[tree-ssa] Garbage collector x bb annotations

[Geoff Keating]

Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz> writes:

> Hello,
> 
> > > I have just run into the following problem: dom_children get released by
> > > ggc_collect call in tree-ssa-pre.  Allocating them by ggc seems wrong to
> > > me, since basic block annotations are allocated from obstack and
> > > invisible to garbage collector.
> > > 
> > Yeah.  But there's more than that, unfortunately.  All the fields in
> > struct bb_ann_d are ggc allocated.  The real solution would be to
> > finally convert basic blocks to ggc.  Volunteers?
> 
> I may try (I need it anyway for tree-ssa-cfg branch).  The whole issue
> is however quite ugly as this combines basically all allocation
> mechanisms that are available in gcc (basic blocks themselves are pool
> allocated).

It's not that ugly to make the fix, you simply have to throw out all
those other allocation mechanisms and use ggc.

-- 
- Geoffrey Keating <geoffk@geoffk.org>