On Tue, Apr 10, 2012 at 9:39 AM, Jakub Jelinek <ja...@redhat.com> wrote: > On Tue, Apr 10, 2012 at 09:22:56AM -0700, Xinliang David Li wrote: >> On Tue, Apr 10, 2012 at 1:46 AM, Jakub Jelinek <ja...@redhat.com> wrote: >> > On Mon, Apr 09, 2012 at 04:34:32PM -0700, Xinliang David Li wrote: >> >> Class hierarchy is one such feature that is useful. Assuming we have >> >> two hierarchies for gcc: one for values rooted at ValExp, and one for >> >> gimple stmts rooted at GimpInst. >> >> >> >> 1) For IR browsing, >> >> *) all the macro accessors can be eliminated -- a big plus for >> >> debugging; >> > >> > Not that clear, if all the macros are replaced by tons of inline functions, >> > the debugging experience can be actually significantly worse. Already >> > some the >> > inline functions used like tree_operand_length used by TREE_OPERAND_LENGTH >> > macro are extremely annoying from debugging POV. >> >> What is the root cause of the annoyance? Mixing macros and inline >> functions does not sound good, but using deeply nested macros do not >> seem to help the debugging situation either. > > That when stepping through code in the debugger you keep enterring/exiting > these one liner inlines, most of them really should be at least by default > considered just as normal statements (e.g. glibc heavily uses artificial > attribute for those, still gdb doesn't hide those by default). > >> > Not to mention it is very questionable if the above stuff is more readable >> > than what we currently have. >> >> The above is just quickly cooked up examples. A carefully designed C++ >> based API can be self documenting and make the client code very >> readable. It is hard to believe that there is no room for improvement >> in GCC. > > Do you have examples? E.g. I haven't touched gold, because, while it is a new > C++ codebase, looks completely unreadable to me, similarly libdw C++ stuff. > A carefully designed C based API can be self documenting and make the code > very readable as well, often more so.
Personally I think the core APIs should be abstract enough to hide IR details, and high level (possibly multi-level) to allow efficient code manipulation -- be it C or C++. However I think this is really more about the general perceptions and how future developers feel about it. thanks, David > > Jakub
