ceph/src/boost/libs/regex/example/snippets/regex_grep_example_2.cpp

   1 /*
   2  *
   3  * Copyright (c) 1998-2002
   4  * John Maddock
   5  *
   6  * Use, modification and distribution are subject to the
   7  * Boost Software License, Version 1.0. (See accompanying file
   8  * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9  *
  10  */
  11
  12  /*
  13   *   LOCATION:    see http://www.boost.org for most recent version.
  14   *   FILE         regex_grep_example_2.cpp
  15   *   VERSION      see <boost/version.hpp>
  16   *   DESCRIPTION: regex_grep example 2: searches a cpp file for class definitions,
  17   *                using a global callback function.
  18   */
  19
  20 #include <boost/regex.hpp>
  21 #include <string>
  22 #include <map>
  23 #include <boost/regex.hpp>
  24
  25 // purpose:
  26 // takes the contents of a file in the form of a string
  27 // and searches for all the C++ class definitions, storing
  28 // their locations in a map of strings/int's
  29
  30 typedef std::map<std::string, std::string::difference_type, std::less<std::string> > map_type;
  31
  32 const char* re =
  33    // possibly leading whitespace:
  34    "^[[:space:]]*"
  35    // possible template declaration:
  36    "(template[[:space:]]*<[^;:{]+>[[:space:]]*)?"
  37    // class or struct:
  38    "(class|struct)[[:space:]]*"
  39    // leading declspec macros etc:
  40    "("
  41       "\\<\\w+\\>"
  42       "("
  43          "[[:blank:]]*\\([^)]*\\)"
  44       ")?"
  45       "[[:space:]]*"
  46    ")*"
  47    // the class name
  48    "(\\<\\w*\\>)[[:space:]]*"
  49    // template specialisation parameters
  50    "(<[^;:{]+>)?[[:space:]]*"
  51    // terminate in { or :
  52    "(\\{|:[^;\\{()]*\\{)";
  53
  54
  55 boost::regex expression(re);
  56 map_type class_index;
  57 std::string::const_iterator base;
  58
  59 bool grep_callback(const boost::match_results<std::string::const_iterator>& what)
  60 {
  61    // what[0] contains the whole string
  62    // what[5] contains the class name.
  63    // what[6] contains the template specialisation if any.
  64    // add class name and position to map:
  65    class_index[std::string(what[5].first, what[5].second) + std::string(what[6].first, what[6].second)] =
  66                what[5].first - base;
  67    return true;
  68 }
  69
  70 void IndexClasses(const std::string& file)
  71 {
  72    std::string::const_iterator start, end;
  73    start = file.begin();
  74    end = file.end();
  75    base = start;
  76    boost::regex_grep(grep_callback, start, end, expression);
  77 }
  78
  79 #include <fstream>
  80 #include <iostream>
  81
  82 using namespace std;
  83
  84 void load_file(std::string& s, std::istream& is)
  85 {
  86    s.erase();
  87    if(is.bad()) return;
  88    s.reserve(static_cast<std::string::size_type>(is.rdbuf()->in_avail()));
  89    char c;
  90    while(is.get(c))
  91    {
  92       if(s.capacity() == s.size())
  93          s.reserve(s.capacity() * 3);
  94       s.append(1, c);
  95    }
  96 }
  97
  98 int main(int argc, const char** argv)
  99 {
 100    std::string text;
 101    for(int i = 1; i < argc; ++i)
 102    {
 103       cout << "Processing file " << argv[i] << endl;
 104       std::ifstream fs(argv[i]);
 105       load_file(text, fs);
 106       fs.close();
 107       IndexClasses(text);
 108       cout << class_index.size() << " matches found" << endl;
 109       map_type::iterator c, d;
 110       c = class_index.begin();
 111       d = class_index.end();
 112       while(c != d)
 113       {
 114          cout << "class \"" << (*c).first << "\" found at index: " << (*c).second << endl;
 115          ++c;
 116       }
 117       class_index.erase(class_index.begin(), class_index.end());
 118    }
 119    return 0;
 120 }
 121
 122
 123