Changed the debugger break handling to support situations where there are no ...

src/runtime.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4740 matching lines @@
   RUNTIME_ASSERT(obj->HasIndexedInterceptor());
   CONVERT_NUMBER_CHECKED(uint32_t, index, Uint32, args[1]);
 
   return obj->GetElementWithInterceptor(*obj, index);
 }
 
 
 static Object* Runtime_CheckExecutionState(Arguments args) {
   ASSERT(args.length() >= 1);
   CONVERT_NUMBER_CHECKED(int, break_id, Int32, args[0]);
-  // Check that the break id is valid and that there is a valid frame
-  // where execution is broken.
-  if (break_id != Top::break_id() ||
-      Top::break_frame_id() == StackFrame::NO_ID) {
+  // Check that the break id is valid.
+  if (Top::break_id() == 0 || break_id != Top::break_id()) {
     return Top::Throw(Heap::illegal_execution_state_symbol());
   }
 
   return Heap::true_value();
 }
 
 
 static Object* Runtime_GetFrameCount(Arguments args) {
   HandleScope scope;
   ASSERT(args.length() == 1);
 
   // Check arguments.
   Object* result = Runtime_CheckExecutionState(args);
   if (result->IsFailure()) return result;
 
   // Count all frames which are relevant to debugging stack trace.
   int n = 0;
   StackFrame::Id id = Top::break_frame_id();
+  if (id == StackFrame::NO_ID) {
+    // If there is no JavaScript stack frame count is 0.
+    return Smi::FromInt(0);
+  }
   for (JavaScriptFrameIterator it(id); !it.done(); it.Advance()) n++;
   return Smi::FromInt(n);
 }
 
 
 static const int kFrameDetailsFrameIdIndex = 0;
 static const int kFrameDetailsReceiverIndex = 1;
 static const int kFrameDetailsFunctionIndex = 2;
 static const int kFrameDetailsArgumentCountIndex = 3;
 static const int kFrameDetailsLocalCountIndex = 4;
@@ skipping 21 matching lines @@
   HandleScope scope;
   ASSERT(args.length() == 2);
 
   // Check arguments.
   Object* check = Runtime_CheckExecutionState(args);
   if (check->IsFailure()) return check;
   CONVERT_NUMBER_CHECKED(int, index, Int32, args[1]);
 
   // Find the relevant frame with the requested index.
   StackFrame::Id id = Top::break_frame_id();
+  if (id == StackFrame::NO_ID) {
+    // If there is no JavaScript stack frame is undefined.

[Mads Ager (chromium), 2008/12/11 07:56:54]

is -> return?

[Søren Thygesen Gjesse, 2008/12/11 08:04:49]

Done.

+    return Heap::undefined_value();
+  }
   int count = 0;
   JavaScriptFrameIterator it(id);
   for (; !it.done(); it.Advance()) {
     if (count == index) break;
     count++;
   }
   if (it.done()) return Heap::undefined_value();
 
   // Traverse the saved contexts chain to find the active context for the
   // selected frame.
@@ skipping 1074 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage();
   }
 }
 
 
 } }  // namespace v8::internal