// generate_re2c.hpp
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// Copyright (c) 2009 Ben Hanson (http://www.benhanson.net/)
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file licence_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_SPIRIT_SUPPORT_DETAIL_LEXER_GENERATE_RE2C_HPP
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#define BOOST_SPIRIT_SUPPORT_DETAIL_LEXER_GENERATE_RE2C_HPP
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#include "char_traits.hpp"
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#include "consts.hpp"
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#include "internals.hpp"
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#include <iostream>
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#include "runtime_error.hpp"
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#include "size_t.hpp"
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#include "state_machine.hpp"
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#include <vector>
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namespace boost
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{
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namespace lexer
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{
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// check whether state0_0 is referenced from any of the other states
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template <typename Char>
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bool need_label0_0(boost::lexer::basic_state_machine<Char> const &sm_)
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{
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typedef typename boost::lexer::basic_state_machine<Char>::iterator
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iterator_type;
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iterator_type iter_ = sm_.begin();
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std::size_t states_ = iter_->states;
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for (std::size_t state_ = 0; state_ < states_; ++state_)
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{
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if (0 == iter_->bol_index || 0 == iter_->eol_index)
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{
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return true;
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}
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std::size_t const transitions_ = iter_->transitions;
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for (std::size_t t_ = 0; t_ < transitions_; ++t_)
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{
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if (0 == iter_->goto_state)
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{
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return true;
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}
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++iter_;
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}
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if (transitions_ == 0) ++iter_;
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}
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return false;
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}
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template<typename CharT>
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void generate_re2c (const basic_state_machine<CharT> &state_machine_,
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std::ostream &os_, const bool use_pointers_ = false,
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const bool skip_unknown_ = true, const bool optimise_parameters_ = true,
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const char *name_ = "next_token")
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{
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typedef typename boost::lexer::basic_string_token<CharT> string_token;
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const detail::internals &sm_ = state_machine_.data ();
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if (sm_._lookup->size () == 0)
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{
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throw runtime_error ("Cannot generate code from an empty "
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"state machine");
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}
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std::string upper_name_ (__DATE__);
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const std::size_t lookups_ = sm_._lookup->front ()->size ();
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typename boost::lexer::basic_state_machine<CharT>::iterator iter_ =
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state_machine_.begin();
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typename boost::lexer::basic_state_machine<CharT>::iterator end_ =
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state_machine_.end();
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const std::size_t dfas_ = sm_._dfa->size ();
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std::string::size_type pos_ = upper_name_.find (' ');
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const char *iterator_ = 0;
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if (use_pointers_)
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{
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if (lookups_ == 256)
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{
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iterator_ = "const char *";
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}
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else
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{
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iterator_ = "const wchar_t *";
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}
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}
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else
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{
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iterator_ = "Iterator &";
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}
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while (pos_ != std::string::npos)
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{
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upper_name_.replace (pos_, 1, "_");
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pos_ = upper_name_.find (' ', pos_);
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}
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upper_name_ += '_';
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upper_name_ += __TIME__;
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pos_ = upper_name_.find (':');
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while (pos_ != std::string::npos)
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{
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upper_name_.erase (pos_, 1);
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pos_ = upper_name_.find (':', pos_);
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}
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upper_name_ = '_' + upper_name_;
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upper_name_ = name_ + upper_name_;
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std::transform (upper_name_.begin (), upper_name_.end (),
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upper_name_.begin (), ::toupper);
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os_ << "#ifndef " << upper_name_ + '\n';
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os_ << "#define " << upper_name_ + '\n';
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os_ << "// Copyright (c) 2008-2009 Ben Hanson\n";
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os_ << "//\n";
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os_ << "// Distributed under the Boost Software License, "
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"Version 1.0. (See accompanying\n";
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os_ << "// file licence_1_0.txt or copy at "
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"http://www.boost.org/LICENSE_1_0.txt)\n\n";
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os_ << "// Auto-generated by boost::lexer\n";
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os_ << "template<typename Iterator>\n";
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os_ << "std::size_t " << name_ << " (";
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if (dfas_ > 1 || !optimise_parameters_)
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{
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os_ << "std::size_t &start_state_, ";
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}
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if (use_pointers_)
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{
