Patch: update documentation for gcj-eclipse merge

[Tom Tromey]

>>>>> "Andrew" == Andrew Haley <aph@redhat.com> writes:

Andrew> Correct.  At leat, I'm pretty certain that the EPL requires that, but
Andrew> even if it didn't it would be irresponsible to make the sources
Andrew> available, so it's safe to assume so.

Yeah... this is on my to-do list, along with a half dozen other
finalizing things.  I'm sorry I put it off so long.

>> Do you expect possible problems if we don't use the 'latest' ecj1
>> with trunk but an earlier version?  What about the other way
>> around?  [I'm basically thinking on how to do a sensible setup for
>> packaging gcc in the future]

Andrew> There aren't any really bad problems AFAIAA, but binaries may be
Andrew> slightly different.  You'd have to be careful when committing .class
Andrew> files back to the libgcj tree that you didn't commit a ton of
Andrew> unnecessary changes, but anyone with write privileges is supposed to
Andrew> *look* at the files they're committing!

Andrew> The script contrib/download_ecj downloads a common version of ecj, and
Andrew> we'd hope that gcj maintainers would use that one; this will surely
Andrew> reduce the potential screwups.

I forgot to mention maintenance of ecj1 in my posts on this topic.

Since ecj will change over time, and since all these generated files
are checked in, we will have to handle ecj1 much the same way that we
handle the auto tools.  That is, all developers will have to use the
same version.  Anything else will lead to chaos.

I think the simplest thing is to have a blessed version of ecj for
each release branch.  We can modify download_ecj on such a branch to
download a separate file.

When we want to update ecj1 for the trunk, we can make a new
'ecj-latest.jar', upload it, and then regenerate all the class files
on the trunk, check them in, and send out email telling all gcj
developers that they must download a new version.

Any comments on this?  I made a note to document the ecj1 maintenance
process; I'll have to look up where this would go.

What distros do is of course up to them.  For Fedora I believe our
current plan is to make a special "ecj only" RPM based on the eclipse
compiler sources plus GCCMain.java (the ecj1 driver code).  GCCMain is
available from sourceware.org:/cvs/rhug, module 'eclipse-gcj'.  It
drops into the eclipse compiler source tree.

Tom