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

 * Stage 2

    27

 * =======

    28

 *

    29

 *  This file contains the syntax definition of the textual

    30

 *  languages IL and ST. The syntax parser, comprising the

    31

 *  2nd stage of the overall compiler, is generated by runing

    32

 *  bison on this file.

    33

 */

    34

    35

    36

    37

    38

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

    39

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

    40

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

    41

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

    42

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

    43

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

    44

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

    45

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

    46

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

    47

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

    48

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

    49

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

    50

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

    51

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

    52

    53

    54

    55

    56

%{

    57

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

    58

    59

    60

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

    61

int yylex(void);

    62

    63

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

    64

void yyerror (const char *error_msg);

    65

    66

/* produce a more verbose parsing error message */

    67

#define YYERROR_VERBOSE

    68

    69

/* Include debuging code.

    70

 * Printing of debug info must then be activated by setting

    71

 * the variable yydebug to 1.

    72

 */

    73

#define YYDEBUG 0

    74

    75

    76

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

    77

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

    78

    79

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

    83

    84

    85

/* an ugly hack!!

    86

 * We will probably not need it when we decide

    87

 *  to cut down the abstract syntax down to size.

    88

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

    89

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

    90

 *  we might just find out that we really do need

    91

 *  the abstract syntax tree to stay as it is

    92

 *  afterall!

    93

 */

    94

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

    95

 * execute the code <code>

    96

 */

    97

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

    98

  symbol_c *elem;					\

    99

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

   100

    elem = list->elements[i];				\

   101

    code;						\

   102

  }							\

   103

}

   104

   105

   106

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

   107

#define ERROR error_exit(__FILE__,__LINE__)

   108

/* function defined in main.cc */

   109

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

   110

   111

   112

   113

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

   114

/* global variables...   */

   115

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

   124

   125

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

   126

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

   127

 * but disallows them in user code...

   128

 */

   136

   137

   138

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

   139

/* forward declarations */

   140

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

   141

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

   142

   143

/* Convert an il_operator_c into an identifier_c */

   144

symbol_c *il_operator_c_2_identifier_c(symbol_c *il_operator);

   145

   146

/* print an error message */

   147

void print_err_msg(const char *filename, int lineno, const char *additional_error_msg);

   148

   149

%}

   150

   151

   152

   154

%glr-parser

   155

// %expect-rr 1

   156

   157

   158

   159

   160

%union {

   161

    symbol_c 	*leaf;

   162

    list_c	*list;

   163

    char 	*ID;	/* token value */

   164

    struct {

   165

      symbol_c	*first;

   166

      symbol_c	*second;

   167

      symbol_c	*third;

   168

      symbol_c	*fourth;

   169

    } tmp_symbol; /* used as a temorary reference to symbols by:

   170

                                     il_simple_operator_clash_il_operand

   171

                                     transaction_tmp

   172

                                     action_tmp

   173

                             */

   174

}

   175

   176

   177

   178

   179

   180

   181

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

   182

/* Prelimenary constructs... */

   183

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

   184

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

   185

/* USE 1:

   186

 * ======

   187

 * This token is currently also being used as the default

   188

 * initialisation value of the token_id member in

   189

 * the symbol_c base class.

   190

 *

   191

 * USE 2

   192

 * =====

   193

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

   194

 * mysterious reduce/reduce conflicts due to the fact

   195

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

   196

 * This means that bison cannot handle it without some

   197

 * caoxing from ourselves. We will then need this token

   198

 * to do the coaxing...

   199

 */

   200

%token BOGUS_TOKEN_ID

   201

   202

   244

/* The pragmas... */

   245

%token <ID>	pragma_token

   246

%type <leaf>	pragma

   247

   248

   249

/* Where do these tokens belong ?? */

   250

/* TODO: get the syntax parser to handle these tokens... */

   251

%token	EN

   252

%token	ENO

   253

   254

   255

   256

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

   257

/* B 0 - Programming Model */

   258

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

   259

%type <list>	library

   260

%type <leaf>	library_element_declaration

   261

   262

   263

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

   264

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

   265

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

   266

/* Done totally within flex...

