/*
 *  matiec - a compiler for the programming languages defined in IEC 61131-3
 *
 *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)
 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * This code is made available on the understanding that it will not be
 * used in safety-critical situations without a full and competent review.
 *
 * Based on the
 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
 *
 */



/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
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class search_location_type_c: public iterator_visitor_c {

  public:
    typedef enum {
      none_lt,
      input_lt,
      output_lt,
      memory_lt
    } locationtype_t;

    locationtype_t current_location_type;

  public:
    search_location_type_c(void) {}

    virtual ~search_location_type_c(void) {}

    locationtype_t get_location_type(symbol_c *symbol) {
      current_location_type = none_lt;
      symbol->accept(*this);
      if (current_location_type == none_lt) ERROR;
      return current_location_type;
    }

  private:

    void *visit(incompl_location_c* symbol) {
      if (symbol->value[1] == 'I')
        current_location_type = input_lt;
     else if (symbol->value[1] == 'Q')
        current_location_type = output_lt;
     else if (symbol->value[1] == 'M')
        current_location_type = memory_lt;
      return NULL;
    }

    void *visit(direct_variable_c *symbol) {
      if (symbol->value[1] == 'I')
        current_location_type = input_lt;
     else if (symbol->value[1] == 'Q')
        current_location_type = output_lt;
     else if (symbol->value[1] == 'M')
        current_location_type = memory_lt;
      return NULL;
    }
};



/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/


class search_type_symbol_c: public iterator_visitor_c {

  public:
    typedef enum {
      none_vtc,
      variable_vtc,
      array_vtc,
      structure_vtc,
      function_block_vtc
    } vartypecategory_t;

    vartypecategory_t current_var_type_category;

  private:
    symbol_c *current_var_type_symbol;
    symbol_c *current_var_type_name;
    search_base_type_c search_base_type;
    search_fb_typedecl_c *search_fb_typedecl;

  public:
    search_type_symbol_c(symbol_c *scope) {
      search_fb_typedecl = new search_fb_typedecl_c(scope);
    }

    virtual ~search_type_symbol_c(void) {
      delete search_fb_typedecl;
    }

    symbol_c *get_type_symbol(symbol_c* symbol) {
      this->current_var_type_category = variable_vtc;
      this->current_var_type_symbol = NULL;
      this->current_var_type_name = NULL;

      symbol_c* var_type_symbol = spec_init_sperator_c::get_spec(symbol);
      if (var_type_symbol == NULL) {
        var_type_symbol = symbol;
      }

      var_type_symbol->accept(*this);

      if (this->current_var_type_symbol == NULL)
    	this->current_var_type_symbol = var_type_symbol;

      return (this->current_var_type_symbol);
    }

    symbol_c *get_current_type_name(void) {
      if (this->current_var_type_name == NULL)
    	return (this->current_var_type_symbol);

      return (this->current_var_type_name);
    }

    void *visit(identifier_c* symbol) {
      if (this->current_var_type_name == NULL) {
        this->current_var_type_name = symbol;

        this->current_var_type_symbol = search_fb_typedecl->get_decl(this->current_var_type_name);
        if (this->current_var_type_symbol != NULL)
          this->current_var_type_category = function_block_vtc;

        else {
          this->current_var_type_symbol = (symbol_c *)(this->current_var_type_name->accept(search_base_type));
          this->current_var_type_symbol->accept(*this);
        }
      }
      return NULL;
    }

    void *visit(array_specification_c* symbol) {
      this->current_var_type_category = array_vtc;

      if (this->current_var_type_name == NULL)
        this->current_var_type_name = symbol->non_generic_type_name;

      return NULL;
    }

    void *visit(structure_element_declaration_list_c* symbol) {
      this->current_var_type_category = structure_vtc;
      return NULL;
    }

};

