Bug 1742437 - move DOM module loader into own file; r=jonco

Differential Revision: https://phabricator.services.mozilla.com/D137531

dom/script/ScriptLoader.cpp

@@ -9,8 +9,8 @@
 #include "ScriptLoadRequest.h"
 #include "ScriptTrace.h"
 #include "LoadedScript.h"
+#include "ModuleLoader.h"
 #include "ModuleLoadRequest.h"
-#include "ModuleLoaderBase.h"
 
 #include "prsystem.h"
 #include "jsapi.h"
@@ -20,7 +20,6 @@
 #include "js/ContextOptions.h"        // JS::ContextOptionsRef
 #include "js/friend/ErrorMessages.h"  // js::GetErrorMessage, JSMSG_*
 #include "js/MemoryFunctions.h"
-#include "js/Modules.h"  // JS::FinishDynamicModuleImport, JS::{G,S}etModuleResolveHook, JS::Get{ModulePrivate,ModuleScript,RequestedModule{s,Specifier,SourcePos}}, JS::SetModule{DynamicImport,Metadata}Hook
 #include "js/OffThreadScriptCompilation.h"
 #include "js/PropertyAndElement.h"  // JS_DefineProperty
 #include "js/Realm.h"
@@ -3366,487 +3365,6 @@ nsAutoScriptLoaderDisabler::~nsAutoScriptLoaderDisabler() {
   }
 }
 
-/*************** DOM Module Loader *******************/
-
-static ScriptLoader* GetCurrentScriptLoader(JSContext* aCx) {
-  auto reportError = mozilla::MakeScopeExit([aCx]() {
-    JS_ReportErrorASCII(aCx, "No ScriptLoader found for the current context");
-  });
-
-  JS::Rooted<JSObject*> object(aCx, JS::CurrentGlobalOrNull(aCx));
-  if (!object) {
-    return nullptr;
-  }
-
-  nsIGlobalObject* global = xpc::NativeGlobal(object);
-  if (!global) {
-    return nullptr;
-  }
-
-  nsGlobalWindowInner* innerWindow = nullptr;
-  if (nsCOMPtr<nsPIDOMWindowInner> win = do_QueryInterface(global)) {
-    innerWindow = nsGlobalWindowInner::Cast(win);
-  } else {
-    innerWindow = xpc::SandboxWindowOrNull(object, aCx);
-  }
-
-  if (!innerWindow) {
-    return nullptr;
-  }
-
-  Document* document = innerWindow->GetDocument();
-  if (!document) {
-    return nullptr;
-  }
-
-  ScriptLoader* loader = document->ScriptLoader();
-  if (!loader) {
-    return nullptr;
-  }
-
-  reportError.release();
-  return loader;
-}
-
-static LoadedScript* GetLoadedScriptOrNull(
-    JSContext* aCx, JS::Handle<JS::Value> aReferencingPrivate) {
-  if (aReferencingPrivate.isUndefined()) {
-    return nullptr;
-  }
-
-  auto* script = static_cast<LoadedScript*>(aReferencingPrivate.toPrivate());
-  if (script->IsEventScript()) {
-    return nullptr;
-  }
-
-  MOZ_ASSERT_IF(
-      script->IsModuleScript(),
-      JS::GetModulePrivate(script->AsModuleScript()->ModuleRecord()) ==
-          aReferencingPrivate);
-
-  return script;
-}
-
-bool HostGetSupportedImportAssertions(JSContext* aCx,
-                                      JS::ImportAssertionVector& aValues) {
-  MOZ_ASSERT(aValues.empty());
-
-  if (!aValues.reserve(1)) {
-    JS_ReportOutOfMemory(aCx);
-    return false;
-  }
-
-  aValues.infallibleAppend(JS::ImportAssertion::Type);
-
-  return true;
-}
-
-// 8.1.3.8.1 HostResolveImportedModule(referencingModule, moduleRequest)
-/**
- * Implement the HostResolveImportedModule abstract operation.
- *
- * Resolve a module specifier string and look this up in the module
- * map, returning the result. This is only called for previously
- * loaded modules and always succeeds.
- *
- * @param aReferencingPrivate A JS::Value which is either undefined
- *                            or contains a LoadedScript private pointer.
- * @param aModuleRequest A module request object.
- * @returns module This is set to the module found.
