js/xpconnect/loader/SyncModuleLoader.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "SyncModuleLoader.h"
   8
   9 #include "nsISupportsImpl.h"
  10
  11 #include "js/loader/ModuleLoadRequest.h"
  12 #include "js/RootingAPI.h"          // JS::Rooted
  13 #include "js/PropertyAndElement.h"  // JS_SetProperty
  14 #include "js/Value.h"               // JS::Value, JS::NumberValue
  15 #include "mozJSModuleLoader.h"
  16
  17 using namespace JS::loader;
  18
  19 namespace mozilla {
  20 namespace loader {
  21
  22 //////////////////////////////////////////////////////////////
  23 // SyncScriptLoader
  24 //////////////////////////////////////////////////////////////
  25
  26 NS_IMPL_ISUPPORTS0(SyncScriptLoader)
  27
  28 nsIURI* SyncScriptLoader::GetBaseURI() const { return nullptr; }
  29
  30 void SyncScriptLoader::ReportErrorToConsole(ScriptLoadRequest* aRequest,
  31                                             nsresult aResult) const {}
  32
  33 void SyncScriptLoader::ReportWarningToConsole(
  34     ScriptLoadRequest* aRequest, const char* aMessageName,
  35     const nsTArray<nsString>& aParams) const {}
  36
  37 nsresult SyncScriptLoader::FillCompileOptionsForRequest(
  38     JSContext* cx, ScriptLoadRequest* aRequest, JS::CompileOptions* aOptions,
  39     JS::MutableHandle<JSScript*> aIntroductionScript) {
  40   return NS_OK;
  41 }
  42
  43 //////////////////////////////////////////////////////////////
  44 // SyncModuleLoader
  45 //////////////////////////////////////////////////////////////
  46
  47 NS_IMPL_ADDREF_INHERITED(SyncModuleLoader, JS::loader::ModuleLoaderBase)
  48 NS_IMPL_RELEASE_INHERITED(SyncModuleLoader, JS::loader::ModuleLoaderBase)
  49
  50 NS_IMPL_CYCLE_COLLECTION_INHERITED(SyncModuleLoader,
  51                                    JS::loader::ModuleLoaderBase, mLoadRequests)
  52
  53 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(SyncModuleLoader)
  54 NS_INTERFACE_MAP_END_INHERITING(JS::loader::ModuleLoaderBase)
  55
  56 SyncModuleLoader::SyncModuleLoader(SyncScriptLoader* aScriptLoader,
  57                                    nsIGlobalObject* aGlobalObject)
  58     : ModuleLoaderBase(aScriptLoader, aGlobalObject) {}
  59
  60 SyncModuleLoader::~SyncModuleLoader() { MOZ_ASSERT(mLoadRequests.isEmpty()); }
  61
  62 already_AddRefed<ModuleLoadRequest> SyncModuleLoader::CreateStaticImport(
  63     nsIURI* aURI, JS::ModuleType aModuleType, ModuleLoadRequest* aParent) {
  64   RefPtr<SyncLoadContext> context = new SyncLoadContext();
  65   RefPtr<ModuleLoadRequest> request = new ModuleLoadRequest(
  66       aURI, aModuleType, aParent->ReferrerPolicy(), aParent->mFetchOptions,
  67       dom::SRIMetadata(), aParent->mURI, context, false, /* is top level */
  68       false,                                             /* is dynamic import */
  69       this, aParent->mVisitedSet, aParent->GetRootModule());
  70   request->NoCacheEntryFound();
  71   return request.forget();
  72 }
  73
  74 already_AddRefed<ModuleLoadRequest> SyncModuleLoader::CreateDynamicImport(
  75     JSContext* aCx, nsIURI* aURI, JS::ModuleType aModuleType,
  76     LoadedScript* aMaybeActiveScript, JS::Handle<JSString*> aSpecifier,
  77     JS::Handle<JSObject*> aPromise) {
  78   RefPtr<SyncLoadContext> context = new SyncLoadContext();
  79   RefPtr<VisitedURLSet> visitedSet =
  80       ModuleLoadRequest::NewVisitedSetForTopLevelImport(aURI, aModuleType);
  81   RefPtr<ModuleLoadRequest> request = new ModuleLoadRequest(
  82       aURI, aModuleType, aMaybeActiveScript->ReferrerPolicy(),
  83       aMaybeActiveScript->GetFetchOptions(), dom::SRIMetadata(),
  84       aMaybeActiveScript->BaseURL(), context,
  85       /* aIsTopLevel = */ true, /* aIsDynamicImport =  */ true, this,
  86       visitedSet, nullptr);
  87
  88   request->SetDynamicImport(aMaybeActiveScript, aSpecifier, aPromise);
  89   request->NoCacheEntryFound();
  90
  91   return request.forget();
  92 }
  93
  94 void SyncModuleLoader::OnDynamicImportStarted(ModuleLoadRequest* aRequest) {
  95   MOZ_ASSERT(aRequest->IsDynamicImport());
  96   MOZ_ASSERT(!mLoadRequests.Contains(aRequest));
  97
  98   if (aRequest->IsFetching()) {
  99     // This module is newly imported.
