Do we still need ggc-simple

[Steven Bosscher]

On Wednesday 10 December 2003 11:41, Nick Burrett wrote:
> Steven Bosscher wrote:
> > Why do we still have ggc-simple?  Are there any targets for which
> > ggc-page doesn't work?
>
> Yes (arm-riscos-aof), though it is maintained outside of the GCC tree.

OK.  So I like bitching.

Why is arm-riscos-aof not using ggc-page with malloc?

Fact:  Virtually no-one is using ggc-simple.

I know for sure since building GCC with ggc-simple.c has been impossible since 
at least 26 Oct 2003.  On that day the zone collector was commited, and 
anyone who has tried to build gcc with ggc-simple as the collector should 
have seen a link failure because tree_zone is not declared anywhere.  I've 
heard no complaint, and my conclusion has to be that in almost two months 
time, nobody has noticed that ggc-simple.c is currently broken.

Ben suggested that a simpler GC could be useful for debugging.  I don't see 
how.  It's easy enough to tweak the better collectors to make them not 
collect at all, or change it in other ways to make debugging easier.

Besides, we have two collectors, and I find it hard to believe that we'd be 
able to break them both without anyone noticing.  Especially ggc-page, which 
is now effectively in "deep freeze": No serious work on this collector has 
been done over the past year (since the pch branch was merged).  So for 
debugging, you can always switch to the another collector.
(I do have to admit that we need a better way to analyse the performance/
characteristics of the other collectors.  But this has little to do with 
debugging.)

Having three collectors like we do now is very unpleasant.  Every time someone 
tries to add a feature to the GC system, it has to be added to _three_ 
collectors.  Bah.  Especially since ggc-simple is almost unused.  I would 
very much like to see it go away.

Gr.
Steven