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/*

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 *  matiec - a compiler for the programming languages defined in IEC 61131-3

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 *

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 *  Copyright (C) 2009-2012  Mario de Sousa (msousa@fe.up.pt)

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 *  Copyright (C) 2012       Manuele Conti (manuele.conti@sirius-es.it)

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 *  Copyright (C) 2012       Matteo Facchinetti (matteo.facchinetti@sirius-es.it)

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 *

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 *  This program is free software: you can redistribute it and/or modify

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 *  it under the terms of the GNU General Public License as published by

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 *  the Free Software Foundation, either version 3 of the License, or

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 *  (at your option) any later version.

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 *

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 *  This program is distributed in the hope that it will be useful,

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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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 *  You should have received a copy of the GNU General Public License

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 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

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 *

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 *

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 * This code is made available on the understanding that it will not be

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 * used in safety-critical situations without a full and competent review.

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 */

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/*

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 * An IEC 61131-3 compiler.

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 *

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 * Based on the

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 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

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 *

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 */

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/* TODO - things yet not checked by this data type checker...

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 *

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 * - check variable declarations

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 * - check data type declarations

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 * - check inside configurations (variable declarations)

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 * - check SFC code

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 * - must fix S and R IL functions (includes potientialy fixing stage4 code!) 

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 */

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/* NOTE: The algorithm implemented here assumes that flow control analysis has already been completed!

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 *       BEFORE running this visitor, be sure to CALL the flow_control_analysis_c visitor!

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 */

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/*

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 *  Fill the candidate datatype list for all symbols that may legally 'have' a data type (e.g. variables, literals, function calls, expressions, etc.)

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 * 

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 *  The candidate datatype list will be filled with a list of all the data types that expression may legally take.

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 *  For example, the very simple literal '0' (as in foo := 0), may represent a:

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 *    BOOL, BYTE, WORD, DWORD, LWORD, USINT, SINT, UINT, INT, UDINT, DINT, ULINT, LINT (as well as the SAFE versions of these data tyes too!)

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 */

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#include <../main.hh>         /* required for UINT64_MAX, INT64_MAX, INT64_MIN, ... */

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#include "fill_candidate_datatypes.hh"

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#include "datatype_functions.hh"

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#include <typeinfo>

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#include <list>

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#include <string>

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#include <string.h>

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#include <strings.h>

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#define GET_CVALUE(dtype, symbol)             ((symbol)->const_value._##dtype.value)

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#define VALID_CVALUE(dtype, symbol)           (symbol_c::cs_const_value == (symbol)->const_value._##dtype.status)

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#define IS_OVERFLOW(dtype, symbol)            (symbol_c::cs_overflow == (symbol)->const_value._##dtype.status)

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

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static int debug = 0;

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

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/*                                                   */

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/*  A small helper class...                          */

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/*                                                   */

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

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/* Add to the local_enumerated_value_symtable the local enum value constants */

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/* Notes:

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 * Some enumerations are 

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 *   (A) declared anonymously inside a VAR ... END_VAR declaration

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 *       (e.g. VAR enum_var : (enumvalue1, enumvalue2); END_VAR)

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 *  while others are 

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 *   (B) declared (with a name) inside a TYPE .. END_TYPE declaration.

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 *

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 *  Values in (A) are added to the enumerated_value_symtable in absyntaxt_utils.cc.

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 *  Values in (B) are only in scope inside the POU with the VAR END_VAR declaration.

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 *

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 * This class will add the enum values in (B) to the local_enumerated_value_symtable.

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 *

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 * If a locally defined enum value is identical to another locally defined enum_value, the

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 *  corresponding entry in local_enumerated_value_symtable is set to NULL.

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 *  However, if a locally defined enum value is identical to another globally defined enum_value, the

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 *  corresponding entry in local_enumerated_value_symtable is set to the local datatype (and not NULL).

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 *  This is because anonynous locally feined enum datatypes are anonymous, and its enum values cannot therefore

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 *  be disambiguated using EnumType#enum_value (since the enum type does not have a name, it is anonymous!).

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 *  For this reason we implement the semantics where locally defined enum values, when in scope, will 'cover'

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 *  the globally defined enum value with the same name/identifier.

