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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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 */

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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) {

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}

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    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_candidate_datatype_list(datatype, symbol->candidate_datatypes) >= 0)

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		symbol->datatype = datatype;  

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}

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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))) {

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			return true;

    74

		}

    75

	}

    76

	return false;

    77

}

    78

    79

/*

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 * 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

 */

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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;

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	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 */

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

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		/* 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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		/* 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!

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		 */

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		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 

   122

		 *       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

		 */

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		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();

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	}

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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

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   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;

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	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

		 */

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		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

	 */

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

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		*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,

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  symbol_c *nonformal_operand_list,

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  symbol_c *   formal_operand_list,

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  std::vector <symbol_c *> &candidate_functions,  

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  symbol_c &*called_function_declaration,

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  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 */

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

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		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

   305

/* a helper function... */

   306

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

   307

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

   308

	 *       in the code.

   309

	 */

   310

	if (symbol == NULL) return NULL;

   311

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

   312

}

   313

   314

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

   315

/* B 1.2 - Constants */

   316

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

   317

   318

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

   319

/* B 1.3 - Data types */

   320

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

   321

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

   322

/* B 1.3.3 - Derived data types */

   323

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

   324

/*  signed_integer DOTDOT signed_integer */

   325

// SYM_REF2(subrange_c, lower_limit, upper_limit)

   326

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

   327

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

   328

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

   329

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

   330

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

   331

	return NULL;

   332

}

   333

   334

/* simple_specification ASSIGN constant */

   335

// SYM_REF2(simple_spec_init_c, simple_specification, constant)

   336

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

   337

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

   338

	if (NULL != symbol->constant) {

   339

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

   340

		if (typeoffset >= 0)

   341

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

   342

	}

   343

	return NULL;

   344

}

   345

   346

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

   347

/* B 1.4 - Variables */

   348

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

   349

   350

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

   351

/* B 1.4.1 - Directly Represented Variables */

   352

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

   353

   354

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

   355

/* B 1.4.2 - Multi-element variables */

   356

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

   357

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

   358

// SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   359

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

   360

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

   361

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

   362

	return NULL;

   363

}

   364

   365

   366

/* subscript_list ',' subscript */

   367

// SYM_LIST(subscript_list_c)

   368

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

   369

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

   370

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

   371

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

   372

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

   373

		}

   374

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

   375

	}

   376

	return NULL;  

   377

}

   378

   379

   380

   381

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

   382

/* B 1.5 Program organization units */

   383

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

   384

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

   385

/* B 1.5.1 Functions */

   386

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

   387

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

   388

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   389

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

   390

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

   391

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

   392

	delete search_varfb_instance_type;

   393

	search_varfb_instance_type = NULL;

   394

	return NULL;

   395

}

   396

   397

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

   398

/* B 1.5.2 Function blocks */

   399

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

   400

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

   401

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   402

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

   403

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

   404

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

   405

	delete search_varfb_instance_type;

   406

	search_varfb_instance_type = NULL;

   407

	return NULL;

   408

}

   409

   410

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

   411

/* B 1.5.3 Programs */

   412

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

   413

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

   414

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   415

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

   416

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

   417

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

   418

	delete search_varfb_instance_type;

   419

	search_varfb_instance_type = NULL;

   420

	return NULL;

   421

}

   422

   423

   424

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

   425

/* B 1.7 Configuration elements */

   426

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

   427

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

   428

	// TODO !!!

   429

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

   430

	return NULL;

   431

}

   432

   433

   434

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

   435

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

   436

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

   437

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

   438

/* B 2.1 Instructions and Operands */

   439

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

   440

   441

/*| instruction_list il_instruction */

   442

// SYM_LIST(instruction_list_c)

   443

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

   444

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

   445

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

   446

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

   447

	}

   448

	return NULL;

   449

}

   450

   451

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

   452

// SYM_REF2(il_instruction_c, label, il_instruction)

   453

// void *visit(instruction_list_c *symbol);

   454

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

   465

	return NULL;

   466

}

   467

   468

   469

   470

   471

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

   472

/* Important NOTE:                                                                               */

   473

/*                                                                                               */

   474

/*   The visit() methods for all the IL instructions must be idem-potent, as they may            */

   475

/*   potentially be called twice to narrow the same object. In other words, they may be called   */

   476

/*   to narrow an object that has already been previously narrowed.                              */

   477

/*   This occurs when that IL instruction imediately precedes an IL non-formal function          */

   478

/*   invocation:                                                                                 */

   479

/*      LD 45.5                                                                                  */

   480

/*      SIN                                                                                      */

   481

/*                                                                                               */

   482

/*   In the above case, 'LD 45.5' will be narrowed once when the code that handles the           */

   483

/*   SIN function call                                                                           */

   484

/*                                                                                               */

   485

/*   narrow_nonformal_call(...), which is called by narrow_function_invocation(...), which is    */

   486

/*   in turn called by visit(il_function_call_c *)                                               */

   487

/*                                                                                               */

   488

/*   calls the call_param_value->accept(*this), where call_param_value will be a pointer         */

   489

/*   to the preceding IL instruction (in the above case, 'LD 45.5').                             */

   490

/*                                                                                               */

   491

/*   That same IL instruction will be again narrowed when called by the for() loop in            */

   492

/*   the visit(instruction_list_c *) visitor method.                                             */

   493

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

   494

   495

   496

   497

   498

   499

// void *visit(instruction_list_c *symbol);

   500

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

   501

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

   502

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

   503

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

   504

	il_operand = symbol->il_operand;

   505

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

   506

	il_operand = NULL;

   507

	return NULL;

   508

}