https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115310
--- Comment #5 from Florian Weimer <fw at gcc dot gnu.org> --- (In reply to Martin Jambor from comment #4) > No. Specifically in openSUSE, -Werror=return-type is part of the > default compiler flags. We would like to silence the new errors such > as implicit-int in packages written in pre-99 C with putting > -std=gnu89 rather than -fpermissive in package spec files. We think > that -std=gnu89 option really better describes what is going on, > i.e. that the code is old rather than somewhat broken. We tried to use -std=gnu89 for this purpose in Fedora originally, and it did not quite work. Quite a few packages use C89 (or K&R) language features *and* C99-only constructs such as for loop initial declarations and C99 inlining semantics.