/*

 *

 * Copyright (c) 2002

 * John Maddock

 *

 * Use, modification and distribution are subject to the 

 * Boost Software License, Version 1.0. (See accompanying file 

 * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

 *

 */

 /*

  *   LOCATION:    see http://www.boost.org for most recent version.

  *   FILE         perl_matcher_common.cpp

  *   VERSION      see <boost/version.hpp>

  *   DESCRIPTION: Definitions of perl_matcher member functions that are 

  *                specific to the non-recursive implementation.

  */

#ifndef BOOST_REGEX_V4_PERL_MATCHER_NON_RECURSIVE_HPP

#define BOOST_REGEX_V4_PERL_MATCHER_NON_RECURSIVE_HPP

#include <new>

#ifdef BOOST_MSVC

#pragma warning(push)

#pragma warning(disable: 4103)

#endif

#ifdef BOOST_HAS_ABI_HEADERS

#  include BOOST_ABI_PREFIX

#endif

#ifdef BOOST_MSVC

#pragma warning(pop)

#endif

#ifdef BOOST_MSVC

#  pragma warning(push)

#  pragma warning(disable: 4800)

#endif

namespace boost{

namespace re_detail{

template <class T>

inline void inplace_destroy(T* p)

{

   (void)p;  // warning suppression

   p->~T();

}

struct saved_state

{

   union{

      unsigned int state_id;

      // this padding ensures correct alignment on 64-bit platforms:

      std::size_t padding1;

      std::ptrdiff_t padding2;

      void* padding3;

   };

   saved_state(unsigned i) : state_id(i) {}

};

template <class BidiIterator>

struct saved_matched_paren : public saved_state

{

   int index;

   sub_match<BidiIterator> sub;

   saved_matched_paren(int i, const sub_match<BidiIterator>& s) : saved_state(1), index(i), sub(s){};

};

template <class BidiIterator>

struct saved_position : public saved_state

{

   const re_syntax_base* pstate;

   BidiIterator position;

   saved_position(const re_syntax_base* ps, BidiIterator pos, int i) : saved_state(i), pstate(ps), position(pos){};

};

template <class BidiIterator>

struct saved_assertion : public saved_position<BidiIterator>

{

   bool positive;

   saved_assertion(bool p, const re_syntax_base* ps, BidiIterator pos) 

      : saved_position<BidiIterator>(ps, pos, saved_type_assertion), positive(p){};

};

template <class BidiIterator>

struct saved_repeater : public saved_state

{

   repeater_count<BidiIterator> count;

   saved_repeater(int i, repeater_count<BidiIterator>** s, BidiIterator start) 

      : saved_state(saved_state_repeater_count), count(i,s,start){}

};

struct saved_extra_block : public saved_state

{

   saved_state *base, *end;

   saved_extra_block(saved_state* b, saved_state* e) 

      : saved_state(saved_state_extra_block), base(b), end(e) {}

};

struct save_state_init

{

   saved_state** stack;

   save_state_init(saved_state** base, saved_state** end)

      : stack(base)

   {

      *base = static_cast<saved_state*>(get_mem_block());

      *end = reinterpret_cast<saved_state*>(reinterpret_cast<char*>(*base)+BOOST_REGEX_BLOCKSIZE);

      --(*end);

      (void) new (*end)saved_state(0);

      BOOST_ASSERT(*end > *base);

   }

   ~save_state_init()

   {

      put_mem_block(*stack);

      *stack = 0;

   }

};

template <class BidiIterator>

struct saved_single_repeat : public saved_state

{

   std::size_t count;

   const re_repeat* rep;

   BidiIterator last_position;

   saved_single_repeat(std::size_t c, const re_repeat* r, BidiIterator lp, int arg_id) 

      : saved_state(arg_id), count(c), rep(r), last_position(lp){}

};

template <class BidiIterator, class Allocator, class traits>

bool perl_matcher<BidiIterator, Allocator, traits>::match_all_states()

