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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.

    17

 *

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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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/*

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 *  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>

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#include <strings.h>

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    47

    48

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

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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

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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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    61

	/* If we are trying to set to the undefined type, and the symbol's datatype has already been set to something else, 

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	 * we abort the compoiler as I don't think this should ever occur. 

    63

	 * NOTE: In order to handle JMPs to labels that come before the JMP itself, we run the narrow algorithm twice.

    64

	 *       This means that this situation may legally occur, so we cannot abort the compiler here!

    65

	 */

    66

// 	if ((NULL == datatype) && (NULL != symbol->datatype)) ERROR;

    67

 	if ((NULL == datatype) && (NULL != symbol->datatype)) return;

    68

	if ((NULL == datatype) && (NULL == symbol->datatype)) return;

    69

    70

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

    71

		symbol->datatype = &(search_constant_type_c::invalid_type_name);   

    72

	else {

    73

		if (NULL == symbol->datatype)   

    74

			/* not yet set to anything, so we set it to the requested data type */

    75

			symbol->datatype = datatype; 

    76

		else {

    77

			/* had already been set previously to some data type. Let's check if they are the same! */

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			if (!is_type_equal(symbol->datatype, datatype))

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				symbol->datatype = &(search_constant_type_c::invalid_type_name);

    80

// 			else 

    81

				/* we leave it unchanged, as it is the same as the requested data type! */

    82

		}

    83

	}

    84

}

    85

    86

    87

    88

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

    89

// static void set_datatype_in_prev_il_instructions(symbol_c *datatype, std::vector <symbol_c *> prev_il_instructions) {

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static void set_datatype_in_prev_il_instructions(symbol_c *datatype, il_instruction_c *symbol) {

    91

	if (NULL == symbol) ERROR;

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	for (unsigned int i = 0; i < symbol->prev_il_instruction.size(); i++)

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		set_datatype(datatype, symbol->prev_il_instruction[i]);

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}

    95

    96

    97

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

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	/* NOTE: According to our algorithm, left_type and right_type should never by NULL (if they are, we have an internal compiler error!

   100

	 *       However, result_type may be NULL if the code has a data type semantic error!

   101

	 */

   102

	if ((NULL == left_type) || (NULL == right_type) || (NULL == result_type))

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		return false;

   104

   105

	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))

   108

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

   109

			if (NULL != deprecated_status)

   110

				*deprecated_status = (widen_table[k].status == widen_entry::deprecated);

   111

			return true;

   112

		}

   113

	}

   114

	return false;

   115

}

   116

   117

/*

   118

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

   119

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

   120

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

   121

 */

   122

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;

   124

	identifier_c *param_name;

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	function_param_iterator_c       fp_iterator(f_decl);

   126

	function_call_param_iterator_c fcp_iterator(f_call);

   127

	int extensible_parameter_highest_index = -1;

   128

	unsigned int i;

   129

   130

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

   131

   132

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

   133

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

   134

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

   135

		/* 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.

   137

		 */

   138

		do {

   139

			param_name = fp_iterator.next();

   140

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

   141

			/* 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

   143

			 * for that code too!

   144

			 */

   145

			if(param_name == NULL) break;

   146

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

   147

   148

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

   149

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

   150

		 * we may be setting this to NULL!

   151

		 */

   152

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

   153

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

   154

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

   155

   156

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

   157

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

   158

		 *       the call 

   159

		 *       call_param_value->accept(*this);

   160

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

   161

		 */

   162

		set_datatype(desired_datatype, call_param_value);

   163

		call_param_value->accept(*this);

   164

   165

		if (NULL != param_name) 

   166

			if (extensible_parameter_highest_index < fp_iterator.extensible_param_index())

   167

				extensible_parameter_highest_index = fp_iterator.extensible_param_index();

   168

	}

   169

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

   170

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

   171

	 * of the function call itself!

   172

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

   173

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

   174

	 * output code.

