Update V8 to r5091 as required by WebKit r63859.

Change-Id: I8e35d765e6f6c7f89eccff900e1cabe2d5dd6110

1 files changed, 151 insertions, 175 deletions

diff --git a/src/scopeinfo.cc b/src/scopeinfo.cc
index 2091ca72..7e7f1525 100644
--- a/src/scopeinfo.cc
+++ b/src/scopeinfo.cc
@@ -148,7 +148,7 @@ ScopeInfo<Allocator>::ScopeInfo(Scope* scope)
 }
 
 
-// Encoding format in the Code object:
+// Encoding format in a FixedArray object:
 //
 // - function name
 //
@@ -204,12 +204,6 @@ static inline Object** ReadSymbol(Object** p, Handle<String>* s) {
 }
 
 
-static inline Object** ReadSentinel(Object** p) {
-  ASSERT(*p == NULL);
-  return p + 1;
-}
-
-
 template <class Allocator>
 static Object** ReadList(Object** p, List<Handle<String>, Allocator >* list) {
   ASSERT(list->is_empty());
@@ -220,7 +214,7 @@ static Object** ReadList(Object** p, List<Handle<String>, Allocator >* list) {
     p = ReadSymbol(p, &s);
     list->Add(s);
   }
-  return ReadSentinel(p);
+  return p;
 }
 
 
@@ -239,27 +233,27 @@ static Object** ReadList(Object** p,
     list->Add(s);
     modes->Add(static_cast<Variable::Mode>(m));
   }
-  return ReadSentinel(p);
+  return p;
 }
 
 
 template<class Allocator>
-ScopeInfo<Allocator>::ScopeInfo(Code* code)
+ScopeInfo<Allocator>::ScopeInfo(SerializedScopeInfo* data)
   : function_name_(Factory::empty_symbol()),
     parameters_(4),
     stack_slots_(8),
     context_slots_(8),
     context_modes_(8) {
-  if (code == NULL || code->sinfo_size() == 0) return;
-
-  Object** p0 = &Memory::Object_at(code->sinfo_start());
-  Object** p = p0;
-  p = ReadSymbol(p, &function_name_);
-  p = ReadBool(p, &calls_eval_);
-  p = ReadList<Allocator>(p, &context_slots_, &context_modes_);
-  p = ReadList<Allocator>(p, &parameters_);
-  p = ReadList<Allocator>(p, &stack_slots_);
-  ASSERT((p - p0) * kPointerSize == code->sinfo_size());
+  if (data->length() > 0) {
+    Object** p0 = data->data_start();
+    Object** p = p0;
+    p = ReadSymbol(p, &function_name_);
+    p = ReadBool(p, &calls_eval_);
+    p = ReadList<Allocator>(p, &context_slots_, &context_modes_);
+    p = ReadList<Allocator>(p, &parameters_);
+    p = ReadList<Allocator>(p, &stack_slots_);
+    ASSERT((p - p0) == FixedArray::cast(data)->length());
+  }
 }
 
 
@@ -281,12 +275,6 @@ static inline Object** WriteSymbol(Object** p, Handle<String> s) {
 }
 
 
-static inline Object** WriteSentinel(Object** p) {
-  *p++ = NULL;
-  return p;
-}
-
-
 template <class Allocator>
 static Object** WriteList(Object** p, List<Handle<String>, Allocator >* list) {
   const int n = list->length();
@@ -294,7 +282,7 @@ static Object** WriteList(Object** p, List<Handle<String>, Allocator >* list) {
   for (int i = 0; i < n; i++) {
     p = WriteSymbol(p, list->at(i));
   }
-  return WriteSentinel(p);
+  return p;
 }
 
