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/*

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 *  matiec - a compiler for the programming languages defined in IEC 61131-3

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 *

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 *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)

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 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant

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 *

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 *  This program is free software: you can redistribute it and/or modify

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 *  it under the terms of the GNU General Public License as published by

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 *  the Free Software Foundation, either version 3 of the License, or

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 *  (at your option) any later version.

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 *

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 *  This program is distributed in the hope that it will be useful,

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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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 *  You should have received a copy of the GNU General Public License

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 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

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 *

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 *

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 * This code is made available on the understanding that it will not be

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 * used in safety-critical situations without a full and competent review.

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 */

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/*

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 * An IEC 61131-3 compiler.

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 *

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 * Based on the

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 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

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 *

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 */

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/* Search in a VAR* END_VAR declaration for the delcration of the specified variable instance. 

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 * Will return:

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 *     - the declaration itself (get_decl() )

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 *     - the type of declaration in which the variable was declared (get_vartype() )

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 *

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 * The variable instance may NOT be a member of a structure of a memeber

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 * of a structure of an element of an array of ...

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 *

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 * For example, considering the following 'variables':

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 *    window.points[1].coordinate.x

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 *    window.points[1].colour

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 *    offset[99]

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 *

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 *   passing a reference to 'points', 'points[1]', 'points[1].colour', 'colour'

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 *    ARE NOT ALLOWED!

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 *

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 * This class must only be passed the name of the variable that will appear

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 * in the variable declaration. In the above examples, this would be

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 *   'window.points[1].coordinate.x'

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 *   'window.points[1].coordinate'

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 *   'window.points[1]'

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 *   'window'

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 *   'window.points[1].colour'

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 *   'offset'

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 *   'offset[99]'

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 *

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 *

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 */

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/* Note: 

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 * Determining the declaration type of a specific variable instance (including

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 * function block instances) really means determining whether the variable was declared in a

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 *  VAR_INPUT

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 *  VAR_OUTPUT

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 *  VAR_IN_OUT

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 *  VAR

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 *  VAR_TEMP

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 *  VAR_EXTERNAL

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 *  VAR_GLOBAL

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 *  VAR <var_name> AT <location>   -> Located variable!

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 * 

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 */

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/* Note:

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 *  The current_type_decl that this class returns may reference the

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 * name of a type, or the type declaration itself!

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 * For an example of the first, consider a variable declared as ...

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 * x : AAA;

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 * where the AAA type is previously declared as whatever.

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 * For an example of the second, consider a variable declared as ...

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 * x : array of int [10];  ---->  is allowed

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 *

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 * If it is the first, we will return a reference to the name, if the second

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 * we return a reference to the declaration!!

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 */

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#include "absyntax_utils.hh"

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search_var_instance_decl_c::search_var_instance_decl_c(symbol_c *search_scope) {

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  this->current_vartype = none_vt;

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  this->search_scope = search_scope;

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  this->search_name = NULL;

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  this->current_type_decl = NULL;

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  this->current_option = none_opt;

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}

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symbol_c *search_var_instance_decl_c::get_decl(symbol_c *variable) {

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  this->current_vartype = none_vt;

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  this->current_option  = none_opt;

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  this->search_name = get_var_name_c::get_name(variable);

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  if (NULL == search_scope) return NULL; // NOTE: This is not an ERROR! declaration_check_c, for e.g., relies on this returning NULL!

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  return (symbol_c *)search_scope->accept(*this);

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}

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search_var_instance_decl_c::vt_t search_var_instance_decl_c::get_vartype(symbol_c *variable) {

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  this->current_vartype = none_vt;

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  this->current_option  = none_opt;

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  this->search_name = get_var_name_c::get_name(variable);

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  if (NULL == search_scope) ERROR;

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  search_scope->accept(*this);

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  return this->current_vartype;

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}

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search_var_instance_decl_c::opt_t search_var_instance_decl_c::get_option(symbol_c *variable) {

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  this->current_vartype = none_vt;

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  this->current_option  = none_opt;

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  this->search_name = get_var_name_c::get_name(variable);

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  if (NULL == search_scope) ERROR;

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  search_scope->accept(*this);

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  return this->current_option;

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}

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

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/* B 0 - Programming Model */

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

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void *search_var_instance_decl_c::visit(library_c *symbol) {

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  /* we do not want to search multiple declaration scopes,

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   * so we do not visit all the functions, function blocks, etc...

