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/*

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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

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 * as published by the Free Software Foundation; either version 2 of the

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 * License, or (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, but

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 * WITHOUT ANY WARRANTY; without even the implied warranty of

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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

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 * Public License for more details.

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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 IL and ST 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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/* Determine the data type of an ST expression.

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 * A reference to the relevant type definition is returned.

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 *

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 * For example:

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 *       2 + 3       -> returns reference to a int_type_name_c object.

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 *       22.2 - 5    -> returns reference to a real_type_name_c object.

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 *       etc...

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 */

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#include "absyntax_utils.hh"

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#include <typeinfo>

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search_expression_type_c::search_expression_type_c(symbol_c *search_scope) {

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  search_varfb_instance_type = new search_varfb_instance_type_c(search_scope);

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}

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search_expression_type_c::~search_expression_type_c(void) {

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  delete search_varfb_instance_type;

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}

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/* A helper function... */

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bool search_expression_type_c::is_bool_type(symbol_c *type_symbol) {

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  bool_type_name_c tt;

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  if (type_symbol == NULL) {return true;}

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  return (typeid(*type_symbol) == typeid(bool_type_name_c));

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}

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/* A helper function... */

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bool search_expression_type_c::is_time_type(symbol_c *type_symbol) {

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  if (type_symbol == NULL) {return true;}

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  if (typeid(*type_symbol) == typeid(time_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(date_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(tod_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(dt_type_name_c)) {return true;}

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  return false;

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}

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/* A helper function... */

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bool search_expression_type_c::is_string_type(symbol_c *type_symbol) {

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  if (type_symbol == NULL) {return true;}

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  if (typeid(*type_symbol) == typeid(string_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(wstring_type_name_c)) {return true;}

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  return false;

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}

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/* A helper function... */

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bool search_expression_type_c::is_integer_type(symbol_c *type_symbol) {

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  if (type_symbol == NULL) {return true;}

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  if (typeid(*type_symbol) == typeid(sint_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(int_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(dint_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(lint_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(usint_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(uint_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(udint_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(ulint_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(constant_int_type_name_c)) {return true;}

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  return false;

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}

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bool search_expression_type_c::is_real_type(symbol_c *type_symbol) {

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  if (type_symbol == NULL) {return true;}

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  if (typeid(*type_symbol) == typeid(real_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(lreal_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(constant_real_type_name_c)) {return true;}

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  return false;

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}

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bool search_expression_type_c::is_num_type(symbol_c *type_symbol) {

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  if (type_symbol == NULL) {return true;}

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  return is_real_type(type_symbol) || is_integer_type(type_symbol);

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}

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bool search_expression_type_c::is_nbinary_type(symbol_c *type_symbol) {

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  if (type_symbol == NULL) {return true;}

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  if (typeid(*type_symbol) == typeid(byte_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(word_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(dword_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(lword_type_name_c)) {return true;}

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  if (typeid(*type_symbol) == typeid(constant_int_type_name_c)) {return true;}

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  return false;

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}

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bool search_expression_type_c::is_binary_type(symbol_c *type_symbol) {

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  if (type_symbol == NULL) {return true;}

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  if (typeid(*type_symbol) == typeid(bool_type_name_c)) {return true;}

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  return is_nbinary_type(type_symbol);

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}

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bool search_expression_type_c::is_same_type(symbol_c *first_type, symbol_c *second_type) {

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  if (first_type == NULL || second_type == NULL) {return true;}

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  if (typeid(*first_type) == typeid(*second_type)) {return true;}

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  if (is_integer_type(first_type) && (typeid(*second_type) == typeid(constant_int_type_name_c))) {return true;}

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  if ((typeid(*first_type) == typeid(constant_int_type_name_c) && is_integer_type(second_type))) {return true;}

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  if (is_binary_type(first_type) && (typeid(*second_type) == typeid(constant_int_type_name_c))) {return true;}

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  if ((typeid(*first_type) == typeid(constant_int_type_name_c) && is_binary_type(second_type))) {return true;}

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  if (is_real_type(first_type) && (typeid(*second_type) == typeid(constant_real_type_name_c))) {return true;}

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  if ((typeid(*first_type) == typeid(constant_real_type_name_c) && is_real_type(second_type))) {return true;}

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  return false;

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}

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symbol_c* search_expression_type_c::common_type(symbol_c *first_type, symbol_c *second_type) {

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  if (first_type == NULL && second_type == NULL) {return NULL;}

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  if (first_type == NULL) {return second_type;}

