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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  (conti.ma@alice.it)

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 *

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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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/*

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 * TODO:

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 *   - Check subscript values fall within allowed range.

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 *     For the checking of subscript values to work correctly, we would need to have constant folding working too:

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 *     array_var[8 + 99] can not be checked without constant folding.

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 *     However, even without constant folding range check may be usefull,

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 *     and later changing it to use the values coming out of constant folding should not be very difficult.

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 *

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 */

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#include "array_range_check.hh"

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#define FIRST_(symbol1, symbol2) (((symbol1)->first_order < (symbol2)->first_order)   ? (symbol1) : (symbol2))

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#define  LAST_(symbol1, symbol2) (((symbol1)->last_order  > (symbol2)->last_order)    ? (symbol1) : (symbol2))

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#define STAGE3_ERROR(error_level, symbol1, symbol2, ...) {                                                                  \

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  if (current_display_error_level >= error_level) {                                                                         \

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    fprintf(stderr, "%s:%d-%d..%d-%d: error: ",                                                                             \

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            FIRST_(symbol1,symbol2)->first_file, FIRST_(symbol1,symbol2)->first_line, FIRST_(symbol1,symbol2)->first_column,\

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                                                 LAST_(symbol1,symbol2) ->last_line,  LAST_(symbol1,symbol2) ->last_column);\

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    fprintf(stderr, __VA_ARGS__);                                                                                           \

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    fprintf(stderr, "\n");                                                                                                  \

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    error_count++;                                                                                                     \

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  }                                                                                                                         \

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}

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#define STAGE3_WARNING(symbol1, symbol2, ...) {                                                                             \

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    fprintf(stderr, "%s:%d-%d..%d-%d: warning: ",                                                                           \

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            FIRST_(symbol1,symbol2)->first_file, FIRST_(symbol1,symbol2)->first_line, FIRST_(symbol1,symbol2)->first_column,\

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                                                 LAST_(symbol1,symbol2) ->last_line,  LAST_(symbol1,symbol2) ->last_column);\

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    fprintf(stderr, __VA_ARGS__);                                                                                           \

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    fprintf(stderr, "\n");                                                                                                  \

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    warning_found = true;                                                                                                   \

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}

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#define GET_CVALUE(dtype, symbol)             ((symbol)->const_value_##dtype->value)

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#define VALID_CVALUE(dtype, symbol)           ((NULL != (symbol)->const_value_##dtype) && (symbol_c::cs_const_value == (symbol)->const_value_##dtype->status))

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array_range_check_c::array_range_check_c(symbol_c *ignore) {

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	error_count = 0;

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	current_display_error_level = 0;

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}

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array_range_check_c::~array_range_check_c(void) {

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}

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int array_range_check_c::get_error_count() {

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	return error_count;

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}

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void array_range_check_c::check_dimension_count(array_variable_c *symbol) {

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	int dimension_count;

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	symbol_c *var_decl;

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	var_decl = search_varfb_instance_type->get_basetype_decl(symbol->subscripted_variable);

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	array_dimension_iterator_c array_dimension_iterator(var_decl);

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	for (dimension_count = 0; NULL != array_dimension_iterator.next(); dimension_count++);

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	if (dimension_count != ((list_c *)symbol->subscript_list)->n)

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		STAGE3_ERROR(0, symbol, symbol, "Number of subscripts/indexes does not match the number of subscripts/indexes in the array's declaration (array has %d indexes)", dimension_count);

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}

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void array_range_check_c::check_bounds(array_variable_c *symbol) {

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  list_c *l; /* the subscript_list */

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  symbol_c *var_decl;

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  l = (list_c *)symbol->subscript_list;

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  var_decl = search_varfb_instance_type->get_basetype_decl(symbol->subscripted_variable);

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  array_dimension_iterator_c array_dimension_iterator(var_decl);

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

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    subrange_c *dimension = array_dimension_iterator.next();

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    /* mismatch between number of indexes/subscripts. This error will be caught in check_dimension_count() so we ignore it. */

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    if (NULL == dimension) 

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      return;

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    if ( VALID_CVALUE( int64, l->elements[i]) && VALID_CVALUE( int64, dimension->lower_limit))

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      if ( GET_CVALUE( int64, l->elements[i])   <  GET_CVALUE( int64, dimension->lower_limit))

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      {STAGE3_ERROR(0, symbol, symbol, "Array access out of bounds."); continue;}

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    if ( VALID_CVALUE( int64, l->elements[i]) && VALID_CVALUE( int64, dimension->upper_limit))

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      if ( GET_CVALUE( int64, l->elements[i])   >  GET_CVALUE( int64, dimension->upper_limit))

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      {STAGE3_ERROR(0, symbol, symbol, "Array access out of bounds."); continue;}

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    if ( VALID_CVALUE(uint64, l->elements[i]) && VALID_CVALUE(uint64, dimension->lower_limit))

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      if ( GET_CVALUE(uint64, l->elements[i])   <  GET_CVALUE(uint64, dimension->lower_limit))

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      {STAGE3_ERROR(0, symbol, symbol, "Array access out of bounds."); continue;}

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    if ( VALID_CVALUE(uint64, l->elements[i]) && VALID_CVALUE(uint64, dimension->upper_limit))

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      if ( GET_CVALUE(uint64, l->elements[i])   >  GET_CVALUE(uint64, dimension->upper_limit))

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      {STAGE3_ERROR(0, symbol, symbol, "Array access out of bounds."); continue;}

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  }

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}

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

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/* B 1.4 - Variables */

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

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

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/* B 1.4.2 - Multi-element variables */

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

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

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	check_dimension_count(symbol);

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	check_bounds(symbol);

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	return NULL;

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}

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

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/* B 1.5 - Program organisation units */

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

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

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/* B 1.5.1 - Functions */

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

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

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	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

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	// search_var_instance_decl = new search_var_instance_decl_c(symbol);

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

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	delete search_varfb_instance_type;

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	// delete search_var_instance_decl;

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	search_varfb_instance_type = NULL;

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	// search_var_instance_decl = NULL;

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	return NULL;

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}

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

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/* B 1.5.2 - Function blocks */

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

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

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	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

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	// search_var_instance_decl = new search_var_instance_decl_c(symbol);

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

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	delete search_varfb_instance_type;

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	// delete search_var_instance_decl;

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	search_varfb_instance_type = NULL;

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	// search_var_instance_decl = NULL;

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	return NULL;

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}

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

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/* B 1.5.3 - Programs */

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

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

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	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

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	// search_var_instance_decl = new search_var_instance_decl_c(symbol);

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

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	delete search_varfb_instance_type;

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	// delete search_var_instance_decl;

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	search_varfb_instance_type = NULL;

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	// search_var_instance_decl = NULL;

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	return NULL;

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}

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