 100     //
 101     // DynamicImportRequests() can contain multiple requests when a dynamic
 102     // import is performed while evaluating the top-level script of other
 103     // dynamic imports.
 104     //
 105     // mLoadRequests should be empty given evaluation is performed after
 106     // handling all fetching requests.
 107     MOZ_ASSERT(DynamicImportRequests().Contains(aRequest));
 108     MOZ_ASSERT(mLoadRequests.isEmpty());
 109
 110     nsresult rv = OnFetchComplete(aRequest, NS_OK);
 111     if (NS_FAILED(rv)) {
 112       mLoadRequests.CancelRequestsAndClear();
 113       CancelDynamicImport(aRequest, rv);
 114       return;
 115     }
 116
 117     rv = ProcessRequests();
 118     if (NS_FAILED(rv)) {
 119       CancelDynamicImport(aRequest, rv);
 120       return;
 121     }
 122   } else {
 123     // This module had already been imported.
 124     MOZ_ASSERT(DynamicImportRequests().isEmpty());
 125     MOZ_ASSERT(mLoadRequests.isEmpty());
 126   }
 127
 128   ProcessDynamicImport(aRequest);
 129 }
 130
 131 bool SyncModuleLoader::CanStartLoad(ModuleLoadRequest* aRequest,
 132                                     nsresult* aRvOut) {
 133   return mozJSModuleLoader::IsTrustedScheme(aRequest->mURI);
 134 }
 135
 136 nsresult SyncModuleLoader::StartFetch(ModuleLoadRequest* aRequest) {
 137   MOZ_ASSERT(aRequest->HasLoadContext());
 138
 139   aRequest->mBaseURL = aRequest->mURI;
 140
 141   // Loading script source and compilation are intertwined in
 142   // mozJSModuleLoader. Perform both operations here but only report load
 143   // failures. Compilation failure is reported in CompileFetchedModule.
 144
 145   dom::AutoJSAPI jsapi;
 146   if (!jsapi.Init(GetGlobalObject())) {
 147     return NS_ERROR_FAILURE;
 148   }
 149
 150   JSContext* cx = jsapi.cx();
 151   JS::RootedScript script(cx);
 152   nsresult rv =
 153       mozJSModuleLoader::LoadSingleModuleScript(this, cx, aRequest, &script);
 154   MOZ_ASSERT_IF(jsapi.HasException(), NS_FAILED(rv));
 155   MOZ_ASSERT(bool(script) == NS_SUCCEEDED(rv));
 156
 157   // Check for failure to load script source and abort.
 158   bool threwException = jsapi.HasException();
 159   if (NS_FAILED(rv) && !threwException) {
 160     nsAutoCString uri;
 161     nsresult rv2 = aRequest->mURI->GetSpec(uri);
 162     NS_ENSURE_SUCCESS(rv2, rv2);
 163
 164     JS_ReportErrorUTF8(cx, "Failed to load %s", PromiseFlatCString(uri).get());
 165
 166     // Remember the error for MaybeReportLoadError.
