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1 /*
2 *******************************************************************************
3 *
4 *   Copyright (C) 1999-2004, International Business Machines
5 *   Corporation and others.  All Rights Reserved.
6 *
7 *******************************************************************************
8 *   file name:  utf.h
9 *   encoding:   US-ASCII
10 *   tab size:   8 (not used)
11 *   indentation:4
12 *
13 *   created on: 1999sep09
14 *   created by: Markus W. Scherer
15 */
16 
17 #ifndef BASE_THIRD_PARTY_ICU_ICU_UTF_H_
18 #define BASE_THIRD_PARTY_ICU_ICU_UTF_H_
19 
20 #include <stdint.h>
21 
22 namespace base_icu {
23 
24 typedef int32_t UChar32;
25 typedef uint16_t UChar;
26 typedef int8_t UBool;
27 
28 // General ---------------------------------------------------------------------
29 // from utf.h
30 
31 /**
32  * This value is intended for sentinel values for APIs that
33  * (take or) return single code points (UChar32).
34  * It is outside of the Unicode code point range 0..0x10ffff.
35  *
36  * For example, a "done" or "error" value in a new API
37  * could be indicated with CBU_SENTINEL.
38  *
39  * ICU APIs designed before ICU 2.4 usually define service-specific "done"
40  * values, mostly 0xffff.
41  * Those may need to be distinguished from
42  * actual U+ffff text contents by calling functions like
43  * CharacterIterator::hasNext() or UnicodeString::length().
44  *
45  * @return -1
46  * @see UChar32
47  * @stable ICU 2.4
48  */
49 #define CBU_SENTINEL (-1)
50 
51 /**
52  * Is this code point a Unicode noncharacter?
53  * @param c 32-bit code point
54  * @return TRUE or FALSE
55  * @stable ICU 2.4
56  */
57 #define CBU_IS_UNICODE_NONCHAR(c)                                          \
58   ((c) >= 0xfdd0 && ((uint32_t)(c) <= 0xfdef || ((c)&0xfffe) == 0xfffe) && \
59    (uint32_t)(c) <= 0x10ffff)
60 
61 /**
62  * Is c a Unicode code point value (0..U+10ffff)
63  * that can be assigned a character?
64  *
65  * Code points that are not characters include:
66  * - single surrogate code points (U+d800..U+dfff, 2048 code points)
67  * - the last two code points on each plane (U+__fffe and U+__ffff, 34 code points)
68  * - U+fdd0..U+fdef (new with Unicode 3.1, 32 code points)
69  * - the highest Unicode code point value is U+10ffff
70  *
71  * This means that all code points below U+d800 are character code points,
72  * and that boundary is tested first for performance.
73  *
74  * @param c 32-bit code point
75  * @return TRUE or FALSE
76  * @stable ICU 2.4
77  */
78 #define CBU_IS_UNICODE_CHAR(c)                             \
79   ((uint32_t)(c) < 0xd800 ||                               \
80    ((uint32_t)(c) > 0xdfff && (uint32_t)(c) <= 0x10ffff && \
81     !CBU_IS_UNICODE_NONCHAR(c)))
82 
83 /**
84  * Is this code point a surrogate (U+d800..U+dfff)?
85  * @param c 32-bit code point
86  * @return TRUE or FALSE
87  * @stable ICU 2.4
88  */
89 #define CBU_IS_SURROGATE(c) (((c)&0xfffff800)==0xd800)
90 
91 /**
92  * Assuming c is a surrogate code point (U_IS_SURROGATE(c)),
93  * is it a lead surrogate?
94  * @param c 32-bit code point
95  * @return TRUE or FALSE
96  * @stable ICU 2.4
97  */
98 #define CBU_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
99 
100 
101 // UTF-8 macros ----------------------------------------------------------------
102 // from utf8.h
103 
104 extern const uint8_t utf8_countTrailBytes[256];
105 
106 /**
107  * Count the trail bytes for a UTF-8 lead byte.