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  if (second_type == NULL) {return first_type;}

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  if (typeid(*first_type) == typeid(*second_type)) {return first_type;}

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  if (is_integer_type(first_type) && (typeid(*second_type) == typeid(constant_int_type_name_c))) {return first_type;}

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  if ((typeid(*first_type) == typeid(constant_int_type_name_c)) && is_integer_type(second_type)) {return second_type;}

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  if (is_binary_type(first_type) && (typeid(*second_type) == typeid(constant_int_type_name_c)))  {return first_type;}

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  if ((typeid(*first_type) == typeid(constant_int_type_name_c)) && is_binary_type(second_type)) {return second_type;}

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  if (is_real_type(first_type) && (typeid(*second_type) == typeid(constant_real_type_name_c))) {return first_type;}

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  if ((typeid(*first_type) == typeid(constant_real_type_name_c)) && is_real_type(second_type)) {return second_type;}

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  return NULL;

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}

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#define compute_standard_function_default search_expression_type_c::compute_standard_function_default

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#define compute_standard_function_il search_expression_type_c::compute_standard_function_il

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#include "search_type_code.c"

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#undef compute_standard_function_default

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#undef compute_standard_function_il

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/*static bool_type_name_c bool_type_name;*/

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/* A helper function... */

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void *search_expression_type_c::compute_boolean_expression(symbol_c *left_type, symbol_c *right_type) {

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  if (!is_same_type(left_type, right_type))

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    ERROR;

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  if (!is_bool_type(left_type) && !is_binary_type(left_type))

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    ERROR;

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  if (typeid(*left_type) == typeid(constant_int_type_name_c)) {return (void *)right_type;}

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  else {return (void *)left_type;}

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}

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/* A helper function... */

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void *search_expression_type_c::compute_numeric_expression(symbol_c *left_type, symbol_c *right_type) {

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  if (!is_same_type(left_type, right_type))

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    ERROR;

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  if (!is_integer_type(left_type) && !is_real_type(left_type))

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    ERROR;

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  if ((typeid(*left_type) == typeid(constant_int_type_name_c)) || (typeid(*left_type) == typeid(constant_real_type_name_c))) {return (void *)right_type;}

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  else {return (void *)left_type;}

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  return NULL;

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}

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/* a helper function... */

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symbol_c *search_expression_type_c::base_type(symbol_c *symbol) {

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  return (symbol_c *)symbol->accept(search_base_type);

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}

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

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/* B 1.4 - Variables */

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

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void *search_expression_type_c::visit(symbolic_variable_c *symbol) {

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  symbol_c *res;

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  /* Nope, now we assume it is a variable, and determine its type... */

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  res = search_varfb_instance_type->get_type(symbol);

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  if (NULL != res) return res;

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  return NULL;

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}

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

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/* B 1.4.1 - Directly Represented Variables */

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

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void *search_expression_type_c::visit(direct_variable_c *symbol) {

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  switch (symbol->value[2]) {

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    case 'X': // bit - 1 bit

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      return (void *)&bool_type_name;

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    case 'B': // byte - 8 bits

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      return (void *)&byte_type_name;

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    case 'W': // word - 16 bits

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      return (void *)&word_type_name;

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    case 'D': // double word - 32 bits

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      return (void *)&dword_type_name;

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    case 'L': // long word - 64 bits

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      return (void *)&lword_type_name;

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    default:  // if none of the above, then the empty string was used <=> boolean 

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      return (void *)&bool_type_name;

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  }

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}

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

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/* B 1.4.2 - Multi-element variables */

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

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void *search_expression_type_c::visit(array_variable_c *symbol) {

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  symbol_c *res;

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  /* Nope, now we assume it is a variable, and determine its type... */

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  res = search_varfb_instance_type->get_type(symbol);

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  if (NULL != res) return res;

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  return NULL;

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}

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void *search_expression_type_c::visit(structured_variable_c *symbol) {

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  symbol_c *res;

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  /* Nope, now we assume it is a variable, and determine its type... */

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  res = search_varfb_instance_type->get_type(symbol);

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  if (NULL != res) return res;

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  return NULL;

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}

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

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

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

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

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/* B 3.1 - Expressions */

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

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void *search_expression_type_c::visit(or_expression_c *symbol) {

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  symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));

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  symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));

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  return compute_boolean_expression(left_type, right_type);

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}

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void *search_expression_type_c::visit(xor_expression_c *symbol) {

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  symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));

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  symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));

