ripper: Check if anonymous parameters defined [Bug #18828]

Merged: https://github.com/ruby/ruby/pull/6016

parse.y

@@ -2856,14 +2856,13 @@ block_arg	: tAMPER arg_value
 		    }
                 | tAMPER
                     {
-                    /*%%%*/
                         if (!local_id(p, ANON_BLOCK_ID)) {
                             compile_error(p, "no anonymous block parameter");
                         }
+                    /*%%%*/
                         $$ = NEW_BLOCK_PASS(NEW_LVAR(ANON_BLOCK_ID, &@1), &@$);
-                    /*%
+                    /*% %*/
-                    $$ = Qnil;
+                    /*% ripper: Qnil %*/
-                    %*/
                     }
 		;
 
@@ -2894,10 +2893,10 @@ args		: arg_value
 		    }
 		| tSTAR
 		    {
-		    /*%%%*/
                         if (!local_id(p, ANON_REST_ID)) {
                             compile_error(p, "no anonymous rest parameter");
                         }
+		    /*%%%*/
 			$$ = NEW_SPLAT(NEW_LVAR(ANON_REST_ID, &@1), &@$);
 		    /*% %*/
 		    /*% ripper: args_add_star!(args_new!, Qnil) %*/
@@ -2918,10 +2917,10 @@ args		: arg_value
 		    }
 		| args ',' tSTAR
 		    {
-		    /*%%%*/
                         if (!local_id(p, ANON_REST_ID)) {
                             compile_error(p, "no anonymous rest parameter");
                         }
+		    /*%%%*/
 			$$ = rest_arg_append(p, $1, NEW_LVAR(ANON_REST_ID, &@3), &@$);
 		    /*% %*/
 		    /*% ripper: args_add_star!($1, Qnil) %*/
@@ -5489,8 +5488,8 @@ f_kwrest	: kwrest_mark tIDENTIFIER
 		    }
 		| kwrest_mark
 		    {
+			arg_var(p, ANON_KEYWORD_REST_ID);
 		    /*%%%*/
-			arg_var(p, shadowing_lvar(p, get_id(ANON_KEYWORD_REST_ID)));
 		    /*% %*/
 		    /*% ripper: kwrest_param!(Qnil) %*/
 		    }
@@ -5564,8 +5563,8 @@ f_rest_arg	: restarg_mark tIDENTIFIER
 		    }
 		| restarg_mark
 		    {
+			arg_var(p, ANON_REST_ID);
 		    /*%%%*/
-                        arg_var(p, shadowing_lvar(p, get_id(ANON_REST_ID)));
 		    /*% %*/
 		    /*% ripper: rest_param!(Qnil) %*/
 		    }
@@ -5585,11 +5584,10 @@ f_block_arg	: blkarg_mark tIDENTIFIER
 		    }
                 | blkarg_mark
                     {
+			arg_var(p, ANON_BLOCK_ID);
                     /*%%%*/
-                        arg_var(p, shadowing_lvar(p, get_id(ANON_BLOCK_ID)));
+                    /*% %*/
-                    /*%
+		    /*% ripper: blockarg!(Qnil) %*/
-                    $$ = dispatch1(blockarg, Qnil);
-                    %*/
                     }
 		;
 
@@ -5721,10 +5719,10 @@ assoc		: arg_value tASSOC arg_value
 		    }
 		| tDSTAR
 		    {
-		    /*%%%*/
                         if (!local_id(p, ANON_KEYWORD_REST_ID)) {
                             compile_error(p, "no anonymous keyword rest parameter");
                         }
+		    /*%%%*/
                         $$ = list_append(p, NEW_LIST(0, &@$),
                                          NEW_LVAR(ANON_KEYWORD_REST_ID, &@$));
 		    /*% %*/

test/ripper/test_parser_events.rb

@@ -155,6 +155,44 @@ class TestRipper::ParserEvents < Test::Unit::TestCase
     end
   end
 
+  def test_anonymous_block_forwarding
+    thru_args_add_block = false
+    parse('def b(&); c(&); end', :on_args_add_block) {thru_args_add_block = true}
+    assert_equal true, thru_args_add_block
+    assert_match "no anonymous block parameter", compile_error('def b; c(&); end')
+  end
+
+  def test_anonymous_rest_forwarding
+    [
+      'c(*)',
+      'c(*, *)',
+    ].each do |code|
+      thru_args_add_star = false
+      src = "def b(*); #{code} end"
+      parse(src, :on_args_add_star) {thru_args_add_star = true}
+      assert_equal true, thru_args_add_star, src
+
+      src = "def b; #{code} end"
+      assert_match "no anonymous rest parameter", compile_error(src), src
+    end
+  end
+
+  def test_anonymous_keyword_rest_forwarding
+    [
+      'c(**)',
+      'c(k: 1, **)',
+      'c(**, k: 1)',
+    ].each do |code|
+      thru_assoc_splat = false
+      src = "def b(**); #{code} end"
+      parse(src, :on_assoc_splat) {thru_assoc_splat = true}
+      assert_equal true, thru_assoc_splat, src
+
+      src = "def b; #{code} end"
+      assert_match "no anonymous keyword rest parameter", compile_error(src), src
+    end
+  end
+
   def test_arg_paren
     # FIXME
   end