Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Fri, 10 Jun 2011 10:14:15 -0500

Hi Lewis,

On 2011-06-09 J. Lewis Muir wrote:
> My vote would be to fix the preprocessor; it shouldn't do that
> substitution.

That means removing $(OP_SYS_CPPFLAGS) from the options passed to the 
preprocessor when we run it before the SNC.  However anyone who has an  #ifdef 
vxWorks  that modifies their SNL code when building it for vxWorks isn't going 
to be very happy with that.

> Why does using "vxWorks.h" work when <vxWorks.h> does not?
> Because it thinks "vxWorks.h" is a C string constant and so
> doesn't touch it?

Correct, the pre-processor does not replace tokens inside quoted strings.

> I'm not the biggest fan of using "vxWorks.h".  It's, as you
> said, a workaround.  When I read that, I think the author wrote
> a vxWorks.h header file and wants to include it.

I just worked out how to fix this nicely: Change the definition in Base's 
configure/os/CONFIG.Common.vxWorksCommon to this:
    OP_SYS_CPPFLAGS += -DvxWorks=vxWorks

Works perfectly, and will only break code where someone is using  #if vxWorks  
instead of  #ifdef vxWorks.  Just don't try %%#including a file called CPU.h 
though, I can't fix that one...

- Andrew
-- 
Optimization is the process of taking something that works and
replacing it with something that almost works, but costs less.
-- Roger Needham

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System