1

/*

     2

 *  matiec - a compiler for the programming languages defined in IEC 61131-3

     3

 *

     4

 *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)

     5

 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant

     6

 *

     7

 *  This program is free software: you can redistribute it and/or modify

     8

 *  it under the terms of the GNU General Public License as published by

     9

 *  the Free Software Foundation, either version 3 of the License, or

    10

 *  (at your option) any later version.

    11

 *

    12

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

    13

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

    14

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    15

 *  GNU General Public License for more details.

    16

 *

    17

 *  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

 *

    20

 *

    21

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

    22

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

    23

 */

    24

    25

/*

    26

 * An IEC 61131-3 compiler.

    27

 *

    28

 * Based on the

    29

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

    30

 *

    31

 */

    32

    33

/*

    34

 * Stage 2

    35

 * =======

    36

 *

    37

 *  This file contains the syntax definition of the textual

    38

 *  languages IL and ST, as well as the textual version of SFC.

    39

 *  The syntax parser, comprising the 2nd stage of the overall 

    40

 *  compiler, is generated by runing bison on this file.

    41

 */

    42

    43

    44

    45

    46

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

    47

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

    48

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

    49

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

    50

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

    51

/*******   The following syntax does not have any conflicts.    *******/

    52

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

    53

/*******   P L E A S E    K E E P    I T    T H A T    W A Y !  *******/

    54

/*******   ===================================================  *******/

    55

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

    56

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

    57

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

    58

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

    59

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

    60

    61

    62

    63

    64

%{

    65

#include <string.h>	/* required for strdup()  */

    66

    67

    68

/* declare the token parser generated by flex... */

    69

int yylex(void);

    70

    71

/* declare the error handler defined at the end of this file */

    72

void yyerror (const char *error_msg);

    73

    74

/* produce a more verbose parsing error message */

    75

#define YYERROR_VERBOSE

    76

    77

/* Include debuging code.

    78

 * Printing of debug info must then be activated by setting

    79

 * the variable yydebug to 1.

    80

 */

    81

#define YYDEBUG 0

    82

    83

    84

/* file with declaration of absyntax classes... */

    85

#include "../absyntax/absyntax.hh"

    86

    87

/* file with declaration of token constants. Generated by bison! */

    88

#include "iec.y.hh"

    89

    90

/* The interface through which bison and flex interact. */

    91

#include "stage1_2_priv.hh"

    92

    93

    94

/* an ugly hack!!

    95

 * We will probably not need it when we decide

    96

 *  to cut down the abstract syntax down to size.

    97

 *  We keep it as it is until we get to write

    98

 *  stages 3 and 4 of the compiler. Who knows,

    99

 *  we might just find out that we really do need

   100

 *  the abstract syntax tree to stay as it is

   101

 *  afterall!

   102

 */

   103

/* for each element <elem> in list_c * <list>

   104

 * execute the code <code>

   105

 */

   106

#define FOR_EACH_ELEMENT(elem, list, code) {		\

   107

  symbol_c *elem;					\

   108

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

   109

    elem = list->elements[i];				\

   110

    code;						\

   111

  }							\

   112

}

   113

   114

   115

   116

/* Macros used to pass the line and column locations when

   117

 * creating a new object for the abstract syntax tree.

   118

 */

   145

   146

   147

/* A macro for printing out internal parser errors... */

   148

#define ERROR error_exit(__FILE__,__LINE__)

   149

/* function defined in main.cc */

   150

extern void error_exit(const char *file_name, int line_no);

   151

   152

   153

   154

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

   155

/* global variables...   */

   156

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

   157

/* NOTE: For some strange reason bison ver 2.3 is including these declarations

   158

 *       in the iec.y.hh file, which is in turn included by flex.

   159

 *       We cannot therefore define any variables over here, but merely declare 

   160

 *       their existance (otherwise we get errors when linking the code, since we

   161

 *       would get a new variable defined each time iec.y.hh is included!).

   162

 *       Even though the variables are declared 'extern' over here, they will in

   163

 *       fact be defined towards the end of this same file (i.e. in the prologue)

   164

 */

   165

   166

   167

/* NOTE: These variable are really parameters we would like the stage2__ function to pass

   168

 *       to the yyparse() function. However, the yyparse() function is created automatically

   169

 *       by bison, so we cannot add parameters to this function. The only other

   170

 *       option is to use global variables! yuck!

   171

 */

   172

   173

/* A global flag used to tell the parser if overloaded funtions should be allowed.

   174

 * The IEC 61131-3 standard allows overloaded funtions in the standard library,

   175

 * but disallows them in user code...

   176

 */

   177

extern bool allow_function_overloading;

   178

   179

/* A global flag used to tell the parser whether to include the full variable location

   180

 * when printing out error messages...

   181

 */

   182

extern bool full_token_loc;

   183

   184

/* A pointer to the root of the parsing tree that will be generated 

   185

 * by bison.

