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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

    18

 *  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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 *

    23

 * 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

    38

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

    40

    41

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

    42

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

    43

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

    44

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

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    46

    48

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  public:

    50

    typedef enum {

    51

      expression_vg,

    52

      complextype_base_vg,

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      complextype_suffix_vg,

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      fparam_output_vg

    55

    } variablegeneration_t;

    56

    57

    typedef enum {

    58

      single_cg,

    59

      subrange_cg,

    60

      none_cg

    61

    } casegeneration_t;

    62

    63

  private:

    64

    /* 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

    66

     * in scope.

    67

     * This class does just that...

    68

     * 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

    71

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

    72

     *

    73

     * Note that functions cannot contain calls to function blocks,

    74

     * so we do not create an object instance when handling

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     * a function declaration.

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     */

    77

    search_fb_instance_decl_c    *search_fb_instance_decl;

    78

    search_varfb_instance_type_c *search_varfb_instance_type;

    79

    search_var_instance_decl_c   *search_var_instance_decl;

    80

    81

    symbol_c *scope_;

    82

    83

    symbol_c* current_array_type;

    84

    symbol_c* current_param_type;

    85

    86

    int fcall_number;

    87

    symbol_c *fbname;

    88

    89

    bool first_subrange_case_list;

    90

    91

    variablegeneration_t wanted_variablegeneration;

    92

    casegeneration_t wanted_casegeneration;

    93

    94

  public:

    95

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

    97

      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);

    99

      search_var_instance_decl   = new search_var_instance_decl_c  (scope);

   100

      scope_ = scope;

   101

   102

      this->set_variable_prefix(variable_prefix);

   103

      current_array_type = NULL;

   104

      current_param_type = NULL;

   105

      fcall_number = 0;

   106

      fbname = name;

   107

      wanted_variablegeneration = expression_vg;

   108

      wanted_casegeneration = none_cg;

   109

    }

   110

   111

    virtual ~generate_c_st_c(void) {

   112

      delete search_fb_instance_decl;

   113

      delete search_varfb_instance_type;

   114

      delete search_var_instance_decl;

   115

    }

   116

   117

   118

  public:

   119

    void generate(statement_list_c *stl) {

   120

      stl->accept(*this);

   121

    }

   122

   123

  private:

   124

   125

   126

   127

   128

   129

   130

void *print_getter(symbol_c *symbol) {

   131

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

   132

  if (wanted_variablegeneration == fparam_output_vg) {

   133

    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);

   137

      else

   138

        s4o.print(GET_EXTERNAL_BY_REF);

   139

    }

   140

    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

   143

      s4o.print(GET_VAR_BY_REF);

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  }

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  else {

   146

    if (vartype == search_var_instance_decl_c::external_vt) {

   147

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

   148

      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);

   152

    }

   153

    else if (vartype == search_var_instance_decl_c::located_vt)

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      s4o.print(GET_LOCATED);

   155

    else

   156

      s4o.print(GET_VAR);

   157

  }

   158

   159

  variablegeneration_t old_wanted_variablegeneration = wanted_variablegeneration;

   160

  s4o.print("(");

   161

  print_variable_prefix();  

   162

  wanted_variablegeneration = complextype_base_vg;

   163

  symbol->accept(*this);

   164

  s4o.print(",");

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  wanted_variablegeneration = complextype_suffix_vg;

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  symbol->accept(*this);

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  s4o.print(")");

   168

  wanted_variablegeneration = old_wanted_variablegeneration;

   169

  return NULL;

   170

}

   171

   172

   173

   174

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,

   178

        symbol_c* fb_value = NULL) {

   179

   180

  if (fb_symbol == NULL) {

   181

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

   182

    symbol_c *first_nonfb = analyse_variable_c::find_first_nonfb(symbol);

   183

    if (first_nonfb == NULL) ERROR;

   184

    if (vartype == search_var_instance_decl_c::external_vt) {

   185

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

   186

      if ( get_datatype_info_c::is_function_block(first_nonfb->datatype)) // handle situation where we are copying a complete fb -> fb1.fb2.fb3 := fb4 (and fb3 is external!)

