ceph/src/boost/libs/program_options/include/boost/program_options/detail/config_file.hpp

   1 // Copyright Vladimir Prus 2002-2004.
   2 // Distributed under the Boost Software License, Version 1.0.
   3 // (See accompanying file LICENSE_1_0.txt
   4 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6
   7 #ifndef BOOST_CONFIG_FILE_VP_2003_01_02
   8 #define BOOST_CONFIG_FILE_VP_2003_01_02
   9
  10 #include <iosfwd>
  11 #include <string>
  12 #include <set>
  13
  14 #include <boost/noncopyable.hpp>
  15 #include <boost/program_options/config.hpp>
  16 #include <boost/program_options/option.hpp>
  17 #include <boost/program_options/eof_iterator.hpp>
  18
  19 #include <boost/detail/workaround.hpp>
  20 #include <boost/program_options/detail/convert.hpp>
  21
  22 #if BOOST_WORKAROUND(__DECCXX_VER, BOOST_TESTED_AT(60590042))
  23 #include <istream> // std::getline
  24 #endif
  25
  26 #include <boost/static_assert.hpp>
  27 #include <boost/type_traits/is_same.hpp>
  28 #include <boost/shared_ptr.hpp>
  29
  30 #ifdef BOOST_MSVC
  31 # pragma warning(push)
  32 # pragma warning(disable: 4251) // class XYZ needs to have dll-interface to be used by clients of class XYZ
  33 #endif
  34
  35
  36
  37 namespace boost { namespace program_options { namespace detail {
  38
  39     /** Standalone parser for config files in ini-line format.
  40         The parser is a model of single-pass lvalue iterator, and
  41         default constructor creates past-the-end-iterator. The typical usage is:
  42         config_file_iterator i(is, ... set of options ...), e;
  43         for(; i !=e; ++i) {
  44             *i;
  45         }
  46
  47         Syntax conventions:
  48
  49         - config file can not contain positional options
  50         - '#' is comment character: it is ignored together with
  51           the rest of the line.
  52         - variable assignments are in the form
  53           name '=' value.
  54           spaces around '=' are trimmed.
  55         - Section names are given in brackets.
  56
  57          The actual option name is constructed by combining current section
  58          name and specified option name, with dot between. If section_name
  59          already contains dot at the end, new dot is not inserted. For example:
  60          @verbatim
  61          [gui.accessibility]
  62          visual_bell=yes
  63          @endverbatim
  64          will result in option "gui.accessibility.visual_bell" with value
  65          "yes" been returned.
  66
  67          TODO: maybe, we should just accept a pointer to options_description
  68          class.
  69      */
  70     class BOOST_PROGRAM_OPTIONS_DECL common_config_file_iterator
  71         : public eof_iterator<common_config_file_iterator, option>
  72     {
  73     public:
  74         common_config_file_iterator() { found_eof(); }
  75         common_config_file_iterator(
  76             const std::set<std::string>& allowed_options,
  77             bool allow_unregistered = false);
  78
  79         virtual ~common_config_file_iterator() {}
  80
  81     public: // Method required by eof_iterator
  82
  83         void get();
  84
  85 #if BOOST_WORKAROUND(_MSC_VER, <= 1900)
  86         void decrement() {}
  87         void advance(difference_type) {}
  88 #endif
  89
  90     protected: // Stubs for derived classes
  91
  92         // Obtains next line from the config file
  93         // Note: really, this design is a bit ugly
  94         // The most clean thing would be to pass 'line_iterator' to
  95         // constructor of this class, but to avoid templating this class
  96         // we'd need polymorphic iterator, which does not exist yet.
  97         virtual bool getline(std::string&) { return false; }
  98
  99     private:
 100         /** Adds another allowed option. If the 'name' ends with
 101             '*', then all options with the same prefix are
 102             allowed. For example, if 'name' is 'foo*', then 'foo1' and
 103             'foo_bar' are allowed. */
 104         void add_option(const char* name);
 105
 106         // Returns true if 's' is a registered option name.
 107         bool allowed_option(const std::string& s) const;
 108
 109         // That's probably too much data for iterator, since
 110         // it will be copied, but let's not bother for now.
 111         std::set<std::string> allowed_options;
 112         // Invariant: no element is prefix of other element.
 113         std::set<std::string> allowed_prefixes;
 114         std::string m_prefix;
 115         bool m_allow_unregistered;
 116     };
 117
 118     template<class charT>
 119     class basic_config_file_iterator : public common_config_file_iterator {
 120     public:
 121         basic_config_file_iterator()
 122         {
 123             found_eof();
 124         }
 125
 126         /** Creates a config file parser for the specified stream.
 127         */
 128         basic_config_file_iterator(std::basic_istream<charT>& is,
 129                                    const std::set<std::string>& allowed_options,
 130                                    bool allow_unregistered = false);
 131
 132     private: // base overrides
 133
 134         bool getline(std::string&);
 135
 136     private: // internal data
 137         shared_ptr<std::basic_istream<charT> > is;
 138     };
 139
 140     typedef basic_config_file_iterator<char> config_file_iterator;
 141     typedef basic_config_file_iterator<wchar_t> wconfig_file_iterator;
 142
 143
 144     struct null_deleter
 145     {
 146         void operator()(void const *) const {}
 147     };
 148
 149
 150     template<class charT>
 151     basic_config_file_iterator<charT>::
 152     basic_config_file_iterator(std::basic_istream<charT>& is,
 153                                const std::set<std::string>& allowed_options,
 154                                bool allow_unregistered)
 155     : common_config_file_iterator(allowed_options, allow_unregistered)
 156     {
 157         this->is.reset(&is, null_deleter());
 158         get();
 159     }
 160
 161     // Specializing this function for wchar_t causes problems on
 162     // borland and vc7, as well as on metrowerks. On the first two
 163     // I don't know a workaround, so make use of 'to_internal' to
 164     // avoid specialization.
 165     template<class charT>
 166     bool
 167     basic_config_file_iterator<charT>::getline(std::string& s)
 168     {
 169         std::basic_string<charT> in;
 170         if (std::getline(*is, in)) {
 171             s = to_internal(in);
 172             return true;
 173         } else {
 174             return false;
 175         }
 176     }
 177
 178     // Specialization is needed to workaround getline bug on Comeau.
 179 #if BOOST_WORKAROUND(__COMO_VERSION__, BOOST_TESTED_AT(4303)) || \
 180         (defined(__sgi) && BOOST_WORKAROUND(_COMPILER_VERSION, BOOST_TESTED_AT(741)))
 181     template<>
 182     bool
 183     basic_config_file_iterator<wchar_t>::getline(std::string& s);
 184 #endif
 185
 186
 187
 188 }}}
 189
 190 #ifdef BOOST_MSVC
 191 # pragma warning(pop)
 192 #endif
 193
 194 #endif