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Date:   Mon, 17 Aug 2020 04:15:18 +0200
From:   Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To:     Randy Dunlap <rdunlap@infradead.org>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Jeff Layton <jlayton@redhat.com>
Subject: Re: Linux 5.9-rc1 (sparse? kernel/time/timekeeping.c)
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On Sun, Aug 16, 2020 at 06:35:26PM -0700, Randy Dunlap wrote:
> 
> on x86_64, allmodconfig:
> 
> $ gcc --version
> gcc (SUSE Linux) 7.5.0
> 
> $ sparse --version
> 0.6.2
> 
> 
> I seem to be having some problems with kernel/time/timekeeping.c,
> including a segfault.
> 
> a. Is it sparse that segfaults?

It's most probably the one fixed in:
  eb6779f6f621 ("generic: fix missing inlining of generic expression")

On the main tree there is a branch with a few fixes since the last release:
  git://git.kernel.org/pub/scm/devel/sparse/sparse.git maint-v0.6.2
 
> b. what prints this message?
> make[3]: *** Deleting file 'kernel/time/timekeeping.o'

It seems like a typical message from make when a command fails.
 
> c. I would prefer to be able to tell the source of warning/error messages,
> i.e., gcc or sparse. Especially when they are intermixed.

You can use the option -fdiagnostic-prefix[=PREFIX] for this. It will
just prefix all messages from from sparse with the given PREFIX or
'sparse: ' if none is given. You can pass this option via 'make CF=...'.

It may be a good idea to directly add it to CHECKFLAGS.

Best regards,
-- Luc