   187

        s4o.print(SET_EXTERNAL_FB);

   188

      else

   189

        s4o.print(SET_EXTERNAL);

   190

    }

   191

    else if (vartype == search_var_instance_decl_c::located_vt)

   192

      s4o.print(SET_LOCATED);

   193

    else

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      s4o.print(SET_VAR);

   195

  }

   196

  else {

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

   198

    if (vartype == search_var_instance_decl_c::external_vt)

   199

      s4o.print(SET_EXTERNAL_FB);

   200

    else

   201

      s4o.print(SET_VAR);

   202

  }

   203

  s4o.print("(");

   204

   205

  if (fb_symbol != NULL) {

   206

    print_variable_prefix();

   207

    // It is my (MJS) conviction that by this time the following will always be true...

   208

    //   wanted_variablegeneration == expression_vg;

   209

    fb_symbol->accept(*this);

   210

    s4o.print(".,");

   211

    symbol->accept(*this);

   212

    s4o.print(",");

   213

    s4o.print(",");    

   214

  } else {

   215

    print_variable_prefix();

   216

    s4o.print(",");    

   217

    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);

   222

    s4o.print(",");

   223

  }

   224

  wanted_variablegeneration = expression_vg;

   225

  print_check_function(type, value, fb_value);

   226

  s4o.print(")");

   227

  wanted_variablegeneration = expression_vg;

   228

  return NULL;

   229

}

   230

   231

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

   232

/* B 1.3.3 - Derived data types */

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

   234

   235

/*  signed_integer DOTDOT signed_integer */

   236

void *visit(subrange_c *symbol) {

   237

  switch (wanted_casegeneration) {

   238

    case subrange_cg:

   239

      s4o.print("__case_expression >= ");

   240

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

   241

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

   242

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

   243

      break;

   244

    default:

   245

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

   246

      break;

   247

  }

   248

  return NULL;

   249

}

   250

   251

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

   252

void *visit(array_specification_c *symbol) {

   253

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

   254

  return NULL;

   255

}

   256

   257

/*  enumerated_type_name ':' enumerated_spec_init */

   258

void *visit(enumerated_type_declaration_c *symbol) {

   259

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

   260

  return NULL;

   261

}

   262

   263

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

   264

/* B 1.4 - Variables */

   265

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

   266

void *visit(symbolic_variable_c *symbol) {

   267

  switch (wanted_variablegeneration) {

   268

    case complextype_base_vg:

   269

      symbol->var_name->accept(*this); //generate_c_base_c::visit(symbol);

   270

      break;

   271

    case complextype_suffix_vg:

   272

      break;

   273

    default:

   274

      if (this->is_variable_prefix_null()) {

   275

        if (wanted_variablegeneration == fparam_output_vg) {

   276

          s4o.print("&(");

   277

          generate_c_base_c::visit(symbol);

   278

          s4o.print(")");

   279

        }

   280

        else {

   281

          generate_c_base_c::visit(symbol);

   282

        }

   283

      }

   284

      else

   285

        print_getter(symbol);

   286

      break;

   287

  }

   288

  return NULL;

   289

}

   290

   291

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

   292

/* B.1.4.1   Directly Represented Variables */

   293

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

   294

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

   295

void *visit(direct_variable_c *symbol) {

   296

  TRACE("direct_variable_c");

   297

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

   298

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

   299

  if (this->is_variable_prefix_null()) {

   300

    if (wanted_variablegeneration != fparam_output_vg)

   301

      s4o.print("*(");

   302

  }

   303

  else {

   304

    switch (wanted_variablegeneration) {

   305

      case expression_vg:

   306

        s4o.print(GET_LOCATED);

   307

        s4o.print("(");

   308

        break;

   309

      case fparam_output_vg:

   310

        s4o.print(GET_LOCATED_BY_REF);

   311

        s4o.print("(");

   312

        break;

   313

      default:

   314

        break;

