dom/script/ScriptLoader.h

   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 #ifndef mozilla_dom_ScriptLoader_h
   8 #define mozilla_dom_ScriptLoader_h
   9
  10 #include "js/TypeDecls.h"
  11 #include "js/Utility.h"  // JS::FreePolicy
  12 #include "js/loader/LoadedScript.h"
  13 #include "js/loader/ScriptKind.h"
  14 #include "js/loader/ScriptLoadRequest.h"
  15 #include "mozilla/dom/ScriptLoadContext.h"
  16 #include "nsCOMPtr.h"
  17 #include "nsRefPtrHashtable.h"
  18 #include "nsIScriptElement.h"
  19 #include "nsCOMArray.h"
  20 #include "nsCycleCollectionParticipant.h"
  21 #include "nsTArray.h"
  22 #include "nsILoadInfo.h"  // nsSecurityFlags
  23 #include "nsINode.h"
  24 #include "nsIObserver.h"
  25 #include "nsIScriptLoaderObserver.h"
  26 #include "nsURIHashKey.h"
  27 #include "mozilla/CORSMode.h"
  28 #include "mozilla/dom/JSExecutionContext.h"  // JSExecutionContext
  29 #include "ModuleLoader.h"
  30 #include "mozilla/MaybeOneOf.h"
  31 #include "mozilla/MozPromise.h"
  32
  33 class nsCycleCollectionTraversalCallback;
  34 class nsIChannel;
  35 class nsIConsoleReportCollector;
  36 class nsIContent;
  37 class nsIIncrementalStreamLoader;
  38 class nsIPrincipal;
  39 class nsIScriptGlobalObject;
  40 class nsIURI;
  41
  42 namespace JS {
  43
  44 class CompileOptions;
  45
  46 template <typename UnitT>
  47 class SourceText;
  48
  49 namespace loader {
  50
  51 class LoadedScript;
  52 class ScriptLoaderInterface;
  53 class ModuleLoadRequest;
  54 class ModuleScript;
  55 class ScriptLoadRequest;
  56 class ScriptLoadRequestList;
  57
  58 enum class ParserMetadata;
  59
  60 }  // namespace loader
  61 }  // namespace JS
  62
  63 namespace mozilla {
  64
  65 class LazyLogModule;
  66 union Utf8Unit;
  67
  68 namespace dom {
  69
  70 class AutoJSAPI;
  71 class DocGroup;
  72 class Document;
  73 class ModuleLoader;
  74 class SRICheckDataVerifier;
  75 class SRIMetadata;
  76 class ScriptLoadHandler;
  77 class ScriptLoadContext;
  78 class ScriptLoader;
  79 class ScriptRequestProcessor;
  80
  81 enum class ReferrerPolicy : uint8_t;
  82 enum class RequestPriority : uint8_t;
  83
  84 class AsyncCompileShutdownObserver final : public nsIObserver {
  85   ~AsyncCompileShutdownObserver() { Unregister(); }
  86
  87  public:
  88   explicit AsyncCompileShutdownObserver(ScriptLoader* aLoader)
  89       : mScriptLoader(aLoader) {}
  90
  91   void OnShutdown();
  92   void Unregister();
  93
  94   NS_DECL_ISUPPORTS
  95   NS_DECL_NSIOBSERVER
  96
  97  private:
  98   // Defined during registration in ScriptLoader constructor, and
  99   // cleared during destructor, ScriptLoader::Destroy() or Shutdown.
