Re: sys/socket.h on IRIX6

[Akim Demaille]

Hi Bruno,

Long ago you wrote this:

| Trying to compile sh-utils-2.0i on IRIX6 with cc.
| I get a compilation failure for lib/canon-host.c:
| 
| "../../lib/canon-host.c", line 68: error(1020): identifier "AF_INET" is
|           undefined
|         case AF_INET:
|              ^
| 
| AF_INET is not defined because it is defined in <sys/socket.h> which has not
| been included. HAVE_SYS_SOCKET_H is not defined, because at configure time
| we got:
| 
| configure:5389: checking for sys/socket.h
| configure:5400: /lib/cpp  conftest.c >/dev/null 2>conftest.out
| cpp: warning /usr/include/sys/socket.h:169: AF_LINK redefined
| configure: failed program was:
| #line 5395 "configure"
| #include "confdefs.h"
| #include <sys/socket.h>
| 
| configure:5412: result: no
| 
| So why was AF_LINK defined twice? Let's look in <sys/socket.h>:
| 
| ...
| #define AF_ROUTE        17              /* Internal Routing Protocol */
| #ifdef __sgi
| #define AF_RAW          18              /* Raw link layer interface */
| #else
| #define AF_LINK         18              /* Link layer interface */
| #endif
| ...
| #define AF_LINK         25              /* Link layer interface */
| ...
| 
| And if I try "/lib/cpp -D__sgi" instead of "/lib/cpp", the warning indeed
| goes away.
| 
| I conclude that configure (more precisely, the macros AC_PROG_CPP and
| AC_PROG_CXXCPP) should set CPP to "/lib/cpp -D__sgi", not "/lib/cpp", on
| Irix.
| 
| Bruno

IMHO, the way CVS Autoconf now handles the preprocessors makes this
hack unnecessary.  May I ask you to check that indeed Autoconf behaves
properly?

Thanks!

        Akim