1

/*

     3

 *

     5

 *

    19

 *

    20

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

    21

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

    22

 */

    23

    24

/*

    26

 *

    27

 * Based on the

    28

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

    29

 *

    30

 */

    31

    32

#include "absyntax_utils.hh"

    33

    34

    35

/* Returns the function block type declaration

    36

 * of a specific function block instance.

    37

 */

    38

    39

    40

    41

/* Returns the type name of a specific function block

    42

 * instance. This class will search the variable

    43

 * declarations inside the scope given to it

    44

 * searching for the declaration of the function

    45

 * block instance.

    46

 *

    47

 * The class constructor must be given the search scope

    48

 * (function, function block or program within which

    49

 * the function block instance was declared).

    50

 *

    51

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

    52

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

    53

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

    54

 * while visiting the variable declaration objects in the parse

    55

 * tree. Unfortuantely, generate_c_c does not visit these

    56

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

    57

 * we would need another specialised class just to build the

    58

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

    59

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

    60

 * class is exactly that...!

    61

 */

    62

search_fb_instance_decl_c::search_fb_instance_decl_c(symbol_c *search_scope) {

    63

  this->search_scope = search_scope;

    64

  this->current_fb_type_name = NULL;

    65

}

    66

    67

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

    68

  this->search_name = fb_instance_name;

    69

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

    70

}

    71

    72

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

    73

/* B 0 - Programming Model */

    74

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

    75

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

    76

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

    77

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

    78

   */

    79

  return NULL;

    80

}

    81

    82

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

    83

/* B 1.4.3 - Declaration & Initialisation */

    84

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

    85

    86

/* name_list ':' function_block_type_name ASSIGN structure_initialization */

    87

/* structure_initialization -> may be NULL ! */

    88

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

    89

  current_fb_type_name = symbol->function_block_type_name;

    90

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

    91

}

    92

    93

/* name_list ',' fb_name */

    94

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

    95

  list_c *list = symbol;

    96

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

    97

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

    98

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

    99

      return current_fb_type_name;

   100

  }

   101

  return NULL;

   102

}

   103

   104

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

   105

/* B.1.5 - Program organization units */

   106

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

   107

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

   108

/* B 1.5.1 - Functions */

   109

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

   110

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

   111

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

   112

   * visit the variable declarations...!

   113

   */

   114

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

   115

}

   116

   117

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

   118

/* B 1.5.2 - Function Blocks */

   119

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

   120

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

   121

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

   122

   * visit the variable declarations...!

   123

   */

   124

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

   125

}

   126

   127

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

   128

/* B 1.5.3 - Programs */

   129

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

   130

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

   131

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

   132

   * visit the variable declarations...!

   133

   */

   134

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

   135

}