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/*

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 *  matiec - a compiler for the programming languages defined in IEC 61131-3

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 *

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 *  Copyright (C) 2009-2012  Mario de Sousa (msousa@fe.up.pt)

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 *  Copyright (C) 2012       Manuele Conti (manuele.conti@sirius-es.it)

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 *  Copyright (C) 2012       Matteo Facchinetti (matteo.facchinetti@sirius-es.it)

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 *

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 *  This program is free software: you can redistribute it and/or modify

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 *  it under the terms of the GNU General Public License as published by

    10

 *  the Free Software Foundation, either version 3 of the License, or

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 *  (at your option) any later version.

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 *

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 *  This program is distributed in the hope that it will be useful,

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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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 *  You should have received a copy of the GNU General Public License

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 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

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 *

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 *

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 * This code is made available on the understanding that it will not be

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 * used in safety-critical situations without a full and competent review.

    24

 */

    25

    26

/*

    27

 * An IEC 61131-3 compiler.

    28

 *

    29

 * Based on the

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 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

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 *

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 */

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    34

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/*

    36

 *  Narrow class select and store a data type from candidate data types list for all symbols

    37

 */

    38

    39

#include "narrow_candidate_datatypes.hh"

    40

#include "datatype_functions.hh"

    41

#include <typeinfo>

    42

#include <list>

    43

#include <string>

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#include <string.h>

    45

#include <strings.h>

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    47

    48

/* set to 1 to see debug info during execution */

    49

static int debug = 0;

    50

    51

narrow_candidate_datatypes_c::narrow_candidate_datatypes_c(symbol_c *ignore) {

    52

}

    53

    54

narrow_candidate_datatypes_c::~narrow_candidate_datatypes_c(void) {

    55

}

    56

    57

    58

/* Only set the symbol's desired datatype to 'datatype' if that datatype is in the candidate_datatype list */

    59

static void set_datatype(symbol_c *datatype, symbol_c *symbol) {

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	symbol->datatype = NULL;   

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	if (search_in_candidate_datatype_list(datatype, symbol->candidate_datatypes) >= 0)

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		symbol->datatype = datatype;  

    63

}

    64

    65

    66

    74

    75

bool narrow_candidate_datatypes_c::is_widening_compatible(symbol_c *left_type, symbol_c *right_type, symbol_c *result_type, const struct widen_entry widen_table[]) {

    76

	for (int k = 0; NULL != widen_table[k].left;  k++) {

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		if        ((typeid(*left_type)   == typeid(*widen_table[k].left))

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		        && (typeid(*right_type)  == typeid(*widen_table[k].right))

    79

				&& (typeid(*result_type) == typeid(*widen_table[k].result))) {

    80

			return true;

    81

		}

    82

	}

    83

	return false;

    84

}

    85

    86

/*

    87

 * All parameters being passed to the called function MUST be in the parameter list to which f_call points to!

    88

 * This means that, for non formal function calls in IL, de current (default value) must be artificially added to the

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 * beginning of the parameter list BEFORE calling handle_function_call().

    90

 */

    91

void narrow_candidate_datatypes_c::narrow_nonformal_call(symbol_c *f_call, symbol_c *f_decl, int *ext_parm_count) {

    92

	symbol_c *call_param_value,  *param_type;

    93

	identifier_c *param_name;

    94

	function_param_iterator_c       fp_iterator(f_decl);

    95

	function_call_param_iterator_c fcp_iterator(f_call);

    96

	int extensible_parameter_highest_index = -1;

    97

	unsigned int i;

    98

    99

	if (NULL != ext_parm_count) *ext_parm_count = -1;

   100

   101

	/* Iterating through the non-formal parameters of the function call */

   102

	while((call_param_value = fcp_iterator.next_nf()) != NULL) {

   103

		/* Obtaining the type of the value being passed in the function call */

   104

		/* Iterate to the next parameter of the function being called.

   105

		 * Get the name of that parameter, and ignore if EN or ENO.