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 *  For example:

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 *

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 *  TYPE  GlobalEnumT: (xxx1, xxx2, xxx3) END_TYPE

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 * 

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 *   FUNCTION_BLOCK FOO

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 *    VAR_INPUT

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 *       GlobalEnumVar: GlobalEnumT;

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 *      LocalEnumVar : (xxx1, yyy2, yyy3);

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 *     END_VAR

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 *     LocalEnumVar  := xxx1;   <-- We consider it OK!!!     xxx1 will reference the anonymous type used for LocalEnumVar

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 *     GlobalEnumVar := xxx1;   <-- We consider it an error. xxx1 will reference the anonymous type used for LocalEnumVar

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 *     GlobalEnumVar := GlobalEnumT#xxx1;

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 *     END_FUNCTION_BLOCK

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 */

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class populate_enumvalue_symtable_c: public iterator_visitor_c {

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  private:

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    symbol_c *current_enumerated_type;

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  public:

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     populate_enumvalue_symtable_c(void) {current_enumerated_type = NULL;};

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    ~populate_enumvalue_symtable_c(void) {}

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  public:

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

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  /* B.1 - Common elements */

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

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

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  /* B.1.3 - Data types */

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

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

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  /* B 1.3.3 - Derived data types */

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

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  /* enumerated_specification ASSIGN enumerated_value */

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  void *visit(enumerated_spec_init_c *symbol) {

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    current_enumerated_type = symbol;

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

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    /* DO NOT visit the symbol->enumerated_value   !!! */

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    current_enumerated_type = NULL;

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    return NULL;

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  }

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  /* [enumerated_type_name '#'] identifier */

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  void *visit(enumerated_value_c *symbol) {

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    /* if the enumerated_value_c is not inside a enumerated_spec_init_c (e.g. used as the inital value of a variable), we simply return */

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    if (current_enumerated_type == NULL) return NULL;  

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    /* this is really an ERROR! The initial value may use the syntax NUM_TYPE#enum_value, but in that case we should have return'd in the above statement !! */

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    if (symbol->type != NULL) ERROR;  

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    symbol_c *local_value_type  = local_enumerated_value_symtable.find_value(symbol->value);

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    if (local_value_type == local_enumerated_value_symtable.end_value())

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      /* This identifier has not yet been used in any previous local declaration of an enumeration data type, so we add it to the local symbol table. */

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      local_enumerated_value_symtable.insert(symbol->value, current_enumerated_type);

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    else 

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      /* This identifier has already been used in a previous declaration of an enumeration data type. so we set the symbol in symbol table pointing to NULL. */

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      local_enumerated_value_symtable.set(symbol->value, NULL);

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    return NULL;

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  }

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}; // class populate_enumvalue_symtable_c

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static populate_enumvalue_symtable_c populate_enumvalue_symtable;

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

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/*                                                   */

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/*  Main  FILL candidate datatypes algorithm...      */

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/*                                                   */

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

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fill_candidate_datatypes_c::fill_candidate_datatypes_c(symbol_c *ignore) {

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	il_operand = NULL;

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	prev_il_instruction = NULL;

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	search_varfb_instance_type = NULL;

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	current_enumerated_spec_type = NULL;

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}

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fill_candidate_datatypes_c::~fill_candidate_datatypes_c(void) {

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}

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symbol_c *fill_candidate_datatypes_c::widening_conversion(symbol_c *left_type, symbol_c *right_type, const struct widen_entry widen_table[]) {

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	int k;

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	/* find a widening table entry compatible */

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	for (k = 0; NULL != widen_table[k].left;  k++)

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		if ((typeid(*left_type) == typeid(*widen_table[k].left)) && (typeid(*right_type) == typeid(*widen_table[k].right)))

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                      return widen_table[k].result;

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	return NULL;

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}

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/* add a data type to a candidate data type list, while guaranteeing no duplicate entries! */

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/* Returns true if it really did add the datatype to the list, or false if it was already present in the list! */

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bool fill_candidate_datatypes_c::add_datatype_to_candidate_list(symbol_c *symbol, symbol_c *datatype) {

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  /* If it is an invalid data type, do not insert!

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   * 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. 