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   */

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  return NULL;

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}

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

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/* B 1.4.3 - Declaration & Initialization */

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

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/* edge -> The F_EDGE or R_EDGE directive */

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// SYM_REF2(edge_declaration_c, edge, var1_list)

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// TODO

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void *search_var_instance_decl_c::visit(constant_option_c *symbol) {

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  current_option = constant_opt;

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  return NULL;

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}

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void *search_var_instance_decl_c::visit(retain_option_c *symbol) {

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  current_option = retain_opt;

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  return NULL;

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}

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void *search_var_instance_decl_c::visit(non_retain_option_c *symbol) {

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  current_option = non_retain_opt;

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  return NULL;

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}

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void *search_var_instance_decl_c::visit(input_declarations_c *symbol) {

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  current_vartype = input_vt;

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  current_option  = none_opt; /* not really required. Just to make the code more readable */

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  if (NULL != symbol->option)  

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    symbol->option->accept(*this);

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  void *res = symbol->input_declaration_list->accept(*this);

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  if (res == NULL) {

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    current_vartype = none_vt;

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    current_option  = none_opt;

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  }

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  return res;

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}

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/* VAR_OUTPUT [RETAIN | NON_RETAIN] var_init_decl_list END_VAR */

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/* option -> may be NULL ! */

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void *search_var_instance_decl_c::visit(output_declarations_c *symbol) {

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  current_vartype = output_vt;

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  current_option  = none_opt; /* not really required. Just to make the code more readable */

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  if (NULL != symbol->option)

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    symbol->option->accept(*this);

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  void *res = symbol->var_init_decl_list->accept(*this);

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  if (res == NULL) {

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    current_vartype = none_vt;

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    current_option  = none_opt;

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  }

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  return res;

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}

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/*  VAR_IN_OUT var_declaration_list END_VAR */

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void *search_var_instance_decl_c::visit(input_output_declarations_c *symbol) {

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  current_vartype = inoutput_vt;

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  current_option  = none_opt; /* not really required. Just to make the code more readable */

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  void *res = symbol->var_declaration_list->accept(*this);

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  if (res == NULL) {

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    current_vartype = none_vt;

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  }

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  return res;

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}

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/* ENO : BOOL */

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void *search_var_instance_decl_c::visit(eno_param_declaration_c *symbol) {

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  if (compare_identifiers(symbol->name, search_name) == 0)

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    return symbol->type;

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  return NULL;

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}

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/* VAR [CONSTANT] var_init_decl_list END_VAR */

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/* option -> may be NULL ! */

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/* helper symbol for input_declarations */

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void *search_var_instance_decl_c::visit(var_declarations_c *symbol) {

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  current_vartype = private_vt;

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  current_option  = none_opt; /* not really required. Just to make the code more readable */

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  if (NULL != symbol->option)

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    symbol->option->accept(*this);

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  void *res = symbol->var_init_decl_list->accept(*this);

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  if (res == NULL) {

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    current_vartype = none_vt;

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    current_option = none_opt;

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  }

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  return res;

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}

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/*  VAR RETAIN var_init_decl_list END_VAR */

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void *search_var_instance_decl_c::visit(retentive_var_declarations_c *symbol) {

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  current_vartype = private_vt;

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  current_option  = retain_opt;

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  void *res = symbol->var_init_decl_list->accept(*this);

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  if (res == NULL) {

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    current_vartype = none_vt;

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    current_option = none_opt;

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  }

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  return res;

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}

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/*  VAR [CONSTANT|RETAIN|NON_RETAIN] located_var_decl_list END_VAR */

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/* option -> may be NULL ! */

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//SYM_REF2(located_var_declarations_c, option, located_var_decl_list)

