Experimental Physics and
Industrial Control System

"Johnson, Andrew N. via Core-talk" <[email protected]> · Mon, 29 Oct 2018 17:19:48 +0000

Hi Martin,

On 10/25/2018 02:44 PM, Konrad, Martin wrote:
> In the past I used something like the following:
> 
> file "a.db" {
>   { }
> }

> With EPICS 3.15.6 this doesn't work anymore. I get
> 
> msi: Parse error, unexpected '}'
> 
> I have to admit that my solution might not be the cleanest approach as
> it probably depends on undefined behavior (neither the AppDev guide nor
> the MSI website talk about this corner case). I'm wondering if you
> consider the change in behavior a bug. I'm able to work around the
> problem by using
> 
> file "a.db" {
>   { DUMMY="" }
> }
> 
> Is there a better way to solve my problem?

> P.S.: Seems like the following commit changed the behavior:
> https://git.launchpad.net/epics-base/commit/?h=3.15&id=67e2b74758982fd46be5529e28fcb93fd7eb59ad

You are right about that commit changing the behaviour, I was fixing a
bug report about the template parser not detecting a syntax error in the
file:
  https://bugs.launchpad.net/epics-base/+bug/1503661
Your original usage probably should be legal though, so I'd accept this
change as introducing a bug.

If you want to take a look at msi.c and propose a fix that doesn't
regress the above bug as well I'd be happy to accept it. You should
include a test (in src/ioc/dbtemplate/test, probably by adjusting some
of the existing substitution and result files) that exercises your
behaviour too, to prevent future regressions.

Thanks,

- Andrew

-- 
Arguing for surveillance because you have nothing to hide is no
different than making the claim, "I don't care about freedom of
speech because I have nothing to say." -- Edward Snowdon

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System