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os_ << iterator_ << " &";
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}
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else
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{
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os_ << iterator_;
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}
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os_ << "start_token_, ";
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if (use_pointers_)
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{
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os_ << iterator_ << " const ";
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}
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else
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{
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os_ << "const " << iterator_;
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}
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os_ << "end_, \n";
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os_ << " std::size_t &unique_id_";
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if (sm_._seen_BOL_assertion || !optimise_parameters_)
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{
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os_ << ", bool &beg_of_line_";
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}
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os_ << ")\n";
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os_ << "{\n";
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os_ << " static const std::size_t npos = static_cast"
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"<std::size_t>(~0);\n";
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os_ << "\n if (start_token_ == end_)\n";
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os_ << " {\n";
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os_ << " unique_id_ = npos;\n";
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os_ << " return 0;\n";
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os_ << " }\n\n";
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if (dfas_ > 1)
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{
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os_ << "again:\n";
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}
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os_ << " Iterator curr_ = start_token_;\n";
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os_ << " bool end_state_ = false;\n";
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os_ << " std::size_t id_ = npos;\n";
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os_ << " std::size_t uid_ = npos;\n";
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if (dfas_ > 1)
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{
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os_ << " std::size_t end_start_state_ = start_state_;\n";
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}
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if (sm_._seen_BOL_assertion)
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{
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os_ << " bool bol_ = beg_of_line_;\n";
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os_ << " bool end_bol_ = bol_;\n";
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}
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os_ << " Iterator end_token_ = start_token_;\n";
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os_ << '\n';
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if (dfas_ > 1)
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{
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os_ << " switch (start_state_)\n";
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os_ << " {\n";
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for (std::size_t i_ = 0; i_ < dfas_; ++i_)
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{
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os_ << " case " << i_ << ":\n";
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os_ << " goto " << i_ << "_0;\n";
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os_ << " // Not needed, but to prevent warnings\n";
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os_ << " break;\n";
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}
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os_ << " default:\n";
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os_ << " throw std::runtime_error (\"Invalid start state!\")\n";
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os_ << " break;\n";
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os_ << " }\n\n";
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}
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os_ << " ";
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if (lookups_ == 256)
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{
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os_ << "char";
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}
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else
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{
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os_ << "wchar_t";
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}
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os_ << " ch_ = 0;\n\n";
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bool need_state0_0_label = need_label0_0(state_machine_);
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for (std::size_t dfa_ = 0; dfa_ < dfas_; ++dfa_)
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{
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const std::size_t states_ = iter_->states;
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for (std::size_t state_ = 0; state_ < states_; ++state_)
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{
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const std::size_t transitions_ = iter_->transitions;
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std::size_t t_ = 0;
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if (dfas_ > 1 || dfa_ != 0 || state_ != 0 || need_state0_0_label)
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{
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os_ << "state" << dfa_ << '_' << state_ << ":\n";
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}
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if (iter_->end_state)
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{
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os_ << " end_state_ = true;\n";
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os_ << " id_ = " << iter_->id << ";\n";
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os_ << " uid_ = " << iter_->unique_id << ";\n";
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os_ << " end_token_ = curr_;\n";
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if (dfas_ > 1)
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{
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os_ << " end_start_state_ = " << iter_->goto_dfa <<
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";\n";
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}
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if (sm_._seen_BOL_assertion)
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{
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os_ << " end_bol_ = bol_;\n";
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}
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if (transitions_) os_ << '\n';
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}
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if (t_ < transitions_ || iter_->bol_index != boost::lexer::npos ||
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iter_->eol_index != boost::lexer::npos)
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{
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os_ << " if (curr_ == end_) goto end;\n\n";
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os_ << " ch_ = *curr_;\n";
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if (iter_->bol_index != boost::lexer::npos)
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{
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os_ << "\n if (bol_) goto state" << dfa_ << '_' <<
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iter_->bol_index << ";\n\n";
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}
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if (iter_->eol_index != boost::lexer::npos)
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{
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os_ << "\n if (ch_ == '\n') goto state" << dfa_ << '_' <<
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iter_->eol_index << ";\n\n";
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}
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os_ << " ++curr_;\n";
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}
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for (; t_ < transitions_; ++t_)
