--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/stage3/fill_candidate_datatypes.cc Wed Aug 22 16:46:17 2012 +0200
@@ -0,0 +1,1571 @@
+/*
+ * matiec - a compiler for the programming languages defined in IEC 61131-3
+ *
+ * Copyright (C) 2009-2012 Mario de Sousa (msousa@fe.up.pt)
+ * Copyright (C) 2012 Manuele Conti (manuele.conti@sirius-es.it)
+ * Copyright (C) 2012 Matteo Facchinetti (matteo.facchinetti@sirius-es.it)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * This code is made available on the understanding that it will not be
+ * used in safety-critical situations without a full and competent review.
+ */
+
+/*
+ * An IEC 61131-3 compiler.
+ *
+ * Based on the
+ * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
+ *
+ */
+
+
+/* TODO - things yet not checked by this data type checker...
+ *
+ * - check variable declarations
+ * - check data type declarations
+ * - check inside configurations (variable declarations)
+ * - check SFC code
+ * - must fix S and R IL functions (includes potientialy fixing stage4 code!)
+ */
+
+
+/* NOTE: The algorithm implemented here assumes that flow control analysis has already been completed!
+ * BEFORE running this visitor, be sure to CALL the flow_control_analysis_c visitor!
+ */
+
+
+/*
+ * Fill the candidate datatype list for all symbols that may legally 'have' a data type (e.g. variables, literals, function calls, expressions, etc.)
+ *
+ * The candidate datatype list will be filled with a list of all the data types that expression may legally take.
+ * For example, the very simple literal '0' (as in foo := 0), may represent a:
+ * BOOL, BYTE, WORD, DWORD, LWORD, USINT, SINT, UINT, INT, UDINT, DINT, ULINT, LINT (as well as the SAFE versions of these data tyes too!)
+ */
+
+#include <../main.hh> /* required for UINT64_MAX, INT64_MAX, INT64_MIN, ... */
+#include "fill_candidate_datatypes.hh"
+#include "datatype_functions.hh"
+#include <typeinfo>
+#include <list>
+#include <string>
+#include <string.h>
+#include <strings.h>
+
+#define GET_CVALUE(dtype, symbol) ((symbol)->const_value._##dtype.value)
+#define VALID_CVALUE(dtype, symbol) (symbol_c::cs_const_value == (symbol)->const_value._##dtype.status)
+#define IS_OVERFLOW(dtype, symbol) (symbol_c::cs_overflow == (symbol)->const_value._##dtype.status)
+
+/* set to 1 to see debug info during execution */
+static int debug = 0;
+
+fill_candidate_datatypes_c::fill_candidate_datatypes_c(symbol_c *ignore) {
+}
+
+fill_candidate_datatypes_c::~fill_candidate_datatypes_c(void) {
+}
+
+symbol_c *fill_candidate_datatypes_c::widening_conversion(symbol_c *left_type, symbol_c *right_type, const struct widen_entry widen_table[]) {
+ int k;
+ /* find a widening table entry compatible */
+ for (k = 0; NULL != widen_table[k].left; k++)
+ if ((typeid(*left_type) == typeid(*widen_table[k].left)) && (typeid(*right_type) == typeid(*widen_table[k].right)))
+ return widen_table[k].result;
+ return NULL;
+}
+
+
+/* add a data type to a candidate data type list, while guaranteeing no duplicate entries! */
+/* Returns true if it really did add the datatype to the list, or false if it was already present in the list! */
+bool fill_candidate_datatypes_c::add_datatype_to_candidate_list(symbol_c *symbol, symbol_c *datatype) {
+ /* If it is an invalid data type, do not insert!
+ * 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.
+ */
+ if (!is_type_valid(datatype)) /* checks for NULL and invalid_type_name_c */
+ return false;
+
+ if (search_in_candidate_datatype_list(datatype, symbol->candidate_datatypes) >= 0)
+ /* already in the list, Just return! */
+ return false;
+
+ /* not yet in the candidate data type list, so we insert it now! */
+ symbol->candidate_datatypes.push_back(datatype);
+ return true;
+}
+
+
+bool fill_candidate_datatypes_c::add_2datatypes_to_candidate_list(symbol_c *symbol, symbol_c *datatype1, symbol_c *datatype2) {
+ add_datatype_to_candidate_list(symbol, datatype1);
+ add_datatype_to_candidate_list(symbol, datatype2);
+ return true;
+}
+
+
+
+void fill_candidate_datatypes_c::remove_incompatible_datatypes(symbol_c *symbol) {
+ #ifdef __REMOVE__
+ #error __REMOVE__ macro already exists. Choose another name!
+ #endif
+ #define __REMOVE__(datatype)\
+ remove_from_candidate_datatype_list(&search_constant_type_c::datatype, symbol->candidate_datatypes);\
+ remove_from_candidate_datatype_list(&search_constant_type_c::safe##datatype, symbol->candidate_datatypes);
+
+ {/* Remove unsigned data types */
+ uint64_t value = 0;
+ if (VALID_CVALUE( uint64, symbol)) value = GET_CVALUE(uint64, symbol);
+ if (IS_OVERFLOW ( uint64, symbol)) value = (uint64_t)UINT32_MAX + (uint64_t)1;
+
+ if (value > 1 ) {__REMOVE__(bool_type_name);}
+ if (value > UINT8_MAX ) {__REMOVE__(usint_type_name); __REMOVE__( byte_type_name);}
+ if (value > UINT16_MAX ) {__REMOVE__( uint_type_name); __REMOVE__( word_type_name);}
+ if (value > UINT32_MAX ) {__REMOVE__(udint_type_name); __REMOVE__(dword_type_name);}
+ if (IS_OVERFLOW( uint64, symbol)) {__REMOVE__(ulint_type_name); __REMOVE__(lword_type_name);}
+ }
+
+ {/* Remove signed data types */
+ int64_t value = 0;
+ if (VALID_CVALUE( int64, symbol)) value = GET_CVALUE(int64, symbol);
+ if (IS_OVERFLOW ( int64, symbol)) value = (int64_t)INT32_MAX + (int64_t)1;
+
+ if ((value < INT8_MIN) || (value > INT8_MAX)) {__REMOVE__(sint_type_name);}
+ if ((value < INT16_MIN) || (value > INT16_MAX)) {__REMOVE__( int_type_name);}
+ if ((value < INT32_MIN) || (value > INT32_MAX)) {__REMOVE__(dint_type_name);}
+ if (IS_OVERFLOW( int64, symbol)) {__REMOVE__(lint_type_name);}
+ }
+
+ {/* Remove floating point data types */
+ real64_t value = 0;
+ if (VALID_CVALUE( real64, symbol)) value = GET_CVALUE(real64, symbol);
+ if (IS_OVERFLOW ( real64, symbol)) value = (real64_t)REAL32_MAX + (real64_t)1;
+ if (value > REAL32_MAX ) {__REMOVE__( real_type_name);}
+ if (value < -REAL32_MAX ) {__REMOVE__( real_type_name);}
+ if (IS_OVERFLOW( real64, symbol)) {__REMOVE__(lreal_type_name);}
+ }
+ #undef __REMOVE__
+}
+
+
+/* returns true if compatible function/FB invocation, otherwise returns false */
+/* Assumes that the candidate_datatype lists of all the parameters being passed haved already been filled in */
+/*
+ * All parameters being passed to the called function MUST be in the parameter list to which f_call points to!
+ * This means that, for non formal function calls in IL, de current (default value) must be artificially added to the
+ * beginning of the parameter list BEFORE calling handle_function_call().
+ */
+bool fill_candidate_datatypes_c::match_nonformal_call(symbol_c *f_call, symbol_c *f_decl) {
+ symbol_c *call_param_value, *param_datatype;
+ identifier_c *param_name;
+ function_param_iterator_c fp_iterator(f_decl);
+ function_call_param_iterator_c fcp_iterator(f_call);
+ int extensible_parameter_highest_index = -1;
+ unsigned int i;
+
+ /* Iterating through the non-formal parameters of the function call */
+ while((call_param_value = fcp_iterator.next_nf()) != NULL) {
+ /* Iterate to the next parameter of the function being called.
+ * Get the name of that parameter, and ignore if EN or ENO.
