/* Header for encoding conversion functions; coding-system object.
#### rename me to coding-system.h
Copyright (C) 1991, 1995 Free Software Foundation, Inc.
Copyright (C) 1995 Sun Microsystems, Inc.
Copyright (C) 2000, 2001, 2002 Ben Wing.
This file is part of XEmacs.
XEmacs 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.
XEmacs 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 XEmacs. If not, see . */
/* Synched up with: Mule 2.3. Not in FSF. */
/* Authorship:
Current primary author: Ben Wing
Written by Ben Wing for XEmacs, 1995, loosely based
on code written 91.10.09 by K.Handa .
Rewritten again 2000-2001 by Ben Wing to support properly
abstracted coding systems.
September 2001: Finished last part of abstraction, the detection
mechanism.
*/
#ifndef INCLUDED_file_coding_h_
#define INCLUDED_file_coding_h_
/* Capsule description of the different structures, what their purpose is,
how they fit together, and where various bits of data are stored.
A "coding system" is an algorithm for converting stream data in one format
into stream data in another format. Currently most of the coding systems
we have created concern internationalized text, and convert between the
XEmacs internal format for multilingual text, and various external
representations of such text. However, any such conversion is possible,
for example, compressing or uncompressing text using the gzip algorithm.
All coding systems provide both encode and decode routines, so that the
conversion can go both ways. Unfortunately encoding and decoding may not
be exact inverses, even for a specific instance of a coding system. Care
must be taken when this is not the case.
The way we handle this is by dividing the various potential coding
systems into types, analogous to classes in C++. Each coding system
type encompasses a series of related coding systems that it can
implement, and it has properties which control how exactly the encoding
works. A particular set of values for each of the properties makes up a
"coding system", and specifies one particular encoding. A `struct
Lisp_Coding_System' object encapsulates those settings -- its type, the
values chosen for all properties of that type, a name for the coding
system, some documentation.
In addition, there are of course methods associated with a coding system
type, implementing the encoding, decoding, etc. These are stored in a
`struct coding_system_methods' object, one per coding-system type, which
contains mostly function pointers. This is retrievable from the
coding-system object (i.e. the struct Lisp_Coding_System), which has a
pointer to it.
In order to actually use a coding system to do an encoding or decoding
operation, you need to use a coding Lstream.
Now let's look more at attached data. All coding systems have certain
common data fields -- name, type, documentation, etc. -- as well as a
bunch more that are defined by the coding system type. To handle this
cleanly, each coding system type defines a structure that holds just the
fields of data particular to it, and calls it e.g. `struct
iso2022_coding_system' for coding system type `iso2022'. When the
memory block holding the coding system object is created, it is sized
such that it can hold both the struct Lisp_Coding_System and the struct
iso2022_coding_system (or whatever) directly following it. (This is a
common trick; another possibility is to have a void * pointer in the
struct Lisp_Coding_System, which points to another memory block holding
the struct iso2022_coding_system.) A macro is provided
(CODING_SYSTEM_TYPE_DATA) to retrieve a pointer of the right type to the
type-specific data contained within the overall `struct
Lisp_Coding_System' block.
Lstreams, similarly, are objects of type `struct lstream' holding data
about the stream operation (how much data has been read or written, any
buffered data, any error conditions, etc.), and like coding systems have
different types. They have a structure called `Lstream_implementation',
one per lstream type, exactly analogous to `struct
coding_system_methods'. In addition, they have type-specific data
(specifying, e.g., the file number, FILE *, memory location, other
lstream, etc. to read the data from or write it to, and for conversion
processes, the current state of the process -- are we decoding ASCII or
Kanji characters? are we in the middle of a processing an escape
sequence? etc.). This type-specific data is stored in a structure
named `struct coding_stream'. Just like for coding systems, the
type-independent data in the `struct lstream' and the type-dependent
data in the `struct coding_stream' are stored together in the same
memory block.
Now things get a bit tricky. The `struct coding_stream' is
type-specific from the point of view of an lstream, but not from the
point of view of a coding system. It contains only general data about
the conversion process, e.g. the name of the coding system used for
conversion, the lstream that we take data from or write it to (depending
on whether this was created as a read stream or a write stream), a
buffer to hold extra data we retrieved but can't send on yet, some
flags, etc. It also needs some data specific to the particular coding
system and thus to the particular operation going on. This data is held
in a structure named (e.g.) `struct iso2022_coding_stream', and it's
held in a separate memory block and pointed to by the generic `struct
coding_stream'. It's not glommed into a single memory block both
because that would require making changes to the generic lstream code
and more importantly because the coding system used in a particular
coding lstream can be changed at any point during the lifetime of the
lstream, and possibly multiple times. (For example, it can be set using
the Lisp primitives `set-process-input-coding-system' and
`set-console-tty-input-coding-system', as well as getting set when a
conversion operation was started with coding system `undecided' and the
correct coding system was then detected.) #### This suggests implementing
compound text extended segments by saving the state of the ctext stream,
and installing an appropriate for the duration of the segment.
IMPORTANT NOTE: There are at least two ancillary data structures
associated with a coding system type. (There may also be detection data;
see elsewhere.) It's important, when writing a coding system type, to
keep straight which type of data goes where. In particular, `struct
foo_coding_system' is attached to the coding system object itself. This
is a permanent object and there's only one per coding system. It's
created once, usually at init time, and never destroyed. So, `struct
foo_coding_system' should in general not contain dynamic data! (Just
data describing the properties of the coding system.) In particular,
*NO* data about any conversion in progress. There may be many
conversions going on simultaneously using a particular coding system,
and by storing conversion data in the coding system, these conversions
will overwrite each other's data.
