Bug 1761938 - Part 4: Give module loaders a global object field r=smaug,yulia

This gives the module loader a field for the current global, since a module map
is only associated with a single global.

This adds a method to Document to tell the script loader when its global
changes. I'm not sure of when we do this exactly.

Differential Revision: https://phabricator.services.mozilla.com/D142831

dom/base/Document.cpp

@@ -7713,6 +7713,11 @@ void Document::SetScriptGlobalObject(
     mTemplateContentsOwner->SetScriptGlobalObject(aScriptGlobalObject);
   }
 
+  // Tell the script loader about the new global object.
+  if (mScriptLoader) {
+    mScriptLoader->SetGlobalObject(mScriptGlobalObject);
+  }
+
   if (!mMaybeServiceWorkerControlled && mDocumentContainer &&
       mScriptGlobalObject && GetChannel()) {
     // If we are shift-reloaded, don't associate with a ServiceWorker.

dom/script/ModuleLoader.cpp

@@ -48,8 +48,9 @@ namespace mozilla::dom {
 // DOM module loader
 //////////////////////////////////////////////////////////////
 
-ModuleLoader::ModuleLoader(ScriptLoader* aLoader, Kind aKind)
-    : ModuleLoaderBase(aLoader), mKind(aKind) {}
+ModuleLoader::ModuleLoader(ScriptLoader* aLoader,
+                           nsIGlobalObject* aGlobalObject, Kind aKind)
+    : ModuleLoaderBase(aLoader, aGlobalObject), mKind(aKind) {}
 
 ScriptLoader* ModuleLoader::GetScriptLoader() {
   return static_cast<ScriptLoader*>(mLoader.get());

dom/script/ModuleLoader.h

@@ -42,7 +42,8 @@ class ModuleLoader final : public JS::loader::ModuleLoaderBase {
  public:
   enum Kind { Normal, WebExtension };
 
-  ModuleLoader(ScriptLoader* aLoader, Kind aKind);
+  ModuleLoader(ScriptLoader* aLoader, nsIGlobalObject* aGlobalObject,
+               Kind aKind);
 
   Kind GetKind() const { return mKind; }
 

dom/script/ScriptLoader.cpp

@@ -187,8 +187,7 @@ ScriptLoader::ScriptLoader(Document* aDocument)
       mBlockingDOMContentLoaded(false),
       mLoadEventFired(false),
       mGiveUpEncoding(false),
-      mReporter(new ConsoleReportCollector()),
-      mModuleLoader(new ModuleLoader(this, ModuleLoader::Normal)) {
+      mReporter(new ConsoleReportCollector()) {
   LOG(("ScriptLoader::ScriptLoader %p", this));
 
   mSpeculativeOMTParsingEnabled = StaticPrefs::
@@ -251,6 +250,24 @@ ScriptLoader::~ScriptLoader() {
   mModuleLoader = nullptr;
 }
 
+void ScriptLoader::SetGlobalObject(nsIGlobalObject* aGlobalObject) {
+  if (!aGlobalObject) {
+    // The document is being detached.
+    return;
+  }
+
+  MOZ_ASSERT(!HasPendingRequests());
+
+  if (mModuleLoader) {
+    MOZ_ASSERT(mModuleLoader->GetGlobalObject() == aGlobalObject);
+    return;
+  }
+
+  // The module loader is associated with a global object, so don't create it
+  // until we have a global set.
+  mModuleLoader = new ModuleLoader(this, aGlobalObject, ModuleLoader::Normal);
+}
+
 void ScriptLoader::RegisterContentScriptModuleLoader(ModuleLoader* aLoader) {
   MOZ_ASSERT(aLoader);
   MOZ_ASSERT(aLoader->GetScriptLoader() == this);
@@ -2543,7 +2560,7 @@ void ScriptLoader::GiveUpBytecodeEncoding() {
   }
 }
 
-bool ScriptLoader::HasPendingRequests() {
+bool ScriptLoader::HasPendingRequests() const {
   return mParserBlockingRequest || !mXSLTRequests.isEmpty() ||
          !mLoadedAsyncRequests.isEmpty() ||
          !mNonAsyncExternalScriptInsertedRequests.isEmpty() ||
@@ -2553,7 +2570,7 @@ bool ScriptLoader::HasPendingRequests() {
 }
 
 bool ScriptLoader::HasPendingDynamicImports() const {
-  if (mModuleLoader->HasPendingDynamicImports()) {
+  if (mModuleLoader && mModuleLoader->HasPendingDynamicImports()) {
     return true;
   }
 
@@ -3354,7 +3371,9 @@ void ScriptLoader::ParsingComplete(bool aTerminated) {
   mNonAsyncExternalScriptInsertedRequests.CancelRequestsAndClear();
   mXSLTRequests.CancelRequestsAndClear();
 
-  mModuleLoader->CancelAndClearDynamicImports();
+  if (mModuleLoader) {
+    mModuleLoader->CancelAndClearDynamicImports();
+  }
 
   for (ModuleLoader* loader : mWebExtModuleLoaders) {
     loader->CancelAndClearDynamicImports();

dom/script/ScriptLoader.h

@@ -132,6 +132,12 @@ class ScriptLoader final : public JS::loader::ScriptLoaderInterface {
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_CLASS(ScriptLoader)
 
