Store SharedFunctionInfos of a Script in a FixedArray indexed by their ID

src/debug/liveedit.cc

Index: src/debug/liveedit.cc
diff --git a/src/debug/liveedit.cc b/src/debug/liveedit.cc
index ace829739faeb6dd93286dd27eeb27bc75980889..742e475866df103cacd8e3d7da91989bab050259 100644
--- a/src/debug/liveedit.cc
+++ b/src/debug/liveedit.cc
@@ -604,12 +604,9 @@ static int GetArrayLength(Handle<JSArray> array) {
   return Smi::cast(length)->value();
 }
 
-
-void FunctionInfoWrapper::SetInitialProperties(Handle<String> name,
-                                               int start_position,
-                                               int end_position, int param_num,
-                                               int literal_count,
-                                               int parent_index) {
+void FunctionInfoWrapper::SetInitialProperties(
+    Handle<String> name, int start_position, int end_position, int param_num,
+    int literal_count, int parent_index, int function_literal_id) {
   HandleScope scope(isolate());
   this->SetField(kFunctionNameOffset_, name);
   this->SetSmiValueField(kStartPositionOffset_, start_position);
@@ -617,6 +614,7 @@ void FunctionInfoWrapper::SetInitialProperties(Handle<String> name,
   this->SetSmiValueField(kParamNumOffset_, param_num);
   this->SetSmiValueField(kLiteralNumOffset_, literal_count);
   this->SetSmiValueField(kParentIndexOffset_, parent_index);
+  this->SetSmiValueField(kFunctionLiteralIdOffset_, function_literal_id);
 }
 
 void FunctionInfoWrapper::SetSharedFunctionInfo(
@@ -1038,15 +1036,38 @@ void LiveEdit::ReplaceFunctionCode(
   isolate->compilation_cache()->Remove(shared_info);
 }
 
-
-void LiveEdit::FunctionSourceUpdated(Handle<JSArray> shared_info_array) {
+void LiveEdit::FunctionSourceUpdated(Handle<JSArray> shared_info_array,
+                                     int new_function_literal_id) {
   SharedInfoWrapper shared_info_wrapper(shared_info_array);
   Handle<SharedFunctionInfo> shared_info = shared_info_wrapper.GetInfo();
 
+  shared_info->set_function_literal_id(new_function_literal_id);
   DeoptimizeDependentFunctions(*shared_info);
   shared_info_array->GetIsolate()->compilation_cache()->Remove(shared_info);
 }
 
+void LiveEdit::FixupScript(Handle<Script> script, int max_function_literal_id) {
+  Isolate* isolate = script->GetIsolate();
+  Handle<FixedArray> old_infos(script->shared_function_infos(), isolate);
+  Handle<FixedArray> new_infos(isolate->factory()->NewFixedArrayWithSmis(
+      max_function_literal_id + 1, 0));
+  script->set_shared_function_infos(*new_infos);
+  for (int index = 0; index < old_infos->length(); ++index) {
+    Object* raw = old_infos->get(index);
+    if (raw->IsSmi() || WeakCell::cast(raw)->cleared()) continue;
+    // We can't use SharedFunctionInfo::SetScript(info, undefined_value()) here,
+    // as we severed the link from the Script to the SharedFunctionInfo above.
+    Handle<SharedFunctionInfo> info(
+        SharedFunctionInfo::cast(WeakCell::cast(raw)->value()), isolate);
+    info->set_script(isolate->heap()->undefined_value());
+    Handle<Object> new_noscript_list = WeakFixedArray::Add(
+        isolate->factory()->noscript_shared_function_infos(), info);
+    isolate->heap()->SetRootNoScriptSharedFunctionInfos(*new_noscript_list);
+
+    // Put the SharedFunctionInfo at its new, correct location.
+    SharedFunctionInfo::SetScript(info, script);
+  }
+}
 
 void LiveEdit::SetFunctionScript(Handle<JSValue> function_wrapper,
                                  Handle<Object> script_handle) {
@@ -1054,6 +1075,21 @@ void LiveEdit::SetFunctionScript(Handle<JSValue> function_wrapper,
       UnwrapSharedFunctionInfoFromJSValue(function_wrapper);
   Isolate* isolate = function_wrapper->GetIsolate();
   CHECK(script_handle->IsScript() || script_handle->IsUndefined(isolate));
+#if 0

[Toon Verwaest, 2016/12/06 21:10:14]

left-over code?

[jochen (gone - plz use gerrit), 2016/12/07 15:57:00]

yes, removed

+  if (shared_info->script()->IsScript()) {
+    Handle<Script> old_script(Script::cast(shared_info->script()), isolate);
+    Handle<Object> raw(old_script->shared_function_infos()->get(
+                           shared_info->function_literal_id()),
+                       isolate);
+    if (raw->IsWeakCell() && !Handle<WeakCell>::cast(raw)->cleared()) {
+      Handle<SharedFunctionInfo> old_info(
+          SharedFunctionInfo::cast(Handle<WeakCell>::cast(raw)->value()),
+          isolate);
+      SharedFunctionInfo::SetScript(old_info,
+                                    isolate->factory()->undefined_value());
+    }
+  }
+#endif
   SharedFunctionInfo::SetScript(shared_info, script_handle);
   shared_info->DisableOptimization(kLiveEdit);
 
@@ -1173,6 +1209,10 @@ static Handle<Script> CreateScriptCopy(Handle<Script> original) {
   copy->set_eval_from_shared(original->eval_from_shared());
   copy->set_eval_from_position(original->eval_from_position());
 
+  Handle<FixedArray> infos(isolate->factory()->NewFixedArrayWithSmis(
+      original->shared_function_infos()->length(), 0));
+  copy->set_shared_function_infos(*infos);
+
   // Copy all the flags, but clear compilation state.
   copy->set_flags(original->flags());
   copy->set_compilation_state(Script::COMPILATION_STATE_INITIAL);
@@ -1180,7 +1220,6 @@ static Handle<Script> CreateScriptCopy(Handle<Script> original) {
   return copy;
 }
 
-
 Handle<Object> LiveEdit::ChangeScriptSource(Handle<Script> original_script,
                                             Handle<String> new_source,
                                             Handle<Object> old_script_name) {
@@ -1856,8 +1895,6 @@ void LiveEditFunctionTracker::VisitFunctionLiteral(FunctionLiteral* node) {
   // Recurse using the regular traversal.
   AstTraversalVisitor::VisitFunctionLiteral(node);
   // FunctionDone are called in post-order.
-  // TODO(jgruber): If required, replace the (linear cost)
-  // FindSharedFunctionInfo call with a more efficient implementation.
   Handle<SharedFunctionInfo> info =
       script_->FindSharedFunctionInfo(node).ToHandleChecked();
   FunctionDone(info, node->scope());
@@ -1869,7 +1906,7 @@ void LiveEditFunctionTracker::FunctionStarted(FunctionLiteral* fun) {
   info.SetInitialProperties(fun->name(), fun->start_position(),
                             fun->end_position(), fun->parameter_count(),
                             fun->materialized_literal_count(),
-                            current_parent_index_);
+                            current_parent_index_, fun->function_literal_id());
   current_parent_index_ = len_;
   SetElementSloppy(result_, len_, info.GetJSArray());
   len_++;