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      1 // Copyright 2016 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef V8_BUILTINS_BUILTINS_CONSTRUCTOR_H_
      6 #define V8_BUILTINS_BUILTINS_CONSTRUCTOR_H_
      7 
      8 #include "src/contexts.h"
      9 #include "src/objects.h"
     10 #include "src/objects/dictionary.h"
     11 #include "src/objects/js-array.h"
     12 
     13 namespace v8 {
     14 namespace internal {
     15 
     16 class ConstructorBuiltins {
     17  public:
     18   static int MaximumFunctionContextSlots() {
     19     return FLAG_test_small_max_function_context_stub_size ? kSmallMaximumSlots
     20                                                           : kMaximumSlots;
     21   }
     22 
     23   // Maximum number of elements in copied array (chosen so that even an array
     24   // backed by a double backing store will fit into new-space).
     25   static const int kMaximumClonedShallowArrayElements =
     26       JSArray::kInitialMaxFastElementArray;
     27   // Maximum number of properties in copied object so that the properties store
     28   // will fit into new-space. This constant is based on the assumption that
     29   // NameDictionaries are 50% over-allocated.
     30   static const int kMaximumClonedShallowObjectProperties =
     31       NameDictionary::kMaxRegularCapacity / 3 * 2;
     32 
     33  private:
     34   static const int kMaximumSlots = 0x8000;
     35   static const int kSmallMaximumSlots = 10;
     36 
     37   // FastNewFunctionContext can only allocate closures which fit in the
     38   // new space.
     39   STATIC_ASSERT(((kMaximumSlots + Context::MIN_CONTEXT_SLOTS) * kPointerSize +
     40                  FixedArray::kHeaderSize) < kMaxRegularHeapObjectSize);
     41 };
     42 
     43 }  // namespace internal
     44 }  // namespace v8
     45 
     46 #endif  // V8_BUILTINS_BUILTINS_CONSTRUCTOR_H_
     47