CPP output link change from 3.14 to 7.0

["Pearson, Matthew via Tech-talk" <tech-talk@aps.anl.gov>]

Hi,

 

We came across an oddity in our upgrade from base 3.14 to 7.0. We had a few IOCs using database logic similar to:

 

record(seq, "matt:seq") {

  field(SCAN, "1 second")

  field(DLY1, "1")

  field(DOL1, "0")

  field(LNK1, "matt:bo CPP")

  field(DLY2, "1")

  field(DOL2, "1")

  field(LNK2, "matt:bo CPP")

}

record(bo, "matt:bo") {

  field(ZNAM, "Zero")

  field(ONAM, "One")

}

 

We know this to be an invalid use of CPP on an output link, and it should be PP instead. We’re in the process of fixing a few database template files.

 

However, in 3.14 when this database is loaded the CPP is automatically changed to PP, and ‘matt:bo’ is processed as expected:

 

caget matt:seq.LNK1

matt:seq.LNK1                  matt:bo PP NMS

caget matt:seq.LNK2

matt:seq.LNK2                  matt:bo PP NMS

 

So, we never noticed the error until the upgrade. However, in 7.0, it seems to default to NPP instead:

 

caget matt:seq.LNK1

matt:seq.LNK1                  matt:bo NPP NMS

caget matt:seq.LNK2

matt:seq.LNK2                  matt:bo NPP NMS

 

I think the 7.0 version is more correct, forcing the user to fix the database logic. Is the change expected?

 

I think I see where the changes are in dbStaticLib.c, and it seems like the section dealing with link attributes are re-written at some point in about 2014. In 3.14 it didn’t test for CPP output links, and it was caught by the PP check instead. In 7.0 it explicitly rejects CPP for output links.

 

I was testing with 3.14.12.8 and 7.0.9.

 

Cheers,

Matt