   267

  letter

   268

  digit

   269

  octal_digit

   270

  hex_digit

   271

*/

   272

%token <ID>	identifier_token

   273

%type  <leaf>	identifier

   274

   275

   276

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

   277

/* B 1.2 - Constants */

   278

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

   279

%type <leaf>	constant

   280

/* a helper symbol for expression */

   281

%type  <leaf> non_negative_constant

   282

   283

   284

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

   285

/* B 1.2.1 - Numeric Literals */

   286

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

   287

/* Done totally within flex...

   288

  bit

   289

*/

   290

%type  <leaf> numeric_literal

   291

/* helper symbol for non_negative_constant */

   292

%type  <leaf> non_negative_numeric_literal

   293

%type  <leaf> integer_literal

   294

%type  <leaf> signed_integer

   295

/* a helper symbol for non_negative_constant */

   296

%type  <leaf> non_negative_signed_integer

   297

%token <ID>   integer_token

   298

%type  <leaf> integer

   299

%token <ID>   binary_integer_token

   300

%type  <leaf> binary_integer

   301

%token <ID>   octal_integer_token

   302

%type  <leaf> octal_integer

   303

%token <ID>   hex_integer_token

   304

%type  <leaf> hex_integer

   305

%token <ID>   real_token

   306

%type  <leaf> real

   307

%type  <leaf> signed_real

   308

/* helper symbol for non_negative_real_literal */

   309

%type  <leaf> non_negative_signed_real

   310

%type  <leaf> real_literal

   311

/* helper symbol for non_negative_numeric_literal */

   312

%type  <leaf> non_negative_real_literal

   313

// %type  <leaf> exponent

   314

%type  <leaf> bit_string_literal

   315

%type  <leaf> boolean_literal

   316

   317

%token FALSE

   318

%token TRUE

   319

   320

   321

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

   322

/* B 1.2.2 - Character Strings */

   323

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

   324

%token <ID>   single_byte_character_string_token

   325

%token <ID>   double_byte_character_string_token

   326

   327

%type  <leaf> character_string

   328

%type  <leaf> single_byte_character_string

   329

%type  <leaf> double_byte_character_string

   330

   331

   332

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

   333

/* B 1.2.3 - Time Literals */

   334

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

   335

%type  <leaf> time_literal

   336

   337

   338

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

   339

/* B 1.2.3.1 - Duration */

   340

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

   341

%type  <leaf>	duration

   342

%type  <leaf>	interval

   343

%type  <leaf>	days

   344

%type  <leaf>	fixed_point

   345

%type  <leaf>	hours

   346

%type  <leaf>	minutes

   347

%type  <leaf>	seconds

   348

%type  <leaf>	milliseconds

   349

   350

%type  <leaf>	integer_d

   351

%type  <leaf>	integer_h

   352

%type  <leaf>	integer_m

   353

%type  <leaf>	integer_s

   354

%type  <leaf>	integer_ms

   355

%type  <leaf>	fixed_point_d

   356

%type  <leaf>	fixed_point_h

   357

%type  <leaf>	fixed_point_m

   358

%type  <leaf>	fixed_point_s

   359

%type  <leaf>	fixed_point_ms

   360

   361

%token <ID>	fixed_point_token

   362

%token <ID>	fixed_point_d_token

   363

%token <ID>	integer_d_token

   364

%token <ID>	fixed_point_h_token

   365

%token <ID>	integer_h_token

   366

%token <ID>	fixed_point_m_token

   367

%token <ID>	integer_m_token

   368

%token <ID>	fixed_point_s_token

   369

%token <ID>	integer_s_token

   370

%token <ID>	fixed_point_ms_token

   371

%token <ID>	integer_ms_token

   372

   373

%token TIME

   374

%token T_SHARP

   375

   376

   377

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

   378

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

   379

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

   380

%type  <leaf>	time_of_day

   381

%type  <leaf>	daytime

   382

%type  <leaf>	day_hour

   383

%type  <leaf>	day_minute

   384

%type  <leaf>	day_second

   385

%type  <leaf>	date

   386

%type  <leaf>	date_literal

   387

%type  <leaf>	year

   388

%type  <leaf>	month

   389

%type  <leaf>	day

   390

%type  <leaf>	date_and_time

   391

   392

%token TIME_OF_DAY

   393

%token DATE

   394

%token D_SHARP

   395

%token DATE_AND_TIME

   396

   397

   398

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

   399

/* B 1.3 - Data Types */

   400

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

   401

/* Strangely, the following symbol does seem to be required! */

   402

// %type  <leaf> data_type_name

   403

%type  <leaf> non_generic_type_name

   404

   405

   406

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

   407

/* B 1.3.1 - Elementary Data Types */

   408

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

   409

/* NOTES:

   410

 *

   411

 *    - To make the definition of bit_string_literal more

   412

 *      concise, it is useful to use an extra non-terminal

   413

 *      symbol (i.e. a grouping or construct) that groups the

   414

 *      following elements (BYTE, WORD, DWORD, LWORD).

