src/transitions-inl.h

   1 // Copyright 2012 the V8 project authors. All rights reserved.
   2 // Redistribution and use in source and binary forms, with or without
   3 // modification, are permitted provided that the following conditions are
   4 // met:
   5 //
   6 //     * Redistributions of source code must retain the above copyright
   7 //       notice, this list of conditions and the following disclaimer.
   8 //     * Redistributions in binary form must reproduce the above
   9 //       copyright notice, this list of conditions and the following
  10 //       disclaimer in the documentation and/or other materials provided
  11 //       with the distribution.
  12 //     * Neither the name of Google Inc. nor the names of its
  13 //       contributors may be used to endorse or promote products derived
  14 //       from this software without specific prior written permission.
  15 //
  16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27
  28 #ifndef V8_TRANSITIONS_INL_H_
  29 #define V8_TRANSITIONS_INL_H_
  30
  31 #include "objects-inl.h"
  32 #include "transitions.h"
  33
  34 namespace v8 {
  35 namespace internal {
  36
  37
  38 #define FIELD_ADDR(p, offset) \
  39   (reinterpret_cast<byte*>(p) + offset - kHeapObjectTag)
  40
  41 #define WRITE_FIELD(p, offset, value) \
  42   (*reinterpret_cast<Object**>(FIELD_ADDR(p, offset)) = value)
  43
  44 #define CONDITIONAL_WRITE_BARRIER(heap, object, offset, value, mode)    \
  45   if (mode == UPDATE_WRITE_BARRIER) {                                   \
  46     heap->incremental_marking()->RecordWrite(                           \
  47       object, HeapObject::RawField(object, offset), value);             \
  48     if (heap->InNewSpace(value)) {                                      \
  49       heap->RecordWrite(object->address(), offset);                     \
  50     }                                                                   \
  51   }
  52
  53
  54 TransitionArray* TransitionArray::cast(Object* object) {
  55   ASSERT(object->IsTransitionArray());
  56   return reinterpret_cast<TransitionArray*>(object);
  57 }
  58
  59
  60 Map* TransitionArray::elements_transition() {
  61   Object* transition_map = get(kElementsTransitionIndex);
  62   return Map::cast(transition_map);
  63 }
  64
  65
  66 void TransitionArray::ClearElementsTransition() {
  67   WRITE_FIELD(this, kElementsTransitionOffset, Smi::FromInt(0));
  68 }
  69
  70
  71 bool TransitionArray::HasElementsTransition() {
  72   return get(kElementsTransitionIndex) != Smi::FromInt(0);
  73 }
  74
  75
  76 void TransitionArray::set_elements_transition(Map* transition_map,
  77                                               WriteBarrierMode mode) {
  78   Heap* heap = GetHeap();
  79   WRITE_FIELD(this, kElementsTransitionOffset, transition_map);
  80   CONDITIONAL_WRITE_BARRIER(
  81       heap, this, kElementsTransitionOffset, transition_map, mode);
  82 }
  83
  84
  85 Object** TransitionArray::GetKeySlot(int transition_number) {
  86   ASSERT(transition_number < number_of_transitions());
  87   return HeapObject::RawField(
  88       reinterpret_cast<HeapObject*>(this),
  89       OffsetOfElementAt(ToKeyIndex(transition_number)));
  90 }
  91
  92
  93 String* TransitionArray::GetKey(int transition_number) {
  94   ASSERT(transition_number < number_of_transitions());
  95   return String::cast(get(ToKeyIndex(transition_number)));
  96 }
  97
  98
  99 void TransitionArray::SetKey(int transition_number, String* key) {
 100   ASSERT(transition_number < number_of_transitions());
 101   set(ToKeyIndex(transition_number), key);
 102 }
 103
 104
 105 Object* TransitionArray::GetValue(int transition_number) {
 106   ASSERT(transition_number < number_of_transitions());
 107   return get(ToValueIndex(transition_number));
 108 }
 109
 110
 111 Object** TransitionArray::GetValueSlot(int transition_number) {
 112   ASSERT(transition_number < number_of_transitions());
 113   return HeapObject::RawField(
 114       reinterpret_cast<HeapObject*>(this),
 115       OffsetOfElementAt(ToValueIndex(transition_number)));
 116 }
 117
 118
 119 void TransitionArray::SetValue(int transition_number, Object* value) {
 120   ASSERT(transition_number < number_of_transitions());
 121   set(ToValueIndex(transition_number), value);
 122 }
 123
 124
 125 Map* TransitionArray::GetTargetMap(int transition_number) {
 126   Object* value = GetValue(transition_number);
 127   if (value->IsAccessorPair()) {
 128     // TODO(verwaest): Currently details are always taken from the getter if it
 129     // is a transition, otherwise from the setter which in that case has to be a
 130     // transition. Details should be dependent on which component is requested.
 131     AccessorPair* accessors = AccessorPair::cast(value);
 132     if (accessors->getter()->IsMap()) {
 133       return Map::cast(accessors->getter());
 134     }
 135     return Map::cast(accessors->setter());
 136   }
 137   return Map::cast(value);
 138 }
 139
 140
 141 PropertyDetails TransitionArray::GetTargetDetails(int transition_number) {
 142   Map* map = GetTargetMap(transition_number);
 143   DescriptorArray* descriptors = map->instance_descriptors();
 144   String* key = GetKey(transition_number);
 145   int descriptor = descriptors->SearchWithCache(key);
 146   ASSERT(descriptor != DescriptorArray::kNotFound);
 147   return descriptors->GetDetails(descriptor);
 148 }
 149
 150
 151 Object** TransitionArray::GetElementsSlot() {
 152   return HeapObject::RawField(reinterpret_cast<HeapObject*>(this),
 153                               kElementsTransitionOffset);
 154 }
 155
 156
 157 int TransitionArray::Search(String* name) {
 158   return internal::Search(this, name);
 159 }
 160
 161
 162 void TransitionArray::Set(int transition_number,
 163                           String* key,
 164                           Object* value,
 165                           const WhitenessWitness&) {
 166   NoIncrementalWriteBarrierSet(this,
 167                                ToKeyIndex(transition_number),
 168                                key);
 169   NoIncrementalWriteBarrierSet(this,
 170                                ToValueIndex(transition_number),
 171                                value);
 172 }
 173
 174
 175 #undef FIELD_ADDR
 176 #undef WRITE_FIELD
 177 #undef CONDITIONAL_WRITE_BARRIER
 178
 179
 180 } }  // namespace v8::internal
 181
 182 #endif  // V8_TRANSITIONS_INL_H_