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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/>.

    19

 *

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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"

    40

    41

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

    42

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

    43

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

    44

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

    45

    46

    47

class generate_c_st_c: public generate_c_typedecl_c {

    48

    49

  public:

    50

    typedef enum {

    51

      expression_vg,

    52

      assignment_vg,

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      complextype_base_vg,

    54

      complextype_base_assignment_vg,

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      complextype_suffix_vg,

    56

      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:

    66

    /* 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.

    78

     */

    79

    search_fb_instance_decl_c *search_fb_instance_decl;

    80

    81

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

    82

     * 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...

    86

     * This object instance will then later be called while the

    87

     * remaining st code is being handled.

    88

     */

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    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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    search_var_instance_decl_c   *search_var_instance_decl;

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    94

    search_base_type_c search_base_type;

    95

    96

    symbol_c* current_array_type;

    97

    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;

   105

    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);

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      search_varfb_instance_type = new search_varfb_instance_type_c(scope);

   113

      search_var_instance_decl   = new search_var_instance_decl_c(scope);

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      this->set_variable_prefix(variable_prefix);

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      current_array_type = NULL;

   117

      current_param_type = NULL;

   118

      fcall_number = 0;

   119

      fbname = name;

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      wanted_variablegeneration = expression_vg;

   121

      wanted_casegeneration = none_cg;

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    }

   123

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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_expression_type;

   127

      delete search_varfb_instance_type;

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      delete search_var_instance_decl;

   129

    }

   130

   131

   132

  public:

   133

    void generate(statement_list_c *stl) {

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      stl->accept(*this);

   135

    }

   136

   137

  private:

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   139

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void *print_getter(symbol_c *symbol) {

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

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  if (wanted_variablegeneration == fparam_output_vg) {

   147

    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);

   157

    else if (vartype == search_var_instance_decl_c::located_vt)

   158

      s4o.print(GET_LOCATED);

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    else

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      s4o.print(GET_VAR);

   161

  }

   162

  s4o.print("(");

   163

   164

  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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  if (search_var_instance_decl->type_is_complex(symbol))

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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,

   180

		symbol_c* fb_value = NULL) {

   181

   182

  bool type_is_complex = false;

   183

  if (fb_symbol == NULL) {

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

   185

    type_is_complex = search_var_instance_decl->type_is_complex(symbol);

   186

    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);

   190

    else

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      s4o.print(SET_VAR);

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  }

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  else

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	s4o.print(SET_VAR);

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  s4o.print("(");

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   197

  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;

   206

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  symbol->accept(*this);

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  s4o.print(",");

   209

  wanted_variablegeneration = expression_vg;

   210

  print_check_function(type, value, fb_value);

   211

  if (type_is_complex) {

   212

    s4o.print(",");

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    wanted_variablegeneration = complextype_suffix_vg;

   214

    symbol->accept(*this);

   215

  }

   216

  s4o.print(")");

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  wanted_variablegeneration = expression_vg;

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  return NULL;

   219

}

   220

   221

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

   222

/* B 1.3.3 - Derived data types */

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

   224

   225

/*  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);

   233

      break;

   234

    default:

   235

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

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      break;

   237

  }

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  return NULL;

   239

}

   240

   241

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

   242

void *visit(array_specification_c *symbol) {

   243

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

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  return NULL;

   245

}

   246

   247

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

   248

/* B 1.4 - Variables */

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

   250

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);

   260

      break;

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    case complextype_suffix_vg:

   262

      break;

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    default:

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      if (this->is_variable_prefix_null()) {

   265

        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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        }

   270

        else {

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          generate_c_base_c::visit(symbol);

   272

        }

   273

      }

   274

      else

   275

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

   282

/* 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;

   299

      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;

   303

      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);

   309

  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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}

   314

   315

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

   316

/* B.1.4.2   Multi-element Variables */

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

   318

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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 = search_var_instance_decl->type_is_complex(symbol->record_variable);

   323

  switch (wanted_variablegeneration) {

   324

    case complextype_base_vg:

   325

    case complextype_base_assignment_vg:

   326

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

   327

      if (!type_is_complex) {

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    	s4o.print(".");

   329

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

   330

      }

   331

      break;

   332

    case complextype_suffix_vg:

   333

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

   334

      if (type_is_complex) {

   335

        s4o.print(".");

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

   337

      }

   338

      break;

   339

    case assignment_vg:

   340

      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;

   344

    default:

   345

      if (this->is_variable_prefix_null()) {

   346

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

   347

    	s4o.print(".");