+ */
+ do {
+ param_name = fp_iterator.next();
+ /* If there is no other parameter declared, then we are passing too many parameters... */
+ if(param_name == NULL) return false;
+ } while ((strcmp(param_name->value, "EN") == 0) || (strcmp(param_name->value, "ENO") == 0));
+
+ /* TODO: verify if it is lvalue when INOUT or OUTPUT parameters! */
+ /* Get the parameter type */
+ param_datatype = base_type(fp_iterator.param_type());
+
+ /* check whether one of the candidate_data_types of the value being passed is the same as the param_type */
+ if (search_in_candidate_datatype_list(param_datatype, call_param_value->candidate_datatypes) < 0)
+ return false; /* return false if param_type not in the list! */
+ }
+ /* call is compatible! */
+ return true;
+}
+
+
+
+/* returns true if compatible function/FB invocation, otherwise returns false */
+/* Assumes that the candidate_datatype lists of all the parameters being passed haved already been filled in */
+bool fill_candidate_datatypes_c::match_formal_call(symbol_c *f_call, symbol_c *f_decl, symbol_c **first_param_datatype) {
+ symbol_c *call_param_value, *call_param_name, *param_datatype;
+ symbol_c *verify_duplicate_param;
+ identifier_c *param_name;
+ function_param_iterator_c fp_iterator(f_decl);
+ function_call_param_iterator_c fcp_iterator(f_call);
+ int extensible_parameter_highest_index = -1;
+ identifier_c *extensible_parameter_name;
+ unsigned int i;
+ bool is_first_param = true;
+
+ /* Iterating through the formal parameters of the function call */
+ while((call_param_name = fcp_iterator.next_f()) != NULL) {
+ /* Obtaining the value being passed in the function call */
+ call_param_value = fcp_iterator.get_current_value();
+ /* the following should never occur. If it does, then we have a bug in our code... */
+ if (NULL == call_param_value) ERROR;
+
+ /* Obtaining the assignment direction: := (assign_in) or => (assign_out) */
+ function_call_param_iterator_c::assign_direction_t call_param_dir = fcp_iterator.get_assign_direction();
+
+ /* Checking if there are duplicated parameter values */
+ verify_duplicate_param = fcp_iterator.search_f(call_param_name);
+ if(verify_duplicate_param != call_param_value)
+ return false;
+
+ /* Obtaining the type of the value being passed in the function call */
+ std::vector <symbol_c *>&call_param_types = call_param_value->candidate_datatypes;
+
+ /* Find the corresponding parameter in function declaration */
+ param_name = fp_iterator.search(call_param_name);
+ if(param_name == NULL) return false;
+ /* Get the parameter data type */
+ param_datatype = base_type(fp_iterator.param_type());
+ /* Get the parameter direction: IN, OUT, IN_OUT */
+ function_param_iterator_c::param_direction_t param_dir = fp_iterator.param_direction();
+
+ /* check whether direction (IN, OUT, IN_OUT) and assignment types (:= , =>) are compatible !!! */
+ if (function_call_param_iterator_c::assign_in == call_param_dir) {
+ if ((function_param_iterator_c::direction_in != param_dir) &&
+ (function_param_iterator_c::direction_inout != param_dir))
+ return false;
+ } else if (function_call_param_iterator_c::assign_out == call_param_dir) {
+ if ((function_param_iterator_c::direction_out != param_dir))
+ return false;
+ } else ERROR;
+
+ /* check whether one of the candidate_data_types of the value being passed is the same as the param_type */
+ if (search_in_candidate_datatype_list(param_datatype, call_param_types) < 0)
+ return false; /* return false if param_type not in the list! */
+
+ /* If this is the first parameter, then copy the datatype to *first_param_datatype */
+ if (is_first_param)
+ if (NULL != first_param_datatype)
+ *first_param_datatype = param_datatype;
+ is_first_param = false;
+ }
+ /* call is compatible! */
+ return true;
+}
+
+
+
+
+/* Handle a generic function call!
+ * Assumes that the parameter_list containing the values being passed in this function invocation
+ * has already had all the candidate_datatype lists filled in!
+ *
+ * All parameters being passed to the called function MUST be in the parameter list to which f_call points to!
+ * This means that, for non formal function calls in IL, de current (default value) must be artificially added to the
+ * beginning of the parameter list BEFORE calling handle_function_call().
+ */
+/*
+typedef struct {
+ symbol_c *function_name,
+ symbol_c *nonformal_operand_list,
+ symbol_c * formal_operand_list,
+
+ std::vector <symbol_c *> &candidate_functions,
+ symbol_c &*called_function_declaration,
+ int &extensible_param_count
+} generic_function_call_t;
+*/
+/*
+void narrow_candidate_datatypes_c::narrow_function_invocation(symbol_c *fcall, generic_function_call_t fcall_data) {
+void *fill_candidate_datatypes_c::handle_function_call(symbol_c *f_call, symbol_c *function_name, invocation_type_t invocation_type,
+ std::vector <symbol_c *> *candidate_datatypes,
+ std::vector <symbol_c *> *candidate_functions) {
+ */
+void fill_candidate_datatypes_c::handle_function_call(symbol_c *fcall, generic_function_call_t fcall_data) {
+ function_declaration_c *f_decl;
+ list_c *parameter_list;
+ list_c *parameter_candidate_datatypes;
+ symbol_c *returned_parameter_type;
+
+ if (debug) std::cout << "function()\n";
+
+ function_symtable_t::iterator lower = function_symtable.lower_bound(fcall_data.function_name);
+ function_symtable_t::iterator upper = function_symtable.upper_bound(fcall_data.function_name);
+ /* If the name of the function being called is not found in the function symbol table, then this is an invalid call */
+ /* Since the lexical parser already checks for this, then if this occurs then we have an internal compiler error. */
+ if (lower == function_symtable.end()) ERROR;
+
+ /* Look for all compatible function declarations, and add their return datatypes
+ * to the candidate_datatype list of this function invocation.
+ *
+ * If only one function exists, we add its return datatype to the candidate_datatype list,
+ * even if the parameters passed to it are invalid.
+ * This guarantees that the remainder of the expression in which the function call is inserted
+ * is treated as if the function call returns correctly, and therefore does not generate
+ * spurious error messages.
+ * Even if the parameters to the function call are invalid, doing this is still safe, as the
+ * expressions inside the function call will themselves have erros and will guarantee that
+ * compilation is aborted in stage3 (in print_datatypes_error_c).
+ */
+ if (function_symtable.multiplicity(fcall_data.function_name) == 1) {
+ f_decl = function_symtable.get_value(lower);
+ returned_parameter_type = base_type(f_decl->type_name);
+ if (add_datatype_to_candidate_list(fcall, returned_parameter_type))
+ /* we only add it to the function declaration list if this entry was not already present in the candidate datatype list! */
+ fcall_data.candidate_functions.push_back(f_decl);
+
+ }
+ for(; lower != upper; lower++) {
+ bool compatible = false;
+
+ f_decl = function_symtable.get_value(lower);
+ /* Check if function declaration in symbol_table is compatible with parameters */
+ if (NULL != fcall_data.nonformal_operand_list) compatible=match_nonformal_call(fcall, f_decl);
+ if (NULL != fcall_data. formal_operand_list) compatible= match_formal_call(fcall, f_decl);
+ if (compatible) {
+ /* Add the data type returned by the called functions.
+ * However, only do this if this data type is not already present in the candidate_datatypes list_c
+ */
+ returned_parameter_type = base_type(f_decl->type_name);
+ if (add_datatype_to_candidate_list(fcall, returned_parameter_type))
+ /* we only add it to the function declaration list if this entry was not already present in the candidate datatype list! */
+ fcall_data.candidate_functions.push_back(f_decl);
+ }
+ }
+ if (debug) std::cout << "end_function() [" << fcall->candidate_datatypes.size() << "] result.\n";
+ return;
+}
+
+
+/* handle implicit FB call in IL.
+ * e.g. CLK ton_var
+ * CU counter_var
+ */
+void *fill_candidate_datatypes_c::handle_implicit_il_fb_call(symbol_c *il_instruction, const char *param_name, symbol_c *&called_fb_declaration) {
+ symbol_c *fb_type_id = search_varfb_instance_type->get_basetype_id(il_operand);
+ /* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
+ if (NULL == fb_type_id) ERROR;
+
+ function_block_declaration_c *fb_decl = function_block_type_symtable.find_value(fb_type_id);
+ if (function_block_type_symtable.end_value() == fb_decl)
+ /* The il_operand is not the name of a FB instance. Most probably it is the name of a variable of some other type.
+ * this is a semantic error.
+ */
+ fb_decl = NULL;
+
+ /* The narrow_candidate_datatypes_c does not rely on this called_fb_declaration pointer being == NULL to conclude that
+ * we have a datatype incompatibility error, so we set it to fb_decl to allow the print_datatype_error_c to print out
+ * more informative error messages!
+ */
+ called_fb_declaration = fb_decl;
+
+ /* This implicit FB call does not change the value stored in the current/default IL variable */
+ /* It does, however, require that the datatype be compatible with the input parameter of the FB being called.
+ * If we were to follow the filling & narrowing algorithm correctly (implemented in fill_candidate_datatypes_c
+ * & narrow_candidate_datatypes_c respectively), we should be restricting the candidate_datatpes to the datatypes
+ * that are compatible to the FB call.
+ * However, doing the above will often result in some very confusing error messages for the user, especially in the case
+ * in which the FB call is wrong, so the resulting cadidate datatypes is an empty list. In this case, the user would see
+ * many error messages related to the IL instructions that follow the FB call, even though those IL instructions may be perfectly
+ * correct.
+ * For now, we will simply let the narrow_candidate_datatypes_c verify if the datatypes are compatible (something that should be done
+ * here).
