msousa@417: /*
msousa@417:  *  matiec - a compiler for the programming languages defined in IEC 61131-3
msousa@417:  *
msousa@417:  *  Copyright (C) 2009-2012  Mario de Sousa (msousa@fe.up.pt)
msousa@417:  *  Copyright (C) 2012       Manuele Conti (manuele.conti@sirius-es.it)
msousa@417:  *  Copyright (C) 2012       Matteo Facchinetti (matteo.facchinetti@sirius-es.it)
msousa@417:  *
msousa@417:  *  This program is free software: you can redistribute it and/or modify
msousa@417:  *  it under the terms of the GNU General Public License as published by
msousa@417:  *  the Free Software Foundation, either version 3 of the License, or
msousa@417:  *  (at your option) any later version.
msousa@417:  *
msousa@417:  *  This program is distributed in the hope that it will be useful,
msousa@417:  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
msousa@417:  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
msousa@417:  *  GNU General Public License for more details.
msousa@417:  *
msousa@417:  *  You should have received a copy of the GNU General Public License
msousa@417:  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
msousa@417:  *
msousa@417:  *
msousa@417:  * This code is made available on the understanding that it will not be
msousa@417:  * used in safety-critical situations without a full and competent review.
msousa@417:  */
msousa@417: 
msousa@417: /*
msousa@417:  * An IEC 61131-3 compiler.
msousa@417:  *
msousa@417:  * Based on the
msousa@417:  * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
msousa@417:  *
msousa@417:  */
msousa@417: 
msousa@417: 
msousa@541: /* TODO - things yet not checked by this data type checker...
msousa@541:  *
msousa@541:  * - check variable declarations
msousa@541:  * - check data type declarations
msousa@541:  * - check inside configurations (variable declarations)
msousa@541:  * - check SFC code
msousa@541:  * - must fix S and R IL functions (includes potientialy fixing stage4 code!) 
msousa@541:  */
msousa@541: 
msousa@541: 
msousa@552: /* NOTE: The algorithm implemented here assumes that flow control analysis has already been completed!
msousa@552:  *       BEFORE running this visitor, be sure to CALL the flow_control_analysis_c visitor!
msousa@552:  */
msousa@552: 
msousa@552: 
msousa@417: /*
msousa@552:  *  Fill the candidate datatype list for all symbols that may legally 'have' a data type (e.g. variables, literals, function calls, expressions, etc.)
msousa@552:  * 
msousa@552:  *  The candidate datatype list will be filled with a list of all the data types that expression may legally take.
msousa@552:  *  For example, the very simple literal '0' (as in foo := 0), may represent a:
msousa@552:  *    BOOL, BYTE, WORD, DWORD, LWORD, USINT, SINT, UINT, INT, UDINT, DINT, ULINT, LINT (as well as the SAFE versions of these data tyes too!)
msousa@417:  */
msousa@417: 
msousa@604: #include <../main.hh>         /* required for UINT64_MAX, INT64_MAX, INT64_MIN, ... */
msousa@417: #include "fill_candidate_datatypes.hh"
msousa@417: #include "datatype_functions.hh"
msousa@417: #include <typeinfo>
msousa@417: #include <list>
msousa@417: #include <string>
msousa@417: #include <string.h>
msousa@417: #include <strings.h>
msousa@417: 
msousa@612: #define GET_CVALUE(dtype, symbol)             ((symbol)->const_value._##dtype.value)
msousa@612: #define VALID_CVALUE(dtype, symbol)           (symbol_c::cs_const_value == (symbol)->const_value._##dtype.status)
msousa@612: #define IS_OVERFLOW(dtype, symbol)            (symbol_c::cs_overflow == (symbol)->const_value._##dtype.status)
conti@603: 
msousa@417: /* set to 1 to see debug info during execution */
msousa@454: static int debug = 0;
msousa@417: 
msousa@417: fill_candidate_datatypes_c::fill_candidate_datatypes_c(symbol_c *ignore) {
msousa@417: }
msousa@417: 
msousa@417: fill_candidate_datatypes_c::~fill_candidate_datatypes_c(void) {
msousa@417: }
msousa@417: 
msousa@478: symbol_c *fill_candidate_datatypes_c::widening_conversion(symbol_c *left_type, symbol_c *right_type, const struct widen_entry widen_table[]) {
msousa@417: 	int k;
msousa@417: 	/* find a widening table entry compatible */
msousa@417: 	for (k = 0; NULL != widen_table[k].left;  k++)
msousa@478: 		if ((typeid(*left_type) == typeid(*widen_table[k].left)) && (typeid(*right_type) == typeid(*widen_table[k].right)))
conti@476:                       return widen_table[k].result;
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@421: 
msousa@465: /* add a data type to a candidate data type list, while guaranteeing no duplicate entries! */
msousa@465: /* Returns true if it really did add the datatype to the list, or false if it was already present in the list! */
msousa@465: bool fill_candidate_datatypes_c::add_datatype_to_candidate_list(symbol_c *symbol, symbol_c *datatype) {
msousa@478:   /* If it is an invalid data type, do not insert!
msousa@478:    * NOTE: it reduces overall code size to do this test here, instead of doing every time before calling the add_datatype_to_candidate_list() function. 
msousa@478:    */
msousa@478:   if (!is_type_valid(datatype)) /* checks for NULL and invalid_type_name_c */
msousa@478:     return false;
msousa@478: 
msousa@465:   if (search_in_candidate_datatype_list(datatype, symbol->candidate_datatypes) >= 0) 
msousa@465:     /* already in the list, Just return! */
msousa@465:     return false;
msousa@465:   
msousa@465:   /* not yet in the candidate data type list, so we insert it now! */
msousa@465:   symbol->candidate_datatypes.push_back(datatype);
msousa@465:   return true;
msousa@465: }
msousa@465:     
msousa@465:     
msousa@472: bool fill_candidate_datatypes_c::add_2datatypes_to_candidate_list(symbol_c *symbol, symbol_c *datatype1, symbol_c *datatype2) {
msousa@472:   add_datatype_to_candidate_list(symbol, datatype1);
msousa@472:   add_datatype_to_candidate_list(symbol, datatype2);
msousa@472:   return true;
msousa@472: }
conti@603: 
msousa@607: 
msousa@607: 
conti@603: void fill_candidate_datatypes_c::remove_incompatible_datatypes(symbol_c *symbol) {
msousa@607:   #ifdef __REMOVE__
msousa@607:     #error __REMOVE__ macro already exists. Choose another name!
msousa@607:   #endif
msousa@607:   #define __REMOVE__(datatype)\
msousa@607:       remove_from_candidate_datatype_list(&search_constant_type_c::datatype,       symbol->candidate_datatypes);\
msousa@607:       remove_from_candidate_datatype_list(&search_constant_type_c::safe##datatype, symbol->candidate_datatypes);
msousa@607:   
msousa@607:   {/* Remove unsigned data types */
msousa@607:     uint64_t value = 0;
msousa@607:     if (VALID_CVALUE( uint64, symbol)) value = GET_CVALUE(uint64, symbol);
msousa@607:     if (IS_OVERFLOW ( uint64, symbol)) value = (uint64_t)UINT32_MAX + (uint64_t)1;
msousa@607:     
msousa@607:     if (value > 1          )          {__REMOVE__(bool_type_name);}
msousa@607:     if (value > UINT8_MAX  )          {__REMOVE__(usint_type_name);  __REMOVE__( byte_type_name);}
msousa@607:     if (value > UINT16_MAX )          {__REMOVE__( uint_type_name);  __REMOVE__( word_type_name);}
msousa@607:     if (value > UINT32_MAX )          {__REMOVE__(udint_type_name);  __REMOVE__(dword_type_name);}
msousa@607:     if (IS_OVERFLOW( uint64, symbol)) {__REMOVE__(ulint_type_name);  __REMOVE__(lword_type_name);}
conti@603:   }
msousa@607: 
msousa@607:   {/* Remove signed data types */
msousa@607:     int64_t value = 0;
msousa@607:     if (VALID_CVALUE(  int64, symbol)) value = GET_CVALUE(int64, symbol);
msousa@607:     if (IS_OVERFLOW (  int64, symbol)) value = (int64_t)INT32_MAX + (int64_t)1;
msousa@607:     
msousa@609:     if ((value <  INT8_MIN) || (value >  INT8_MAX)) {__REMOVE__(sint_type_name);}
msousa@609:     if ((value < INT16_MIN) || (value > INT16_MAX)) {__REMOVE__( int_type_name);}
msousa@609:     if ((value < INT32_MIN) || (value > INT32_MAX)) {__REMOVE__(dint_type_name);}
msousa@609:     if (IS_OVERFLOW( int64, symbol))                {__REMOVE__(lint_type_name);}
conti@603:   }
msousa@607:     
msousa@607:   {/* Remove floating point data types */
msousa@607:     real64_t value = 0;
msousa@607:     if (VALID_CVALUE( real64, symbol)) value = GET_CVALUE(real64, symbol);
msousa@610:     if (IS_OVERFLOW ( real64, symbol)) value = (real64_t)REAL32_MAX + (real64_t)1;
msousa@607:     if (value >  REAL32_MAX )         {__REMOVE__( real_type_name);}
msousa@607:     if (value < -REAL32_MAX )         {__REMOVE__( real_type_name);}
msousa@607:     if (IS_OVERFLOW( real64, symbol)) {__REMOVE__(lreal_type_name);}
conti@603:   }
msousa@607:   #undef __REMOVE__
conti@603: }
msousa@465:     
msousa@421: 
msousa@420: /* returns true if compatible function/FB invocation, otherwise returns false */
msousa@424: /* Assumes that the candidate_datatype lists of all the parameters being passed haved already been filled in */
msousa@443: /*
msousa@443:  * All parameters being passed to the called function MUST be in the parameter list to which f_call points to!
msousa@443:  * This means that, for non formal function calls in IL, de current (default value) must be artificially added to the
msousa@443:  * beginning of the parameter list BEFORE calling handle_function_call().
msousa@443:  */
msousa@420: bool fill_candidate_datatypes_c::match_nonformal_call(symbol_c *f_call, symbol_c *f_decl) {
msousa@449: 	symbol_c *call_param_value,  *param_datatype;
msousa@417: 	identifier_c *param_name;
msousa@417: 	function_param_iterator_c       fp_iterator(f_decl);
msousa@417: 	function_call_param_iterator_c fcp_iterator(f_call);
msousa@417: 	int extensible_parameter_highest_index = -1;
msousa@417: 	unsigned int i;
msousa@417: 
msousa@417: 	/* Iterating through the non-formal parameters of the function call */
msousa@417: 	while((call_param_value = fcp_iterator.next_nf()) != NULL) {
msousa@417: 		/* Iterate to the next parameter of the function being called.
msousa@417: 		 * Get the name of that parameter, and ignore if EN or ENO.
