/*
 *  matiec - a compiler for the programming languages defined in IEC 61131-3
 *
 *  Copyright (C) 2009-2011  Mario de Sousa (msousa@fe.up.pt)
 *  Copyright (C) 20011-2012 Manuele Conti (manuele.conti@sirius-es.it)
 *  Copyright (C) 20011-2012 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)
 *
 */


/*
 *  Fill candidate list of data types for all symbols
 */

#include "print_datatypes_error.hh"
#include <typeinfo>
#include <list>
#include <string>
#include <string.h>
#include <strings.h>


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

#define STAGE3_ERROR(symbol1, symbol2, ...) {                                          \
    fprintf(stderr, "%s:%d-%d..%d-%d: error : ",                                       \
           FIRST_(symbol1,symbol2)->first_file, FIRST_(symbol1,symbol2)->first_line, FIRST_(symbol1,symbol2)->first_column, \
                                                LAST_(symbol1,symbol2) ->last_line,  LAST_(symbol1,symbol2) ->last_column); \
    fprintf(stderr, __VA_ARGS__);                                                      \
    fprintf(stderr, "\n");                                                             \
    il_error = true;                                                                   \
    error_found = true;\
  }


/* set to 1 to see debug info during execution */
static int debug = 0;

print_datatypes_error_c::print_datatypes_error_c(symbol_c *ignore) {
	error_found = false;
}

print_datatypes_error_c::~print_datatypes_error_c(void) {
	error_found = false;
}

int print_datatypes_error_c::get_error_found() {
	return error_found;
}

/* a helper function... */
symbol_c *print_datatypes_error_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 */
/******************************/
void *print_datatypes_error_c::visit(real_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_REAL data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_REAL data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(integer_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_INT data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_INT data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(neg_real_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_REAL data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_REAL data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(neg_integer_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_INT data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_INT data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(binary_integer_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_INT data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_INT data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(octal_integer_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_INT data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_INT data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(hex_integer_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_INT data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_INT data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(integer_literal_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_INT data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_INT data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(real_literal_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_REAL data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_REAL data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(bit_string_literal_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_BIT data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_BIT data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(boolean_literal_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_BOOL data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_BOOL data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(boolean_true_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_BOOL data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_BOOL data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(boolean_false_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for ANY_BOOL data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "ANY_BOOL data type not valid in this location.");
	}
	return NULL;
}

/*******************************/
/* B.1.2.2   Character Strings */
/*******************************/
void *print_datatypes_error_c::visit(double_byte_character_string_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for WSTRING data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "WSTRING data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(single_byte_character_string_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for STRING data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "STRING data type not valid in this location.");
	}
	return NULL;
}

/***************************/
/* B 1.2.3 - Time Literals */
/***************************/
/************************/
/* B 1.2.3.1 - Duration */
/************************/
void *print_datatypes_error_c::visit(duration_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Invalid syntax for TIME data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "TIME data type not valid in this location.");
	}
	return NULL;
}

/************************************/
/* B 1.2.3.2 - Time of day and Date */
/************************************/
void *print_datatypes_error_c::visit(time_of_day_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Invalid syntax for TOD data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "TOD data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(date_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Invalid syntax for DATE data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "DATE data type not valid in this location.");
	}
	return NULL;
}

void *print_datatypes_error_c::visit(date_and_time_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0) {
		STAGE3_ERROR(symbol, symbol, "Invalid syntax for DT data type.");
	} else if (NULL == symbol->datatype) {
		STAGE3_ERROR(symbol, symbol, "DT data type not valid in this location.");
	}
	return NULL;
}

/**********************/
/* B 1.3 - Data types */
/**********************/
/********************************/
/* B 1.3.3 - Derived data types */
/********************************/
void *print_datatypes_error_c::visit(data_type_declaration_c *symbol) {
	// TODO !!!
	/* for the moment we must return NULL so semantic analysis of remaining code is not interrupted! */
	return NULL;
}

void *print_datatypes_error_c::visit(enumerated_value_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0)
		STAGE3_ERROR(symbol, symbol, "Ambiguous enumerate value or Variable not declared in this scope.");
	return NULL;
}


/*********************/
/* B 1.4 - Variables */
/*********************/
void *print_datatypes_error_c::visit(symbolic_variable_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0)
		STAGE3_ERROR(symbol, symbol, "Variable not declared in this scope.");
	return NULL;
}

/********************************************/
/* B 1.4.1 - Directly Represented Variables */
/********************************************/
void *print_datatypes_error_c::visit(direct_variable_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0)
		STAGE3_ERROR(symbol, symbol, "Numerical result exceeds range for located variable data type.");
	return NULL;
}

