/* Copyright (C) 1997-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

The GNU C Library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */

/* This header provides no interface for a user to the internals of
the gconv implementation in the libc. Therefore there is no use
for these definitions beside for writing additional gconv modules. */

#ifndef _GCONV_H
#define _GCONV_H 1

#include <features.h>
#include <bits/types/__mbstate_t.h>
#include <bits/types/wint_t.h>

#define __need_size_t
#define __need_wchar_t
#include <stddef.h>

/* ISO 10646 value used to signal invalid value. */
#define __UNKNOWN_10646_CHAR ((wchar_t) 0xfffd)

/* Error codes for gconv functions. */
enum
{
__GCONV_OK = 0,
__GCONV_NOCONV,
__GCONV_NODB,
__GCONV_NOMEM,

__GCONV_EMPTY_INPUT,
__GCONV_FULL_OUTPUT,
__GCONV_ILLEGAL_INPUT,
__GCONV_INCOMPLETE_INPUT,

__GCONV_ILLEGAL_DESCRIPTOR,
__GCONV_INTERNAL_ERROR
};


/* Flags the `__gconv_open' function can set. */
enum
{
__GCONV_IS_LAST = 0x0001,
__GCONV_IGNORE_ERRORS = 0x0002,
__GCONV_SWAP = 0x0004,
__GCONV_TRANSLIT = 0x0008
};


/* Forward declarations. */
struct __gconv_step;
struct __gconv_step_data;
struct __gconv_loaded_object;


/* Type of a conversion function. */
typedef int (*__gconv_fct) (struct __gconv_step *, struct __gconv_step_data *,
const unsigned char **, const unsigned char *,
unsigned char **, size_t *, int, int);

/* Type of a specialized conversion function for a single byte to INTERNAL. */
typedef wint_t (*__gconv_btowc_fct) (struct __gconv_step *, unsigned char);

/* Constructor and destructor for local data for conversion step. */
typedef int (*__gconv_init_fct) (struct __gconv_step *);
typedef void (*__gconv_end_fct) (struct __gconv_step *);


/* Description of a conversion step. */
struct __gconv_step
{
struct __gconv_loaded_object *__shlib_handle;
const char *__modname;

int __counter;

char *__from_name;
char *__to_name;

__gconv_fct __fct;
__gconv_btowc_fct __btowc_fct;
__gconv_init_fct __init_fct;
__gconv_end_fct __end_fct;

/* Information about the number of bytes needed or produced in this
step. This helps optimizing the buffer sizes. */
int __min_needed_from;
int __max_needed_from;
int __min_needed_to;
int __max_needed_to;

/* Flag whether this is a stateful encoding or not. */
int __stateful;

void *__data; /* Pointer to step-local data. */
};

/* Additional data for steps in use of conversion descriptor. This is
allocated by the `init' function. */
struct __gconv_step_data
{
unsigned char *__outbuf; /* Output buffer for this step. */
unsigned char *__outbufend; /* Address of first byte after the output
buffer. */

/* Is this the last module in the chain. */
int __flags;

/* Counter for number of invocations of the module function for this
descriptor. */
int __invocation_counter;

/* Flag whether this is an internal use of the module (in the mb*towc*
and wc*tomb* functions) or regular with iconv(3). */
int __internal_use;

__mbstate_t *__statep;
__mbstate_t __state; /* This element must not be used directly by
any module; always use STATEP! */
};


/* Combine conversion step description with data. */
typedef struct __gconv_info
{
size_t __nsteps;
struct __gconv_step *__steps;
__extension__ struct __gconv_step_data __data[0];
} *__gconv_t;

/* Transliteration using the locale's data. */
extern int __gconv_transliterate (struct __gconv_step *step,
struct __gconv_step_data *step_data,
const unsigned char *inbufstart,
const unsigned char **inbufp,
const unsigned char *inbufend,
unsigned char **outbufstart,
size_t *irreversible);

#endif /* gconv.h */