content: /*
   *  This file is part of AndroidIDE.
   *
   *  AndroidIDE is free software: you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  AndroidIDE is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *   along with AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
   */
  
  /*
   * reserved comment block
   * DO NOT REMOVE OR ALTER!
   */
  /*
   * Copyright 2001-2005 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: ParentLocationPath.java,v 1.2.4.1 2005/09/12 10:56:30 pvedula Exp $
   */
  
  package jaxp.sun.org.apache.xalan.internal.xsltc.compiler;
  
  import jaxp.sun.org.apache.bcel.internal.generic.ALOAD;
  import jaxp.sun.org.apache.bcel.internal.generic.ASTORE;
  import jaxp.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
  import jaxp.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
  import jaxp.sun.org.apache.bcel.internal.generic.INVOKESPECIAL;
  import jaxp.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
  import jaxp.sun.org.apache.bcel.internal.generic.InstructionList;
  import jaxp.sun.org.apache.bcel.internal.generic.LocalVariableGen;
  import jaxp.sun.org.apache.bcel.internal.generic.NEW;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
  import jaxp.sun.org.apache.xml.internal.dtm.Axis;
  import jaxp.sun.org.apache.xml.internal.dtm.DTM;
  
  /**
   * @author Jacek Ambroziak
   * @author Santiago Pericas-Geertsen
   */
  final class ParentLocationPath extends RelativeLocationPath {
      private Expression _step;
      private final RelativeLocationPath _path;
      private Type stype;
      private boolean _orderNodes = false;
      private boolean _axisMismatch = false;
  
      public ParentLocationPath(RelativeLocationPath path, Expression step) {
          _path = path;
          _step = step;
          _path.setParent(this);
          _step.setParent(this);
  
          if (_step instanceof Step) {
              _axisMismatch = checkAxisMismatch();
          }
      }
  
      public void setAxis(int axis) {
          _path.setAxis(axis);
      }
  
      public int getAxis() {
          return _path.getAxis();
      }
  
      public RelativeLocationPath getPath() {
          return(_path);
      }
  
      public Expression getStep() {
          return(_step);
      }
  
      public void setParser(Parser parser) {
          super.setParser(parser);
          _step.setParser(parser);
          _path.setParser(parser);
      }
  
      public String toString() {
          return "ParentLocationPath(" + _path + ", " + _step + ')';
      }
  
      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
          stype = _step.typeCheck(stable);
          _path.typeCheck(stable);
  
          if (_axisMismatch) enableNodeOrdering();
  
          return _type = Type.NodeSet;
      }
  
      public void enableNodeOrdering() {
          SyntaxTreeNode parent = getParent();
          if (parent instanceof ParentLocationPath)
              ((ParentLocationPath)parent).enableNodeOrdering();
          else {
              _orderNodes = true;
          }
      }
  
      /**
       * This method is used to determine if this parent location path is a
       * combination of two step's with axes that will create duplicate or
       * unordered nodes.
       */
      public boolean checkAxisMismatch() {
  
          int left = _path.getAxis();
          int right = ((Step)_step).getAxis();
  
          if (((left == Axis.ANCESTOR) || (left == Axis.ANCESTORORSELF)) &&
              ((right == Axis.CHILD) ||
               (right == Axis.DESCENDANT) ||
               (right == Axis.DESCENDANTORSELF) ||
               (right == Axis.PARENT) ||
               (right == Axis.PRECEDING) ||
               (right == Axis.PRECEDINGSIBLING)))
              return true;
  
          if ((left == Axis.CHILD) &&
              (right == Axis.ANCESTOR) ||
              (right == Axis.ANCESTORORSELF) ||
              (right == Axis.PARENT) ||
              (right == Axis.PRECEDING))
              return true;
  
          if ((left == Axis.DESCENDANT) || (left == Axis.DESCENDANTORSELF))
              return true;
  
          if (((left == Axis.FOLLOWING) || (left == Axis.FOLLOWINGSIBLING)) &&
              ((right == Axis.FOLLOWING) ||
               (right == Axis.PARENT) ||
               (right == Axis.PRECEDING) ||
               (right == Axis.PRECEDINGSIBLING)))
              return true;
  