/*************************************/
/* B 1.4.2 - Multi-element variables */
/*************************************/
/*  subscripted_variable '[' subscript_list ']' */
// SYM_REF2(array_variable_c, subscripted_variable, subscript_list)
void *print_datatypes_error_c::visit(array_variable_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0)
		STAGE3_ERROR(symbol, symbol, "Array variable not declared in this scope.");
	
	/* recursively call the subscript list to print any errors in the expressions used in the subscript...*/
	symbol->subscript_list->accept(*this);
	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... */
#if 0
void *print_datatypes_error_c::visit(subscript_list_c *symbol) {
}
#endif


/*  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 recursively determine the data types of each field_selector in fill_candidate_datatypes_c,
 * so it does not make sense to recursively visit all the field_selectors to print out error messages. 
 * Maybe in the future, if we find the need to print out more detailed error messages, we might do it that way. For now, we don't!
 */
void *print_datatypes_error_c::visit(structured_variable_c *symbol) {
	if (symbol->candidate_datatypes.size() == 0)
		STAGE3_ERROR(symbol, symbol, "Structure variable not declared in this scope.");
	return NULL;
}

/************************************/
/* B 1.5 Program organization units */
/************************************/
/*********************/
/* B 1.5.1 Functions */
/*********************/
void *print_datatypes_error_c::visit(function_declaration_c *symbol) {
	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);
	/* We do not check for data type errors in variable declarations, Skip this for now... */
// 	symbol->var_declarations_list->accept(*this);
	if (debug) printf("Print error data types list in body of function %s\n", ((token_c *)(symbol->derived_function_name))->value);
	il_parenthesis_level = 0;
	il_error = false;
	prev_il_instruction = NULL;
	symbol->function_body->accept(*this);
	prev_il_instruction = NULL;
	delete search_varfb_instance_type;
	search_varfb_instance_type = NULL;
	return NULL;
}

/***************************/
/* B 1.5.2 Function blocks */
/***************************/
void *print_datatypes_error_c::visit(function_block_declaration_c *symbol) {
	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);
	/* We do not check for data type errors in variable declarations, Skip this for now... */
// 	symbol->var_declarations->accept(*this);
	if (debug) printf("Print error data types list in body of FB %s\n", ((token_c *)(symbol->fblock_name))->value);
	il_parenthesis_level = 0;
	il_error = false;
	prev_il_instruction = NULL;
	symbol->fblock_body->accept(*this);
	prev_il_instruction = NULL;
	delete search_varfb_instance_type;
	search_varfb_instance_type = NULL;
	return NULL;
}

/**********************/
/* B 1.5.3 - Programs */
/**********************/
void *print_datatypes_error_c::visit(program_declaration_c *symbol) {
	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);
	/* We do not check for data type errors in variable declarations, Skip this for now... */
// 	symbol->var_declarations->accept(*this);
	if (debug) printf("Print error data types list in body of program %s\n", ((token_c *)(symbol->program_type_name))->value);
	il_parenthesis_level = 0;
	il_error = false;
	prev_il_instruction = NULL;
	symbol->function_block_body->accept(*this);
	prev_il_instruction = NULL;
	delete search_varfb_instance_type;
	search_varfb_instance_type = NULL;
	return NULL;
}



/********************************/
/* B 1.7 Configuration elements */
/********************************/
void *print_datatypes_error_c::visit(configuration_declaration_c *symbol) {
#if 0
	// TODO !!!
	/* for the moment we must return NULL so semantic analysis of remaining code is not interrupted! */
#endif
	return NULL;
}

/****************************************/
/* B.2 - Language IL (Instruction List) */
/****************************************/
/***********************************/
/* B 2.1 Instructions and Operands */
/***********************************/
// void *visit(instruction_list_c *symbol);
void *print_datatypes_error_c::visit(il_simple_operation_c *symbol) {
	il_operand = symbol->il_operand;
	if (NULL != symbol->il_operand) {
		symbol->il_operand->accept(*this);
	}
	/* recursive call to see whether data types are compatible */
	symbol->il_simple_operator->accept(*this);
	il_operand = NULL;
	return NULL;
}

void *print_datatypes_error_c::visit(il_function_call_c *symbol) {
	return NULL;
}

void *print_datatypes_error_c::visit(il_expression_c *symbol) {
	return NULL;
}

void *print_datatypes_error_c::visit(il_fb_call_c *symbol) {
	return NULL;
}

void *print_datatypes_error_c::visit(il_formal_funct_call_c *symbol) {
	return NULL;
}


