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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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 */

    27

    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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    37

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

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    41

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

    42

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

    43

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

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

    45

    46

    47

class generate_c_st_c: public generate_c_typedecl_c {

    48

    49

  public:

    50

    typedef enum {

    51

      expression_vg,

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      assignment_vg,

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      complextype_base_vg,

    54

      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 {

    60

      single_cg,

    61

      subrange_cg,

    62

      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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     */

    79

    search_fb_instance_decl_c *search_fb_instance_decl;

    80

    81

    /* When compiling st code, it becomes necessary to determine the

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     * data type of st expressions. To do this, we must first find the

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     * st operand's declaration, within the scope of the function block

    84

     * or function currently being processed.

    85

     * The following object does just that...

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     * This object instance will then later be called while the

    87

     * remaining st code is being handled.

    88

     */

    89

    search_expression_type_c *search_expression_type;

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    91

    search_varfb_instance_type_c *search_varfb_instance_type;

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    94

    search_base_type_c search_base_type;

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    96

    symbol_c* current_array_type;

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    symbol_c* current_param_type;

    98

    99

    int fcall_number;

   100

    symbol_c *fbname;

   101

   102

    bool first_subrange_case_list;

   103

   104

    variablegeneration_t wanted_variablegeneration;

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    casegeneration_t wanted_casegeneration;

   106

   107

  public:

   108

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

   109

    : generate_c_typedecl_c(s4o_ptr) {

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      search_fb_instance_decl = new search_fb_instance_decl_c(scope);

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      search_expression_type = new search_expression_type_c(scope);

   112

      search_varfb_instance_type = new search_varfb_instance_type_c(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;

   121

      wanted_casegeneration = none_cg;

   122

    }

   123

   124

    virtual ~generate_c_st_c(void) {

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      delete search_fb_instance_decl;

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      delete search_expression_type;

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      delete search_varfb_instance_type;

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    }

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   131

   132

  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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   137

  private:

   138

   139

void *print_getter(symbol_c *symbol) {

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  if (wanted_variablegeneration == fparam_output_vg) {

   142

    if (vartype == search_var_instance_decl_c::external_vt)

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      s4o.print(GET_EXTERNAL_BY_REF);

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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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      s4o.print(GET_EXTERNAL);

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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;

   160

  wanted_variablegeneration = complextype_base_vg;

   161

  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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   177

  bool type_is_complex = false;

   178

  if (fb_symbol == NULL) {

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    if (vartype == search_var_instance_decl_c::external_vt)

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      s4o.print(SET_EXTERNAL);

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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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  }

   188

  else

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	s4o.print(SET_VAR);

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  s4o.print("(");

   191

   192

  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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   202

  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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   216

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

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/* B 1.3.3 - Derived data types */

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

   219

   220

/*  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;

   229

    default:

   230

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

   231

      break;

   232

  }

   233

  return NULL;

   234

}

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   236

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

   243

/* B 1.4 - Variables */

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

   245

void *visit(symbolic_variable_c *symbol) {

   246

  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;

   253

    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;

   258

    default:

   259

      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;

   284

  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;

   308

}

   309

   310

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

   311

/* B.1.4.2   Multi-element Variables */

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

   313

   314

// 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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  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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      break;

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    case complextype_suffix_vg:

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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);

   331

    	s4o.print(".");

   332

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

   333

      }

   334

      else

   335

    	print_getter(symbol);

   336

      break;

   337

  }

   338

  return NULL;

   339

}

   340

   341

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

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//SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   343

void *visit(array_variable_c *symbol) {

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  switch (wanted_variablegeneration) {

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    case complextype_base_vg:

   346

    case complextype_base_assignment_vg:

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

   348

      break;

   349

    case complextype_suffix_vg:

   350

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

   351

   352

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

   353

      if (current_array_type == NULL) ERROR;

   354

   355

      s4o.print(".table");

   356

      wanted_variablegeneration = expression_vg;

   357

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

   358

      wanted_variablegeneration = complextype_suffix_vg;

   359

   360

      current_array_type = NULL;

   361

      break;

   362

    default:

   363

      if (this->is_variable_prefix_null()) {

   364

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

   365

   366

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

   367

    	if (current_array_type == NULL) ERROR;

   368

   369

    	s4o.print(".table");

   370

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

   371

   372

        current_array_type = NULL;