108  * @internal
109  */
110 #define CBU8_COUNT_TRAIL_BYTES(leadByte) \
111   (base_icu::utf8_countTrailBytes[(uint8_t)leadByte])
112 
113 /**
114  * Mask a UTF-8 lead byte, leave only the lower bits that form part of the code point value.
115  * @internal
116  */
117 #define CBU8_MASK_LEAD_BYTE(leadByte, countTrailBytes) ((leadByte)&=(1<<(6-(countTrailBytes)))-1)
118 
119 /**
120  * Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)?
121  * @param c 8-bit code unit (byte)
122  * @return TRUE or FALSE
123  * @stable ICU 2.4
124  */
125 #define CBU8_IS_SINGLE(c) (((c)&0x80)==0)
126 
127 /**
128  * Is this code unit (byte) a UTF-8 lead byte?
129  * @param c 8-bit code unit (byte)
130  * @return TRUE or FALSE
131  * @stable ICU 2.4
132  */
133 #define CBU8_IS_LEAD(c) ((uint8_t)((c)-0xc0) < 0x3e)
134 
135 /**
136  * Is this code unit (byte) a UTF-8 trail byte?
137  * @param c 8-bit code unit (byte)
138  * @return TRUE or FALSE
139  * @stable ICU 2.4
140  */
141 #define CBU8_IS_TRAIL(c) (((c)&0xc0)==0x80)
142 
143 /**
144  * How many code units (bytes) are used for the UTF-8 encoding
145  * of this Unicode code point?
146  * @param c 32-bit code point
147  * @return 1..4, or 0 if c is a surrogate or not a Unicode code point
148  * @stable ICU 2.4
149  */
150 #define CBU8_LENGTH(c)                                                      \
151   ((uint32_t)(c) <= 0x7f                                                    \
152        ? 1                                                                  \
153        : ((uint32_t)(c) <= 0x7ff                                            \
154               ? 2                                                           \
155               : ((uint32_t)(c) <= 0xd7ff                                    \
156                      ? 3                                                    \
157                      : ((uint32_t)(c) <= 0xdfff || (uint32_t)(c) > 0x10ffff \
158                             ? 0                                             \
159                             : ((uint32_t)(c) <= 0xffff ? 3 : 4)))))
160 
161 /**
162  * The maximum number of UTF-8 code units (bytes) per Unicode code point (U+0000..U+10ffff).
163  * @return 4
164  * @stable ICU 2.4
165  */
166 #define CBU8_MAX_LENGTH 4
167 
168 /**
169  * Function for handling "next code point" with error-checking.
170  * @internal
171  */
172 UChar32 utf8_nextCharSafeBody(const uint8_t* s,
173                               int32_t* pi,
174                               int32_t length,
175                               UChar32 c,
176                               UBool strict);
177 
178 /**
179  * Get a code point from a string at a code point boundary offset,
180  * and advance the offset to the next code point boundary.
181  * (Post-incrementing forward iteration.)
182  * "Safe" macro, checks for illegal sequences and for string boundaries.
183  *
184  * The offset may point to the lead byte of a multi-byte sequence,
185  * in which case the macro will read the whole sequence.
186  * If the offset points to a trail byte or an illegal UTF-8 sequence, then
187  * c is set to a negative value.
188  *
189  * @param s const uint8_t * string
190  * @param i string offset, i<length
191  * @param length string length
192  * @param c output UChar32 variable, set to <0 in case of an error
193  * @see CBU8_NEXT_UNSAFE
194  * @stable ICU 2.4
195  */
196 #define CBU8_NEXT(s, i, length, c)                                       \
197   {                                                                      \
198     (c) = (s)[(i)++];                                                    \
199     if (((uint8_t)(c)) >= 0x80) {                                        \
200       if (CBU8_IS_LEAD(c)) {                                             \
201         (c) = base_icu::utf8_nextCharSafeBody((const uint8_t*)s, &(i),   \
202                                               (int32_t)(length), c, -1); \
203       } else {                                                           \
204         (c) = CBU_SENTINEL;                                              \
205       }                                                                  \
206     }                                                                    \
207   }
208 
209 /**
210  * Append a code point to a string, overwriting 1 to 4 bytes.
