On Wed, Sep 2, 2009 at 10:06 PM, Basile STARYNKEVITCH<bas...@starynkevitch.net> wrote: > Hello All, > > My feeling is that the Link Time Optimisation (LTO) effort should be soon > (=is expected to be, or is already) merged inside GCC trunk (future 4.5). > > Several years ago, I asked if there is any possibility for an additional > pass to profit of LTO infrastructure to add some extra data into LTO stuff > (which is probably DWARF related inside ELF object files, but I am not sure) > and to retrieve it. I remember that the answer was of course not. > > Now we have a working plugin infrastructure, and I believe it would be very > sensible for some plugin to register passes which add persistent information > (as does LTO with its Gimple related representation) into object files and > to retrieve it. > > Is there is still a major objection against that, or is there some API > usable from plguins for that purpose? > > Even the mere ability to add inside the LTO data a chunk of bytes identified > by the name of the plugin would be great. Of course, some more features > could be welcome (e.g. the ability to add data specific to each compiled > function or cgraph_node or whatever, or even to each gimple...). > > I could imagine that a plugin might be interested in adding say some > information into the object file (when ordinary compilation for LTO of a > single compilation unit happens) and later retrieve it (when link time > optimisation occur merging several object files.) > > A dream case example would be a plugin for whole program static analysis.
The IPA pass infrastructure has all the necessary bits for this. Richard. > Regards. > -- > Basile STARYNKEVITCH http://starynkevitch.net/Basile/ > email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359 > 8, rue de la Faiencerie, 92340 Bourg La Reine, France > *** opinions {are only mines, sont seulement les miennes} *** >