/*
    void *visit(il_operand_list_c *symbol);
    void *visit(simple_instr_list_c *symbol);
    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 *print_datatypes_error_c::visit(LD_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(LDN_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'LDN' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(ST_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;
	/* MANU:
	 * if prev_instruction is NULL we can print a message error or warning error like:
	 * we can't use a ST like first instruction.
	 * What do you think?
	 */
	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'ST' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(STN_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;
	/* MANU:
	 * if prev_instruction is NULL we can print a message error or warning error like:
	 * we can't use a ST like first instruction.
	 * What do you think?
	 */
	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'STN' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(NOT_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(S_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'S' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(R_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'R' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(S1_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'S1' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(R1_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'R1' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(CLK_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(CU_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(CD_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(PV_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(IN_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(PT_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(AND_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'AND' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(OR_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'OR' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(XOR_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'XOR' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(ANDN_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'ANDN' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(ORN_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'ORN' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(XORN_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'ORN' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(ADD_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'ADD' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(SUB_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'SUB' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(MUL_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'MUL' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(DIV_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'DIV' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(MOD_operator_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	il_operand->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(il_operand->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'MOD' operator.");
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(GT_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(GE_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(EQ_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(LT_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(LE_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(NE_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(CAL_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(CALC_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(CALCN_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(RET_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(RETC_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(RETCN_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(JMP_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(JMPC_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

void *print_datatypes_error_c::visit(JMPCN_operator_c *symbol) {
	prev_il_instruction = symbol;
	return NULL;
}

/* 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 *print_datatypes_error_c::visit(or_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'OR' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(xor_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'XOR' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(and_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for 'AND' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(equ_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for '=' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(notequ_expression_c *symbol)  {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for '<>' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(lt_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for '<' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(gt_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for '>' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(le_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for '<=' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(ge_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for '>=' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(add_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Current '+' result and operand not of same data type.");

	return NULL;
}



void *print_datatypes_error_c::visit(sub_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
			STAGE3_ERROR(symbol, symbol, "Current '-' result and operand not of same data type.");
	return NULL;
}

void *print_datatypes_error_c::visit(mul_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Current '*' result and operand not of same data type.");
	return NULL;
}

void *print_datatypes_error_c::visit(div_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Current '/' result and operand not of same data type.");
	return NULL;
}


void *print_datatypes_error_c::visit(mod_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Current 'MOD' result and operand not of same data type.");
	return NULL;
}


void *print_datatypes_error_c::visit(power_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0) 		&&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Data type mismatch for '**' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(neg_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0)      &&
		(symbol->exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'NEG' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(not_expression_c *symbol) {
	if (NULL != symbol->datatype) return NULL;

	symbol->exp->accept(*this);
	if ((symbol->candidate_datatypes.size() == 0)      &&
		(symbol->exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'NOT' expression.");
	return NULL;
}


void *print_datatypes_error_c::visit(function_invocation_c *symbol) {
	list_c *parameter_list;

	if (NULL != symbol->formal_param_list)
		parameter_list = (list_c *)symbol->formal_param_list;
	else if (NULL != symbol->nonformal_param_list)
		parameter_list = (list_c *)symbol->nonformal_param_list;
	else ERROR;

	parameter_list->accept(*this);

	if (symbol->candidate_datatypes.size() == 0) {
		/* No compatible function exists */
		STAGE3_ERROR(symbol, symbol, "Invalid parameters in function invocation: %s\n", ((identifier_c *)symbol->function_name)->value);
	} 
#if 0	
	else
	if (NULL == symbol->datatype) {
		/* One or compatible functions exists, but none chosen! */
		STAGE3_ERROR(symbol, symbol, "Invalid parameters in function invocation: %s\n", f_name->value);
	}
#endif

	return NULL;
}

/********************/
/* B 3.2 Statements */
/********************/

/*********************************/
/* B 3.2.1 Assignment Statements */
/*********************************/
void *print_datatypes_error_c::visit(assignment_statement_c *symbol) {
	symbol->l_exp->accept(*this);
	symbol->r_exp->accept(*this);
	if ((NULL == symbol->l_exp->datatype) &&
	    (NULL == symbol->r_exp->datatype) &&
		(symbol->l_exp->candidate_datatypes.size() > 0)	&&
		(symbol->r_exp->candidate_datatypes.size() > 0))
		STAGE3_ERROR(symbol, symbol, "Invalid data types for ':=' operation.");
	return NULL;
}