Instead, use the lstream object, whose purpose is to encapsulate a
particular conversion and all associated data. From the lstream object,
you can get the struct coding_stream using something like
struct coding_stream *str = LSTREAM_TYPE_DATA (lstr, coding);
But usually this structure is already passed to you as one of the
parameters of the method being invoked.
From the struct coding_stream, you can retrieve the
coding-system-type-specific data using something like
struct foo_coding_stream *data = CODING_STREAM_TYPE_DATA (str, foo);
Then, use this structure to hold all data relevant to the particular
conversion being done.
Initialize this structure whenever init_coding_stream_method is called
(this may happen more than once), and finalize it (free resources, etc.)
when finalize_coding_stream_method is called.
*/
struct coding_stream;
struct detection_state;
extern const struct sized_memory_description coding_system_methods_description;
struct coding_system_methods;
enum source_sink_type
{
DECODES_CHARACTER_TO_BYTE,
DECODES_BYTE_TO_BYTE,
DECODES_BYTE_TO_CHARACTER,
DECODES_CHARACTER_TO_CHARACTER
};
enum eol_type
{
EOL_LF,
EOL_CRLF,
EOL_CR,
EOL_AUTODETECT
};
struct Lisp_Coding_System
{
NORMAL_LISP_OBJECT_HEADER header;
struct coding_system_methods *methods;
#define CODING_SYSTEM_SLOT_DECLARATION
#define MARKED_SLOT(x) Lisp_Object x;
#include "coding-system-slots.h"
/* Eol type requested by user. See comment about EOL junk in
coding-system-slots.h. */
enum eol_type eol_type;
/* If true, this is an internal coding system, which will not show up in
coding-system-list unless a special parameter is given to it. */
int internal_p;
/* type-specific extra data attached to a coding_system */
char data[1];
};
typedef struct Lisp_Coding_System Lisp_Coding_System;
DECLARE_LISP_OBJECT (coding_system, Lisp_Coding_System);
#define XCODING_SYSTEM(x) XRECORD (x, coding_system, Lisp_Coding_System)
#define wrap_coding_system(p) wrap_record (p, coding_system)
#define CODING_SYSTEMP(x) RECORDP (x, coding_system)
#define CHECK_CODING_SYSTEM(x) CHECK_RECORD (x, coding_system)
#define CONCHECK_CODING_SYSTEM(x) CONCHECK_RECORD (x, coding_system)
enum coding_system_variant
{
no_conversion_coding_system,
convert_eol_coding_system,
undecided_coding_system,
chain_coding_system,
text_file_wrapper_coding_system,
internal_coding_system,
gzip_coding_system,
mswindows_multibyte_to_unicode_coding_system,
mswindows_multibyte_coding_system,
iso2022_coding_system,
ccl_coding_system,
shift_jis_coding_system,
big5_coding_system,
unicode_coding_system,
fixed_width_coding_system
};
struct coding_system_methods
{
Lisp_Object type;
Lisp_Object predicate_symbol;
/* Type expressed as an enum, needed for KKCC marking of the
type-specific lstream data; copied into the struct coding_stream. */
enum coding_system_variant enumtype;
/* Implementation specific methods: */
/* Init method: Initialize coding-system data. Optional. */
void (*init_method) (Lisp_Object coding_system);
/* Mark method: Mark any Lisp objects in the type-specific data
attached to the coding-system object. Optional. */
void (*mark_method) (Lisp_Object coding_system);
/* Print method: Print the type-specific properties of this coding
system, as part of `print'-ing the object. If this method is defined
and prints anything, it should print a space as the first thing it
does. Optional. */
void (*print_method) (Lisp_Object cs, Lisp_Object printcharfun,
int escapeflag);
/* Canonicalize method: Convert this coding system to another one; called
once, at creation time, after all properties have been parsed. The
returned value should be a coding system created with
make_internal_coding_system() (passing the existing coding system as the
first argument), and will become the coding system returned by
`make-coding-system'. Optional.
NOTE: There are *three* different uses of "canonical" or "canonicalize"
w.r.t. coding systems, and it's important to keep them straight.
1. The canonicalize method. Used to specify a different coding
system, used when doing conversions, in place of the actual coding
system itself. Stored in the CANONICAL field of a coding system.
2. The canonicalize-after-coding method. Used to return the encoding
that was "actually" used to decode some text, such that this
particular encoding can be used to encode the text again with the
expectation that the result will be the same as the original encoding.
Particularly important with auto-detecting coding systems.
3. From the perspective of aliases, a "canonical" coding system is one
that's not an alias to some other coding system, and "canonicalization"
is the process of traversing the alias pointers to find the canonical
coding system that's equivalent to the alias.
*/
Lisp_Object (*canonicalize_method) (Lisp_Object coding_system);
/* Canonicalize after coding method: Convert this coding system to
another one, after coding (usually decoding) has finished. This is
meant to be used by auto-detecting coding systems, which should return
the actually detected coding system. Optional. */
Lisp_Object (*canonicalize_after_coding_method)
(struct coding_stream *str);
/* Convert method: Decode or encode the data in SRC of size N, writing
the results into the Dynarr DST. If the conversion_end_type method
indicates that the source is characters (as opposed to bytes), you are
guaranteed to get only whole characters in the data in SRC/N. STR, a
struct coding_stream, stores all necessary state and other info about
the conversion. Coding-specific state (struct TYPE_coding_stream) can
be retrieved from STR using CODING_STREAM_TYPE_DATA(). Return value
indicates the number of bytes of the *INPUT* that were converted (not
the number of bytes written to the Dynarr!). This can be less than
the total amount of input passed in; if so, the remainder is
considered "rejected" and will appear again at the beginning of the
data passed in the next time the convert method is called. When EOF
is returned on the other end and there's no more data, the convert
method will be called one last time, STR->eof set and the passed-in
data will consist only of any rejected data from the previous
call. (At this point, file handles and similar resources can be
closed, but do NOT arbitrarily free data structures in the
type-specific data, because there are operations that can be done on
closed streams to query the results of the processing -- specifically,
for coding streams, there's the canonicalize_after_coding() method.)
