Improve delete property with undefined base (#3312)

This patch finally resolves #2891 also the removes the related bytecode since it has become unnecessary.

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

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

@@ -528,8 +528,8 @@
               VM_OC_BLOCK_CREATE_CONTEXT) \
   CBC_FORWARD_BRANCH (CBC_EXT_CATCH, 1, \
                       VM_OC_CATCH) \
-  CBC_OPCODE (CBC_EXT_PUSH_UNDEFINED_BASE, CBC_NO_FLAG, 1, \
-              VM_OC_PUSH_UNDEFINED_BASE | VM_OC_PUT_STACK) \
+  CBC_OPCODE (CBC_EXT_RESOLVE_BASE, CBC_NO_FLAG, 0, \
+              VM_OC_RESOLVE_BASE_FOR_CALL) \
   CBC_FORWARD_BRANCH (CBC_EXT_FINALLY, 0, \
                       VM_OC_FINALLY) \
   CBC_OPCODE (CBC_EXT_CLASS_EXPR_CONTEXT_END, CBC_NO_FLAG, 0, \
@@ -576,8 +576,6 @@
               VM_OC_SET_GETTER | VM_OC_GET_STACK_LITERAL) \
   CBC_OPCODE (CBC_EXT_SET_STATIC_COMPUTED_SETTER, CBC_HAS_LITERAL_ARG, -1, \
               VM_OC_SET_SETTER | VM_OC_GET_STACK_LITERAL) \
-  CBC_OPCODE (CBC_EXT_RESOLVE_BASE, CBC_NO_FLAG, 0, \
-              VM_OC_RESOLVE_BASE_FOR_CALL) \
   CBC_OPCODE (CBC_EXT_THROW_REFERENCE_ERROR, CBC_NO_FLAG, 1, \
               VM_OC_THROW_REFERENCE_ERROR) \
   \

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

@@ -201,8 +201,14 @@ parser_emit_unary_lvalue_opcode (parser_context_t *context_p, /**< context */
   else
   {
     /* Invalid LeftHandSide expression. */
-    parser_emit_cbc_ext (context_p, (opcode == CBC_DELETE_PUSH_RESULT) ? CBC_EXT_PUSH_UNDEFINED_BASE
-                                                                       : CBC_EXT_THROW_REFERENCE_ERROR);
+    if (opcode == CBC_DELETE_PUSH_RESULT)
+    {
+      parser_emit_cbc (context_p, CBC_POP);
+      parser_emit_cbc (context_p, CBC_PUSH_TRUE);
+      return;
+    }
+
+    parser_emit_cbc_ext (context_p, CBC_EXT_THROW_REFERENCE_ERROR);
   }
 
   parser_emit_cbc (context_p, (uint16_t) opcode);

jerry-core/vm/opcodes.c

@@ -176,10 +176,12 @@ vm_op_delete_prop (ecma_value_t object, /**< base object */
                    ecma_value_t property, /**< property name */
                    bool is_strict) /**< strict mode */
 {
+#if !ENABLED (JERRY_ES2015)
   if (ecma_is_value_undefined (object))
   {
     return ECMA_VALUE_TRUE;
   }
+#endif /* !ENABLED (JERRY_ES2015) */
 
   ecma_value_t check_coercible = ecma_op_check_object_coercible (object);
   if (ECMA_IS_VALUE_ERROR (check_coercible))

jerry-core/vm/vm.c

@@ -1917,13 +1917,6 @@ vm_loop (vm_frame_ctx_t *frame_ctx_p) /**< frame context */
 #endif /* ENABLED (JERRY_ES2015) */
           continue;
         }
-        case VM_OC_PUSH_UNDEFINED_BASE:
-        {
-          stack_top_p[0] = stack_top_p[-1];
-          stack_top_p[-1] = ECMA_VALUE_UNDEFINED;
-          stack_top_p++;
-          continue;
-        }
         case VM_OC_IDENT_REFERENCE:
         {
           uint16_t literal_index;

jerry-core/vm/vm.h

@@ -125,7 +125,6 @@ typedef enum
 
   VM_OC_SET_GETTER,              /**< set getter */
   VM_OC_SET_SETTER,              /**< set setter */
-  VM_OC_PUSH_UNDEFINED_BASE,     /**< push undefined base */
   VM_OC_PUSH_ARRAY,              /**< push array */
   VM_OC_PUSH_ELISON,             /**< push elison */
   VM_OC_APPEND_ARRAY,            /**< append array */

tests/jerry/es2015/regression-test-issue-2891.js

@@ -0,0 +1,26 @@
+// 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 f (name){
+  delete this.keywords[name];
+  assert (false);
+}
+
+try {
+  f ("jerry");
+  assert (false);
+} catch (e) {
+  assert (e instanceof TypeError);
+}