Sun Studio 12: C User's Guide

B.2.3 -Aname[(tokens)]

Associates name as a predicate with the specified tokens as if by a #assert preprocessing directive. Preassertions:

These preassertions are not valid in -Xc mode.

If -A is followed by a dash (-) only, it causes all predefined macros (other than those that begin with __) and predefined assertions to be forgotten.