[patch] allow suppression of fde encoding warning

[Sandra Loosemore]

On 01/19/2013 11:02 PM, Ian Lance Taylor wrote:
> On Sat, Jan 19, 2013 at 12:14 PM, Sandra Loosemore
> <sandra@codesourcery.com>  wrote:
>>
>> Google turned up a few references to this problem on other targets that
>> indicated that the "right" solution is for GCC to emit section-relative
>> references in the FDE data.  But, not all architectures support such a thing
>> in the ABI (and, in particular, the Nios II ABI doesn't have an appropriate
>> relocation for this purpose).  So, it seems like we should be able to turn
>> the warning off on architectures where the optimization cannot possibly
>> work.
>
> I think the correct solution is to avoid using the --eh-frame-hdr
> option on architectures where it can not work.  I think the linker is
> correctly warning you that although you explicitly specified
> --eh-frame-hdr, you aren't going to get an exception frame header.

Actually, I did not explicitly specify --eh-frame-hdr.  GCC adds it to 
the link spec by default if the linker supports it, and ld thinks that 
all ELF targets support this option.  So, where's the right place to 
suppress that -- GCC or ld?  Is --eh-frame-hdr never useful for anything 
on this architecture, or is it only the combination with -fpie that is bad?

-Sandra