On Tue, Apr 10, 2018 at 08:14:54AM -0700, Joe Perches wrote: > Whinging about bool <foo> : <x> seems entirely sensible > and straightforward to do. > > I'm not so sure about bool in structs as a patch context > could be adding a bool to local stack definitions and > there's no real ability to determine if the bool is in a > struct or on the stack. > > Also, I think there's nothing really wrong with using > bool in structs. Steven Rostedt's rationale in > https://lkml.org/lkml/2017/11/21/207 isn't really right > as sizeof(int) is 4 not 1 and sizeof(bool) is 1 on arches > without alignment issues. I believe when using gcc, > sizeof(bool) is always 1 and there may be alignment padding > added on some arches. Dunno.
C std simply does not define sizeof(_Bool) and leaves it up to architecture ABI, therefore I refuse to use _Bool in composite types, because I care about layout. Also, not all architectures can do byte addressing, see Alpha <EV56 and for those _Bool would have to be a whole word (the existence of such architectures likely influenced the vague definition of _Bool in the first place). > But I think the battle is already lost anyway. > > git grep -P '(?<!static|extern)\s+bool\s+\w+\s*;' include | wc -l > 1543 Yes I know, doesn't mean we shouldn't discourage it for new code; also Linus.