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/*

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

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 *

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

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

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 *

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

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

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

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 *  (at your option) any later version.

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 *

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

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

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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

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

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 *

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 *

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 * 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.

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 */

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/*

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 * An IEC 61131-3 compiler.

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 *

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 * Based on the

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

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 *

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 */

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/*

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 * Function parameter iterator.

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 * Iterate through the in/out parameters of a function declaration.

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 * Function blocks are also suported.

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 *

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 * This is part of the 4th stage that generates

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 * a c++ source program equivalent to the IL and ST

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 * code.

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 */

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/* Given a function_declaration_c, iterate through each

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 * function in/out/inout parameter, returning the name

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 * of each parameter...function_param_iterator_c

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 */

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#include "function_param_iterator.hh"  /* no longer required, aready included by absyntax_utils.hh */

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#include "spec_init_separator.hh"  /* no longer required, aready included by absyntax_utils.hh */

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#include <stdlib.h>  /* required for strtol() */

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#include <string.h>

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#include <strings.h>

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#include <limits> // required for std::numeric_limits< XXX >::max()

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#include <errno.h> // required for errno

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#include "../main.hh" // required for ERROR() and ERROR_MSG() macros.

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//#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

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/* NOTE: The following function is not really needed, as we could get the value that constant_folding_c determined for this

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 *       integer. Remember that currently constant_folding_c runs before this class is ever used/called!

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 *       However, I (Mario) do not currently feel it would be a good idea to restrict the use of this

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 *       abstract syntax utility to only after the constant_folding_c has had a chance to fill in the constant value

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 *       of this symbol. 

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 *       For this reason only, I have opted to let this abstract syntax utility have its own private copy of the

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 *       extract_integer() function.

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 *       Another aspect that makes this OK is that this function will only be used to extract the integer value of the

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 *       index for the first extensible paramater (examples follow shortly). Since this is an extension to IEC 61131-3 

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 *       that we created to allow us to handle extensible functions with very little hard coding, it is OK if we

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 *       impose extra/different limits on how an integer may be legally be formated in this case. This will also 

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 *       only show up in code that describes the interface to the standard function of IEC 61131-3, which the user

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 *       will not ever get to see. We write that IEC 61131-3 code ourselves!

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 *

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 *      Example of source code we will be parsing and analysing:

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 *

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 *      FUNCTION ADD : REAL VAR_INPUT IN 1 .. : REAL; END_VAR RETURN; END_FUNCTION

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 *                                      ^^^

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 *

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 *      FUNCTION MUX : REAL VAR_INPUT K : USINT; IN 0 .. : REAL; END_VAR RETURN; END_FUNCTION

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 *                                                 ^^^

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 *

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 *      Basically, currently this will only be either a '0' or a '1' !!

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 */

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/* NOTE: it must ignore underscores! */

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static int extract_first_index_value(symbol_c *sym) {

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  std::string str = "";

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  integer_c *integer;

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  long int ret;

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  if ((integer = dynamic_cast<integer_c *>(sym)) == NULL) ERROR;

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  for(unsigned int i = 0; i < strlen(integer->value); i++)

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    if (integer->value[i] != '_')  str += integer->value[i];

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  errno = 0; // since strtoXX() may legally return 0, we must set errno to 0 to detect errors correctly!

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  ret = strtol(str.c_str(), NULL, 10);

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  if (errno != 0) ERROR;

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  if (ret < 0) ERROR; // the following code assumes that the first index will never be negative!

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  if (ret > std::numeric_limits< int >::max()) ERROR; // output of this function is only an int!!

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  return ret;

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}

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/* compare the name of two __extensible__ function parameters.

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 * The usual use case is to have one of the parameters as used

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 * in the function declaration, and another as used in a formal function call.

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 *

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 * Will return:

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 *         < 0 : if two parameters are not compatible, or one is invalid

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 *        >= 0 : if both parameters ..........

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 */

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/*

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 *   ("in", "i0")      -> returns error (<0)

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 *   ("in1", "in")     -> returns error (<0)

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 *   ("in", "in")      -> returns error (<0)

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 *   ("in", "inw")     -> returns error (<0)

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 *   ("in", "in10.4")  -> returns error (<0)

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 *   ("in", "in10e")   -> returns error (<0)

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 *   ("in", "")        -> returns error (<0)

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 *   ("", "in10e")     -> returns error (<0)

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 *   ("in", "in0")     -> returns 0

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 *   ("in", "in9")     -> returns 9

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 *   ("in", "in42")    -> returns 42

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 *   ("in", "in-42")   -> returns -42 (error!)

