ohair@286: /*
ohair@286:  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
ohair@286:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ohair@286:  *
ohair@286:  * This code is free software; you can redistribute it and/or modify it
ohair@286:  * under the terms of the GNU General Public License version 2 only, as
ohair@286:  * published by the Free Software Foundation.  Oracle designates this
ohair@286:  * particular file as subject to the "Classpath" exception as provided
ohair@286:  * by Oracle in the LICENSE file that accompanied this code.
ohair@286:  *
ohair@286:  * This code is distributed in the hope that it will be useful, but WITHOUT
ohair@286:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ohair@286:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ohair@286:  * version 2 for more details (a copy is included in the LICENSE file that
ohair@286:  * accompanied this code).
ohair@286:  *
ohair@286:  * You should have received a copy of the GNU General Public License version
ohair@286:  * 2 along with this work; if not, write to the Free Software Foundation,
ohair@286:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ohair@286:  *
ohair@286:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@286:  * or visit www.oracle.com if you need additional information or have any
ohair@286:  * questions.
ohair@286:  */
ohair@286: 
ohair@286: package com.sun.tools.internal.xjc.reader.xmlschema.ct;
ohair@286: 
ohair@286: import java.util.HashMap;
ohair@286: import java.util.Iterator;
ohair@286: import java.util.Map;
ohair@286: 
ohair@286: import com.sun.tools.internal.xjc.reader.xmlschema.WildcardNameClassBuilder;
ohair@286: import com.sun.xml.internal.xsom.XSAttributeUse;
ohair@286: import com.sun.xml.internal.xsom.XSComplexType;
ohair@286: import com.sun.xml.internal.xsom.XSContentType;
ohair@286: import com.sun.xml.internal.xsom.XSDeclaration;
ohair@286: import com.sun.xml.internal.xsom.XSElementDecl;
ohair@286: import com.sun.xml.internal.xsom.XSModelGroup;
ohair@286: import com.sun.xml.internal.xsom.XSModelGroupDecl;
ohair@286: import com.sun.xml.internal.xsom.XSParticle;
ohair@286: import com.sun.xml.internal.xsom.XSType;
ohair@286: import com.sun.xml.internal.xsom.XSWildcard;
ohair@286: import com.sun.xml.internal.xsom.visitor.XSTermFunction;
mkos@408: import javax.xml.namespace.QName;
ohair@286: 
ohair@286: import com.sun.xml.internal.rngom.nc.ChoiceNameClass;
ohair@286: import com.sun.xml.internal.rngom.nc.NameClass;
ohair@286: import com.sun.xml.internal.rngom.nc.SimpleNameClass;
ohair@286: 
ohair@286: /**
ohair@286:  * Binds a complex type derived from another complex type by extension.
ohair@286:  *
ohair@286:  * @author
ohair@286:  *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
ohair@286:  */
ohair@286: abstract class AbstractExtendedComplexTypeBuilder extends CTBuilder {
ohair@286: 
ohair@286:     /**
ohair@286:      * Map from {@link XSComplexType} to {@link NameClass}[2] that
ohair@286:      * represents the names used in its child elements [0] and
ohair@286:      * attributes [1].
ohair@286:      */
ohair@286:     protected final Map<XSComplexType, NameClass[]> characteristicNameClasses = new HashMap<XSComplexType, NameClass[]>();
ohair@286: 
ohair@286:     /**
ohair@286:      * Computes a name class that represents everything in a given content model.
ohair@286:      */
ohair@286:     protected final XSTermFunction<NameClass> contentModelNameClassBuilder = new XSTermFunction<NameClass>() {
mkos@408:         @Override
ohair@286:         public NameClass wildcard(XSWildcard wc) {
ohair@286:             return WildcardNameClassBuilder.build(wc);
ohair@286:         }
ohair@286: 
mkos@408:         @Override
ohair@286:         public NameClass modelGroupDecl(XSModelGroupDecl decl) {
ohair@286:             return modelGroup(decl.getModelGroup());
ohair@286:         }
ohair@286: 
mkos@408:         @Override
ohair@286:         public NameClass modelGroup(XSModelGroup group) {
ohair@286:             NameClass nc = NameClass.NULL;
ohair@286:             for( int i=0; i<group.getSize(); i++ )
ohair@286:                 nc = new ChoiceNameClass(nc, group.getChild(i).getTerm().apply(this));
ohair@286:             return nc;
ohair@286:         }
ohair@286: 
ohair@286:         public NameClass elementDecl(XSElementDecl decl) {
ohair@286:             return getNameClass(decl);
ohair@286:         }
ohair@286:     };
ohair@286: 
ohair@286:     /**
ohair@286:      * Checks if the particles/attributes defined in the type parameter
ohair@286:      * collides with the name classes of anc/enc.
ohair@286:      *
ohair@286:      * @return true if there's a collision.