msousa@417: 		 */
msousa@417: 		do {
msousa@417: 			param_name = fp_iterator.next();
msousa@417: 			/* If there is no other parameter declared, then we are passing too many parameters... */
msousa@420: 			if(param_name == NULL) return false;
msousa@417: 		} while ((strcmp(param_name->value, "EN") == 0) || (strcmp(param_name->value, "ENO") == 0));
msousa@417: 
msousa@455: 		/* TODO: verify if it is lvalue when INOUT or OUTPUT parameters! */
msousa@417: 		/* Get the parameter type */
msousa@449: 		param_datatype = base_type(fp_iterator.param_type());
msousa@420: 		
msousa@420: 		/* check whether one of the candidate_data_types of the value being passed is the same as the param_type */
msousa@449: 		if (search_in_candidate_datatype_list(param_datatype, call_param_value->candidate_datatypes) < 0)
msousa@442: 			return false; /* return false if param_type not in the list! */
msousa@420: 	}
msousa@420: 	/* call is compatible! */
msousa@420: 	return true;
msousa@420: }
msousa@420: 
msousa@421: 
msousa@421: 
msousa@420: /* returns true if compatible function/FB invocation, otherwise returns false */
msousa@424: /* Assumes that the candidate_datatype lists of all the parameters being passed haved already been filled in */
msousa@455: bool fill_candidate_datatypes_c::match_formal_call(symbol_c *f_call, symbol_c *f_decl, symbol_c **first_param_datatype) {
msousa@449: 	symbol_c *call_param_value, *call_param_name, *param_datatype;
msousa@417: 	symbol_c *verify_duplicate_param;
msousa@417: 	identifier_c *param_name;
msousa@417: 	function_param_iterator_c       fp_iterator(f_decl);
msousa@417: 	function_call_param_iterator_c fcp_iterator(f_call);
msousa@417: 	int extensible_parameter_highest_index = -1;
msousa@417: 	identifier_c *extensible_parameter_name;
msousa@417: 	unsigned int i;
msousa@455: 	bool is_first_param = true;
msousa@417: 
msousa@417: 	/* Iterating through the formal parameters of the function call */
msousa@417: 	while((call_param_name = fcp_iterator.next_f()) != NULL) {
msousa@417: 		/* Obtaining the value being passed in the function call */
msousa@417: 		call_param_value = fcp_iterator.get_current_value();
msousa@417: 		/* the following should never occur. If it does, then we have a bug in our code... */
msousa@417: 		if (NULL == call_param_value) ERROR;
msousa@417: 
msousa@449: 		/* Obtaining the assignment direction:  := (assign_in) or => (assign_out) */
msousa@449: 		function_call_param_iterator_c::assign_direction_t call_param_dir = fcp_iterator.get_assign_direction();
msousa@449: 
msousa@417: 		/* Checking if there are duplicated parameter values */
msousa@417: 		verify_duplicate_param = fcp_iterator.search_f(call_param_name);
msousa@417: 		if(verify_duplicate_param != call_param_value)
msousa@420: 			return false;
msousa@417: 
msousa@417: 		/* Obtaining the type of the value being passed in the function call */
msousa@417: 		std::vector <symbol_c *>&call_param_types = call_param_value->candidate_datatypes;
msousa@417: 
msousa@417: 		/* Find the corresponding parameter in function declaration */
msousa@417: 		param_name = fp_iterator.search(call_param_name);
msousa@421: 		if(param_name == NULL) return false;
msousa@449: 		/* Get the parameter data type */
msousa@449: 		param_datatype = base_type(fp_iterator.param_type());
msousa@449: 		/* Get the parameter direction: IN, OUT, IN_OUT */
msousa@449: 		function_param_iterator_c::param_direction_t param_dir = fp_iterator.param_direction();
msousa@449: 
msousa@449: 		/* check whether direction (IN, OUT, IN_OUT) and assignment types (:= , =>) are compatible !!! */
msousa@449: 		if          (function_call_param_iterator_c::assign_in  == call_param_dir) {
msousa@449: 			if ((function_param_iterator_c::direction_in    != param_dir) &&
msousa@449: 			    (function_param_iterator_c::direction_inout != param_dir))
msousa@449: 				return false;
msousa@449: 		} else if   (function_call_param_iterator_c::assign_out == call_param_dir) {
msousa@449: 			if ((function_param_iterator_c::direction_out   != param_dir))
msousa@449: 				return false;
msousa@449: 		} else ERROR;
msousa@449: 		
msousa@421: 		/* check whether one of the candidate_data_types of the value being passed is the same as the param_type */
msousa@449: 		if (search_in_candidate_datatype_list(param_datatype, call_param_types) < 0)
msousa@442: 			return false; /* return false if param_type not in the list! */
msousa@455: 		
msousa@455: 		/* If this is the first parameter, then copy the datatype to *first_param_datatype */
msousa@455: 		if (is_first_param)
msousa@455: 			if (NULL != first_param_datatype)
msousa@455: 				*first_param_datatype = param_datatype;
msousa@455: 		is_first_param = false;
msousa@421: 	}
msousa@421: 	/* call is compatible! */
msousa@420: 	return true;
msousa@417: }
msousa@417: 
msousa@421: 
msousa@421: 
msousa@421: 
msousa@438: /* Handle a generic function call!
msousa@438:  * Assumes that the parameter_list containing the values being passed in this function invocation
msousa@438:  * has already had all the candidate_datatype lists filled in!
msousa@438:  *
msousa@438:  * All parameters being passed to the called function MUST be in the parameter list to which f_call points to!
msousa@438:  * This means that, for non formal function calls in IL, de current (default value) must be artificially added to the
msousa@438:  * beginning of the parameter list BEFORE calling handle_function_call().
msousa@438:  */
msousa@438: /*
msousa@438: typedef struct {
msousa@438:   symbol_c *function_name,
msousa@438:   symbol_c *nonformal_operand_list,
msousa@438:   symbol_c *   formal_operand_list,
msousa@438: 
msousa@438:   std::vector <symbol_c *> &candidate_functions,  
msousa@438:   symbol_c &*called_function_declaration,
msousa@438:   int      &extensible_param_count
msousa@438: } generic_function_call_t;
msousa@438: */
msousa@438: /*
msousa@438: void narrow_candidate_datatypes_c::narrow_function_invocation(symbol_c *fcall, generic_function_call_t fcall_data) {
msousa@438: void *fill_candidate_datatypes_c::handle_function_call(symbol_c *f_call, symbol_c *function_name, invocation_type_t invocation_type,
msousa@438:                                                        std::vector <symbol_c *> *candidate_datatypes,
msousa@438:                                                        std::vector <symbol_c *> *candidate_functions) {
msousa@438:   */
msousa@438: void fill_candidate_datatypes_c::handle_function_call(symbol_c *fcall, generic_function_call_t fcall_data) {
msousa@438: 	function_declaration_c *f_decl;
msousa@438: 	list_c *parameter_list;
msousa@438: 	list_c *parameter_candidate_datatypes;
msousa@438: 	symbol_c *returned_parameter_type;
msousa@438: 
msousa@438: 	if (debug) std::cout << "function()\n";
msousa@438: 
msousa@438: 	function_symtable_t::iterator lower = function_symtable.lower_bound(fcall_data.function_name);
msousa@438: 	function_symtable_t::iterator upper = function_symtable.upper_bound(fcall_data.function_name);
msousa@438: 	/* If the name of the function being called is not found in the function symbol table, then this is an invalid call */
msousa@438: 	/* Since the lexical parser already checks for this, then if this occurs then we have an internal compiler error. */
msousa@438: 	if (lower == function_symtable.end()) ERROR;
msousa@438: 	
msousa@438: 	/* Look for all compatible function declarations, and add their return datatypes 
msousa@438: 	 * to the candidate_datatype list of this function invocation. 
msousa@438: 	 *
msousa@438: 	 * If only one function exists, we add its return datatype to the candidate_datatype list,
msousa@438: 	 * even if the parameters passed to it are invalid.
msousa@438: 	 * This guarantees that the remainder of the expression in which the function call is inserted
msousa@438: 	 * is treated as if the function call returns correctly, and therefore does not generate
msousa@438: 	 * spurious error messages.
msousa@438: 	 * Even if the parameters to the function call are invalid, doing this is still safe, as the 
msousa@438: 	 * expressions inside the function call will themselves have erros and will  guarantee that 
msousa@438: 	 * compilation is aborted in stage3 (in print_datatypes_error_c).
msousa@438: 	 */
msousa@438: 	if (function_symtable.multiplicity(fcall_data.function_name) == 1) {
msousa@438: 		f_decl = function_symtable.get_value(lower);
msousa@438: 		returned_parameter_type = base_type(f_decl->type_name);
msousa@465: 		if (add_datatype_to_candidate_list(fcall, returned_parameter_type))
msousa@465: 			/* we only add it to the function declaration list if this entry was not already present in the candidate datatype list! */
msousa@465: 			fcall_data.candidate_functions.push_back(f_decl);
msousa@465: 		
msousa@438: 	}
msousa@438: 	for(; lower != upper; lower++) {
msousa@438: 		bool compatible = false;
msousa@438: 		
msousa@438: 		f_decl = function_symtable.get_value(lower);
msousa@438: 		/* Check if function declaration in symbol_table is compatible with parameters */
msousa@438: 		if (NULL != fcall_data.nonformal_operand_list) compatible=match_nonformal_call(fcall, f_decl);
msousa@438: 		if (NULL != fcall_data.   formal_operand_list) compatible=   match_formal_call(fcall, f_decl);
msousa@438: 		if (compatible) {
msousa@438: 			/* Add the data type returned by the called functions. 
msousa@438: 			 * However, only do this if this data type is not already present in the candidate_datatypes list_c
msousa@438: 			 */
msousa@465: 			returned_parameter_type = base_type(f_decl->type_name);		
msousa@465: 			if (add_datatype_to_candidate_list(fcall, returned_parameter_type))
msousa@465: 				/* we only add it to the function declaration list if this entry was not already present in the candidate datatype list! */
msousa@438: 				fcall_data.candidate_functions.push_back(f_decl);
msousa@438: 		}
msousa@438: 	}
msousa@438: 	if (debug) std::cout << "end_function() [" << fcall->candidate_datatypes.size() << "] result.\n";
msousa@438: 	return;
msousa@438: }
msousa@438: 
msousa@438: 
msousa@447: /* handle implicit FB call in IL.
msousa@448:  * e.g.  CLK ton_var
msousa@447:  *        CU counter_var
msousa@447:  */
msousa@489: void *fill_candidate_datatypes_c::handle_implicit_il_fb_call(symbol_c *il_instruction, const char *param_name, symbol_c *&called_fb_declaration) {
msousa@447: 	symbol_c *fb_type_id = search_varfb_instance_type->get_basetype_id(il_operand);
msousa@455:   	/* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
msousa@455: 	if (NULL == fb_type_id) ERROR;
msousa@447: 
msousa@447: 	function_block_declaration_c *fb_decl = function_block_type_symtable.find_value(fb_type_id);
msousa@447: 	if (function_block_type_symtable.end_value() == fb_decl)
msousa@447: 		/* The il_operand is not the name of a FB instance. Most probably it is the name of a variable of some other type.
msousa@455: 		 * this is a semantic error.
msousa@447: 		 */
msousa@455: 		fb_decl = NULL;
msousa@455: 	
msousa@455: 	/* The narrow_candidate_datatypes_c does not rely on this called_fb_declaration pointer being == NULL to conclude that
msousa@455: 	 * we have a datatype incompatibility error, so we set it to fb_decl to allow the print_datatype_error_c to print out
msousa@455: 	 * more informative error messages!
msousa@450: 	 */
msousa@455: 	called_fb_declaration = fb_decl;
msousa@455: 
msousa@455: 	/* This implicit FB call does not change the value stored in the current/default IL variable */
msousa@456: 	/* It does, however, require that the datatype be compatible with the input parameter of the FB being called. 
msousa@456: 	 * If we were to follow the filling & narrowing algorithm correctly (implemented in fill_candidate_datatypes_c
msousa@456: 	 * & narrow_candidate_datatypes_c respectively), we should be restricting the candidate_datatpes to the datatypes
msousa@456: 	 * that are compatible to the FB call. 
