1 /*
2 * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
3 * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
4 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
5 * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
6 * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
7 * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
8 * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
9 * Copyright (C) 2012 Intel Corporation. All rights reserved.
10 *
11 * This library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Library General Public
13 * License as published by the Free Software Foundation; either
14 * version 2 of the License, or (at your option) any later version.
15 *
16 * This library is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Library General Public License for more details.
20 *
21 * You should have received a copy of the GNU Library General Public License
22 * along with this library; see the file COPYING.LIB. If not, write to
23 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 * Boston, MA 02110-1301, USA.
25 */
26
27 #include "config.h"
28 #include "core/css/CSSMarkup.h"
29
30 #include "wtf/HexNumber.h"
31 #include "wtf/text/StringBuffer.h"
32
33 namespace WebCore {
34
35 template <typename CharacterType>
isCSSTokenizerIdentifier(const CharacterType * characters,unsigned length)36 static inline bool isCSSTokenizerIdentifier(const CharacterType* characters, unsigned length)
37 {
38 const CharacterType* end = characters + length;
39
40 // -?
41 if (characters != end && characters[0] == '-')
42 ++characters;
43
44 // {nmstart}
45 if (characters == end || !(characters[0] == '_' || characters[0] >= 128 || isASCIIAlpha(characters[0])))
46 return false;
47 ++characters;
48
49 // {nmchar}*
50 for (; characters != end; ++characters) {
51 if (!(characters[0] == '_' || characters[0] == '-' || characters[0] >= 128 || isASCIIAlphanumeric(characters[0])))
52 return false;
53 }
54
55 return true;
56 }
57
58 // "ident" from the CSS tokenizer, minus backslash-escape sequences
isCSSTokenizerIdentifier(const String & string)59 static bool isCSSTokenizerIdentifier(const String& string)
60 {
61 unsigned length = string.length();
62
63 if (!length)
64 return false;
65
66 if (string.is8Bit())
67 return isCSSTokenizerIdentifier(string.characters8(), length);
68 return isCSSTokenizerIdentifier(string.characters16(), length);
69 }
70
71 template <typename CharacterType>
isCSSTokenizerURL(const CharacterType * characters,unsigned length)72 static inline bool isCSSTokenizerURL(const CharacterType* characters, unsigned length)
73 {
74 const CharacterType* end = characters + length;
75
76 for (; characters != end; ++characters) {
77 CharacterType c = characters[0];
78 switch (c) {
79 case '!':
80 case '#':
81 case '$':
82 case '%':
83 case '&':
84 break;
85 default:
86 if (c < '*')
87 return false;
88 if (c <= '~')
89 break;
90 if (c < 128)
91 return false;
92 }
93 }
94
95 return true;
96 }
97
98 // "url" from the CSS tokenizer, minus backslash-escape sequences
isCSSTokenizerURL(const String & string)99 static bool isCSSTokenizerURL(const String& string)
100 {
101 unsigned length = string.length();
102
103 if (!length)
104 return true;
105
106 if (string.is8Bit())
107 return isCSSTokenizerURL(string.characters8(), length);
108 return isCSSTokenizerURL(string.characters16(), length);
109 }
110
111 template <typename CharacterType>
quoteCSSStringInternal(const CharacterType * characters,unsigned length)112 static inline String quoteCSSStringInternal(const CharacterType* characters, unsigned length)
113 {
114 // For efficiency, we first pre-calculate the length of the quoted string, then we build the actual one.
115 // Please see below for the actual logic.
116 unsigned quotedStringSize = 2; // Two quotes surrounding the entire string.
117 bool afterEscape = false;
118 for (unsigned i = 0; i < length; ++i) {
119 CharacterType ch = characters[i];
120 if (ch == '\\' || ch == '\'') {
121 quotedStringSize += 2;
122 afterEscape = false;
123 } else if (ch < 0x20 || ch == 0x7F) {
124 quotedStringSize += 2 + (ch >= 0x10);
125 afterEscape = true;
126 } else {
127 quotedStringSize += 1 + (afterEscape && (isASCIIHexDigit(ch) || ch == ' '));
128 afterEscape = false;
129 }
130 }
131
132 StringBuffer<CharacterType> buffer(quotedStringSize);
133 unsigned index = 0;
134 buffer[index++] = '\'';
135 afterEscape = false;
136 for (unsigned i = 0; i < length; ++i) {
137 CharacterType ch = characters[i];
138 if (ch == '\\' || ch == '\'') {
139 buffer[index++] = '\\';
140 buffer[index++] = ch;
141 afterEscape = false;
142 } else if (ch < 0x20 || ch == 0x7F) { // Control characters.
143 buffer[index++] = '\\';
144 placeByteAsHexCompressIfPossible(ch, buffer, index, Lowercase);
145 afterEscape = true;
146 } else {
147 // Space character may be required to separate backslash-escape sequence and normal characters.
148 if (afterEscape && (isASCIIHexDigit(ch) || ch == ' '))
149 buffer[index++] = ' ';
150 buffer[index++] = ch;
151 afterEscape = false;
152 }
153 }
154 buffer[index++] = '\'';
155
156 ASSERT(quotedStringSize == index);
157 return String::adopt(buffer);
158 }
159
160 // We use single quotes for now because markup.cpp uses double quotes.
quoteCSSString(const String & string)161 String quoteCSSString(const String& string)
162 {
163 // This function expands each character to at most 3 characters ('\u0010' -> '\' '1' '0') as well as adds
164 // 2 quote characters (before and after). Make sure the resulting size (3 * length + 2) will not overflow unsigned.
165
166 unsigned length = string.length();
167
168 if (!length)
169 return String("\'\'");
170
171 if (length > std::numeric_limits<unsigned>::max() / 3 - 2)
172 return emptyString();
173
174 if (string.is8Bit())
175 return quoteCSSStringInternal(string.characters8(), length);
176 return quoteCSSStringInternal(string.characters16(), length);
177 }
178
quoteCSSStringIfNeeded(const String & string)179 String quoteCSSStringIfNeeded(const String& string)
180 {
181 return isCSSTokenizerIdentifier(string) ? string : quoteCSSString(string);
182 }
183
quoteCSSURLIfNeeded(const String & string)184 String quoteCSSURLIfNeeded(const String& string)
185 {
186 return isCSSTokenizerURL(string) ? string : quoteCSSString(string);
187 }
188
189 } // namespace WebCore
190