1 /*
2 * Copyright (C) 2004, 2008, 2009 Apple Inc. All rights reserved.
3 * Copyright (C) 2008 Collabora Ltd.
4 * Copyright (C) 2011 Peter Varga (pvarga@webkit.org), University of Szeged
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include "config.h"
29 #include "RegularExpression.h"
30
31 #include <wtf/BumpPointerAllocator.h>
32 #include <yarr/Yarr.h>
33 #include "Logging.h"
34
35 namespace WebCore {
36
37 class RegularExpression::Private : public RefCounted<RegularExpression::Private> {
38 public:
create(const String & pattern,TextCaseSensitivity caseSensitivity)39 static PassRefPtr<Private> create(const String& pattern, TextCaseSensitivity caseSensitivity)
40 {
41 return adoptRef(new Private(pattern, caseSensitivity));
42 }
43
44 int lastMatchLength;
45
46 unsigned m_numSubpatterns;
47 OwnPtr<JSC::Yarr::BytecodePattern> m_regExpByteCode;
48
49 private:
Private(const String & pattern,TextCaseSensitivity caseSensitivity)50 Private(const String& pattern, TextCaseSensitivity caseSensitivity)
51 : lastMatchLength(-1)
52 , m_regExpByteCode(compile(pattern, caseSensitivity))
53 , m_constructionError(0)
54 {
55 }
56
compile(const String & patternString,TextCaseSensitivity caseSensitivity)57 PassOwnPtr<JSC::Yarr::BytecodePattern> compile(const String& patternString, TextCaseSensitivity caseSensitivity)
58 {
59 JSC::Yarr::YarrPattern pattern(JSC::UString(patternString.impl()), (caseSensitivity == TextCaseInsensitive), false, &m_constructionError);
60 if (m_constructionError) {
61 LOG_ERROR("RegularExpression: YARR compile failed with '%s'", m_constructionError);
62 return nullptr;
63 }
64
65 m_numSubpatterns = pattern.m_numSubpatterns;
66
67 return JSC::Yarr::byteCompile(pattern, &m_regexAllocator);
68 }
69
70 BumpPointerAllocator m_regexAllocator;
71 const char* m_constructionError;
72 };
73
RegularExpression(const String & pattern,TextCaseSensitivity caseSensitivity)74 RegularExpression::RegularExpression(const String& pattern, TextCaseSensitivity caseSensitivity)
75 : d(Private::create(pattern, caseSensitivity))
76 {
77 }
78
RegularExpression(const RegularExpression & re)79 RegularExpression::RegularExpression(const RegularExpression& re)
80 : d(re.d)
81 {
82 }
83
~RegularExpression()84 RegularExpression::~RegularExpression()
85 {
86 }
87
operator =(const RegularExpression & re)88 RegularExpression& RegularExpression::operator=(const RegularExpression& re)
89 {
90 d = re.d;
91 return *this;
92 }
93
match(const String & str,int startFrom,int * matchLength) const94 int RegularExpression::match(const String& str, int startFrom, int* matchLength) const
95 {
96 if (!d->m_regExpByteCode)
97 return -1;
98
99 if (str.isNull())
100 return -1;
101
102 int offsetVectorSize = (d->m_numSubpatterns + 1) * 2;
103 int* offsetVector;
104 Vector<int, 32> nonReturnedOvector;
105
106 nonReturnedOvector.resize(offsetVectorSize);
107 offsetVector = nonReturnedOvector.data();
108
109 ASSERT(offsetVector);
110 for (unsigned j = 0, i = 0; i < d->m_numSubpatterns + 1; j += 2, i++)
111 offsetVector[j] = -1;
112
113 int result = JSC::Yarr::interpret(d->m_regExpByteCode.get(), str.characters(), startFrom, str.length(), offsetVector);
114 ASSERT(result >= -1);
115
116 if (result < 0) {
117 d->lastMatchLength = -1;
118 return -1;
119 }
120
121 // 1 means 1 match; 0 means more than one match. First match is recorded in offsetVector.
122 d->lastMatchLength = offsetVector[1] - offsetVector[0];
123 if (matchLength)
124 *matchLength = d->lastMatchLength;
125 return offsetVector[0];
126 }
127
searchRev(const String & str) const128 int RegularExpression::searchRev(const String& str) const
129 {
130 // FIXME: This could be faster if it actually searched backwards.
131 // Instead, it just searches forwards, multiple times until it finds the last match.
132
133 int start = 0;
134 int pos;
135 int lastPos = -1;
136 int lastMatchLength = -1;
137 do {
138 int matchLength;
139 pos = match(str, start, &matchLength);
140 if (pos >= 0) {
141 if (pos + matchLength > lastPos + lastMatchLength) {
142 // replace last match if this one is later and not a subset of the last match
143 lastPos = pos;
144 lastMatchLength = matchLength;
145 }
146 start = pos + 1;
147 }
148 } while (pos != -1);
149 d->lastMatchLength = lastMatchLength;
150 return lastPos;
151 }
152
matchedLength() const153 int RegularExpression::matchedLength() const
154 {
155 return d->lastMatchLength;
156 }
157
replace(String & string,const RegularExpression & target,const String & replacement)158 void replace(String& string, const RegularExpression& target, const String& replacement)
159 {
160 int index = 0;
161 while (index < static_cast<int>(string.length())) {
162 int matchLength;
163 index = target.match(string, index, &matchLength);
164 if (index < 0)
165 break;
166 string.replace(index, matchLength, replacement);
167 index += replacement.length();
168 if (!matchLength)
169 break; // Avoid infinite loop on 0-length matches, e.g. [a-z]*
170 }
171 }
172
173 } // namespace WebCore
174