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{
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const char *ptr_ = iter_->token._charset.c_str();
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const char *end_ = ptr_ + iter_->token._charset.size();
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char start_char_ = 0;
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char curr_char_ = 0;
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bool range_ = false;
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bool first_char_ = true;
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os_ << "\n if (";
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while (ptr_ != end_)
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{
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curr_char_ = *ptr_++;
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if (*ptr_ == curr_char_ + 1)
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{
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if (!range_)
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{
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start_char_ = curr_char_;
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}
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range_ = true;
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}
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else
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{
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if (!first_char_)
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{
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if (iter_->token._negated)
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{
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os_ << " && ";
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}
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else
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{
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os_ << " || ";
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}
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}
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first_char_ = false;
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if (range_)
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{
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typename string_token::string temp_;
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if (iter_->token._negated)
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{
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os_ << "!";
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}
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string_token::escape_char (start_char_, temp_);
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os_ << "(ch_ >= '" << temp_;
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temp_.clear ();
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string_token::escape_char (curr_char_, temp_);
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os_ << "' && ch_ <= '" << temp_ << "')";
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range_ = false;
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}
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else
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{
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typename string_token::string temp_;
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os_ << "ch_ ";
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if (iter_->token._negated)
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{
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os_ << "!=";
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}
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else
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{
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os_ << "==";
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}
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string_token::escape_char (curr_char_, temp_);
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os_ << " '" << temp_ << "'";
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}
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}
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}
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os_ << ") goto state" << dfa_ << '_' << iter_->goto_state <<
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";\n\n";
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++iter_;
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}
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if (!(dfa_ == dfas_ - 1 && state_ == states_ - 1))
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{
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os_ << " goto end;\n";
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}
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if (transitions_ == 0) ++iter_;
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}
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}
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os_ << "end:\n";
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os_ << " if (end_state_)\n";
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os_ << " {\n";
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os_ << " // return longest match\n";
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if (dfas_ > 1)
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{
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os_ << " start_state_ = end_start_state_;\n";
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}
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if (sm_._seen_BOL_assertion && dfas_ < 2)
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{
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os_ << " beg_of_line_ = end_bol_;\n";
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}
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os_ << " start_token_ = end_token_;\n";
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if (dfas_ > 1)
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{
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os_ << '\n';
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os_ << " if (id_ == 0)\n";
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os_ << " {\n";
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if (sm_._seen_BOL_assertion)
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{
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os_ << " bol_ = end_bol_;\n";
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}
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os_ << " goto again;\n";
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os_ << " }\n";
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if (sm_._seen_BOL_assertion)
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{
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os_ << " else\n";
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os_ << " {\n";
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os_ << " beg_of_line_ = end_bol_;\n";
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os_ << " }\n";
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}
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}
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os_ << " }\n";
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os_ << " else\n";
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os_ << " {\n";
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if (sm_._seen_BOL_assertion)
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{
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os_ << " beg_of_line_ = *start_token_ == '\\n';\n";
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}
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if (skip_unknown_)
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{
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os_ << " // No match causes char to be skipped\n";
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os_ << " ++start_token_;\n";
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}
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os_ << " id_ = npos;\n";
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os_ << " uid_ = npos;\n";
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os_ << " }\n";
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os_ << '\n';
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os_ << " unique_id_ = uid_;\n";
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os_ << " return id_;\n";
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os_ << "}\n";
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os_ << "\n#endif\n";
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}
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}
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}
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#endif
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