USB_ATTACH_SETUP macros question

[Hans Petter Selasky]

>
> Made a little test which shows that this code is going to be executed only
> once.How did i miss that :) Now the other question comes next:
> Why don not we use just:
> #define USB_ATTACH_SETUP \
> sc->sc_dev = self; \
> device_set_desc_copy(self, devinfo); \
> device_printf(self, "%s\n", devinfo);

Because that is dangerous.

Consider the following:

if (1) USB_ATTACH_SETUP;

What is the meaning of the statement above?

What is going to get executed?

--HPS