Convert function.length to API-style accessor.

src/accessors.cc

 // Copyright 2012 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 871 matching lines @@
                       &FunctionPrototypeSetter,
                       attributes);
 }
 
 
 //
 // Accessors::FunctionLength
 //
 
 
-Object* Accessors::FunctionGetLength(Isolate* isolate,
-                                     Object* object,
-                                     void*) {
-  JSFunction* function = FindInstanceOf<JSFunction>(isolate, object);
-  if (function == NULL) return Smi::FromInt(0);
-  // Check if already compiled.
-  if (function->shared()->is_compiled()) {
-    return Smi::FromInt(function->shared()->length());
+void Accessors::FunctionLengthGetter(
+    v8::Local<v8::String> name,
+    const v8::PropertyCallbackInfo<v8::Value>& info) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
+  HandleScope scope(isolate);
+  Handle<Object> object = Utils::OpenHandle(*info.This());
+  MaybeHandle<JSFunction> maybe_function;
+
+  {
+    DisallowHeapAllocation no_allocation;
+    JSFunction* function = FindInstanceOf<JSFunction>(isolate, *object);
+    if (function != NULL) maybe_function = Handle<JSFunction>(function);
   }
-  // If the function isn't compiled yet, the length is not computed correctly
-  // yet. Compile it now and return the right length.
-  HandleScope scope(isolate);
-  Handle<JSFunction> function_handle(function);
-  if (Compiler::EnsureCompiled(function_handle, KEEP_EXCEPTION)) {
-    return Smi::FromInt(function_handle->shared()->length());
+
+  int length = 0;
+  Handle<JSFunction> function;
+  if (maybe_function.ToHandle(&function)) {
+    if (function->shared()->is_compiled()) {
+      length = function->shared()->length();
+    } else {
+      // If the function isn't compiled yet, the length is not computed
+      // correctly yet. Compile it now and return the right length.
+      if (Compiler::EnsureCompiled(function, KEEP_EXCEPTION)) {
+        length = function->shared()->length();
+      }
+      if (isolate->has_pending_exception()) {
+        isolate->OptionalRescheduleException(false);

[ulan, 2014/04/24 10:27:03]

I added a test that checks this.

+      }
+    }
   }
-  return isolate->heap()->exception();
+  Handle<Object> result(Smi::FromInt(length), isolate);
+  info.GetReturnValue().Set(Utils::ToLocal(result));
 }
 
 
-const AccessorDescriptor Accessors::FunctionLength = {
-  FunctionGetLength,
-  ReadOnlySetAccessor,
-  0
-};
+void Accessors::FunctionLengthSetter(
+    v8::Local<v8::String> name,
+    v8::Local<v8::Value> val,
+    const v8::PropertyCallbackInfo<void>& info) {
+  // Do nothing.
+}
+
+
+Handle<AccessorInfo> Accessors::FunctionLengthInfo(
+      Isolate* isolate, PropertyAttributes attributes) {
+  return MakeAccessor(isolate,
+                      isolate->factory()->length_string(),
+                      &FunctionLengthGetter,
+                      &FunctionLengthSetter,
+                      attributes);
+}
 
 
 //
 // Accessors::FunctionName
 //
 
 
 Object* Accessors::FunctionGetName(Isolate* isolate,
                                    Object* object,
                                    void*) {
@@ skipping 295 matching lines @@
   info->set_data(Smi::FromInt(index));
   Handle<Object> getter = v8::FromCData(isolate, &ModuleGetExport);
   Handle<Object> setter = v8::FromCData(isolate, &ModuleSetExport);
   info->set_getter(*getter);
   if (!(attributes & ReadOnly)) info->set_setter(*setter);
   return info;
 }
 
 
 } }  // namespace v8::internal