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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.

    24

 */

    25

    26

/*

    27

 * An IEC 61131-3 compiler.

    28

 *

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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"

    40

#include "datatype_functions.hh"

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#include <typeinfo>

    42

#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

    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) {

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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;  

    63

}

    64

    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))

    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

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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;

    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.

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		 */

   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

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			 * for that code too!

   106

			 */

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			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. */

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		/* 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());

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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'

   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);

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		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

}

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   142

   143

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

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	symbol_c *call_param_value, *call_param_name, *param_type;

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	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

		call_param_value->accept(*this);

   179

   182

		if (NULL != param_name) 

   183

			if (extensible_parameter_highest_index < fp_iterator.extensible_param_index())

   184

				extensible_parameter_highest_index = fp_iterator.extensible_param_index();

   185

	}

   186

	/* call is compatible! */

   187

   188

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

   189

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

   190

	 * of the function call itself!

   191

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

   192

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

   193

	 * output code.

   194

	 */

   195

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

   196

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

   197

}

   198

   199

   200

/*

   201

typedef struct {

   202

  symbol_c *function_name,

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  symbol_c *nonformal_operand_list,

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  symbol_c *   formal_operand_list,

   205

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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

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} generic_function_call_t;

   210

*/

   211

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

   212

	/* set the called_function_declaration. */

   213

	fcall_data.called_function_declaration = NULL;

   214

   215

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

   216

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

   217

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

   218

			fcall_data.called_function_declaration = fcall_data.candidate_functions[i];

   219

			break;

   220

		}

   221

	}

   222

   223

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

   224

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

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

   226

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

   227

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

   228

	 *       invocation.

   229

	 */

   230

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

   231

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

   232

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

   233

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

   234

		 * function invocation.

   235

		 */

   236

		fcall_data.called_function_declaration = fcall_data.candidate_functions[0];

   237

	}

   238

   239

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

   240

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

   241

	 * We simply give up!

   242

	 */

   243

	if (NULL == fcall_data.called_function_declaration)

   244

		return;

   245

   246

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

   247

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

   248

   249

	return;

   250

}

   251

   252

   253

   254

   255

/* narrow implicit FB call in IL.

   256

 * e.g.  CLK ton_var

   257

 *        CU counter_var

   258

 *

   259

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

   260

 * the visit(il_fb_call_c *) method handle it!

   261

 */

   262

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

   272

	if (NULL == prev_il_instruction) {

   273

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

   274

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

   275

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

   276

		 */

   277

		return;

   278

	}

   279

   289

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

   290

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

   291

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

   292

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

   293

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

   294

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

   295

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

   296

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

   297

	 */

   298

	symbol_c param_value = *prev_il_instruction;

   300

	identifier_c variable_name(param_name);

   301

	// SYM_REF1(il_assign_operator_c, variable_name)

   302

	il_assign_operator_c il_assign_operator(&variable_name);  

   303

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

   304

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

   305

	il_param_list_c il_param_list;

   306

	il_param_list.add_element(&il_param_assignment);

   307

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

   311

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

   312

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

   313

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

   314

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

   315

	 *

   316

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

   317

	 * correctly set up the il_fb_call.datatype variable!

   318

	 */

   321

	il_fb_call.accept(*this);

   323

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

   324

	/* NOTE:

   325

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

   326

	 * is actually the prev_il_instruction.

   327

	 * 

   328

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

   329

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

   330

	 *

   331

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

   332

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

   333

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

   334

	 * and we set it to NULL.

   335

	 *

   336

	 * However, we only do that if:

   337

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

   338

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

   339

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

   340

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

   341

	 *     FB call must be left unchanged!

   342

	 */

   348

}

   349

   350

   351

/* a helper function... */

   352

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

   353

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

   354

	 *       in the code.

   355

	 */

   356

	if (symbol == NULL) return NULL;

   357

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

   358

}

   359

   360

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

   361

/* B 1.2 - Constants */

   362

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

   363

   364

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

   365

/* B 1.3 - Data types */

   366

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

   367

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

   368

/* B 1.3.3 - Derived data types */

   369

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

   370

/*  signed_integer DOTDOT signed_integer */

   371

// SYM_REF2(subrange_c, lower_limit, upper_limit)

   372

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

   373

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

   374

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

   375

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

   376

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

   377

	return NULL;

   378

}

   379

   380

/* simple_specification ASSIGN constant */

   381

// SYM_REF2(simple_spec_init_c, simple_specification, constant)

   382

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

   383

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

   384

	if (NULL != symbol->constant) {

   385

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

   386

		if (typeoffset >= 0)

   387

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

   388

	}

   389

	return NULL;

   390

}

   391

   392

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

   393

/* B 1.4 - Variables */

   394

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

   395

   396

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

   397

/* B 1.4.1 - Directly Represented Variables */

   398

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

   399

   400

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

   401

/* B 1.4.2 - Multi-element variables */

   402

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

   403

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

   404

// SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   405

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

   406

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

   407

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

   408

	return NULL;

   409

}

   410

   411

   412

/* subscript_list ',' subscript */

   413

// SYM_LIST(subscript_list_c)

   414

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

   415

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

   416

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

   417

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

   418

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

   419

		}

   420

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

   421

	}

   422

	return NULL;  

   423

}

   424

   425

   426

   427

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

   428

/* B 1.5 Program organization units */

   429

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

   430

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

   431

/* B 1.5.1 Functions */

   432

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

   433

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

   434

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   435

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

   436

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

   437

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

   438

	delete search_varfb_instance_type;

   439

	search_varfb_instance_type = NULL;

   440

	return NULL;

   441

}

   442

   443

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

   444

/* B 1.5.2 Function blocks */

   445

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

   446

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

   447

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   448

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

   449

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

   450

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

   451

	delete search_varfb_instance_type;

   452

	search_varfb_instance_type = NULL;

   453

	return NULL;

   454

}

   455

   456

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

   457

/* B 1.5.3 Programs */

   458

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

   459

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

   460

	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

   461

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

   462

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

   463

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

   464

	delete search_varfb_instance_type;

   465

	search_varfb_instance_type = NULL;

   466

	return NULL;

   467

}

   468

   469

   470

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

   471

/* B 1.7 Configuration elements */

   472

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

   473

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

   474

	// TODO !!!

   475

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

   476

	return NULL;

   477

}

   478

   479

   480

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

   481

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

   482

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

   483

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

   484

/* B 2.1 Instructions and Operands */

   485

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

   486

   487

/*| instruction_list il_instruction */

   488

// SYM_LIST(instruction_list_c)

   489

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

   490

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

   491

	 * so we can not use the base class' visitor 

   492

	 */

   493

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

   494

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

   495

	}

   496

	return NULL;

   497

}

   498

   499

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

   500

// SYM_REF2(il_instruction_c, label, il_instruction)

   501

// void *visit(instruction_list_c *symbol);

   502

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

   503

	if (NULL == symbol->il_instruction) {

   504

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

   505

		if (NULL != symbol->prev_il_instruction)

   506

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