclipse.dltk.javascript.ast.StatementBlock;
import org.eclipse.dltk.javascript.ast.ThrowStatement;
import org.eclipse.dltk.javascript.ast.UnaryOperation;
import org.eclipse.dltk.javascript.ast.VariableDeclaration;
import org.eclipse.dltk.javascript.ast.VariableStatement;
import org.eclipse.dltk.javascript.core.JSBindings;
import org.eclipse.dltk.javascript.core.JavaScriptProblems;
import org.eclipse.dltk.javascript.internal.core.TemporaryBindings;
import org.eclipse.dltk.javascript.internal.core.ThreadTypeSystemImpl;
import org.eclipse.dltk.javascript.parser.ISuppressWarningsState;
import org.eclipse.dltk.javascript.parser.JSParser;
import org.eclipse.dltk.javascript.parser.JSProblemReporter;
import org.eclipse.dltk.javascript.parser.PropertyExpressionUtils;
import org.eclipse.dltk.javascript.parser.Reporter;
import org.eclipse.dltk.javascript.typeinference.IAssignProtection;
import org.eclipse.dltk.javascript.typeinference.IAssignProtection2;
import org.eclipse.dltk.javascript.typeinference.IValueCollection;
import org.eclipse.dltk.javascript.typeinference.IValueReference;
import org.eclipse.dltk.javascript.typeinference.PhantomValueReference;
import org.eclipse.dltk.javascript.typeinference.ReferenceKind;
import org.eclipse.dltk.javascript.typeinference.ReferenceLocation;
import org.eclipse.dltk.javascript.typeinference.ValueReferenceUtil;
import org.eclipse.dltk.javascript.typeinfo.IModelBuilder.IVariable;
import org.eclipse.dltk.javascript.typeinfo.IRArrayType;
import org.eclipse.dltk.javascript.typeinfo.IRClassType;
import org.eclipse.dltk.javascript.typeinfo.IRConstructor;
import org.eclipse.dltk.javascript.typeinfo.IRElement;
import org.eclipse.dltk.javascript.typeinfo.IRFunctionType;
import org.eclipse.dltk.javascript.typeinfo.IRLocalType;
import org.eclipse.dltk.javascript.typeinfo.IRMapType;
import org.eclipse.dltk.javascript.typeinfo.IRMember;
import org.eclipse.dltk.javascript.typeinfo.IRMethod;
import org.eclipse.dltk.javascript.typeinfo.IRParameter;
import org.eclipse.dltk.javascript.typeinfo.IRProperty;
import org.eclipse.dltk.javascript.typeinfo.IRRecordMember;
import org.eclipse.dltk.javascript.typeinfo.IRRecordType;
import org.eclipse.dltk.javascript.typeinfo.IRType;
import org.eclipse.dltk.javascript.typeinfo.IRTypeDeclaration;
import org.eclipse.dltk.javascript.typeinfo.IRTypeExtension;
import org.eclipse.dltk.javascript.typeinfo.IRUnionType;
import org.eclipse.dltk.javascript.typeinfo.IRVariable;
import org.eclipse.dltk.javascript.typeinfo.ITypeChecker;
import org.eclipse.dltk.javascript.typeinfo.ITypeCheckerExtension;
import org.eclipse.dltk.javascript.typeinfo.ITypeInfoContext;
import org.eclipse.dltk.javascript.typeinfo.ITypeNames;
import org.eclipse.dltk.javascript.typeinfo.ITypeSystem;
import org.eclipse.dltk.javascript.typeinfo.JSTypeSet;
import org.eclipse.dltk.javascript.typeinfo.RTypes;
import org.eclipse.dltk.javascript.typeinfo.TypeCompatibility;
import org.eclipse.dltk.javascript.typeinfo.TypeInfoManager;
import org.eclipse.dltk.javascript.typeinfo.TypeUtil;
import org.eclipse.dltk.javascript.typeinfo.model.Member;
import org.eclipse.dltk.javascript.typeinfo.model.ParameterKind;
import org.eclipse.dltk.javascript.typeinfo.model.Property;
import org.eclipse.dltk.javascript.typeinfo.model.Type;
import org.eclipse.dltk.javascript.typeinfo.model.TypeKind;
import org.eclipse.dltk.javascript.typeinfo.model.Visibility;
import org.eclipse.dltk.javascript.validation.IValidatorExtension;
import org.eclipse.osgi.util.NLS;

public class TypeInfoValidator implements IBuildParticipant,
		IBuildParticipantExtension, IBuildParticipantExtension4 {

	/**
	 * Public identifier of this build participant.
	 */
	public static final String ID = "org.eclipse.dltk.javascript.core.buildParticipant.typeinfo";

	private boolean hasDependents;

	public boolean beginBuild(int buildType) {
		return true;
	}

	public void notifyDependents(IBuildParticipant[] dependents) {
		hasDependents = true;
	}

	private TypeInferencer2 inferencer;

	public void build(IBuildContext context) throws CoreException {
		final Script script = JavaScriptValidations.parse(context);
		if (script == null) {
			return;
		}
		if (inferencer == null) {
			inferencer = createTypeInferencer();
		}
		inferencer.setModelElement(context.getSourceModule());
		inferencer.pushAttribute(ITypeInfoContext.BUILD_CONTEXT, context);
		final JSProblemReporter reporter = JavaScriptValidations
				.createReporter(context);
		@SuppressWarnings("unchecked")
		@Nullable
		final Set<FunctionStatement> inconsistentReturns = (Set<FunctionStatement>) context
				.get(JavaScriptValidations.ATTR_INCONSISTENT_RETURNS);
		final ValidationVisitor visitor = new ValidationVisitor(inferencer,
				reporter, inconsistentReturns, hasDependents);
		inferencer.setVisitor(visitor);
		inferencer.doInferencing(script);
		if (hasDependents) {
			inferencer.resetLocalState();
			context.set(TypeInfoValidator.ATTR_BINDINGS, visitor.bindings);
			saveCachedBindings(script, new TemporaryBindings(inferencer,
					visitor.bindings));
			((ThreadTypeSystemImpl) ITypeSystem.CURRENT).set(inferencer);
		}
	}

	public void afterBuild(IBuildContext context) {
		if (hasDependents) {
			((ThreadTypeSystemImpl) ITypeSystem.CURRENT).set(null);
		}
	}

	public void endBuild(IProgressMonitor monitor) {
		removeCachedBindings();
		inferencer = null;
	}

	/**
	 * The name of the {@link IBuildContext} attribute containing "bindings"
	 * <code>(Map<ASTNode,IValueReference>)</code>
	 */
	public static final String ATTR_BINDINGS = TypeInfoValidator.class
			.getName() + ".BINDINGS";

	private static final int CACHED_BINDINGS_SIZE = 32;

	/**
	 * Thread specific bindings, so methods from {@link JSBindings} called from
	 * {@link IBuildParticipant} will return validation specific bindings.
	 */
	private static final ThreadLocal<Map<Script, JSBindings>> CACHED_BINDINGS = new ThreadLocal<Map<Script, JSBindings>>();

	@SuppressWarnings("serial")
	private static void saveCachedBindings(Script script, JSBindings bindings) {
		Map<Script, JSBindings> map = CACHED_BINDINGS.get();
		if (map == null) {
			map = new LinkedHashMap<Script, JSBindings>(
					(CACHED_BINDINGS_SIZE + CACHED_BINDINGS_SIZE / 3), 0.75f,
					true) {
				@Override
				protected boolean removeEldestEntry(
						Map.Entry<Script, JSBindings> eldest) {
					return size() >= CACHED_BINDINGS_SIZE;
				}
			};
			CACHED_BINDINGS.set(map);
		}
		map.put(script, bindings);
	}

	private static void removeCachedBindings() {
		final Map<Script, JSBindings> map = CACHED_BINDINGS.get();
		if (map != null && !map.isEmpty()) {
			map.clear();
		}
	}

	/**
	 * Returns cached "bindings" for the specified script, if any.
	 * 
	 * @param script
	 * @return
	 */
	public static JSBindings getCachedBindings(Script script) {
		final Map<Script, JSBindings> map = CACHED_BINDINGS.get();
		if (map != null) {
			return map.get(script);
		}
		return null;
	}

	protected TypeInferencer2 createTypeInferencer() {
		return new TypeInferencer2();
	}

	private static enum VisitorMode {
		NORMAL, CALL
	}

	private static abstract class ExpressionValidator {
		abstract void call(ValidationVisitor visitor);

		public ExpressionValidator() {
		}

		private ISuppressWarningsState suppressed;

		public ISuppressWarningsState getSuppressed() {
			return suppressed;
		}

		public void setSuppressed(ISuppressWarningsState suppressed) {
			this.suppressed = suppressed;
		}

		public boolean isRelatedTo(IValueReference reference) {
			return false;
		}
	}

	private static class CallExpressionValidator extends ExpressionValidator {
		private final FunctionScope scope;
		private final CallExpression node;
		private final IValueReference reference;
		private final IValueReference[] arguments;
		private final List<IRMethod> methods;

		public CallExpressionValidator(FunctionScope scope,
				CallExpression node, IValueReference reference,
				IValueReference[] arguments, List<IRMethod> methods) {
			this.scope = scope;
			this.node = node;
			this.reference = reference;
			this.arguments = arguments;
			this.methods = methods;
		}

		@Override
		public void call(ValidationVisitor visitor) {
			visitor.validateCallExpression(scope, node, reference, arguments,
					methods);
		}

		@Override
		public boolean isRelatedTo(IValueReference reference) {
			return reference.isParentOf(this.reference);
		}

		@Override
		public String toString() {
			return getClass().getSimpleName() + " - " + reference + "()";
		}
	}

	private static class ReturnNode {

		final ReturnStatement node;
		final IValueReference returnValueReference;

		public ReturnNode(ReturnStatement node,
				IValueReference returnValueReference) {
			this.node = node;
			this.returnValueReference = returnValueReference;
		}

		@Override
		public String toString() {
			return String.valueOf(node).trim() + " -> " + returnValueReference;
		}
	}

	private static class TestReturnStatement extends ExpressionValidator {

		private final List<ReturnNode> lst;
		private final IRMethod jsMethod;

		public TestReturnStatement(IRMethod jsMethod, List<ReturnNode> lst) {
			this.jsMethod = jsMethod;
			this.lst = lst;
		}

