File: regex_grep_example_2.cpp

package info (click to toggle)
boost1.62 1.62.0%2Bdfsg-4
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 686,420 kB
  • sloc: cpp: 2,609,004; xml: 972,558; ansic: 53,674; python: 32,437; sh: 8,829; asm: 3,071; cs: 2,121; makefile: 964; perl: 859; yacc: 472; php: 132; ruby: 94; f90: 55; sql: 13; csh: 6
file content (122 lines) | stat: -rw-r--r-- 3,158 bytes parent folder | download | duplicates (3)
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
/*
 *
 * Copyright (c) 1998-2002
 * John Maddock
 *
 * Use, modification and distribution are subject to the 
 * Boost Software License, Version 1.0. (See accompanying file 
 * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 *
 */

 /*
  *   LOCATION:    see http://www.boost.org for most recent version.
  *   FILE         regex_grep_example_2.cpp
  *   VERSION      see <boost/version.hpp>
  *   DESCRIPTION: regex_grep example 2: searches a cpp file for class definitions,
  *                using a global callback function.
  */

#include <string>
#include <map>
#include <boost/regex.hpp>

// purpose:
// takes the contents of a file in the form of a string
// and searches for all the C++ class definitions, storing
// their locations in a map of strings/int's

typedef std::map<std::string, std::string::difference_type, std::less<std::string> > map_type;

const char* re = 
   // possibly leading whitespace:   
   "^[[:space:]]*" 
   // possible template declaration:
   "(template[[:space:]]*<[^;:{]+>[[:space:]]*)?"
   // class or struct:
   "(class|struct)[[:space:]]*" 
   // leading declspec macros etc:
   "("
      "\\<\\w+\\>"
      "("
         "[[:blank:]]*\\([^)]*\\)"
      ")?"
      "[[:space:]]*"
   ")*" 
   // the class name
   "(\\<\\w*\\>)[[:space:]]*" 
   // template specialisation parameters
   "(<[^;:{]+>)?[[:space:]]*"
   // terminate in { or :
   "(\\{|:[^;\\{()]*\\{)";


boost::regex expression(re);
map_type class_index;
std::string::const_iterator base;

bool grep_callback(const boost::match_results<std::string::const_iterator>& what)
{
   // what[0] contains the whole string
   // what[5] contains the class name.
   // what[6] contains the template specialisation if any.
   // add class name and position to map:
   class_index[std::string(what[5].first, what[5].second) + std::string(what[6].first, what[6].second)] = 
               what[5].first - base;
   return true;
}

void IndexClasses(const std::string& file)
{
   std::string::const_iterator start, end;
   start = file.begin();
   end = file.end();
   base = start;
   boost::regex_grep(grep_callback, start, end, expression);
}

#include <fstream>
#include <iostream>

using namespace std;

void load_file(std::string& s, std::istream& is)
{
   s.erase();
   if(is.bad()) return;
   s.reserve(static_cast<std::string::size_type>(is.rdbuf()->in_avail()));
   char c;
   while(is.get(c))
   {
      if(s.capacity() == s.size())
         s.reserve(s.capacity() * 3);
      s.append(1, c);
   }
}

int main(int argc, const char** argv)
{
   std::string text;
   for(int i = 1; i < argc; ++i)
   {
      cout << "Processing file " << argv[i] << endl;
      std::ifstream fs(argv[i]);
      load_file(text, fs);
      fs.close();
      IndexClasses(text);
      cout << class_index.size() << " matches found" << endl;
      map_type::iterator c, d;
      c = class_index.begin();
      d = class_index.end();
      while(c != d)
      {
         cout << "class \"" << (*c).first << "\" found at index: " << (*c).second << endl;
         ++c;
      }
      class_index.erase(class_index.begin(), class_index.end());
   }
   return 0;
}