Required. */
Bytecount (*convert_method) (struct coding_stream *str,
const unsigned char *src,
unsigned_char_dynarr *dst, Bytecount n);
/* Query method: Check whether the buffer text between point and END
can be encoded by this coding system. Returns
either nil (meaning the text can be encoded by the coding system) or a
range table object describing the stretches that the coding system
cannot encode.
Possible values for flags are below, search for
QUERY_METHOD_IGNORE_INVALID_SEQUENCES.
Coding systems are expected to be able to behave sensibly with all
possible octets on decoding, which is why this method is only available
for encoding. */
Lisp_Object (*query_method) (Lisp_Object coding_system, struct buffer *buf,
Charbpos end, int flags);
/* Same as the previous method, but this works in the context of
lstreams. (Where the data do need to be copied, unfortunately.) The
intention is to implement the query method for the mswindows-multibyte
coding systems in terms of a query_lstream method. */
Lisp_Object (*query_lstream_method) (struct coding_stream *str,
const Ibyte *start, Bytecount n);
/* Coding mark method: Mark any Lisp objects in the type-specific data
attached to `struct coding_stream'. Optional. */
void (*mark_coding_stream_method) (struct coding_stream *str);
/* Init coding stream method: Initialize the type-specific data attached
to the coding stream (i.e. in struct TYPE_coding_stream), when the
coding stream is opened. The type-specific data will be zeroed out.
Optional. */
void (*init_coding_stream_method) (struct coding_stream *str);
/* Rewind coding stream method: Reset any necessary type-specific data as
a result of the stream being rewound. Optional. */
void (*rewind_coding_stream_method) (struct coding_stream *str);
/* Finalize coding stream method: Clean up the type-specific data
attached to the coding stream (i.e. in struct TYPE_coding_stream).
Happens when the Lstream is deleted using Lstream_delete() or is
garbage-collected. Most streams are deleted after they've been used,
so it's less likely (but still possible) that allocated data will
stick around until GC time. (File handles can also be closed when EOF
is signalled; but some data must stick around after this point, for
the benefit of canonicalize_after_coding. See the convert method.)
Called only once. Optional. */
void (*finalize_coding_stream_method) (struct coding_stream *str);
/* Finalize method: Clean up type-specific data (e.g. free allocated
data) attached to the coding system (i.e. in struct
TYPE_coding_system), when the coding system is about to be garbage
collected. (Currently not called.) Called only once. Optional. */
void (*finalize_method) (Lisp_Object codesys);
/* Conversion end type method: Does this coding system encode bytes ->
characters, characters -> characters, bytes -> bytes, or
characters -> bytes?. Default is characters -> bytes. Optional. */
enum source_sink_type (*conversion_end_type_method) (Lisp_Object codesys);
/* Putprop method: Set the value of a type-specific property. If
the property name is unrecognized, return 0. If the value is disallowed
or erroneous, signal an error. Currently called only at creation time.
Optional. */
int (*putprop_method) (Lisp_Object codesys,
Lisp_Object key,
Lisp_Object value);
/* Getprop method: Return the value of a type-specific property. If
the property name is unrecognized, return Qunbound. Optional.
*/
Lisp_Object (*getprop_method) (Lisp_Object coding_system,
Lisp_Object prop);
/* These next three are set as part of the call to
INITIALIZE_CODING_SYSTEM_TYPE_WITH_DATA. */
/* Description of the extra data (struct foo_coding_system) attached to a
coding system, for pdump purposes. */
const struct sized_memory_description *extra_description;
/* size of struct foo_coding_system -- extra data associated with
the coding system */
int extra_data_size;
/* size of struct foo_coding_stream -- extra data associated with the
struct coding_stream, needed for each active coding process
using this coding system. note that we can have more than one
process active at once (simply by creating more than one coding
lstream using this coding system), so we can't store this data in
the coding system object. */
int coding_data_size;
};
/* Values for flags, as passed to query_method. */
#define QUERY_METHOD_IGNORE_INVALID_SEQUENCES 0x0001
#define QUERY_METHOD_ERRORP 0x0002
#define QUERY_METHOD_HIGHLIGHT 0x0004
enum query_coding_failure_reasons
{
query_coding_succeeded = 0,
query_coding_unencodable = 1,
query_coding_invalid_sequence = 2
};
extern Lisp_Object Qquery_coding_warning_face;
Lisp_Object default_query_method (Lisp_Object, struct buffer *, Charbpos,
int);
/***** Calling a coding-system method *****/
#define RAW_CODESYSMETH(cs, m) ((cs)->methods->m##_method)
#define HAS_CODESYSMETH_P(cs, m) (!!RAW_CODESYSMETH (cs, m))
#define CODESYSMETH(cs, m, args) (((cs)->methods->m##_method) args)
/* Call a void-returning coding-system method, if it exists. */
#define MAYBE_CODESYSMETH(cs, m, args) do { \
Lisp_Coding_System *maybe_codesysmeth_cs = (cs); \
if (HAS_CODESYSMETH_P (maybe_codesysmeth_cs, m)) \
CODESYSMETH (maybe_codesysmeth_cs, m, args); \
} while (0)
/* Call a coding-system method, if it exists, or return GIVEN.
