absyntax_utils/array_dimension_iterator.cc
author Laurent Bessard
Tue, 11 Sep 2012 01:05:24 +0200
changeset 628 fe0d516fe291
parent 596 4efb11e44065
child 830 6f45ec6ed011
permissions -rwxr-xr-x
Fix bug in SFC generated code. Action state was declared in the list of variables to debug, but wasn't stored using structure with flags. This error had side effects that makes Beremiz debug crash.
/*
 *  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.
 */

/*
 * An IEC 61131-3 compiler.
 *
 * Based on the
 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
 *
 */


/*
 * Array dimension iterator.
 * Iterate through the dimensions of array specification.
 *
 * This is part of the 4th stage that generates
 * a c++ source program equivalent to the IL and ST
 * code.
 */

/* Given a array_specification_c, iterate through
 * each subrange, returning the symbol of each subrange
 * ...array_dimension_iterator_c
 */




#include "array_dimension_iterator.hh"
#include "../main.hh" // required for ERROR() and ERROR_MSG() macros.


//#define DEBUG
#ifdef DEBUG
#define TRACE(classname) printf("\n____%s____\n",classname);
#else
#define TRACE(classname)
#endif



void* array_dimension_iterator_c::iterate_list(list_c *list) {
  void *res;
  for (int i = 0; i < list->n; i++) {
    res = list->elements[i]->accept(*this);
    if (res != NULL)
        return res;
  }
  return NULL;
}

/* start off at the first case element once again... */
void array_dimension_iterator_c::reset(void) {
  current_array_dimension = NULL;
}


/* initialize the iterator object.
 * We must be given a reference to a array_specification_c that will be analyzed...
 */
array_dimension_iterator_c::array_dimension_iterator_c(symbol_c *symbol) {
  /* do some consistency check... */
  array_specification_c* array_spec = dynamic_cast<array_specification_c*>(symbol);

  if (NULL == array_spec) ERROR;

  /* OK. Now initialize this object... */
  this->array_specification = symbol;
  reset();
}



/* Skip to the next subrange. After object creation,
 * the object references on subrange _before_ the first, so
 * this function must be called once to get the object to
 * reference the first subrange...
 *
 * Returns the subrange symbol!
 */
subrange_c *array_dimension_iterator_c::next(void) {
  void *res = array_specification->accept(*this);
  if (res == NULL) 
    return NULL;

  return current_array_dimension;
}

/********************************/
/* B 1.3.3 - Derived data types */
/********************************/
/*  signed_integer DOTDOT signed_integer */
void *array_dimension_iterator_c::visit(subrange_c *symbol) {
  if (current_array_dimension == symbol) {
	current_array_dimension = NULL;
  }
  else if (current_array_dimension == NULL) {
	current_array_dimension = symbol;
	return symbol;
  }

  /* Not found! */
  return NULL;
}

/* ARRAY '[' array_subrange_list ']' OF non_generic_type_name */
void *array_dimension_iterator_c::visit(array_specification_c *symbol) {
  return symbol->array_subrange_list->accept(*this);
}

/* array_subrange_list ',' subrange */
void *array_dimension_iterator_c::visit(array_subrange_list_c *symbol) {
  return iterate_list(symbol);
}