   106

		 */

   107

		do {

   108

			param_name = fp_iterator.next();

   109

			/* If there is no other parameter declared, then we are passing too many parameters... */

   110

			/* This error should have been caught in fill_candidate_datatypes_c, but may occur here again when we handle FB invocations! 

   111

			 * In this case, we carry on analysing the code in order to be able to provide relevant error messages

   112

			 * for that code too!

   113

			 */

   114

			if(param_name == NULL) break;

   115

		} while ((strcmp(param_name->value, "EN") == 0) || (strcmp(param_name->value, "ENO") == 0));

   116

   117

		/* Set the desired datatype for this parameter, and call it recursively. */

   118

		/* Note that if the call has more parameters than those declared in the function/FB declaration,

   119

		 * we may be setting this to NULL!

   120

		 */

   121

		symbol_c *desired_datatype = base_type(fp_iterator.param_type());

   122

		if ((NULL != param_name) && (NULL == desired_datatype)) ERROR;

   123

		if ((NULL == param_name) && (NULL != desired_datatype)) ERROR;

   124

   125

		/* NOTE: When we are handling a nonformal function call made from IL, the first parameter is the 'default' or 'current'

   126

		 *       il value. However, a pointer to a copy of the prev_il_instruction is pre-pended into the operand list, so 

   127

		 *       the call 

   128

		 *       call_param_value->accept(*this);

   129

		 *       may actually be calling an object of the base symbol_c .

   130

		 */

   131

		set_datatype(desired_datatype, call_param_value);

   132

		call_param_value->accept(*this);

   133

   134

		if (NULL != param_name) 

   135

			if (extensible_parameter_highest_index < fp_iterator.extensible_param_index())

   136

				extensible_parameter_highest_index = fp_iterator.extensible_param_index();

   137

	}

   138

	/* In the case of a call to an extensible function, we store the highest index 

   139

	 * of the extensible parameters this particular call uses, in the symbol_c object

   140

	 * of the function call itself!

   141

	 * In calls to non-extensible functions, this value will be set to -1.

   142

	 * This information is later used in stage4 to correctly generate the

   143

	 * output code.

   144

	 */

   145

	if ((NULL != ext_parm_count) && (extensible_parameter_highest_index >=0) /* if call to extensible function */)

   146

		*ext_parm_count = 1 + extensible_parameter_highest_index - fp_iterator.first_extensible_param_index();

   147

}

   148

   149

   150

   151

void narrow_candidate_datatypes_c::narrow_formal_call(symbol_c *f_call, symbol_c *f_decl, int *ext_parm_count) {

   152

	symbol_c *call_param_value, *call_param_name, *param_type;

   153

	symbol_c *verify_duplicate_param;

   154

	identifier_c *param_name;

   155

	function_param_iterator_c       fp_iterator(f_decl);

   156

	function_call_param_iterator_c fcp_iterator(f_call);

   157

	int extensible_parameter_highest_index = -1;

   158

	identifier_c *extensible_parameter_name;

   159

	unsigned int i;

   160

   161

	if (NULL != ext_parm_count) *ext_parm_count = -1;

   162

	/* Iterating through the formal parameters of the function call */

   163

	while((call_param_name = fcp_iterator.next_f()) != NULL) {

   164

   165

		/* Obtaining the value being passed in the function call */

   166

		call_param_value = fcp_iterator.get_current_value();

   167

		/* the following should never occur. If it does, then we have a bug in our code... */

   168

		if (NULL == call_param_value) ERROR;

   169

   170

		/* Find the corresponding parameter in function declaration */

   171

		param_name = fp_iterator.search(call_param_name);

   172

   173

		/* Set the desired datatype for this parameter, and call it recursively. */

   174

		/* NOTE: When handling a FB call, this narrow_formal_call() may be called to analyse

   175

		 *       an invalid FB call (call with parameters that do not exist on the FB declaration).

   176

		 *       For this reason, the param_name may come out as NULL!