{

   static matcher_proc_type const s_match_vtable[29] = 

   {

      (&perl_matcher<BidiIterator, Allocator, traits>::match_startmark),

      &perl_matcher<BidiIterator, Allocator, traits>::match_endmark,

      &perl_matcher<BidiIterator, Allocator, traits>::match_literal,

      &perl_matcher<BidiIterator, Allocator, traits>::match_start_line,

      &perl_matcher<BidiIterator, Allocator, traits>::match_end_line,

      &perl_matcher<BidiIterator, Allocator, traits>::match_wild,

      &perl_matcher<BidiIterator, Allocator, traits>::match_match,

      &perl_matcher<BidiIterator, Allocator, traits>::match_word_boundary,

      &perl_matcher<BidiIterator, Allocator, traits>::match_within_word,

      &perl_matcher<BidiIterator, Allocator, traits>::match_word_start,

      &perl_matcher<BidiIterator, Allocator, traits>::match_word_end,

      &perl_matcher<BidiIterator, Allocator, traits>::match_buffer_start,

      &perl_matcher<BidiIterator, Allocator, traits>::match_buffer_end,

      &perl_matcher<BidiIterator, Allocator, traits>::match_backref,

      &perl_matcher<BidiIterator, Allocator, traits>::match_long_set,

      &perl_matcher<BidiIterator, Allocator, traits>::match_set,

      &perl_matcher<BidiIterator, Allocator, traits>::match_jump,

      &perl_matcher<BidiIterator, Allocator, traits>::match_alt,

      &perl_matcher<BidiIterator, Allocator, traits>::match_rep,

      &perl_matcher<BidiIterator, Allocator, traits>::match_combining,

      &perl_matcher<BidiIterator, Allocator, traits>::match_soft_buffer_end,

      &perl_matcher<BidiIterator, Allocator, traits>::match_restart_continue,

      (::boost::is_random_access_iterator<BidiIterator>::value ? &perl_matcher<BidiIterator, Allocator, traits>::match_dot_repeat_fast : &perl_matcher<BidiIterator, Allocator, traits>::match_dot_repeat_slow),

      &perl_matcher<BidiIterator, Allocator, traits>::match_char_repeat,

      &perl_matcher<BidiIterator, Allocator, traits>::match_set_repeat,

      &perl_matcher<BidiIterator, Allocator, traits>::match_long_set_repeat,

      &perl_matcher<BidiIterator, Allocator, traits>::match_backstep,

      &perl_matcher<BidiIterator, Allocator, traits>::match_assert_backref,

      &perl_matcher<BidiIterator, Allocator, traits>::match_toggle_case,

   };

   push_recursion_stopper();

   do{

      while(pstate)

      {

         matcher_proc_type proc = s_match_vtable[pstate->type];

         ++state_count;

         if(!(this->*proc)())

         {

            if(state_count > max_state_count)

               raise_error(traits_inst, regex_constants::error_space);

            if((m_match_flags & match_partial) && (position == last) && (position != search_base))

               m_has_partial_match = true;

            bool successful_unwind = unwind(false);

            if((m_match_flags & match_partial) && (position == last) && (position != search_base))

               m_has_partial_match = true;

            if(false == successful_unwind)

               return m_recursive_result;

         }

      }

   }while(unwind(true));

   return m_recursive_result;

}

template <class BidiIterator, class Allocator, class traits>

void perl_matcher<BidiIterator, Allocator, traits>::extend_stack()

{

   if(used_block_count)

   {

      --used_block_count;

      saved_state* stack_base;

      saved_state* backup_state;

      stack_base = static_cast<saved_state*>(get_mem_block());

      backup_state = reinterpret_cast<saved_state*>(reinterpret_cast<char*>(stack_base)+BOOST_REGEX_BLOCKSIZE);

      saved_extra_block* block = static_cast<saved_extra_block*>(backup_state);

      --block;

      (void) new (block) saved_extra_block(m_stack_base, m_backup_state);

      m_stack_base = stack_base;

      m_backup_state = block;

   }

   else

      raise_error(traits_inst, regex_constants::error_size);

}

template <class BidiIterator, class Allocator, class traits>

inline void perl_matcher<BidiIterator, Allocator, traits>::push_matched_paren(int index, const sub_match<BidiIterator>& sub)

{

   BOOST_ASSERT(index);

   saved_matched_paren<BidiIterator>* pmp = static_cast<saved_matched_paren<BidiIterator>*>(m_backup_state);

   --pmp;

   if(pmp < m_stack_base)

   {

      extend_stack();

      pmp = static_cast<saved_matched_paren<BidiIterator>*>(m_backup_state);

      --pmp;

   }

   (void) new (pmp)saved_matched_paren<BidiIterator>(index, sub);

   m_backup_state = pmp;

}

template <class BidiIterator, class Allocator, class traits>

inline void perl_matcher<BidiIterator, Allocator, traits>::push_recursion_stopper()

{

   saved_state* pmp = m_backup_state;

   --pmp;

   if(pmp < m_stack_base)

   {

      extend_stack();

      pmp = m_backup_state;

      --pmp;

   }

   (void) new (pmp)saved_state(saved_type_recurse);

   m_backup_state = pmp;

}

template <class BidiIterator, class Allocator, class traits>

inline void perl_matcher<BidiIterator, Allocator, traits>::push_assertion(const re_syntax_base* ps, bool positive)

