Attach disciplines to wires

Allow discipline declaration of nets that attaches the discipline to
a new wire or a wire that is already declared.

PWire.h

@@ -36,6 +36,7 @@ class ostream;
 
 class PExpr;
 class Design;
+class discipline_t;
 
 /*
  * The different type of PWire::set_range() calls.
@@ -78,10 +79,12 @@ class PWire : public LineInfo {
       ivl_variable_type_t get_data_type() const;
 
       void set_range(PExpr*msb, PExpr*lsb, PWSRType type);
-      void set_net_range();
 
       void set_memory_idx(PExpr*ldx, PExpr*rdx);
 
+      void set_discipline(discipline_t*);
+      discipline_t* get_discipline(void) const;
+
       map<perm_string,PExpr*> attributes;
 
 	// Write myself to the specified stream.
@@ -112,6 +115,8 @@ class PWire : public LineInfo {
       PExpr*lidx_;
       PExpr*ridx_;
 
+      discipline_t*discipline_;
+
     private: // not implemented
       PWire(const PWire&);
       PWire& operator= (const PWire&);