/*
** Copyright (C) 1997 The University of Melbourne.
** This file may only be copied under the terms of the GNU Library General
** Public License - see the file COPYING.LIB in the Mercury distribution.
**
** $Id: mb_bytecode.h,v 1.1 2001-01-24 07:42:22 lpcam Exp $
**
** This file contains the bytecode format and data types
** This must be the same as that in compiler/bytecode.m
*/


#ifndef MB_BYTECODE_H
#define	MB_BYTECODE_H

#include <stdio.h>

#include "mercury_conf.h"
#include "mercury_types.h"
#include "mercury_float.h"

#include "mb_util.h"

/* XXX expects sizeof(unsigned char) == 1 */
typedef unsigned char
	MB_Byte;

typedef MR_INT_LEAST16_TYPE
	MB_Short;

typedef MR_Word
	MB_Word;

typedef MR_Integer
	MB_Integer;

typedef MR_Float
	MB_Float;

typedef MR_Float64
	MB_Float64;

typedef MR_Bool
	MB_Bool;

typedef struct MB_Tag_struct {
	MB_Byte	id;
	union {
		MB_Byte	primary;
		struct {
			MB_Byte	primary;
			MB_Word	secondary; 
		} pair;
		MB_Byte	enum_tag;
	} opt;
} MB_Tag;

/* 
 *	Possible values for Tag.id ...
 */
#define	MB_TAG_SIMPLE			0
#define	MB_TAG_COMPLICATED		1
#define	MB_TAG_COMPLICATED_CONSTANT	2
#define	MB_TAG_ENUM			3
#define	MB_TAG_NONE			4

typedef MB_Byte
	MB_Determinism;
/*
 *	Possible values for Determinism ...
 */
#define	MB_DET_DET			0
#define	MB_DET_SEMIDET			1
#define	MB_DET_MULTIDET			2
#define	MB_DET_NONDET			3
#define	MB_DET_CC_MULTIDET		4
#define	MB_DET_CC_NONDET		5
#define	MB_DET_ERRONEOUS		6
#define	MB_DET_FAILURE			7

typedef struct MB_Op_arg_struct {
	MB_Byte	id;
	union {
		MB_Short	var;
		MB_Integer 	int_const;
		MB_Float	float_const;
	} opt;
} MB_Op_arg;

/*
 *	Possible values for Op_arg.id
 */
#define	MB_ARG_VAR			0
#define	MB_ARG_INT_CONST		1
#define	MB_ARG_FLOAT_CONST		2


typedef MB_Byte
	MB_Direction;

typedef struct MB_Var_dir_struct {
	MB_Short	var;
	MB_Direction	dir;
} MB_Var_dir;

/*
 *	Possible values for Direction ...
 */
#define	MB_DIR_TO_ARG		0
#define	MB_DIR_TO_VAR		1
#define	MB_DIR_TO_NONE		2


typedef struct MB_Cons_id_struct {
	MB_Byte	id;
	union {
		struct {
			MB_CString	module_id;
			MB_CString	string;
			MB_Short	arity;
			MB_Tag		tag;
		} cons;
		MB_Integer	int_const;	
		MB_CString	string_const;
		MB_Float	float_const;
		struct {
			MB_CString	module_id;
			MB_CString	pred_id;
			MB_Short	arity;
			MB_Byte		proc_id;
		} pred_const;
		struct {
			MB_CString	module_id;
			MB_CString	pred_id;
			MB_Short	arity;
			MB_Byte		proc_id;
		} code_addr_const;
		struct {
			MB_CString	module_id;
			MB_CString	type_name;
			MB_Byte		type_arity;
		} base_type_info_const;
		struct {
			MB_Byte		ch;
		} char_const;
	} opt;
} MB_Cons_id;

/*
 *	Possible values for Cons_id.id ...
 */
#define	MB_CONSID_CONS			0
#define	MB_CONSID_INT_CONST		1
#define	MB_CONSID_STRING_CONST		2
#define	MB_CONSID_FLOAT_CONST		3
#define	MB_CONSID_PRED_CONST		4
#define	MB_CONSID_CODE_ADDR_CONST	5
#define	MB_CONSID_BASE_TYPE_INFO_CONST	6
#define	MB_CONSID_CHAR_CONST		7

typedef union MB_Bytecode_Arg_tag {
	struct {
		MB_CString	pred_name;	/* XXX: malloc */
		MB_Short	pred_arity;
		MB_Byte		is_func;
		MB_Short	proc_count;
	} enter_pred;

	struct {
	} endof_pred;

	struct {
		MB_Byte		proc_id;
		MB_Determinism	det;
		MB_Short	label_count;
		MB_Short	temp_count;
		MB_Short	list_length;
		MB_CString	*var_info_list; /* XXX: malloc */
		
		/* index onto label heap for label indexes
		 * (not in the file) */
		MB_Word		label_index; 	
	} enter_proc;

	struct {
	} endof_proc;

	struct {
		MB_Short	label;
	} label;

	struct {
		MB_Short	end_label;
	} enter_disjunction;

	struct {
	} endof_disjunction;

	struct {
		MB_Short	next_label;
	} enter_disjunct;

	struct {
		MB_Short	label; /* XXX: what's label for? */
	} endof_disjunct;

	struct {
		MB_Short	var;
		MB_Short	end_label;
	} enter_switch;

	struct {
	} endof_switch;

	struct {
		MB_Cons_id	cons_id;
		MB_Short	next_label;
	} enter_switch_arm;

	struct {
		MB_Short	label;	/* XXX: what's this label for? */
	} endof_switch_arm;

	struct {
		MB_Short	else_label;
		MB_Short	end_label;
		MB_Short	frame_ptr_tmp;
	} enter_if;