 100   ScriptLoader* mScriptLoader;
 101 };
 102
 103 //////////////////////////////////////////////////////////////
 104 // Script loader implementation
 105 //////////////////////////////////////////////////////////////
 106
 107 class ScriptLoader final : public JS::loader::ScriptLoaderInterface {
 108   class MOZ_STACK_CLASS AutoCurrentScriptUpdater {
 109    public:
 110     AutoCurrentScriptUpdater(ScriptLoader* aScriptLoader,
 111                              nsIScriptElement* aCurrentScript)
 112         : mOldScript(aScriptLoader->mCurrentScript),
 113           mScriptLoader(aScriptLoader) {
 114       nsCOMPtr<nsINode> node = do_QueryInterface(aCurrentScript);
 115       mScriptLoader->mCurrentScript =
 116           node && !node->IsInShadowTree() ? aCurrentScript : nullptr;
 117     }
 118
 119     ~AutoCurrentScriptUpdater() {
 120       mScriptLoader->mCurrentScript.swap(mOldScript);
 121     }
 122
 123    private:
 124     nsCOMPtr<nsIScriptElement> mOldScript;
 125     ScriptLoader* mScriptLoader;
 126   };
 127
 128   friend class JS::loader::ModuleLoadRequest;
 129   friend class ScriptRequestProcessor;
 130   friend class ModuleLoader;
 131   friend class ScriptLoadHandler;
 132   friend class AutoCurrentScriptUpdater;
 133
 134  public:
 135   using MaybeSourceText =
 136       mozilla::MaybeOneOf<JS::SourceText<char16_t>, JS::SourceText<Utf8Unit>>;
 137
 138   explicit ScriptLoader(Document* aDocument);
 139
 140   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
 141   NS_DECL_CYCLE_COLLECTION_CLASS(ScriptLoader)
 142
 143   /**
 144    * Called when the document that owns this script loader changes global. The
 145    * argument is null when the document is detached from a window.
 146    */
 147   void SetGlobalObject(nsIGlobalObject* aGlobalObject);
 148
 149   /**
 150    * The loader maintains a weak reference to the document with
 151    * which it is initialized. This call forces the reference to
 152    * be dropped.
 153    */
 154   void DropDocumentReference() { mDocument = nullptr; }
 155
 156   /**
 157    * Add an observer for all scripts loaded through this loader.
 158    *
 159    * @param aObserver observer for all script processing.
 160    */
 161   nsresult AddObserver(nsIScriptLoaderObserver* aObserver) {
 162     return mObservers.AppendObject(aObserver) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
 163   }
 164
 165   /**
 166    * Remove an observer.
 167    *
 168    * @param aObserver observer to be removed
 169    */
 170   void RemoveObserver(nsIScriptLoaderObserver* aObserver) {
 171     mObservers.RemoveObject(aObserver);
 172   }
 173
 174   /**
 175    * Process a script element. This will include both loading the
 176    * source of the element if it is not inline and evaluating
 177    * the script itself.
 178    *
 179    * If the script is an inline script that can be executed immediately
 180    * (i.e. there are no other scripts pending) then ScriptAvailable
 181    * and ScriptEvaluated will be called before the function returns.
 182    *
 183    * If true is returned the script could not be executed immediately.
 184    * In this case ScriptAvailable is guaranteed to be called at a later
 185    * point (as well as possibly ScriptEvaluated).
 186    *
 187    * @param aElement The element representing the script to be loaded and
 188    *        evaluated.
 189    */
 190   bool ProcessScriptElement(nsIScriptElement* aElement);
 191
 192   /**
 193    * Gets the currently executing script. This is useful if you want to
 194    * generate a unique key based on the currently executing script.
 195    */
 196   nsIScriptElement* GetCurrentScript() { return mCurrentScript; }
 197
 198   nsIScriptElement* GetCurrentParserInsertedScript() {
 199     return mCurrentParserInsertedScript;
 200   }
 201
 202   /**
 203    * Whether the loader is enabled or not.
 204    * When disabled, processing of new script elements is disabled.
 205    * Any call to ProcessScriptElement() will return false. Note that
 206    * this DOES NOT disable currently loading or executing scripts.
 207    */
 208   bool GetEnabled() { return mEnabled; }
 209
 210   void SetEnabled(bool aEnabled) {
 211     if (!mEnabled && aEnabled) {
 212       ProcessPendingRequestsAsync();
 213     }
 214     mEnabled = aEnabled;
 215   }
 216
 217   ModuleLoader* GetModuleLoader() { return mModuleLoader; }
 218
 219   void RegisterContentScriptModuleLoader(ModuleLoader* aLoader);
 220   void RegisterShadowRealmModuleLoader(ModuleLoader* aLoader);
 221
 222   /**
 223    *  Check whether to speculatively OMT parse scripts as soon as
 224    *  they are fetched, even if not a parser blocking request.
