Generator declaration is not allowed in single statement position (#4815)

JerryScript-DCO-1.0-Signed-off-by: Robert Sipka robert.sipka@h-lab.eu

jerry-core/parser/js/js-parser-statm.c

@@ -600,7 +600,9 @@ parser_parse_function_statement (parser_context_t *context_p) /**< context */
   JERRY_ASSERT (context_p->token.type == LEXER_KEYW_FUNCTION);
 
 #if JERRY_ESNEXT
-  if (JERRY_UNLIKELY (parser_statement_flags[context_p->stack_top_uint8] & PARSER_STATM_SINGLE_STATM))
+  bool is_single_statement = (parser_statement_flags[context_p->stack_top_uint8] & PARSER_STATM_SINGLE_STATM) != 0;
+
+  if (JERRY_UNLIKELY (is_single_statement))
   {
     if (context_p->status_flags & PARSER_IS_STRICT)
     {
@@ -667,6 +669,10 @@ parser_parse_function_statement (parser_context_t *context_p) /**< context */
 
   if (lexer_consume_generator (context_p))
   {
+    if (is_single_statement)
+    {
+      parser_raise_error (context_p, PARSER_ERR_GENERATOR_IN_SINGLE_STATEMENT_POS);
+    }
     is_generator_function = true;
   }
 #endif /* JERRY_ESNEXT */

jerry-core/parser/js/js-parser-util.c

@@ -1243,6 +1243,10 @@ parser_error_to_string (parser_error_t error) /**< error code */
     {
       return "Lexical declaration cannot appear in a single-statement context";
     }
+    case PARSER_ERR_GENERATOR_IN_SINGLE_STATEMENT_POS:
+    {
+      return "Generator function cannot appear in a single-statement context";
+    }
     case PARSER_ERR_LABELLED_FUNC_NOT_IN_BLOCK:
     {
       return "Labelled functions are only allowed inside blocks";

jerry-core/parser/js/js-parser.h

@@ -141,6 +141,7 @@ typedef enum
 #if JERRY_ESNEXT
   PARSER_ERR_VARIABLE_REDECLARED, /**< a variable redeclared */
   PARSER_ERR_LEXICAL_SINGLE_STATEMENT, /**< lexical declaration in single statement context */
+  PARSER_ERR_GENERATOR_IN_SINGLE_STATEMENT_POS, /**< generator func not allowed in single statement position */
   PARSER_ERR_LABELLED_FUNC_NOT_IN_BLOCK, /**< labelled functions are only allowed inside blocks */
   PARSER_ERR_LEXICAL_LET_BINDING, /**< let binding cannot be declared in let/const */
   PARSER_ERR_MISSING_ASSIGN_AFTER_CONST, /**< an assignment is required after a const declaration */

tests/jerry/es.next/generator-function-in-single-statement.js

@@ -0,0 +1,27 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+function parse(txt) {
+    try {
+        eval(txt)
+        assert(false)
+    } catch (e) {
+        assert(e instanceof SyntaxError)
+    }
+}
+
+parse("if (true) function* g() {  }")
+parse("if (false) ; else function* g() {  }")

tests/test262-esnext-excludelist.xml

@@ -365,13 +365,8 @@
   <test id="language/statements/if/cptn-no-else-false.js"><reason></reason></test>
   <test id="language/statements/if/cptn-no-else-true-abrupt-empty.js"><reason></reason></test>
   <test id="language/statements/if/cptn-no-else-true-nrml.js"><reason></reason></test>
-  <test id="language/statements/if/if-gen-else-gen.js"><reason></reason></test>
-  <test id="language/statements/if/if-gen-else-stmt.js"><reason></reason></test>
-  <test id="language/statements/if/if-gen-no-else.js"><reason></reason></test>
-  <test id="language/statements/if/if-stmt-else-gen.js"><reason></reason></test>
   <test id="language/statements/if/let-block-with-newline.js"><reason></reason></test>
   <test id="language/statements/if/let-identifier-with-newline.js"><reason></reason></test>
-  <test id="language/statements/labeled/decl-gen.js"><reason></reason></test>
   <test id="language/statements/labeled/let-block-with-newline.js"><reason></reason></test>
   <test id="language/statements/labeled/let-identifier-with-newline.js"><reason></reason></test>
   <test id="language/statements/let/syntax/let-newline-yield-in-generator-function.js"><reason></reason></test>