1

/*

     2

 *  matiec - a compiler for the programming languages defined in IEC 61131-3

     3

 *

     4

 *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)

     5

 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant

     6

 *

     7

 *  This program is free software: you can redistribute it and/or modify

     8

 *  it under the terms of the GNU General Public License as published by

     9

 *  the Free Software Foundation, either version 3 of the License, or

    10

 *  (at your option) any later version.

    11

 *

    12

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

    13

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

    14

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    15

 *  GNU General Public License for more details.

    16

 *

    17

 *  You should have received a copy of the GNU General Public License

    18

 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

    19

 *

    20

 *

    21

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

    22

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

    23

 */

    24

    25

/*

    26

 * An IEC 61131-3 compiler.

    27

 *

    28

 * Based on the

    29

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

    30

 *

    31

 */

    32

    33

#include "absyntax_utils.hh"

    34

    35

    36

/* Returns the function block type declaration

    37

 * of a specific function block instance.

    38

 */

    39

    40

    41

    42

/* Returns the type name of a specific function block

    43

 * instance. This class will search the variable

    44

 * declarations inside the scope given to it

    45

 * searching for the declaration of the function

    46

 * block instance.

    47

 *

    48

 * The class constructor must be given the search scope

    49

 * (function, function block or program within which

    50

 * the function block instance was declared).

    51

 *

    52

 * This class will search the tree from the root given to the

    53

 * constructor. Another option would be to build a symbol table,

    54

 * and search that instead. Building the symbol table would be done

    55

 * while visiting the variable declaration objects in the parse

    56

 * tree. Unfortuantely, generate_c_c does not visit these

    57

 * objects, delegating it to another class. This means that

    58

 * we would need another specialised class just to build the

    59

 * symbol table. We might just as well have a specialised class

    60

 * that searches the tree itself for the relevant info. This

    61

 * class is exactly that...!

    62

 */

    63

search_fb_instance_decl_c::search_fb_instance_decl_c(symbol_c *search_scope) {

    64

  this->search_scope = search_scope;

    65

  this->current_fb_type_name = NULL;

    66

}

    67

    68

symbol_c *search_fb_instance_decl_c::get_type_name(symbol_c *fb_instance_name) {

    69

  this->search_name = fb_instance_name;

    70

  return (symbol_c *)search_scope->accept(*this);

    71

}

    72

    73

/***************************/

    74

/* B 0 - Programming Model */

    75

/***************************/

    76

void *search_fb_instance_decl_c::visit(library_c *symbol) {

    77

  /* we do not want to search multiple declaration scopes,

    78

   * so we do not visit all the functions, fucntion blocks, etc...

    79

   */

    80

  return NULL;

    81

}

    82

    83

/******************************************/

    84

/* B 1.4.3 - Declaration & Initialisation */

    85

/******************************************/

    86

    87

/* name_list ':' function_block_type_name ASSIGN structure_initialization */

    88

/* structure_initialization -> may be NULL ! */

    89

void *search_fb_instance_decl_c::visit(fb_name_decl_c *symbol) {

    90

  current_fb_type_name = spec_init_sperator_c::get_spec(symbol->fb_spec_init);

    91

  return symbol->fb_name_list->accept(*this);

    92

}

    93

    94

/* name_list ',' fb_name */

    95

void *search_fb_instance_decl_c::visit(fb_name_list_c *symbol) {

    96

  list_c *list = symbol;

    97

  for(int i = 0; i < list->n; i++) {

    98

    if (compare_identifiers(list->elements[i], search_name) == 0)

    99

  /* by now, current_fb_declaration should be != NULL */

   100

      return current_fb_type_name;

   101

  }

   102

  return NULL;

   103

}

   104

   105

/* name_list ',' fb_name */

   106

void *search_fb_instance_decl_c::visit(external_declaration_c *symbol) {

   107

  if (compare_identifiers(symbol->global_var_name, search_name) == 0)

   108

    return spec_init_sperator_c::get_spec(symbol->specification);

   109

  return NULL;

   110

}

   111

   112

/**************************************/

   113

/* B.1.5 - Program organization units */

   114

/**************************************/

   115

/***********************/

   116

/* B 1.5.1 - Functions */

   117

/***********************/

   118

void *search_fb_instance_decl_c::visit(function_declaration_c *symbol) {

   119

  /* no need to search through all the body, so we only

   120

   * visit the variable declarations...!

   121

   */

   122

  return symbol->var_declarations_list->accept(*this);

   123

}

   124

   125

/*****************************/

   126

/* B 1.5.2 - Function Blocks */

   127

/*****************************/

   128

void *search_fb_instance_decl_c::visit(function_block_declaration_c *symbol) {

   129

  /* no need to search through all the body, so we only

   130

   * visit the variable declarations...!

   131

   */

   132

  return symbol->var_declarations->accept(*this);

   133

}

   134

   135

/**********************/

   136

/* B 1.5.3 - Programs */

   137

/**********************/

   138

void *search_fb_instance_decl_c::visit(program_declaration_c *symbol) {

   139

  /* no need to search through all the body, so we only

   140

   * visit the variable declarations...!

   141

   */

   142

  return symbol->var_declarations->accept(*this);

   143

}