NOTE: Multiply-evaluates CS. */
#define CODESYSMETH_OR_GIVEN(cs, m, args, given) \
(HAS_CODESYSMETH_P (cs, m) ? \
CODESYSMETH (cs, m, args) : (given))
#define XCODESYSMETH(cs, m, args) \
CODESYSMETH (XCODING_SYSTEM (cs), m, args)
#define MAYBE_XCODESYSMETH(cs, m, args) \
MAYBE_CODESYSMETH (XCODING_SYSTEM (cs), m, args)
#define XCODESYSMETH_OR_GIVEN(cs, m, args, given) \
CODESYSMETH_OR_GIVEN (XCODING_SYSTEM (cs), m, args, given)
/***** Defining new coding-system types *****/
extern const struct sized_memory_description coding_system_empty_extra_description;
#ifdef ERROR_CHECK_TYPES
#define DECLARE_CODING_SYSTEM_TYPE(type) \
\
extern struct coding_system_methods * type##_coding_system_methods; \
DECLARE_INLINE_HEADER ( \
struct type##_coding_system * \
error_check_##type##_coding_system_data (Lisp_Coding_System *cs) \
) \
{ \
assert (CODING_SYSTEM_TYPE_P (cs, type)); \
/* Catch accidental use of INITIALIZE_CODING_SYSTEM_TYPE in place \
of INITIALIZE_CODING_SYSTEM_TYPE_WITH_DATA. */ \
assert (cs->methods->extra_data_size > 0); \
return (struct type##_coding_system *) cs->data; \
} \
\
DECLARE_INLINE_HEADER ( \
struct type##_coding_stream * \
error_check_##type##_coding_stream_data (struct coding_stream *s) \
) \
{ \
assert (XCODING_SYSTEM_TYPE_P (s->codesys, type)); \
return (struct type##_coding_stream *) s->data; \
} \
\
DECLARE_INLINE_HEADER ( \
Lisp_Coding_System * \
error_check_##type##_coding_system_type (Lisp_Object obj) \
) \
{ \
Lisp_Coding_System *cs = XCODING_SYSTEM (obj); \
assert (CODING_SYSTEM_TYPE_P (cs, type)); \
return cs; \
} \
\
DECLARE_NOTHING
#else
#define DECLARE_CODING_SYSTEM_TYPE(type) \
extern struct coding_system_methods * type##_coding_system_methods
#endif /* ERROR_CHECK_TYPES */
#define DEFINE_CODING_SYSTEM_TYPE(type) \
struct coding_system_methods * type##_coding_system_methods
#define DEFINE_CODING_SYSTEM_TYPE_WITH_DATA(type) \
struct coding_system_methods * type##_coding_system_methods; \
static const struct sized_memory_description \
type##_coding_system_description_0 = { \
sizeof (struct type##_coding_system), \
type##_coding_system_description \
}
#define INITIALIZE_CODING_SYSTEM_TYPE(ty, pred_sym) do { \
ty##_coding_system_methods = \
xnew_and_zero (struct coding_system_methods); \
ty##_coding_system_methods->type = Q##ty; \
ty##_coding_system_methods->extra_description = \
&coding_system_empty_extra_description; \
ty##_coding_system_methods->enumtype = ty##_coding_system; \
ty##_coding_system_methods->query_method = default_query_method; \
defsymbol_nodump (&ty##_coding_system_methods->predicate_symbol, \
pred_sym); \
add_entry_to_coding_system_type_list (ty##_coding_system_methods); \
dump_add_root_block_ptr (&ty##_coding_system_methods, \
&coding_system_methods_description); \
} while (0)
#define REINITIALIZE_CODING_SYSTEM_TYPE(type) do { \
staticpro_nodump (&type##_coding_system_methods->predicate_symbol); \
} while (0)
/* This assumes the existence of two structures:
struct foo_coding_system (attached to the coding system)
struct foo_coding_stream (per coding process, attached to the
struct coding_stream)
const struct memory_description foo_coding_system_description[]
(data description of struct foo_coding_system)
For an example of how to do the description, see
chain_coding_system_description.