 225    *  Controlled by
 226    *  dom.script_loader.external_scripts.speculative_omt_parse_enabled
 227    */
 228   bool SpeculativeOMTParsingEnabled() const {
 229     return mSpeculativeOMTParsingEnabled;
 230   }
 231
 232   /**
 233    * Add/remove a blocker for parser-blocking scripts (and XSLT
 234    * scripts). Blockers will stop such scripts from executing, but not from
 235    * loading.
 236    */
 237   void AddParserBlockingScriptExecutionBlocker() {
 238     ++mParserBlockingBlockerCount;
 239   }
 240
 241   void RemoveParserBlockingScriptExecutionBlocker() {
 242     if (!--mParserBlockingBlockerCount && ReadyToExecuteScripts()) {
 243       ProcessPendingRequestsAsync();
 244     }
 245   }
 246
 247   /**
 248    * Add/remove a blocker for execution of all scripts.  Blockers will stop
 249    * scripts from executing, but not from loading.
 250    */
 251   void AddExecuteBlocker() { ++mBlockerCount; }
 252
 253   void RemoveExecuteBlocker() {
 254     MOZ_ASSERT(mBlockerCount);
 255     if (!--mBlockerCount) {
 256       ProcessPendingRequestsAsync();
 257     }
 258   }
 259
 260   /**
 261    * Convert the given buffer to a UTF-16 string.  If the buffer begins with a
 262    * BOM, it is interpreted as that encoding; otherwise the first of |aChannel|,
 263    * |aHintCharset|, or |aDocument| that provides a recognized encoding is used,
 264    * or Windows-1252 if none of them do.
 265    *
 266    * Encoding errors in the buffer are converted to replacement characters, so
 267    * allocation failure is the only way this function can fail.
 268    *
 269    * @param aChannel     Channel corresponding to the data. May be null.
 270    * @param aData        The data to convert
 271    * @param aLength      Length of the data
 272    * @param aHintCharset Character set hint (e.g., from a charset attribute).
 273    * @param aDocument    Document which the data is loaded for. May be null.
 274    * @param aBufOut      [out] fresh char16_t array containing data converted to
 275    *                     Unicode.
 276    * @param aLengthOut   [out] Length of array returned in aBufOut in number
 277    *                     of char16_t code units.
 278    */
 279   static nsresult ConvertToUTF16(nsIChannel* aChannel, const uint8_t* aData,
 280                                  uint32_t aLength,
 281                                  const nsAString& aHintCharset,
 282                                  Document* aDocument,
 283                                  UniquePtr<char16_t[], JS::FreePolicy>& aBufOut,
 284                                  size_t& aLengthOut);
 285
 286   /**
 287    * Convert the given buffer to a UTF-8 string.  If the buffer begins with a
 288    * BOM, it is interpreted as that encoding; otherwise the first of |aChannel|,
 289    * |aHintCharset|, or |aDocument| that provides a recognized encoding is used,
 290    * or Windows-1252 if none of them do.
 291    *
 292    * Encoding errors in the buffer are converted to replacement characters, so
 293    * allocation failure is the only way this function can fail.
 294    *
 295    * @param aChannel     Channel corresponding to the data. May be null.
 296    * @param aData        The data to convert
 297    * @param aLength      Length of the data
 298    * @param aHintCharset Character set hint (e.g., from a charset attribute).
 299    * @param aDocument    Document which the data is loaded for. May be null.
 300    * @param aBufOut      [out] fresh Utf8Unit array containing data converted to
 301    *                     Unicode.
 302    * @param aLengthOut   [out] Length of array returned in aBufOut in UTF-8 code
 303    *                     units (i.e. in bytes).
 304    */
 305   static nsresult ConvertToUTF8(nsIChannel* aChannel, const uint8_t* aData,
 306                                 uint32_t aLength, const nsAString& aHintCharset,
 307                                 Document* aDocument,
 308                                 UniquePtr<Utf8Unit[], JS::FreePolicy>& aBufOut,
 309                                 size_t& aLengthOut);
 310
 311   /**
 312    * Handle the completion of a stream.  This is called by the
 313    * ScriptLoadHandler object which observes the IncrementalStreamLoader
 314    * loading the script. The streamed content is expected to be stored on the
 315    * aRequest argument.
