1

/*

    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

/*

    33

 * Function call parameter iterator.

    34

 * It will iterate through the non-formal parameters of a function call

    35

 * (i.e. function calls using the foo(<param1>, <param2>, ...) syntax).

    36

 * and/or search through the formal parameters of a function call

    37

 * (i.e. function calls using the foo(<name1> = <param1>, <name2> = <param2>, ...) syntax).

    38

 *

    39

 * Calls to function blocks and programs are also supported.

    40

 *

    41

 * Note that calls to next_nf() will only iterate through non-formal parameters,

    42

 * calls to next_f() will only iterate through formal parameters,

    43

 * and calls to search_f() will only serach through formal parameters.

    44

 */

    45

    46

    47

    48

#include "function_call_param_iterator.hh"

    49

#include <strings.h>

    50

    51

    52

//#define DEBUG

    53

#ifdef DEBUG

    54

#define TRACE(classname) printf("\n____%s____\n",classname);

    55

#else

    56

#define TRACE(classname)

    57

#endif

    58

    59

#define ERROR error_exit(__FILE__,__LINE__)

    60

/* function defined in main.cc */

    61

extern void error_exit(const char *file_name, int line_no);

    62

    63

    64

    65

    66

    67

void *function_call_param_iterator_c::search_list(list_c *list) {

    68

  switch (current_operation) {

    69

    case iterate_nf_op:

    70

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

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        void *res = list->elements[i]->accept(*this);

    72

        if (NULL != res) {

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          /* It went through the handle_parameter_assignment() function,

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           * and is therefore a parameter assignment (<param> = <value>),

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           * and not a simple expression (<value>).

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           */

    77

          /* we do nothing... */

    78

        } else {

    79

          param_count++;

    80

          if (param_count == iterate_nf_next_param) {

    81

            return list->elements[i];

    82

          }

    83

        }

    84

      }

    85

      return NULL;

    86

      break;

    87

    88

    case iterate_f_op:

    89

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

    90

        void *res = list->elements[i]->accept(*this);

    91

        if (NULL != res) {

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          /* It went through the handle_parameter_assignment() function,

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           * and is therefore a parameter assignment (<param> = <value>),

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           * and not a simple expression (<value>).

    95

           */

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          param_count++;

    97

          if (param_count == iterate_f_next_param) {

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            return res;

    99

          }

   100

        } else {

   101

          /* we do nothing... */

   102

        }

   103

      }

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      return NULL;

   105

      break;

   106

   107

    case search_f_op:

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

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        void *res = list->elements[i]->accept(*this);

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        if (res != NULL)

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          return res;

   112

      }

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      return NULL;

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      break;

   115

  } /* switch */

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  return NULL;

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}

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   119

   120

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void *function_call_param_iterator_c::handle_parameter_assignment(symbol_c *variable_name, symbol_c *expression) {

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  switch (current_operation) {

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    case iterate_nf_op:

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          /* UGLY HACK -> this will be detected in the search_list() function */

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      return (void *)variable_name; /* anything, as long as it is not NULL!! */

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      break;

   127

   128

    case iterate_f_op:

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      current_value = expression;

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      return (void *)variable_name;

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      break;

   132

   133

    case search_f_op:

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      identifier_c *variable_name2 = dynamic_cast<identifier_c *>(variable_name);

   135

   136

      if (variable_name2 == NULL) ERROR;

   137

   138

      if (strcasecmp(search_param_name->value, variable_name2->value) == 0)

   139

        /* FOUND! This is the same parameter!! */

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        return (void *)expression;

   141

      return NULL;

   142

      break;

   143

  }

   144

   145

  ERROR;

   146

  return NULL;

   147

}

   148

   149

   150

/* start off at the first parameter once again... */

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void function_call_param_iterator_c::reset(void) {

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  iterate_nf_next_param = 0;

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  iterate_f_next_param  = 0;

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  param_count = 0;

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}

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/* initialise the iterator object.

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 * We must be given a reference to the function/program/function block call

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 * that will be analysed...

   160

 */

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function_call_param_iterator_c::function_call_param_iterator_c(symbol_c *f_call) {

   162

  /* It is expected that f_call will reference one of the following:

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   *  program_configuration_c

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   *  function_invocation_c

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   *  fb_invocation_c

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   *  il_function_call_c

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   *  il_formal_funct_call_c

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   *  ... (have I missed any?)

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   */

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  this->f_call = f_call;

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  search_param_name = NULL;

   172

  reset();

   173

}

   174

   175

/* Skip to the next formal parameter. After object creation,

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 * the object references on parameter _before_ the first, so

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 * this function must be called once to get the object to

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 * reference the first parameter...

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 *

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 * Returns the paramater name to which a value is being passed!

