- Create frame work for adding read only handles for symbols in the VM isolate

vm/symbols.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_SYMBOLS_H_
 #define VM_SYMBOLS_H_
 
 #include "vm/object.h"
 #include "vm/snapshot_ids.h"
 
@@ skipping 126 matching lines @@
   V(_ExternalInt32Array, "_ExternalInt32Array")                                \
   V(_ExternalUint32Array, "_ExternalUint32Array")                              \
   V(_ExternalInt64Array, "_ExternalInt64Array")                                \
   V(_ExternalUint64Array, "_ExternalUint64Array")                              \
   V(_ExternalFloat32Array, "_ExternalFloat32Array")                            \
   V(_ExternalFloat64Array, "_ExternalFloat64Array")                            \
   V(_WeakProperty, "_WeakProperty")                                            \
   V(InvocationMirror, "_InvocationMirror")                                     \
   V(AllocateInvocationMirror, "_allocateInvocationMirror")                     \
 
+#define PREDEFINED_SYMBOL_HANDLES_LIST(V)                                      \
+  V(Dot)                                                                       \
+
 // Contains a list of frequently used strings in a canonicalized form. This
 // list is kept in the vm_isolate in order to share the copy across isolates
 // without having to maintain copies in each isolate.
 class Symbols : public AllStatic {
  public:
   enum { kMaxOneCharCodeSymbol = 0xFF };
 
   // List of strings that are pre created in the vm isolate.
   enum SymbolId {
     kIllegal = 0,
 
 #define DEFINE_SYMBOL_INDEX(symbol, literal)                                   \
     k##symbol,
 PREDEFINED_SYMBOLS_LIST(DEFINE_SYMBOL_INDEX)
 #undef DEFINE_SYMBOL_INDEX
     kMaxPredefinedId,
     kNullCharId = kMaxPredefinedId,
     kMaxId = kNullCharId + kMaxOneCharCodeSymbol + 1,
   };
 
   // Access methods for symbols stored in the vm isolate.
 #define DEFINE_SYMBOL_ACCESSOR(symbol, literal)                                \
   static RawString* symbol() { return predefined_[k##symbol]; }
 PREDEFINED_SYMBOLS_LIST(DEFINE_SYMBOL_ACCESSOR)
 #undef DEFINE_SYMBOL_ACCESSOR
 
+  // Access methods for symbol handles stored in the vm isolate.
+#define DEFINE_SYMBOL_HANDLE_ACCESSOR(symbol)                                  \
+  static const String& symbol##Handle() { return *symbol##_handle_; }
+PREDEFINED_SYMBOL_HANDLES_LIST(DEFINE_SYMBOL_HANDLE_ACCESSOR)
+#undef DEFINE_SYMBOL_HANDLE_ACCESSOR
+
   // Initialize frequently used symbols in the vm isolate.
   static void InitOnce(Isolate* isolate);
 
   // Initialize and setup a symbol table for the isolate.
   static void SetupSymbolTable(Isolate* isolate);
 
   // Get number of symbols in an isolate's symbol table.
   static intptr_t Size(Isolate* isolate);
 
   // Creates a Symbol given a C string that is assumed to contain
@@ skipping 65 matching lines @@
   static intptr_t LookupVMSymbol(RawObject* obj);
   static RawObject* GetVMSymbol(intptr_t object_id);
   static bool IsVMSymbolId(intptr_t object_id) {
     return (object_id >= kMaxPredefinedObjectIds &&
             object_id < (kMaxPredefinedObjectIds + kMaxId));
   }
 
   // List of symbols that are stored in the vm isolate for easy access.
   static RawString* predefined_[kMaxId];
 
+  // Structure for managing handles allocation for symbols that are
+  // stored in the vm isolate.
+  static VMHandles predefined_handles_;
+
+#define DECLARE_SYMBOL_HANDLE(symbol)                                          \
+  static String* symbol##_handle_;
+PREDEFINED_SYMBOL_HANDLES_LIST(DECLARE_SYMBOL_HANDLE)
+#undef DECLARE_SYMBOL_HANDLE
+
   friend class String;
   friend class SnapshotReader;
   friend class SnapshotWriter;
   friend class ApiMessageReader;
 
   DISALLOW_COPY_AND_ASSIGN(Symbols);
 };
 
 }  // namespace dart
 
 #endif  // VM_SYMBOLS_H_