On Tue, Jul 2, 2024 at 10:30 AM Warner Losh <i...@bsdimp.com> wrote:
> Hey John, > > On Tue, Jul 2, 2024 at 9:44 AM John Baldwin <j...@freebsd.org> wrote: > >> On 7/1/24 4:09 PM, Warner Losh wrote: >> > On Mon, Jul 1, 2024, 3:53 PM John Baldwin <j...@freebsd.org> wrote: >> > >> >> On 6/20/24 7:41 PM, Warner Losh wrote: >> >>> The branch main has been updated by imp: >> >>> >> >>> URL: >> >> >> https://cgit.FreeBSD.org/src/commit/?id=67d1a1cd9e772e2ef94003579f4fbc271d38be7d >> >>> >> >>> commit 67d1a1cd9e772e2ef94003579f4fbc271d38be7d >> >>> Author: Warner Losh <i...@freebsd.org> >> >>> AuthorDate: 2024-06-20 23:02:56 +0000 >> >>> Commit: Warner Losh <i...@freebsd.org> >> >>> CommitDate: 2024-06-21 02:41:08 +0000 >> >>> >> >>> cdefs.h: Remove support for pre gcc 4.0 >> >>> >> >>> All supported compilers support the gcc 3 attribute extensions. >> >> Remove >> >>> the #else clauses for this. Also, latter-day pcc compilers also >> >> define >> >>> __GNUC__, so there's not need to also test for __PCC__. >> >>> >> >>> Reviewed by: brooks >> >>> Differential Revision: https://reviews.freebsd.org/D45654 >> >>> Sponsored by: Netflix >> >>> --- >> >>> sys/sys/cdefs.h | 42 ++++-------------------------------------- >> >>> 1 file changed, 4 insertions(+), 38 deletions(-) >> >>> >> >>> diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h >> >>> index 88019819eb35..a6ecdca5d8b9 100644 >> >>> --- a/sys/sys/cdefs.h >> >>> +++ b/sys/sys/cdefs.h >> >>> @@ -408,15 +389,10 @@ >> >>> * assign pointer x to a local variable, to check that its type is >> >>> * compatible with member m. >> >>> */ >> >>> -#if __GNUC_PREREQ__(3, 1) >> >>> #define __containerof(x, s, m) ({ >> >> \ >> >>> const volatile __typeof(((s *)0)->m) *__x = (x); >> \ >> >>> __DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, >> m));\ >> >>> }) >> >>> -#else >> >>> -#define __containerof(x, s, m) >> >> \ >> >>> - __DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m)) >> >>> -#endif >> >>> >> >>> /* >> >>> * Compiler-dependent macros to declare that functions take >> printf-like >> >>> @@ -434,14 +410,8 @@ >> >>> #define __strftimelike(fmtarg, firstvararg) \ >> >>> __attribute__((__format__ (__strftime__, fmtarg, >> firstvararg))) >> >>> >> >>> -/* Compiler-dependent macros that rely on FreeBSD-specific >> extensions. >> >> */ >> >>> -#if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 >> && \ >> >>> - defined(__GNUC__) >> >>> #define __printf0like(fmtarg, firstvararg) \ >> >>> __attribute__((__format__ (__printf0__, fmtarg, >> firstvararg))) >> >>> -#else >> >>> -#define __printf0like(fmtarg, firstvararg) >> >>> -#endif >> >> >> >> Does this still work with external GCC? I didn't think printf0 was >> >> supported >> >> by external GCC (or maybe I had to readd it in the port and that's >> what I >> >> remember). Ah, yes, printf0 is a local patch in the devel/freebsd-gccX >> >> ports, but is not available in stock GCC (e.g. lang/gcc does not >> support >> >> it). >> >> >> > >> > Ah. That would explain why it just worked for me. That's what I tested >> > with. Clang also seemed happy with it. But that was the in tree clang. >> Is >> > there a similar issue? Gnuc is defined for both. >> >> So we don't support building the base system with lang/gcc, only >> devel/freebsd-gccX (which has a local patch to add printf0 support). >> The only question might be, do we support using __printf0like for things >> that aren't in the base system that could be built with lang/gcc. If so, >> we might need to guard this somehow. I'm not sure though that we care >> about random software not in base using a FreeBSD-specific keyword from >> <sys/cdefs.h>. >> > > Yes. The question is "do we use __printf0like in our headers" since we > definitely > can't build FreeBSD itself w/o at least some of the extensions for other > things... > and the answer is "yes". err.h uses it, for example, as does setproctitle > in stdlib.h > > The interesting thing for me is that gcc13 will produce no warnings if I > include errr.h > because -Wsystem-header is off. With it on, warnings crop up too. This is > why my testing > didn't see it... > > It looks like clang has it as a builtin for all versions we care about, so > I'll create a phab to add some > of this back. Maybe we should upstream what we have, for this and > freebsd_printf since that's also > in clang and one of the small number of patches we have for the lang/gcc* > family? > https://reviews.freebsd.org/D45836 Warner
