[CMake] Pparallel build on multiple directories?

[Bill Hoffman]

Alexandre Feblot wrote:
> I tried with the standard gmake 3.81 that I compiled on .net 2003 with
> support for an old MKS sh.exe that we already own (define HAVE_MKS_SHELL
> in the config.h.W32), but can't get it working in parallel. Maybe sh is
> too old too.
> 
> We'd rather avoid cygwin, as it's not simple to install once and share
> between multiple servers.
> 
> I might give it a try though, just to see if I can have it working
> here...
> 
> Thanks for the suggestion.
> 

I am pretty sure that you have to have 2005 or greater to do parallel 
builds with cl.  The debug pdb files do not support multiple cl's 
working on the same library or executable at the same time.

You have to use the cygwin make because it is the only one that has 
support for parallel job control.   gmake has a job server that makes 
sure no more than -j N processes are running at the same time.  All of 
the other gmake versions on windows are lacking this support.   The only 
support -j in simple make files and not in recursive ones like the ones 
CMake generates.  You don't need much of cygwin to do this, just the 
base stuff and the gmake I pointed you at.

-Bill