Using BSD queue.h for linked lists

[Derek Atkins]

Nico Williams <nico at cryptonector.com> writes:

> I would hope that the krb5 API itself won't be depending on the
> application using these macros.  Greg didn't imply that the API would
> expose the BSD queue.h, so I don't see a problem.

It was unclear if "public" structures would contain the queue pointers.
I had assumed "yes", which implies that k5-queue would necessarily be
required for inclusion of those structures in an application.  Obviously
it's not the case for 100% opaque objects where the application never
gets the structure definition.

However, for public structures this means that if an application pulls
in the krb structure header (that pulls in k5-queue) but the application
also wants to use the standard queue, that could result in a double
definition.

John,

> Perhaps I'm not following, but it's protected by:
> 
> #ifndef _SYS_QUEUE_H_
> #define _SYS_QUEUE_H_
>    ...
> #endif

I would hope that k5-queue does not use #ifndef _SYS_QUEUE_H ...
Moreover, what happens if the definitions change?  It would suck if the
library is built with k5-queue but an application with sys/queue,
especially if they don't provide the same ABI.  If we're copying the
header then it is possible that they may diverge over time resulting in
an ABI incompatibility.

> Nico

-derek

-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
       warlord at MIT.EDU                        PGP key available