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 */

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int function_param_iterator_c::cmp_extparam_names(const char* s1, const char* s2) {

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  int res;

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  char *endptr;

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  int len;

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  if ((s1 == NULL) || (s2 == NULL) || (*s1 == '\0') || (*s2 == '\0')) return -1;

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  len = strlen(s1);

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  if (strncasecmp(s1, s2, len)) return -2;

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  s1 = &s2[len];

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  if (*s1 == '\0') return -3;

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  res = strtol(s1, &endptr, 10);

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  if (*endptr != '\0') return -4;

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  return res;

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}

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void* function_param_iterator_c::handle_param_list(list_c *list) {

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  switch (current_operation) {

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    case iterate_op:

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      if (next_param <= param_count + list->n)

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        return list->get_element(next_param - param_count - 1);

   171

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      /* the desired param is not on this list... */

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      param_count += list->n;

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      break;

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   176

    case search_op:

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

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        symbol_c *sym = list->get_element(i);

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        extensible_input_parameter_c *extensible_parameter = dynamic_cast<extensible_input_parameter_c *>(sym);

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        if (extensible_parameter != NULL) {

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          sym = extensible_parameter->var_name;

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          current_param_is_extensible = true;

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          _first_extensible_param_index = extract_first_index_value(extensible_parameter->first_index);

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        }

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

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        if (variable_name == NULL) ERROR;

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        if (!current_param_is_extensible)

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

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

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            return (void *)variable_name;

   192

   193

        if (current_param_is_extensible) {

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          current_extensible_param_index = cmp_extparam_names(variable_name->value, search_param_name->value);

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          if (current_extensible_param_index >= 0)

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            /* FOUND! This is a compatible extensible parameter!! */

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            return (void *)variable_name;

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        }  

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      }

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      break;

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  } /* switch */

   202

   203

  /* Not found! */

   204

  return NULL;

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}

   206

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void* function_param_iterator_c::handle_single_param(symbol_c *var_name) {

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  switch (current_operation) {

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    case iterate_op:

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      param_count++;

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      if (next_param == param_count)

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        return var_name;

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      break;

   214

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    case search_op:

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      extensible_input_parameter_c *extensible_parameter = dynamic_cast<extensible_input_parameter_c *>(var_name);

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      if (extensible_parameter != NULL) {

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        var_name = extensible_parameter->var_name;

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        current_param_is_extensible = true;

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        _first_extensible_param_index = extract_first_index_value(extensible_parameter->first_index);

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      }

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

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      if (variable_name == NULL) ERROR;

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   225

      if (!current_param_is_extensible)

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

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

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          return (void *)variable_name;

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      if (current_param_is_extensible) {

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        current_extensible_param_index = cmp_extparam_names(variable_name->value, search_param_name->value);

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        if (current_extensible_param_index >= 0)

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          /* FOUND! This is a compatible extensible parameter!! */

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          return (void *)variable_name;

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      }  

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      break;

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  } /* switch */

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   239

  /* Not found! */

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  return NULL;

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}

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   243

void* function_param_iterator_c::iterate_list(list_c *list) {

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  void *res;

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

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    res = list->get_element(i)->accept(*this);

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    if (res != NULL)

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        return res;

   249

  }

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  return NULL;

   251

}

   252

   253

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

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void function_param_iterator_c::reset(void) {

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  next_param = param_count = 0;

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  _first_extensible_param_index = -1;

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  current_param_is_extensible = false;

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  current_param_name = NULL;

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  current_param_type = NULL;

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  current_param_default_value = NULL;

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  last_returned_parameter = NULL; /* the last parameter returned by search() or next() */

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}

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   264

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/* initialise the iterator object.

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 * We must be given a reference to one of the following

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 *     - function_declaration_c

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 *     - function_block_declaration_c

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 *     - program_declaration_c

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 * that will be analysed...

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 */

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function_param_iterator_c::function_param_iterator_c(symbol_c *pou_decl) {

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  /* do some consistency checks... */

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  function_declaration_c       * f_decl = dynamic_cast<function_declaration_c       *>(pou_decl);

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  function_block_declaration_c *fb_decl = dynamic_cast<function_block_declaration_c *>(pou_decl);

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  program_declaration_c        * p_decl = dynamic_cast<program_declaration_c        *>(pou_decl);

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   278

  if ((NULL == f_decl) && (NULL == fb_decl) && (NULL == p_decl)) 

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    ERROR;

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   281

  /* OK. Now initialise this object... */

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  this->f_decl = pou_decl;

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  reset();

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}

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   286

   287

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/* Skip to the next 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 parameter's name!

