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 2001-2004 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: ForEach.java,v 1.2.4.1 2005/09/01 15:23:46 pvedula Exp $
   */
  
  package jaxp.sun.org.apache.xalan.internal.xsltc.compiler;
  
  import java.util.Enumeration;
  import java.util.Vector;
  
  import jaxp.sun.org.apache.bcel.internal.generic.BranchHandle;
  import jaxp.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
  import jaxp.sun.org.apache.bcel.internal.generic.GOTO;
  import jaxp.sun.org.apache.bcel.internal.generic.IFGT;
  import jaxp.sun.org.apache.bcel.internal.generic.InstructionHandle;
  import jaxp.sun.org.apache.bcel.internal.generic.InstructionList;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeSetType;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeType;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.ReferenceType;
  import jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType;
  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;
  
  /**
   * @author Jacek Ambroziak
   * @author Santiago Pericas-Geertsen
   * @author Morten Jorgensen
   */
  final class ForEach extends Instruction {
  
      private Expression _select;
      private Type _type;
  
      public void display(int indent) {
          indent(indent);
          Util.println("ForEach");
          indent(indent + IndentIncrement);
          Util.println("select " + _select.toString());
          displayContents(indent + IndentIncrement);
      }
  
      public void parseContents(Parser parser) {
          _select = parser.parseExpression(this, "select", null);
  
          parseChildren(parser);
  
          // make sure required attribute(s) have been set
          if (_select.isDummy()) {
              reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "select");
          }
      }
  
      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
          _type = _select.typeCheck(stable);
  
          if (_type instanceof ReferenceType || _type instanceof NodeType) {
              _select = new CastExpr(_select, Type.NodeSet);
              typeCheckContents(stable);
              return Type.Void;
          }
          if (_type instanceof NodeSetType ||_type instanceof ResultTreeType) {
              typeCheckContents(stable);
              return Type.Void;
          }
          throw new TypeCheckError(this);
      }
  
      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
          final ConstantPoolGen cpg = classGen.getConstantPool();
          final InstructionList il = methodGen.getInstructionList();
  
          // Save current node and current iterator on the stack
          il.append(methodGen.loadCurrentNode());
          il.append(methodGen.loadIterator());
  
          // Collect sort objects associated with this instruction
          final Vector sortObjects = new Vector();
          Enumeration children = elements();
          while (children.hasMoreElements()) {
              final Object child = children.nextElement();
              if (child instanceof Sort) {
                  sortObjects.addElement(child);
              }
          }
  
          if ((_type != null) && (_type instanceof ResultTreeType)) {
              // Store existing DOM on stack - must be restored when loop is done
              il.append(methodGen.loadDOM());
  
              // <xsl:sort> cannot be applied to a result tree - issue warning
              if (sortObjects.size() > 0) {
                  ErrorMsg msg = new ErrorMsg(ErrorMsg.RESULT_TREE_SORT_ERR,this);
                  getParser().reportError(WARNING, msg);
              }
  
              // Put the result tree on the stack (DOM)
              _select.translate(classGen, methodGen);
              // Get an iterator for the whole DOM - excluding the root node
              _type.translateTo(classGen, methodGen, Type.NodeSet);
              // Store the result tree as the default DOM
              il.append(SWAP);
              il.append(methodGen.storeDOM());
          }
          else {
              // Compile node iterator
              if (sortObjects.size() > 0) {
                  Sort.translateSortIterator(classGen, methodGen,
                                             _select, sortObjects);
              }
              else {
                  _select.translate(classGen, methodGen);
              }
  
              if (_type instanceof ReferenceType == false) {
                  il.append(methodGen.loadContextNode());
                  il.append(methodGen.setStartNode());
              }
          }
  
  
          // Overwrite current iterator
          il.append(methodGen.storeIterator());
  
          // Give local variables (if any) default values before starting loop
          initializeVariables(classGen, methodGen);
  
          final BranchHandle nextNode = il.append(new GOTO(null));
          final InstructionHandle loop = il.append(NOP);
  
          translateContents(classGen, methodGen);
  
          nextNode.setTarget(il.append(methodGen.loadIterator()));
          il.append(methodGen.nextNode());
          il.append(DUP);
          il.append(methodGen.storeCurrentNode());
          il.append(new IFGT(loop));
  
          // Restore current DOM (if result tree was used instead for this loop)
          if ((_type != null) && (_type instanceof ResultTreeType)) {
              il.append(methodGen.storeDOM());
          }
  
          // Restore current node and current iterator from the stack
          il.append(methodGen.storeIterator());
          il.append(methodGen.storeCurrentNode());
      }
  
      /**
       * The code that is generated by nested for-each loops can appear to some
       * JVMs as if it is accessing un-initialized variables. We must add some
       * code that pushes the default variable value on the stack and pops it
       * into the variable slot. This is done by the Variable.initialize()
       * method. The code that we compile for this loop looks like this:
       *
       *           initialize iterator
       *           initialize variables <-- HERE!!!
       *           goto   Iterate
       *  Loop:    :
       *           : (code for <xsl:for-each> contents)
       *           :
       *  Iterate: node = iterator.next();
       *           if (node != END) goto Loop
       */
      public void initializeVariables(ClassGenerator classGen,
                                     MethodGenerator methodGen) {
          final int n = elementCount();
          for (int i = 0; i < n; i++) {
              final Object child = getContents().elementAt(i);
              if (child instanceof Variable) {
                  Variable var = (Variable)child;
                  var.initialize(classGen, methodGen);
              }
          }
      }
  
  }
  