 316    */
 317   nsresult OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
 318                             ScriptLoadRequest* aRequest,
 319                             nsresult aChannelStatus, nsresult aSRIStatus,
 320                             SRICheckDataVerifier* aSRIDataVerifier);
 321
 322   /**
 323    * Returns wether any request is queued, and not executed yet.
 324    */
 325   bool HasPendingRequests() const;
 326
 327   /**
 328    * Returns wether there are any dynamic module import requests pending.
 329    */
 330   bool HasPendingDynamicImports() const;
 331
 332   /**
 333    * Processes any pending requests that are ready for processing.
 334    */
 335   void ProcessPendingRequests();
 336
 337   /**
 338    * Starts deferring deferred scripts and puts them in the mDeferredRequests
 339    * queue instead.
 340    */
 341   void BeginDeferringScripts();
 342
 343   /**
 344    * Notifies the script loader that parsing is done.  If aTerminated is true,
 345    * this will drop any pending scripts that haven't run yet, otherwise it will
 346    * do nothing.
 347    */
 348   void ParsingComplete(bool aTerminated);
 349
 350   /**
 351    * Notifies the script loader that the checkpoint to begin execution of defer
 352    * scripts has been reached. This is either the end of of the document parse
 353    * or the end of loading of parser-inserted stylesheets, whatever happens
 354    * last.
 355    *
 356    * Otherwise, it will stop deferring scripts and immediately processes the
 357    * mDeferredRequests queue.
 358    *
 359    * WARNING: This function will synchronously execute content scripts, so be
 360    * prepared that the world might change around you.
 361    */
 362   void DeferCheckpointReached();
 363
 364   /**
 365    * Returns the number of pending scripts, deferred or not.
 366    */
 367   uint32_t HasPendingOrCurrentScripts() {
 368     return mCurrentScript || mParserBlockingRequest;
 369   }
 370
 371   /**
 372    * Adds aURI to the preload list and starts loading it.
 373    *
 374    * @param aURI The URI of the external script.
 375    * @param aCharset The charset parameter for the script.
 376    * @param aType The type parameter for the script.
 377    * @param aCrossOrigin The crossorigin attribute for the script.
 378    *                     Void if not present.
 379    * @param aFetchPriority
 380    * <https://html.spec.whatwg.org/#the-script-element:attr-script-fetchpriority>.
 381    * @param aIntegrity The expect hash url, if avail, of the request
 382
 383    * @param aScriptFromHead Whether or not the script was a child of head
 384    */
 385   virtual void PreloadURI(nsIURI* aURI, const nsAString& aCharset,
 386                           const nsAString& aType, const nsAString& aCrossOrigin,
 387                           const nsAString& aNonce,
 388                           const nsAString& aFetchPriority,
 389                           const nsAString& aIntegrity, bool aScriptFromHead,
 390                           bool aAsync, bool aDefer, bool aLinkPreload,
 391                           const ReferrerPolicy aReferrerPolicy,
 392                           uint64_t aEarlyHintPreloaderId);
 393
 394   /**
 395    * Process a request that was deferred so that the script could be compiled
 396    * off thread.
 397    */
 398   nsresult ProcessOffThreadRequest(ScriptLoadRequest* aRequest);
 399
 400   bool AddPendingChildLoader(ScriptLoader* aChild) {
 401     // XXX(Bug 1631371) Check if this should use a fallible operation as it
 402     // pretended earlier. Else, change the return type to void.
 403     mPendingChildLoaders.AppendElement(aChild);
 404     return true;
 405   }
 406
 407   mozilla::dom::DocGroup* GetDocGroup() const;
 408
 409   /**
 410    * Register the fact that we saw the load event, and that we need to save the
 411    * bytecode at the next loop cycle unless new scripts are waiting in the
 412    * pipeline.
 413    */
 414   void LoadEventFired();
 415
 416   /**
 417    * Destroy and prevent the ScriptLoader or the ScriptLoadRequests from owning
 418    * any references to the JSScript or to the Request which might be used for
 419    * caching the encoded bytecode.
 420    */
 421   void Destroy();
 422
 423   /*
 424    * Get the currently active script. This is used as the initiating script when
 425    * executing timeout handler scripts.
