Experimental Physics and
Industrial Control System

Dirk Zimoch via Tech-talk <[email protected]> · Tue, 2 Apr 2019 12:18:59 +0200

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