Fix divide by 0 bug.
/*
* 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);}