diff --git a/extflat/EFbuild.c b/extflat/EFbuild.c
index 20c31830..e1688680 100644
--- a/extflat/EFbuild.c
+++ b/extflat/EFbuild.c
@@ -463,7 +463,7 @@ efBuildDist(def, driver, receiver, min, max)
 #endif	/* notdef */
 
     he = HashFind(&def->def_dists, (char *) &distKey);
-    if (dist = (Distance *) HashGetValue(he))
+    if ((dist = (Distance *) HashGetValue(he)))
     {
 	/*
 	 * There was already an entry in the table; update it
@@ -659,7 +659,7 @@ efBuildEquiv(def, nodeName1, nodeName2, resist, isspice)
 	     * node that was just removed.
 	     */
 	    HashStartSearch(&hs);
-	    while (he = HashNext(&def->def_devs, &hs))
+	    while ((he = HashNext(&def->def_devs, &hs)))
 	    {
 	    	Dev *dev;
 		int n;
@@ -679,7 +679,7 @@ efBuildEquiv(def, nodeName1, nodeName2, resist, isspice)
 	    {
 		nn2->efnn_refc += nn1->efnn_refc + 1;
     		HashStartSearch(&hs);
-    		while (he1 = HashNext(&def->def_nodes, &hs))
+		while ((he1 = HashNext(&def->def_nodes, &hs)))
 		    if ((EFNodeName *)HashGetValue(he1) == nn1)
 			HashSetValue(he1, (char *)nn2);
 	    }
@@ -687,7 +687,7 @@ efBuildEquiv(def, nodeName1, nodeName2, resist, isspice)
 	    {
 		nn1->efnn_refc += nn2->efnn_refc + 1;
     		HashStartSearch(&hs);
-    		while (he2 = HashNext(&def->def_nodes, &hs))
+		while ((he2 = HashNext(&def->def_nodes, &hs)))
 		    if ((EFNodeName *)HashGetValue(he2) == nn2)
 			HashSetValue(he2, (char *)nn1);
 	    }
@@ -1757,7 +1757,7 @@ again:
     *dstp++ = ']';
 
     /* Copy remainder of path */
-    while (*dstp++ = *cp++)
+    while ((*dstp++ = *cp++))
 	/* Nothing */;
 
     cnp->cn_name = StrDup((char **) NULL, newname);
@@ -1970,7 +1970,7 @@ efNodeMerge(node1ptr, node2ptr)
     keeping->efnode_num += removing->efnode_num;
 
     /* Merge attribute lists */
-    if (ap = removing->efnode_attrs)
+    if ((ap = removing->efnode_attrs))
     {
 	while (ap->efa_next)
 	    ap = ap->efa_next;
@@ -2059,8 +2059,8 @@ efFreeUseTable(table)
     EFNodeName *nn;
 
     HashStartSearch(&hs);
-    while (he = HashNext(table, &hs))
-	if (use = (Use *) HashGetValue(he))
+    while ((he = HashNext(table, &hs)))
+	if ((use = (Use *) HashGetValue(he)))
 	{
 	    if (use->use_id != NULL) freeMagic((char *)use->use_id);
 	    freeMagic(use);
@@ -2088,7 +2088,7 @@ efFreeDevTable(table)
     int n;
 
     HashStartSearch(&hs);
-    while (he = HashNext(table, &hs))
+    while ((he = HashNext(table, &hs)))
     {
 	dev = (Dev *)HashGetValue(he);
 	for (n = 0; n < (int)dev->dev_nterm; n++)
@@ -2131,8 +2131,8 @@ efFreeNodeTable(table)
     EFNodeName *nn;
 
