Merge arguments branch to bleeding edge (second try).

src/objects.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1420 matching lines @@
   enum ElementsKind {
     // The "fast" kind for tagged values. Must be first to make it possible
     // to efficiently check maps if they have fast elements.
     FAST_ELEMENTS,
 
     // The "fast" kind for unwrapped, non-tagged double values.
     FAST_DOUBLE_ELEMENTS,
 
     // The "slow" kind.
     DICTIONARY_ELEMENTS,
+    NON_STRICT_ARGUMENTS_ELEMENTS,
     // The "fast" kind for external arrays
     EXTERNAL_BYTE_ELEMENTS,
     EXTERNAL_UNSIGNED_BYTE_ELEMENTS,
     EXTERNAL_SHORT_ELEMENTS,
     EXTERNAL_UNSIGNED_SHORT_ELEMENTS,
     EXTERNAL_INT_ELEMENTS,
     EXTERNAL_UNSIGNED_INT_ELEMENTS,
     EXTERNAL_FLOAT_ELEMENTS,
     EXTERNAL_DOUBLE_ELEMENTS,
     EXTERNAL_PIXEL_ELEMENTS,
@@ skipping 17 matching lines @@
   inline StringDictionary* property_dictionary();  // Gets slow properties.
 
   // [elements]: The elements (properties with names that are integers).
   //
   // Elements can be in two general modes: fast and slow. Each mode
   // corrensponds to a set of object representations of elements that
   // have something in common.
   //
   // In the fast mode elements is a FixedArray and so each element can
   // be quickly accessed. This fact is used in the generated code. The
-  // elements array can have one of the two maps in this mode:
-  // fixed_array_map or fixed_cow_array_map (for copy-on-write
-  // arrays). In the latter case the elements array may be shared by a
-  // few objects and so before writing to any element the array must
-  // be copied. Use EnsureWritableFastElements in this case.
+  // elements array can have one of three maps in this mode:
+  // fixed_array_map, non_strict_arguments_elements_map or
+  // fixed_cow_array_map (for copy-on-write arrays). In the latter case
+  // the elements array may be shared by a few objects and so before
+  // writing to any element the array must be copied. Use
+  // EnsureWritableFastElements in this case.
   //
-  // In the slow mode elements is either a NumberDictionary or an ExternalArray.
+  // In the slow mode the elements is either a NumberDictionary, an
+  // ExternalArray, or a FixedArray parameter map for a (non-strict)
+  // arguments object.
   DECL_ACCESSORS(elements, HeapObject)
   inline void initialize_elements();
   MUST_USE_RESULT inline MaybeObject* ResetElements();
   inline ElementsKind GetElementsKind();
   inline bool HasFastElements();
   inline bool HasFastDoubleElements();
   inline bool HasDictionaryElements();
   inline bool HasExternalPixelElements();
   inline bool HasExternalArrayElements();
   inline bool HasExternalByteElements();
   inline bool HasExternalUnsignedByteElements();
   inline bool HasExternalShortElements();
   inline bool HasExternalUnsignedShortElements();
   inline bool HasExternalIntElements();
   inline bool HasExternalUnsignedIntElements();
   inline bool HasExternalFloatElements();
   inline bool HasExternalDoubleElements();
+  bool HasFastArgumentsElements();
+  bool HasDictionaryArgumentsElements();
   inline bool AllowsSetElementsLength();
   inline NumberDictionary* element_dictionary();  // Gets slow elements.
-  // Requires: this->HasFastElements().
+
+  // Requires: HasFastElements().
   MUST_USE_RESULT inline MaybeObject* EnsureWritableFastElements();
 
   // Collects elements starting at index 0.
   // Undefined values are placed after non-undefined values.
   // Returns the number of non-undefined values.
   MUST_USE_RESULT MaybeObject* PrepareElementsForSort(uint32_t limit);
   // As PrepareElementsForSort, but only on objects where elements is
   // a dictionary, and it will stay a dictionary.
   MUST_USE_RESULT MaybeObject* PrepareSlowElementsForSort(uint32_t limit);
 
@@ skipping 165 matching lines @@
   };
 
   LocalElementType HasLocalElement(uint32_t index);
 
   bool HasElementWithInterceptor(JSReceiver* receiver, uint32_t index);
   bool HasElementPostInterceptor(JSReceiver* receiver, uint32_t index);
 
   MUST_USE_RESULT MaybeObject* SetFastElement(uint32_t index,
                                               Object* value,
                                               StrictModeFlag strict_mode,
-                                              bool check_prototype = true);
+                                              bool check_prototype);
+  MUST_USE_RESULT MaybeObject* SetDictionaryElement(uint32_t index,
+                                                    Object* value,
+                                                    StrictModeFlag strict_mode,
+                                                    bool check_prototype);
 
