On 18/02/2021 13:31, Florian Weimer via Gcc wrote: > * Jonathan Wakely via Gcc: > >> Declare your functions. Don't ignore warnings. > > It's actually a GCC bug that this isn't an error. However, too many > configure scripts would still break if we changed the default. >
People have had 22 years to fix them. Implicit function declarations were a terrible idea from day 1, and banned outright in C99. It was reasonable for them to be accepted when the default C standard for gcc was "gnu90" - they should have never been acceptable in any later standards without needing an explicit flag. Since gcc 5 they have given a warning by default - surely it is time for them to be a hard error? > So either use -Werror=implicit-function-declaration or C++ for the time > being. > > Thanks, > Florian > >