- */
-JSObject* HostResolveImportedModule(JSContext* aCx,
-                                    JS::Handle<JS::Value> aReferencingPrivate,
-                                    JS::Handle<JSObject*> aModuleRequest) {
-  JS::Rooted<JSObject*> module(aCx);
-
-  {
-    // LoadedScript should only live in this block, otherwise it will be a GC
-    // hazard
-    RefPtr<LoadedScript> script(
-        GetLoadedScriptOrNull(aCx, aReferencingPrivate));
-
-    JS::Rooted<JSString*> specifierString(
-        aCx, JS::GetModuleRequestSpecifier(aCx, aModuleRequest));
-    if (!specifierString) {
-      return nullptr;
-    }
-
-    // Let url be the result of resolving a module specifier given referencing
-    // module script and specifier.
-    nsAutoJSString string;
-    if (!string.init(aCx, specifierString)) {
-      return nullptr;
-    }
-
-    RefPtr<ScriptLoader> loader = GetCurrentScriptLoader(aCx);
-    if (!loader) {
-      return nullptr;
-    }
-
-    nsCOMPtr<nsIURI> uri =
-        ModuleLoaderBase::ResolveModuleSpecifier(loader, script, string);
-
-    // This cannot fail because resolving a module specifier must have been
-    // previously successful with these same two arguments.
-    MOZ_ASSERT(uri, "Failed to resolve previously-resolved module specifier");
-
-    // Use sandboxed global when doing a WebExtension content-script load.
-    nsCOMPtr<nsIGlobalObject> global;
-    if (BasePrincipal::Cast(nsContentUtils::SubjectPrincipal(aCx))
-            ->ContentScriptAddonPolicy()) {
-      global = xpc::CurrentNativeGlobal(aCx);
-      MOZ_ASSERT(global);
-      MOZ_ASSERT(
-          xpc::IsWebExtensionContentScriptSandbox(global->GetGlobalJSObject()));
-    }
-
-    // Let resolved module script be moduleMap[url]. (This entry must exist for
-    // us to have gotten to this point.)
-    ModuleScript* ms = loader->GetModuleLoader()->GetFetchedModule(uri, global);
-    MOZ_ASSERT(ms, "Resolved module not found in module map");
-    MOZ_ASSERT(!ms->HasParseError());
-    MOZ_ASSERT(ms->ModuleRecord());
-
-    module.set(ms->ModuleRecord());
-  }
-  return module;
-}
-
-bool HostPopulateImportMeta(JSContext* aCx,
-                            JS::Handle<JS::Value> aReferencingPrivate,
-                            JS::Handle<JSObject*> aMetaObject) {
-  RefPtr<ModuleScript> script =
-      static_cast<ModuleScript*>(aReferencingPrivate.toPrivate());
-  MOZ_ASSERT(script->IsModuleScript());
-  MOZ_ASSERT(JS::GetModulePrivate(script->ModuleRecord()) ==
-             aReferencingPrivate);
-
-  nsAutoCString url;
-  MOZ_DIAGNOSTIC_ASSERT(script->BaseURL());
-  MOZ_ALWAYS_SUCCEEDS(script->BaseURL()->GetAsciiSpec(url));
-
-  JS::Rooted<JSString*> urlString(aCx, JS_NewStringCopyZ(aCx, url.get()));
-  if (!urlString) {
-    JS_ReportOutOfMemory(aCx);
-    return false;
-  }
-
-  return JS_DefineProperty(aCx, aMetaObject, "url", urlString,
-                           JSPROP_ENUMERATE);
-}
-
-bool HostImportModuleDynamically(JSContext* aCx,
-                                 JS::Handle<JS::Value> aReferencingPrivate,
-                                 JS::Handle<JSObject*> aModuleRequest,
-                                 JS::Handle<JSObject*> aPromise) {
-  RefPtr<LoadedScript> script(GetLoadedScriptOrNull(aCx, aReferencingPrivate));
-
-  JS::Rooted<JSString*> specifierString(
-      aCx, JS::GetModuleRequestSpecifier(aCx, aModuleRequest));
-  if (!specifierString) {
-    return false;
-  }
-
-  // Attempt to resolve the module specifier.
-  nsAutoJSString specifier;
-  if (!specifier.init(aCx, specifierString)) {
-    return false;
-  }
-
-  RefPtr<ScriptLoader> loader = GetCurrentScriptLoader(aCx);
-  if (!loader) {
-    return false;
-  }
-
-  nsCOMPtr<nsIURI> uri =
-      ModuleLoaderBase::ResolveModuleSpecifier(loader, script, specifier);
-  if (!uri) {
-    JS::Rooted<JS::Value> error(aCx);
-    nsresult rv = ModuleLoaderBase::HandleResolveFailure(aCx, script, specifier,
-                                                         0, 0, &error);
-    if (NS_FAILED(rv)) {
-      JS_ReportOutOfMemory(aCx);
-      return false;
-    }
-
-    JS_SetPendingException(aCx, error);
-    return false;
-  }
-
-  // Create a new top-level load request.
