> -----Original Message----- > From: Tamar Christina <tamar.christ...@arm.com> > Sent: Friday, January 17, 2025 5:07 PM > To: Kyrylo Tkachov <ktkac...@nvidia.com>; Richard Sandiford > <richard.sandif...@arm.com> > Cc: GCC Patches <gcc-patches@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 > > > -----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.
I realized I wasn't explicit enough here.. but if it ok to document this when we do the GCC 15 changes? Or did you want it done now before I commit this fix? Thanks, Tamar > > Thanks, > Tamar > > > Thanks for handling this. > > Kyrill > > > > > > > > Thanks, > > > Richard