     HashStartSearch(&hs);
-    while (he = HashNext(table, &hs))
-	if (nn = (EFNodeName *) HashGetValue(he))
+    while ((he = HashNext(table, &hs)))
+	if ((nn = (EFNodeName *) HashGetValue(he)))
 	{
 	    for (hn = nn->efnn_hier; hn; hn = hn->hn_parent)
 		(void) HashFind(&efFreeHashTable, (char *) hn);
diff --git a/extflat/EFread.c b/extflat/EFread.c
index 7692a9d6..29742c72 100644
--- a/extflat/EFread.c
+++ b/extflat/EFread.c
@@ -670,7 +670,7 @@ resistChanged:
     /* Read in each def that has not yet been read in */
 
     HashStartSearch(&hs);
-    while (he = HashNext(&def->def_uses, &hs))
+    while ((he = HashNext(&def->def_uses, &hs)))
     {
         use = (Use *)HashGetValue(he);
 	if ((use->use_def->def_flags & DEF_AVAILABLE) == 0)
diff --git a/extract/ExtArray.c b/extract/ExtArray.c
index 2ea8b6ea..b1f9f43f 100644
--- a/extract/ExtArray.c
+++ b/extract/ExtArray.c
@@ -690,7 +690,7 @@ extArrayAdjust(ha, et1, et2)
     extHierAdjustments(ha, &ha->ha_cumFlat, et2, et2);
 
     HashStartSearch(&hs);
-    while (he = HashNext(&ha->ha_cumFlat.et_coupleHash, &hs))
+    while ((he = HashNext(&ha->ha_cumFlat.et_coupleHash, &hs)))
     {
 	cap = extGetCapValue(he)  / ExtCurStyle->exts_capScale;
 	if (cap == 0)
@@ -797,7 +797,7 @@ extArrayTileToNode(tp, pNum, et, ha, doHard)
     }
 
     if (!DebugIsSet(extDebugID, extDebNoHard))
-	if (reg = (LabRegion *) extArrayHardNode(tp, pNum, def, ha))
+	if ((reg = (LabRegion *) extArrayHardNode(tp, pNum, def, ha)))
 	    goto found;
 
     /* Blew it */
diff --git a/extract/ExtBasic.c b/extract/ExtBasic.c
index 2c73d98c..8ab90e68 100644
--- a/extract/ExtBasic.c
+++ b/extract/ExtBasic.c
@@ -4566,7 +4566,7 @@ extNodeAreaFunc(tile, arg)
     }
 
     /* Compute the resistance for the previous region */
-    if (old = (NodeRegion *) arg->fra_region)
+    if ((old = (NodeRegion *) arg->fra_region))
 	if (ExtOptions & EXT_DORESISTANCE)
 	    extSetResist(old);
 
@@ -4946,7 +4946,7 @@ donesides:
 	 * 1-lambda halo to find everything it overlaps or touches
 	 * on the other plane.
 	 */
-	if (pMask = DBAllConnPlanes[type])
+	if ((pMask = DBAllConnPlanes[type]))
 	{
 	    Rect biggerArea;
 	    bool is_split = IsSplit(tile);
@@ -5029,7 +5029,7 @@ extCapHashKill(ht)
     HashEntry *he;
 
     HashStartSearch(&hs);
-    while (he = HashNext(ht, &hs))
+    while ((he = HashNext(ht, &hs)))
     {
 	if (HashGetValue(he) != NULL)
 	{
diff --git a/extract/ExtCell.c b/extract/ExtCell.c
index 48d33751..d425c4d4 100644
--- a/extract/ExtCell.c
+++ b/extract/ExtCell.c
@@ -215,7 +215,7 @@ extFileOpen(def, file, mode, prealfile)
 	name = def->cd_file;
 	ends = strrchr(def->cd_file, '/');
 	if (ends == NULL) ends = def->cd_file;
-	if (endp = strrchr(ends + 1, '.'))
+	if ((endp = strrchr(ends + 1, '.')))
 	{
 	    name = namebuf;
 	    len = endp - def->cd_file;
diff --git a/extract/ExtCouple.c b/extract/ExtCouple.c
index 80a177d6..9b669248 100644
--- a/extract/ExtCouple.c
+++ b/extract/ExtCouple.c
@@ -219,7 +219,7 @@ extRelocateSubstrateCoupling(table, subsnode)
     NodeRegion *rbp;
 