   175

	 */

   176

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

   177

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

   178

}

   179

   180

   181

   182

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

   183

	symbol_c *call_param_value, *call_param_name, *param_type;

   184

	symbol_c *verify_duplicate_param;

   185

	identifier_c *param_name;

   186

	function_param_iterator_c       fp_iterator(f_decl);

   187

	function_call_param_iterator_c fcp_iterator(f_call);

   188

	int extensible_parameter_highest_index = -1;

   189

	identifier_c *extensible_parameter_name;

   190

	unsigned int i;

   191

   192

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

   193

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

   194

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

   195

   196

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

   197

		call_param_value = fcp_iterator.get_current_value();

   198

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

   199

		if (NULL == call_param_value) ERROR;

   200

   201

		/* Find the corresponding parameter in function declaration */

   202

		param_name = fp_iterator.search(call_param_name);

   203

   204

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

   205

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

   206

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

   207

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

   208

		 */

   209

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

   210

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

   211

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

   212

   213

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

   214

		set_datatype(desired_datatype, call_param_value);

   215

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

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		call_param_value->accept(*this);

   217

   218

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

   219

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

   220

		if (NULL != param_name) 

   221

			if (extensible_parameter_highest_index < fp_iterator.extensible_param_index())

   222

				extensible_parameter_highest_index = fp_iterator.extensible_param_index();

   223

	}

   224

	/* call is compatible! */

   225

   226

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

   227

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

   228

	 * of the function call itself!

   229

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

   230

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

   231

	 * output code.

   232

	 */

   233

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

   234

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

   235

}

   236

   237

   238

/*

   239

typedef struct {

   240

  symbol_c *function_name,

   241

  symbol_c *nonformal_operand_list,

   242

  symbol_c *   formal_operand_list,

   243

   244

  std::vector <symbol_c *> &candidate_functions,  

   245

  symbol_c &*called_function_declaration,

   246

  int      &extensible_param_count

   247

} generic_function_call_t;

   248

*/

   249

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

   250

	/* set the called_function_declaration. */

   251

	fcall_data.called_function_declaration = NULL;

   252

   253

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

   254

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

   255

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

   256

			fcall_data.called_function_declaration = fcall_data.candidate_functions[i];

   257

			break;

   258

		}

   259

	}

   260

   261

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

   262

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

   263

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

   264

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

   265

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

   266

	 *       invocation.

   267

	 */

   268

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

   269

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

   270

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

   271

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

   272

		 * function invocation.

   273

		 */

   274

		fcall_data.called_function_declaration = fcall_data.candidate_functions[0];

   275

	}

   276

   277

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

   278

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

   279

	 * We simply give up!

   280

	 */

   281

	if (NULL == fcall_data.called_function_declaration)

   282

		return;

   283

   284

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

   285

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

   286

   287

	return;

   288

}

   289

   290

   291

   292

   293

/* narrow implicit FB call in IL.

   294

 * e.g.  CLK ton_var

   295

 *        CU counter_var

   296

 *

   297

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

   298

 * the visit(il_fb_call_c *) method handle it!

   299

 */

   300

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

   301

   302

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

   303

	if (NULL != il_operand) {

   304

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

   305

		set_datatype(called_fb_declaration, il_operand);

   306

		il_operand->accept(*this);

   307

	}

   308

	symbol_c *fb_decl = il_operand->datatype;

   309

   310

	if (0 == fake_prev_il_instruction->prev_il_instruction.size()) {

   311

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

   312

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

   313

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

   314

		 */

   315

		return NULL;

   316

	}

   317

   318

	if (NULL == fb_decl) {

   319

		/* the il_operand is a not FB instance */

   320

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

   321

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

   322

		set_datatype_in_prev_il_instructions(il_instruction->datatype, fake_prev_il_instruction);

   323

		return NULL;

   324

	}

   325

   326

   327

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

   328

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

   329

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

   330

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

   331

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

   332

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

   333

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

   334

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

   335

	 */

   336

	symbol_c param_value = *fake_prev_il_instruction; /* copy the candidate_datatypes list ! */

   337

   338

	identifier_c variable_name(param_name);

   339

	// SYM_REF1(il_assign_operator_c, variable_name)

   340

	il_assign_operator_c il_assign_operator(&variable_name);  

   341

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

   342

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

   343

	il_param_list_c il_param_list;

   344

	il_param_list.add_element(&il_param_assignment);

   345

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

   346

	CAL_operator_c CAL_operator;

   347

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

   348

   349

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

   350

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

   351

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

   352

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

   353

	 *

   354

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

   355

	 * correctly set up the il_fb_call.datatype variable!