*/
#define INITIALIZE_CODING_SYSTEM_TYPE_WITH_DATA(type, pred_sym) \
do { \
INITIALIZE_CODING_SYSTEM_TYPE (type, pred_sym); \
type##_coding_system_methods->extra_data_size = \
sizeof (struct type##_coding_system); \
type##_coding_system_methods->extra_description = \
&type##_coding_system_description_0; \
type##_coding_system_methods->coding_data_size = \
sizeof (struct type##_coding_stream); \
} while (0)
/* Declare that coding-system-type TYPE has method METH; used in
initialization routines */
#define CODING_SYSTEM_HAS_METHOD(type, meth) \
(type##_coding_system_methods->meth##_method = type##_##meth)
/***** Macros for accessing coding-system types *****/
#define CODING_SYSTEM_TYPE_P(cs, type) \
((cs)->methods == type##_coding_system_methods)
#define XCODING_SYSTEM_TYPE_P(cs, type) \
CODING_SYSTEM_TYPE_P (XCODING_SYSTEM (cs), type)
#ifdef ERROR_CHECK_TYPES
# define CODING_SYSTEM_TYPE_DATA(cs, type) \
error_check_##type##_coding_system_data (cs)
#else
# define CODING_SYSTEM_TYPE_DATA(cs, type) \
((struct type##_coding_system *) \
(cs)->data)
#endif
#define XCODING_SYSTEM_TYPE_DATA(cs, type) \
CODING_SYSTEM_TYPE_DATA (XCODING_SYSTEM_OF_TYPE (cs, type), type)
#ifdef ERROR_CHECK_TYPES
# define XCODING_SYSTEM_OF_TYPE(x, type) \
error_check_##type##_coding_system_type (x)
# define XSETCODING_SYSTEM_OF_TYPE(x, p, type) do \
{ \
x = wrap_coding_system (p); \
assert (CODING_SYSTEM_TYPEP (XCODING_SYSTEM (x), type)); \
} while (0)
#else
# define XCODING_SYSTEM_OF_TYPE(x, type) XCODING_SYSTEM (x)
# define XSETCODING_SYSTEM_OF_TYPE(x, p, type) do \
{ \
x = wrap_coding_system (p); \
} while (0)
#endif /* ERROR_CHECK_TYPE_CHECK */
#define CODING_SYSTEM_TYPEP(x, type) \
(CODING_SYSTEMP (x) && CODING_SYSTEM_TYPE_P (XCODING_SYSTEM (x), type))
#define CHECK_CODING_SYSTEM_OF_TYPE(x, type) do { \
CHECK_CODING_SYSTEM (x); \
if (!CODING_SYSTEM_TYPE_P (XCODING_SYSTEM (x), type)) \
dead_wrong_type_argument \
(type##_coding_system_methods->predicate_symbol, x); \
} while (0)
#define CONCHECK_CODING_SYSTEM_OF_TYPE(x, type) do { \
CONCHECK_CODING_SYSTEM (x); \
if (!(CODING_SYSTEM_TYPEP (x, type))) \
x = wrong_type_argument \
(type##_coding_system_methods->predicate_symbol, x); \
} while (0)
#define CODING_SYSTEM_METHODS(codesys) ((codesys)->methods)
#define CODING_SYSTEM_NAME(codesys) ((codesys)->name)
#define CODING_SYSTEM_DESCRIPTION(codesys) ((codesys)->description)
#define CODING_SYSTEM_TYPE(codesys) ((codesys)->methods->type)
#define CODING_SYSTEM_MNEMONIC(codesys) ((codesys)->mnemonic)
#define CODING_SYSTEM_DOCUMENTATION(codesys) ((codesys)->documentation)
#define CODING_SYSTEM_POST_READ_CONVERSION(codesys) \
((codesys)->post_read_conversion)
#define CODING_SYSTEM_PRE_WRITE_CONVERSION(codesys) \
((codesys)->pre_write_conversion)
#define CODING_SYSTEM_EOL_TYPE(codesys) ((codesys)->eol_type)
#define CODING_SYSTEM_EOL_LF(codesys) ((codesys)->eol[EOL_LF])
#define CODING_SYSTEM_EOL_CRLF(codesys) ((codesys)->eol[EOL_CRLF])
#define CODING_SYSTEM_EOL_CR(codesys) ((codesys)->eol[EOL_CR])
#define CODING_SYSTEM_TEXT_FILE_WRAPPER(codesys) ((codesys)->text_file_wrapper)
#define CODING_SYSTEM_AUTO_EOL_WRAPPER(codesys) ((codesys)->auto_eol_wrapper)
#define CODING_SYSTEM_SUBSIDIARY_PARENT(codesys) ((codesys)->subsidiary_parent)
#define CODING_SYSTEM_CANONICAL(codesys) ((codesys)->canonical)
#define CODING_SYSTEM_SAFE_CHARSETS(codesys) ((codesys)->safe_charsets)
#define CODING_SYSTEM_SAFE_CHARS(codesys) ((codesys)->safe_chars)
#define CODING_SYSTEM_CHAIN_CHAIN(codesys) \
(CODING_SYSTEM_TYPE_DATA (codesys, chain)->chain)
#define CODING_SYSTEM_CHAIN_COUNT(codesys) \
(CODING_SYSTEM_TYPE_DATA (codesys, chain)->count)
#define CODING_SYSTEM_CHAIN_CANONICALIZE_AFTER_CODING(codesys) \
(CODING_SYSTEM_TYPE_DATA (codesys, chain)->canonicalize_after_coding)
#define XCODING_SYSTEM_METHODS(codesys) \
CODING_SYSTEM_METHODS (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_NAME(codesys) \
CODING_SYSTEM_NAME (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_DESCRIPTION(codesys) \
CODING_SYSTEM_DESCRIPTION (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_TYPE(codesys) \
CODING_SYSTEM_TYPE (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_MNEMONIC(codesys) \
CODING_SYSTEM_MNEMONIC (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_DOCUMENTATION(codesys) \
CODING_SYSTEM_DOCUMENTATION (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_POST_READ_CONVERSION(codesys) \
CODING_SYSTEM_POST_READ_CONVERSION (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_PRE_WRITE_CONVERSION(codesys) \
CODING_SYSTEM_PRE_WRITE_CONVERSION (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_EOL_TYPE(codesys) \
CODING_SYSTEM_EOL_TYPE (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_EOL_LF(codesys) \
CODING_SYSTEM_EOL_LF (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_EOL_CRLF(codesys) \
CODING_SYSTEM_EOL_CRLF (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_EOL_CR(codesys) \
CODING_SYSTEM_EOL_CR (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_TEXT_FILE_WRAPPER(codesys) \
CODING_SYSTEM_TEXT_FILE_WRAPPER (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_AUTO_EOL_WRAPPER(codesys) \
CODING_SYSTEM_AUTO_EOL_WRAPPER (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_SUBSIDIARY_PARENT(codesys) \
CODING_SYSTEM_SUBSIDIARY_PARENT (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_CANONICAL(codesys) \
CODING_SYSTEM_CANONICAL (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_SAFE_CHARSETS(codesys) \
CODING_SYSTEM_SAFE_CHARSETS (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_SAFE_CHARS(codesys) \
CODING_SYSTEM_SAFE_CHARS (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_CHAIN_CHAIN(codesys) \
CODING_SYSTEM_CHAIN_CHAIN (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_CHAIN_COUNT(codesys) \
CODING_SYSTEM_CHAIN_COUNT (XCODING_SYSTEM (codesys))
#define XCODING_SYSTEM_CHAIN_CANONICALIZE_AFTER_CODING(codesys) \
CODING_SYSTEM_CHAIN_CANONICALIZE_AFTER_CODING (XCODING_SYSTEM (codesys))
/**************************************************/
/* Detection */
/**************************************************/
#define MAX_DETECTOR_CATEGORIES 256
#define MAX_DETECTORS 64
#define MAX_BYTES_PROCESSED_FOR_DETECTION 65536
struct detection_state
{
int seen_non_ascii;
Bytecount bytes_seen;
char categories[MAX_DETECTOR_CATEGORIES];
Bytecount data_offset[MAX_DETECTORS];
/* ... more data follows; data_offset[detector_##TYPE] points to
the data for that type */
};
#define DETECTION_STATE_DATA(st, type) \
((struct type##_detector *) \
((char *) (st) + (st)->data_offset[detector_##type]))
/* Distinguishable categories of encodings.
