Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Wed, 29 Nov 2017 21:13:08 +0000

> On 29.11.2017 01:05, Andrew Johnson wrote:
> > Hi Timo,
> >
> > On 11/28/2017 10:46 AM, Timo Korhonen wrote:
> >> Referring to Dirk's request earlier in this chain:
> >>
> >> So it would be nice to have an option in one of the CONFIG files to
> >> declare that a specific architecture should build EPICS 7 without PVA
> >> support.
> >>
> >>
> >> If I understand the intention right, he would like to be able to build the
> >> EPICS 7 base for many architectures but so that not all of them are
> >> required to support PVA.
> >>
> >> I think that is a legitimate request: this way he can keep up with the
> >> other updates in the base and does not have to abandon (at least
> >> immediately) those architectures that are not able to support PVA.
> >>
> >> I think this could make the adoption of EPICS 7 easier not only for Dirk
> >> but for other sites, too. The change does not look impossible to me.
> >
> > I agree that this is worthwhile goal, but I'm not sure how easy it will
> > be to implement at this stage. The complication is that GNUmake descends
> > through the tree just once, and it's not until it gets to the bottom
> > Makefiles that it decides which target architectures to compile the code
> > for. I don't want to have to edit every Makefile and put a conditional
> > test in them, but I might be able to do something in the modules' own
> > configure/CONFIG files.
> >
> > I can't promise anything for the -rc1, but I will try to implement
> > something for the final release if I can do so cleanly.
> >
> > - Andrew
> >
> 
> I will try to implement something. My first attempt failed for the
> reason Andrew outlined. It is not possible to simply skip the all PVA
> modules for a specific T_A because at that time T_A is not yet defined.
> A flag needs to be checked inside every module.
> 
> Dirk

This is a pain.  I have had to do it in ADSupport for all of the libraries (TIFF, JPEG,  GraphicsMagick, HDF5, etc.).  In GraphicsMagick alone there were 13 Makefiles where I added lines like this:

ifeq ($(WITH_GRAPHICSMAGICK),YES)
  ifeq ($(GRAPHICSMAGICK_EXTERNAL),NO)

    LIBRARY = wmf

...

It would have been very nice to put that logic in a single Makefile above GraphicsMagickSrc, but it does not seem to be possible with gnumake.

Mark

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System