[PATCH] D130566: [Driver] Default to DWARF 4 on Linux/sparc64

Thu Jul 28 06:47:54 PDT 2022

ro added a comment.

In D130566#3682923 <https://reviews.llvm.org/D130566#3682923>, @dblaikie wrote:

>> This is all extremely weird, but until the error shows up again, I'll put this patch on hold (not yet abandoning since there seems to be no way to unabandon if necessary).
>
> You can abandon and then "reclaim" the revision to reopen it and continue work.

Ah, I missed that: the reclaim action is only offered for abandoned patches, I assume.  Thanks.

In D130566#3683174 <https://reviews.llvm.org/D130566#3683174>, @MaskRay wrote:

> I accepted this because this seems a major showstopper and we want to resolve it for the upcoming major release
> But I just recall that clang 14.0.0 has defaulted to DWARF v5 for most ELF operating systems on all architectures, including Sparc.
> I think we need more justification to downgrade the DWARV version.

Fully agreed.  However, clang 14.0.0 was in a way worse shape on Debian/sparc64 (wouldn't even build), so we wouldn't have noticed.  Solaris/sparcv9 wouldn't notice either since it uses the native linker, not GNU ld.

>> So far, I had only seen it with the GNU ld 2.38.50 bundled with Debian 11/sparc64, but couldn't reproduce on Ubuntu 20.04/x86_64 (neither bundled GNU ld 2.34, nor self-compiled 2.38.90)
>
> Thanks for the additional note. Seems worth investigating whether it is an issue which should be addressed on GNU ld side.
> binutils 2.39 will be released on 2022-08-06 (https://sourceware.org/pipermail/binutils/2022-July/121656.html) and such a regression style issue should be worked on quickly.

Indeed.  However, I won't be able to spend much time on this: Linux/sparc64 is only tangential to my work (as a vehicle to test SPARC patches where I want to make sure they don't break that target).  I've got enough to do testing binutils 2.39 on Solaris ;-)

That said, I've now filed binutils PR binutils PR ld/29424 <https://sourceware.org/bugzilla/show_bug.cgi?id=29424>.  The binutils maintainers can now decide what the want to do about this, if anything.

> The binutils code does suggest it doesn't handle the DWARF v5 features, but I am curious why older releases don't have the problem.

They might if one tried.  However, the bundled GNU ld is already 2.38.50.

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