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

    82

/* file with the declarations of symbol tables... */

    83

#include "../util/symtable.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

   107

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

   108

#define ERROR error_exit(__FILE__,__LINE__)

   109

/* function defined in main.cc */

   110

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

   111

   112

   113

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

   114

/* The global symbol tables...   */

   115

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

   116

/* NOTE: declared static because they are not accessed

   117

 *       directly by the lexical parser (flex), but rather

   118

 *       through the function get_identifier_token()

   119

 */

   120

/* A symbol table to store all the library elements */

   121

/* e.g.: <function_name , function_decl>

   122

 *       <fb_name , fb_decl>

   123

 *       <type_name , type_decl>

   124

 *       <program_name , program_decl>

   125

 *       <configuration_name , configuration_decl>

   126

 */

   127

static symtable_c<int, BOGUS_TOKEN_ID> library_element_symtable;

   128

   129

/* A symbol table to store the declared variables of

   130

 * the function currently being parsed...

   131

 */

   132

static symtable_c<int, BOGUS_TOKEN_ID> variable_name_symtable;

   133

   134

   135

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

   136

/* global variables...   */

   137

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

   138

static symbol_c *tree_root = NULL;

   139

   140

/* The name of the file currently being parsed...

   141

 * Note that flex accesses and updates this global variable

   142

 * apropriately whenever it comes across an (*#include <filename> *)

   143

 * directive...

   144

 */

   145

const char *current_filename = NULL;

   146

   147

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

   148

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

   149

 * but disallows them in user code...

   150

 */

   151

bool allow_function_overloading = false;

   152

   153

   154

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

   155

/* forward declarations */

   156

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

   157

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

   158

   159

/* Convert an il_operator_c into an identifier_c */

   160

symbol_c *il_operator_c_2_identifier_c(symbol_c *il_operator);

   161

   162

/* print an error message */

   163

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

   164

   165

   166

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

   167

/* forward declarations */

   168

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

   169

/* The functions declared here are defined in iec.flex... */

   170

void print_include_stack(void);

   171

void cmd_goto_body_state(void);

   172

int  get_goto_body_state(void);

   173

void rst_goto_body_state(void);

   174

   175

%}

   176

   177

   178

   185

%union {

   186

    symbol_c 	*leaf;

   187

    list_c	*list;

   188

    char 	*ID;	/* token value */

   189

    struct {

   190

      symbol_c	*first;

   191

      symbol_c	*second;

   192

      symbol_c	*third;

   193

      symbol_c	*fourth;

   194

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

   195

                                     il_simple_operator_clash_il_operand

   196

                                     transaction_tmp

   197

                                     action_tmp

   198

                             */

   199

}

   200

   201

   202

   203

   204

   205

   206

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

   207

/* Prelimenary constructs... */

   208

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

   209

%type <leaf> start

   210

   211

%type <leaf>	any_identifier

   212

   213

%token <ID>	prev_declared_variable_name_token

   214

%token <ID>	prev_declared_fb_name_token

   215

%type <leaf>	prev_declared_variable_name

   216

%type <leaf>	prev_declared_fb_name

   217

   218

%token  <ID>	prev_declared_simple_type_name_token

   219

%token  <ID>	prev_declared_subrange_type_name_token

   220

%token  <ID>	prev_declared_enumerated_type_name_token

   221

%token  <ID>	prev_declared_array_type_name_token

   222

%token  <ID>	prev_declared_structure_type_name_token

   223

%token  <ID>	prev_declared_string_type_name_token

   224

   225

%type  <leaf>	prev_declared_simple_type_name

   226

%type  <leaf>	prev_declared_subrange_type_name

   227

%type  <leaf>	prev_declared_enumerated_type_name

   228

%type  <leaf>	prev_declared_array_type_name

   229

%type  <leaf>	prev_declared_structure_type_name

   230

%type  <leaf>	prev_declared_string_type_name

   231

   232

%token <ID>	prev_declared_derived_function_name_token

   233

%token <ID>	prev_declared_derived_function_block_name_token

   234

%token <ID>	prev_declared_program_type_name_token

   235

%type  <leaf>	prev_declared_derived_function_name

   236

%type  <leaf>	prev_declared_derived_function_block_name

   237

%type  <leaf>	prev_declared_program_type_name

   238

   239

   240

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

   241

/* USE 1:

   242

 * ======

   243

 * This token is currently also being used as the default

   244

 * initialisation value of the token_id member in

   245

 * the symbol_c base class.

