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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Fri, 19 Aug 2022 10:42:06 -0700
Message-ID: <CAKwvOdnnSAozX8bQ9HeSw12BV9OjpzyDmXk_BGczjVVQNN+7tQ@mail.gmail.com>
Subject: Re: [PATCH v3] kbuild: add debug level and macro defs options
To:     Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
Cc:     masahiroy@kernel.org, akpm@linux-foundation.org,
        dan.j.williams@intel.com, edumazet@google.com,
        isabbasso@riseup.net, jpoimboe@kernel.org, keescook@chromium.org,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux@rasmusvillemoes.dk, maskray@google.com,
        michal.lkml@markovi.net, nathan@kernel.org, peterz@infradead.org,
        vbabka@suse.cz
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On Sun, Aug 14, 2022 at 6:34 PM Dmitrii Bundin
<dmitrii.bundin.a@gmail.com> wrote:
>
> Adds config options to control debug info level and producing of macro
> definitions for GCC/Clang.
>
> Option DEBUG_INFO_LEVEL is responsible for controlling debug info level.
> Before GCC 11 and Clang 12 -gsplit-dwarf implicitly uses -g2. To provide
> a way to override the setting with, e.g. -g1, DEBUG_INFO_LEVEL is set
> independently from DEBUG_INFO_SPLIT.
>
> Option DEBUG_MACRO_DEFINITIONS is responsible for controlling inclusion
> of macro definitions. Since Clang uses -fdebug-macro to control if macro
> definitions are produced which is different from GCC, provides a
> compiler-specific way of handling macro inclusion. The option is handled
> after DEBUG_INFO_LEVEL since -g3 -g2 implies -g2, but -g2 -g3 implies
> -g3 and GCC uses -g3 to produce macro definitions.
>
> Signed-off-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
> ---
>
> Changes in v2: https://lore.kernel.org/all/20220804223504.4739-1-dmitrii.bundin.a@gmail.com/

Is any of this really necessary?  It seems like a great way to bloat
vmlinux artifacts built with CONFIG_DEBUG_INFO even further.  The
above link mentions "when debugging with GDB."  In that case, please
don't add new Kconfigs for these; just set -g3 when
CONFIG_GDB_SCRIPTS=y.

-- 
Thanks,
~Nick Desaulniers