 
@@ -308,73 +296,99 @@ static Object** WriteList(Object** p,
     p = WriteSymbol(p, list->at(i));
     p = WriteInt(p, modes->at(i));
   }
-  return WriteSentinel(p);
+  return p;
 }
 
 
 template<class Allocator>
-int ScopeInfo<Allocator>::Serialize(Code* code) {
-  // function name, calls eval, length & sentinel for 3 tables:
-  const int extra_slots = 1 + 1 + 2 * 3;
-  int size = (extra_slots +
-              context_slots_.length() * 2 +
-              parameters_.length() +
-              stack_slots_.length()) * kPointerSize;
-
-  if (code != NULL) {
-    CHECK(code->sinfo_size() == size);
-    Object** p0 = &Memory::Object_at(code->sinfo_start());
-    Object** p = p0;
-    p = WriteSymbol(p, function_name_);
-    p = WriteBool(p, calls_eval_);
-    p = WriteList(p, &context_slots_, &context_modes_);
-    p = WriteList(p, &parameters_);
-    p = WriteList(p, &stack_slots_);
-    ASSERT((p - p0) * kPointerSize == size);
-  }
+Handle<SerializedScopeInfo> ScopeInfo<Allocator>::Serialize() {
+  // function name, calls eval, length for 3 tables:
+  const int extra_slots = 1 + 1 + 3;
+  int length = extra_slots +
+               context_slots_.length() * 2 +
+               parameters_.length() +
+               stack_slots_.length();
+
+  Handle<SerializedScopeInfo> data(
+      SerializedScopeInfo::cast(*Factory::NewFixedArray(length, TENURED)));
+  AssertNoAllocation nogc;
+
+  Object** p0 = data->data_start();
+  Object** p = p0;
+  p = WriteSymbol(p, function_name_);
+  p = WriteBool(p, calls_eval_);
+  p = WriteList(p, &context_slots_, &context_modes_);
+  p = WriteList(p, &parameters_);
+  p = WriteList(p, &stack_slots_);
+  ASSERT((p - p0) == length);
 
-  return size;
+  return data;
 }
 
 
 template<class Allocator>
-void ScopeInfo<Allocator>::IterateScopeInfo(Code* code, ObjectVisitor* v) {
-  Object** start = &Memory::Object_at(code->sinfo_start());
-  Object** end = &Memory::Object_at(code->sinfo_start() + code->sinfo_size());
-  v->VisitPointers(start, end);
+Handle<String> ScopeInfo<Allocator>::LocalName(int i) const {
+  // A local variable can be allocated either on the stack or in the context.
+  // For variables allocated in the context they are always preceded by
+  // Context::MIN_CONTEXT_SLOTS of fixed allocated slots in the context.
+  if (i < number_of_stack_slots()) {
+    return stack_slot_name(i);
+  } else {
+    return context_slot_name(i - number_of_stack_slots() +
+                             Context::MIN_CONTEXT_SLOTS);
+  }
 }
 
 
-static Object** ContextEntriesAddr(Code* code) {
-  ASSERT(code->sinfo_size() > 0);
-  // +2 for function name and calls eval:
-  return &Memory::Object_at(code->sinfo_start()) + 2;
+template<class Allocator>
+int ScopeInfo<Allocator>::NumberOfLocals() const {
+  int number_of_locals = number_of_stack_slots();
+  if (number_of_context_slots() > 0) {
+    ASSERT(number_of_context_slots() >= Context::MIN_CONTEXT_SLOTS);
+    number_of_locals += number_of_context_slots() - Context::MIN_CONTEXT_SLOTS;
+  }
+  return number_of_locals;
 }
 
 
-static Object** ParameterEntriesAddr(Code* code) {
-  ASSERT(code->sinfo_size() > 0);
-  Object** p = ContextEntriesAddr(code);
-  int n;  // number of context slots;
-  p = ReadInt(p, &n);
-  return p + n*2 + 1;  // *2 for pairs, +1 for sentinel
+Handle<SerializedScopeInfo> SerializedScopeInfo::Create(Scope* scope) {
+  ScopeInfo<ZoneListAllocationPolicy> sinfo(scope);
+  return sinfo.Serialize();
 }
 
 
-static Object** StackSlotEntriesAddr(Code* code) {
-  ASSERT(code->sinfo_size() > 0);
-  Object** p = ParameterEntriesAddr(code);
-  int n;  // number of parameter slots;
-  p = ReadInt(p, &n);
-  return p + n + 1;  // +1 for sentinel
+SerializedScopeInfo* SerializedScopeInfo::Empty() {
+  return reinterpret_cast<SerializedScopeInfo*>(Heap::empty_fixed_array());
 }
 