ohair@286:      */
ohair@286:     protected boolean checkCollision(NameClass anc, NameClass enc, XSComplexType type) {
ohair@286:         NameClass[] chnc = characteristicNameClasses.get(type);
ohair@286:         if (chnc == null) {
ohair@286:             chnc = new NameClass[2];
ohair@286:             chnc[0] = getNameClass(type.getContentType());
ohair@286: 
ohair@286:             // build attribute name classes
ohair@286:             NameClass nc = NameClass.NULL;
ohair@286:             Iterator itr = type.iterateAttributeUses();
ohair@286:             while( itr.hasNext() )
ohair@286:                 anc = new ChoiceNameClass(anc, getNameClass(((XSAttributeUse) itr.next()).getDecl()));
ohair@286:             XSWildcard wc = type.getAttributeWildcard();
ohair@286:             if(wc!=null)
ohair@286:                 nc = new ChoiceNameClass(nc, WildcardNameClassBuilder.build(wc));
ohair@286:             chnc[1] = nc;
ohair@286: 
ohair@286:             characteristicNameClasses.put(type, chnc);
ohair@286:         }
ohair@286: 
ohair@286:         return chnc[0].hasOverlapWith(enc) || chnc[1].hasOverlapWith(anc);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Looks for the derivation chain t_1 > t_2 > ... > t
ohair@286:      * and find t_i such that t_i derives by restriction but
ohair@286:      * for every j>i, t_j derives by extension.
ohair@286:      *
ohair@286:      * @return null
ohair@286:      *      If there's no such t_i or if t_i is any type.
ohair@286:      */
ohair@286:     protected XSComplexType getLastRestrictedType(XSComplexType t) {
ohair@286:         if (t.getBaseType() == schemas.getAnyType()) {
ohair@286:             return null;   // we don't count the restriction from anyType
ohair@286:         }
ohair@286:         if (t.getDerivationMethod() == XSType.RESTRICTION) {
ohair@286:             return t;
ohair@286:         }
ohair@286: 
ohair@286:         XSComplexType baseType = t.getBaseType().asComplexType();
ohair@286:         if (baseType != null) {
ohair@286:             return getLastRestrictedType(baseType);
ohair@286:         } else {
ohair@286:             return null;
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Checks if this new extension is safe.
ohair@286:      *
ohair@286:      * UGLY.
ohair@286:      * <p>
ohair@286:      * If you have ctA extending ctB and ctB restricting ctC, our
ohair@286:      * Java classes will look like CtAImpl extending CtBImpl
ohair@286:      * extending CtCImpl.
ohair@286:      *
ohair@286:      * <p>
ohair@286:      * Since a derived class unmarshaller uses the base class unmarshaller,
ohair@286:      * this could potentially result in incorrect unmarshalling.
ohair@286:      * We used to just reject such a case, but then we found that
ohair@286:      * there are schemas that are using it.
ohair@286:      *
ohair@286:      * <p>
ohair@286:      * One generalized observation that we reached is that if the extension
ohair@286:      * is only adding new elements/attributes which has never been used
ohair@286:      * in any of its base class (IOW, if none of the particle / attribute use /
ohair@286:      * attribute wildcard can match the name of newly added elements/attributes)
ohair@286:      * then it is safe to add them.
ohair@286:      *
ohair@286:      * <p>
ohair@286:      * This function checks if the derivation chain to this type is
ohair@286:      * not using restriction, and if it is, then checks if it is safe
ohair@286:      * according to the above condition.
ohair@286:      *
ohair@286:      * @return false
ohair@286:      *      If this complex type needs to be rejected.
ohair@286:      */
ohair@286:     protected boolean checkIfExtensionSafe(XSComplexType baseType, XSComplexType thisType) {
ohair@286:         XSComplexType lastType = getLastRestrictedType(baseType);
ohair@286: 
ohair@286:         if (lastType == null) {
ohair@286:             return true;    // no restriction in derivation chain
ohair@286:         }
ohair@286:         NameClass anc = NameClass.NULL;
ohair@286:         // build name class for attributes in new complex type
ohair@286:         Iterator itr = thisType.iterateDeclaredAttributeUses();
ohair@286:         while (itr.hasNext()) {
ohair@286:             anc = new ChoiceNameClass(anc, getNameClass(((XSAttributeUse) itr.next()).getDecl()));
ohair@286:         }
ohair@286:         // TODO: attribute wildcard
ohair@286: 
ohair@286:         NameClass enc = getNameClass(thisType.getExplicitContent());
ohair@286: 
ohair@286:         // check against every base type ... except the root anyType
ohair@286:         while (lastType != lastType.getBaseType()) {
ohair@286:             if (checkCollision(anc, enc, lastType)) {
ohair@286:                 return false;
ohair@286:             }
ohair@286: 
ohair@286:             if (lastType.getBaseType().isSimpleType()) // if the base type is a simple type, there won't be
ohair@286:             // any further name collision.
ohair@286:             {
ohair@286:                 return true;
ohair@286:             }
ohair@286: 
ohair@286:             lastType = lastType.getBaseType().asComplexType();
ohair@286:         }
ohair@286: 
ohair@286:         return true;    // OK
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Gets a {@link NameClass} that represents all the terms in the given content type.
ohair@286:      * If t is not a particle, just return an empty name class.
ohair@286:      */
ohair@286:     private NameClass getNameClass(XSContentType t) {
ohair@286:         if(t==null) return NameClass.NULL;
ohair@286:         XSParticle p = t.asParticle();
ohair@286:         if(p==null) return NameClass.NULL;
ohair@286:         else        return p.getTerm().apply(contentModelNameClassBuilder);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Gets a {@link SimpleNameClass} from the name of a {@link XSDeclaration}.
ohair@286:      */
ohair@286:     private NameClass getNameClass(XSDeclaration decl) {
mkos@408:         return new SimpleNameClass(new QName(decl.getTargetNamespace(), decl.getName()));
ohair@286:     }
ohair@286: 
ohair@286: }