     HashStartSearch(&hs);
-    while (he = HashNext(table, &hs))
+    while ((he = HashNext(table, &hs)))
     {
 	cap = extGetCapValue(he);
 	if (cap == 0) continue;
@@ -275,7 +275,7 @@ extOutputCoupling(table, outFile)
     CapValue cap;  /* value of capacitance. */
 
     HashStartSearch(&hs);
-    while (he = HashNext(table, &hs))
+    while ((he = HashNext(table, &hs)))
     {
 	cap = extGetCapValue(he) / ExtCurStyle->exts_capScale;
 	if (cap == 0)
@@ -464,7 +464,7 @@ extAddOverlap(tbelow, ecpls)
      * Deduct the area shielded from the area of the overlap, so we adjust
      * the overlap capacitance correspondingly.
      */
-    if (ov.o_pmask = ExtCurStyle->exts_overlapShieldPlanes[ta][tb])
+    if ((ov.o_pmask = ExtCurStyle->exts_overlapShieldPlanes[ta][tb]))
     {
 	ov.o_tmask = ExtCurStyle->exts_overlapShieldTypes[ta][tb];
 	for (pNum = PL_TECHDEPBASE; pNum < DBNumPlanes; pNum++)
diff --git a/extract/ExtHard.c b/extract/ExtHard.c
index 923c2041..8f1fef43 100644
--- a/extract/ExtHard.c
+++ b/extract/ExtHard.c
@@ -376,7 +376,7 @@ extHardSetLabel(scx, reg, arg)
 	do { *dstp++ = *srcp++; } while (--prefixlen > 0);
     }
     srcp = text;
-    while (*dstp++ = *srcp++) /* Nothing */;
+    while ((*dstp++ = *srcp++)) /* Nothing */;
 
     arg->hw_label = newlab;
     if (DebugIsSet(extDebugID, extDebHardWay))
@@ -455,7 +455,7 @@ extHardGenerateLabel(scx, reg, arg)
 	do { *dstp++ = *srcp++; } while (--prefixlen > 0);
     }
     srcp = gen;
-    while (*dstp++ = *srcp++) /* Nothing */;
+    while ((*dstp++ = *srcp++)) /* Nothing */;
     arg->hw_label = newlab;
     if (DebugIsSet(extDebugID, extDebHardWay))
 	TxPrintf("Hard way: generated label = \"%s\"\n", newlab->lab_text);
diff --git a/extract/ExtHier.c b/extract/ExtHier.c
index 24c8e036..87d223b8 100644
--- a/extract/ExtHier.c
+++ b/extract/ExtHier.c
@@ -737,7 +737,7 @@ extHierAdjustments(ha, cumFlat, oneFlat, lookFlat)
     if (ExtOptions & EXT_DOCOUPLING)
     {
 	HashStartSearch(&hs);
-	while (he = HashNext(&oneFlat->et_coupleHash, &hs))
+	while ((he = HashNext(&oneFlat->et_coupleHash, &hs)))
 	{
 	    ckpOne = ((CoupleKey *) he->h_key.h_words);
 
@@ -828,7 +828,7 @@ extOutputConns(table, outf)
     HashEntry *he;
 
     HashStartSearch(&hs);
-    while (he = HashNext(table, &hs))
+    while ((he = HashNext(table, &hs)))
     {
 	nfirst = (NodeName *) HashGetValue(he);
 
@@ -838,7 +838,7 @@ extOutputConns(table, outf)
 	 * for a node appearing earlier in the table.  If so, we need
 	 * only free the NodeName without any further processing.
 	 */
-	if (node = nfirst->nn_node)
+	if ((node = nfirst->nn_node))
 	{
 	    /*
 	     * If there are N names for this node, output N-1 merge lines.
@@ -848,7 +848,7 @@ extOutputConns(table, outf)
 	    /* Note 3/1/2017:  Cap value no longer used */
 	    c = (node->node_cap) / ExtCurStyle->exts_capScale;
 	    nn = node->node_names;
-	    if (nnext = nn->nn_next)
+	    if ((nnext = nn->nn_next))
 	    {
 		/* First merge */
 		fprintf(outf, "merge \"%s\" \"%s\" %lg",
@@ -862,7 +862,7 @@ extOutputConns(table, outf)
 		nn->nn_node = (Node *) NULL;		/* Processed */
 
