On Thu, Oct 23, 2014 at 02:34:04PM +0200, Marek Polacek wrote:
> The issue here was that we were diagnosing an artificial check
> that we created within the scope of shift instrumentation. In
> other words, for shifts we create something like
> (unsigned) A >> (B - C) and signed-integer-overflow triggered
> on that subtraction. Fixed by making the subtraction work on
> unsigned types. This only happened in C99/C++11 mode.
> Middle end seems to cope well with RSHIFT_EXPR whose second op
> has an unsigned type.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2014-10-23 Marek Polacek <pola...@redhat.com>
>
> * c-ubsan.c (ubsan_instrument_shift): Perform the MINUS_EXPR
> in unsigned type.
>
> * c-c++-common/ubsan/undefined-2.c: New test.
Ok. Can you please queue it for 4.9 branch too, after 4.9.2 is released?
There is no -f*sanitize-recover* support, but it can be supposedly left out
from dg-options for the branch.
Jakub