/*****************************************/
/* B 3.2.2 Subprogram Control Statements */
/*****************************************/
/* fb_name '(' [param_assignment_list] ')' */
/*    formal_param_list -> may be NULL ! */
/* nonformal_param_list -> may be NULL ! */
/* NOTES:
 *    The parameter 'called_fb_declaration'... 
 *       ...is used to pass data between two passes of stage 3.
 *       (actually set in fill_candidate_datatypes_c, and used in narrow_candidate_datatypes_c and print_datatypes_error_c).
 *       This allows fill_candidate_datatypes_c to figure out whether it is a valid FB call,
 *       and let the other classes handle it aproproately.
 *       It could also be used in stage 4, if required.
 */
// SYM_REF3(fb_invocation_c, fb_name, formal_param_list, nonformal_param_list, symbol_c *called_fb_declaration;)
void *print_datatypes_error_c::visit(fb_invocation_c *symbol) {
	list_c *parameter_list;

	if (NULL != symbol->formal_param_list)
		parameter_list = (list_c *)symbol->formal_param_list;
	else if (NULL != symbol->nonformal_param_list)
		parameter_list = (list_c *)symbol->nonformal_param_list;
	else ERROR;

	parameter_list->accept(*this);

	if (NULL == symbol->called_fb_declaration) {
		/* Invalid parameters for FB call! */
		STAGE3_ERROR(symbol, symbol, "Invalid parameters in FB invocation: %s\n", ((identifier_c *)symbol->fb_name)->value);
	} 

	return NULL;
}


/********************************/
/* B 3.2.3 Selection Statements */
/********************************/

void *print_datatypes_error_c::visit(if_statement_c *symbol) {
	symbol->expression->accept(*this);
	if ((NULL == symbol->expression->datatype) &&
		(symbol->expression->candidate_datatypes.size() > 0)) {
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'IF' condition.");
	}
	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 *print_datatypes_error_c::visit(elseif_statement_c *symbol) {
	symbol->expression->accept(*this);
	if ((NULL == symbol->expression->datatype) &&
		(symbol->expression->candidate_datatypes.size() > 0)) {
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'ELSIF' condition.");
	}
	if (NULL != symbol->statement_list)
		symbol->statement_list->accept(*this);
	return NULL;
}


void *print_datatypes_error_c::visit(case_statement_c *symbol) {
	symbol->expression->accept(*this);
	if ((NULL == symbol->expression->datatype) &&
		(symbol->expression->candidate_datatypes.size() > 0)) {
		STAGE3_ERROR(symbol, symbol, "'CASE' quantity not an integer or enumerated.");
	}
	symbol->case_element_list->accept(*this);
	if (NULL != symbol->statement_list)
		symbol->statement_list->accept(*this);
	return NULL;
}

/********************************/
/* B 3.2.4 Iteration Statements */
/********************************/

void *print_datatypes_error_c::visit(for_statement_c *symbol) {
	symbol->control_variable->accept(*this);
	symbol->beg_expression->accept(*this);
	symbol->end_expression->accept(*this);
	/* Control variable */
	if ((NULL == symbol->control_variable->datatype) &&
		(symbol->control_variable->candidate_datatypes.size() > 0)) {
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'FOR' control variable.");
	}
	/* BEG expression */
	if ((NULL == symbol->beg_expression->datatype) &&
		(symbol->beg_expression->candidate_datatypes.size() > 0)) {
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'FOR' begin expression.");
	}
	/* END expression */
	if ((NULL == symbol->end_expression->datatype) &&
		(symbol->end_expression->candidate_datatypes.size() > 0)) {
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'FOR' end expression.");
	}
	/* BY expression */
	if ((NULL != symbol->by_expression) &&
		(NULL == symbol->by_expression->datatype) &&
		(symbol->end_expression->candidate_datatypes.size() > 0)) {
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'FOR' by expression.");
	}
	/* DO statement */
	if (NULL != symbol->statement_list)
		symbol->statement_list->accept(*this);

	return NULL;
}

void *print_datatypes_error_c::visit(while_statement_c *symbol) {
	symbol->expression->accept(*this);
	if (symbol->candidate_datatypes.size() != 1) {
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'WHILE' condition.");
		return NULL;
	}
	if (NULL != symbol->statement_list)
		symbol->statement_list->accept(*this);
	return NULL;
}

void *print_datatypes_error_c::visit(repeat_statement_c *symbol) {
	if (symbol->candidate_datatypes.size() != 1) {
		STAGE3_ERROR(symbol, symbol, "Invalid data type for 'REPEAT' condition.");
		return NULL;
	}
	if (NULL != symbol->statement_list)
		symbol->statement_list->accept(*this);
	symbol->expression->accept(*this);
	return NULL;
}