/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/

class generate_var_list_c: protected generate_c_typedecl_c {
  
  public:
    typedef struct
    {
      symbol_c *symbol;
    } SYMBOL;

    typedef enum {
      none_dt,
      programs_dt,
      variables_dt
    } declarationtype_t;

    declarationtype_t current_declarationtype;
    
    typedef enum {
      none_vcc,
      external_vcc,
      located_input_vcc,
      located_memory_vcc,
      located_output_vcc,
    } varclasscategory_t;

    varclasscategory_t current_var_class_category;
    
  private:
    symbol_c *current_var_type_symbol;
    symbol_c *current_var_type_name;
    unsigned int current_var_number;
    unsigned int step_number;
    unsigned int transition_number;
    unsigned int action_number;
    bool configuration_defined;
    std::list<SYMBOL> current_symbol_list;
    search_type_symbol_c *search_type_symbol;
    
  public:
    generate_var_list_c(stage4out_c *s4o_ptr, symbol_c *scope)
    : generate_c_typedecl_c(s4o_ptr) {
      search_type_symbol = new search_type_symbol_c(scope);
      current_var_number = 0;
      current_var_type_symbol = NULL;
      current_var_type_name = NULL;
      current_declarationtype = none_dt;
      current_var_class_category = none_vcc;
    }
    
    ~generate_var_list_c(void) {
      delete search_type_symbol;
    }
    
    void update_var_type_symbol(symbol_c *symbol) {
      this->current_var_type_symbol = search_type_symbol->get_type_symbol(symbol);
      this->current_var_type_name = search_type_symbol->get_current_type_name();
    }

    void reset_var_type_symbol(void) {
      this->current_var_type_symbol = NULL;
    }
    
    void generate_programs(symbol_c *symbol) {
      s4o.print("// Programs\n");
      current_var_number = 0;
      configuration_defined = false;
      current_declarationtype = programs_dt;
      symbol->accept(*this);
      current_declarationtype = none_dt;
      s4o.print("\n");
    }
    
    void generate_variables(symbol_c *symbol) {
      s4o.print("// Variables\n");
      current_var_number = 0;
      configuration_defined = false;
      current_declarationtype = variables_dt;
      symbol->accept(*this);
      current_declarationtype = none_dt;
      s4o.print("\n");
    }
    
    void declare_variables(symbol_c *symbol) {
      list_c *list = dynamic_cast<list_c *>(symbol);
      /* should NEVER EVER occur!! */
      if (list == NULL) ERROR;

      for(int i = 0; i < list->n; i++) {
        declare_variable(list->elements[i]);
      }
    }
    
    void declare_variable(symbol_c *symbol) {
      // Arrays and structures are not supported in debugging
      switch (search_type_symbol->current_var_type_category) {
          case search_type_symbol_c::array_vtc:
          case search_type_symbol_c::structure_vtc:
          return;
          default:
           break;
      }
      print_var_number();
      s4o.print(";");
      switch (search_type_symbol->current_var_type_category) {
        case search_type_symbol_c::array_vtc:
          s4o.print("ARRAY");
          break;
        case search_type_symbol_c::structure_vtc:
          s4o.print("STRUCT");
          break;
        case search_type_symbol_c::function_block_vtc:
          s4o.print("FB");
          break;
        default:
          switch (this->current_var_class_category) {
            case external_vcc:
             s4o.print("EXT");
             break;
            case located_input_vcc:
             s4o.print("IN");
             break;
            case located_memory_vcc:
             s4o.print("MEM");
             break;
            case located_output_vcc:
             s4o.print("OUT");
             break;
            default:
             s4o.print("VAR");
             break;
          }
          break;
      }
      s4o.print(";");
      print_symbol_list();
      symbol->accept(*this);
      s4o.print(";");
      print_symbol_list();
      symbol->accept(*this);
      s4o.print(";");
      switch (search_type_symbol->current_var_type_category) {
        case search_type_symbol_c::structure_vtc:
        case search_type_symbol_c::function_block_vtc:
          this->current_var_type_name->accept(*this);
          s4o.print(";\n");
          SYMBOL *current_name;
          current_name = new SYMBOL;
          current_name->symbol = symbol;
          current_symbol_list.push_back(*current_name);
          this->current_var_type_symbol->accept(*this);
          current_symbol_list.pop_back();
          break;
        case search_type_symbol_c::array_vtc:
          this->current_var_type_name->accept(*this);
          s4o.print(";\n");
          break;
        default:
          this->current_var_type_symbol->accept(*this);
          s4o.print(";\n");
          break;
      }
    }

    void print_var_number(void) {
      char str[10];
      sprintf(str, "%d", current_var_number);
      s4o.print(str);
      current_var_number++;
    }
        
    void print_step_number(void) {
      char str[10];
      sprintf(str, "%d", step_number);
      s4o.print(str);
    }
    
    void print_transition_number(void) {
      char str[10];
      sprintf(str, "%d", transition_number);
      s4o.print(str);
    }
    
    void print_action_number(void) {
      char str[10];
      sprintf(str, "%d", action_number);
      s4o.print(str);
    }
    
    void print_symbol_list(void) {
      std::list<SYMBOL>::iterator pt;
      for(pt = current_symbol_list.begin(); pt != current_symbol_list.end(); pt++) {
        pt->symbol->accept(*this);
        s4o.print(".");
      }
    }

