From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from conssluserg-04.nifty.com (conssluserg-04.nifty.com [210.131.2.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A75D612F for ; Fri, 9 Sep 2022 20:57:31 +0000 (UTC) Received: from mail-oa1-f51.google.com (mail-oa1-f51.google.com [209.85.160.51]) (authenticated) by conssluserg-04.nifty.com with ESMTP id 289KvJIg028200 for ; Sat, 10 Sep 2022 05:57:20 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-04.nifty.com 289KvJIg028200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1662757040; bh=uqz24ZSjysiHUZlmL5XaHf2ZhL6SzB9+49wyUsEx67Q=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=BweEZeCLjEO3xjp9rjSb1j7Wn1RQaEjuczoyUfGU+LW3RPcEBOZuRacHEHeKVLIOD cYdZKvbxAohqLXWOsu/wacwUJSG9Rc/c7YI+AH+AcfX22brU/5zSUEhHJIV4xEy/cZ nr9ZYZn8NmAvVO+kognjgfxz1Q6lt7e+5S89SnKH+SRKW8yVjrYNzzoWeNcWkT0w7H uJikYJCj1f0hnpnn5kBf7Q1K31fSuIocfIHii/OsyyXvShUxypquucrB4g3xQ3iT1w Nx6JZtaDyRc5iFxSbM3ZQy7nGSlUNZuJkdlgnsk2phBqgU4MAL+MLjiCicU0KkkQzL 6oTmxQszYInjg== X-Nifty-SrcIP: [209.85.160.51] Received: by mail-oa1-f51.google.com with SMTP id 586e51a60fabf-1278a61bd57so7045640fac.7 for ; Fri, 09 Sep 2022 13:57:20 -0700 (PDT) X-Gm-Message-State: ACgBeo0q6q5ioLNfQvjvMTd8nZvZDDBrGqo+cUfxenPTRD6GR1/biuZT 42CaPwLp5+ni5ev/JuCJmO2LjlxEs5NFFUoPnbg= X-Google-Smtp-Source: AA6agR66+XO9Ke2tjFAZRiZGfx7pHOR7RKRdiA3vlsCmufJS6NDQDpZTXaoqbZ/Ykghz+SYA4kk37sT798vD5adC45g= X-Received: by 2002:a05:6870:f626:b0:10d:a798:f3aa with SMTP id ek38-20020a056870f62600b0010da798f3aamr5953724oab.194.1662757038871; Fri, 09 Sep 2022 13:57:18 -0700 (PDT) Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20220907045907.484043-1-ndesaulniers@google.com> <20220907045907.484043-6-ndesaulniers@google.com> In-Reply-To: <20220907045907.484043-6-ndesaulniers@google.com> From: Masahiro Yamada Date: Sat, 10 Sep 2022 05:56:42 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v3 5/5] Makefile.debug: set -g unconditional on CONFIG_DEBUG_INFO_SPLIT To: Nick Desaulniers Cc: Michal Marek , Nathan Chancellor , Tom Rix , Linux Kbuild mailing list , Linux Kernel Mailing List , clang-built-linux , X86 ML , Dmitrii Bundin , Fangrui Song , Alexey Alexandrov , Bill Wendling , Greg Thelen , Andi Kleen Content-Type: text/plain; charset="UTF-8" On Wed, Sep 7, 2022 at 1:59 PM Nick Desaulniers wrote: > > Dmitrii, Fangrui, and Mashahiro note: > > Before GCC 11 and Clang 12 -gsplit-dwarf implicitly uses -g2. > > Fix CONFIG_DEBUG_INFO_SPLIT for gcc-11+ & clang-12+ which now need -g > specified in order for -gsplit-dwarf to work at all. > > -gsplit-dwarf has been mutually exclusive with -g since support for > CONFIG_DEBUG_INFO_SPLIT was introduced in > commit 866ced950bcd ("kbuild: Support split debug info v4") > I don't think it ever needed to be. > > Link: https://lore.kernel.org/lkml/20220815013317.26121-1-dmitrii.bundin.a@gmail.com/ > Link: https://lore.kernel.org/lkml/CAK7LNARPAmsJD5XKAw7m_X2g7Fi-CAAsWDQiP7+ANBjkg7R7ng@mail.gmail.com/ > Link: https://reviews.llvm.org/D80391 > Cc: Andi Kleen > Reported-by: Dmitrii Bundin > Reported-by: Fangrui Song > Reported-by: Masahiro Yamada > Suggested-by: Dmitrii Bundin > Reviewed-by: Nathan Chancellor > Signed-off-by: Nick Desaulniers > --- > Changes v2 -> v3: > * Pick up Nathan's RB tag. > > Changes v1 -> v2: > * Add reference to 866ced950bcd, cc Andi, in commit message. > > scripts/Makefile.debug | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug > index 2845145c1220..c20f8f2e76bf 100644 > --- a/scripts/Makefile.debug > +++ b/scripts/Makefile.debug > @@ -1,10 +1,4 @@ > -DEBUG_CFLAGS := > - > -ifdef CONFIG_DEBUG_INFO_SPLIT > -DEBUG_CFLAGS += -gsplit-dwarf > -else > -debug-cflags-y += -g > -endif > +DEBUG_CFLAGS := -g > > debug-flags-$(CONFIG_DEBUG_INFO_DWARF4) += -gdwarf-4 > debug-flags-$(CONFIG_DEBUG_INFO_DWARF5) += -gdwarf-5 > @@ -15,6 +9,8 @@ ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_AS_IS_GNU),yy) > KBUILD_AFLAGS += $(addprefix -Wa$(comma), $(debug-flags-y)) > endif > > +debug-flags-$(CONFIG_DEBUG_INFO_SPLIT) += -gsplit-dwarf > + This patch changes the behavior that is not mentioned in the commit log. Previously, -gsplit-dwarf was passed only when compiling *.c files. (DEBUG_CFLAGS). Now it is passed also when compiling *.S files. (debug-flags-y is appended to KBUILD_AFLAGS) Please confirm if this makes sense, and if so, please mention it in the commit log. As far as I tested, I did not see this change was useful. When *.S is compiled to *.o, *.dwo is also created, but it does not contain any debug info. > ifdef CONFIG_DEBUG_INFO_REDUCED > DEBUG_CFLAGS += -fno-var-tracking > ifdef CONFIG_CC_IS_GCC > -- > 2.37.2.789.g6183377224-goog > -- Best Regards Masahiro Yamada