1

/*

     2

 * (c) 2003-2007 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, ST and SFC 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, as well as the textual version of SFC.

    31

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

    32

 *  compiler, is generated by runing 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

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

    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

   107

   108

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

   109

 * creating a new object for the abstract syntax tree.

   110

 */

   111

#define locloc(foo) foo.first_line, foo.first_column, foo.last_line, foo.last_column

   112

#define   locf(foo) foo.first_line, foo.first_column

   113

#define   locl(foo) foo.last_line,  foo.last_column

   114

   115

   116

   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

   137

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

   138

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

   139

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

   140

 *       option is to use global variables! yuck!

   141

 */

   142

   143

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

   144

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

   145

 * but disallows them in user code...

   146

 */

   147

extern bool allow_function_overloading;

   148

   149

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

   150

 * when printing out error messages...

   151

 */

   152

extern bool full_token_loc;

   153

   154

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

   155

 * by bison.

   156

 */

   157

extern symbol_c *tree_root;

   158

   159

   160

   161

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

   162

/* forward declarations */

   163

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

   164

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

   165

   166

/* Convert an il_operator_c into an identifier_c */

   167

symbol_c *il_operator_c_2_identifier_c(symbol_c *il_operator);

   168

   169

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

   170

bool is_current_syntax_token();

   171

   172

/* print an error message */

   173

void print_err_msg(int first_line,

   174

                   int first_column,

   175

                   int last_line,

   176

                   int last_column,

   177

                   const char *additional_error_msg);

   178

%}

   179

   180

   181

   182

   183

// %glr-parser

   184

// %expect-rr 1

   185

   186

   187

   188

   189

%union {

   190

    symbol_c 	*leaf;

   191

    list_c	*list;

   192

    char 	*ID;	/* token value */

   193

}

   194

   195

/*

   196

 TODO: DO we need to define a destructor do free

   197

       memory when recovering from errors, or do the

   198

       class destructors already handle this?

   199

       Following is example on how to define

   200

       detructors, using the syntax:

   201

       %destructor { CODE } SYMBOLS

   202

%union

   203

      {

   204

        char *string;

   205

      }

   206

      %token <string> STRING

   207

      %type  <string> string

   208

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

   209

*/

   210

   211

   212

   213

   214

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

   215

/* Prelimenary constructs... */

   216

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

   217

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

   218

 * after all includes have already been processed.

   219

 *

   220

 * Flex automatically returns the token with value 0

   221

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

   222

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

   223

 * to detect the very end of the input files.

   224

 */

   225

%token END_OF_INPUT 0

   226

   227

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

   228

/* USE 1:

   229

 * ======

   230

 * This token is currently also being used as the default

   231

 * initialisation value of the token_id member in

   232

 * the symbol_c base class.

   233

 *

   234

 * USE 2

   235

 * =====

   236

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

   237

 * mysterious reduce/reduce conflicts due to the fact

   238

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

   239

 * This means that bison cannot handle it without some

   240

 * caoxing from ourselves. We will then need this token

   241

 * to do the coaxing...

