cpython/Modules/cjkcodecs/iso2022common.h

257 lines
9.8 KiB
C

/*
* iso2022common.h: Common Codec Routines for ISO-2022 codecs.
*
* Written by Hye-Shik Chang <perky@FreeBSD.org>
* $CJKCodecs: iso2022common.h,v 1.8 2003/12/31 05:46:55 perky Exp $
*/
/* This ISO-2022 implementation is intended to comply ECMA-43 Level 1
* rather than RFCs itself */
#define ESC 0x1b
#define SO 0x0e
#define SI 0x0f
#define MAX_ESCSEQLEN 16
#define IS_ESCEND(c) (((c) >= 'A' && (c) <= 'Z') || (c) == '@')
#define IS_ISO2022ESC(c2) ((c2) == '(' || (c2) == ')' || (c2) == '$' || \
(c2) == '.' || (c2) == '&')
/* this is not a full list of ISO-2022 escape sequence headers.
* but, it's enough to implement CJK instances of iso-2022. */
/* STATE
state->c[0-3]
00000000
||^^^^^|
|+-----+---- G0-3 Character Set
+----------- Is G0-3 double byte?
state->c[4]
00000000
||
|+---- Locked-Shift?
+----- ESC Throughout
*/
#define CHARSET_DOUBLEBYTE 0x80
#define CHARSET_ASCII 'B'
#define CHARSET_ISO8859_1 'A'
#define CHARSET_ISO8859_7 'F'
#define CHARSET_KSX1001 ('C'|CHARSET_DOUBLEBYTE)
#define CHARSET_JISX0201_R 'J'
#define CHARSET_JISX0201_K 'I'
#define CHARSET_JISX0208 ('B'|CHARSET_DOUBLEBYTE)
#define CHARSET_JISX0208_O ('@'|CHARSET_DOUBLEBYTE)
#define CHARSET_JISX0212 ('D'|CHARSET_DOUBLEBYTE)
#define CHARSET_JISX0213_1 ('O'|CHARSET_DOUBLEBYTE)
#define CHARSET_JISX0213_2 ('P'|CHARSET_DOUBLEBYTE)
#define CHARSET_GB2312 ('A'|CHARSET_DOUBLEBYTE)
#define CHARSET_GB2312_8565 ('E'|CHARSET_DOUBLEBYTE)
#define CHARSET_DESIGN(c) ((c) & 0x7f)
#define CHARSET_ISDBCS(c) ((c) & 0x80)
#define F_SHIFTED 0x01
#define F_ESCTHROUGHOUT 0x02
#define STATE_SETG(dn, s, v) ((s)->c[dn]) = (v);
#define STATE_GETG(dn, s) ((s)->c[dn])
#define STATE_SETG0(s, v) STATE_SETG(0, s, v)
#define STATE_GETG0(s) STATE_GETG(0, s)
#define STATE_SETG1(s, v) STATE_SETG(1, s, v)
#define STATE_GETG1(s) STATE_GETG(1, s)
#define STATE_SETG2(s, v) STATE_SETG(2, s, v)
#define STATE_GETG2(s) STATE_GETG(2, s)
#define STATE_SETG3(s, v) STATE_SETG(3, s, v)
#define STATE_GETG3(s) STATE_GETG(3, s)
#define STATE_SETFLAG(s, f) ((s)->c[4]) |= (f);
#define STATE_GETFLAG(s, f) ((s)->c[4] & (f))
#define STATE_CLEARFLAG(s, f) ((s)->c[4]) &= ~(f);
#define STATE_CLEARFLAGS(s) ((s)->c[4]) = 0;
#define ISO2022_GETCHARSET(charset, c1) \
if ((c) >= 0x80) \
return 1; \
if (STATE_GETFLAG(state, F_SHIFTED)) /* G1 */ \
(charset) = STATE_GETG1(state); \
else /* G1 */ \
(charset) = STATE_GETG0(state); \
#ifdef ISO2022_USE_G2_DESIGNATION
/* hardcoded for iso-2022-jp-2 for now. we'll need to generalize it
when we have more G2 designating encodings */
#define SS2_ROUTINE \
if (IN2 == 'N') { /* SS2 */ \
RESERVE_INBUF(3) \
if (STATE_GETG2(state) == CHARSET_ISO8859_1) { \
ISO8859_1_DECODE(IN3 ^ 0x80, **outbuf) \
else return 3; \
} else if (STATE_GETG2(state) == CHARSET_ISO8859_7) { \
ISO8859_7_DECODE(IN3 ^ 0x80, **outbuf) \
else return 3; \
} else if (STATE_GETG2(state) == CHARSET_ASCII) { \
