Implement Symbol.unscopables (#3405)

Added a new property for Array.prototype based on ECMA-262 v6, 22.1.3.31
Also upgraded the HasBinding operation with ECMA-262 v6, 8.1.1.2.1 steps 7-9

JerryScript-DCO-1.0-Signed-off-by: Adam Szilagyi aszilagy@inf.u-szeged.hu

jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype-unscopables.c

@@ -0,0 +1,28 @@
+/* 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.
+ */
+
+#include "ecma-builtin-helpers.h"
+#include "ecma-builtins.h"
+
+#if ENABLED (JERRY_ES2015)
+
+#define ECMA_BUILTINS_INTERNAL
+#include "ecma-builtins-internal.h"
+
+#define BUILTIN_INC_HEADER_NAME "ecma-builtin-array-prototype-unscopables.inc.h"
+#define BUILTIN_UNDERSCORED_ID array_prototype_unscopables
+#include "ecma-builtin-internal-routines-template.inc.h"
+
+#endif /* ENABLED (JERRY_ES2015) */

jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype-unscopables.inc.h

@@ -0,0 +1,55 @@
+/* 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.
+ */
+
+/*
+ * Array.prototype[@@unscopables] built-in description
+ */
+
+#include "ecma-builtin-helpers-macro-defines.inc.h"
+
+
+#if ENABLED (JERRY_ES2015)
+
+SIMPLE_VALUE (LIT_MAGIC_STRING_COPY_WITHIN,
+              ECMA_VALUE_TRUE,
+              ECMA_PROPERTY_CONFIGURABLE_ENUMERABLE_WRITABLE)
+
+SIMPLE_VALUE (LIT_MAGIC_STRING_ENTRIES,
+              ECMA_VALUE_TRUE,
+              ECMA_PROPERTY_CONFIGURABLE_ENUMERABLE_WRITABLE)
+
+SIMPLE_VALUE (LIT_MAGIC_STRING_FILL,
+              ECMA_VALUE_TRUE,
+              ECMA_PROPERTY_CONFIGURABLE_ENUMERABLE_WRITABLE)
+
+SIMPLE_VALUE (LIT_MAGIC_STRING_FIND,
+              ECMA_VALUE_TRUE,
+              ECMA_PROPERTY_CONFIGURABLE_ENUMERABLE_WRITABLE)
+
+SIMPLE_VALUE (LIT_MAGIC_STRING_FIND_INDEX,
+              ECMA_VALUE_TRUE,
+              ECMA_PROPERTY_CONFIGURABLE_ENUMERABLE_WRITABLE)
+
+SIMPLE_VALUE (LIT_MAGIC_STRING_KEYS,
+              ECMA_VALUE_TRUE,
+              ECMA_PROPERTY_CONFIGURABLE_ENUMERABLE_WRITABLE)
+
+SIMPLE_VALUE (LIT_MAGIC_STRING_VALUES,
+              ECMA_VALUE_TRUE,
+              ECMA_PROPERTY_CONFIGURABLE_ENUMERABLE_WRITABLE)
+
+#endif /* ENABLED (JERRY_ES2015) */
+
+#include "ecma-builtin-helpers-macro-undefs.inc.h"

jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.inc.h

@@ -29,6 +29,13 @@ OBJECT_VALUE (LIT_MAGIC_STRING_CONSTRUCTOR,
               ECMA_BUILTIN_ID_ARRAY,
               ECMA_PROPERTY_CONFIGURABLE_WRITABLE)
 
+#if ENABLED (JERRY_ES2015)
+/* ECMA-262 v6, 22.1.3.31 */
+OBJECT_VALUE (LIT_GLOBAL_SYMBOL_UNSCOPABLES,
+              ECMA_BUILTIN_ID_ARRAY_PROTOTYPE_UNSCOPABLES,
+              ECMA_PROPERTY_FLAG_CONFIGURABLE)
+#endif /* ENABLED (JERRY_ES2015) */
+
 /* Number properties:
  *  (property name, object pointer getter) */
 

jerry-core/ecma/builtin-objects/ecma-builtins.inc.h

@@ -510,6 +510,13 @@ BUILTIN_ROUTINE (ECMA_BUILTIN_ID_WEAKSET,
 
 #if ENABLED (JERRY_ES2015)
 
