[tree-ssa] Garbage collector x bb annotations

[Daniel Berlin]

On Oct 8, 2003, at 9:53 AM, Zdenek Dvorak wrote:

> 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).

They used to be obstack allocated, so consider yourself lucky :P.

You could add a "fields_only" flag and modify gengtype to not mark the 
actual bb, only it's fields.

I could probably do this if you guys think it's a viable solution.
--Dan