Re: [PATCH 1/5] kbuild: thin archives final link close --whole-archives option

[Nicholas Piggin <npiggin@gmail.com>]

On Mon, 19 Jun 2017 15:16:17 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Hi Nicholas,
> 
> 
> 2017-06-09 14:24 GMT+09:00 Nicholas Piggin <npiggin@gmail.com>:
> > Close the --whole-archives option with --no-whole-archive. Some
> > architectures end up including additional .o and files multiple
> > times after this, and they get duplicate symbols when they are
> > brought under the --whole-archives option.  
> 
> Which architectures have additional files after --no-whole-archive ?
> 
> I see this case only for ARCH = "um" in vmlinux_link()
> where it adds some -l* options after --no-whole-archive.
> 
> I think it is good to close the --whole-archives everywhere.
> So, the code looks OK to me, but I just wondered about the log.

Actually a number of archs seemed to get build errors without this,
and they seem to come from libgcc perhaps.

binfmt_elf.c:(.text+0x4851): undefined reference to `__kernel_syscall_via_epc'
/c/gcc/libgcc/libgcc2.c:1318: multiple definition of `__ucmpdi2'
/c/gcc/libgcc/libgcc2.c:405: multiple definition of `__lshrdi3'
/c/gcc/libgcc/libgcc2.c:433: multiple definition of `__ashldi3'
/c/gcc/libgcc/libgcc2.c:461: multiple definition of `__ashrdi3'

/home/tony/buildall/src/gcc/libgcc/config/xtensa/lib2funcs.S:36: multiple definition of `__xtensa_libgcc_window_spill'

etc

m32r, parisc, xtensa seemed to be getting such errors. I wonder if
the linker implicitly adds some runtime libs at the end that get
caught up here. Either way I didn't look too far into it because this
fix seems obviously correct and solved the problem.

Thanks,
Nick