This list determines the initial priority of the categories.
For better or worse, currently Mule files are encoded in 7-bit ISO 2022.
For this reason, under Mule ISO_7 gets highest priority.
Putting NO_CONVERSION second prevents "binary corruption" in the
default case in all but the (presumably) extremely rare case of a
binary file which contains redundant escape sequences but no 8-bit
characters.
The remaining priorities are based on perceived "internationalization
political correctness." An exception is UCS-4 at the bottom, since
basically everything is compatible with UCS-4, but it is likely to
be very rare as an external encoding. */
/* Macros to define code of control characters for ISO2022's functions. */
/* Used by the detection routines of other coding system types as well. */
/* code */ /* function */
#define ISO_CODE_LF 0x0A /* line-feed */
#define ISO_CODE_CR 0x0D /* carriage-return */
#define ISO_CODE_SO 0x0E /* shift-out */
#define ISO_CODE_SI 0x0F /* shift-in */
#define ISO_CODE_ESC 0x1B /* escape */
#define ISO_CODE_DEL 0x7F /* delete */
#define ISO_CODE_SS2 0x8E /* single-shift-2 */
#define ISO_CODE_SS3 0x8F /* single-shift-3 */
#define ISO_CODE_CSI 0x9B /* control-sequence-introduce */
enum detection_result
{
/* Basically means a magic cookie was seen indicating this type, or
something similar. */
DET_NEAR_CERTAINTY = 4,
DET_HIGHEST = 4,
/* Characteristics seen that are unlikely to be other coding system types
-- e.g. ISO-2022 escape sequences, or perhaps a consistent pattern of
alternating zero bytes in UTF-16, along with Unicode LF or CRLF
sequences at regular intervals. (Zero bytes are unlikely or impossible
in most text encodings.) */
DET_QUITE_PROBABLE = 3,
/* Strong or medium statistical likelihood. At least some
characteristics seen that match what's normally found in this encoding
-- e.g. in Shift-JIS, a number of two-byte Japanese character
sequences in the right range, and nothing out of range; or in Unicode,
much higher statistical variance in the odd bytes than in the even
bytes, or vice-versa (perhaps the presence of regular EOL sequences
would bump this too to DET_QUITE_PROBABLE). This is quite often a
statistical test. */
DET_SOMEWHAT_LIKELY = 2,
/* Weak statistical likelihood. Pretty much any features at all that
characterize this encoding, and nothing that rules against it. */
DET_SLIGHTLY_LIKELY = 1,
/* Default state. Perhaps it indicates pure ASCII or something similarly
vague seen in Shift-JIS, or, exactly as the level says, it might mean
in a statistical-based detector that the pros and cons are balanced
out. This is also the lowest level that will be accepted by the
auto-detector without asking the user: If all available detectors
report lower levels for all categories with attached coding systems,
the user will be shown the results and explicitly prompted for action.
