[debugger] simplify debug stepping.

src/debug/debug.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_DEBUG_DEBUG_H_
 #define V8_DEBUG_DEBUG_H_
 
 #include "src/allocation.h"
 #include "src/arguments.h"
 #include "src/assembler.h"
@@ skipping 444 matching lines @@
   void ChangeBreakOnException(ExceptionBreakType type, bool enable);
   bool IsBreakOnException(ExceptionBreakType type);
 
   // Stepping handling.
   void PrepareStep(StepAction step_action);
   void PrepareStepIn(Handle<JSFunction> function);
   void PrepareStepInSuspendedGenerator();
   void PrepareStepOnThrow();
   void ClearStepping();
   void ClearStepOut();
-  void EnableStepIn();
 
   bool PrepareFunctionForBreakPoints(Handle<SharedFunctionInfo> shared);
 
   void RecordAsyncFunction(Handle<JSGeneratorObject> generator_object);
 
   // Returns whether the operation succeeded. Compilation can only be triggered
   // if a valid closure is passed as the second argument, otherwise the shared
   // function needs to be compiled already.
   bool EnsureDebugInfo(Handle<SharedFunctionInfo> shared,
                        Handle<JSFunction> function);
@@ skipping 63 matching lines @@
 
   // Support for embedding into generated code.
   Address is_active_address() {
     return reinterpret_cast<Address>(&is_active_);
   }
 
   Address after_break_target_address() {
     return reinterpret_cast<Address>(&after_break_target_);
   }
 
-  Address step_in_enabled_address() {
-    return reinterpret_cast<Address>(&thread_local_.step_in_enabled_);
+  Address last_step_action_address() {
+    return reinterpret_cast<Address>(&thread_local_.last_step_action_);
   }
 
   Address suspended_generator_address() {
     return reinterpret_cast<Address>(&thread_local_.suspended_generator_);
   }
 
   StepAction last_step_action() { return thread_local_.last_step_action_; }
 
   DebugFeatureTracker* feature_tracker() { return &feature_tracker_; }
 
@@ skipping 125 matching lines @@
 
     // Source statement position from last step next action.
     int last_statement_position_;
 
     // Frame pointer from last step next or step frame action.
     Address last_fp_;
 
     // Frame pointer of the target frame we want to arrive at.
     Address target_fp_;
 
-    // Whether functions are flooded on entry for step-in and step-frame.
-    // If we stepped out to the embedder, disable flooding to spill stepping
-    // to the next call that the embedder makes.
-    bool step_in_enabled_;
-
     // Stores the way how LiveEdit has patched the stack. It is used when
     // debugger returns control back to user script.
     LiveEdit::FrameDropMode frame_drop_mode_;
 
     // Value of accumulator in interpreter frames. In non-interpreter frames
     // this value will be the hole.
     Handle<Object> return_value_;
 
     Object* suspended_generator_;
   };
@@ skipping 106 matching lines @@
                                   Handle<Code> code);
   static bool DebugBreakSlotIsPatched(Address pc);
   static void ClearDebugBreakSlot(Isolate* isolate, Address pc);
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_DEBUG_DEBUG_H_