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utf8.h

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00001 /* 00002 ******************************************************************************* 00003 * 00004 * Copyright (C) 1999-2001, International Business Machines 00005 * Corporation and others. All Rights Reserved. 00006 * 00007 ******************************************************************************* 00008 * file name: utf8.h 00009 * encoding: US-ASCII 00010 * tab size: 8 (not used) 00011 * indentation:4 00012 * 00013 * created on: 1999sep13 00014 * created by: Markus W. Scherer 00015 */ 00016 00032 /* utf.h must be included first. */ 00033 #ifndef __UTF_H__ 00034 # include "unicode/utf.h" 00035 #endif 00036 00037 #ifndef __UTF8_H__ 00038 #define __UTF8_H__ 00039 00040 /* internal definitions ----------------------------------------------------- */ 00041 00042 #ifdef U_UTF8_IMPL 00043 U_CAPI const uint8_t 00044 utf8_countTrailBytes[256]; 00045 #else 00046 U_CFUNC const uint8_t /* U_IMPORT2? */ U_IMPORT 00047 utf8_countTrailBytes[256]; 00048 #endif 00049 00050 /* 00051 * Count the trail bytes for a lead byte - 00052 * this macro should be used so that the assembler code 00053 * that is mentioned in utf_impl.c could be used here. 00054 */ 00055 #define UTF8_COUNT_TRAIL_BYTES(leadByte) (utf8_countTrailBytes[(uint8_t)leadByte]) 00056 00057 /* use a macro here, too - there may be a simpler way with some machines */ 00058 #define UTF8_MASK_LEAD_BYTE(leadByte, countTrailBytes) ((leadByte)&=(1<<(6-(countTrailBytes)))-1) 00059 00060 U_CAPI UChar32 U_EXPORT2 00061 utf8_nextCharSafeBody(const uint8_t *s, int32_t *pi, int32_t length, UChar32 c, UBool strict); 00062 00063 U_CAPI int32_t U_EXPORT2 00064 utf8_appendCharSafeBody(uint8_t *s, int32_t i, int32_t length, UChar32 c); 00065 00066 U_CAPI UChar32 U_EXPORT2 00067 utf8_prevCharSafeBody(const uint8_t *s, int32_t start, int32_t *pi, UChar32 c, UBool strict); 00068 00069 U_CAPI int32_t U_EXPORT2 00070 utf8_back1SafeBody(const uint8_t *s, int32_t start, int32_t i); 00071 00072 /* 00073 * For the semantics of all of these macros, see utf16.h. 00074 * The UTF-8 macros favor sequences more the shorter they are. 00075 * Sometimes, only the single-byte case is covered by a macro, 00076 * while longer sequences are handled by a function call. 00077 */ 00078 00079 /* single-code point definitions -------------------------------------------- */ 00080 00081 /* classes of code unit values */ 00082 #define UTF8_IS_SINGLE(uchar) (((uchar)&0x80)==0) 00083 #define UTF8_IS_LEAD(uchar) ((uint8_t)((uchar)-0xc0)<0x3e) 00084 #define UTF8_IS_TRAIL(uchar) (((uchar)&0xc0)==0x80) 00085 00086 /* number of code units per code point */ 00087 #define UTF8_NEED_MULTIPLE_UCHAR(c) ((uint32_t)(c)>0x7f) 00088 00089 /* 00090 * ICU does not deal with code points >0x10ffff 00091 * unless necessary for advancing in the byte stream. 00092 * 00093 * These length macros take into account that for values >0x10ffff 00094 * the "safe" append macros would write the error code point 0xffff 00095 * with 3 bytes. 00096 * Code point comparisons need to be in uint32_t because UChar32 00097 * may be a signed type, and negative values must be recognized. 00098 */ 00099 #if 1 00100 # define UTF8_CHAR_LENGTH(c) \ 00101 ((uint32_t)(c)<=0x7f ? 1 : \ 00102 ((uint32_t)(c)<=0x7ff ? 2 : \ 00103 ((uint32_t)((c)-0x10000)>0xfffff ? 3 : 4) \ 00104 ) \ 00105 ) 00106 #else 00107 # define UTF8_CHAR_LENGTH(c) \ 00108 ((uint32_t)(c)<=0x7f ? 1 : \ 00109 ((uint32_t)(c)<=0x7ff ? 2 : \ 00110 ((uint32_t)(c)<=0xffff ? 3 : \ 00111 ((uint32_t)(c)<=0x10ffff ? 4 : \ 00112 ((uint32_t)(c)<=0x3ffffff ? 5 : \ 00113 ((uint32_t)(c)<=0x7fffffff ? 