C standards and committees (was Re: strangest systems I've sent email from)

Mouse mouse at Rodents-Montreal.ORG
Sun May 22 07:40:13 CDT 2016

>>> First off, the C standard mandates that the order of fields in a
>>> struct cannot be reordered,
>> Yes.  (I think this is a Bad Thing, but I can see why they did it.)
> Given that C is a systems implementation language, how would you
> define HW related data structures where the order of the fields is
> critical (ie HW defines them).

I can see three answers.

1) Don't use structs for that.  Look at NetBSD's bus-space abstraction
   for one possible way.

2) Make any reordering implementation-defined, so that code for
   specific implementations can know how the implementation does it.

3) Make reordering optional.  Which way the default should go is
   arguable; since my guess is that most structs are not
   hardware-interface structs, the default should be reordering, with
   some keyword specifying no reordering.

/~\ The ASCII				  Mouse
\ / Ribbon Campaign
 X  Against HTML		mouse at rodents-montreal.org
/ \ Email!	     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B

More information about the cctalk mailing list