   246

 *

   247

 * USE 2

   248

 * =====

   249

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

   250

 * mysterious reduce/reduce conflicts due to the fact

   251

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

   252

 * This means that bison cannot handle it without some

   253

 * caoxing from ourselves. We will then need this token

   254

 * to do the coaxing...

   255

 */

   256

%token BOGUS_TOKEN_ID

   257

   258

   259

/* The pragmas... */

   260

%token <ID>	pragma_token

   261

%type <leaf>	pragma

   262

   263

   264

/* Where do these tokens belong ?? */

   265

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

   266

%token	EN

   267

%token	ENO

   268

   269

   270

   271

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

   272

/* B 0 - Programming Model */

   273

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

   274

%type <list>	library

   275

%type <leaf>	library_element_declaration

   276

   277

   278

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

   279

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

   280

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

   281

/* Done totally within flex...

   282

  letter

   283

  digit

   284

  octal_digit

   285

  hex_digit

   286

*/

   287

%token <ID>	identifier_token

   288

%type  <leaf>	identifier

   289

   290

   291

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

   292

/* B 1.2 - Constants */

   293

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

   294

%type <leaf>	constant

   295

/* a helper symbol for expression */

   296

%type  <leaf> non_negative_constant

   297

   298

   299

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

   300

/* B 1.2.1 - Numeric Literals */

   301

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

   302

/* Done totally within flex...