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void *search_var_instance_decl_c::visit(located_var_declarations_c *symbol) {

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  current_vartype = located_vt;

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  current_option  = none_opt; /* not really required. Just to make the code more readable */

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  if (NULL != symbol->option)

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    symbol->option->accept(*this);

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  void *res = symbol->located_var_decl_list->accept(*this);

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  if (res == NULL) {

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    current_vartype = none_vt;

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    current_option  = none_opt;

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  }

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  return res;

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}

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/*| VAR_EXTERNAL [CONSTANT] external_declaration_list END_VAR */

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/* option -> may be NULL ! */

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//SYM_REF2(external_var_declarations_c, option, external_declaration_list)

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void *search_var_instance_decl_c::visit(external_var_declarations_c *symbol) {

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  current_vartype = external_vt;

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  current_option  = none_opt; /* not really required. Just to make the code more readable */

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  if (NULL != symbol->option)

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    symbol->option->accept(*this);

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  void *res = symbol->external_declaration_list->accept(*this);

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  if (res == NULL) {

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    current_vartype = none_vt;

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    current_option = none_opt;

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  }

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  return res;

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}

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/*| VAR_GLOBAL [CONSTANT|RETAIN] global_var_decl_list END_VAR */

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/* option -> may be NULL ! */

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//SYM_REF2(global_var_declarations_c, option, global_var_decl_list)

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void *search_var_instance_decl_c::visit(global_var_declarations_c *symbol) {

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  current_vartype = global_vt;

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  current_option  = none_opt; /* not really required. Just to make the code more readable */

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  if (NULL != symbol->option)

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    symbol->option->accept(*this);

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  void *res = symbol->global_var_decl_list->accept(*this);

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  if (res == NULL) {

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    current_vartype = none_vt;

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    current_option = none_opt;

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  }

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  return res;

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}

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/* var1_list is one of the following...

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 *    simple_spec_init_c *

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 *    subrange_spec_init_c *

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 *    enumerated_spec_init_c *

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 */

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// SYM_REF2(var1_init_decl_c, var1_list, spec_init)

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void *search_var_instance_decl_c::visit(var1_init_decl_c *symbol) {

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  current_type_decl = symbol->spec_init;

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  return symbol->var1_list->accept(*this);

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}

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   301

/* var1_list ',' variable_name */

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// SYM_LIST(var1_list_c)

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void *search_var_instance_decl_c::visit(var1_list_c *symbol) {

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  list_c *list = symbol;

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  for(int i = 0; i < list->n; i++) {

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    if (compare_identifiers(list->elements[i], search_name) == 0)

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   /* by now, current_type_decl should be != NULL */

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      return current_type_decl;

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  }

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  return NULL;

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}

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/* name_list ':' function_block_type_name ASSIGN structure_initialization */

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/* structure_initialization -> may be NULL ! */

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void *search_var_instance_decl_c::visit(fb_name_decl_c *symbol) {

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  // TODO: The following line is wrong! It should be

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  // current_type_decl = symbol->fb_spec_init;

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  //  However, this change will require a check of all callers, to see if they would handle this correctly.

   319

  //  For now, just keep what we have had historically, and seems to be working.

   320

  current_type_decl = spec_init_sperator_c::get_spec(symbol->fb_spec_init);

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  return symbol->fb_name_list->accept(*this);

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}

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/* name_list ',' fb_name */

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void *search_var_instance_decl_c::visit(fb_name_list_c *symbol) {

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  list_c *list = symbol;

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  for(int i = 0; i < list->n; i++) {

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    if (compare_identifiers(list->elements[i], search_name) == 0)

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    /* by now, current_fb_declaration should be != NULL */

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      return current_type_decl;

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  }

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  return NULL;

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}

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/* var1_list ':' array_spec_init */

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// SYM_REF2(array_var_init_decl_c, var1_list, array_spec_init)

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void *search_var_instance_decl_c::visit(array_var_init_decl_c *symbol) {

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  current_type_decl = symbol->array_spec_init;

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  return symbol->var1_list->accept(*this);

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}

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/*  var1_list ':' initialized_structure */

