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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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 * 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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 * 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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    28

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/*

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 * Conversion of st statements (i.e. ST code).

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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, or SFC

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 * code.

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 */

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#include "../../util/strdup.hh"

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

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

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

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

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class generate_c_st_c: public generate_c_base_c {

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  public:

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    typedef enum {

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      expression_vg,

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      assignment_vg,

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      complextype_base_vg,

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      complextype_base_assignment_vg,

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      complextype_suffix_vg,

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      fparam_output_vg

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    } variablegeneration_t;

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    59

    typedef enum {

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      single_cg,

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      subrange_cg,

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      none_cg

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    } casegeneration_t;

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  private:

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    /* When calling a function block, we must first find it's type,

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     * by searching through the declarations of the variables currently

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     * in scope.

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     * This class does just that...

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     * A new class is instantiated whenever we begin generating the code

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     * for a function block type declaration, or a program declaration.

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     * This object instance will then later be called while the

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     * function block's or the program's body is being handled.

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     *

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     * Note that functions cannot contain calls to function blocks,

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     * so we do not create an object instance when handling

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     * a function declaration.

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     */

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    search_fb_instance_decl_c    *search_fb_instance_decl;

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    search_varfb_instance_type_c *search_varfb_instance_type;

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    search_var_instance_decl_c   *search_var_instance_decl;

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    symbol_c *scope_;

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    symbol_c* current_array_type;

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    symbol_c* current_param_type;

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    88

    int fcall_number;

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    symbol_c *fbname;

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    bool first_subrange_case_list;

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    variablegeneration_t wanted_variablegeneration;

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    casegeneration_t wanted_casegeneration;

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    96

  public:

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    generate_c_st_c(stage4out_c *s4o_ptr, symbol_c *name, symbol_c *scope, const char *variable_prefix = NULL)

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    : generate_c_base_c(s4o_ptr) {

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      search_fb_instance_decl    = new search_fb_instance_decl_c   (scope);

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      search_varfb_instance_type = new search_varfb_instance_type_c(scope);

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      search_var_instance_decl   = new search_var_instance_decl_c  (scope);

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      scope_ = scope;

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      this->set_variable_prefix(variable_prefix);

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      current_array_type = NULL;

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      current_param_type = NULL;

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      fcall_number = 0;

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      fbname = name;

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      wanted_variablegeneration = expression_vg;

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      wanted_casegeneration = none_cg;

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    }

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    virtual ~generate_c_st_c(void) {

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      delete search_fb_instance_decl;

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      delete search_varfb_instance_type;

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      delete search_var_instance_decl;

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    }

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  public:

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    void generate(statement_list_c *stl) {

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      stl->accept(*this);

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    }

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  private:

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void *print_getter(symbol_c *symbol) {

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  unsigned int vartype = analyse_variable_c::first_nonfb_vardecltype(symbol, scope_);

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  if (wanted_variablegeneration == fparam_output_vg) {

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    if (vartype == search_var_instance_decl_c::external_vt) {

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      if (!get_datatype_info_c::is_type_valid    (symbol->datatype)) ERROR;

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      if ( get_datatype_info_c::is_function_block(symbol->datatype))

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        s4o.print(GET_EXTERNAL_FB_BY_REF);

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      else

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        s4o.print(GET_EXTERNAL_BY_REF);

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    }

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    else if (vartype == search_var_instance_decl_c::located_vt)

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      s4o.print(GET_LOCATED_BY_REF);

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    else

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      s4o.print(GET_VAR_BY_REF);

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  }

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  else {

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    if (vartype == search_var_instance_decl_c::external_vt) {

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      if (!get_datatype_info_c::is_type_valid    (symbol->datatype)) ERROR;

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      if ( get_datatype_info_c::is_function_block(symbol->datatype))

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        s4o.print(GET_EXTERNAL_FB);

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      else

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        s4o.print(GET_EXTERNAL);

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    }

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    else if (vartype == search_var_instance_decl_c::located_vt)

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      s4o.print(GET_LOCATED);

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    else

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      s4o.print(GET_VAR);

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  }

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  s4o.print("(");

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  variablegeneration_t old_wanted_variablegeneration = wanted_variablegeneration;

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  wanted_variablegeneration = complextype_base_vg;

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  symbol->accept(*this);

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  s4o.print(",");

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  wanted_variablegeneration = complextype_suffix_vg;

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  symbol->accept(*this);

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  s4o.print(")");

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  wanted_variablegeneration = old_wanted_variablegeneration;

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  return NULL;

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}

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void *print_setter(symbol_c* symbol,

