On Fri, Jun 08, 2018 at 12:04:36PM +0200, Sedat Dilek wrote: > On Fri, Jun 8, 2018 at 9:59 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Thu, Jun 7, 2018 at 10:49 PM, Nick Desaulniers > > <ndesaulniers@xxxxxxxxxx> wrote: > >> Functions marked extern inline do not emit an externally visible > >> function when the gnu89 C standard is used. Some KBUILD Makefiles > >> overwrite KBUILD_CFLAGS. This is an issue for GCC 5.1+ users as without > >> an explicit C standard specified, the default is gnu11. Since c99, the > >> semantics of extern inline have changed such that an externally visible > >> function is always emitted. This can lead to multiple definition errors > >> of extern inline functions at link time of compilation units whose build > >> files have removed an explicit C standard compiler flag for users of GCC > >> 5.1+ or Clang. > >> > >> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > >> Suggested-by: H. Peter Anvin <hpa@xxxxxxxxx> > >> Suggested-by: Joe Perches <joe@xxxxxxxxxxx> > > > > I suspect this will break Geert's gcc-4.1.2, which I think doesn't have that > > attribute yet (4.1.3 or higher have it according to the documentation. > > > > It wouldn't be hard to work around that if we want to keep that version > > working, or we could decide that it's time to officially stop supporting > > that version, but we should probably decide on one or the other. > > > > Good point. > What is the minimum requirement of GCC version currently? Good question ;-) (I recently had the impression that Documentation/process/changes.rst was making fun of me ;-) > AFAICS x86/asm-goto support requires GCC >= 4.5? > > Just FYI... > ...saw the last days in upstream commits that kbuild/kconfig for > 4.18-rc1 offers possibilities to check for cc-version dependencies. Good to know! Mind retrieving/sharing the commit id(s) or links to the corresponding discussion on LKML? Thanks, Andrea > > - sed@ - -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
