/*
* 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: VariableRefBase.java,v 1.13 2004/02/16 22:25:10 minchau Exp $
*/
package com.sun.org.apache.xalan.internal.xsltc.compiler;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
/**
* @author Morten Jorgensen
* @author Santiago Pericas-Geertsen
*/
class VariableRefBase extends Expression {
/**
* A reference to the associated variable.
*/
protected final VariableBase _variable;
/**
* A reference to the enclosing expression/instruction for which a
* closure is needed (Predicate, Number or Sort).
*/
protected Closure _closure = null;
public VariableRefBase(VariableBase variable) {
_variable = variable;
variable.addReference(this);
}
public VariableRefBase() {
_variable = null;
}
/**
* Returns a reference to the associated variable
*/
public VariableBase getVariable() {
return _variable;
}
/**
* Returns a reference to any parent variable
*/
public VariableBase findParentVariable() {
SyntaxTreeNode node = this;
while (node != null && !(node instanceof VariableBase)) {
node = node.getParent();
}
return (VariableBase) node;
}
/**
* Two variable references are deemed equal if they refer to the
* same variable.
*/
public boolean equals(Object obj) {
try {
return (_variable == ((VariableRefBase) obj)._variable);
}
catch (ClassCastException e) {
return false;
}
}
/**
* Returns a string representation of this variable reference on the
* format 'variable-ref(<var-name>)'.
* @return Variable reference description
*/
public String toString() {
return "variable-ref("+_variable.getName()+'/'+_variable.getType()+')';
}
public Type typeCheck(SymbolTable stable)
throws TypeCheckError
{
// Returned cached type if available
if (_type != null) return _type;
// Find nearest closure to add a variable reference
if (_variable.isLocal()) {
SyntaxTreeNode node = getParent();
do {
if (node instanceof Closure) {
_closure = (Closure) node;
break;
}
if (node instanceof TopLevelElement) {
break; // way up in the tree
}
node = node.getParent();
} while (node != null);
if (_closure != null) {
_closure.addVariable(this);
}
}
// Insert a dependency link from one variable to another
VariableBase parent = findParentVariable();
if (parent != null) {
VariableBase var = _variable;
if (_variable._ignore) {
if (_variable instanceof Variable) {
var = parent.getSymbolTable()
.lookupVariable(_variable._name);
} else if (_variable instanceof Param) {
var = parent.getSymbolTable().lookupParam(_variable._name);
}
}
parent.addDependency(var);
}
// Attempt to get the cached variable type
_type = _variable.getType();
// If that does not work we must force a type-check (this is normally
// only needed for globals in included/imported stylesheets
if (_type == null) {
_variable.typeCheck(stable);
_type = _variable.getType();
}
// Return the type of the referenced variable
return _type;
}
}
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