make struct GENinstance truly generic

drop the GENnode struct member, which is actually part of
  the derived instance structs

src/include/ngspice/gendefs.h

@@ -21,10 +21,21 @@ struct GENinstance {
                                      * current model*/
     IFuid GENname;  /* pointer to character string naming this instance */
     int GENstate;   /* state index number */
-    int GENnode[7]; /* node numbers to which this instance is connected to */
+
+    /* The actual devices have to place their node elements
+     *   right after the the end of struct GENinstance
+     *   where there can be accessed by generic GENnode()[]
+     * A notable exception is the XSPICE MIF device
+     */
+#if 0
+    int GENnode[];  /* node numbers to which this instance is connected to */
                     /* carefull, thats overlayed into the actual device structs */
+#endif
 };
 
+static inline int *GENnode(struct GENinstance *inst)
+{ return (int*)(inst + 1); }
+
 
 /* per model data */
 

src/spicelib/analysis/ckti2nod.c

@@ -26,7 +26,7 @@ CKTinst2Node(CKTcircuit *ckt, void *instPtr, int terminal, CKTnode **node, IFuid
 
     if (*(DEVices[type]->DEVpublic.terms) >= terminal && terminal > 0) {
         /* argh, terminals are counted from 1 */
-        int nodenum = inst->GENnode[terminal - 1];
+        int nodenum = GENnode(inst)[terminal - 1];
 
         for (here = ckt->CKTnodes; here; here = here->next)
             if (here->number == nodenum) {

src/spicelib/analysis/tfanal.c

@@ -76,8 +76,8 @@ TFanal(CKTcircuit *ckt, int restart)
     }
 
     if (job->TFinIsI) {
-        ckt->CKTrhs[ptr->GENnode[0]] -= 1;
-        ckt->CKTrhs[ptr->GENnode[1]] += 1;
+        ckt->CKTrhs[GENnode(ptr)[0]] -= 1;
+        ckt->CKTrhs[GENnode(ptr)[1]] += 1;
     } else {
         insrc = CKTfndBranch(ckt, job->TFinSrc);
         ckt->CKTrhs[insrc] += 1;
@@ -119,8 +119,8 @@ TFanal(CKTcircuit *ckt, int restart)
 
     /* now for input resistance */
     if (job->TFinIsI) {
-        outputs[1] = ckt->CKTrhs[ptr->GENnode[1]] -
-                ckt->CKTrhs[ptr->GENnode[0]];
+        outputs[1] = ckt->CKTrhs[GENnode(ptr)[1]] -
+            ckt->CKTrhs[GENnode(ptr)[0]];
     } else {
         if(fabs(ckt->CKTrhs[insrc])<1e-20) {
             outputs[1]=1e20;

src/spicelib/devices/cktbindnode.c

@@ -26,7 +26,7 @@ CKTbindNode(CKTcircuit *ckt, GENinstance *instance, int term, CKTnode *node)
 
     if (*(devs[type]->DEVpublic.terms) >= term && term > 0) {
         /* argh, terminals are counted from 1 */
-        instance->GENnode[term - 1] = node->number;
+        GENnode(instance)[term - 1] = node->number;
         return OK;
     } else {
         return E_NOTERM;

src/spicelib/devices/urc/urcsetup.c

@@ -302,7 +302,7 @@ URCunsetup(GENmodel *inModel, CKTcircuit *ckt)
 		return E_NOMOD;
 
 	    for (in = modfast->GENinstances; in; in = in->GENnextInstance)
-		CKTdltNNum(ckt, in->GENnode[0]);
+		CKTdltNNum(ckt, GENnode(in)[0]);
 
 	    CKTdltMod(ckt, modfast);	/* Does the elements too */
 

src/spicelib/parser/inp2m.c

@@ -142,7 +142,7 @@ INP2M(CKTcircuit *ckt, INPtables *tab, card *current)
         if (i < numnodes)
             IFC (bindNode, (ckt, fast, i + 1, node[i]));
         else
-            fast->GENnode[i] = -1;
+            GENnode(fast)[i] = -1;
 
     PARSECALL ((&line, ckt, type, fast, &leadval, &waslead, tab));
     if (waslead)