Fix object destructuring for empty pattern (#3571)

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

jerry-core/include/jerryscript-snapshot.h

@@ -30,7 +30,7 @@ extern "C"
 /**
  * Jerry snapshot format version.
  */
-#define JERRY_SNAPSHOT_VERSION (39u)
+#define JERRY_SNAPSHOT_VERSION (40u)
 
 /**
  * Flags for jerry_generate_snapshot and jerry_generate_function_snapshot.

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

@@ -576,6 +576,8 @@
               VM_OC_ERROR) \
   CBC_OPCODE (CBC_EXT_THROW_REFERENCE_ERROR, CBC_NO_FLAG, 1, \
               VM_OC_THROW_REFERENCE_ERROR) \
+  CBC_OPCODE (CBC_EXT_REQUIRE_OBJECT_COERCIBLE, CBC_NO_FLAG, 0, \
+              VM_OC_REQUIRE_OBJECT_COERCIBLE) \
   \
   /* Computed / class property related opcodes. */ \
   CBC_OPCODE (CBC_EXT_SET_COMPUTED_PROPERTY, CBC_NO_FLAG, -2, \

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

@@ -2798,6 +2798,15 @@ parser_parse_object_initializer (parser_context_t *context_p, /**< context */
 {
   parser_pattern_end_marker_t end_pos = parser_pattern_get_target (context_p, flags);
 
+  /* 12.14.5.2:  ObjectAssignmentPattern : { } */
+  if (lexer_check_next_character (context_p, LIT_CHAR_RIGHT_BRACE))
+  {
+    parser_emit_cbc_ext (context_p, CBC_EXT_REQUIRE_OBJECT_COERCIBLE);
+    lexer_consume_next_character (context_p);
+    parser_pattern_finalize (context_p, flags, &end_pos);
+    return;
+  }
+
   while (true)
   {
     lexer_expect_object_literal_id (context_p, LEXER_OBJ_IDENT_OBJECT_PATTERN);

jerry-core/vm/vm.c

@@ -2229,6 +2229,16 @@ vm_loop (vm_frame_ctx_t *frame_ctx_p) /**< frame context */
           }
           continue;
         }
+        case VM_OC_REQUIRE_OBJECT_COERCIBLE:
+        {
+          result = ecma_op_check_object_coercible (stack_top_p[-1]);
+
+          if (ECMA_IS_VALUE_ERROR (result))
+          {
+            goto error;
+          }
+          continue;
+        }
 #endif /* ENABLED (JERRY_ES2015) */
         case VM_OC_PUSH_ELISON:
         {

jerry-core/vm/vm.h

@@ -268,6 +268,7 @@ typedef enum
   VM_OC_STRING_CONCAT,           /**< string concatenation */
   VM_OC_GET_TEMPLATE_OBJECT,     /**< GetTemplateObject operation */
   VM_OC_PUSH_NEW_TARGET,         /**< push new.target onto the stack */
+  VM_OC_REQUIRE_OBJECT_COERCIBLE,/**< RequireObjectCoercible opretaion */
 #endif /* ENABLED (JERRY_ES2015) */
   VM_OC_NONE,                    /**< a special opcode for unsupported byte codes */
 } vm_oc_types;
@@ -327,6 +328,7 @@ typedef enum
   VM_OC_STRING_CONCAT = VM_OC_NONE,           /**< string concatenation */
   VM_OC_GET_TEMPLATE_OBJECT = VM_OC_NONE,     /**< GetTemplateObject operation */
   VM_OC_PUSH_NEW_TARGET = VM_OC_NONE,         /**< push new.target onto the stack */
+  VM_OC_REQUIRE_OBJECT_COERCIBLE = VM_OC_NONE,/**< RequireObjectCoercible opretaion */
 #endif /* !ENABLED (JERRY_ES2015) */
 
   VM_OC_UNUSED = VM_OC_NONE                   /**< placeholder if the list is empty */

tests/jerry/es2015/object-pattern.js

@@ -54,6 +54,8 @@ checkSyntax ("let {a:(a)} = {a:1}");
 
 mustThrow ("var {a} = null");
 mustThrow ("var {a} = undefined");
+mustThrow ("function f ({a : {}}) {}; f({});");
+mustThrow ("function f ({}) {}; f();");
 
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment
 

tests/unit-core/test-snapshot.c

@@ -223,7 +223,7 @@ main (void)
     /* Check the snapshot data. Unused bytes should be filled with zeroes */
     const uint8_t expected_data[] =
     {
-      0x4A, 0x52, 0x52, 0x59, 0x27, 0x00, 0x00, 0x00,
+      0x4A, 0x52, 0x52, 0x59, 0x28, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00, 0x48, 0x00, 0x00, 0x00,
       0x01, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00, 0x00,
       0x03, 0x00, 0x01, 0x00, 0x41, 0x00, 0x01, 0x00,