root/usr/src/tools/smatch/src/validation/builtin_unreachable.c
/* example from gcc documents */

void function_that_never_returns (void);

static int g (int c)
{
        if (c)
                return 1;
        function_that_never_returns ();
        __builtin_unreachable ();
}
     
/*
 * check-name: __builtin_unreachable()
 */