js/loader/ModuleLoadRequest.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 "ModuleLoadRequest.h"
   8
   9 #include "mozilla/HoldDropJSObjects.h"
  10 #include "mozilla/dom/ScriptLoadContext.h"
  11
  12 #include "LoadedScript.h"
  13 #include "LoadContextBase.h"
  14 #include "ModuleLoaderBase.h"
  15
  16 namespace JS::loader {
  17
  18 #undef LOG
  19 #define LOG(args)                                                           \
  20   MOZ_LOG(ModuleLoaderBase::gModuleLoaderBaseLog, mozilla::LogLevel::Debug, \
  21           args)
  22
  23 NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED_0(ModuleLoadRequest,
  24                                                ScriptLoadRequest)
  25
  26 NS_IMPL_CYCLE_COLLECTION_CLASS(ModuleLoadRequest)
  27
  28 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(ModuleLoadRequest,
  29                                                 ScriptLoadRequest)
  30   if (tmp->mWaitingParentRequest) {
  31     tmp->mWaitingParentRequest->ChildModuleUnlinked();
  32   }
  33   NS_IMPL_CYCLE_COLLECTION_UNLINK(mLoader, mRootModule, mModuleScript, mImports,
  34                                   mWaitingParentRequest,
  35                                   mDynamicReferencingScript)
  36   tmp->ClearDynamicImport();
  37 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
  38
  39 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(ModuleLoadRequest,
  40                                                   ScriptLoadRequest)
  41   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLoader, mRootModule, mModuleScript,
  42                                     mImports, mWaitingParentRequest,
  43                                     mDynamicReferencingScript)
  44 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
  45
  46 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(ModuleLoadRequest,
  47                                                ScriptLoadRequest)
  48   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDynamicSpecifier)
  49   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDynamicPromise)
  50 NS_IMPL_CYCLE_COLLECTION_TRACE_END
  51
  52 /* static */
  53 VisitedURLSet* ModuleLoadRequest::NewVisitedSetForTopLevelImport(
  54     nsIURI* aURI, JS::ModuleType aModuleType) {
  55   auto set = new VisitedURLSet();
  56   set->PutEntry(ModuleMapKey(aURI, aModuleType));
  57   return set;
  58 }
  59
  60 ModuleLoadRequest::ModuleLoadRequest(
  61     nsIURI* aURI, JS::ModuleType aModuleType,
  62     mozilla::dom::ReferrerPolicy aReferrerPolicy,
  63     ScriptFetchOptions* aFetchOptions,
  64     const mozilla::dom::SRIMetadata& aIntegrity, nsIURI* aReferrer,
  65     LoadContextBase* aContext, bool aIsTopLevel, bool aIsDynamicImport,
  66     ModuleLoaderBase* aLoader, VisitedURLSet* aVisitedSet,
  67     ModuleLoadRequest* aRootModule)
  68     : ScriptLoadRequest(ScriptKind::eModule, aURI, aReferrerPolicy,
  69                         aFetchOptions, aIntegrity, aReferrer, aContext),
  70       mIsTopLevel(aIsTopLevel),
  71       mModuleType(aModuleType),
  72       mIsDynamicImport(aIsDynamicImport),
  73       mLoader(aLoader),
  74       mRootModule(aRootModule),
  75       mVisitedSet(aVisitedSet) {
  76   MOZ_ASSERT(mLoader);
  77 }
  78
  79 nsIGlobalObject* ModuleLoadRequest::GetGlobalObject() {
  80   return mLoader->GetGlobalObject();
  81 }
  82
  83 bool ModuleLoadRequest::IsErrored() const {
  84   return !mModuleScript || mModuleScript->HasParseError();
  85 }
  86
  87 void ModuleLoadRequest::Cancel() {
  88   if (IsCanceled()) {
  89     AssertAllImportsCancelled();
  90     return;
  91   }
  92
  93   if (IsFinished()) {
  94     return;
  95   }
  96
  97   ScriptLoadRequest::Cancel();
  98
  99   mModuleScript = nullptr;
 100   CancelImports();
 101
 102   if (mWaitingParentRequest) {
 103     ChildLoadComplete(false);
 104   }
 105 }
 106
 107 void ModuleLoadRequest::SetReady() {
 108   MOZ_ASSERT(!IsFinished());
 109
 110   // Mark a module as ready to execute. This means that this module and all it
 111   // dependencies have had their source loaded, parsed as a module and the
 112   // modules instantiated.
 113
 114   ScriptLoadRequest::SetReady();
 115
 116   if (mWaitingParentRequest) {
 117     ChildLoadComplete(true);
 118   }
 119 }
 120
 121 void ModuleLoadRequest::ModuleLoaded() {
 122   // A module that was found to be marked as fetching in the module map has now
 123   // been loaded.
 124
 125   LOG(("ScriptLoadRequest (%p): Module loaded", this));
 126
 127   if (IsCanceled()) {
 128     AssertAllImportsCancelled();
 129     return;
 130   }
 131
 132   MOZ_ASSERT(IsFetching() || IsPendingFetchingError());
 133
 134   mModuleScript = mLoader->GetFetchedModule(ModuleMapKey(mURI, mModuleType));
 135   if (IsErrored()) {
 136     ModuleErrored();
 137     return;
 138   }
 139
 140   mLoader->StartFetchingModuleDependencies(this);
 141 }
 142
 143 void ModuleLoadRequest::LoadFailed() {
 144   // We failed to load the source text or an error occurred unrelated to the
 145   // content of the module (e.g. OOM).
