Validation of extension api callback and event parameters in DEBUG

chrome/renderer/extensions/bindings_utils.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/extensions/bindings_utils.h"
 
 #include "base/string_util.h"
 #include "chrome/renderer/render_view.h"
 #include "webkit/api/public/WebFrame.h"
 
 using WebKit::WebFrame;
 
 namespace bindings_utils {
 
 const char* kChromeHidden = "chromeHidden";
+const char* kValidateCallbacks = "validateCallbacks";
 
 struct SingletonData {
   ContextList contexts;
   PendingRequestMap pending_requests;
 };
 
 // ExtensionBase
 
 v8::Handle<v8::FunctionTemplate>
     ExtensionBase::GetNativeFunction(v8::Handle<v8::String> name) {
   if (name->Equals(v8::String::New("GetChromeHidden"))) {
     return v8::FunctionTemplate::New(GetChromeHidden);
   }
 
   return v8::Handle<v8::FunctionTemplate>();
 }
 
 v8::Handle<v8::Value> ExtensionBase::GetChromeHidden(
     const v8::Arguments& args) {
   v8::Local<v8::Context> context = v8::Context::GetCurrent();
   v8::Local<v8::Object> global = context->Global();
   v8::Local<v8::Value> hidden = global->GetHiddenValue(
       v8::String::New(kChromeHidden));
 
   if (hidden.IsEmpty() || hidden->IsUndefined()) {
     hidden = v8::Object::New();
     global->SetHiddenValue(v8::String::New(kChromeHidden), hidden);
+
+#ifdef _DEBUG
+    // Tell extension_process_bindings.js to validate callbacks and events
+    // against their schema definitions in api/extension_api.json.
+    v8::Local<v8::Object>::Cast(hidden)
+        ->Set(v8::String::New(kValidateCallbacks), v8::True());
+#endif
   }
 
   DCHECK(hidden->IsObject());
   return hidden;
 }
 
 ContextList& GetContexts() {
   return Singleton<SingletonData>::get()->contexts;
 }
 
@@ skipping 34 matching lines @@
 
   WebView* webview = webframe->view();
   if (!webview)
     return NULL;  // can happen during closing
 
   RenderView* renderview = static_cast<RenderView*>(webview->GetDelegate());
   DCHECK(renderview) << "Encountered a WebView without a WebViewDelegate";
   return renderview;
 }
 
-void CallFunctionInContext(v8::Handle<v8::Context> context,
-                           const std::string& function_name, int argc,
-                           v8::Handle<v8::Value>* argv) {
+v8::Handle<v8::Value> CallFunctionInContext(v8::Handle<v8::Context> context,
+    const std::string& function_name, int argc,
+    v8::Handle<v8::Value>* argv) {
   v8::Context::Scope context_scope(context);
 
   // Look up the function name, which may be a sub-property like
   // "Port.dispatchOnMessage" in the hidden global variable.
   v8::Local<v8::Value> value =
       context->Global()->GetHiddenValue(v8::String::New(kChromeHidden));
   std::vector<std::string> components;
   SplitStringDontTrim(function_name, '.', &components);
   for (size_t i = 0; i < components.size(); ++i) {
     if (!value.IsEmpty() && value->IsObject())
       value = value->ToObject()->Get(v8::String::New(components[i].c_str()));
   }
   if (value.IsEmpty() || !value->IsFunction()) {
     NOTREACHED();
-    return;
+    return v8::Undefined();
   }
 
   v8::Local<v8::Function> function = v8::Local<v8::Function>::Cast(value);
   if (!function.IsEmpty())
-    function->Call(v8::Object::New(), argc, argv);
+    return function->Call(v8::Object::New(), argc, argv);
+
+  return v8::Undefined();
 }
 
 }  // namespace bindings_utils