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 */

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identifier_c *function_param_iterator_c::next(void) {

   296

  void *res;

   297

  identifier_c *identifier;

   298

   299

  if (current_param_is_extensible) {

   300

    current_extensible_param_index++;

   301

    return current_param_name;

   302

  }

   303

   304

  last_returned_parameter = NULL; 

   305

  param_count = 0;

   306

  en_eno_param_implicit = false;

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  next_param++;

   308

  current_operation = function_param_iterator_c::iterate_op;

   309

  res = f_decl->accept(*this);

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  if (res == NULL) 

   311

    return NULL;

   312

   313

  symbol_c *sym = (symbol_c *)res;

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  extensible_input_parameter_c *extensible_parameter = dynamic_cast<extensible_input_parameter_c *>(sym);

   315

  if (extensible_parameter != NULL) {

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    sym = extensible_parameter->var_name;

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    current_param_is_extensible = true;

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    _first_extensible_param_index = extract_first_index_value(extensible_parameter->first_index);

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    current_extensible_param_index = _first_extensible_param_index;

   320

  }

   321

  identifier = dynamic_cast<identifier_c *>(sym);

   322

  if (identifier == NULL)

   323

    ERROR;

   324

  current_param_name = identifier;

   325

  last_returned_parameter = current_param_name; 

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  return current_param_name;

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}

   328

   329

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

   330

identifier_c *function_param_iterator_c::search(symbol_c *param_name) {

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  if (NULL == param_name) ERROR;

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  search_param_name = dynamic_cast<identifier_c *>(param_name);

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  if (NULL == search_param_name) ERROR;

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  en_eno_param_implicit = false;

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  current_param_is_extensible = false;

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  current_operation = function_param_iterator_c::search_op;

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

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  identifier_c *res_param_name = dynamic_cast<identifier_c *>((symbol_c *)res);

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  last_returned_parameter = res_param_name; 

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  return res_param_name;

   341

}

   342

   343

identifier_c *function_param_iterator_c::search(const char *param_name) {

   344

  identifier_c   param_name_id(param_name);

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  return search(&param_name_id);

   346

}

   347

   348

   349

   350

/* Returns the currently referenced parameter's default value,

   351

 * or NULL if none is specified in the function declrataion itself.

   352

 */

   353

symbol_c *function_param_iterator_c::default_value(void) {

   354

  if (NULL == last_returned_parameter) 

   355

    return NULL;

   356

  return current_param_default_value;

   357

}

   358

   359

/* Returns the currently referenced parameter's type name. */

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symbol_c *function_param_iterator_c::param_type(void) {

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  if (NULL == last_returned_parameter) 

   362

    return NULL;

   363

  return current_param_type;

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}

   365

   366

/* Returns if currently referenced parameter is an implicit defined EN/ENO parameter. */

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bool function_param_iterator_c::is_en_eno_param_implicit(void) {

   368

  if (NULL == last_returned_parameter) 

   369

    ERROR;

   370

  return en_eno_param_implicit;

   371

}

   372

   373

/* Returns if currently referenced parameter is an extensible parameter. */

   374

/* extensible paramters only occur in some standard functions, e.g. AND(word#34, word#44, word#65); */

   375

bool function_param_iterator_c::is_extensible_param(void) {

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  if (NULL == last_returned_parameter) 

   377

    ERROR;

   378

  return current_param_is_extensible;

   379

}

   380

   381

/* Returns the index of the current extensible parameter. */             

   382

/* If the current parameter is not an extensible paramter, returns -1 */

   383

int function_param_iterator_c::extensible_param_index(void) {

   384

  if (NULL == last_returned_parameter) 

   385

    ERROR;

   386

  return (current_param_is_extensible? current_extensible_param_index : -1);

   387

}

   388

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/* Returns the index of the first extensible parameter, or -1 if no extensible parameter found. */             

   390

/* WARNING: Will only return the correct value _after_ an extensible parameter has been found! */

   391

int function_param_iterator_c::first_extensible_param_index(void) {

   392

  return _first_extensible_param_index;

   393

}

   394

   395

/* Returns the currently referenced parameter's data passing direction.