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        symbol_c* type,

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        symbol_c* value,

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        symbol_c* fb_symbol = NULL,

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        symbol_c* fb_value = NULL) {

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  bool type_is_complex = false;

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  if (fb_symbol == NULL) {

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    unsigned int vartype = analyse_variable_c::first_nonfb_vardecltype(symbol, scope_);

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    type_is_complex = analyse_variable_c::contains_complex_type(symbol);

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    if (vartype == search_var_instance_decl_c::external_vt) {

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      if (!get_datatype_info_c::is_type_valid    (symbol->datatype)) ERROR;

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      if ( get_datatype_info_c::is_function_block(symbol->datatype))

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        s4o.print(SET_EXTERNAL_FB);

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      else

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        s4o.print(SET_EXTERNAL);

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    }

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    else if (vartype == search_var_instance_decl_c::located_vt)

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      s4o.print(SET_LOCATED);

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    else

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      s4o.print(SET_VAR);

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  }

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  else {

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    unsigned int vartype = search_var_instance_decl->get_vartype(fb_symbol);

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    if (vartype == search_var_instance_decl_c::external_vt)

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      s4o.print(SET_EXTERNAL_FB);

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    else

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      s4o.print(SET_VAR);

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  }

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  s4o.print("(");

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  if (fb_symbol != NULL) {

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    print_variable_prefix();

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    fb_symbol->accept(*this);

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    s4o.print(".,");

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  }

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  else if (type_is_complex)

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    wanted_variablegeneration = complextype_base_assignment_vg;

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  else

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    wanted_variablegeneration = assignment_vg;

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  symbol->accept(*this);

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  s4o.print(",");

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  wanted_variablegeneration = expression_vg;

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  print_check_function(type, value, fb_value);

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  if (type_is_complex) {

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    s4o.print(",");

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    wanted_variablegeneration = complextype_suffix_vg;

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    symbol->accept(*this);

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  }

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  s4o.print(")");

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  wanted_variablegeneration = expression_vg;

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  return NULL;

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}

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

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/* B 1.3.3 - Derived data types */

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

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/*  signed_integer DOTDOT signed_integer */

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void *visit(subrange_c *symbol) {

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  switch (wanted_casegeneration) {

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    case subrange_cg:

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      s4o.print("__case_expression >= ");

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      symbol->lower_limit->accept(*this);

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      s4o.print(" && __case_expression <= ");

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      symbol->upper_limit->accept(*this);

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      break;

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    default:

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      symbol->lower_limit->accept(*this);

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      break;

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  }

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  return NULL;

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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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  symbol->non_generic_type_name->accept(*this);

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  return NULL;

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}

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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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  symbol->enumerated_type_name->accept(*this);

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  return NULL;

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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 *visit(symbolic_variable_c *symbol) {

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  switch (wanted_variablegeneration) {

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    case complextype_base_assignment_vg:

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    case assignment_vg:

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      this->print_variable_prefix();

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      s4o.print(",");

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      symbol->var_name->accept(*this);

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      break;

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    case complextype_base_vg:

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      generate_c_base_c::visit(symbol);

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      break;

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    case complextype_suffix_vg:

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      break;

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    default:

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      if (this->is_variable_prefix_null()) {

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        if (wanted_variablegeneration == fparam_output_vg) {

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          s4o.print("&(");

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          generate_c_base_c::visit(symbol);

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          s4o.print(")");

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        }

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        else {

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          generate_c_base_c::visit(symbol);

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        }

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      }

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      else

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        print_getter(symbol);

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      break;

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  }

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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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// direct_variable: direct_variable_token   {$$ = new direct_variable_c($1);};

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void *visit(direct_variable_c *symbol) {

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  TRACE("direct_variable_c");

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  /* Do not use print_token() as it will change everything into uppercase */

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  if (strlen(symbol->value) == 0) ERROR;

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  if (this->is_variable_prefix_null()) {

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    if (wanted_variablegeneration != fparam_output_vg)

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      s4o.print("*(");

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  }

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  else {

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    switch (wanted_variablegeneration) {

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      case expression_vg:

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        s4o.print(GET_LOCATED);

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        s4o.print("(");

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        break;

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      case fparam_output_vg:

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        s4o.print(GET_LOCATED_BY_REF);

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        s4o.print("(");

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        break;

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      default:

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        break;

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    }

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  }

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  this->print_variable_prefix();

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  s4o.printlocation(symbol->value + 1);

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  if ((this->is_variable_prefix_null() && wanted_variablegeneration != fparam_output_vg) ||