The user will also be prompted if this is the highest available level
and more than one detector reports the level. (See below about the
consequent necessity of an "ASCII" detector, which will return level 1
or higher for most plain text files.) */
DET_AS_LIKELY_AS_UNLIKELY = 0,
/* Some characteristics seen that are unusual for this encoding --
e.g. unusual control characters in a plain-text encoding, lots of
8-bit characters, or little statistical variance in the odd and even
bytes in UTF-16. */
DET_SOMEWHAT_UNLIKELY = -1,
/* This indicates that there is very little chance the data is in the
right format; this is probably the lowest level you can get when
presenting random binary data to a text file, because there are no
"specific sequences" you can see that would totally rule out
recognition. */
DET_QUITE_IMPROBABLE = -2,
/* An erroneous sequence was seen. */
DET_NEARLY_IMPOSSIBLE = -3,
DET_LOWEST = -3
};
extern int coding_detector_count;
extern int coding_detector_category_count;
struct detector_category
{
int id;
Lisp_Object sym;
};
typedef struct
{
Dynarr_declare (struct detector_category);
} detector_category_dynarr;
struct detector
{
int id;
detector_category_dynarr *cats;
Bytecount data_size;
/* Detect method: Required. */
void (*detect_method) (struct detection_state *st,
const unsigned char *src, Bytecount n);
/* Finalize detection state method: Clean up any allocated data in the
detection state. Called only once. Optional. */
void (*finalize_detection_state_method) (struct detection_state *st);
};
/* Lvalue for a particular detection result -- detection state ST,
category CAT */
#define DET_RESULT(st, cat) ((st)->categories[detector_category_##cat])
/* In state ST, set all detection results associated with detector DET to
RESULT. */
#define SET_DET_RESULTS(st, det, result) \
set_detection_results (st, detector_##det, result)
typedef struct
{
Dynarr_declare (struct detector);
} detector_dynarr;
extern detector_dynarr *all_coding_detectors;
#define DEFINE_DETECTOR_CATEGORY(detector, cat) \
int detector_category_##cat
#define DECLARE_DETECTOR_CATEGORY(detector, cat) \
extern int detector_category_##cat
#define INITIALIZE_DETECTOR_CATEGORY(detector, cat) \
do { \
struct detector_category dog; \
xzero (dog); \
detector_category_##cat = coding_detector_category_count++; \
dump_add_opaque_int (&detector_category_##cat); \
dog.id = detector_category_##cat; \
dog.sym = Q##cat; \
Dynarr_add (Dynarr_at (all_coding_detectors, detector_##detector).cats, \
dog); \
} while (0)
#define DEFINE_DETECTOR(Detector) \
int detector_##Detector
#define DECLARE_DETECTOR(Detector) \
extern int detector_##Detector
#define INITIALIZE_DETECTOR(Detector) \
do { \
struct detector det; \
xzero (det); \
detector_##Detector = coding_detector_count++; \
dump_add_opaque_int (&detector_##Detector); \
det.id = detector_##Detector; \
det.cats = Dynarr_new2 (detector_category_dynarr, \
struct detector_category); \
det.data_size = sizeof (struct Detector##_detector); \
Dynarr_add (all_coding_detectors, det); \
} while (0)
#define DETECTOR_HAS_METHOD(Detector, Meth) \
Dynarr_at (all_coding_detectors, detector_##Detector).Meth##_method = \
Detector##_##Meth
/**************************************************/
/* Decoding/Encoding */
/**************************************************/
/* Is the source (SOURCEP == 1) or sink (SOURCEP == 0) when encoding specified
in characters? */
enum source_or_sink
{
CODING_SOURCE,
CODING_SINK
};
enum encode_decode
{
CODING_ENCODE,
CODING_DECODE
};
/* Data structure attached to an lstream of type `coding',
containing values specific to the coding process. Additional
data is stored in the DATA field below; the exact form of that data
is controlled by the type of the coding system that governs the
conversion (field CODESYS). CODESYS may be set at any time
throughout the lifetime of the lstream and possibly more than once.
See long comment above for more info. */
struct coding_stream
{
/* Enumerated constant listing which type of console this is (TTY, X,
MS-Windows, etc.). This duplicates the method structure in
XCODING_SYSTEM (str->codesys)->methods->type, which formerly was the
only way to determine the coding system type. We need this constant
now for KKCC, so that it can be used in an XD_UNION clause to
determine the Lisp objects in the type-specific data. */
enum coding_system_variant type;
/* Coding system that governs the conversion. */
Lisp_Object codesys;
/* Original coding system, pre-canonicalization. */
Lisp_Object orig_codesys;
/* Back pointer to current stream. */
Lstream *us;
/* Stream that we read the unprocessed data from or write the processed
data to. */
Lstream *other_end;
/* In order to handle both reading to and writing from a coding stream,
we phrase the conversion methods like write methods -- we can
implement reading in terms of a write method but not vice-versa,
because the write method is forced to take only what it's given but
the read method can read more data from the other end if necessary.
On the other hand, the write method is free to generate all the data
it wants (and just write it to the other end), but the read method
can return only as much as was asked for, so we need to implement our
own buffering. */
/* If we are reading, then we can return only a fixed amount of data, but
the converter is free to return as much as it wants, so we direct it
to store the data here and lop off chunks as we need them. If we are