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 * You can determine the value being passed by calling 

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 * function_call_param_iterator_c::search_f()

   183

 */

   184

symbol_c *function_call_param_iterator_c::next_f(void) {

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  current_value = NULL;

   186

  param_count = 0;

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  iterate_f_next_param++;

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  current_operation = function_call_param_iterator_c::iterate_f_op;

   189

  void *res = f_call->accept(*this);

   190

  return (symbol_c *)res;

   191

}

   192

   193

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/* Skip to the next non-formal parameter. After object creation,

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 * the object references on parameter _before_ the first, so

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 * this function must be called once to get the object to

   197

 * reference the first parameter...

   198

 *

   199

 * Returns whatever is being passed to the parameter!

   200

 */

   201

symbol_c *function_call_param_iterator_c::next_nf(void) {

   202

  current_value = NULL;

   203

  param_count = 0;

   204

  iterate_nf_next_param++;

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  current_operation = function_call_param_iterator_c::iterate_nf_op;

   206

  void *res = f_call->accept(*this);

   207

  current_value = (symbol_c *)res;

   208

  return (symbol_c *)res;

   209

}

   210

   211

/* Search for the value passed to the parameter named <param_name>...  */

   212

symbol_c *function_call_param_iterator_c::search_f(symbol_c *param_name) {

   213

  current_value = NULL;

   214

  if (NULL == param_name) ERROR;

   215

  search_param_name = dynamic_cast<identifier_c *>(param_name);

   216

  if (NULL == search_param_name) ERROR;

   217

  current_operation = function_call_param_iterator_c::search_f_op;

   218

  void *res = f_call->accept(*this);

   219

  current_value = (symbol_c *)res;

   220

  return (symbol_c *)res;

   221

}

   222

   223

/* Returns the value being passed to the current parameter. */

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symbol_c *function_call_param_iterator_c::get_current_value(void) {

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  return current_value;

   226

}

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   228

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

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/* B 1.7 Configuration elements */

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

   231

   232

/*

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CONFIGURATION configuration_name

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   optional_global_var_declarations

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   (resource_declaration_list | single_resource_declaration)

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   optional_access_declarations

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   optional_instance_specific_initializations

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END_CONFIGURATION

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*/

   240

/*

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SYM_REF6(configuration_declaration_c, configuration_name, global_var_declarations, resource_declarations, access_declarations, instance_specific_initializations, unused)

   242

*/

   243

   244

/* helper symbol for configuration_declaration */

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/*

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SYM_LIST(resource_declaration_list_c)

   247

*/

   248

   249

/*

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RESOURCE resource_name ON resource_type_name

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   optional_global_var_declarations

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   single_resource_declaration

   253

END_RESOURCE

   254

*/

   255

/*

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SYM_REF4(resource_declaration_c, resource_name, resource_type_name, global_var_declarations, resource_declaration)

   257

*/

   258

   259

/* task_configuration_list program_configuration_list */

   260

/*

   261

SYM_REF2(single_resource_declaration_c, task_configuration_list, program_configuration_list)

   262

*/

   263

   264

/* helper symbol for single_resource_declaration */

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/*

   266

SYM_LIST(task_configuration_list_c)

   267

*/

   268

   269

/* helper symbol for single_resource_declaration */

   270

/*

   271

SYM_LIST(program_configuration_list_c)

   272

*/

   273

   274

/* helper symbol for

   275

 *  - access_path

   276

 *  - instance_specific_init

   277

 */

   278

/*

   279

SYM_LIST(any_fb_name_list_c)

   280

*/

   281

   282

/*  [resource_name '.'] global_var_name ['.' structure_element_name] */

   283

/*

   284

SYM_REF4(global_var_reference_c, resource_name, global_var_name, structure_element_name, unused)

   285

*/

   286

   287

/*  prev_declared_program_name '.' symbolic_variable */

   288

/*

   289

SYM_REF2(program_output_reference_c, program_name, symbolic_variable)

   290

*/

   291

   292

/*  TASK task_name task_initialization */

   293

/*

   294

SYM_REF2(task_configuration_c, task_name, task_initialization)

   295

*/

   296

   297

/*  '(' [SINGLE ASSIGN data_source ','] [INTERVAL ASSIGN data_source ','] PRIORITY ASSIGN integer ')' */

   298

/*

   299

SYM_REF4(task_initialization_c, single_data_source, interval_data_source, priority_data_source, unused)

   300

*/

   301

   302

/*  PROGRAM [RETAIN | NON_RETAIN] program_name [WITH task_name] ':' program_type_name ['(' prog_conf_elements ')'] */

   303

// SYM_REF6(program_configuration_c, retain_option, program_name, task_name, program_type_name, prog_conf_elements, unused)

