Parse Sky entities according to the spec

sky/engine/core/html/parser/HTMLEntityParser.cpp

-/*
- * Copyright (C) 2008 Apple Inc. All Rights Reserved.
- * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/
- * Copyright (C) 2010 Google, Inc. All Rights Reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
 
 #include "config.h"
 #include "core/html/parser/HTMLEntityParser.h"
 
-#include "core/html/parser/HTMLEntitySearch.h"
-#include "core/html/parser/HTMLEntityTable.h"
-#include "wtf/text/StringBuilder.h"
+#include "wtf/unicode/CharacterNames.h"
 
 using namespace WTF;
 
 namespace blink {
 
-static const UChar windowsLatin1ExtensionArray[32] = {
-    0x20AC, 0x0081, 0x201A, 0x0192, 0x201E, 0x2026, 0x2020, 0x2021, // 80-87
-    0x02C6, 0x2030, 0x0160, 0x2039, 0x0152, 0x008D, 0x017D, 0x008F, // 88-8F
-    0x0090, 0x2018, 0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, // 90-97
-    0x02DC, 0x2122, 0x0161, 0x203A, 0x0153, 0x009D, 0x017E, 0x0178, // 98-9F
-};
+static const UChar32 kInvalidUnicode = -1;
+
+static UChar asHexDigit(UChar cc)
+{
+    if (cc >= '0' && cc <= '9')
+      return cc - '0';
+    if (cc >= 'a' && cc <= 'f')
+      return 10 + cc - 'a';
+    if (cc >= 'A' && cc <= 'F')
+      return 10 + cc - 'A';
+    ASSERT_NOT_REACHED();
+    return 0;
+}
 
 static bool isAlphaNumeric(UChar cc)
 {
     return (cc >= '0' && cc <= '9') || (cc >= 'a' && cc <= 'z') || (cc >= 'A' && cc <= 'Z');
 }
 
-static UChar adjustEntity(UChar32 value)
-{
-    if ((value & ~0x1F) != 0x0080)
-        return value;
-    return windowsLatin1ExtensionArray[value - 0x80];
-}
-
-static void appendLegalEntityFor(UChar32 c, DecodedHTMLEntity& decodedEntity)
-{
-    // FIXME: A number of specific entity values generate parse errors.
-    if (c <= 0 || c > 0x10FFFF || (c >= 0xD800 && c <= 0xDFFF)) {
-        decodedEntity.append(0xFFFD);
-        return;
-    }
-    if (U_IS_BMP(c)) {
-        decodedEntity.append(adjustEntity(c));
-        return;
-    }
-    decodedEntity.append(c);
-}
-
-static const UChar32 kInvalidUnicode = -1;
-
 static bool isHexDigit(UChar cc)
 {
     return (cc >= '0' && cc <= '9') || (cc >= 'a' && cc <= 'f') || (cc >= 'A' && cc <= 'F');
 }
 
-static UChar asHexDigit(UChar cc)
+static UChar decodeEntity(HTMLEntityParser::OutputBuffer buffer)
 {
-    if (cc >= '0' && cc <= '9')
-      return cc - '0';
-    if (cc >= 'a' && cc <= 'z')
-      return 10 + cc - 'a';
-    if (cc >= 'A' && cc <= 'Z')
-      return 10 + cc - 'A';
-    ASSERT_NOT_REACHED();
-    return 0;
+    if (equalIgnoringNullity(buffer, "&amp"))
+        return '&';
+    if (equalIgnoringNullity(buffer, "&apos"))
+        return '\'';
+    if (equalIgnoringNullity(buffer, "&gt"))
+        return '>';
+    if (equalIgnoringNullity(buffer, "&lt"))
+        return '<';
+    if (equalIgnoringNullity(buffer, "&quot"))
+        return '"';
+    return replacementCharacter;
 }
 
-typedef Vector<UChar, 64> ConsumedCharacterBuffer;
-
-static void unconsumeCharacters(SegmentedString& source, ConsumedCharacterBuffer& consumedCharacters)
+HTMLEntityParser::HTMLEntityParser()
 {
-    if (consumedCharacters.size() == 1)
-        source.push(consumedCharacters[0]);
-    else if (consumedCharacters.size() == 2) {
-        source.push(consumedCharacters[0]);
-        source.push(consumedCharacters[1]);
-    } else
-        source.prepend(SegmentedString(String(consumedCharacters)));
 }
 