msousa@456: 	 * However, doing the above will often result in some very confusing error messages for the user, especially in the case
msousa@456: 	 * in which the FB call is wrong, so the resulting cadidate datatypes is an empty list. In this case, the user would see
msousa@456: 	 * many error messages related to the IL instructions that follow the FB call, even though those IL instructions may be perfectly
msousa@456: 	 * correct.
msousa@456: 	 * For now, we will simply let the narrow_candidate_datatypes_c verify if the datatypes are compatible (something that should be done
msousa@456: 	 * here).
msousa@456: 	 */
msousa@455: 	if (NULL != prev_il_instruction)
msousa@467: 		il_instruction->candidate_datatypes = prev_il_instruction->candidate_datatypes; 
msousa@455: 
msousa@455: 	if (debug) std::cout << "handle_implicit_il_fb_call() [" << prev_il_instruction->candidate_datatypes.size() << "] ==> " << il_instruction->candidate_datatypes.size() << " result.\n";
msousa@489: 	return NULL;
msousa@447: }
msousa@438: 
msousa@438: 
msousa@479: 
msousa@479: 
msousa@479: /* handle a binary IL operator, like ADD, SUB, etc... */
msousa@479: void *fill_candidate_datatypes_c::handle_binary_operator(const struct widen_entry widen_table[], symbol_c *symbol, symbol_c *l_expr, symbol_c *r_expr) {
msousa@479: 	if (NULL == l_expr) /* if no prev_il_instruction */
msousa@479: 		return NULL; 
msousa@479: 
msousa@479: 	for(unsigned int i = 0; i < l_expr->candidate_datatypes.size(); i++)
msousa@479: 		for(unsigned int j = 0; j < r_expr->candidate_datatypes.size(); j++)
msousa@479: 			/* NOTE: add_datatype_to_candidate_list() will only really add the datatype if it is != NULL !!! */
msousa@479: 			add_datatype_to_candidate_list(symbol, widening_conversion(l_expr->candidate_datatypes[i], r_expr->candidate_datatypes[j], widen_table));
conti@603: 	remove_incompatible_datatypes(symbol);
msousa@479: 	if (debug) std::cout <<  "[" << l_expr->candidate_datatypes.size() << "," << r_expr->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@479: 	return NULL;
msousa@479: }
msousa@479: 
msousa@479: 
msousa@652: 
msousa@479: /* handle a binary ST expression, like '+', '-', etc... */
msousa@479: void *fill_candidate_datatypes_c::handle_binary_expression(const struct widen_entry widen_table[], symbol_c *symbol, symbol_c *l_expr, symbol_c *r_expr) {
msousa@479: 	l_expr->accept(*this);
msousa@479: 	r_expr->accept(*this);
msousa@479: 	return handle_binary_operator(widen_table, symbol, l_expr, r_expr);
msousa@479: }
msousa@479: 
msousa@479: 
msousa@479: 
msousa@652: /* handle the two equality comparison operations, i.e. = (euqal) and != (not equal) */
msousa@652: /* This function is special, as it will also allow enumeration data types to be compared, with the result being a BOOL data type!
msousa@652:  * This possibility os not expressed in the 'widening' tables, so we need to hard code it here
msousa@652:  */
msousa@652: void *fill_candidate_datatypes_c::handle_equality_comparison(const struct widen_entry widen_table[], symbol_c *symbol, symbol_c *l_expr, symbol_c *r_expr) {
msousa@652: 	search_base_type_c search_base_type;
msousa@652: 	handle_binary_expression(widen_table, symbol, l_expr, r_expr);
msousa@652: 	for(unsigned int i = 0; i < l_expr->candidate_datatypes.size(); i++)
msousa@652: 		for(unsigned int j = 0; j < r_expr->candidate_datatypes.size(); j++) {
msousa@652: 			if ((l_expr->candidate_datatypes[i] == r_expr->candidate_datatypes[j]) && search_base_type.type_is_enumerated(l_expr->candidate_datatypes[i]))
msousa@652: 				add_datatype_to_candidate_list(symbol, &search_constant_type_c::bool_type_name);
msousa@652: 		}
msousa@652: 	return NULL;
msousa@652: }
msousa@652: 
msousa@652: 
msousa@479: 
msousa@417: /* a helper function... */
msousa@417: symbol_c *fill_candidate_datatypes_c::base_type(symbol_c *symbol) {
msousa@417: 	/* NOTE: symbol == NULL is valid. It will occur when, for e.g., an undefined/undeclared symbolic_variable is used
msousa@417: 	 *       in the code.
msousa@417: 	 */
msousa@417: 	if (symbol == NULL) return NULL;
msousa@417: 	return (symbol_c *)symbol->accept(search_base_type);
msousa@417: }
msousa@417: 
msousa@417: /*********************/
msousa@417: /* B 1.2 - Constants */
msousa@417: /*********************/
msousa@417: /******************************/
msousa@417: /* B 1.2.1 - Numeric Literals */
msousa@417: /******************************/
msousa@472: #define sizeoftype(symbol) get_sizeof_datatype_c::getsize(symbol)
msousa@472: 
msousa@472: void *fill_candidate_datatypes_c::handle_any_integer(symbol_c *symbol) {
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::bool_type_name,  &search_constant_type_c::safebool_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::byte_type_name,  &search_constant_type_c::safebyte_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::word_type_name,  &search_constant_type_c::safeword_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::dword_type_name, &search_constant_type_c::safedword_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::lword_type_name, &search_constant_type_c::safelword_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::sint_type_name,  &search_constant_type_c::safesint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::int_type_name,   &search_constant_type_c::safeint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::dint_type_name,  &search_constant_type_c::safedint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::lint_type_name,  &search_constant_type_c::safelint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::usint_type_name, &search_constant_type_c::safeusint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::uint_type_name,  &search_constant_type_c::safeuint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::udint_type_name, &search_constant_type_c::safeudint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::ulint_type_name, &search_constant_type_c::safeulint_type_name);
conti@603: 	remove_incompatible_datatypes(symbol);
msousa@479: 	if (debug) std::cout << "ANY_INT [" << symbol->candidate_datatypes.size()<< "]" << std::endl;
msousa@472: 	return NULL;
msousa@472: }
msousa@472: 
msousa@472: 
msousa@472: 
msousa@488: void *fill_candidate_datatypes_c::handle_any_real(symbol_c *symbol) {
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::real_type_name,  &search_constant_type_c::safereal_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::lreal_type_name, &search_constant_type_c::safelreal_type_name);
conti@603: 	remove_incompatible_datatypes(symbol);
msousa@417: 	if (debug) std::cout << "ANY_REAL [" << symbol->candidate_datatypes.size() << "]" << std::endl;
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@472: 
msousa@488: 
msousa@488: void *fill_candidate_datatypes_c::handle_any_literal(symbol_c *symbol, symbol_c *symbol_value, symbol_c *symbol_type) {
msousa@488: 	symbol_value->accept(*this);
msousa@488: 	if (search_in_candidate_datatype_list(symbol_type, symbol_value->candidate_datatypes) >= 0)
msousa@488: 		add_datatype_to_candidate_list(symbol, symbol_type);
conti@603: 	remove_incompatible_datatypes(symbol);
msousa@643: 	if (debug) std::cout << "ANY_LITERAL [" << symbol->candidate_datatypes.size() << "]\n";
msousa@488: 	return NULL;
msousa@488: }
msousa@488: 
msousa@488: 
msousa@488: 
msousa@488: void *fill_candidate_datatypes_c::visit(    real_c *symbol) {return handle_any_real(symbol);}
msousa@488: void *fill_candidate_datatypes_c::visit(neg_real_c *symbol) {return handle_any_real(symbol);}
msousa@488: 
msousa@417: 
msousa@472: 
msousa@417: void *fill_candidate_datatypes_c::visit(neg_integer_c *symbol) {
msousa@650: 	/* Please read the comment in neg_expression_c method, as it also applies here */
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::int_type_name, &search_constant_type_c::safeint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::sint_type_name, &search_constant_type_c::safesint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::dint_type_name, &search_constant_type_c::safedint_type_name);
conti@603: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::lint_type_name, &search_constant_type_c::safelint_type_name);
conti@603: 	remove_incompatible_datatypes(symbol);
msousa@417: 	if (debug) std::cout << "neg ANY_INT [" << symbol->candidate_datatypes.size() << "]" << std::endl;
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@472: 
msousa@488: 
msousa@479: void *fill_candidate_datatypes_c::visit(integer_c        *symbol) {return handle_any_integer(symbol);}
msousa@479: void *fill_candidate_datatypes_c::visit(binary_integer_c *symbol) {return handle_any_integer(symbol);}
msousa@479: void *fill_candidate_datatypes_c::visit(octal_integer_c  *symbol) {return handle_any_integer(symbol);}
msousa@479: void *fill_candidate_datatypes_c::visit(hex_integer_c    *symbol) {return handle_any_integer(symbol);}
msousa@417: 
msousa@472: 
msousa@488: 
msousa@427: // SYM_REF2(integer_literal_c, type, value)
msousa@472: /*
msousa@472:  * integer_literal:
msousa@472:  *   integer_type_name '#' signed_integer
msousa@472:  * | integer_type_name '#' binary_integer
msousa@472:  * | integer_type_name '#' octal_integer
msousa@472:  * | integer_type_name '#' hex_integer
msousa@472:  */
msousa@488: void *fill_candidate_datatypes_c::visit(   integer_literal_c *symbol) {return handle_any_literal(symbol, symbol->value, symbol->type);}
msousa@488: void *fill_candidate_datatypes_c::visit(      real_literal_c *symbol) {return handle_any_literal(symbol, symbol->value, symbol->type);}
msousa@488: void *fill_candidate_datatypes_c::visit(bit_string_literal_c *symbol) {return handle_any_literal(symbol, symbol->value, symbol->type);}
msousa@488: 
msousa@488: void *fill_candidate_datatypes_c::visit(   boolean_literal_c *symbol) {
msousa@488: 	if (NULL != symbol->type) return handle_any_literal(symbol, symbol->value, symbol->type);
msousa@488: 
msousa@427: 	symbol->value->accept(*this);
msousa@488: 	symbol->candidate_datatypes = symbol->value->candidate_datatypes;
msousa@488: 	return NULL;
msousa@488: }
msousa@488: 
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(boolean_true_c *symbol) {
msousa@472: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::bool_type_name, &search_constant_type_c::safebool_type_name);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(boolean_false_c *symbol) {
msousa@472: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::bool_type_name, &search_constant_type_c::safebool_type_name);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: /*******************************/
msousa@417: /* B.1.2.2   Character Strings */
msousa@417: /*******************************/
msousa@417: void *fill_candidate_datatypes_c::visit(double_byte_character_string_c *symbol) {
msousa@472: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::wstring_type_name, &search_constant_type_c::safewstring_type_name);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(single_byte_character_string_c *symbol) {
msousa@472: 	add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::string_type_name, &search_constant_type_c::safestring_type_name);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: /***************************/
msousa@417: /* B 1.2.3 - Time Literals */
msousa@417: /***************************/
msousa@417: /************************/
msousa@417: /* B 1.2.3.1 - Duration */
msousa@417: /************************/
msousa@417: void *fill_candidate_datatypes_c::visit(duration_c *symbol) {
msousa@437: 	/* TODO: check whether the literal follows the rules specified in section '2.2.3.1 Duration' of the standard! */
msousa@459: 	
msousa@472: 	add_datatype_to_candidate_list(symbol, symbol->type_name);
msousa@417: 	if (debug) std::cout << "TIME_LITERAL [" << symbol->candidate_datatypes.size() << "]\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: /************************************/
msousa@417: /* B 1.2.3.2 - Time of day and Date */
msousa@417: /************************************/
msousa@479: void *fill_candidate_datatypes_c::visit(time_of_day_c   *symbol) {add_datatype_to_candidate_list(symbol, symbol->type_name); return NULL;}
msousa@479: void *fill_candidate_datatypes_c::visit(date_c          *symbol) {add_datatype_to_candidate_list(symbol, symbol->type_name); return NULL;}
msousa@479: void *fill_candidate_datatypes_c::visit(date_and_time_c *symbol) {add_datatype_to_candidate_list(symbol, symbol->type_name); return NULL;}
msousa@417: 
msousa@417: /**********************/
msousa@417: /* B 1.3 - Data types */
msousa@417: /**********************/
msousa@417: /********************************/
msousa@417: /* B 1.3.3 - Derived data types */
msousa@417: /********************************/
msousa@502: 
msousa@502: /* simple_specification ASSIGN constant */
msousa@502: // SYM_REF2(simple_spec_init_c, simple_specification, constant)
msousa@502: void *fill_candidate_datatypes_c::visit(simple_spec_init_c *symbol) {
msousa@502: 	if (NULL != symbol->constant) symbol->constant->accept(*this);
msousa@502: 	add_datatype_to_candidate_list(symbol->simple_specification, base_type(symbol->simple_specification));
msousa@502: 	symbol->candidate_datatypes = symbol->simple_specification->candidate_datatypes;
msousa@502: 	/* NOTE: Even if the constant and the type are of incompatible data types, we let the
msousa@502: 	 *       simple_spec_init_c object inherit the data type of the type declaration (simple_specification)
msousa@502: 	 *       This will let us produce more informative error messages when checking data type compatibility
msousa@502: 	 *       with located variables (AT %QW3.4 : WORD).
