Disconnects code objects from infrequently used unoptimized functions.

runtime/vm/object.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_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 1459 matching lines @@
   // Parameter names are valid for all valid parameter indices, and are not
   // limited to named optional parameters.
   RawString* ParameterNameAt(intptr_t index) const;
   void SetParameterNameAt(intptr_t index, const String& value) const;
   RawArray* parameter_names() const { return raw_ptr()->parameter_names_; }
   void set_parameter_names(const Array& value) const;
 
   // Sets function's code and code's function.
   void SetCode(const Code& value) const;
 
+  // Detaches code from the function by setting the code to null.
+  void DetachCode() const;
+
   // Disables optimized code and switches to unoptimized code.
   void SwitchToUnoptimizedCode() const;
 
   // Return the most recently compiled and installed code for this function.
   // It is not the only Code object that points to this function.
   RawCode* CurrentCode() const { return raw_ptr()->code_; }
 
   RawCode* unoptimized_code() const { return raw_ptr()->unoptimized_code_; }
   void set_unoptimized_code(const Code& value) const;
   static intptr_t code_offset() { return OFFSET_OF(RawFunction, code_); }
+  static intptr_t unoptimized_code_offset() {
+    return OFFSET_OF(RawFunction, unoptimized_code_);
+  }
   inline bool HasCode() const;
 
   // Returns true if there is at least one debugger breakpoint
   // set in this function.
   bool HasBreakpoint() const;
 
   RawContextScope* context_scope() const;
   void set_context_scope(const ContextScope& value) const;
 
   // Enclosing function of this local function.
@@ skipping 1154 matching lines @@
 
   FINAL_HEAP_OBJECT_IMPLEMENTATION(Namespace, Object);
   friend class Class;
 };
 
 
 class Instructions : public Object {
  public:
   intptr_t size() const { return raw_ptr()->size_; }  // Excludes HeaderSize().
   RawCode* code() const { return raw_ptr()->code_; }
+  static intptr_t code_offset() {
+    return OFFSET_OF(RawInstructions, code_);
+  }
   RawArray* object_pool() const { return raw_ptr()->object_pool_; }
   static intptr_t object_pool_offset() {
     return OFFSET_OF(RawInstructions, object_pool_);
   }
 
   uword EntryPoint() const {
     return reinterpret_cast<uword>(raw_ptr()) + HeaderSize();
   }
 
   static const intptr_t kMaxElements = (kIntptrMax -
@@ skipping 3606 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_