1 /*

     2  * (c) 2009 Mario de Sousa

     3  *

     4  * Offered to the public under the terms of the GNU General Public License

     5  * as published by the Free Software Foundation; either version 2 of the

     6  * License, or (at your option) any later version.

     7  *

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

     9  * WITHOUT ANY WARRANTY; without even the implied warranty of

    10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

    11  * Public License for more details.

    12  *

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

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

    15  */

    16 

    17 /*

    18  * An IEC 61131-3 IL and ST compiler.

    19  *

    20  * Based on the

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

    22  *

    23  */

    24 

    25 

    26 /*

    27  * Iterate through all declared functions and Function Blocks, 

    28  * and, for each function/FB, add a declaration of the EN and ENO 

    29  * parameters, if they have not already been explicitly declared.

    30  *

    31  * EN and ENO parameters declared explicitly (by the user in the source code)

    32  * and implicitly (by the comnpiler, i.e. by this visitor class) may be

    33  * distinguished later on by the 'method' flag in the en_param_declaration_c

    34  * and eno_param_declaration_c objects.

    35  */

    36 

    37 #include "../absyntax/visitor.hh"

    38 

    39 

    40 class add_en_eno_param_decl_c : public null_visitor_c {

    41   public:

    42     static symbol_c *add_to(symbol_c *tree_root);

    43     ~add_en_eno_param_decl_c(void);

    44 

    45   private:

    46     /* this class is a singleton. So we need a pointer to the single instance... */

    47     static add_en_eno_param_decl_c *singleton;

    48 

    49     /* flags to remember whether the EN and/or ENO parameters have already

    50      * been explicitly declared by the user in the IEC 61131-3 source code we are parsing...

    51      */

    52     bool en_declared;

    53     bool eno_declared;

    54 

    55   private:

    56     void* iterate_list(list_c *list);

    57     input_declarations_c  *build_en_param (void);

    58     output_declarations_c *build_eno_param(void);

    59 

    60   private:

    61     /***************************/

    62     /* B 0 - Programming Model */

    63     /***************************/

    64     void *visit(library_c *symbol);

    65 

    66     /***********************/

    67     /* B 1.5.1 - Functions */

    68     /***********************/

    69     void *visit(function_declaration_c *symbol);

    70     /* intermediate helper symbol for function_declaration */

    71     void *visit(var_declarations_list_c *symbol);

    72 

    73     /******************************************/

    74     /* B 1.4.3 - Declaration & Initialisation */

    75     /******************************************/

    76     void *visit(input_declarations_c *symbol);

    77     void *visit(input_declaration_list_c *symbol);

    78     void *visit(en_param_declaration_c *symbol);

    79     void *visit(eno_param_declaration_c *symbol);

    80     void *visit(output_declarations_c *symbol);

    81     void *visit(var_init_decl_list_c *symbol);

    82 

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

    84     /* B 1.5.2 - Function Blocks */

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

    86     /*  FUNCTION_BLOCK derived_function_block_name io_OR_other_var_declarations function_block_body END_FUNCTION_BLOCK */

    87     void *visit(function_block_declaration_c *symbol);

    88 

    89 }; // function_param_iterator_c

    90 

    91 

    92 

    93 

    94 

    95 

    96