r310401 - PR19668, PR23034: Fix handling of move constructors and deleted copy

[Richard Smith via cfe-commits]

On 14 August 2017 at 03:27, Diana Picus via cfe-commits <
cfe-commits at lists.llvm.org> wrote:

> Hi,
>
> Strangely enough, it turns out that if I run
> Asan-armhf-with-calls-Noinst-Test on the command line it fails,
> although it doesn't fail when run with lit.


Looks like the crash is within the "use_colors == true" portion of
ColoredPrintf, so this would make sense if running the test within lit
turns off color support (perhaps because the output is not a terminal).


> I've attached the stack
> trace from gdb. It looks like some trouble passing down va_arg
> parameters, but I haven't looked into too much details. The segfault
> happens when we try to do a   ldrb   r3, [r0, r1], with r1 set to 0 by
> the current function and r0 passed down from the caller. I'm not sure
> if this is the exact same problem as the other tests, but feel free to
> have a look at that code.
>

Have you tried running Asan-armhf-with-calls-Noinst-Test on the command
line without this patch applied? (It's possible that this is a pre-existing
bug in ARM varargs call lowering, and is unrelated to the bug we're trying
to track down. This code path performs an unrelated varargs call between a
va_start / va_end pair, which seems like quite a rare situation, and I
could easily believe there's something wrong with our lowering that allows
some portion of the outer va_list state to be clobbered in that scenario.)

Meanwhile, I've removed some clutter from Asan-armhf-with-calls-Test
> (which is the original failure that we were seeing) and left only one
> failing test that seemed small enough. I'll try to look at the
> disassembly before/after the patch and maybe even run valgrind on it
> (running it on the original binary naturally takes forever).
>
> Let me know if there's anything else I could try. I can also send you
> disassembly or even LLVM IR for the Asan-armhf-with-calls-Noinst-Test
> if you think it helps.
>
> Cheers,
> Diana
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