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   */

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  if (!get_datatype_info_c::is_type_valid(datatype)) /* checks for NULL and invalid_type_name_c */

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    return false;

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

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    /* already in the list, Just return! */

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    return false;

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  /* not yet in the candidate data type list, so we insert it now! */

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  symbol->candidate_datatypes.push_back(datatype);

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  return true;

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}

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bool fill_candidate_datatypes_c::add_2datatypes_to_candidate_list(symbol_c *symbol, symbol_c *datatype1, symbol_c *datatype2) {

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  add_datatype_to_candidate_list(symbol, datatype1);

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  add_datatype_to_candidate_list(symbol, datatype2);

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  return true;

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}

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void fill_candidate_datatypes_c::remove_incompatible_datatypes(symbol_c *symbol) {

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  #ifdef __REMOVE__

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    #error __REMOVE__ macro already exists. Choose another name!

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  #endif

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  #define __REMOVE__(datatype)\

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      remove_from_candidate_datatype_list(&get_datatype_info_c::datatype,       symbol->candidate_datatypes);\

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      remove_from_candidate_datatype_list(&get_datatype_info_c::safe##datatype, symbol->candidate_datatypes);

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  {/* Remove unsigned data types */

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    uint64_t value = 0;

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    if (VALID_CVALUE( uint64, symbol)) value = GET_CVALUE(uint64, symbol);

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    if (IS_OVERFLOW ( uint64, symbol)) value = (uint64_t)UINT32_MAX + (uint64_t)1;

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    if (value > 1          )          {__REMOVE__(bool_type_name);}

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    if (value > UINT8_MAX  )          {__REMOVE__(usint_type_name);  __REMOVE__( byte_type_name);}

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    if (value > UINT16_MAX )          {__REMOVE__( uint_type_name);  __REMOVE__( word_type_name);}

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    if (value > UINT32_MAX )          {__REMOVE__(udint_type_name);  __REMOVE__(dword_type_name);}

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    if (IS_OVERFLOW( uint64, symbol)) {__REMOVE__(ulint_type_name);  __REMOVE__(lword_type_name);}

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  }

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  {/* Remove signed data types */

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    int64_t value = 0;

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    if (VALID_CVALUE(  int64, symbol)) value = GET_CVALUE(int64, symbol);

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    if (IS_OVERFLOW (  int64, symbol)) value = (int64_t)INT32_MAX + (int64_t)1;

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    if ((value <  INT8_MIN) || (value >  INT8_MAX)) {__REMOVE__(sint_type_name);}

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    if ((value < INT16_MIN) || (value > INT16_MAX)) {__REMOVE__( int_type_name);}

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    if ((value < INT32_MIN) || (value > INT32_MAX)) {__REMOVE__(dint_type_name);}

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    if (IS_OVERFLOW( int64, symbol))                {__REMOVE__(lint_type_name);}

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  }

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  {/* Remove floating point data types */

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    real64_t value = 0;

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    if (VALID_CVALUE( real64, symbol)) value = GET_CVALUE(real64, symbol);

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    if (IS_OVERFLOW ( real64, symbol)) value = (real64_t)REAL32_MAX + (real64_t)1;

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    if (value >  REAL32_MAX )         {__REMOVE__( real_type_name);}

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    if (value < -REAL32_MAX )         {__REMOVE__( real_type_name);}

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    if (IS_OVERFLOW( real64, symbol)) {__REMOVE__(lreal_type_name);}

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  }

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  #undef __REMOVE__

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}

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/* returns true if compatible function/FB invocation, otherwise returns false */

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/* Assumes that the candidate_datatype lists of all the parameters being passed haved already been filled in */

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/*

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

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

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

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 */

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bool fill_candidate_datatypes_c::match_nonformal_call(symbol_c *f_call, symbol_c *f_decl) {

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	symbol_c *call_param_value,  *param_datatype;

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	identifier_c *param_name;

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	function_param_iterator_c       fp_iterator(f_decl);

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	function_call_param_iterator_c fcp_iterator(f_call);

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	int extensible_parameter_highest_index = -1;

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	unsigned int i;

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

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

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		/* Iterate to the next parameter of the function being called.

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		 * Get the name of that parameter, and ignore if EN or ENO.

