author Iain Ireland <>
Fri, 11 Jan 2019 18:05:36 +0000
changeset 453523 025feea5945bffc625e9cca2e23be51ee8670315
parent 448947 6f3709b3878117466168c40affa7bca0b60cf75b
child 472056 e1993a1f09ac53cd1a04fdf6a87f8cad8e44f73e
permissions -rw-r--r--
Bug 1480390: Move ForOfIterClose logic inside TryNoteIter r=tcampbell This patch was intended to be a pure refactoring of existing code with no side-effects, moving the logic for handling for-of/for-of-iterclose trynotes inside TryNoteIter to avoid duplicating logic in all users of TryNoteIter. However, it turns out that there was a subtle preexisting bug in TryNoteIter that is fixed by the refactoring. Specifically, the logic to skip from a for-of-iterclose to its enclosing for-of must run before the logic to skip trynotes based on stack depth. Otherwise, the stack depth code may filter out the enclosing for-of (see the attached test case for an example) and we will skip too many try-notes. Differential Revision:

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at */


#include "expat_config.h"
#include "expat.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "nsIDTD.h"
#include "nsITokenizer.h"
#include "nsIInputStream.h"
#include "nsIParser.h"
#include "nsCycleCollectionParticipant.h"

class nsIExpatSink;
struct nsCatalogData;

class nsExpatDriver : public nsIDTD, public nsITokenizer {
  virtual ~nsExpatDriver();



  int HandleExternalEntityRef(const char16_t *aOpenEntityNames,
                              const char16_t *aBase, const char16_t *aSystemId,
                              const char16_t *aPublicId);
  nsresult HandleStartElement(const char16_t *aName, const char16_t **aAtts);
  nsresult HandleEndElement(const char16_t *aName);
  nsresult HandleCharacterData(const char16_t *aCData, const uint32_t aLength);
  nsresult HandleComment(const char16_t *aName);
  nsresult HandleProcessingInstruction(const char16_t *aTarget,
                                       const char16_t *aData);
  nsresult HandleXMLDeclaration(const char16_t *aVersion,
                                const char16_t *aEncoding, int32_t aStandalone);
  nsresult HandleDefault(const char16_t *aData, const uint32_t aLength);
  nsresult HandleStartCdataSection();
  nsresult HandleEndCdataSection();
  nsresult HandleStartDoctypeDecl(const char16_t *aDoctypeName,
                                  const char16_t *aSysid,
                                  const char16_t *aPubid,
                                  bool aHasInternalSubset);
  nsresult HandleEndDoctypeDecl();

  // Load up an external stream to get external entity information
  nsresult OpenInputStreamFromExternalDTD(const char16_t *aFPIStr,
                                          const char16_t *aURLStr,
                                          const char16_t *aBaseURL,
                                          nsIInputStream **aStream,
                                          nsAString &aAbsURL);

   * Pass a buffer to Expat. If Expat is blocked aBuffer should be null and
   * aLength should be 0. The result of the call will be stored in
   * mInternalState. Expat will parse as much of the buffer as it can and store
   * the rest in its internal buffer.
   * @param aBuffer the buffer to pass to Expat. May be null.
   * @param aLength the length of the buffer to pass to Expat (in number of
   *                char16_t's). Must be 0 if aBuffer is null and > 0 if
   *                aBuffer is not null.
   * @param aIsFinal whether there will definitely not be any more new buffers
   *                 passed in to ParseBuffer
   * @param aConsumed [out] the number of PRUnichars that Expat consumed. This
   *                        doesn't include the PRUnichars that Expat stored in
   *                        its buffer but didn't parse yet.
  void ParseBuffer(const char16_t *aBuffer, uint32_t aLength, bool aIsFinal,
                   uint32_t *aConsumed);
  nsresult HandleError();

  void MaybeStopParser(nsresult aState);

  bool BlockedOrInterrupted() {
    return mInternalState == NS_ERROR_HTMLPARSER_BLOCK ||
           mInternalState == NS_ERROR_HTMLPARSER_INTERRUPTED;

  XML_Parser mExpatParser;
  nsString mLastLine;
  nsString mCDataText;
  // Various parts of a doctype
  nsString mDoctypeName;
  nsString mSystemID;
  nsString mPublicID;
  nsString mInternalSubset;
  bool mInCData;
  bool mInInternalSubset;
  bool mInExternalDTD;
  bool mMadeFinalCallToExpat;

  // Whether we're sure that we won't be getting more buffers to parse from
  // Necko
  bool mIsFinalChunk;

  nsresult mInternalState;

  // The length of the data in Expat's buffer (in number of PRUnichars).
  uint32_t mExpatBuffered;

  // These sinks all refer the same conceptual object. mOriginalSink is
  // identical with the nsIContentSink* passed to WillBuildModel, and exists
  // only to avoid QI-ing back to nsIContentSink*.
  nsCOMPtr<nsIContentSink> mOriginalSink;
  nsCOMPtr<nsIExpatSink> mSink;

  const nsCatalogData *mCatalogData;  // weak
  nsString mURISpec;

  // Used for error reporting.
  uint64_t mInnerWindowID;