Very first steps for a debugger

runtime/vm/code_patcher.h

 // Copyright (c) 2011, 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.
 // Class for patching compiled code.
 
 #ifndef VM_CODE_PATCHER_H_
 #define VM_CODE_PATCHER_H_
 
 #include "vm/allocation.h"
 
 namespace dart {
 
 // Forward declaration.
 class Array;
 class Code;
 class ExternalLabel;
 class Function;
 class RawArray;
 class String;
 
 class CodePatcher : public AllStatic {
  public:
   // Dart static calls have a distinct, machine-dependent code pattern.
 
   // Patch static call to the new target.
   static void PatchStaticCallAt(uword addr, uword new_target_address);
 
+  // Patch instance call to the new target.
+  static void PatchInstanceCallAt(uword addr, uword new_target_address);
+
   // Patch entry point with a jump as specified in the code's patch region.
   static void PatchEntry(const Code& code);
 
   // Restore entry point with original code (i.e., before patching).
   static void RestoreEntry(const Code& code);
 
   // Returns true if the code can be patched with a jump at beginnning (checks
   // that there are no conflicts with object pointers).
   static bool CodeIsPatchable(const Code& code);
 
@@ skipping 17 matching lines @@
 
   static void SetInstanceCallIcDataAt(uword return_address,
                                       const Array& ic_data);
 
   static intptr_t InstanceCallSizeInBytes();
 };
 
 }  // namespace dart
 
 #endif  // VM_CODE_PATCHER_H_