1

/*

     2

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

     3

 *

     4

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

     5

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

     6

 *

     7

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

     8

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

     9

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

    10

 *  (at your option) any later version.

    11

 *

    12

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

    13

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

    14

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    15

 *  GNU General Public License for more details.

    16

 *

    17

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

    18

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

    19

 *

    20

 *

    21

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

    22

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

    23

 */

    24

    25

/*

    26

 * An IEC 61131-3 compiler.

    27

 *

    28

 * Based on the

    29

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

    30

 *

    31

 */

    32

    33

    34

/*

    35

 * Case element iterator.

    36

 * Iterate through the elements of a case list.

    37

 *

    38

 * This is part of the 4th stage that generates

    39

 * a c++ source program equivalent to the IL and ST

    40

 * code.

    41

 */

    42

    43

/* Given a case_list_c and a type of element, iterate through

    44

 * each element, returning the symbol of each element if from

    45

 * the good type...case_element_iterator_c

    46

 */

    47

    48

    49

    50

    51

#include "case_element_iterator.hh"

    52

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

    53

    54

    55

//#define DEBUG

    56

#ifdef DEBUG

    57

#define TRACE(classname) printf("\n____%s____\n",classname);

    58

#else

    59

#define TRACE(classname)

    60

#endif

    61

    62

    63

    64

    65

void* case_element_iterator_c::handle_case_element(symbol_c *case_element) {

    66

  if (current_case_element == case_element) {

    67

    current_case_element = NULL;

    68

  }

    69

  else if (current_case_element == NULL) {

    70

	current_case_element = case_element;

    71

	return case_element;

    72

  }

    73

    74

  /* Not found! */

    75

  return NULL;

    76

}

    77

    78

void* case_element_iterator_c::iterate_list(list_c *list) {

    79

  void *res;

    80

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

    81

    res = list->get_element(i)->accept(*this);

    82

    if (res != NULL)

    83

        return res;

    84

  }

    85

  return NULL;

    86

}

    87

    88

/* start off at the first case element once again... */

    89

void case_element_iterator_c::reset(void) {

    90

  current_case_element = NULL;

    91

}

    92

    93

    94

/* initialize the iterator object.

    95

 * We must be given a reference to a case_list_c that will be analyzed...

    96

 */

    97

case_element_iterator_c::case_element_iterator_c(symbol_c *list, case_element_t element_type) {

    98

  /* do some consistency check... */

    99

  case_list_c* case_list = dynamic_cast<case_list_c*>(list);

   100

   101

  if (NULL == case_list) ERROR;

   102

   103

  /* OK. Now initialize this object... */

   104

  this->case_list = list;

   105

  this->wanted_element_type = element_type;

   106

  reset();

   107

}

   108

   109

   110

   111

/* Skip to the next case element of type chosen. After object creation,

   112

 * the object references on case element _before_ the first, so

   113

 * this function must be called once to get the object to

   114

 * reference the first element...

   115

 *

   116

 * Returns the case element's symbol!

   117

 */

   118

symbol_c *case_element_iterator_c::next(void) {

   119

  void *res = case_list->accept(*this);

   120

  if (res == NULL) 

   121

    return NULL;

   122

   123

  return current_case_element;

   124

}

   125

   126

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

   127

/* B 1.2.1 - Numeric Literals */

   128

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

   129

void *case_element_iterator_c::visit(integer_c *symbol) {

   130

  switch (wanted_element_type) {

   131

	case element_single:

   132

	  return handle_case_element(symbol);

   133

	  break;

   134

	default:

   135

	  break;

   136

  }

   137

  return NULL;

   138

}

   139

   140

void *case_element_iterator_c::visit(neg_integer_c *symbol) {

   141

  switch (wanted_element_type) {

   142

	case element_single:

   143

	  return handle_case_element(symbol);

   144

	  break;

   145

	default:

   146

	  break;

   147

  }

   148

  return NULL;

   149

}

   150

   151

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

   152

/* B 1.3.3 - Derived data types */

   153

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

   154

/*  signed_integer DOTDOT signed_integer */

   155

void *case_element_iterator_c::visit(subrange_c *symbol) {

   156

  switch (wanted_element_type) {

   157

    case element_subrange:

   158

      return handle_case_element(symbol);

   159

      break;

   160

    default:

   161

      break;

   162

  }

   163

  return NULL;

   164

}

   165

   166

/* enumerated_type_name '#' identifier */

   167

void *case_element_iterator_c::visit(enumerated_value_c *symbol) {

   168

  switch (wanted_element_type) {

   169

    case element_single:

   170

      return handle_case_element(symbol);

   171

      break;

   172

    default:

   173

      break;

   174

  }

   175

  return NULL;

   176

}

   177

   178

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

   179

/* B 3.2.3 Selection Statements */

   180

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

   181

void *case_element_iterator_c::visit(case_list_c *symbol) {

   182

  return iterate_list(symbol);

   183

}

   184