msousa@511: /*
msousa@511:  *  matiec - a compiler for the programming languages defined in IEC 61131-3
msousa@511:  *
msousa@511:  *  Copyright (C) 2012  Mario de Sousa (msousa@fe.up.pt)
msousa@511:  *
msousa@511:  *  This program is free software: you can redistribute it and/or modify
msousa@511:  *  it under the terms of the GNU General Public License as published by
msousa@511:  *  the Free Software Foundation, either version 3 of the License, or
msousa@511:  *  (at your option) any later version.
msousa@511:  *
msousa@511:  *  This program is distributed in the hope that it will be useful,
msousa@511:  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
msousa@511:  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
msousa@511:  *  GNU General Public License for more details.
msousa@511:  *
msousa@511:  *  You should have received a copy of the GNU General Public License
msousa@511:  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
msousa@511:  *
msousa@511:  *
msousa@511:  * This code is made available on the understanding that it will not be
msousa@511:  * used in safety-critical situations without a full and competent review.
msousa@511:  */
msousa@511: 
msousa@511: /*
msousa@511:  * An IEC 61131-3 compiler.
msousa@511:  *
msousa@511:  * Based on the
msousa@511:  * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
msousa@511:  *
msousa@511:  */
msousa@511: 
msousa@511: /*
msousa@511:  *  A small helper visitor class, that will   
msousa@511:  *  return the name (tokn_c *) of a variable, as it will
msousa@511:  *  appear in the variable declaration.
msousa@511:  */
msousa@511: 
msousa@511: /*  For ex.:
msousa@511:  *       VAR
msousa@511:  *          A : int;
msousa@511:  *          B : ARRAY [1..9] of int;
msousa@511:  *          C : some_struct_t;
msousa@511:  *       END_VAR
msousa@511:  *
msousa@511:  *          A    := 56;
msousa@511:  *          B[8] := 99;
msousa@511:  *          C.e  := 77;
msousa@511:  *
msousa@511:  *       Calling this visitor class with symbolic_variable_c instance referencing 'A' in
msousa@511:  *       the line 'A := 56', will return the string "A".
msousa@511:  *
msousa@511:  *       Calling this visitor class with array_variable_c instance referencing 'B[8]' in
msousa@511:  *       the line 'B[8] := 99', will return the string "B".
msousa@511:  *
msousa@511:  *       Calling this visitor class with array_variable_c instance referencing 'C.e' in
msousa@511:  *       the line 'C.e := 77', will return the string "C".
msousa@511:  */
msousa@511: 
msousa@511: 
msousa@511: 
msousa@511: 
msousa@511: class get_var_name_c : public search_visitor_c {    
msousa@511:   public:
msousa@511:     get_var_name_c(void)  {};
msousa@511:     ~get_var_name_c(void) {};  
msousa@511:     static token_c *get_name(symbol_c *symbol);
msousa@511: 
msousa@511:   private:
msousa@511:     static get_var_name_c *singleton_instance_;
msousa@511:     
msousa@511:   private:  
msousa@511:     /*************************/
msousa@511:     /* B.1 - Common elements */
msousa@511:     /*************************/
msousa@511:     /*******************************************/
msousa@511:     /* B 1.1 - Letters, digits and identifiers */
msousa@511:     /*******************************************/
msousa@511:     // SYM_TOKEN(identifier_c)
msousa@511:     void *visit(identifier_c *symbol);
msousa@511: 
msousa@511:     /*********************/
msousa@511:     /* B 1.4 - Variables */
msousa@511:     /*********************/
msousa@511:     // SYM_REF2(symbolic_variable_c, var_name, unused)
msousa@511:     void *visit(symbolic_variable_c *symbol);
msousa@511: 
msousa@511:     /********************************************/
msousa@511:     /* B.1.4.1   Directly Represented Variables */
msousa@511:     /********************************************/
msousa@511:     // SYM_TOKEN(direct_variable_c)
msousa@511:     // void *visit(direct_variable_c *symbol);
msousa@511: 
msousa@511:     /*************************************/
msousa@511:     /* B.1.4.2   Multi-element Variables */
msousa@511:     /*************************************/
msousa@511:     /*  subscripted_variable '[' subscript_list ']' */
msousa@511:     // SYM_REF2(array_variable_c, subscripted_variable, subscript_list)
msousa@511:     void *visit(array_variable_c *symbol);
msousa@511: 
msousa@511:     /* subscript_list ',' subscript */
msousa@511:     // SYM_LIST(subscript_list_c)
msousa@511:     // void *visit(subscript_list_c *symbol);
msousa@511: 
msousa@511:     /*  record_variable '.' field_selector */
msousa@511:     /*  WARNING: input and/or output variables of function blocks
msousa@511:      *           may be accessed as fields of a tructured variable!
msousa@511:      *           Code handling a structured_variable_c must take
msousa@511:      *           this into account!
msousa@511:      */
msousa@511:     // SYM_REF2(structured_variable_c, record_variable, field_selector)
msousa@511:     void *visit(structured_variable_c *symbol);
msousa@511: };
msousa@511: 
msousa@511: 
msousa@511: