Date: Sun, 19 Nov 2017 18:19:04 -0800 From: Mark Millard <markmi@dsl-only.net> To: Pedro Giffuni <pfg@FreeBSD.org> Cc: svn-src-head@freebsd.org Subject: Re: svn commit: r325954 - in head: . share/mk sys/conf usr.sbin/config Message-ID: <7230AC67-7F9A-4FE2-BC32-B2BA8091206D@dsl-only.net> In-Reply-To: <297A2FDE-6105-4F64-921B-9510066F0420@FreeBSD.org> References: <59284FA3-1659-49D0-A860-366B98B02209@dsl-only.net> <26aaac2e-01d5-a11c-1182-39363d5cafc5@FreeBSD.org> <4DCBA4BA-1803-4B8F-B232-7558227E4002@dsl-only.net> <297A2FDE-6105-4F64-921B-9510066F0420@FreeBSD.org>
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[Continuing the gcc 4.2.1 side issue a bit.] On 2017-Nov-19, at 5:40 PM, Pedro Giffuni <pfg@FreeBSD.org> wrote: >> On Nov 19, 2017, at 19:11, Mark Millard <markmi@dsl-only.net> wrote: >>=20 >> [As long as things do not go the direction of >> eliminating gcc 4.2.1 being able to do buildworld >> and buildkernel for certain architectures, I >> agree that this would stay an off-topic subject.] >>=20 >> On 2017-Nov-19, at 3:43 PM, Pedro Giffuni <pfg at FreeBSD.org> wrote: >>=20 >>> .... >>> On 19/11/2017 17:38, Mark Millard wrote: >>>> Pedro Giffuni pfg at FreeBSD.org wrote on >>>> Sun Nov 19 15:29:33 UTC 2017 : >>>>=20 >>>>> Yes, we should >>>>> avoid breaking existing stuff (however old) in ports but no one is >>>>> expecting to build modern FreeBSD with gcc 3.4 or even gcc 4.1. We = did >>>>> what we could with gcc 4.2.1 but it's time is also over. >>>> Unfortunately for powerpc64 no alternative >>>> works fully. For example: >>>>=20 >>>> A) With a buildworld by clang and C++ programs linked against >>>> the system libraries, any C++ exception thrown causes the >>>> program to crash: clang generates bad code in the library. >>>>=20 >>>> B) Modern gcc's build a lib32 based on generating a messed up >>>> crtbeginS.o content (bad register usage) and so 32-bit >>>> programs crash. >>>>=20 >>>> As far as I know gcc 4.2.1 is still the only environment that >>>> generally works for powerpc64. >>> Hmm ... >>> At some point some of the newer GCC was generating good code. >>> I have had reports of openoffice-devel working on FreeBSD powerpc64 = and, >>> even on x86, openoffice stopped building with our base gcc. >>=20 >> openoffice likely does not depend on lib32 (support of 32-bit >> code under a powerpc64 environment) even being present, much >> less working? >>=20 >=20 > Yes, right: it=E2=80=99s pretty native: either all 64 bit or all 32 = bit.. > The port had endianness issues but once Curtis Hamilton fixed those = the port worked. > For the record: AOO generally needs two things: working java and a = low-level "bridges" code. > I don=E2=80=99t have access to the platform but patches to build the = arch-dependent =E2=80=9Cbridges=E2=80=9D code with clang would be very = welcome. >=20 >> As far as I know, for powerpc64 WITHOUT_LIB32=3D buildworld, >> devel/powerpc64-gcc is sufficient. It is WITH_LIB32=3D coverage >> that makes it insufficient overall. Anything that does not >> depend on lib32 likely works as well as on other architectures. >>=20 >>>> [There is no devel/powerpc-gcc like there is a devel/powerpc64-gcc >>>> and I've never managed to to make a working powerpc build from a >>>> gcc other than 4.2.1 . (A) prevents clang from counting as working >>>> overall. So powerpc may be in the same boat as powerpc64 as far as >>>> having a known way to build without gcc 4.2.1 goes.] >>> At least PPC64 is alive, I am afraid that I don't see a solution for = sparc64. >>=20 >> I do not have direct experience for sparc*'s but I'd >> not be surprised. >>=20 >>> But this is very off-topic to lint issue :). >>=20 >> As long as things do not go the direction of >> eliminating gcc 4.2.1 being able to do buildworld >> and buildkernel for certain architectures, I >> agree that this would stay an off-topic subject. >>=20 >=20 > I have no interest in killing any platform but we are reaching a point = where, other than being unmaintained, gcc-4.2.1 won=E2=80=99t be able to = build newer clang or gcc. gcc 4.2.1 has not been able to build the system clang for a long time. Getting from a gcc 4.2.1 powerpc64 or powerpc to a clang-based one is a pain when self hosting. Cross building with clang in use is handier when one has a supporting context for such. gcc* tends to have a bootstrapping stage available that builds xgcc (as I remember the name), avoiding modern stuff to get xgcc built. xgcc builds the full gcc* build, avoiding the original host compiler. This may still work with gcc 4.2.1 . I've not tried in a long time. Avoiding a full-bootstrap for a gcc* requires something more modern than gcc 4.2.1 . =3D=3D=3D Mark Millard markmi at dsl-only.net
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