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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

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 *  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.

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 */

    25

    26

/*

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 * An IEC 61131-3 compiler.

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 *

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 * 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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/*

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

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 */

    38

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#include "narrow_candidate_datatypes.hh"

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#include "datatype_functions.hh"

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#include <typeinfo>

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#include <list>

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#include <string>

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#include <string.h>

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#include <strings.h>

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    47

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

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static int debug = 0;

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narrow_candidate_datatypes_c::narrow_candidate_datatypes_c(symbol_c *ignore) {

    52

}

    53

    54

narrow_candidate_datatypes_c::~narrow_candidate_datatypes_c(void) {

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}

    56

    57

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

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

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	symbol->datatype = NULL;   

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

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		symbol->datatype = datatype;  

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}

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    65

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    67

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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))

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				&& (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!

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 * 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().

    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;

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	function_param_iterator_c       fp_iterator(f_decl);

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	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 */

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		/* 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.

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		 */

   100

		do {

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			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! 

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

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			 * for that code too!

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			 */

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			if(param_name == NULL) break;

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

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   110

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

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

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		 * we may be setting this to NULL!

   113

		 */

   114

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

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

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		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'

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		 *       il value. However, a pointer to the prev_il_instruction is pre-pended into the operand list (done in fill_candidate_datatypes_c,

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		 *       and later undone in print_datatypes_error_c - this class is run after the first, and before the latter!), so 

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		 *       the call 

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		 *       call_param_value->accept(*this);

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		 *       may actually be calling an object of the il_instruction_c class.

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		 *       If that is the case, that same il_instruction_c object will be called again inside the for() loop

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		 *       of void *narrow_candidate_datatypes_c::visit(instruction_list_c *symbol);

   126

		 *       This is actually safe, as the narrow algorithm for all IL instructions is idem-potent.

   127

		 *       (It is easier to just let it be called twice than to hack the code to guarantee that it is 

   128

		 *       only called once - this would also make this hacked code ugly an un-elegant, so we leave

   129

		 *       it as it is for now...)

   130

		 */

   131

		set_datatype(desired_datatype, call_param_value);

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		call_param_value->accept(*this);

   133

   134

		if (NULL != param_name) 

   135

			if (extensible_parameter_highest_index < fp_iterator.extensible_param_index())

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				extensible_parameter_highest_index = fp_iterator.extensible_param_index();

   137

	}

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

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

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	 * of the function call itself!

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

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	 * 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;

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	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_datatype(desired_datatype, call_param_value);

   183

		call_param_value->accept(*this);

   184

   185

		if (NULL != param_name) 

   186

			if (extensible_parameter_highest_index < fp_iterator.extensible_param_index())

   187

				extensible_parameter_highest_index = fp_iterator.extensible_param_index();

   188

	}

   189

	/* call is compatible! */

   190

   191

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

   192

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

   193

	 * of the function call itself!

   194

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

   195

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

   196

	 * output code.

   197

	 */

   198

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

   199

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

   200

}

   201

   202

   203

/*

   204

typedef struct {

   205

  symbol_c *function_name,

   206

  symbol_c *nonformal_operand_list,

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  symbol_c *   formal_operand_list,

   208

   209

  std::vector <symbol_c *> &candidate_functions,  

   210

  symbol_c &*called_function_declaration,

   211

  int      &extensible_param_count

   212

} generic_function_call_t;

   213

*/

   214

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

   215

	/* set the called_function_declaration. */

   216

	fcall_data.called_function_declaration = NULL;

   217

   218

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

   219

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

   220

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

   221

			fcall_data.called_function_declaration = fcall_data.candidate_functions[i];

   222

			break;

   223

		}

   224

	}

   225

   226

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

   227

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

   228

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

   229

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

   230

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

   231

	 *       invocation.

   232

	 */

   233

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

   234

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

   235

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

   236

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

   237

		 * function invocation.

   238

		 */

   239

		fcall_data.called_function_declaration = fcall_data.candidate_functions[0];

   240

	}

   241

   242

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

   243

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

   244

	 * We simply give up!

   245

	 */

   246

	if (NULL == fcall_data.called_function_declaration)

   247

		return;

   248

   249

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

   250

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

   251

   252

	return;

   253

}

   254

   255

   256

   257

/* a helper function... */

   258

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

   259

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

   260

	 *       in the code.

   261

	 */

   262

	if (symbol == NULL) return NULL;

   263

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

   264

}

   265

   266

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

   267

/* B 1.2 - Constants */

   268

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

   269

   270

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

   271

/* B 1.3 - Data types */

   272

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

   273

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

   274

/* B 1.3.3 - Derived data types */

   275

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

   276

/*  signed_integer DOTDOT signed_integer */

   277

// SYM_REF2(subrange_c, lower_limit, upper_limit)

   278

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

   279

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

   280

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

   281

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

   282

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

   283

	return NULL;

   284

}

   285

   286

/* simple_specification ASSIGN constant */

   287

// SYM_REF2(simple_spec_init_c, simple_specification, constant)

   288

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

   289

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

   290

	if (NULL != symbol->constant) {

   291

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

   292

		if (typeoffset >= 0)

   293

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

   294

	}

   295

	return NULL;

   296

}

   297

   298

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

   299

/* B 1.4 - Variables */

   300

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

   301

   302

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

   303

/* B 1.4.1 - Directly Represented Variables */

   304

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

   305

   306

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

   307

/* B 1.4.2 - Multi-element variables */

   308

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

   309

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

   310

// SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   311

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

   312

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

   313

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

   314

	return NULL;

   315

}

   316

   317

   318

/* subscript_list ',' subscript */

   319

// SYM_LIST(subscript_list_c)