   373

      }

   374

      else

   375

    	print_getter(symbol);

   376

      break;

   377

  }

   378

  return NULL;

   379

}

   380

   381

/* subscript_list ',' subscript */

   382

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);

   384

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

   385

    symbol_c* dimension = array_dimension_iterator->next();

   386

	if (dimension == NULL) ERROR;

   387

   388

	s4o.print("[(");

   389

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

   390

    s4o.print(") - (");

   391

    dimension->accept(*this);

   392

    s4o.print(")]");

   393

  }

   394

  delete array_dimension_iterator;

   395

  return NULL;

   396

}

   397

   398

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

   399

/* B 1.4.3 - Declaration & Initialisation */

   400

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

   401

   402

/* helper symbol for structure_initialization */

   403

/* structure_element_initialization_list ',' structure_element_initialization */

   404

void *visit(structure_element_initialization_list_c *symbol) {

   405

  generate_c_structure_initialization_c *structure_initialization = new generate_c_structure_initialization_c(&s4o);

   406

  structure_initialization->init_structure_default(this->current_param_type);

   407

  structure_initialization->init_structure_values(symbol);

   408

  delete structure_initialization;

   409

  return NULL;

   410

}

   411

   412

/* helper symbol for array_initialization */

   413

/* array_initial_elements_list ',' array_initial_elements */

   414

void *visit(array_initial_elements_list_c *symbol) {

   415

  generate_c_array_initialization_c *array_initialization = new generate_c_array_initialization_c(&s4o);

   416

  array_initialization->init_array_size(this->current_param_type);

   417

  array_initialization->init_array_values(symbol);

   418

  delete array_initialization;

   419

  return NULL;

   420

}

   421

   422

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

   423

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

   424

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

   425

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

   426

/* B 3.1 - Expressions */

   427

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

   428

void *visit(or_expression_c *symbol) {

   429

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   430

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   431

  if (!search_expression_type->is_same_type(left_type, right_type))

   432

      ERROR;

   433

  if (search_expression_type->is_bool_type(left_type))

   434

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " || ");

   435

  if (search_expression_type->is_binary_type(left_type))

   436

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " | ");

   437

  ERROR;

   438

  return NULL;

   439

}

   440

   441

void *visit(xor_expression_c *symbol) {

   442

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   443

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   444

  if (!search_expression_type->is_same_type(left_type, right_type))

   445

      ERROR;

   446

  if (search_expression_type->is_bool_type(left_type)) {

   447

    s4o.print("(");

   448

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

   449

    s4o.print(" && !");

   450

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

   451

    s4o.print(") || (!");

   452

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

   453

    s4o.print(" && ");

   454

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

   455

    s4o.print(")");

   456

    return NULL;

   457

  }

   458

  if (search_expression_type->is_binary_type(left_type))

   459

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " ^ ");

   460

  ERROR;

   461

  return NULL;

   462

}

   463

   464

void *visit(and_expression_c *symbol) {

   465

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   466

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   467

  if (!search_expression_type->is_same_type(left_type, right_type))

   468

      ERROR;

   469

  if (search_expression_type->is_bool_type(left_type))

   470

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " && ");

   471

  if (search_expression_type->is_binary_type(left_type))

   472

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " & ");

   473

  ERROR;

   474

  return NULL;

   475

}

   476

   477

void *visit(equ_expression_c *symbol) {

   478

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   479

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   480

  if (!search_expression_type->is_same_type(left_type, right_type))

   481

      ERROR;

   482

  if (search_expression_type->is_time_type(left_type) ||

   483

      search_expression_type->is_string_type(left_type))

   484

    return print_compare_function("EQ_", left_type, symbol->l_exp, symbol->r_exp);

   485

  return print_binary_expression(symbol->l_exp, symbol->r_exp, " == ");

   486

}

   487

   488

void *visit(notequ_expression_c *symbol) {

   489

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   490

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   491

  if (!search_expression_type->is_same_type(left_type, right_type))

   492

      ERROR;

   493

  if (search_expression_type->is_time_type(left_type) ||

   494

      search_expression_type->is_string_type(left_type))

   495

    return print_compare_function("NE_", left_type, symbol->l_exp, symbol->r_exp);

   496

  return print_binary_expression(symbol->l_exp, symbol->r_exp, " != ");

   497

}

   498