Reimplement stack manipulations for LiveEdit

src/liveedit.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 65 matching lines @@
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
 
 class LiveEdit : AllStatic {
  public:
   static JSArray* GatherCompileInfo(Handle<Script> script,
                                     Handle<String> source);
 
   static void WrapSharedFunctionInfos(Handle<JSArray> array);
 
+  // Replaces function code. The function mustn't be running anywhere on stack.
+  // The only exception is when stack_manipulation data is provided.
+  // The stack manipulations are performed in this method. It is expected that
+  // as a result the function gets restarted.
+  // \param stack_manipulation_data possibly null handle to stack manipulations
+  //        that are to be performed
   static Object* ReplaceFunctionCode(Handle<JSArray> new_compile_info_array,
-                                     Handle<JSArray> shared_info_array);
+                                     Handle<JSArray> shared_info_array,
+                                     Handle<ByteArray> stack_manipulation_data);
 
   // Updates script field in FunctionSharedInfo.
   static void SetFunctionScript(Handle<JSValue> function_wrapper,
                                 Handle<Object> script_handle);
 
   static Object* PatchFunctionPositions(
       Handle<JSArray> shared_info_array, Handle<JSArray> position_change_array);
 
   // For a script updates its source field. If old_script_name is provided
   // (i.e. is a String), also creates a copy of the script with its original
   // source and sends notification to debugger.
   static Object* ChangeScriptSource(Handle<Script> original_script,
                                     Handle<String> new_source,
                                     Handle<Object> old_script_name);
 
   // In a code of a parent function replaces original function as embedded
   // object with a substitution one.
   static void ReplaceRefToNestedFunction(Handle<JSValue> parent_function_shared,
                                          Handle<JSValue> orig_function_shared,
                                          Handle<JSValue> subst_function_shared);
 
-  // Checks listed functions on stack and return array with corresponding
-  // FunctionPatchabilityStatus statuses; extra array element may
-  // contain general error message. Modifies the current stack and
-  // has restart the lowest found frames and drops all other frames above
-  // if possible and if do_drop is true.
-  static Handle<JSArray> CheckAndDropActivations(
-      Handle<JSArray> shared_info_array, bool do_drop);
+  // Checks the listed functions against the current stacks and plans
+  // possible stack manipulations: all frames running listed functions
+  // must be removed (dropped) from stack.
+  // \param shared_info_array contains array of wrapped shared function
+  //        infos or undefined elements
+  // \return array-packed StackManipulationInfo structure
+  static Handle<JSArray> CheckActivations(Handle<JSArray> shared_info_array);
 
-  // A copy of this is in liveedit-debugger.js.
-  enum FunctionPatchabilityStatus {
-    FUNCTION_AVAILABLE_FOR_PATCH = 1,
-    FUNCTION_BLOCKED_ON_ACTIVE_STACK = 2,
-    FUNCTION_BLOCKED_ON_OTHER_STACK = 3,
-    FUNCTION_BLOCKED_UNDER_NATIVE_CODE = 4,
-    FUNCTION_REPLACED_ON_ACTIVE_STACK = 5
-  };
+  // Returns whether the frame is paused at function restarter code.
+  static bool IsAtFrameResetPatch(const JavaScriptFrame*);
+
+  // Returns pointer to entry of function restarted code (the code must
+  // be patched).
+  static Address GetRestarterPatchEntryPoint(Code* code);
 
   // Compares 2 strings line-by-line and returns diff in form of array of
   // triplets (pos1, pos1_end, pos2_end) describing list of diff chunks.
   static Handle<JSArray> CompareStringsLinewise(Handle<String> s1,
                                                 Handle<String> s2);
 };
 
 
 // A general-purpose comparator between 2 arrays.
 class Comparator {
@@ skipping 25 matching lines @@
   // Finds the difference between 2 arrays of elements.
   static void CalculateDifference(Input* input,
                                   Output* result_writer);
 };
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 } }  // namespace v8::internal
 
-#endif /* V*_LIVEEDIT_H_ */
+#endif /* V8_LIVEEDIT_H_ */