 
-template<class Allocator>
-bool ScopeInfo<Allocator>::CallsEval(Code* code) {
-  if (code->sinfo_size() > 0) {
-    // +1 for function name:
-    Object** p = &Memory::Object_at(code->sinfo_start()) + 1;
+Object** SerializedScopeInfo::ContextEntriesAddr() {
+  ASSERT(length() > 0);
+  return data_start() + 2;  // +2 for function name and calls eval.
+}
+
+
+Object** SerializedScopeInfo::ParameterEntriesAddr() {
+  ASSERT(length() > 0);
+  Object** p = ContextEntriesAddr();
+  int number_of_context_slots;
+  p = ReadInt(p, &number_of_context_slots);
+  return p + number_of_context_slots*2;  // *2 for pairs
+}
+
+
+Object** SerializedScopeInfo::StackSlotEntriesAddr() {
+  ASSERT(length() > 0);
+  Object** p = ParameterEntriesAddr();
+  int number_of_parameter_slots;
+  p = ReadInt(p, &number_of_parameter_slots);
+  return p + number_of_parameter_slots;
+}
+
+
+bool SerializedScopeInfo::CallsEval() {
+  if (length() > 0) {
+    Object** p = data_start() + 1;  // +1 for function name.
     bool calls_eval;
     p = ReadBool(p, &calls_eval);
     return calls_eval;
@@ -383,53 +397,49 @@ bool ScopeInfo<Allocator>::CallsEval(Code* code) {
 }
 
 
-template<class Allocator>
-int ScopeInfo<Allocator>::NumberOfStackSlots(Code* code) {
-  if (code->sinfo_size() > 0) {
-    Object** p = StackSlotEntriesAddr(code);
-    int n;  // number of stack slots;
-    ReadInt(p, &n);
-    return n;
+int SerializedScopeInfo::NumberOfStackSlots() {
+  if (length() > 0) {
+    Object** p = StackSlotEntriesAddr();
+    int number_of_stack_slots;
+    ReadInt(p, &number_of_stack_slots);
+    return number_of_stack_slots;
   }
   return 0;
 }
 
 
-template<class Allocator>
-int ScopeInfo<Allocator>::NumberOfContextSlots(Code* code) {
-  if (code->sinfo_size() > 0) {
-    Object** p = ContextEntriesAddr(code);
-    int n;  // number of context slots;
-    ReadInt(p, &n);
-    return n + Context::MIN_CONTEXT_SLOTS;
+int SerializedScopeInfo::NumberOfContextSlots() {
+  if (length() > 0) {
+    Object** p = ContextEntriesAddr();
+    int number_of_context_slots;
+    ReadInt(p, &number_of_context_slots);
+    return number_of_context_slots + Context::MIN_CONTEXT_SLOTS;
   }
   return 0;
 }
 
 
-template<class Allocator>
-bool ScopeInfo<Allocator>::HasHeapAllocatedLocals(Code* code) {
-  if (code->sinfo_size() > 0) {
-    Object** p = ContextEntriesAddr(code);
-    int n;  // number of context slots;
-    ReadInt(p, &n);
-    return n > 0;
+bool SerializedScopeInfo::HasHeapAllocatedLocals() {
+  if (length() > 0) {
+    Object** p = ContextEntriesAddr();
+    int number_of_context_slots;
+    ReadInt(p, &number_of_context_slots);
+    return number_of_context_slots > 0;
   }
   return false;
 }
 
 
-template<class Allocator>
-int ScopeInfo<Allocator>::StackSlotIndex(Code* code, String* name) {
+int SerializedScopeInfo::StackSlotIndex(String* name) {
   ASSERT(name->IsSymbol());
-  if (code->sinfo_size() > 0) {
-    // Loop below depends on the NULL sentinel after the stack slot names.
-    ASSERT(NumberOfStackSlots(code) > 0 ||
-           *(StackSlotEntriesAddr(code) + 1) == NULL);
-    // slots start after length entry
-    Object** p0 = StackSlotEntriesAddr(code) + 1;
+  if (length() > 0) {
+    // Slots start after length entry.
+    Object** p0 = StackSlotEntriesAddr();
+    int number_of_stack_slots;
+    p0 = ReadInt(p0, &number_of_stack_slots);
     Object** p = p0;
-    while (*p != NULL) {
+    Object** end = p0 + number_of_stack_slots;
+    while (p != end) {
       if (*p == name) return static_cast<int>(p - p0);
       p++;
     }
@@ -437,24 +447,18 @@ int ScopeInfo<Allocator>::StackSlotIndex(Code* code, String* name) {
   return -1;
 }
 
