/*
* 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: If.java,v 1.2.4.1 2005/09/01 15:39:47 pvedula Exp $
*/
package com.sun.org.apache.xalan.internal.xsltc.compiler;
import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.BooleanType;
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.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
/**
* @author Jacek Ambroziak
* @author Santiago Pericas-Geertsen
* @author Morten Jorgensen
*/
final class If extends Instruction {
private Expression _test;
private boolean _ignore = false;
/**
* Display the contents of this element
*/
public void display(int indent) {
indent(indent);
Util.println("If");
indent(indent + IndentIncrement);
System.out.print("test ");
Util.println(_test.toString());
displayContents(indent + IndentIncrement);
}
/**
* Parse the "test" expression and contents of this element.
*/
public void parseContents(Parser parser) {
// Parse the "test" expression
_test = parser.parseExpression(this, "test", null);
// Make sure required attribute(s) have been set
if (_test.isDummy()) {
reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "test");
return;
}
// Ignore xsl:if when test is false (function-available() and
// element-available())
Object result = _test.evaluateAtCompileTime();
if (result != null && result instanceof Boolean) {
_ignore = !((Boolean) result).booleanValue();
}
parseChildren(parser);
}
/**
* Type-check the "test" expression and contents of this element.
* The contents will be ignored if we know the test will always fail.
*/
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
// Type-check the "test" expression
if (_test.typeCheck(stable) instanceof BooleanType == false) {
_test = new CastExpr(_test, Type.Boolean);
}
// Type check the element contents
if (!_ignore) {
typeCheckContents(stable);
}
return Type.Void;
}
/**
* Translate the "test" expression and contents of this element.
* The contents will be ignored if we know the test will always fail.
*/
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final InstructionList il = methodGen.getInstructionList();
_test.translateDesynthesized(classGen, methodGen);
// remember end of condition
final InstructionHandle truec = il.getEnd();
if (!_ignore) {
translateContents(classGen, methodGen);
}
_test.backPatchFalseList(il.append(NOP));
_test.backPatchTrueList(truec.getNext());
}
}