/*
* 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: Param.java,v 1.28 2004/02/23 17:29:35 aruny Exp $
*/
package com.sun.org.apache.xalan.internal.xsltc.compiler;
import com.sun.org.apache.bcel.internal.classfile.Field;
import com.sun.org.apache.bcel.internal.generic.BranchHandle;
import com.sun.org.apache.bcel.internal.generic.CHECKCAST;
import com.sun.org.apache.bcel.internal.generic.IFNONNULL;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.Instruction;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.bcel.internal.generic.PUTFIELD;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ReferenceType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ObjectType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary;
/**
* @author Jacek Ambroziak
* @author Santiago Pericas-Geertsen
* @author Morten Jorgensen
* @author Erwin Bolwidt <ejb@klomp.org>
* @author John Howard <JohnH@schemasoft.com>
*/
final class Param extends VariableBase {
/**
* True if this Param is declared in a simple named template.
* This is used to optimize codegen for parameter passing
* in named templates.
*/
private boolean _isInSimpleNamedTemplate = false;
/**
* Display variable as single string
*/
public String toString() {
return "param(" + _name + ")";
}
/**
* Set the instruction for loading the value of this variable onto the
* JVM stack and returns the old instruction.
*/
public Instruction setLoadInstruction(Instruction instruction) {
Instruction tmp = _loadInstruction;
_loadInstruction = instruction;
return tmp;
}
/**
* Set the instruction for storing a value from the stack into this
* variable and returns the old instruction.
*/
public Instruction setStoreInstruction(Instruction instruction) {
Instruction tmp = _storeInstruction;
_storeInstruction = instruction;
return tmp;
}
/**
* Display variable in a full AST dump
*/
public void display(int indent) {
indent(indent);
System.out.println("param " + _name);
if (_select != null) {
indent(indent + IndentIncrement);
System.out.println("select " + _select.toString());
}
displayContents(indent + IndentIncrement);
}
/**
* Parse the contents of the <xsl:param> element. This method must read
* the 'name' (required) and 'select' (optional) attributes.
*/
public void parseContents(Parser parser) {
// Parse 'name' and 'select' attributes plus parameter contents
super.parseContents(parser);
// Add a ref to this param to its enclosing construct
final SyntaxTreeNode parent = getParent();
if (parent instanceof Stylesheet) {
// Mark this as a global parameter
_isLocal = false;
// Check if a global variable with this name already exists...
Param param = parser.getSymbolTable().lookupParam(_name);
// ...and if it does we need to check import precedence
if (param != null) {
final int us = this.getImportPrecedence();
final int them = param.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 {
param.disable();
}
}
// Add this variable if we have higher precedence
((Stylesheet)parent).addParam(this);
parser.getSymbolTable().addParam(this);
}
else if (parent instanceof Template) {
Template template = (Template) parent;
_isLocal = true;
template.addParameter(this);
if (template.isSimpleNamedTemplate()) {
_isInSimpleNamedTemplate = true;
}
}
}
/**
* Type-checks the parameter. The parameter type is determined by the
* 'select' expression (if present) or is a result tree if the parameter
* element has a body and no 'select' expression.
*/
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
if (_select != null) {
_type = _select.typeCheck(stable);
if (_type instanceof ReferenceType == false && !(_type instanceof ObjectType)) {
_select = new CastExpr(_select, Type.Reference);
}
}
else if (hasContents()) {
typeCheckContents(stable);
}
_type = Type.Reference;
// This element has no type (the parameter does, but the parameter
// element itself does not).
return Type.Void;
}
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
if (_ignore) return;
_ignore = true;
/*
* To fix bug 24518 related to setting parameters of the form
* {namespaceuri}localName which will get mapped to an instance
* variable in the class.
*/
final String name = BasisLibrary.mapQNameToJavaName(_name.toString());
final String signature = _type.toSignature();
final String className = _type.getClassName();
if (isLocal()) {
/*
* If simple named template then generate a conditional init of the
* param using its default value:
* if (param == null) param = <default-value>
*/
if (_isInSimpleNamedTemplate) {
il.append(loadInstruction());
BranchHandle ifBlock = il.append(new IFNONNULL(null));
translateValue(classGen, methodGen);
il.append(storeInstruction());
ifBlock.setTarget(il.append(NOP));
return;
}
il.append(classGen.loadTranslet());
il.append(new PUSH(cpg, name));
translateValue(classGen, methodGen);
il.append(new PUSH(cpg, true));
// Call addParameter() from this class
il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
ADD_PARAMETER,
ADD_PARAMETER_SIG)));
if (className != EMPTYSTRING) {
il.append(new CHECKCAST(cpg.addClass(className)));
}
_type.translateUnBox(classGen, methodGen);
if (_refs.isEmpty()) { // nobody uses the value
il.append(_type.POP());
_local = null;
}
else { // normal case
_local = methodGen.addLocalVariable2(name,
_type.toJCType(),
il.getEnd());
// Cache the result of addParameter() in a local variable
il.append(_type.STORE(_local.getIndex()));
}
}
else {
if (classGen.containsField(name) == null) {
classGen.addField(new Field(ACC_PUBLIC, cpg.addUtf8(name),
cpg.addUtf8(signature),
null, cpg.getConstantPool()));
il.append(classGen.loadTranslet());
il.append(DUP);
il.append(new PUSH(cpg, name));
translateValue(classGen, methodGen);
il.append(new PUSH(cpg, true));
// Call addParameter() from this class
il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
ADD_PARAMETER,
ADD_PARAMETER_SIG)));
_type.translateUnBox(classGen, methodGen);
// Cache the result of addParameter() in a field
if (className != EMPTYSTRING) {
il.append(new CHECKCAST(cpg.addClass(className)));
}
il.append(new PUTFIELD(cpg.addFieldref(classGen.getClassName(),
name, signature)));
}
}
}
}
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