1 /*
   2  * reserved comment block
   3  * DO NOT REMOVE OR ALTER!
   4  */
   5 /*
   6  * Copyright 2001-2004 The Apache Software Foundation.
   7  *
   8  * Licensed under the Apache License, Version 2.0 (the "License");
   9  * you may not use this file except in compliance with the License.
  10  * You may obtain a copy of the License at
  11  *
  12  *     http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20 /*
  21  * $Id: CastCall.java,v 1.2.4.1 2005/09/01 11:47:58 pvedula Exp $
  22  */
  23 
  24 package com.sun.org.apache.xalan.internal.xsltc.compiler;
  25 
  26 import java.util.Vector;
  27 
  28 import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
  29 import com.sun.org.apache.bcel.internal.generic.CHECKCAST;
  30 import com.sun.org.apache.bcel.internal.generic.InstructionList;
  31 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
  32 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
  33 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
  34 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
  35 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ObjectType;
  36 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
  37 
  38 /**
  39  * @author Santiago Pericas-Geertsen
  40  */
  41 final class CastCall extends FunctionCall {
  42 
  43     /**
  44      * Name of the class that is the target of the cast. Must be a
  45      * fully-qualified Java class Name.
  46      */
  47     private String _className;
  48 
  49     /**
  50      * A reference to the expression being casted.
  51      */
  52     private Expression _right;
  53 
  54     /**
  55      * Constructor.
  56      */
  57     public CastCall(QName fname, Vector arguments) {
  58         super(fname, arguments);
  59     }
  60 
  61     /**
  62      * Type check the two parameters for this function
  63      */
  64     public Type typeCheck(SymbolTable stable) throws TypeCheckError {
  65         // Check that the function was passed exactly two arguments
  66         if (argumentCount() != 2) {
  67             throw new TypeCheckError(new ErrorMsg(ErrorMsg.ILLEGAL_ARG_ERR,
  68                                                   getName(), this));
  69         }
  70 
  71         // The first argument must be a literal String
  72         Expression exp = argument(0);
  73         if (exp instanceof LiteralExpr) {
  74             _className = ((LiteralExpr) exp).getValue();
  75             _type = Type.newObjectType(_className);
  76         }
  77         else {
  78             throw new TypeCheckError(new ErrorMsg(ErrorMsg.NEED_LITERAL_ERR,
  79                                                   getName(), this));
  80         }
  81 
  82          // Second argument must be of type reference or object
  83         _right = argument(1);
  84         Type tright = _right.typeCheck(stable);
  85         if (tright != Type.Reference &&
  86             tright instanceof ObjectType == false)
  87         {
  88             throw new TypeCheckError(new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
  89                                                   tright, _type, this));
  90         }
  91 
  92         return _type;
  93     }
  94 
  95     public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
  96         final ConstantPoolGen cpg = classGen.getConstantPool();
  97         final InstructionList il = methodGen.getInstructionList();
  98 
  99         _right.translate(classGen, methodGen);
 100         il.append(new CHECKCAST(cpg.addClass(_className)));
 101     }
 102 }