   396

 * i.e. VAR_INPUT, VAR_OUTPUT or VAR_INOUT

   397

 */

   398

function_param_iterator_c::param_direction_t function_param_iterator_c::param_direction(void) {

   399

  if (NULL == last_returned_parameter) 

   400

    ERROR;

   401

  return current_param_direction;

   402

}

   403

   404

void *function_param_iterator_c::visit(implicit_definition_c *symbol) {

   405

	en_eno_param_implicit = true;

   406

	return NULL;

   407

}

   408

   409

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

   410

/* 1.4.3 - Declaration & Initialisation */

   411

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

   412

void *function_param_iterator_c::visit(input_declarations_c *symbol) {

   413

  TRACE("input_declarations_c");

   414

  current_param_direction = direction_in;

   415

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

   416

}

   417

   418

void *function_param_iterator_c::visit(input_declaration_list_c *symbol) {TRACE("input_declaration_list_c"); return iterate_list(symbol);}

   419

   420

void *function_param_iterator_c::visit(edge_declaration_c *symbol) {TRACE("edge_declaration_c"); return symbol->var1_list->accept(*this);}

   421

   422

void *function_param_iterator_c::visit(en_param_declaration_c *symbol) {

   423

  TRACE("en_param_declaration_c");

   424

  /* It is OK to store these values in the current_param_XXX

   425

   * variables, because if the desired parameter is not in the

   426

   * variable list we will be analysing, the current_param_XXXX

   427

   * variables will get overwritten when we visit the next

   428

   * var1_init_decl_c list!

   429

   */

   430

  current_param_default_value = spec_init_sperator_c::get_init(symbol->type_decl);

   431

  current_param_type = spec_init_sperator_c::get_spec(symbol->type_decl);

   432

   433

  void *res = handle_single_param(symbol->name);

   434

   435

    /* If we have found the parameter we will be returning, we set the en_eno_param_implicit to TRUE if implicitly defined */

   436

  if (res != NULL) symbol->method->accept(*this);

   437

   438

  return res;

   439

}

   440

   441

/* var1_list ':' array_spec_init */

   442

//SYM_REF2(array_var_init_decl_c, var1_list, array_spec_init)

   443

void *function_param_iterator_c::visit(array_var_init_decl_c *symbol) {

   444

  TRACE("array_var_init_decl_c");

   445

  current_param_default_value = spec_init_sperator_c::get_init(symbol->array_spec_init);

   446

  current_param_type = spec_init_sperator_c::get_spec(symbol->array_spec_init);

   447

   448

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

   449

}

   450

   451

/*  var1_list ':' initialized_structure */

   452

//SYM_REF2(structured_var_init_decl_c, var1_list, initialized_structure)

   453

void *function_param_iterator_c::visit(structured_var_init_decl_c *symbol) {

   454

  TRACE("structured_var_init_decl_c");

   455

   456

  current_param_default_value = spec_init_sperator_c::get_init(symbol->initialized_structure);

   457

  current_param_type = spec_init_sperator_c::get_spec(symbol->initialized_structure);

   458

   459

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

   460

}

   461

   462

   463

   464

   465

/* fb_name_list ':' function_block_type_name ASSIGN structure_initialization */

   466

/* structure_initialization -> may be NULL ! */

   467

// SYM_REF3(fb_name_decl_c, fb_name_list, function_block_type_name, structure_initialization)

   468

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

   469

  TRACE("structured_var_init_decl_c");

   470

  current_param_default_value = spec_init_sperator_c::get_init(symbol->fb_spec_init); 

   471

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

   472

   473

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

   474

}

   475

   476

   477

/* fb_name_list ',' fb_name */

   478

// SYM_LIST(fb_name_list_c)

   479

void *function_param_iterator_c::visit(fb_name_list_c *symbol) {TRACE("fb_name_list_c"); return handle_param_list(symbol);}

   480

   481

   482

void *function_param_iterator_c::visit(output_declarations_c *symbol) {

   483

  TRACE("output_declarations_c");

   484

  current_param_direction = direction_out;

   485

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

   486

}

   487

   488

void *function_param_iterator_c::visit(eno_param_declaration_c *symbol) {

   489

  TRACE("eno_param_declaration_c");

   490

  /* It is OK to store these values in the current_param_XXX

   491

   * variables, because if the desired parameter is not in the

   492

   * variable list we will be analysing, the current_param_XXXX

   493

   * variables will get overwritten when we visit the next

   494

   * var1_init_decl_c list!

   495

   */

   496

  current_param_default_value = NULL;

   497

  current_param_type = symbol->type;

   498