 		/* Subsequent merges */
-		for (nn = nnext; nnext = nn->nn_next; nn = nnext)
+		for (nn = nnext; (nnext = nn->nn_next); nn = nnext)
 		{
 		    fprintf(outf, "merge \"%s\" \"%s\"\n",
 				    nn->nn_name, nnext->nn_name);
diff --git a/extract/ExtLength.c b/extract/ExtLength.c
index bfb2ba6f..b896d3e2 100644
--- a/extract/ExtLength.c
+++ b/extract/ExtLength.c
@@ -261,7 +261,7 @@ extLength(rootUse, f)
      * be from a single cell.
      */
     HashStartSearch(&hs);
-    while (he = HashNext(&extDriverHash, &hs))
+    while ((he = HashNext(&extDriverHash, &hs)))
     {
 	dList = extPathLabel(rootUse, he->h_key.h_name);
 	HashSetValue(he, (ClientData) dList);
@@ -273,7 +273,7 @@ extLength(rootUse, f)
      * then compute and output the distance to each.
      */
     HashStartSearch(&hs);
-    while (he = HashNext(&extDriverHash, &hs))
+    while ((he = HashNext(&extDriverHash, &hs)))
     {
 	/* Ignore drivers whose labels couldn't be found */
 	dList = (Label *) HashGetValue(he);
@@ -875,7 +875,7 @@ extPathFlood(tile, p, distance, epa)
      * 1-lambda halo to find everything it overlaps or touches
      * on the other plane.
      */
-    if (pMask = DBAllConnPlanes[type])
+    if ((pMask = DBAllConnPlanes[type]))
     {
 	int saveplane = epa->epa_pNum;
 	struct extPathFloodArg epfa;
diff --git a/extract/ExtMain.c b/extract/ExtMain.c
index ab9b38c0..eac2b5ee 100644
--- a/extract/ExtMain.c
+++ b/extract/ExtMain.c
@@ -496,7 +496,7 @@ ExtUnique(rootUse, option)
 
     /* Now process all the cells we just found */
     nwarn = 0;
-    while (def = (CellDef *) StackPop(extDefStack))
+    while ((def = (CellDef *) StackPop(extDefStack)))
     {
 	/* EXT_UNIQ_NOTOPPORTS:  Use EXT_UNIQ_ALL on all cells other than the top */
 	if ((option == EXT_UNIQ_NOTOPPORTS) &&
@@ -967,7 +967,7 @@ extExtractStack(stack, doExtract, rootDef)
     CellDef *def;
     struct saveList *newsl, *sl = (struct saveList *)NULL;
 
-    while (def = (CellDef *) StackPop(stack))
+    while ((def = (CellDef *) StackPop(stack)))
     {
 	def->cd_client = (ClientData) 0;
 	if (!SigInterruptPending)
diff --git a/extract/ExtNghbors.c b/extract/ExtNghbors.c
index bdfa8ce0..9ea7b21a 100644
--- a/extract/ExtNghbors.c
+++ b/extract/ExtNghbors.c
@@ -295,7 +295,7 @@ donesides:
 	 * 1-lambda halo to find everything it overlaps or touches
 	 * on the other plane.
 	 */
-	if (pMask = DBAllConnPlanes[type])
+	if ((pMask = DBAllConnPlanes[type]))
 	{
 	    TITORECT(tile, &pla.area);
 	    GEO_EXPAND(&pla.area, 1, &biggerArea);
diff --git a/extract/ExtSubtree.c b/extract/ExtSubtree.c
index cd7944ee..d1a854bf 100644
--- a/extract/ExtSubtree.c
+++ b/extract/ExtSubtree.c
@@ -680,7 +680,7 @@ extSubtreeOutputCoupling(ha)
     char *name;
 