+ */
+ if (NULL != prev_il_instruction)
+ il_instruction->candidate_datatypes = prev_il_instruction->candidate_datatypes;
+
+ if (debug) std::cout << "handle_implicit_il_fb_call() [" << prev_il_instruction->candidate_datatypes.size() << "] ==> " << il_instruction->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+
+
+
+/* handle a binary IL operator, like ADD, SUB, etc... */
+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) {
+ if (NULL == l_expr) /* if no prev_il_instruction */
+ return NULL;
+
+ for(unsigned int i = 0; i < l_expr->candidate_datatypes.size(); i++)
+ for(unsigned int j = 0; j < r_expr->candidate_datatypes.size(); j++)
+ /* NOTE: add_datatype_to_candidate_list() will only really add the datatype if it is != NULL !!! */
+ add_datatype_to_candidate_list(symbol, widening_conversion(l_expr->candidate_datatypes[i], r_expr->candidate_datatypes[j], widen_table));
+ remove_incompatible_datatypes(symbol);
+ if (debug) std::cout << "[" << l_expr->candidate_datatypes.size() << "," << r_expr->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+
+/* handle a binary ST expression, like '+', '-', etc... */
+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) {
+ l_expr->accept(*this);
+ r_expr->accept(*this);
+ return handle_binary_operator(widen_table, symbol, l_expr, r_expr);
+}
+
+
+
+
+/* a helper function... */
+symbol_c *fill_candidate_datatypes_c::base_type(symbol_c *symbol) {
+ /* NOTE: symbol == NULL is valid. It will occur when, for e.g., an undefined/undeclared symbolic_variable is used
+ * in the code.
+ */
+ if (symbol == NULL) return NULL;
+ return (symbol_c *)symbol->accept(search_base_type);
+}
+
+/*********************/
+/* B 1.2 - Constants */
+/*********************/
+/******************************/
+/* B 1.2.1 - Numeric Literals */
+/******************************/
+#define sizeoftype(symbol) get_sizeof_datatype_c::getsize(symbol)
+
+void *fill_candidate_datatypes_c::handle_any_integer(symbol_c *symbol) {
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::bool_type_name, &search_constant_type_c::safebool_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::byte_type_name, &search_constant_type_c::safebyte_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::word_type_name, &search_constant_type_c::safeword_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::dword_type_name, &search_constant_type_c::safedword_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::lword_type_name, &search_constant_type_c::safelword_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::sint_type_name, &search_constant_type_c::safesint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::int_type_name, &search_constant_type_c::safeint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::dint_type_name, &search_constant_type_c::safedint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::lint_type_name, &search_constant_type_c::safelint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::usint_type_name, &search_constant_type_c::safeusint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::uint_type_name, &search_constant_type_c::safeuint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::udint_type_name, &search_constant_type_c::safeudint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::ulint_type_name, &search_constant_type_c::safeulint_type_name);
+ remove_incompatible_datatypes(symbol);
+ if (debug) std::cout << "ANY_INT [" << symbol->candidate_datatypes.size()<< "]" << std::endl;
+ return NULL;
+}
+
+
+
+void *fill_candidate_datatypes_c::handle_any_real(symbol_c *symbol) {
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::real_type_name, &search_constant_type_c::safereal_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::lreal_type_name, &search_constant_type_c::safelreal_type_name);
+ remove_incompatible_datatypes(symbol);
+ if (debug) std::cout << "ANY_REAL [" << symbol->candidate_datatypes.size() << "]" << std::endl;
+ return NULL;
+}
+
+
+
+void *fill_candidate_datatypes_c::handle_any_literal(symbol_c *symbol, symbol_c *symbol_value, symbol_c *symbol_type) {
+ symbol_value->accept(*this);
+ if (search_in_candidate_datatype_list(symbol_type, symbol_value->candidate_datatypes) >= 0)
+ add_datatype_to_candidate_list(symbol, symbol_type);
+ remove_incompatible_datatypes(symbol);
+ if (debug) std::cout << "XXX_LITERAL [" << symbol->candidate_datatypes.size() << "]\n";
+ return NULL;
+}
+
+
+
+void *fill_candidate_datatypes_c::visit( real_c *symbol) {return handle_any_real(symbol);}
+void *fill_candidate_datatypes_c::visit(neg_real_c *symbol) {return handle_any_real(symbol);}
+
+
+
+void *fill_candidate_datatypes_c::visit(neg_integer_c *symbol) {
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::int_type_name, &search_constant_type_c::safeint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::sint_type_name, &search_constant_type_c::safesint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::dint_type_name, &search_constant_type_c::safedint_type_name);
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::lint_type_name, &search_constant_type_c::safelint_type_name);
+ remove_incompatible_datatypes(symbol);
+ if (debug) std::cout << "neg ANY_INT [" << symbol->candidate_datatypes.size() << "]" << std::endl;
+ return NULL;
+}
+
+
+
+void *fill_candidate_datatypes_c::visit(integer_c *symbol) {return handle_any_integer(symbol);}
+void *fill_candidate_datatypes_c::visit(binary_integer_c *symbol) {return handle_any_integer(symbol);}
+void *fill_candidate_datatypes_c::visit(octal_integer_c *symbol) {return handle_any_integer(symbol);}
+void *fill_candidate_datatypes_c::visit(hex_integer_c *symbol) {return handle_any_integer(symbol);}
+
+
+
+// SYM_REF2(integer_literal_c, type, value)
+/*
+ * integer_literal:
+ * integer_type_name '#' signed_integer
+ * | integer_type_name '#' binary_integer
+ * | integer_type_name '#' octal_integer
+ * | integer_type_name '#' hex_integer
+ */
+void *fill_candidate_datatypes_c::visit( integer_literal_c *symbol) {return handle_any_literal(symbol, symbol->value, symbol->type);}
+void *fill_candidate_datatypes_c::visit( real_literal_c *symbol) {return handle_any_literal(symbol, symbol->value, symbol->type);}
+void *fill_candidate_datatypes_c::visit(bit_string_literal_c *symbol) {return handle_any_literal(symbol, symbol->value, symbol->type);}
+
+void *fill_candidate_datatypes_c::visit( boolean_literal_c *symbol) {
+ if (NULL != symbol->type) return handle_any_literal(symbol, symbol->value, symbol->type);
+
+ symbol->value->accept(*this);
+ symbol->candidate_datatypes = symbol->value->candidate_datatypes;
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit(boolean_true_c *symbol) {
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::bool_type_name, &search_constant_type_c::safebool_type_name);
+ return NULL;
+}
+
+void *fill_candidate_datatypes_c::visit(boolean_false_c *symbol) {
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::bool_type_name, &search_constant_type_c::safebool_type_name);
+ return NULL;
+}
+
+/*******************************/
+/* B.1.2.2 Character Strings */
+/*******************************/
+void *fill_candidate_datatypes_c::visit(double_byte_character_string_c *symbol) {
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::wstring_type_name, &search_constant_type_c::safewstring_type_name);
+ return NULL;
+}
+
+void *fill_candidate_datatypes_c::visit(single_byte_character_string_c *symbol) {
+ add_2datatypes_to_candidate_list(symbol, &search_constant_type_c::string_type_name, &search_constant_type_c::safestring_type_name);
+ return NULL;
+}
+
+/***************************/
+/* B 1.2.3 - Time Literals */
+/***************************/
+/************************/
+/* B 1.2.3.1 - Duration */
+/************************/
+void *fill_candidate_datatypes_c::visit(duration_c *symbol) {
+ /* TODO: check whether the literal follows the rules specified in section '2.2.3.1 Duration' of the standard! */
+
+ add_datatype_to_candidate_list(symbol, symbol->type_name);
+ if (debug) std::cout << "TIME_LITERAL [" << symbol->candidate_datatypes.size() << "]\n";
+ return NULL;
+}
+
+/************************************/
+/* B 1.2.3.2 - Time of day and Date */
+/************************************/
+void *fill_candidate_datatypes_c::visit(time_of_day_c *symbol) {add_datatype_to_candidate_list(symbol, symbol->type_name); return NULL;}
+void *fill_candidate_datatypes_c::visit(date_c *symbol) {add_datatype_to_candidate_list(symbol, symbol->type_name); return NULL;}
+void *fill_candidate_datatypes_c::visit(date_and_time_c *symbol) {add_datatype_to_candidate_list(symbol, symbol->type_name); return NULL;}
+
+/**********************/
+/* B 1.3 - Data types */
+/**********************/
+/********************************/
+/* B 1.3.3 - Derived data types */
+/********************************/
+
+/* simple_specification ASSIGN constant */
+// SYM_REF2(simple_spec_init_c, simple_specification, constant)
+void *fill_candidate_datatypes_c::visit(simple_spec_init_c *symbol) {
+ if (NULL != symbol->constant) symbol->constant->accept(*this);
+ add_datatype_to_candidate_list(symbol->simple_specification, base_type(symbol->simple_specification));
+ symbol->candidate_datatypes = symbol->simple_specification->candidate_datatypes;
+ /* NOTE: Even if the constant and the type are of incompatible data types, we let the
+ * simple_spec_init_c object inherit the data type of the type declaration (simple_specification)
+ * This will let us produce more informative error messages when checking data type compatibility
+ * with located variables (AT %QW3.4 : WORD).
