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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 size, in bits, of the data type.

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 * 

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 * NOTE: Currently, only elementary data types with well defined sizes (in the standard) are supported.

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 *       - derived data types are not supported, and these will return 0

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 *       - TIME, DATE, TIME_OF_DAY, and DATE_AND_TIME are not supported, and will return 0

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 *       - STRING and WSTRING are not supported, and the standard merely defines bit per character,

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 *              and not the maximum number of characters, so these will return 0

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 *

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 *       We also support the 'Numeric Literals' Data types.

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 *       i.e., numeric literals are considerd basic data types

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 *       as their data type is undefined (e.g. the datat type of '30'

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 *       could be 'INT' or 'SINT' or 'LINT' or 'USINT' or ...

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 *       NOTE: for base 10 numeric literals, any number taking up more than 64 bits

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 *             will only return a bitsize of 1024!

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 *

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 *       For numeric literals, we return the minimum number of bits

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 *       required to store the value.

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 *

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 * E.g. TYPE new_int_t : INT; END_TYPE;

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 *      TYPE new_int2_t : INT = 2; END_TYPE;

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 *      TYPE new_subr_t : INT (4..5); END_TYPE;

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 *

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 *    sizeof(SINT) ->  8

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 *    sizeof(INT)  -> 16

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 *    sizeof(DINT) -> 32

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 *    sizeof(LINT) -> 64

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 *

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 *    sizeof('1')       ->  1

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 *    sizeof('015')     ->  4    # Leading zeros are ignored!

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 *    sizeof('0')       ->  1    # This is a special case! Even the value 0 needs at least 1 bit to store!

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 *    sizeof('16')      ->  5

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 *    sizeof('2#00101') ->  3

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 *    sizeof('8#334')   ->  9

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 *    sizeof('16#2A')   ->  8

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 *

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 *    sizeof('7.4')     ->  32   # all real literals return 32 bits, the size of a 'REAL'

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 *                               # TODO: study IEC 60559 for the range of values that may be

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 *                               #       stored in a REAL (basic single width floating point format)

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 *                               #       and in a LREAL (basic double width floating point format)

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 *                               #       and see if some real literals need to return 64 instead!

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 */

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#include "get_sizeof_datatype.hh"

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#include <stdlib.h>

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#include <string.h>

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#include <limits.h>  // get definition of ULLONG_MAX

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/* tell stdint.h we want the definition of UINT64_MAX */

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#define __STDC_LIMIT_MACROS

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#include <stdint.h>  // get definition of uint64_t and UINT64_MAX

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#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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/* This class is a singleton.

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 * So we need a pointer to the singe instance...

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 */

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get_sizeof_datatype_c *get_sizeof_datatype_c::singleton = NULL;

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#define _encode_int(value)   ((void *)(((char *)NULL) + value))

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#define _decode_int(ptr)     (((char *)ptr) - ((char *)NULL))

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/* divide a base 10 literal in a string by 2 */

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/* returns remainder of division (0 or 1)    */

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static int strdivby2(char **strptr) {

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  char *str = *strptr;

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  int carry = 0;

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  while (*str != '\0') {

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    /* Assumes ASCII */

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    int newcarry;

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//     newcarry = ((*str-'0') mod 2);

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    newcarry = ((*str-'0') - ((*str-'0')/2)*2);

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    *str = (((*str-'0') + 10*carry)/2) + '0';

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    carry = newcarry;

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    str++;

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  }

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  /* ignore leading zeros in result... */

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  while (**strptr == '0') 

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    (*strptr)++;

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  return carry;

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}

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/* Constructor for the singleton class */

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int get_sizeof_datatype_c::getsize(symbol_c *data_type_symbol) {

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      if (NULL == singleton) {

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        singleton = new get_sizeof_datatype_c;

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        if (NULL == singleton)

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          ERROR;

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      }

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      return _decode_int(data_type_symbol->accept(*singleton));

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    }

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/* Destructor for the singleton class */

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get_sizeof_datatype_c::~get_sizeof_datatype_c(void) {

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      if (NULL != singleton) delete singleton;

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      singleton = NULL;

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    }

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

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/* B 1.2 - Constants */

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

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

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/* B 1.2.1 - Numeric Literals */

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

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 /* Numeric literals without any explicit type cast have unknown data type, 

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  * so we continue considering them as their own basic data types until

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  * they can be resolved (for example, when using '30+x' where 'x' is a LINT variable, the

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  * numeric literal '30' must then be considered a LINT so the ADD function may be called

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  * with all inputs of the same data type.

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  * If 'x' were a SINT, then the '30' would have to be a SINT too!

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  */

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/* NOTE: all integer and real literal tokens will always be positive (i.e. no leading '-')

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 * due to the way the source code is parsed by iec.flex.

