Fix handling of state. Optimize a bit.
[kopensolaris-gnu/glibc.git] / iconvdata / ibm937.c
1 /* Conversion to and from IBM937.
2    Copyright (C) 2000, 2001 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4    Contributed by Masahide Washizawa <washi@yamato.ibm.co.jp>, 2000.
5
6    The GNU C Library is free software; you can redistribute it and/or
7    modify it under the terms of the GNU Library General Public License as
8    published by the Free Software Foundation; either version 2 of the
9    License, or (at your option) any later version.
10
11    The GNU C Library is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14    Library General Public License for more details.
15
16    You should have received a copy of the GNU Library General Public
17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19    Boston, MA 02111-1307, USA.  */
20
21 #include <dlfcn.h>
22 #include <stdint.h>
23 #include <wchar.h>
24 #include <byteswap.h>
25 #include "ibm937.h"
26
27 /* The shift sequences for this charset (it does not use ESC).  */
28 #define SI              0x0F  /* Shift In, host code to turn DBCS off.  */
29 #define SO              0x0E  /* Shift Out, host code to turn DBCS on.  */
30
31 /* Definitions used in the body of the `gconv' function.  */
32 #define CHARSET_NAME    "IBM937//"
33 #define FROM_LOOP       from_ibm937
34 #define TO_LOOP         to_ibm937
35 #define MIN_NEEDED_FROM 1
36 #define MAX_NEEDED_FROM 2
37 #define MIN_NEEDED_TO   4
38 #define MAX_NEEDED_TO   4
39 #define PREPARE_LOOP \
40   int save_curcs;                                                             \
41   int *curcsp = &data->__statep->__count;
42 #define EXTRA_LOOP_ARGS         , curcsp
43
44 /* Definitions of initialization and destructor function.  */
45 #define DEFINE_INIT     1
46 #define DEFINE_FINI     1
47
48
49 /* Since this is a stateful encoding we have to provide code which resets
50    the output state to the initial state.  This has to be done during the
51    flushing.  */
52 #define EMIT_SHIFT_TO_INIT \
53   if ((data->__statep->__count & ~7) != sb)                                   \
54     {                                                                         \
55       if (FROM_DIRECTION)                                                     \
56         data->__statep->__count &= 7;                                         \
57       else                                                                    \
58         {                                                                     \
59           unsigned char *outbuf = data->__outbuf;                             \
60                                                                               \
61           /* We are not in the initial state.  To switch back we have         \
62              to emit `SI'.  */                                                \
63           if (__builtin_expect (outbuf >= data->__outbufend, 0))              \
64             /* We don't have enough room in the output buffer.  */            \
65             status = __GCONV_FULL_OUTPUT;                                     \
66           else                                                                \
67             {                                                                 \
68               /* Write out the shift sequence.  */                            \
69               *outbuf++ = SI;                                                 \
70               data->__outbuf = outbuf;                                        \
71               data->__statep->__count &= 7;                                   \
72             }                                                                 \
73         }                                                                     \
74     }
75
76
77 /* Since we might have to reset input pointer we must be able to save
78    and retore the state.  */
79 #define SAVE_RESET_STATE(Save) \
80   if (Save)                                                                   \
81     save_curcs = *curcsp;                                                     \
82   else                                                                        \
83     *curcsp = save_curcs
84
85
86 /* Current codeset type.  */
87 enum
88 {
89   sb = 0,
90   db = 64
91 };
92
93 /* First, define the conversion function from IBM-937 to UCS4.  */
94 #define MIN_NEEDED_INPUT        MIN_NEEDED_FROM
95 #define MAX_NEEDED_INPUT        MAX_NEEDED_FROM
96 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_TO
97 #define LOOPFCT                 FROM_LOOP
98 #define BODY \
99   {                                                                           \
100     uint32_t ch = *inptr;                                                     \
101                                                                               \
102     if (__builtin_expect (ch, 0) == SO)                                       \
103       {                                                                       \
104         /* Shift OUT, change to DBCS converter.  */                           \
105         if (curcs == db)                                                      \
106           {                                                                   \
107             result = __GCONV_ILLEGAL_INPUT;                                   \
108             break;                                                            \
109           }                                                                   \
110         curcs = db;                                                           \
111         ++inptr;                                                              \
112         continue;                                                             \
113       }                                                                       \
114     else if (__builtin_expect (ch, 0) == SI)                                  \
115       {                                                                       \
116         /* Shift IN, change to SBCS converter.  */                            \
117         if (curcs == sb)                                                      \
118           {                                                                   \
119             result = __GCONV_ILLEGAL_INPUT;                                   \
120             break;                                                            \
121           }                                                                   \
122         curcs = sb;                                                           \
123         ++inptr;                                                              \
124         continue;                                                             \
125       }                                                                       \
126                                                                               \
127     if (curcs == sb)                                                          \
128       {                                                                       \
129         /* Use the UCS4 table for single byte.  */                            \
130         ch = __ibm937sb_to_ucs4[ch];                                          \
131         if (__builtin_expect (ch, L'\1') == L'\0' && *inptr != '\0')          \
132           {                                                                   \
133             /* This is an illegal character.  */                              \
134             if (! ignore_errors_p ())                                         \
135               {                                                               \
136                 result = __GCONV_ILLEGAL_INPUT;                               \
137                 break;                                                        \
138               }                                                               \
139             ++*irreversible;                                                  \