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// SYM_REF2(structured_var_init_decl_c, var1_list, initialized_structure)

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void *search_var_instance_decl_c::visit(structured_var_init_decl_c *symbol) {

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  current_type_decl = symbol->initialized_structure;

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  return symbol->var1_list->accept(*this);

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}

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/*  var1_list ':' array_specification */

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// SYM_REF2(array_var_declaration_c, var1_list, array_specification)

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void *search_var_instance_decl_c::visit(array_var_declaration_c *symbol) {

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  current_type_decl = symbol->array_specification;

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  return symbol->var1_list->accept(*this);

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}

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/*  var1_list ':' structure_type_name */

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// SYM_REF2(structured_var_declaration_c, var1_list, structure_type_name)

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void *search_var_instance_decl_c::visit(structured_var_declaration_c *symbol) {

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  current_type_decl = symbol->structure_type_name;

   360

  return symbol->var1_list->accept(*this);

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}

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/*  [variable_name] location ':' located_var_spec_init */

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/* variable_name -> may be NULL ! */

   365

// SYM_REF4(located_var_decl_c, variable_name, location, located_var_spec_init, unused)

   366

// TODO!!

   367

   368

/*  global_var_name ':' (simple_specification|subrange_specification|enumerated_specification|array_specification|prev_declared_structure_type_name|function_block_type_name */

   369

// SYM_REF2(external_declaration_c, global_var_name, specification)

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void *search_var_instance_decl_c::visit(external_declaration_c *symbol) {

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  if (compare_identifiers(symbol->global_var_name, search_name) == 0)

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      return symbol->specification;

   373

  return NULL;

   374

}

   375

   376

/*| global_var_spec ':' [located_var_spec_init|function_block_type_name] */

   377

/* type_specification ->may be NULL ! */

   378

// SYM_REF2(global_var_decl_c, global_var_spec, type_specification)

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void *search_var_instance_decl_c::visit(global_var_decl_c *symbol) {

   380

  if (symbol->type_specification != NULL) {

   381

    current_type_decl = symbol->type_specification;

   382

    return symbol->global_var_spec->accept(*this);

   383

  }

   384

  else

   385

    return NULL;

   386

}

   387

   388

/*| global_var_name location */

   389

//SYM_REF2(global_var_spec_c, global_var_name, location)

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void *search_var_instance_decl_c::visit(global_var_spec_c *symbol) {

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  if (symbol->global_var_name != NULL && compare_identifiers(symbol->global_var_name, search_name) == 0)

   392

      return current_type_decl;

   393

  else

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    return symbol->location->accept(*this);

   395

}

   396

   397

/*| global_var_list ',' global_var_name */

   398

//SYM_LIST(global_var_list_c)

   399

void *search_var_instance_decl_c::visit(global_var_list_c *symbol) {

   400

  list_c *list = symbol;

   401

  for(int i = 0; i < list->n; i++) {

   402

    if (compare_identifiers(list->elements[i], search_name) == 0)

   403

      /* by now, current_type_decl should be != NULL */

   404

      return current_type_decl;

   405

  }

   406

  return NULL;

   407

}

   408

   409

/*  [variable_name] location ':' located_var_spec_init */

   410

/* variable_name -> may be NULL ! */

   411

//SYM_REF4(located_var_decl_c, variable_name, location, located_var_spec_init, unused)

   412

void *search_var_instance_decl_c::visit(located_var_decl_c *symbol) {

   413

  if (symbol->variable_name != NULL && compare_identifiers(symbol->variable_name, search_name) == 0)

   414

    return symbol->located_var_spec_init;

   415

  else {

   416

    current_type_decl = symbol->located_var_spec_init;

   417

    return symbol->location->accept(*this);

   418

  }

   419

}

   420

   421

/*| global_var_spec ':' [located_var_spec_init|function_block_type_name] */

   422

/* type_specification ->may be NULL ! */

   423

// SYM_REF2(global_var_decl_c, global_var_spec, type_specification)

   424

// TODO!!

