Re: ld: --gc-sections incompatible with --emit-relocs ?

[Nick Clifton <nickc at redhat dot com>]

Hi David,

> After some tests, it appears that I also specify --emit-relocs on the
> linker line, and removing this --emit-relocs causes --gc-sections to
> work as expected.

> Is any of you aware of such a limitation ? 

Yes.  The problem is that if relocations are being emitted, then the 
linker cannot safely discard sections.  This is because the linker does 
not know why the relocations are being emitted, so it cannot tell if the 
relocations associated with (potentially) garbage collected sections 
should be emitted or not.

> I did not find any reference in the manual.

True, this should be documented.  I will fix that.

> I would appreciate any hints on how to try to remove/workaround this 
> limitation.

You would need to add extra code to the linker.  Probably a new command 
line switch to tell the linker to aggressively garbage collect sections. 
 You will need to make sure that any section that is removed in this 
way also has any relocations associated with it removed from its 
equivalent *.rel or *.rela section.  (Or at least not emitted when the 
other relocs are emitted).

Cheers
  Nick