		@Override
		public void call(ValidationVisitor visitor) {
			final IRType methodType = jsMethod.getType();
			IRType firstType = null;
			ReturnNode firstNode = null;
			for (ReturnNode element : lst) {
				if (element.returnValueReference == null)
					continue;
				final IRType type = JavaScriptValidations
						.typeOf(element.returnValueReference);
				TypeCompatibility compatibility = null;
				if (methodType instanceof IRTypeExtension) {
					final IValidationStatus status = ((IRTypeExtension) methodType)
							.isAssignableFrom(element.returnValueReference);
					if (status != null) {
						if (status instanceof TypeCompatibility) {
							compatibility = (TypeCompatibility) status;
						} else if (status != ValidationStatus.OK) {
							JavaScriptValidations
									.reportValidationStatus(
											visitor.getProblemReporter(),
											status,
											element.node,
											JavaScriptProblems.DECLARATION_MISMATCH_ACTUAL_RETURN_TYPE,
											ValidationMessages.DeclarationMismatchWithActualReturnType,
											jsMethod.getName());
						}
					}
				} else if (type != null && methodType != null) {
					compatibility = methodType.isAssignableFrom(type);
				}
				if (compatibility != null
						&& compatibility != TypeCompatibility.TRUE) {
					final ReturnStatement node = element.node;
					visitor.getProblemReporter()
							.reportProblem(
									compatibility == TypeCompatibility.FALSE ? JavaScriptProblems.DECLARATION_MISMATCH_ACTUAL_RETURN_TYPE
											: JavaScriptProblems.DECLARATION_MISMATCH_ACTUAL_RETURN_TYPE_PARAMETERIZATION,
									NLS.bind(
											ValidationMessages.DeclarationMismatchWithActualReturnType,
											new String[] {
													jsMethod.getName(),
													TypeUtil.getName(methodType),
													TypeUtil.getName(type) }),
									node.sourceStart(), node.sourceEnd());
				}
				if (methodType == null && firstType == null && type != null) {
					// remember first type only if return type is not declared.
					// consistency check makes sense only if no return type
					// declaration.
					firstType = type.normalize();
					firstNode = element;
				}
			}

			if (firstType != null) {
				for (ReturnNode next : lst) {
					if (next == firstNode) {
						continue;
					}
					IRType nextType = JavaScriptValidations
							.typeOf(next.returnValueReference);
					if (nextType != null) {
						nextType = nextType.normalize();
						if (!nextType.isAssignableFrom(firstType).ok()
								&& !firstType.isAssignableFrom(nextType).ok()) {
							visitor.getProblemReporter()
									.reportProblem(
											JavaScriptProblems.RETURN_INCONSISTENT,
											NLS.bind(
													ValidationMessages.ReturnTypeInconsistentWithPreviousReturn,
													new String[] {
															TypeUtil.getName(nextType),
															TypeUtil.getName(firstType) }),
											next.node.sourceStart(),
											next.node.sourceEnd());
						}
					}
				}
			}
		}

		@Override
		public String toString() {
			return getClass().getSimpleName() + " - " + jsMethod.getName();
		}
	}

	private static class NewExpressionValidator extends ExpressionValidator {
		private final FunctionScope scope;
		private final NewExpression node;
		private final IValueReference reference;
		private final IValueReference typeReference;
		private final IValueReference[] arguments;
		private final IValueCollection collection;

		public NewExpressionValidator(FunctionScope scope, NewExpression node,
				IValueReference reference, IValueReference typeReference,
				IValueReference[] arguments, IValueCollection collection) {
			this.scope = scope;
			this.node = node;
			this.reference = reference;
			this.typeReference = typeReference;
			this.arguments = arguments;
			this.collection = collection;
		}

		@Override
		public void call(ValidationVisitor visitor) {
			visitor.validateNewExpression(scope, collection,
					node.getObjectClass(), reference, typeReference, arguments);
		}

		@Override
		public String toString() {
			return getClass().getSimpleName() + " - " + reference;
		}
	}

	private static class PropertyExpressionHolder extends ExpressionValidator {
		private final FunctionScope scope;
		private final PropertyExpression node;
		private final IValueReference reference;
		private final boolean exists;

		public PropertyExpressionHolder(FunctionScope scope,
				PropertyExpression node, IValueReference reference,
				boolean exists) {
			this.scope = scope;
			this.node = node;
			this.reference = reference;
			this.exists = exists;
		}

		@Override
		public void call(ValidationVisitor visitor) {
			visitor.validateProperty(scope, node, reference, exists);
		}

		@Override
		public String toString() {
			return getClass().getSimpleName() + " - " + reference;
		}
	}

	static class FunctionScope {
		// Set<Expression or IValueReference>
		final Set<Object> reported = new HashSet<Object>();
		final List<ReturnNode> returnNodes = new ArrayList<ReturnNode>();
		boolean throwsException;

		void add(Path path) {
			if (path != null) {
				reported.add(path.start);
				reported.add(path.references[0]);
			}
		}

		boolean contains(Path path) {
			if (path != null) {
				if (reported.contains(path.start)) {
					return true;
				}
				for (IValueReference reference : path.references) {
					if (reported.contains(reference)) {
						return true;
					}
				}
			}
			return false;
		}
	}

	static class Path {
		final Expression start;
		final IValueReference[] references;

		public Path(Expression start, IValueReference[] references) {
			this.start = start;
			this.references = references;
		}
	}

	public static class ValidationVisitor extends TypeInferencerVisitor {

		private final List<ExpressionValidator> expressionValidators = new ArrayList<ExpressionValidator>();
		private final Set<FunctionStatement> inconsistentReturns;

		public ValidationVisitor(ITypeInferenceContext context,
				JSProblemReporter reporter,
				Set<FunctionStatement> inconsistentReturns) {
			this(context, reporter, inconsistentReturns, false);
		}

		public ValidationVisitor(ITypeInferenceContext context,
				JSProblemReporter reporter,
				Set<FunctionStatement> inconsistentReturns,
				boolean hasDependents) {
			super(context);
			this.reporter = reporter;
			this.inconsistentReturns = inconsistentReturns;
			this.bindings = hasDependents ? new HashMap<ASTNode, IValueReference>()
					: null;
		}

		private final Map<ASTNode, VisitorMode> modes = new IdentityHashMap<ASTNode, VisitorMode>();

		private final Stack<ASTNode> visitStack = new Stack<ASTNode>();

		final Map<ASTNode, IValueReference> bindings;

		@Override
		public IValueReference visit(ASTNode node) {
			visitStack.push(node);
			try {
				final IValueReference value = super.visit(node);
				if (bindings != null && value != null) {
					bindings.put(node, value);
				}
				return value;
			} finally {
				visitStack.pop();
			}
		}

		@Override
		public void initialize() {
			super.initialize();
			modes.clear();
			visitStack.clear();
			expressionValidators.clear();
			variables.clear();
			functionScopes.clear();
			functionScopes.add(new FunctionScope());
			final List<IValidatorExtension> extensions = TypeInfoManager
					.createExtensions(context, IValidatorExtension.class, null);
			if (!extensions.isEmpty()) {
				this.extensions = extensions
						.toArray(new IValidatorExtension[extensions.size()]);
			} else {
				this.extensions = null;
			}
			if (getTypeChecker() instanceof ITypeCheckerExtension) {
				((ITypeCheckerExtension) getTypeChecker())
						.setExtensions(this.extensions);
			}
		}

		private IValidatorExtension[] extensions;

		/**
		 * Returns {@link ITypeChecker} which can be used for type validations.
		 */
		@NonNull
		@Override
		public ITypeChecker getTypeChecker() {
			ITypeChecker result = super.getTypeChecker();
			if (result == null) {
				result = new TypeChecker(context, reporter);
				typeChecker = result;
			}
			return result;
		}

		@Override
		public void done() {
			super.done();
			if (inconsistentReturns != null && !inconsistentReturns.isEmpty()
					&& reporter instanceof Reporter) {
				final Reporter r = (Reporter) reporter;
				for (FunctionStatement statement : inconsistentReturns) {
					FlowValidation.reportInconsistentReturn(r, statement);
				}
			}
			runDelayedValidations();
			for (IValueReference variable : variables) {
				if (variable.getAttribute(IReferenceAttributes.ACCESS) == null) {
					final IRVariable jsVariable = (IRVariable) variable
							.getAttribute(IReferenceAttributes.R_VARIABLE);
					if (jsVariable != null
							&& jsVariable
									.isSuppressed(JavaScriptProblems.UNUSED_VARIABLE))
						continue;
					final ReferenceLocation location = variable.getLocation();
					reporter.reportProblem(
							JavaScriptProblems.UNUSED_VARIABLE,
							NLS.bind("Variable {0} is never used",
									variable.getName()),
							location.getNameStart(), location.getNameEnd());
				}
			}
			((TypeChecker) typeChecker).validate();
		}

		/**
		 * Executes all the delayed validations collected so far.
		 */
		public void runDelayedValidations() {
			if (expressionValidators.isEmpty()) {
				return;
			}
			final ExpressionValidator[] copy = expressionValidators
					.toArray(new ExpressionValidator[expressionValidators
							.size()]);
			expressionValidators.clear();
			runExpressionValidations(Arrays.asList(copy));
		}

		/**
		 * Executes the delayed validations for the specified references.
		 */
		public void runDelayedValidationsFor(IValueReference... references) {
			if (expressionValidators.isEmpty() || references.length == 0) {
				return;
			}
			final List<ExpressionValidator> selected = new ArrayList<ExpressionValidator>();
			for (Iterator<ExpressionValidator> i = expressionValidators
					.iterator(); i.hasNext();) {
				final ExpressionValidator validator = i.next();
				for (IValueReference reference : references) {
					if (validator.isRelatedTo(reference)) {
						selected.add(validator);
						i.remove();
						break;
					}
				}
			}
			if (!selected.isEmpty()) {
				runExpressionValidations(selected);
			}
		}

		private void runExpressionValidations(
				Iterable<ExpressionValidator> validators) {
			final ISuppressWarningsState suppressWarnings = reporter
					.getSuppressWarnings();
			try {
				for (ExpressionValidator validator : validators) {
					reporter.restoreSuppressWarnings(validator.getSuppressed());
					validator.call(this);
				}
			} finally {
				reporter.restoreSuppressWarnings(suppressWarnings);
			}
		}

		private VisitorMode currentMode() {
			final VisitorMode mode = modes.get(visitStack.peek());
			return mode != null ? mode : VisitorMode.NORMAL;
		}

