/*
* JBoss, Home of Professional Open Source
* Copyright 2008-10 Red Hat and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*
* @authors Andrew Dinn
*/
package org.jboss.byteman.rule.expression;
import org.jboss.byteman.rule.compiler.CompileContext;
import org.jboss.byteman.rule.type.Type;
import org.jboss.byteman.rule.exception.TypeException;
import org.jboss.byteman.rule.exception.ExecuteException;
import org.jboss.byteman.rule.exception.CompileException;
import org.jboss.byteman.rule.Rule;
import org.jboss.byteman.rule.helper.HelperAdapter;
import org.jboss.byteman.rule.grammar.ParseNode;
import org.objectweb.asm.MethodVisitor;
import java.io.StringWriter;
/**
* an expression which identifies a character string.
*/
public class StringLiteral extends Expression
{
public StringLiteral(Rule rule, ParseNode token)
{
super(rule, Type.STRING, token);
String string = ((String)token.getChild(0));
this.text = string.intern();
}
/**
* verify that variables mentioned in this expression are actually available in the supplied
* bindings list and infer/validate the type of this expression or its subexpressions
* where possible
*/
public void bind()
{
// nothing to do
}
public Type typeCheck(Type expected) throws TypeException {
// if (!expected.isUndefined() && !expected.isVoid() && expected != Type.OBJECT && expected != Type.STRING) {
if (!expected.isUndefined() && !expected.isVoid() && !expected.isAssignableFrom(Type.STRING)) {
throw new TypeException("StringLiteral.typeCheck : invalid expected type " + expected.getName() + getPos());
}
return type;
}
public Object interpret(HelperAdapter helper) throws ExecuteException {
return text;
}
public void compile(MethodVisitor mv, CompileContext compileContext) throws CompileException
{
// make sure we are at the right source line
compileContext.notifySourceLine(line);
// compile a load constant instruction
mv.visitLdcInsn(text);
compileContext.addStackCount(1);
}
public void writeTo(StringWriter stringWriter) {
stringWriter.write("\"");
stringWriter.write(text);
stringWriter.write("\"");
}
private String text;
}