Re: gengtype needs for C++?

[Basile Starynkevitch <basile at starynkevitch dot net>]

On Wed, Jun 30, 2010 at 11:51:46AM +0200, Paolo Bonzini wrote:
> 
> Now:
> 
> /* A zillion macros like this one: */
[...]
> 
> 
> After:
> 
> /* Two templates like these: */
> template <class T> static inline void
> ggc_mark_all (T *const x)
> {
>   if (x != NULL) ggc_mark_all_1 (x);
> }
> 
> template <class T> static inline void
> ggc_mark_all_1 (T *const x)
> {
>   gcc_unreachable();
> }
> 
> /* Many specializations like this (generated by gengtype). */
> template <> void
> ggc_mark_all_1 (struct eh_catch_d * const x)
> {
>   if (ggc_test_and_set_mark (x))
>     {
>       ggc_mark_all ((*x).next_catch);
>       ggc_mark_all ((*x).prev_catch);
>       ggc_mark_all ((*x).type_list);
>       ggc_mark_all ((*x).filter_list);
>       ggc_mark_all ((*x).label);
>     }
> }
> 
> /* A single specialization for all std::vectors, whose treatment
>    is simpler than VECs in gengtype: */
> template <std::vector<T, ggc_allocator> > void
> ggc_mark_all_1 (std::vector<T, ggc_allocator> * const x)
> {
>   typedef typename std::vector<T, ggc_allocator> vec_type;
>   typedef typename vec_type::iterator iterator;
> 
>   for (iterator p = x.begin(), q = x.end(); p != q; ++p)
>     gcc_mark_all (*p);
> }
> 
> 
> Of course it may be too bad for compilation times, it may require
> other changes (e.g. to the way roots are enumerated, or because
> templates require stuff to be in header files that used to be in
> gtype-desc.c), it may not work at all.  No idea. :)


Thanks for the nice explanations.

Cheers.

-- 
Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
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