Debugger step 2

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;
 
+
+// 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_; }
+
+  RawScript* SourceCode();

[siva, 2011/12/05 19:21:44]

const?

[hausner, 2011/12/05 21:11:23]

Can't be const because it's not initialized in the constructor.

+  RawString* SourceUrl();

[siva, 2011/12/05 19:21:44]

const?

[hausner, 2011/12/05 21:11:23]

ditto.

+  intptr_t LineNumber();
+
+ private:
+  void VisitObjectPointers(ObjectPointerVisitor* visitor);
+
+  void set_next(Breakpoint* value) { next_ = value; }
+  Breakpoint* next() const { return this->next_; }
+
+  RawFunction* function_;
+  intptr_t pc_desc_index_;
+  intptr_t token_index_;
+  uword pc_;
+  intptr_t line_number_;
+  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 pc() const { return pc_; }
+
+  RawFunction* DartFunction();
+  RawString* SourceUrl();
+  RawScript* SourceScript();
+  intptr_t TokenIndex();

[siva, 2011/12/05 19:21:44]

above 4 methods can be 'const'?

[hausner, 2011/12/05 21:11:23]

Unfortunately not. DartFunction() assigns to a field in ActivationFrame. The
other functions call DartFunction. It's the price to pay for lazy evaluation.

+  intptr_t LineNumber();
+  char* ToCString();

[siva, 2011/12/05 19:21:44]

'const'?

[hausner, 2011/12/05 21:11:23]

const char* as the return type? Yes. Done. The function itself cannot be const
because it calls DartFunction().

+
+  // Returns an array of String values containing variable names
+  // in this activation frame.
+  RawArray* Variables();
+
+  // Returns the value of the given variable in the context of the
+  // activation frame.
+  RawInstance* Value(const String& variable_name);
+
+ private:
+  uword pc_;
+  RawFunction* function_;
+  intptr_t token_index_;
+  intptr_t line_number_;
+
+  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(); }
+
+  ActivationFrame* ActivationFrameAt(int i) const {
+    ASSERT(i < trace_.length());
+    return trace_[i];
+  }
+ private:
+  void AddActivation(ActivationFrame* frame);
+  ZoneGrowableArray<ActivationFrame*> trace_;
+
+  friend class Debugger;
+  DISALLOW_COPY_AND_ASSIGN(StackTrace);
+};
+
+
+typedef void BreakpointHandler(Breakpoint* bpt, StackTrace* stack);
+
+
 class Debugger {
  public:
   Debugger();
 
   void Initialize(Isolate* isolate);
 
+  void SetBreakpointHandler(BreakpointHandler* handler);
+
   // Set breakpoint at closest location to function entry.
   void SetBreakpointAtEntry(const String& class_name,
                             const String& function_name);
 
   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();
+
  private:
   void AddBreakpoint(Breakpoint* bpt);
 
   bool initialized_;
+  BreakpointHandler* bp_handler_;
   Breakpoint* breakpoints_;
   DISALLOW_COPY_AND_ASSIGN(Debugger);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_DEBUGGER_H_