[Bug #20409] Make break and redo in END syntax error

Author: nobu

parse.y

@@ -1659,7 +1659,22 @@ static NODE *add_block_exit(struct parser_params *p, NODE *node);
 static rb_node_exits_t *init_block_exit(struct parser_params *p);
 static rb_node_exits_t *allow_block_exit(struct parser_params *p);
 static void restore_block_exit(struct parser_params *p, rb_node_exits_t *exits);
-static void clear_block_exit(struct parser_params *p, bool error);
+static void clear_block_exit(struct parser_params *p, unsigned int error_mask);
+
+static unsigned int
+exits_mask(enum node_type t)
+{
+    switch (t) {
+      case NODE_BREAK:
+      case NODE_NEXT:
+      case NODE_REDO:
+        return 1u << (t - NODE_BREAK);
+      default:
+        UNREACHABLE_RETURN(0);
+    }
+}
+
+#define EXITS_MASK_ALL (exits_mask(NODE_BREAK)|exits_mask(NODE_NEXT)|exits_mask(NODE_REDO))
 
 static void
 next_rescue_context(struct lex_context *next, const struct lex_context *outer, enum rescue_context def)
@@ -1677,7 +1692,7 @@ restore_defun(struct parser_params *p, rb_node_def_temp_t *temp)
     p->ctxt.in_rescue = ctxt.in_rescue;
     p->max_numparam = temp->save.max_numparam;
     numparam_pop(p, temp->save.numparam_save);
-    clear_block_exit(p, true);
+    clear_block_exit(p, EXITS_MASK_ALL);
 }
 
 static void
@@ -1834,20 +1849,23 @@ restore_block_exit(struct parser_params *p, rb_node_exits_t *exits)
 }
 
 static void
-clear_block_exit(struct parser_params *p, bool error)
+clear_block_exit(struct parser_params *p, unsigned int error_mask)
 {
     rb_node_exits_t *exits = p->exits;
     if (!exits) return;
-    if (error) {
+    if (error_mask) {
         for (NODE *e = RNODE(exits); (e = RNODE_EXITS(e)->nd_chain) != 0; ) {
             switch (nd_type(e)) {
               case NODE_BREAK:
+                if (!(error_mask & exits_mask(NODE_BREAK))) break;
                 yyerror1(&e->nd_loc, "Invalid break");
                 break;
               case NODE_NEXT:
+                if (!(error_mask & exits_mask(NODE_NEXT))) break;
                 yyerror1(&e->nd_loc, "Invalid next");
                 break;
               case NODE_REDO:
+                if (!(error_mask & exits_mask(NODE_REDO))) break;
                 yyerror1(&e->nd_loc, "Invalid redo");
                 break;
               default:
@@ -3212,7 +3230,7 @@ top_stmts	: none
 
 top_stmt	: stmt
                     {
-                        clear_block_exit(p, true);
+                        clear_block_exit(p, EXITS_MASK_ALL);
                         $$ = $1;
                     }
                 | keyword_BEGIN begin_block
@@ -3352,7 +3370,7 @@ stmt		: keyword_alias[kw] fitem[new] {SET_LEX_STATE(EXPR_FNAME|EXPR_FITEM);} fit
                     }
                 | stmt[body] modifier_while[mod] expr_value[cond_expr]
                     {
-                        clear_block_exit(p, false);
+                        clear_block_exit(p, 0);
                         if ($body && nd_type_p($body, NODE_BEGIN)) {
                             $$ = NEW_WHILE(cond(p, $cond_expr, &@cond_expr), RNODE_BEGIN($body)->nd_body, 0, &@$, &@mod, &NULL_LOC);
                         }
@@ -3363,7 +3381,7 @@ stmt		: keyword_alias[kw] fitem[new] {SET_LEX_STATE(EXPR_FNAME|EXPR_FITEM);} fit
                     }
                 | stmt[body] modifier_until[mod] expr_value[cond_expr]
                     {
-                        clear_block_exit(p, false);
+                        clear_block_exit(p, 0);
                         if ($body && nd_type_p($body, NODE_BEGIN)) {
                             $$ = NEW_UNTIL(cond(p, $cond_expr, &@cond_expr), RNODE_BEGIN($body)->nd_body, 0, &@$, &@mod, &NULL_LOC);
                         }
@@ -3381,9 +3399,10 @@ stmt		: keyword_alias[kw] fitem[new] {SET_LEX_STATE(EXPR_FNAME|EXPR_FITEM);} fit
                         $$ = NEW_RESCUE(remove_begin($body), resq, 0, &@$);
                     /*% ripper: rescue_mod!($:body, $:resbody) %*/
                     }
-                | k_END[k_end] allow_exits[allow] '{'[lbrace] compstmt(stmts)[body] '}'[rbrace]
+                | k_END[k_end] block_open[lbrace] compstmt(stmts)[body] '}'[rbrace]
                     {
-                        restore_block_exit(p, $allow);
+                        clear_block_exit(p, exits_mask(NODE_BREAK) | exits_mask(NODE_REDO));
+                        restore_block_exit(p, $block_open);
                         p->ctxt = $k_end;
                         {
                             NODE *scope = NEW_SCOPE2(0 /* tbl */, 0 /* args */, $body /* body */, NULL /* parent */, &@$);

test/ruby/test_ast.rb

@@ -255,7 +255,11 @@ def test_invalid_exit
       assert_invalid_parse(msg, "#{code}")
       assert_invalid_parse(msg, "def m; #{code}; end")
       assert_invalid_parse(msg, "begin; #{code}; end")
-      assert_parse("END {#{code}}")
+      if code.start_with?("next")
+        assert_parse("END {#{code}}")
+      else
+        assert_invalid_parse(msg, "END {#{code}}")
+      end
 
       assert_parse("!defined?(#{code})")
       assert_parse("def m; defined?(#{code}); end")