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/*

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 * (c) 2003 Mario de Sousa

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 *

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 * Offered to the public under the terms of the GNU General Public License

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 * as published by the Free Software Foundation; either version 2 of the

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 * License, or (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, but

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 * WITHOUT ANY WARRANTY; without even the implied warranty of

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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

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 * Public License for more details.

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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 IL and ST 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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/*

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 * VISITOR.CC

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 *

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 * Three base implementations of the visitor interface,

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 * that may be later extended to execute a particular algorithm.

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 *

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 * The null (class null_visitor_c) does nothing.

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 *

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 * The iterator (class iterator_visitor_c) iterates through

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 * every object in the syntax tree.

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 *

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 * The search class (class search_visitor_c) iterates through

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 * every object, until one returns a value != NULL.

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 */

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#include <unistd.h>

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#include <stdio.h>  /* required for NULL */

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#include "visitor.hh"

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#include <iostream>

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

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/* visitor_c      */

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

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visitor_c::~visitor_c(void) {return;}

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

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/* null_visitor_c */

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

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null_visitor_c::~null_visitor_c(void) {return;}

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#define SYM_LIST(class_name_c)	\

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  void *null_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#define SYM_TOKEN(class_name_c)	\

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  void *null_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#define SYM_REF0(class_name_c)	\

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  void *null_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#define SYM_REF2(class_name_c, ref1, ref2)	\

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  void *null_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#define SYM_REF4(class_name_c, ref1, ref2, ref3, ref4)	\

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  void *null_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#define SYM_REF6(class_name_c, ref1, ref2, ref3, ref4, ref5, ref6)	\

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  void *null_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#include "absyntax.def"

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#undef SYM_LIST

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#undef SYM_TOKEN

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#undef SYM_REF0

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#undef SYM_REF2

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#undef SYM_REF4

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#undef SYM_REF6

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

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/* iterator_visitor_c */

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

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iterator_visitor_c::~iterator_visitor_c(void) {return;}

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void *iterator_visitor_c::visit_list(list_c *list) {

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

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    list->elements[i]->accept(*this);

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  }

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  return NULL;

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}

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#define SYM_LIST(class_name_c)	\

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  void *iterator_visitor_c::visit(class_name_c *symbol) {return visit_list(symbol);}

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#define SYM_TOKEN(class_name_c)	\

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  void *iterator_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#define SYM_REF0(class_name_c)	\

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  void *iterator_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#define SYM_REF2(class_name_c, ref1, ref2)		\

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void *iterator_visitor_c::visit(class_name_c *symbol) {	\

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  if (symbol->ref1!=NULL) symbol->ref1->accept(*this);	\

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  if (symbol->ref2!=NULL) symbol->ref2->accept(*this);	\

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  return NULL;						\

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}

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#define SYM_REF4(class_name_c, ref1, ref2, ref3, ref4)	\

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void *iterator_visitor_c::visit(class_name_c *symbol) {	\

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  if (symbol->ref1) symbol->ref1->accept(*this);	\

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  if (symbol->ref2) symbol->ref2->accept(*this);	\

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  if (symbol->ref3) symbol->ref3->accept(*this);	\

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  if (symbol->ref4) symbol->ref4->accept(*this);	\

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  return NULL;						\

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}

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#define SYM_REF6(class_name_c, ref1, ref2, ref3, ref4, ref5, ref6)	\

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void *iterator_visitor_c::visit(class_name_c *symbol) {			\

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  if (symbol->ref1) symbol->ref1->accept(*this);			\

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  if (symbol->ref2) symbol->ref2->accept(*this);			\

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  if (symbol->ref3) symbol->ref3->accept(*this);			\

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  if (symbol->ref4) symbol->ref4->accept(*this);			\

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  if (symbol->ref5) symbol->ref5->accept(*this);			\

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  if (symbol->ref6) symbol->ref6->accept(*this);			\

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  return NULL;								\

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}

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#include "absyntax.def"

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#undef SYM_LIST

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#undef SYM_TOKEN

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#undef SYM_REF0

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#undef SYM_REF2

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#undef SYM_REF4

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#undef SYM_REF6

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

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/* search_visitor_c */

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

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search_visitor_c::~search_visitor_c(void) {return;}

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void *search_visitor_c::visit_list(list_c *list) {

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

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    void *res = list->elements[i]->accept(*this);

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    if (res != NULL)

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      return res;

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  }

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  return NULL;

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}

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#define SYM_LIST(class_name_c)	\

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  void *search_visitor_c::visit(class_name_c *symbol) {return visit_list(symbol);}

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#define SYM_TOKEN(class_name_c)	\

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  void *search_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#define SYM_REF0(class_name_c)	\

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  void *search_visitor_c::visit(class_name_c *symbol) {return NULL;}

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#define SYM_REF2(class_name_c, ref1, ref2)			\

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void *search_visitor_c::visit(class_name_c *symbol) {		\

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  void *res = NULL;						\

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  if (symbol->ref1) res =  symbol->ref1->accept(*this);		\

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  if (res != NULL)  return res;					\

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  if (symbol->ref2) return symbol->ref2->accept(*this);		\

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  return NULL;							\

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}

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#define SYM_REF4(class_name_c, ref1, ref2, ref3, ref4)		\

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void *search_visitor_c::visit(class_name_c *symbol) {		\

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  void *res = NULL;						\

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  if (symbol->ref1) res =  symbol->ref1->accept(*this);		\

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  if (res != NULL)  return res;					\

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  if (symbol->ref2) res =  symbol->ref2->accept(*this);		\

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  if (res != NULL)  return res;					\

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  if (symbol->ref3) res =  symbol->ref3->accept(*this);		\

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  if (res != NULL)  return res;					\

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  if (symbol->ref4) return symbol->ref4->accept(*this);		\

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  return NULL;							\

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}

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#define SYM_REF6(class_name_c, ref1, ref2, ref3, ref4, ref5, ref6)	\

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void *search_visitor_c::visit(class_name_c *symbol) {			\

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  void *res = NULL;							\

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  if (symbol->ref1) res =  symbol->ref1->accept(*this);			\

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  if (res != NULL)  return res;						\

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  if (symbol->ref2) res =  symbol->ref2->accept(*this);			\

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  if (res != NULL)  return res;						\

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  if (symbol->ref3) res =  symbol->ref3->accept(*this);			\

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  if (res != NULL)  return res;						\

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  if (symbol->ref4) res =  symbol->ref4->accept(*this);			\

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  if (res != NULL)  return res;						\

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  if (symbol->ref5) res =  symbol->ref5->accept(*this);			\

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  if (res != NULL)  return res;						\

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  if (symbol->ref6) return symbol->ref6->accept(*this);			\

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  return NULL;								\

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}

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#include "absyntax.def"

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#undef SYM_LIST

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#undef SYM_TOKEN

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#undef SYM_REF0

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#undef SYM_REF2

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#undef SYM_REF4

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#undef SYM_REF6

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