Avoid usage of the dummy empty BEGIN node

Use NODE_SPECIAL_NO_NAME_REST instead.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67629 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ast.c

@@ -634,10 +634,12 @@ node_children(rb_ast_t *ast, NODE *node)
       case NODE_ARYPTN:
         {
             struct rb_ary_pattern_info *apinfo = node->nd_apinfo;
+            VALUE rest = NODE_NAMED_REST_P(apinfo->rest_arg) ? NEW_CHILD(ast, apinfo->rest_arg) :
+                                                               ID2SYM(rb_intern("NODE_SPECIAL_NO_NAME_REST"));
             return rb_ary_new_from_args(4,
                                         NEW_CHILD(ast, node->nd_pconst),
                                         NEW_CHILD(ast, apinfo->pre_args),
-                                        NEW_CHILD(ast, apinfo->rest_arg),
+                                        rest,
                                         NEW_CHILD(ast, apinfo->post_args));
         }
       case NODE_HSHPTN:

compile.c

@@ -5305,8 +5305,8 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
         const int post_args_num = apinfo->post_args ? rb_long2int(apinfo->post_args->nd_alen) : 0;
 
         const int min_argc = pre_args_num + post_args_num;
-        const int use_rest_num = apinfo->rest_arg && ((nd_type(apinfo->rest_arg) != NODE_BEGIN) ||
-                                                      (nd_type(apinfo->rest_arg) == NODE_BEGIN && post_args_num > 0));
+        const int use_rest_num = apinfo->rest_arg && (NODE_NAMED_REST_P(apinfo->rest_arg) ||
+                                                      (!NODE_NAMED_REST_P(apinfo->rest_arg) && post_args_num > 0));
 
         LABEL *match_failed, *type_error, *fin;
         int i;
@@ -5354,17 +5354,7 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
         }
 
         if (apinfo->rest_arg) {
-            if (nd_type(apinfo->rest_arg) == NODE_BEGIN) {
-                if (post_args_num > 0) {
-                    ADD_INSN(ret, line, dup);
-                    ADD_SEND(ret, line, idLength, INT2FIX(0));
-                    ADD_INSN1(ret, line, putobject, INT2FIX(min_argc));
-                    ADD_SEND(ret, line, idMINUS, INT2FIX(1));
-                    ADD_INSN1(ret, line, setn, INT2FIX(2));
-                    ADD_INSN(ret, line, pop);
-                }
-            }
-            else {
+            if (NODE_NAMED_REST_P(apinfo->rest_arg)) {
                 ADD_INSN(ret, line, dup);
                 ADD_INSN1(ret, line, putobject, INT2FIX(pre_args_num));
                 ADD_INSN1(ret, line, topn, INT2FIX(1));
@@ -5377,6 +5367,16 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
                 iseq_compile_pattern_each(iseq, ret, apinfo->rest_arg, in_alt_pattern);
                 ADD_INSNL(ret, line, branchunless, match_failed);
             }
+            else {
+                if (post_args_num > 0) {
+                    ADD_INSN(ret, line, dup);
+                    ADD_SEND(ret, line, idLength, INT2FIX(0));
+                    ADD_INSN1(ret, line, putobject, INT2FIX(min_argc));
+                    ADD_SEND(ret, line, idMINUS, INT2FIX(1));
+                    ADD_INSN1(ret, line, setn, INT2FIX(2));
+                    ADD_INSN(ret, line, pop);
+                }
+            }
         }
 
         args = apinfo->post_args;

node.c

@@ -1040,7 +1040,12 @@ dump_node(VALUE buf, VALUE indent, int comment, const NODE * node)
         ANN("format: [nd_pconst]([pre_args], ..., *[rest_arg], [post_args], ...)");
         F_NODE(nd_pconst, "constant");
         F_NODE(nd_apinfo->pre_args, "pre arguments");
+        if (NODE_NAMED_REST_P(node->nd_apinfo->rest_arg)) {
             F_NODE(nd_apinfo->rest_arg, "rest argument");
+        }
+        else {
+            F_MSG(nd_apinfo->rest_arg, "rest argument", "NODE_SPECIAL_NO_NAME_REST (rest argument without name)");
+        }
         LAST_NODE;
         F_NODE(nd_apinfo->post_args, "post arguments");
         return;

parse.y

@@ -11037,7 +11037,7 @@ new_array_pattern_tail(struct parser_params *p, NODE *pre_args, int has_rest, ID
 	if (rest_arg) {
 	    apinfo->rest_arg = assignable(p, rest_arg, 0, loc);
 	} else {
-	    apinfo->rest_arg = NEW_BEGIN(0, loc);
+	    apinfo->rest_arg = NODE_SPECIAL_NO_NAME_REST;
 	}
     } else {
 	apinfo->rest_arg = NULL;