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! */

    80

// #include "iec.y.hh"

    81

    83

#include "stage1_2_priv.hh"

    84

    85

    86

/* an ugly hack!!

    87

 * We will probably not need it when we decide

    88

 *  to cut down the abstract syntax down to size.

    89

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

    90

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

    91

 *  we might just find out that we really do need

    92

 *  the abstract syntax tree to stay as it is

    93

 *  afterall!

    94

 */

    95

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

    96

 * execute the code <code>

    97

 */

    98

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

    99

  symbol_c *elem;					\

   100

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

   101

    elem = list->elements[i];				\

   102

    code;						\

   103

  }							\

   104

}

   105

   106

   117

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

   118

#define ERROR error_exit(__FILE__,__LINE__)

   119

/* function defined in main.cc */

   120

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

   121

   122

   123

   124

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

   125

/* global variables...   */

   126

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

   127

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

   128

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

   129

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

   130

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

   131

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

   132

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

   133

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

   134

 */

   135

   136

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

   137

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

   138

 * but disallows them in user code...

   139

 */

   140

extern bool allow_function_overloading;

   141

   142

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

   143

 * by bison.

   144

 */

   145

extern symbol_c *tree_root;

   146

   147

   148

   149

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

   150

/* forward declarations */

   151

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

   152

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

   153

   154

/* Convert an il_operator_c into an identifier_c */

   155

symbol_c *il_operator_c_2_identifier_c(symbol_c *il_operator);

   156

   157

/* print an error message */

   158

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

   159

   160

%}

   161

   162

   163

   164

   165

// %glr-parser

   166

// %expect-rr 1

   167

   168

   169

   170

   171

%union {

   172

    symbol_c 	*leaf;

   173

    list_c	*list;

   174

    char 	*ID;	/* token value */

   175

    struct {

   176

      symbol_c	*first;

   177

      symbol_c	*second;

   178

      symbol_c	*third;

   179

      symbol_c	*fourth;

   180

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

   181

                                     il_simple_operator_clash_il_operand

   182

                                     transaction_tmp

   183

                                     action_tmp

   184

                             */

   185

}

   186

   202

   203

   204

   205

   206

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

   207

/* Prelimenary constructs... */

   208

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

   209

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

   210

/* USE 1:

   211

 * ======

   212

 * This token is currently also being used as the default

   213

 * initialisation value of the token_id member in

   214

 * the symbol_c base class.

   215

 *

   216

 * USE 2

   217

 * =====

   218

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

   219

 * mysterious reduce/reduce conflicts due to the fact

   220

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

   221

 * This means that bison cannot handle it without some

   222

 * caoxing from ourselves. We will then need this token

   223

 * to do the coaxing...

   224

 */

   225

%token BOGUS_TOKEN_ID

   226

   227

   229

   230

%type <leaf>	any_identifier

   231

   232

%token <ID>	prev_declared_variable_name_token

   233

%token <ID>	prev_declared_fb_name_token

   234

%type <leaf>	prev_declared_variable_name

   235

%type <leaf>	prev_declared_fb_name

   236

   237

%token  <ID>	prev_declared_simple_type_name_token

   238

%token  <ID>	prev_declared_subrange_type_name_token

   239

%token  <ID>	prev_declared_enumerated_type_name_token

   240

%token  <ID>	prev_declared_array_type_name_token

   241

%token  <ID>	prev_declared_structure_type_name_token

   242

%token  <ID>	prev_declared_string_type_name_token

   243

   244

%type  <leaf>	prev_declared_simple_type_name

   245

%type  <leaf>	prev_declared_subrange_type_name

   246

%type  <leaf>	prev_declared_enumerated_type_name

   247

%type  <leaf>	prev_declared_array_type_name

   248

%type  <leaf>	prev_declared_structure_type_name

   249

%type  <leaf>	prev_declared_string_type_name

   250

   251

%token <ID>	prev_declared_derived_function_name_token

   252

%token <ID>	prev_declared_derived_function_block_name_token

   253

%token <ID>	prev_declared_program_type_name_token

   254

%type  <leaf>	prev_declared_derived_function_name

   255

%type  <leaf>	prev_declared_derived_function_block_name

   256

%type  <leaf>	prev_declared_program_type_name

   257

   258

   259

   260

   261

/* The pragmas... */

   262

%token <ID>	pragma_token

   263

%type <leaf>	pragma

   264

   265

   266

/* Where do these tokens belong ?? */

   267

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

   268

%token	EN

   269

%token	ENO

   270

   271

   272

   273

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

   274

/* B 0 - Programming Model */

   275

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

   276

%type <list>	library

   277

%type <leaf>	library_element_declaration

   278

   279

   280

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

   281

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

   282

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

   283

/* Done totally within flex...

