Added cast to type support (#4284)

Author: rherveille

frontends/ast/ast.cc

@@ -478,6 +478,10 @@ void AstNode::dumpVlog(FILE *f, std::string indent) const
 		fprintf(f, ";\n");
 		break;
 
+	case AST_WIRETYPE:
+		fprintf(f, "%s", id2vl(str).c_str());
+		break;
+
 	case AST_MEMORY:
 		fprintf(f, "%s" "memory", indent.c_str());
 		if (is_signed)
@@ -694,7 +698,17 @@ void AstNode::dumpVlog(FILE *f, std::string indent) const
 		break;
 
 	case AST_CAST_SIZE:
-		children[0]->dumpVlog(f, "");
+		switch (children[0]->type)
+		{
+		case AST_WIRE:
+			if (children[0]->children.size() > 0)
+				children[0]->children[0]->dumpVlog(f, "");
+			else
+				fprintf(f, "%d'", children[0]->range_left - children[0]->range_right + 1);
+			break;
+		default:
+			children[0]->dumpVlog(f, "");
+		}
 		fprintf(f, "'(");
 		children[1]->dumpVlog(f, "");
 		fprintf(f, ")");

frontends/ast/simplify.cc

@@ -1500,11 +1500,69 @@ bool AstNode::simplify(bool const_fold, int stage, int width_hint, bool sign_hin
 		}
 		break;
 
+	case AST_CAST_SIZE: {
+		int width = 1;
+		AstNode *node;
+		AstNode *child = children[0];
+
+		if (child->type == AST_WIRE) {
+			if (child->children.size() == 0) {
+				// Base type (e.g., int)
+				width = child->range_left - child->range_right +1;
+				node = mkconst_int(width, child->is_signed);
+			} else {
+				// User defined type
+				log_assert(child->children[0]->type == AST_WIRETYPE);
+
+				const std::string &type_name = child->children[0]->str;
+				if (!current_scope.count(type_name))
+					input_error("Unknown identifier `%s' used as type name\n", type_name.c_str());
+				AstNode *resolved_type_node = current_scope.at(type_name);
+				if (resolved_type_node->type != AST_TYPEDEF)
+					input_error("`%s' does not name a type\n", type_name.c_str());
+				log_assert(resolved_type_node->children.size() == 1);
+				AstNode *template_node = resolved_type_node->children[0];
+
+				// Ensure typedef itself is fully simplified
+				while (template_node->simplify(const_fold, stage, width_hint, sign_hint)) {};
+
+				switch (template_node->type)
+				{
+				case AST_WIRE: {
+					if (template_node->children.size() > 0 && template_node->children[0]->type == AST_RANGE)
+						width = range_width(this, template_node->children[0]);
+					child->delete_children();
+					node = mkconst_int(width, true);
+					break;
+				}
+
+				case AST_STRUCT:
+				case AST_UNION: {
+					child->delete_children();
+					width = size_packed_struct(template_node, 0);
+					node = mkconst_int(width, false);
+					break;
+				}
+
+				default:
+					log_error("Don't know how to translate static cast of type %s\n", type2str(template_node->type).c_str());
+				}
+			}
+
+			delete child;
+			children.erase(children.begin());
+			children.insert(children.begin(), node);
+		}
+
+		detect_width_simple = true;
+		children_are_self_determined = true;
+		break;
+	}
+
 	case AST_TO_BITS:
 	case AST_TO_SIGNED:
 	case AST_TO_UNSIGNED:
 	case AST_SELFSZ:
-	case AST_CAST_SIZE:
 	case AST_CONCAT:
 	case AST_REPLICATE:
 	case AST_REDUCE_AND:

frontends/verilog/verilog_parser.y

@@ -3506,6 +3506,12 @@ basic_expr:
 		$$ = new AstNode(AST_CAST_SIZE, $1, $4);
 		SET_AST_NODE_LOC($$, @1, @4);
 	} |
+	typedef_base_type OP_CAST '(' expr ')' {
+		if (!sv_mode)
+			frontend_verilog_yyerror("Static cast is only supported in SystemVerilog mode.");
+		$$ = new AstNode(AST_CAST_SIZE, $1, $4);
+		SET_AST_NODE_LOC($$, @1, @4);
+	} |
 	'(' expr '=' expr ')' {
 		ensureAsgnExprAllowed();
 		AstNode *node = new AstNode(AST_ASSIGN_EQ, $2, $4);