/********************************************/
/* B.1.4.3 - Declaration and initialization */
/********************************************/
    
    /*  [variable_name] location ':' located_var_spec_init */
    /* variable_name -> may be NULL ! */
    //SYM_REF4(located_var_decl_c, variable_name, location, located_var_spec_init, unused)
    void *visit(located_var_decl_c *symbol) {
        /* Start off by setting the current_var_type_symbol and
         * current_var_init_symbol private variables...
         */
        update_var_type_symbol(symbol->located_var_spec_init);
        
        search_location_type_c search_location_type;
        switch (search_location_type.get_location_type(symbol->location)) {
          case search_location_type_c::input_lt:
            this->current_var_class_category = located_input_vcc;
            break;
          case search_location_type_c::memory_lt:
            this->current_var_class_category = located_memory_vcc;
            break;
          case search_location_type_c::output_lt:
              this->current_var_class_category = located_output_vcc;
              break;
          default:
            ERROR;
            break;
        }

        if (symbol->variable_name != NULL)
          declare_variable(symbol->variable_name);
        else
          declare_variable(symbol->location);
        
        this->current_var_class_category = none_vcc;

        /* Values no longer in scope, and therefore no longer used.
         * Make an effort to keep them set to NULL when not in use
         * in order to catch bugs as soon as possible...
         */
        reset_var_type_symbol();
        return NULL;
    }

    /* variable_name incompl_location ':' var_spec */
    /* variable_name -> may be NULL ! */
    //SYM_REF3(incompl_located_var_decl_c, variable_name, incompl_location, var_spec)
    void *visit(incompl_located_var_decl_c *symbol) {
        /* Start off by setting the current_var_type_symbol and
         * current_var_init_symbol private variables...
         */
        update_var_type_symbol(symbol->var_spec);

        search_location_type_c search_location_type;
        switch (search_location_type.get_location_type(symbol->incompl_location)) {
          case search_location_type_c::input_lt:
            this->current_var_class_category = located_input_vcc;
            break;
          case search_location_type_c::memory_lt:
            this->current_var_class_category = located_memory_vcc;
            break;
          case search_location_type_c::output_lt:
            this->current_var_class_category = located_output_vcc;
            break;
          default:
            ERROR;
            break;
        }

        if (symbol->variable_name != NULL)
          declare_variable(symbol->variable_name);
        else
          declare_variable(symbol->incompl_location);

        this->current_var_class_category = none_vcc;

        /* Values no longer in scope, and therefore no longer used.
        * Make an effort to keep them set to NULL when not in use
        * in order to catch bugs as soon as possible...
        */
       reset_var_type_symbol();
        return NULL;
    }
    
    /*  var1_list ':' array_spec_init */
    // SYM_REF2(array_var_init_decl_c, var1_list, array_spec_init)
    void *visit(array_var_init_decl_c *symbol) {
      TRACE("array_var_init_decl_c");
      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol->array_spec_init);
      
      declare_variables(symbol->var1_list);

      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();
    
      return NULL;
    }

    /*  var1_list ':' array_specification */
    //SYM_REF2(array_var_declaration_c, var1_list, array_specification)
    void *visit(array_var_declaration_c *symbol) {
       TRACE("array_var_declaration_c");
       /* Start off by setting the current_var_type_symbol and
        * current_var_init_symbol private variables...
        */
       update_var_type_symbol(symbol->array_specification);

       declare_variables(symbol->var1_list);

       /* Values no longer in scope, and therefore no longer used.
        * Make an effort to keep them set to NULL when not in use
        * in order to catch bugs as soon as possible...
        */
       reset_var_type_symbol();

       return NULL;
    }

    /*  var1_list ':' initialized_structure */
    // SYM_REF2(structured_var_init_decl_c, var1_list, initialized_structure)
    void *visit(structured_var_init_decl_c *symbol) {
      TRACE("structured_var_init_decl_c");
      /* Please read the comments inside the var1_init_decl_c
       * visitor, as they apply here too.
       */
    
