Correctly use __builtin_expect.
[kopensolaris-gnu/glibc.git] / iconvdata / utf-16.c
1 /* Conversion module for UTF-16.
2    Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
5
6    The GNU C Library is free software; you can redistribute it and/or
7    modify it under the terms of the GNU Lesser General Public
8    License as published by the Free Software Foundation; either
9    version 2.1 of the 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    Lesser General Public License for more details.
15
16    You should have received a copy of the GNU Lesser General Public
17    License along with the GNU C Library; if not, write to the Free
18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19    02111-1307 USA.  */
20
21 #include <byteswap.h>
22 #include <dlfcn.h>
23 #include <gconv.h>
24 #include <stddef.h>
25 #include <stdint.h>
26 #include <stdlib.h>
27 #include <string.h>
28
29 /* This is the Byte Order Mark character (BOM).  */
30 #define BOM     0xfeff
31 /* And in the other byte order.  */
32 #define BOM_OE  0xfffe
33
34
35 /* Definitions used in the body of the `gconv' function.  */
36 #define FROM_LOOP               from_utf16_loop
37 #define TO_LOOP                 to_utf16_loop
38 #define DEFINE_INIT             0
39 #define DEFINE_FINI             0
40 #define MIN_NEEDED_FROM         2
41 #define MAX_NEEDED_FROM         4
42 #define MIN_NEEDED_TO           4
43 #define FROM_DIRECTION          (dir == from_utf16)
44 #define PREPARE_LOOP \
45   enum direction dir = ((struct utf16_data *) step->__data)->dir;             \
46   enum variant var = ((struct utf16_data *) step->__data)->var;               \
47   int swap;                                                                   \
48   if (FROM_DIRECTION && var == UTF_16)                                        \
49     {                                                                         \
50       if (data->__invocation_counter == 0)                                    \
51         {                                                                     \
52           /* We have to find out which byte order the file is encoded in.  */ \
53           if (inptr + 2 > inend)                                              \
54             return __GCONV_EMPTY_INPUT;                                       \
55                                                                               \
56           if (get16u (inptr) == BOM)                                          \
57             /* Simply ignore the BOM character.  */                           \
58             *inptrp = inptr += 2;                                             \
59           else if (get16u (inptr) == BOM_OE)                                  \
60             {                                                                 \
61               ((struct utf16_data *) step->__data)->swap = 1;                 \
62               *inptrp = inptr += 2;                                           \
63             }                                                                 \
64         }                                                                     \
65     }                                                                         \
66   else if (!FROM_DIRECTION && var == UTF_16 && !data->__internal_use          \
67            && data->__invocation_counter == 0)                                \
68     {                                                                         \
69       /* Emit the Byte Order Mark.  */                                        \
70       if (__builtin_expect (outbuf + 2 > outend, 0))                          \
71         return __GCONV_FULL_OUTPUT;                                           \
72                                                                               \
73       put16u (outbuf, BOM);                                                   \
74       outbuf += 2;                                                            \
75     }                                                                         \
76   swap = ((struct utf16_data *) step->__data)->swap;
77 #define EXTRA_LOOP_ARGS         , var, swap
78
79
80 /* Direction of the transformation.  */
81 enum direction
82 {
83   illegal_dir,
84   to_utf16,
85   from_utf16
86 };
87
88 enum variant
89 {
90   illegal_var,
91   UTF_16,
92   UTF_16LE,
93   UTF_16BE
94 };
95
96 struct utf16_data
97 {
98   enum direction dir;
99   enum variant var;
100   int swap;
101 };
102
103
104 extern int gconv_init (struct __gconv_step *step);
105 int
106 gconv_init (struct __gconv_step *step)
107 {
108   /* Determine which direction.  */
109   struct utf16_data *new_data;
110   enum direction dir = illegal_dir;
111   enum variant var = illegal_var;
112   int result;
113
114   if (__strcasecmp (step->__from_name, "UTF-16//") == 0)
115     {
116       dir = from_utf16;
117       var = UTF_16;
118     }
119   else if (__strcasecmp (step->__to_name, "UTF-16//") == 0)
120     {
121       dir = to_utf16;
122       var = UTF_16;
123     }
124   else if (__strcasecmp (step->__from_name, "UTF-16BE//") == 0)
125     {
126       dir = from_utf16;
127       var = UTF_16BE;
128     }
129   else if (__strcasecmp (step->__to_name, "UTF-16BE//") == 0)
130     {
131       dir = to_utf16;
132       var = UTF_16BE;
133     }
134   else if (__strcasecmp (step->__from_name, "UTF-16LE//") == 0)
135     {
136       dir = from_utf16;
137       var = UTF_16LE;
138     }
139   else if (__strcasecmp (step->__to_name, "UTF-16LE//") == 0)
140     {
141       dir = to_utf16;
142       var = UTF_16LE;
143     }
144
145   result = __GCONV_NOCONV;
146   if (__builtin_expect (dir, to_utf16) != illegal_dir)
147     {
148       new_data = (struct utf16_data *) malloc (sizeof (struct utf16_data));
149
150       result = __GCONV_NOMEM;
151       if (new_data != NULL)
152         {
153           new_data->dir = dir;
154           new_data->var = var;
155           new_data->swap = ((var == UTF_16LE && BYTE_ORDER == BIG_ENDIAN)
156                             || (var == UTF_16BE
157                                 && BYTE_ORDER == LITTLE_ENDIAN));
158           step->__data = new_data;
159
160           if (dir == from_utf16)
161             {
162               step->__min_needed_from = MIN_NEEDED_FROM;
163               step->__max_needed_from = MAX_NEEDED_FROM;
164               step->__min_needed_to = MIN_NEEDED_TO;
165               step->__max_needed_to = MIN_NEEDED_TO;
166             }
167           else
168             {
169               step->__min_needed_from = MIN_NEEDED_TO;
170               step->__max_needed_from = MIN_NEEDED_TO;
171               step->__min_needed_to = MIN_NEEDED_FROM;
172               step->__max_needed_to = MAX_NEEDED_FROM;
173             }
174
175           step->__stateful = 0;
176
177           result = __GCONV_OK;
178         }
179     }
180
181   return result;
182 }
183
184
185 extern void gconv_end (struct __gconv_step *data);
186 void
187 gconv_end (struct __gconv_step *data)
188 {
189   free (data->__data);
190 }
191
192
193 /* Convert from the internal (UCS4-like) format to UTF-16.  */
194 #define MIN_NEEDED_INPUT        MIN_NEEDED_TO