 426    */
 427   static JS::loader::LoadedScript* GetActiveScript(JSContext* aCx);
 428
 429   Document* GetDocument() const { return mDocument; }
 430
 431   nsIURI* GetBaseURI() const override;
 432
 433  private:
 434   ~ScriptLoader();
 435
 436   already_AddRefed<ScriptLoadRequest> CreateLoadRequest(
 437       ScriptKind aKind, nsIURI* aURI, nsIScriptElement* aElement,
 438       nsIPrincipal* aTriggeringPrincipal, mozilla::CORSMode aCORSMode,
 439       const nsAString& aNonce, RequestPriority aRequestPriority,
 440       const SRIMetadata& aIntegrity, ReferrerPolicy aReferrerPolicy,
 441       JS::loader::ParserMetadata aParserMetadata);
 442
 443   /**
 444    * Unblocks the creator parser of the parser-blocking scripts.
 445    */
 446   void UnblockParser(ScriptLoadRequest* aParserBlockingRequest);
 447
 448   /**
 449    * Asynchronously resumes the creator parser of the parser-blocking scripts.
 450    */
 451   void ContinueParserAsync(ScriptLoadRequest* aParserBlockingRequest);
 452
 453   bool ProcessExternalScript(nsIScriptElement* aElement, ScriptKind aScriptKind,
 454                              nsIContent* aScriptContent);
 455
 456   bool ProcessInlineScript(nsIScriptElement* aElement, ScriptKind aScriptKind);
 457
 458   JS::loader::ScriptLoadRequest* LookupPreloadRequest(
 459       nsIScriptElement* aElement, ScriptKind aScriptKind,
 460       const SRIMetadata& aSRIMetadata);
 461
 462   void GetSRIMetadata(const nsAString& aIntegrityAttr,
 463                       SRIMetadata* aMetadataOut);
 464
 465   /**
 466    * Given a script element, get the referrer policy should be applied to load
 467    * requests.
 468    */
 469   ReferrerPolicy GetReferrerPolicy(nsIScriptElement* aElement);
 470
 471   /**
 472    * Helper function to check the content policy for a given request.
 473    */
 474   static nsresult CheckContentPolicy(Document* aDocument,
 475                                      nsIScriptElement* aElement,
 476                                      const nsAString& aNonce,
 477                                      ScriptLoadRequest* aRequest);
 478
 479   /**
 480    * Helper function to determine whether an about: page loads a chrome: URI.
 481    * Please note that this function only returns true if:
 482    *   * the about: page uses a ContentPrincipal with scheme about:
 483    *   * the about: page is not linkable from content
 484    *     (e.g. the function will return false for about:blank or about:srcdoc)
 485    */
 486   static bool IsAboutPageLoadingChromeURI(ScriptLoadRequest* aRequest,
 487                                           Document* aDocument);
 488
 489   /**
 490    * Start a load for aRequest's URI.
 491    */
 492   nsresult StartLoad(ScriptLoadRequest* aRequest,
 493                      const Maybe<nsAutoString>& aCharsetForPreload);
 494   /**
 495    * Start a load for a classic script URI.
 496    * Sets up the necessary security flags before calling StartLoadInternal.
 497    */
 498   nsresult StartClassicLoad(ScriptLoadRequest* aRequest,
 499                             const Maybe<nsAutoString>& aCharsetForPreload);
 500
 501   static void PrepareCacheInfoChannel(nsIChannel* aChannel,
 502                                       ScriptLoadRequest* aRequest);
 503
 504   static void PrepareRequestPriorityAndRequestDependencies(
 505       nsIChannel* aChannel, ScriptLoadRequest* aRequest);
 506
 507   [[nodiscard]] static nsresult PrepareHttpRequestAndInitiatorType(
 508       nsIChannel* aChannel, ScriptLoadRequest* aRequest,
 509       const Maybe<nsAutoString>& aCharsetForPreload);
 510
 511   [[nodiscard]] nsresult PrepareIncrementalStreamLoader(
 512       nsIIncrementalStreamLoader** aOutLoader, ScriptLoadRequest* aRequest);
 513
 514   /**
 515    * Start a load for a script (module or classic) URI.
 516    *
 517    * aCharsetForPreload is only needed when this load is a preload (via
 518    * ScriptLoader::PreloadURI), because ScriptLoadRequest doesn't
 519    * have this information.
