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/*

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 * (c) 2003 Mario de Sousa

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 *

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 * 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

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 * Public License for more details.

    12

 *

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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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 */

    16

    17

/*

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 * An IEC 61131-3 IL and ST compiler.

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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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 */

    24

    25

    26

/*

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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

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 * code.

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 */

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    34

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

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

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

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

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    40

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class generate_cc_st_c: public generate_cc_typedecl_c {

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    43

  private:

    44

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

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     * by searching through the declarations of the variables currently

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     * in scope.

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     * This class does just that...

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

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

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     * This object instance will then later be called while the

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

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     *

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     * Note that functions cannot contain calls to function blocks,

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     * so we do not create an object instance when handling

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     * a function declaration.

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     */

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    search_fb_instance_decl_c *search_fb_instance_decl;

    58

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    /* 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

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     * or function currently being processed.

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     * The following object does just that...

    64

     * This object instance will then later be called while the

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     * remaining st code is being handled.

    66

     */

    67

    search_expression_type_c *search_expression_type;

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    69

    search_varfb_instance_type_c *search_varfb_instance_type;

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    71

  public:

    72

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

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    : generate_cc_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);

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      this->set_variable_prefix(variable_prefix);

    78

    }

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    virtual ~generate_cc_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;

    84

    }

    85

    86

    87

  private:

    88

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

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     * 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,

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

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     * parameters set correctly.

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

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     * the apropriate default value, but for output parameters

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

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     *

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

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

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

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

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

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     * expression, or another function call!

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     *

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

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

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

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     * instead of keeping it in some list.

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

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     * has been called!

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     *

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     * This function will genertae code similar to...

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     *

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     *     INT __TMP_0 = 23;

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     *     REAL __TMP_1 = 45.5;

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     *     ...

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     */

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    temp_var_name_c temp_var_name_factory;

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  public:

   121

    void generate(statement_list_c *stl) {

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      generate_cc_tempvardecl_c generate_cc_tempvardecl(&s4o);

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      generate_cc_tempvardecl.generate(stl, &temp_var_name_factory);

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      stl->accept(*this);

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    }

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  private:

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

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/* B 1.4 - Variables */

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

   132

void *visit(symbolic_variable_c *symbol) {

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

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    s4o.print("*(");

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    generate_cc_base_c::visit(symbol);

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    s4o.print(")");

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  }

   139

  else {

   140

    generate_cc_base_c::visit(symbol);

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  }

   142

  return NULL;

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}

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

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

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

   148

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

   149

/* B 3.1 - Expressions */

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

   151

void *visit(or_expression_c *symbol) {

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

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

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  if (search_expression_type->is_bool_type(left_type) && search_expression_type->is_bool_type(right_type)) {

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

   156

  }

   157

  if (search_expression_type->is_numeric_compatible(left_type) && search_expression_type->is_numeric_compatible(right_type)) {

   158

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

   159

  }

   160

  ERROR;

   161

  return NULL;

   162

}

   163

   164

void *visit(xor_expression_c *symbol) {

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  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_bool_type(left_type) && search_expression_type->is_bool_type(right_type)) {

   168

    s4o.print("(");

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

   170

    s4o.print(" && !");

   171

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

   172

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

   173

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

   174

    s4o.print(" && ");

   175

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

   176

    s4o.print(")");

   177

  }

   178

  if (search_expression_type->is_numeric_compatible(left_type) && search_expression_type->is_numeric_compatible(right_type)) {

   179

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

   180

  }

   181

  ERROR;

   182

  return NULL;

   183

}

   184

   185

void *visit(and_expression_c *symbol) {

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

   187

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

   188

  if (search_expression_type->is_bool_type(left_type) && search_expression_type->is_bool_type(right_type)) {

   189

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

   190

  }

   191

  if (search_expression_type->is_numeric_compatible(left_type) && search_expression_type->is_numeric_compatible(right_type)) {

   192

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

   193

  }

   194

  ERROR;

   195

  return NULL;

