[runtime] Allocate space for computed property names

src/objects.cc

 // Copyright 2015 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.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ skipping 9791 matching lines @@
 
 
 void FixedArray::CopyTo(int pos, FixedArray* dest, int dest_pos, int len) {
   DisallowHeapAllocation no_gc;
   WriteBarrierMode mode = dest->GetWriteBarrierMode(no_gc);
   for (int index = 0; index < len; index++) {
     dest->set(dest_pos+index, get(pos+index), mode);
   }
 }
 
+int const ConstantProperties::number_of_properties() {
+  if (has_number_of_properties()) {
+    return Smi::cast(this->get(FixedArray::length() - 1))->value();
+  }
+  return FixedArray::length() / 2;
+}
+
+int const ConstantProperties::length() {
+  return FixedArray::length() - (this->has_number_of_properties() ? 1 : 0);

[Toon Verwaest, 2017/01/18 08:49:53]

Perhaps better to not call this length; it's a little confusing this overlaps
with FixedArray::length.

[Franzi, 2017/01/18 14:23:10]

Done. Using size() which is intuitive for lists and not conflicting with the
underlying length. 

+}
+
+bool const ConstantProperties::has_number_of_properties() {
+  return FixedArray::length() % 2 != 0;
+}
 
 #ifdef DEBUG
 bool FixedArray::IsEqualTo(FixedArray* other) {
   if (length() != other->length()) return false;
   for (int i = 0 ; i < length(); ++i) {
     if (get(i) != other->get(i)) return false;
   }
   return true;
 }
 #endif
@@ skipping 10079 matching lines @@
       // depend on this.
       return DICTIONARY_ELEMENTS;
     }
     DCHECK_LE(kind, LAST_ELEMENTS_KIND);
     return kind;
   }
 }
 
 }  // namespace internal
 }  // namespace v8