		@Override
		public IValueReference visitNewExpression(NewExpression node) {
			final VisitNewResult result = visitNew(node);
			if (result.getTypeValue() != null) {
				pushExpressionValidator(new NewExpressionValidator(
						peekFunctionScope(), node, result.getValue(),
						result.getTypeValue(), result.getArguments(),
						peekContext()));
			}
			return result.getValue();
		}

		private final Stack<FunctionScope> functionScopes = new Stack<FunctionScope>();

		private static Path path(Expression expression,
				IValueReference reference) {
			final List<IValueReference> refs = new ArrayList<IValueReference>(8);
			for (;;) {
				if (expression instanceof PropertyExpression) {
					expression = ((PropertyExpression) expression).getObject();
				} else if (expression instanceof CallExpression) {
					expression = ((CallExpression) expression).getExpression();
				} else if (expression instanceof GetArrayItemExpression) {
					expression = ((GetArrayItemExpression) expression)
							.getArray();
				} else {
					break;
				}
				refs.add(reference);
				reference = reference.getParent();
				if (reference == null) {
					return null;
				}
			}
			refs.add(reference);
			return new Path(expression, refs.toArray(new IValueReference[refs
					.size()]));
		}

		protected final FunctionScope peekFunctionScope() {
			return functionScopes.peek();
		}

		public void enterFunctionScope() {
			functionScopes.push(new FunctionScope());
		}

		public void leaveFunctionScope(IRMethod method,
				FunctionStatement function) {
			final FunctionScope scope = functionScopes.pop();
			if (method != null) {
				if (inconsistentReturns != null && method.getType() != null
						&& RTypes.isUndefined(method.getType())) {
					inconsistentReturns.remove(function);
				}
				if (!scope.returnNodes.isEmpty()) {
					// method.setType(context.resolveTypeRef(method.getType()));
					pushExpressionValidator(new TestReturnStatement(method,
							scope.returnNodes));
				} else if (!scope.throwsException && method.getType() != null
						&& !RTypes.isUndefined(method.getType())) {
					final ReferenceLocation location = locationOf(method);
					if (location == null) {
						return;
					}
					reporter.reportProblem(
							JavaScriptProblems.DECLARATION_MISMATCH_ACTUAL_RETURN_TYPE,
							NLS.bind(
									ValidationMessages.DeclarationMismatchNoReturnType,
									new String[] { method.getName(),
											TypeUtil.getName(method.getType()) }),
							location.getNameStart(), location.getNameEnd());
				}
			}
		}

		@Override
		public IValueReference visitFunctionStatement(FunctionStatement node) {
			enterFunctionScope();
			IValueReference reference = super.visitFunctionStatement(node);
			final IRMethod method = (IRMethod) reference.getAttribute(R_METHOD);
			leaveFunctionScope(method, node);

			return reference;
		}

		@Override
		protected JSMethod createMethod(FunctionStatement node) {
			validateHidesByFunction(node);
			return super.createMethod(node);
		}

		private void validateHidesByFunction(FunctionStatement node) {
			IValueCollection peekContext = peekContext();
			final boolean inlineBlock = node.isInlineBlock();
			for (Argument argument : node.getArguments()) {
				if (inlineBlock
						&& ITypeNames.UNDEFINED.equals(argument
								.getArgumentName())) {
					// TODO (alex) alternatively, set Element.isHideAllowed()
					// for the "undefined" property
					continue;
				}
				IValueReference child = peekContext.getChild(argument
						.getArgumentName());
				if (child.exists()) {
					if (child.getKind() == ReferenceKind.PROPERTY) {
						final Property property = ValueReferenceUtil
								.extractElement(child, Property.class);
						if (!property.isHideAllowed()) {
							if (property.getDeclaringType() != null) {
								reporter.reportProblem(
										JavaScriptProblems.PARAMETER_HIDES_VARIABLE,
										NLS.bind(
												ValidationMessages.ParameterHidesPropertyOfType,
												new String[] {
														argument.getArgumentName(),
														property.getDeclaringType()
																.getName() }),
										argument.sourceStart(), argument
												.sourceEnd());
							} else {
								reporter.reportProblem(
										JavaScriptProblems.PARAMETER_HIDES_VARIABLE,
										NLS.bind(
												ValidationMessages.ParameterHidesProperty,
												argument.getArgumentName()),
										argument.sourceStart(), argument
												.sourceEnd());
							}
						}
					} else if (!Boolean.TRUE.equals(child
							.getAttribute(IReferenceAttributes.HIDE_ALLOWED))) {
						if (child.getKind() == ReferenceKind.FUNCTION) {
							reporter.reportProblem(
									JavaScriptProblems.PARAMETER_HIDES_FUNCTION,
									NLS.bind(
											ValidationMessages.ParameterHidesFunction,
											argument.getArgumentName()),
									argument.sourceStart(), argument
											.sourceEnd());
						} else {
							reporter.reportProblem(
									JavaScriptProblems.PARAMETER_HIDES_VARIABLE,
									NLS.bind(
											ValidationMessages.ParameterHidesVariable,
											argument.getArgumentName()),
									argument.sourceStart(), argument
											.sourceEnd());
						}
					}
				}
			}
			if (node.isDeclaration()) {
				final IValueReference child;
				final IValueCollection parentScope = getParentScope(peekContext);
				if (parentScope == null) {
					child = peekContext.getChild(node.getName().getName());
					if (getSource().equals(child.getLocation().getSource())) {
						return;
					}
				} else {
					child = parentScope.getChild(node.getName().getName());
				}
				if (child.exists()) {
					final ReferenceKind kind = child.getKind();
					if (kind == ReferenceKind.PROPERTY) {
						final Property property = ValueReferenceUtil
								.extractElement(child, Property.class);
						if (!property.isHideAllowed()) {
							if (property.getDeclaringType() != null) {
								reporter.reportProblem(
										JavaScriptProblems.FUNCTION_HIDES_VARIABLE,
										NLS.bind(
												ValidationMessages.FunctionHidesPropertyOfType,
												new String[] {
														node.getName()
																.getName(),
														property.getDeclaringType()
																.getName() }),
										node.getName().sourceStart(), node
												.getName().sourceEnd());
							} else {
								reporter.reportProblem(
										JavaScriptProblems.FUNCTION_HIDES_VARIABLE,
										NLS.bind(
												ValidationMessages.FunctionHidesProperty,
												node.getName().getName()), node
												.getName().sourceStart(), node
												.getName().sourceEnd());
							}
						}
					} else if (!Boolean.TRUE.equals(child
							.getAttribute(IReferenceAttributes.HIDE_ALLOWED))) {
						if (kind == ReferenceKind.FUNCTION) {
							reporter.reportProblem(
									JavaScriptProblems.FUNCTION_HIDES_FUNCTION,
									NLS.bind(
											ValidationMessages.FunctionHidesFunction,
											node.getName().getName()), node
											.getName().sourceStart(), node
											.getName().sourceEnd());
						} else if (kind == ReferenceKind.LOCAL
								|| kind == ReferenceKind.GLOBAL) {
							reporter.reportProblem(
									JavaScriptProblems.FUNCTION_HIDES_VARIABLE,
									NLS.bind(
											ValidationMessages.FunctionHidesVariable,
											node.getName().getName()), node
											.getName().sourceStart(), node
											.getName().sourceEnd());
						} else {
							reporter.reportProblem(
									JavaScriptProblems.FUNCTION_HIDES_PREDEFINED,
									NLS.bind(
											ValidationMessages.FunctionHidesPredefinedIdentifier,
											node.getName().getName()), node
											.getName().sourceStart(), node
											.getName().sourceEnd());
						}
					}
				}
			}
		}

		@Override
		public IValueReference visitReturnStatement(ReturnStatement node) {
			IValueReference returnValueReference = super
					.visitReturnStatement(node);
			if (node.getValue() != null) {
				peekFunctionScope().returnNodes.add(new ReturnNode(node,
						returnValueReference));
			}
			return returnValueReference;
		}

		@Override
		public IValueReference visitThrowStatement(ThrowStatement node) {
			peekFunctionScope().throwsException = true;
			return super.visitThrowStatement(node);
		}

