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_ow4RyJVPwFTg@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.