StepOver, StepInto, StepOut

runtime/vm/debugger.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.
 
 #ifndef VM_DEBUGGER_H_
 #define VM_DEBUGGER_H_
 
 #include "vm/object.h"
 
 namespace dart {
 
 class Breakpoint;
 class Isolate;
 class ObjectPointerVisitor;
 class ActiveVariables;
 
 
 // Breakpoint represents a location in Dart source and the corresponding
 // address in compiled code.
 class Breakpoint {
  public:
   Breakpoint(const Function& func, intptr_t pc_desc_index);
 
   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);
 
   void set_next(Breakpoint* value) { next_ = value; }
   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;
   DISALLOW_COPY_AND_ASSIGN(Breakpoint);
 };
 
 
 // ActivationFrame represents one dart function activation frame
 // 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();
   RawString* SourceUrl();
   RawScript* SourceScript();
   intptr_t TokenIndex();
   intptr_t LineNumber();
   const char* ToCString();
 
   intptr_t NumLocalVariables();
 
   void VariableAt(intptr_t i,
                   String* name,
                   intptr_t* token_pos,
                   intptr_t* end_pos,
                   Instance* value);
 
   RawArray* GetLocalVariables();
 
  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_;
 
   LocalVarDescriptors* var_descriptors_;
   ZoneGrowableArray<intptr_t> desc_indices_;
 
+  friend class Debugger;
   DISALLOW_COPY_AND_ASSIGN(ActivationFrame);
 };
 
 
 // Array of function activations on the call stack.
 class StackTrace : public ZoneAllocated {
  public:
   explicit StackTrace(int capacity) : trace_(capacity) { }
 
   intptr_t Length() const { return trace_.length(); }
@@ skipping 31 matching lines @@
 
   // Set breakpoint at closest location to function entry.
   Breakpoint* SetBreakpointAtEntry(const Function& target_function,
                                    Error* error);
   Breakpoint* SetBreakpointAtLine(const String& script_url,
                                   intptr_t line_number,
                                   Error* error);
 
   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.
   Breakpoint* GetBreakpoint(uword breakpoint_address);
 
   // Called from Runtime when a breakpoint in Dart code is reached.
   void BreakpointCallback();
 
   RawArray* GetInstanceFields(const Instance& obj);
   RawArray* GetStaticFields(const Class& cls);
 
   // Utility functions.
   static const char* QualifiedFunctionName(const Function& func);
 
   RawObject* GetInstanceField(const Class& cls,
                               const String& field_name,
                               const Instance& object);
   RawObject* GetStaticField(const Class& cls,
                             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,
                                       intptr_t token_index);
 
   Isolate* isolate_;
   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);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_DEBUGGER_H_