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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 "base/basictypes.h"
21 
22 namespace base_icu {
23 
24 typedef int32 UChar32;
25 typedef uint16 UChar;
26 typedef int8 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 && \
59      ((uint32)(c)<=0xfdef || ((c)&0xfffe)==0xfffe) && \
60      (uint32)(c)<=0x10ffff)
61 
62 /**
63  * Is c a Unicode code point value (0..U+10ffff)
64  * that can be assigned a character?
65  *
66  * Code points that are not characters include:
67  * - single surrogate code points (U+d800..U+dfff, 2048 code points)
68  * - the last two code points on each plane (U+__fffe and U+__ffff, 34 code points)
69  * - U+fdd0..U+fdef (new with Unicode 3.1, 32 code points)
70  * - the highest Unicode code point value is U+10ffff
71  *
72  * This means that all code points below U+d800 are character code points,
73  * and that boundary is tested first for performance.
74  *
75  * @param c 32-bit code point
76  * @return TRUE or FALSE
77  * @stable ICU 2.4
78  */
79 #define CBU_IS_UNICODE_CHAR(c) \
80     ((uint32)(c)<0xd800 || \
81         ((uint32)(c)>0xdfff && \
82          (uint32)(c)<=0x10ffff && \
83          !CBU_IS_UNICODE_NONCHAR(c)))
84 
85 /**
86  * Is this code point a surrogate (U+d800..U+dfff)?
87  * @param c 32-bit code point
88  * @return TRUE or FALSE
89  * @stable ICU 2.4
90  */
91 #define CBU_IS_SURROGATE(c) (((c)&0xfffff800)==0xd800)
92 
93 /**
94  * Assuming c is a surrogate code point (U_IS_SURROGATE(c)),
95  * is it a lead surrogate?
96  * @param c 32-bit code point
97  * @return TRUE or FALSE
98  * @stable ICU 2.4
99  */
100 #define CBU_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
101 
102 
103 // UTF-8 macros ----------------------------------------------------------------
104 // from utf8.h
105 
106 extern const uint8 utf8_countTrailBytes[256];
107 
108 /**
109  * Count the trail bytes for a UTF-8 lead byte.
110  * @internal
111  */
112 #define CBU8_COUNT_TRAIL_BYTES(leadByte) (base_icu::utf8_countTrailBytes[(uint8)leadByte])
113 
114 /**
115  * Mask a UTF-8 lead byte, leave only the lower bits that form part of the code point value.
116  * @internal
117  */
118 #define CBU8_MASK_LEAD_BYTE(leadByte, countTrailBytes) ((leadByte)&=(1<<(6-(countTrailBytes)))-1)
119 
120 /**
121  * Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)?
122  * @param c 8-bit code unit (byte)
123  * @return TRUE or FALSE
124  * @stable ICU 2.4
125  */
126 #define CBU8_IS_SINGLE(c) (((c)&0x80)==0)
127 
128 /**
129  * Is this code unit (byte) a UTF-8 lead byte?
130  * @param c 8-bit code unit (byte)
131  * @return TRUE or FALSE
132  * @stable ICU 2.4
133  */
134 #define CBU8_IS_LEAD(c) ((uint8)((c)-0xc0)<0x3e)
135 
136 /**
137  * Is this code unit (byte) a UTF-8 trail byte?
138  * @param c 8-bit code unit (byte)
139  * @return TRUE or FALSE
140  * @stable ICU 2.4
141  */
142 #define CBU8_IS_TRAIL(c) (((c)&0xc0)==0x80)
143 
144 /**
145  * How many code units (bytes) are used for the UTF-8 encoding
146  * of this Unicode code point?
147  * @param c 32-bit code point
148  * @return 1..4, or 0 if c is a surrogate or not a Unicode code point
149  * @stable ICU 2.4
150  */
151 #define CBU8_LENGTH(c) \
152     ((uint32)(c)<=0x7f ? 1 : \
153         ((uint32)(c)<=0x7ff ? 2 : \
154             ((uint32)(c)<=0xd7ff ? 3 : \
155                 ((uint32)(c)<=0xdfff || (uint32)(c)>0x10ffff ? 0 : \
156                     ((uint32)(c)<=0xffff ? 3 : 4)\
157                 ) \
158             ) \
159         ) \
160     )
161 
162 /**
163  * The maximum number of UTF-8 code units (bytes) per Unicode code point (U+0000..U+10ffff).
164  * @return 4
165  * @stable ICU 2.4
166  */
167 #define CBU8_MAX_LENGTH 4
168 
169 /**
170  * Function for handling "next code point" with error-checking.