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		 */

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		do {

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			param_name = fp_iterator.next();

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

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			if(param_name == NULL) return false;

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

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		/* TODO: verify if it is lvalue when INOUT or OUTPUT parameters! */

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		/* Get the parameter type */

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		param_datatype = base_type(fp_iterator.param_type());

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		/* check whether one of the candidate_data_types of the value being passed is the same as the param_type */

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		if (search_in_candidate_datatype_list(param_datatype, call_param_value->candidate_datatypes) < 0)

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			return false; /* return false if param_type not in the list! */

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	}

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	/* call is compatible! */

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	return true;

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}

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/* returns true if compatible function/FB invocation, otherwise returns false */

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/* Assumes that the candidate_datatype lists of all the parameters being passed haved already been filled in */

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bool fill_candidate_datatypes_c::match_formal_call(symbol_c *f_call, symbol_c *f_decl, symbol_c **first_param_datatype) {

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	symbol_c *call_param_value, *call_param_name, *param_datatype;

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	symbol_c *verify_duplicate_param;

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	identifier_c *param_name;

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	function_param_iterator_c       fp_iterator(f_decl);

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	function_call_param_iterator_c fcp_iterator(f_call);

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	int extensible_parameter_highest_index = -1;

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	identifier_c *extensible_parameter_name;

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	unsigned int i;

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	bool is_first_param = true;

   426

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

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

   429

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

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		call_param_value = fcp_iterator.get_current_value();

   431

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

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		if (NULL == call_param_value) ERROR;

   433

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		/* Obtaining the assignment direction:  := (assign_in) or => (assign_out) */

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		function_call_param_iterator_c::assign_direction_t call_param_dir = fcp_iterator.get_assign_direction();

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		/* Checking if there are duplicated parameter values */

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		verify_duplicate_param = fcp_iterator.search_f(call_param_name);

   439

		if(verify_duplicate_param != call_param_value)

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			return false;

   441

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

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		std::vector <symbol_c *>&call_param_types = call_param_value->candidate_datatypes;

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		/* Find the corresponding parameter in function declaration */

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		param_name = fp_iterator.search(call_param_name);

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		if(param_name == NULL) return false;

   448

		/* Get the parameter data type */

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		param_datatype = base_type(fp_iterator.param_type());

   450

		/* Get the parameter direction: IN, OUT, IN_OUT */

   451

		function_param_iterator_c::param_direction_t param_dir = fp_iterator.param_direction();

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   453

		/* check whether direction (IN, OUT, IN_OUT) and assignment types (:= , =>) are compatible !!! */

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		if          (function_call_param_iterator_c::assign_in  == call_param_dir) {

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			if ((function_param_iterator_c::direction_in    != param_dir) &&

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			    (function_param_iterator_c::direction_inout != param_dir))

   457

				return false;

   458

		} else if   (function_call_param_iterator_c::assign_out == call_param_dir) {

   459

			if ((function_param_iterator_c::direction_out   != param_dir))

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				return false;

   461

		} else ERROR;

   462

   463

		/* check whether one of the candidate_data_types of the value being passed is the same as the param_type */

   464

		if (search_in_candidate_datatype_list(param_datatype, call_param_types) < 0)

   465

			return false; /* return false if param_type not in the list! */

   466

   467

		/* If this is the first parameter, then copy the datatype to *first_param_datatype */

   468

		if (is_first_param)

   469

			if (NULL != first_param_datatype)

   470

				*first_param_datatype = param_datatype;

   471

		is_first_param = false;

   472

	}

   473

	/* call is compatible! */

   474

	return true;

   475

}

   476

   477

   478

   479

   480

/* Handle a generic function call!

   481

 * Assumes that the parameter_list containing the values being passed in this function invocation

   482

 * has already had all the candidate_datatype lists filled in!

   483

 *

   484

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

   485

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

   486

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

   487

 */

   488

/*

   489

typedef struct {

   490

  symbol_c *function_name,

   491

  symbol_c *nonformal_operand_list,

   492

  symbol_c *   formal_operand_list,

   493

   494

  std::vector <symbol_c *> &candidate_functions,  

   495

  symbol_c &*called_function_declaration,

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  int      &extensible_param_count

   497

} generic_function_call_t;