Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 31 May 2017 17:21:51 +0200 | From | Michal Hocko <> | Subject | Re: [Patch v2] mm/vmscan: fix unsequenced modification and access warning |
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On Thu 25-05-17 21:43:43, Nick Desaulniers wrote: > On Tue, May 16, 2017 at 10:27:46AM +0200, Michal Hocko wrote: > > I guess it is worth reporting this to clang bugzilla. Could you take > > care of that Nick? > > >From https://bugs.llvm.org//show_bug.cgi?id=33065#c5 > it seems that this is indeed a sequence bug in the previous version of > this code and not a compiler bug. You can read that response for the > properly-cited wording but my TL;DR/understanding is for the given code: > > struct foo bar = { > .a = (c = 0), > .b = c, > }; > > That the compiler is allowed to reorder the initializations of bar.a and > bar.b, so what the value of c here might not be what you expect.
This is interesting because what I hear from our gcc people is something different. I am not in a possition to argue here, though. -- Michal Hocko SUSE Labs
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