Reimplement stack manipulations for LiveEdit

src/liveedit.h

Index: src/liveedit.h
diff --git a/src/liveedit.h b/src/liveedit.h
index d8e2a1375b52b862ea8ba23a611163378a6192c2..c2e7502d1a5177808a506b3619b0efe846236286 100644
--- a/src/liveedit.h
+++ b/src/liveedit.h
@@ -83,8 +83,15 @@ class LiveEdit : AllStatic {
 
   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,
@@ -106,22 +113,20 @@ class LiveEdit : AllStatic {
                                          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);
-
-  // 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
-  };
+  // 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);
+
+  // 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.
@@ -167,4 +172,4 @@ class Comparator {
 
 } }  // namespace v8::internal
 
-#endif /* V*_LIVEEDIT_H_ */
+#endif /* V8_LIVEEDIT_H_ */