195 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_FROM
196 #define MAX_NEEDED_OUTPUT       MAX_NEEDED_FROM
197 #define LOOPFCT                 TO_LOOP
198 #define BODY \
199   {                                                                           \
200     uint32_t c = get32 (inptr);                                               \
201                                                                               \
202     if (__builtin_expect (c >= 0xd800 && c < 0xe000, 0))                      \
203       {                                                                       \
204         /* Surrogate characters in UCS-4 input are not valid.                 \
205            We must catch this.  If we let surrogates pass through,            \
206            attackers could make a security hole exploit by                    \
207            synthesizing any desired plane 1-16 character.  */                 \
208         if (! ignore_errors_p ())                                             \
209           {                                                                   \
210             result = __GCONV_ILLEGAL_INPUT;                                   \
211             break;                                                            \
212           }                                                                   \
213         inptr += 4;                                                           \
214         ++*irreversible;                                                      \
215         continue;                                                             \
216       }                                                                       \
217                                                                               \
218     if (swap)                                                                 \
219       {                                                                       \
220         if (__builtin_expect (c >= 0x10000, 0))                               \
221           {                                                                   \
222             if (__builtin_expect (c >= 0x110000, 0))                          \
223               {                                                               \
224                 STANDARD_ERR_HANDLER (4);                                     \
225               }                                                               \
226                                                                               \
227             /* Generate a surrogate character.  */                            \
228             if (__builtin_expect (outptr + 4 > outend, 0))                    \
229               {                                                               \
230                 /* Overflow in the output buffer.  */                         \
231                 result = __GCONV_FULL_OUTPUT;                                 \
232                 break;                                                        \
233               }                                                               \
234                                                                               \
235             put16 (outptr, bswap_16 (0xd7c0 + (c >> 10)));                    \
236             outptr += 2;                                                      \
237             put16 (outptr, bswap_16 (0xdc00 + (c & 0x3ff)));                  \
238           }                                                                   \
239         else                                                                  \
240           put16 (outptr, bswap_16 (c));                                       \
241       }                                                                       \
242     else                                                                      \
243       {                                                                       \
244         if (__builtin_expect (c >= 0x10000, 0))                               \
245           {                                                                   \
246             if (__builtin_expect (c >= 0x110000, 0))                          \
247               {                                                               \
248                 STANDARD_ERR_HANDLER (4);                                     \
249               }                                                               \
250                                                                               \
251             /* Generate a surrogate character.  */                            \
252             if (__builtin_expect (outptr + 4 > outend, 0))                    \
253               {                                                               \
254                 /* Overflow in the output buffer.  */                         \
255                 result = __GCONV_FULL_OUTPUT;                                 \
256                 break;                                                        \
257               }                                                               \
258                                                                               \
259             put16 (outptr, 0xd7c0 + (c >> 10));                               \
260             outptr += 2;                                                      \
261             put16 (outptr, 0xdc00 + (c & 0x3ff));                             \
262           }                                                                   \
263         else                                                                  \
264           put16 (outptr, c);                                                  \
265       }                                                                       \
266     outptr += 2;                                                              \
267     inptr += 4;                                                               \
268   }
269 #define LOOP_NEED_FLAGS
270 #define EXTRA_LOOP_DECLS \
271         , enum variant var, int swap
272 #include <iconv/loop.c>
273
274
275 /* Convert from UTF-16 to the internal (UCS4-like) format.  */
276 #define MIN_NEEDED_INPUT        MIN_NEEDED_FROM
277 #define MAX_NEEDED_INPUT        MAX_NEEDED_FROM
278 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_TO
279 #define LOOPFCT                 FROM_LOOP
280 #define BODY \
281   {                                                                           \
282     uint16_t u1 = get16 (inptr);                                              \
283                                                                               \
284     if (swap)                                                                 \
285       {                                                                       \
286         u1 = bswap_16 (u1);                                                   \
287                                                                               \
288         if (__builtin_expect (u1 < 0xd800, 1) || u1 > 0xdfff)                 \
289           {                                                                   \