-static bool consumeNamedEntity(SegmentedString& source, DecodedHTMLEntity& decodedEntity, bool& notEnoughCharacters, UChar additionalAllowedCharacter, UChar& cc)
+HTMLEntityParser::~HTMLEntityParser()
 {
-    ConsumedCharacterBuffer consumedCharacters;
-    HTMLEntitySearch entitySearch;
+}
+
+void HTMLEntityParser::reset()
+{
+    m_state = Initial;
+    m_result = '\0';
+    m_buffer.clear();
+    m_buffer.append('&');
+}
+
+bool HTMLEntityParser::parse(SegmentedString& source)
+{
     while (!source.isEmpty()) {
-        cc = source.currentChar();
-        entitySearch.advance(cc);
-        if (!entitySearch.isEntityPrefix())
-            break;
-        consumedCharacters.append(cc);
+        UChar cc = source.currentChar();
+        switch (m_state) {
+        case Initial: {
+            if (cc == '#') {
+                m_state = Numeric;
+                break;
+            }
+            if (isAlphaNumeric(cc)) {
+                m_state = Named;
+                continue;
+            }
+            return true;
+        }
+        case Numeric: {
+            if (cc == 'x' || cc == 'X') {
+                m_state = PossiblyHex;
+                break;
+            }
+            if (cc >= '0' && cc <= '9') {
+                m_state = Decimal;
+                continue;
+            }
+            return true;
+        }
+        case PossiblyHex: {
+            if (isHexDigit(cc)) {
+                m_state = Hex;
+                continue;
+            }
+            return true;
+        }
+        case Hex: {
+            if (isHexDigit(cc)) {
+                if (m_result != kInvalidUnicode)
+                    m_result = m_result * 16 + asHexDigit(cc);
+                break;
+            }
+            if (cc == ';') {
+                source.advanceAndASSERT(cc);
+                finalizeNumericEntity();
+                return true;
+            }
+            return true;
+        }
+        case Decimal: {
+            if (cc >= '0' && cc <= '9') {
+                if (m_result != kInvalidUnicode)
+                    m_result = m_result * 10 + cc - '0';
+                break;
+            }
+            if (cc == ';') {
+                source.advanceAndASSERT(cc);
+                finalizeNumericEntity();
+                return true;
+            }
+            return true;
+        }
+        case Named: {
+            if (isAlphaNumeric(cc))
+                break;
+            if (cc == ';') {
+                source.advanceAndASSERT(cc);
+                finalizeNamedEntity();
+                return true;
+            }
+            return true;
+        }
+        }
+
+        if (m_result > UCHAR_MAX_VALUE)
+            m_result = kInvalidUnicode;
+
+        m_buffer.append(cc);
         source.advanceAndASSERT(cc);
     }
-    notEnoughCharacters = source.isEmpty();
-    if (notEnoughCharacters) {
-        // We can't decide on an entity because there might be a longer entity
-        // that we could match if we had more data.
-        unconsumeCharacters(source, consumedCharacters);
-        return false;
-    }
-    if (!entitySearch.mostRecentMatch()) {
-        unconsumeCharacters(source, consumedCharacters);
-        return false;
-    }
-    if (entitySearch.mostRecentMatch()->length != entitySearch.currentLength()) {
-        // We've consumed too many characters. We need to walk the
-        // source back to the point at which we had consumed an
-        // actual entity.
-        unconsumeCharacters(source, consumedCharacters);
-        consumedCharacters.clear();
-        const HTMLEntityTableEntry* mostRecent = entitySearch.mostRecentMatch();
-        const int length = mostRecent->length;
-        const LChar* reference = HTMLEntityTable::entityString(*mostRecent);
-        for (int i = 0; i < length; ++i) {
-            cc = source.currentChar();
-            ASSERT_UNUSED(reference, cc == static_cast<UChar>(*reference++));
-            consumedCharacters.append(cc);
-            source.advanceAndASSERT(cc);
-            ASSERT(!source.isEmpty());
-        }
-        cc = source.currentChar();
-    }
-    if (entitySearch.mostRecentMatch()->lastCharacter() == ';'
-        || !additionalAllowedCharacter
-        || !(isAlphaNumeric(cc) || cc == '=')) {
-        decodedEntity.append(entitySearch.mostRecentMatch()->firstValue);
-        if (UChar32 second = entitySearch.mostRecentMatch()->secondValue)
-            decodedEntity.append(second);
-        return true;
-    }
-    unconsumeCharacters(source, consumedCharacters);
+    ASSERT(source.isEmpty());
     return false;
 }
 