msousa@502: 	 */
msousa@502: 	// if (NULL != symbol->constant) intersect_candidate_datatype_list(symbol /*origin, dest.*/, symbol->constant /*with*/);
msousa@502: 	return NULL;
msousa@502: }
msousa@502: 
msousa@417: /*  signed_integer DOTDOT signed_integer */
msousa@417: // SYM_REF2(subrange_c, lower_limit, upper_limit)
msousa@417: void *fill_candidate_datatypes_c::visit(subrange_c *symbol) {
msousa@417: 	symbol->lower_limit->accept(*this);
msousa@417: 	symbol->upper_limit->accept(*this);
msousa@417: 	
msousa@417: 	for (unsigned int u = 0; u < symbol->upper_limit->candidate_datatypes.size(); u++) {
msousa@417: 		for(unsigned int l = 0; l < symbol->lower_limit->candidate_datatypes.size(); l++) {
msousa@417: 			if (is_type_equal(symbol->upper_limit->candidate_datatypes[u], symbol->lower_limit->candidate_datatypes[l]))
msousa@465: 				add_datatype_to_candidate_list(symbol, symbol->lower_limit->candidate_datatypes[l]);
msousa@417: 		}
msousa@417: 	}
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@443: /*  TYPE type_declaration_list END_TYPE */
msousa@443: // SYM_REF1(data_type_declaration_c, type_declaration_list)
msousa@443: /* NOTE: Not required. already handled by iterator_visitor_c base class */
msousa@443: /*
msousa@417: void *fill_candidate_datatypes_c::visit(data_type_declaration_c *symbol) {
msousa@443: 	symbol->type_declaration_list->accept(*this);
msousa@443: 	return NULL;
msousa@443: }
msousa@443: */
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(enumerated_value_c *symbol) {
msousa@417: 	symbol_c *enumerated_type;
msousa@417: 
msousa@417: 	if (NULL != symbol->type)
msousa@417: 		enumerated_type = symbol->type;
msousa@417: 	else {
msousa@417: 		enumerated_type = enumerated_value_symtable.find_value(symbol->value);
msousa@417: 		if (enumerated_type == enumerated_value_symtable.end_value())
msousa@417: 			enumerated_type = NULL;
msousa@417: 	}
msousa@417: 	enumerated_type = base_type(enumerated_type);
msousa@417: 	if (NULL != enumerated_type)
msousa@465: 		add_datatype_to_candidate_list(symbol, enumerated_type);
msousa@417: 
msousa@417: 	if (debug) std::cout << "ENUMERATE [" << symbol->candidate_datatypes.size() << "]\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: /*********************/
msousa@417: /* B 1.4 - Variables */
msousa@417: /*********************/
msousa@417: void *fill_candidate_datatypes_c::visit(symbolic_variable_c *symbol) {
msousa@479: 	add_datatype_to_candidate_list(symbol, search_varfb_instance_type->get_basetype_decl(symbol)); /* will only add if non NULL */
msousa@417: 	if (debug) std::cout << "VAR [" << symbol->candidate_datatypes.size() << "]\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@502: 
msousa@417: /********************************************/
msousa@417: /* B 1.4.1 - Directly Represented Variables */
msousa@417: /********************************************/
msousa@417: void *fill_candidate_datatypes_c::visit(direct_variable_c *symbol) {
msousa@417: 	/* Comment added by mario:
msousa@417: 	 * The following code is safe, actually, as the lexical parser guarantees the correct IEC61131-3 syntax was used.
msousa@417: 	 */
msousa@417: 	/* However, we should probably add an assertion in case we later change the lexical parser! */
msousa@417: 	/* if (symbol->value == NULL) ERROR;
msousa@417: 	 * if (symbol->value[0] == '\0') ERROR;
msousa@417: 	 * if (symbol->value[1] == '\0') ERROR;
msousa@417: 	 */
msousa@417: 	switch (symbol->value[2]) {
msousa@502: 		case 'x': case 'X': /* bit   -  1 bit  */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::bool_type_name);  break;
msousa@502: 		case 'b': case 'B': /* byte  -  8 bits */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::byte_type_name);  break;
msousa@502: 		case 'w': case 'W': /* word  - 16 bits */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::word_type_name);  break;
msousa@502: 		case 'd': case 'D': /* dword - 32 bits */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::dword_type_name); break;
msousa@502: 		case 'l': case 'L': /* lword - 64 bits */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::lword_type_name); break;
msousa@479:         	          /* if none of the above, then the empty string was used <=> boolean */
msousa@479: 		default:                        add_datatype_to_candidate_list(symbol, &search_constant_type_c::bool_type_name);  break;
msousa@417: 	}
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: /*************************************/
msousa@417: /* B 1.4.2 - Multi-element variables */
msousa@417: /*************************************/
msousa@417: /*  subscripted_variable '[' subscript_list ']' */
msousa@417: // SYM_REF2(array_variable_c, subscripted_variable, subscript_list)
msousa@417: void *fill_candidate_datatypes_c::visit(array_variable_c *symbol) {
msousa@417: 	/* get the declaration of the data type __stored__ in the array... */
msousa@417: 	/* if we were to want the data type of the array itself, then we should call_param_name
msousa@417: 	 * search_varfb_instance_type->get_basetype_decl(symbol->subscripted_variable)
msousa@417: 	 */
msousa@417: 	symbol_c *result = search_varfb_instance_type->get_basetype_decl(symbol);
msousa@465: 	if (NULL != result) add_datatype_to_candidate_list(symbol, result);
msousa@417: 	
msousa@417: 	/* recursively call the subscript list, so we can check the data types of the expressions used for the subscripts */
msousa@417: 	symbol->subscript_list->accept(*this);
msousa@417: 
msousa@417: 	if (debug) std::cout << "ARRAY_VAR [" << symbol->candidate_datatypes.size() << "]\n";	
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: /* subscript_list ',' subscript */
msousa@417: // SYM_LIST(subscript_list_c)
msousa@417: /* NOTE: we inherit from iterator visitor, so we do not need to implement this method... */
msousa@455: // void *fill_candidate_datatypes_c::visit(subscript_list_c *symbol)
msousa@417: 
msousa@417: 
msousa@417: /*  record_variable '.' field_selector */
msousa@417: /*  WARNING: input and/or output variables of function blocks
msousa@417:  *           may be accessed as fields of a structured variable!
msousa@417:  *           Code handling a structured_variable_c must take
msousa@417:  *           this into account!
msousa@417:  */
msousa@417: // SYM_REF2(structured_variable_c, record_variable, field_selector)
msousa@417: /* NOTE: We do not need to recursively determine the data types of each field_selector, as the search_varfb_instance_type
msousa@417:  * will do that for us. So we determine the candidate datatypes only for the full structured_variable.
msousa@417:  */
msousa@417: void *fill_candidate_datatypes_c::visit(structured_variable_c *symbol) {
msousa@479: 	add_datatype_to_candidate_list(symbol, search_varfb_instance_type->get_basetype_decl(symbol));  /* will only add if non NULL */
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@502: 
msousa@502: 
msousa@502: /******************************************/
msousa@502: /* B 1.4.3 - Declaration & Initialisation */
msousa@502: /******************************************/
msousa@502: 
msousa@502: void *fill_candidate_datatypes_c::visit(var1_list_c *symbol) {
msousa@502: #if 0   /* We don't really need to set the datatype of each variable. We just check the declaration itself! */
msousa@502:   for(int i = 0; i < symbol->n; i++) {
msousa@502:     add_datatype_to_candidate_list(symbol->elements[i], search_varfb_instance_type->get_basetype_decl(symbol->elements[i])); /* will only add if non NULL */
msousa@502:   }
msousa@502: #endif
msousa@502:   return NULL;
msousa@502: }  
msousa@502: 
msousa@502: 
msousa@502: /*  AT direct_variable */
msousa@502: // SYM_REF1(location_c, direct_variable)
msousa@502: void *fill_candidate_datatypes_c::visit(location_c *symbol) {
msousa@558:  /* This is a special situation. 
msousa@558:   *
msousa@558:   * The reason is that a located variable may be declared to be of any data type, as long as the size
msousa@558:   * matches the location (lines 1 3 and 4 of table 17). For example:
msousa@558:   *   var1 AT %MB42.0 : BYTE;
msousa@558:   *   var1 AT %MB42.1 : SINT;
msousa@558:   *   var1 AT %MB42.2 : USINT;
msousa@558:   *   var1 AT %MW64   : INT;
msousa@558:   *   var1 AT %MD56   : DINT;
msousa@558:   *   var1 AT %MD57   : REAL;
msousa@558:   *  are all valid!!
msousa@558:   *
msousa@558:   *  However, when used inside an expression, the direct variable (uses the same syntax as the location
msousa@558:   *  of a located variable) is limited to the following (ANY_BIT) data types:
msousa@558:   *    %MX --> BOOL
msousa@558:   *    %MB --> BYTE
msousa@558:   *    %MW --> WORD
msousa@558:   *    %MD --> DWORD
msousa@558:   *    %ML --> LWORD
msousa@558:   *
msousa@558:   *  So, in order to be able to analyse expressions with direct variables
msousa@558:   *   e.g:  var1 := 66 OR %MW34
msousa@558:   *  where the direct variable may only take the ANY_BIT data types, the fill_candidate_datatypes_c
msousa@558:   *  considers that only the ANY_BIT data types are allowed for a direct variable.
msousa@558:   *  However, it appears from the examples in the standard (lines 1 3 and 4 of table 17)
msousa@558:   *  a location may have any data type (presumably as long as the size in bits match).