-  RefPtr<ScriptFetchOptions> options;
-  nsIURI* baseURL = nullptr;
-  nsCOMPtr<Element> element;
-  RefPtr<DOMScriptLoadContext> context;
-  // This will be null in all cases except WebExtensions.
-  if (script) {
-    options = script->GetFetchOptions();
-    baseURL = script->BaseURL();
-    nsCOMPtr<Element> element = script->GetScriptElement();
-    context = new DOMScriptLoadContext(element);
-  } else {
-    // We don't have a referencing script so fall back on using
-    // options from the document. This can happen when the user
-    // triggers an inline event handler, as there is no active script
-    // there.
-    Document* document = loader->GetDocument();
-
-    // Use the document's principal for all loads, except WebExtension
-    // content-scripts.
-    // Only remember the global for content-scripts as well.
-    nsCOMPtr<nsIPrincipal> principal = nsContentUtils::SubjectPrincipal(aCx);
-    nsCOMPtr<nsIGlobalObject> global = xpc::CurrentNativeGlobal(aCx);
-    if (!BasePrincipal::Cast(principal)->ContentScriptAddonPolicy()) {
-      principal = document->NodePrincipal();
-      MOZ_ASSERT(global);
-      global = nullptr;  // Null global is the usual case for most loads.
-    } else {
-      MOZ_ASSERT(
-          xpc::IsWebExtensionContentScriptSandbox(global->GetGlobalJSObject()));
-    }
-
-    options = new ScriptFetchOptions(mozilla::CORS_NONE,
-                                     document->GetReferrerPolicy(), principal);
-    baseURL = document->GetDocBaseURI();
-    context = new DOMScriptLoadContext(nullptr, global);
-  }
-
-  RefPtr<ModuleLoadRequest> request = ModuleLoader::CreateDynamicImport(
-      uri, options, baseURL, context, loader, aReferencingPrivate,
-      specifierString, aPromise);
-
-  loader->GetModuleLoader()->StartDynamicImport(request);
-  return true;
-}
-
-void DynamicImportPrefChangedCallback(const char* aPrefName, void* aClosure) {
-  bool enabled = Preferences::GetBool(aPrefName);
-  JS::ModuleDynamicImportHook hook =
-      enabled ? HostImportModuleDynamically : nullptr;
-
-  AutoJSAPI jsapi;
-  jsapi.Init();
-  JSRuntime* rt = JS_GetRuntime(jsapi.cx());
-  JS::SetModuleDynamicImportHook(rt, hook);
-}
-
-ModuleLoader::ModuleLoader(ScriptLoader* aLoader) : ModuleLoaderBase(aLoader) {
-  EnsureModuleHooksInitialized();
-}
-
-void ModuleLoader::EnsureModuleHooksInitialized() {
-  AutoJSAPI jsapi;
-  jsapi.Init();
-  JSRuntime* rt = JS_GetRuntime(jsapi.cx());
-  if (JS::GetModuleResolveHook(rt)) {
-    return;
-  }
-
-  JS::SetModuleResolveHook(rt, HostResolveImportedModule);
-  JS::SetModuleMetadataHook(rt, HostPopulateImportMeta);
-  JS::SetScriptPrivateReferenceHooks(rt, HostAddRefTopLevelScript,
-                                     HostReleaseTopLevelScript);
-  JS::SetSupportedAssertionsHook(rt, HostGetSupportedImportAssertions);
-
-  Preferences::RegisterCallbackAndCall(DynamicImportPrefChangedCallback,
-                                       "javascript.options.dynamicImport",
-                                       (void*)nullptr);
-}
-
-nsresult ModuleLoader::StartModuleLoad(ScriptLoadRequest* aRequest) {
-  MOZ_ASSERT(aRequest->IsLoading());
-  NS_ENSURE_TRUE(GetScriptLoader()->GetDocument(), NS_ERROR_NULL_POINTER);
-  aRequest->SetUnknownDataType();
-
-  // If this document is sandboxed without 'allow-scripts', abort.
-  if (GetScriptLoader()->GetDocument()->HasScriptsBlockedBySandbox()) {
-    return NS_OK;
-  }
-
-  if (LOG_ENABLED()) {
-    nsAutoCString url;
-    aRequest->mURI->GetAsciiSpec(url);
-    LOG(("ScriptLoadRequest (%p): Start Module Load (url = %s)", aRequest,
-         url.get()));
-  }
-
-  // To prevent dynamic code execution, content scripts can only
-  // load moz-extension URLs.