+/* The Array.prototype[@@unscopables] object */
+BUILTIN (ECMA_BUILTIN_ID_ARRAY_PROTOTYPE_UNSCOPABLES,
+         ECMA_OBJECT_TYPE_GENERAL,
+         ECMA_BUILTIN_ID__COUNT,
+         true,
+         array_prototype_unscopables)
+
 /* The Symbol prototype object (ECMA-262 v6, 19.4.2.7) */
 BUILTIN (ECMA_BUILTIN_ID_SYMBOL_PROTOTYPE,
          ECMA_OBJECT_TYPE_GENERAL,

jerry-core/ecma/operations/ecma-reference.c

@@ -91,6 +91,57 @@ ecma_op_resolve_super_reference_value (ecma_object_t *lex_env_p) /**< starting l
     lex_env_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, lex_env_p->u2.outer_reference_cp);
   }
 } /* ecma_op_resolve_super_reference_value */
+
+/**
+ * Helper method for HasBindig operation
+ *
+ * See also:
+ *         ECMA-262 v6, 8.1.1.2.1 steps 7-9;
+ *
+ * @return ECMA_VALUE_TRUE - if the property is unscopable
+ *         ECMA_VALUE_FALSE - if a the property is not unscopable
+ *         ECMA_VALUE_ERROR - otherwise
+ */
+static ecma_value_t
+ecma_op_is_prop_unscopable (ecma_object_t *lex_env_p, /**< lexical environment */
+                            ecma_string_t *prop_name_p) /**< property's name */
+{
+  if (lex_env_p == ecma_get_global_environment ())
+  {
+    return ECMA_VALUE_FALSE;
+  }
+
+  ecma_object_t *binding_obj_p = ecma_get_lex_env_binding_object (lex_env_p);
+
+  ecma_value_t unscopables = ecma_op_object_get_by_symbol_id (binding_obj_p, LIT_MAGIC_STRING_UNSCOPABLES);
+
+  if (ECMA_IS_VALUE_ERROR (unscopables))
+  {
+    return unscopables;
+  }
+
+  if (ecma_is_value_object (unscopables))
+  {
+    ecma_object_t *unscopables_obj_p = ecma_get_object_from_value (unscopables);
+    ecma_value_t get_unscopables_value = ecma_op_object_get (unscopables_obj_p, prop_name_p);
+    ecma_deref_object (unscopables_obj_p);
+
+    if (ECMA_IS_VALUE_ERROR (get_unscopables_value))
+    {
+      return get_unscopables_value;
+    }
+
+    bool is_blocked = ecma_op_to_boolean (get_unscopables_value);
+
+    ecma_free_value (get_unscopables_value);
+
+    return ecma_make_boolean_value (is_blocked);
+  }
+
+  ecma_free_value (unscopables);
+
+  return ECMA_VALUE_FALSE;
+} /* ecma_op_is_prop_unscopable */
 #endif /* ENABLED (JERRY_ES2015) */
 
 /**
@@ -131,39 +182,67 @@ ecma_op_resolve_reference_value (ecma_object_t *lex_env_p, /**< starting lexical
     {
       ecma_object_t *binding_obj_p = ecma_get_lex_env_binding_object (lex_env_p);
 
-#if ENABLED (JERRY_LCACHE)
+#if ENABLED (JERRY_ES2015)
-      ecma_property_t *property_p = ecma_lcache_lookup (binding_obj_p, name_p);
+      bool lcache_lookup_allowed = (lex_env_p == ecma_get_global_environment ());
+#else /* !ENABLED (JERRY_ES2015)*/
+      bool lcache_lookup_allowed = true;
+#endif /* ENABLED (JERRY_ES2015) */
 
-      if (property_p != NULL)
+      if (lcache_lookup_allowed)
       {
-        ecma_property_value_t *prop_value_p = ECMA_PROPERTY_VALUE_PTR (property_p);
+#if ENABLED (JERRY_LCACHE)
+        ecma_property_t *property_p = ecma_lcache_lookup (binding_obj_p, name_p);
 