msousa@558:   *  For this reason, a location_c may have more allowable data types than a direct_variable_c
msousa@558:   */
msousa@558: 
msousa@502: 	symbol->direct_variable->accept(*this);
msousa@558: 	for (unsigned int i = 0; i < symbol->direct_variable->candidate_datatypes.size(); i++) {
msousa@558:         	switch (get_sizeof_datatype_c::getsize(symbol->direct_variable->candidate_datatypes[i])) {
msousa@558: 			case  1: /* bit   -  1 bit  */
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::bool_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safebool_type_name);
msousa@558: 					break;
msousa@558: 			case  8: /* byte  -  8 bits */
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::byte_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safebyte_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::sint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safesint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::usint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeusint_type_name);
msousa@558: 					break;
msousa@558: 			case 16: /* word  - 16 bits */
msousa@558: 	 				add_datatype_to_candidate_list(symbol, &search_constant_type_c::word_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeword_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::int_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::uint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeuint_type_name);
msousa@558: 					break;
msousa@558: 			case 32: /* dword - 32 bits */
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::dword_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safedword_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::dint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safedint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::udint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeudint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::real_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safereal_type_name);
msousa@558: 					break;
msousa@558: 			case 64: /* lword - 64 bits */
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::lword_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safelword_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::lint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safelint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::ulint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeulint_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::lreal_type_name);
msousa@558: 					add_datatype_to_candidate_list(symbol, &search_constant_type_c::safelreal_type_name);
msousa@558: 					break;
msousa@558: 			default: /* if none of the above, then no valid datatype allowed... */
msousa@558: 					break;
msousa@558: 		} /* switch() */
msousa@558: 	} /* for */
msousa@558: 
msousa@502: 	return NULL;
msousa@502: }
msousa@502: 
msousa@502: 
msousa@502: /*  [variable_name] location ':' located_var_spec_init */
msousa@502: /* variable_name -> may be NULL ! */
msousa@502: // SYM_REF3(located_var_decl_c, variable_name, location, located_var_spec_init)
msousa@502: void *fill_candidate_datatypes_c::visit(located_var_decl_c *symbol) {
msousa@502:   symbol->located_var_spec_init->accept(*this);
msousa@502:   symbol->location->accept(*this);
msousa@523:   if (NULL != symbol->variable_name) {
msousa@523:     symbol->variable_name->candidate_datatypes = symbol->location->candidate_datatypes;
msousa@523:     intersect_candidate_datatype_list(symbol->variable_name /*origin, dest.*/, symbol->located_var_spec_init /*with*/);
msousa@523:   }
msousa@502:   return NULL;
msousa@502: }  
msousa@502: 
msousa@502: 
msousa@502: 
msousa@502: 
msousa@502: 
msousa@417: /************************************/
msousa@417: /* B 1.5 Program organization units */
msousa@417: /************************************/
msousa@417: /*********************/
msousa@417: /* B 1.5.1 Functions */
msousa@417: /*********************/
msousa@417: void *fill_candidate_datatypes_c::visit(function_declaration_c *symbol) {
msousa@479: 	if (debug) printf("Filling candidate data types list of function %s\n", ((token_c *)(symbol->derived_function_name))->value);
msousa@417: 	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);
msousa@417: 	symbol->var_declarations_list->accept(*this);
msousa@417: 	symbol->function_body->accept(*this);
msousa@417: 	delete search_varfb_instance_type;
msousa@417: 	search_varfb_instance_type = NULL;
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: /***************************/
msousa@417: /* B 1.5.2 Function blocks */
msousa@417: /***************************/
msousa@417: void *fill_candidate_datatypes_c::visit(function_block_declaration_c *symbol) {
msousa@479: 	if (debug) printf("Filling candidate data types list of FB %s\n", ((token_c *)(symbol->fblock_name))->value);
msousa@417: 	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);
msousa@417: 	symbol->var_declarations->accept(*this);
msousa@417: 	symbol->fblock_body->accept(*this);
msousa@417: 	delete search_varfb_instance_type;
msousa@417: 	search_varfb_instance_type = NULL;
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: /**********************/
msousa@417: /* B 1.5.3 - Programs */
msousa@417: /**********************/
msousa@417: void *fill_candidate_datatypes_c::visit(program_declaration_c *symbol) {
msousa@479: 	if (debug) printf("Filling candidate data types list in program %s\n", ((token_c *)(symbol->program_type_name))->value);
msousa@417: 	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);
msousa@417: 	symbol->var_declarations->accept(*this);
msousa@417: 	symbol->function_block_body->accept(*this);
msousa@417: 	delete search_varfb_instance_type;
msousa@417: 	search_varfb_instance_type = NULL;
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: 
msousa@417: /********************************/
msousa@417: /* B 1.7 Configuration elements */
msousa@417: /********************************/
msousa@417: void *fill_candidate_datatypes_c::visit(configuration_declaration_c *symbol) {
msousa@417: 	// TODO !!!
msousa@417: 	/* for the moment we must return NULL so semantic analysis of remaining code is not interrupted! */
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: /****************************************/
msousa@417: /* B.2 - Language IL (Instruction List) */
msousa@417: /****************************************/
msousa@417: /***********************************/
msousa@417: /* B 2.1 Instructions and Operands */
msousa@417: /***********************************/
msousa@443: 
msousa@443: /*| instruction_list il_instruction */
msousa@443: // SYM_LIST(instruction_list_c)
msousa@464: void *fill_candidate_datatypes_c::visit(instruction_list_c *symbol) {
msousa@465: 	/* In order to fill the data type candidates correctly
msousa@465: 	 * in IL instruction lists containing JMPs to labels that come before the JMP instruction
msousa@464: 	 * itself, we need to run the fill candidate datatypes algorithm twice on the Instruction List.
msousa@464: 	 * e.g.:  ...
msousa@464: 	 *          ld 23
msousa@464: 	 *   label1:st byte_var
msousa@464: 	 *          ld 34
msousa@464: 	 *          JMP label1     
msousa@464: 	 *
msousa@464: 	 * Note that the second time we run the algorithm, most of the candidate datatypes are already filled
msousa@464: 	 * in, so it will be able to produce tha correct candidate datatypes for the IL instruction referenced
msousa@464: 	 * by the label, as in the 2nd pass we already know the candidate datatypes of the JMP instruction!
msousa@464: 	 */
msousa@464: 	for(int j = 0; j < 2; j++) {
msousa@464: 		for(int i = 0; i < symbol->n; i++) {
msousa@464: 			symbol->elements[i]->accept(*this);
msousa@464: 		}
msousa@464: 	}
msousa@464: 	return NULL;
msousa@464: }
msousa@443: 
msousa@443: 
msousa@459: 
msousa@443: /* | label ':' [il_incomplete_instruction] eol_list */
msousa@443: // SYM_REF2(il_instruction_c, label, il_instruction)
msousa@443: // void *visit(instruction_list_c *symbol);
msousa@443: void *fill_candidate_datatypes_c::visit(il_instruction_c *symbol) {
msousa@448: 	if (NULL == symbol->il_instruction) {
msousa@450: 		/* This empty/null il_instruction does not change the value of the current/default IL variable.
msousa@450: 		 * So it inherits the candidate_datatypes from it's previous IL instructions!
msousa@450: 		 */
msousa@459: 		intersect_prev_candidate_datatype_lists(symbol);
msousa@448: 	} else {
msousa@459: 		il_instruction_c fake_prev_il_instruction = *symbol;
msousa@459: 		intersect_prev_candidate_datatype_lists(&fake_prev_il_instruction);
msousa@459: 
msousa@457: 		if (symbol->prev_il_instruction.size() == 0)  prev_il_instruction = NULL;
msousa@459: 		else                                          prev_il_instruction = &fake_prev_il_instruction;
msousa@448: 		symbol->il_instruction->accept(*this);
msousa@448: 		prev_il_instruction = NULL;
msousa@448: 
msousa@448: 		/* This object has (inherits) the same candidate datatypes as the il_instruction */
msousa@467: 		symbol->candidate_datatypes = symbol->il_instruction->candidate_datatypes;
msousa@448: 	}
msousa@443: 
msousa@443: 	return NULL;
msousa@443: }
msousa@443: 
msousa@443: 
msousa@443: 
msousa@417: void *fill_candidate_datatypes_c::visit(il_simple_operation_c *symbol) {
msousa@417: 	/* determine the data type of the operand */
msousa@417: 	if (NULL != symbol->il_operand) {
msousa@417: 		symbol->il_operand->accept(*this);
msousa@417: 	}
msousa@417: 	/* recursive call to fill the candidate data types list */
msousa@417: 	il_operand = symbol->il_operand;
msousa@417: 	symbol->il_simple_operator->accept(*this);
msousa@417: 	il_operand = NULL;
msousa@443: 	/* This object has (inherits) the same candidate datatypes as the il_simple_operator */
msousa@467: 	symbol->candidate_datatypes = symbol->il_simple_operator->candidate_datatypes;
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@438: 
msousa@438: /* | function_name [il_operand_list] */
msousa@438: /* NOTE: The parameters 'called_function_declaration' and 'extensible_param_count' are used to pass data between the stage 3 and stage 4. */
msousa@438: // SYM_REF2(il_function_call_c, function_name, il_operand_list, symbol_c *called_function_declaration; int extensible_param_count;)
msousa@417: void *fill_candidate_datatypes_c::visit(il_function_call_c *symbol) {
msousa@438: 	/* The first parameter of a non formal function call in IL will be the 'current value' (i.e. the prev_il_instruction)
msousa@438: 	 * In order to be able to handle this without coding special cases, we will simply prepend that symbol
msousa@451: 	 * to the il_operand_list, and remove it after calling handle_function_call().
msousa@438: 	 *
msousa@438: 	 * However, if no further paramters are given, then il_operand_list will be NULL, and we will
msousa@438: 	 * need to create a new object to hold the pointer to prev_il_instruction.