   242

 */

   243

%token BOGUS_TOKEN_ID

   244

   245

%type <leaf>	start

   246

   247

%type <leaf>	any_identifier

   248

   249

%token <ID>	prev_declared_variable_name_token

   250

%token <ID>	prev_declared_direct_variable_token

   251

%token <ID>	prev_declared_fb_name_token

   252

%type <leaf>	prev_declared_variable_name

   253

%type <leaf>	prev_declared_direct_variable

   254

%type <leaf>	prev_declared_fb_name

   255

   256

%token  <ID>	prev_declared_simple_type_name_token

   257

%token  <ID>	prev_declared_subrange_type_name_token

   258

%token  <ID>	prev_declared_enumerated_type_name_token

   259

%token  <ID>	prev_declared_array_type_name_token

   260

%token  <ID>	prev_declared_structure_type_name_token

   261

%token  <ID>	prev_declared_string_type_name_token

   262

   263

%type  <leaf>	prev_declared_simple_type_name

   264

%type  <leaf>	prev_declared_subrange_type_name

   265

%type  <leaf>	prev_declared_enumerated_type_name

   266

%type  <leaf>	prev_declared_array_type_name

   267

%type  <leaf>	prev_declared_structure_type_name

   268

%type  <leaf>	prev_declared_string_type_name

   269

   270

%token <ID>	prev_declared_derived_function_name_token

   271

%token <ID>	prev_declared_derived_function_block_name_token

   272

%token <ID>	prev_declared_program_type_name_token

   273

%type  <leaf>	prev_declared_derived_function_name

   274

%type  <leaf>	prev_declared_derived_function_block_name

   275

%type  <leaf>	prev_declared_program_type_name

   276

   277

   278

   279

   280

/* The pragmas... */

   281

%token <ID>	pragma_token

   282

%type <leaf>	pragma

   283

   284

   285

/* Where do these tokens belong ?? */

   286

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

   287

%token	EN

   288

%token	ENO

   289

%type <leaf>	en_param

   290

%type <leaf>	eno_param

   291

   292

   293

   294

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

   295

/* B 0 - Programming Model */

   296

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

   297

%type <list>	library

   298

%type <leaf>	library_element_declaration

   299

   300

   301

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

   302

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

   303

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

   304

/* Done totally within flex...

   305

  letter

   306

  digit

   307

  octal_digit

   308

  hex_digit

   309

*/

   310

%token <ID>	identifier_token

   311

%type  <leaf>	identifier

   312

   313

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

   314

/* B 1.2 - Constants */

   315

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

   316

%type <leaf>	constant

   317

/* a helper symbol for expression */

   318

%type  <leaf> non_negative_constant

   319

   320

   321

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

   322

/* B 1.2.1 - Numeric Literals */

   323

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

   324

/* Done totally within flex...