-        if (ECMA_PROPERTY_GET_TYPE (*property_p) == ECMA_PROPERTY_TYPE_NAMEDDATA)
+        if (property_p != NULL)
         {
-          return ecma_fast_copy_value (prop_value_p->value);
+          ecma_property_value_t *prop_value_p = ECMA_PROPERTY_VALUE_PTR (property_p);
+
+          if (ECMA_PROPERTY_GET_TYPE (*property_p) == ECMA_PROPERTY_TYPE_NAMEDDATA)
+          {
+            return ecma_fast_copy_value (prop_value_p->value);
+          }
+
+          JERRY_ASSERT (ECMA_PROPERTY_GET_TYPE (*property_p) == ECMA_PROPERTY_TYPE_NAMEDACCESSOR);
+
+          ecma_getter_setter_pointers_t *get_set_pair_p = ecma_get_named_accessor_property (prop_value_p);
+
+          if (get_set_pair_p->getter_cp == JMEM_CP_NULL)
+          {
+            return ECMA_VALUE_UNDEFINED;
+          }
+
+          ecma_object_t *getter_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, get_set_pair_p->getter_cp);
+
+          ecma_value_t base_value = ecma_make_object_value (binding_obj_p);
+          return ecma_op_function_call (getter_p, base_value, NULL, 0);
         }
-
-        JERRY_ASSERT (ECMA_PROPERTY_GET_TYPE (*property_p) == ECMA_PROPERTY_TYPE_NAMEDACCESSOR);
-
-        ecma_getter_setter_pointers_t *get_set_pair_p = ecma_get_named_accessor_property (prop_value_p);
-
-        if (get_set_pair_p->getter_cp == JMEM_CP_NULL)
-        {
-          return ECMA_VALUE_UNDEFINED;
-        }
-
-        ecma_object_t *getter_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, get_set_pair_p->getter_cp);
-
-        ecma_value_t base_value = ecma_make_object_value (binding_obj_p);
-        return ecma_op_function_call (getter_p, base_value, NULL, 0);
-      }
 #endif /* ENABLED (JERRY_LCACHE) */
+      }
 
       ecma_value_t prop_value = ecma_op_object_find (binding_obj_p, name_p);
 
       if (ecma_is_value_found (prop_value))
       {
+#if ENABLED (JERRY_ES2015)
+        ecma_value_t blocked = ecma_op_is_prop_unscopable (lex_env_p, name_p);
+
+        if (ECMA_IS_VALUE_ERROR (blocked))
+        {
+          ecma_free_value (prop_value);
+          return blocked;
+        }
+
+        if (ecma_is_value_true (blocked))
+        {
+          ecma_free_value (prop_value);
+        }
+        else
+        {
+          return prop_value;
+        }
+#else /* !ENABLED (JERRY_ES2015) */
         return prop_value;
+#endif /* ENABLED (JERRY_ES2015) */
       }
     }
     else