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 */

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void *get_sizeof_datatype_c::visit(real_c *symbol) {

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  return _encode_int(32);

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}

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/* NOTE: all integer and real literal tokens will always be positive (i.e. no leading '-')

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 * due to the way the source code is parsed by iec.flex.

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 */

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void *get_sizeof_datatype_c::visit(integer_c *symbol) {

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  int bitsize = 0;

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  if (NULL ==   symbol->value ) ERROR;

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  if ('\0' == *(symbol->value)) ERROR;

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#if 0

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  char *endptr;

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  /* Convert the string to an unsigned 64 bit integer */

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  /* We can use strtoull(), but we are not guaranteed that an unsigned long long int

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   * is 64 bits wide. First make sure that it is...

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   *

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   * We could also use the strtouq() instead, which converts

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   * to a quad word (64 bits). However, this requires either GCC or BSD extensions.

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   */

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  #ifdef strtoull // this ifdef does not work!!

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    /* we have long long int, use it... */

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    #define ival_MAX ULLONG_MAX

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    unsigned long long int ival = 0;

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    ival = strtoull (symbol->value, &endptr, 10 /* base */);

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  #else

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    /* use long int ... */

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    #define ival_MAX ULONG_MAX

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    unsigned long int ival = 0;

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    ival = strtoul (symbol->value, &endptr, 10 /* base */);

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  #endif

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  #if (ival_MAX < UINT64_MAX)

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  #error Largest strtoint() conversion function converts to an int less than 64 bits wide!

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  #endif

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  if (NULL ==  endptr) ERROR;

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  if ('\0' != *endptr) ERROR;

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  // TODO: return _encode_int(1024) if value takes up more than 64 bits! 

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  /* determine the number of bits used... */

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  for (bitsize = 0; ival > 0; ival /= 2, bitsize++);

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  /* special case... if (value == 0) <=> (bitsize == 0), return bit size of 1 ! */

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  if (0 == bitsize) bitsize = 1;

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  return _encode_int(bitsize);

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#endif

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  /* We could first convert from string to some kind of integer, and then

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   * determine the the bitsize using integer aritmetic.

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   * However, we are then limited to the bit size of the widest available integer

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   * (usually 64 bits), which is not good at all!

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   */

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  /* Let's try to determine bitsize by converting directly from the string!! */

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  char *sval = strdup(symbol->value);

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  char *oval = sval;

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  if (NULL ==  sval) ERROR;

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  if ('\0' == *sval) ERROR;

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  for (bitsize = 0; *sval != '\0'; strdivby2(&sval), bitsize ++);

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  /* Even for (value == 0), the above loop will return bitsize == 1!, 

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   * so we don't need to handle the special case...

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   */

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  /* special case... if (value == 0) <=> (bitsize == 0), return bit size of 1 ! */

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  // if (0 == bitsize) bitsize = 1;

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  free(oval);

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  return _encode_int(bitsize);

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}

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/* NOTE: all integer and real literal tokens will always be positive (i.e. no leading '-')

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 * due to the way the source code is parsed by iec.flex.

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 */

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void *get_sizeof_datatype_c::visit(binary_integer_c *symbol) {

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  const char *sval = symbol->value;

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  int bitsize = 0;

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  /* first 2 characters had better be "2#" ! */

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  if (NULL ==  sval) ERROR;

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  if ('\0' == *sval) ERROR;

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  if ( '2' != *sval) ERROR;

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  sval++;

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  if ('\0' == *sval) ERROR;

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  if ( '#' != *sval) ERROR;

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  sval++;

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  if ('\0' == *sval) ERROR;

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  /* determine the number of bits used... */

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  for (bitsize = 0; '\0' != *sval; sval++, bitsize++) {

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    /* consistency check: make sure we only have binary digits! */

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    if (('0' != *sval) && ('1' != *sval))

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      ERROR;

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  }

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  /* special case... if (value == 0) <=> (bitsize == 0), return bit size of 1 ! */

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  if (0 == bitsize) bitsize = 1;

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  return _encode_int(bitsize);

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}

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/* NOTE: all integer and real literal tokens will always be positive (i.e. no leading '-')

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 * due to the way the source code is parsed by iec.flex.

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 */

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void *get_sizeof_datatype_c::visit(octal_integer_c *symbol) {

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  const char *sval = symbol->value;

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  int bitsize = 0;

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  /* first 2 characters had better be "8#" ! */

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  if (NULL ==  sval) ERROR;

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  if ('\0' == *sval) ERROR;

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  if ( '8' != *sval) ERROR;

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  sval++;

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  if ('\0' == *sval) ERROR;

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  if ( '#' != *sval) ERROR;

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  sval++;

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  if ('\0' == *sval) ERROR;

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  /* determine the number of bits used... */

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  for (bitsize = 0; '\0' != *sval; sval++, bitsize += 3 /* 3 bits per octal digit */) {

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    /* consistency check: make sure we only have octal digits! */

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    /* Assumes ASCII */

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    if (('0' > *sval) || ('7' < *sval))

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      ERROR;

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  }

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  /* special case... if (value == 0) <=> (bitsize == 0), return bit size of 1 ! */

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  if (0 == bitsize) bitsize = 1;

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  return _encode_int(bitsize);

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}

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/* NOTE: all integer and real literal tokens will always be positive (i.e. no leading '-')

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 * due to the way the source code is parsed by iec.flex.