   177

		 */

   178

		symbol_c *desired_datatype = base_type(fp_iterator.param_type());

   179

		if ((NULL != param_name) && (NULL == desired_datatype)) ERROR;

   180

		if ((NULL == param_name) && (NULL != desired_datatype)) ERROR;

   181

   182

		/* set the desired data type for this parameter */

   183

		set_datatype(desired_datatype, call_param_value);

   184

		/* And recursively call that parameter/expression, so it can propagate that info */

   185

		call_param_value->accept(*this);

   186

   187

		/* set the extensible_parameter_highest_index, which will be needed in stage 4 */

   188

		/* This value says how many extensible parameters are being passed to the standard function */

   189

		if (NULL != param_name) 

   190

			if (extensible_parameter_highest_index < fp_iterator.extensible_param_index())

   191

				extensible_parameter_highest_index = fp_iterator.extensible_param_index();

   192

	}

   193

	/* call is compatible! */

   194

   195

	/* In the case of a call to an extensible function, we store the highest index 

   196

	 * of the extensible parameters this particular call uses, in the symbol_c object

   197

	 * of the function call itself!

   198

	 * In calls to non-extensible functions, this value will be set to -1.

   199

	 * This information is later used in stage4 to correctly generate the

   200

	 * output code.

   201

	 */

   202

	if ((NULL != ext_parm_count) && (extensible_parameter_highest_index >=0) /* if call to extensible function */)

   203

		*ext_parm_count = 1 + extensible_parameter_highest_index - fp_iterator.first_extensible_param_index();

   204

}

   205

   206

   207

/*

   208

typedef struct {

   209

  symbol_c *function_name,

   210

  symbol_c *nonformal_operand_list,

   211

  symbol_c *   formal_operand_list,

   212

   213

  std::vector <symbol_c *> &candidate_functions,  

   214

  symbol_c &*called_function_declaration,

   215

  int      &extensible_param_count

   216

} generic_function_call_t;

   217

*/

   218

void narrow_candidate_datatypes_c::narrow_function_invocation(symbol_c *fcall, generic_function_call_t fcall_data) {

   219

	/* set the called_function_declaration. */

   220

	fcall_data.called_function_declaration = NULL;

   221

   222

	/* set the called_function_declaration taking into account the datatype that we need to return */

   223

	for(unsigned int i = 0; i < fcall->candidate_datatypes.size(); i++) {

   224

		if (is_type_equal(fcall->candidate_datatypes[i], fcall->datatype)) {

   225

			fcall_data.called_function_declaration = fcall_data.candidate_functions[i];

   226

			break;

   227

		}

   228

	}

   229

   230

	/* NOTE: If we can't figure out the declaration of the function being called, this is not 

   231

	 *       necessarily an internal compiler error. It could be because the symbol->datatype is NULL

   232

	 *       (because the ST code being analysed has an error _before_ this function invocation).

   233

	 *       However, we don't just give, up, we carry on recursivly analysing the code, so as to be

   234

	 *       able to print out any error messages related to the parameters being passed in this function 

   235

	 *       invocation.

   236

	 */

   237

	/* if (NULL == symbol->called_function_declaration) ERROR; */

   238

	if (fcall->candidate_datatypes.size() == 1) {

   239

		/* If only one function declaration, then we use that (even if symbol->datatypes == NULL)

   240

		 * so we can check for errors in the expressions used to pass parameters in this

   241

		 * function invocation.

   242

		 */

   243

		fcall_data.called_function_declaration = fcall_data.candidate_functions[0];

   244

	}

   245

   246

	/* If an overloaded function is being invoked, and we cannot determine which version to use,

   247

	 * then we can not meaningfully verify the expressions used inside that function invocation.

   248

	 * We simply give up!

