Experimental Physics and
Industrial Control System

Dirk Zimoch via Core-talk <[email protected]> · Wed, 3 Apr 2019 10:25:59 +0200

On 02.04.19 19:37, Johnson, Andrew N. wrote:

Hi Dirk,

On 4/2/19 9:24 AM, Dirk Zimoch via Core-talk wrote:

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.

Not sure what you mean by "compiler branches" there.

I meant preprocessor branches: #if EPICS_VERSION >= 7

You could do this:

#include <errMdef.h>
#ifndef M_syd
#include <errSymTbl.h>
#endif

I believe the M_syd macro has not been used since before I started with

EPICS. The comment for it said "Sync Data Routines; see sydDefs.h" but

that header has not been present in any 3.13 release so I finally

deleted that symbol while restructuring the libcom/src/error files.

Alternatively you could do a version number check (see the other

epicsVersion.h thread for details) but the above suggestion is simpler

and faster.

M_syd does not exist in 7.0.1. Also M_* macros seem to come and go. For

example M_ts disappears. So this type of branching would be not only

obfuscating the real reason for the branch but would also be unstable

against future changes.

Instead I did the second alternative, branching on EPICS_VERSION.

- Andrew

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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System