   315

    }

   316

  }

   317

  this->print_variable_prefix();

   318

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

   319

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

   320

      (!this->is_variable_prefix_null() && (wanted_variablegeneration == expression_vg   )) ||

   321

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

   322

    s4o.print(")");

   323

  return NULL;

   324

}

   325

   326

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

   327

/* B.1.4.2   Multi-element Variables */

   328

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

   329

   330

// SYM_REF2(structured_variable_c, record_variable, field_selector)

   331

void *visit(structured_variable_c *symbol) {

   332

  TRACE("structured_variable_c");

   333

  switch (wanted_variablegeneration) {

   334

    case complextype_base_vg:

   335

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

   336

      /* NOTE: The following test includes a special case for SFC Steps. They are currently mapped onto a C data structure

   337

       *        that does not follow the standard IEC_<typename> pattern used for user defined structure datatypes 

   338

       *        (i.e. it does not include the 'values' and 'flag' structure 

   339

       *        elements that are tested by __GET_VAR and __SET_VAR acessor macros defined in acessor.h). However, the

   340

       *        STEP.T and STEP.X elements of this step structure are of the IEC_BOOL and IEC_TIME datatypes, and are 

   341

       *        actually structures that do have the 'value' and 'flags' elements. So, it is safe to say that any  variable

   342

       *        that is a STEPname is not of a complex type, as its .T and .X elements are and can later be safely accessed

   343

       *        using the __SET_VAR and __GET_VAR macros.

   344

       * 

   345

       *        For the above reason, a STEP must be handled as a FB, i.e. it does NOT contain the 'flags' and 'value' elements!

   346

       */

   347

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

   348

          || get_datatype_info_c::is_sfc_step      (symbol->record_variable->datatype)) {

   349

        if (NULL == symbol->record_variable->scope) ERROR;

   350

        search_var_instance_decl_c search_var_instance_decl(symbol->record_variable->scope);

   351

        if      (search_var_instance_decl_c::external_vt == search_var_instance_decl.get_vartype(get_var_name_c::get_last_field(symbol->record_variable)))

   352

          s4o.print("->");

   353

        else if (dynamic_cast<deref_operator_c *>(symbol->record_variable) != NULL)

   354

          s4o.print("->"); /* please read the comment in visit(deref_operator_c *) tio understand what this line is doing! */

   355

        else  

   356

          s4o.print(".");

   357

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

   358

      }

   359

      break;

   360

    case complextype_suffix_vg:

   361

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

   362

      // the following condition MUST be a negation of the above condition used in the 'case complextype_base_vg:'

   363

      if (!(   get_datatype_info_c::is_function_block(symbol->record_variable->datatype)     // if the record variable is not a FB... 

   364

            || get_datatype_info_c::is_sfc_step      (symbol->record_variable->datatype))) { // ...nor an SFC step name, then it will certainly be a structure!

   365

        if (dynamic_cast<deref_operator_c *>(symbol->record_variable) != NULL)

   366

          s4o.print("->"); /* please read the comment in visit(deref_operator_c *) tio understand what this line is doing! */

   367

        else

   368

          s4o.print(".");

   369

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

   370

      }

   371

      break;

   372

    default:

   373

      if (this->is_variable_prefix_null()) {

   374

        /* We are writing code for a FUNCTION. In this case, deref_operator_c are not transformed into the C pointer derefence syntax '->' (e.g. ptr->elem).

   375

         * We use instead the '*' syntax (e.g. (*ptr).elem)

   376

         * While in FB the '->' is generated by this structured_variable_c visitor, in Functions the '*' syntax is generated by the deref_operator_c visitor

   377

         * This is why here we do NOT have --> {if (dynamic_cast<deref_operator_c *>(symbol->record_variable) != NULL)  ..}

   378

	 *  

   379

	 * please read the comment in visit(deref_operator_c *) for more information!