+ */
+ // if (NULL != symbol->constant) intersect_candidate_datatype_list(symbol /*origin, dest.*/, symbol->constant /*with*/);
+ return NULL;
+}
+
+/* signed_integer DOTDOT signed_integer */
+// SYM_REF2(subrange_c, lower_limit, upper_limit)
+void *fill_candidate_datatypes_c::visit(subrange_c *symbol) {
+ symbol->lower_limit->accept(*this);
+ symbol->upper_limit->accept(*this);
+
+ for (unsigned int u = 0; u < symbol->upper_limit->candidate_datatypes.size(); u++) {
+ for(unsigned int l = 0; l < symbol->lower_limit->candidate_datatypes.size(); l++) {
+ if (is_type_equal(symbol->upper_limit->candidate_datatypes[u], symbol->lower_limit->candidate_datatypes[l]))
+ add_datatype_to_candidate_list(symbol, symbol->lower_limit->candidate_datatypes[l]);
+ }
+ }
+ return NULL;
+}
+
+/* TYPE type_declaration_list END_TYPE */
+// SYM_REF1(data_type_declaration_c, type_declaration_list)
+/* NOTE: Not required. already handled by iterator_visitor_c base class */
+/*
+void *fill_candidate_datatypes_c::visit(data_type_declaration_c *symbol) {
+ symbol->type_declaration_list->accept(*this);
+ return NULL;
+}
+*/
+
+void *fill_candidate_datatypes_c::visit(enumerated_value_c *symbol) {
+ symbol_c *enumerated_type;
+
+ if (NULL != symbol->type)
+ enumerated_type = symbol->type;
+ else {
+ enumerated_type = enumerated_value_symtable.find_value(symbol->value);
+ if (enumerated_type == enumerated_value_symtable.end_value())
+ enumerated_type = NULL;
+ }
+ enumerated_type = base_type(enumerated_type);
+ if (NULL != enumerated_type)
+ add_datatype_to_candidate_list(symbol, enumerated_type);
+
+ if (debug) std::cout << "ENUMERATE [" << symbol->candidate_datatypes.size() << "]\n";
+ return NULL;
+}
+
+
+/*********************/
+/* B 1.4 - Variables */
+/*********************/
+void *fill_candidate_datatypes_c::visit(symbolic_variable_c *symbol) {
+ add_datatype_to_candidate_list(symbol, search_varfb_instance_type->get_basetype_decl(symbol)); /* will only add if non NULL */
+ if (debug) std::cout << "VAR [" << symbol->candidate_datatypes.size() << "]\n";
+ return NULL;
+}
+
+
+/********************************************/
+/* B 1.4.1 - Directly Represented Variables */
+/********************************************/
+void *fill_candidate_datatypes_c::visit(direct_variable_c *symbol) {
+ /* Comment added by mario:
+ * The following code is safe, actually, as the lexical parser guarantees the correct IEC61131-3 syntax was used.
+ */
+ /* However, we should probably add an assertion in case we later change the lexical parser! */
+ /* if (symbol->value == NULL) ERROR;
+ * if (symbol->value[0] == '\0') ERROR;
+ * if (symbol->value[1] == '\0') ERROR;
+ */
+ switch (symbol->value[2]) {
+ case 'x': case 'X': /* bit - 1 bit */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::bool_type_name); break;
+ case 'b': case 'B': /* byte - 8 bits */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::byte_type_name); break;
+ case 'w': case 'W': /* word - 16 bits */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::word_type_name); break;
+ case 'd': case 'D': /* dword - 32 bits */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::dword_type_name); break;
+ case 'l': case 'L': /* lword - 64 bits */ add_datatype_to_candidate_list(symbol, &search_constant_type_c::lword_type_name); break;
+ /* if none of the above, then the empty string was used <=> boolean */
+ default: add_datatype_to_candidate_list(symbol, &search_constant_type_c::bool_type_name); break;
+ }
+ return NULL;
+}
+
+/*************************************/
+/* B 1.4.2 - Multi-element variables */
+/*************************************/
+/* subscripted_variable '[' subscript_list ']' */
+// SYM_REF2(array_variable_c, subscripted_variable, subscript_list)
+void *fill_candidate_datatypes_c::visit(array_variable_c *symbol) {
+ /* get the declaration of the data type __stored__ in the array... */
+ /* if we were to want the data type of the array itself, then we should call_param_name
+ * search_varfb_instance_type->get_basetype_decl(symbol->subscripted_variable)
+ */
+ symbol_c *result = search_varfb_instance_type->get_basetype_decl(symbol);
+ if (NULL != result) add_datatype_to_candidate_list(symbol, result);
+
+ /* recursively call the subscript list, so we can check the data types of the expressions used for the subscripts */
+ symbol->subscript_list->accept(*this);
+
+ if (debug) std::cout << "ARRAY_VAR [" << symbol->candidate_datatypes.size() << "]\n";
+ return NULL;
+}
+
+
+/* subscript_list ',' subscript */
+// SYM_LIST(subscript_list_c)
+/* NOTE: we inherit from iterator visitor, so we do not need to implement this method... */
+// void *fill_candidate_datatypes_c::visit(subscript_list_c *symbol)
+
+
+/* record_variable '.' field_selector */
+/* WARNING: input and/or output variables of function blocks
+ * may be accessed as fields of a structured variable!
+ * Code handling a structured_variable_c must take
+ * this into account!
+ */
+// SYM_REF2(structured_variable_c, record_variable, field_selector)
+/* NOTE: We do not need to recursively determine the data types of each field_selector, as the search_varfb_instance_type
+ * will do that for us. So we determine the candidate datatypes only for the full structured_variable.
+ */
+void *fill_candidate_datatypes_c::visit(structured_variable_c *symbol) {
+ add_datatype_to_candidate_list(symbol, search_varfb_instance_type->get_basetype_decl(symbol)); /* will only add if non NULL */
+ return NULL;
+}
+
+
+
+/******************************************/
+/* B 1.4.3 - Declaration & Initialisation */
+/******************************************/
+
+void *fill_candidate_datatypes_c::visit(var1_list_c *symbol) {
+#if 0 /* We don't really need to set the datatype of each variable. We just check the declaration itself! */
+ for(int i = 0; i < symbol->n; i++) {
+ add_datatype_to_candidate_list(symbol->elements[i], search_varfb_instance_type->get_basetype_decl(symbol->elements[i])); /* will only add if non NULL */
+ }
+#endif
+ return NULL;
+}
+
+
+/* AT direct_variable */
+// SYM_REF1(location_c, direct_variable)
+void *fill_candidate_datatypes_c::visit(location_c *symbol) {
+ /* This is a special situation.
+ *
+ * The reason is that a located variable may be declared to be of any data type, as long as the size
+ * matches the location (lines 1 3 and 4 of table 17). For example:
+ * var1 AT %MB42.0 : BYTE;
+ * var1 AT %MB42.1 : SINT;
+ * var1 AT %MB42.2 : USINT;
+ * var1 AT %MW64 : INT;
+ * var1 AT %MD56 : DINT;
+ * var1 AT %MD57 : REAL;
+ * are all valid!!
+ *
+ * However, when used inside an expression, the direct variable (uses the same syntax as the location
+ * of a located variable) is limited to the following (ANY_BIT) data types:
+ * %MX --> BOOL
+ * %MB --> BYTE
+ * %MW --> WORD
+ * %MD --> DWORD
+ * %ML --> LWORD
+ *
+ * So, in order to be able to analyse expressions with direct variables
+ * e.g: var1 := 66 OR %MW34
+ * where the direct variable may only take the ANY_BIT data types, the fill_candidate_datatypes_c
+ * considers that only the ANY_BIT data types are allowed for a direct variable.
+ * However, it appears from the examples in the standard (lines 1 3 and 4 of table 17)
+ * a location may have any data type (presumably as long as the size in bits match).
