Add support for class static properties.

Static properties are like variables in a named scope.
Detect these variables during elaboration so that the
code generator just sees them as variables.

PExpr.h

@@ -387,9 +387,9 @@ class PEIdent : public PExpr {
       bool elaborate_lval_net_idx_(Design*, NetScope*, NetAssign_*,
                                    index_component_t::ctype_t,
 				   bool need_const_idx) const;
-      bool elaborate_lval_net_class_member_(Design*, NetScope*,
-					    NetAssign_*,
-					    const perm_string&) const;
+      NetAssign_*elaborate_lval_net_class_member_(Design*, NetScope*,
+						   NetNet*,
+						   const perm_string&) const;
       bool elaborate_lval_net_packed_member_(Design*, NetScope*,
 					     NetAssign_*,
 					     const perm_string&) const;

elab_expr.cc

@@ -1759,6 +1759,17 @@ static NetExpr* check_for_struct_members(const LineInfo*li,
       return sel;
 }
 
+static NetExpr* class_static_property_expression(const LineInfo*li,
+						 const netclass_t*class_type,
+						 perm_string name)
+{
+      NetNet*sig = class_type->find_static_property(name);
+      ivl_assert(*li, sig);
+      NetESignal*expr = new NetESignal(sig);
+      expr->set_line(*li);
+      return expr;
+}
+
 static NetExpr* check_for_class_property(const LineInfo*li,
 					 Design*des, NetScope*scope,
 					 NetNet*net,
@@ -1791,6 +1802,12 @@ static NetExpr* check_for_class_property(const LineInfo*li,
 	    des->errors += 1;
       }
 
+      if (qual.test_static()) {
+	    perm_string prop_name = lex_strings.make(class_type->get_prop_name(pidx));
+	    return class_static_property_expression(li, class_type,
+						    prop_name);
+      }
+
       NetEProperty*tmp = new NetEProperty(net, comp.name);
       tmp->set_line(*li);
       return tmp;
@@ -2888,6 +2905,10 @@ NetExpr* PEIdent::elaborate_expr_class_member_(Design*des, NetScope*scope,
 	    des->errors += 1;
       }
 
+      if (qual.test_static()) {
+	    return class_static_property_expression(this, class_type, member_name);
+      }
+
       NetEProperty*tmp = new NetEProperty(this_net, member_name);
       tmp->set_line(*this);
       return tmp;

elab_lval.cc

@@ -256,8 +256,7 @@ NetAssign_* PEIdent::elaborate_lval(Design*des,
       }
 
       if (reg->class_type() && !method_name.nil() && gn_system_verilog()) {
-	    NetAssign_*lv = new NetAssign_(reg);
-	    elaborate_lval_net_class_member_(des, use_scope, lv, method_name);
+	    NetAssign_*lv = elaborate_lval_net_class_member_(des, use_scope, reg, method_name);
 	    return lv;
       }
 
@@ -846,17 +845,16 @@ bool PEIdent::elaborate_lval_net_idx_(Design*des,
       return true;
 }
 
-bool PEIdent::elaborate_lval_net_class_member_(Design*des, NetScope*scope,
-					       NetAssign_*lv,
-					       const perm_string&method_name) const
+NetAssign_* PEIdent::elaborate_lval_net_class_member_(Design*des, NetScope*scope,
+				    NetNet*sig, const perm_string&method_name) const
 {
       if (debug_elaborate) {
 	    cerr << get_fileline() << ": elaborate_lval_net_class_member_: "
 		 << "l-value is property " << method_name
-		 << " of " << lv->sig()->name() << "." << endl;
+		 << " of " << sig->name() << "." << endl;
       }
 
-      const netclass_t*class_type = lv->sig()->class_type();
+      const netclass_t*class_type = sig->class_type();
       ivl_assert(*this, class_type);
 
 	/* Make sure the property is really present in the class. If
@@ -866,7 +864,7 @@ bool PEIdent::elaborate_lval_net_class_member_(Design*des, NetScope*scope,
 	    cerr << get_fileline() << ": error: Class " << class_type->get_name()
 		 << " does not have a property " << method_name << "." << endl;
 	    des->errors += 1;
-	    return false;
+	    return 0;
       }
 
       property_qualifier_t qual = class_type->get_prop_qual(pidx);
@@ -877,6 +875,17 @@ bool PEIdent::elaborate_lval_net_class_member_(Design*des, NetScope*scope,
 		 << " (scope=" << scope_path(scope) << ")" << endl;
 	    des->errors += 1;
 
+      } else if (qual.test_static()) {
+
+	      // Special case: this is a static property. Ignore the
+	      // "this" sig and use the property itself, which is not
+	      // part of the sig, as the l-value.
+	    NetNet*psig = class_type->find_static_property(method_name);
+	    ivl_assert(*this, psig);
+
+	    NetAssign_*lv = new NetAssign_(psig);
+	    return lv;
+
       } else if (qual.test_const()) {
 	    cerr << get_fileline() << ": error: "
 		 << "Property " << class_type->get_prop_name(pidx)
@@ -884,6 +893,7 @@ bool PEIdent::elaborate_lval_net_class_member_(Design*des, NetScope*scope,
 	    des->errors += 1;
       }
 
+      NetAssign_*lv = new NetAssign_(sig);
       lv->set_property(method_name);
 
       ivl_type_t ptype = class_type->get_prop_type(pidx);
@@ -898,7 +908,7 @@ bool PEIdent::elaborate_lval_net_class_member_(Design*des, NetScope*scope,
 	    }
       }
 