if (IN3 & 0x80) return 3; \
else **outbuf = IN3; \
} else \
return MBERR_INTERNAL; \
NEXT(3, 1) \
} else
#else
#define SS2_ROUTINE
#endif
#ifndef ISO2022_NO_SHIFT
#define SHIFT_CASES \
case SI: \
STATE_CLEARFLAG(state, F_SHIFTED) \
NEXT_IN(1) \
break; \
case SO: \
STATE_SETFLAG(state, F_SHIFTED) \
NEXT_IN(1) \
break;
#else
/* for compatibility with JapaneseCodecs */
#define SHIFT_CASES
#endif
#define ISO2022_BASECASES(c1) \
case ESC: \
RESERVE_INBUF(2) \
if (IS_ISO2022ESC(IN2)) { \
int err; \
err = iso2022processesc(state, inbuf, &inleft); \
if (err != 0) \
return err; \
} else SS2_ROUTINE { \
STATE_SETFLAG(state, F_ESCTHROUGHOUT) \
OUT1(ESC) \
NEXT(1, 1) \
} \
break; \
SHIFT_CASES \
case '\n': \
STATE_CLEARFLAG(state, F_SHIFTED) \
WRITE1('\n') \
NEXT(1, 1) \
break;
#define ISO2022_ESCTHROUGHOUT(c) \
if (STATE_GETFLAG(state, F_ESCTHROUGHOUT)) { \
/* ESC throughout mode: for non-iso2022 escape sequences */ \
RESERVE_OUTBUF(1) \
OUT1(c) /* assume as ISO-8859-1 */ \
NEXT(1, 1) \
if (IS_ESCEND(c)) { \
STATE_CLEARFLAG(state, F_ESCTHROUGHOUT) \
} \
continue; \
}
#define ISO2022_LOOP_BEGIN \
while (inleft > 0) { \
unsigned char c = IN1; \
ISO2022_ESCTHROUGHOUT(c) \
switch(c) { \
ISO2022_BASECASES(c) \
default: \
if (c < 0x20) { /* C0 */ \
RESERVE_OUTBUF(1) \
OUT1(c) \
NEXT(1, 1) \
} else if (c >= 0x80) \
return 1; \
else {
#define ISO2022_LOOP_END \
} \
} \
}
static int
iso2022processesc(MultibyteCodec_State *state,
const unsigned char **inbuf, size_t *inleft)
{
unsigned char charset, designation;
size_t i, esclen;
for (i = 1;i < MAX_ESCSEQLEN;i++) {
if (i >= *inleft)
return MBERR_TOOFEW;
if (IS_ESCEND((*inbuf)[i])) {
esclen = i + 1;
break;
}
#ifdef ISO2022_USE_JISX0208EXT
else if (i+1 < *inleft && (*inbuf)[i] == '&' && (*inbuf)[i+1] == '@')
i += 2;
#endif
}
if (i >= MAX_ESCSEQLEN)
return 1; /* unterminated escape sequence */
switch (esclen) {
case 3:
if (IN2 == '$') {
charset = IN3 | CHARSET_DOUBLEBYTE;
designation = 0;
} else {
charset = IN3;
if (IN2 == '(') designation = 0;
else if (IN2 == ')') designation = 1;
#ifdef ISO2022_USE_G2_DESIGNATION
else if (IN2 == '.') designation = 2;
#endif
else return 3;
}
break;
case 4:
if (IN2 != '$')
return 4;
charset = IN4 | CHARSET_DOUBLEBYTE;
if (IN3 == '(') designation = 0;
else if (IN3 == ')') designation = 1;
else return 4;
break;
#ifdef ISO2022_USE_JISX0208EXT
case 6: /* designation with prefix */
if ((*inbuf)[3] == ESC && (*inbuf)[4] == '$' && (*inbuf)[5] == 'B') {
charset = 'B' | CHARSET_DOUBLEBYTE;
designation = 0;
} else
return 6;
break;
#endif
default:
return esclen;
}
{ /* raise error when the charset is not designated for this encoding */
const unsigned char dsgs[] = {ISO2022_DESIGNATIONS, '\x00'};
for (i = 0; dsgs[i] != '\x00'; i++)
if (dsgs[i] == charset)
break;
if (dsgs[i] == '\x00')
return esclen;
}
STATE_SETG(designation, state, charset)
*inleft -= esclen;
(*inbuf) += esclen;
return 0;
}