   304

void *function_call_param_iterator_c::visit(program_configuration_c *symbol) {

   305

  TRACE("program_configuration_c");

   306

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

   307

}

   308

   309

/* prog_conf_elements ',' prog_conf_element */

   310

// SYM_LIST(prog_conf_elements_c)

   311

void *function_call_param_iterator_c::visit(prog_conf_elements_c *symbol) {

   312

  TRACE("prog_conf_elements_c");

   313

  return search_list(symbol);

   314

}

   315

   316

/*  fb_name WITH task_name */

   317

/*

   318

SYM_REF2(fb_task_c, fb_name, task_name)

   319

*/

   320

   321

/*  any_symbolic_variable ASSIGN prog_data_source */

   322

// SYM_REF2(prog_cnxn_assign_c, symbolic_variable, prog_data_source)

   323

void *function_call_param_iterator_c::visit(prog_cnxn_assign_c *symbol) {

   324

  TRACE("prog_cnxn_assign_c");

   325

   326

  /* NOTE: symbolic_variable may be something other than a symbolic_variable_c, but I (Mario)

   327

   *       do not understand the semantics that should be implmeneted if it is not a

   328

   *        symbolic_variable, so for the moment we simply give up!

   329

   */

   330

  symbolic_variable_c *symb_var = dynamic_cast<symbolic_variable_c *>(symbol->symbolic_variable);

   331

  if (NULL == symb_var)

   332

    ERROR;

   333

   334

  return handle_parameter_assignment(symb_var->var_name, symbol->prog_data_source);

   335

}

   336

   337

/* any_symbolic_variable SENDTO data_sink */

   338

// SYM_REF2(prog_cnxn_sendto_c, symbolic_variable, prog_data_source)

   339

void *function_call_param_iterator_c::visit(prog_cnxn_sendto_c *symbol) {

   340

  TRACE("prog_cnxn_sendto_c");

   341

   342

  /* NOTE: symbolic_variable may be something other than a symbolic_variable_c, but I (Mario)

   343

   *       do not understand the semantics that should be implmeneted if it is not a

   344

   *        symbolic_variable, so for the moment we simply give up!

   345

   */

   346

  symbolic_variable_c *symb_var = dynamic_cast<symbolic_variable_c *>(symbol->symbolic_variable);

   347

  if (NULL == symb_var)

   348

    ERROR;

   349

   350

  return handle_parameter_assignment(symb_var->var_name, symbol->data_sink);

   351

}

   352

   353

/* VAR_CONFIG instance_specific_init_list END_VAR */

   354

/*

   355

SYM_REF2(instance_specific_initializations_c, instance_specific_init_list, unused)

   356

*/

   357

   358

/* helper symbol for instance_specific_initializations */

   359

/*

   360

SYM_LIST(instance_specific_init_list_c)

   361

*/

   362

   363

/* resource_name '.' program_name '.' {fb_name '.'}

   364

    ((variable_name [location] ':' located_var_spec_init) | (fb_name ':' fb_initialization))

   365

*/

   366

/*

   367

SYM_REF6(instance_specific_init_c, resource_name, program_name, any_fb_name_list, variable_name, location, initialization)

   368

*/

   369

   370

/* helper symbol for instance_specific_init */

   371

/* function_block_type_name ':=' structure_initialization */

   372

/*

   373

SYM_REF2(fb_initialization_c, function_block_type_name, structure_initialization)

   374

*/

   375

   376

   377

   378

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

   379

/* B.2 - Language IL (Instruction List) */

   380

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

   381

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

   382

/* B 2.1 Instructions and Operands */

   383

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

   384

   385

/* | function_name [il_operand_list] */

   386

// SYM_REF2(il_function_call_c, function_name, il_operand_list)

   387

void *function_call_param_iterator_c::visit(il_function_call_c *symbol) {

   388

  TRACE("il_function_call_c");

   389

  if (NULL != symbol->il_operand_list)

   390

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

   391

  return NULL;

   392

}

   393

   394

   395

/* | function_name '(' eol_list [il_param_list] ')' */

   396

// SYM_REF2(il_formal_funct_call_c, function_name, il_param_list)

   397

void *function_call_param_iterator_c::visit(il_formal_funct_call_c *symbol) {

   398

  TRACE("il_formal_funct_call_c");

   399

  if (NULL != symbol->il_param_list)

   400

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

   401

  return NULL;

   402

}

   403

   404

   405

/*   il_call_operator prev_declared_fb_name

   406

 * | il_call_operator prev_declared_fb_name '(' ')'

   407

 * | il_call_operator prev_declared_fb_name '(' eol_list ')'

   408

 * | il_call_operator prev_declared_fb_name '(' il_operand_list ')'