   325

  bit

   326

*/

   327

%type  <leaf> numeric_literal

   328

/* helper symbol for non_negative_constant */

   329

%type  <leaf> non_negative_numeric_literal

   330

%type  <leaf> integer_literal

   331

%type  <leaf> signed_integer

   332

/* a helper symbol for non_negative_constant */

   333

%type  <leaf> non_negative_signed_integer

   334

%token <ID>   integer_token

   335

%type  <leaf> integer

   336

%token <ID>   binary_integer_token

   337

%type  <leaf> binary_integer

   338

%token <ID>   octal_integer_token

   339

%type  <leaf> octal_integer

   340

%token <ID>   hex_integer_token

   341

%type  <leaf> hex_integer

   342

%token <ID>   real_token

   343

%type  <leaf> real

   344

%type  <leaf> signed_real

   345

/* helper symbol for non_negative_real_literal */

   346

%type  <leaf> non_negative_signed_real

   347

%type  <leaf> real_literal

   348

/* helper symbol for non_negative_numeric_literal */

   349

%type  <leaf> non_negative_real_literal

   350

// %type  <leaf> exponent

   351

%type  <leaf> bit_string_literal

   352

%type  <leaf> boolean_literal

   353

   354

%token FALSE

   355

%token TRUE

   356

   357

   358

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

   359

/* B 1.2.2 - Character Strings */

   360

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

   361

%token <ID>   single_byte_character_string_token

   362

%token <ID>   double_byte_character_string_token

   363

   364

%type  <leaf> character_string

   365

%type  <leaf> single_byte_character_string

   366

%type  <leaf> double_byte_character_string

   367

   368

   369

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

   370

/* B 1.2.3 - Time Literals */

   371

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

   372

%type  <leaf> time_literal

   373

   374

   375

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

   376

/* B 1.2.3.1 - Duration */

   377

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

   378

%type  <leaf>	duration

   379

%type  <leaf>	interval

   380

%type  <leaf>	days

   381

%type  <leaf>	fixed_point

   382

%type  <leaf>	hours

   383

%type  <leaf>	minutes

   384

%type  <leaf>	seconds

   385

%type  <leaf>	milliseconds

   386

   387

%type  <leaf>	integer_d

   388

%type  <leaf>	integer_h

   389

%type  <leaf>	integer_m

   390

%type  <leaf>	integer_s

   391

%type  <leaf>	integer_ms

   392

%type  <leaf>	fixed_point_d

   393

%type  <leaf>	fixed_point_h

   394

%type  <leaf>	fixed_point_m

   395

%type  <leaf>	fixed_point_s

   396

%type  <leaf>	fixed_point_ms

   397

   398

%token <ID>	fixed_point_token

   399

%token <ID>	fixed_point_d_token

   400

%token <ID>	integer_d_token

   401

%token <ID>	fixed_point_h_token

   402

%token <ID>	integer_h_token

   403

%token <ID>	fixed_point_m_token

   404

%token <ID>	integer_m_token

   405

%token <ID>	fixed_point_s_token

   406

%token <ID>	integer_s_token

   407

%token <ID>	fixed_point_ms_token

   408

%token <ID>	integer_ms_token

   409

   410

%token TIME

   411

%token T_SHARP

   412

   413

   414

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

   415

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

   416

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

   417

%type  <leaf>	time_of_day

   418

%type  <leaf>	daytime

   419

%type  <leaf>	day_hour

   420

%type  <leaf>	day_minute

   421

%type  <leaf>	day_second

   422

%type  <leaf>	date

   423

%type  <leaf>	date_literal

   424

%type  <leaf>	year

   425

%type  <leaf>	month

   426

%type  <leaf>	day

   427

%type  <leaf>	date_and_time

   428

   429

%token TIME_OF_DAY

   430

%token DATE

   431

%token D_SHARP

   432

%token DATE_AND_TIME

   433

   434

   435

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

   436

/* B 1.3 - Data Types */

   437

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

   438

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

   439

// %type  <leaf> data_type_name

   440

%type  <leaf> non_generic_type_name

   441

   442

   443

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

   444

/* B 1.3.1 - Elementary Data Types */

   445

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

   446

/* NOTES:

   447

 *

   448

 *    - To make the definition of bit_string_literal more

   449

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

   450

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

   451

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

   452

 *      Note that the definition of bit_string_type_name

   453

 *      (according to the spec) includes the above elements

   454

 *      and an extra BOOL.

   455

 *      We could use an extra construct with the first four

   456

 *      elements to be used solely in the definition of

   457

 *      bit_string_literal, but with the objective of not

   458

 *      having to replicate the actions (if we ever need

   459

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

   460

 *      bit_string_type_name and the extra grouping), we

   461

 *      have re-defined bit_string_type_name as only including

   462

 *      the first four elements.

   463

 *      In order to have our parser implement the specification

   464

 *      correctly we have augmented every occurence of

   465

 *      bit_string_type_name in other rules with the BOOL

   466

 *      token. Since bit_string_type_name only appears in

   467

 *      the rule for elementary_type_name, this does not

   468

 *      seem to be a big concession to make!

   469

 *

   470

 *    - We have added a helper symbol to concentrate the

   471

 *      instantiation of STRING and WSTRING into a single

   472

 *      location (elementary_string_type_name).

   473

 *      These two elements show up in several other rules,

   474

 *      but we want to create the equivalent abstract syntax

   475

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

   476

 *      possible future changes easier to edit...

   477

 */

   478

%type  <leaf>	elementary_type_name

   479

%type  <leaf>	numeric_type_name

   480

%type  <leaf>	integer_type_name

   481

%type  <leaf>	signed_integer_type_name

   482

%type  <leaf>	unsigned_integer_type_name

   483

%type  <leaf>	real_type_name

   484

%type  <leaf>	date_type_name

   485

%type  <leaf>	bit_string_type_name

   486

/* helper symbol to concentrate the instantiation

   487

 * of STRING and WSTRING into a single location

   488

 */

   489

%type  <leaf>	elementary_string_type_name

   490

   491

%token BYTE

   492

%token WORD

   493

%token DWORD

   494

%token LWORD

   495

   496

%token LREAL

   497

%token REAL

   498

   499

%token SINT

   500

%token INT

   501

%token DINT

   502

%token LINT

   503

   504

%token USINT

   505

%token UINT

   506

%token UDINT

   507

%token ULINT

   508

   509

%token WSTRING

   510

%token STRING

   511

%token BOOL

   512

   513

// %token TIME

   514

// %token DATE

   515

// %token DATE_AND_TIME

   516

%token DT

   517

// %token TIME_OF_DAY

   518