[PATCH 6/13] mips musl support

[Rich Felker]

On Fri, May 08, 2015 at 02:25:11PM +0000, Matthew Fortune wrote:
> H.J. Lu <hjl.tools@gmail.com> writes:
> > On Mon, Apr 27, 2015 at 7:40 AM, Szabolcs Nagy <szabolcs.nagy@arm.com>
> > wrote:
> > >
> > >
> > > On 21/04/15 15:59, Matthew Fortune wrote:
> > >> Rich Felker <dalias@libc.org> writes:
> > >>> On Tue, Apr 21, 2015 at 01:58:02PM +0000, Matthew Fortune wrote:
> > >>>> There does however appear to be both soft and hard float variants
> > >
> > > Patch v2.
> > >
> > > Now all the ABI variants musl plans to support are represented.
> > >
> > > gcc/Changelog:
> > >
> > > 2015-04-27  Gregor Richards  <gregor.richards@uwaterloo.ca>
> > >             Szabolcs Nagy  <szabolcs.nagy@arm.com>
> > >
> > >         * config/mips/linux.h (MUSL_DYNAMIC_LINKER32): Define.
> > >         (MUSL_DYNAMIC_LINKER64, MUSL_DYNAMIC_LINKERN32): Define.
> > >         (GNU_USER_DYNAMIC_LINKERN32): Update.
> > 
> > You checked in config/linux.h CHOOSE_DYNAMIC_LINKER change without
> > config/mips/linux.h change.  Now linux-mips is broken.
> 
> The MIPS patch is OK. I am concerned that you are aiming for one
> dynamic linker per ABI variant in musl but are not accounting for
> soft-float up front in n32/n64. There is time to reconsider this
> before any of this code gets to a versioned GCC release though.

I'm not aware of whether there are mips64 chips for which softfloat
would be desirable, so I don't know if it's an ABI we'll ever have,
but I'm not opposed to adding it here just to be safe (in case we need
it).

> I.e. as it stands this patch is not OK for backporting to GCC 5
> without further discussion.
> 
> There is also the perspective that we should be able to aim for
> an ABI variant agnostic dynamic linker at some point over the next
> year by working towards a build that truly uses no float and is
> hence compatible with all the ABI variants.

For musl that's not going to happen. The dynamic linker and shared
libc are one file, which therefore has lots of public interfaces that
depend on the argument passing ABI.

Rich