   409

 * | il_call_operator prev_declared_fb_name '(' eol_list il_param_list ')'

   410

 */

   411

// SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list)

   412

void *function_call_param_iterator_c::visit(il_fb_call_c *symbol) {

   413

  TRACE("il_fb_call_c");

   414

  /* the following should never occur. In reality the syntax parser

   415

   * will guarantee that they never occur, but it makes it easier to

   416

   * understand the remaining code :-)

   417

   */

   418

  //if ((NULL == symbol->il_operand_list) && (NULL == symbol->il_param_list)) ERROR;

   419

  //if ((NULL != symbol->il_operand_list) && (NULL != symbol->il_param_list)) ERROR;

   420

   421

  if (NULL != symbol->il_operand_list)

   422

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

   423

  if (NULL != symbol->il_param_list)

   424

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

   425

  return NULL;

   426

}

   427

   428

/* | il_operand_list ',' il_operand */

   429

// SYM_LIST(il_operand_list_c)

   430

void *function_call_param_iterator_c::visit(il_operand_list_c *symbol) {

   431

  TRACE("il_operand_list_c");

   432

  return search_list(symbol);

   433

}

   434

   435

   436

/* | il_initial_param_list il_param_instruction */

   437

// SYM_LIST(il_param_list_c)

   438

void *function_call_param_iterator_c::visit(il_param_list_c *symbol) {

   439

  TRACE("il_param_list_c");

   440

  return search_list(symbol);

   441

}

   442

   443

/*  il_assign_operator il_operand

   444

 * | il_assign_operator '(' eol_list simple_instr_list ')'

   445

 */

   446

// SYM_REF4(il_param_assignment_c, il_assign_operator, il_operand, simple_instr_list, unused)

   447

void *function_call_param_iterator_c::visit(il_param_assignment_c *symbol) {

   448

  TRACE("il_param_assignment_c");

   449

   450

  // TODO : We do not yet handle a instruction list passed as parameter !!!

   451

  // since we do not yet support it, it is best to simply stop than to fail silently...

   452

  if (NULL != symbol->simple_instr_list) ERROR;

   453

   454

  return handle_parameter_assignment((symbol_c *)symbol->il_assign_operator->accept(*this), symbol->il_operand);

   455

}

   456

   457

/*  il_assign_out_operator variable */

   458

// SYM_REF2(il_param_out_assignment_c, il_assign_out_operator, variable);

   459

void *function_call_param_iterator_c::visit(il_param_out_assignment_c *symbol) {

   460

  TRACE("il_param_out_assignment_c");

   461

  return handle_parameter_assignment((symbol_c *)symbol->il_assign_out_operator->accept(*this), symbol->variable);

   462

}

   463

   464

   465

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

   466

/* B 2.2 Operators */

   467

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

   468

/*  any_identifier ASSIGN */

   469

// SYM_REF1(il_assign_operator_c, variable_name)

   470

void *function_call_param_iterator_c::visit(il_assign_operator_c *symbol) {

   471

  TRACE("il_assign_operator_c");

   472

  return (void *)symbol->variable_name;

   473

}

   474

   475

/*| [NOT] any_identifier SENDTO */

   476

// SYM_REF2(il_assign_out_operator_c, option, variable_name)

   477

void *function_call_param_iterator_c::visit(il_assign_out_operator_c *symbol) {

   478

  TRACE("il_assign_out_operator_c");

   479

   480

  // TODO : Handle not_param !!!

   481

  // we do not yet support it, so it is best to simply stop than to fail silently...

   482

  // if (NULL != symbol->option) ERROR;

   483

   484

  return (void *)symbol->variable_name;

   485

}

   486

   487

   488

   489

   490

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

   491

/* B.3 - Language ST (Structured Text) */

   492

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

   493

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

   494

/* B 3.1 - Expressions */

   495

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

   496

   497

/*

   498

SYM_REF2(function_invocation_c, function_name, parameter_assignment_list)

   499

*/

   500

void *function_call_param_iterator_c::visit(function_invocation_c *symbol) {

   501

  TRACE("function_invocation_c");

   502

  /* If the syntax parser is working correctly, exactly one of the 

   503

   * following two symbols will be NULL, while the other is != NULL.

   504

   */

   505

  if (symbol == (function_invocation_c *)f_call) {

   506

	if (symbol->   formal_param_list != NULL) return symbol->   formal_param_list->accept(*this);

   507

    if (symbol->nonformal_param_list != NULL) return symbol->nonformal_param_list->accept(*this);

   508

  }

   509

   510

  return NULL;

   511

}

   512

   513

   514

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

   515

/* B 3.2 Statements */

   516

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

   517

   518

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

   519