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 */

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void *get_sizeof_datatype_c::visit(hex_integer_c *symbol) {

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  const char *sval = symbol->value;

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  int bitsize = 0;

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  /* first 3 characters had better be "16#" ! */

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  if (NULL ==  sval) ERROR;

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  if ('\0' == *sval) ERROR;

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  if ( '1' != *sval) ERROR;

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  sval++;

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  if ('\0' == *sval) ERROR;

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  if ( '6' != *sval) ERROR;

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  sval++;

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  if ('\0' == *sval) ERROR;

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  if ( '#' != *sval) ERROR;

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  sval++;

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  if ('\0' == *sval) ERROR;

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  /* determine the number of bits used... */

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  for (bitsize = 0; '\0' != *sval; sval++, bitsize += 4 /* 4 bits per hex digit */) {

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    /* consistency check: make sure we only have hex digits! */

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    /* Assumes ASCII */

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    if (!(('0' <= *sval) && ('9' >= *sval)) && 

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        !(('A' <= *sval) && ('F' >= *sval)) &&

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        !(('a' <= *sval) && ('b' >= *sval)))

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      ERROR;

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  }

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  /* special case... if (value == 0) <=> (bitsize == 0), return bit size of 1 ! */

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  if (0 == bitsize) bitsize = 1;

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  return _encode_int(bitsize);

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}

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

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/* B 1.3.1 - Elementary Data Types */

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

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// void *get_sizeof_datatype_c::visit(time_type_name_c *symbol)	{return _encode_int(0); }

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void *get_sizeof_datatype_c::visit(bool_type_name_c *symbol)	{return _encode_int(1); }

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void *get_sizeof_datatype_c::visit(sint_type_name_c *symbol)	{return _encode_int(8); }

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void *get_sizeof_datatype_c::visit(int_type_name_c *symbol)	{return _encode_int(16);}

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void *get_sizeof_datatype_c::visit(dint_type_name_c *symbol)	{return _encode_int(32);}

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void *get_sizeof_datatype_c::visit(lint_type_name_c *symbol)	{return _encode_int(64);}

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void *get_sizeof_datatype_c::visit(usint_type_name_c *symbol)	{return _encode_int(8); }

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void *get_sizeof_datatype_c::visit(uint_type_name_c *symbol)	{return _encode_int(16);}

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void *get_sizeof_datatype_c::visit(udint_type_name_c *symbol)	{return _encode_int(32);}

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void *get_sizeof_datatype_c::visit(ulint_type_name_c *symbol)	{return _encode_int(64);}

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void *get_sizeof_datatype_c::visit(real_type_name_c *symbol)	{return _encode_int(32);}

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void *get_sizeof_datatype_c::visit(lreal_type_name_c *symbol)	{return _encode_int(64);}

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// void *get_sizeof_datatype_c::visit(date_type_name_c *symbol)	{return _encode_int(0); }

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// void *get_sizeof_datatype_c::visit(tod_type_name_c *symbol)	{return _encode_int(0); }

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// void *get_sizeof_datatype_c::visit(dt_type_name_c *symbol)	{return _encode_int(0); }

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void *get_sizeof_datatype_c::visit(byte_type_name_c *symbol)	{return _encode_int(8); }

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void *get_sizeof_datatype_c::visit(word_type_name_c *symbol)	{return _encode_int(16);}

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void *get_sizeof_datatype_c::visit(dword_type_name_c *symbol)	{return _encode_int(32);}

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void *get_sizeof_datatype_c::visit(lword_type_name_c *symbol)	{return _encode_int(64);}

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// void *get_sizeof_datatype_c::visit(string_type_name_c *symbol)	{return _encode_int(0); }

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// void *get_sizeof_datatype_c::visit(wstring_type_name_c *symbol)	{return _encode_int(0); }

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

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/* Extensions to the base standard as defined in      */

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/* "Safety Software Technical Specification,          */

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/*  Part 1: Concepts and Function Blocks,             */

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/*  Version 1.0 – Official Release"                   */

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/* by PLCopen - Technical Committee 5 - 2006-01-31    */

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

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void *get_sizeof_datatype_c::visit(safebool_type_name_c *symbol)	{return _encode_int(1);}

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

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/* B 1.3.3 - Derived data types */

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

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// Not yet supported...