Index: trunk/src/obj_pstk.h
===================================================================
--- trunk/src/obj_pstk.h	(revision 20428)
+++ trunk/src/obj_pstk.h	(revision 20429)
@@ -252,6 +252,14 @@
 /* Overwrite all fields of a proto in-place; returns the id or INVALID on error */
 pcb_cardinal_t pcb_pstk_proto_replace(pcb_data_t *data, pcb_cardinal_t proto_id, const pcb_pstk_proto_t *src);
 
+/* Cycle through all (first level) padstacks of data and count how many times
+   each prototype is referenced by them. The result is returned as an array
+   of counts per prototype ID; the array is as large as data's prototype array.
+   len_out is always filled with the length of the array. If the length is 0,
+   NULL is returned. The caller needs to call free() on the returned array. */
+pcb_cardinal_t *pcb_pstk_proto_used_all(pcb_data_t *data, pcb_cardinal_t *len_out);
+
+
 /*** layer info ***/
 typedef struct pcb_proto_layer_s {
 	const char *name;
Index: trunk/src/obj_pstk_proto.c
===================================================================
--- trunk/src/obj_pstk_proto.c	(revision 20428)
+++ trunk/src/obj_pstk_proto.c	(revision 20429)
@@ -1135,7 +1135,27 @@
 	pcb_pstk_proto_del_shape_idx(proto, idx);
 }
 
+pcb_cardinal_t *pcb_pstk_proto_used_all(pcb_data_t *data, pcb_cardinal_t *len_out)
+{
+	pcb_cardinal_t len, n, *res;
+	pcb_pstk_t *ps;
 
+	len = data->ps_protos.used;
+	if (len == 0) {
+		*len_out = 0;
+		return NULL;
+	}
+
+	res = calloc(sizeof(pcb_cardinal_t), len);
+	for(ps = padstacklist_first(&data->padstack); ps != NULL; ps = padstacklist_next(ps)) {
+		if ((ps->proto >= 0) && (ps->proto < len))
+			res[ps->proto]++;
+	}
+
+	*len_out = len;
+	return res;
+}
+
 /*** hash ***/
 static unsigned int pcb_pstk_shape_hash(const pcb_pstk_shape_t *sh)
 {