ioc/dbStatic: add dbGetDevLink()

src/ioc/db/dbAccess.c

@@ -709,6 +709,18 @@ void dbInitEntryFromRecord(struct dbCommon *prec, DBENTRY *pdbentry)
     pdbentry->precnode = ppvt->recnode;
 }
 
+struct link* dbGetDevLink(struct dbCommon* prec)
+{
+    DBLINK *plink = 0;
+    DBENTRY entry;
+    dbInitEntryFromRecord(prec, &entry);
+    if(dbFindField(&entry, "INP")==0 || dbFindField(&entry, "OUT")==0) {
+        plink = (DBLINK*)entry.pfield;
+    }
+    dbFinishEntry(&entry);
+    return plink;
+}
+
 long dbValueSize(short dbr_type)
 {
     /* sizes for value associated with each DBR request type */

src/ioc/dbStatic/devSup.h

@@ -22,6 +22,7 @@
 struct dbCommon;
 struct devSup;
 struct ioscan_head; /* aka IOSCANPVT */
+struct link; /* aka DBLINK */
 
 #ifdef __cplusplus
 extern "C" {
@@ -112,6 +113,12 @@ typedef struct dsxt {   /* device support extension table */
     /* Recordtypes are *not* allowed to extend this table */
 } dsxt;
 
+/** Fetch INP or OUT link (or NULL if record type has neither).
+ *
+ * Recommended for use in device support init_record()
+ */
+epicsShareFunc struct link* dbGetDevLink(struct dbCommon* prec);
+
 epicsShareExtern dsxt devSoft_DSXT;  /* Allow anything table */
 
 epicsShareFunc void devExtend(dsxt *pdsxt);