1

/*

     2

 * (c) 2003 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

/* Determine the data type of a specific variable instance, including

    26

 * function block instances.

    27

 * A reference to the relevant variable declaration is returned.

    28

 * The variable instance may NOT be a member of a structure of a memeber

    29

 * of a structure of an element of an array of ...

    30

 *

    31

 * example:

    32

 *    window.points[1].coordinate.x

    33

 *    window.points[1].colour

    34

 *    etc... ARE NOT ALLOWED!

    35

 *

    36

 * This class must only be passed the name of the variable that will appear

    37

 * in the variable declaration. In the above examples, this would be

    38

 *   'window' !!

    39

 *

    40

 *

    41

 * If you need to pass a complete name of a variable instance (such as

    42

 * 'window.points[1].coordinate.x') use the search_varfb_instance_type_c instead!

    43

 */

    44

/* Note that current_type_decl that this class returns may reference the

    45

 * name of a type, or the type declaration itself!

    46

 * For an example of the first, consider a variable declared as ...

    47

 * x : AAA;

    48

 * where the AAA type is previously declared as whatever.

    49

 * For an example of the second, consider a variable declared as ...

    50

 * x : array of int [10];  ---->  is allowed

    51

 *

    52

 * If it is the first, we will return a reference to the name, if the second

    53

 * we return a reference to the declaration!!

    54

 */

    55

class search_var_instance_decl_c: public search_visitor_c {

    56

    57

  private:

    58

    symbol_c *search_scope;

    59

    symbol_c *search_name;

    60

    symbol_c *current_type_decl;

    61

    62

  public:

    63

    search_var_instance_decl_c(symbol_c *search_scope) {

    64

      this->search_scope = search_scope;

    65

      this->search_name = NULL;

    66

      this->current_type_decl = NULL;

    67

    }

    68

    69

    symbol_c *get_decl(symbol_c *variable_instance_name) {

    70

      this->search_name = variable_instance_name;

    71

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

    72

    }

    73

    74

  public:

    75

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

    76

/* B 0 - Programming Model */

    77

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

    78

    void *visit(library_c *symbol) {

    79

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

    80

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

    81

       */

    82

      return NULL;

    83

    }

    84

    85

    86

    87

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

    88

/* B 1.4.3 - Declaration & Initialisation */

    89

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

    90

/* edge -> The F_EDGE or R_EDGE directive */

    91

// SYM_REF2(edge_declaration_c, edge, var1_list)

    92

// TODO

    93

    94

/* var1_list is one of the following...

    95

 *    simple_spec_init_c *

    96

 *    subrange_spec_init_c *

    97

 *    enumerated_spec_init_c *

    98

 */

    99

// SYM_REF2(var1_init_decl_c, var1_list, spec_init)

   100

    void *visit(var1_init_decl_c *symbol) {

   101

      current_type_decl = symbol->spec_init;

   102

      return symbol->var1_list->accept(*this);

   103

    }

   104

   105

/* var1_list ',' variable_name */

   106

// SYM_LIST(var1_list_c)

   107

    void *visit(var1_list_c *symbol) {

   108

      list_c *list = symbol;

   109

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

   110

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

   111

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

   112

          return current_type_decl;

   113

      }

   114

      return NULL;

   115

    }

   116

   117

/* name_list ':' function_block_type_name ASSIGN structure_initialization */

   118

/* structure_initialization -> may be NULL ! */

   119

    void *visit(fb_name_decl_c *symbol) {

   120

      current_type_decl = symbol->function_block_type_name;

   121

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

   122

    }

   123

   124

/* name_list ',' fb_name */

   125

    void *visit(fb_name_list_c *symbol) {

   126

      list_c *list = symbol;

   127

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

   128

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

   129

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

   130

          return current_type_decl;

   131

      }

   132

      return NULL;

   133

    }

   134

   135

/* var1_list ':' array_spec_init */

   136

// SYM_REF2(array_var_init_decl_c, var1_list, array_spec_init)

   137

    void *visit(array_var_init_decl_c *symbol) {

   138

      current_type_decl = symbol->array_spec_init;

   139

      return symbol->var1_list->accept(*this);

   140

    }

   141

   142

/*  var1_list ':' initialized_structure */

   143

// SYM_REF2(structured_var_init_decl_c, var1_list, initialized_structure)

   144

    void *visit(structured_var_init_decl_c *symbol) {

   145

      current_type_decl = symbol->initialized_structure;

   146

      return symbol->var1_list->accept(*this);

   147

    }

   148

   149

/*  var1_list ':' array_specification */

   150

// SYM_REF2(array_var_declaration_c, var1_list, array_specification)

   151

    void *visit(array_var_declaration_c *symbol) {

   152

      current_type_decl = symbol->array_specification;

   153

      return symbol->var1_list->accept(*this);

   154

    }

   155

   156

/*  var1_list ':' structure_type_name */

   157

// SYM_REF2(structured_var_declaration_c, var1_list, structure_type_name)

   158

    void *visit(structured_var_declaration_c *symbol) {

   159

      current_type_decl = symbol->structure_type_name;

   160

      return symbol->var1_list->accept(*this);

   161

    }

   162

   163

/*  [variable_name] location ':' located_var_spec_init */

   164

/* variable_name -> may be NULL ! */

   165

// SYM_REF4(located_var_decl_c, variable_name, location, located_var_spec_init, unused)

   166

// TODO!!