msousa@438: 	 */
msousa@438: 	if (NULL == symbol->il_operand_list)  symbol->il_operand_list = new il_operand_list_c;
msousa@438: 	if (NULL == symbol->il_operand_list)  ERROR;
msousa@438: 
msousa@438: 	symbol->il_operand_list->accept(*this);
msousa@438: 
msousa@451: 	if (NULL != prev_il_instruction) {
msousa@451: 		((list_c *)symbol->il_operand_list)->insert_element(prev_il_instruction, 0);	
msousa@451: 
msousa@451: 		generic_function_call_t fcall_param = {
msousa@451: 			/* fcall_param.function_name               = */ symbol->function_name,
msousa@451: 			/* fcall_param.nonformal_operand_list      = */ symbol->il_operand_list,
msousa@451: 			/* fcall_param.formal_operand_list         = */ NULL,
msousa@451: 			/* enum {POU_FB, POU_function} POU_type    = */ generic_function_call_t::POU_function,
msousa@451: 			/* fcall_param.candidate_functions         = */ symbol->candidate_functions,
msousa@451: 			/* fcall_param.called_function_declaration = */ symbol->called_function_declaration,
msousa@451: 			/* fcall_param.extensible_param_count      = */ symbol->extensible_param_count
msousa@451: 		};
msousa@451: 		handle_function_call(symbol, fcall_param);
msousa@451: 
msousa@451: 		/* Undo the changes to the abstract syntax tree we made above... */
msousa@451: 		((list_c *)symbol->il_operand_list)->remove_element(0);
msousa@451: 	}
msousa@451: 
msousa@451: 	/* Undo the changes to the abstract syntax tree we made above... */
msousa@451: 	if (((list_c *)symbol->il_operand_list)->n == 0) {
msousa@451: 		/* if the list becomes empty, then that means that it did not exist before we made these changes, so we delete it! */
msousa@451: 		delete 	symbol->il_operand_list;
msousa@451: 		symbol->il_operand_list = NULL;
msousa@451: 	}
msousa@451: 	
msousa@438: 	if (debug) std::cout << "il_function_call_c [" << symbol->candidate_datatypes.size() << "] result.\n";
msousa@438: 	return NULL;
msousa@438: }
msousa@438: 
msousa@438: 
msousa@417: /* | il_expr_operator '(' [il_operand] eol_list [simple_instr_list] ')' */
msousa@417: // SYM_REF3(il_expression_c, il_expr_operator, il_operand, simple_instr_list);
msousa@417: void *fill_candidate_datatypes_c::visit(il_expression_c *symbol) {
msousa@453:   symbol_c *prev_il_instruction_backup = prev_il_instruction;
msousa@453:   
msousa@417:   if (NULL != symbol->il_operand)
msousa@417:     symbol->il_operand->accept(*this);
msousa@453: 
msousa@453:   if(symbol->simple_instr_list != NULL)
msousa@417:     symbol->simple_instr_list->accept(*this);
msousa@417: 
msousa@417:   /* Now check the if the data type semantics of operation are correct,  */
msousa@452:   il_operand = symbol->simple_instr_list;
msousa@417:   prev_il_instruction = prev_il_instruction_backup;
msousa@417:   symbol->il_expr_operator->accept(*this);
msousa@417:   il_operand = NULL;
msousa@454:   
msousa@454:   /* This object has the same candidate datatypes as the il_expr_operator. */
msousa@467:   symbol->candidate_datatypes = symbol->il_expr_operator->candidate_datatypes;
msousa@417:   return NULL;
msousa@417: }
msousa@417: 
msousa@462: 
msousa@417: void *fill_candidate_datatypes_c::visit(il_jump_operation_c *symbol) {
msousa@417:   /* recursive call to fill the candidate data types list */
msousa@417:   il_operand = NULL;
msousa@417:   symbol->il_jump_operator->accept(*this);
msousa@417:   il_operand = NULL;
msousa@462:   /* This object has the same candidate datatypes as the il_jump_operator. */
msousa@467:   symbol->candidate_datatypes = symbol->il_jump_operator->candidate_datatypes;
msousa@417:   return NULL;
msousa@417: }
msousa@417: 
msousa@439: 
msousa@439: /*   il_call_operator prev_declared_fb_name
msousa@439:  * | il_call_operator prev_declared_fb_name '(' ')'
msousa@439:  * | il_call_operator prev_declared_fb_name '(' eol_list ')'
msousa@439:  * | il_call_operator prev_declared_fb_name '(' il_operand_list ')'
msousa@439:  * | il_call_operator prev_declared_fb_name '(' eol_list il_param_list ')'
msousa@439:  */
msousa@439: /* 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 */
msousa@439: // SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list, symbol_c *called_fb_declaration)
msousa@417: void *fill_candidate_datatypes_c::visit(il_fb_call_c *symbol) {
msousa@455: 	/* We do not call
msousa@455: 	 * fb_decl = search_varfb_instance_type->get_basetype_decl(symbol->fb_name);
msousa@455: 	 * because we want to make sure it is a FB instance, and not some other data type...
msousa@455: 	 */
msousa@455: 	symbol_c *fb_type_id = search_varfb_instance_type->get_basetype_id(symbol->fb_name);
msousa@455: 	/* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
msousa@455: 	if (NULL == fb_type_id) ERROR;
msousa@455: 
msousa@455:  	function_block_declaration_c *fb_decl = function_block_type_symtable.find_value(fb_type_id);
msousa@455: 	if (function_block_type_symtable.end_value() == fb_decl) 
msousa@455: 		/* The fb_name not the name of a FB instance. Most probably it is the name of a variable of some other type. */
msousa@455: 		fb_decl = NULL;
msousa@455: 
msousa@439: 	/* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
msousa@439: 	if (NULL == fb_decl) ERROR;
msousa@439: 
msousa@455: 	if (symbol->  il_param_list != NULL) symbol->il_param_list->accept(*this);
msousa@455: 	if (symbol->il_operand_list != NULL) symbol->il_operand_list->accept(*this);
msousa@439: 
msousa@439: 	/* The print_datatypes_error_c does not rely on this called_fb_declaration pointer being != NULL to conclude that
msousa@439: 	 * we have a datat type incompatibility error, so setting it to the correct fb_decl is actually safe,
msousa@439: 	 * as the compiler will never reach the compilation stage!
msousa@439: 	 */
msousa@439: 	symbol->called_fb_declaration = fb_decl;
msousa@439: 
msousa@455: 	/* Let the il_call_operator (CAL, CALC, or CALCN) determine the candidate datatypes of the il_fb_call_c... */
msousa@455: 	/* NOTE: We ignore whether the call is 'compatible' or not when filling in the candidate datatypes list.
msousa@455: 	 *       Even if it is not compatible, we fill in the candidate datatypes list correctly so that the following
msousa@455: 	 *       IL instructions may be handled correctly and debuged.
msousa@455: 	 *       Doing this is actually safe, as the parameter_list will still contain errors that will be found by
msousa@455: 	 *       print_datatypes_error_c, so the code will never reach stage 4!
msousa@455: 	 */
msousa@455: 	symbol->il_call_operator->accept(*this);
msousa@467: 	symbol->candidate_datatypes = symbol->il_call_operator->candidate_datatypes;
msousa@450: 
msousa@439: 	if (debug) std::cout << "FB [] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@439: 	return NULL;
msousa@439: }
msousa@439: 
msousa@417: 
msousa@438: /* | function_name '(' eol_list [il_param_list] ')' */
msousa@438: /* NOTE: The parameter 'called_function_declaration' is used to pass data between the stage 3 and stage 4. */
msousa@438: // SYM_REF2(il_formal_funct_call_c, function_name, il_param_list, symbol_c *called_function_declaration; int extensible_param_count;)
msousa@417: void *fill_candidate_datatypes_c::visit(il_formal_funct_call_c *symbol) {
msousa@438: 	symbol->il_param_list->accept(*this);
msousa@438: 
msousa@438: 	generic_function_call_t fcall_param = {
msousa@441: 		/* fcall_param.function_name               = */ symbol->function_name,
msousa@441: 		/* fcall_param.nonformal_operand_list      = */ NULL,
msousa@441: 		/* fcall_param.formal_operand_list         = */ symbol->il_param_list,
msousa@441: 		/* enum {POU_FB, POU_function} POU_type    = */ generic_function_call_t::POU_function,
msousa@441: 		/* fcall_param.candidate_functions         = */ symbol->candidate_functions,
msousa@441: 		/* fcall_param.called_function_declaration = */ symbol->called_function_declaration,
msousa@441: 		/* fcall_param.extensible_param_count      = */ symbol->extensible_param_count
msousa@438: 	};
msousa@438: 	handle_function_call(symbol, fcall_param);
msousa@438: 
msousa@438: 	if (debug) std::cout << "il_formal_funct_call_c [" << symbol->candidate_datatypes.size() << "] result.\n";
msousa@438: 	return NULL;
msousa@417: }
msousa@417: 
msousa@452: 
msousa@452: //     void *visit(il_operand_list_c *symbol);
msousa@452: 
msousa@452: 
msousa@452: /* | simple_instr_list il_simple_instruction */
msousa@452: /* This object is referenced by il_expression_c objects */
msousa@452: void *fill_candidate_datatypes_c::visit(simple_instr_list_c *symbol) {
msousa@453:   if (symbol->n <= 0)
msousa@453:     return NULL;  /* List is empty! Nothing to do. */
msousa@453:     
msousa@453:   for(int i = 0; i < symbol->n; i++)
msousa@452:     symbol->elements[i]->accept(*this);
msousa@453: 
msousa@453:   /* This object has (inherits) the same candidate datatypes as the last il_instruction */
msousa@467:   symbol->candidate_datatypes = symbol->elements[symbol->n-1]->candidate_datatypes;
msousa@452:   
msousa@452:   if (debug) std::cout << "simple_instr_list_c [" << symbol->candidate_datatypes.size() << "] result.\n";
msousa@452:   return NULL;
msousa@452: }
msousa@452: 
msousa@457: 
msousa@457: 
msousa@457: 
msousa@453: // SYM_REF1(il_simple_instruction_c, il_simple_instruction, symbol_c *prev_il_instruction;)
msousa@453: void *fill_candidate_datatypes_c::visit(il_simple_instruction_c *symbol) {
msousa@459:   if (symbol->prev_il_instruction.size() > 1) ERROR; /* There should be no labeled insructions inside an IL expression! */
msousa@457:   if (symbol->prev_il_instruction.size() == 0)  prev_il_instruction = NULL;
msousa@457:   else                                          prev_il_instruction = symbol->prev_il_instruction[0];
msousa@453:   symbol->il_simple_instruction->accept(*this);
msousa@453:   prev_il_instruction = NULL;
msousa@453: 
msousa@453:   /* This object has (inherits) the same candidate datatypes as the il_simple_instruction it points to */
msousa@467:   symbol->candidate_datatypes = symbol->il_simple_instruction->candidate_datatypes;
msousa@453:   return NULL;
msousa@453: }
msousa@453: 
msousa@453: 
msousa@417: /*
msousa@417:     void *visit(il_param_list_c *symbol);
msousa@417:     void *visit(il_param_assignment_c *symbol);
msousa@417:     void *visit(il_param_out_assignment_c *symbol);
msousa@417: */
msousa@417: 
msousa@417: /*******************/
msousa@417: /* B 2.2 Operators */
msousa@417: /*******************/
msousa@417: void *fill_candidate_datatypes_c::visit(LD_operator_c *symbol) {
msousa@417: 	for(unsigned int i = 0; i < il_operand->candidate_datatypes.size(); i++) {
msousa@465: 		add_datatype_to_candidate_list(symbol, il_operand->candidate_datatypes[i]);
msousa@417: 	}
msousa@417: 	if (debug) std::cout << "LD [" <<  il_operand->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(LDN_operator_c *symbol) {
msousa@417: 	for(unsigned int i = 0; i < il_operand->candidate_datatypes.size(); i++) {
msousa@417: 		if      (is_ANY_BIT_compatible(il_operand->candidate_datatypes[i]))
msousa@465: 			add_datatype_to_candidate_list(symbol, il_operand->candidate_datatypes[i]);
msousa@417: 	}
msousa@417: 	if (debug) std::cout << "LDN [" << il_operand->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(ST_operator_c *symbol) {
msousa@417: 	symbol_c *prev_instruction_type, *operand_type;
msousa@417: 
msousa@417: 	if (NULL == prev_il_instruction) return NULL;
msousa@417: 	for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
msousa@417: 		for(unsigned int j = 0; j < il_operand->candidate_datatypes.size(); j++) {
msousa@417: 			prev_instruction_type = prev_il_instruction->candidate_datatypes[i];
msousa@417: 			operand_type = il_operand->candidate_datatypes[j];
conti@440: 			if (is_type_equal(prev_instruction_type, operand_type))
msousa@465: 				add_datatype_to_candidate_list(symbol, prev_instruction_type);
msousa@417: 		}
msousa@417: 	}
msousa@417: 	if (debug) std::cout << "ST [" << prev_il_instruction->candidate_datatypes.size() << "," << il_operand->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(STN_operator_c *symbol) {
msousa@417: 	symbol_c *prev_instruction_type, *operand_type;
msousa@417: 
msousa@417: 	if (NULL == prev_il_instruction) return NULL;
msousa@417: 	for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
msousa@417: 		for(unsigned int j = 0; j < il_operand->candidate_datatypes.size(); j++) {
msousa@417: 			prev_instruction_type = prev_il_instruction->candidate_datatypes[i];
msousa@417: 			operand_type = il_operand->candidate_datatypes[j];
conti@440: 			if (is_type_equal(prev_instruction_type,operand_type) && is_ANY_BIT_compatible(operand_type))
msousa@465: 				add_datatype_to_candidate_list(symbol, prev_instruction_type);
msousa@417: 		}
msousa@417: 	}
msousa@417: 	if (debug) std::cout << "STN [" << prev_il_instruction->candidate_datatypes.size() << "," << il_operand->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(NOT_operator_c *symbol) {
msousa@470: 	/* NOTE: the standard allows syntax in which the NOT operator is followed by an optional <il_operand>
msousa@470: 	 *              NOT [<il_operand>]
msousa@470: 	 *       However, it does not define the semantic of the NOT operation when the <il_operand> is specified.
