[CMake] Getting CMake to run on OpenVMS

[Bill Hoffman]

Alan Antonuk wrote:
> Update:
> I've ported the bootstrap script to DCL (yuck) and it has most of the 
> functionality of the bash version of the script.
> I decided to take a dependency on the A9 porting library a.k.a. "The 
> Jackets" ( 
> http://h71000.www7.hp.com/openvms/products/ips/porting.html) to help 
> with some of the small issues I was having with compatibility of unix 
> header files.  It also includes a port of gmake ( 3.76.1).
>
> Compiling the bootstrap I run into only one issue:
> In ProcessUNIX.c, there is a sigaction struct, and the version on VMS 
> does not have the sa_sigaction member of the sigaction struct, and 
> correspondingly the SA_SIGINFO constant is not defined.  The sigaction 
> struct looks like this:
>  void        (*sa_handler)(int);
>  sigset_t    sa_mask;
>  int         sa_flags;
>
> As a fix would I get correct results if I were to instead of 
> sa_sigaction, assign to sa_handler (the Unix manpage seems to claim 
> that on some implementations sa_sigaction and sa_handler are a union - 
> so they end up being called for the same reasons.  My logic maybe 
> flawed here.
Well, either an ifdef VMS, or a try_compile should be used to get the 
right signature for the handler. 
Sounds like you are making good progress.  I would recommend getting it 
to build any way possible,
then send diffs to me and we can work out the right way to do it.  
Sounds like you are making good
progress!

-Bill