   415

 *      Note that the definition of bit_string_type_name

   416

 *      (according to the spec) includes the above elements

   417

 *      and an extra BOOL.

   418

 *      We could use an extra construct with the first four

   419

 *      elements to be used solely in the definition of

   420

 *      bit_string_literal, but with the objective of not

   421

 *      having to replicate the actions (if we ever need

   422

 *      to change them, they would need to be changed in both

   423

 *      bit_string_type_name and the extra grouping), we

   424

 *      have re-defined bit_string_type_name as only including

   425

 *      the first four elements.

   426

 *      In order to have our parser implement the specification

   427

 *      correctly we have augmented every occurence of

   428

 *      bit_string_type_name in other rules with the BOOL

   429

 *      token. Since bit_string_type_name only appears in

   430

 *      the rule for elementary_type_name, this does not

   431

 *      seem to be a big concession to make!

   432

 *

   433

 *    - We have added a helper symbol to concentrate the

   434

 *      instantiation of STRING and WSTRING into a single

   435

 *      location (elementary_string_type_name).

   436

 *      These two elements show up in several other rules,

   437

 *      but we want to create the equivalent abstract syntax

   438

 *      in a single location of this file, in order to make

   439

 *      possible future changes easier to edit...

   440

 */

   441

%type  <leaf>	elementary_type_name

   442

%type  <leaf>	numeric_type_name

   443

%type  <leaf>	integer_type_name

   444

%type  <leaf>	signed_integer_type_name

   445

%type  <leaf>	unsigned_integer_type_name

   446

%type  <leaf>	real_type_name

   447

%type  <leaf>	date_type_name

   448

%type  <leaf>	bit_string_type_name

   449

/* helper symbol to concentrate the instantiation

   450

 * of STRING and WSTRING into a single location

   451

 */

   452

%type  <leaf>	elementary_string_type_name

   453

   454

%token BYTE

   455

%token WORD

   456

%token DWORD

   457

%token LWORD

   458

   459

%token LREAL

   460

%token REAL

   461

   462

%token SINT

   463

%token INT

   464

%token DINT

   465

%token LINT

   466

   467

%token USINT

   468

%token UINT

   469

%token UDINT

   470

%token ULINT

   471

   472

%token WSTRING

   473

%token STRING

   474

%token BOOL

   475

   479

%token DT

   481

%token TOD

   482

   483

   484

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

   485

/* B 1.3.2 - Generic data types */

   486

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

   487

/* Strangely, the following symbol does seem to be required! */

   488

// %type  <leaf>	generic_type_name

   489

   490

/* The following tokens do not seem to be used either

   491

 * but we declare them so they become reserved words...

   492

 */

   493

%token ANY

   494

%token ANY_DERIVED

   495

%token ANY_ELEMENTARY

   496

%token ANY_MAGNITUDE

   497

%token ANY_NUM

   498

%token ANY_REAL

   499

%token ANY_INT

   500

%token ANY_BIT

   501

%token ANY_STRING

   502

%token ANY_DATE

   503

   504

   505

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

   506

/* B 1.3.3 - Derived data types */

   507

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

   508

%type  <leaf>	derived_type_name

   509

%type  <leaf>	single_element_type_name

   510

// %type  <leaf>	simple_type_name

   511

// %type  <leaf>	subrange_type_name

   512

// %type  <leaf>	enumerated_type_name

   513

// %type  <leaf>	array_type_name

   514

// %type  <leaf>	structure_type_name

   515

   516

%type  <leaf>	data_type_declaration

   517

/* helper symbol for data_type_declaration */

   518

%type  <list>	type_declaration_list

   519

%type  <leaf>	type_declaration

   520

%type  <leaf>	single_element_type_declaration

   521

   522

%type  <leaf>	simple_type_declaration

   523

%type  <leaf>	simple_spec_init