+ * For this reason, a location_c may have more allowable data types than a direct_variable_c
+ */
+
+ symbol->direct_variable->accept(*this);
+ for (unsigned int i = 0; i < symbol->direct_variable->candidate_datatypes.size(); i++) {
+ switch (get_sizeof_datatype_c::getsize(symbol->direct_variable->candidate_datatypes[i])) {
+ case 1: /* bit - 1 bit */
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::bool_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safebool_type_name);
+ break;
+ case 8: /* byte - 8 bits */
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::byte_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safebyte_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::sint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safesint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::usint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeusint_type_name);
+ break;
+ case 16: /* word - 16 bits */
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::word_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeword_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::int_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::uint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeuint_type_name);
+ break;
+ case 32: /* dword - 32 bits */
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::dword_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safedword_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::dint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safedint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::udint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeudint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::real_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safereal_type_name);
+ break;
+ case 64: /* lword - 64 bits */
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::lword_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safelword_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::lint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safelint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::ulint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safeulint_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::lreal_type_name);
+ add_datatype_to_candidate_list(symbol, &search_constant_type_c::safelreal_type_name);
+ break;
+ default: /* if none of the above, then no valid datatype allowed... */
+ break;
+ } /* switch() */
+ } /* for */
+
+ return NULL;
+}
+
+
+/* [variable_name] location ':' located_var_spec_init */
+/* variable_name -> may be NULL ! */
+// SYM_REF3(located_var_decl_c, variable_name, location, located_var_spec_init)
+void *fill_candidate_datatypes_c::visit(located_var_decl_c *symbol) {
+ symbol->located_var_spec_init->accept(*this);
+ symbol->location->accept(*this);
+ if (NULL != symbol->variable_name) {
+ symbol->variable_name->candidate_datatypes = symbol->location->candidate_datatypes;
+ intersect_candidate_datatype_list(symbol->variable_name /*origin, dest.*/, symbol->located_var_spec_init /*with*/);
+ }
+ return NULL;
+}
+
+
+
+
+
+/************************************/
+/* B 1.5 Program organization units */
+/************************************/
+/*********************/
+/* B 1.5.1 Functions */
+/*********************/
+void *fill_candidate_datatypes_c::visit(function_declaration_c *symbol) {
+ if (debug) printf("Filling candidate data types list of function %s\n", ((token_c *)(symbol->derived_function_name))->value);
+ search_varfb_instance_type = new search_varfb_instance_type_c(symbol);
+ symbol->var_declarations_list->accept(*this);
+ symbol->function_body->accept(*this);
+ delete search_varfb_instance_type;
+ search_varfb_instance_type = NULL;
+ return NULL;
+}
+
+/***************************/
+/* B 1.5.2 Function blocks */
+/***************************/
+void *fill_candidate_datatypes_c::visit(function_block_declaration_c *symbol) {
+ if (debug) printf("Filling candidate data types list of FB %s\n", ((token_c *)(symbol->fblock_name))->value);
+ search_varfb_instance_type = new search_varfb_instance_type_c(symbol);
+ symbol->var_declarations->accept(*this);
+ symbol->fblock_body->accept(*this);
+ delete search_varfb_instance_type;
+ search_varfb_instance_type = NULL;
+ return NULL;
+}
+
+/**********************/
+/* B 1.5.3 - Programs */
+/**********************/
+void *fill_candidate_datatypes_c::visit(program_declaration_c *symbol) {
+ if (debug) printf("Filling candidate data types list in program %s\n", ((token_c *)(symbol->program_type_name))->value);
+ search_varfb_instance_type = new search_varfb_instance_type_c(symbol);
+ symbol->var_declarations->accept(*this);
+ symbol->function_block_body->accept(*this);
+ delete search_varfb_instance_type;
+ search_varfb_instance_type = NULL;
+ return NULL;
+}
+
+
+
+/********************************/
+/* B 1.7 Configuration elements */
+/********************************/
+void *fill_candidate_datatypes_c::visit(configuration_declaration_c *symbol) {
+ // TODO !!!
+ /* for the moment we must return NULL so semantic analysis of remaining code is not interrupted! */
+ return NULL;
+}
+
+/****************************************/
+/* B.2 - Language IL (Instruction List) */
+/****************************************/
+/***********************************/
+/* B 2.1 Instructions and Operands */
+/***********************************/
+
+/*| instruction_list il_instruction */
+// SYM_LIST(instruction_list_c)
+void *fill_candidate_datatypes_c::visit(instruction_list_c *symbol) {
+ /* In order to fill the data type candidates correctly
+ * in IL instruction lists containing JMPs to labels that come before the JMP instruction
+ * itself, we need to run the fill candidate datatypes algorithm twice on the Instruction List.
+ * e.g.: ...
+ * ld 23
+ * label1:st byte_var
+ * ld 34
+ * JMP label1
+ *
+ * Note that the second time we run the algorithm, most of the candidate datatypes are already filled
+ * in, so it will be able to produce tha correct candidate datatypes for the IL instruction referenced
+ * by the label, as in the 2nd pass we already know the candidate datatypes of the JMP instruction!
+ */
+ for(int j = 0; j < 2; j++) {
+ for(int i = 0; i < symbol->n; i++) {
+ symbol->elements[i]->accept(*this);
+ }
+ }
+ return NULL;
+}
+
+
+
+/* | label ':' [il_incomplete_instruction] eol_list */
+// SYM_REF2(il_instruction_c, label, il_instruction)
+// void *visit(instruction_list_c *symbol);
+void *fill_candidate_datatypes_c::visit(il_instruction_c *symbol) {
+ if (NULL == symbol->il_instruction) {
+ /* This empty/null il_instruction does not change the value of the current/default IL variable.
+ * So it inherits the candidate_datatypes from it's previous IL instructions!
+ */
+ intersect_prev_candidate_datatype_lists(symbol);
+ } else {
+ il_instruction_c fake_prev_il_instruction = *symbol;
+ intersect_prev_candidate_datatype_lists(&fake_prev_il_instruction);
+
+ if (symbol->prev_il_instruction.size() == 0) prev_il_instruction = NULL;
+ else prev_il_instruction = &fake_prev_il_instruction;
+ symbol->il_instruction->accept(*this);
+ prev_il_instruction = NULL;
+
+ /* This object has (inherits) the same candidate datatypes as the il_instruction */
+ symbol->candidate_datatypes = symbol->il_instruction->candidate_datatypes;
+ }
+
+ return NULL;
+}
+
+
+
+void *fill_candidate_datatypes_c::visit(il_simple_operation_c *symbol) {
+ /* determine the data type of the operand */
+ if (NULL != symbol->il_operand) {
+ symbol->il_operand->accept(*this);
+ }
+ /* recursive call to fill the candidate data types list */
+ il_operand = symbol->il_operand;
+ symbol->il_simple_operator->accept(*this);
+ il_operand = NULL;
+ /* This object has (inherits) the same candidate datatypes as the il_simple_operator */
+ symbol->candidate_datatypes = symbol->il_simple_operator->candidate_datatypes;
+ return NULL;
+}
+
+
+/* | function_name [il_operand_list] */
+/* NOTE: The parameters 'called_function_declaration' and 'extensible_param_count' are used to pass data between the stage 3 and stage 4. */
+// SYM_REF2(il_function_call_c, function_name, il_operand_list, symbol_c *called_function_declaration; int extensible_param_count;)
+void *fill_candidate_datatypes_c::visit(il_function_call_c *symbol) {
+ /* The first parameter of a non formal function call in IL will be the 'current value' (i.e. the prev_il_instruction)
+ * In order to be able to handle this without coding special cases, we will simply prepend that symbol
+ * to the il_operand_list, and remove it after calling handle_function_call().
+ *
+ * However, if no further paramters are given, then il_operand_list will be NULL, and we will
+ * need to create a new object to hold the pointer to prev_il_instruction.
+ */
+ if (NULL == symbol->il_operand_list) symbol->il_operand_list = new il_operand_list_c;
+ if (NULL == symbol->il_operand_list) ERROR;
+
+ symbol->il_operand_list->accept(*this);
+
+ if (NULL != prev_il_instruction) {
+ ((list_c *)symbol->il_operand_list)->insert_element(prev_il_instruction, 0);
+
+ generic_function_call_t fcall_param = {
+ /* fcall_param.function_name = */ symbol->function_name,
+ /* fcall_param.nonformal_operand_list = */ symbol->il_operand_list,
+ /* fcall_param.formal_operand_list = */ NULL,
+ /* enum {POU_FB, POU_function} POU_type = */ generic_function_call_t::POU_function,
+ /* fcall_param.candidate_functions = */ symbol->candidate_functions,
+ /* fcall_param.called_function_declaration = */ symbol->called_function_declaration,
+ /* fcall_param.extensible_param_count = */ symbol->extensible_param_count
+ };
+ handle_function_call(symbol, fcall_param);
+
+ /* Undo the changes to the abstract syntax tree we made above... */
+ ((list_c *)symbol->il_operand_list)->remove_element(0);
+ }
+
+ /* Undo the changes to the abstract syntax tree we made above... */
+ if (((list_c *)symbol->il_operand_list)->n == 0) {
+ /* if the list becomes empty, then that means that it did not exist before we made these changes, so we delete it! */
+ delete symbol->il_operand_list;
+ symbol->il_operand_list = NULL;
+ }
+
+ if (debug) std::cout << "il_function_call_c [" << symbol->candidate_datatypes.size() << "] result.\n";
+ return NULL;
+}
+
+
+/* | il_expr_operator '(' [il_operand] eol_list [simple_instr_list] ')' */
+// SYM_REF3(il_expression_c, il_expr_operator, il_operand, simple_instr_list);
+void *fill_candidate_datatypes_c::visit(il_expression_c *symbol) {
+ symbol_c *prev_il_instruction_backup = prev_il_instruction;
+
+ if (NULL != symbol->il_operand)
+ symbol->il_operand->accept(*this);
+
+ if(symbol->simple_instr_list != NULL)
+ symbol->simple_instr_list->accept(*this);
+
+ /* Now check the if the data type semantics of operation are correct, */
+ il_operand = symbol->simple_instr_list;
+ prev_il_instruction = prev_il_instruction_backup;
+ symbol->il_expr_operator->accept(*this);
+ il_operand = NULL;
+
+ /* This object has the same candidate datatypes as the il_expr_operator. */
+ symbol->candidate_datatypes = symbol->il_expr_operator->candidate_datatypes;
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit(il_jump_operation_c *symbol) {
+ /* recursive call to fill the candidate data types list */
+ il_operand = NULL;
+ symbol->il_jump_operator->accept(*this);
+ il_operand = NULL;
+ /* This object has the same candidate datatypes as the il_jump_operator. */
+ symbol->candidate_datatypes = symbol->il_jump_operator->candidate_datatypes;
+ return NULL;
+}
+
+
+/* il_call_operator prev_declared_fb_name
+ * | il_call_operator prev_declared_fb_name '(' ')'
+ * | il_call_operator prev_declared_fb_name '(' eol_list ')'
+ * | il_call_operator prev_declared_fb_name '(' il_operand_list ')'
+ * | il_call_operator prev_declared_fb_name '(' eol_list il_param_list ')'
+ */
+/* 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 */
+// SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list, symbol_c *called_fb_declaration)
+void *fill_candidate_datatypes_c::visit(il_fb_call_c *symbol) {
+ /* We do not call
+ * fb_decl = search_varfb_instance_type->get_basetype_decl(symbol->fb_name);
+ * because we want to make sure it is a FB instance, and not some other data type...