-  nsCOMPtr<nsIPrincipal> principal = aRequest->TriggeringPrincipal();
-  if (BasePrincipal::Cast(principal)->ContentScriptAddonPolicy() &&
-      !aRequest->mURI->SchemeIs("moz-extension")) {
-    return NS_ERROR_DOM_WEBEXT_CONTENT_SCRIPT_URI;
-  }
-
-  // Check whether the module has been fetched or is currently being fetched,
-  // and if so wait for it rather than starting a new fetch.
-  ModuleLoadRequest* request = aRequest->AsModuleRequest();
-  if (ModuleMapContainsURL(request->mURI,
-                           aRequest->GetLoadContext()->GetWebExtGlobal())) {
-    LOG(("ScriptLoadRequest (%p): Waiting for module fetch", aRequest));
-    WaitForModuleFetch(request->mURI,
-                       aRequest->GetLoadContext()->GetWebExtGlobal())
-        ->Then(GetMainThreadSerialEventTarget(), __func__, request,
-               &ModuleLoadRequest::ModuleLoaded,
-               &ModuleLoadRequest::LoadFailed);
-    return NS_OK;
-  }
-
-  nsSecurityFlags securityFlags;
-
-  // According to the spec, module scripts have different behaviour to classic
-  // scripts and always use CORS. Only exception: Non linkable about: pages
-  // which load local module scripts.
-  if (GetScriptLoader()->IsAboutPageLoadingChromeURI(
-          aRequest, GetScriptLoader()->GetDocument())) {
-    securityFlags = nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL;
-  } else {
-    securityFlags = nsILoadInfo::SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT;
-    if (aRequest->CORSMode() == CORS_NONE ||
-        aRequest->CORSMode() == CORS_ANONYMOUS) {
-      securityFlags |= nsILoadInfo::SEC_COOKIES_SAME_ORIGIN;
-    } else {
-      MOZ_ASSERT(aRequest->CORSMode() == CORS_USE_CREDENTIALS);
-      securityFlags |= nsILoadInfo::SEC_COOKIES_INCLUDE;
-    }
-  }
-
-  securityFlags |= nsILoadInfo::SEC_ALLOW_CHROME;
-
-  // Delegate Shared Behavior to base ScriptLoader
-  nsresult rv = GetScriptLoader()->StartLoadInternal(aRequest, securityFlags);
-
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  // We successfully started fetching a module so put its URL in the module
-  // map and mark it as fetching.
-  SetModuleFetchStarted(aRequest->AsModuleRequest());
-  LOG(("ScriptLoadRequest (%p): Start fetching module", aRequest));
-
-  return NS_OK;
-}
-
-void ModuleLoader::ProcessLoadedModuleTree(ModuleLoadRequest* aRequest) {
-  MOZ_ASSERT(aRequest->IsReadyToRun());
-
-  if (aRequest->IsTopLevel()) {
-    if (aRequest->IsDynamicImport()) {
-      MOZ_ASSERT(aRequest->isInList());
-      RefPtr<ScriptLoadRequest> req = mDynamicImportRequests.Steal(aRequest);
-      GetScriptLoader()->RunScriptWhenSafe(aRequest);
-    } else if (aRequest->GetLoadContext()->mIsInline &&
-               aRequest->GetLoadContext()->GetParserCreated() ==
-                   NOT_FROM_PARSER) {
-      MOZ_ASSERT(!aRequest->isInList());
-      GetScriptLoader()->RunScriptWhenSafe(aRequest);
-    } else {
-      GetScriptLoader()->MaybeMoveToLoadedList(aRequest);
-      GetScriptLoader()->ProcessPendingRequests();
-    }
-  }
-
-  aRequest->GetLoadContext()->MaybeUnblockOnload();
-}
-
-nsresult ModuleLoader::CompileOrFinishModuleScript(
-    JSContext* aCx, JS::Handle<JSObject*> aGlobal, JS::CompileOptions& aOptions,
-    ModuleLoadRequest* aRequest, JS::MutableHandle<JSObject*> aModule) {
-  nsresult rv;
-  if (aRequest->GetLoadContext()->mWasCompiledOMT) {
-    JS::Rooted<JS::InstantiationStorage> storage(aCx);
-
-    RefPtr<JS::Stencil> stencil = JS::FinishCompileModuleToStencilOffThread(