      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol->initialized_structure);
    
      /* now to produce the c equivalent... */
      declare_variables(symbol->var1_list);
    
      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();
    
      return NULL;
    }
    
    /*  var1_list ':' structure_type_name */
    //SYM_REF2(structured_var_declaration_c, var1_list, structure_type_name)
    void *visit(structured_var_declaration_c *symbol) {
      TRACE("structured_var_declaration_c");
      /* Please read the comments inside the var1_init_decl_c
       * visitor, as they apply here too.
       */

      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol->structure_type_name);

      /* now to produce the c equivalent... */
      declare_variables(symbol->var1_list);

      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();

      return NULL;
    }

    /* enumerated_value_list ',' enumerated_value */
    void *visit(enumerated_value_list_c *symbol) {
      this->current_var_type_name->accept(*this);
      return NULL;
    }
    
    /* fb_name_list ':' function_block_type_name ASSIGN structure_initialization */
    /* structure_initialization -> may be NULL ! */
    void *visit(fb_name_decl_c *symbol) {
      TRACE("fb_name_decl_c");
      /* Please read the comments inside the var1_init_decl_c
       * visitor, as they apply here too.
       */
    
      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol);
    
      /* now to produce the c equivalent... */
      declare_variables(symbol->fb_name_list);
    
      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();
    
      return NULL;
    }

    /*  global_var_name ':' (simple_specification|subrange_specification|enumerated_specification|array_specification|prev_declared_structure_type_name|function_block_type_name */
    //SYM_REF2(external_declaration_c, global_var_name, specification)
    void *visit(external_declaration_c *symbol) {
      TRACE("external_declaration_c");
      /* Please read the comments inside the var1_init_decl_c
       * visitor, as they apply here too.
       */
    
      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol->specification);
      
      this->current_var_class_category = external_vcc;

      /* now to produce the c equivalent... */
      declare_variable(symbol->global_var_name);
      
      this->current_var_class_category = none_vcc;

      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();
      return NULL;
    }

    /*| global_var_spec ':' [located_var_spec_init|function_block_type_name] */
    /* type_specification ->may be NULL ! */
    // SYM_REF2(global_var_decl_c, global_var_spec, type_specification)
    void *visit(global_var_decl_c *symbol) {
      TRACE("global_var_decl_c");
      /* Please read the comments inside the var1_init_decl_c
       * visitor, as they apply here too.
       */
    
      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol->type_specification);
    
      /* now to produce the c equivalent... */
      symbol->global_var_spec->accept(*this);
    
      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();
    
      return NULL;
    }
    
    void *visit(global_var_list_c *symbol) {
      declare_variables(symbol);
      return NULL;
    }
    
    /*| global_var_name location */
    // SYM_REF2(global_var_spec_c, global_var_name, location)
    void *visit(global_var_spec_c *symbol) {
      search_location_type_c search_location_type;
	  switch (search_location_type.get_location_type(symbol->location)) {
		case search_location_type_c::input_lt:
		  this->current_var_class_category = located_input_vcc;
		  break;
		case search_location_type_c::memory_lt:
		  this->current_var_class_category = located_memory_vcc;
		  break;
		case search_location_type_c::output_lt:
		  this->current_var_class_category = located_output_vcc;
		  break;
		default:
		  ERROR;
	      break;
	  }

      if (symbol->global_var_name != NULL)
        declare_variable(symbol->global_var_name);
      else
        declare_variable(symbol->location);

      this->current_var_class_category = none_vcc;

      return NULL;
    }
    
    void *visit(var1_init_decl_c *symbol) {
      TRACE("var1_init_decl_c");
    
      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol->spec_init);
    
      /* now to produce the c equivalent... */
      declare_variables(symbol->var1_list);
    
      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();
    
      return NULL;
    }

    void *visit(en_param_declaration_c *symbol) {
      TRACE("en_param_declaration_c");

      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol->type);

      /* now to produce the c equivalent... */
      declare_variable(symbol->name);

      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();

      return NULL;
    }

    void *visit(eno_param_declaration_c *symbol) {
      TRACE("eno_param_declaration_c");

      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol->type);

      /* now to produce the c equivalent... */
      declare_variable(symbol->name);