   284

  letter

   285

  digit

   286

  octal_digit

   287

  hex_digit

   288

*/

   289

%token <ID>	identifier_token

   290

%type  <leaf>	identifier

   291

   292

   293

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

   294

/* B 1.2 - Constants */

   295

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

   296

%type <leaf>	constant

   297

/* a helper symbol for expression */

   298

%type  <leaf> non_negative_constant

   299

   300

   301

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

   302

/* B 1.2.1 - Numeric Literals */

   303

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

   304

/* Done totally within flex...

   305

  bit

   306

*/

   307

%type  <leaf> numeric_literal

   308

/* helper symbol for non_negative_constant */

   309

%type  <leaf> non_negative_numeric_literal

   310

%type  <leaf> integer_literal

   311

%type  <leaf> signed_integer

   312

/* a helper symbol for non_negative_constant */

   313

%type  <leaf> non_negative_signed_integer

   314

%token <ID>   integer_token

   315

%type  <leaf> integer

   316

%token <ID>   binary_integer_token

   317

%type  <leaf> binary_integer

   318

%token <ID>   octal_integer_token

   319

%type  <leaf> octal_integer

   320

%token <ID>   hex_integer_token

   321

%type  <leaf> hex_integer

   322

%token <ID>   real_token

   323

%type  <leaf> real

   324

%type  <leaf> signed_real

   325

/* helper symbol for non_negative_real_literal */

   326

%type  <leaf> non_negative_signed_real

   327

%type  <leaf> real_literal

   328

/* helper symbol for non_negative_numeric_literal */

   329

%type  <leaf> non_negative_real_literal

   330

// %type  <leaf> exponent

   331

%type  <leaf> bit_string_literal

   332

%type  <leaf> boolean_literal

   333

   334

%token FALSE

   335

%token TRUE

   336

   337

   338

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

   339

/* B 1.2.2 - Character Strings */

   340

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

   341

%token <ID>   single_byte_character_string_token

   342

%token <ID>   double_byte_character_string_token

   343

   344

%type  <leaf> character_string

   345

%type  <leaf> single_byte_character_string

   346

%type  <leaf> double_byte_character_string

   347

   348

   349

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

   350

/* B 1.2.3 - Time Literals */

   351

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

   352

%type  <leaf> time_literal

   353

   354

   355

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

   356

/* B 1.2.3.1 - Duration */

   357

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

   358

%type  <leaf>	duration

   359

%type  <leaf>	interval

   360

%type  <leaf>	days

   361

%type  <leaf>	fixed_point

   362

%type  <leaf>	hours

   363

%type  <leaf>	minutes

   364

%type  <leaf>	seconds

   365

%type  <leaf>	milliseconds

   366

   367

%type  <leaf>	integer_d

   368

%type  <leaf>	integer_h

   369

%type  <leaf>	integer_m

   370

%type  <leaf>	integer_s

   371

%type  <leaf>	integer_ms

   372

%type  <leaf>	fixed_point_d

   373

%type  <leaf>	fixed_point_h

   374

%type  <leaf>	fixed_point_m

   375

%type  <leaf>	fixed_point_s

   376

%type  <leaf>	fixed_point_ms

   377

   378

%token <ID>	fixed_point_token

   379

%token <ID>	fixed_point_d_token

   380

%token <ID>	integer_d_token

   381

%token <ID>	fixed_point_h_token

   382

%token <ID>	integer_h_token

   383

%token <ID>	fixed_point_m_token

   384

%token <ID>	integer_m_token

   385

%token <ID>	fixed_point_s_token

   386

%token <ID>	integer_s_token

   387

%token <ID>	fixed_point_ms_token

   388

%token <ID>	integer_ms_token

   389

   390

%token TIME

   391

%token T_SHARP

   392

   393

   394

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

   395

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

   396

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

   397

%type  <leaf>	time_of_day

   398

%type  <leaf>	daytime

   399

%type  <leaf>	day_hour

   400

%type  <leaf>	day_minute

   401

%type  <leaf>	day_second

   402

%type  <leaf>	date

   403

%type  <leaf>	date_literal

   404

%type  <leaf>	year

   405

%type  <leaf>	month

   406

