Re: Including libraries in subroutines

[Andrew Johnson <anj@aps.anl.gov>]

Hi Stephen,

On 06/27/2016 04:53 PM, Stephen Molloy wrote:
> I have some C code that I would like to convert to a subroutine record.
> I normally build the executable with g++ using a  -lwiringPi flag,
> but I don’t know the correct way to do this in order to compile the
> EPICS subroutine.  Is there a standard place I should put the library,
> or is there some change I need to make to the Makefile (and, if so,
> which Makefile?) to get this to work?

If libwiringPi.a or .so is found in a standard system library location
such as /usr/lib or /usr/local/lib then to your Makefile that builds the
IOC executable (probably in a somethingApp/src directory) you would add
the line

  PROD_SYS_LIBS += wiringPi

which tells the build that it needs to link the IOC with this system
library after it compiles your subroutine record code found in the same
directory.

If you are building libwiringPi.{a,so} yourself as part of this IOC then
I will have more questions about how and where you are building that
library to give you the correct answer. Let's start with that one though.

- Andrew

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