aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/pcre/pcre_scanner.cc
blob: 30400294d24e7684410c0d10437507aae909fcf0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
// Copyright (c) 2005, 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:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * 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.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "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 THE COPYRIGHT
// OWNER 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.
//
// Author: Sanjay Ghemawat

#ifdef HAVE_CONFIG_H
#include "pcre_config.h"
#endif

#include <vector>
#include <assert.h>

#include "pcrecpp_internal.h"
#include "pcre_scanner.h"

using std::vector;

namespace pcrecpp {

Scanner::Scanner()
  : data_(),
    input_(data_),
    skip_(NULL),
    should_skip_(false),
    skip_repeat_(false),
    save_comments_(false),
    comments_(NULL),
    comments_offset_(0) {
}

Scanner::Scanner(const string& in)
  : data_(in),
    input_(data_),
    skip_(NULL),
    should_skip_(false),
    skip_repeat_(false),
    save_comments_(false),
    comments_(NULL),
    comments_offset_(0) {
}

Scanner::~Scanner() {
  delete skip_;
  delete comments_;
}

void Scanner::SetSkipExpression(const char* re) {
  delete skip_;
  if (re != NULL) {
    skip_ = new RE(re);
    should_skip_ = true;
    skip_repeat_ = true;
    ConsumeSkip();
  } else {
    skip_ = NULL;
    should_skip_ = false;
    skip_repeat_ = false;
  }
}

void Scanner::Skip(const char* re) {
  delete skip_;
  if (re != NULL) {
    skip_ = new RE(re);
    should_skip_ = true;
    skip_repeat_ = false;
    ConsumeSkip();
  } else {
    skip_ = NULL;
    should_skip_ = false;
    skip_repeat_ = false;
  }
}

void Scanner::DisableSkip() {
  assert(skip_ != NULL);
  should_skip_ = false;
}

void Scanner::EnableSkip() {
  assert(skip_ != NULL);
  should_skip_ = true;
  ConsumeSkip();
}

int Scanner::LineNumber() const {
  // TODO: Make it more efficient by keeping track of the last point
  // where we computed line numbers and counting newlines since then.
  // We could use std:count, but not all systems have it. :-(
  int count = 1;
  for (const char* p = data_.data(); p < input_.data(); ++p)
    if (*p == '\n')
      ++count;
  return count;
}

int Scanner::Offset() const {
  return (int)(input_.data() - data_.c_str());
}

bool Scanner::LookingAt(const RE& re) const {
  int consumed;
  return re.DoMatch(input_, RE::ANCHOR_START, &consumed, 0, 0);
}


bool Scanner::Consume(const RE& re,
                      const Arg& arg0,
                      const Arg& arg1,
                      const Arg& arg2) {
  const bool result = re.Consume(&input_, arg0, arg1, arg2);
  if (result && should_skip_) ConsumeSkip();
  return result;
}

// helper function to consume *skip_ and honour save_comments_
void Scanner::ConsumeSkip() {
  const char* start_data = input_.data();
  while (skip_->Consume(&input_)) {
    if (!skip_repeat_) {
      // Only one skip allowed.
      break;
    }
  }
  if (save_comments_) {
    if (comments_ == NULL) {
      comments_ = new vector<StringPiece>;
    }
    // already pointing one past end, so no need to +1
    int length = (int)(input_.data() - start_data);
    if (length > 0) {
      comments_->push_back(StringPiece(start_data, length));
    }
  }
}


void Scanner::GetComments(int start, int end, vector<StringPiece> *ranges) {
  // short circuit out if we've not yet initialized comments_
  // (e.g., when save_comments is false)
  if (!comments_) {
    return;
  }
  // TODO: if we guarantee that comments_ will contain StringPieces
  // that are ordered by their start, then we can do a binary search
  // for the first StringPiece at or past start and then scan for the
  // ones contained in the range, quit early (use equal_range or
  // lower_bound)
  for (vector<StringPiece>::const_iterator it = comments_->begin();
       it != comments_->end(); ++it) {
    if ((it->data() >= data_.c_str() + start &&
         it->data() + it->size() <= data_.c_str() + end)) {
      ranges->push_back(*it);
    }
  }
}


void Scanner::GetNextComments(vector<StringPiece> *ranges) {
  // short circuit out if we've not yet initialized comments_
  // (e.g., when save_comments is false)
  if (!comments_) {
    return;
  }
  for (vector<StringPiece>::const_iterator it =
         comments_->begin() + comments_offset_;
       it != comments_->end(); ++it) {
    ranges->push_back(*it);
    ++comments_offset_;
  }
}

}   // namespace pcrecpp