LiveEdit: implement frame dropping

src/runtime.cc

 // Copyright 2006-2009 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 9675 matching lines @@
   HandleScope scope;
   CONVERT_ARG_CHECKED(JSArray, shared_array, 0);
   CONVERT_ARG_CHECKED(JSArray, position_change_array, 1);
 
   LiveEdit::PatchFunctionPositions(shared_array, position_change_array);
 
   return Heap::undefined_value();
 }
 
 
-static LiveEdit::FunctionPatchabilityStatus FindFunctionCodeOnStacks(
-    Handle<SharedFunctionInfo> shared) {
-  // TODO(635): check all threads, not only the current one.
-  for (StackFrameIterator it; !it.done(); it.Advance()) {
-    StackFrame* frame = it.frame();
-    if (frame->code() == shared->code()) {
-      return LiveEdit::FUNCTION_BLOCKED_ON_STACK;
-    }
-  }
-  return LiveEdit::FUNCTION_AVAILABLE_FOR_PATCH;
-}
-
 // For array of SharedFunctionInfo's (each wrapped in JSValue)
 // checks that none of them have activations on stacks (of any thread).
 // Returns array of the same length with corresponding results of
 // LiveEdit::FunctionPatchabilityStatus type.
-static Object* Runtime_LiveEditCheckStackActivations(Arguments args) {
-  ASSERT(args.length() == 1);
+static Object* Runtime_LiveEditCheckAndDropActivations(Arguments args) {
+  ASSERT(args.length() == 2);
   HandleScope scope;
   CONVERT_ARG_CHECKED(JSArray, shared_array, 0);
+  CONVERT_BOOLEAN_CHECKED(do_drop, args[1]);
 
 
-  int len = Smi::cast(shared_array->length())->value();
-  Handle<JSArray> result = Factory::NewJSArray(len);
-
-  for (int i = 0; i < len; i++) {
-    JSValue* wrapper = JSValue::cast(shared_array->GetElement(i));
-    Handle<SharedFunctionInfo> shared(
-        SharedFunctionInfo::cast(wrapper->value()));
-    LiveEdit::FunctionPatchabilityStatus check_res =
-        FindFunctionCodeOnStacks(shared);
-    SetElement(result, i, Handle<Smi>(Smi::FromInt(check_res)));
-  }
-
-  return *result;
+  return *LiveEdit::CheckAndDropActivations(shared_array, do_drop);
 }
 
 
 // A testing entry. Returns statement position which is the closest to
 // source_position.
 static Object* Runtime_GetFunctionCodePositionFromSource(Arguments args) {
   ASSERT(args.length() == 2);
   HandleScope scope;
   CONVERT_ARG_CHECKED(JSFunction, function, 0);
   CONVERT_NUMBER_CHECKED(int32_t, source_position, Int32, args[1]);
@@ skipping 13 matching lines @@
       // Check whether we can't get any closer.
       if (distance == 0) break;
     }
     it.next();
   }
 
   return Smi::FromInt(closest_pc);
 }
 
 
+// Calls specified function with or without entering the debugger.
+// This is used in unit tests to run code as if debugger is entered or simply
+// to have a stack with C++ frame in the middle.
+static Object* Runtime_ExecuteInDebugContext(Arguments args) {
+  ASSERT(args.length() == 2);
+  HandleScope scope;
+  CONVERT_ARG_CHECKED(JSFunction, function, 0);
+  CONVERT_BOOLEAN_CHECKED(without_debugger, args[1]);
+
+  Handle<Object> result;
+  bool pending_exception;
+  {
+    if (without_debugger) {
+      result = Execution::Call(function, Top::global(), 0, NULL,
+                               &pending_exception);
+    } else {
+      EnterDebugger enter_debugger;
+      result = Execution::Call(function, Top::global(), 0, NULL,
+                               &pending_exception);
+    }
+  }
+  if (!pending_exception) {
+    return *result;
+  } else {
+    return Failure::Exception();
+  }
+}
+
+
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
 static Object* Runtime_ProfilerResume(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
   CONVERT_CHECKED(Smi, smi_modules, args[0]);
   CONVERT_CHECKED(Smi, smi_tag, args[1]);
@@ skipping 265 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(false);
   }
 }
 
 
 } }  // namespace v8::internal