/*
* $Id: TryStatement.java,v 1.7 2002/09/16 08:05:06 jkl Exp $
*
* Copyright (c) 2002 Njet Communications Ltd. All Rights Reserved.
*
* Use is subject to license terms, as defined in
* Anvil Sofware License, Version 1.1. See LICENSE
* file, or http://njet.org/license-1.1.txt
*/
package anvil.script.statements;
import anvil.Location;
import anvil.codec.Code;
import anvil.codec.ExceptionHandler;
import anvil.parser.Tag;
import anvil.ErrorListener;
import anvil.script.compiler.ByteCompiler;
import anvil.script.Context;
import anvil.script.ScriptException;
import anvil.script.parser.TemplateParser;
import java.io.IOException;
/**
* class TryStatement
*
* @author: Jani Lehtim�ki
*/
public class TryStatement extends ScopedStatement
{
protected Statement _statement = EMPTY;
protected CatchStatement[] _catch = new CatchStatement[4];
protected int _catches = 0;
protected FinallyStatement _finally = null;
protected ExceptionHandler _handler = null;
public TryStatement(Statement parent, Location location)
{
super(parent, location);
}
public int typeOf()
{
return Statement.ST_TRY;
}
public String name()
{
return "try";
}
public Statement getChildStatement()
{
return _statement;
}
public void setChildStatement(Statement statement)
{
_statement = statement;
}
public FinallyStatement getFinally()
{
return _finally;
}
public boolean hasFinally()
{
return _finally != null;
}
public void addCatch(CatchStatement stmt)
{
int n = _catch.length;
if (_catches >= n) {
CatchStatement[] katch = new CatchStatement[n += 4];
System.arraycopy(_catch, 0, katch, 0, n);
_catch = katch;
}
_catch[_catches++] = stmt;
}
public void setFinally(FinallyStatement stmt)
{
_finally = stmt;
}
public boolean onTag(TemplateParser parser, int type, Tag tag)
{
return true;
}
public void check(ErrorListener context)
{
_statement.check(context);
boolean seentypeless = false;
for(int i=0; i<_catches; i++) {
CatchStatement katch = _catch[i];
if (seentypeless) {
context.error(katch.getLocation(), "Dead code: preceding non-typed catch renders this catch block inaccessible");
}
if (katch.isTypeless()) {
if (seentypeless) {
context.error(katch.getLocation(), "There may be only one non-typed catch statement in catch sequence");
}
seentypeless = true;
}
katch.check(context);
}
if (_finally != null) {
_finally.check(context);
}
}
public Jumps eliminate(ErrorListener context)
{
Jumps jumps = _statement.eliminate(context);
for(int i=0; i<_catches; i++) {
Statement katch = _catch[i];
boolean blocked = jumps.isBlocked();
jumps.setThrow(false).setBlocked(false);
Jumps j = katch.eliminate(context);
blocked = blocked && j.isBlocked();
jumps.merge(j);
jumps.setBlocked(blocked);
}
if (_finally != null) {
boolean blocked = jumps.isBlocked();
Jumps j = _finally.eliminate(context);
blocked = blocked || j.isBlocked();
jumps.merge(j);
jumps.setBlocked(blocked);
}
//_isblocked = jumps.isBlocked();
return jumps;
}
public void compile(ByteCompiler context)
{
boolean has_try = (_catches > 0) || (_finally != null);
if (has_try) {
Code code = context.getCode();
// try
ExceptionHandler handler = code.startExceptionHandler(_finally != null);
_handler = handler;
if (_statement == EMPTY) {
code.nop();
} else {
_statement.compile(context);
}
handler.endTry();
if (!_statement.isBlocked()) {
handler.callFinally();
handler.jumpOut();
}
// catch
if (_catches > 0) {
handler.startCatch(code.getPool().addClass("anvil/script/ScriptException"));
int l_throwable = code.addLocal();
int l_data = code.addLocal();
code.astore(l_throwable);
code.aload(l_throwable);
code.invokevirtual(code.getPool().addMethodRef("anvil/script/ScriptException", "getData", "()Lanvil/core/Any;"));
code.astore(l_data);
for(int i=0; i<_catches; i++) {
_catch[i].compile(context, handler, l_data);
}
code.aload(l_throwable);
code.athrow();
}
handler.endProtectedRegion();
if (_finally != null) {
handler.startCatch(0);
int thrown = code.addLocal();
code.astore(thrown);
handler.callFinally();
code.aload(thrown);
code.athrow();
}
handler.endCatches();
_handler = null;
// finally
if (_finally != null) {
handler.startFinally();
int returnto = code.addLocal();
code.astore(returnto);
_finally.compile(context);
if (!_finally.isBlocked()) {
code.ret(returnto);
}
handler.endFinally();
}
handler.end();
} else {
_statement.compile(context);
}
}
public boolean callFinalizer()
{
if (_handler == null) {
return false;
}
if (_finally != null) {
_handler.callFinally();
if (_finally.isBlocked()) {
return true;
}
}
return false;
}
}