1

/*

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 * (c) 2003 Mario de Sousa

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 *

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 * 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

 *

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 * 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

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 * 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

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

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 *

    23

 */

    24

    25

/*

    26

 * Function call parameter iterator.

    27

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

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

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

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

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 *

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 * Calls to function blocks and programs are also supported.

    33

 *

    34

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

    35

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

    36

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

    37

 */

    38

    39

    40

    41

#include "function_call_param_iterator.hh"

    42

#include <strings.h>

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    44

    45

//#define DEBUG

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#ifdef DEBUG

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

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#else

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#define TRACE(classname)

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#endif

    51

    52

#define ERROR error_exit(__FILE__,__LINE__)

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/* function defined in main.cc */

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

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    56

    57

    58

    59

    60

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

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  switch (current_operation) {

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    case iterate_nf_op:

    63

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

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

    65

        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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           */

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          /* we do nothing... */

    71

        } else {

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          param_count++;

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          if (param_count == iterate_nf_next_param) {

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            return list->elements[i];

    75

          }

    76

        }

    77

      }

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      return NULL;

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      break;

    80

    81

    case iterate_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 (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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           */

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          param_count++;

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          if (param_count == iterate_f_next_param) {

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            return res;

    92

          }

    93

        } else {

    94

          /* we do nothing... */

    95

        }

    96

      }

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      return NULL;

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      break;

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   100

    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;

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      }

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      return NULL;

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      break;

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  } /* switch */

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  return NULL;

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}

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   112

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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;

   120

   121

    case iterate_f_op:

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      current_value = expression;

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      return (void *)variable_name;

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      break;

   125

   126

    case search_f_op:

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

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   129

      if (variable_name2 == NULL) ERROR;

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   131

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

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

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        return (void *)expression;

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      return NULL;

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      break;

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  }

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   138

  ERROR;

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  return NULL;

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}

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   142

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/* 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...

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 */

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function_call_param_iterator_c::function_call_param_iterator_c(symbol_c *f_call) {

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  /* 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;

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  reset();

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}

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/* 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()

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 */

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symbol_c *function_call_param_iterator_c::next_f(void) {

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  current_value = NULL;

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  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;

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

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  return (symbol_c *)res;

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}

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   186

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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

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 * reference the first parameter...

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 *

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 * Returns whatever is being passed to the parameter!

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 */

   194

symbol_c *function_call_param_iterator_c::next_nf(void) {

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  current_value = NULL;

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  param_count = 0;

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  iterate_nf_next_param++;

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  current_operation = function_call_param_iterator_c::iterate_nf_op;

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

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  current_value = (symbol_c *)res;

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  return (symbol_c *)res;

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}

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   204

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

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

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  current_value = NULL;

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  if (NULL == param_name) ERROR;

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  search_param_name = dynamic_cast<identifier_c *>(param_name);

   209

  if (NULL == search_param_name) ERROR;

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  current_operation = function_call_param_iterator_c::search_f_op;

   211

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

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  current_value = (symbol_c *)res;

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  return (symbol_c *)res;

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}

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/* 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;

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}

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

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/* B 1.7 Configuration elements */

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

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/*

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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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*/

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/*

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

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*/

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   237

/* helper symbol for configuration_declaration */

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/*

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SYM_LIST(resource_declaration_list_c)

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*/

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/*

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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

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END_RESOURCE

   247

*/

   248

/*

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

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*/

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   252

/* task_configuration_list program_configuration_list */

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/*

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SYM_REF2(single_resource_declaration_c, task_configuration_list, program_configuration_list)

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*/

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/* helper symbol for single_resource_declaration */

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/*

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SYM_LIST(task_configuration_list_c)

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*/

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/* helper symbol for single_resource_declaration */

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/*

   264

SYM_LIST(program_configuration_list_c)

   265

*/

   266

   267

/* helper symbol for

   268

 *  - access_path

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 *  - instance_specific_init

   270

 */

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/*

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SYM_LIST(any_fb_name_list_c)

   273

*/

   274

   275

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

   276

/*

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

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*/

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   280

/*  prev_declared_program_name '.' symbolic_variable */

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/*

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SYM_REF2(program_output_reference_c, program_name, symbolic_variable)

   283

*/

   284

   285

/*  TASK task_name task_initialization */

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/*

   287

SYM_REF2(task_configuration_c, task_name, task_initialization)

   288

*/

   289

   290

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

   291

/*

   292

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

   293

*/

   294

   295

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

   296

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

   297

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

   298

  TRACE("program_configuration_c");

   299

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

   300

}

   301

   302

/* prog_conf_elements ',' prog_conf_element */

   303

// SYM_LIST(prog_conf_elements_c)

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

   305

  TRACE("prog_conf_elements_c");

   306

  return search_list(symbol);

   307

}

   308

   309

/*  fb_name WITH task_name */

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/*

   311

SYM_REF2(fb_task_c, fb_name, task_name)

   312

*/

   313

   314

/*  any_symbolic_variable ASSIGN prog_data_source */

   315

// SYM_REF2(prog_cnxn_assign_c, symbolic_variable, prog_data_source)

   316

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

   317

  TRACE("prog_cnxn_assign_c");

