/*
* @(#)$Id$
*
* 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
*
*/
package org.apache.xalan.xsltc.compiler;
import java.util.Vector;
import org.apache.xalan.xsltc.compiler.util.Type;
import de.fub.bytecode.generic.Instruction;
import de.fub.bytecode.generic.*;
import de.fub.bytecode.classfile.Field;
import org.apache.xalan.xsltc.compiler.util.*;
final class Variable extends TopLevelElement {
// The name of the variable.
private QName _name;
// The type of this variable.
private Type _type;
// True if the variable is local.
private boolean _isLocal;
private LocalVariableGen _local;
private Instruction _loadInstruction;
// A reference to the select expression.
private Expression _select;
// Index of this variable in the variable stack relative to base ptr
private int _stackIndex = -1;
private boolean _escapes;
private boolean _usedLocally;
/**
* If the variable is of result tree type, and this result tree
* is implemented as a method, this is the name of the method.
*/
private String _methodName;
// references to this variable (when local)
private Vector _refs = new Vector(2);
// to make sure parameter field is not added twice
private boolean _compiled = false;
public void addReference(VariableRef vref) {
_refs.addElement(vref);
}
public void setEscapes() {
_escapes = true;
if (_stackIndex == -1) { // unassigned
Template template = getTemplate();
if (template != null) {
_stackIndex = template.allocateIndex(_name);
}
}
}
public Expression getExpression() {
return(_select);
}
public String toString() {
return("variable("+_name+")");
}
public void setUsedLocally() {
_usedLocally = true;
}
public void removeReference(VariableRef vref, MethodGenerator methodGen) {
_refs.remove(vref);
if (_refs.isEmpty()) {
_local.setEnd(methodGen.getInstructionList().getEnd());
methodGen.removeLocalVariable(_local);
_refs = null;
_local = null;
}
}
public Instruction loadInstruction() {
final Instruction instr = _loadInstruction;
return instr != null
? instr : (_loadInstruction = _type.LOAD(_local.getIndex()));
}
public void display(int indent) {
indent(indent);
System.out.println("Variable " + _name);
if (_select != null) {
indent(indent + IndentIncrement);
System.out.println("select " + _select.toString());
}
displayContents(indent + IndentIncrement);
}
public String getMethodName() {
return _methodName;
}
public Type getType() {
return _type;
}
public boolean isLocal() {
return _isLocal;
}
public QName getName() {
return _name;
}
public int getStackIndex() {
return _stackIndex;
}
public void parseContents(Parser parser) {
// parse attributes name and select (if present)
final String name = getAttribute("name");
if (name.length() > 0) {
_name = parser.getQName(name);
_name.clearDefaultNamespace();
}
else {
reportError(this, parser, ErrorMsg.NREQATTR_ERR, "name");
}
// check whether variable/param of the same name is already in scope
if (parser.lookupVariable(_name) != null) {
reportError(this, parser, ErrorMsg.VARREDEF_ERR, _name.toString());
}
final String select = getAttribute("select");
if (select.length() > 0) {
_select = parser.parseExpression(this, "select", null);
}
// Children must be parsed first -> static scoping
parseChildren(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) {
reportError(this, parser, ErrorMsg.VARREDEF_ERR,
_name.toString());
}
// Ignore this if previous definition has higher precedence
else if (them > us) {
return;
}
// Add this variable if we have higher precedence
}
((Stylesheet)parent).addVariable(this);
parser.getSymbolTable().addVariable(this);
}
else {
_isLocal = true;
}
}
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
if (_select == null) {
typeCheckContents(stable);
if (dependentContents() == false) {
_methodName = "%rt%" + getXSLTC().nextVariableSerial();
_type = new ResultTreeType(_methodName);
}
else {
_type = Type.ResultTree;
}
}
else {
_type = _select.typeCheck(stable);
}
return Type.Void;
}
private void compileRtMethod(ClassGenerator classGen,
MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = new InstructionList();
final String DOM_CLASS_SIG = classGen.getDOMClassSig();
final RtMethodGenerator rtMethodGen =
new RtMethodGenerator(ACC_PROTECTED,
de.fub.bytecode.generic.Type.VOID,
new de.fub.bytecode.generic.Type[] {
Util.getJCRefType(DOM_CLASS_SIG),
Util.getJCRefType(TRANSLET_OUTPUT_SIG)
},
new String[] {
DOCUMENT_PNAME,
TRANSLET_OUTPUT_PNAME
},
_methodName,
classGen.getClassName(),
il, cpg);