   186

 */

   187

extern symbol_c *tree_root;

   188

   189

   190

   191

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

   192

/* forward declarations */

   193

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

   194

/* The functions declared here are defined at the end of this file... */

   195

   196

/* Convert an il_operator_c into an identifier_c */

   197

symbol_c *il_operator_c_2_identifier_c(symbol_c *il_operator);

   198

   199

/* return if current token is a syntax element */

   200

/* ERROR_CHECK_BEGIN */

   201

bool is_current_syntax_token();

   202

/* ERROR_CHECK_END */

   203

   204

/* print an error message */

   205

void print_err_msg(int first_line,

   206

                   int first_column,

   208

                   int last_line,

   209

                   int last_column,

   211

                   const char *additional_error_msg);

   212

%}

   213

   214

   215

   216

   217

// %glr-parser

   218

// %expect-rr 1

   219

   220

   259

   260

   261

%union {

   262

    symbol_c 	*leaf;

   263

    list_c	*list;

   264

    char 	*ID;	/* token value */

   265

}

   266

   267

/*

   268

 TODO: DO we need to define a destructor do free

   269

       memory when recovering from errors, or do the

   270

       class destructors already handle this?

   271

       Following is example on how to define

   272

       detructors, using the syntax:

   273

       %destructor { CODE } SYMBOLS

   274

%union

   275

      {

   276

        char *string;

   277

      }

   278

      %token <string> STRING

   279

      %type  <string> string

   280

      %destructor { free ($$); } STRING string

   281

*/

   282

   283

   284

   285

   286

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

   287

/* Prelimenary helpful constructs... */

   288

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

   289

/* A token used to identify the very end of the input file

   290

 * after all includes have already been processed.

   291

 *

   292

 * Flex automatically returns the token with value 0

   293

 * at the end of the file. We therefore specify here

   294

 * a token with that exact same value here, so we can use it

   295

 * to detect the very end of the input files.

   296

 */

   297

%token END_OF_INPUT 0

   298

   299

/* A bogus token that, in principle, flex MUST NEVER generate */

   300

/* USE 1:

   301

 * ======

   302

 * This token is currently also being used as the default

   303

 * initialisation value of the token_id member in

   304

 * the symbol_c base class.

   305

 *

   306

 * USE 2

   307

 * =====

   308

 * This token may also be used in the future to remove

   309

 * mysterious reduce/reduce conflicts due to the fact

   310

 * that our grammar may not be LALR(1) but merely LR(1).

   311

 * This means that bison cannot handle it without some

   312

 * caoxing from ourselves. We will then need this token

   313

 * to do the coaxing...

   314

 */

   315

%token BOGUS_TOKEN_ID

   316

   317

%type <leaf>	start

   318

   319

%type <leaf>	any_identifier

   320

   321

%token <ID>	prev_declared_variable_name_token

   322

%token <ID>	prev_declared_direct_variable_token

   323

%token <ID>	prev_declared_fb_name_token

   324

%type <leaf>	prev_declared_variable_name

   325

%type <leaf>	prev_declared_direct_variable

   326

%type <leaf>	prev_declared_fb_name

   327

   328

%token  <ID>	prev_declared_simple_type_name_token

   329

%token  <ID>	prev_declared_subrange_type_name_token

   330

%token  <ID>	prev_declared_enumerated_type_name_token

   331

%token  <ID>	prev_declared_array_type_name_token

   332

%token  <ID>	prev_declared_structure_type_name_token

   333

%token  <ID>	prev_declared_string_type_name_token

   334

   335

%type  <leaf>	prev_declared_simple_type_name

   336

%type  <leaf>	prev_declared_subrange_type_name

   337

%type  <leaf>	prev_declared_enumerated_type_name

   338

%type  <leaf>	prev_declared_array_type_name

   339

%type  <leaf>	prev_declared_structure_type_name

   340

%type  <leaf>	prev_declared_string_type_name

   341

   342

%token <ID>	prev_declared_derived_function_name_token

   343

%token <ID>	prev_declared_derived_function_block_name_token

   344

%token <ID>	prev_declared_program_type_name_token

   345

%type  <leaf>	prev_declared_derived_function_name

   346

%type  <leaf>	prev_declared_derived_function_block_name

   347

%type  <leaf>	prev_declared_program_type_name

   348

   349

   350

   351

   352

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

   353

/* B XXX - Things that are missing from the standard, but should have been there! */

   354

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

   355

   356

/* Pragmas that our compiler will accept.

   357

 * See the comment in iec.flex for why these pragmas exist. 

   358

 */

   359

%token          disable_code_generation_pragma_token

   360

%token          enable_code_generation_pragma_token

   361

%type <leaf>	disable_code_generation_pragma

   362

%type <leaf>	enable_code_generation_pragma

   363

   364

   365

/* All other pragmas that we do not support... */

   366

/* In most stage 4, the text inside the pragmas will simply be copied to the output file.