   249

	 */

   250

	if (NULL == fcall_data.called_function_declaration)

   251

		return;

   252

   253

	if (NULL != fcall_data.nonformal_operand_list)  narrow_nonformal_call(fcall, fcall_data.called_function_declaration, &(fcall_data.extensible_param_count));

   254

	if (NULL != fcall_data.   formal_operand_list)     narrow_formal_call(fcall, fcall_data.called_function_declaration, &(fcall_data.extensible_param_count));

   255

   256

	return;

   257

}

   258

   259

   260

   261

   262

/* narrow implicit FB call in IL.

   263

 * e.g.  CLK ton_var

   264

 *        CU counter_var

   265

 *

   266

 * The algorithm will be to build a fake il_fb_call_c equivalent to the implicit IL FB call, and let 

   267

 * the visit(il_fb_call_c *) method handle it!

   268

 */

   269

void *narrow_candidate_datatypes_c::narrow_implicit_il_fb_call(symbol_c *il_instruction, const char *param_name, symbol_c *&called_fb_declaration) {

   270

   271

	/* set the datatype of the il_operand, this is, the FB being called! */

   272

	if (NULL != il_operand) {

   273

		/* only set it if it is in the candidate datatypes list! */  

   274

		set_datatype(called_fb_declaration, il_operand);

   275

		il_operand->accept(*this);

   276

	}

   277

	symbol_c *fb_decl = il_operand->datatype;

   278

   279

	if (NULL == prev_il_instruction) {

   280

		/* This IL implicit FB call (e.g. CLK ton_var) is not preceded by another IL instruction

   281

		 * (or list of instructions) that will set the IL current/default value.

   282

		 * We cannot proceed verifying type compatibility of something that does not exist.

   283

		 */

   284

		return NULL;

   285

	}

   286

   287

	if (NULL == fb_decl) {

   288

		/* the il_operand is a not FB instance */

   289

		/* so we simply pass on the required datatype to the prev_il_instruction */

   290

		/* The invalid FB invocation will be caught by the print_datatypes_error_c by analysing NULL value in il_operand->datatype! */

   291

		prev_il_instruction->datatype = il_instruction->datatype;

   292

		return NULL;

   293

	}

   294

   295

   296

	/* The value being passed to the 'param_name' parameter is actually the prev_il_instruction.

   297

	 * However, we do not place that object directly in the fake il_param_list_c that we will be

   298

	 * creating, since the visit(il_fb_call_c *) method will recursively call every object in that list.

   299

	 * The il_prev_intruction object will be visited once we have handled this implici IL FB call

   300

	 * (called from the instruction_list_c for() loop that works backwards). We DO NOT want to visit it twice.

   301

	 * (Anyway, if we let the visit(il_fb_call_c *) recursively visit the current prev_il_instruction, this pointer

   302

	 * would be changed to the IL instruction coming before the current prev_il_instruction! => things would get all messed up!)

   303

	 * The easiest way to work around this is to simply use a new object, and copy the relevant details to that object!

   304

	 */

   305

	symbol_c param_value = *prev_il_instruction;

   306

   307

	identifier_c variable_name(param_name);

   308

	// SYM_REF1(il_assign_operator_c, variable_name)

   309

	il_assign_operator_c il_assign_operator(&variable_name);  

   310

	// SYM_REF3(il_param_assignment_c, il_assign_operator, il_operand, simple_instr_list)

   311

	il_param_assignment_c il_param_assignment(&il_assign_operator, &param_value/*il_operand*/, NULL);

   312

	il_param_list_c il_param_list;

   313

	il_param_list.add_element(&il_param_assignment);

   314

	// SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list, symbol_c *called_fb_declaration)

   315

	CAL_operator_c CAL_operator;

   316

	il_fb_call_c il_fb_call(&CAL_operator, il_operand, NULL, &il_param_list);

   317

   318

	/* A FB call does not return any datatype, but the IL instructions that come after this

   319

	 * FB call may require a specific datatype in the il current/default variable, 

   320

	 * so we must pass this information up to the IL instruction before the FB call, since it will

   321

	 * be that IL instruction that will be required to produce the desired dtataype.