   348

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

   349

      }

   350

      else

   351

    	print_getter(symbol);

   352

      break;

   353

  }

   354

  return NULL;

   355

}

   356

   357

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

   358

//SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   359

void *visit(array_variable_c *symbol) {

   360

  switch (wanted_variablegeneration) {

   361

    case complextype_base_vg:

   362

    case complextype_base_assignment_vg:

   363

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

   364

      break;

   365

    case complextype_suffix_vg:

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

   367

   368

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

   369

      if (current_array_type == NULL) ERROR;

   370

   371

      s4o.print(".table");

   372

      wanted_variablegeneration = expression_vg;

   373

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

   374

      wanted_variablegeneration = complextype_suffix_vg;

   375

   376

      current_array_type = NULL;

   377

      break;

   378

    default:

   379

      if (this->is_variable_prefix_null()) {

   380

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

   381

   382

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

   383

    	if (current_array_type == NULL) ERROR;

   384

   385

    	s4o.print(".table");

   386

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

   387

   388

        current_array_type = NULL;

   389

      }

   390

      else

   391

    	print_getter(symbol);

   392

      break;

   393

  }

   394

  return NULL;

   395

}

   396

   397

/* subscript_list ',' subscript */

   398

void *visit(subscript_list_c *symbol) {

   399

  array_dimension_iterator_c* array_dimension_iterator = new array_dimension_iterator_c(current_array_type);

   400

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

   401

    symbol_c* dimension = array_dimension_iterator->next();

   402

	if (dimension == NULL) ERROR;

   403

   404

	s4o.print("[(");

   405

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

   406

    s4o.print(") - (");

   407

    dimension->accept(*this);

   408

    s4o.print(")]");

   409

  }

   410

  delete array_dimension_iterator;

   411

  return NULL;

   412

}

   413

   414

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

   415

/* B 1.4.3 - Declaration & Initialisation */

   416

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

   417

   418

/* helper symbol for structure_initialization */

   419

/* structure_element_initialization_list ',' structure_element_initialization */

   420

void *visit(structure_element_initialization_list_c *symbol) {

   421

  generate_c_structure_initialization_c *structure_initialization = new generate_c_structure_initialization_c(&s4o);

   422

  structure_initialization->init_structure_default(this->current_param_type);

   423

  structure_initialization->init_structure_values(symbol);

   424

  delete structure_initialization;

   425

  return NULL;

   426

}

   427

   428

/* helper symbol for array_initialization */

   429

/* array_initial_elements_list ',' array_initial_elements */

   430

void *visit(array_initial_elements_list_c *symbol) {

   431

  generate_c_array_initialization_c *array_initialization = new generate_c_array_initialization_c(&s4o);

   432

  array_initialization->init_array_size(this->current_param_type);

   433

  array_initialization->init_array_values(symbol);

   434

  delete array_initialization;

   435

  return NULL;

   436

}

   437

   438

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

   439

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

   440

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

   441

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

   442

/* B 3.1 - Expressions */

   443

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

   444

void *visit(or_expression_c *symbol) {

   445

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

   446

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

   447

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

   448

      ERROR;

   449

  if (search_expression_type->is_bool_type(left_type))

   450

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

   451

  if (search_expression_type->is_binary_type(left_type))

   452

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

   453

  ERROR;

   454

  return NULL;

   455

}

   456

   457

void *visit(xor_expression_c *symbol) {

   458

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

   459

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

   460

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

   461

      ERROR;

   462

  if (search_expression_type->is_bool_type(left_type)) {

   463

    s4o.print("(");

   464

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

   465

    s4o.print(" && !");

   466

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

   467

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

   468

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

   469

    s4o.print(" && ");

   470

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

   471

    s4o.print(")");

   472

    return NULL;

   473

  }

   474

  if (search_expression_type->is_binary_type(left_type))

   475

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

   476

  ERROR;

   477

  return NULL;

   478

}

   479

   480

void *visit(and_expression_c *symbol) {

   481

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

   482

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

   483

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

   484

      ERROR;

   485

  if (search_expression_type->is_bool_type(left_type))

   486

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

   487

  if (search_expression_type->is_binary_type(left_type))

   488

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

   489

  ERROR;

   490

  return NULL;

   491

}

   492

   493

void *visit(equ_expression_c *symbol) {

   494

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

   495

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

   496

  // if (!search_expression_type->is_same_type(left_type, right_type))    ERROR;  // This check is no longer needed!

   497