/*
	statement.h

	Internal statements

	Copyright (C) 2011 Bill Currie <bill@taniwha.org>

	Author: Bill Currie <bill@taniwha.org>
	Date: 2011/01/18

	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 2
	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, write to:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
#ifndef statement_h
#define statement_h

#include "QF/pr_comp.h"

typedef enum {
	op_symbol,
	op_value,
	op_label,
	op_temp,
	op_pointer,
	op_alias,
} op_type_e;

typedef struct {
	struct def_s   *def;
	struct flowvar_s *flowvar;
	struct daglabel_s *daglabel;
	int         users;
} tempop_t;

typedef struct operand_s {
	struct operand_s *next;
	op_type_e   op_type;
	etype_t     type;			///< possibly override symbol's type
	int         size;			///< for structures
	union {
		struct symbol_s *symbol;
		struct ex_value_s *value;
		struct ex_label_s *label;
		tempop_t    tempop;
		struct operand_s *alias;
	} o;
} operand_t;

/** Overall type of statement.

	Statement types are broken down into expressions (binary and unary,
	includes address and pointer dereferencing (read)), assignment, pointer
	assignment (write to dereference pointer), move (special case of pointer
	assignment), state, function related (call, rcall, return and done), and
	flow control (conditional branches, goto, jump (single pointer and jump
	table)).
*/
typedef enum {
	st_none,		///< not a (valid) statement. Used in dags.
	st_expr,		///< c = a op b; or c = op a;
	st_assign,		///< b = a
	st_ptrassign,	///< *b = a; or *(b + c) = a;
	st_move,		///< memcpy (c, a, b);
	st_state,		///< state (a, b); or state (a, b, c)
	st_func,		///< call, rcall or return/done
	st_flow,		///< if/ifa/ifae/ifb/ifbe/ifnot or goto or jump/jumpb
} st_type_t;

typedef struct statement_s {
	struct statement_s *next;
	st_type_t   type;
	const char *opcode;
	operand_t  *opa;
	operand_t  *opb;
	operand_t  *opc;
	struct expr_s *expr;		///< source expression for this statement
	int         number;			///< number of this statement in function
} statement_t;

typedef struct sblock_s {
	struct sblock_s *next;
	struct reloc_s *relocs;
	struct ex_label_s *labels;
	int         offset;			///< offset of first statement of block
	int         reachable;
	int         number;			///< number of this block in flow graph
	statement_t *statements;
	statement_t **tail;
} sblock_t;

struct expr_s;
struct type_s;

operand_t *alias_operand (operand_t *op, etype_t type);
operand_t *temp_operand (struct type_s *type);
sblock_t *new_sblock (void);
statement_t *new_statement (st_type_t type, const char *opcode,
							struct expr_s *expr);
void sblock_add_statement (sblock_t *sblock, statement_t *statement);
sblock_t *make_statements (struct expr_s *expr);
void print_statement (statement_t *s);
void dump_dot_sblock (void *data, const char *fname);
void print_sblock (sblock_t *sblock, const char *filename);
const char *operand_string (operand_t *op);

#endif//statement_h