msousa@470: 	 *       We therefore consider it an error if an il_operand is specified!
msousa@612: 	 *       We do not need to generate an error message. This error will be caught somewhere else!
msousa@470: 	 */
msousa@470: 	if (NULL == prev_il_instruction) return NULL;
msousa@470: 	for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
msousa@470: 		if (is_ANY_BIT_compatible(prev_il_instruction->candidate_datatypes[i]))
msousa@470: 			add_datatype_to_candidate_list(symbol, prev_il_instruction->candidate_datatypes[i]);
msousa@470: 	}
msousa@470: 	if (debug) std::cout <<  "NOT_operator [" << prev_il_instruction->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@447: 
msousa@417: void *fill_candidate_datatypes_c::visit(S_operator_c *symbol) {
msousa@447:   /* TODO: what if this is a FB call ?? */
msousa@417: 	symbol_c *prev_instruction_type, *operand_type;
msousa@417: 
msousa@417: 	if (NULL == prev_il_instruction) return NULL;
msousa@417: 	for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
msousa@417: 		for(unsigned int j = 0; j < il_operand->candidate_datatypes.size(); j++) {
msousa@417: 			prev_instruction_type = prev_il_instruction->candidate_datatypes[i];
msousa@417: 			operand_type = il_operand->candidate_datatypes[j];
msousa@473: 			/* TODO: I believe the following is wrong! The data types of prev_instruction_type and operand_type DO NOT have to be equal.
msousa@473: 			 * the prev_instruction_type MUST be BOOL compatible.
msousa@473: 			 * I am not too sure about operand_type, does it have to be BOOL compatible, or can it be ANY_BIT compatible? Must check!
msousa@473: 			 */
conti@440: 			if (is_type_equal(prev_instruction_type,operand_type) && is_ANY_BOOL_compatible(operand_type))
msousa@465: 				add_datatype_to_candidate_list(symbol, prev_instruction_type);
msousa@417: 		}
msousa@417: 	}
msousa@417: 	if (debug) std::cout << "S [" << prev_il_instruction->candidate_datatypes.size() << "," << il_operand->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@447: 
msousa@417: void *fill_candidate_datatypes_c::visit(R_operator_c *symbol) {
msousa@447:   /* TODO: what if this is a FB call ?? */
msousa@417: 	symbol_c *prev_instruction_type, *operand_type;
msousa@417: 
msousa@417: 	if (NULL == prev_il_instruction) return NULL;
msousa@417: 	for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
msousa@417: 		for(unsigned int j = 0; j < il_operand->candidate_datatypes.size(); j++) {
msousa@417: 			prev_instruction_type = prev_il_instruction->candidate_datatypes[i];
msousa@417: 			operand_type = il_operand->candidate_datatypes[j];
msousa@473: 			/* TODO: I believe the following is wrong! The data types of prev_instruction_type and operand_type DO NOT have to be equal.
msousa@473: 			 * the prev_instruction_type MUST be BOOL compatible.
msousa@473: 			 * I am not too sure about operand_type, does it have to be BOOL compatible, or can it be ANY_BIT compatible? Must check!
msousa@473: 			 */
conti@440: 			if (is_type_equal(prev_instruction_type,operand_type) && is_ANY_BOOL_compatible(operand_type))
msousa@465: 				add_datatype_to_candidate_list(symbol, prev_instruction_type);
msousa@417: 		}
msousa@417: 	}
msousa@417: 	if (debug) std::cout << "R [" << prev_il_instruction->candidate_datatypes.size() << "," << il_operand->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@447: 
msousa@489: void *fill_candidate_datatypes_c::visit( S1_operator_c  *symbol) {return handle_implicit_il_fb_call(symbol,  "S1", symbol->called_fb_declaration);}
msousa@489: void *fill_candidate_datatypes_c::visit( R1_operator_c  *symbol) {return handle_implicit_il_fb_call(symbol,  "R1", symbol->called_fb_declaration);}
msousa@489: void *fill_candidate_datatypes_c::visit( CLK_operator_c *symbol) {return handle_implicit_il_fb_call(symbol, "CLK", symbol->called_fb_declaration);}
msousa@489: void *fill_candidate_datatypes_c::visit( CU_operator_c  *symbol) {return handle_implicit_il_fb_call(symbol,  "CU", symbol->called_fb_declaration);}
msousa@489: void *fill_candidate_datatypes_c::visit( CD_operator_c  *symbol) {return handle_implicit_il_fb_call(symbol,  "CD", symbol->called_fb_declaration);}
msousa@489: void *fill_candidate_datatypes_c::visit( PV_operator_c  *symbol) {return handle_implicit_il_fb_call(symbol,  "PV", symbol->called_fb_declaration);}
msousa@489: void *fill_candidate_datatypes_c::visit( IN_operator_c  *symbol) {return handle_implicit_il_fb_call(symbol,  "IN", symbol->called_fb_declaration);}
msousa@489: void *fill_candidate_datatypes_c::visit( PT_operator_c  *symbol) {return handle_implicit_il_fb_call(symbol,  "PT", symbol->called_fb_declaration);}
msousa@447: 
msousa@483: void *fill_candidate_datatypes_c::visit( AND_operator_c *symbol) {return handle_binary_operator(widen_AND_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit(  OR_operator_c *symbol) {return handle_binary_operator( widen_OR_table, symbol, prev_il_instruction, il_operand);}
msousa@483: void *fill_candidate_datatypes_c::visit( XOR_operator_c *symbol) {return handle_binary_operator(widen_XOR_table, symbol, prev_il_instruction, il_operand);}
msousa@483: void *fill_candidate_datatypes_c::visit(ANDN_operator_c *symbol) {return handle_binary_operator(widen_AND_table, symbol, prev_il_instruction, il_operand);}
msousa@483: void *fill_candidate_datatypes_c::visit( ORN_operator_c *symbol) {return handle_binary_operator( widen_OR_table, symbol, prev_il_instruction, il_operand);}
msousa@483: void *fill_candidate_datatypes_c::visit(XORN_operator_c *symbol) {return handle_binary_operator(widen_XOR_table, symbol, prev_il_instruction, il_operand);}
msousa@417: 
msousa@489: void *fill_candidate_datatypes_c::visit( ADD_operator_c *symbol) {return handle_binary_operator(widen_ADD_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit( SUB_operator_c *symbol) {return handle_binary_operator(widen_SUB_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit( MUL_operator_c *symbol) {return handle_binary_operator(widen_MUL_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit( DIV_operator_c *symbol) {return handle_binary_operator(widen_DIV_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit( MOD_operator_c *symbol) {return handle_binary_operator(widen_MOD_table, symbol, prev_il_instruction, il_operand);}
msousa@489: 
msousa@489: void *fill_candidate_datatypes_c::visit(  GT_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit(  GE_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit(  EQ_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit(  LT_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit(  LE_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
msousa@489: void *fill_candidate_datatypes_c::visit(  NE_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
msousa@484: 
msousa@484: 
msousa@417: 
msousa@487: void *fill_candidate_datatypes_c::handle_conditional_il_flow_control_operator(symbol_c *symbol) {
msousa@417: 	if (NULL == prev_il_instruction) return NULL;
msousa@417: 	for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
msousa@472: 		if (is_ANY_BOOL_compatible(prev_il_instruction->candidate_datatypes[i]))
msousa@465: 			add_datatype_to_candidate_list(symbol, prev_il_instruction->candidate_datatypes[i]);
msousa@417: 	}
msousa@487: 	return NULL;
msousa@487: }
msousa@487: 
msousa@489: void *fill_candidate_datatypes_c::visit(  CAL_operator_c *symbol) {if (NULL != prev_il_instruction) symbol->candidate_datatypes = prev_il_instruction->candidate_datatypes; return NULL;}
msousa@489: void *fill_candidate_datatypes_c::visit(  RET_operator_c *symbol) {if (NULL != prev_il_instruction) symbol->candidate_datatypes = prev_il_instruction->candidate_datatypes; return NULL;}
msousa@489: void *fill_candidate_datatypes_c::visit(  JMP_operator_c *symbol) {if (NULL != prev_il_instruction) symbol->candidate_datatypes = prev_il_instruction->candidate_datatypes; return NULL;}
msousa@487: void *fill_candidate_datatypes_c::visit( CALC_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
msousa@487: void *fill_candidate_datatypes_c::visit(CALCN_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
msousa@487: void *fill_candidate_datatypes_c::visit( RETC_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
msousa@487: void *fill_candidate_datatypes_c::visit(RETCN_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
msousa@487: void *fill_candidate_datatypes_c::visit( JMPC_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
msousa@487: void *fill_candidate_datatypes_c::visit(JMPCN_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
msousa@487: 
msousa@487: 
msousa@487: 
msousa@487: 
msousa@417: /* Symbol class handled together with function call checks */
msousa@417: // void *visit(il_assign_operator_c *symbol, variable_name);
msousa@417: /* Symbol class handled together with function call checks */
msousa@417: // void *visit(il_assign_operator_c *symbol, option, variable_name);
msousa@417: 
msousa@417: /***************************************/
msousa@417: /* B.3 - Language ST (Structured Text) */
msousa@417: /***************************************/
msousa@417: /***********************/
msousa@417: /* B 3.1 - Expressions */
msousa@417: /***********************/
msousa@652: void *fill_candidate_datatypes_c::visit(   or_expression_c  *symbol) {return handle_binary_expression  (widen_OR_table,  symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(   xor_expression_c *symbol) {return handle_binary_expression  (widen_XOR_table, symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(   and_expression_c *symbol) {return handle_binary_expression  (widen_AND_table, symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: 
msousa@652: void *fill_candidate_datatypes_c::visit(   equ_expression_c *symbol) {return handle_equality_comparison(widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(notequ_expression_c *symbol) {return handle_equality_comparison(widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(    lt_expression_c *symbol) {return handle_binary_expression  (widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(    gt_expression_c *symbol) {return handle_binary_expression  (widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(    le_expression_c *symbol) {return handle_binary_expression  (widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(    ge_expression_c *symbol) {return handle_binary_expression  (widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
msousa@652:  
msousa@652: void *fill_candidate_datatypes_c::visit(   add_expression_c *symbol) {return handle_binary_expression  (widen_ADD_table,  symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(   sub_expression_c *symbol) {return handle_binary_expression  (widen_SUB_table,  symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(   mul_expression_c *symbol) {return handle_binary_expression  (widen_MUL_table,  symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(   div_expression_c *symbol) {return handle_binary_expression  (widen_DIV_table,  symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit(   mod_expression_c *symbol) {return handle_binary_expression  (widen_MOD_table,  symbol, symbol->l_exp, symbol->r_exp);}
msousa@652: void *fill_candidate_datatypes_c::visit( power_expression_c *symbol) {return handle_binary_expression  (widen_EXPT_table, symbol, symbol->l_exp, symbol->r_exp);}
msousa@417: 
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(neg_expression_c *symbol) {
msousa@435:   /* NOTE: The standard defines the syntax for this 'negation' operation, but
msousa@435:    *       does not define the its semantics.
