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  * Array dimension iterator.

    36  * Iterate through the dimensions of array specification.

    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 array_specification_c, iterate through

    44  * each subrange, returning the symbol of each subrange

    45  * ...array_dimension_iterator_c

    46  */

    47 

    48 

    49 

    50 

    51 #include "array_dimension_iterator.hh"

    52 

    53 

    54 //#define DEBUG

    55 #ifdef DEBUG

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

    57 #else

    58 #define TRACE(classname)

    59 #endif

    60 

    61 

    62 #define ERROR error_exit(__FILE__,__LINE__)

    63 /* function defined in main.cc */

    64 extern void error_exit(const char *file_name, int line_no);

    65 

    66 void* array_dimension_iterator_c::iterate_list(list_c *list) {

    67   void *res;

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

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

    70     if (res != NULL)

    71         return res;

    72   }

    73   return NULL;

    74 }

    75 

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

    77 void array_dimension_iterator_c::reset(void) {

    78   current_array_dimension = NULL;

    79 }

    80 

    81 

    82 /* initialize the iterator object.

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

    84  */

    85 array_dimension_iterator_c::array_dimension_iterator_c(symbol_c *symbol) {

    86   /* do some consistency check... */

    87   array_specification_c* array_spec = dynamic_cast<array_specification_c*>(symbol);

    88 

    89   if (NULL == array_spec) ERROR;

    90 

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

    92   this->array_specification = symbol;

    93   reset();

    94 }

    95 

    96 

    97 

    98 /* Skip to the next subrange. After object creation,

    99  * the object references on subrange _before_ the first, so

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

   101  * reference the first subrange...

   102  *

   103  * Returns the subrange symbol!

   104  */

   105 symbol_c *array_dimension_iterator_c::next(void) {

   106   void *res = array_specification->accept(*this);

   107   if (res == NULL) 

   108     return NULL;

   109 

   110   return current_array_dimension;

   111 }

   112 

   113 /********************************/

   114 /* B 1.3.3 - Derived data types */

   115 /********************************/

   116 /*  signed_integer DOTDOT signed_integer */

   117 void *array_dimension_iterator_c::visit(subrange_c *symbol) {

   118   if (current_array_dimension == symbol) {

   119 	current_array_dimension = NULL;

   120   }

   121   else if (current_array_dimension == NULL) {

   122 	current_array_dimension = symbol;

   123 	return symbol;

   124   }

   125 

   126   /* Not found! */

   127   return NULL;

   128 }

   129 

   130 /* ARRAY '[' array_subrange_list ']' OF non_generic_type_name */

   131 void *array_dimension_iterator_c::visit(array_specification_c *symbol) {

   132   return symbol->array_subrange_list->accept(*this);

   133 }

   134 

   135 /* array_subrange_list ',' subrange */

   136 void *array_dimension_iterator_c::visit(array_subrange_list_c *symbol) {

   137   return iterate_list(symbol);

   138 }

   139