On Sun, Sep 25, 2016 at 3:46 AM, Bernd Edlinger <bernd.edlin...@hotmail.de> wrote: > This patch makes -Wint-in-bool-context warn on suspicious integer left > shifts, when the integer is signed, which is most likely some kind of > programming error, for instance using "<<" instead of "<". > > The warning is motivated by the fact, that an overflow on integer shift > left is undefined behavior, even if gcc won't optimize the shift based > on the undefined behavior. > > So in absence of undefined behavior the boolean result does not depend > on the shift value, thus the whole shifting is pointless.
It's pointless for unsigned integers, too; why not warn for them as well? And why not warn for 0 << 0 and 1 << 0, which are just as pointless? Jason