-        aCx, aRequest->GetLoadContext()->mOffThreadToken, storage.address());
-    if (stencil) {
-      JS::InstantiateOptions instantiateOptions(aOptions);
-      aModule.set(JS::InstantiateModuleStencil(aCx, instantiateOptions, stencil,
-                                               storage.address()));
-    }
-
-    aRequest->GetLoadContext()->mOffThreadToken = nullptr;
-    rv = aModule ? NS_OK : NS_ERROR_FAILURE;
-  } else {
-    MaybeSourceText maybeSource;
-    rv = aRequest->GetScriptSource(aCx, &maybeSource);
-    if (NS_SUCCEEDED(rv)) {
-      rv = maybeSource.constructed<SourceText<char16_t>>()
-               ? nsJSUtils::CompileModule(
-                     aCx, maybeSource.ref<SourceText<char16_t>>(), aGlobal,
-                     aOptions, aModule)
-               : nsJSUtils::CompileModule(
-                     aCx, maybeSource.ref<SourceText<Utf8Unit>>(), aGlobal,
-                     aOptions, aModule);
-    }
-  }
-  return rv;
-}
-
-/* static */
-already_AddRefed<ModuleLoadRequest> ModuleLoader::CreateTopLevel(
-    nsIURI* aURI, ScriptFetchOptions* aFetchOptions,
-    const SRIMetadata& aIntegrity, nsIURI* aReferrer, ScriptLoader* aLoader,
-    DOMScriptLoadContext* aContext) {
-  RefPtr<ModuleLoadRequest> request = new ModuleLoadRequest(
-      aURI, aFetchOptions, aIntegrity, aReferrer, aContext, true,
-      /* is top level */ false, /* is dynamic import */
-      aLoader->GetModuleLoader(),
-      ModuleLoadRequest::NewVisitedSetForTopLevelImport(aURI), nullptr);
-
-  return request.forget();
-}
-
-/* static */
-already_AddRefed<ModuleLoadRequest> ModuleLoader::CreateStaticImport(
-    nsIURI* aURI, ModuleLoadRequest* aParent) {
-  RefPtr<DOMScriptLoadContext> newContext =
-      new DOMScriptLoadContext(aParent->GetLoadContext()->mElement,
-                               aParent->GetLoadContext()->mWebExtGlobal);
-  newContext->mIsInline = false;
-  // Propagated Parent values. TODO: allow child modules to use root module's
-  // script mode.
-  newContext->mScriptMode = aParent->GetLoadContext()->mScriptMode;
-
-  RefPtr<ModuleLoadRequest> request = new ModuleLoadRequest(
-      aURI, aParent->mFetchOptions, SRIMetadata(), aParent->mURI, newContext,
-      false, /* is top level */
-      false, /* is dynamic import */
-      aParent->mLoader, aParent->mVisitedSet, aParent->GetRootModule());
-
-  return request.forget();
-}
-
-/* static */
-already_AddRefed<ModuleLoadRequest> ModuleLoader::CreateDynamicImport(
-    nsIURI* aURI, ScriptFetchOptions* aFetchOptions, nsIURI* aBaseURL,
-    DOMScriptLoadContext* aContext, ScriptLoader* aLoader,
-    JS::Handle<JS::Value> aReferencingPrivate, JS::Handle<JSString*> aSpecifier,
-    JS::Handle<JSObject*> aPromise) {
-  MOZ_ASSERT(aSpecifier);
-  MOZ_ASSERT(aPromise);
-
-  aContext->mIsInline = false;
-  aContext->mScriptMode = DOMScriptLoadContext::ScriptMode::eAsync;
-
-  RefPtr<ModuleLoadRequest> request = new ModuleLoadRequest(
-      aURI, aFetchOptions, SRIMetadata(), aBaseURL, aContext, true,
-      /* is top level */ true, /* is dynamic import */
-      aLoader->GetModuleLoader(),
-      ModuleLoadRequest::NewVisitedSetForTopLevelImport(aURI), nullptr);
-
-  request->mDynamicReferencingPrivate = aReferencingPrivate;
-  request->mDynamicSpecifier = aSpecifier;
-  request->mDynamicPromise = aPromise;
-
-  HoldJSObjects(request.get());
-
-  return request.forget();
-}
-
-ModuleLoader::~ModuleLoader() {
-  LOG(("ModuleLoader::~ModuleLoader %p", this));
-  mLoader = nullptr;
-}
-
 #undef TRACE_FOR_TEST
 #undef TRACE_FOR_TEST_BOOL
 #undef TRACE_FOR_TEST_NONE