          if (((left == Axis.PRECEDING) || (left == Axis.PRECEDINGSIBLING)) &&
              ((right == Axis.DESCENDANT) ||
               (right == Axis.DESCENDANTORSELF) ||
               (right == Axis.FOLLOWING) ||
               (right == Axis.FOLLOWINGSIBLING) ||
               (right == Axis.PARENT) ||
               (right == Axis.PRECEDING) ||
               (right == Axis.PRECEDINGSIBLING)))
              return true;
  
          if ((right == Axis.FOLLOWING) && (left == Axis.CHILD)) {
              // Special case for '@*/following::*' expressions. The resulting
              // iterator is initialised with the parent's first child, and this
              // can cause duplicates in the output if the parent has more than
              // one attribute that matches the left step.
              if (_path instanceof Step) {
                  int type = ((Step)_path).getNodeType();
                  if (type == DTM.ATTRIBUTE_NODE) return true;
              }
          }
  
          return false;
      }
  
      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
  
          // Compile path iterator
          _path.translate(classGen, methodGen); // iterator on stack....
  
          translateStep(classGen, methodGen);
      }
  
      public void translateStep(ClassGenerator classGen, MethodGenerator methodGen) {
          final ConstantPoolGen cpg = classGen.getConstantPool();
          final InstructionList il = methodGen.getInstructionList();
  
          // Backwards branches are prohibited if an uninitialized object is
          // on the stack by section 4.9.4 of the JVM Specification, 2nd Ed.
          // We don't know whether this code might contain backwards branches
          // so we mustn't create the new object until after we've created
          // the suspect arguments to its constructor.  Instead we calculate
          // the values of the arguments to the constructor first, store them
          // in temporary variables, create the object and reload the
          // arguments from the temporaries to avoid the problem.
  
          LocalVariableGen pathTemp
                  = methodGen.addLocalVariable("parent_location_path_tmp1",
                                           Util.getJCRefType(NODE_ITERATOR_SIG),
                                           null, null);
          pathTemp.setStart(il.append(new ASTORE(pathTemp.getIndex())));
  
          _step.translate(classGen, methodGen);
          LocalVariableGen stepTemp
                  = methodGen.addLocalVariable("parent_location_path_tmp2",
                                           Util.getJCRefType(NODE_ITERATOR_SIG),
                                           null, null);
          stepTemp.setStart(il.append(new ASTORE(stepTemp.getIndex())));
  
          // Create new StepIterator
          final int initSI = cpg.addMethodref(STEP_ITERATOR_CLASS,
                                              "<init>",
                                              "("
                                              +NODE_ITERATOR_SIG
                                              +NODE_ITERATOR_SIG
                                              +")V");
          il.append(new NEW(cpg.addClass(STEP_ITERATOR_CLASS)));
          il.append(DUP);
  
          pathTemp.setEnd(il.append(new ALOAD(pathTemp.getIndex())));
          stepTemp.setEnd(il.append(new ALOAD(stepTemp.getIndex())));
  
          // Initialize StepIterator with iterators from the stack
          il.append(new INVOKESPECIAL(initSI));
  
          // This is a special case for the //* path with or without predicates
          Expression stp = _step;
          if (stp instanceof ParentLocationPath)
              stp = ((ParentLocationPath)stp).getStep();
  
          if ((_path instanceof Step) && (stp instanceof Step)) {
              final int path = ((Step)_path).getAxis();
              final int step = ((Step)stp).getAxis();
              if ((path == Axis.DESCENDANTORSELF && step == Axis.CHILD) ||
                  (path == Axis.PRECEDING        && step == Axis.PARENT)) {
                  final int incl = cpg.addMethodref(NODE_ITERATOR_BASE,
                                                    "includeSelf",
                                                    "()" + NODE_ITERATOR_SIG);
                  il.append(new INVOKEVIRTUAL(incl));
              }
          }
  
          /*
           * If this pattern contains a sequence of descendant iterators we
           * run the risk of returning the same node several times. We put
           * a new iterator on top of the existing one to assure node order
           * and prevent returning a single node multiple times.
           */
          if (_orderNodes) {
              final int order = cpg.addInterfaceMethodref(DOM_INTF,
                                                          ORDER_ITERATOR,
                                                          ORDER_ITERATOR_SIG);
              il.append(methodGen.loadDOM());
              il.append(SWAP);
              il.append(methodGen.loadContextNode());
              il.append(new INVOKEINTERFACE(order, 3));
          }
      }
  }
  