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? 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. - 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
