Re: [PATCH v6 2/2] Kbuild: implement support for DWARF v5

[Nick Desaulniers]

On Fri, Jan 29, 2021 at 1:11 PM Jakub Jelinek <jakub@xxxxxxxxxx> wrote:
>
> On Fri, Jan 29, 2021 at 01:05:56PM -0800, Nick Desaulniers wrote:
> > > Wasn't that fixed in GAS?
> > > https://sourceware.org/bugzilla/show_bug.cgi?id=27195
> >
> > $ make LLVM=1 -j72 defconfig
> > $ ./scripts/config -e DEBUG_INFO -e DEBUG_INFO_DWARF5
> > $ make LLVM=1 -j72
> > ...
> > /tmp/init-d50d89.s: Assembler messages:
> > /tmp/init-d50d89.s:10: Error: file number less than one
> > /tmp/init-d50d89.s:11: Error: junk at end of line, first unrecognized
> > character is `m'
> >
> > which is https://sourceware.org/bugzilla/show_bug.cgi?id=25611.
> >
> > $ as --version | head -n1
> > GNU assembler (GNU Binutils for Debian) 2.35.1
> >
> > Maybe GAS should not need to be told -gdwarf-5 to parse these?  Then
> > we would not need to pass -Wa,-gdwarf-5 via clang with
> > -no-integrated-as.
>
> That is what sw#27195 is about, just try current binutils 2.35, 2.36 or
> trunk branches.

Ok, yep, I can confirm.  I just built ToT binutils and I no longer
need to specify -Wa,-gdwarf-5 when building with clang with
-no-integrated-as.

I will update scripts/test_dwarf5_support.sh to check for that and
update the comments/documentation/commit messages to say binutils
2.35.2+, link to https://sourceware.org/bugzilla/show_bug.cgi?id=27195
instead, then drop hunk that was passing -Wa,-gdwarf-5.
-- 
Thanks,
~Nick Desaulniers