absyntax_utils/get_var_name.cc
author Manuele Conti <conti.ma@alice.it>
Mon, 30 Jul 2012 22:59:00 +0200
changeset 622 eaa49b276e17
parent 511 b22ae67d8003
child 889 5f380b99e95e
permissions -rw-r--r--
Add check bison version in configure.ac file.
To build correctly matiec we need bison greater or equals than 2.4 version.
Now the "configure" script is able to check if system has correctly requirements.
/*
 *  matiec - a compiler for the programming languages defined in IEC 61131-3
 *
 *  Copyright (C) 2012  Mario de Sousa (msousa@fe.up.pt)
 *
 *  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)
 *
 */

/*
 *  A small helper visitor class, that will   
 *  return the name (tokn_c *) of a variable, as it will
 *  appear in the variable declaration.
 */

/*  For ex.:
 *       VAR
 *          A : int;
 *          B : ARRAY [1..9] of int;
 *          C : some_struct_t;
 *       END_VAR
 *
 *          A    := 56;
 *          B[8] := 99;
 *          C.e  := 77;
 *
 *       Calling this visitor class with symbolic_variable_c instance referencing 'A' in
 *       the line 'A := 56', will return the string "A".
 *
 *       Calling this visitor class with array_variable_c instance referencing 'B[8]' in
 *       the line 'B[8] := 99', will return the string "B".
 *
 *       Calling this visitor class with array_variable_c instance referencing 'C.e' in
 *       the line 'C.e := 77', will return the string "C".
 */


#include "absyntax_utils.hh"



   
    

get_var_name_c *get_var_name_c::singleton_instance_ = NULL;




token_c *get_var_name_c::get_name(symbol_c *symbol) {
  if (NULL == singleton_instance_) singleton_instance_ = new get_var_name_c(); 
  if (NULL == singleton_instance_) ERROR; 
  
  return (token_c *)(symbol->accept(*singleton_instance_));
}


/*************************/
/* B.1 - Common elements */
/*************************/
/*******************************************/
/* B 1.1 - Letters, digits and identifiers */
/*******************************************/
// SYM_TOKEN(identifier_c)
void *get_var_name_c::visit(identifier_c *symbol) {return (void *)symbol;}

/*********************/
/* B 1.4 - Variables */
/*********************/
// SYM_REF2(symbolic_variable_c, var_name, unused)
void *get_var_name_c::visit(symbolic_variable_c *symbol) {return symbol->var_name->accept(*this);}

/********************************************/
/* B.1.4.1   Directly Represented Variables */
/********************************************/
// SYM_TOKEN(direct_variable_c)

/*************************************/
/* B.1.4.2   Multi-element Variables */
/*************************************/
/*  subscripted_variable '[' subscript_list ']' */
// SYM_REF2(array_variable_c, subscripted_variable, subscript_list)
void *get_var_name_c::visit(array_variable_c *symbol) {return symbol->subscripted_variable->accept(*this);}

/* subscript_list ',' subscript */
// SYM_LIST(subscript_list_c)

/*  record_variable '.' field_selector */
/*  WARNING: input and/or output variables of function blocks
 *           may be accessed as fields of a tructured variable!
 *           Code handling a structured_variable_c must take
 *           this into account!
 */
// SYM_REF2(structured_variable_c, record_variable, field_selector)
void *get_var_name_c::visit(structured_variable_c *symbol) {return symbol->record_variable->accept(*this);}