1

/*

     2

 * (c) 2003 Mario de Sousa

     3

 *

     4

 * Offered to the public under the terms of the GNU General Public License

     5

 * as published by the Free Software Foundation; either version 2 of the

     6

 * License, or (at your option) any later version.

     7

 *

     8

 * This program is distributed in the hope that it will be useful, but

     9

 * WITHOUT ANY WARRANTY; without even the implied warranty of

    10

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

    11

 * Public License for more details.

    12

 *

    13

 * This code is made available on the understanding that it will not be

    14

 * used in safety-critical situations without a full and competent review.

    15

 */

    16

    17

/*

    18

 * An IEC 61131-3 IL and ST compiler.

    19

 *

    20

 * Based on the

    21

 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

    22

 *

    23

 */

    24

    25

    26

/*

    27

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

    28

 *

    29

 * This is part of the 4th stage that generates

    30

 * a c++ source program equivalent to the IL and ST

    31

 * code.

    32

 */

    33

    34

    35

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

    36

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

    37

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

    38

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

    39

    40

    41

class generate_cc_st_c: public generate_cc_typedecl_c {

    42

    43

  private:

    44

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

    45

     * by searching through the declarations of the variables currently

    46

     * in scope.

    47

     * This class does just that...

    48

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

    49

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

    50

     * This object instance will then later be called while the

    51

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

    52

     *

    53

     * Note that functions cannot contain calls to function blocks,

    54

     * so we do not create an object instance when handling

    55

     * a function declaration.

    56

     */

    57

    search_fb_instance_decl_c *search_fb_instance_decl;

    58

    59

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

    60

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

    61

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

    62

     * or function currently being processed.

    63

     * The following object does just that...

    64

     * This object instance will then later be called while the

    65

     * remaining st code is being handled.

    66

     */

    67

    search_expression_type_c *search_expression_type;

    68

    69

    search_varfb_instance_type_c *search_varfb_instance_type;

    70

    71

  public:

    72

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

    73

    : generate_cc_typedecl_c(s4o_ptr) {

    74

      search_fb_instance_decl = new search_fb_instance_decl_c(scope);

    75

      search_expression_type = new search_expression_type_c(scope);

    76

      search_varfb_instance_type = new search_varfb_instance_type_c(scope);

    77

      this->set_variable_prefix(variable_prefix);

    78

    }

    79

    80

    virtual ~generate_cc_st_c(void) {

    81

      delete search_fb_instance_decl;

    82

      delete search_expression_type;

    83

      delete search_varfb_instance_type;

    84

    }

    85

    86

    87

  private:

    88

    /* Some function calls in the body of functions or function blocks

    89

     * may leave some parameters to their default values, and

    90

     * ignore some output parameters of the function being called.

    91

     * Our conversion of ST functions to C++ does not contemplate that,

    92

     * i.e. each called function must get all it's input and output

    93

     * parameters set correctly.

    94

     * For input parameters we merely need to call the function with

    95

     * the apropriate default value, but for output parameters

    96

     * we must create temporary variables to hold the output value.

    97

     *

    98

     * We declare all the temporary output variables at the begining of

    99

     * the body of each function or function block, and use them as

   100

     * in function calls later on as they become necessary...

   101

     * Note that we cannot create these variables just before a function

   102

     * call, as the function call itself may be integrated within an

   103

     * expression, or another function call!

   104

     *

   105

     * The variables are declared in the exact same order in which they

   106

     * will be used later on during the function calls, which allows us

   107

     * to simply re-create the name that was used for the temporary variable

   108

     * instead of keeping it in some list.

   109

     * The names are recreated by the temp_var_name_factory, after reset()

   110

     * has been called!

   111

     *

   112

     * This function will genertae code similar to...

   113

     *

   114

     *     INT __TMP_0 = 23;

   115

     *     REAL __TMP_1 = 45.5;

   116

     *     ...

