Experimental Physics and
Industrial Control System

"Daykin, Evan via Tech-talk" <tech-talk at aps.anl.gov> · Wed, 30 Mar 2022 16:30:10 +0000

OK, thanks for the advice. I just saw your reply after opening https://github.com/epics-base/epics-base/pull/228, which adds an ABSOLUTE_DBD option in configure/CONFIG_SITE (default behavior is still relative path). Feel free to close if you’d rather not merge it.

-Evan

-----Original Message-----
From: Michael Davidsaver <mdavidsaver at gmail.com> 
Sent: Wednesday, March 30, 2022 11:55 AM
To: Daykin, Evan <daykin at frib.msu.edu>
Cc: tech-talk at aps.anl.gov
Subject: Re: softIoc compiling-in relative path to softIoc.dbd

[EXTERNAL] This email originated from outside of FRIB

On 3/30/22 05:55, Daykin, Evan via Tech-talk wrote:
> Hi tech-talk,
> 
> I am finishing up a Debian package for base 7.0.6. In the finished product, I discovered that the compiled-in path to softIoc.dbd is not what I expect. I would like the path to be /usr/lib/epics/dbd/softIoc.dbd, but it is instead always pointing to <pwd>/../../dbd/softIoc.dbd, no matter where the softIoc executable resides. This causes an issue, since the Debian package drops the executables in /usr/bin, with symlinks to those executables in /usr/lib/epics. Thus, the calculated DBD path is /usr/bin/../../dbd/softIoc.dbd, which points to nothing.
> 
> If I understand correctly, this is happening like so:
> 
> 1.modules/database/src/std/softIoc/RULES generates epicsInstallDir.h by calling makeInstallDir.pl “$(FINAL_LOCATION)”. (resolves to /usr/lib/epics)
> 
> 2.softMain.cpp pulls in the EPICS_BASE #define macro from epicsInstallDir.h.
> 
> 3.softMain.cpp creates a constant DBD_FILE, defined as EPICS_BASE/dbd/softIoc.dbd
> 
> 4.softMain.cpp’s main method attempts to calculate a relative path based on DBD_FILE, and this is ultimately what is used.
> 
> So my question is, what is the preferred course of action here?
> 
> -Re-arrange the package to drop executables in $(EPICS_BASE)/bin/$(EPICS_HOST_ARCH), and link to them from /usr/bin?

This seems preferable to me.

> -Add a compile-time flag to insist on an absolute path?
> 
> -Something else?

* Patch softMain.cpp to use a static, absolute, path for softIoc.dbd.

> Thank you,
> 
> Evan
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System