 146
 147   LOG(("ScriptLoadRequest (%p): Module load failed", this));
 148
 149   if (IsCanceled()) {
 150     AssertAllImportsCancelled();
 151     return;
 152   }
 153
 154   MOZ_ASSERT(IsFetching() || IsPendingFetchingError());
 155   MOZ_ASSERT(!mModuleScript);
 156
 157   Cancel();
 158   LoadFinished();
 159 }
 160
 161 void ModuleLoadRequest::ModuleErrored() {
 162   // Parse error, failure to resolve imported modules or error loading import.
 163
 164   LOG(("ScriptLoadRequest (%p): Module errored", this));
 165
 166   if (IsCanceled() || IsCancelingImports()) {
 167     return;
 168   }
 169
 170   MOZ_ASSERT(!IsFinished());
 171
 172   CheckModuleDependenciesLoaded();
 173   MOZ_ASSERT(IsErrored());
 174
 175   CancelImports();
 176   if (IsFinished()) {
 177     // Cancelling an outstanding import will error this request.
 178     return;
 179   }
 180
 181   SetReady();
 182   LoadFinished();
 183 }
 184
 185 void ModuleLoadRequest::DependenciesLoaded() {
 186   // The module and all of its dependencies have been successfully fetched and
 187   // compiled.
 188
 189   LOG(("ScriptLoadRequest (%p): Module dependencies loaded", this));
 190
 191   if (IsCanceled()) {
 192     return;
 193   }
 194
 195   MOZ_ASSERT(IsLoadingImports());
 196   MOZ_ASSERT(!IsErrored());
 197
 198   CheckModuleDependenciesLoaded();
 199   AssertAllImportsFinished();
 200   SetReady();
 201   LoadFinished();
 202 }
 203
 204 void ModuleLoadRequest::CheckModuleDependenciesLoaded() {
 205   LOG(("ScriptLoadRequest (%p): Check dependencies loaded", this));
 206
 207   if (!mModuleScript || mModuleScript->HasParseError()) {
 208     return;
 209   }
 210
 211   for (const auto& childRequest : mImports) {
 212     ModuleScript* childScript = childRequest->mModuleScript;
 213     if (!childScript) {
 214       mModuleScript = nullptr;
 215       LOG(("ScriptLoadRequest (%p):   %p failed (load error)", this,
 216            childRequest.get()));
 217       return;
 218     }
 219
 220     MOZ_DIAGNOSTIC_ASSERT(mModuleScript->HadImportMap() ==
 221                           childScript->HadImportMap());
 222   }
 223
 224   LOG(("ScriptLoadRequest (%p):   all ok", this));
 225 }
 226
 227 void ModuleLoadRequest::CancelImports() {
 228   State origState = mState;
 229
 230   // To prevent reentering ModuleErrored() for this request via mImports[i]'s
 231   // ChildLoadComplete().
 232   mState = State::CancelingImports;
 233
 234   for (size_t i = 0; i < mImports.Length(); i++) {
 235     if (mLoader->IsFetchingAndHasWaitingRequest(mImports[i])) {
 236       LOG(("CancelImports import %p is fetching and has waiting\n",
 237            mImports[i].get()));
 238       continue;
 239     }
 240     mImports[i]->Cancel();
 241   }
 242
 243   mState = origState;
 244 }
 245
 246 void ModuleLoadRequest::LoadFinished() {
 247   RefPtr<ModuleLoadRequest> request(this);
 248   if (IsTopLevel() && IsDynamicImport()) {
 249     mLoader->RemoveDynamicImport(request);
 250   }
 251
 252   mLoader->OnModuleLoadComplete(request);
 253 }
 254
 255 void ModuleLoadRequest::ChildModuleUnlinked() {
 256   // This module was waiting for a child request, but the child reqeust
 257   // got unlinked by CC and will never complete.
 258   // It also means this module itself is also in the cycle, and will be
 259   // unlinked or has already been unlinked, and will be collected.
 260   // There's no need to normally finish the module request.
 261   // Just reflect the awaiting imports count, so that the assertion in the
 262   // destructor passes.
 263   MOZ_ASSERT(mAwaitingImports > 0);
 264   mAwaitingImports--;
 265 }
 266
 267 void ModuleLoadRequest::SetDynamicImport(LoadedScript* aReferencingScript,
 268                                          JS::Handle<JSString*> aSpecifier,
 269                                          JS::Handle<JSObject*> aPromise) {
 270   mDynamicReferencingScript = aReferencingScript;
 271   mDynamicSpecifier = aSpecifier;
 272   mDynamicPromise = aPromise;
 273
 274   mozilla::HoldJSObjects(this);
 275 }
 276
 277 void ModuleLoadRequest::ClearDynamicImport() {
 278   mDynamicReferencingScript = nullptr;
 279   mDynamicSpecifier = nullptr;
 280   mDynamicPromise = nullptr;
 281 }
 282
 283 inline void ModuleLoadRequest::AssertAllImportsFinished() const {
 284 #ifdef DEBUG
 285   for (const auto& request : mImports) {
 286     MOZ_ASSERT(request->IsFinished());
 287   }
 288 #endif
 289 }
 290
 291 inline void ModuleLoadRequest::AssertAllImportsCancelled() const {
 292 #ifdef DEBUG
 293   for (const auto& request : mImports) {
 294     MOZ_ASSERT(request->IsCanceled());
 295   }
 296 #endif
 297 }
 298
 299 }  // namespace JS::loader