   117

     */

   118

    temp_var_name_c temp_var_name_factory;

   119

   120

  public:

   121

    void generate(statement_list_c *stl) {

   122

      generate_cc_tempvardecl_c generate_cc_tempvardecl(&s4o);

   123

      generate_cc_tempvardecl.generate(stl, &temp_var_name_factory);

   124

      stl->accept(*this);

   125

    }

   126

   127

  private:

   128

   129

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

   130

/* B 1.4 - Variables */

   131

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

   132

void *visit(symbolic_variable_c *symbol) {

   133

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

   134

  if (vartype == search_var_instance_decl_c::external_vt || vartype == search_var_instance_decl_c::located_vt) {

   135

    s4o.print("*(");

   136

    generate_cc_base_c::visit(symbol);

   137

    s4o.print(")");

   138

  }

   139

  else {

   140

    generate_cc_base_c::visit(symbol);

   141

  }

   142

  return NULL;

   143

}

   144

   145

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

   146

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

   147

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

   148

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

   149

/* B 3.1 - Expressions */

   150

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

   151

void *visit(or_expression_c *symbol) {

   152

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

   153

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

   154

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

   155

      ERROR;

   156

  if (search_expression_type->is_bool_type(left_type))

   157

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

   158

  if (search_expression_type->is_binary_type(left_type))

   159

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

   160

  ERROR;

   161

  return NULL;

   162

}

   163

   164

void *visit(xor_expression_c *symbol) {

   165

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

   166

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

   167

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

   168

      ERROR;

   169

  if (search_expression_type->is_bool_type(left_type)) {

   170

    s4o.print("(");

   171

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

   172

    s4o.print(" && !");

   173

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

   174

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

   175

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

   176

    s4o.print(" && ");

   177

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

   178

    s4o.print(")");

   179

  }

   180

  if (search_expression_type->is_binary_type(left_type))

   181

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

   182

  ERROR;

   183

  return NULL;

   184

}

   185

   186

void *visit(and_expression_c *symbol) {

   187

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

   188

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

   189

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

   190

      ERROR;

   191

  if (search_expression_type->is_bool_type(left_type))

   192

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

   193

  if (search_expression_type->is_binary_type(left_type))

   194

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

   195

  ERROR;

   196

  return NULL;

   197

}

   198

   199

void *visit(equ_expression_c *symbol) {

   200

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

   201

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

   202

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

   203

      ERROR;

   204

  if (search_expression_type->is_time_type(left_type))

   206

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

   207

}

   208

   209

void *visit(notequ_expression_c *symbol) {

   210

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

   211

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

   212

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

   213

      ERROR;

   214

  if (search_expression_type->is_time_type(left_type))

   216

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

   217

}

   218

   219

void *visit(lt_expression_c *symbol) {

   220

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

   221

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

   222

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

   223

      ERROR;

   224

  if (search_expression_type->is_time_type(left_type))

   226

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

   227

}

   228

   229

void *visit(gt_expression_c *symbol) {

   230

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

   231

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

   232

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

   233

      ERROR;

   234

  if (search_expression_type->is_time_type(left_type))

   236

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

   237

}

   238

   239

void *visit(le_expression_c *symbol) {

   240

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

   241

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

   242

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

   243

      ERROR;

   244

  if (search_expression_type->is_time_type(left_type))

   246

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

   247

}

   248

   249

void *visit(ge_expression_c *symbol) {

   250

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

   251

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

   252

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

   253

      ERROR;

   254

  if (search_expression_type->is_time_type(left_type))

   256

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

   257

}

   258

   259

void *visit(add_expression_c *symbol) {

   260

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

   261

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

   262

	if ((typeid(*left_type) == typeid(time_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) ||

   263

      (typeid(*left_type) == typeid(tod_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) ||

   264

      (typeid(*left_type) == typeid(dt_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)))

   266

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

   267

      ERROR;

   268

  if (search_expression_type->is_integer_type(left_type) || search_expression_type->is_real_type(left_type))

   269

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

   270

  ERROR;

   271

  return NULL;

   272

}

   273

   274

void *visit(sub_expression_c *symbol) {

   275

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

   276

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

   277

  if ((typeid(*left_type) == typeid(time_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) ||

   278

      (typeid(*left_type) == typeid(date_type_name_c) && typeid(*right_type) == typeid(date_type_name_c)) ||

   279

      (typeid(*left_type) == typeid(tod_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) ||

