Re: [PATCH v9 0/3] Kbuild: DWARF v5 support

From: Masahiro Yamada
Date: Sat Feb 06 2021 - 07:22:17 EST


On Sat, Feb 6, 2021 at 6:00 AM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
>
> On Fri, Feb 5, 2021 at 9:22 PM Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote:
> >
> > DWARF v5 is the latest standard of the DWARF debug info format.
> >
> > DWARF5 wins significantly in terms of size and especially so when mixed
> > with compression (CONFIG_DEBUG_INFO_COMPRESSED).
> >
> > Link: http://www.dwarfstd.org/doc/DWARF5.pdf
> >
> > Patch 1 places the DWARF v5 sections explicitly in the kernel linker
> > script.
> > Patch 2 modifies Kconfig for DEBUG_INFO_DWARF4 to be used as a fallback.
> > Patch 3 adds an explicit Kconfig for DWARF v5 for clang and older GCC
> > where the implicit default DWARF version is not 5.
> >
> > Changes from v8:
> > * Separate out the linker script changes (from v7 0002). Put those
> > first. Carry Reviewed by and tested by tags. Least contentious part
> > of the series. Tagged for stable; otherwise users upgrading to GCC 11
> > may find orphan section warnings from the implicit default DWARF
> > version changing and generating the new debug info sections.
> > * Add CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT in 0002, make it the
> > default rather than CONFIG_DEBUG_INFO_DWARF4, as per Mark, Jakub,
> > Arvind.
> > * Drop reviewed by and tested by tags for 0002 and 0003; sorry
> > reviewers/testers, but I view that as a big change. I will buy you
> > beers if you're fatigued, AND for the help so far. I appreciate you.
>
> All 3 patches NACKed - I drink no beer.

LoL.
Other than beer, I am fine with v9.

Personally, I thought v8 (no CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT)
was good too, but I do not have a strong opinion about
leaving the compiler's freedom to choose the dwarf version.

Unless somebody has an objection, I will pick up v9 for the next MW.


Meanwhile, if you want to give reviewed-by / tested-by
please do so.



--
Best Regards
Masahiro Yamada