| /* |
| * @(#)$Id$ |
| * |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 2001 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Xalan" and "Apache Software Foundation" must |
| * not be used to endorse or promote products derived from this |
| * software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * nor may "Apache" appear in their name, without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation and was |
| * originally based on software copyright (c) 2001, Sun |
| * Microsystems., http://www.sun.com. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| * |
| * @author Jacek Ambroziak |
| * @author Santiago Pericas-Geertsen |
| * @author Morten Jorgensen |
| * @author Erwin Bolwidt <ejb@klomp.org> |
| * @author John Howard <JohnH@schemasoft.com> |
| * |
| */ |
| |
| package org.apache.xalan.xsltc.compiler; |
| |
| import java.util.Vector; |
| |
| import org.apache.xalan.xsltc.compiler.util.Type; |
| import org.apache.bcel.generic.Instruction; |
| import org.apache.bcel.generic.*; |
| import org.apache.bcel.classfile.Field; |
| import org.apache.xalan.xsltc.compiler.util.*; |
| import org.apache.xalan.xsltc.dom.Axis; |
| |
| final class Variable extends VariableBase { |
| |
| public int getIndex() { |
| return (_local != null) ? _local.getIndex() : -1; |
| } |
| |
| /** |
| * Parse the contents of the variable |
| */ |
| public void parseContents(Parser parser) { |
| // Parse 'name' and 'select' attributes plus parameter contents |
| super.parseContents(parser); |
| |
| // Add a ref to this var to its enclosing construct |
| SyntaxTreeNode parent = getParent(); |
| if (parent instanceof Stylesheet) { |
| // Mark this as a global variable |
| _isLocal = false; |
| // Check if a global variable with this name already exists... |
| Variable var = parser.getSymbolTable().lookupVariable(_name); |
| // ...and if it does we need to check import precedence |
| if (var != null) { |
| final int us = this.getImportPrecedence(); |
| final int them = var.getImportPrecedence(); |
| // It is an error if the two have the same import precedence |
| if (us == them) { |
| final String name = _name.toString(); |
| reportError(this, parser, ErrorMsg.VARIABLE_REDEF_ERR,name); |
| } |
| // Ignore this if previous definition has higher precedence |
| else if (them > us) { |
| _ignore = true; |
| return; |
| } |
| else { |
| var.disable(); |
| } |
| // Add this variable if we have higher precedence |
| } |
| ((Stylesheet)parent).addVariable(this); |
| parser.getSymbolTable().addVariable(this); |
| } |
| else { |
| _isLocal = true; |
| } |
| } |
| |
| /** |
| * Runs a type check on either the variable element body or the |
| * expression in the 'select' attribute |
| */ |
| public Type typeCheck(SymbolTable stable) throws TypeCheckError { |
| |
| // Type check the 'select' expression if present |
| if (_select != null) { |
| _type = _select.typeCheck(stable); |
| } |
| // Type check the element contents otherwise |
| else if (hasContents()) { |
| typeCheckContents(stable); |
| _type = Type.ResultTree; |
| } |
| else { |
| _type = Type.Reference; |
| } |
| // The return type is void as the variable element does not leave |
| // anything on the JVM's stack. The '_type' global will be returned |
| // by the references to this variable, and not by the variable itself. |
| return Type.Void; |
| } |
| |
| /** |
| * This method is part of a little trick that is needed to use local |
| * variables inside nested for-each loops. See the initializeVariables() |
| * method in the ForEach class for an explanation |
| */ |
| public void initialize(ClassGenerator classGen, MethodGenerator methodGen) { |
| final ConstantPoolGen cpg = classGen.getConstantPool(); |
| final InstructionList il = methodGen.getInstructionList(); |
| |
| // This is only done for local variables that are actually used |
| if (isLocal() && !_refs.isEmpty()) { |
| // Create a variable slot if none is allocated |
| if (_local == null) { |
| _local = methodGen.addLocalVariable2(_name.getLocalPart(), |
| _type.toJCType(), |
| il.getEnd()); |
| } |
| // Push the default value on the JVM's stack |
| if ((_type instanceof IntType) || |
| (_type instanceof NodeType) || |
| (_type instanceof BooleanType)) |
| il.append(new ICONST(0)); // 0 for node-id, integer and boolean |
| else if (_type instanceof RealType) |
| il.append(new DCONST(0)); // 0.0 for floating point numbers |
| else |
| il.append(new ACONST_NULL()); // and 'null' for anything else |
| il.append(_type.STORE(_local.getIndex())); |
| } |
| } |
| |
| public void translate(ClassGenerator classGen, MethodGenerator methodGen) { |
| final ConstantPoolGen cpg = classGen.getConstantPool(); |
| final InstructionList il = methodGen.getInstructionList(); |
| |
| final String name = getVariable(); |
| |
| // Make sure that a variable instance is only compiled once |
| if (_ignore) return; |
| _ignore = true; |
| |
| if (isLocal()) { |
| // Compile variable value computation |
| translateValue(classGen, methodGen); |
| |
| // Add a new local variable and store value |
| if (_refs.isEmpty()) { // Remove it if nobody uses the value |
| il.append(_type.POP()); |
| _local = null; |
| } |
| else { // Store in local var slot if referenced |
| if (_local == null) mapRegister(methodGen); |
| il.append(_type.STORE(_local.getIndex())); |
| } |
| } |
| else { |
| String signature = _type.toSignature(); |
| |
| // Global variables are store in class fields |
| if (classGen.containsField(name) == null) { |
| classGen.addField(new Field(ACC_PUBLIC, |
| cpg.addUtf8(name), |
| cpg.addUtf8(signature), |
| null, cpg.getConstantPool())); |
| |
| // Push a reference to "this" for putfield |
| il.append(classGen.loadTranslet()); |
| // Compile variable value computation |
| translateValue(classGen, methodGen); |
| // Store the variable in the allocated field |
| il.append(new PUTFIELD(cpg.addFieldref(classGen.getClassName(), |
| name, signature))); |
| } |
| } |
| } |
| } |