This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] Fix PR52977


On Thu, Apr 26, 2012 at 06:43, Dodji Seketeli <dodji@seketeli.org> wrote:

> I guess it's also worth noting one limitation of PPHs that is, if I
> believe the wiki:
>
> Â ÂIn essence, the only headers that can be pre-parsed are those that
> Â Âproduce the same result when they are compiled in isolation or as
> Â Âpart of another translation unit. So, header files that are affected
> Â Âby pre-processor symbols defined before inclusion are not going to
> Â Âbe considered (e.g., stddef.h).
>
> [1]: http://gcc.gnu.org/wiki/pph#Scope_and_limitations
>
> How hard would it be to drop that limitation?

It's an explicit non-goal, actually.  If you relax this requirements,
you might as well re-parse the header file.  The work needed to make
flexible PPH images will rob you of most/all the performance you were
looking for.


Diego.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]