jerry-core/lit/lit-magic-strings.inc.h

@@ -136,10 +136,13 @@ LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_EVAL, "eval")
 #if ENABLED (JERRY_BUILTIN_REGEXP)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_EXEC, "exec")
 #endif
-#if ENABLED (JERRY_BUILTIN_ARRAY) && ENABLED (JERRY_ES2015) \
+#if ENABLED (JERRY_ES2015) \
 || ENABLED (JERRY_ES2015_BUILTIN_TYPEDARRAY)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_FILL, "fill")
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_FIND, "find")
+#endif
+#if ENABLED (JERRY_BUILTIN_ARRAY) && ENABLED (JERRY_ES2015) \
+|| ENABLED (JERRY_ES2015_BUILTIN_TYPEDARRAY)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_FROM, "from")
 #endif
 #if ENABLED (JERRY_BUILTIN_ARRAY) \
@@ -353,10 +356,7 @@ LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_SYMBOL, "symbol")
 || ENABLED (JERRY_BUILTIN_JSON)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_TO_JSON_UL, "toJSON")
 #endif
-#if ENABLED (JERRY_BUILTIN_ARRAY) && ENABLED (JERRY_ES2015) \
+#if ENABLED (JERRY_ES2015)
-|| ENABLED (JERRY_ES2015) && ENABLED (JERRY_ES2015_BUILTIN_MAP) \
-|| ENABLED (JERRY_ES2015) && ENABLED (JERRY_ES2015_BUILTIN_SET) \
-|| ENABLED (JERRY_ES2015) && ENABLED (JERRY_ES2015_BUILTIN_TYPEDARRAY)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_VALUES, "values")
 #endif
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_BOOLEAN_UL, "Boolean")
@@ -392,10 +392,7 @@ LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_COMPILE, "compile")
 || ENABLED (JERRY_ES2015_MODULE_SYSTEM)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_DEFAULT, "default")
 #endif
-#if ENABLED (JERRY_BUILTIN_ARRAY) && ENABLED (JERRY_ES2015) \
+#if ENABLED (JERRY_ES2015)
-|| ENABLED (JERRY_ES2015) && ENABLED (JERRY_ES2015_BUILTIN_MAP) \
-|| ENABLED (JERRY_ES2015) && ENABLED (JERRY_ES2015_BUILTIN_SET) \
-|| ENABLED (JERRY_ES2015) && ENABLED (JERRY_ES2015_BUILTIN_TYPEDARRAY)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_ENTRIES, "entries")
 #endif
 #if ENABLED (JERRY_BUILTIN_ARRAY) \
@@ -539,7 +536,7 @@ LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_UNDEFINED_UL, "Undefined")
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_ARGUMENTS, "arguments")
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_DECODE_URI, "decodeURI")
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_ENCODE_URI, "encodeURI")
-#if ENABLED (JERRY_BUILTIN_ARRAY) && ENABLED (JERRY_ES2015) \
+#if ENABLED (JERRY_ES2015) \
 || ENABLED (JERRY_ES2015_BUILTIN_TYPEDARRAY)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_FIND_INDEX, "findIndex")
 #endif
@@ -592,7 +589,7 @@ LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_BYTE_OFFSET_UL, "byteOffset")
 #if ENABLED (JERRY_BUILTIN_STRING)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_CHAR_CODE_AT_UL, "charCodeAt")
 #endif
-#if ENABLED (JERRY_BUILTIN_ARRAY) && ENABLED (JERRY_ES2015) \
+#if ENABLED (JERRY_ES2015) \
 || ENABLED (JERRY_ES2015_BUILTIN_TYPEDARRAY)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_COPY_WITHIN, "copyWithin")
 #endif
@@ -865,7 +862,7 @@ LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE (10, LIT_MAGIC_STRING_TYPED_ARRAY_UL)
 LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE (10, LIT_MAGIC_STRING_BYTE_LENGTH_UL)
 #elif ENABLED (JERRY_BUILTIN_STRING)
 LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE (10, LIT_MAGIC_STRING_CHAR_CODE_AT_UL)
-#elif ENABLED (JERRY_BUILTIN_ARRAY) && ENABLED (JERRY_ES2015) \
+#elif ENABLED (JERRY_ES2015) \
 || ENABLED (JERRY_ES2015_BUILTIN_TYPEDARRAY)
 LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE (10, LIT_MAGIC_STRING_COPY_WITHIN)
 #else

tests/jerry/es2015/symbol-unscopables.js

@@ -0,0 +1,88 @@
+// 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.
+
+var obj = {
+    prop1: 42,
+    prop2: 13,
+    prop3: "foo",
+    prop4: 1
+};
+
+var obj2 = {
+    foo: "foo"
+};
+
+obj[Symbol.unscopables] = {
+    prop1: false,
+    prop2: true,
+    prop3: undefined,
+    prop4: obj2
+};
+
+with (obj)
+{
+    assert(prop1 === 42);
+
+    try {
+      prop2;
+      assert(false);
+    } catch (e) {
+      assert(e instanceof ReferenceError);
+    }
+
+    assert (prop3 === "foo");
+
+    try {
+      prop4;
+      assert(false);
+    } catch (e) {
+      assert(e instanceof ReferenceError);
+    }
+
+    try {
+      prop5;
+      assert(false);
+    } catch (e) {
+      assert(e instanceof ReferenceError);
+    }
+}
+
+var obj2 = {};
+Object.defineProperty(obj2, Symbol.unscopables, { get: function () { throw 42; } });
+
+with (obj2) {
+  try {
+    prop;
+    assert(false);
+  } catch (e) {
+    assert(e instanceof ReferenceError);
+  }
+}
+
+var symbol_obj = Array.prototype[Symbol.unscopables];
+assert(symbol_obj.copyWithin === true);
+assert(symbol_obj.entries === true);
+assert(symbol_obj.fill === true);
+assert(symbol_obj.find === true);
+assert(symbol_obj.findIndex === true);
+assert(symbol_obj.keys === true);
+assert(symbol_obj.values === true);
+
+assert(Object.getPrototypeOf(Array.prototype[Symbol.unscopables]) === null);
+
+var obj3 = Object.getOwnPropertyDescriptor(Array.prototype[Symbol.unscopables], "find");
+assert(obj3.value === true);
+assert(obj3.writable === true);
+assert(obj3.enumerable == true);
+assert(obj3.configurable == true);