+ */
+ symbol_c *fb_type_id = search_varfb_instance_type->get_basetype_id(symbol->fb_name);
+ /* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
+ if (NULL == fb_type_id) ERROR;
+
+ function_block_declaration_c *fb_decl = function_block_type_symtable.find_value(fb_type_id);
+ if (function_block_type_symtable.end_value() == fb_decl)
+ /* The fb_name not the name of a FB instance. Most probably it is the name of a variable of some other type. */
+ fb_decl = NULL;
+
+ /* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
+ if (NULL == fb_decl) ERROR;
+
+ if (symbol-> il_param_list != NULL) symbol->il_param_list->accept(*this);
+ if (symbol->il_operand_list != NULL) symbol->il_operand_list->accept(*this);
+
+ /* The print_datatypes_error_c does not rely on this called_fb_declaration pointer being != NULL to conclude that
+ * we have a datat type incompatibility error, so setting it to the correct fb_decl is actually safe,
+ * as the compiler will never reach the compilation stage!
+ */
+ symbol->called_fb_declaration = fb_decl;
+
+ /* Let the il_call_operator (CAL, CALC, or CALCN) determine the candidate datatypes of the il_fb_call_c... */
+ /* NOTE: We ignore whether the call is 'compatible' or not when filling in the candidate datatypes list.
+ * Even if it is not compatible, we fill in the candidate datatypes list correctly so that the following
+ * IL instructions may be handled correctly and debuged.
+ * Doing this is actually safe, as the parameter_list will still contain errors that will be found by
+ * print_datatypes_error_c, so the code will never reach stage 4!
+ */
+ symbol->il_call_operator->accept(*this);
+ symbol->candidate_datatypes = symbol->il_call_operator->candidate_datatypes;
+
+ if (debug) std::cout << "FB [] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+
+/* | function_name '(' eol_list [il_param_list] ')' */
+/* NOTE: The parameter 'called_function_declaration' is used to pass data between the stage 3 and stage 4. */
+// SYM_REF2(il_formal_funct_call_c, function_name, il_param_list, symbol_c *called_function_declaration; int extensible_param_count;)
+void *fill_candidate_datatypes_c::visit(il_formal_funct_call_c *symbol) {
+ symbol->il_param_list->accept(*this);
+
+ generic_function_call_t fcall_param = {
+ /* fcall_param.function_name = */ symbol->function_name,
+ /* fcall_param.nonformal_operand_list = */ NULL,
+ /* fcall_param.formal_operand_list = */ symbol->il_param_list,
+ /* enum {POU_FB, POU_function} POU_type = */ generic_function_call_t::POU_function,
+ /* fcall_param.candidate_functions = */ symbol->candidate_functions,
+ /* fcall_param.called_function_declaration = */ symbol->called_function_declaration,
+ /* fcall_param.extensible_param_count = */ symbol->extensible_param_count
+ };
+ handle_function_call(symbol, fcall_param);
+
+ if (debug) std::cout << "il_formal_funct_call_c [" << symbol->candidate_datatypes.size() << "] result.\n";
+ return NULL;
+}
+
+
+// void *visit(il_operand_list_c *symbol);
+
+
+/* | simple_instr_list il_simple_instruction */
+/* This object is referenced by il_expression_c objects */
+void *fill_candidate_datatypes_c::visit(simple_instr_list_c *symbol) {
+ if (symbol->n <= 0)
+ return NULL; /* List is empty! Nothing to do. */
+
+ for(int i = 0; i < symbol->n; i++)
+ symbol->elements[i]->accept(*this);
+
+ /* This object has (inherits) the same candidate datatypes as the last il_instruction */
+ symbol->candidate_datatypes = symbol->elements[symbol->n-1]->candidate_datatypes;
+
+ if (debug) std::cout << "simple_instr_list_c [" << symbol->candidate_datatypes.size() << "] result.\n";
+ return NULL;
+}
+
+
+
+
+// SYM_REF1(il_simple_instruction_c, il_simple_instruction, symbol_c *prev_il_instruction;)
+void *fill_candidate_datatypes_c::visit(il_simple_instruction_c *symbol) {
+ if (symbol->prev_il_instruction.size() > 1) ERROR; /* There should be no labeled insructions inside an IL expression! */
+ if (symbol->prev_il_instruction.size() == 0) prev_il_instruction = NULL;
+ else prev_il_instruction = symbol->prev_il_instruction[0];
+ symbol->il_simple_instruction->accept(*this);
+ prev_il_instruction = NULL;
+
+ /* This object has (inherits) the same candidate datatypes as the il_simple_instruction it points to */
+ symbol->candidate_datatypes = symbol->il_simple_instruction->candidate_datatypes;
+ return NULL;
+}
+
+
+/*
+ void *visit(il_param_list_c *symbol);
+ void *visit(il_param_assignment_c *symbol);
+ void *visit(il_param_out_assignment_c *symbol);
+*/
+
+/*******************/
+/* B 2.2 Operators */
+/*******************/
+void *fill_candidate_datatypes_c::visit(LD_operator_c *symbol) {
+ for(unsigned int i = 0; i < il_operand->candidate_datatypes.size(); i++) {
+ add_datatype_to_candidate_list(symbol, il_operand->candidate_datatypes[i]);
+ }
+ if (debug) std::cout << "LD [" << il_operand->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+void *fill_candidate_datatypes_c::visit(LDN_operator_c *symbol) {
+ for(unsigned int i = 0; i < il_operand->candidate_datatypes.size(); i++) {
+ if (is_ANY_BIT_compatible(il_operand->candidate_datatypes[i]))
+ add_datatype_to_candidate_list(symbol, il_operand->candidate_datatypes[i]);
+ }
+ if (debug) std::cout << "LDN [" << il_operand->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+void *fill_candidate_datatypes_c::visit(ST_operator_c *symbol) {
+ symbol_c *prev_instruction_type, *operand_type;
+
+ if (NULL == prev_il_instruction) return NULL;
+ for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
+ for(unsigned int j = 0; j < il_operand->candidate_datatypes.size(); j++) {
+ prev_instruction_type = prev_il_instruction->candidate_datatypes[i];
+ operand_type = il_operand->candidate_datatypes[j];
+ if (is_type_equal(prev_instruction_type, operand_type))
+ add_datatype_to_candidate_list(symbol, prev_instruction_type);
+ }
+ }
+ if (debug) std::cout << "ST [" << prev_il_instruction->candidate_datatypes.size() << "," << il_operand->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+void *fill_candidate_datatypes_c::visit(STN_operator_c *symbol) {
+ symbol_c *prev_instruction_type, *operand_type;
+
+ if (NULL == prev_il_instruction) return NULL;
+ for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
+ for(unsigned int j = 0; j < il_operand->candidate_datatypes.size(); j++) {
+ prev_instruction_type = prev_il_instruction->candidate_datatypes[i];
+ operand_type = il_operand->candidate_datatypes[j];
+ if (is_type_equal(prev_instruction_type,operand_type) && is_ANY_BIT_compatible(operand_type))
+ add_datatype_to_candidate_list(symbol, prev_instruction_type);
+ }
+ }
+ if (debug) std::cout << "STN [" << prev_il_instruction->candidate_datatypes.size() << "," << il_operand->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+void *fill_candidate_datatypes_c::visit(NOT_operator_c *symbol) {
+ /* NOTE: the standard allows syntax in which the NOT operator is followed by an optional <il_operand>
+ * NOT [<il_operand>]
+ * However, it does not define the semantic of the NOT operation when the <il_operand> is specified.
+ * We therefore consider it an error if an il_operand is specified!
