Re: Multiple layers of DB templates?

[Bruce Hill <bhill@slac.stanford.edu>]

Hi Martin,
I think the dbLoad* routines only support simple macro substitution and 
not the
full msi feature set, so I think you're best trying to do this at build 
time by invoking
msi twice.

The .db and .substitutions suffixes are significant as RULES.Db knows 
how to build
%.db from %.substitutions, but I think you can use anything in place of 
.template,
including another .db.

I solved this need for multiple substitutions several years ago by 
creating a new
%.db: %.sub2 rule in my local Db/Makefile, but I think it's easier to do 
this by having
two directories.   For example, you could create a module for your 
device that builds
mydevice.db, and then your ioc Db directory could have another 
substitutions file
that creates a single db file w/ all 60 instances.

You could also create a deviceDb folder in your ioc/*App directory as 
long as you
add a dependency so deviceDb gets built before Db.

Cheers,
- Bruce

On 4/4/2016 11:43 AM, Konrad, Martin wrote:
> Hi all,
> I need to create an EPICS database for a soft IOC with 60 identical
> devices. Each of these devices has a set of records that are identical
> for multiple inputs. Having the DRY pattern in mind, I was wondering if
> I could somehow use two levels of DB templates. Here is what I have in mind:
>
> st.cmd:
> dbLoadTemplate("myproject.substitutions")
>
> myproject.substitutions:
> global { SYS=...,SUBSYS=... }
> file mydevice.db {
>     pattern { ... }
>     { ... }
>     { ... }
> }
>
> mydevice.db:
> <some records here>
> substitute "INPUT=1"
> include "myinput.db"
> substitute "INPUT=2"
> include "myinput.db"
>
> myinput.db:
> <a couple of records needed for each input>
>
> A manual run of MSI tool on mydevice.db handles both the "substitute"
> and the "include" keyword correctly but by default macro expansion is
> done at dbLoadTemplate time. This however results in
>
> Error: syntax error
>    at or before "substitute" in file "mydevice.db" line 16
>
> It seems like dbLoadTemplate doesn't support the "substitute" keyword. I
> found a BNF definition of the substitution file format in chapter 6.12.1
> of the Application Developer's Guide [1]. Unfortunately I did not find a
> definition like this for DB files/templates. Can you please help me out
> here?
>
> I am aware that I could use 60 dbLoadTemplate lines instead (that would
> clutter IOC boot output, though). I could also pull in both mydevice.db
> and myinput.db from the substitutions file directly - but for that I
> need to add N lines referring to myinput.db in the substitution file for
> each line referring to mydevice.db (assuming a device with N inputs). Is
> there a nicer way to do this?
>
> Thanks a lot,
>
> Martin
>
> P.S.: BTW: Is there a difference between a DB file and a template? Are
> their file names supposed to have different suffix (".template" vs. ".db"?
>
> [1] http://www.aps.anl.gov/epics/base/R3-15/3-docs/AppDevGuide.pdf