Re: More C type errors by default for GCC 14
On Wed, May 10, 2023 at 6:48 AM Sam James wrote: > > > Eric Gallager via Gcc writes: > > > On 5/9/23, Jonathan Wakely via Gcc wrote: > >> On Tue, 9 May 2023 at 23:38, Joel Sherrill wrote: > >>> We are currently using gcc 12 and specifying C11. To experiment with > >>> these stricter warnings and slowly address them, would we need to build > >>> with a newer C version? > >> > >> No, the proposed changes are to give errors (instead of warnings) for > >> rules introduced in C99. GCC is just two decades late in enforcing the > >> C99 rules properly! > >> > >> > >>> What practices might the GCC community recommend to a project > >>> wanting to discover the issues uncovered and slowly address them? I > >> > >> -Werror=implicit-int > >> -Werror=implicit-function-declaration > >> -Werror=int-conversion > >> > > > > Idea for a compromise: What if, instead of flipping the switch on all > > 3 of these at once, we staggered them so that each one becomes a > > default in a separate release? i.e., something like: > > > > - GCC 14: -Werror=implicit-function-declaration gets added to the defaults > > - GCC 15: -Werror=implicit-int gets added to the defaults > > - GCC 16: -Werror=int-conversion gets added to the defaults > > > > That would give people more time to catch up on a particular warning, > > rather than overwhelming them with a whole bunch all at once. Just an > > idea. > > I think this might be more frustrating than not, althuogh I appreciate > the intent. > > Neal Gompa wasn't keen on the idea at > https://lore.kernel.org/c-std-porting/CAEg-Je8=dQo-jAdu=od5dh+h9aqzge_4ghzgx_ow4ryjvpw...@mail.gmail.com/ > because it'd feel like essentially "repeated punches". > > Maybe it'd work with some tweaks: I would, however, be more open to GCC 14 > having > implicit-function-declaration,implicit-int (these are so closely related > that it's not worth dividing the two up) and then say, GCC 15 having > int-conversion and maybe > incompatible-pointer-types. But spreading it out too much is likely > counterproductive. Right, we've been going through a similar effort with C++ over the past decade. GCC incrementally becoming more strict on C++ has been an incredibly painful experience, and it eats away a ton of time that I would have spent dealing with other problems. Having one big event where the majority of changes to make the C compiler strict happen will honestly make it less painful, even if it doesn't seem like it at the moment. This is because with as much C++ stuff we have in Linux distributions, we have so much more C stuff. -- 真実はいつも一つ！/ Always, there's only one truth!
Re: More C type errors by default for GCC 14
On Wed, May 10, 2023 at 8:05 AM Eli Zaretskii wrote: > > > From: Neal Gompa > > Date: Wed, 10 May 2023 06:56:32 -0400 > > Cc: Eric Gallager , Jonathan Wakely > > , j...@rtems.org, > > David Edelsohn , Eli Zaretskii , > > Jakub Jelinek , > > Arsen Arsenović , gcc@gcc.gnu.org, > > c-std-port...@lists.linux.dev > > > > On Wed, May 10, 2023 at 6:48 AM Sam James wrote: > > > > > > Neal Gompa wasn't keen on the idea at > > > https://lore.kernel.org/c-std-porting/CAEg-Je8=dQo-jAdu=od5dh+h9aqzge_4ghzgx_ow4ryjvpw...@mail.gmail.com/ > > > because it'd feel like essentially "repeated punches". > > > > > > Maybe it'd work with some tweaks: I would, however, be more open to GCC > > > 14 having > > > implicit-function-declaration,implicit-int (these are so closely related > > > that it's not worth dividing the two up) and then say, GCC 15 having > > > int-conversion and maybe > > > incompatible-pointer-types. But spreading it out too much is likely > > > counterproductive. > > > > Right, we've been going through a similar effort with C++ over the > > past decade. GCC incrementally becoming more strict on C++ has been an > > incredibly painful experience, and it eats away a ton of time that I > > would have spent dealing with other problems. Having one big event > > where the majority of changes to make the C compiler strict happen > > will honestly make it less painful, even if it doesn't seem like it at > > the moment. > > But not having such an event, ever, would be even less painful. That's not going to happen. An event will eventually happen when GCC and Clang switch their default C standard version. And making the compilers stricter is something that has enough benefit to outweigh the pain. The question is "how often" rather than "should we do it". -- 真実はいつも一つ！/ Always, there's only one truth!
