> -----Original Message----- > From: Kyrylo Tkachov <ktkac...@nvidia.com> > Sent: Friday, January 17, 2025 3:10 PM > To: Richard Sandiford <richard.sandif...@arm.com> > Cc: Tamar Christina <tamar.christ...@arm.com>; GCC Patches <gcc- > patc...@gcc.gnu.org>; nd <n...@arm.com>; Richard Earnshaw > <richard.earns...@arm.com>; ktkac...@gcc.gnu.org > Subject: Re: [PATCH]AArch64: Drop ILP32 from default elf multilibs after > deprecation > > > > > On 17 Jan 2025, at 14:47, Richard Sandiford <richard.sandif...@arm.com> > wrote: > > > > Tamar Christina <tamar.christ...@arm.com> writes: > >>> -----Original Message----- > >>> From: Kyrylo Tkachov <ktkac...@nvidia.com> > >>> Sent: Friday, January 17, 2025 1:22 PM > >>> To: Tamar Christina <tamar.christ...@arm.com> > >>> Cc: GCC Patches <gcc-patches@gcc.gnu.org>; nd <n...@arm.com>; Richard > >>> Earnshaw <richard.earns...@arm.com>; ktkac...@gcc.gnu.org; Richard > >>> Sandiford <richard.sandif...@arm.com> > >>> Subject: Re: [PATCH]AArch64: Drop ILP32 from default elf multilibs after > >>> deprecation > >>> > >>> > >>> > >>>> On 17 Jan 2025, at 14:06, Tamar Christina <tamar.christ...@arm.com> > wrote: > >>>> > >>>>> -----Original Message----- > >>>>> From: Kyrylo Tkachov <ktkac...@nvidia.com> > >>>>> Sent: Friday, January 17, 2025 1:04 PM > >>>>> To: Tamar Christina <tamar.christ...@arm.com> > >>>>> Cc: GCC Patches <gcc-patches@gcc.gnu.org>; nd <n...@arm.com>; Richard > >>>>> Earnshaw <richard.earns...@arm.com>; ktkac...@gcc.gnu.org; Richard > >>>>> Sandiford <richard.sandif...@arm.com> > >>>>> Subject: Re: [PATCH]AArch64: Drop ILP32 from default elf multilibs after > >>>>> deprecation > >>>>> > >>>>> > >>>>> > >>>>>> On 17 Jan 2025, at 13:56, Tamar Christina <tamar.christ...@arm.com> > wrote: > >>>>>> > >>>>>> Hi All, > >>>>>> > >>>>>> Following the deprecation of ILP32 *-elf builds fail now due to > >>>>>> -Werror on > the > >>>>>> deprecation warning. This is because on embedded builds ILP32 is part > >>>>>> of > the > >>>>>> default multilib. > >>>>>> > >>>>>> This patch removed it from the default target as the build would fail > anyway. > >>>>>> > >>>>>> Cross compiled on aarch64-none-elf and build succeeds now. > >>>>>> > >>>>>> Ok for master? > >>>>> > >>>>> I was going to say that it’s more common to just announce deprecation in > the > >>>>> documentation/release notes for one release cycle, to give time for > >>>>> potential > >>> users > >>>>> to come forward. > >>>>> If we remove the multilib build now we’d be helping the support bitrot > >>>>> much > >>>>> faster, which would make it harder to restore if such a user does come > forward. > >>>>> > >>>> > >>>> The alternative approach would be to suppress the warning during build, > >>>> the > >>> downside > >>>> is ofcourse that this warning does not have a unique identifier, so I > >>>> believe > we'd > >>> have to > >>>> suppress all deprecation warnings: > >>>> > >>>> cc1: error: '-mabi=ilp32' is deprecated [-Werror=deprecated] > >>>> > >>>> But could work.. > >>>> > >>> > >>> I think if the warning suppression only happened for the ILP32 multilib > >>> build > that > >>> would be okay. > >>> Other deprecation warnings would be caught in the LP64 build > >> > >> I can make that work by conditionally changing MULTILIB_OPTIONS in > >> gcc/config/aarch64/t-aarch64 when it's collecting the options for ILP32. > >> > >> What do others think? > > > > To be honest, it seems like a waste of effort to me. If anyone complains > > about the removal of the multilib in GCC 15, we can always revert it for > > later releases in the GCC 15 series. A reversion like that would > > presumably also mean reverting the deprecation, since it wouldn't be > > worth reinstating the multilib for one release series only. > > Ok, let’s get rid of the multilib in this release then. > My comment about documenting that in the release notes still stands
Not a problem, Thanks for the discussion, > I don’t know if we document the ILP32 multilib somewhere. If so, it should be > updated. From what I can tell, we've never documented what the default multilib is for AArch64. There are documentation for other targets but can't find any for AArch64. > In any case the gcc-15 release notes should also mention this change. Agreed, we haven't written out release notes yet this year, and I'm waiting till features stabilize a bit. Is it ok if I do this when I publish the remainder? As it stands we haven't documented any Arm or AArch64 changes yet to https://gcc.gnu.org/gcc-15/changes.html But I've added it to the internal list. Thanks, Tamar > Thanks for handling this. > Kyrill > > > > > Thanks, > > Richard