   280

      (typeid(*left_type) == typeid(tod_type_name_c) && typeid(*right_type) == typeid(tod_type_name_c)) ||

   281

      (typeid(*left_type) == typeid(dt_type_name_c) && typeid(*right_type) == typeid(time_type_name_c)) ||

   282

      (typeid(*left_type) == typeid(dt_type_name_c) && typeid(*right_type) == typeid(dt_type_name_c)))

   284

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

   285

      ERROR;

   286

  if (search_expression_type->is_integer_type(left_type) || search_expression_type->is_real_type(left_type))

   287

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

   288

  ERROR;

   289

  return NULL;

   290

}

   291

   292

void *visit(mul_expression_c *symbol) {

   293

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

   294

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

   295

  if ((typeid(*left_type) == typeid(time_type_name_c) && search_expression_type->is_integer_type(right_type)) ||

   296

      (typeid(*left_type) == typeid(time_type_name_c) && search_expression_type->is_real_type(right_type)))

   298

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

   299

      ERROR;

   300

  if (search_expression_type->is_integer_type(left_type) || search_expression_type->is_real_type(left_type))

   301

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

   302

  ERROR;

   303

  return NULL;

   304

}

   305

   306

void *visit(div_expression_c *symbol) {

   307

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

   308

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

   309

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

   310

      ERROR;

   311

  if (search_expression_type->is_integer_type(left_type) || search_expression_type->is_real_type(left_type))

   312

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

   313

  ERROR;

   314

  return NULL;

   315

}

   316

   317

void *visit(mod_expression_c *symbol) {

   318

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

   319

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

   320

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

   321

      ERROR;

   322

  if (search_expression_type->is_integer_type(left_type) || search_expression_type->is_real_type(left_type)) {

   323

    s4o.print("((");

   324

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

   325

    s4o.print(" == 0)?0:");

   326

    print_binary_expression(symbol->l_exp, symbol->r_exp, " % ");

   327

    s4o.print(")");

   328

    return NULL;

   329

  }

   330

  ERROR;

   331

  return NULL;

   332

}

   333

   334

/* TODO: power expression... */

   335

void *visit(power_expression_c *symbol) {ERROR; return print_binary_expression(symbol->l_exp, symbol->r_exp, " ** ");}

   336

void *visit(neg_expression_c *symbol) {return print_unary_expression(symbol->exp, " -");}

   337

void *visit(not_expression_c *symbol) {return print_unary_expression(symbol->exp, "!");}

   338

   339

void *visit(function_invocation_c *symbol) {

   340

  function_declaration_c *f_decl = function_symtable.find_value(symbol->function_name);

   341

   342

  if (f_decl == function_symtable.end_value()) {

   343

    /* The function called is not in the symtable, so we test if it is a

   344

     * standard function defined in standard */

   345

   346

    function_type_t current_function_type = get_function_type((identifier_c *)symbol->function_name);

   347

    if (current_function_type == function_none) ERROR;

   348

   349

    symbol_c *function_return_type = search_expression_type->get_type(symbol);

   350

   351

    function_call_param_iterator_c function_call_param_iterator(symbol);

   352

   353

    int nb_param = ((list_c *)symbol->parameter_assignment_list)->n;

   354

   355

#include "st_code_gen.c"

   356

   357

#if 0

   358

    for(int current_param = 0; current_param < nb_param; current_param++) {

   359

      symbol_c *param_name = NULL;

   360

      switch (current_function_type) {

   361

        case function_add:

   362

        case function_and:

   363

        case function_or:

   364

          param_name = generate_param_name("IN%d", current_param + 1);

   365

          break;

   366

        case function_sub:

   367

          if (current_param < 2)

   368

            param_name = generate_param_name("IN%d", current_param + 1);

   369

          else

   370

            ERROR;

   371

          break;

   372

        default: ERROR;

   373

      }

   374

   375

      /* Get the value from a foo(<param_name> = <param_value>) style call */

   376

      symbol_c *param_value = function_call_param_iterator.search(param_name);

   377

      delete param_name;

   378

   379

      /* Get the value from a foo(<param_value>) style call */

   380

      if (param_value == NULL)