   367

 * This allows us to insert C code (if using stage 4 generating C code) 

   368

 * inside/interningled with the IEC 61131-3 code!

   369

 */

   370

%token <ID>	pragma_token

   371

%type <leaf>	pragma

   372

   373

/* The joining of all previous pragmas, i.e. any possible pragma */

   374

%type <leaf>	any_pragma

   375

   376

   377

/* Where do these tokens belong?? They are missing from the standard! */

   378

/* NOTE: There are other tokens related to these 'EN' ENO', that are also 

   379

 * missing from the standard. However, their location in the annex B is 

   380

 * relatively obvious, so they have been inserted in what seems to us their 

   381

 * correct place in order to ease understanding of the parser...

   382

 */

   383

%token	EN

   384

%token	ENO

   385

%type <leaf>	en_identifier

   386

%type <leaf>	eno_identifier

   387

   388

   389

   390

   391

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

   392

/* B 0 - Programming Model */

   393

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

   394

%type <list>	library

   395

%type <leaf>	library_element_declaration

   396

   397

   398

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

   399

/* B 1.1 - Letters, digits and identifiers */

   400

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

   401

/* Done totally within flex...

   402

  letter

   403

  digit

   404

  octal_digit

   405

  hex_digit

   406

*/

   407

%token <ID>	identifier_token

   408

%type  <leaf>	identifier

   409

   410

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

   411

/* B 1.2 - Constants */

   412

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

   413

%type <leaf>	constant

   414

%type <leaf>	non_negative_constant

   415

   416

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

   417

/* B 1.2.1 - Numeric Literals */

   418

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

   419

/* Done totally within flex...

   420

  bit

   421

*/

   422

%type  <leaf> numeric_literal

   423

%type  <leaf> integer_literal

   424

%type  <leaf> signed_integer

   425

%token <ID>   integer_token

   426

%type  <leaf> integer

   427

%token <ID>   binary_integer_token

   428

%type  <leaf> binary_integer

   429

%token <ID>   octal_integer_token

   430

%type  <leaf> octal_integer

   431

%token <ID>   hex_integer_token

   432

%type  <leaf> hex_integer

   433

%token <ID>   real_token

   434

%type  <leaf> real

   435

%type  <leaf> signed_real

   436

%type  <leaf> real_literal

   437

// %type  <leaf> exponent

   438

%type  <leaf> bit_string_literal

   439

%type  <leaf> boolean_literal

   440

   441

%token safeboolean_true_literal_token

   442

%token safeboolean_false_literal_token

   443

%token boolean_true_literal_token

   444

%token boolean_false_literal_token

   445

   446

%token FALSE

   447

%token TRUE

   448

   449

   450

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

   451

/* B 1.2.2 - Character Strings */

   452

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

   453

%token <ID>   single_byte_character_string_token

   454

%token <ID>   double_byte_character_string_token

   455

   456

%type  <leaf> character_string

   457

%type  <leaf> single_byte_character_string

   458

%type  <leaf> double_byte_character_string

   459

   460

   461

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

   462

/* B 1.2.3 - Time Literals */

   463

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

   464

%type  <leaf> time_literal

   465

   466

   467

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

   468

/* B 1.2.3.1 - Duration */

   469

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

   470

%type  <leaf>	duration

   471

%type  <leaf>	interval

   472

%type  <leaf>	days

   473

%type  <leaf>	fixed_point

   474

%type  <leaf>	hours

   475

%type  <leaf>	minutes

   476

%type  <leaf>	seconds

   477

%type  <leaf>	milliseconds

   478

   479

%type  <leaf>	integer_d

   480

%type  <leaf>	integer_h

   481

%type  <leaf>	integer_m

   482

%type  <leaf>	integer_s

   483

%type  <leaf>	integer_ms

   484

%type  <leaf>	fixed_point_d

   485

%type  <leaf>	fixed_point_h

   486

%type  <leaf>	fixed_point_m

   487

%type  <leaf>	fixed_point_s

   488

%type  <leaf>	fixed_point_ms

   489

   490

%token <ID>	fixed_point_token

   491

%token <ID>	fixed_point_d_token

   492

%token <ID>	integer_d_token

   493

%token <ID>	fixed_point_h_token

   494

%token <ID>	integer_h_token

   495

%token <ID>	fixed_point_m_token

   496

%token <ID>	integer_m_token

   497

%token <ID>	fixed_point_s_token

   498

%token <ID>	integer_s_token

   499

%token <ID>	fixed_point_ms_token

   500

%token <ID>	integer_ms_token

   501

   502

// %token TIME

   503

%token T_SHARP

   504

   505

   506

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

   507

/* B 1.2.3.2 - Time of day and Date */

   508

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