On Thu, 20 Feb 2020, Kees Cook wrote: > Variables declared in a switch statement before any case statements > cannot be automatically initialized with compiler instrumentation (as > they are not part of any execution flow). With GCC's proposed automatic > stack variable initialization feature, this triggers a warning (and they > don't get initialized). Clang's automatic stack variable initialization > (via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also > doesn't initialize such variables[1]. Note that these warnings (or silent > skipping) happen before the dead-store elimination optimization phase, > so even when the automatic initializations are later elided in favor of > direct initializations, the warnings remain. > > To avoid these problems, move such variables into the "case" where > they're used or lift them up into the main function body. > > drivers/usb/gadget/udc/net2280.c: In function ‘handle_stat0_irqs_superspeed’: > drivers/usb/gadget/udc/net2280.c:2871:22: warning: statement will never be executed [-Wswitch-unreachable] > 2871 | struct net2280_ep *e; > | ^ > > [1] https://bugs.llvm.org/show_bug.cgi?id=44916 > > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > --- > v2: put everything in function body (Alan Stern) > v1: https://lore.kernel.org/lkml/20200220062315.69253-1-keescook@xxxxxxxxxxxx You might want to remove part of the last sentence in the patch description. Aside from that, Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Alan Stern