		@Override
		public IValueReference visitCallExpression(CallExpression node) {
			final Expression expression = node.getExpression();
			modes.put(expression, VisitorMode.CALL);

			final IValueReference reference = visit(expression);
			modes.remove(expression);
			if (reference == null) {
				visitList(node.getArguments());
				return null;
			}
			if (reference.getAttribute(PHANTOM, true) != null) {
				visitList(node.getArguments());
				return PhantomValueReference.REFERENCE;
			}
			if (isUntyped(reference)) {
				visitList(node.getArguments());
				return null;
			}
			if (reference.getKind() == ReferenceKind.ARGUMENT) {
				if (reference.getDeclaredTypes().contains(RTypes.FUNCTION)) {
					for (ASTNode argument : node.getArguments()) {
						visit(argument);
					}
					// don't validate function pointer
					return null;
				}
			}
			final List<ASTNode> args = node.getArguments();
			final IValueReference[] arguments = new IValueReference[args.size()];
			for (int i = 0, size = args.size(); i < size; ++i) {
				arguments[i] = visit(args.get(i));
			}
			final List<IRMethod> methods = ValueReferenceUtil.extractElements(
					reference, IRMethod.class);
			if (methods != null && methods.size() == 1) {
				final IRMethod method = methods.get(0);
				IValueReference ref = checkSpecialJavascriptFunctionCalls(
						reference, arguments, method);
				if (ref != null)
					return ref;
				if (method.isGeneric()) {
					if (!JavaScriptValidations.checkParameterCount(method,
							args.size())) {
						final Expression methodNode = expression instanceof PropertyExpression ? ((PropertyExpression) expression)
								.getProperty() : expression;
						reportMethodParameterError(methodNode, arguments,
								method);
						return null;
					}
					final IRType result = evaluateGenericCall(method, arguments);
					return ConstantValue.of(result);
				} else {
					pushExpressionValidator(new CallExpressionValidator(
							peekFunctionScope(), node, reference, arguments,
							methods));
					return ConstantValue.of(method.getType());
				}
			} else {
				pushExpressionValidator(new CallExpressionValidator(
						peekFunctionScope(), node, reference, arguments,
						methods));
				if (methods != null && methods.size() > 1) {
					// try to found the best match
					IRMethod bestMatch = null;
					outer: for (IRMethod method : methods) {
						if (method.getParameterCount() == arguments.length) {
							for (int i = 0; i < arguments.length; i++) {
								TypeCompatibility tc = testArgumentType(method
										.getParameters().get(i).getType(),
										arguments[i]);
								if (tc != TypeCompatibility.TRUE) {
									continue outer;
								}
							}
							// both match, which one is the more specific one
							if (bestMatch != null) {
								List<IRParameter> parameters = method
										.getParameters();
								for (int i = 0; i < parameters.size(); i++) {
									IRType type = parameters.get(i).getType();
									if (type != null) {
										IRType bestMatchType = bestMatch
												.getParameters().get(i)
												.getType();
										if (bestMatchType == null) {
											break;
										}
										if (type.isAssignableFrom(bestMatchType) == TypeCompatibility.TRUE) {
											continue outer;
										}
									}
								}

							}
							bestMatch = method;
						}
					}
					if (bestMatch != null)
						return ConstantValue.of(bestMatch.getType());
				}
				final IRType expressionType = JavaScriptValidations
						.typeOf(reference);
				if (expressionType != null) {
					if (expressionType instanceof IRFunctionType) {
						return ConstantValue
								.of(((IRFunctionType) expressionType)
										.getReturnType());
					} else if (expressionType instanceof IRClassType) {
						final IRTypeDeclaration target = ((IRClassType) expressionType)
								.getDeclaration();
						if (target != null) {
							final IRConstructor constructor = target
									.getStaticConstructor();
							if (constructor != null
									&& constructor.getType() != null) {
								return new ConstantValue(constructor.getType());
							}
						}
					}
				}
			}
			return reference.getChild(IValueReference.FUNCTION_OP);
		}

		private void pushExpressionValidator(
				ExpressionValidator expressionValidator) {
			expressionValidator.setSuppressed(reporter.getSuppressWarnings());
			expressionValidators.add(expressionValidator);
		}

		/**
		 * @param node
		 * @param reference
		 * @param methods
		 * @return
		 */
		protected void validateCallExpression(FunctionScope scope,
				CallExpression node, final IValueReference reference,
				IValueReference[] arguments, List<IRMethod> methods) {

			final Expression expression = node.getExpression();
			final Path path = path(expression, reference);
			if (scope.contains(path)) {
				return;
			}
			final Expression methodNode;
			if (expression instanceof PropertyExpression) {
				methodNode = ((PropertyExpression) expression).getProperty();
			} else {
				methodNode = expression;
			}

			if (methods == null || methods.size() == 0)
				methods = ValueReferenceUtil.extractElements(reference,
						IRMethod.class);
			if (methods != null) {
				IRMethod method = JavaScriptValidations.selectMethod(methods,
						arguments, true);
				if (method == null) {
					final IRType type = JavaScriptValidations.typeOf(reference
							.getParent());
					if (type != null) {
						if (TypeUtil.kind(type) == TypeKind.JAVA) {
							reporter.reportProblem(
									JavaScriptProblems.WRONG_JAVA_PARAMETERS,
									NLS.bind(
											ValidationMessages.MethodNotSelected,
											new String[] {
													reference.getName(),
													type.getName(),
													describeArguments(arguments) }),
									methodNode.sourceStart(), methodNode
											.sourceEnd());

						} else {
							// TODO also a JS error (that should be
							// configurable)
						}
					}
				} else {
					validateCallExpressionMethod(node, reference, arguments,
							methodNode, method);
				}
				return;
			}
			final Object attrRMethod = reference.getAttribute(R_METHOD, true);
			if (attrRMethod instanceof IRMethod) {
				validateCallExpressionRMethod(reference, arguments, methodNode,
						(IRMethod) attrRMethod);
				return;
			}
			final IRType expressionType = JavaScriptValidations
					.typeOf(reference);
			if (expressionType != null) {
				if (expressionType instanceof IRFunctionType) {
					validateCallExpressionRMethod(reference, arguments,
							methodNode, new RMethodFunctionWrapper(
									(IRFunctionType) expressionType, reference));
					return;
				} else if (expressionType instanceof IRClassType) {
					final IRTypeDeclaration target = ((IRClassType) expressionType)
							.getDeclaration();
					if (target != null) {
						final IRConstructor constructor = target
								.getStaticConstructor();
						if (constructor != null) {
							validateCallExpressionMethod(node, reference,
									arguments, methodNode, constructor);
							return;
						}
					}
				} else if (expressionType != RTypes.any()
						&& expressionType != RTypes.none()
						&& !RTypes.FUNCTION.isAssignableFrom(expressionType)
								.ok()) {
					if (expressionType instanceof IRUnionType) {
						if (expressionType.isAssignableFrom(RTypes.FUNCTION)
								.ok())
							return;
					}
					reporter.reportProblem(
							JavaScriptProblems.WRONG_FUNCTION,
							isIdentifier(expression) ? NLS.bind(
									ValidationMessages.WrongFunction,
									reference.getName())
									: ValidationMessages.WrongFunctionExpression,
							methodNode.sourceStart(), methodNode.sourceEnd());
					return;
				}
				// we've got expressionType, reference exists, so return.
				return;
			}
			scope.add(path);
			if (!isDynamicArrayAccess(reference)
					&& !isUntypedParameter(reference)) {

				final IRType type = JavaScriptValidations.typeOf(reference
						.getParent());
				if (type != null) {
					if (type == RTypes.any()) {
						return;
					}
					if (TypeUtil.kind(type) == TypeKind.JAVA) {
						reporter.reportProblem(
								JavaScriptProblems.UNDEFINED_JAVA_METHOD,
								NLS.bind(ValidationMessages.UndefinedMethod,
										reference.getName(), type.getName()),
								methodNode.sourceStart(), methodNode
										.sourceEnd());
					} else if (!reference.exists()) {
						reporter.reportProblem(
								JavaScriptProblems.UNDEFINED_METHOD,
								NLS.bind(
										ValidationMessages.UndefinedMethodOnObject,
										reference.getName(), reference
												.getParent().getName()),
								methodNode.sourceStart(), methodNode
										.sourceEnd());
					}
				} else {
					if (expression instanceof NewExpression) {
						if (reference.getKind() == ReferenceKind.TYPE) {
							return;
						}
						IRType newType = JavaScriptValidations
								.typeOf(reference);
						if (newType != null) {
							return;
						}
					}
					if (expression instanceof NewExpression) {
						reporter.reportProblem(
								JavaScriptProblems.WRONG_TYPE_EXPRESSION,
								NLS.bind(
										ValidationMessages.UndefinedJavascriptType,
										((NewExpression) expression)
												.getObjectClass()
												.toSourceString("")),
								methodNode.sourceStart(), methodNode
										.sourceEnd());

					} else {
						if (reference.getParent() == null) {
							if (isIdentifier(expression) && !reference.exists()) {
								reporter.reportProblem(
										JavaScriptProblems.UNDEFINED_FUNCTION,
										NLS.bind(
												ValidationMessages.UndefinedMethodInScript,
												reference.getName()),
										methodNode.sourceStart(), methodNode
												.sourceEnd());
							} else {
								reporter.reportProblem(
										JavaScriptProblems.WRONG_FUNCTION,
										isIdentifier(expression) ? NLS
												.bind(ValidationMessages.WrongFunction,
														reference.getName())
												: ValidationMessages.WrongFunctionExpression,
										methodNode.sourceStart(), methodNode
												.sourceEnd());
							}
						} else {
							reporter.reportProblem(
									JavaScriptProblems.UNDEFINED_METHOD,
									NLS.bind(
											ValidationMessages.UndefinedMethodOnObject,
											reference.getName(), reference
													.getParent().getName()),
									methodNode.sourceStart(), methodNode
											.sourceEnd());
						}
					}
				}
			}
		}

		private void validateCallExpressionRMethod(
				final IValueReference reference, IValueReference[] arguments,
				final Expression methodNode, IRMethod method) {
			if (method.isDeprecated()) {
				String name = reference.getName();
				if (name == null || "".equals(name)) {
					name = method.getName();
				}
				reporter.reportProblem(JavaScriptProblems.DEPRECATED_FUNCTION,
						NLS.bind(ValidationMessages.DeprecatedFunction,
								name), methodNode.sourceStart(),
						methodNode.sourceEnd());
			}
			validateAccessibility(methodNode, reference, method);
			final List<IRParameter> parameters = method.getParameters();
			final TypeCompatibility compatibility = validateParameters(
					parameters, arguments, methodNode);
			if (compatibility != TypeCompatibility.TRUE) {
				String name = method.getName();
				if (name == null) {
					Identifier identifier = PropertyExpressionUtils
							.getIdentifier(methodNode);
					if (identifier != null)
						name = identifier.getName();
				}
				final IProblemIdentifier problemId;
				if (method.isTyped()) {
					if (compatibility == TypeCompatibility.FALSE) {
						problemId = JavaScriptProblems.WRONG_PARAMETERS;
					} else {
						problemId = JavaScriptProblems.WRONG_PARAMETERS_PARAMETERIZATION;
					}
				} else {
					problemId = JavaScriptProblems.WRONG_PARAMETERS_UNTYPED;
				}
				reporter.reportProblem(problemId, NLS.bind(
						ValidationMessages.MethodNotApplicableInScript,
						new String[] { name, describeParamTypes(parameters),
								describeArguments(arguments, parameters) }),
						methodNode.sourceStart(), methodNode.sourceEnd());
			}
		}

