MIPS gas/ld -xgot handling is broken for at least mips*-linux

[Daniel Jacobowitz]

On Wed, Aug 18, 2004 at 07:57:49PM +0200, Thiemo Seufer wrote:
> David Daney wrote:
> > Thiemo Seufer wrote:
> > > Hello All,
> > > 
> > > since the introduction of multi-got in the mips gas/ld the -xgot
> > > option breaks in ld as soon as the GOT size grows over the
> > > (single-GOT) 64 kB limit. ld tries to handle it as multi-GOT
> > > instead of a large single GOT.
> > > 
> > > I see two approaches to fix this:
> > > - Disallow the -xgot option for traditional mips. The appended patch
> > >   does so. This will leave SGI-style configurations broken. On IRIX,
> > >   this would imply using the native ld.
> > > - Let ld handle xgot compiled code as large single GOT again. For this,
> > >   it needs either some xgot flag, or has to generally disable multi-GOT
> > >   for SGI-style configurations. The elf header provides a EF_MIPS_XGOT
> > >   flag, but this isn't set by gas yet.
> > > 
> > > I tend to do the first because I don't know if xgot ever really
> > > worked on linux. Comments?
> > > 
> > 
> > On mipsel-linux (and the untested mips-linux configuration):
> > 
> > The java support in gcc-3.4.x and beyond currently uses the compiler's
> > -mxgot flag which generates large got code via explicit relocs.
> > 
> > Earlier private versions of this support for gcc-3.3 use the gas -xgot
> > option.
> > 
> > We are forced to do this (I think) due to the screwed up way that
> > libtool generates the libgcj.so shared library (piece-wise linking due
> > to command line length restrictions).
> 
> Hm, the multi-GOT support in gas/ld is supposed to handle this well.

GOTs are created at final link time, and only one per .o is supported. 
Libtool has this tendency (see Alan's posting about ppc64 earlier) to
create objects using ld -r.

-- 
Daniel Jacobowitz