On Mac OS X, also a UNIX flavor, the stack limit can be set compile-time with the -stack_size linker option, see https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man1/ld.1.html.
Therefore it can be set through gpc with -Wl,-stack_size,hhh where hhh is the stacksize in hexadecimal.
You can even set the stack size dynamically in the running application with setrlimit, see http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man2/getrlimit.2.html and http://developer.apple.com/library/mac/#qa/qa1419/_index.html.
Regards,
Adriaan van Os