   303

  bit

   304

*/

   305

%type  <leaf> numeric_literal

   306

/* helper symbol for non_negative_constant */

   307

%type  <leaf> non_negative_numeric_literal

   308

%type  <leaf> integer_literal

   309

%type  <leaf> signed_integer

   310

/* a helper symbol for non_negative_constant */

   311

%type  <leaf> non_negative_signed_integer

   312

%token <ID>   integer_token

   313

%type  <leaf> integer

   314

%token <ID>   binary_integer_token

   315

%type  <leaf> binary_integer

   316

%token <ID>   octal_integer_token

   317

%type  <leaf> octal_integer

   318

%token <ID>   hex_integer_token

   319

%type  <leaf> hex_integer

   320

%token <ID>   real_token

   321

%type  <leaf> real

   322

%type  <leaf> signed_real

   323

/* helper symbol for non_negative_real_literal */

   324

%type  <leaf> non_negative_signed_real

   325

%type  <leaf> real_literal

   326

/* helper symbol for non_negative_numeric_literal */

   327

%type  <leaf> non_negative_real_literal

   328

// %type  <leaf> exponent

   329

%type  <leaf> bit_string_literal

   330

%type  <leaf> boolean_literal

   331

   332

%token FALSE

   333

%token TRUE

   334

   335

   336

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

   337

/* B 1.2.2 - Character Strings */

   338

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

   339

%token <ID>   single_byte_character_string_token

   340

%token <ID>   double_byte_character_string_token

   341

   342

%type  <leaf> character_string

   343

%type  <leaf> single_byte_character_string

   344

%type  <leaf> double_byte_character_string

   345

   346

   347

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

   348

/* B 1.2.3 - Time Literals */

   349

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

   350

%type  <leaf> time_literal

   351

   352

   353

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

   354

/* B 1.2.3.1 - Duration */

   355

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

   356

%type  <leaf>	duration

   357

%type  <leaf>	interval

   358

%type  <leaf>	days

   359

%type  <leaf>	fixed_point

   360

%type  <leaf>	hours

   361

%type  <leaf>	minutes

   362

%type  <leaf>	seconds

   363

%type  <leaf>	milliseconds

   364

   365

%type  <leaf>	integer_d

   366

%type  <leaf>	integer_h

   367

%type  <leaf>	integer_m

   368

%type  <leaf>	integer_s

   369

%type  <leaf>	integer_ms

   370

%type  <leaf>	fixed_point_d

   371

%type  <leaf>	fixed_point_h

   372

%type  <leaf>	fixed_point_m

   373

%type  <leaf>	fixed_point_s

   374

%type  <leaf>	fixed_point_ms

   375

   376

%token <ID>	fixed_point_token

   377

%token <ID>	fixed_point_d_token

   378

%token <ID>	integer_d_token

   379

%token <ID>	fixed_point_h_token

   380

%token <ID>	integer_h_token

   381

%token <ID>	fixed_point_m_token

   382

%token <ID>	integer_m_token

   383

%token <ID>	fixed_point_s_token

   384

%token <ID>	integer_s_token

   385

%token <ID>	fixed_point_ms_token

   386

%token <ID>	integer_ms_token

   387

   388

%token TIME

   389

%token T_SHARP

   390

   391

   392

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

   393

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

   394

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

   395

%type  <leaf>	time_of_day

   396

%type  <leaf>	daytime

   397

%type  <leaf>	day_hour

   398

%type  <leaf>	day_minute

   399

%type  <leaf>	day_second

   400

%type  <leaf>	date

   401

%type  <leaf>	date_literal

   402

%type  <leaf>	year

   403

%type  <leaf>	month

   404

%type  <leaf>	day

   405

%type  <leaf>	date_and_time

   406

   407

%token TIME_OF_DAY

   408

%token DATE

   409

%token D_SHARP

   410

%token DATE_AND_TIME

   411

   412

   413

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

   414

/* B 1.3 - Data Types */

   415

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

   416

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

   417

// %type  <leaf> data_type_name

   418

%type  <leaf> non_generic_type_name

   419

   420

   421

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

   422

/* B 1.3.1 - Elementary Data Types */

   423

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

   424

/* NOTES:

   425

 *

   426

 *    - To make the definition of bit_string_literal more

   427

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

   428

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

   429

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

   430

 *      Note that the definition of bit_string_type_name

   431

 *      (according to the spec) includes the above elements

   432

 *      and an extra BOOL.

   433

 *      We could use an extra construct with the first four

   434

 *      elements to be used solely in the definition of

   435

 *      bit_string_literal, but with the objective of not

   436

 *      having to replicate the actions (if we ever need

   437

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

   438

 *      bit_string_type_name and the extra grouping), we

   439

 *      have re-defined bit_string_type_name as only including

   440

 *      the first four elements.

   441

 *      In order to have our parser implement the specification

   442

 *      correctly we have augmented every occurence of

   443

 *      bit_string_type_name in other rules with the BOOL

   444

 *      token. Since bit_string_type_name only appears in

   445

 *      the rule for elementary_type_name, this does not

   446

 *      seem to be a big concession to make!

   447

 *

   448

 *    - We have added a helper symbol to concentrate the

   449

 *      instantiation of STRING and WSTRING into a single

   450

 *      location (elementary_string_type_name).

   451

 *      These two elements show up in several other rules,

   452

 *      but we want to create the equivalent abstract syntax

   453

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

   454

 *      possible future changes easier to edit...

   455

 */

   456

%type  <leaf>	elementary_type_name

   457

%type  <leaf>	numeric_type_name

   458

%type  <leaf>	integer_type_name

   459

%type  <leaf>	signed_integer_type_name

   460

%type  <leaf>	unsigned_integer_type_name

   461

%type  <leaf>	real_type_name

   462

%type  <leaf>	date_type_name

   463

%type  <leaf>	bit_string_type_name

   464

/* helper symbol to concentrate the instantiation

   465

 * of STRING and WSTRING into a single location

   466

 */

   467

%type  <leaf>	elementary_string_type_name

   468

   469

%token BYTE

   470

%token WORD

   471

%token DWORD

   472

%token LWORD

   473

   474

%token LREAL

   475

%token REAL

   476

   477

%token SINT

   478

%token INT

   479

%token DINT

   480

%token LINT

   481

   482

%token USINT

   483

%token UINT

   484

%token UDINT

   485

%token ULINT

   486

   487

%token WSTRING

   488

%token STRING

   489

%token BOOL

   490

   491

%token TIME

   492

%token DATE

   493

%token DATE_AND_TIME

   494

%token DT

   495

%token TIME_OF_DAY

   496

%token TOD

   497

   498

   499

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

   500

/* B 1.3.2 - Generic data types */

   501

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

   502

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

   503

// %type  <leaf>	generic_type_name

   504

   505

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

   506

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

   507

 */

   508

%token ANY

   509

%token ANY_DERIVED

   510

%token ANY_ELEMENTARY

   511

%token ANY_MAGNITUDE

   512

%token ANY_NUM

   513

%token ANY_REAL

   514

%token ANY_INT

   515

%token ANY_BIT

   516

%token ANY_STRING

   517

%token ANY_DATE

   518

   519

   520

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

   521

/* B 1.3.3 - Derived data types */

   522

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

   523

%type  <leaf>	derived_type_name

   524

%type  <leaf>	single_element_type_name

   525

// %type  <leaf>	simple_type_name

   526

// %type  <leaf>	subrange_type_name

   527

// %type  <leaf>	enumerated_type_name

   528

// %type  <leaf>	array_type_name