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

/* NOTE: the following file contains many rules used merely for detecting errors in

    62

 * the IEC source code being parsed.

    63

 * To remove all these rules, simply execute the command (first replace all '%' with '/'):

    64

 * $sed '\:%\* ERROR_CHECK_BEGIN \*%:,\:%\* ERROR_CHECK_END \*%: d' iec_bison.yy

    65

 *

    66

 * The above command had to be edited ('/' replaced by '%') so as not to include the C syntax that closes

    67

 * comments inside this comment!

    68

 * If you place the command in a shell script, be sure to remove the backslashes '\' before each asterisk '*' !!

    69

 */

    70

    71

    72

    73

    74

    75

%{

    76

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

    77

    78

    79

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

    80

int yylex(void);

    81

    82

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

    83

void yyerror (const char *error_msg);

    84

    85

/* produce a more verbose parsing error message */

    86

#define YYERROR_VERBOSE

    87

    88

/* Include debuging code.

    89

 * Printing of debug info must then be activated by setting

    90

 * the variable yydebug to 1.

    91

 */

    92

#define YYDEBUG 0

    93

    94

    95

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

    96

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

    97

    98

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

    99

#include "iec_bison.h"

   100

   101

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

   102

#include "stage1_2_priv.hh"

   103

#include "create_enumtype_conversion_functions.hh"

   104

   105

#include "../absyntax_utils/add_en_eno_param_decl.hh"	/* required for  add_en_eno_param_decl_c */

   106

   107

/* an ugly hack!!

   108

 * We will probably not need it when we decide

   109

 *  to cut down the abstract syntax down to size.

   110

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

   111

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

   112

 *  we might just find out that we really do need

   113

 *  the abstract syntax tree to stay as it is

   114

 *  afterall!

   115

 */

   116

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

   117

 * execute the code <code>

   118

 */

   119

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

   120

  symbol_c *elem;					\

   121

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

   122

    elem = list->elements[i];				\

   123

    code;						\

   124

  }							\

   125

}

   126

   127

   128

   129

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

   130

 * creating a new object for the abstract syntax tree.

   131

 */

   132

#define locloc(foo) foo.first_line, foo.first_column, foo.first_file, foo.first_order, foo.last_line, foo.last_column, foo.last_file, foo.last_order

   133

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

   134

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

   135

   136

/* Redefine the default action to take for each rule, so that the filenames are correctly processed... */

   137

# define YYLLOC_DEFAULT(Current, Rhs, N)                                \

   138

         do                                                                  \

   139

           if (N)                                                            \

   140

             {                                                               \

   141

               (Current).first_line   = YYRHSLOC(Rhs, 1).first_line;         \

   142

               (Current).first_column = YYRHSLOC(Rhs, 1).first_column;       \

   143

               (Current).first_file   = YYRHSLOC(Rhs, 1).first_file;         \

   144

               (Current).first_order  = YYRHSLOC(Rhs, 1).first_order;        \

   145

               (Current).last_line    = YYRHSLOC(Rhs, N).last_line;          \

   146

               (Current).last_column  = YYRHSLOC(Rhs, N).last_column;        \

   147

               (Current).last_file    = YYRHSLOC(Rhs, 1).last_file;          \

   148

               (Current).last_order   = YYRHSLOC(Rhs, 1).last_order;         \

   149

             }                                                               \

   150

           else                                                              \

   151

             {                                                               \

   152

               (Current).first_line   = (Current).last_line   =              \

   153

                 YYRHSLOC(Rhs, 0).last_line;                                 \

   154

               (Current).first_column = (Current).last_column =              \

   155

                 YYRHSLOC(Rhs, 0).last_column;                               \

   156

               (Current).first_file   = (Current).last_file   =              \

   157

                 YYRHSLOC(Rhs, 0).last_file;                                 \

   158

               (Current).first_order  = (Current).last_order  =              \

   159

                 YYRHSLOC(Rhs, 0).last_order;                                \

   160

             }                                                               \

   161

         while (0)

   162

   163

   164

#include "../main.hh" // required for ERROR() and ERROR_MSG() macros.

   165

   166

   167

   168

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

   169

/* global variables...   */

   170

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

   171

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

   172

 *       in the iec_bison.h file, which is in turn included by flex.

   173

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

   174

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

   175

 *       would get a new variable defined each time iec_bison.h is included!).

   176

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

   177

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

   178

 */

   179

   180

   181

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

   182

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

   183

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

   184

 *       option is to use global variables! yuck!

   185

 */

   186

   187

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

   188

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

   189

 * but disallows them in user code...

   190

 */

   191

extern bool allow_function_overloading;

   192

   193

/* A flag to tell the compiler whether to allow the declaration

   194

 * of extensible function (i.e. functions that may have a variable number of

   195

 * input parameters, such as AND(word#33, word#44, word#55, word#66).

