Error with -ansi command line flag.

[William R. Buckley]

I have posted a message on gcc newsgroups but, have had no answer for
several 
weeks.  I am hoping someone here has seen this problem, and solved it.
 
On RH6.2, using gcc v egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)
 
with parameter -ansi, I get compilation errors with the NET-SNMP file 
 
ucd-snmp/asn1.h  at line 40.  If I compile without the -ansi flag,
there 
is no error.  What happens is that u_long is not defined, so the error
reports the phrase  "parse error before 'oid'", which is the compilers
way of saying that the token prior to 'oid' is not understood, and so 
there is an apparent syntax error in the line of code. 
 
Now, I have looked at the file sys/types.h, and it includes  
 
typedef __u_long u_long 
 
and bits/types.h includes 
 
typedef unsigned long __u_long 
 
and sys/types.h relies upon the defined label 
 
__USE_BSD 
 
to include or exclude the conversion from the bits/types.h 
definition to the form u_long. 
 
What I don't understand is why the command line option -ansi 
should result in u_long becoming undefined. 
 
Any clues? 
 
William R. Buckley