   196

}

   197

   198

void *visit(equ_expression_c *symbol) {

   199

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

   200

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

   201

  if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {

   202

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

   203

  }

   204

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

   205

}

   206

   207

void *visit(notequ_expression_c *symbol) {

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

   209

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

   210

  if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {

   211

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

   212

  }

   213

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

   214

}

   215

   216

void *visit(lt_expression_c *symbol) {

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

   218

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

   219

  if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {

   220

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

   221

  }

   222

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

   223

}

   224

   225

void *visit(gt_expression_c *symbol) {

   226

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

   227

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

   228

  if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {

   229

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

   230

  }

   231

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

   232

}

   233

   234

void *visit(le_expression_c *symbol) {

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

   236

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

   237

  if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {

   238

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

   239

  }

   240

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

   241

}

   242

   243

void *visit(ge_expression_c *symbol) {

   244

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

   245

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

   246

  if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {

   247

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

   248

  }

   249

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

   250

}

   251

   252

void *visit(add_expression_c *symbol) {

   253

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

   254

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

   255

	if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {

   256

		return print_binary_function("__add_timespec", symbol->l_exp, symbol->r_exp);

   257

	}

   258

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

   259

}

   260

   261

void *visit(sub_expression_c *symbol) {

   262

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

   263

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

   264

  if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {

   265

    return print_binary_function("__sub_timespec", symbol->l_exp, symbol->r_exp);

   266

  }

   267

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

   268

}

   269

   270

void *visit(mul_expression_c *symbol) {

   271

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

   272

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

   273

  if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {

   274

    return print_binary_function("__mul_timespec", symbol->l_exp, symbol->r_exp);

   275

  }

   276

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

   277

}

   278

   279

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

   280

void *visit(mod_expression_c *symbol) {

   281

  s4o.print("((");

   282

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

   283

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

   284

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

   285

  s4o.print(")");

   286

  return NULL;

   287

}

   288

   289

/* TODO: power expression... */

   290

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

   291

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

   292

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

   293

   294

void *visit(function_invocation_c *symbol) {

   295

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

   296

   297

  if (f_decl == function_symtable.end_value())

   298

    /* should never occur. The function being called MUST be in the symtable... */

   299

    ERROR;

   300

   301

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

   302

  s4o.print("(");

   303

   304

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

   305

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

   306

   */

   307

   308

  function_param_iterator_c fp_iterator(f_decl);

   309

  identifier_c *param_name;

   310

  function_call_param_iterator_c function_call_param_iterator(symbol);

   311

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

   312

    if (i != 1)

   313

      s4o.print(", ");

   314

   315

    symbol_c *param_type = fp_iterator.param_type();

   316

    if (param_type == NULL) ERROR;

   317

   318

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

   319

   320

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

   321

    symbol_c *param_value = function_call_param_iterator.search(param_name);

   322

   323

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

   324

    if (param_value == NULL)

   325

      param_value = function_call_param_iterator.next();

   326

   327

    switch (param_direction) {

   328

      case function_param_iterator_c::direction_in:

   329

        if (param_value == NULL) {

   330

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

   331

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

   332

          param_value = fp_iterator.default_value();

   333

        }

   334

        if (param_value == NULL) {

   335

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

   336

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

   337

        }

   338

        if (param_value == NULL) ERROR;

   339

        param_value->accept(*this);

   340

	break;

   341

      case function_param_iterator_c::direction_out:

   342

      case function_param_iterator_c::direction_inout:

   343

        if (param_value == NULL) {

   344

	  /* no parameter value given, so we pass a previously declared temporary variable. */

   345

          std::string *temp_var_name = temp_var_name_factory.new_name();

   346

          s4o.print(*temp_var_name);

   347

          delete temp_var_name;

   348

	} else {

   349

          param_value->accept(*this);

   350

	}

   351

	break;

   352

      case function_param_iterator_c::direction_extref:

   353

        /* TODO! */

   354

        ERROR;

   355

        break;

   356

    } /* switch */

   357

  } /* for(...) */

   358

   359

  // symbol->parameter_assignment->accept(*this);

   360

  s4o.print(")");

   361

  return NULL;

   362

}

   363

   364

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

   365

/* B 3.2 Statements */

   366

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

   367

void *visit(statement_list_c *symbol) {

   368

  return print_list(symbol, s4o.indent_spaces, ";\n" + s4o.indent_spaces, ";\n");

   369

}

   370

   371

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

   372

/* B 3.2.1 Assignment Statements */

   373

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

   374

void *visit(assignment_statement_c *symbol) {

   375

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

   376

  s4o.print(" = ");

   377

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

   378

  return NULL;

   379

}

   380

   381

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

   382

/* B 3.2.2 Subprogram Control Statements */

   383

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

   384

   385

/* fb_name '(' [param_assignment_list] ')' */

   386

/* param_assignment_list -> may be NULL ! */

   387

//SYM_REF2(fb_invocation_c, fb_name, param_assignment_list)