   425

   426

/*  AT direct_variable */

   427

// SYM_REF2(location_c, direct_variable, unused)

   428

void *search_var_instance_decl_c::visit(location_c *symbol) {

   429

  if (compare_identifiers(symbol->direct_variable, search_name) == 0)

   430

    return current_type_decl;

   431

  else

   432

    return NULL;

   433

}

   434

   435

/*| global_var_list ',' global_var_name */

   436

// SYM_LIST(global_var_list_c)

   437

// TODO!!

   438

   439

/*  var1_list ':' single_byte_string_spec */

   440

// SYM_REF2(single_byte_string_var_declaration_c, var1_list, single_byte_string_spec)

   441

void *search_var_instance_decl_c::visit(single_byte_string_var_declaration_c *symbol) {

   442

  current_type_decl = symbol->single_byte_string_spec;

   443

  return symbol->var1_list->accept(*this);

   444

}

   445

   446

/*  STRING ['[' integer ']'] [ASSIGN single_byte_character_string] */

   447

/* integer ->may be NULL ! */

   448

/* single_byte_character_string ->may be NULL ! */

   449

// SYM_REF2(single_byte_string_spec_c, integer, single_byte_character_string)

   450

// TODO!!

   451

   452

/*  var1_list ':' double_byte_string_spec */

   453

// SYM_REF2(double_byte_string_var_declaration_c, var1_list, double_byte_string_spec)

   454

void *search_var_instance_decl_c::visit(double_byte_string_var_declaration_c *symbol) {

   455

  current_type_decl = symbol->double_byte_string_spec;

   456

  return symbol->var1_list->accept(*this);

   457

}

   458

   459

/*  WSTRING ['[' integer ']'] [ASSIGN double_byte_character_string] */

   460

/* integer ->may be NULL ! */

   461

/* double_byte_character_string ->may be NULL ! */

   462

// SYM_REF2(double_byte_string_spec_c, integer, double_byte_character_string)

   463

// TODO!!

   464

   465

/*  variable_name incompl_location ':' var_spec */

   466

// SYM_REF4(incompl_located_var_decl_c, variable_name, incompl_location, var_spec, unused)

   467

// TODO!!

   468

   469

/*  AT incompl_location_token */

   470

// SYM_TOKEN(incompl_location_c)

   471

// TODO!!

   472

   473

   474

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

   475

/* B.1.5 - Program organization units */

   476

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

   477

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

   478

/* B 1.5.1 - Functions */

   479

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

   480

// SYM_REF4(function_declaration_c, derived_function_name, type_name, var_declarations_list, function_body)

   481

void *search_var_instance_decl_c::visit(function_declaration_c *symbol) {

   482

  /* functions have a variable named after themselves, to store

   483

   * the variable that will be returned!!

   484

   */

   485

  if (compare_identifiers(symbol->derived_function_name, search_name) == 0)

   486

      return symbol->type_name;

   487

   488

  /* no need to search through all the body, so we only

   489

   * visit the variable declarations...!

   490

   */

   491

  return symbol->var_declarations_list->accept(*this);

   492

}

   493

   494

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

   495

/* B 1.5.2 - Function Blocks */

   496

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

   497

/*  FUNCTION_BLOCK derived_function_block_name io_OR_other_var_declarations function_block_body END_FUNCTION_BLOCK */

   498

// SYM_REF3(function_block_declaration_c, fblock_name, var_declarations, fblock_body)

   499

void *search_var_instance_decl_c::visit(function_block_declaration_c *symbol) {

   500

  /* visit the variable declarations...! */

   501

  void *res = symbol->var_declarations->accept(*this);

   502

  if (NULL != res)

   503

    return res;

   504

   505

  /* not yet found, so we look into the body, to see if it is an SFC step! */

   506

  return symbol->fblock_body->accept(*this);

   507

}

   508

   509

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

   510

/* B 1.5.3 - Programs */

   511

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

   512

/*  PROGRAM program_type_name program_var_declarations_list function_block_body END_PROGRAM */

   513

// SYM_REF3(program_declaration_c, program_type_name, var_declarations, function_block_body)