On Tue, May 9, 2023 at 9:45 AM Florian Weimer via Gcc <gcc@gcc.gnu.org> wrote: > > The part David quoted above is about this: > > $ gcc -fno-gnu89-inline -std=gnu89 t.c > cc1: error: ‘-fno-gnu89-inline’ is only supported in GNU99 or C99 mode > > And some packages need -fno-gnu89-inline, but also rely on implicit ints > and implicit function declarations heavily. With a purely C89-based > opt-out and the -fno-gnu89-inline limitation, we wouldn't have a way to > compile these self-contradictory programs. Hence the idea of > -fpermissive, in addition to the -std=gnu89 escape hatch. > > But perhaps the -fno-gnu89-inline limitation is easy to eliminate. The > remaining reason for -fpermissive would be a flag that is accepted by > both gcc and g++, in case a package build system passes CFLAGS to g++ as > well, which sometimes happens. And -fno-gnu89-inline is currently not > accepted by g++. But in the Fedora package set, this (some C++ and a > C89 requirement) must be exceedingly rare because it's a subset of the > already tiny set of -fno-gnu89-inline -std=gnu89 packages.
I think I wrote that error, back in 2007, because I thought it was odd to rely on the C99 semantics for inline functions when not using C99. And to encourage people to move to C99. But I wouldn't be surprised if the compiler just works without the error. It would just require adding a few test cases similar to gcc.dg/inline-18.c through inline-21.c (well, inline-21.c would have to be removed or rewritten). Ian
