- /*
- * 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;
- }
-
- }