aboutsummaryrefslogtreecommitdiffstats
path: root/source/Utility/RegularExpression.cpp
blob: d58b315d0d1df4250653c9435fbd02d6c57c15f1 (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
//===-- RegularExpression.cpp -----------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/Utility/RegularExpression.h"

#include "llvm/ADT/StringRef.h"

#include <string>

//----------------------------------------------------------------------
// Enable enhanced mode if it is available. This allows for things like
// \d for digit, \s for space, and many more, but it isn't available
// everywhere.
//----------------------------------------------------------------------
#if defined(REG_ENHANCED)
#define DEFAULT_COMPILE_FLAGS (REG_ENHANCED | REG_EXTENDED)
#else
#define DEFAULT_COMPILE_FLAGS (REG_EXTENDED)
#endif

using namespace lldb_private;

RegularExpression::RegularExpression() : m_re(), m_comp_err(1), m_preg() {
  memset(&m_preg, 0, sizeof(m_preg));
}

//----------------------------------------------------------------------
// Constructor that compiles "re" using "flags" and stores the
// resulting compiled regular expression into this object.
//----------------------------------------------------------------------
RegularExpression::RegularExpression(llvm::StringRef str)
    : m_re(), m_comp_err(1), m_preg() {
  memset(&m_preg, 0, sizeof(m_preg));
  Compile(str);
}

RegularExpression::RegularExpression(const RegularExpression &rhs) {
  memset(&m_preg, 0, sizeof(m_preg));
  Compile(rhs.GetText());
}

const RegularExpression &RegularExpression::
operator=(const RegularExpression &rhs) {
  if (&rhs != this)
    Compile(rhs.GetText());
  return *this;
}

//----------------------------------------------------------------------
// Destructor
//
// Any previously compiled regular expression contained in this
// object will be freed.
//----------------------------------------------------------------------
RegularExpression::~RegularExpression() { Free(); }

//----------------------------------------------------------------------
// Compile a regular expression using the supplied regular
// expression text and flags. The compiled regular expression lives
// in this object so that it can be readily used for regular
// expression matches. Execute() can be called after the regular
// expression is compiled. Any previously compiled regular
// expression contained in this object will be freed.
//
// RETURNS
//  True if the regular expression compiles successfully, false
//  otherwise.
//----------------------------------------------------------------------
bool RegularExpression::Compile(llvm::StringRef str) {
  Free();

  // regcomp() on darwin does not recognize "" as a valid regular expression, so
  // we substitute it with an equivalent non-empty one.
  m_re = str.empty() ? "()" : str;
  m_comp_err = ::regcomp(&m_preg, m_re.c_str(), DEFAULT_COMPILE_FLAGS);
  return m_comp_err == 0;
}

//----------------------------------------------------------------------
// Execute a regular expression match using the compiled regular
// expression that is already in this object against the match
// string "s". If any parens are used for regular expression
// matches "match_count" should indicate the number of regmatch_t
// values that are present in "match_ptr". The regular expression
// will be executed using the "execute_flags".
//---------------------------------------------------------------------
bool RegularExpression::Execute(llvm::StringRef str, Match *match) const {
  int err = 1;
  if (m_comp_err == 0) {
    // Argument to regexec must be null-terminated.
    std::string reg_str = str;
    if (match) {
      err = ::regexec(&m_preg, reg_str.c_str(), match->GetSize(),
                      match->GetData(), 0);
    } else {
      err = ::regexec(&m_preg, reg_str.c_str(), 0, nullptr, 0);
    }
  }

  if (err != 0) {
    // The regular expression didn't compile, so clear the matches
    if (match)
      match->Clear();
    return false;
  }
  return true;
}

bool RegularExpression::Match::GetMatchAtIndex(llvm::StringRef s, uint32_t idx,
                                               std::string &match_str) const {
  llvm::StringRef match_str_ref;
  if (GetMatchAtIndex(s, idx, match_str_ref)) {
    match_str = match_str_ref.str();
    return true;
  }
  return false;
}

bool RegularExpression::Match::GetMatchAtIndex(
    llvm::StringRef s, uint32_t idx, llvm::StringRef &match_str) const {
  if (idx < m_matches.size()) {
    if (m_matches[idx].rm_eo == -1 && m_matches[idx].rm_so == -1)
      return false;

    if (m_matches[idx].rm_eo == m_matches[idx].rm_so) {
      // Matched the empty string...
      match_str = llvm::StringRef();
      return true;
    } else if (m_matches[idx].rm_eo > m_matches[idx].rm_so) {
      match_str = s.substr(m_matches[idx].rm_so,
                           m_matches[idx].rm_eo - m_matches[idx].rm_so);
      return true;
    }
  }
  return false;
}

bool RegularExpression::Match::GetMatchSpanningIndices(
    llvm::StringRef s, uint32_t idx1, uint32_t idx2,
    llvm::StringRef &match_str) const {
  if (idx1 < m_matches.size() && idx2 < m_matches.size()) {
    if (m_matches[idx1].rm_so == m_matches[idx2].rm_eo) {
      // Matched the empty string...
      match_str = llvm::StringRef();
      return true;
    } else if (m_matches[idx1].rm_so < m_matches[idx2].rm_eo) {
      match_str = s.substr(m_matches[idx1].rm_so,
                           m_matches[idx2].rm_eo - m_matches[idx1].rm_so);
      return true;
    }
  }
  return false;
}

//----------------------------------------------------------------------
// Returns true if the regular expression compiled and is ready
// for execution.
//----------------------------------------------------------------------
bool RegularExpression::IsValid() const { return m_comp_err == 0; }

//----------------------------------------------------------------------
// Returns the text that was used to compile the current regular
// expression.
//----------------------------------------------------------------------
llvm::StringRef RegularExpression::GetText() const { return m_re; }

//----------------------------------------------------------------------
// Free any contained compiled regular expressions.
//----------------------------------------------------------------------
void RegularExpression::Free() {
  if (m_comp_err == 0) {
    m_re.clear();
    regfree(&m_preg);
    // Set a compile error since we no longer have a valid regex
    m_comp_err = 1;
  }
}

size_t RegularExpression::GetErrorAsCString(char *err_str,
                                            size_t err_str_max_len) const {
  if (m_comp_err == 0) {
    if (err_str && err_str_max_len)
      *err_str = '\0';
    return 0;
  }

  return ::regerror(m_comp_err, &m_preg, err_str, err_str_max_len);
}

bool RegularExpression::operator<(const RegularExpression &rhs) const {
  return (m_re < rhs.m_re);
}