LiveEdit: implement frame dropping

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 40b37d96e1dcb4405cb0bf0b94ad5b1997e53686..fe4ad9518d3f58bc36cbbd4aac5f87df8b5b996f 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -9693,41 +9693,18 @@ static Object* Runtime_LiveEditPatchFunctionPositions(Arguments args) {
 }
 
 
-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);
 }
 
 
@@ -9761,6 +9738,35 @@ static Object* Runtime_GetFunctionCodePositionFromSource(Arguments args) {
 }
 
 
+// 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