+ * We do not need to generate an error message. This error will be caught somewhere else!
+ */
+ if (NULL == prev_il_instruction) return NULL;
+ for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
+ if (is_ANY_BIT_compatible(prev_il_instruction->candidate_datatypes[i]))
+ add_datatype_to_candidate_list(symbol, prev_il_instruction->candidate_datatypes[i]);
+ }
+ if (debug) std::cout << "NOT_operator [" << prev_il_instruction->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit(S_operator_c *symbol) {
+ /* TODO: what if this is a FB call ?? */
+ symbol_c *prev_instruction_type, *operand_type;
+
+ if (NULL == prev_il_instruction) return NULL;
+ for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
+ for(unsigned int j = 0; j < il_operand->candidate_datatypes.size(); j++) {
+ prev_instruction_type = prev_il_instruction->candidate_datatypes[i];
+ operand_type = il_operand->candidate_datatypes[j];
+ /* TODO: I believe the following is wrong! The data types of prev_instruction_type and operand_type DO NOT have to be equal.
+ * the prev_instruction_type MUST be BOOL compatible.
+ * I am not too sure about operand_type, does it have to be BOOL compatible, or can it be ANY_BIT compatible? Must check!
+ */
+ if (is_type_equal(prev_instruction_type,operand_type) && is_ANY_BOOL_compatible(operand_type))
+ add_datatype_to_candidate_list(symbol, prev_instruction_type);
+ }
+ }
+ if (debug) std::cout << "S [" << prev_il_instruction->candidate_datatypes.size() << "," << il_operand->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit(R_operator_c *symbol) {
+ /* TODO: what if this is a FB call ?? */
+ symbol_c *prev_instruction_type, *operand_type;
+
+ if (NULL == prev_il_instruction) return NULL;
+ for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
+ for(unsigned int j = 0; j < il_operand->candidate_datatypes.size(); j++) {
+ prev_instruction_type = prev_il_instruction->candidate_datatypes[i];
+ operand_type = il_operand->candidate_datatypes[j];
+ /* TODO: I believe the following is wrong! The data types of prev_instruction_type and operand_type DO NOT have to be equal.
+ * the prev_instruction_type MUST be BOOL compatible.
+ * I am not too sure about operand_type, does it have to be BOOL compatible, or can it be ANY_BIT compatible? Must check!
+ */
+ if (is_type_equal(prev_instruction_type,operand_type) && is_ANY_BOOL_compatible(operand_type))
+ add_datatype_to_candidate_list(symbol, prev_instruction_type);
+ }
+ }
+ if (debug) std::cout << "R [" << prev_il_instruction->candidate_datatypes.size() << "," << il_operand->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit( S1_operator_c *symbol) {return handle_implicit_il_fb_call(symbol, "S1", symbol->called_fb_declaration);}
+void *fill_candidate_datatypes_c::visit( R1_operator_c *symbol) {return handle_implicit_il_fb_call(symbol, "R1", symbol->called_fb_declaration);}
+void *fill_candidate_datatypes_c::visit( CLK_operator_c *symbol) {return handle_implicit_il_fb_call(symbol, "CLK", symbol->called_fb_declaration);}
+void *fill_candidate_datatypes_c::visit( CU_operator_c *symbol) {return handle_implicit_il_fb_call(symbol, "CU", symbol->called_fb_declaration);}
+void *fill_candidate_datatypes_c::visit( CD_operator_c *symbol) {return handle_implicit_il_fb_call(symbol, "CD", symbol->called_fb_declaration);}
+void *fill_candidate_datatypes_c::visit( PV_operator_c *symbol) {return handle_implicit_il_fb_call(symbol, "PV", symbol->called_fb_declaration);}
+void *fill_candidate_datatypes_c::visit( IN_operator_c *symbol) {return handle_implicit_il_fb_call(symbol, "IN", symbol->called_fb_declaration);}
+void *fill_candidate_datatypes_c::visit( PT_operator_c *symbol) {return handle_implicit_il_fb_call(symbol, "PT", symbol->called_fb_declaration);}
+
+void *fill_candidate_datatypes_c::visit( AND_operator_c *symbol) {return handle_binary_operator(widen_AND_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( OR_operator_c *symbol) {return handle_binary_operator( widen_OR_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( XOR_operator_c *symbol) {return handle_binary_operator(widen_XOR_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit(ANDN_operator_c *symbol) {return handle_binary_operator(widen_AND_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( ORN_operator_c *symbol) {return handle_binary_operator( widen_OR_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit(XORN_operator_c *symbol) {return handle_binary_operator(widen_XOR_table, symbol, prev_il_instruction, il_operand);}
+
+void *fill_candidate_datatypes_c::visit( ADD_operator_c *symbol) {return handle_binary_operator(widen_ADD_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( SUB_operator_c *symbol) {return handle_binary_operator(widen_SUB_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( MUL_operator_c *symbol) {return handle_binary_operator(widen_MUL_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( DIV_operator_c *symbol) {return handle_binary_operator(widen_DIV_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( MOD_operator_c *symbol) {return handle_binary_operator(widen_MOD_table, symbol, prev_il_instruction, il_operand);}
+
+void *fill_candidate_datatypes_c::visit( GT_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( GE_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( EQ_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( LT_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( LE_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
+void *fill_candidate_datatypes_c::visit( NE_operator_c *symbol) {return handle_binary_operator(widen_CMP_table, symbol, prev_il_instruction, il_operand);}
+
+
+
+void *fill_candidate_datatypes_c::handle_conditional_il_flow_control_operator(symbol_c *symbol) {
+ if (NULL == prev_il_instruction) return NULL;
+ for (unsigned int i = 0; i < prev_il_instruction->candidate_datatypes.size(); i++) {
+ if (is_ANY_BOOL_compatible(prev_il_instruction->candidate_datatypes[i]))
+ add_datatype_to_candidate_list(symbol, prev_il_instruction->candidate_datatypes[i]);
+ }
+ return NULL;
+}
+
+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;}
+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;}
+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;}
+void *fill_candidate_datatypes_c::visit( CALC_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
+void *fill_candidate_datatypes_c::visit(CALCN_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
+void *fill_candidate_datatypes_c::visit( RETC_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
+void *fill_candidate_datatypes_c::visit(RETCN_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
+void *fill_candidate_datatypes_c::visit( JMPC_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
+void *fill_candidate_datatypes_c::visit(JMPCN_operator_c *symbol) {return handle_conditional_il_flow_control_operator(symbol);}
+
+
+
+
+/* Symbol class handled together with function call checks */
+// void *visit(il_assign_operator_c *symbol, variable_name);
+/* Symbol class handled together with function call checks */
+// void *visit(il_assign_operator_c *symbol, option, variable_name);
+
+/***************************************/
+/* B.3 - Language ST (Structured Text) */
+/***************************************/
+/***********************/
+/* B 3.1 - Expressions */
+/***********************/
+void *fill_candidate_datatypes_c::visit( or_expression_c *symbol) {return handle_binary_expression(widen_OR_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( xor_expression_c *symbol) {return handle_binary_expression(widen_XOR_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( and_expression_c *symbol) {return handle_binary_expression(widen_AND_table, symbol, symbol->l_exp, symbol->r_exp);}
+
+void *fill_candidate_datatypes_c::visit( equ_expression_c *symbol) {return handle_binary_expression(widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit(notequ_expression_c *symbol) {return handle_binary_expression(widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( lt_expression_c *symbol) {return handle_binary_expression(widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( gt_expression_c *symbol) {return handle_binary_expression(widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( le_expression_c *symbol) {return handle_binary_expression(widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( ge_expression_c *symbol) {return handle_binary_expression(widen_CMP_table, symbol, symbol->l_exp, symbol->r_exp);}
+
+
+/* The following code is correct when handling the addition of 2 symbolic_variables
+ * In this case, adding two variables (e.g. USINT_var1 + USINT_var2) will always yield
+ * the same data type, even if the result of the adition could not fit inside the same
+ * data type (due to overflowing)
+ *
+ * However, when adding two literals (e.g. USINT#42 + USINT#3)
+ * we should be able to detect overflows of the result, and therefore not consider
+ * that the result may be of type USINT.
+ * Currently we do not yet detect these overflows, and allow handling the sum of two USINTs
+ * as always resulting in an USINT, even in the following expression
+ * (USINT#65535 + USINT#2).
+ *
+ * In the future we can add some code to reduce
+ * all the expressions that are based on literals into the resulting literal
+ * value (maybe some visitor class that will run before or after data type
+ * checking). Since this class will have to be very careful to make sure it implements the same mathematical
+ * details (e.g. how to round and truncate numbers) as defined in IEC 61131-3, we will leave this to the future.
+ * Also, the question will arise if we should also replace calls to standard
+ * functions if the input parameters are all literals (e.g. ADD(42, 42)). This
+ * means this class will be more difficult than it appears at first.