	struct {
		MB_Short	frame_ptr_tmp;
	} enter_then;
	
	struct {
		MB_Short	follow_label;
	} endof_then;	/* XXX: should rename to enter_else */

	struct {
	} endof_if;

	struct {
		MB_Short	end_label;
	} enter_negation;

	struct {
	} endof_negation;

	struct {
		MB_Short	temp;	
	} enter_commit;

	struct {
		MB_Short	temp;	
	} endof_commit;

	struct {
		MB_Short	to_var;
		MB_Short	from_var;
	} assign;

	struct {
		MB_Short	var1;
		MB_Short	var2;
	} test;

	struct {
		MB_Short	to_var;
		MB_Cons_id	consid;
		MB_Short	list_length;
		MB_Short	*var_list;	/* XXX: malloc */
	} construct;

	struct {
		MB_Short	from_var;
		MB_Cons_id	consid;
		MB_Short	list_length;
		MB_Short	*var_list;	/* XXX: malloc */
	} deconstruct;

	struct {
		MB_Short	to_var;
		MB_Cons_id	consid;
		MB_Short	list_length;
		MB_Var_dir	*var_dir_list;/* XXX: malloc */	
	} complex_construct;

	struct {
		MB_Short	from_var;
		MB_Cons_id	consid;
		MB_Short	list_length;
		MB_Var_dir	*var_dir_list;/* XXX: malloc */
	} complex_deconstruct;

	struct {
		MB_Byte		to_reg;
		MB_Short	from_var;
	} place_arg;

	struct {
		MB_Byte		from_reg;
		MB_Short	to_var;
	} pickup_arg;
		
	struct {
		MB_CString	module_id;	/* XXX: malloc */
		MB_CString	pred_id;	/* XXX: malloc */
		MB_Short	arity;
		MB_Byte		proc_id;

		/* code address to call (generated when file is loaded) */
		MB_Word		adr;
	} call;

	struct  {
		MB_Short	pred_var;
		MB_Short	in_var_count;
		MB_Short	out_var_count;
		MB_Determinism	det;
	} higher_order_call;

	struct {
		MB_Byte		binop;
		MB_Op_arg	arg1;
		MB_Op_arg	arg2;
		MB_Short	to_var;
	} builtin_binop;

	struct {
		MB_Byte		unop;
		MB_Op_arg	arg;
		MB_Short	to_var;
	} builtin_unop;

	struct {
		MB_Byte		binop;
		MB_Op_arg	arg1;
		MB_Op_arg	arg2;
	} builtin_bintest;	

	struct {
		MB_Byte		unop;
		MB_Op_arg	arg;
	} builtin_untest;	

	struct {
	} semidet_succeed;

	struct {
	} semidet_success_check;

	struct {
	} fail;

	struct {
		/* XXX: is this int or short?? */
		MB_Short	line_number;
	} context;

	struct {
	} not_supported;
} MB_Bytecode_Arg;

typedef struct MB_Bytecode_struct {
	MB_Byte	id;	/* Which bytecode instruction. e.g. BC_fail */
	MB_Bytecode_Arg	opt;
} MB_Bytecode;

/*
** Possible Bytecode.id values
*/
#define	MB_BC_enter_pred		0
#define	MB_BC_endof_pred		1
#define	MB_BC_enter_proc		2
#define	MB_BC_endof_proc		3
#define	MB_BC_label			4
#define MB_BC_enter_disjunction		5
#define	MB_BC_endof_disjunction		6
#define	MB_BC_enter_disjunct		7
#define	MB_BC_endof_disjunct		8
#define	MB_BC_enter_switch		9
#define	MB_BC_endof_switch		10
#define	MB_BC_enter_switch_arm		11
#define	MB_BC_endof_switch_arm		12
#define	MB_BC_enter_if			13
#define	MB_BC_enter_then		14
/* XXX: enter_else would be a better name than endof_then */
#define	MB_BC_endof_then		15
#define	MB_BC_endof_if			16
#define	MB_BC_enter_negation		17
#define	MB_BC_endof_negation		18
#define	MB_BC_enter_commit		19
#define	MB_BC_endof_commit		20
#define	MB_BC_assign			21
#define	MB_BC_test			22
#define	MB_BC_construct			23
#define	MB_BC_deconstruct		24
#define	MB_BC_complex_construct		25
#define	MB_BC_complex_deconstruct	26
#define	MB_BC_place_arg			27
#define	MB_BC_pickup_arg		28
#define	MB_BC_call			29
#define	MB_BC_higher_order_call		30
#define	MB_BC_builtin_binop		31
#define	MB_BC_builtin_unop		32
#define	MB_BC_builtin_bintest		33
#define	MB_BC_builtin_untest		34
#define	MB_BC_semidet_succeed		35
#define	MB_BC_semidet_success_check	36
#define	MB_BC_fail			37
#define	MB_BC_context			38
#define	MB_BC_not_supported		39

/* These are used internally by the interpreter */
/* all codes above MB_BC_debug are debugging values */
#define MB_BC_debug			254
#define	MB_BC_debug_trap		254
#define	MB_BC_debug_invalid		255
/*#define	MB_BC_noop			255*/

/*
 *	Read the next bytecode from the stream fp.
 *	If no bytecode can be read, return FALSE.
 *	Otherwise, return TRUE.
 */
MB_Bool
MB_read_bytecode(FILE *fp, MB_Bytecode *bc_p);

/*
 *	Read the bytecode version number from the stream fp.
 *	If the version number cannot be read, return FALSE.
 *	Otherwise, return TRUE.
 */
MB_Bool
MB_read_bytecode_version_number(FILE *fp, MB_Short *version_number_p);

#endif	/* MB_BYTECODE_H */