/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Copyright 2001-2004 The Apache Software Foundation.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

/*

 * $Id: AbsolutePathPattern.java,v 1.2.4.1 2005/09/01 09:17:09 pvedula Exp $

 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.BranchHandle;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;

import com.sun.org.apache.bcel.internal.generic.GOTO_W;

import com.sun.org.apache.bcel.internal.generic.IF_ICMPEQ;

import com.sun.org.apache.bcel.internal.generic.ILOAD;

import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;

import com.sun.org.apache.bcel.internal.generic.ISTORE;

import com.sun.org.apache.bcel.internal.generic.InstructionHandle;

import com.sun.org.apache.bcel.internal.generic.InstructionList;

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;

import com.sun.org.apache.bcel.internal.generic.PUSH;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;

import com.sun.org.apache.xml.internal.dtm.DTM;

/**

 * @author Jacek Ambroziak

 * @author Santiago Pericas-Geertsen

 */

final class AbsolutePathPattern extends LocationPathPattern {

    private final RelativePathPattern _left; // may be null

    public AbsolutePathPattern(RelativePathPattern left) {

        _left = left;

        if (left != null) {

            left.setParent(this);

        }

    }

    public void setParser(Parser parser) {

        super.setParser(parser);

        if (_left != null)

            _left.setParser(parser);

    }

    public Type typeCheck(SymbolTable stable) throws TypeCheckError {

        return _left == null ? Type.Root : _left.typeCheck(stable);

    }

    public boolean isWildcard() {

        return false;

    }

    public StepPattern getKernelPattern() {

        return _left != null ? _left.getKernelPattern() : null;

    }

    public void reduceKernelPattern() {

        _left.reduceKernelPattern();

    }

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {

        final ConstantPoolGen cpg = classGen.getConstantPool();

        final InstructionList il = methodGen.getInstructionList();

        if (_left != null) {

            if (_left instanceof StepPattern) {

                final LocalVariableGen local =

                    // absolute path pattern temporary

                    methodGen.addLocalVariable2("apptmp",

                                                Util.getJCRefType(NODE_SIG),

                                                il.getEnd());

                il.append(DUP);

                il.append(new ISTORE(local.getIndex()));

                _left.translate(classGen, methodGen);

                il.append(methodGen.loadDOM());

                local.setEnd(il.append(new ILOAD(local.getIndex())));

                methodGen.removeLocalVariable(local);

            }

            else {

                _left.translate(classGen, methodGen);

            }

        }

        final int getParent = cpg.addInterfaceMethodref(DOM_INTF,

                                                        GET_PARENT,

                                                        GET_PARENT_SIG);

        final int getType = cpg.addInterfaceMethodref(DOM_INTF,

                                                      "getExpandedTypeID",

                                                      "(I)I");

        InstructionHandle begin = il.append(methodGen.loadDOM());

        il.append(SWAP);

        il.append(new INVOKEINTERFACE(getParent, 2));

        if (_left instanceof AncestorPattern) {

            il.append(methodGen.loadDOM());

            il.append(SWAP);

        }

        il.append(new INVOKEINTERFACE(getType, 2));

        il.append(new PUSH(cpg, DTM.DOCUMENT_NODE));

        final BranchHandle skip = il.append(new IF_ICMPEQ(null));

        _falseList.add(il.append(new GOTO_W(null)));

        skip.setTarget(il.append(NOP));

        if (_left != null) {

            _left.backPatchTrueList(begin);

            /*

             * If _left is an ancestor pattern, backpatch this pattern's false

             * list to the loop that searches for more ancestors.

             */

            if (_left instanceof AncestorPattern) {

                final AncestorPattern ancestor = (AncestorPattern) _left;

                _falseList.backPatch(ancestor.getLoopHandle());         // clears list

            }

            _falseList.append(_left._falseList);

        }

    }

    public String toString() {

        return "absolutePathPattern(" + (_left != null ? _left.toString() : ")");

    }

}