   356

	 */

   357

	il_fb_call.called_fb_declaration = called_fb_declaration;

   358

	il_fb_call.accept(*this);

   359

   360

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

   361

	/* NOTE:

   362

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

   363

	 * is actually the prev_il_instruction.

   364

	 * 

   365

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

   366

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

   367

	 *

   368

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

   369

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

   370

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

   371

	 * and we set it to invalid_type_name.

   372

	 *

   373

	 * However, we only do that if:

   374

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

   375

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

   376

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

   377

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

   378

	 *     FB call must be left unchanged!

   379

	 */

   380

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

   381

		set_datatype_in_prev_il_instructions(param_value.datatype, fake_prev_il_instruction);

   382

	} else {

   383

		set_datatype_in_prev_il_instructions(&search_constant_type_c::invalid_type_name, fake_prev_il_instruction);

   384

	}

   385

	return NULL;

   386

}

   387

   388

   389

/* a helper function... */

   390

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

   391

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

   392

	 *       in the code.

   393

	 */

   394

	if (symbol == NULL) return NULL;

   395

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

   396

}

   397

   398

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

   399

/* B 1.2 - Constants */

   400

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

   401

   402

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

   403

/* B 1.3 - Data types */

   404

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

   405

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

   406

/* B 1.3.3 - Derived data types */

   407

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

   408

/* simple_specification ASSIGN constant */

   409

// SYM_REF2(simple_spec_init_c, simple_specification, constant)

   410

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

   411

	if (symbol->candidate_datatypes.size() == 1)

   412

	  symbol->datatype = symbol->candidate_datatypes[0];

   413

   414

	if (symbol->simple_specification->candidate_datatypes.size() == 1)

   415

	  symbol->simple_specification->datatype = symbol->simple_specification->candidate_datatypes[0];

   416

   417

	if (NULL != symbol->constant) {

   418

		set_datatype(symbol->datatype, symbol->constant);

   419

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

   420

	}

   421

	return NULL;

   422

}

   423

   424

   425

   426

/*  signed_integer DOTDOT signed_integer */

   427

// SYM_REF2(subrange_c, lower_limit, upper_limit)

   428

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

   429

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

   430

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

   431

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

   432

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

   433

	return NULL;

   434

}

   435

   436

   437

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

   438

/* B 1.4 - Variables */

   439

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

   440

   441

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

   442

/* B 1.4.1 - Directly Represented Variables */

   443

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

   444

   445

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

   446

/* B 1.4.2 - Multi-element variables */

   447

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

   448

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

   449

// SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   450

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

   451

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

   452

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

   453

	return NULL;

   454

}

   455

   456

   457

/* subscript_list ',' subscript */

   458

// SYM_LIST(subscript_list_c)

   459

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

   460

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

   461

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

   462

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

   463

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

   464

		}

   465

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

   466

	}

   467

	return NULL;  

   468

}

   469

   470

   471

   472

   473

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

   474

/* B 1.4.3 - Declaration & Initialisation */

   475

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

   476

   477

void *narrow_candidate_datatypes_c::visit(var1_list_c *symbol) {

   478

#if 0   /* We don't really need to set the datatype of each variable. We just check the declaration itself! */

   479

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

   480

    if (symbol->elements[i]->candidate_datatypes.size() == 1)

   481

      symbol->elements[i]->datatype = symbol->elements[i]->candidate_datatypes[0];

   482

  }

   483

#endif

   484

  return NULL;

   485

}  

   486

   487

   488

/*  AT direct_variable */

   489

// SYM_REF1(location_c, direct_variable)

   490

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

   491

  set_datatype(symbol->datatype, symbol->direct_variable);

   492

  symbol->direct_variable->accept(*this); /* currently does nothing! */

   493

  return NULL;

   494

}

   495

   496

   497

/*  [variable_name] location ':' located_var_spec_init */

   498

/* variable_name -> may be NULL ! */

   499

// SYM_REF3(located_var_decl_c, variable_name, location, located_var_spec_init)

   500

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

   501

  /* let the var_spec_init set its own symbol->datatype value */