code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you 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.
   */
  /*
   * $Id$
   */
  
  package org.apache.xalan.xsltc.compiler;
  
  import org.apache.bcel.generic.BranchHandle;
  import org.apache.bcel.generic.ConstantPoolGen;
  import org.apache.bcel.generic.GOTO_W;
  import org.apache.bcel.generic.IF_ICMPEQ;
  import org.apache.bcel.generic.ILOAD;
  import org.apache.bcel.generic.INVOKEINTERFACE;
  import org.apache.bcel.generic.ISTORE;
  import org.apache.bcel.generic.InstructionHandle;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.bcel.generic.LocalVariableGen;
  import org.apache.bcel.generic.PUSH;
  import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
  import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
  import org.apache.xalan.xsltc.compiler.util.Type;
  import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
  import org.apache.xalan.xsltc.compiler.util.Util;
  import org.apache.xml.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),
  						null);
  		il.append(DUP);
  		local.setStart(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() : ")");
      }
  }
  