ceph/src/boost/libs/wave/samples/emit_custom_line_directives/emit_custom_line_directives.hpp

   1 /*=============================================================================
   2     Boost.Wave: A Standard compliant C++ preprocessor library
   3     http://www.boost.org/
   4
   5     Copyright (c) 2001-2012 Hartmut Kaiser. Distributed under the Boost
   6     Software License, Version 1.0. (See accompanying file
   7     LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   8 =============================================================================*/
   9
  10 #if !defined(BOOST_WAVE_emit_custom_line_directives_HOOKS_INCLUDED)
  11 #define BOOST_WAVE_emit_custom_line_directives_HOOKS_INCLUDED
  12
  13 #include <cstdio>
  14 #include <ostream>
  15 #include <string>
  16 #include <algorithm>
  17
  18 #include <boost/assert.hpp>
  19 #include <boost/config.hpp>
  20
  21 #include <boost/wave/token_ids.hpp>
  22 #include <boost/wave/util/macro_helpers.hpp>
  23 #include <boost/wave/preprocessing_hooks.hpp>
  24
  25 ///////////////////////////////////////////////////////////////////////////////
  26 //
  27 //  The emit_custom_line_directives_hooks policy class is used to register some
  28 //  of the more advanced (and probably more rarely used hooks with the Wave
  29 //  library.
  30 //
  31 //  This policy type is used as a template parameter to the boost::wave::context<>
  32 //  object.
  33 //
  34 ///////////////////////////////////////////////////////////////////////////////
  35 class emit_custom_line_directives_hooks
  36 :   public boost::wave::context_policies::default_preprocessing_hooks
  37 {
  38 public:
  39     ///////////////////////////////////////////////////////////////////////////
  40     //
  41     //  The function 'emit_line_directive' is called whenever a #line directive
  42     //  has to be emitted into the generated output.
  43     //
  44     //  The parameter 'ctx' is a reference to the context object used for
  45     //  instantiating the preprocessing iterators by the user.
  46     //
  47     //  The parameter 'pending' may be used to push tokens back into the input
  48     //  stream, which are to be used instead of the default output generated
  49     //  for the #line directive.
  50     //
  51     //  The parameter 'act_token' contains the actual #pragma token, which may
  52     //  be used for error output. The line number stored in this token can be
  53     //  used as the line number emitted as part of the #line directive.
  54     //
  55     //  If the return value is 'false', a default #line directive is emitted
  56     //  by the library. A return value of 'true' will inhibit any further
  57     //  actions, the tokens contained in 'pending' will be copied verbatim
  58     //  to the output.
  59     //
  60     ///////////////////////////////////////////////////////////////////////////
  61     template <typename ContextT, typename ContainerT>
  62     bool
  63     emit_line_directive(ContextT const& ctx, ContainerT &pending,
  64         typename ContextT::token_type const& act_token)
  65     {
  66         // emit a #line directive showing the relative filename instead
  67         typename ContextT::position_type pos = act_token.get_position();
  68         unsigned int column = 1;
  69
  70         typedef typename ContextT::token_type result_type;
  71         using namespace boost::wave;
  72
  73         pos.set_column(column);
  74         pending.push_back(result_type(T_POUND, "#", pos));
  75
  76         pos.set_column(++column);      // account for '#'
  77         pending.push_back(result_type(T_SPACE, " ", pos));
  78
  79         std::string buffer = std::to_string(pos.get_line());
  80
  81         pos.set_column(++column);                 // account for ' '
  82         pending.push_back(result_type(T_INTLIT, buffer.c_str(), pos));
  83         pos.set_column(column += buffer.size()); // account for <number>
  84         pending.push_back(result_type(T_SPACE, " ", pos));
  85         pos.set_column(++column);                 // account for ' '
  86
  87         std::string file("\"");
  88         boost::filesystem::path filename(
  89         boost::wave::util::create_path(ctx.get_current_relative_filename().c_str()));
  90
  91         using boost::wave::util::impl::escape_lit;
  92         file += escape_lit(boost::wave::util::native_file_string(filename)) + "\"";
  93
  94         pending.push_back(result_type(T_STRINGLIT, file.c_str(), pos));
  95         pos.set_column(column += (unsigned int)file.size());    // account for filename
  96         pending.push_back(result_type(T_GENERATEDNEWLINE, "\n", pos));
  97
  98         return true;
  99     }
 100 };
 101
 102 #endif // !defined(BOOST_WAVE_ADVANCED_PREPROCESSING_HOOKS_INCLUDED)