+  /**
+   * Called when the document that owns this script loader changes global. The
+   * argument is null when the document is detached from a window.
+   */
+  void SetGlobalObject(nsIGlobalObject* aGlobalObject);
+
   /**
    * The loader maintains a weak reference to the document with
    * which it is initialized. This call forces the reference to
@@ -322,7 +328,7 @@ class ScriptLoader final : public JS::loader::ScriptLoaderInterface {
   /**
    * Returns wether any request is queued, and not executed yet.
    */
-  bool HasPendingRequests();
+  bool HasPendingRequests() const;
 
   /**
    * Returns wether there are any dynamic module import requests pending.

js/loader/ModuleLoaderBase.cpp

@@ -52,7 +52,7 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ModuleLoaderBase)
 NS_INTERFACE_MAP_END
 
 NS_IMPL_CYCLE_COLLECTION(ModuleLoaderBase, mFetchedModules,
-                         mDynamicImportRequests, mLoader)
+                         mDynamicImportRequests, mGlobalObject, mLoader)
 
 NS_IMPL_CYCLE_COLLECTING_ADDREF(ModuleLoaderBase)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(ModuleLoaderBase)
@@ -255,6 +255,8 @@ ModuleLoaderBase* ModuleLoaderBase::GetCurrentModuleLoader(JSContext* aCx) {
     return nullptr;
   }
 
+  MOZ_ASSERT(loader->mGlobalObject == global);
+
   reportError.release();
   return loader;
 }
@@ -461,6 +463,8 @@ nsresult ModuleLoaderBase::CreateModuleScript(ModuleLoadRequest* aRequest) {
     return NS_ERROR_FAILURE;
   }
 
+  MOZ_ASSERT(globalObject == mGlobalObject);
+
   AutoJSAPI jsapi;
   if (!jsapi.Init(globalObject)) {
     return NS_ERROR_FAILURE;
@@ -832,8 +836,12 @@ void ModuleLoaderBase::FinishDynamicImport(
   aRequest->ClearDynamicImport();
 }
 
-ModuleLoaderBase::ModuleLoaderBase(ScriptLoaderInterface* aLoader)
-    : mLoader(aLoader) {
+ModuleLoaderBase::ModuleLoaderBase(ScriptLoaderInterface* aLoader,
+                                   nsIGlobalObject* aGlobalObject)
+    : mGlobalObject(aGlobalObject), mLoader(aLoader) {
+  MOZ_ASSERT(mGlobalObject);
+  MOZ_ASSERT(mLoader);
+
   EnsureModuleHooksInitialized();
 }
 
@@ -992,6 +1000,7 @@ void ModuleLoaderBase::ProcessDynamicImport(ModuleLoadRequest* aRequest) {
 nsresult ModuleLoaderBase::EvaluateModule(nsIGlobalObject* aGlobalObject,
                                           ModuleLoadRequest* aRequest) {
   MOZ_ASSERT(aRequest->mLoader == this);
+  MOZ_ASSERT(aGlobalObject == mGlobalObject);
 
   AUTO_PROFILER_LABEL("ModuleLoaderBase::EvaluateModule", JS);
 

js/loader/ModuleLoaderBase.h

@@ -92,6 +92,8 @@ class ModuleLoaderBase : public nsISupports {
   // List of dynamic imports that are currently being loaded.
   ScriptLoadRequestList mDynamicImportRequests;
 
+  nsCOMPtr<nsIGlobalObject> mGlobalObject;
+
  protected:
   RefPtr<ScriptLoaderInterface> mLoader;
 
@@ -100,7 +102,8 @@ class ModuleLoaderBase : public nsISupports {
  public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_CLASS(ModuleLoaderBase)
-  explicit ModuleLoaderBase(ScriptLoaderInterface* aLoader);
+  explicit ModuleLoaderBase(ScriptLoaderInterface* aLoader,
+                            nsIGlobalObject* aGlobalObject);
 
   using LoadedScript = JS::loader::LoadedScript;
   using ScriptFetchOptions = JS::loader::ScriptFetchOptions;
@@ -143,6 +146,8 @@ class ModuleLoaderBase : public nsISupports {
  public:
   ScriptLoaderInterface* GetScriptLoaderInterface() const { return mLoader; }
 
+  nsIGlobalObject* GetGlobalObject() const { return mGlobalObject; }
+
   bool HasPendingDynamicImports() const;
   void CancelDynamicImport(ModuleLoadRequest* aRequest, nsresult aResult);
 #ifdef DEBUG

js/xpconnect/src/Sandbox.cpp

@@ -2230,7 +2230,7 @@ ModuleLoaderBase* SandboxPrivate::GetModuleLoader(JSContext* aCx) {
   ScriptLoader* scriptLoader = mainModuleLoader->GetScriptLoader();
 
   ModuleLoader* moduleLoader =
-      new ModuleLoader(scriptLoader, ModuleLoader::WebExtension);
+      new ModuleLoader(scriptLoader, this, ModuleLoader::WebExtension);
   scriptLoader->RegisterContentScriptModuleLoader(moduleLoader);
   mModuleLoader = moduleLoader;