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      wanted_variablegeneration != assignment_vg)

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    s4o.print(")");

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  return NULL;

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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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// SYM_REF2(structured_variable_c, record_variable, field_selector)

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void *visit(structured_variable_c *symbol) {

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  TRACE("structured_variable_c");

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  bool type_is_complex = analyse_variable_c::is_complex_type(symbol->record_variable);

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  switch (wanted_variablegeneration) {

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    case complextype_base_vg:

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    case complextype_base_assignment_vg:

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      symbol->record_variable->accept(*this);

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      if (!type_is_complex) {

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        s4o.print(".");

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        symbol->field_selector->accept(*this);

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      }

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      break;

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    case complextype_suffix_vg:

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      symbol->record_variable->accept(*this);

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      if (type_is_complex) {

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        s4o.print(".");

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        symbol->field_selector->accept(*this);

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      }

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      break;

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    case assignment_vg:

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      symbol->record_variable->accept(*this);

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      s4o.print(".");

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      symbol->field_selector->accept(*this);

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      break;

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    default:

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      if (this->is_variable_prefix_null()) {

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        symbol->record_variable->accept(*this);

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        s4o.print(".");

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        symbol->field_selector->accept(*this);

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      }

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      else

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        print_getter(symbol);

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      break;

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  }

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  return NULL;

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}

   371

   372

/*  subscripted_variable '[' subscript_list ']' */

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//SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   374

void *visit(array_variable_c *symbol) {

   375

  switch (wanted_variablegeneration) {

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    case complextype_base_vg:

   377

    case complextype_base_assignment_vg:

   378

      symbol->subscripted_variable->accept(*this);

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      break;

   380

    case complextype_suffix_vg:

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      symbol->subscripted_variable->accept(*this);

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   383

      current_array_type = search_varfb_instance_type->get_basetype_decl(symbol->subscripted_variable);

   384

      if (current_array_type == NULL) ERROR;

   385

   386

      s4o.print(".table");

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      wanted_variablegeneration = expression_vg;

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      symbol->subscript_list->accept(*this);

   389

      wanted_variablegeneration = complextype_suffix_vg;

   390

   391

      current_array_type = NULL;

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      break;

   393

    default:

   394

      if (this->is_variable_prefix_null()) {

   395

        symbol->subscripted_variable->accept(*this);

   396

   397

        current_array_type = search_varfb_instance_type->get_basetype_decl(symbol->subscripted_variable);

   398

        if (current_array_type == NULL) ERROR;

   399

   400

        s4o.print(".table");

   401

        symbol->subscript_list->accept(*this);

   402

   403

        current_array_type = NULL;

   404

      }

   405

      else

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        print_getter(symbol);

   407

      break;

   408

  }

   409

  return NULL;

   410

}

   411

   412

/* subscript_list ',' subscript */

   413

void *visit(subscript_list_c *symbol) {

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  array_dimension_iterator_c* array_dimension_iterator = new array_dimension_iterator_c(current_array_type);

   415

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

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    symbol_c* dimension = array_dimension_iterator->next();

   417

    if (dimension == NULL) ERROR;

   418

   419

    s4o.print("[(");

   420

    symbol->elements[i]->accept(*this);

   421

    s4o.print(") - (");

   422

    dimension->accept(*this);

   423

    s4o.print(")]");

   424

  }

   425

  delete array_dimension_iterator;

   426

  return NULL;

   427

}

   428

   429

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

   430

/* B 1.4.3 - Declaration & Initialisation */

   431

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

   432

   433

/* helper symbol for structure_initialization */

   434

/* structure_element_initialization_list ',' structure_element_initialization */

   435

void *visit(structure_element_initialization_list_c *symbol) {

   436

  generate_c_structure_initialization_c *structure_initialization = new generate_c_structure_initialization_c(&s4o);

   437

  structure_initialization->init_structure_default(this->current_param_type);

   438

  structure_initialization->init_structure_values(symbol);

   439

  delete structure_initialization;

   440

  return NULL;

   441

}

   442

   443

/* helper symbol for array_initialization */

   444

/* array_initial_elements_list ',' array_initial_elements */

   445

void *visit(array_initial_elements_list_c *symbol) {

   446

  generate_c_array_initialization_c *array_initialization = new generate_c_array_initialization_c(&s4o);

   447

  array_initialization->init_array_size(this->current_param_type);

   448

  array_initialization->init_array_values(symbol);

   449

  delete array_initialization;

   450

  return NULL;

   451

}

   452

   453

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

   454

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

   455

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

   456

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

   457

/* B 3.1 - Expressions */

   458

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