rtMethodGen.addException("org.apache.xalan.xsltc.TransletException");
translateContents(classGen, rtMethodGen);
il.append(RETURN);
rtMethodGen.stripAttributes(true);
rtMethodGen.setMaxLocals();
rtMethodGen.setMaxStack();
rtMethodGen.removeNOPs();
classGen.addMethod(rtMethodGen.getMethod());
}
public void compileRtDom(ClassGenerator classGen,
MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
// Save the current handler base on the stack
il.append(methodGen.loadHandler());
final String DOM_CLASS = classGen.getDOMClass();
// Create new instance of DOM class (with 64 nodes)
int index = cpg.addMethodref(DOM_IMPL, "<init>", "(I)V");
il.append(new NEW(cpg.addClass(DOM_IMPL)));
il.append(DUP);
il.append(DUP);
il.append(new PUSH(cpg, 64));
il.append(new INVOKESPECIAL(index));
// Overwrite old handler with DOM handler
index = cpg.addMethodref(DOM_IMPL,
"getOutputDomBuilder",
"()" + TRANSLET_OUTPUT_SIG);
il.append(new INVOKEVIRTUAL(index));
il.append(DUP);
il.append(methodGen.storeHandler());
// Call startDocument on the new handler
il.append(methodGen.startDocument());
// Instantiate result tree fragment
translateContents(classGen, methodGen);
// Call endDocument on the new handler
il.append(methodGen.loadHandler());
il.append(methodGen.endDocument());
// Check if we need to wrap the DOMImpl object in a DOMAdapter object
if (!DOM_CLASS.equals(DOM_IMPL_CLASS)) {
// new org.apache.xalan.xsltc.dom.DOMAdapter(DOMImpl,String[]);
index = cpg.addMethodref(DOM_ADAPTER_CLASS, "<init>",
"("+DOM_IMPL_SIG+
"["+STRING_SIG+
"["+STRING_SIG+")V");
il.append(new NEW(cpg.addClass(DOM_ADAPTER_CLASS)));
il.append(new DUP_X1());
il.append(SWAP);
il.append(new ICONST(0));
il.append(new ANEWARRAY(cpg.addClass(STRING)));
il.append(DUP);
il.append(new INVOKESPECIAL(index)); // leave DOMAdapter on stack
// Must we wrap the DOMAdapter object in an MultiDOM object?
if (DOM_CLASS.equals("org.apache.xalan.xsltc.dom.MultiDOM")) {
// new org.apache.xalan.xsltc.dom.MultiDOM(DOMAdapter);
index = cpg.addMethodref(MULTI_DOM_CLASS, "<init>",
"("+DOM_ADAPTER_SIG+")V");
il.append(new NEW(cpg.addClass(MULTI_DOM_CLASS)));
il.append(new DUP_X1());
il.append(SWAP);
il.append(new INVOKESPECIAL(index)); // leave MultiDOM on stack
}
}
// Restore old handler base from stack
il.append(SWAP);
il.append(methodGen.storeHandler());
}
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
final String name = _name.getLocalPart();
if (_compiled) return;
_compiled = true;
if (isLocal()) {
// If rt implemented as method then compile and return
if (_select == null && _type != Type.ResultTree) {
compileRtMethod(classGen, methodGen);
return;
}
// Push args to call addVariable()
if (_escapes) {
il.append(classGen.loadTranslet());
il.append(new PUSH(cpg, _stackIndex));
}
// Compile rt or expression and store in local
if (_select == null) {
if (hasContents()) {
compileRtDom(classGen, methodGen);
}
else {
// If no select and no contents push the empty string
il.append(new PUSH(cpg, Constants.EMPTYSTRING));
}
}
else {
_select.translate(classGen, methodGen);
_select.startResetIterator(classGen, methodGen);
}
// Dup value only when needed
if (_escapes) {
il.append(_type.DUP());
}
// Add a new local variable and store value
if (_refs.isEmpty()) { // nobody uses the value
il.append(_type.POP());
_local = null;
}
else { // normal case
_local = methodGen.addLocalVariable2(name,
_type.toJCType(),
il.getEnd());
il.append(_type.STORE(_local.getIndex()));
}
// Store boxed value into the template's variable stack
if (_escapes) {
_type.translateBox(classGen, methodGen);
il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
ADD_VARIABLE,
ADD_VARIABLE_SIG)
));
}
}
else {
// If rt implemented as method then compile and return
if (_select == null && _type != Type.ResultTree) {
compileRtMethod(classGen, methodGen);
return;
}
String signature = _type.toSignature();
if (signature.equals(DOM_IMPL_SIG))
signature = classGen.getDOMClassSig();
// Add a new field to this class
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 rt or expression and store in field
if (_select == null) {
if (hasContents()) {
compileRtDom(classGen, methodGen);
}
else {
// If no select and no contents push the empty string
il.append(new PUSH(cpg, Constants.EMPTYSTRING));
}
}
else {
_select.translate(classGen, methodGen);
_select.startResetIterator(classGen, methodGen);
}
il.append(new PUTFIELD(cpg.addFieldref(classGen.getClassName(),
name, signature)));
}
}
}
}