-
-template<class Allocator>
-int ScopeInfo<Allocator>::ContextSlotIndex(Code* code,
-                                           String* name,
-                                           Variable::Mode* mode) {
+int SerializedScopeInfo::ContextSlotIndex(String* name, Variable::Mode* mode) {
   ASSERT(name->IsSymbol());
-  int result = ContextSlotCache::Lookup(code, name, mode);
+  int result = ContextSlotCache::Lookup(this, name, mode);
   if (result != ContextSlotCache::kNotFound) return result;
-  if (code->sinfo_size() > 0) {
-    // Loop below depends on the NULL sentinel after the context slot names.
-    ASSERT(NumberOfContextSlots(code) >= Context::MIN_CONTEXT_SLOTS ||
-           *(ContextEntriesAddr(code) + 1) == NULL);
-
-    // slots start after length entry
-    Object** p0 = ContextEntriesAddr(code) + 1;
+  if (length() > 0) {
+    // Slots start after length entry.
+    Object** p0 = ContextEntriesAddr();
+    int number_of_context_slots;
+    p0 = ReadInt(p0, &number_of_context_slots);
     Object** p = p0;
-    // contexts may have no variable slots (in the presence of eval()).
-    while (*p != NULL) {
+    Object** end = p0 + number_of_context_slots * 2;
+    while (p != end) {
       if (*p == name) {
         ASSERT(((p - p0) & 1) == 0);
         int v;
@@ -462,21 +466,20 @@ int ScopeInfo<Allocator>::ContextSlotIndex(Code* code,
         Variable::Mode mode_value = static_cast<Variable::Mode>(v);
         if (mode != NULL) *mode = mode_value;
         result = static_cast<int>((p - p0) >> 1) + Context::MIN_CONTEXT_SLOTS;
-        ContextSlotCache::Update(code, name, mode_value, result);
+        ContextSlotCache::Update(this, name, mode_value, result);
         return result;
       }
       p += 2;
     }
   }
-  ContextSlotCache::Update(code, name, Variable::INTERNAL, -1);
+  ContextSlotCache::Update(this, name, Variable::INTERNAL, -1);
   return -1;
 }
 
 
-template<class Allocator>
-int ScopeInfo<Allocator>::ParameterIndex(Code* code, String* name) {
+int SerializedScopeInfo::ParameterIndex(String* name) {
   ASSERT(name->IsSymbol());
-  if (code->sinfo_size() > 0) {
+  if (length() > 0) {
     // We must read parameters from the end since for
     // multiply declared parameters the value of the
     // last declaration of that parameter is used
@@ -487,10 +490,10 @@ int ScopeInfo<Allocator>::ParameterIndex(Code* code, String* name) {
     // once, with corresponding index. This requires a new
     // implementation of the ScopeInfo code. See also other
     // comments in this file regarding this.
-    Object** p = ParameterEntriesAddr(code);
-    int n;  // number of parameters
-    Object** p0 = ReadInt(p, &n);
-    p = p0 + n;
+    Object** p = ParameterEntriesAddr();
+    int number_of_parameter_slots;
+    Object** p0 = ReadInt(p, &number_of_parameter_slots);
+    p = p0 + number_of_parameter_slots;
     while (p > p0) {
       p--;
       if (*p == name) return static_cast<int>(p - p0);
@@ -500,64 +503,37 @@ int ScopeInfo<Allocator>::ParameterIndex(Code* code, String* name) {
 }
 
 
-template<class Allocator>
-int ScopeInfo<Allocator>::FunctionContextSlotIndex(Code* code, String* name) {
+int SerializedScopeInfo::FunctionContextSlotIndex(String* name) {
   ASSERT(name->IsSymbol());
-  if (code->sinfo_size() > 0) {
-    Object** p = &Memory::Object_at(code->sinfo_start());
+  if (length() > 0) {
+    Object** p = data_start();
     if (*p == name) {
-      p = ContextEntriesAddr(code);
-      int n;  // number of context slots
-      ReadInt(p, &n);
-      ASSERT(n != 0);
+      p = ContextEntriesAddr();
+      int number_of_context_slots;
+      ReadInt(p, &number_of_context_slots);
+      ASSERT(number_of_context_slots != 0);
       // The function context slot is the last entry.
-      return n + Context::MIN_CONTEXT_SLOTS - 1;
+      return number_of_context_slots + Context::MIN_CONTEXT_SLOTS - 1;
     }
   }
   return -1;
 }
 
