Re: bug(?) in ppc relocations

[Momchil Velikov <velco at fadata dot bg>]

Ian Lance Taylor wrote:
> 
>    Date: Mon, 20 Mar 2000 23:32:07 +0200
>    From: Momchil Velikov <velco@fadata.bg>
>
>    Nope, I don't assume that. I see the output offset of the linker .sdata
>    secton being greater than zero, so the value of _SDA_BASE_ in the
>    output file is == (the address of .sdata + something greater than
>    32768), thus
>    the data items near the beginning of .sdata cannot be addressed with
>    signed 16-bit offset from _SDA_BASE_.
> 
> In that case, it sounds to me like _SDA_BASE_ was set to an
> inappropriate value.  _SDA_BASE_ should be set to something like the
> address where the first .sdata section is stored plus 32768.  The
> address where the first .sdata section is stored may have a non-zero
> output_offset.
> 
> Personally, I think something like _SDA_BASE_ should be set in the
> linker script.  That is what linker scripts are for.  However, I see
> that the PowerPC backend appears to be trying to set it directly.
> Perhaps that is the problem.  How does the PowerPC backend set
> _SDA_BASE_?

It's created in elf32-ppc.c:ppc_elf_create_linker_section() with offset
32768. And if this section is not the first to be output, it gets wrong
value.

Regards,
-velco