		private void validateCallExpressionMethod(CallExpression node,
				final IValueReference reference, IValueReference[] arguments,
				final Expression methodNode, IRMethod method) {
			if (method.getVisibility() != Visibility.PUBLIC) {
				if (!validateAccessibility(methodNode, method)) {
					return;
				}
			}
			if (method.isDeprecated()) {
				reportDeprecatedMethod(methodNode, reference, method);
			}
			if (!JavaScriptValidations.checkParameterCount(method, node
					.getArguments().size())) {
				reportMethodParameterError(methodNode, arguments, method);
				return;
			}
			final List<IRParameter> parameters = method.getParameters();
			final TypeCompatibility compatibility = validateParameters(
					parameters, arguments, methodNode);
			if (compatibility != TypeCompatibility.TRUE) {
				String name = method.getName();
				if (name == null) {
					Identifier identifier = PropertyExpressionUtils
							.getIdentifier(methodNode);
					if (identifier != null)
						name = identifier.getName();
				}
				reporter.reportProblem(
						compatibility == TypeCompatibility.FALSE ? JavaScriptProblems.WRONG_PARAMETERS
								: JavaScriptProblems.WRONG_PARAMETERS_PARAMETERIZATION,
						NLS.bind(
								ValidationMessages.MethodNotApplicableInScript,
								new String[] {
										name,
										describeParamTypes(parameters),
										describeArguments(arguments, parameters) }),
						methodNode.sourceStart(), methodNode.sourceEnd());
			}
		}

		/**
		 * Checks if the passed reference is an untyped parameter. This method
		 * helps to identify the common case of callbacks.
		 * 
		 * @param reference
		 * @return
		 */
		private boolean isUntypedParameter(IValueReference reference) {
			return reference.getKind() == ReferenceKind.ARGUMENT
					&& reference.getDeclaredType() == null;
		}

		public static boolean isUntyped(IValueReference reference) {
			while (reference != null) {
				final ReferenceKind kind = reference.getKind();
				if (kind == ReferenceKind.ARGUMENT) {
					final IRType type = reference.getDeclaredType();
					if (type == null || type == RTypes.any()) {
						return true;
					}
				} else if (kind == ReferenceKind.THIS
						&& reference.getDeclaredType() == null
						&& reference.getDirectChildren().isEmpty()) {
					return true;
				}
				reference = reference.getParent();
			}
			return false;
		}

		/**
		 * Tests if reference has array access somewhere above which is not
		 * applied to {@link IRArrayType} or {@link IRMapType} types.
		 */
		private boolean isDynamicArrayAccess(IValueReference reference) {
			for (; reference != null; reference = reference.getParent()) {
				if (reference.getName() == IValueReference.ARRAY_OP) {
					final IRType containerType = JavaScriptValidations
							.typeOf(reference.getParent());
					if (containerType instanceof IRArrayType
							|| containerType instanceof IRMapType) {
						break;
					}
					// ignore array lookup function calls
					// like: array[1](),
					// those are dynamic.
					return true;
				}
			}
			return false;
		}

		private void reportDeprecatedMethod(ASTNode methodNode,
				IValueReference reference, IRMethod method) {
			if (method.getDeclaringType() != null) {
				reporter.reportProblem(
						JavaScriptProblems.DEPRECATED_METHOD,
						NLS.bind(ValidationMessages.DeprecatedMethod, reference
								.getName(), method.getDeclaringType().getName()),
						methodNode.sourceStart(), methodNode.sourceEnd());
			} else {
				reporter.reportProblem(JavaScriptProblems.DEPRECATED_METHOD,
						NLS.bind(ValidationMessages.DeprecatedTopLevelMethod,
								reference.getName()), methodNode.sourceStart(),
						methodNode.sourceEnd());
			}
		}

		private void reportDeprecatedRecordMember(ASTNode node,
				IValueReference reference, IRRecordMember method) {
			IRType type = JavaScriptValidations.typeOf(reference.getParent());
			final String msg = NLS.bind(ValidationMessages.DeprecatedProperty,
					method.getName(), type != null ? type.getName() : null);
			reporter.reportProblem(JavaScriptProblems.DEPRECATED_PROPERTY, msg,
					node.sourceStart(), node.sourceEnd());
		}

		private void reportMethodParameterError(ASTNode methodNode,
				IValueReference[] arguments, IRMethod method) {
			if (method.getDeclaringType() != null) {
				IProblemIdentifier problemId = JavaScriptProblems.WRONG_PARAMETERS;
				if (method.getDeclaringType().getKind() == TypeKind.JAVA) {
					problemId = JavaScriptProblems.WRONG_JAVA_PARAMETERS;
				}
				reporter.reportProblem(problemId, NLS.bind(
						ValidationMessages.MethodNotApplicable,
						new String[] { method.getName(),
								describeParamTypes(method.getParameters()),
								method.getDeclaringType().getName(),
								describeArguments(arguments) }), methodNode
						.sourceStart(), methodNode.sourceEnd());
			} else {
				reporter.reportProblem(JavaScriptProblems.WRONG_PARAMETERS, NLS
						.bind(ValidationMessages.TopLevelMethodNotApplicable,
								new String[] {
										method.getName(),
										describeParamTypes(method
												.getParameters()),
										describeArguments(arguments) }),
						methodNode.sourceStart(), methodNode.sourceEnd());
			}
		}

		private final List<ValidationStatus> statuses = new ArrayList<ValidationStatus>();

		private TypeCompatibility validateParameters(
				List<IRParameter> parameters, IValueReference[] arguments,
				ISourceNode problemNode) {
			if (arguments.length > parameters.size()
					&& !(parameters.size() > 0 && parameters.get(
							parameters.size() - 1).getKind() == ParameterKind.VARARGS))
				return TypeCompatibility.FALSE;
			int testTypesSize = parameters.size();
			if (parameters.size() > arguments.length) {
				for (int i = arguments.length; i < parameters.size(); i++) {
					final IRParameter p = parameters.get(i);
					if (!p.isOptional() && !p.isVarargs())
						return TypeCompatibility.FALSE;
				}
				testTypesSize = arguments.length;
			} else if (parameters.size() < arguments.length) {
				// is var args..
				testTypesSize = parameters.size() - 1;
			}

			statuses.clear();
			TypeCompatibility result = TypeCompatibility.TRUE;
			for (int i = 0; i < testTypesSize; i++) {
				final IValueReference argument = arguments[i];
				final IRParameter parameter = parameters.get(i);
				if (parameter.getType() instanceof IRTypeExtension) {
					final IValidationStatus status = ((IRTypeExtension) parameter
							.getType()).isAssignableFrom(argument);
					if (status instanceof TypeCompatibility) {
						final TypeCompatibility pResult = (TypeCompatibility) status;
						if (pResult.after(result)) {
							if (pResult == TypeCompatibility.FALSE
									&& statuses.isEmpty()) {
								return pResult;
							}
							result = pResult;
						}
					} else if (status instanceof ValidationStatus) {
						statuses.add((ValidationStatus) status);
					} else if (status instanceof ValidationMultiStatus) {
						Collections.addAll(statuses,
								((ValidationMultiStatus) status).getChildren());
					}
				} else {
					final TypeCompatibility pResult = testArgumentType(
							parameter.getType(), argument);
					if (pResult.after(result)) {
						if (pResult == TypeCompatibility.FALSE
								&& statuses.isEmpty()) {
							return pResult;
						}
						result = pResult;
					}
				}
			}
			// test var args
			if (parameters.size() < arguments.length) {
				int varargsParameter = parameters.size() - 1;
				IRType paramType = parameters.get(varargsParameter).getType();

				for (int i = varargsParameter; i < arguments.length; i++) {
					IValueReference argument = arguments[i];
					final TypeCompatibility pResult = testArgumentType(
							paramType, argument);
					if (pResult.after(result)) {
						if (pResult == TypeCompatibility.FALSE
								&& statuses.isEmpty()) {
							return pResult;
						}
						result = pResult;
					}
				}

			}
			if (!statuses.isEmpty()) {
				for (ValidationStatus status : statuses) {
					final int start;
					final int end;
					if (status.hasRange()) {
						start = status.start();
						end = status.end();
					} else {
						start = problemNode.start();
						end = problemNode.end();
					}
					reporter.reportProblem(status.identifier(),
							status.message(), start, end);
				}
				return TypeCompatibility.TRUE;
			}
			return result;
		}

		/**
		 * @param paramType
		 * @param argument
		 * @return
		 */
		private TypeCompatibility testArgumentType(IRType paramType,
				IValueReference argument) {
			if (argument != null && paramType != null) {
				final IRType argumentType;
				if (argument.getAttribute(IReferenceAttributes.R_METHOD) != null) {
					IRMethod method = (IRMethod) argument
							.getAttribute(IReferenceAttributes.R_METHOD);
					argumentType = RTypes.functionType(getContext(),
							method.getParameters(), method.getType());
				} else {
					argumentType = JavaScriptValidations
						.typeOf(argument);
				}
				if (argumentType != null) {
					return paramType.isAssignableFrom(argumentType);
				}
			}
			return TypeCompatibility.TRUE;
		}

		private String describeParamTypes(List<IRParameter> parameters) {
			StringBuilder sb = new StringBuilder();
			for (IRParameter parameter : parameters) {
				if (sb.length() != 0) {
					sb.append(',');
				}
				if (parameter.getType() instanceof IRRecordType) {
					sb.append('{');
					for (IRRecordMember member : ((IRRecordType) parameter
							.getType()).getMembers()) {
						if (sb.length() > 1)
							sb.append(", ");
						final boolean optional = member.isOptional();
						if (optional)
							sb.append('[');
						sb.append(member.getName());
						if (member.getType() != null) {
							sb.append(':');
							sb.append(member.getType().getName());
						}
						if (optional)
							sb.append(']');
					}
					sb.append('}');
				} else if (parameter.getType() != null) {
					if (parameter.getKind() == ParameterKind.OPTIONAL)
						sb.append("[");
					if (parameter.getKind() == ParameterKind.VARARGS)
						sb.append("...");
					sb.append(parameter.getType().getName());
					if (parameter.getKind() == ParameterKind.OPTIONAL)
						sb.append("]");
				} else {
					sb.append('?');
				}
			}
			return sb.toString();
		}

