[strong] Implement strong mode restrictions on property access

src/ic/ic-state.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_IC_STATE_H_
 #define V8_IC_STATE_H_
 
 #include "src/macro-assembler.h"
 
 namespace v8 {
@@ skipping 183 matching lines @@
 
   static const char* GetStateName(CompareICState::State state);
 
   static State TargetState(State old_state, State old_left, State old_right,
                            Token::Value op, bool has_inlined_smi_code,
                            Handle<Object> x, Handle<Object> y);
 };
 
 
 class LoadICState final BASE_EMBEDDED {
+ private:
+  class ContextualModeBits : public BitField<ContextualMode, 0, 1> {};
+  class StrengthBits : public BitField<bool, 1, 1> {};
+  STATIC_ASSERT(static_cast<int>(NOT_CONTEXTUAL) == 0);
+  const ExtraICState state_;
+
  public:
+  static const ExtraICState kStrongModeState = 1 << StrengthBits::kShift;
+
   explicit LoadICState(ExtraICState extra_ic_state) : state_(extra_ic_state) {}
 
-  explicit LoadICState(ContextualMode mode)
-      : state_(ContextualModeBits::encode(mode)) {}
+  explicit LoadICState(ContextualMode mode, Strength strength)
+      : state_(ContextualModeBits::encode(mode) |
+               StrengthBits::encode(is_strong(strength))) {}
 
   ExtraICState GetExtraICState() const { return state_; }
 
   ContextualMode contextual_mode() const {
     return ContextualModeBits::decode(state_);
   }
 
+  Strength strength() const {
+    return StrengthBits::decode(state_) ? Strength::STRONG : Strength::WEAK;
+  }
+
   static ContextualMode GetContextualMode(ExtraICState state) {
     return LoadICState(state).contextual_mode();
   }
 
- private:
-  class ContextualModeBits : public BitField<ContextualMode, 0, 1> {};
-  STATIC_ASSERT(static_cast<int>(NOT_CONTEXTUAL) == 0);
-
-  const ExtraICState state_;
+  static Strength GetStrength(ExtraICState state) {
+    return LoadICState(state).strength();
+  }
 };
 
 
 class StoreICState final BASE_EMBEDDED {
  public:
   explicit StoreICState(ExtraICState extra_ic_state) : state_(extra_ic_state) {}
 
   explicit StoreICState(LanguageMode mode)
       : state_(LanguageModeState::encode(mode)) {}
 
@@ skipping 15 matching lines @@
   static const ExtraICState kStrictModeState = STRICT
                                                << LanguageModeState::kShift;
 
  private:
   const ExtraICState state_;
 };
 }
 }
 
 #endif  // V8_IC_STATE_H_