src/third_party/WebKit/Source/core/html/parser/HTMLTokenizer.h

   1 /*
   2  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
   3  * Copyright (C) 2010 Google, Inc. All Rights Reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef HTMLTokenizer_h
  28 #define HTMLTokenizer_h
  29
  30 #include "core/html/parser/HTMLParserOptions.h"
  31 #include "core/html/parser/HTMLToken.h"
  32 #include "core/html/parser/InputStreamPreprocessor.h"
  33 #include "platform/text/SegmentedString.h"
  34
  35 namespace blink {
  36
  37 class HTMLTokenizer {
  38     WTF_MAKE_NONCOPYABLE(HTMLTokenizer);
  39     WTF_MAKE_FAST_ALLOCATED;
  40 public:
  41     static PassOwnPtr<HTMLTokenizer> create(const HTMLParserOptions& options) { return adoptPtr(new HTMLTokenizer(options)); }
  42     ~HTMLTokenizer();
  43
  44     void reset();
  45
  46     enum State {
  47         DataState,
  48         CharacterReferenceInDataState,
  49         RCDATAState,
  50         CharacterReferenceInRCDATAState,
  51         RAWTEXTState,
  52         ScriptDataState,
  53         PLAINTEXTState,
  54         TagOpenState,
  55         EndTagOpenState,
  56         TagNameState,
  57         RCDATALessThanSignState,
  58         RCDATAEndTagOpenState,
  59         RCDATAEndTagNameState,
  60         RAWTEXTLessThanSignState,
  61         RAWTEXTEndTagOpenState,
  62         RAWTEXTEndTagNameState,
  63         ScriptDataLessThanSignState,
  64         ScriptDataEndTagOpenState,
  65         ScriptDataEndTagNameState,
  66         ScriptDataEscapeStartState,
  67         ScriptDataEscapeStartDashState,
  68         ScriptDataEscapedState,
  69         ScriptDataEscapedDashState,
  70         ScriptDataEscapedDashDashState,
  71         ScriptDataEscapedLessThanSignState,
  72         ScriptDataEscapedEndTagOpenState,
  73         ScriptDataEscapedEndTagNameState,
  74         ScriptDataDoubleEscapeStartState,
  75         ScriptDataDoubleEscapedState,
  76         ScriptDataDoubleEscapedDashState,
  77         ScriptDataDoubleEscapedDashDashState,
  78         ScriptDataDoubleEscapedLessThanSignState,
  79         ScriptDataDoubleEscapeEndState,
  80         BeforeAttributeNameState,
  81         AttributeNameState,
  82         AfterAttributeNameState,
  83         BeforeAttributeValueState,
  84         AttributeValueDoubleQuotedState,
  85         AttributeValueSingleQuotedState,
  86         AttributeValueUnquotedState,
  87         CharacterReferenceInAttributeValueState,
  88         AfterAttributeValueQuotedState,
  89         SelfClosingStartTagState,
  90         BogusCommentState,
  91         // The ContinueBogusCommentState is not in the HTML5 spec, but we use
  92         // it internally to keep track of whether we've started the bogus
  93         // comment token yet.
  94         ContinueBogusCommentState,
  95         MarkupDeclarationOpenState,
  96         CommentStartState,
  97         CommentStartDashState,
  98         CommentState,
  99         CommentEndDashState,
 100         CommentEndState,
 101         CommentEndBangState,
 102         DOCTYPEState,
 103         BeforeDOCTYPENameState,
 104         DOCTYPENameState,
 105         AfterDOCTYPENameState,
 106         AfterDOCTYPEPublicKeywordState,
 107         BeforeDOCTYPEPublicIdentifierState,
 108         DOCTYPEPublicIdentifierDoubleQuotedState,
 109         DOCTYPEPublicIdentifierSingleQuotedState,
 110         AfterDOCTYPEPublicIdentifierState,
 111         BetweenDOCTYPEPublicAndSystemIdentifiersState,
 112         AfterDOCTYPESystemKeywordState,
 113         BeforeDOCTYPESystemIdentifierState,
 114         DOCTYPESystemIdentifierDoubleQuotedState,
 115         DOCTYPESystemIdentifierSingleQuotedState,
 116         AfterDOCTYPESystemIdentifierState,
 117         BogusDOCTYPEState,
 118         CDATASectionState,
 119         // These CDATA states are not in the HTML5 spec, but we use them internally.
 120         CDATASectionRightSquareBracketState,
 121         CDATASectionDoubleRightSquareBracketState,
 122     };
 123
 124     struct Checkpoint {
 125         HTMLParserOptions options;
 126         State state;
 127         UChar additionalAllowedCharacter;
 128         bool skipNextNewLine;
 129         bool shouldAllowCDATA;
 130
 131         Checkpoint()
 132             : options(0)
 133             , state()
 134             , additionalAllowedCharacter('\0')
 135             , skipNextNewLine(false)
 136             , shouldAllowCDATA(false)
 137         {
 138         }
 139     };
 140
 141     bool canCreateCheckpoint() const;
 142     void createCheckpoint(Checkpoint&) const;
 143     void restoreFromCheckpoint(const Checkpoint&);
 144
 145     // This function returns true if it emits a token. Otherwise, callers
 146     // must provide the same (in progress) token on the next call (unless
 147     // they call reset() first).
 148     bool nextToken(SegmentedString&, HTMLToken&);
 149
 150     // Returns a copy of any characters buffered internally by the tokenizer.
 151     // The tokenizer buffers characters when searching for the </script> token
 152     // that terminates a script element.
