[nios2, committed] Disable --eh-frame-hdr with -pie or -shared on nios2-linux-gnu

[Sandra Loosemore]

On 12/5/19 2:47 PM, Sandra Loosemore wrote:
> I've checked in this patch to fix a long-standing bug on nios2-linux-gnu 
> that resulted in linker errors like
> 
> ../nios2-linux-gnu/bin/ld: FDE encoding in /tmp/cccfpQ2l.o(.eh_frame) 
> prevents .eh_frame_hdr table being created
> 
> when linking with -pie or -shared.  The nios2 ABI doesn't provide the 
> relocations needed for those situations, so we shouldn't be passing 
> --eh-frame-hdr to the linker.
> 
> I've also checked in a related patch to the linker:Â  it was emitting 
> these diagnostics unconditionally, even when --eh-frame-hdr was not 
> enabled.  See
> 
> https://sourceware.org/ml/binutils/2019-12/msg00013.html
> 
> -Sandra

I've reverted this patch, as it appears I accidentally tested a 
different version of it (that disabled the option for -pie only and not 
-shared) than I committed, and the one committed triggers other errors. 
I need to revisit my original analysis of the linker bug and figure out 
why it is being triggered for -shared too.  And there's probably another 
bug lurking somewhere that's causing the execution errors in shared 
libraries linked without --eh-frame-hdr.  Needs More Thought.

BTW, the test case for -shared is the C++ version of the program used to 
test for { dg-require-effective-target shared } support.  :-(  (But 
libstdc++ builds fine as a shared library and doesn't fall over during 
testing....)

-Sandra