ceph/src/boost/libs/regex/example/snippets/regex_grep_example_3.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_3.cpp
  15   *   VERSION      see <boost/version.hpp>
  16   *   DESCRIPTION: regex_grep example 3: searches a cpp file for class definitions,
  17   *                using a bound member function callback.
  18   */
  19
  20 #include <string>
  21 #include <map>
  22 #include <boost/regex.hpp>
  23 #include <functional>
  24 #include <boost/detail/workaround.hpp>
  25
  26 // purpose:
  27 // takes the contents of a file in the form of a string
  28 // and searches for all the C++ class definitions, storing
  29 // their locations in a map of strings/int's
  30
  31 typedef std::map<std::string, std::string::difference_type, std::less<std::string> > map_type;
  32
  33 const char* re =
  34    // possibly leading whitespace:
  35    "^[[:space:]]*"
  36    // possible template declaration:
  37    "(template[[:space:]]*<[^;:{]+>[[:space:]]*)?"
  38    // class or struct:
  39    "(class|struct)[[:space:]]*"
  40    // leading declspec macros etc:
  41    "("
  42       "\\<\\w+\\>"
  43       "("
  44          "[[:blank:]]*\\([^)]*\\)"
  45       ")?"
  46       "[[:space:]]*"
  47    ")*"
  48    // the class name
  49    "(\\<\\w*\\>)[[:space:]]*"
  50    // template specialisation parameters
  51    "(<[^;:{]+>)?[[:space:]]*"
  52    // terminate in { or :
  53    "(\\{|:[^;\\{()]*\\{)";
  54
  55
  56 class class_index
  57 {
  58    boost::regex expression;
  59    map_type index;
  60    std::string::const_iterator base;
  61
  62    bool grep_callback(boost::match_results<std::string::const_iterator> what);
  63 public:
  64    map_type& get_map() { return index; }
  65    void IndexClasses(const std::string& file);
  66    class_index()
  67       : expression(re) {}
  68 };
  69
  70 bool class_index::grep_callback(boost::match_results<std::string::const_iterator> what)
  71 {
  72    // what[0] contains the whole string
  73    // what[5] contains the class name.
  74    // what[6] contains the template specialisation if any.
  75    // add class name and position to map:
  76    index[std::string(what[5].first, what[5].second) + std::string(what[6].first, what[6].second)] =
  77                what[5].first - base;
  78    return true;
  79 }
  80
  81 void class_index::IndexClasses(const std::string& file)
  82 {
  83    std::string::const_iterator start, end;
  84    start = file.begin();
  85    end = file.end();
  86    base = start;
  87 #if BOOST_WORKAROUND(_MSC_VER, < 1300) && !defined(_STLP_VERSION)
  88    boost::regex_grep(std::bind1st(std::mem_fun1(&class_index::grep_callback), this),
  89             start,
  90             end,
  91             expression);
  92 #else
  93    boost::regex_grep(std::bind1st(std::mem_fun(&class_index::grep_callback), this),
  94             start,
  95             end,
  96             expression);
  97 #endif
  98 }
  99
 100
 101 #include <fstream>
 102 #include <iostream>
 103
 104 using namespace std;
 105
 106 void load_file(std::string& s, std::istream& is)
 107 {
 108    s.erase();
 109    if(is.bad()) return;
 110    s.reserve(static_cast<std::string::size_type>(is.rdbuf()->in_avail()));
 111    char c;
 112    while(is.get(c))
 113    {
 114       if(s.capacity() == s.size())
 115          s.reserve(s.capacity() * 3);
 116       s.append(1, c);
 117    }
 118 }
 119
 120 int main(int argc, const char** argv)
 121 {
 122    std::string text;
 123    for(int i = 1; i < argc; ++i)
 124    {
 125       cout << "Processing file " << argv[i] << endl;
 126       std::ifstream fs(argv[i]);
 127       load_file(text, fs);
 128       fs.close();
 129       class_index idx;
 130       idx.IndexClasses(text);
 131       cout << idx.get_map().size() << " matches found" << endl;
 132       map_type::iterator c, d;
 133       c = idx.get_map().begin();
 134       d = idx.get_map().end();
 135       while(c != d)
 136       {
 137          cout << "class \"" << (*c).first << "\" found at index: " << (*c).second << endl;
 138          ++c;
 139       }
 140    }
 141    return 0;
 142 }
 143
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