		/**
		 * Describes the specified arguments.
		 */
		private String describeArguments(IValueReference[] arguments) {
			return describeArguments(arguments,
					Collections.<IRParameter> emptyList());
		}

		/**
		 * Describes the specified arguments, expanding properties for those
		 * where record type parameter is expected.
		 */
		private String describeArguments(IValueReference[] arguments,
				List<IRParameter> parameters) {
			final StringBuilder sb = new StringBuilder();
			for (int i = 0; i < arguments.length; i++) {
				final IValueReference argument = arguments[i];
				final IRParameter parameter = i < parameters.size() ? parameters
						.get(i) : null;
				if (sb.length() != 0) {
					sb.append(',');
				}
				if (argument == null) {
					sb.append("null");
				} else if (parameter != null
						&& parameter.getType() instanceof IRRecordType) {
					describeRecordTypeArgument(sb, argument,
							(IRRecordType) parameter.getType());
				} else if (argument.getAttribute(IReferenceAttributes.R_METHOD) != null) {
					IRMethod method = (IRMethod) argument
							.getAttribute(IReferenceAttributes.R_METHOD);
					sb.append(RTypes.functionType(getContext(),
							method.getParameters(), method.getType()).getName());
				} else if (argument.getDeclaredType() != null) {
					sb.append(argument.getDeclaredType().getName());
				} else {
					final JSTypeSet types = argument.getTypes();
					if (types.size() > 0) {
						sb.append(types.toRType().getName());
					} else {
						sb.append('?');
					}
				}
			}
			return sb.toString();
		}

		/**
		 * Describes the specified argument which is expected to be of the
		 * record type.
		 */
		private void describeRecordTypeArgument(StringBuilder sb,
				IValueReference argument, @Nullable IRRecordType expectedType) {
			sb.append('{');
			boolean appendComma = false;
			HashSet<String> children = new HashSet<String>(
					argument.getDirectChildren());
			JSTypeSet types = argument.getTypes();
			for (IRType type : types) {
				if (type instanceof IRRecordType) {
					Collection<IRRecordMember> members = ((IRRecordType) type)
							.getMembers();
					for (IRRecordMember member : members) {
						children.add(member.getName());
					}
				}
			}
			for (String childName : children) {
				if (appendComma)
					sb.append(", ");
				appendComma = true;
				sb.append(childName);

				final IRType expectedMemberType;
				if (expectedType != null) {
					final IRRecordMember member = expectedType
							.getMember(childName);
					expectedMemberType = member != null ? member.getType()
							: null;
				} else {
					expectedMemberType = null;
				}
				if (expectedMemberType instanceof IRRecordType) {
					sb.append(": ");
					describeRecordTypeArgument(sb,
							argument.getChild(childName),
							(IRRecordType) expectedMemberType);
				} else {
					final IValueReference child = argument.getChild(childName);
					final IRType type = JavaScriptValidations.typeOf(child);
					if (type != null) {
						if (expectedType != null
								&& type.getName().equals(ITypeNames.OBJECT)
								&& !child.getDirectChildren().isEmpty()) {
							sb.append(": ");
							describeRecordTypeArgument(sb, child, null);
						} else {
							sb.append(':');
							sb.append(type.getName());
						}
					}
				}
			}
			sb.append('}');
		}

		@Override
		public IValueReference visitPropertyExpression(PropertyExpression node) {
			final IValueReference result = super.visitPropertyExpression(node);
			if (result == null || result.getAttribute(PHANTOM, true) != null
					|| isUntyped(result)) {
				return result;
			}
			if (currentMode() != VisitorMode.CALL) {
				pushExpressionValidator(new PropertyExpressionHolder(
						peekFunctionScope(), node, result, result.exists()));
			}
			return result;
		}

		@Override
		protected IValueReference visitAssign(IValueReference left,
				IValueReference right, BinaryOperation node) {
			if (left != null) {
				checkAssign(left, node);
			}
			return super.visitAssign(left, right, node);
		}

		private static boolean isVarOrFunction(IValueReference reference) {
			final ReferenceKind kind = reference.getKind();
			return kind.isVariable() || kind == ReferenceKind.FUNCTION;
		}

		private static boolean isAccess(Identifier node) {
			return isAccess(node, node.getParent());
		}

		private static boolean isAccess(Identifier node, final ASTNode parent) {
			if (parent instanceof BinaryOperation) {
				return !((BinaryOperation) parent).isAssignmentTo(node);
			} else if (parent instanceof StatementBlock
					|| parent instanceof Script) {
				return false;
			} else if (parent instanceof UnaryOperation) {
				final UnaryOperation operation = (UnaryOperation) parent;
				final int op = operation.getOperation();
				return op != JSParser.INC && op != JSParser.DEC
						&& op != JSParser.PINC && op != JSParser.PDEC
						|| isAccess(node, operation.getParent());
			} else {
				return true;
			}
		}

		@Override
		public IValueReference visitIdentifier(Identifier node) {
			final IValueReference result = super.visitIdentifier(node);
			if (isAccess(node) && isVarOrFunction(result)
					&& getSource().equals(result.getLocation().getSource())) {
				if (result.getAttribute(IReferenceAttributes.ACCESS) == null) {
					result.setAttribute(IReferenceAttributes.ACCESS,
							Boolean.TRUE);
				}
			}
			final IRProperty property = ValueReferenceUtil.extractElement(
					result, IRProperty.class);
			if (property != null && property.isDeprecated()) {
				reportDeprecatedProperty(property, null, node);
			} else {
				if (!result.exists() && !isParentCallOrNew(node)) {
					peekFunctionScope().add(path(node, result));
					reporter.reportProblem(
							JavaScriptProblems.UNDECLARED_VARIABLE, NLS.bind(
									ValidationMessages.UndeclaredVariable,
									node.getName()), node.sourceStart(), node
									.sourceEnd());
				} else {
					validateAccessibility(node, result, null);
					if (result.exists()
							&& node.getParent() instanceof BinaryOperation
							&& ((BinaryOperation) node.getParent())
									.getOperation() == JSParser.INSTANCEOF
							&& ((BinaryOperation) node.getParent())
									.getRightExpression() == node) {
						checkTypeReference(node,
								JavaScriptValidations.typeOf(result),
								peekContext());
					}
				}
			}
			return result;
		}

		private boolean isParentCallOrNew(Identifier node) {
			final JSNode parent = node.getParent();
			if (parent instanceof CallExpression) {
				return ((CallExpression) parent).getExpression() == node;
			} else if (parent instanceof NewExpression) {
				return ((NewExpression) parent).getObjectClass() == node;
			} else {
				return false;
			}
		}

		private static IValueCollection getParentScope(
				final IValueCollection collection) {
			IValueCollection c = collection;
			while (c != null && !c.isScope()) {
				c = c.getParent();
			}
			if (c != null) {
				c = c.getParent();
				if (c != null) {
					return c;
				}
			}
			return null;
		}

		private final List<IValueReference> variables = new ArrayList<IValueReference>();

		@Override
		protected IValueReference createVariable(IValueCollection context,
				VariableDeclaration declaration) {
			validateHidesByVariable(context, declaration);
			final IValueReference variable = super.createVariable(context,
					declaration);
			if (context.getParent() != null
					|| canValidateUnusedVariable(context, variable)) {
				variables.add(variable);
			}
			return variable;
		}

		private boolean canValidateUnusedVariable(IValueCollection collection,
				IValueReference reference) {
			if (extensions != null) {
				for (IValidatorExtension extension : extensions) {
					final IValidatorExtension.UnusedVariableValidation result = extension
							.canValidateUnusedVariable(collection, reference);
					if (result != null) {
						return result == IValidatorExtension.UnusedVariableValidation.TRUE;
					}
				}
			}
			return isPrivate(reference);
		}

		private static boolean isPrivate(IValueReference reference) {
			final IVariable variable = (IVariable) reference
					.getAttribute(IReferenceAttributes.VARIABLE);
			return variable != null
					&& variable.getVisibility() == Visibility.PRIVATE;
		}

		private void checkAssign(IValueReference reference, ASTNode node) {
			final Object value = reference
					.getAttribute(IAssignProtection.ATTRIBUTE);
			if (value != null) {
				final IAssignProtection assign;
				if (value instanceof IAssignProtection2) {
					if (((IAssignProtection2) value).isReadOnly(reference)) {
						assign = (IAssignProtection) value;
					} else {
						return;
					}
				} else {
					assign = value instanceof IAssignProtection ? (IAssignProtection) value
							: PROTECT_CONST;
				}
				reporter.reportProblem(assign.problemId(),
						assign.problemMessage(), node.sourceStart(),
						node.sourceEnd());
			} else if (reference.getKind() == ReferenceKind.FUNCTION) {
				// test if it is not a function override of a super local type class.
				Set<String> directChildren = null;
				if (reference.getParent() != null)
					if (reference.getParent().getName()
							.equals(IRLocalType.PROTOTYPE_PROPERTY)) {
						directChildren = Collections.emptySet(); // just ignore
																	// it if it
																	// is an
																	// assignment
																	// to
																	// prototype
					} else {
						directChildren = reference.getParent()
								.getDirectChildren(
							IValue.NO_LOCAL_TYPES);
					}
				if (directChildren == null
						|| directChildren.contains(reference.getName())) {
				reporter.reportProblem(JavaScriptProblems.UNASSIGNABLE_ELEMENT,
						ValidationMessages.UnassignableFunction,
						node.sourceStart(), node.sourceEnd());
				}
			}
		}