   320

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

   321

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

   322

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

   323

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

   324

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

   325

		}

   326

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

   327

	}

   328

	return NULL;  

   329

}

   330

   331

   332

   333

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

   334

/* B 1.5 Program organization units */

   335

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

   336

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

   337

/* B 1.5.1 Functions */

   338

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

   339

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

   340

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   341

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

   342

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

   343

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

   344

	delete search_varfb_instance_type;

   345

	search_varfb_instance_type = NULL;

   346

	return NULL;

   347

}

   348

   349

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

   350

/* B 1.5.2 Function blocks */

   351

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

   352

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

   353

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   354

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

   355

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

   356

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

   357

	delete search_varfb_instance_type;

   358

	search_varfb_instance_type = NULL;

   359

	return NULL;

   360

}

   361

   362

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

   363

/* B 1.5.3 Programs */

   364

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

   365

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

   366

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   367

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

   368

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

   369

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

   370

	delete search_varfb_instance_type;

   371

	search_varfb_instance_type = NULL;

   372

	return NULL;

   373

}

   374

   375

   376

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

   377

/* B 1.7 Configuration elements */

   378

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

   379

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

   380

	// TODO !!!

   381

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

   382

	return NULL;

   383

}

   384

   385

   386

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

   387

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

   388

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

   389

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

   390

/* B 2.1 Instructions and Operands */

   391

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

   392

   393

/*| instruction_list il_instruction */

   394

// SYM_LIST(instruction_list_c)

   395

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

   396

	/* We need to go through the instructions backwards, so we can not use the base class' visitor */

   397

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

   398

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

   399

	}

   400

	return NULL;

   401

}

   402

   403

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

   404

// SYM_REF2(il_instruction_c, label, il_instruction)

   405

// void *visit(instruction_list_c *symbol);

   406

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

   407

	if (NULL == symbol->il_instruction)

   408

		return NULL;

   409

   410

	prev_il_instruction = symbol->prev_il_instruction;

   411

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

   412

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

   413

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

   414

	return NULL;

   415

}

   416

   417

   448

// void *visit(instruction_list_c *symbol);

   449

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

   450

	/* Tell the il_simple_operator the datatype that it must generate - this was chosen by the next il_instruction (we iterate backwards!) */

   451

	symbol->il_simple_operator->datatype = symbol->datatype;

   452

	/* recursive call to see whether data types are compatible */

   453

	il_operand = symbol->il_operand;

   454

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

   455

	il_operand = NULL;

   456

	return NULL;

   457

}

   458

   459

/* | function_name [il_operand_list] */

   460

/* NOTE: The parameters 'called_function_declaration' and 'extensible_param_count' are used to pass data between the stage 3 and stage 4. */

   461

// SYM_REF2(il_function_call_c, function_name, il_operand_list, symbol_c *called_function_declaration; int extensible_param_count;)

   462

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

   463

	generic_function_call_t fcall_param = {

   464

		/* fcall_param.function_name               = */ symbol->function_name,

   465

		/* fcall_param.nonformal_operand_list      = */ symbol->il_operand_list,

   466

		/* fcall_param.formal_operand_list         = */ NULL,

   467

		/* enum {POU_FB, POU_function} POU_type    = */ generic_function_call_t::POU_function,

   468

		/* fcall_param.candidate_functions         = */ symbol->candidate_functions,

   469

		/* fcall_param.called_function_declaration = */ symbol->called_function_declaration,

   470

		/* fcall_param.extensible_param_count      = */ symbol->extensible_param_count

   471

	};

   472

   473

	/* The first parameter of a non formal function call in IL will be the 'current value' (i.e. the prev_il_instruction)

   474

	 * In order to be able to handle this without coding special cases, we simply prepend that symbol

   475

	 * to the il_operand_list (done in fill_candidate_datatypes_c), and remove it later (in the print_datatypes_error_c).

   476

	 *

   477

	 * Since this class is executed after fill_candidate_datatypes_c, and before print_datatypes_error_c,

   478

	 * the following code is actually correct!

   479

	 */

   480

	narrow_function_invocation(symbol, fcall_param);

   481

	/* set the desired datatype of the previous il instruction */

   482

	prev_il_instruction->datatype = symbol->datatype;

   483

	return NULL;

   484

}

   485

   486

/* MJS: Manuele, could you please not delete the following 2 lines of comments. They help me understand where this class is used

   487

 *     and when it is created by bison - syntax parse, and how it can show up in the abstract syntax tree.

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 *

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 *       Actually, it could be helpful if we could have all the similar comments already present in visit_expression_type_c

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 *       in the 3 new classes fill/narrow/print candidate datatype 

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 */

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/* | il_expr_operator '(' [il_operand] eol_list [simple_instr_list] ')' */

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// SYM_REF3(il_expression_c, il_expr_operator, il_operand, simple_instr_list);

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

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/* MJS: TODO... */

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return NULL;

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}

   498

   499

/*   il_call_operator prev_declared_fb_name

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 * | il_call_operator prev_declared_fb_name '(' ')'

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 * | il_call_operator prev_declared_fb_name '(' eol_list ')'

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 * | il_call_operator prev_declared_fb_name '(' il_operand_list ')'

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 * | il_call_operator prev_declared_fb_name '(' eol_list il_param_list ')'

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 */

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/* NOTE: The parameter 'called_fb_declaration'is used to pass data between stage 3 and stage4 (although currently it is not used in stage 4 */

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

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

   508

	/* Note: We do not use the symbol->called_fb_declaration value (set in fill_candidate_datatypes_c)

   509

	 *       because we try to identify any other datatype errors in the expressions used in the