211  * The offset points to the current end of the string contents
212  * and is advanced (post-increment).
213  * "Unsafe" macro, assumes a valid code point and sufficient space in the
214  * string.
215  * Otherwise, the result is undefined.
216  *
217  * @param s const uint8_t * string buffer
218  * @param i string offset
219  * @param c code point to append
220  * @see CBU8_APPEND
221  * @stable ICU 2.4
222  */
223 #define CBU8_APPEND_UNSAFE(s, i, c)                            \
224   {                                                            \
225     if ((uint32_t)(c) <= 0x7f) {                               \
226       (s)[(i)++] = (uint8_t)(c);                               \
227     } else {                                                   \
228       if ((uint32_t)(c) <= 0x7ff) {                            \
229         (s)[(i)++] = (uint8_t)(((c) >> 6) | 0xc0);             \
230       } else {                                                 \
231         if ((uint32_t)(c) <= 0xffff) {                         \
232           (s)[(i)++] = (uint8_t)(((c) >> 12) | 0xe0);          \
233         } else {                                               \
234           (s)[(i)++] = (uint8_t)(((c) >> 18) | 0xf0);          \
235           (s)[(i)++] = (uint8_t)((((c) >> 12) & 0x3f) | 0x80); \
236         }                                                      \
237         (s)[(i)++] = (uint8_t)((((c) >> 6) & 0x3f) | 0x80);    \
238       }                                                        \
239       (s)[(i)++] = (uint8_t)(((c)&0x3f) | 0x80);               \
240     }                                                          \
241   }
242 
243 // UTF-16 macros ---------------------------------------------------------------
244 // from utf16.h
245 
246 /**
247  * Does this code unit alone encode a code point (BMP, not a surrogate)?
248  * @param c 16-bit code unit
249  * @return TRUE or FALSE
250  * @stable ICU 2.4
251  */
252 #define CBU16_IS_SINGLE(c) !CBU_IS_SURROGATE(c)
253 
254 /**
255  * Is this code unit a lead surrogate (U+d800..U+dbff)?
256  * @param c 16-bit code unit
257  * @return TRUE or FALSE
258  * @stable ICU 2.4
259  */
260 #define CBU16_IS_LEAD(c) (((c)&0xfffffc00)==0xd800)
261 
262 /**
263  * Is this code unit a trail surrogate (U+dc00..U+dfff)?
264  * @param c 16-bit code unit
265  * @return TRUE or FALSE
266  * @stable ICU 2.4
267  */
268 #define CBU16_IS_TRAIL(c) (((c)&0xfffffc00)==0xdc00)
269 
270 /**
271  * Is this code unit a surrogate (U+d800..U+dfff)?
272  * @param c 16-bit code unit
273  * @return TRUE or FALSE
274  * @stable ICU 2.4
275  */
276 #define CBU16_IS_SURROGATE(c) CBU_IS_SURROGATE(c)
277 
278 /**
279  * Assuming c is a surrogate code point (U16_IS_SURROGATE(c)),
280  * is it a lead surrogate?
281  * @param c 16-bit code unit
282  * @return TRUE or FALSE
283  * @stable ICU 2.4
284  */
285 #define CBU16_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
286 
287 /**
288  * Helper constant for CBU16_GET_SUPPLEMENTARY.
289  * @internal
290  */
291 #define CBU16_SURROGATE_OFFSET ((0xd800<<10UL)+0xdc00-0x10000)
292 
293 /**
294  * Get a supplementary code point value (U+10000..U+10ffff)
295  * from its lead and trail surrogates.
296  * The result is undefined if the input values are not
297  * lead and trail surrogates.
298  *
299  * @param lead lead surrogate (U+d800..U+dbff)
300  * @param trail trail surrogate (U+dc00..U+dfff)
301  * @return supplementary code point (U+10000..U+10ffff)
302  * @stable ICU 2.4
303  */
304 #define CBU16_GET_SUPPLEMENTARY(lead, trail) \
305     (((base_icu::UChar32)(lead)<<10UL)+(base_icu::UChar32)(trail)-CBU16_SURROGATE_OFFSET)
306 
307 
308 /**
309  * Get the lead surrogate (0xd800..0xdbff) for a
310  * supplementary code point (0x10000..0x10ffff).
