Copyright (c) 2011, 2014 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Stephan Herrmann - Contribution for
							Bug 429958 - [1.8][null] evaluate new DefaultLocation attribute of @NonNullByDefault
/*******************************************************************************
 * Copyright (c) 2011, 2014 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Stephan Herrmann - Contribution for
 *								Bug 429958 - [1.8][null] evaluate new DefaultLocation attribute of @NonNullByDefault
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;

import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.lookup.Binding;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.eclipse.jdt.internal.compiler.lookup.ClassScope;
import org.eclipse.jdt.internal.compiler.lookup.Scope;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.TypeIds;

public class UnionTypeReference extends TypeReference {
	public TypeReference[] typeReferences;

	public UnionTypeReference(TypeReference[] typeReferences) {
		this.bits |= ASTNode.IsUnionType;
		this.typeReferences = typeReferences;
		this.sourceStart = typeReferences[0].sourceStart;
		int length = typeReferences.length;
		this.sourceEnd = typeReferences[length - 1].sourceEnd;
	}

	@Override
	public char[] getLastToken() {
		return null;
	}

	
See Also:
getTypeBinding.getTypeBinding(Scope)/**
	 * @see org.eclipse.jdt.internal.compiler.ast.ArrayQualifiedTypeReference#getTypeBinding(org.eclipse.jdt.internal.compiler.lookup.Scope)
	 */
	@Override
	protected TypeBinding getTypeBinding(Scope scope) {
		return null; // not supported here - combined with resolveType(...)
	}

	@Override
	public TypeBinding resolveType(BlockScope scope, boolean checkBounds, int location) {
		// return the lub (least upper bound of all type binding) 
		int length = this.typeReferences.length;
		TypeBinding[] allExceptionTypes = new TypeBinding[length];
		boolean hasError = false;
		for (int i = 0; i < length; i++) {
			TypeBinding exceptionType = this.typeReferences[i].resolveType(scope, checkBounds, location);
			if (exceptionType == null) {
				return null;
			}
			switch(exceptionType.kind()) {
				case Binding.PARAMETERIZED_TYPE :
					if (exceptionType.isBoundParameterizedType()) {
						hasError = true;
						scope.problemReporter().invalidParameterizedExceptionType(exceptionType, this.typeReferences[i]);
						// fall thru to create the variable - avoids additional errors because the variable is missing
					}
					break;
				case Binding.TYPE_PARAMETER :
					scope.problemReporter().invalidTypeVariableAsException(exceptionType, this.typeReferences[i]);
					hasError = true;
					// fall thru to create the variable - avoids additional errors because the variable is missing
					break;
			}
			if (exceptionType.findSuperTypeOriginatingFrom(TypeIds.T_JavaLangThrowable, true) == null
					&& exceptionType.isValidBinding()) {
				scope.problemReporter().cannotThrowType(this.typeReferences[i], exceptionType);
				hasError = true;
			}
			allExceptionTypes[i] = exceptionType;
			// https://bugs.eclipse.org/bugs/show_bug.cgi?id=340486, ensure types are of union type.
			for (int j = 0; j < i; j++) {
				if (allExceptionTypes[j].isCompatibleWith(exceptionType)) {
					scope.problemReporter().wrongSequenceOfExceptionTypes(
							this.typeReferences[j],
							allExceptionTypes[j],
							exceptionType);
					hasError = true;
				} else if (exceptionType.isCompatibleWith(allExceptionTypes[j])) {
					scope.problemReporter().wrongSequenceOfExceptionTypes(
							this.typeReferences[i],
							exceptionType,
							allExceptionTypes[j]);
					hasError = true;
				}
			}
		}
		if (hasError) {
			return null;
		}
		// compute lub
		return (this.resolvedType = scope.lowerUpperBound(allExceptionTypes));
	}

	@Override
	public char[][] getTypeName() {
		// we need to keep a return value that is a char[][]
		return this.typeReferences[0].getTypeName();
	}

	@Override
	public void traverse(ASTVisitor visitor, BlockScope scope) {
		if (visitor.visit(this, scope)) {
			int length = this.typeReferences == null ? 0 : this.typeReferences.length;
			for (int i = 0; i < length; i++) {
				this.typeReferences[i].traverse(visitor, scope);
			}
		}
		visitor.endVisit(this, scope);
	}

	@Override
	public void traverse(ASTVisitor visitor, ClassScope scope) {
		if (visitor.visit(this, scope)) {
			int length = this.typeReferences == null ? 0 : this.typeReferences.length;
			for (int i = 0; i < length; i++) {
				this.typeReferences[i].traverse(visitor, scope);
			}
		}
		visitor.endVisit(this, scope);
	}

	@Override
	public StringBuffer printExpression(int indent, StringBuffer output) {
		int length = this.typeReferences == null ? 0 : this.typeReferences.length;
		printIndent(indent, output);
		for (int i = 0; i < length; i++) {
			this.typeReferences[i].printExpression(0, output);
			if (i != length - 1) {
				output.append(" | "); //$NON-NLS-1$
			}
		}
		return output;
	}
	@Override
	public boolean isUnionType() {
		return true;
	}
	@Override
	public TypeReference augmentTypeWithAdditionalDimensions(int additionalDimensions, Annotation[][] additionalAnnotations, boolean isVarargs) {
		return this; // arrays are not legal as union types.
	}

}