 167     if (!mLoadException.initialized()) {
 168       mLoadException.init(cx);
 169     }
 170     if (!jsapi.StealException(&mLoadException)) {
 171       return NS_ERROR_OUT_OF_MEMORY;
 172     }
 173
 174     if (mLoadException.isObject()) {
 175       // Expose `nsresult`.
 176       JS::Rooted<JS::Value> resultVal(cx, JS::NumberValue(uint32_t(rv)));
 177       JS::Rooted<JSObject*> exceptionObj(cx, &mLoadException.toObject());
 178       if (!JS_SetProperty(cx, exceptionObj, "result", resultVal)) {
 179         // Ignore the error and keep reporting the exception without the result
 180         // property.
 181         JS_ClearPendingException(cx);
 182       }
 183     }
 184
 185     return rv;
 186   }
 187
 188   // Otherwise remember the results in this context so we can report them later.
 189   SyncLoadContext* context = aRequest->GetSyncLoadContext();
 190   context->mRv = rv;
 191   if (threwException) {
 192     context->mExceptionValue.init(cx);
 193     if (!jsapi.StealException(&context->mExceptionValue)) {
 194       return NS_ERROR_OUT_OF_MEMORY;
 195     }
 196   }
 197   if (script) {
 198     context->mScript.init(cx);
 199     context->mScript = script;
 200   }
 201
 202   if (!aRequest->IsDynamicImport()) {
 203     // NOTE: Dynamic import is stored into mDynamicImportRequests.
 204     mLoadRequests.AppendElement(aRequest);
 205   }
 206
 207   return NS_OK;
 208 }
 209
 210 nsresult SyncModuleLoader::CompileFetchedModule(
 211     JSContext* aCx, JS::Handle<JSObject*> aGlobal, JS::CompileOptions& aOptions,
 212     ModuleLoadRequest* aRequest, JS::MutableHandle<JSObject*> aModuleOut) {
 213   // Compilation already happened in StartFetch. Report the result here.
 214   SyncLoadContext* context = aRequest->GetSyncLoadContext();
 215   nsresult rv = context->mRv;
 216   if (context->mScript) {
 217     aModuleOut.set(JS::GetModuleObject(context->mScript));
 218     context->mScript = nullptr;
 219   }
 220   if (NS_FAILED(rv)) {
 221     JS_SetPendingException(aCx, context->mExceptionValue);
 222     context->mExceptionValue = JS::UndefinedValue();
 223   }
 224
 225   MOZ_ASSERT(JS_IsExceptionPending(aCx) == NS_FAILED(rv));
 226   MOZ_ASSERT(bool(aModuleOut) == NS_SUCCEEDED(rv));
 227
 228   return rv;
 229 }
 230
 231 void SyncModuleLoader::MaybeReportLoadError(JSContext* aCx) {
 232   if (JS_IsExceptionPending(aCx)) {
 233     // Do not override.
 234     return;
 235   }
 236
 237   if (mLoadException.isUndefined()) {
 238     return;
 239   }
 240
 241   JS_SetPendingException(aCx, mLoadException);
 242   mLoadException = JS::UndefinedValue();
 243 }
 244
 245 void SyncModuleLoader::OnModuleLoadComplete(ModuleLoadRequest* aRequest) {}
 246
 247 nsresult SyncModuleLoader::ProcessRequests() {
 248   // Work list to drive module loader since this is all synchronous.
 249   while (!mLoadRequests.isEmpty()) {
 250     RefPtr<ScriptLoadRequest> request = mLoadRequests.StealFirst();
 251     nsresult rv = OnFetchComplete(request->AsModuleRequest(), NS_OK);
 252     if (NS_FAILED(rv)) {
 253       mLoadRequests.CancelRequestsAndClear();
 254       return rv;
 255     }
 256   }
 257
 258   return NS_OK;
 259 }
 260
 261 }  // namespace loader
 262 }  // namespace mozilla