140           }                                                                   \
141         else                                                                  \
142           {                                                                   \
143             put32 (outptr, ch);                                               \
144             outptr += 4;                                                      \
145           }                                                                   \
146         ++inptr;                                                              \
147       }                                                                       \
148     else                                                                      \
149       {                                                                       \
150         /* Use the IBM937 table for double byte.  */                          \
151                                                                               \
152         assert (curcs == db);                                                 \
153                                                                               \
154         ch = ibm937db_to_ucs4(inptr[0], inptr[1]);                            \
155         if (__builtin_expect (ch, L'\1') == L'\0' && *inptr != '\0')          \
156           {                                                                   \
157             /* This is an illegal character.  */                              \
158             if (! ignore_errors_p ())                                         \
159               {                                                               \
160                 result = __GCONV_ILLEGAL_INPUT;                               \
161                 break;                                                        \
162               }                                                               \
163             ++*irreversible;                                                  \
164           }                                                                   \
165         else                                                                  \
166           {                                                                   \
167             put32 (outptr, ch);                                               \
168             outptr += 4;                                                      \
169           }                                                                   \
170         inptr += 2;                                                           \
171       }                                                                       \
172   }
173 #define LOOP_NEED_FLAGS
174 #define EXTRA_LOOP_DECLS        , int *curcsp
175 #define INIT_PARAMS             int curcs = *curcsp & ~7
176 #define UPDATE_PARAMS           *curcsp = curcs
177 #include <iconv/loop.c>
178
179 /* Next, define the other direction.  */
180 #define MIN_NEEDED_INPUT        MIN_NEEDED_TO
181 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_FROM
182 #define MAX_NEEDED_OUTPUT       MAX_NEEDED_FROM
183 #define LOOPFCT                 TO_LOOP
184 #define BODY \
185   {                                                                           \
186     uint32_t ch = get32 (inptr);                                              \
187     const char *cp;                                                           \
188                                                                               \
189     /* Use the UCS4 table for single byte.  */                                \
190     cp = __ucs4_to_ibm937sb[ch];                                              \
191     if (__builtin_expect (ch >= sizeof (__ucs4_to_ibm937sb)                   \
192                           / sizeof (__ucs4_to_ibm937sb[0]), 0)                \
193         || (__builtin_expect (cp[0], '\1') == '\0' && ch != 0))               \
194       {                                                                       \
195         /* Use the UCS4 table for double byte.  */                            \
196         cp = __ucs4_to_ibm937db[ch];                                          \
197         if (__builtin_expect (cp[0], '\1') == '\0' && ch != 0)                \
198           {                                                                   \
199             /* This is an illegal character.  */                              \
200             if (! ignore_errors_p ())                                         \
201               {                                                               \
202                 result = __GCONV_ILLEGAL_INPUT;                               \
203                 break;                                                        \
204               }                                                               \
205             ++*irreversible;                                                  \
206           }                                                                   \
207         else                                                                  \
208           {                                                                   \
209             if (curcs == sb)                                                  \
210               {                                                               \
211                 *outptr++ = SO;                                               \
212                 if (__builtin_expect (outptr == outend, 0))                   \
213                   {                                                           \
214                     result = __GCONV_FULL_OUTPUT;                             \
215                     break;                                                    \
216                   }                                                           \
217                 curcs = db;                                                   \
218               }                                                               \
219             *outptr++ = cp[0];                                                \
220             *outptr++ = cp[1];                                                \
221           }                                                                   \
222       }                                                                       \
223     else                                                                      \
224       {                                                                       \
225         if (curcs == db)                                                      \
226           {                                                                   \
227             *outptr++ = SI;                                                   \
228             if (__builtin_expect (outptr == outend, 0))                       \
229               {                                                               \
230                 result = __GCONV_FULL_OUTPUT;                                 \
231                 break;                                                        \
232               }                                                               \
233           }                                                                   \
234         curcs = sb;                                                           \
235         *outptr++ = cp[0];                                                    \
236       }                                                                       \
237                                                                               \
238     /* Now that we wrote the output increment the input pointer.  */          \
239     inptr += 4;                                                               \
240   }
241 #define LOOP_NEED_FLAGS
242 #define EXTRA_LOOP_DECLS        , int *curcsp
243 #define INIT_PARAMS             int curcs = *curcsp & ~7
244 #define UPDATE_PARAMS           *curcsp = curcs
245 #include <iconv/loop.c>
246
247 /* Now define the toplevel functions.  */
248 #include <iconv/skeleton.c>