Experimental Physics and
Industrial Control System

Michael Davidsaver via Core-talk <[email protected]> · Tue, 2 Apr 2019 09:15:06 -0700

On 4/2/19 9:00 AM, Dirk Zimoch via Core-talk wrote:
> 
> 
> On 02.04.19 16:24, Dirk Zimoch via Core-talk wrote:
>> [I had originally sent this to tech-talk instead of core-talk by accident. Sorry for the spam.]
>>
>> Hi folks,
>>
>> Today while compiling a driver for EPICS 7 I found an incompatibility.
>>
>> The function definition errSymbolAdd() (and others) have disappeared from errMdef.h. Thus when compiling a driver including errMdef.h and using errSymbolAdd(), I get a compiler warning because of the missing function prototype.
>>
>> The prototypes are now in the new header file errSymTbl.h. But simply including the new file instead is no good solution, because then the driver does not compile with older EPICS versions any more.
>>
>> Instead I have use compiler branches based on EPICS versions. That is a bit inconvenient.
>>
>> What is the policy about backward compatibility in EPICS 7? Should we expect more compatibility breaking changes in the future in an attempt to "move forwards" or will EPICS 7 aim to stay backward compatible for 3rd party code like drivers?
>>
>> Dirk
> 
> The question is actually: Should I consider this a bug in EPICS 7 (and propose a fix)? Or was there a good reason for it and should I better put a preprocessor branch in the driver? (With the changes e.g. in rset and maybe in the future in dset as well such a branch may probably sooner or later be necessary anyway.)

Thank you for clarifying ;)

In fact there has been a discussion ongoing about this very topic:

https://code.launchpad.net/~anj/epics-base/+git/base-7.0/+merge/361344

Could you add something concerning the application which is call errSymbolAdd()?
It it published anywhere?

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System