Re: Bug#432541: eclipse-cdt FTBFS with gcj-4.2

[Andrew Haley <aph@redhat.com>]

Andrew Haley wrote:
> Michael Koch wrote:
> > On Sun, Mar 02, 2008 at 12:01:03PM +0000, Andrew Haley wrote:
> > > Michael Koch wrote:
> > > > On Sun, Mar 02, 2008 at 10:35:28AM +0000, Andrew Haley wrote:
> > > > > And what was the reason?  I need to know.
> > > > !ENTRY org.eclipse.osgi 4 0 2008-03-02 12:38:50.196
> > > > !MESSAGE Application error
> > > > !STACK 1
> > > > java.lang.ClassNotFoundException: org.eclipse.core.runtime.Plugin
> > > >    at 
> > > > org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.java:402) 
> > > >
> > > >    at 
> > > > org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.java:347) 
> > > >
> > > > make: *** [build-stamp] Fehler 13
> > > >
> > > > The only small strange thing is that org.eclipse.core.runtime.Plugin 
> > > > and
> > > > org.eclipse.core.runtime.Platform are in the same Jar. This must be 
> > > > some
> > > > OSGi issue. At least I know now where to start debugging.
> > > Oh, right, so you *don't* actually know what the cause of this is.  
> > > Me either, but
> > > I'm debugging it at the moment.
> >
> > Yeah, yesterday I thought it was just a missing jar file. Today I took a
> > closer look at at it...
> >
> > > gcj should not distinguish between natively compiled code and bytecode.
> > > The fact that it makes a difference must be a bug.
> >
> > Sounds like it. Can I somehow help? I know this is a hard case and
> > currently cant think of a simpler testcase.
>
> OK, I've found it.  The ClassNotFoundException is thrown from a security 
> check
> in libgcj.  We are calling Method m1 from method m0, and m1's class loader
> is different from m0's class loader.  We have to check that for every arg
> in m1, the actual type is the same in both m1.loader and m0.loader.
>
> The method in question is 
> org.eclipse.core.runtime.Platform.getPlugin(String), which returns an 
> instance of org.eclipse.core.runtime.Plugin.  It gets this
> by calling org.eclipse.core.internal.plugins.PluginDescriptor.getPlugin().

To be clear: the two class loaders being checked are those of

 interface org.eclipse.core.runtime.IPluginDescriptor

and

 class org.eclipse.core.runtime.Platform

Tromey: are you quite sure we should be checking the class loader
of the interface type instead of the class loader of the method we're
invoking?

Andrew.