171  * @internal
172  */
173 UChar32 utf8_nextCharSafeBody(const uint8 *s, int32 *pi, int32 length, UChar32 c, UBool strict);
174 
175 /**
176  * Get a code point from a string at a code point boundary offset,
177  * and advance the offset to the next code point boundary.
178  * (Post-incrementing forward iteration.)
179  * "Safe" macro, checks for illegal sequences and for string boundaries.
180  *
181  * The offset may point to the lead byte of a multi-byte sequence,
182  * in which case the macro will read the whole sequence.
183  * If the offset points to a trail byte or an illegal UTF-8 sequence, then
184  * c is set to a negative value.
185  *
186  * @param s const uint8 * string
187  * @param i string offset, i<length
188  * @param length string length
189  * @param c output UChar32 variable, set to <0 in case of an error
190  * @see CBU8_NEXT_UNSAFE
191  * @stable ICU 2.4
192  */
193 #define CBU8_NEXT(s, i, length, c) { \
194     (c)=(s)[(i)++]; \
195     if(((uint8)(c))>=0x80) { \
196         if(CBU8_IS_LEAD(c)) { \
197             (c)=base_icu::utf8_nextCharSafeBody((const uint8 *)s, &(i), (int32)(length), c, -1); \
198         } else { \
199             (c)=CBU_SENTINEL; \
200         } \
201     } \
202 }
203 
204 /**
205  * Append a code point to a string, overwriting 1 to 4 bytes.
206  * The offset points to the current end of the string contents
207  * and is advanced (post-increment).
208  * "Unsafe" macro, assumes a valid code point and sufficient space in the string.
209  * Otherwise, the result is undefined.
210  *
211  * @param s const uint8 * string buffer
212  * @param i string offset
213  * @param c code point to append
214  * @see CBU8_APPEND
215  * @stable ICU 2.4
216  */
217 #define CBU8_APPEND_UNSAFE(s, i, c) { \
218     if((uint32)(c)<=0x7f) { \
219         (s)[(i)++]=(uint8)(c); \
220     } else { \
221         if((uint32)(c)<=0x7ff) { \
222             (s)[(i)++]=(uint8)(((c)>>6)|0xc0); \
223         } else { \
224             if((uint32)(c)<=0xffff) { \
225                 (s)[(i)++]=(uint8)(((c)>>12)|0xe0); \
226             } else { \
227                 (s)[(i)++]=(uint8)(((c)>>18)|0xf0); \
228                 (s)[(i)++]=(uint8)((((c)>>12)&0x3f)|0x80); \
229             } \
230             (s)[(i)++]=(uint8)((((c)>>6)&0x3f)|0x80); \
231         } \
232         (s)[(i)++]=(uint8)(((c)&0x3f)|0x80); \
233     } \
234 }
235 
236 // UTF-16 macros ---------------------------------------------------------------
237 // from utf16.h
238 
239 /**
240  * Does this code unit alone encode a code point (BMP, not a surrogate)?
241  * @param c 16-bit code unit
242  * @return TRUE or FALSE
243  * @stable ICU 2.4
244  */
245 #define CBU16_IS_SINGLE(c) !CBU_IS_SURROGATE(c)
246 
247 /**
248  * Is this code unit a lead surrogate (U+d800..U+dbff)?
249  * @param c 16-bit code unit
250  * @return TRUE or FALSE
251  * @stable ICU 2.4
252  */
253 #define CBU16_IS_LEAD(c) (((c)&0xfffffc00)==0xd800)
254 
255 /**
256  * Is this code unit a trail surrogate (U+dc00..U+dfff)?
257  * @param c 16-bit code unit
258  * @return TRUE or FALSE
259  * @stable ICU 2.4
260  */
261 #define CBU16_IS_TRAIL(c) (((c)&0xfffffc00)==0xdc00)
262 
263 /**
264  * Is this code unit a surrogate (U+d800..U+dfff)?
265  * @param c 16-bit code unit
266  * @return TRUE or FALSE
267  * @stable ICU 2.4
268  */
269 #define CBU16_IS_SURROGATE(c) CBU_IS_SURROGATE(c)
270 
271 /**
272  * Assuming c is a surrogate code point (U16_IS_SURROGATE(c)),
273  * is it a lead surrogate?
274  * @param c 16-bit code unit
275  * @return TRUE or FALSE
276  * @stable ICU 2.4
277  */
278 #define CBU16_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
279 
280 /**
281  * Helper constant for CBU16_GET_SUPPLEMENTARY.
