implemented union parsing

lc.c

@@ -142,6 +142,14 @@ void print_ast(ast_node *node, int depth) {
 				m = m->next;
 			}
 			break;
+		case NODE_UNION:
+			printf("Union: %.*s\n", (int)node->expr.structure.name_len, node->expr.structure.name);
+			m = node->expr.structure.members;
+			while (m) {
+				print_ast(m->type, depth + 1);
+				m = m->next;
+			}
+			break;
 		case NODE_IF:
 			printf("IfStmt (Fields missing in struct)\n");
 			break;

parser.c

@@ -684,6 +684,10 @@ static member *parse_member(parser *p)
 	if (match(p, TOKEN_STRUCT)) {
 		type = parse_struct(p);
 	}
+	if (match(p, TOKEN_UNION)) {
+		type = parse_struct(p);
+		type->type = NODE_UNION;
+	}
 	if (!type) {
 		type = parse_factor(p);
 		if (!type) {
@@ -899,6 +903,12 @@ static ast_node *parse_statement(parser *p)
 	{
 		return parse_struct(p);
 	}
+	else if (match(p, TOKEN_UNION))
+	{
+		ast_node *u = parse_struct(p);
+		u->type = NODE_UNION;
+		return u;
+	}
 	else
 	{
 		ast_node *expr = parse_expression(p);

test.c

@@ -1,4 +1,4 @@
 struct {
-	struct { u32 x, u32 y } a,
+	union { u32 x, u32 y } a,
 	u32 b,
 }