   167

   168

/*  global_var_name ':' (simple_specification|subrange_specification|enumerated_specification|array_specification|prev_declared_structure_type_name|function_block_type_name */

   169

// SYM_REF2(external_declaration_c, global_var_name, specification)

   170

    void *visit(external_declaration_c *symbol) {

   171

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

   172

          return symbol->specification;

   173

      return NULL;

   174

    }

   175

   176

/*| global_var_spec ':' [located_var_spec_init|function_block_type_name] */

   177

/* type_specification ->may be NULL ! */

   178

// SYM_REF2(global_var_decl_c, global_var_spec, type_specification)

   179

// TODO!!

   180

   181

/*| global_var_name location */

   182

// SYM_REF2(global_var_spec_c, global_var_name, location)

   183

// TODO!!

   184

   185

/*  AT direct_variable */

   186

// SYM_REF2(location_c, direct_variable, unused)

   187

// TODO!!

   188

   189

/*| global_var_list ',' global_var_name */

   190

// SYM_LIST(global_var_list_c)

   191

// TODO!!

   192

   193

/*  var1_list ':' single_byte_string_spec */

   194

// SYM_REF2(single_byte_string_var_declaration_c, var1_list, single_byte_string_spec)

   195

    void *visit(single_byte_string_var_declaration_c *symbol) {

   196

      current_type_decl = symbol->single_byte_string_spec;

   197

      return symbol->var1_list->accept(*this);

   198

    }

   199

   200

/*  STRING ['[' integer ']'] [ASSIGN single_byte_character_string] */

   201

/* integer ->may be NULL ! */

   202

/* single_byte_character_string ->may be NULL ! */

   203

// SYM_REF2(single_byte_string_spec_c, integer, single_byte_character_string)

   204

// TODO!!

   205

   206

/*  var1_list ':' double_byte_string_spec */

   207

// SYM_REF2(double_byte_string_var_declaration_c, var1_list, double_byte_string_spec)

   208

    void *visit(double_byte_string_var_declaration_c *symbol) {

   209

      current_type_decl = symbol->double_byte_string_spec;

   210

      return symbol->var1_list->accept(*this);

   211

    }

   212

   213

/*  WSTRING ['[' integer ']'] [ASSIGN double_byte_character_string] */

   214

/* integer ->may be NULL ! */

   215

/* double_byte_character_string ->may be NULL ! */

   216

// SYM_REF2(double_byte_string_spec_c, integer, double_byte_character_string)

   217

// TODO!!

   218

   219

/*  variable_name incompl_location ':' var_spec */

   220

// SYM_REF4(incompl_located_var_decl_c, variable_name, incompl_location, var_spec, unused)

   221

// TODO!!

   222

   223

/*  AT incompl_location_token */

   224

// SYM_TOKEN(incompl_location_c)

   225

// TODO!!

   226

   227

   228

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

   229

/* B.1.5 - Program organization units */

   230

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

   231

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

   232

/* B 1.5.1 - Functions */

   233

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

   234

// SYM_REF4(function_declaration_c, derived_function_name, type_name, var_declarations_list, function_body)

   235

    void *visit(function_declaration_c *symbol) {

   236

      /* functions have a variable named after themselves, to store

   237

       * the variable that will be returned!!

   238

       */

   239

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

   240

          return symbol->type_name;

   241

   242

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

   243

       * visit the variable declarations...!

   244

       */

   245

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

   246

    }

   247

   248

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

   249

/* B 1.5.2 - Function Blocks */

   250

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

   251

    void *visit(function_block_declaration_c *symbol) {

   252

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

   253

       * visit the variable declarations...!

   254

       */

   255

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

   256

    }

   257

   258

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

   259

/* B 1.5.3 - Programs */

   260

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

   261

    void *visit(program_declaration_c *symbol) {

   262

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

   263

       * visit the variable declarations...!

   264

       */

   265

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

   266

    }

   267

   268

   269

#if 0

   270

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

   271

/* B 1.4 - Variables */

   272

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

   273

SYM_REF2(symbolic_variable_c, var_name, unused)

   274

   275

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

   276

/* B.1.4.1   Directly Represented Variables */

   277

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

   278

SYM_TOKEN(direct_variable_c)

   279

   280

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

   281

/* B.1.4.2   Multi-element Variables */

   282

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

   283

/*  subscripted_variable '[' subscript_list ']' */

   284

SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   285

   286

/* subscript_list ',' subscript */

   287

SYM_LIST(subscript_list_c)

   288

   289

/*  record_variable '.' field_selector */

   290

/*  WARNING: input and/or output variables of function blocks

   291

 *           may be accessed as fields of a tructured variable!

   292

 *           Code handling a structured_variable_c must take

   293

 *           this into account!

   294

 */

   295

SYM_REF2(structured_variable_c, record_variable, field_selector)

   296

   297

   298

#endif

   299

};

   300

   301

   302

   303

   304