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bug#16304: Upcoming clang-3.4 apparently miscompiles coreutils.
From: |
Markus Trippelsdorf |
Subject: |
bug#16304: Upcoming clang-3.4 apparently miscompiles coreutils. |
Date: |
Tue, 31 Dec 2013 20:39:02 +0100 |
On 2013.12.31 at 11:12 -0800, Andrew Trick wrote:
>
> On Dec 30, 2013, at 1:47 PM, Markus Trippelsdorf <address@hidden> wrote:
>
> > On 2013.12.30 at 18:47 +0000, Pádraig Brady wrote:
> >> On 12/30/2013 12:32 PM, Markus Trippelsdorf wrote:
> >>> coreutils-8.22 build with clang-3.4 doesn't copy permissions correctly:
> >>>
> >>> address@hidden tmp % touch test1
> >>> address@hidden tmp % chmod 600 test1
> >>> address@hidden tmp % ls -al test1
> >>> -rw------- 1 markus markus 0 Dec 30 13:25 test1
> >>> address@hidden tmp % /var/tmp/coreutils-8.22/src/cp test1 test2
> >>> address@hidden tmp % ls -al test2
> >>> ---------- 1 markus markus 0 Dec 30 13:25 test2
> >>> address@hidden tmp %
> >>
> >> Ouch.
> >>
> >> Note as part of the 8.22 release process
> >> I did verify that `make check` passed with
> >> clang-3.3-3.fc20.x86_64
> >>
> >> I've again verified that clang-3.3 passes your test above.
> >>
> >> Can you pinpoint the erroneous code?
> >> It does seem like a clang regression TBH.
> >
> > Started with LLVM r192750 (Enable MI Sched for x86).
> > I've opened a LLVM bug here:
> > http://llvm.org/bugs/show_bug.cgi?id=18346
> >
> > (I will try to come up with a testcase after the holidays)
>
> To determine whether a bug exists in MI scheduler pass (or downstream) you
> can do this:
> -mllvm -enable-misched=false.
>
> Duncan committed a post-3.4 fix, r197503, for a varargs bug exposed by
> changes to the SD scheduling policy.
Yes, r197503 fixes the issue. Would be nice to get the fix applied
before 3.4 gets released...
--
Markus