   196

 * This is an extension to the standard syntax.

   197

 * See comments below for details why we support this!

   198

 */

   199

extern bool allow_extensible_function_parameters;

   200

   201

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

   202

 * when printing out error messages...

   203

 */

   204

extern bool full_token_loc;

   205

   206

/* A global flag used to tell the parser whether to generate conversion function

   207

 * for enumerated data types.

   208

 */

   209

extern bool conversion_functions_;

   210

   211

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

   212

 * by bison.

   213

 */

   214

extern symbol_c *tree_root;

   215

   216

   217

   218

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

   219

/* forward declarations */

   220

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

   221

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

   222

   223

/* Convert an il_operator_c into an identifier_c */

   224

symbol_c *il_operator_c_2_identifier_c(symbol_c *il_operator);

   225

   226

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

   227

/* ERROR_CHECK_BEGIN */

   228

bool is_current_syntax_token();

   229

/* ERROR_CHECK_END */

   230

   231

/* print an error message */

   232

void print_err_msg(int first_line,

   233

                   int first_column,

   234

                   const char *first_filename,

   235

                   long int first_order,

   236

                   int last_line,

   237

                   int last_column,

   238

                   const char *last_filename,

   239

                   long int last_order,

   240

                   const char *additional_error_msg);    

   241

%}

   242

   243

   244

   245

   246

// %glr-parser

   247

// %expect-rr 1

   248

   249

   250

/* The following definitions need to be inside a '%code requires' 

   251

 * so that they are also included in the header files. If this were not the case,

   252

 * YYLTYPE would be delcared as something in the iec.cc file, and another thing

   253

 * (actually the default value of YYLTYPE) in the iec_bison.h heder file.

   254

 */

   255

%code requires {

   256

/* define a new data type to store the locations, so we can also store

   257

 * the filename in which the token is expressed.

   258

 */

   259

/* NOTE: since this code will be placed in the iec_bison.h header file,

   260

 * as well as the iec.cc file that also includes the iec_bison.h header file,

   261

 * declaring the typedef struct yyltype__local here would result in a 

   262

 * compilation error when compiling iec.cc, as this struct would be

   263

 * declared twice.

   264

 * We therefore use the #if !defined YYLTYPE ...

   265

 * to make sure only the first declaration is parsed by the C++ compiler.

   266

 */

   267

#if ! defined YYLTYPE && ! defined YYLTYPE_IS_DECLARED

   268

typedef struct YYLTYPE {

   269

    int         first_line;

   270

    int         first_column;

   271

    const char *first_file;

   272

    long int    first_order;

   273

    int         last_line;

   274

    int         last_column;

   275

    const char *last_file;

   276

    long int    last_order;

   277

} YYLTYPE;

   278

#define YYLTYPE_IS_DECLARED 1

   279

#define YYLTYPE_IS_TRIVIAL 0

   280

#endif

   281

   282

}

   283

   284

   285

   286

%union {

   287

    symbol_c 	*leaf;

   288

    list_c	*list;

   289

    char 	*ID;	/* token value */

   290

}

   291

   292

/*

   293

 TODO: DO we need to define a destructor do free

   294

       memory when recovering from errors, or do the

   295

       class destructors already handle this?

   296

       Following is example on how to define

   297

       detructors, using the syntax:

   298

       %destructor { CODE } SYMBOLS

   299

%union

   300

      {

   301

        char *string;

   302

      }

   303

      %token <string> STRING

   304

      %type  <string> string

   305

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

   306

*/

   307

   308

   309

   310

   311

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

   312

/* Prelimenary helpful constructs... */

   313

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

   314

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

   315

 * after all includes have already been processed.

   316

 *

   317

 * Flex automatically returns the token with value 0

   318

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

   319

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

   320

 * to detect the very end of the input files.

   321

 */

   322

%token END_OF_INPUT 0

   323

   324

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

   325

/* USE 1:

   326

 * ======

   327

 * This token is currently also being used as the default

   328

 * initialisation value of the token_id member in

   329

 * the symbol_c base class.

   330

 *

   331

 * USE 2

   332

 * =====

   333

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

   334

 * mysterious reduce/reduce conflicts due to the fact

   335

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

   336

 * This means that bison cannot handle it without some

   337

 * caoxing from ourselves. We will then need this token

   338

 * to do the coaxing...