 520    */
 521   nsresult StartLoadInternal(ScriptLoadRequest* aRequest,
 522                              nsSecurityFlags securityFlags,
 523                              const Maybe<nsAutoString>& aCharsetForPreload);
 524
 525   /**
 526    * Abort the current stream, and re-start with a new load request from scratch
 527    * without requesting any alternate data. Returns NS_BINDING_RETARGETED on
 528    * success, as this error code is used to abort the input stream.
 529    */
 530   nsresult RestartLoad(ScriptLoadRequest* aRequest);
 531
 532   void HandleLoadError(ScriptLoadRequest* aRequest, nsresult aResult);
 533
 534   /**
 535    * Process any pending requests asynchronously (i.e. off an event) if there
 536    * are any. Note that this is a no-op if there aren't any currently pending
 537    * requests.
 538    *
 539    * This function is virtual to allow cross-library calls to SetEnabled()
 540    */
 541   virtual void ProcessPendingRequestsAsync();
 542
 543   /**
 544    * If true, the loader is ready to execute parser-blocking scripts, and so are
 545    * all its ancestors.  If the loader itself is ready but some ancestor is not,
 546    * this function will add an execute blocker and ask the ancestor to remove it
 547    * once it becomes ready.
 548    */
 549   bool ReadyToExecuteParserBlockingScripts();
 550
 551   /**
 552    * Return whether just this loader is ready to execute parser-blocking
 553    * scripts.
 554    */
 555   bool SelfReadyToExecuteParserBlockingScripts() {
 556     return ReadyToExecuteScripts() && !mParserBlockingBlockerCount;
 557   }
 558
 559   /**
 560    * Return whether this loader is ready to execute scripts in general.
 561    */
 562   bool ReadyToExecuteScripts() { return mEnabled && !mBlockerCount; }
 563
 564   nsresult VerifySRI(ScriptLoadRequest* aRequest,
 565                      nsIIncrementalStreamLoader* aLoader, nsresult aSRIStatus,
 566                      SRICheckDataVerifier* aSRIDataVerifier) const;
 567
 568   nsresult SaveSRIHash(ScriptLoadRequest* aRequest,
 569                        SRICheckDataVerifier* aSRIDataVerifier) const;
 570
 571   void ReportErrorToConsole(ScriptLoadRequest* aRequest,
 572                             nsresult aResult) const override;
 573
 574   void ReportWarningToConsole(
 575       ScriptLoadRequest* aRequest, const char* aMessageName,
 576       const nsTArray<nsString>& aParams = nsTArray<nsString>()) const override;
 577
 578   void ReportPreloadErrorsToConsole(ScriptLoadRequest* aRequest);
 579
 580   nsresult AttemptOffThreadScriptCompile(ScriptLoadRequest* aRequest,
 581                                          bool* aCouldCompileOut);
 582
 583   nsresult CreateOffThreadTask(JSContext* aCx, ScriptLoadRequest* aRequest,
 584                                JS::CompileOptions& aOptions,
 585                                CompileOrDecodeTask** aCompileOrDecodeTask);
 586
 587   nsresult ProcessRequest(ScriptLoadRequest* aRequest);
 588   nsresult CompileOffThreadOrProcessRequest(ScriptLoadRequest* aRequest);
 589   void FireScriptAvailable(nsresult aResult, ScriptLoadRequest* aRequest);
 590   // TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230)
 591   MOZ_CAN_RUN_SCRIPT_BOUNDARY void FireScriptEvaluated(
 592       nsresult aResult, ScriptLoadRequest* aRequest);
 593
 594   // Implements https://html.spec.whatwg.org/#execute-the-script-block
 595   nsresult EvaluateScriptElement(ScriptLoadRequest* aRequest);
 596
 597   // Handles both bytecode and text source scripts; populates exec with a
 598   // compiled script
 599   nsresult CompileOrDecodeClassicScript(JSContext* aCx,
 600                                         JSExecutionContext& aExec,
 601                                         ScriptLoadRequest* aRequest);
 602
 603   static nsCString& BytecodeMimeTypeFor(ScriptLoadRequest* aRequest);
 604
 605   // Decide whether to encode bytecode for given script load request,
 606   // and store the script into the request if necessary.