      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();

      return NULL;
    }

/********************************/
/* B 1.3.3 - Derived data types */
/********************************/
    void *visit(data_type_declaration_c *symbol) {
      return NULL;
    }

    void *visit(structure_element_declaration_list_c *symbol) {
      for(int i = 0; i < symbol->n; i++) {
        symbol->elements[i]->accept(*this);
      }
      return NULL;
    }

    void *visit(structure_element_declaration_c *symbol) {
      /* Start off by setting the current_var_type_symbol and
       * current_var_init_symbol private variables...
       */
      update_var_type_symbol(symbol->spec_init);
      
      /* now to produce the c equivalent... */
      declare_variable(symbol->structure_element_name);
      
      /* Values no longer in scope, and therefore no longer used.
       * Make an effort to keep them set to NULL when not in use
       * in order to catch bugs as soon as possible...
       */
      reset_var_type_symbol();
      
      return NULL;
    }

/**************************************/
/* B.1.5 - Program organization units */
/**************************************/

/***********************/
/* B 1.5.1 - Functions */
/***********************/
    void *visit(function_declaration_c *symbol) {
      return NULL;
    }

/*****************************/
/* B 1.5.2 - Function Blocks */
/*****************************/
    void *visit(function_block_declaration_c *symbol) {
      if (current_declarationtype == variables_dt && configuration_defined) {
        symbol->var_declarations->accept(*this);
        symbol->fblock_body->accept(*this);
      }
      return NULL;
    }

/**********************/
/* B 1.5.3 - Programs */
/**********************/
    void *visit(program_declaration_c *symbol) {
      if (current_declarationtype == variables_dt && configuration_defined) {
        symbol->var_declarations->accept(*this);
        symbol->function_block_body->accept(*this);
      }
      return NULL;
    }

/**********************************************/
/* B 1.6 - Sequential function chart elements */
/**********************************************/
    
    /* | sequential_function_chart sfc_network */
    //SYM_LIST(sequential_function_chart_c)
    void *visit(sequential_function_chart_c *symbol) {
      step_number = 0;
      transition_number = 0;
      action_number = 0;
      for(int i = 0; i < symbol->n; i++) {
        symbol->elements[i]->accept(*this);
      }
      return NULL;
    }
    
    /* INITIAL_STEP step_name ':' action_association_list END_STEP */
    //SYM_REF2(initial_step_c, step_name, action_association_list)
    void *visit(initial_step_c *symbol) {
      print_var_number();
      s4o.print(";VAR;");
      print_symbol_list();
      symbol->step_name->accept(*this);
      s4o.print(".X;");
      print_symbol_list();
      s4o.print("__step_list[");
      print_step_number();
      s4o.print("].state;BOOL;\n");
      step_number++;
      return NULL;
    }
    
    /* STEP step_name ':' action_association_list END_STEP */
    //SYM_REF2(step_c, step_name, action_association_list)
    void *visit(step_c *symbol) {
      print_var_number();
      s4o.print(";VAR;");
      print_symbol_list();
      symbol->step_name->accept(*this);
      s4o.print(".X;");
      print_symbol_list();
      s4o.print("__step_list[");
      print_step_number();
      s4o.print("].state;BOOL;\n");
      step_number++;
      return NULL;
    }
    
    /* TRANSITION [transition_name] ['(' PRIORITY ASSIGN integer ')'] 
     *   FROM steps TO steps 
     *   transition_condition 
     * END_TRANSITION
     */
    /* transition_name -> may be NULL ! */
    /* integer -> may be NULL ! */
    //SYM_REF5(transition_c, transition_name, integer, from_steps, to_steps, transition_condition)
    void *visit(transition_c *symbol) {
      print_var_number();
      s4o.print(";VAR;");
      print_symbol_list();
      symbol->from_steps->accept(*this);
      s4o.print("->");
      symbol->to_steps->accept(*this);
      s4o.print(";");
      print_symbol_list();
      s4o.print("__debug_transition_list[");
      print_transition_number();
      s4o.print("];BOOL;\n");
      transition_number++;
      return NULL;
    }
    
    /* step_name | '(' step_name_list ')' */
    /* step_name      -> may be NULL ! */
    /* step_name_list -> may be NULL ! */
    //SYM_REF2(steps_c, step_name, step_name_list)
    void *visit(steps_c *symbol) {
      if (symbol->step_name != NULL)
        symbol->step_name->accept(*this);
      if (symbol->step_name_list != NULL)
        symbol->step_name_list->accept(*this);
      return NULL;
    }
    