		@Override
		protected void initializeVariable(IValueReference reference,
				VariableDeclaration declaration) {
			if (declaration.getInitializer() != null
					&& declaration.getParent() instanceof VariableStatement) {
				checkAssign(reference, declaration);
			}
			super.initializeVariable(reference, declaration);
		}

		private void validateHidesByVariable(IValueCollection context,
				VariableDeclaration declaration) {
			final IValueReference child;
			final Identifier identifier = declaration.getIdentifier();
			final IValueCollection parentScope = getParentScope(context);
			if (parentScope == null) {
				child = context.getChild(identifier.getName());
				if (getSource().equals(child.getLocation().getSource())) {
					return;
				}
			} else {
				child = parentScope.getChild(identifier.getName());
			}
			if (child.exists()) {
				final ReferenceKind kind = child.getKind();
				if (kind == ReferenceKind.ARGUMENT) {
					reporter.reportProblem(
							JavaScriptProblems.VAR_HIDES_PARAMETER, NLS.bind(
									ValidationMessages.VariableHidesParameter,
									declaration.getVariableName()), identifier
									.sourceStart(), identifier.sourceEnd());
				} else if (kind == ReferenceKind.FUNCTION) {
					reporter.reportProblem(
							JavaScriptProblems.VAR_HIDES_FUNCTION, NLS.bind(
									ValidationMessages.VariableHidesFunction,
									declaration.getVariableName()), identifier
									.sourceStart(), identifier.sourceEnd());
				} else if (kind == ReferenceKind.PROPERTY) {
					final Property property = ValueReferenceUtil
							.extractElement(child, Property.class);
					if (property != null && property.getDeclaringType() != null) {
						reporter.reportProblem(
								JavaScriptProblems.VAR_HIDES_PROPERTY,
								NLS.bind(
										ValidationMessages.VariableHidesPropertyOfType,
										declaration.getVariableName(), property
												.getDeclaringType().getName()),
								identifier.sourceStart(), identifier
										.sourceEnd());
					} else {
						reporter.reportProblem(
								JavaScriptProblems.VAR_HIDES_PROPERTY,
								NLS.bind(
										ValidationMessages.VariableHidesProperty,
										declaration.getVariableName()),
								identifier.sourceStart(), identifier
										.sourceEnd());

					}
				} else if (kind == ReferenceKind.METHOD) {
					final IRMethod method = ValueReferenceUtil.extractElement(
							child, IRMethod.class);
					if (method != null && method.getDeclaringType() != null) {
						reporter.reportProblem(
								JavaScriptProblems.VAR_HIDES_METHOD,
								NLS.bind(
										ValidationMessages.VariableHidesMethodOfType,
										declaration.getVariableName(), method
												.getDeclaringType().getName()),
								identifier.sourceStart(), identifier
										.sourceEnd());
					} else {
						reporter.reportProblem(
								JavaScriptProblems.VAR_HIDES_METHOD, NLS.bind(
										ValidationMessages.VariableHidesMethod,
										declaration.getVariableName()),
								identifier.sourceStart(), identifier
										.sourceEnd());
					}
				} else if (kind == ReferenceKind.LOCAL
						|| kind == ReferenceKind.GLOBAL) {
					reporter.reportProblem(
							JavaScriptProblems.DUPLICATE_VAR_DECLARATION,
							NLS.bind(ValidationMessages.VariableHidesVariable,
									declaration.getVariableName()), identifier
									.sourceStart(), identifier.sourceEnd());
				} else {
					reporter.reportProblem(
							JavaScriptProblems.VAR_HIDES_PREDEFINED,
							NLS.bind(
									ValidationMessages.VariableHidesPredefinedIdentifier,
									declaration.getVariableName()), identifier
									.sourceStart(), identifier.sourceEnd());
				}
			}
		}

		protected void validateProperty(final FunctionScope scope,
				PropertyExpression propertyExpression, IValueReference result,
				boolean exists) {
			final Path path = path(propertyExpression, result);
			if (scope.contains(path)) {
				return;
			}
			final Expression propName = propertyExpression.getProperty();
			final IRMember member = ValueReferenceUtil.extractElement(result,
					IRMember.class);
			if (member != null) {
				if (member.isDeprecated()) {
					final IRProperty parentProperty = ValueReferenceUtil
							.extractElement(result.getParent(),
									IRProperty.class);
					if (parentProperty != null
							&& parentProperty.getDeclaringType() == null) {
						if (member instanceof IRProperty)
							reportDeprecatedProperty((IRProperty) member,
									parentProperty, propName);
						else if (member instanceof IRMethod)
							reportDeprecatedMethod(propName, result,
									(IRMethod) member);
					} else {
						if (member instanceof IRProperty)
							reportDeprecatedProperty((IRProperty) member,
									member.getDeclaringType(), propName);
						else if (member instanceof IRMethod)
							reportDeprecatedMethod(propName, result,
									(IRMethod) member);
						else if (member instanceof IRRecordMember)
							reportDeprecatedRecordMember(propName, result,
									(IRRecordMember) member);
					}
				} else if (!member.isVisible()) {
					final IRProperty parentProperty = ValueReferenceUtil
							.extractElement(result.getParent(),
									IRProperty.class);
					if (parentProperty != null
							&& parentProperty.getDeclaringType() == null) {
						if (member instanceof IRProperty)
							reportHiddenProperty((IRProperty) member,
									parentProperty, propName);
						// else if (member instanceof Method)
						// reportDeprecatedMethod(propName, result,
						// (Method) member);
					} else if (member instanceof IRProperty) {
						reportHiddenProperty((IRProperty) member,
								member.getDeclaringType(), propName);
					}
					// } else if
					// (JavaScriptValidations.isStatic(result.getParent())
					// && !member.isStatic()) {
					// IRType type = JavaScriptValidations.typeOf(result
					// .getParent());
					// reporter.reportProblem(
					// JavaScriptProblems.INSTANCE_PROPERTY,
					// NLS.bind(
					// ValidationMessages.StaticReferenceToNoneStaticProperty,
					// result.getName(), TypeUtil.getName(type)),
					// propName.sourceStart(), propName.sourceEnd());
					// } else if
					// (!JavaScriptValidations.isStatic(result.getParent())
					// && member.isStatic()) {
					// IRType type = JavaScriptValidations.typeOf(result
					// .getParent());
					// reporter.reportProblem(
					// JavaScriptProblems.STATIC_PROPERTY,
					// NLS.bind(
					// ValidationMessages.ReferenceToStaticProperty,
					// result.getName(), type.getName()), propName
					// .sourceStart(), propName.sourceEnd());
				} else if (member.getVisibility() != Visibility.PUBLIC) {
					validateAccessibility(propName, result, member);
				}
			} else if ((!exists && !result.exists())
					&& !isDynamicArrayAccess(result)) {
				scope.add(path);
				final IRType parentType = typeOf(result.getParent());
				if (parentType != null && parentType.isExtensible()) {
					return;
				}
				final TypeKind parentKind = TypeUtil.kind(parentType);
				if (parentType != null && parentKind == TypeKind.JAVA) {
					reporter.reportProblem(
							JavaScriptProblems.UNDEFINED_JAVA_PROPERTY, NLS
									.bind(ValidationMessages.UndefinedProperty,
											result.getName(),
											parentType.getName()), propName
									.sourceStart(), propName.sourceEnd());
				} else if (!belongsToLogicalExpression(propertyExpression)) {
					if (parentType != null
							&& (parentKind == TypeKind.JAVASCRIPT || parentKind == TypeKind.PREDEFINED)) {
						reporter.reportProblem(
								JavaScriptProblems.UNDEFINED_PROPERTY,
								NLS.bind(
										ValidationMessages.UndefinedPropertyInScriptType,
										result.getName(), parentType.getName()),
								propName.sourceStart(), propName.sourceEnd());
					} else {
						final String parentPath = PropertyExpressionUtils
								.getPath(propertyExpression.getObject());
						reporter.reportProblem(
								JavaScriptProblems.UNDEFINED_PROPERTY,
								NLS.bind(
										ValidationMessages.UndefinedPropertyInScript,
										result.getName(),
										parentPath != null ? parentPath
												: "javascript"), propName
										.sourceStart(), propName.sourceEnd());
					}
				}
			} else {
				IRVariable variable = (IRVariable) result
						.getAttribute(IReferenceAttributes.R_VARIABLE);
				if (variable != null) {
					if (variable.isDeprecated()) {
						reporter.reportProblem(
								JavaScriptProblems.DEPRECATED_VARIABLE,
								NLS.bind(ValidationMessages.DeprecatedVariable,
										variable.getName()), propName
										.sourceStart(), propName.sourceEnd());
					}
					validateAccessibility(propName, result, variable);
					return;
				} else {
					IRMethod method = (IRMethod) result.getAttribute(R_METHOD);
					if (method != null) {
						if (method.isDeprecated()) {
							boolean report = true;
							JSNode parent = propertyExpression.getParent();
							if (parent instanceof BinaryOperation) {
								Expression rightExpression = ((BinaryOperation) parent)
										.getRightExpression();
								report = !(rightExpression instanceof FunctionStatement);
							}
							if (report)
								reporter.reportProblem(
									JavaScriptProblems.DEPRECATED_FUNCTION,
									NLS.bind(
											ValidationMessages.DeprecatedFunction,
											method.getName()), propName
											.sourceStart(), propName
											.sourceEnd());
						}
						validateAccessibility(propName, result, method);
						return;

