On Tue, Nov 20, 2012 at 6:21 PM, Konstantin Serebryany <konstantin.s.serebry...@gmail.com> wrote: > On Tue, Nov 20, 2012 at 6:18 PM, Evgeniy Stepanov > <eugeni.stepa...@gmail.com> wrote: >> On Tue, Nov 20, 2012 at 5:52 PM, Konstantin Serebryany >> <konstantin.s.serebry...@gmail.com> wrote: >>> >>> On Tue, Nov 20, 2012 at 5:41 PM, Peter Bergner <berg...@vnet.ibm.com> >>> wrote: >>> > On Tue, 2012-11-20 at 11:07 +0400, Konstantin Serebryany wrote: >>> >> I've applied your patch (with minor style and comment changes) >>> >> upstream: >>> >> http://llvm.org/viewvc/llvm-project?view=rev&revision=168356 >>> >> I did not have any way to test it though. Also, gmail does something >>> >> horrible with patches inlined in a message, so I might have missed >>> >> something. >>> > >>> > Doing a quick peruse through your LLVM commit, I see you grabbed the >>> > PopStackFrames() addition, but the asan_linux.cc changes do not include >>> > the call to PopStackFrames() after the _Unwind_Backtrace() call. >>> > Specifically, the following patch hunk: >>> > >>> >> _Unwind_Backtrace(Unwind_Trace, stack); >>> >> > + // Pop off the two ASAN functions from the backtrace. >>> >> > + stack->PopStackFrames(2); >> >> >> I wonder if under some conditions we may get a different number of extra >> frames (inlining comes to mind). What do you think of removing any number of >> frames that belong to the runtime library - we have memory layout info for >> that? > > Bad idea, imho. > Hard to implement, slower to run (remember, this *is* a hotspot). > The frames in question are in our run-time and we can fully control inlining. > What is the current number of redundant frames on ARM?
And we can have output tests that verify that we remove the right number of frames.
