Giorgos Keramidas <[EMAIL PROTECTED]> writes: > On 2002-05-11 18:34, Dag-Erling Smorgrav wrote: > > Hmm, does this mean Duff's Device is not valid C? > It is ugly. I'm not sure if it's non-standard too. My impression > until now was that jumping from an outter block 'inside' a contained > block is not a Good Thing(TM). Note that the switch cases also lack a > 'break' and are falling through. All of them!
Yes, this is intentional. > This makes me wonder that happens the second time the loop runs. Does > the code start the second iteration at the beginning of the while > body? Or does it start at where the loop was entered the first time > (the proper 'case' of the switch statement)? At the top of the loop. This is a classic, if somewhat obscure, construct, named Duff's Device after Tom Duff, who devised it as a way of unrolling an I/O loop on a machine that had memory-mapped I/O. See the comp.lang.c FAQ for additional details. I think the proper way to silence this warning is to move the top of the while loop into 'case 0'. DES -- Dag-Erling Smorgrav - [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
