Re: PR java/19285: Interfaces not initialized by static field access

[Bryce McKinlay <mckinlay at redhat dot com>]

Andrew Haley wrote:

> Bryce McKinlay writes:
> > Tom Tromey wrote:
> > 
> > >Anyway, I think the rule for incrementing the ABI version should be:
> > >
> > >* C++ ABI tracks the gcc version number, so is auto-incremented each
> > >  release.
> > >
> > >* The generated BC ABI version number should be incremented either
> > >  zero or one time between releases.  In particular it should only be
> > >  incremented the first time a non-backward-compatible change is made.
> > >  
> > >
> > Is this a flexible enough rule? Say we found some nasty bug in GCJ 4.0.2 
> > that could only be fixed by an ABI change in 4.0.3 (but of course old 
> > binaries that didn't hit the bug could still be supported). It would 
> > make sense in that scenario to be able to increment the BC version 
> > number for the 4.0.x series, and have 4.1 support both the old version 
> > IDs. The current version scheme doesn't really permit this. I think 
> > GCJ_BOOTSTRAP_LOADER_ADDITION also reduces our flexibility here. Perhaps 
> > we need an extra digit between GNUC_MINOR and the "additions" to allow 
> > for the possibility of increments within each GNUC_MINOR release.
> > 
> > On the other hand, hopefully that won't happen, and if it does we could 
> > always improvise something at the time.
> > 
> > 
> > >Bryce> How about something like this? Or would it be better to explicitly
> > >Bryce> define each different version somewhere?
> > >
> > >The compiler side of this looks reasonable to me.
> > >
> > >On the runtime side I would prefer the addition of a new define and
> > >explicit recognition of it.  I think it is better to be very clear
> > >than to try to micro-optimize this.
> > >  
> > >
> > OK, here's an updated patch.
> > 
> > Andrew, I still need approval for the compiler side.
>
> OK.  As I've also changed the ABI on the branch it needs to go there too.
>  

Err, well thats where we run into the problems I mentioned above. What 
version ID should the branch use? Although the ABI between 4.0 and 4.1 
is the same now, its quite likely that we'll make further changes in 4.1 
- thus 4.0.1 shouldn't be using 4.1's ID.

Bryce