On Fri, Mar 3, 2017 at 12:05 AM, Josh Poimboeuf <[email protected]> wrote:
> I assume '-Wdiv-by-zero' is enabled and gcc isn't showing the "division
> by zero" warning for either of these? The 'ud2' is guaranteed to
> trigger since the function has no branches. Surely at least the missing
> warning is a gcc bug.
>
> The good news is objtool is flushing these out, albeit with a confusing
> message.
I'm still not sure if it's intentional or not. I've reduced the test case to the
simple
static inline int return0(void) { return 0; }
int provoke_div0_warning(void) { return 1 / return0(); }
which does not generate a compile-time warning, but will generate
an unconditional runtime warning if built with -fsanitze=integer-divide-by-zero.
Arnd
