RFC: GAS: Add option to generate unused section symbols

[H.J. Lu]

On Fri, Mar 4, 2022 at 7:54 AM Nick Clifton via Binutils
<binutils@sourceware.org> wrote:
>
> Hi Guys,
>
>   With the 2.36 release of the binutils we stopped generating section
>   symbols if they were not needed by relocations.  This helps to reduce
>   object file size and enhances compatibility with the LLVM compiler.
>   But I have received some bug reports about this feature, most notably
>   from kernel maintainers who have found that the new behaviour breaks
>   the recordmcount tool.  So I am proposing the attached patch as a

I ran into this problem in the Linux kernel build.   I believe the proper
solution is to change the Linux kernel not to include the .o files which
are empty and unused.  It isn't so hard to do.

>   solution.
>
>   The patch adds an option to the assembler: --keep-unused-section-symbols=[yes|no]
>   which is pretty much self describing.  The patch itself is fairly
>   simple, although there is one area that might provoke comment:  Since
>   the xvec structure in a BFD is accessed via a const pointer, its
>   contents cannot be changed.  This makes sense most of the time, but
>   poses a problem for this patch since it wants to change the
>   keep_unused_section_symbols field.  So I decided that the simplest way
>   to resolve this would be to allocate a new xvec structure, fill it in,
>   and then change the pointer in the bfd.  This might be a bit wasteful
>   of memory, but I am not expecting this feature to be used very often
>   and I thought that it was better to preserve the const pointer
>   semantics.
>
>   Any comments ?
>
> Cheers
>   Nick


-- 
H.J.