[Clirr-devel] CVS: clirr/src/test/net/sf/clirr/checks ClassModifierCheck.java,NONE,1.1

[Simon K. <s_k...@us...>]

Update of /cvsroot/clirr/clirr/src/test/net/sf/clirr/checks
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv10004

Added Files:
	ClassModifierCheck.java 
Log Message:
ClassModifierCheck tests.


--- NEW FILE ---
//////////////////////////////////////////////////////////////////////////////
// Clirr: compares two versions of a java library for binary compatibility
// Copyright (C) 2003 - 2004  Lars K?hne
//
// This library 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 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser 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 net.sf.clirr.checks;

import net.sf.clirr.event.Severity;
import net.sf.clirr.framework.AbstractDiffReporter;
import net.sf.clirr.framework.ApiDiffDispatcher;
import net.sf.clirr.framework.ClassChangeCheck;
import net.sf.clirr.framework.CheckerException;
import net.sf.clirr.event.ScopeSelector;

import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;

/**
 * Detects changes in class modifiers (abstract, final).
 *
 * @author lkuehne
 */
public final class ClassModifierCheck
        extends AbstractDiffReporter
        implements ClassChangeCheck
{
    /**
     * Create a new instance of this check.
     * @param dispatcher the diff dispatcher that distributes the detected changes to the listeners.
     */
    public ClassModifierCheck(ApiDiffDispatcher dispatcher)
    {
        super(dispatcher);
    }

    /** {@inheritDoc} */
    public boolean check(JavaClass compatBaseLine, JavaClass currentVersion)
    {
        final String className = compatBaseLine.getClassName();

        try
        {
            ScopeSelector.Scope currentScope = ScopeSelector.getClassScope(currentVersion);
            if (currentScope == ScopeSelector.SCOPE_PRIVATE)
            {
                // for private classes, we don't care if they are now final,
                // or now abstract, or now an interface.
                return true;
            }
        }
        catch (CheckerException ex)
        {
            log("Unable to determine whether class is private", 
                    Severity.ERROR, className, null, null);
            return true;
        }
        
        final boolean currentIsFinal = currentVersion.isFinal();
        final boolean compatIsFinal = compatBaseLine.isFinal();
        final boolean currentIsAbstract = currentVersion.isAbstract();
        final boolean compatIsAbstract = compatBaseLine.isAbstract();
        final boolean currentIsInterface = currentVersion.isInterface();
        final boolean compatIsInterface = compatBaseLine.isInterface();

        if (compatIsFinal && !currentIsFinal)
        {
            log("Removed final modifier in class " + className,
                    Severity.INFO, className, null, null);
        }
        else if (!compatIsFinal && currentIsFinal)
        {
            if (isEffectivelyFinal(compatBaseLine))
            {
                log("Added final modifier in class " + className
                        + " (but class was effectively final anyway)",
                        Severity.INFO, className, null, null);
                }
            else
            {
                log("Added final modifier in class " + className,
                        Severity.ERROR, className, null, null);
            }
        }

        // interfaces are always abstract, don't report gender change here
        if (compatIsAbstract && !currentIsAbstract && !compatIsInterface)
        {
            log("Removed abstract modifier in class " + className,
                    Severity.INFO, className, null, null);
        }
        else if (!compatIsAbstract && currentIsAbstract && !currentIsInterface)
        {
            log("Added abstract modifier in class " + className,
                    Severity.ERROR, className, null, null);
        }

        return true;
    }
    
    /**
     * There are cases where nonfinal classes are effectively final
     * because they do not have public or protected ctors. For such
     * classes we should not emit errors when a final modifier is
     * introduced.
     */
    private boolean isEffectivelyFinal(JavaClass clazz)
    {
        if (clazz.isFinal())
        {
            return true;
        }

        // iterate over all constructors, and detect whether any are
        // public or protected. If so, return false.
        Method[] methods = clazz.getMethods();
        for(int i=0; i<methods.length; ++i)
        {
            Method method = methods[i];
            final String methodName = method.getName();
            if (methodName.equals("<init>"))
            {
                if (method.isPublic() || method.isProtected())
                {
                    return false;
                }
            }
        }
        
        // no public or protected constructor found
        return true;
    }
}