 607   //
 608   // This method must be called before executing the script.
 609   void MaybePrepareForBytecodeEncodingBeforeExecute(
 610       ScriptLoadRequest* aRequest, JS::Handle<JSScript*> aScript);
 611
 612   // Queue the script load request for bytecode encoding if we decided to
 613   // encode, or cleanup the script load request fields otherwise.
 614   //
 615   // This method must be called after executing the script.
 616   nsresult MaybePrepareForBytecodeEncodingAfterExecute(
 617       ScriptLoadRequest* aRequest, nsresult aRv);
 618
 619   // Returns true if MaybePrepareForBytecodeEncodingAfterExecute is called
 620   // for given script load request.
 621   bool IsAlreadyHandledForBytecodeEncodingPreparation(
 622       ScriptLoadRequest* aRequest);
 623
 624   void MaybePrepareModuleForBytecodeEncodingBeforeExecute(
 625       JSContext* aCx, ModuleLoadRequest* aRequest) override;
 626
 627   nsresult MaybePrepareModuleForBytecodeEncodingAfterExecute(
 628       ModuleLoadRequest* aRequest, nsresult aRv) override;
 629
 630   // Implements https://html.spec.whatwg.org/#run-a-classic-script
 631   nsresult EvaluateScript(nsIGlobalObject* aGlobalObject,
 632                           ScriptLoadRequest* aRequest);
 633
 634   /**
 635    * Queue the current script load request to be saved, when the page
 636    * initialization ends. The page initialization end is defined as being the
 637    * time when the load event got received, and when no more scripts are waiting
 638    * to be executed.
 639    */
 640   void RegisterForBytecodeEncoding(ScriptLoadRequest* aRequest);
 641
 642   /**
 643    * Check if all conditions are met, i-e that the onLoad event fired and that
 644    * no more script have to be processed.  If all conditions are met, queue an
 645    * event to encode all the bytecode and save them on the cache.
 646    */
 647   void MaybeTriggerBytecodeEncoding() override;
 648
 649   /**
 650    * Iterate over all script load request and save the bytecode of executed
 651    * functions on the cache provided by the channel.
 652    */
 653   void EncodeBytecode();
 654   void EncodeRequestBytecode(JSContext* aCx, ScriptLoadRequest* aRequest);
 655
 656   void GiveUpBytecodeEncoding();
 657
 658   already_AddRefed<nsIGlobalObject> GetGlobalForRequest(
 659       ScriptLoadRequest* aRequest);
 660
 661   already_AddRefed<nsIScriptGlobalObject> GetScriptGlobalObject();
 662
 663   // Fill in CompileOptions, as well as produce the introducer script for
 664   // subsequent calls to UpdateDebuggerMetadata
 665   nsresult FillCompileOptionsForRequest(
 666       JSContext* aCx, ScriptLoadRequest* aRequest, JS::CompileOptions* aOptions,
 667       JS::MutableHandle<JSScript*> aIntroductionScript) override;
 668
 669   uint32_t NumberOfProcessors();
 670   int32_t PhysicalSizeOfMemoryInGB();
 671
 672   nsresult PrepareLoadedRequest(ScriptLoadRequest* aRequest,
 673                                 nsIIncrementalStreamLoader* aLoader,
 674                                 nsresult aStatus);
 675
 676   void AddDeferRequest(ScriptLoadRequest* aRequest);
 677   void AddAsyncRequest(ScriptLoadRequest* aRequest);
 678   bool MaybeRemovedDeferRequests();
 679
 680   bool ShouldApplyDelazifyStrategy(ScriptLoadRequest* aRequest);
 681   void ApplyDelazifyStrategy(JS::CompileOptions* aOptions);
 682
 683   bool ShouldCompileOffThread(ScriptLoadRequest* aRequest);
 684
 685   void MaybeMoveToLoadedList(ScriptLoadRequest* aRequest);
 686
 687   // Returns wether we should save the bytecode of this script after the
 688   // execution of the script.
 689   static bool ShouldCacheBytecode(ScriptLoadRequest* aRequest);
 690
 691   void RunScriptWhenSafe(ScriptLoadRequest* aRequest);
 692
 693   /**
 694    * Cancel and remove all outstanding load requests, including waiting for any
 695    * off thread compilations to finish.