   318

   319

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

   320

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

   321

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

   322

   */

   323

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

   324

  if (NULL == symb_var)

   325

    ERROR;

   326

   327

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

   328

}

   329

   330

/* any_symbolic_variable SENDTO data_sink */

   331

// SYM_REF2(prog_cnxn_sendto_c, symbolic_variable, prog_data_source)

   332

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

   333

  TRACE("prog_cnxn_sendto_c");

   334

   335

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

   336

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

   337

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

   338

   */

   339

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

   340

  if (NULL == symb_var)

   341

    ERROR;

   342

   343

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

   344

}

   345

   346

/* VAR_CONFIG instance_specific_init_list END_VAR */

   347

/*

   348

SYM_REF2(instance_specific_initializations_c, instance_specific_init_list, unused)

   349

*/

   350

   351

/* helper symbol for instance_specific_initializations */

   352

/*

   353

SYM_LIST(instance_specific_init_list_c)

   354

*/

   355

   356

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

   357

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

   358

*/

   359

/*

   360

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

   361

*/

   362

   363

/* helper symbol for instance_specific_init */

   364

/* function_block_type_name ':=' structure_initialization */

   365

/*

   366

SYM_REF2(fb_initialization_c, function_block_type_name, structure_initialization)

   367

*/

   368

   369

   370

   371

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

   372

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

   373

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

   374

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

   375

/* B 2.1 Instructions and Operands */

   376

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

   377

   378

/* | function_name [il_operand_list] */

   379

// SYM_REF2(il_function_call_c, function_name, il_operand_list)

   380

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

   381

  TRACE("il_function_call_c");

   382

  if (NULL != symbol->il_operand_list)

   383

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

   384

  return NULL;

   385

}

   386

   387

   388

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

   389

// SYM_REF2(il_formal_funct_call_c, function_name, il_param_list)

   390

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

   391

  TRACE("il_formal_funct_call_c");

   392

  if (NULL != symbol->il_param_list)

   393

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

   394

  return NULL;

   395

}

   396

   397

   398

/*   il_call_operator prev_declared_fb_name

   399

 * | il_call_operator prev_declared_fb_name '(' ')'

   400

 * | il_call_operator prev_declared_fb_name '(' eol_list ')'

   401

 * | il_call_operator prev_declared_fb_name '(' il_operand_list ')'

   402

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

   403

 */

   404

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

   405

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

   406

  TRACE("il_fb_call_c");

   407

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

   408

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

   409

   * understand the remaining code :-)

   410

   */

   411

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

   412

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

   413

   414

  if (NULL != symbol->il_operand_list)

   415

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

   416

  if (NULL != symbol->il_param_list)

   417

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

   418

  return NULL;

   419

}

   420

   421

/* | il_operand_list ',' il_operand */

   422

// SYM_LIST(il_operand_list_c)

   423

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

   424

  TRACE("il_operand_list_c");

   425

  return search_list(symbol);

   426

}

   427

   428

   429

/* | il_initial_param_list il_param_instruction */

   430

// SYM_LIST(il_param_list_c)

   431

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

   432

  TRACE("il_param_list_c");

   433

  return search_list(symbol);

   434

}

   435

   436

/*  il_assign_operator il_operand

   437

 * | il_assign_operator '(' eol_list simple_instr_list ')'

   438

 */

   439

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

   440

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

   441

  TRACE("il_param_assignment_c");

   442

   443

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

   444

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

   445

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

   446

   447

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

   448

}

   449

   450

/*  il_assign_out_operator variable */

   451

// SYM_REF2(il_param_out_assignment_c, il_assign_out_operator, variable);

   452

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

   453

  TRACE("il_param_out_assignment_c");

   454

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

   455

}

   456

   457

   458

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

   459

/* B 2.2 Operators */

   460

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

   461

/*  any_identifier ASSIGN */

   462

// SYM_REF1(il_assign_operator_c, variable_name)

   463

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

   464

  TRACE("il_assign_operator_c");

   465

  return (void *)symbol->variable_name;

   466

}

   467

   468

/*| [NOT] any_identifier SENDTO */

   469

// SYM_REF2(il_assign_out_operator_c, option, variable_name)

   470

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

   471

  TRACE("il_assign_out_operator_c");

   472

   473

  // TODO : Handle not_param !!!

   474

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

   475

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

   476

   477

  return (void *)symbol->variable_name;

   478

}

   479

   480

   481

   482

   483

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

   484

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

   485

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

   486

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

   487

/* B 3.1 - Expressions */

   488

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

   489

   490

/*

   491

SYM_REF2(function_invocation_c, function_name, parameter_assignment_list)

   492

*/

   493

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

   494

  TRACE("function_invocation_c");

   495

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

   496

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

   497

   */

   498

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

   499

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

   500

   501

  return NULL;

   502

}

   503

   504

   505

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

   506

/* B 3.2 Statements */

   507

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

   508

   509

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

   510

/* B 3.2.1 Assignment Statements */

   511

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

   512

/*

   513

SYM_REF2(assignment_statement_c, l_exp, r_exp)

   514

*/

   515

   516

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

   517

/* B 3.2.2 Subprogram Control Statements */

   518

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

   519

/*  RETURN */

   520

// SYM_REF0(return_statement_c)