C Extensions in gcc 2.95.1

[Peter Butterfield]

Greetings.

I need help with Gnu C extensions.

Compiling an existing module which worked fine under gcc 2.7.2, 
the gcc 2.95.1 compiler errors out with the complaint:
 "dereferencing pointer to incomplete type"  or
 "arithmetic on pointer to an incomplete type"

The Info pages on gcc tell me that this error comes from a Gnu 
C Extension, allowing incomplete "enum" declarations (to be 
completed later).  That's fine, but this enum is included from 
a standard X11 header file, that we didn't write, that I don't 
want to change.  Our module uses a typedef from that header 
file, and gets the error.

My question:  Can I disable the "Incomplete Enums" gcc extension? 
Or all the extensions?  The info pages don't answer this.

-- Peter Butterfield
Penta Software, Inc.