282  * @internal
283  */
284 #define CBU16_SURROGATE_OFFSET ((0xd800<<10UL)+0xdc00-0x10000)
285 
286 /**
287  * Get a supplementary code point value (U+10000..U+10ffff)
288  * from its lead and trail surrogates.
289  * The result is undefined if the input values are not
290  * lead and trail surrogates.
291  *
292  * @param lead lead surrogate (U+d800..U+dbff)
293  * @param trail trail surrogate (U+dc00..U+dfff)
294  * @return supplementary code point (U+10000..U+10ffff)
295  * @stable ICU 2.4
296  */
297 #define CBU16_GET_SUPPLEMENTARY(lead, trail) \
298     (((base_icu::UChar32)(lead)<<10UL)+(base_icu::UChar32)(trail)-CBU16_SURROGATE_OFFSET)
299 
300 
301 /**
302  * Get the lead surrogate (0xd800..0xdbff) for a
303  * supplementary code point (0x10000..0x10ffff).
304  * @param supplementary 32-bit code point (U+10000..U+10ffff)
305  * @return lead surrogate (U+d800..U+dbff) for supplementary
306  * @stable ICU 2.4
307  */
308 #define CBU16_LEAD(supplementary) \
309     (base_icu::UChar)(((supplementary)>>10)+0xd7c0)
310 
311 /**
312  * Get the trail surrogate (0xdc00..0xdfff) for a
313  * supplementary code point (0x10000..0x10ffff).
314  * @param supplementary 32-bit code point (U+10000..U+10ffff)
315  * @return trail surrogate (U+dc00..U+dfff) for supplementary
316  * @stable ICU 2.4
317  */
318 #define CBU16_TRAIL(supplementary) \
319     (base_icu::UChar)(((supplementary)&0x3ff)|0xdc00)
320 
321 /**
322  * How many 16-bit code units are used to encode this Unicode code point? (1 or 2)
323  * The result is not defined if c is not a Unicode code point (U+0000..U+10ffff).
324  * @param c 32-bit code point
325  * @return 1 or 2
326  * @stable ICU 2.4
327  */
328 #define CBU16_LENGTH(c) ((uint32)(c)<=0xffff ? 1 : 2)
329 
330 /**
331  * The maximum number of 16-bit code units per Unicode code point (U+0000..U+10ffff).
332  * @return 2
333  * @stable ICU 2.4
334  */
335 #define CBU16_MAX_LENGTH 2
336 
337 /**
338  * Get a code point from a string at a code point boundary offset,
339  * and advance the offset to the next code point boundary.
340  * (Post-incrementing forward iteration.)
341  * "Safe" macro, handles unpaired surrogates and checks for string boundaries.
342  *
343  * The offset may point to the lead surrogate unit
344  * for a supplementary code point, in which case the macro will read
345  * the following trail surrogate as well.
346  * If the offset points to a trail surrogate or
347  * to a single, unpaired lead surrogate, then that itself
348  * will be returned as the code point.
349  *
350  * @param s const UChar * string
351  * @param i string offset, i<length
352  * @param length string length
353  * @param c output UChar32 variable
354  * @stable ICU 2.4
355  */
356 #define CBU16_NEXT(s, i, length, c) { \
357     (c)=(s)[(i)++]; \
358     if(CBU16_IS_LEAD(c)) { \
359         uint16 __c2; \
360         if((i)<(length) && CBU16_IS_TRAIL(__c2=(s)[(i)])) { \
361             ++(i); \
362             (c)=CBU16_GET_SUPPLEMENTARY((c), __c2); \
363         } \
364     } \
365 }
366 
367 /**
368  * Append a code point to a string, overwriting 1 or 2 code units.
369  * The offset points to the current end of the string contents
370  * and is advanced (post-increment).
371  * "Unsafe" macro, assumes a valid code point and sufficient space in the string.
372  * Otherwise, the result is undefined.
373  *
374  * @param s const UChar * string buffer
375  * @param i string offset
376  * @param c code point to append
377  * @see CBU16_APPEND
378  * @stable ICU 2.4
379  */
380 #define CBU16_APPEND_UNSAFE(s, i, c) { \
381     if((uint32)(c)<=0xffff) { \
382         (s)[(i)++]=(uint16)(c); \
383     } else { \
384         (s)[(i)++]=(uint16)(((c)>>10)+0xd7c0); \
385         (s)[(i)++]=(uint16)(((c)&0x3ff)|0xdc00); \
386     } \
387 }
388 
389 }  // namesapce base_icu
390 
391 #endif  // BASE_THIRD_PARTY_ICU_ICU_UTF_H_
392