{

   saved_assertion<BidiIterator>* pmp = static_cast<saved_assertion<BidiIterator>*>(m_backup_state);

   --pmp;

   if(pmp < m_stack_base)

   {

      extend_stack();

      pmp = static_cast<saved_assertion<BidiIterator>*>(m_backup_state);

      --pmp;

   }

   (void) new (pmp)saved_assertion<BidiIterator>(positive, ps, position);

   m_backup_state = pmp;

}

template <class BidiIterator, class Allocator, class traits>

inline void perl_matcher<BidiIterator, Allocator, traits>::push_alt(const re_syntax_base* ps)

{

   saved_position<BidiIterator>* pmp = static_cast<saved_position<BidiIterator>*>(m_backup_state);

   --pmp;

   if(pmp < m_stack_base)

   {

      extend_stack();

      pmp = static_cast<saved_position<BidiIterator>*>(m_backup_state);

      --pmp;

   }

   (void) new (pmp)saved_position<BidiIterator>(ps, position, saved_state_alt);

   m_backup_state = pmp;

}

template <class BidiIterator, class Allocator, class traits>

inline void perl_matcher<BidiIterator, Allocator, traits>::push_non_greedy_repeat(const re_syntax_base* ps)

{

   saved_position<BidiIterator>* pmp = static_cast<saved_position<BidiIterator>*>(m_backup_state);

   --pmp;

   if(pmp < m_stack_base)

   {

      extend_stack();

      pmp = static_cast<saved_position<BidiIterator>*>(m_backup_state);

      --pmp;

   }

   (void) new (pmp)saved_position<BidiIterator>(ps, position, saved_state_non_greedy_long_repeat);

   m_backup_state = pmp;

}

template <class BidiIterator, class Allocator, class traits>

inline void perl_matcher<BidiIterator, Allocator, traits>::push_repeater_count(int i, repeater_count<BidiIterator>** s)

{

   saved_repeater<BidiIterator>* pmp = static_cast<saved_repeater<BidiIterator>*>(m_backup_state);

   --pmp;

   if(pmp < m_stack_base)

   {

      extend_stack();

      pmp = static_cast<saved_repeater<BidiIterator>*>(m_backup_state);

      --pmp;

   }

   (void) new (pmp)saved_repeater<BidiIterator>(i, s, position);

   m_backup_state = pmp;

}

template <class BidiIterator, class Allocator, class traits>

inline void perl_matcher<BidiIterator, Allocator, traits>::push_single_repeat(std::size_t c, const re_repeat* r, BidiIterator last_position, int state_id)

{

   saved_single_repeat<BidiIterator>* pmp = static_cast<saved_single_repeat<BidiIterator>*>(m_backup_state);

   --pmp;

   if(pmp < m_stack_base)

   {

      extend_stack();

      pmp = static_cast<saved_single_repeat<BidiIterator>*>(m_backup_state);

      --pmp;

   }

   (void) new (pmp)saved_single_repeat<BidiIterator>(c, r, last_position, state_id);

   m_backup_state = pmp;

}

template <class BidiIterator, class Allocator, class traits>

bool perl_matcher<BidiIterator, Allocator, traits>::match_startmark()

{

   int index = static_cast<const re_brace*>(pstate)->index;

   switch(index)

   {

   case 0:

      pstate = pstate->next.p;

      break;

   case -1:

   case -2:

      {

         // forward lookahead assert:

         const re_syntax_base* next_pstate = static_cast<const re_jump*>(pstate->next.p)->alt.p->next.p;

         pstate = pstate->next.p->next.p;

         push_assertion(next_pstate, index == -1);

         break;

      }

   case -3:

      {

         // independent sub-expression, currently this is always recursive:

         bool old_independent = m_independent;

         m_independent = true;

         const re_syntax_base* next_pstate = static_cast<const re_jump*>(pstate->next.p)->alt.p->next.p;

         pstate = pstate->next.p->next.p;

         bool r = match_all_states();

         pstate = next_pstate;

         m_independent = old_independent;

#ifdef BOOST_REGEX_MATCH_EXTRA

         if(r && (m_match_flags & match_extra))

         {

            //

            // our captures have been stored in *m_presult

            // we need to unpack them, and insert them

            // back in the right order when we unwind the stack:

            //

            match_results<BidiIterator, Allocator> temp_match(*m_presult);

            unsigned i;

            for(i = 0; i < temp_match.size(); ++i)

               (*m_presult)[i].get_captures().clear();

            // match everything else:

            r = match_all_states();

            // now place the stored captures back:

            for(i = 0; i < temp_match.size(); ++i)