 
-template<class Allocator>
-Handle<String> ScopeInfo<Allocator>::LocalName(int i) const {
-  // A local variable can be allocated either on the stack or in the context.
-  // For variables allocated in the context they are always preceded by the
-  // number Context::MIN_CONTEXT_SLOTS number of fixed allocated slots in the
-  // context.
-  if (i < number_of_stack_slots()) {
-    return stack_slot_name(i);
-  } else {
-    return context_slot_name(i - number_of_stack_slots() +
-                             Context::MIN_CONTEXT_SLOTS);
-  }
-}
-
-
-template<class Allocator>
-int ScopeInfo<Allocator>::NumberOfLocals() const {
-  int number_of_locals = number_of_stack_slots();
-  if (number_of_context_slots() > 0) {
-    ASSERT(number_of_context_slots() >= Context::MIN_CONTEXT_SLOTS);
-    number_of_locals += number_of_context_slots() - Context::MIN_CONTEXT_SLOTS;
-  }
-  return number_of_locals;
-}
-
-
-int ContextSlotCache::Hash(Code* code, String* name) {
+int ContextSlotCache::Hash(Object* data, String* name) {
   // Uses only lower 32 bits if pointers are larger.
   uintptr_t addr_hash =
-      static_cast<uint32_t>(reinterpret_cast<uintptr_t>(code)) >> 2;
+      static_cast<uint32_t>(reinterpret_cast<uintptr_t>(data)) >> 2;
   return static_cast<int>((addr_hash ^ name->Hash()) % kLength);
 }
 
 
-int ContextSlotCache::Lookup(Code* code,
+int ContextSlotCache::Lookup(Object* data,
                              String* name,
                              Variable::Mode* mode) {
-  int index = Hash(code, name);
+  int index = Hash(data, name);
   Key& key = keys_[index];
-  if ((key.code == code) && key.name->Equals(name)) {
+  if ((key.data == data) && key.name->Equals(name)) {
     Value result(values_[index]);
     if (mode != NULL) *mode = result.mode();
     return result.index() + kNotFound;
@@ -566,28 +542,28 @@ int ContextSlotCache::Lookup(Code* code,
 }
 
 
-void ContextSlotCache::Update(Code* code,
+void ContextSlotCache::Update(Object* data,
                               String* name,
                               Variable::Mode mode,
                               int slot_index) {
   String* symbol;
   ASSERT(slot_index > kNotFound);
   if (Heap::LookupSymbolIfExists(name, &symbol)) {
-    int index = Hash(code, symbol);
+    int index = Hash(data, symbol);
     Key& key = keys_[index];
-    key.code = code;
+    key.data = data;
     key.name = symbol;
     // Please note value only takes a uint as index.
     values_[index] = Value(mode, slot_index - kNotFound).raw();
 #ifdef DEBUG
-    ValidateEntry(code, name, mode, slot_index);
+    ValidateEntry(data, name, mode, slot_index);
 #endif
   }
 }
 
 
 void ContextSlotCache::Clear() {
-  for (int index = 0; index < kLength; index++) keys_[index].code = NULL;
+  for (int index = 0; index < kLength; index++) keys_[index].data = NULL;
 }
 
 
@@ -599,15 +575,15 @@ uint32_t ContextSlotCache::values_[ContextSlotCache::kLength];
 
 #ifdef DEBUG
 
-void ContextSlotCache::ValidateEntry(Code* code,
+void ContextSlotCache::ValidateEntry(Object* data,
                                      String* name,
                                      Variable::Mode mode,
                                      int slot_index) {
   String* symbol;
   if (Heap::LookupSymbolIfExists(name, &symbol)) {
-    int index = Hash(code, name);
+    int index = Hash(data, name);
     Key& key = keys_[index];
-    ASSERT(key.code == code);
+    ASSERT(key.data == data);
     ASSERT(key.name->Equals(name));
     Value result(values_[index]);
     ASSERT(result.mode() == mode);