-      return true;
+      return lv;
 }
 
 

elab_sig.cc

@@ -314,6 +314,25 @@ bool Module::elaborate_sig(Design*des, NetScope*scope) const
 
 void netclass_t::elaborate_sig(Design*des, PClass*pclass)
 {
+      for (map<perm_string,struct class_type_t::prop_info_t>::iterator cur = pclass->type->properties.begin()
+		 ; cur != pclass->type->properties.end() ; ++ cur) {
+
+	    if (! cur->second.qual.test_static())
+		  continue;
+
+	    if (debug_elaborate) {
+		  cerr << pclass->get_fileline() << ": netclass_t::elaborate_sig: "
+		       << "Elaborate static property " << cur->first
+		       << " as signal in scope " << scope_path(class_scope_)
+		       << "." << endl;
+	    }
+
+	    list<netrange_t> nil_list;
+	    ivl_type_t use_type = cur->second.type->elaborate_type(des, class_scope_);
+	    NetNet*sig = new NetNet(class_scope_, cur->first, NetNet::REG,
+				    nil_list, use_type);
+      }
+
       for (map<perm_string,PFunction*>::iterator cur = pclass->funcs.begin()
 		 ; cur != pclass->funcs.end() ; ++ cur) {
 	    if (debug_elaborate) {

elaborate.cc

@@ -2361,11 +2361,17 @@ NetProc* PAssign::elaborate_compressed_(Design*des, NetScope*scope) const
       return cur;
 }
 
+/*
+ * Assignments within program blocks can only write to certain types
+ * of variables. We can only write to:
+ *    - variables in a program block
+ *    - static properties of a class
+ */
 static bool lval_not_program_variable(const NetAssign_*lv)
 {
       while (lv) {
 	    NetScope*sig_scope = lv->sig()->scope();
-	    if (! sig_scope->program_block())
+	    if (! sig_scope->program_block() && sig_scope->type()!=NetScope::CLASS)
 		  return true;
 
 	    lv = lv->more;
@@ -4969,6 +4975,19 @@ bool Module::elaborate(Design*des, NetScope*scope) const
  */
 void netclass_t::elaborate(Design*des, PClass*pclass)
 {
+      if (! pclass->type->initialize_static.empty()) {
+	    std::vector<Statement*>&stmt_list = pclass->type->initialize_static;
+	    NetBlock*stmt = new NetBlock(NetBlock::SEQU, 0);
+	    for (size_t idx = 0 ; idx < stmt_list.size() ; idx += 1) {
+		  NetProc*tmp = stmt_list[idx]->elaborate(des, class_scope_);
+		  if (tmp == 0) continue;
+		  stmt->append(tmp);
+	    }
+	    NetProcTop*top = new NetProcTop(class_scope_, IVL_PR_INITIAL, stmt);
+	    top->set_line(*pclass);
+	    des->add_process(top);
+      }
+
       for (map<perm_string,PFunction*>::iterator cur = pclass->funcs.begin()
 		 ; cur != pclass->funcs.end() ; ++ cur) {
 	    if (debug_elaborate) {

netclass.cc

@@ -122,6 +122,11 @@ NetScope*netclass_t::method_from_name(perm_string name) const
 
 }
 
+NetNet* netclass_t::find_static_property(perm_string name) const
+{
+      NetNet*tmp = class_scope_->find_signal(name);
+}
+
 bool netclass_t::test_scope_is_method(const NetScope*scope) const
 {
       while (scope && scope != class_scope_) {

netclass.h

@@ -27,6 +27,7 @@
 # include  <map>
 
 class Design;
+class NetNet;
 class NetScope;
 class PClass;
 
@@ -72,6 +73,11 @@ class netclass_t : public ivl_type_s {
 	// The task method scopes from the method name.
       NetScope*method_from_name(perm_string mname) const;
 
+	// Find the elaborated signal (NetNet) for a static
+	// property. Search by name. The signal is created by the
+	// elaborate_sig pass.
+      NetNet*find_static_property(perm_string name) const;
+
 	// Test if this scope is a method within the class. This is
 	// used to check scope for handling data protection keywords
 	// "local" and "protected".

pform_pclass.cc

@@ -41,15 +41,6 @@ void pform_class_property(const struct vlltype&loc,
 {
       assert(pform_cur_class);
 
-      if (property_qual.test_static()) {
-	      // I think the thing to do with static properties is to
-	      // make them PWires directly in the PClass scope. They
-	      // are wires like program/modules wires, and not
-	      // instance members.
-	    VLerror(loc, "sorry: static class properties not implemented.");
-	    return;
-      }
-
 	// Add the non-static properties to the class type
 	// object. Unwind the list of names to make a map of name to
 	// type.
@@ -72,7 +63,11 @@ void pform_class_property(const struct vlltype&loc,
 		  FILE_NAME(lval, loc);
 		  PAssign*tmp = new PAssign(lval, rval);
 		  FILE_NAME(tmp, loc);
-		  pform_cur_class->type->initialize.push_back(tmp);
+
+		  if (property_qual.test_static())
+			pform_cur_class->type->initialize_static.push_back(tmp);
+		  else
+			pform_cur_class->type->initialize.push_back(tmp);
 	    }
       }
 }

pform_types.h

@@ -233,6 +233,11 @@ struct class_type_t : public data_type_t {
 	// the expression that is assigned.
       std::vector<Statement*> initialize;
 
+	// This is an ordered list of property initializers for static
+	// properties. These are run in a synthetic "initial" block
+	// without waiting for any constructor.
+      std::vector<Statement*> initialize_static;
+
       ivl_type_s* elaborate_type(Design*, NetScope*) const;
 };