writing, we use this because the converter takes a Dynarr but we are
supposed to write into a fixed buffer. (NOTE: This introduces an extra
memory copy.) */
unsigned_char_dynarr *convert_to;
/* The conversion method might reject some of the data -- this typically
includes partial characters, partial escape sequences, etc. When
writing, we just pass the rejection up to the Lstream module, and it
will buffer the data. When reading, however, we need to do the
buffering ourselves, and we put it here, combined with newly read
data. */
unsigned_char_dynarr *convert_from;
/* If set, this is the last chunk of data being processed. When this is
finished, output any necessary terminating control characters, escape
sequences, etc. */
unsigned int eof:1;
/* CH holds a partially built-up character. This is really part of the
state-dependent data and should be moved there. */
unsigned int ch;
/* Coding-system-specific data holding extra state about the
conversion. Logically a struct TYPE_coding_stream; a pointer
to such a struct, with (when ERROR_CHECK_TYPES is defined)
error-checking that this is really a structure of that type
(checking the corresponding coding system type) can be retrieved using
CODING_STREAM_TYPE_DATA(). Allocated at the same time that
CODESYS is set (which may occur at any time, even multiple times,
during the lifetime of the stream). The size comes from
methods->coding_data_size. */
void *data;
enum encode_decode direction;
/* If set, don't close the stream at the other end when being closed. */
unsigned int no_close_other:1;
/* If set, read only one byte at a time from other end to avoid any
possible blocking. */
unsigned int one_byte_at_a_time:1;
/* If set, and we're a read stream, we init char mode on ourselves as
necessary to prevent the caller from getting partial characters. (the
default) */
unsigned int set_char_mode_on_us_when_reading:1;
/* #### Temporary test */
unsigned int finalized:1;
};
#define CODING_STREAM_DATA(stream) LSTREAM_TYPE_DATA (stream, coding)
#ifdef ERROR_CHECK_TYPES
# define CODING_STREAM_TYPE_DATA(s, type) \
error_check_##type##_coding_stream_data (s)
#else
# define CODING_STREAM_TYPE_DATA(s, type) \
((struct type##_coding_stream *) (s)->data)
#endif
/* C should be a binary character in the range 0 - 255; convert
to internal format and add to Dynarr DST. */
#ifdef MULE
#define DECODE_ADD_BINARY_CHAR(c, dst) \
do { \
if (byte_ascii_p (c)) \
Dynarr_add (dst, c); \
else if (byte_c1_p (c)) \
{ \
Dynarr_add (dst, LEADING_BYTE_CONTROL_1); \
Dynarr_add (dst, c + 0x20); \
} \
else \
{ \
Dynarr_add (dst, LEADING_BYTE_LATIN_ISO8859_1); \
Dynarr_add (dst, c); \
} \
} while (0)
#else /* not MULE */
#define DECODE_ADD_BINARY_CHAR(c, dst) \
do { \
Dynarr_add (dst, c); \
} while (0)
#endif /* MULE */
#define DECODE_OUTPUT_PARTIAL_CHAR(ch, dst) \
do { \
if (ch) \
{ \
DECODE_ADD_BINARY_CHAR (ch, dst); \
ch = 0; \
} \
} while (0)
#ifdef MULE
/* Convert shift-JIS code (sj1, sj2) into internal string
representation (c1, c2). (The leading byte is assumed.) */
#define DECODE_SHIFT_JIS(sj1, sj2, c1, c2) \
do { \
int I1 = sj1, I2 = sj2; \
if (I2 >= 0x9f) \
c1 = (I1 << 1) - ((I1 >= 0xe0) ? 0xe0 : 0x60), \
c2 = I2 + 2; \
else \
c1 = (I1 << 1) - ((I1 >= 0xe0) ? 0xe1 : 0x61), \
c2 = I2 + ((I2 >= 0x7f) ? 0x60 : 0x61); \
} while (0)
/* Convert the internal string representation of a Shift-JIS character
(c1, c2) into Shift-JIS code (sj1, sj2). The leading byte is
assumed. */
#define ENCODE_SHIFT_JIS(c1, c2, sj1, sj2) \
do { \
int I1 = c1, I2 = c2; \
if (I1 & 1) \
sj1 = (I1 >> 1) + ((I1 < 0xdf) ? 0x31 : 0x71), \
sj2 = I2 - ((I2 >= 0xe0) ? 0x60 : 0x61); \
else \
sj1 = (I1 >> 1) + ((I1 < 0xdf) ? 0x30 : 0x70), \
sj2 = I2 - 2; \
} while (0)
#endif /* MULE */
DECLARE_CODING_SYSTEM_TYPE (no_conversion);
DECLARE_CODING_SYSTEM_TYPE (convert_eol);
#if 0
DECLARE_CODING_SYSTEM_TYPE (text_file_wrapper);
#endif /* 0 */
DECLARE_CODING_SYSTEM_TYPE (undecided);
DECLARE_CODING_SYSTEM_TYPE (chain);
#ifdef DEBUG_XEMACS
DECLARE_CODING_SYSTEM_TYPE (internal);
#endif
#ifdef MULE
DECLARE_CODING_SYSTEM_TYPE (iso2022);
DECLARE_CODING_SYSTEM_TYPE (ccl);
DECLARE_CODING_SYSTEM_TYPE (fixed_width);
DECLARE_CODING_SYSTEM_TYPE (shift_jis);
DECLARE_CODING_SYSTEM_TYPE (big5);
#endif
#ifdef HAVE_ZLIB
DECLARE_CODING_SYSTEM_TYPE (gzip);
#endif
DECLARE_CODING_SYSTEM_TYPE (unicode);
#ifdef WIN32_ANY
DECLARE_CODING_SYSTEM_TYPE (mswindows_multibyte_to_unicode);
DECLARE_CODING_SYSTEM_TYPE (mswindows_multibyte);
#endif
Lisp_Object coding_stream_detected_coding_system (Lstream *stream);
Lisp_Object coding_stream_coding_system (Lstream *stream);
void set_coding_stream_coding_system (Lstream *stream,
Lisp_Object codesys);
Lisp_Object detect_coding_stream (Lisp_Object stream);
Ichar decode_big5_char (int o1, int o2);
void add_entry_to_coding_system_type_list (struct coding_system_methods *m);
Lisp_Object make_internal_coding_system (Lisp_Object existing,
const Ascbyte *prefix,
Lisp_Object type,
Lisp_Object description,
Lisp_Object props);
#define LSTREAM_FL_NO_CLOSE_OTHER (1 << 16)
#define LSTREAM_FL_READ_ONE_BYTE_AT_A_TIME (1 << 17)
#define LSTREAM_FL_NO_INIT_CHAR_MODE_WHEN_READING (1 << 18)
Lisp_Object make_coding_input_stream (Lstream *stream, Lisp_Object codesys,
enum encode_decode direction,
int flags);
Lisp_Object make_coding_output_stream (Lstream *stream, Lisp_Object codesys,
enum encode_decode direction,
int flags);
void set_detection_results (struct detection_state *st, int detector,
int given);
#endif /* INCLUDED_file_coding_h_ */