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/*

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

     3

 *

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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/>.

    20

 *

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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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 *

    32

 */

    33

    34

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/*

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

    37

 */

    38

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#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;   

    61

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

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		symbol->datatype = datatype;  

    63

}

    64

    65

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    67

    68

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[]) {

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	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))

    72

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

    73

			return true;

    74

		}

    75

	}

    76

	return false;

    77

}

    78

    79

/*

    80

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

    81

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

    82

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

    83

 */

    84

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

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	symbol_c *call_param_value,  *param_type;

    86

	identifier_c *param_name;

    87

	function_param_iterator_c       fp_iterator(f_decl);

    88

	function_call_param_iterator_c fcp_iterator(f_call);

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	int extensible_parameter_highest_index = -1;

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	unsigned int i;

    91

    92

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

    93

    94

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

    95

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

    96

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

    97

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

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

    99

		 */

   100

		do {

   101

			param_name = fp_iterator.next();

   102

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

   103

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

   104

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

   105

			 * for that code too!

   106

			 */

   107

			if(param_name == NULL) break;

   108

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

   109

   110

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

   111

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

   112

		 * we may be setting this to NULL!

   113

		 */

   114

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

   115

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

   116

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

   117

   118

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

   119

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

   120

		 *       the call 

   121

		 *       call_param_value->accept(*this);

   122

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

   123

		 */

   124

		set_datatype(desired_datatype, call_param_value);

   125

		call_param_value->accept(*this);

   126

   127

		if (NULL != param_name) 

   128

			if (extensible_parameter_highest_index < fp_iterator.extensible_param_index())

   129

				extensible_parameter_highest_index = fp_iterator.extensible_param_index();

   130

	}

   131

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

   132

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

   133

	 * of the function call itself!

   134

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

   135

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

   136

	 * output code.

   137

	 */

   138

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

   139

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

   140

}

   141

   142

   143

   144

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

   145

	symbol_c *call_param_value, *call_param_name, *param_type;

   146

	symbol_c *verify_duplicate_param;

   147

	identifier_c *param_name;

   148

	function_param_iterator_c       fp_iterator(f_decl);

   149

	function_call_param_iterator_c fcp_iterator(f_call);

   150

	int extensible_parameter_highest_index = -1;

   151

	identifier_c *extensible_parameter_name;

   152

	unsigned int i;

   153

   154

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

   155

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

   156

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

   157

   158

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

   159

		call_param_value = fcp_iterator.get_current_value();

   160

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

   161

		if (NULL == call_param_value) ERROR;

   162

   163

		/* Find the corresponding parameter in function declaration */

   164

		param_name = fp_iterator.search(call_param_name);

   165

   166

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

   167

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

   168

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

   169

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

   170

		 */

   171

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

   172

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

   173

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

   174

   175

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

   176

		set_datatype(desired_datatype, call_param_value);

   177

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

   178

		/* However, when handling an implicit IL FB call, the first parameter is fake (a copy of the prev_il_instruction).

   179

		 * so the call call_param_value->accept(*this) may actually be calling an object of the base symbol_c .

   180

		 */

   181

		call_param_value->accept(*this);

   182

   183

		if (NULL != param_name) 

   184

			if (extensible_parameter_highest_index < fp_iterator.extensible_param_index())

   185

				extensible_parameter_highest_index = fp_iterator.extensible_param_index();

   186

	}

   187

	/* call is compatible! */

   188

   189

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

   190

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

   191

	 * of the function call itself!

   192

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

   193

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

   194

	 * output code.

   195

	 */

   196

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

   197

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

   198

}

   199

   200

   201

/*

   202

typedef struct {

   203

  symbol_c *function_name,

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  symbol_c *nonformal_operand_list,

   205

  symbol_c *   formal_operand_list,

   206

   207

  std::vector <symbol_c *> &candidate_functions,  

   208

  symbol_c &*called_function_declaration,

   209

  int      &extensible_param_count

   210

} generic_function_call_t;

   211

*/

   212

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

   213

	/* set the called_function_declaration. */

   214

	fcall_data.called_function_declaration = NULL;

   215

   216

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

   217

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

   218

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

   219

			fcall_data.called_function_declaration = fcall_data.candidate_functions[i];

   220

			break;

   221

		}

   222

	}

   223

   224

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

   225

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

   226

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

   227

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

   228

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

   229

	 *       invocation.

   230

	 */

   231

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

   232

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

   233

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

   234

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

   235

		 * function invocation.

   236

		 */

   237

		fcall_data.called_function_declaration = fcall_data.candidate_functions[0];

   238

	}

   239

   240

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

   241

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

   242

	 * We simply give up!

   243

	 */

   244

	if (NULL == fcall_data.called_function_declaration)

   245

		return;

   246

   247

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

   248

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

   249

   250

	return;

   251

}

   252

   253

   254

   255

   256

/* narrow implicit FB call in IL.

   257

 * e.g.  CLK ton_var

   258

 *        CU counter_var

   259

 *

   260

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

   261

 * the visit(il_fb_call_c *) method handle it!

   262

 */

   263

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

   264

	if (NULL == called_fb_declaration)

   265

		/* The fill_candidate_datatypes_c was not able to determine which FB is being called!

   266

		 * This may be because the il_operand is not the name of a FB instance, or no operand was given. 

   267

		 * In that case, we just give up!