   322

	 *

   323

	 * The above will be done by the visit(il_fb_call_c *) method, so we must make sure to

   324

	 * correctly set up the il_fb_call.datatype variable!

   325

	 */

   326

// 	copy_candidate_datatype_list(il_instruction/*from*/, &il_fb_call/*to*/);

   327

	il_fb_call.called_fb_declaration = called_fb_declaration;

   328

	il_fb_call.accept(*this);

   329

   330

	/* set the required datatype of the previous IL instruction! */

   331

	/* NOTE:

   332

	 * When handling these implicit IL calls, the parameter_value being passed to the FB parameter

   333

	 * is actually the prev_il_instruction.

   334

	 * 

   335

	 * However, since the FB call does not change the value in the current/default IL variable, this value

   336

	 * must also be used ny the IL instruction coming after this FB call.

   337

	 *

   338

	 * This means that we have two consumers/users for the same value. 

   339

	 * We must therefore check whether the datatype required by the IL instructions following this FB call 

   340

	 * is the same as that required for the first parameter. If not, then we have a semantic error,

   341

	 * and we set it to NULL.

   342

	 *

   343

	 * However, we only do that if:

   344

	 *  - The IL instruction that comes after this IL FB call actually asked this FB call for a specific 

   345

	 *     datatype in the current/default vairable, once this IL FB call returns.

   346

	 *     However, sometimes, (for e.g., this FB call is the last in the IL list) the subsequent FB to not aks this

   347

	 *     FB call for any datatype. In that case, then the datatype required to pass to the first parameter of the

   348

	 *     FB call must be left unchanged!

   349

	 */

   350

	if ((NULL == il_instruction->datatype) || (is_type_equal(param_value.datatype, il_instruction->datatype))) {

   351

		prev_il_instruction->datatype = param_value.datatype;

   352

	} else {

   353

		prev_il_instruction->datatype = NULL;

   354

	}

   355

	return NULL;

   356

}

   357

   358

   359

/* a helper function... */

   360

symbol_c *narrow_candidate_datatypes_c::base_type(symbol_c *symbol) {

   361

	/* NOTE: symbol == NULL is valid. It will occur when, for e.g., an undefined/undeclared symbolic_variable is used

   362

	 *       in the code.

   363

	 */

   364

	if (symbol == NULL) return NULL;

   365

	return (symbol_c *)symbol->accept(search_base_type);	

   366

}

   367

   368

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

   369

/* B 1.2 - Constants */

   370

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

   371

   372

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

   373

/* B 1.3 - Data types */

   374

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

   375

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

   376

/* B 1.3.3 - Derived data types */

   377

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

   378

/*  signed_integer DOTDOT signed_integer */

   379

// SYM_REF2(subrange_c, lower_limit, upper_limit)

   380

void *narrow_candidate_datatypes_c::visit(subrange_c *symbol) {

   381

	symbol->lower_limit->datatype = symbol->datatype;

   382

	symbol->lower_limit->accept(*this);

   383

	symbol->upper_limit->datatype = symbol->datatype;

   384

	symbol->upper_limit->accept(*this);

   385

	return NULL;

   386

}

   387

   388

/* simple_specification ASSIGN constant */

   389

// SYM_REF2(simple_spec_init_c, simple_specification, constant)

   390

void *narrow_candidate_datatypes_c::visit(simple_spec_init_c *symbol) {

   391

	symbol_c *datatype = base_type(symbol->simple_specification); 

   392

	if (NULL != symbol->constant) {

   393

		int typeoffset = search_in_candidate_datatype_list(datatype, symbol->constant->candidate_datatypes);

   394

		if (typeoffset >= 0)

   395

			symbol->constant->datatype = symbol->constant->candidate_datatypes[typeoffset];

   396

	}

   397

	return NULL;

