1 /*

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

     3  *

     4  *  Copyright (C) 2012  Mario de Sousa (msousa@fe.up.pt)

     5  *

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

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

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

     9  *  (at your option) any later version.

    10  *

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

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

    13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    14  *  GNU General Public License for more details.

    15  *

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

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

    18  *

    19  *

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

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

    22  */

    23 

    24 /*

    25  * An IEC 61131-3 compiler.

    26  *

    27  * Based on the

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

    29  *

    30  */

    31 

    32 /*

    33  *  A small helper visitor class, that will   

    34  *  return the name (tokn_c *) of a variable, as it will

    35  *  appear in the variable declaration.

    36  */

    37 

    38 /*  For ex.:

    39  *       VAR

    40  *          A : int;

    41  *          B : ARRAY [1..9] of int;

    42  *          C : some_struct_t;

    43  *       END_VAR

    44  *

    45  *          A    := 56;

    46  *          B[8] := 99;

    47  *          C.e  := 77;

    48  *

    49  *       Calling this visitor class with symbolic_variable_c instance referencing 'A' in

    50  *       the line 'A := 56', will return the string "A".

    51  *

    52  *       Calling this visitor class with array_variable_c instance referencing 'B[8]' in

    53  *       the line 'B[8] := 99', will return the string "B".

    54  *

    55  *       Calling this visitor class with array_variable_c instance referencing 'C.e' in

    56  *       the line 'C.e := 77', will return the string "C".

    57  */

    58 

    59 

    60 #include "absyntax_utils.hh"

    61 

    62 

    63 

    64    

    65     

    66 

    67 get_var_name_c *get_var_name_c::singleton_instance_ = NULL;

    68 

    69 

    70 

    71 

    72 token_c *get_var_name_c::get_name(symbol_c *symbol) {

    73   if (NULL == singleton_instance_) singleton_instance_ = new get_var_name_c(); 

    74   if (NULL == singleton_instance_) ERROR; 

    75   

    76   return (token_c *)(symbol->accept(*singleton_instance_));

    77 }

    78 

    79 

    80 /*************************/

    81 /* B.1 - Common elements */

    82 /*************************/

    83 /*******************************************/

    84 /* B 1.1 - Letters, digits and identifiers */

    85 /*******************************************/

    86 // SYM_TOKEN(identifier_c)

    87 void *get_var_name_c::visit(identifier_c *symbol) {return (void *)symbol;}

    88 

    89 /*********************/

    90 /* B 1.4 - Variables */

    91 /*********************/

    92 // SYM_REF2(symbolic_variable_c, var_name, unused)

    93 void *get_var_name_c::visit(symbolic_variable_c *symbol) {return symbol->var_name->accept(*this);}

    94 

    95 /********************************************/

    96 /* B.1.4.1   Directly Represented Variables */

    97 /********************************************/

    98 // SYM_TOKEN(direct_variable_c)

    99 

   100 /*************************************/

   101 /* B.1.4.2   Multi-element Variables */

   102 /*************************************/

   103 /*  subscripted_variable '[' subscript_list ']' */

   104 // SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   105 void *get_var_name_c::visit(array_variable_c *symbol) {return symbol->subscripted_variable->accept(*this);}

   106 

   107 /* subscript_list ',' subscript */

   108 // SYM_LIST(subscript_list_c)

   109 

   110 /*  record_variable '.' field_selector */

   111 /*  WARNING: input and/or output variables of function blocks

   112  *           may be accessed as fields of a tructured variable!

   113  *           Code handling a structured_variable_c must take

   114  *           this into account!

   115  */

   116 // SYM_REF2(structured_variable_c, record_variable, field_selector)

   117 void *get_var_name_c::visit(structured_variable_c *symbol) {return symbol->record_variable->accept(*this);}

   118 

   119 

   120