   MUST_USE_RESULT MaybeObject* SetFastDoubleElement(
       uint32_t index,
       Object* value,
       StrictModeFlag strict_mode,
       bool check_prototype = true);
 
   // Set the index'th array element.
   // A Failure object is returned if GC is needed.
   MUST_USE_RESULT MaybeObject* SetElement(uint32_t index,
                                           Object* value,
                                           StrictModeFlag strict_mode,
-                                          bool check_prototype = true);
+                                          bool check_prototype);
 
   // Returns the index'th element.
   // The undefined object if index is out of bounds.
   MaybeObject* GetElementWithReceiver(Object* receiver, uint32_t index);
   MaybeObject* GetElementWithInterceptor(Object* receiver, uint32_t index);
 
   // Get external element value at index if there is one and undefined
   // otherwise. Can return a failure if allocation of a heap number
   // failed.
   MaybeObject* GetExternalElement(uint32_t index);
 
+  // Replace the elements' backing store with fast elements of the given
+  // capacity.  Update the length for JSArrays.  Returns the new backing
+  // store.
   MUST_USE_RESULT MaybeObject* SetFastElementsCapacityAndLength(int capacity,
                                                                 int length);
   MUST_USE_RESULT MaybeObject* SetFastDoubleElementsCapacityAndLength(
       int capacity,
       int length);
   MUST_USE_RESULT MaybeObject* SetSlowElements(Object* length);
 
   // Lookup interceptors are used for handling properties controlled by host
   // objects.
   inline bool HasNamedInterceptor();
@@ skipping 109 matching lines @@
                                            PropertyAttributes attributes,
                                            StrictModeFlag strict_mode);
 
   // Convert the object to use the canonical dictionary
   // representation. If the object is expected to have additional properties
   // added this number can be indicated to have the backing store allocated to
   // an initial capacity for holding these properties.
   MUST_USE_RESULT MaybeObject* NormalizeProperties(
       PropertyNormalizationMode mode,
       int expected_additional_properties);
+
+  // Convert and update the elements backing store to be a NumberDictionary
+  // dictionary.  Returns the backing after conversion.
   MUST_USE_RESULT MaybeObject* NormalizeElements();
 
   MUST_USE_RESULT MaybeObject* UpdateMapCodeCache(String* name, Code* code);
 
   // Transform slow named properties to fast variants.
   // Returns failure if allocation failed.
   MUST_USE_RESULT MaybeObject* TransformToFastProperties(
       int unused_property_fields);
 
   // Access fast-case object properties at index.
@@ skipping 125 matching lines @@
   MaybeObject* GetElementPostInterceptor(Object* receiver, uint32_t index);
 
   MUST_USE_RESULT MaybeObject* DeletePropertyPostInterceptor(String* name,
                                                              DeleteMode mode);
   MUST_USE_RESULT MaybeObject* DeletePropertyWithInterceptor(String* name);
 
   MUST_USE_RESULT MaybeObject* DeleteElementPostInterceptor(uint32_t index,
                                                             DeleteMode mode);
   MUST_USE_RESULT MaybeObject* DeleteElementWithInterceptor(uint32_t index);
 
+  MUST_USE_RESULT MaybeObject* DeleteFastElement(uint32_t index);
+  MUST_USE_RESULT MaybeObject* DeleteDictionaryElement(uint32_t index,
+                                                       DeleteMode mode);
+
+  bool ReferencesObjectFromElements(FixedArray* elements,
+                                    ElementsKind kind,
+                                    Object* object);
+  bool HasElementInElements(FixedArray* elements,
+                            ElementsKind kind,
+                            uint32_t index);
+
   // Returns true if most of the elements backing storage is used.
   bool HasDenseElements();
 
   bool CanSetCallback(String* name);
   MUST_USE_RESULT MaybeObject* SetElementCallback(
       uint32_t index,
       Object* structure,
       PropertyAttributes attributes);
   MUST_USE_RESULT MaybeObject* SetPropertyCallback(
       String* name,
@@ skipping 1888 matching lines @@
     set_bit_field2((bit_field2() & ~kElementsKindMask) |
         (elements_kind << kElementsKindShift));
     ASSERT(this->elements_kind() == elements_kind);
   }
 
   inline JSObject::ElementsKind elements_kind() {
     return static_cast<JSObject::ElementsKind>(
         (bit_field2() & kElementsKindMask) >> kElementsKindShift);
   }
 
+  // Tells whether the instance has fast elements.
+  // Equivalent to instance->GetElementsKind() == FAST_ELEMENTS.
   inline bool has_fast_elements() {
     return elements_kind() == JSObject::FAST_ELEMENTS;
   }
 
   inline bool has_fast_double_elements() {
     return elements_kind() == JSObject::FAST_DOUBLE_ELEMENTS;
   }
 
   inline bool has_external_array_elements() {
     JSObject::ElementsKind kind(elements_kind());
@@ skipping 561 matching lines @@
   // is weak. IsInobjectSlackTrackingInProgress is false after this call.
   void DetachInitialMap();
 
