StepOver, StepInto, StepOut

runtime/vm/debugger.h

Index: runtime/vm/debugger.h
===================================================================
--- runtime/vm/debugger.h	(revision 4638)
+++ runtime/vm/debugger.h	(working copy)
@@ -24,11 +24,16 @@
   RawFunction* function() const { return function_; }
   uword pc() const { return pc_; }
   intptr_t token_index() const { return token_index_; }
+  bool is_temporary() const { return is_temporary_; }
+  void set_temporary(bool value) { is_temporary_ = value; }
 
   RawScript* SourceCode();
   RawString* SourceUrl();
   intptr_t LineNumber();
 
+  void SetActive(bool value);
+  bool IsActive();
+
  private:
   void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
@@ -36,12 +41,25 @@
   Breakpoint* next() const { return this->next_; }
   intptr_t pc_desc_index() const { return pc_desc_index_; }
 
+  void PatchCode();
+  void RestoreCode();
+  void PatchFunctionReturn();
+  void RestoreFunctionReturn();
+
   RawFunction* function_;
   intptr_t pc_desc_index_;
   intptr_t token_index_;
   uword pc_;
-  uword saved_bytes_;
   intptr_t line_number_;
+  bool is_temporary_;
+
+  bool is_patched_;
+  PcDescriptors::Kind breakpoint_kind_;
+  union {
+    uword target_address_;
+    uint8_t raw[2 * sizeof(uword)];
+  } saved_bytes_;
+
   Breakpoint* next_;
 
   friend class Debugger;
@@ -53,10 +71,11 @@
 // on the call stack.
 class ActivationFrame : public ZoneAllocated {
  public:
-  explicit ActivationFrame(uword pc, uword fp);
+  explicit ActivationFrame(uword pc, uword fp, uword sp);
 
   uword pc() const { return pc_; }
   uword fp() const { return fp_; }
+  uword sp() const { return sp_; }
 
   const Function& DartFunction();
   RawString* QualifiedFunctionName();
@@ -79,9 +98,11 @@
  private:
   void GetDescIndices();
   RawInstance* GetLocalVarValue(intptr_t slot_index);
+  RawInstance* GetInstanceCallReceiver(intptr_t num_actual_args);
 
   uword pc_;
   uword fp_;
+  uword sp_;
   Function& function_;
   intptr_t token_index_;
   intptr_t line_number_;
@@ -89,6 +110,7 @@
   LocalVarDescriptors* var_descriptors_;
   ZoneGrowableArray<intptr_t> desc_indices_;
 
+  friend class Debugger;
   DISALLOW_COPY_AND_ASSIGN(ActivationFrame);
 };
 
@@ -140,6 +162,10 @@
 
   void RemoveBreakpoint(Breakpoint* bpt);
 
+  void SetStepOver() { resume_action_ = kStepOver; }
+  void SetStepInto() { resume_action_ = kStepInto; }
+  void SetStepOut() { resume_action_ = kStepOut; }
+
   void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
   // Returns NULL if no breakpoint exists for the given address.
@@ -161,10 +187,19 @@
                             const String& field_name);
 
  private:
+  enum ResumeAction {
+    kContinue,
+    kStepOver,
+    kStepInto,
+    kStepOut
+  };
+
+  void InstrumentForStepping(const Function &target_function);
   Breakpoint* SetBreakpoint(const Function& target_function,
                             intptr_t token_index,
                             Error* error);
   void UnsetBreakpoint(Breakpoint* bpt);
+  void RemoveTemporaryBreakpoints();
   Breakpoint* NewBreakpoint(const Function& func, intptr_t pc_desc_index);
   void RegisterBreakpoint(Breakpoint* bpt);
   Breakpoint* GetBreakpointByFunction(const Function& func,
@@ -174,6 +209,10 @@
   bool initialized_;
   BreakpointHandler* bp_handler_;
   Breakpoint* breakpoints_;
+
+  // Tells debugger what to do when resuming execution after a breakpoint.
+  ResumeAction resume_action_;
+
   DISALLOW_COPY_AND_ASSIGN(Debugger);
 };