Date: Tue, 2 Jul 2024 14:27:48 -0400 From: John Baldwin <jhb@FreeBSD.org> To: Warner Losh <imp@bsdimp.com> Cc: Warner Losh <imp@freebsd.org>, src-committers <src-committers@freebsd.org>, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 67d1a1cd9e77 - main - cdefs.h: Remove support for pre gcc 4.0 Message-ID: <3e59b5b4-5807-49bd-a069-642f321c9662@FreeBSD.org> In-Reply-To: <CANCZdfqRusqMiJtbh_iBr2cDwTccDyti0mJo36GeNee%2B7ns4dQ@mail.gmail.com> References: <202406210241.45L2fOkP057010@gitrepo.freebsd.org> <4ecc814d-5df1-4db8-b9e0-4919895c5e6a@FreeBSD.org> <CANCZdfrrLWW=JSZ_%2BJcZkbyXnz4Av6dbqn2RBZRyh=8=R6n4zQ@mail.gmail.com> <df672d3e-8b34-478a-b2a7-1ed7fece0b9b@FreeBSD.org> <CANCZdfqRusqMiJtbh_iBr2cDwTccDyti0mJo36GeNee%2B7ns4dQ@mail.gmail.com>
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On 7/2/24 12:30, Warner Losh wrote: > Hey John, > > On Tue, Jul 2, 2024 at 9:44 AM John Baldwin <jhb@freebsd.org> wrote: > >> On 7/1/24 4:09 PM, Warner Losh wrote: >>> On Mon, Jul 1, 2024, 3:53 PM John Baldwin <jhb@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 <imp@FreeBSD.org> >>>>> AuthorDate: 2024-06-20 23:02:56 +0000 >>>>> Commit: Warner Losh <imp@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? Yeah, I should do my FSF paperwork for GCC sometime and try to upstream at least the printf changes and a few others (i386 defaulting to i686 on recent releases as well) -- John Baldwin
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