Re: [RFC PATCH 1/2] kbuild: add CONFIG_LD_IS_BINUTILS

[Masahiro Yamada]

On Fri, Apr 24, 2020 at 3:44 AM Nick Desaulniers
<ndesaulniers@xxxxxxxxxx> wrote:
>
> On Sun, Apr 19, 2020 at 6:19 AM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
> >
> > This patch is currently not mandatory but a prerequisites for the second one.
> >
> > Folks from ClangBuiltLinux project like the combination of Clang compiler
> > and LLD linker from LLVM project to build their Linux kernels.
> >
> > Sami Tolvanen <samitolvanen@xxxxxxxxxx> has a patch for using LD_IS_LLD (see [1]).
> >
> > Documentation/process/changes.rst says and uses "binutils" that's why I called
> > it LD_IS_BINUTILS (see [2] and [3]).
> >
> > The second patch will rename existing LD_VERSION to BINUTILS_VERSION to have
> > a consistent naming convention like:
> >
> > 1. CC_IS_GCC and GCC_VERSION
> > 2. CC_IS_CLANG and CLANG_VERSION
> > 3. LD_IS_BINUTILS and BINUTILS_VERSION
> >
> > [1] https://github.com/samitolvanen/linux/commit/61889e01f0ed4f07a9d631f163bba6c6637bfa46
> > [2] https://git.kernel.org/linus/tree/Documentation/process/changes.rst#n34
> > [3] https://git.kernel.org/linus/tree/Documentation/process/changes.rst#n76
> >
> > Signed-off-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
>
> Just some background on Sami's patch.  Originally we were using
> ld.gold (for LTO for Pixel 3) before moving to ld.lld (for LTO for
> Pixel 4 and later).  Not sure if Kconfig would be a better place to
> check if gold is used, then warn?  I kind of prefer the distinction
> that binutils contains two different linkers, though if no one is
> supporting ld.gold, and it doesn't work for the kernel, then maybe
> that preference is moot?


I prefer LD_IS_BFD, like this patch:
https://lore.kernel.org/patchwork/patch/1039719/

We do not need LD_IS_GOLD, though.




-- 
Best Regards
Masahiro Yamada