   388

void *visit(fb_invocation_c *symbol) {

   389

  TRACE("fb_invocation_c");

   390

  /* first figure out what is the name of the function block type of the function block being called... */

   391

  symbol_c *function_block_type_name = this->search_fb_instance_decl->get_type_name(symbol->fb_name);

   392

    /* should never occur. The function block instance MUST have been declared... */

   393

  if (function_block_type_name == NULL) ERROR;

   394

   395

  /* Now find the declaration of the function block type being called... */

   396

  function_block_declaration_c *fb_decl = function_block_type_symtable.find_value(function_block_type_name);

   397

    /* should never occur. The function block type being called MUST be in the symtable... */

   398

  if (fb_decl == function_block_type_symtable.end_value()) ERROR;

   399

   400

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

   401

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

   402

   */

   403

  function_param_iterator_c fp_iterator(fb_decl);

   404

  identifier_c *param_name;

   405

  function_call_param_iterator_c function_call_param_iterator(symbol);

   406

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

   407

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

   408

   409

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

   410

    symbol_c *param_value = function_call_param_iterator.search(param_name);

   411

   412

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

   413

    if (param_value == NULL)

   414

      param_value = function_call_param_iterator.next();

   415

   416

    /* now output the value assignment */

   417

    if (param_value != NULL)

   418

      if ((param_direction == function_param_iterator_c::direction_in) ||

   419

          (param_direction == function_param_iterator_c::direction_inout)) {

   420

        print_variable_prefix();

   421

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

   422

        s4o.print(".");

   423

        param_name->accept(*this);

   424

        s4o.print(" = ");

   425

        param_value->accept(*this);

   426

        s4o.print(";\n" + s4o.indent_spaces);

   427

      }

   428

  } /* for(...) */

   429

   430

  /* now call the function... */

   431

  function_block_type_name->accept(*this);

   432

  s4o.print(FB_FUNCTION_SUFFIX);

   433

  s4o.print("(");

   434

  print_variable_prefix();

   435

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

   436

  s4o.print(")");

   437

   438

  /* loop through each function parameter, find the variable to which

   439

   * we should atribute the value of all output or inoutput parameters.

   440

   */

   441

  fp_iterator.reset();

   442

  function_call_param_iterator.reset();

   443

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

   444

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

   445

   446

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

   447

    symbol_c *param_value = function_call_param_iterator.search(param_name);

   448

   449

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

   450

    if (param_value == NULL)

   451

      param_value = function_call_param_iterator.next();

   452

   453

    /* now output the value assignment */

   454

    if (param_value != NULL)

   455

      if ((param_direction == function_param_iterator_c::direction_out) ||

   456

          (param_direction == function_param_iterator_c::direction_inout)) {

   457

        s4o.print(";\n"+ s4o.indent_spaces);

   458

        param_value->accept(*this);

   459

        s4o.print(" = ");

   460

        print_variable_prefix();

   461

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

   462

        s4o.print(".");

   463

        param_name->accept(*this);

   464

      }

   465

  } /* for(...) */

   466

   467

  return NULL;

   468

}

   469

   470

   471

   472

   473

/* helper symbol for fb_invocation */

   474

/* param_assignment_list ',' param_assignment */

   475

void *visit(param_assignment_list_c *symbol) {

   476

  TRACE("param_assignment_list_c");

   477

  /* this should never be called... */

   478

  ERROR;

   479

  return NULL;

   480

//  return print_list(symbol, "", ", ");

   481

}

   482

   483

   484

void *visit(input_variable_param_assignment_c *symbol) {

   485

  TRACE("input_variable_param_assignment_c");

   486

  /* this should never be called... */

   487

  ERROR;

   488

  return NULL;

   489

/*

   490

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

   491

  s4o.print(" = ");

   492

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

   493

  return NULL;

   494

*/

   495

}

   496

   497

void *visit(output_variable_param_assignment_c *symbol) {

   498

  TRACE("output_variable_param_assignment_c");

   499

  /* this should never be called... */

   500

  ERROR;

   501

  return NULL;

   502

/*

   503

  s4o.print(s4o.indent_spaces);

   504

  if (symbol->not_param != NULL)

   505

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

   506

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

   507

  s4o.print(" => ");

   508

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

   509

  return NULL;

   510

*/

   511

}

   512

   513

// TODO: the NOT symbol in function (block) calls...

   514

void *visit(not_paramassign_c *symbol) {

   515

  TRACE("not_paramassign_c");

   516

  /* this should never be called... */