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  return compute_boolean_expression(left_type, right_type);

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}

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void *search_expression_type_c::visit(and_expression_c *symbol) {

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  symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));

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  symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));

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  return compute_boolean_expression(left_type, right_type); 

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}

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void *search_expression_type_c::visit(equ_expression_c *symbol) {return (void *)&bool_type_name;}

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void *search_expression_type_c::visit(notequ_expression_c *symbol) {return (void *)&bool_type_name;}

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void *search_expression_type_c::visit(lt_expression_c *symbol) {return (void *)&bool_type_name;}

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void *search_expression_type_c::visit(gt_expression_c *symbol) {return (void *)&bool_type_name;}

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void *search_expression_type_c::visit(le_expression_c *symbol) {return (void *)&bool_type_name;}

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void *search_expression_type_c::visit(ge_expression_c *symbol) {return (void *)&bool_type_name;}

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void *search_expression_type_c::visit(add_expression_c *symbol) {

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  symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));

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  symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));

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  if (typeid(*left_type) == typeid(time_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) {return (void *)&time_type_name;}

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  if (typeid(*left_type) == typeid(tod_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) {return (void *)&tod_type_name;}

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  if (typeid(*left_type) == typeid(dt_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) {return (void *)&dt_type_name;}

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  return compute_numeric_expression(left_type, right_type);

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}

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void *search_expression_type_c::visit(sub_expression_c *symbol) {

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  symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));

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  symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));

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  if (typeid(*left_type) == typeid(time_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) {return (void *)&time_type_name;}

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  if (typeid(*left_type) == typeid(date_type_name_c) && typeid(*right_type) == typeid(date_type_name_c)) {return (void *)&time_type_name;}

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  if (typeid(*left_type) == typeid(tod_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) {return (void *)&tod_type_name;}

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  if (typeid(*left_type) == typeid(tod_type_name_c) && typeid(*right_type) == typeid(tod_type_name_c)) {return (void *)&time_type_name;}

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  if (typeid(*left_type) == typeid(dt_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) {return (void *)&dt_type_name;}

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  if (typeid(*left_type) == typeid(dt_type_name_c) && typeid(*right_type) == typeid(dt_type_name_c)) {return (void *)&time_type_name;}

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  return compute_numeric_expression(left_type, right_type);

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}

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void *search_expression_type_c::visit(mul_expression_c *symbol) {

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  symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));

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  symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));

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  if (typeid(*left_type) == typeid(time_type_name_c) && is_num_type(right_type)) {

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      return (void *)&time_type_name;

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  }

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  return compute_numeric_expression(left_type, right_type);

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}

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void *search_expression_type_c::visit(div_expression_c *symbol) {

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  symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));

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  symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));

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  if (typeid(*left_type) == typeid(time_type_name_c) && is_num_type(right_type)){

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      return (void *)&time_type_name;

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  }

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  return compute_numeric_expression(left_type, right_type);

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}

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void *search_expression_type_c::visit(mod_expression_c *symbol) {

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  symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));

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  symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));

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  return compute_numeric_expression(left_type, right_type);

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}

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   311

void *search_expression_type_c::visit(power_expression_c *symbol) {

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  symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));

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  symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));

   314

  if (is_real_type(left_type) && is_num_type(right_type)) {

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      return (void *)left_type;

   316

  }

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  ERROR;

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  return NULL;

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}

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   321

void *search_expression_type_c::visit(neg_expression_c *symbol) {

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  symbol_c *exp_type = base_type((symbol_c *)symbol->exp->accept(*this));

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  if (is_num_type(exp_type) || typeid(*exp_type) == typeid(time_type_name_c)){

   324

      return (void *)exp_type;

   325

  }

   326

  ERROR;

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  return NULL;

   328

}

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   330

void *search_expression_type_c::visit(not_expression_c *symbol) {

   331

  symbol_c *exp_type = base_type((symbol_c *)symbol->exp->accept(*this));

   332

  return compute_boolean_expression(exp_type, exp_type);

   333

}

   334

   335

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

   336

  function_declaration_c *f_decl = function_symtable.find_value(symbol->function_name);

   337

  if (f_decl == function_symtable.end_value()) {

   338

    void *res = compute_standard_function_default(symbol);

   339

    if (res == NULL)

   340

       ERROR;

   341

    return res;

   342

  }

   343

  return base_type(f_decl->type_name);

   344

}

   345

   346

/*bool_type_name_c     search_expression_type_c::bool_type_name;*/

   347