   381

        param_value = function_call_param_iterator.next();

   382

   383

      if (param_value == NULL) ERROR;

   384

   385

      switch (current_function_type) {

   386

        case function_add:

   387

          if (search_expression_type->is_time_type(function_return_type)) {

   388

            if (current_param == 0) {

   390

              param_value->accept(*this);

   391

            }

   392

            else if (current_param == 1) {

   393

              s4o.print(", ");

   394

              param_value->accept(*this);

   395

              s4o.print(")");

   396

            }

   397

            else ERROR;

   398

          }

   399

          else {

   400

            if (current_param == 0)

   401

              s4o.print("(");

   402

            else

   403

              s4o.print(" + ");

   404

            param_value->accept(*this);

   405

            if (current_param == nb_param - 1)

   406

              s4o.print(")");

   407

          }

   408

          break;

   409

        case function_sub:

   410

          if (search_expression_type->is_time_type(function_return_type)) {

   411

            if (current_param == 0) {

   413

              param_value->accept(*this);

   414

            }

   415

            else if (current_param == 1) {

   416

              s4o.print(", ");

   417

              param_value->accept(*this);

   418

              s4o.print(")");

   419

            }

   420

            else ERROR;

   421

          }

   422

          else {

   423

            if (current_param == 0) {

   424

              s4o.print("(");

   425

              param_value->accept(*this);

   426

            }

   427

            else if (current_param == 1) {

   428

              s4o.print(" - ");

   429

              param_value->accept(*this);

   430

              s4o.print(")");

   431

            }

   432

            else ERROR;

   433

          }

   434

          break;

   435

        case function_and:

   436

          if (current_param == 0)

   437

            s4o.print("(");

   438

          else

   439

            if (search_expression_type->is_bool_type(function_return_type))

   440

              s4o.print(" && ");

   441

            else

   442

              s4o.print(" & ");

   443

          param_value->accept(*this);

   444

          if (current_param == nb_param - 1)

   445

            s4o.print(")");

   446

          break;

   447

        case function_or:

   448

          if (current_param == 0)

   449

            s4o.print("(");

   450

          else

   451

            if (search_expression_type->is_bool_type(function_return_type))

   452

              s4o.print(" || ");

   453

            else

   454

              s4o.print(" | ");

   455

          param_value->accept(*this);

   456

          if (current_param == nb_param - 1)

   457

            s4o.print(")");

   458

          break;

   459

        default: ERROR;

   460

      }

   461

    } /* for(...) */

   462

#endif

   463

  }

   464

  else {

   465

    /* loop through each function parameter, find the value we should pass

   466

     * to it, and then output the c equivalent...

   467

     */

   468

    function_param_iterator_c fp_iterator(f_decl);

   469

   470

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

   471

    s4o.print("(");

   472

   473

    identifier_c *param_name;

   474

    function_call_param_iterator_c function_call_param_iterator(symbol);

   475

    for(int i = 1; (param_name = fp_iterator.next()) != NULL; i++) {

   476

      if (i != 1)

   477

        s4o.print(", ");

   478

   479

      function_param_iterator_c::param_direction_t param_direction = fp_iterator.param_direction();

   480

   481

      /* Get the value from a foo(<param_name> = <param_value>) style call */

   482

      symbol_c *param_value = function_call_param_iterator.search(param_name);

   483

   484

      /* Get the value from a foo(<param_value>) style call */

   485

      if (param_value == NULL)

   486

        param_value = function_call_param_iterator.next();

   487

   488

      symbol_c *param_type = fp_iterator.param_type();

   489

      if (param_type == NULL) ERROR;

   490

   491

      switch (param_direction) {

   492

        case function_param_iterator_c::direction_in:

   493

          if (param_value == NULL) {

   494

            /* No value given for parameter, so we must use the default... */

   495

            /* First check whether default value specified in function declaration...*/

   496

            param_value = fp_iterator.default_value();

   497

          }

   498

          if (param_value == NULL) {

   499

            /* If not, get the default value of this variable's type */

   500

            param_value = (symbol_c *)param_type->accept(*type_initial_value_c::instance());