-bool consumeHTMLEntity(SegmentedString& source, DecodedHTMLEntity& decodedEntity, bool& notEnoughCharacters, UChar additionalAllowedCharacter)
+void HTMLEntityParser::finalizeNumericEntity()
 {
-    ASSERT(!additionalAllowedCharacter || additionalAllowedCharacter == '"' || additionalAllowedCharacter == '\'' || additionalAllowedCharacter == '>');
-    ASSERT(!notEnoughCharacters);
-    ASSERT(decodedEntity.isEmpty());
-
-    enum EntityState {
-        Initial,
-        Number,
-        MaybeHexLowerCaseX,
-        MaybeHexUpperCaseX,
-        Hex,
-        Decimal,
-        Named
-    };
-    EntityState entityState = Initial;
-    UChar32 result = 0;
-    ConsumedCharacterBuffer consumedCharacters;
-
-    while (!source.isEmpty()) {
-        UChar cc = source.currentChar();
-        switch (entityState) {
-        case Initial: {
-            if (cc == '\x09' || cc == '\x0A' || cc == '\x0C' || cc == ' ' || cc == '<' || cc == '&')
-                return false;
-            if (additionalAllowedCharacter && cc == additionalAllowedCharacter)
-                return false;
-            if (cc == '#') {
-                entityState = Number;
-                break;
-            }
-            if ((cc >= 'a' && cc <= 'z') || (cc >= 'A' && cc <= 'Z')) {
-                entityState = Named;
-                continue;
-            }
-            return false;
-        }
-        case Number: {
-            if (cc == 'x') {
-                entityState = MaybeHexLowerCaseX;
-                break;
-            }
-            if (cc == 'X') {
-                entityState = MaybeHexUpperCaseX;
-                break;
-            }
-            if (cc >= '0' && cc <= '9') {
-                entityState = Decimal;
-                continue;
-            }
-            source.push('#');
-            return false;
-        }
-        case MaybeHexLowerCaseX: {
-            if (isHexDigit(cc)) {
-                entityState = Hex;
-                continue;
-            }
-            source.push('#');
-            source.push('x');
-            return false;
-        }
-        case MaybeHexUpperCaseX: {
-            if (isHexDigit(cc)) {
-                entityState = Hex;
-                continue;
-            }
-            source.push('#');
-            source.push('X');
-            return false;
-        }
-        case Hex: {
-            if (isHexDigit(cc)) {
-                if (result != kInvalidUnicode)
-                    result = result * 16 + asHexDigit(cc);
-            } else if (cc == ';') {
-                source.advanceAndASSERT(cc);
-                appendLegalEntityFor(result, decodedEntity);
-                return true;
-            } else {
-                appendLegalEntityFor(result, decodedEntity);
-                return true;
-            }
-            break;
-        }
-        case Decimal: {
-            if (cc >= '0' && cc <= '9') {
-                if (result != kInvalidUnicode)
-                    result = result * 10 + cc - '0';
-            } else if (cc == ';') {
-                source.advanceAndASSERT(cc);
-                appendLegalEntityFor(result, decodedEntity);
-                return true;
-            } else {
-                appendLegalEntityFor(result, decodedEntity);
-                return true;
-            }
-            break;
-        }
-        case Named: {
-            return consumeNamedEntity(source, decodedEntity, notEnoughCharacters, additionalAllowedCharacter, cc);
-        }
-        }
-
-        if (result > UCHAR_MAX_VALUE)
-            result = kInvalidUnicode;
-
-        consumedCharacters.append(cc);
-        source.advanceAndASSERT(cc);
+    m_buffer.clear();
+    if (m_result <= 0 || m_result > 0x10FFFF || (m_result >= 0xD800 && m_result <= 0xDFFF)) {
+        m_buffer.append(replacementCharacter);
+    } else if (U_IS_BMP(m_result)) {
+        m_buffer.append(m_result);
+    } else {
+        m_buffer.append(U16_LEAD(m_result));
+        m_buffer.append(U16_TRAIL(m_result));
     }
-    ASSERT(source.isEmpty());
-    notEnoughCharacters = true;
-    unconsumeCharacters(source, consumedCharacters);
-    return false;
 }
 
-static size_t appendUChar32ToUCharArray(UChar32 value, UChar* result)
+void HTMLEntityParser::finalizeNamedEntity()
 {
-    if (U_IS_BMP(value)) {
-        UChar character = static_cast<UChar>(value);
-        ASSERT(character == value);
-        result[0] = character;
-        return 1;
-    }
-
-    result[0] = U16_LEAD(value);
-    result[1] = U16_TRAIL(value);
-    return 2;
-}
-
-size_t decodeNamedEntityToUCharArray(const char* name, UChar result[4])
-{
-    HTMLEntitySearch search;
-    while (*name) {
-        search.advance(*name++);
-        if (!search.isEntityPrefix())
-            return 0;
-    }
-    search.advance(';');
-    if (!search.isEntityPrefix())
-        return 0;
-
-    size_t numberOfCodePoints = appendUChar32ToUCharArray(search.mostRecentMatch()->firstValue, result);
-    if (!search.mostRecentMatch()->secondValue)
-        return numberOfCodePoints;
-    return numberOfCodePoints + appendUChar32ToUCharArray(search.mostRecentMatch()->secondValue, result + numberOfCodePoints);
+    UChar decodedEntity = decodeEntity(m_buffer);
+    m_buffer.clear();
+    m_buffer.append(decodedEntity);
 }
 
 } // namespace blink