Re: [PATCH 1/2] Convert symtab, cgraph and varpool nodes into a real class hierarchy

[Jan Hubicka <hubicka at ucw dot cz>]

> > +  while (x != xlimit)
> > +    {
> > +      /* Code common to all symtab nodes. */
> > +      gt_ggc_m_9tree_node (x->decl);
> > +      gt_ggc_mx_symtab_node_base (x->next);
> > +      gt_ggc_mx_symtab_node_base (x->previous);
> > +      gt_ggc_mx_symtab_node_base (x->next_sharing_asm_name);
> > +      gt_ggc_mx_symtab_node_base (x->previous_sharing_asm_name);
> > +      gt_ggc_mx_symtab_node_base (x->same_comdat_group);
> > +      gt_ggc_m_20vec_ipa_ref_t_va_gc_ (x->ref_list.references);
> > +      gt_ggc_m_9tree_node (x->alias_target);
> > +      gt_ggc_m_18lto_file_decl_data (x->lto_file_data);
> 
> Don't we have template specializations so we just can do
> 
>          gt_ggc_mark (x->decl);
>          gt_ggc_mark (x->next);
Yep, that is what I hope for.
> ...
> etc?
> 
> Also all of the symbol table is reachable from the global symbol_table
> dynamic array which is a GC root.  So instead of walking ->next/previous
> and edges you should have a custom marker for the symbol_table global
> which does more efficient marking with loops.

Indeed, good point!
All of the pointers linking symbol table together (i.e. pointer to other symbol
table entries) can be ignored for PCH mark (since we are explicitely allocated,
and all we need is to mark the trees/lto data and other stuff we point to.

These are annotated primarily to get PCH working, where we obviously need
to keep them.

It would be nice to progress on this patch soon :)

Honza
> 
> Richard.