            {

               typedef typename sub_match<BidiIterator>::capture_sequence_type seq;

               seq& s1 = (*m_presult)[i].get_captures();

               const seq& s2 = temp_match[i].captures();

               s1.insert(

                  s1.end(), 

                  s2.begin(), 

                  s2.end());

            }

         }

#endif

         return r;

      }

   case -4:

      {

      // conditional expression:

      const re_alt* alt = static_cast<const re_alt*>(pstate->next.p);

      BOOST_ASSERT(alt->type == syntax_element_alt);

      pstate = alt->next.p;

      if(pstate->type == syntax_element_assert_backref)

      {

         if(!match_assert_backref())

            pstate = alt->alt.p;

         break;

      }

      else

      {

         // zero width assertion, have to match this recursively:

         BOOST_ASSERT(pstate->type == syntax_element_startmark);

         bool negated = static_cast<const re_brace*>(pstate)->index == -2;

         BidiIterator saved_position = position;

         const re_syntax_base* next_pstate = static_cast<const re_jump*>(pstate->next.p)->alt.p->next.p;

         pstate = pstate->next.p->next.p;

         bool r = match_all_states();

         position = saved_position;

         if(negated)

            r = !r;

         if(r)

            pstate = next_pstate;

         else

            pstate = alt->alt.p;

         break;

      }

      }

   default:

   {

      BOOST_ASSERT(index > 0);

      if((m_match_flags & match_nosubs) == 0)

      {

         push_matched_paren(index, (*m_presult)[index]);

         m_presult->set_first(position, index);

      }

      pstate = pstate->next.p;

      break;

   }

   }

   return true;

}

template <class BidiIterator, class Allocator, class traits>

bool perl_matcher<BidiIterator, Allocator, traits>::match_alt()

{

   bool take_first, take_second;

   const re_alt* jmp = static_cast<const re_alt*>(pstate);

   // find out which of these two alternatives we need to take:

   if(position == last)

   {

      take_first = jmp->can_be_null & mask_take;

      take_second = jmp->can_be_null & mask_skip;

   }

   else

   {

      take_first = can_start(*position, jmp->_map, (unsigned char)mask_take);

      take_second = can_start(*position, jmp->_map, (unsigned char)mask_skip);

  }

   if(take_first)

   {

      // we can take the first alternative,

      // see if we need to push next alternative:

      if(take_second)

      {

         push_alt(jmp->alt.p);

      }

      pstate = pstate->next.p;

      return true;

   }

   if(take_second)

   {

      pstate = jmp->alt.p;

      return true;

   }

   return false;  // neither option is possible

}

template <class BidiIterator, class Allocator, class traits>

bool perl_matcher<BidiIterator, Allocator, traits>::match_rep()

{

#ifdef BOOST_MSVC

#pragma warning(push)

#pragma warning(disable:4127 4244)

#endif

#ifdef __BORLANDC__

#pragma option push -w-8008 -w-8066 -w-8004

#endif

   const re_repeat* rep = static_cast<const re_repeat*>(pstate);

   // find out which of these two alternatives we need to take:

   bool take_first, take_second;

   if(position == last)

   {

      take_first = rep->can_be_null & mask_take;

      take_second = rep->can_be_null & mask_skip;

   }

   else

   {

      take_first = can_start(*position, rep->_map, (unsigned char)mask_take);

      take_second = can_start(*position, rep->_map, (unsigned char)mask_skip);

   }

   if((m_backup_state->state_id != saved_state_repeater_count) 

      || (static_cast<saved_repeater<BidiIterator>*>(m_backup_state)->count.get_id() != rep->state_id)

      || (next_count->get_id() != rep->state_id))

   {

      // we're moving to a different repeat from the last

      // one, so set up a counter object:

      push_repeater_count(rep->state_id, &next_count);

   }

   //

   // If we've had at least one repeat already, and the last one 

   // matched the NULL string then set the repeat count to

   // maximum:

   //

   next_count->check_null_repeat(position, rep->max);

   if(next_count->get_count() < rep->min)

   {

      // we must take the repeat:

      if(take_first)

      {

         // increase the counter:

         ++(*next_count);

         pstate = rep->next.p;

         return true;

      }

      return false;

   }

   bool greedy = (rep->greedy) && (!(m_match_flags & regex_constants::match_any) || m_independent);   

   if(greedy)

   {

      // try and take the repeat if we can:

      if((next_count->get_count() < rep->max) && take_first)

      {

         if(take_second)

         {

            // store position in case we fail:

            push_alt(rep->alt.p);

         }

         // increase the counter:

         ++(*next_count);

         pstate = rep->next.p;

         return true;

      }

      else if(take_second)

      {

         pstate = rep->alt.p;

         return true;

      }

      return false; // can't take anything, fail...