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Date:   Fri, 29 Jan 2021 22:41:37 +0100
From:   Jakub Jelinek <jakub@redhat.com>
To:     Arvind Sankar <nivedita@alum.mit.edu>
Cc:     Nick Desaulniers <ndesaulniers@google.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Nathan Chancellor <natechancellor@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Sedat Dilek <sedat.dilek@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        Fangrui Song <maskray@google.com>,
        Caroline Tice <cmtice@google.com>,
        Nick Clifton <nickc@redhat.com>, Yonghong Song <yhs@fb.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Andrii Nakryiko <andrii@kernel.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>
Subject: Re: [PATCH v6 1/2] Kbuild: make DWARF version a choice
Message-ID: <20210129214137.GW4020736@tucnak>
Reply-To: Jakub Jelinek <jakub@redhat.com>
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On Fri, Jan 29, 2021 at 04:32:32PM -0500, Arvind Sankar wrote:
> Given what Jakub is saying, i.e. it was previously impossible to get
> dwarf2 with gcc, and you get dwarf4 whether or not DEBUG_INFO_DWARF4 was

It isn't impossible to get it, -gdwarf-2 works, it is just not a very good
choice (at least unless one knows some debug info consumer is not DWARF3 or
later ready).
Though, even gcc -gdwarf-2 will use many extensions from DWARF3 and later,
as long as there is no way to describe stuff in DWARF2.  -gstrict-dwarf
option requests that no DWARF extensions are used.

	Jakub