					}
				}
			}
		}

		/**
		 * Tests if the specified expression is part of {@link BinaryOperation}
		 * combining parts with logical AND or OR.
		 */
		private boolean belongsToLogicalExpression(Expression expression) {
			if (expression.getParent() instanceof BinaryOperation) {
				final BinaryOperation bo = (BinaryOperation) expression
						.getParent();
				return bo.getOperation() == JSParser.LAND
						|| bo.getOperation() == JSParser.LOR;
			}
			return false;
		}

		private void reportDeprecatedProperty(IRProperty property,
				IRElement owner, ASTNode node) {
			final String msg;
			if (owner instanceof IRType) {
				msg = NLS.bind(ValidationMessages.DeprecatedProperty,
						property.getName(), owner.getName());
			} else if (owner instanceof IRProperty) {
				msg = NLS.bind(ValidationMessages.DeprecatedPropertyOfInstance,
						property.getName(), owner.getName());
			} else {
				msg = NLS.bind(ValidationMessages.DeprecatedPropertyNoType,
						property.getName());
			}
			reporter.reportProblem(JavaScriptProblems.DEPRECATED_PROPERTY, msg,
					node.sourceStart(), node.sourceEnd());
		}

		private void reportHiddenProperty(IRProperty property, IRElement owner,
				ASTNode node) {
			final String msg;
			if (owner instanceof IRType) {
				msg = NLS.bind(ValidationMessages.HiddenProperty,
						property.getName(), owner.getName());
			} else if (owner instanceof IRProperty) {
				msg = NLS.bind(ValidationMessages.HiddenPropertyOfInstance,
						property.getName(), owner.getName());
			} else {
				msg = NLS.bind(ValidationMessages.HiddenPropertyNoType,
						property.getName());
			}
			reporter.reportProblem(JavaScriptProblems.HIDDEN_PROPERTY, msg,
					node.sourceStart(), node.sourceEnd());
		}

		private static boolean isIdentifier(Expression node) {
			return node instanceof Identifier || node instanceof CallExpression
					&& isIdentifier(((CallExpression) node).getExpression());
		}

		private static Identifier getIdentifier(Expression node) {
			if (node instanceof Identifier) {
				return (Identifier) node;
			} else if (node instanceof CallExpression) {
				return getIdentifier(((CallExpression) node).getExpression());
			} else {
				return null;
			}
		}

		private IRTypeDeclaration extractClassType(IValueReference typeReference) {
			IRType type = typeReference.getDeclaredType();
			if (type == null) {
				final JSTypeSet types = typeReference.getTypes();
				if (types.size() > 0) {
					type = types.toRType();
				}
			}
			if (type != null && type instanceof IRClassType) {
				return ((IRClassType) type).getDeclaration();
			} else {
				return null;
			}
		}

		/**
		 * Lazy validation of the {@link NewExpression}.
		 */
		protected void validateNewExpression(FunctionScope scope,
				IValueCollection collection, Expression node,
				IValueReference reference, IValueReference typeReference,
				IValueReference[] arguments) {
			final Identifier identifier = getIdentifier(node);
			final Expression problemNode = identifier != null ? identifier
					: node;
			if (typeReference.getParent() == null && isIdentifier(node)
					&& !typeReference.exists()) {
				scope.add(path(node, typeReference));
				reportUnknownType(JavaScriptProblems.UNDECLARED_VARIABLE,
						problemNode, identifier != null ? identifier.getName()
								: "?");
				return;
			}
			final IRTypeDeclaration type = extractClassType(typeReference);
			if (type != null) {
				if (type.getKind() != TypeKind.UNKNOWN) {
					if (!validateInstantiability(problemNode, type.getSource(),
							typeReference)) {
						return;
					}
					checkTypeReference(problemNode, type);
					final List<IRConstructor> constructors = TypeUtil
							.findConstructors(type);
					if (!constructors.isEmpty()) {
						final IRConstructor constructor = JavaScriptValidations
								.selectMethod(constructors, arguments, false);
						if (constructor == null) {
							reporter.reportProblem(
									JavaScriptProblems.WRONG_PARAMETERS,
									NLS.bind(
											"The constructor {0}({1}) is undefined",
											new String[] {
													typeReference.getName(),
													describeArguments(arguments) }),
									problemNode.sourceStart(), problemNode
											.sourceEnd());
							return;
						}
						if (constructor.isDeprecated()) {
							reportDeprecatedMethod(problemNode, typeReference,
									constructor);
						}
						final List<IRParameter> parameters = context
								.contextualize(constructor, type)
								.getParameters();
						final TypeCompatibility compatibility = validateParameters(
								parameters, arguments, problemNode);
						if (compatibility != TypeCompatibility.TRUE) {
							reporter.reportProblem(
									compatibility == TypeCompatibility.FALSE ? JavaScriptProblems.WRONG_PARAMETERS
											: JavaScriptProblems.WRONG_PARAMETERS_PARAMETERIZATION,
									NLS.bind(
											"The constructor {0}({1}) is not applicable for the arguments ({2})",
											new String[] {
													typeReference.getName(),
													describeParamTypes(parameters),
													describeArguments(
															arguments,
															parameters) }),
									problemNode.sourceStart(), problemNode
											.sourceEnd());
						}
					}
				}
			} else {
				if (typeReference.getKind() == ReferenceKind.FUNCTION) {
					final Object attrRMethod = typeReference.getAttribute(
							R_METHOD, true);
					if (attrRMethod instanceof IRMethod) {
						validateCallExpressionRMethod(reference, arguments,
								problemNode, (IRMethod) attrRMethod);
						return;
					}
				} else {
					final String lazyName = ValueReferenceUtil
							.getLazyName(reference);
					if (lazyName != null) {
						reportProblem(
								JavaScriptProblems.WRONG_TYPE_EXPRESSION,
								bind(ValidationMessages.UndefinedJavascriptType,
										lazyName), node);
					}
				}
			}
		}

		/**
		 * @param node
		 * @param type
		 */
		protected void checkTypeReference(ASTNode node, IRType type,
				IValueCollection collection) {
			if (type == null) {
				return;
			}
			if (type instanceof IRClassType) {
				final IRTypeDeclaration t = ((IRClassType) type)
						.getDeclaration();
				if (t != null && t.getKind() != TypeKind.UNKNOWN) {
					checkTypeReference(node, t);
				}
			}
		}

		private void checkTypeReference(ASTNode node, final IRTypeDeclaration t) {
			if (t.isDeprecated()) {
				reporter.reportProblem(JavaScriptProblems.DEPRECATED_TYPE, NLS
						.bind(ValidationMessages.DeprecatedType, t.getName()),
						node.sourceStart(), node.sourceEnd());
			}
		}

		/**
		 * Validates instantiability of the specified type. Returns
		 * <code>true</code> if type could be instantiated and
		 * <code>false</code> otherwise.
		 * 
		 * @param node
		 * @param type
		 * @param typeReference
		 * @return
		 */
		private boolean validateInstantiability(ASTNode node, final Type type,
				IValueReference typeReference) {
			if (extensions != null) {
				for (IValidatorExtension extension : extensions) {
					final IValidationStatus result = extension.canInstantiate(
							type, typeReference);
					if (result != null) {
						if (result == ValidationStatus.OK) {
							return true;
						} else {
							JavaScriptValidations.reportValidationStatus(
									reporter, result, node,
									JavaScriptProblems.NON_INSTANTIABLE_TYPE,
									ValidationMessages.NonInstantiableType,
									type.getName());
							return false;
						}
					}
				}
			}
			if (!type.isInstantiable()) {
				reporter.reportProblem(
						JavaScriptProblems.NON_INSTANTIABLE_TYPE,
						NLS.bind(ValidationMessages.NonInstantiableType,
								type.getName()), node.sourceStart(),
						node.sourceEnd());
				return false;
			}
			return true;
		}

		/**
		 * Tests if the member is accessible. Returns <code>true</code> if
		 * access is allowed and <code>false</code> otherwise.
		 * 
		 * @param node
		 * @param member
		 * @return
		 */
		private boolean validateAccessibility(ASTNode node, IRMember member) {
			if (extensions != null && member.getSource() instanceof Member) {
				final Member source = (Member) member.getSource();
				for (IValidatorExtension extension : extensions) {
					final IValidationStatus result = extension
							.validateAccessibility(source);
					if (result != null) {
						if (result == ValidationStatus.OK) {
							return true;
						} else {
							JavaScriptValidations.reportValidationStatus(
									reporter, result, node,
									JavaScriptProblems.INACCESSIBLE_MEMBER,
									ValidationMessages.InaccessibleMember,
									member.getName());
							return false;
						}
					}
				}
			}
			return true;
		}

		private MemberValidationEvent memberValidationEvent;

		/**
		 * Tests if the specified member is accessible.
		 * 
		 * @param expression
		 *            AST node
		 * @param reference
		 *            evaluated value reference
		 * @param member
		 *            runtime variable/function reference if already evaluated
		 *            or <code>null</code> if not evaluated yet
		 */
		private void validateAccessibility(Expression expression,
				IValueReference reference, IRMember member) {
			if (extensions != null) {
				if (memberValidationEvent == null) {
					memberValidationEvent = new MemberValidationEvent();
				}
				memberValidationEvent.set(reference, member);
				for (IValidatorExtension extension : extensions) {
					final IValidationStatus result = extension
							.validateAccessibility(memberValidationEvent);
					if (result != null) {
						if (result == ValidationStatus.OK) {
							return;
						} else {
							IRMember rMember = memberValidationEvent
									.getRMember();
							JavaScriptValidations.reportValidationStatus(
									reporter, result, expression,
									JavaScriptProblems.INACCESSIBLE_MEMBER,
									ValidationMessages.InaccessibleMember,
									rMember == null ? reference.getName()
											: rMember.getName());
							return;
						}
					}
				}
			}
		}

		@Deprecated
		public void reportUnknownType(IProblemIdentifier identifier,
				String message, ASTNode node, String name) {
			reportProblem(identifier, NLS.bind(message, name), node);
		}

		public void reportUnknownType(IProblemIdentifier identifier,
				ASTNode node, String name) {
			reportProblem(identifier,
					bind(ValidationMessages.UnknownType, name), node);
		}

		public void reportProblem(IProblemIdentifier identifier,
				String message, ISourceNode node) {
			reporter.reportProblem(identifier, message, node.start(),
					node.end());
		}

		private static boolean stronglyTyped(IValueReference reference) {
			final IRType parentType = typeOf(reference);
			if (parentType != null) {
				if (parentType instanceof IRRecordType) {
					return true;
				}
				return TypeUtil.kind(parentType) == TypeKind.JAVA;
			}
			return false;
		}

		@Override
		public IValueReference visitIfStatement(IfStatement node) {
			final IValueReference condition = visit(node.getCondition());
			if (condition != null && !condition.exists()
					&& node.getCondition() instanceof PropertyExpression) {
				final IValueReference parent = condition.getParent();
				if (parent != null && parent.exists() && !stronglyTyped(parent)) {
					if (DEBUG) {
						System.out.println("visitIfStatement("
								+ node.getCondition() + ") doesn't exist "
								+ condition + " - create it");
					}
					condition.setValue(PhantomValueReference.REFERENCE);
				}
			}
			visitIfStatements(node);
			return null;
		}
	}

	static final boolean DEBUG = false;

}