+ */
+void *fill_candidate_datatypes_c::visit( add_expression_c *symbol) {return handle_binary_expression(widen_ADD_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( sub_expression_c *symbol) {return handle_binary_expression(widen_SUB_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( mul_expression_c *symbol) {return handle_binary_expression(widen_MUL_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( div_expression_c *symbol) {return handle_binary_expression(widen_DIV_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit( mod_expression_c *symbol) {return handle_binary_expression(widen_MOD_table, symbol, symbol->l_exp, symbol->r_exp);}
+void *fill_candidate_datatypes_c::visit(power_expression_c *symbol) {return handle_binary_expression(widen_EXPT_table, symbol, symbol->l_exp, symbol->r_exp);}
+
+
+void *fill_candidate_datatypes_c::visit(neg_expression_c *symbol) {
+ /* NOTE: The standard defines the syntax for this 'negation' operation, but
+ * does not define the its semantics.
+ *
+ * We could be tempted to consider that the semantics of the
+ * 'negation' operation are similar/identical to the semantics of the
+ * SUB expression/operation. This would include assuming that the
+ * possible datatypes for the 'negation' operation is also
+ * the same as those for the SUB expression/operation, namely ANY_MAGNITUDE.
+ *
+ * However, this would then mean that the following ST code would be
+ * syntactically and semantically correct:
+ * uint_var := - (uint_var);
+ *
+ * According to the standard, the above code should result in a
+ * runtime error, when we try to apply a negative value to the
+ * UINT typed variable 'uint_var'.
+ *
+ * It is much easier for the compiler to detect this at compile time,
+ * and it is probably safer to the resulting code too.
+ *
+ * To detect these tyes of errors at compile time, the easisest solution
+ * is to only allow ANY_NUM datatytpes that are signed.
+ * So, that is what we do here!
+ */
+ symbol->exp->accept(*this);
+ for (unsigned int i = 0; i < symbol->exp->candidate_datatypes.size(); i++) {
+ if (is_ANY_signed_MAGNITUDE_compatible(symbol->exp->candidate_datatypes[i]))
+ add_datatype_to_candidate_list(symbol, symbol->exp->candidate_datatypes[i]);
+ }
+ if (debug) std::cout << "neg [" << symbol->exp->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit(not_expression_c *symbol) {
+ symbol->exp->accept(*this);
+ for (unsigned int i = 0; i < symbol->exp->candidate_datatypes.size(); i++) {
+ if (is_ANY_BIT_compatible(symbol->exp->candidate_datatypes[i]))
+ add_datatype_to_candidate_list(symbol, symbol->exp->candidate_datatypes[i]);
+ }
+ if (debug) std::cout << "not [" << symbol->exp->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit(function_invocation_c *symbol) {
+ if (NULL != symbol->formal_param_list) symbol-> formal_param_list->accept(*this);
+ else if (NULL != symbol->nonformal_param_list) symbol->nonformal_param_list->accept(*this);
+ else ERROR;
+
+ generic_function_call_t fcall_param = {
+ /* fcall_param.function_name = */ symbol->function_name,
+ /* fcall_param.nonformal_operand_list = */ symbol->nonformal_param_list,
+ /* fcall_param.formal_operand_list = */ symbol->formal_param_list,
+ /* enum {POU_FB, POU_function} POU_type = */ generic_function_call_t::POU_function,
+ /* fcall_param.candidate_functions = */ symbol->candidate_functions,
+ /* fcall_param.called_function_declaration = */ symbol->called_function_declaration,
+ /* fcall_param.extensible_param_count = */ symbol->extensible_param_count
+ };
+ handle_function_call(symbol, fcall_param);
+
+ if (debug) std::cout << "function_invocation_c [" << symbol->candidate_datatypes.size() << "] result.\n";
+ return NULL;
+}
+
+
+
+/********************/
+/* B 3.2 Statements */
+/********************/
+// SYM_LIST(statement_list_c)
+/* The visitor of the base class search_visitor_c will handle calling each instruction in the list.
+ * We do not need to do anything here...
+ */
+// void *fill_candidate_datatypes_c::visit(statement_list_c *symbol)
+
+
+/*********************************/
+/* B 3.2.1 Assignment Statements */
+/*********************************/
+void *fill_candidate_datatypes_c::visit(assignment_statement_c *symbol) {
+ symbol_c *left_type, *right_type;
+
+ symbol->l_exp->accept(*this);
+ symbol->r_exp->accept(*this);
+ for (unsigned int i = 0; i < symbol->l_exp->candidate_datatypes.size(); i++) {
+ for(unsigned int j = 0; j < symbol->r_exp->candidate_datatypes.size(); j++) {
+ left_type = symbol->l_exp->candidate_datatypes[i];
+ right_type = symbol->r_exp->candidate_datatypes[j];
+ if (is_type_equal(left_type, right_type))
+ add_datatype_to_candidate_list(symbol, left_type);
+ }
+ }
+ if (debug) std::cout << ":= [" << symbol->l_exp->candidate_datatypes.size() << "," << symbol->r_exp->candidate_datatypes.size() << "] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+/*****************************************/
+/* B 3.2.2 Subprogram Control Statements */
+/*****************************************/
+void *fill_candidate_datatypes_c::visit(fb_invocation_c *symbol) {
+ symbol_c *fb_type_id = search_varfb_instance_type->get_basetype_id(symbol->fb_name);
+ /* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
+ if (NULL == fb_type_id) ERROR;
+
+ function_block_declaration_c *fb_decl = function_block_type_symtable.find_value(fb_type_id);
+ if (function_block_type_symtable.end_value() == fb_decl)
+ /* The fb_name not the name of a FB instance. Most probably it is the name of a variable of some other type. */
+ fb_decl = NULL;
+
+ /* Although a call to a non-declared FB is a semantic error, this is currently caught by stage 2! */
+ if (NULL == fb_decl) ERROR;
+
+ if (symbol-> formal_param_list != NULL) symbol->formal_param_list->accept(*this);
+ if (symbol->nonformal_param_list != NULL) symbol->nonformal_param_list->accept(*this);
+
+ /* The print_datatypes_error_c does not rely on this called_fb_declaration pointer being != NULL to conclude that
+ * we have a datat type incompatibility error, so setting it to the correct fb_decl is actually safe,
+ * as the compiler will never reach the compilation stage!
+ */
+ symbol->called_fb_declaration = fb_decl;
+
+ if (debug) std::cout << "FB [] ==> " << symbol->candidate_datatypes.size() << " result.\n";
+ return NULL;
+}
+
+
+
+/********************************/
+/* B 3.2.3 Selection Statements */
+/********************************/
+void *fill_candidate_datatypes_c::visit(if_statement_c *symbol) {
+ symbol->expression->accept(*this);
+ if (NULL != symbol->statement_list)
+ symbol->statement_list->accept(*this);
+ if (NULL != symbol->elseif_statement_list)
+ symbol->elseif_statement_list->accept(*this);
+ if (NULL != symbol->else_statement_list)
+ symbol->else_statement_list->accept(*this);
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit(elseif_statement_c *symbol) {
+ symbol->expression->accept(*this);
+ if (NULL != symbol->statement_list)
+ symbol->statement_list->accept(*this);
+ return NULL;
+}
+
+/* CASE expression OF case_element_list ELSE statement_list END_CASE */
+// SYM_REF3(case_statement_c, expression, case_element_list, statement_list)
+void *fill_candidate_datatypes_c::visit(case_statement_c *symbol) {
+ symbol->expression->accept(*this);
+ if (NULL != symbol->case_element_list)
+ symbol->case_element_list->accept(*this);
+ if (NULL != symbol->statement_list)
+ symbol->statement_list->accept(*this);
+ return NULL;
+}
+
+
+/* helper symbol for case_statement */
+// SYM_LIST(case_element_list_c)
+/* NOTE: visitor method for case_element_list_c is not required since we inherit from iterator_visitor_c */
+
+/* case_list ':' statement_list */
+// SYM_REF2(case_element_c, case_list, statement_list)
+/* NOTE: visitor method for case_element_c is not required since we inherit from iterator_visitor_c */
+
+// SYM_LIST(case_list_c)
+/* NOTE: visitor method for case_list_c is not required since we inherit from iterator_visitor_c */
+
+/********************************/
+/* B 3.2.4 Iteration Statements */
+/********************************/
+
+void *fill_candidate_datatypes_c::visit(for_statement_c *symbol) {
+ symbol->control_variable->accept(*this);
+ symbol->beg_expression->accept(*this);
+ symbol->end_expression->accept(*this);
+ if (NULL != symbol->by_expression)
+ symbol->by_expression->accept(*this);
+ if (NULL != symbol->statement_list)
+ symbol->statement_list->accept(*this);
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit(while_statement_c *symbol) {
+ symbol->expression->accept(*this);
+ if (NULL != symbol->statement_list)
+ symbol->statement_list->accept(*this);
+ return NULL;
+}
+
+
+void *fill_candidate_datatypes_c::visit(repeat_statement_c *symbol) {
+ symbol->expression->accept(*this);
+ if (NULL != symbol->statement_list)
+ symbol->statement_list->accept(*this);
+ return NULL;
+}
+
+
+
+
+
+