   // Restores the link to the initial map after the GC marking phase.
   // IsInobjectSlackTrackingInProgress is true after this call.
   void AttachInitialMap(Map* map);
 
   // False if there are definitely no live objects created from this function.
   // True if live objects _may_ exist (existence not guaranteed).
   // May go back from true to false after GC.
-  inline bool live_objects_may_exist();
-
-  inline void set_live_objects_may_exist(bool value);
+  DECL_BOOLEAN_ACCESSORS(live_objects_may_exist)
 
   // [instance class name]: class name for instances.
   DECL_ACCESSORS(instance_class_name, Object)
 
   // [function data]: This field holds some additional data for function.
   // Currently it either has FunctionTemplateInfo to make benefit the API
   // or Smi identifying a builtin function.
   // In the long run we don't want all functions to have this field but
   // we can fix that when we have a better model for storing hidden data
   // on objects.
@@ skipping 70 matching lines @@
   // Clear information on assignments of the form this.x = ...;
   void ClearThisPropertyAssignmentsInfo();
 
   // Indicate that this function only consists of assignments of the form
   // this.x = y; where y is either a constant or refers to an argument.
   inline bool has_only_simple_this_property_assignments();
 
   // Indicates if this function can be lazy compiled.
   // This is used to determine if we can safely flush code from a function
   // when doing GC if we expect that the function will no longer be used.
-  inline bool allows_lazy_compilation();
-  inline void set_allows_lazy_compilation(bool flag);
+  DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation)
 
   // Indicates how many full GCs this function has survived with assigned
   // code object. Used to determine when it is relatively safe to flush
   // this code object and replace it with lazy compilation stub.
   // Age is reset when GC notices that the code object is referenced
   // from the stack or compilation cache.
   inline int code_age();
   inline void set_code_age(int age);
 
   // Indicates whether optimizations have been disabled for this
   // shared function info. If a function is repeatedly optimized or if
   // we cannot optimize the function we disable optimization to avoid
   // spending time attempting to optimize it again.
-  inline bool optimization_disabled();
-  inline void set_optimization_disabled(bool value);
+  DECL_BOOLEAN_ACCESSORS(optimization_disabled)
 
   // Indicates whether the function is a strict mode function.
-  inline bool strict_mode();
-  inline void set_strict_mode(bool value);
+  DECL_BOOLEAN_ACCESSORS(strict_mode)
+
+  // False if the function definitely does not allocate an arguments object.
+  DECL_BOOLEAN_ACCESSORS(uses_arguments)
+
+  // True if the function has any duplicated parameter names.
+  DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters)
 
   // Indicates whether the function is a native function.
   // These needs special threatment in .call and .apply since
   // null passed as the receiver should not be translated to the
   // global object.
   inline bool native();
   inline void set_native(bool value);
 
   // Indicates whether the function is a bound function created using
   // the bind function.
@@ skipping 171 matching lines @@
 
   // Bit positions in start_position_and_type.
   // The source code start position is in the 30 most significant bits of
   // the start_position_and_type field.
   static const int kIsExpressionBit = 0;
   static const int kIsTopLevelBit   = 1;
   static const int kStartPositionShift = 2;
   static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1);
 
   // Bit positions in compiler_hints.
-  static const int kHasOnlySimpleThisPropertyAssignments = 0;
-  static const int kAllowLazyCompilation = 1;
-  static const int kLiveObjectsMayExist = 2;
-  static const int kCodeAgeShift = 3;
-  static const int kCodeAgeMask = 0x7;
-  static const int kOptimizationDisabled = 6;
-  static const int kStrictModeFunction = 7;
-  static const int kNative = 8;
+  static const int kCodeAgeSize = 3;
+  static const int kCodeAgeMask = (1 << kCodeAgeSize) - 1;
   static const int kBoundFunction = 9;
 
+  enum CompilerHints {
+    kHasOnlySimpleThisPropertyAssignments,
+    kAllowLazyCompilation,
+    kLiveObjectsMayExist,
+    kCodeAgeShift,
+    kOptimizationDisabled = kCodeAgeShift + kCodeAgeSize,
+    kStrictModeFunction,
+    kUsesArguments,
+    kHasDuplicateParameters,
+    kNative
+  };
+
  private:
 #if V8_HOST_ARCH_32_BIT
   // On 32 bit platforms, compiler hints is a smi.
   static const int kCompilerHintsSmiTagSize = kSmiTagSize;
   static const int kCompilerHintsSize = kPointerSize;
 #else
   // On 64 bit platforms, compiler hints is not a smi, see comment above.
   static const int kCompilerHintsSmiTagSize = 0;
   static const int kCompilerHintsSize = kIntSize;
 #endif
@@ skipping 2282 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_