From c71afb631cffbd60b8f94cea4f67bb82fb9b339b Mon Sep 17 00:00:00 2001
From: Andrew Johnson <anj@aps.anl.gov>
Date: Tue, 25 Apr 2017 20:37:09 -0500
Subject: [PATCH] Make dbLinkIs{Constant|Volatile}() return only true/false

---
 src/ioc/db/dbLink.c         | 10 ++--------
 src/ioc/db/dbLink.h         |  6 +++---
 src/std/link/lnkCalc.c      |  2 +-
 src/std/rec/calcoutRecord.c | 11 ++++++-----
 4 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/src/ioc/db/dbLink.c b/src/ioc/db/dbLink.c
index a8b7f62ad..6fb936ae4 100644
--- a/src/ioc/db/dbLink.c
+++ b/src/ioc/db/dbLink.c
@@ -190,20 +190,14 @@ int dbLinkIsConstant(const struct link *plink)
 {
     lset *plset = plink->lset;
 
-    if (plset)
-        return plset->isConstant;
-
-    return -1;
+    return !plset || plset->isConstant;
 }
 
 int dbLinkIsVolatile(const struct link *plink)
 {
     lset *plset = plink->lset;
 
-    if (plset)
-        return plset->isVolatile;
-
-    return -1;
+    return plset && plset->isVolatile;
 }
 
 long dbLoadLink(struct link *plink, short dbrType, void *pbuffer)
diff --git a/src/ioc/db/dbLink.h b/src/ioc/db/dbLink.h
index 6f5858b65..ad4ac2f45 100644
--- a/src/ioc/db/dbLink.h
+++ b/src/ioc/db/dbLink.h
@@ -89,8 +89,8 @@ epicsShareFunc void dbLinkOpen(struct link *plink);
 epicsShareFunc void dbRemoveLink(struct dbLocker *locker, struct link *plink);
 
 epicsShareFunc int dbLinkIsDefined(const struct link *plink);  /* 0 or 1 */
-epicsShareFunc int dbLinkIsConstant(const struct link *plink); /* -1, 0 or 1 */
-epicsShareFunc int dbLinkIsVolatile(const struct link *plink); /* -1, 0 or 1 */
+epicsShareFunc int dbLinkIsConstant(const struct link *plink); /* 0 or 1 */
+epicsShareFunc int dbLinkIsVolatile(const struct link *plink); /* 0 or 1 */
 
 epicsShareFunc long dbLoadLink(struct link *plink, short dbrType,
         void *pbuffer);
@@ -98,7 +98,7 @@ epicsShareFunc long dbLoadLinkArray(struct link *, short dbrType, void *pbuffer,
         long *pnRequest);
 
 epicsShareFunc long dbGetNelements(const struct link *plink, long *nelements);
-epicsShareFunc int dbIsLinkConnected(const struct link *plink);
+epicsShareFunc int dbIsLinkConnected(const struct link *plink); /* 0 or 1 */
 epicsShareFunc int dbGetLinkDBFtype(const struct link *plink);
 epicsShareFunc long dbGetLink(struct link *, short dbrType, void *pbuffer,
         long *options, long *nRequest);
diff --git a/src/std/link/lnkCalc.c b/src/std/link/lnkCalc.c
index ea02ad039..70d47426e 100644
--- a/src/std/link/lnkCalc.c
+++ b/src/std/link/lnkCalc.c
@@ -466,7 +466,7 @@ static int lnkCalc_isConn(const struct link *plink)
     for (i = 0; i < clink->nArgs; i++) {
         struct link *child = &clink->inp[i];
 
-        if (dbLinkIsVolatile(child) > 0 &&
+        if (dbLinkIsVolatile(child) &&
             !dbIsLinkConnected(child))
             connected = 0;
     }
diff --git a/src/std/rec/calcoutRecord.c b/src/std/rec/calcoutRecord.c
index 92a292140..8b5525527 100644
--- a/src/std/rec/calcoutRecord.c
+++ b/src/std/rec/calcoutRecord.c
@@ -172,10 +172,10 @@ static long init_record(struct dbCommon *pcommon, int pass)
             recGblInitConstantLink(plink, DBF_DOUBLE, pvalue);
         }
 
-        if (dbLinkIsConstant(plink) > 0) {
+        if (dbLinkIsConstant(plink)) {
             *plinkValid = calcoutINAV_CON;
         }
-        else if (dbLinkIsVolatile(plink) > 0) {
+        else if (dbLinkIsVolatile(plink)) {
             int conn = dbIsLinkConnected(plink);
 
             if (conn)
@@ -366,10 +366,11 @@ static long special(DBADDR *paddr, int after)
 
         if (fieldIndex != calcoutRecordOUT)
             recGblInitConstantLink(plink, DBF_DOUBLE, pvalue);
-        if (dbLinkIsConstant(plink) > 0) {
+
+        if (dbLinkIsConstant(plink)) {
             db_post_events(prec, pvalue, DBE_VALUE);
             *plinkValid = calcoutINAV_CON;
-        } else if (dbLinkIsVolatile(plink) > 0) {
+        } else if (dbLinkIsVolatile(plink)) {
             int conn = dbIsLinkConnected(plink);
 
             if (conn)
@@ -734,7 +735,7 @@ static void checkLinks(calcoutRecord *prec)
     plinkValid = &prec->inav;
 
     for (i = 0; i<CALCPERFORM_NARGS+1; i++, plink++, plinkValid++) {
-        if (dbLinkIsVolatile(plink) == 1) {
+        if (dbLinkIsVolatile(plink)) {
             caLink = 1;
             stat = dbIsLinkConnected(plink);
             if (!stat && (*plinkValid == calcoutINAV_EXT_NC)) {