290             /* No surrogate.  */                                              \
291             put32 (outptr, u1);                                               \
292             inptr += 2;                                                       \
293           }                                                                   \
294         else                                                                  \
295           {                                                                   \
296             uint16_t u2;                                                      \
297                                                                               \
298             /* It's a surrogate character.  At least the first word says      \
299                it is.  */                                                     \
300             if (__builtin_expect (inptr + 4 > inend, 0))                      \
301               {                                                               \
302                 /* We don't have enough input for another complete input      \
303                    character.  */                                             \
304                 result = __GCONV_INCOMPLETE_INPUT;                            \
305                 break;                                                        \
306               }                                                               \
307                                                                               \
308             inptr += 2;                                                       \
309             u2 = bswap_16 (get16 (inptr));                                    \
310             if (__builtin_expect (u2 < 0xdc00, 0)                             \
311                 || __builtin_expect (u2 == 0xdfff, 0))                        \
312               {                                                               \
313                 /* This is no valid second word for a surrogate.  */          \
314                 if (! ignore_errors_p ())                                     \
315                   {                                                           \
316                     inptr -= 2;                                               \
317                     result = __GCONV_ILLEGAL_INPUT;                           \
318                     break;                                                    \
319                   }                                                           \
320                                                                               \
321                 ++*irreversible;                                              \
322                 continue;                                                     \
323               }                                                               \
324                                                                               \
325             put32 (outptr, ((u1 - 0xd7c0) << 10) + (u2 - 0xdc00));            \
326             inptr += 2;                                                       \
327           }                                                                   \
328       }                                                                       \
329     else                                                                      \
330       {                                                                       \
331         if (__builtin_expect (u1 < 0xd800, 1) || u1 > 0xdfff)                 \
332           {                                                                   \
333             /* No surrogate.  */                                              \
334             put32 (outptr, u1);                                               \
335             inptr += 2;                                                       \
336           }                                                                   \
337         else                                                                  \
338           {                                                                   \
339             uint16_t u2;                                                      \
340                                                                               \
341             /* It's a surrogate character.  At least the first word says      \
342                it is.  */                                                     \
343             if (__builtin_expect (inptr + 4 > inend, 0))                      \
344               {                                                               \
345                 /* We don't have enough input for another complete input      \
346                    character.  */                                             \
347                 result = __GCONV_INCOMPLETE_INPUT;                            \
348                 break;                                                        \
349               }                                                               \
350                                                                               \
351             inptr += 2;                                                       \
352             u2 = get16 (inptr);                                               \
353             if (__builtin_expect (u2 < 0xdc00, 0)                             \
354                 || __builtin_expect (u2 >= 0xdfff, 0))                        \
355               {                                                               \
356                 /* This is no valid second word for a surrogate.  */          \
357                 if (! ignore_errors_p ())                                     \
358                   {                                                           \
359                     inptr -= 2;                                               \
360                     result = __GCONV_ILLEGAL_INPUT;                           \
361                     break;                                                    \
362                   }                                                           \
363                                                                               \
364                 ++*irreversible;                                              \
365                 continue;                                                     \
366               }                                                               \
367                                                                               \
368             put32 (outptr, ((u1 - 0xd7c0) << 10) + (u2 - 0xdc00));            \
369             inptr += 2;                                                       \
370           }                                                                   \
371       }                                                                       \
372     outptr += 4;                                                              \
373   }
374 #define LOOP_NEED_FLAGS
375 #define EXTRA_LOOP_DECLS \
376         , enum variant var, int swap
377 #include <iconv/loop.c>
378
379
380 /* Now define the toplevel functions.  */
381 #include <iconv/skeleton.c>