    /* | step_name_list ',' step_name */
    //SYM_LIST(step_name_list_c)
    void *visit(step_name_list_c *symbol) {
      for(int i = 0; i < symbol->n; i++) {
        symbol->elements[i]->accept(*this);
        if (i < symbol->n - 1)
          s4o.print(",");
      }
      return NULL;
    }

    /* ACTION action_name ':' function_block_body END_ACTION */
    //SYM_REF2(action_c, action_name, function_block_body)
    void *visit(action_c *symbol) {
      print_var_number();
      s4o.print(";VAR;");
      print_symbol_list();
      symbol->action_name->accept(*this);
      s4o.print(".Q;");
      print_symbol_list();
      s4o.print("__action_list[");
      print_action_number();
      s4o.print("].state;BOOL;\n");
      action_number++;
      return NULL;
    }


/**************************************/
/* B.1.7 - Configuration elements     */
/**************************************/

    /*  PROGRAM [RETAIN | NON_RETAIN] program_name [WITH task_name] ':' program_type_name ['(' prog_conf_elements ')'] */
    //SYM_REF6(program_configuration_c, retain_option, program_name, task_name, program_type_name, prog_conf_elements, unused)
    void *visit(program_configuration_c *symbol) {
      
      switch (current_declarationtype) {
        case programs_dt:
          print_var_number();
          s4o.print(";");
          print_symbol_list();
          symbol->program_name->accept(*this);
          s4o.print(";");
          symbol->program_type_name->accept(*this);
          s4o.print(";\n");
          break;
        case variables_dt:
          /* Start off by setting the current_var_type_symbol and
           * current_var_init_symbol private variables...
           */
          update_var_type_symbol(symbol->program_type_name);
          
          declare_variable(symbol->program_name);
          
          /* Values no longer in scope, and therefore no longer used.
           * Make an effort to keep them set to NULL when not in use
           * in order to catch bugs as soon as possible...
           */
          reset_var_type_symbol();
          
          break;
        default:
          break;
      }
      
      return NULL;
    }

    /* CONFIGURATION configuration_name
     *   optional_global_var_declarations
     *   (resource_declaration_list | single_resource_declaration)
     *   optional_access_declarations
     *   optional_instance_specific_initializations
     * END_CONFIGURATION
     */
    //SYM_REF5(configuration_declaration_c, configuration_name, global_var_declarations, resource_declarations, access_declarations, instance_specific_initializations)
    void *visit(configuration_declaration_c *symbol) {
      SYMBOL *current_name;
      current_name = new SYMBOL;
      current_name->symbol = symbol->configuration_name;
      current_symbol_list.push_back(*current_name);
      configuration_defined = true;
      
      switch (current_declarationtype) {
        case variables_dt:
          if (symbol->global_var_declarations != NULL)
            symbol->global_var_declarations->accept(*this);
          break;
        default:
          break;
      }

      symbol->resource_declarations->accept(*this);
      current_symbol_list.pop_back();
      configuration_defined = false;
      return NULL;
    }
    
    /* RESOURCE resource_name ON resource_type_name
     *   optional_global_var_declarations
     *   single_resource_declaration
     * END_RESOURCE
     */
    //SYM_REF4(resource_declaration_c, resource_name, resource_type_name, global_var_declarations, resource_declaration)
    void *visit(resource_declaration_c *symbol) {
      SYMBOL *current_name;
      current_name = new SYMBOL;
      current_name->symbol = symbol->resource_name;
      current_symbol_list.push_back(*current_name);

      switch (current_declarationtype) {
        case variables_dt:
          if (symbol->global_var_declarations != NULL)
            symbol->global_var_declarations->accept(*this);
          break;
        default:
          break;
      }
      
      
      symbol->resource_declaration->accept(*this);
      
      current_symbol_list.pop_back();
      return NULL;
    }

    /* task_configuration_list program_configuration_list */
    //SYM_REF2(single_resource_declaration_c, task_configuration_list, program_configuration_list)
    void *visit(single_resource_declaration_c *symbol) {
      symbol->program_configuration_list->accept(*this);
      return NULL;
    }
    
    
/*************************************/
/* B 2.1 - Instructions and operands */
/*************************************/
    void *visit(instruction_list_c *symbol) {
      return NULL;
    }
    
/************************/
/* B 3.2 - Statements   */
/************************/
    void *visit(statement_list_c *symbol) {
      return NULL;
    }
    
};