Undefined type in gl.h

I’m trying to run a demo on a SUN Ultra 30 SPARC, but I can’t even do a make on a demo file as I get the following error from a declaration in gl.h:

“signed is a reserved ANSI C word”

since gl.h has a value defined as “signed”

A truckload of other errors also results as other types/declarations are not found.

The demo is finding the OpenGL library and cc on my c programs work. Could there be a C compiler/OpenGl version conflict?

Any ideas.