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

    42

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

    43

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

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

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    46

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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

    57

    } variablegeneration_t;

    58

    59

    typedef enum {

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      single_cg,

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      subrange_cg,

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      none_cg

    63

    } casegeneration_t;

    64

    65

  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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    83

    symbol_c *scope_;

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    85

    symbol_c* current_array_type;

    86

    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:

    97

    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);

   102

      scope_ = scope;

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   104

      this->set_variable_prefix(variable_prefix);

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      current_array_type = NULL;

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      current_param_type = NULL;

   107

      fcall_number = 0;

   108

      fbname = name;

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      wanted_variablegeneration = expression_vg;

   110

      wanted_casegeneration = none_cg;

   111

    }

   112

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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;

   117

    }

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   119

   120

  public:

   121

    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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    }

   155

    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;

   187

      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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   206

  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;

   242

}

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   244

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

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/* B 1.3.3 - Derived data types */

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

   247

   248

/*  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;

   257

    default:

   258

      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("(");

   331

        break;

   332

      default:

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        break;

   334

    }

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  }

   336

  this->print_variable_prefix();

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

   338

  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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}

   343

   344

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

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/* B.1.4.2   Multi-element Variables */

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

   347

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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) {

   353

    case complextype_base_vg:

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    case complextype_base_assignment_vg:

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

   356

      if (!type_is_complex) {

   357

        s4o.print(".");

   358

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

   359

      }

   360

      break;

   361

    case complextype_suffix_vg:

   362

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

   363

      if (type_is_complex) {

   364

        s4o.print(".");

   365

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

   366

      }

   367

      break;

   368

    case assignment_vg:

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

   370

      s4o.print(".");

   371

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

   372

      break;

   373

    default:

   374

      if (this->is_variable_prefix_null()) {

   375

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

   376

        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);

   381

      break;

   382

  }

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  return NULL;

   384

}

   385

   386

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

   387

//SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   388

void *visit(array_variable_c *symbol) {

   389

  switch (wanted_variablegeneration) {

   390

    case complextype_base_vg:

   391

    case complextype_base_assignment_vg:

   392

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

   393

      break;

   394

    case complextype_suffix_vg:

   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

      wanted_variablegeneration = expression_vg;

   402

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

   403

      wanted_variablegeneration = complextype_suffix_vg;

   404

   405

      current_array_type = NULL;

   406

      break;

   407

    default:

   408

      if (this->is_variable_prefix_null()) {

   409

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

   410

   411

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

   412

        if (current_array_type == NULL) ERROR;

   413

   414

        s4o.print(".table");

   415

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

   416

   417

        current_array_type = NULL;

   418

      }

   419

      else

   420

        print_getter(symbol);

   421

      break;

   422

  }

   423

  return NULL;

   424

}

   425

   426

/* subscript_list ',' subscript */

   427

void *visit(subscript_list_c *symbol) {

   428

  array_dimension_iterator_c* array_dimension_iterator = new array_dimension_iterator_c(current_array_type);

   429

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

   430

    symbol_c* dimension = array_dimension_iterator->next();

   431

    if (dimension == NULL) ERROR;

   432

   433

    s4o.print("[(");

   434

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

   435

    s4o.print(") - (");

   436

    dimension->accept(*this);

   437

    s4o.print(")]");

   438

  }

   439

  delete array_dimension_iterator;

   440

  return NULL;

   441

}

   442

   443

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

   444

/* B 1.4.3 - Declaration & Initialisation */

   445

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

   446

   447

/* helper symbol for structure_initialization */

   448

/* structure_element_initialization_list ',' structure_element_initialization */

   449

void *visit(structure_element_initialization_list_c *symbol) {

   450

  generate_c_structure_initialization_c *structure_initialization = new generate_c_structure_initialization_c(&s4o);

   451

  structure_initialization->init_structure_default(this->current_param_type);

   452

  structure_initialization->init_structure_values(symbol);

   453

  delete structure_initialization;

   454

  return NULL;

   455

}

   456

   457

/* helper symbol for array_initialization */

   458

/* array_initial_elements_list ',' array_initial_elements */

   459

void *visit(array_initial_elements_list_c *symbol) {

   460

  generate_c_array_initialization_c *array_initialization = new generate_c_array_initialization_c(&s4o);

   461

  array_initialization->init_array_size(this->current_param_type);

   462

  array_initialization->init_array_values(symbol);

   463

  delete array_initialization;

   464

  return NULL;

   465

}

   466

   467

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

   468

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

   469

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

   470

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

   471

/* B 3.1 - Expressions */

   472

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

   473

void *visit(ref_expression_c *symbol) {

   474

  s4o.print("((IEC_UDINT)");  

   475

  if (this->is_variable_prefix_null()) {  

   476

    /* For code in FUNCTIONs */

   477

    s4o.print("&(");  

   478

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

   479

    s4o.print(")");  

   480

  } else {

   481

    /* For code in FBs, and PROGRAMS... */

   482

    s4o.print("(");  

   483

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

   484

    if (vartype == search_var_instance_decl_c::external_vt) {

   485

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

   486

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

   487

        s4o.print(GET_EXTERNAL_FB_REF);

   488

      else

   489

        s4o.print(GET_EXTERNAL_REF);

   490

    }

   491

    else if (vartype == search_var_instance_decl_c::located_vt)