311  * @param supplementary 32-bit code point (U+10000..U+10ffff)
312  * @return lead surrogate (U+d800..U+dbff) for supplementary
313  * @stable ICU 2.4
314  */
315 #define CBU16_LEAD(supplementary) \
316     (base_icu::UChar)(((supplementary)>>10)+0xd7c0)
317 
318 /**
319  * Get the trail surrogate (0xdc00..0xdfff) for a
320  * supplementary code point (0x10000..0x10ffff).
321  * @param supplementary 32-bit code point (U+10000..U+10ffff)
322  * @return trail surrogate (U+dc00..U+dfff) for supplementary
323  * @stable ICU 2.4
324  */
325 #define CBU16_TRAIL(supplementary) \
326     (base_icu::UChar)(((supplementary)&0x3ff)|0xdc00)
327 
328 /**
329  * How many 16-bit code units are used to encode this Unicode code point? (1 or 2)
330  * The result is not defined if c is not a Unicode code point (U+0000..U+10ffff).
331  * @param c 32-bit code point
332  * @return 1 or 2
333  * @stable ICU 2.4
334  */
335 #define CBU16_LENGTH(c) ((uint32_t)(c) <= 0xffff ? 1 : 2)
336 
337 /**
338  * The maximum number of 16-bit code units per Unicode code point (U+0000..U+10ffff).
339  * @return 2
340  * @stable ICU 2.4
341  */
342 #define CBU16_MAX_LENGTH 2
343 
344 /**
345  * Get a code point from a string at a code point boundary offset,
346  * and advance the offset to the next code point boundary.
347  * (Post-incrementing forward iteration.)
348  * "Safe" macro, handles unpaired surrogates and checks for string boundaries.
349  *
350  * The offset may point to the lead surrogate unit
351  * for a supplementary code point, in which case the macro will read
352  * the following trail surrogate as well.
353  * If the offset points to a trail surrogate or
354  * to a single, unpaired lead surrogate, then that itself
355  * will be returned as the code point.
356  *
357  * @param s const UChar * string
358  * @param i string offset, i<length
359  * @param length string length
360  * @param c output UChar32 variable
361  * @stable ICU 2.4
362  */
363 #define CBU16_NEXT(s, i, length, c)                            \
364   {                                                            \
365     (c) = (s)[(i)++];                                          \
366     if (CBU16_IS_LEAD(c)) {                                    \
367       uint16_t __c2;                                           \
368       if ((i) < (length) && CBU16_IS_TRAIL(__c2 = (s)[(i)])) { \
369         ++(i);                                                 \
370         (c) = CBU16_GET_SUPPLEMENTARY((c), __c2);              \
371       }                                                        \
372     }                                                          \
373   }
374 
375 /**
376  * Append a code point to a string, overwriting 1 or 2 code units.
377  * The offset points to the current end of the string contents
378  * and is advanced (post-increment).
379  * "Unsafe" macro, assumes a valid code point and sufficient space in the string.
380  * Otherwise, the result is undefined.
381  *
382  * @param s const UChar * string buffer
383  * @param i string offset
384  * @param c code point to append
385  * @see CBU16_APPEND
386  * @stable ICU 2.4
387  */
388 #define CBU16_APPEND_UNSAFE(s, i, c)                 \
389   {                                                  \
390     if ((uint32_t)(c) <= 0xffff) {                   \
391       (s)[(i)++] = (uint16_t)(c);                    \
392     } else {                                         \
393       (s)[(i)++] = (uint16_t)(((c) >> 10) + 0xd7c0); \
394       (s)[(i)++] = (uint16_t)(((c)&0x3ff) | 0xdc00); \
395     }                                                \
396   }
397 
398 }  // namesapce base_icu
399 
400 #endif  // BASE_THIRD_PARTY_ICU_ICU_UTF_H_
401