 696    */
 697   void CancelAndClearScriptLoadRequests();
 698
 699   Document* mDocument;  // [WEAK]
 700   nsCOMArray<nsIScriptLoaderObserver> mObservers;
 701   ScriptLoadRequestList mNonAsyncExternalScriptInsertedRequests;
 702   // mLoadingAsyncRequests holds async requests while they're loading; when they
 703   // have been loaded they are moved to mLoadedAsyncRequests.
 704   ScriptLoadRequestList mLoadingAsyncRequests;
 705   // mLoadedAsyncRequests holds async script requests and dynamic module import
 706   // requests, which are processed in the same way.
 707   ScriptLoadRequestList mLoadedAsyncRequests;
 708   ScriptLoadRequestList mDeferRequests;
 709   ScriptLoadRequestList mXSLTRequests;
 710   RefPtr<ScriptLoadRequest> mParserBlockingRequest;
 711   ScriptLoadRequestList mOffThreadCompilingRequests;
 712
 713   // List of script load request that are holding a buffer which has to be saved
 714   // on the cache.
 715   ScriptLoadRequestList mBytecodeEncodingQueue;
 716
 717   // In mRequests, the additional information here is stored by the element.
 718   struct PreloadInfo {
 719     RefPtr<ScriptLoadRequest> mRequest;
 720     nsString mCharset;
 721   };
 722
 723   friend void ImplCycleCollectionUnlink(ScriptLoader::PreloadInfo& aField);
 724   friend void ImplCycleCollectionTraverse(
 725       nsCycleCollectionTraversalCallback& aCallback,
 726       ScriptLoader::PreloadInfo& aField, const char* aName, uint32_t aFlags);
 727
 728   struct PreloadRequestComparator {
 729     bool Equals(const PreloadInfo& aPi,
 730                 ScriptLoadRequest* const& aRequest) const {
 731       return aRequest == aPi.mRequest;
 732     }
 733   };
 734
 735   struct PreloadURIComparator {
 736     bool Equals(const PreloadInfo& aPi, nsIURI* const& aURI) const;
 737   };
 738
 739   nsTArray<PreloadInfo> mPreloads;
 740
 741   nsCOMPtr<nsIScriptElement> mCurrentScript;
 742   nsCOMPtr<nsIScriptElement> mCurrentParserInsertedScript;
 743   nsTArray<RefPtr<ScriptLoader>> mPendingChildLoaders;
 744   uint32_t mParserBlockingBlockerCount;
 745   uint32_t mBlockerCount;
 746   uint32_t mNumberOfProcessors;
 747   uint32_t mTotalFullParseSize;
 748   int32_t mPhysicalSizeOfMemory;
 749   bool mEnabled;
 750   bool mDeferEnabled;
 751   bool mSpeculativeOMTParsingEnabled;
 752   bool mDeferCheckpointReached;
 753   bool mBlockingDOMContentLoaded;
 754   bool mLoadEventFired;
 755   bool mGiveUpEncoding;
 756
 757   TimeDuration mMainThreadParseTime;
 758
 759   nsCOMPtr<nsIConsoleReportCollector> mReporter;
 760
 761   // ShutdownObserver for off thread compilations
 762   RefPtr<AsyncCompileShutdownObserver> mShutdownObserver;
 763
 764   RefPtr<ModuleLoader> mModuleLoader;
 765   nsTArray<RefPtr<ModuleLoader>> mWebExtModuleLoaders;
 766   nsTArray<RefPtr<ModuleLoader>> mShadowRealmModuleLoaders;
 767
 768   // Logging
 769  public:
 770   static LazyLogModule gCspPRLog;
 771   static LazyLogModule gScriptLoaderLog;
 772 };
 773
 774 class nsAutoScriptLoaderDisabler {
 775  public:
 776   explicit nsAutoScriptLoaderDisabler(Document* aDoc);
 777
 778   ~nsAutoScriptLoaderDisabler();
 779
 780   bool mWasEnabled;
 781   RefPtr<ScriptLoader> mLoader;
 782 };
 783
 784 }  // namespace dom
 785 }  // namespace mozilla
 786
 787 #endif  // mozilla_dom_ScriptLoader_h