   268

		 */

   269

		return;

   270

	if (NULL == prev_il_instruction) {

   271

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

   272

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

   273

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

   274

		 */

   275

		return;

   276

	}

   277

   278

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

   279

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

   280

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

   281

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

   282

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

   283

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

   284

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

   285

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

   286

	 */

   287

	symbol_c param_value = *prev_il_instruction;

   288

   289

	identifier_c variable_name(param_name);

   290

	// SYM_REF1(il_assign_operator_c, variable_name)

   291

	il_assign_operator_c il_assign_operator(&variable_name);  

   292

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

   293

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

   294

	il_param_list_c il_param_list;

   295

	il_param_list.add_element(&il_param_assignment);

   296

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

   297

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

   298

   299

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

   300

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

   301

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

   302

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

   303

	 *

   304

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

   305

	 * correctly set up the il_fb_call.datatype variable!

   306

	 */

   307

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

   308

	il_fb_call.accept(*this);

   309

   310

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

   311

	/* NOTE:

   312

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

   313

	 * is actually the prev_il_instruction.

   314

	 * 

   315

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

   316

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

   317

	 *

   318

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

   319

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

   320

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

   321

	 * and we set it to NULL.

   322

	 *

   323

	 * However, we only do that if:

   324

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

   325

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

   326

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

   327

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

   328

	 *     FB call must be left unchanged!

   329

	 */

   330

// 	if (NULL != prev_il_instruction) /* already checked above! */

   331

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

   332

			prev_il_instruction->datatype = param_value.datatype;

   333

		} else {

   334

			prev_il_instruction->datatype = NULL;

   335

		}

   336

   337

}

   338

   339

   340

/* a helper function... */

   341

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

   342

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

   343

	 *       in the code.

   344

	 */

   345

	if (symbol == NULL) return NULL;

   346

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

   347

}

   348

   349

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

   350

/* B 1.2 - Constants */

   351

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

   352

   353

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

   354

/* B 1.3 - Data types */

   355

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

   356

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

   357

/* B 1.3.3 - Derived data types */

   358

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

   359

/*  signed_integer DOTDOT signed_integer */

   360

// SYM_REF2(subrange_c, lower_limit, upper_limit)

   361

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

   362

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

   363

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

   364

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

   365

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

   366

	return NULL;

   367

}

   368

   369

/* simple_specification ASSIGN constant */

   370

// SYM_REF2(simple_spec_init_c, simple_specification, constant)

   371

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

   372

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

   373

	if (NULL != symbol->constant) {

   374

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

   375

		if (typeoffset >= 0)

   376

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

   377

	}

   378

	return NULL;

   379

}

   380

   381

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

   382

/* B 1.4 - Variables */

   383

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

   384

   385

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

   386

/* B 1.4.1 - Directly Represented Variables */

   387

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

   388

   389

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

   390

/* B 1.4.2 - Multi-element variables */

   391

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

   392

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

   393

// SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   394

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

   395

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

   396

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

   397

	return NULL;

   398

}

   399

   400

   401

/* subscript_list ',' subscript */

   402

// SYM_LIST(subscript_list_c)

   403

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

   404

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

   405

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

   406

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

   407

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

   408

		}

   409

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

   410

	}

   411

	return NULL;  

   412

}

   413

   414

   415

   416

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

   417

/* B 1.5 Program organization units */

   418

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

   419

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

   420

/* B 1.5.1 Functions */

   421

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

   422

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

   423

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   424

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

   425

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

   426

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

   427

	delete search_varfb_instance_type;

   428

	search_varfb_instance_type = NULL;

   429

	return NULL;

   430

}

   431

   432

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

   433

/* B 1.5.2 Function blocks */

   434

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

   435

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

   436

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   437

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

   438

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

   439

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

   440

	delete search_varfb_instance_type;

   441

	search_varfb_instance_type = NULL;

   442

	return NULL;

   443

}

   444

   445

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

   446

/* B 1.5.3 Programs */

   447

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

   448

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

   449

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   450

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

   451

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

   452

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

   453

	delete search_varfb_instance_type;

   454

	search_varfb_instance_type = NULL;

   455

	return NULL;

   456

}

   457

   458

   459

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

   460

/* B 1.7 Configuration elements */

   461

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

   462

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

   463

	// TODO !!!

   464

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

   465

	return NULL;

   466

}

   467

   468

   469

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

   470

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

   471

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

   472

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

   473

/* B 2.1 Instructions and Operands */

   474

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

   475

   476

/*| instruction_list il_instruction */

   477

// SYM_LIST(instruction_list_c)

   478

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

   479

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

   480

	 * so we can not use the base class' visitor 

   481

	 */

   482

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

   483

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

   484

	}

   485

	return NULL;

   486

}

   487

   488

/* | label ':' [il_incomplete_instruction] eol_list */

   489

// SYM_REF2(il_instruction_c, label, il_instruction)

   490

// void *visit(instruction_list_c *symbol);

   491

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

   492

	if (NULL == symbol->il_instruction) {

   493

		/* this empty/null il_instruction cannot generate the desired datatype. We pass on the request to the previous il instruction. */

   494

		if (NULL != symbol->prev_il_instruction)

   495

			symbol->prev_il_instruction->datatype = symbol->datatype;

   496

	} else {

   497

		/* Tell the il_instruction the datatype that it must generate - this was chosen by the next il_instruction (remember: we are iterating backwards!) */

   498

		symbol->il_instruction->datatype = symbol->datatype;

   499

		prev_il_instruction = symbol->prev_il_instruction;

   500

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

   501

		prev_il_instruction = NULL;

   502

	}

   503

	return NULL;

   504

}

   505

   506