absyntax_utils/get_var_name.hh
author Laurent Bessard
Tue, 11 Sep 2012 01:05:24 +0200
changeset 628 fe0d516fe291
parent 511 b22ae67d8003
child 889 5f380b99e95e
permissions -rw-r--r--
Fix bug in SFC generated code. Action state was declared in the list of variables to debug, but wasn't stored using structure with flags. This error had side effects that makes Beremiz debug crash.
/*
 *  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".
 */




class get_var_name_c : public search_visitor_c {    
  public:
    get_var_name_c(void)  {};
    ~get_var_name_c(void) {};  
    static token_c *get_name(symbol_c *symbol);

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

    /*********************/
    /* B 1.4 - Variables */
    /*********************/
    // SYM_REF2(symbolic_variable_c, var_name, unused)
    void *visit(symbolic_variable_c *symbol);

    /********************************************/
    /* B.1.4.1   Directly Represented Variables */
    /********************************************/
    // SYM_TOKEN(direct_variable_c)
    // void *visit(direct_variable_c *symbol);

    /*************************************/
    /* B.1.4.2   Multi-element Variables */
    /*************************************/
    /*  subscripted_variable '[' subscript_list ']' */
    // SYM_REF2(array_variable_c, subscripted_variable, subscript_list)
    void *visit(array_variable_c *symbol);

    /* subscript_list ',' subscript */
    // SYM_LIST(subscript_list_c)
    // void *visit(subscript_list_c *symbol);

    /*  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 *visit(structured_variable_c *symbol);
};