msousa@435:    *
msousa@435:    *       We could be tempted to consider that the semantics of the
msousa@435:    *       'negation' operation are similar/identical to the semantics of the 
msousa@435:    *       SUB expression/operation. This would include assuming that the
msousa@435:    *       possible datatypes for the 'negation' operation is also
msousa@435:    *       the same as those for the SUB expression/operation, namely ANY_MAGNITUDE.
msousa@435:    *
msousa@435:    *       However, this would then mean that the following ST code would be 
msousa@435:    *       syntactically and semantically correct:
msousa@650:    *       VAR uint_var : UINT END_VAR;
msousa@435:    *       uint_var := - (uint_var);
msousa@435:    *
msousa@650:    *       Assuming uint_var is not 0, the standard states that the above code should result in a 
msousa@650:    *       runtime error since the operation will result in an overflow. Since the above operation
msousa@650:    *       is only valid when uint_var=0, it would probably make more sense for the programmer to
msousa@650:    *       use if (uint_var=0) ..., so we will simply assume that the above statement simply
msousa@650:    *       does not make sense in any situation (whether or not uint_var is 0), and therefore
msousa@650:    *       we will not allow it.
msousa@650:    *       (Notice that doing so does not ago against the standard, as the standard does not
msousa@650:    *       explicitly define the semantics of the NEG operator, nor the data types it may accept
msousa@650:    *       as input. We are simply assuming that the NEG operator may not be applied to unsigned
msousa@650:    *       ANY_NUM data types!).
msousa@435:    *
msousa@435:    *       It is much easier for the compiler to detect this at compile time,
msousa@435:    *       and it is probably safer to the resulting code too.
msousa@435:    *
msousa@435:    *       To detect these tyes of errors at compile time, the easisest solution
msousa@435:    *       is to only allow ANY_NUM datatytpes that are signed.
msousa@435:    *        So, that is what we do here!
msousa@650:    *
msousa@650:    * NOTE: The above argument also applies to the neg_integer_c method!
msousa@435:    */
msousa@417: 	symbol->exp->accept(*this);
msousa@417: 	for (unsigned int i = 0; i < symbol->exp->candidate_datatypes.size(); i++) {
msousa@435: 		if (is_ANY_signed_MAGNITUDE_compatible(symbol->exp->candidate_datatypes[i]))
msousa@465: 			add_datatype_to_candidate_list(symbol, symbol->exp->candidate_datatypes[i]);
msousa@417: 	}
msousa@417: 	if (debug) std::cout << "neg [" << symbol->exp->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(not_expression_c *symbol) {
msousa@417: 	symbol->exp->accept(*this);
msousa@417: 	for (unsigned int i = 0; i < symbol->exp->candidate_datatypes.size(); i++) {
msousa@417: 		if      (is_ANY_BIT_compatible(symbol->exp->candidate_datatypes[i]))
msousa@465: 			add_datatype_to_candidate_list(symbol, symbol->exp->candidate_datatypes[i]);
msousa@417: 	}
msousa@417: 	if (debug) std::cout << "not [" << symbol->exp->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(function_invocation_c *symbol) {
msousa@438: 	if      (NULL != symbol->formal_param_list)        symbol->   formal_param_list->accept(*this);
msousa@438: 	else if (NULL != symbol->nonformal_param_list)     symbol->nonformal_param_list->accept(*this);
msousa@417: 	else ERROR;
msousa@438: 
msousa@438: 	generic_function_call_t fcall_param = {
msousa@441: 		/* fcall_param.function_name               = */ symbol->function_name,
msousa@441: 		/* fcall_param.nonformal_operand_list      = */ symbol->nonformal_param_list,
msousa@441: 		/* fcall_param.formal_operand_list         = */ symbol->formal_param_list,
msousa@441: 		/* enum {POU_FB, POU_function} POU_type    = */ generic_function_call_t::POU_function,
msousa@441: 		/* fcall_param.candidate_functions         = */ symbol->candidate_functions,
msousa@441: 		/* fcall_param.called_function_declaration = */ symbol->called_function_declaration,
msousa@441: 		/* fcall_param.extensible_param_count      = */ symbol->extensible_param_count
msousa@438: 	};
msousa@438: 	handle_function_call(symbol, fcall_param);
msousa@438: 
msousa@438: 	if (debug) std::cout << "function_invocation_c [" << symbol->candidate_datatypes.size() << "] result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@421: 
msousa@421: 
msousa@417: /********************/
msousa@417: /* B 3.2 Statements */
msousa@417: /********************/
msousa@417: // SYM_LIST(statement_list_c)
msousa@417: /* The visitor of the base class search_visitor_c will handle calling each instruction in the list.
msousa@417:  * We do not need to do anything here...
msousa@417:  */
msousa@417: // void *fill_candidate_datatypes_c::visit(statement_list_c *symbol)
msousa@417: 
msousa@417: 
msousa@417: /*********************************/
msousa@417: /* B 3.2.1 Assignment Statements */
msousa@417: /*********************************/
msousa@417: void *fill_candidate_datatypes_c::visit(assignment_statement_c *symbol) {
msousa@417: 	symbol_c *left_type, *right_type;
msousa@417: 
msousa@417: 	symbol->l_exp->accept(*this);
msousa@417: 	symbol->r_exp->accept(*this);
msousa@417: 	for (unsigned int i = 0; i < symbol->l_exp->candidate_datatypes.size(); i++) {
msousa@417: 		for(unsigned int j = 0; j < symbol->r_exp->candidate_datatypes.size(); j++) {
msousa@417: 			left_type = symbol->l_exp->candidate_datatypes[i];
msousa@417: 			right_type = symbol->r_exp->candidate_datatypes[j];
msousa@417: 			if (is_type_equal(left_type, right_type))
msousa@465: 				add_datatype_to_candidate_list(symbol, left_type);
msousa@417: 		}
msousa@417: 	}
msousa@417: 	if (debug) std::cout << ":= [" << symbol->l_exp->candidate_datatypes.size() << "," << symbol->r_exp->candidate_datatypes.size() << "] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
conti@418: /*****************************************/
conti@418: /* B 3.2.2 Subprogram Control Statements */
conti@418: /*****************************************/
conti@418: void *fill_candidate_datatypes_c::visit(fb_invocation_c *symbol) {
msousa@455: 	symbol_c *fb_type_id = search_varfb_instance_type->get_basetype_id(symbol->fb_name);
msousa@455: 	/* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
msousa@455: 	if (NULL == fb_type_id) ERROR;
msousa@455: 
msousa@455: 	function_block_declaration_c *fb_decl = function_block_type_symtable.find_value(fb_type_id);
msousa@455: 	if (function_block_type_symtable.end_value() == fb_decl) 
msousa@455: 		/* The fb_name not the name of a FB instance. Most probably it is the name of a variable of some other type. */
msousa@455: 		fb_decl = NULL;
msousa@455: 
msousa@424: 	/* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
conti@418: 	if (NULL == fb_decl) ERROR;
msousa@455: 	
msousa@455: 	if (symbol->   formal_param_list != NULL) symbol->formal_param_list->accept(*this);
msousa@455: 	if (symbol->nonformal_param_list != NULL) symbol->nonformal_param_list->accept(*this);
msousa@424: 
msousa@431: 	/* The print_datatypes_error_c does not rely on this called_fb_declaration pointer being != NULL to conclude that
msousa@431: 	 * we have a datat type incompatibility error, so setting it to the correct fb_decl is actually safe,
msousa@431: 	 * as the compiler will never reach the compilation stage!
msousa@431: 	 */
msousa@431: 	symbol->called_fb_declaration = fb_decl;
msousa@424: 
conti@418: 	if (debug) std::cout << "FB [] ==> "  << symbol->candidate_datatypes.size() << " result.\n";
conti@418: 	return NULL;
conti@418: }
conti@418: 
msousa@417: 
msousa@417: 
msousa@417: /********************************/
msousa@417: /* B 3.2.3 Selection Statements */
msousa@417: /********************************/
msousa@417: void *fill_candidate_datatypes_c::visit(if_statement_c *symbol) {
msousa@417: 	symbol->expression->accept(*this);
msousa@417: 	if (NULL != symbol->statement_list)
msousa@417: 		symbol->statement_list->accept(*this);
msousa@417: 	if (NULL != symbol->elseif_statement_list)
msousa@417: 		symbol->elseif_statement_list->accept(*this);
msousa@417: 	if (NULL != symbol->else_statement_list)
msousa@417: 		symbol->else_statement_list->accept(*this);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(elseif_statement_c *symbol) {
msousa@417: 	symbol->expression->accept(*this);
msousa@417: 	if (NULL != symbol->statement_list)
msousa@417: 		symbol->statement_list->accept(*this);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: /* CASE expression OF case_element_list ELSE statement_list END_CASE */
msousa@417: // SYM_REF3(case_statement_c, expression, case_element_list, statement_list)
msousa@417: void *fill_candidate_datatypes_c::visit(case_statement_c *symbol) {
msousa@417: 	symbol->expression->accept(*this);
msousa@417: 	if (NULL != symbol->case_element_list)
msousa@417: 		symbol->case_element_list->accept(*this);
msousa@417: 	if (NULL != symbol->statement_list)
msousa@417: 		symbol->statement_list->accept(*this);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: /* helper symbol for case_statement */
msousa@417: // SYM_LIST(case_element_list_c)
msousa@417: /* NOTE: visitor method for case_element_list_c is not required since we inherit from iterator_visitor_c */
msousa@417: 
msousa@417: /*  case_list ':' statement_list */
msousa@417: // SYM_REF2(case_element_c, case_list, statement_list)
msousa@417: /* NOTE: visitor method for case_element_c is not required since we inherit from iterator_visitor_c */
msousa@417: 
msousa@417: // SYM_LIST(case_list_c)
msousa@417: /* NOTE: visitor method for case_list_c is not required since we inherit from iterator_visitor_c */
msousa@417: 
msousa@417: /********************************/
msousa@417: /* B 3.2.4 Iteration Statements */
msousa@417: /********************************/
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(for_statement_c *symbol) {
msousa@417: 	symbol->control_variable->accept(*this);
msousa@417: 	symbol->beg_expression->accept(*this);
msousa@417: 	symbol->end_expression->accept(*this);
msousa@417: 	if (NULL != symbol->by_expression)
msousa@417: 		symbol->by_expression->accept(*this);
msousa@417: 	if (NULL != symbol->statement_list)
msousa@417: 		symbol->statement_list->accept(*this);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(while_statement_c *symbol) {
msousa@417: 	symbol->expression->accept(*this);
msousa@417: 	if (NULL != symbol->statement_list)
msousa@417: 		symbol->statement_list->accept(*this);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: void *fill_candidate_datatypes_c::visit(repeat_statement_c *symbol) {
msousa@417: 	symbol->expression->accept(*this);
msousa@417: 	if (NULL != symbol->statement_list)
msousa@417: 		symbol->statement_list->accept(*this);
msousa@417: 	return NULL;
msousa@417: }
msousa@417: 
msousa@417: 
msousa@417: 
msousa@417: 
msousa@417: 
msousa@417: