On Thu, 2019-02-28 at 14:23 -0800, Jon Flatley wrote: > Thanks for the patch and comments. > > On Thu, Feb 28, 2019 at 1:53 PM Joe Perches <joe@xxxxxxxxxxx> wrote: > > On Thu, 2019-02-28 at 12:24 +0000, Louis Taylor wrote: > > > When compiling with -Wformat, clang warns: > > > ./include/linux/usb/wusb.h:245:5: warning: format specifies type > > > 'unsigned short' but the argument has type 'u8' (aka 'unsigned char') > > > [-Wformat] > > > ckhdid->data[0], ckhdid->data[1], > > > ^~~~~~~~~~~~~~~ > > > > I think the message is somewhat misguided as all the > > vararg arguments have implicit integer promotions. > > That's a fair point, but Clang checks the arguments against their > format specifier before they're promoted when using -Wformat. Perhaps clang could be a bit more verbose if checking signed types emitted as unsigned or unsigned types emitted as signed instead. > When > considering integer promotions it's difficult to say if this is > "wrong", I didn't write "wrong", I wrote misguided. > but since 'unsigned char' corresponds to the "hh" length > specifier I don't think this is misguided. Otherwise, why use the "h" > length specifier at all? e.g.: signed char as %x needs %hhx cheers, Joe