   339

 */

   340

%token BOGUS_TOKEN_ID

   341

   342

%type <leaf>	start

   343

   344

%type <leaf>	any_identifier

   345

   346

%token <ID>	prev_declared_variable_name_token

   347

%token <ID>	prev_declared_direct_variable_token

   348

%token <ID>	prev_declared_fb_name_token

   349

%type <leaf>	prev_declared_variable_name

   350

%type <leaf>	prev_declared_direct_variable

   351

%type <leaf>	prev_declared_fb_name

   352

   353

%token  <ID>	prev_declared_simple_type_name_token

   354

%token  <ID>	prev_declared_subrange_type_name_token

   355

%token  <ID>	prev_declared_enumerated_type_name_token

   356

%token  <ID>	prev_declared_array_type_name_token

   357

%token  <ID>	prev_declared_structure_type_name_token

   358

%token  <ID>	prev_declared_string_type_name_token

   359

   360

%type  <leaf>	prev_declared_simple_type_name

   361

%type  <leaf>	prev_declared_subrange_type_name

   362

%type  <leaf>	prev_declared_enumerated_type_name

   363

%type  <leaf>	prev_declared_array_type_name

   364

%type  <leaf>	prev_declared_structure_type_name

   365

%type  <leaf>	prev_declared_string_type_name

   366

   367

%token <ID>	prev_declared_derived_function_name_token

   368

%token <ID>	prev_declared_derived_function_block_name_token

   369

%token <ID>	prev_declared_program_type_name_token

   370

%type  <leaf>	prev_declared_derived_function_name

   371

%type  <leaf>	prev_declared_derived_function_block_name

   372

%type  <leaf>	prev_declared_program_type_name

   373

   374

   375

   376

   377

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

   378

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

   379

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

   380

   381

/* Pragmas that our compiler will accept.

   382

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

   383

 */

   384

%token          disable_code_generation_pragma_token

   385

%token          enable_code_generation_pragma_token

   386

%type <leaf>	disable_code_generation_pragma

   387

%type <leaf>	enable_code_generation_pragma

   388

   389

   390

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

   391

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

   392

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

   393

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

   394

 */

   395

%token <ID>	pragma_token

   396

%type <leaf>	pragma

   397

   398

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

   399

%type <leaf>	any_pragma

   400

   401

   402

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

   403

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

   404

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

   405

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

   406

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

   407

 *

   408

 * please read the comment above the definition of 'variable' in section B1.4 for details.

   409

 */

   410

%token	EN

   411

%token	ENO

   412

%type <leaf>	en_identifier

   413

%type <leaf>	eno_identifier

   414

   415

   416

   417

   418

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

   419

/* B 0 - Programming Model */

   420

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

   421

%type <list>	library

   422

%type <leaf>	library_element_declaration

   423

   424

   425

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

   426

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

   427

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

   428

/* Done totally within flex...

   429

  letter

   430

  digit

   431

  octal_digit

   432

  hex_digit

   433

*/

   434

%token <ID>	identifier_token

   435

%type  <leaf>	identifier

   436

   437

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

   438

/* B 1.2 - Constants */

   439

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

   440

%type <leaf>	constant

   441

%type <leaf>	non_int_or_real_constant

   442

   443

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

   444

/* B 1.2.1 - Numeric Literals */

   445

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

   446

/* Done totally within flex...

   447

  bit

   448

*/

   449

%type  <leaf> numeric_literal

   450

%type  <leaf> integer_literal

   451

%type  <leaf> signed_integer

   452

%token <ID>   integer_token

   453

%type  <leaf> integer

   454

%token <ID>   binary_integer_token

   455

%type  <leaf> binary_integer

   456

%token <ID>   octal_integer_token

   457

%type  <leaf> octal_integer

   458

%token <ID>   hex_integer_token

   459

%type  <leaf> hex_integer

   460

%token <ID>   real_token

   461

%type  <leaf> real

   462

%type  <leaf> signed_real

   463

%type  <leaf> real_literal

   464

// %type  <leaf> exponent

   465

%type  <leaf> bit_string_literal

   466

%type  <leaf> boolean_literal

   467

   468

%token safeboolean_true_literal_token

   469

%token safeboolean_false_literal_token

   470

%token boolean_true_literal_token

   471

%token boolean_false_literal_token

   472

   473

%token FALSE

   474

%token TRUE

   475

   476

   477

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

   478

/* B 1.2.2 - Character Strings */

   479

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

   480

%token <ID>   single_byte_character_string_token

   481

%token <ID>   double_byte_character_string_token

   482

   483

%type  <leaf> character_string

   484

%type  <leaf> single_byte_character_string

   485

%type  <leaf> double_byte_character_string

   486

   487

   488

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

   489

/* B 1.2.3 - Time Literals */

   490

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

   491

%type  <leaf> time_literal

   492

   493

   494

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

   495

/* B 1.2.3.1 - Duration */

   496

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

   497

%type  <leaf>	duration

   498

%type  <leaf>	interval

   499

%type  <leaf>	days

   500

%type  <leaf>	fixed_point

   501

%type  <leaf>	hours

   502

%type  <leaf>	minutes

   503

%type  <leaf>	seconds

   504

%type  <leaf>	milliseconds