 153     String bufferedCharacters() const;
 154
 155     size_t numberOfBufferedCharacters() const
 156     {
 157         // Notice that we add 2 to the length of the m_temporaryBuffer to
 158         // account for the "</" characters, which are effecitvely buffered in
 159         // the tokenizer's state machine.
 160         return m_temporaryBuffer.size() ? m_temporaryBuffer.size() + 2 : 0;
 161     }
 162
 163     // Updates the tokenizer's state according to the given tag name. This is
 164     // an approximation of how the tree builder would update the tokenizer's
 165     // state. This method is useful for approximating HTML tokenization. To
 166     // get exactly the correct tokenization, you need the real tree builder.
 167     //
 168     // The main failures in the approximation are as follows:
 169     //
 170     //  * The first set of character tokens emitted for a <pre> element might
 171     //    contain an extra leading newline.
 172     //  * The replacement of U+0000 with U+FFFD will not be sensitive to the
 173     //    tree builder's insertion mode.
 174     //  * CDATA sections in foreign content will be tokenized as bogus comments
 175     //    instead of as character tokens.
 176     //
 177     void updateStateFor(const String& tagName);
 178
 179     bool forceNullCharacterReplacement() const { return m_forceNullCharacterReplacement; }
 180     void setForceNullCharacterReplacement(bool value) { m_forceNullCharacterReplacement = value; }
 181
 182     bool shouldAllowCDATA() const { return m_shouldAllowCDATA; }
 183     void setShouldAllowCDATA(bool value) { m_shouldAllowCDATA = value; }
 184
 185     State state() const { return m_state; }
 186     void setState(State state) { m_state = state; }
 187
 188     inline bool shouldSkipNullCharacters() const
 189     {
 190         return !m_forceNullCharacterReplacement
 191             && (m_state == HTMLTokenizer::DataState
 192                 || m_state == HTMLTokenizer::RCDATAState
 193                 || m_state == HTMLTokenizer::RAWTEXTState);
 194     }
 195
 196 private:
 197     explicit HTMLTokenizer(const HTMLParserOptions&);
 198
 199     inline bool processEntity(SegmentedString&);
 200
 201     inline void parseError();
 202
 203     inline void bufferCharacter(UChar character)
 204     {
 205         ASSERT(character != kEndOfFileMarker);
 206         m_token->ensureIsCharacterToken();
 207         m_token->appendToCharacter(character);
 208     }
 209
 210     inline bool emitAndResumeIn(SegmentedString& source, State state)
 211     {
 212         saveEndTagNameIfNeeded();
 213         m_state = state;
 214         source.advanceAndUpdateLineNumber();
 215         return true;
 216     }
 217
 218     inline bool emitAndReconsumeIn(SegmentedString&, State state)
 219     {
 220         saveEndTagNameIfNeeded();
 221         m_state = state;
 222         return true;
 223     }
 224
 225     inline bool emitEndOfFile(SegmentedString& source)
 226     {
 227         if (haveBufferedCharacterToken())
 228             return true;
 229         m_state = HTMLTokenizer::DataState;
 230         source.advanceAndUpdateLineNumber();
 231         m_token->clear();
 232         m_token->makeEndOfFile();
 233         return true;
 234     }
 235
 236     inline bool flushEmitAndResumeIn(SegmentedString&, State);
 237
 238     // Return whether we need to emit a character token before dealing with
 239     // the buffered end tag.
 240     inline bool flushBufferedEndTag(SegmentedString&);
 241     inline bool temporaryBufferIs(const String&);
 242
 243     // Sometimes we speculatively consume input characters and we don't
 244     // know whether they represent end tags or RCDATA, etc. These
 245     // functions help manage these state.
 246     inline void addToPossibleEndTag(LChar cc);
 247
 248     inline void saveEndTagNameIfNeeded()
 249     {
 250         ASSERT(m_token->type() != HTMLToken::Uninitialized);
 251         if (m_token->type() == HTMLToken::StartTag)
 252             m_appropriateEndTagName = m_token->name();
 253     }
 254     inline bool isAppropriateEndTag();
 255
 256
 257     inline bool haveBufferedCharacterToken()
 258     {
 259         return m_token->type() == HTMLToken::Character;
 260     }
 261
 262     State m_state;
 263     bool m_forceNullCharacterReplacement;
 264     bool m_shouldAllowCDATA;
 265
 266     // m_token is owned by the caller. If nextToken is not on the stack,
 267     // this member might be pointing to unallocated memory.
 268     HTMLToken* m_token;
 269
 270     // http://www.whatwg.org/specs/web-apps/current-work/#additional-allowed-character
 271     UChar m_additionalAllowedCharacter;
 272
 273     // http://www.whatwg.org/specs/web-apps/current-work/#preprocessing-the-input-stream
 274     InputStreamPreprocessor<HTMLTokenizer> m_inputStreamPreprocessor;
 275
 276     Vector<UChar, 32> m_appropriateEndTagName;
 277
 278     // http://www.whatwg.org/specs/web-apps/current-work/#temporary-buffer
 279     Vector<LChar, 32> m_temporaryBuffer;
 280
 281     // We occationally want to emit both a character token and an end tag
 282     // token (e.g., when lexing script). We buffer the name of the end tag
 283     // token here so we remember it next time we re-enter the tokenizer.
 284     Vector<LChar, 32> m_bufferedEndTagName;
 285
 286     HTMLParserOptions m_options;
 287 };
 288
 289 }
 290
 291 #endif