Merge pull request #958 from diffblue/class_identifier

SystemVerilog: class identifiers

Author: tautschnig

regression/verilog/class/class1.sv

@@ -3,4 +3,5 @@ class myClass;
 endclass
 
 module main;
+  myClass c = null;
 endmodule

src/hw_cbmc_irep_ids.h

@@ -251,6 +251,7 @@ IREP_ID_ONE(verilog_empty_item)
 IREP_ID_ONE(verilog_import_item)
 IREP_ID_ONE(verilog_interface)
 IREP_ID_ONE(verilog_class)
+IREP_ID_ONE(verilog_class_type)
 IREP_ID_ONE(verilog_module)
 IREP_ID_ONE(verilog_package)
 IREP_ID_ONE(verilog_package_import)

src/verilog/expr2verilog.cpp

@@ -2052,10 +2052,14 @@ std::string expr2verilogt::convert(const typet &type)
   }
   else if(type.id() == ID_verilog_chandle)
     return "chandle";
+  else if(type.id() == ID_verilog_class_type)
+    return "class";
   else if(type.id() == ID_verilog_event)
     return "event";
   else if(type.id() == ID_verilog_genvar)
     return "genvar";
+  else if(type.id() == ID_verilog_new)
+    return "new";
   else if(type.id()==ID_integer)
     return "integer";
   else if(type.id()==ID_verilog_shortreal)

src/verilog/parser.y

@@ -537,6 +537,7 @@ int yyverilogerror(const char *error)
 /* Others */
 %token TOK_ENDOFFILE
 %token TOK_NON_TYPE_IDENTIFIER
+%token TOK_CLASS_IDENTIFIER
 %token TOK_PACKAGE_IDENTIFIER
 %token TOK_TYPE_IDENTIFIER
 %token TOK_NUMBER           // number, any base
@@ -819,12 +820,13 @@ checker_port_direction_opt:
 	;
 
 class_declaration:
-	  TOK_CLASS class_identifier
+	  TOK_CLASS any_identifier
 	  ';'
 		{
 		  init($$, ID_verilog_class);
-		  stack_expr($$).set(ID_base_name, stack_expr($2).id());
-	          push_scope(stack_expr($2).id(), "::", verilog_scopet::CLASS);
+		  auto base_name = stack_expr($2).get(ID_base_name);
+		  stack_expr($$).set(ID_base_name, base_name);
+	          push_scope(base_name, "::", verilog_scopet::CLASS);
 	        }
 	  class_item_brace
 	  TOK_ENDCLASS
@@ -1553,7 +1555,7 @@ data_type:
 		{ mto($1, $2);
 		  add_as_subtype(stack_type($3), stack_type($1));
 		  $$ = $3; }
-//	| class_type
+	| class_type
 	| TOK_EVENT
 	        { init($$, ID_verilog_event); }
 	/*
@@ -2033,6 +2035,9 @@ variable_decl_assignment:
 		  addswap($$, ID_type, $2);
 		  addswap($$, ID_value, $4); }
 	| variable_identifier variable_dimension_brace '=' class_new
+		{ $$ = $1; stack_expr($$).id(ID_declarator);
+		  addswap($$, ID_type, $2);
+		  addswap($$, ID_value, $4); }
 	;
 
 class_new:
@@ -4383,7 +4388,14 @@ non_type_identifier: TOK_NON_TYPE_IDENTIFIER
 
 block_identifier: TOK_NON_TYPE_IDENTIFIER;
 
-class_identifier: TOK_NON_TYPE_IDENTIFIER;
+class_identifier: TOK_CLASS_IDENTIFIER
+		{
+		  init($$, ID_verilog_class_type);
+		  auto base_name = stack_expr($1).id();
+		  stack_expr($$).set(ID_base_name, base_name);
+		  stack_expr($$).set(ID_identifier, PARSER.scopes.current_scope().prefix+id2string(base_name));
+		}
+	;
 
 constraint_identifier: TOK_NON_TYPE_IDENTIFIER;
 

src/verilog/verilog_elaborate_type.cpp

@@ -438,6 +438,10 @@ typet verilog_typecheck_exprt::elaborate_type(const typet &src)
   {
     return src;
   }
+  else if(src.id() == ID_verilog_class_type)
+  {
+    return src;
+  }
   else if(src.id() == ID_verilog_package_scope)
   {
     // package::typedef

src/verilog/verilog_scope.cpp

@@ -62,7 +62,7 @@ unsigned verilog_scopest::identifier_token(irep_idt base_name) const
     case verilog_scopet::FILE:      return TOK_NON_TYPE_IDENTIFIER;
     case verilog_scopet::PACKAGE:   return TOK_PACKAGE_IDENTIFIER;
     case verilog_scopet::MODULE:    return TOK_NON_TYPE_IDENTIFIER;
-    case verilog_scopet::CLASS:     return TOK_NON_TYPE_IDENTIFIER;
+    case verilog_scopet::CLASS:     return TOK_CLASS_IDENTIFIER;
     case verilog_scopet::BLOCK:     return TOK_NON_TYPE_IDENTIFIER;
     case verilog_scopet::ENUM_NAME: return TOK_NON_TYPE_IDENTIFIER;
     case verilog_scopet::TASK:      return TOK_NON_TYPE_IDENTIFIER;

src/verilog/verilog_typecheck_expr.cpp

@@ -2062,6 +2062,7 @@ void verilog_typecheck_exprt::implicit_typecast(
   {
     if(
       dest_type.id() == ID_verilog_chandle ||
+      dest_type.id() == ID_verilog_class_type ||
       dest_type.id() == ID_verilog_event)
     {
       if(expr.id() == ID_constant)
@@ -2594,6 +2595,11 @@ exprt verilog_typecheck_exprt::convert_unary_expr(unary_exprt expr)
     convert_expr(expr.op());
     expr.type() = expr.op().type();
   }
+  else if(expr.id() == ID_verilog_new)
+  {
+    // The type of these expressions is determined by their context.
+    expr.type() = typet(ID_verilog_new);
+  }
   else
   {
     throw errort() << "no conversion for unary expression " << expr.id();