   380

         */

   381

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

   382

        s4o.print(".");

   383

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

   384

      }

   385

      else

   386

        print_getter(symbol);

   387

      break;

   388

  }

   389

  return NULL;

   390

}

   391

   392

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

   393

//SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   394

void *visit(array_variable_c *symbol) {

   395

  switch (wanted_variablegeneration) {

   396

    case complextype_base_vg:

   397

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

   398

      break;

   399

    case complextype_suffix_vg:

   400

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

   401

   402

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

   403

      if (current_array_type == NULL) ERROR;

   404

   405

      if (dynamic_cast<deref_operator_c *>(symbol->subscripted_variable) != NULL)

   406

        s4o.print("->"); /* please read the comment in visit(deref_operator_c *) tio understand what this line is doing! */

   407

      else

   408

        s4o.print(".");

   409

      s4o.print("table");

   410

      wanted_variablegeneration = expression_vg;

   411

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

   412

      wanted_variablegeneration = complextype_suffix_vg;

   413

   414

      current_array_type = NULL;

   415

      break;

   416

    default:

   417

      if (this->is_variable_prefix_null()) {

   418

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

   419

   420

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

   421

        if (current_array_type == NULL) ERROR;

   422

   423

        s4o.print(".table");

   424

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

   425

   426

        current_array_type = NULL;

   427

      }

   428

      else

   429

        print_getter(symbol);

   430

      break;

   431

  }

   432

  return NULL;

   433

}

   434

   435

/* subscript_list ',' subscript */

   436

void *visit(subscript_list_c *symbol) {

   437

  array_dimension_iterator_c* array_dimension_iterator = new array_dimension_iterator_c(current_array_type);

   438

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

   439

    symbol_c* dimension = array_dimension_iterator->next();

   440

    if (dimension == NULL) ERROR;

   441

   442

    s4o.print("[(");

   443

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

   444

    s4o.print(") - (");

   445

    dimension->accept(*this);

   446

    s4o.print(")]");

   447

  }

   448

  delete array_dimension_iterator;

   449

  return NULL;

   450

}

   451

   452

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

   453

/* B 1.4.3 - Declaration & Initialisation */

   454

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

   455

   456

/* helper symbol for structure_initialization */

   457

/* structure_element_initialization_list ',' structure_element_initialization */

   458

void *visit(structure_element_initialization_list_c *symbol) {

   459

  generate_c_structure_initialization_c *structure_initialization = new generate_c_structure_initialization_c(&s4o);

   460

  structure_initialization->init_structure_default(this->current_param_type);

   461

  structure_initialization->init_structure_values(symbol);

   462

  delete structure_initialization;

   463

  return NULL;

   464

}

   465

   466

/* helper symbol for array_initialization */

   467

/* array_initial_elements_list ',' array_initial_elements */

   468

void *visit(array_initial_elements_list_c *symbol) {

   469

  generate_c_array_initialization_c *array_initialization = new generate_c_array_initialization_c(&s4o);

   470

  array_initialization->init_array_size(this->current_param_type);

   471

  array_initialization->init_array_values(symbol);

   472

  delete array_initialization;

   473

  return NULL;

   474

}

   475

   476

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

   477

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

   478

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

   479

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

   480

/* B 3.1 - Expressions */

   481

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

   482

void *visit(deref_operator_c *symbol) {

   483

  /* When producing C code for FUNCTION_BLOCKS, we use the '*' syntax (e.g. (*ptr).elem)

   484

   * When producing C code for a FUNCTION_BLOCK, the deref_operator_c are transformed in two ways, depending on where they occur.

   485

   *    - deref_operator between a struct and its elem (e.g. struct_ref^.elem1) 

   486

   *        are transformed into C using the C pointer derefence syntax '->' (e.g. struct_ref->elem1).

   487

   *        (In this case, '->' is generated by this structured_variable_c visitor)

   488

   *    - deref_operator at the end of a struct variable (e.g. struct.elem_ptr^)

   489

   *        are transformed using the '*' syntax for C pointer dereferencing (e.g. *(struct.elem_ptr) )

   490

   * 

   491

   *   NOTE: Ideally, we should always use the '*' C pointer dereferencing syntax. However, due to the