   398

}

   399

   400

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

   401

/* B 1.4 - Variables */

   402

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

   403

   404

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

   405

/* B 1.4.1 - Directly Represented Variables */

   406

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

   407

   408

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

   409

/* B 1.4.2 - Multi-element variables */

   410

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

   411

/*  subscripted_variable '[' subscript_list ']' */

   412

// SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   413

void *narrow_candidate_datatypes_c::visit(array_variable_c *symbol) {

   414

	/* we need to check the data types of the expressions used for the subscripts... */

   415

	symbol->subscript_list->accept(*this);

   416

	return NULL;

   417

}

   418

   419

   420

/* subscript_list ',' subscript */

   421

// SYM_LIST(subscript_list_c)

   422

void *narrow_candidate_datatypes_c::visit(subscript_list_c *symbol) {

   423

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

   424

		for (unsigned int k = 0; k < symbol->elements[i]->candidate_datatypes.size(); k++) {

   425

			if (is_ANY_INT_type(symbol->elements[i]->candidate_datatypes[k]))

   426

				symbol->elements[i]->datatype = symbol->elements[i]->candidate_datatypes[k];

   427

		}

   428

		symbol->elements[i]->accept(*this);

   429

	}

   430

	return NULL;  

   431

}

   432

   433

   434

   435

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

   436

/* B 1.5 Program organization units */

   437

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

   438

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

   439

/* B 1.5.1 Functions */

   440

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

   441

void *narrow_candidate_datatypes_c::visit(function_declaration_c *symbol) {

   442

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   443

	symbol->var_declarations_list->accept(*this);

   444

	if (debug) printf("Narrowing candidate data types list in body of function %s\n", ((token_c *)(symbol->derived_function_name))->value);

   445

	symbol->function_body->accept(*this);

   446

	delete search_varfb_instance_type;

   447

	search_varfb_instance_type = NULL;

   448

	return NULL;

   449

}

   450

   451

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

   452

/* B 1.5.2 Function blocks */

   453

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

   454

void *narrow_candidate_datatypes_c::visit(function_block_declaration_c *symbol) {

   455

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   456

	symbol->var_declarations->accept(*this);

   457

	if (debug) printf("Narrowing candidate data types list in body of FB %s\n", ((token_c *)(symbol->fblock_name))->value);

   458

	symbol->fblock_body->accept(*this);

   459

	delete search_varfb_instance_type;

   460

	search_varfb_instance_type = NULL;

   461

	return NULL;

   462

}

   463

   464

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

   465

/* B 1.5.3 Programs */

   466

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

   467

void *narrow_candidate_datatypes_c::visit(program_declaration_c *symbol) {

   468

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   469

	symbol->var_declarations->accept(*this);

   470

	if (debug) printf("Narrowing candidate data types list in body of program %s\n", ((token_c *)(symbol->program_type_name))->value);

   471

	symbol->function_block_body->accept(*this);

   472

	delete search_varfb_instance_type;

   473

	search_varfb_instance_type = NULL;

   474

	return NULL;

   475

}

   476

   477

   478

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

   479

/* B 1.7 Configuration elements */

   480

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

   481

void *narrow_candidate_datatypes_c::visit(configuration_declaration_c *symbol) {

   482

	// TODO !!!

   483

	/* for the moment we must return NULL so semantic analysis of remaining code is not interrupted! */

   484

	return NULL;

   485

}

   486

   487

   488

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

   489

/* B.2 - Language IL (Instruction List) */

   490

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

   491

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

   492

/* B 2.1 Instructions and Operands */

   493

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

   494

   495

/*| instruction_list il_instruction */

   496

// SYM_LIST(instruction_list_c)

   497

void *narrow_candidate_datatypes_c::visit(instruction_list_c *symbol) {

   498

	/* In order to execute the narrow algoritm correctly, we need to go through the instructions backwards,

   499

	 * so we can not use the base class' visitor 

   500

	 */

   501

	for(int i = symbol->n-1; i >= 0; i--) {

   502

		symbol->elements[i]->accept(*this);

   503

	}

   504

	return NULL;

   505

}

   506