%type  <leaf>	day

   407

%type  <leaf>	date_and_time

   408

   409

%token TIME_OF_DAY

   410

%token DATE

   411

%token D_SHARP

   412

%token DATE_AND_TIME

   413

   414

   415

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

   416

/* B 1.3 - Data Types */

   417

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

   418

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

   419

// %type  <leaf> data_type_name

   420

%type  <leaf> non_generic_type_name

   421

   422

   423

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

   424

/* B 1.3.1 - Elementary Data Types */

   425

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

   426

/* NOTES:

   427

 *

   428

 *    - To make the definition of bit_string_literal more

   429

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

   430

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

   431

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

   432

 *      Note that the definition of bit_string_type_name

   433

 *      (according to the spec) includes the above elements

   434

 *      and an extra BOOL.

   435

 *      We could use an extra construct with the first four

   436

 *      elements to be used solely in the definition of

   437

 *      bit_string_literal, but with the objective of not

   438

 *      having to replicate the actions (if we ever need

   439

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

   440

 *      bit_string_type_name and the extra grouping), we

   441

 *      have re-defined bit_string_type_name as only including

   442

 *      the first four elements.

   443

 *      In order to have our parser implement the specification

   444

 *      correctly we have augmented every occurence of

   445

 *      bit_string_type_name in other rules with the BOOL

   446

 *      token. Since bit_string_type_name only appears in

   447

 *      the rule for elementary_type_name, this does not

   448

 *      seem to be a big concession to make!

   449

 *

   450

 *    - We have added a helper symbol to concentrate the

   451

 *      instantiation of STRING and WSTRING into a single

   452

 *      location (elementary_string_type_name).

   453

 *      These two elements show up in several other rules,

   454

 *      but we want to create the equivalent abstract syntax

   455

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

   456

 *      possible future changes easier to edit...

   457

 */

   458

%type  <leaf>	elementary_type_name

   459

%type  <leaf>	numeric_type_name

   460

%type  <leaf>	integer_type_name

   461

%type  <leaf>	signed_integer_type_name

   462

%type  <leaf>	unsigned_integer_type_name

   463

%type  <leaf>	real_type_name

   464

%type  <leaf>	date_type_name

   465

%type  <leaf>	bit_string_type_name

   466

/* helper symbol to concentrate the instantiation

   467

 * of STRING and WSTRING into a single location

   468

 */

   469

%type  <leaf>	elementary_string_type_name

   470

   471

%token BYTE

   472

%token WORD

   473

%token DWORD

   474

%token LWORD

   475

   476

%token LREAL

   477

%token REAL

   478

   479

%token SINT

   480

%token INT

   481

%token DINT

   482

%token LINT

   483

   484

%token USINT

   485

%token UINT

   486

%token UDINT

   487

%token ULINT

   488

   489

%token WSTRING

   490

%token STRING

   491

%token BOOL

   492

   493

// %token TIME

   494

// %token DATE

   495

// %token DATE_AND_TIME

   496

%token DT

   497

// %token TIME_OF_DAY

   498

%token TOD

   499

   500

   501

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

   502

/* B 1.3.2 - Generic data types */

   503

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

   504

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

   505

// %type  <leaf>	generic_type_name

   506

   507

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

   508

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

   509

 */

   510

%token ANY

   511

%token ANY_DERIVED

   512

%token ANY_ELEMENTARY

   513

%token ANY_MAGNITUDE

   514

%token ANY_NUM

   515

%token ANY_REAL

   516

%token ANY_INT

   517

%token ANY_BIT

   518

%token ANY_STRING

   519

%token ANY_DATE

   520

   521