Experimental Physics and
Industrial Control System

[email protected] (Peter Kurpis) · Mon, 23 Apr 2001 12:05:01 -1000 (HST)

> > > > I have immensely enjoyed looking at the $(EPICS_BASE)/config/RULES.Vx MAKE instructions. 
> > > 
> > > Given the increasing complexities of C++ development we were thinking of rewriting 
> > > all of EPICS for execution by the GNU make interpreter. An obvious advantage would
> > > be a reduction in the complexity of the build system. What do you think?
> > 
> > Having built and watched others build EPICS, I think this would be a *very* welcome
> > change.
> > 
> > As for the implementation, I am guessing you mean using the standard GNU configure
> > build.  Is that what you are suggesting?
> 
> Sorry about the confusion. The above was an attempt at some ( possibly
> warped ) dry humor.

Well, it's Monday morning here, and I think I'll need another cup of
coffee before I wake up :-)

> incomprehensible machine generated low level Makefiles. The gnu build 
> system is also very complex, it is very much chained to UNIX, and it 
> tends to ( as I understand it ) port software by encouraging the build 
> system to modify the source code. Not my favorite approach.

I am not aware of this.  I understand it searches for tools and defines
them in a makefile that it modifies.

>From a user's perspective, it is very simple, as anyone who has installed
GNU tools would attest.  From a maintainer's perspective, I don't think
it's too bad either -- but it always depends on what you're used to.

I don't think it easily supports a Win32 build, however.  And I think
the Cygnus installation installs some tools to make DOS look like more
like a UNIX environment, and uses that environment for building, not
the vanilla DOS environment.

> The systems strong points are its operating system 
> independence, and the low effort required to introduce a new architecture. 
> I suspect that our system is very unique in that we are able to use the same 
> Makefiles for both UNIX and MS Windows. 

But should this be a design goal, considering the cost in complexity?  Or
perhaps reverting to maintaining two simpler make systems could be 
reconsidered?  (Just asking.  I of course have not considered this as
carefully as y'all have, but I have worked with software that has 
adopted this philiosophy, so there's some reasonableness to the 
suggestion.)

> In R3.14 this set is expanded to 
> include RTEMS and vxWorks. Its difficult to reach these goals without some 
> complexity, and also without introducing some constraints on the application's 
> Makefiles.
> 
> One goal of the build system was to, where ever possible, move complexity
> out of application makefiles, and into the build system. Consequently,
> the system's internals _are_ very complicated, and if the answers are not 
> obvious while introducing off normal application Makefile syntax, then it 
> might be best to discuss your situation with someone that works with the 
> build system internals every day. In any case thats what I do.

Thanks!  I appreciate the offer.  One thing that is great about this build
system is the support behind it.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System