Array or object pattern must be assignment expression. (#3744)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

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

@@ -1460,16 +1460,27 @@ parser_parse_tagged_template_literal (parser_context_t *context_p) /**< context
   return call_arguments;
 } /* parser_parse_tagged_template_literal */
 
+/**
+ * Checks wheteher the current expression can be an assignment expression.
+ *
+ * @return true if the current expression can be an assignment expression, false otherwise
+ */
+static inline bool JERRY_ATTR_ALWAYS_INLINE
+parser_is_assignment_expr (parser_context_t *context_p)
+{
+  return (context_p->stack_top_uint8 == LEXER_EXPRESSION_START
+          || context_p->stack_top_uint8 == LEXER_LEFT_PAREN
+          || context_p->stack_top_uint8 == LEXER_COMMA_SEP_LIST
+          || LEXER_IS_BINARY_LVALUE_TOKEN (context_p->stack_top_uint8));
+} /* parser_is_assignment_expr */
+
 /**
  * Throws an error if the current expression is not an assignment expression.
  */
 static inline void JERRY_ATTR_ALWAYS_INLINE
 parser_check_assignment_expr (parser_context_t *context_p)
 {
-  if (context_p->stack_top_uint8 != LEXER_EXPRESSION_START
+  if (!parser_is_assignment_expr (context_p))
-      && context_p->stack_top_uint8 != LEXER_LEFT_PAREN
-      && context_p->stack_top_uint8 != LEXER_COMMA_SEP_LIST
-      && !LEXER_IS_BINARY_LVALUE_TOKEN (context_p->stack_top_uint8))
   {
     parser_raise_error (context_p, PARSER_ERR_ASSIGNMENT_EXPECTED);
   }
@@ -1719,9 +1730,15 @@ parser_parse_unary_expression (parser_context_t *context_p, /**< context */
       if (context_p->next_scanner_info_p->source_p == context_p->source_p)
       {
         JERRY_ASSERT (context_p->next_scanner_info_p->type == SCANNER_TYPE_INITIALIZER);
+
+        if (parser_is_assignment_expr (context_p))
+        {
           parser_parse_object_initializer (context_p, PARSER_PATTERN_NO_OPTS);
           return false;
         }
+
+        scanner_release_next (context_p, sizeof (scanner_location_info_t));
+      }
 #endif /* ENABLED (JERRY_ES2015) */
 
       parser_parse_object_literal (context_p);
@@ -1733,9 +1750,15 @@ parser_parse_unary_expression (parser_context_t *context_p, /**< context */
       if (context_p->next_scanner_info_p->source_p == context_p->source_p)
       {
         JERRY_ASSERT (context_p->next_scanner_info_p->type == SCANNER_TYPE_INITIALIZER);
+
+        if (parser_is_assignment_expr (context_p))
+        {
           parser_parse_array_initializer (context_p, PARSER_PATTERN_NO_OPTS);
           return false;
         }
+
+        scanner_release_next (context_p, sizeof (scanner_location_info_t));
+      }
 #endif /* ENABLED (JERRY_ES2015) */
 
       parser_parse_array_literal (context_p);

tests/jerry/es2015/array-pattern.js

@@ -304,3 +304,10 @@ mustThrow ("try { throw 5 } catch (e) {"
            + "var iter = __createIterableObject([], "
            + "{ 'return': function() { return 5; }});"
            + "var [a] = iter }");
+
+try {
+  eval ("var a = 0; 1 + [a] = [1]");
+  assert (false);
+} catch (e) {
+  assert (e instanceof ReferenceError);
+}

tests/jerry/es2015/object-pattern.js

@@ -225,3 +225,10 @@ mustThrow ("function f ({}) {}; f();");
   ({"a": ((a)) } = {a : 7});
   assert (a === 7);
 }) ();
+
+try {
+  eval ("var a = 0; -{a} = {a:1}");
+  assert (false);
+} catch (e) {
+  assert (e instanceof ReferenceError);
+}