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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 on which another data type is based on.

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 * If a new default initial value is given, we DO NOT consider it a

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 * new base class, and continue looking further!

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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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 *    new_int_t is really an INT!!

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 *    new_int2_t is also really an INT!!

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 *    new_subr_t is also really an INT!!

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 */

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class search_base_type_c: public null_visitor_c {

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  private:

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    symbol_c *current_type_name;

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  public:

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    search_base_type_c(void) {current_type_name = NULL;}

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  public:

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    void *visit(identifier_c *type_name) {

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      this->current_type_name = type_name;

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      /* look up the type declaration... */

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      symbol_c *type_decl = type_symtable.find_value(type_name);

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      if (type_decl == type_symtable.end_value())

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        /* Type declaration not found!! */

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	ERROR;

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      return type_decl->accept(*this);

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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 *visit(time_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(bool_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(sint_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(int_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(dint_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(lint_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(usint_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(uint_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(udint_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(ulint_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(real_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(lreal_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(date_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(tod_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(dt_type_name_c *symbol)		{return (void *)symbol;}

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    void *visit(byte_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(word_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(dword_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(lword_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(string_type_name_c *symbol)	{return (void *)symbol;}

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    void *visit(wstring_type_name_c *symbol)	{return (void *)symbol;}

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

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/* B 1.3.3 - Derived data types */

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

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/*  simple_type_name ':' simple_spec_init */

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    void *visit(simple_type_declaration_c *symbol) {

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

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    }

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/* simple_specification ASSIGN constant */

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    void *visit(simple_spec_init_c *symbol) {

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

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    }

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/*  subrange_type_name ':' subrange_spec_init */

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    void *visit(subrange_type_declaration_c *symbol) {

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

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    }

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/* subrange_specification ASSIGN signed_integer */

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    void *visit(subrange_spec_init_c *symbol) {

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

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    }

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/*  integer_type_name '(' subrange')' */

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    void *visit(subrange_specification_c *symbol) {

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

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    }

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/*  signed_integer DOTDOT signed_integer */

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    void *visit(subrange_c *symbol) {ERROR; return NULL;} /* should never get called... */

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/*  enumerated_type_name ':' enumerated_spec_init */

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    void *visit(enumerated_type_declaration_c *symbol) {

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      this->current_type_name = symbol->enumerated_type_name;

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

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    }

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/* enumerated_specification ASSIGN enumerated_value */

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    void *visit(enumerated_spec_init_c *symbol) {

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

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    }

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/* helper symbol for enumerated_specification->enumerated_spec_init */

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/* enumerated_value_list ',' enumerated_value */

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    void *visit(enumerated_value_list_c *symbol) {

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      if (NULL == this->current_type_name) ERROR;

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      return (void *)this->current_type_name;

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    }

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/* enumerated_type_name '#' identifier */

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// SYM_REF2(enumerated_value_c, type, value)

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    void *visit(enumerated_value_c *symbol) {ERROR; return NULL;} /* should never get called... */

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/*  identifier ':' array_spec_init */

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    void *visit(array_type_declaration_c *symbol) {

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      this->current_type_name = symbol->identifier;

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

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    }

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/* array_specification [ASSIGN array_initialization} */

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/* array_initialization may be NULL ! */

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    void *visit(array_spec_init_c *symbol) {

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

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    }

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/* ARRAY '[' array_subrange_list ']' OF non_generic_type_name */

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    void *visit(array_specification_c *symbol)	{

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      if (NULL == this->current_type_name) ERROR;

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      return (void *)this->current_type_name;

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    }

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/* helper symbol for array_specification */

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/* array_subrange_list ',' subrange */

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    void *visit(array_subrange_list_c *symbol)	{ERROR; return NULL;} /* should never get called... */

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/* array_initialization:  '[' array_initial_elements_list ']' */

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/* helper symbol for array_initialization */

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/* array_initial_elements_list ',' array_initial_elements */

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    void *visit(array_initial_elements_list_c *symbol)	{ERROR; return NULL;} /* should never get called... */

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/* integer '(' [array_initial_element] ')' */

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/* array_initial_element may be NULL ! */

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    void *visit(array_initial_elements_c *symbol)	{ERROR; return NULL;} /* should never get called... */

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/*  structure_type_name ':' structure_specification */

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      /* NOTE: structure_specification will point to either a

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       *       initialized_structure_c

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       *       OR A

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       *       structure_element_declaration_list_c

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       */

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    void *visit(structure_type_declaration_c *symbol)  {

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      this->current_type_name = symbol->structure_type_name;

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

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    }

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/* structure_type_name ASSIGN structure_initialization */

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/* structure_initialization may be NULL ! */

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    void *visit(initialized_structure_c *symbol)	{

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

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    }

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/* helper symbol for structure_declaration */

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/* structure_declaration:  STRUCT structure_element_declaration_list END_STRUCT */

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/* structure_element_declaration_list structure_element_declaration ';' */

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    void *visit(structure_element_declaration_list_c *symbol)	{

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      if (NULL == this->current_type_name) ERROR;

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      return (void *)this->current_type_name;

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    }

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/*  structure_element_name ':' *_spec_init */

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    void *visit(structure_element_declaration_c *symbol) {ERROR; return NULL;} /* should never get called... */

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/* helper symbol for structure_initialization */

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/* structure_initialization: '(' structure_element_initialization_list ')' */

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/* structure_element_initialization_list ',' structure_element_initialization */

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    void *visit(structure_element_initialization_list_c *symbol) {ERROR; return NULL;} /* should never get called... */

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/*  structure_element_name ASSIGN value */

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    void *visit(structure_element_initialization_c *symbol) {ERROR; return NULL;} /* should never get called... */

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/*  string_type_name ':' elementary_string_type_name string_type_declaration_size string_type_declaration_init */

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/*

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SYM_REF4(string_type_declaration_c,	string_type_name,

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					elementary_string_type_name,

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					string_type_declaration_size,

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					string_type_declaration_init) // may be == NULL!

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*/

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    void *visit(string_type_declaration_c *symbol)	{return symbol;}

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};

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