/* Soot - a J*va Optimization Framework
* Copyright (C) 2004 John Jorgensen
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
package soot.toolkits.exceptions;
import soot.AnySubType;
import soot.RefType;
import soot.Type;
import soot.Unit;
import soot.UnknownType;
import soot.NullType;
import soot.Value;
import soot.grimp.NewInvokeExpr;
import soot.jimple.ThrowStmt;
/**
* Abstract class implementing parts of the {@link ThrowAnalysis}
* interface which may be common to multiple concrete
* <code>ThrowAnalysis</code> classes.
* <code>AbstractThrowAnalysis</code> provides straightforward
* implementations of {@link mightThrowExplicitly(ThrowInst)} and
* {@link mightThrowExplicitly(ThrowStmt)}, since concrete
* implementations of <code>ThrowAnalysis</code> seem likely to differ
* mainly in their treatment of implicit exceptions.
*/
public abstract class AbstractThrowAnalysis implements ThrowAnalysis {
abstract public ThrowableSet mightThrow(Unit u);
public ThrowableSet mightThrowExplicitly(ThrowStmt t) {
Value thrownExpression = t.getOp();
Type thrownType = thrownExpression.getType();
if (thrownType == null || thrownType instanceof UnknownType) {
// We can't identify the type of thrownExpression, so...
return ThrowableSet.Manager.v().ALL_THROWABLES;
} else if (thrownType instanceof NullType) {
ThrowableSet result = ThrowableSet.Manager.v().EMPTY;
result = result.add(ThrowableSet.Manager.v().NULL_POINTER_EXCEPTION);
return result;
} else if (! (thrownType instanceof RefType)) {
throw new IllegalStateException("UnitThrowAnalysis StmtSwitch: type of throw argument is not a RefType!");
} else {
ThrowableSet result = ThrowableSet.Manager.v().EMPTY;
if (thrownExpression instanceof NewInvokeExpr) {
// In this case, we know the exact type of the
// argument exception.
result = result.add((RefType) thrownType);
} else {
result = result.add(AnySubType.v((RefType) thrownType));
}
return result;
}
}
abstract public ThrowableSet mightThrowImplicitly(ThrowStmt t);
}