     HashStartSearch(&hs);
-    while (he = HashNext(&ha->ha_cumFlat.et_coupleHash, &hs))
+    while ((he = HashNext(&ha->ha_cumFlat.et_coupleHash, &hs)))
     {
 	cap = extGetCapValue(he) / ExtCurStyle->exts_capScale;
 	if (cap == 0)
diff --git a/extract/ExtTest.c b/extract/ExtTest.c
index 7217707e..38b9c3fe 100644
--- a/extract/ExtTest.c
+++ b/extract/ExtTest.c
@@ -454,7 +454,7 @@ extShowTech(name)
 				out);
 		    fprintf(out, "\n");
 		}
-		if (e = ExtCurStyle->exts_sideCoupleCap[s][t])
+		if ((e = ExtCurStyle->exts_sideCoupleCap[s][t]))
 		    for ( ; e; e = e->ec_next)
 		    {
 			fprintf(out, "                COUPLE: ");
@@ -463,7 +463,7 @@ extShowTech(name)
 			extShowMask(&e->ec_far, out);
 			fprintf(out, ": %lf\n", e->ec_cap);
 		    }
-		if (e = ExtCurStyle->exts_sideOverlapCap[s][t])
+		if ((e = ExtCurStyle->exts_sideOverlapCap[s][t]))
 		    for ( ; e; e = e->ec_next)
 		    {
 			fprintf(out, "                OVERLAP: ");
diff --git a/extract/ExtTimes.c b/extract/ExtTimes.c
index 1f1d21e7..7d3a6431 100644
--- a/extract/ExtTimes.c
+++ b/extract/ExtTimes.c
@@ -213,7 +213,7 @@ ExtTimes(rootUse, f)
      */
     TxPrintf("Computing individual cell statistics:\n"); TxFlush();
     HashStartSearch(&hs);
-    while (he = HashNext(&cellStatsTable, &hs))
+    while ((he = HashNext(&cellStatsTable, &hs)))
 	extTimesCellFunc((struct cellStats *) HashGetValue(he));
 
     /*
@@ -223,7 +223,7 @@ ExtTimes(rootUse, f)
      */
     TxPrintf("Computing hierarchical and incremental statistics:\n"); TxFlush();
     HashStartSearch(&hs);
-    while (he = HashNext(&cellStatsTable, &hs))
+    while ((he = HashNext(&cellStatsTable, &hs)))
 	extTimesIncrFunc((struct cellStats *) HashGetValue(he));
 
     /*
@@ -232,7 +232,7 @@ ExtTimes(rootUse, f)
      */
     TxPrintf("Computing summary statistics:\n"); TxFlush();
     HashStartSearch(&hs);
-    while (he = HashNext(&cellStatsTable, &hs))
+    while ((he = HashNext(&cellStatsTable, &hs)))
     {
 	extTimesSummaryFunc((struct cellStats *) HashGetValue(he), f);
 	freeMagic((char *) HashGetValue(he));
diff --git a/extract/ExtYank.c b/extract/ExtYank.c
index ace872ee..b89c4256 100644
--- a/extract/ExtYank.c
+++ b/extract/ExtYank.c
@@ -233,9 +233,9 @@ extHierLabelFunc(scx, label, tpath, targetDef)
     newlab->lab_flags = label->lab_flags;
     newlab->lab_port = label->lab_port;
     dstp = newlab->lab_text;
-    for (srcp = tpath->tp_first; *dstp++ = *srcp++; )
+    for (srcp = tpath->tp_first; (*dstp++ = *srcp++); )
 	/* Nothing */;
-    for (--dstp, srcp = label->lab_text; *dstp++ = *srcp++; )
+    for (--dstp, srcp = label->lab_text; (*dstp++ = *srcp++); )
 	/* Nothing */;
 
     newlab->lab_next = targetDef->cd_labels;