6 : 3) \ 00114 ) \ 00115 ) \ 00116 ) \ 00117 ) \ 00118 ) 00119 #endif 00120 00121 #define UTF8_MAX_CHAR_LENGTH 4 00122 00123 /* average number of code units compared to UTF-16 */ 00124 #define UTF8_ARRAY_SIZE(size) ((5*(size))/2) 00125 00126 #define UTF8_GET_CHAR_UNSAFE(s, i, c) { \ 00127 int32_t __I=(int32_t)(i); \ 00128 UTF8_SET_CHAR_START_UNSAFE(s, __I); \ 00129 UTF8_NEXT_CHAR_UNSAFE(s, __I, c); \ 00130 } 00131 00132 #define UTF8_GET_CHAR_SAFE(s, start, i, length, c, strict) { \ 00133 int32_t __I=(int32_t)(i); \ 00134 UTF8_SET_CHAR_START_SAFE(s, start, __I); \ 00135 UTF8_NEXT_CHAR_SAFE(s, __I, length, c, strict); \ 00136 } 00137 00138 /* definitions with forward iteration --------------------------------------- */ 00139 00140 /* 00141 * Read a Unicode scalar value from an array of UTF-8 bytes. 00142 * Only values <=0x10ffff are accepted, and if an error occurs, 00143 * then c will be set such that UTF_IS_ERROR(c). 00144 * The _UNSAFE macro is fast and does not check for errors. 00145 * The _SAFE macro checks for errors and optionally for 00146 * irregular sequences, too, i.e., for sequences that 00147 * are longer than necessary, such as <c0 80> instead of <0>. 00148 * The strict checks also check for non-characters. 00149 */ 00150 #define UTF8_NEXT_CHAR_UNSAFE(s, i, c) { \ 00151 (c)=(s)[(i)++]; \ 00152 if((uint8_t)((c)-0xc0)<0x35) { \ 00153 uint8_t __count=UTF8_COUNT_TRAIL_BYTES(c); \ 00154 UTF8_MASK_LEAD_BYTE(c, __count); \ 00155 switch(__count) { \ 00156 /* each following branch falls through to the next one */ \ 00157 case 3: \ 00158 (c)=((c)<<6)|((s)[(i)++]&0x3f); \ 00159 case 2: \ 00160 (c)=((c)<<6)|((s)[(i)++]&0x3f); \ 00161 case 1: \ 00162 (c)=((c)<<6)|((s)[(i)++]&0x3f); \ 00163 /* no other branches to optimize switch() */ \ 00164 break; \ 00165 } \ 00166 } \ 00167 } 00168 00169 #define UTF8_APPEND_CHAR_UNSAFE(s, i, c) { \ 00170 if((uint32_t)(c)<=0x7f) { \ 00171 (s)[(i)++]=(uint8_t)(c); \ 00172 } else { \ 00173 if((uint32_t)(c)<=0x7ff) { \ 00174 (s)[(i)++]=(uint8_t)(((c)>>6)|0xc0); \ 00175 } else { \ 00176 if((uint32_t)(c)<=0xffff) { \ 00177 (s)[(i)++]=(uint8_t)(((c)>>12)|0xe0); \ 00178 } else { \ 00179 (s)[(i)++]=(uint8_t)(((c)>>18)|0xf0); \ 00180 (s)[(i)++]=(uint8_t)((((c)>>12)&0x3f)|0x80); \ 00181 } \ 00182 (s)[(i)++]=(uint8_t)((((c)>>6)&0x3f)|0x80); \ 00183 } \ 00184 (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \ 00185 } \ 00186 } 00187 00188 #define UTF8_FWD_1_UNSAFE(s, i) { \ 00189 (i)+=1+UTF8_COUNT_TRAIL_BYTES((s)[i]); \ 00190 } 00191 00192 #define UTF8_FWD_N_UNSAFE(s, i, n) { \ 00193 int32_t __N=(n); \ 00194 while(__N>0) { \ 00195 UTF8_FWD_1_UNSAFE(s, i); \ 00196 --__N; \ 00197 } \ 00198 } 00199 00200 #define UTF8_SET_CHAR_START_UNSAFE(s, i) { \ 00201 while(UTF8_IS_TRAIL((s)[i])) { --(i); } \ 00202 } 00203 00204 #define UTF8_NEXT_CHAR_SAFE(s, i, length, c, strict) { \ 00205 (c)=(s)[(i)++]; \ 00206 if((c)>=0x80) { \ 00207 if(UTF8_IS_LEAD(c)) { \ 00208 (c)=utf8_nextCharSafeBody(s, &(i), (int32_t)(length), c, strict); \ 00209 } else { \ 00210 (c)=UTF8_ERROR_VALUE_1; \ 00211 } \ 00212 } \ 00213 } 00214 00215 #define UTF8_APPEND_CHAR_SAFE(s, i, length, c) { \ 00216 if((uint32_t)(c)<=0x7f) { \ 00217 (s)[(i)++]=(uint8_t)(c); \ 00218 } else { \ 00219 (i)=utf8_appendCharSafeBody(s, (int32_t)(i), (int32_t)(length), c); \ 00220 } \ 00221 } 00222 00223 #define UTF8_FWD_1_SAFE(s, i, length) { \ 00224 uint8_t __b=(s)[(i)++]; \ 00225 if(UTF8_IS_LEAD(__b)) { \ 00226 uint8_t __count=UTF8_COUNT_TRAIL_BYTES(__b); \ 00227 if((i)+__count>(length)) { \ 00228 __count=(uint8_t)((length)-(i)); \ 00229 } \ 00230 while(__count>0 && UTF8_IS_TRAIL((s)[i])) { \ 00231 ++(i); \ 00232 --__count; \ 00233 } \ 00234 } \ 00235 } 00236 00237 #define UTF8_FWD_N_SAFE(s, i, length, n) { \ 00238 int32_t __N=(n); \ 00239 while(__N>0 && (i)<(length)) { \ 00240 UTF8_FWD_1_SAFE(s, i, length); \ 00241 --__N; \ 00242 } \ 00243 } 00244 00245 #define UTF8_SET_CHAR_START_SAFE(s, start, i) { \ 00246 if(UTF8_IS_TRAIL((s)[(i)])) { \ 00247 (i)=utf8_back1SafeBody(s, start, (int32_t)(i)); \ 00248 } \ 00249 } 00250 00251 /* definitions with backward iteration -------------------------------------- */ 00252 00253 #define UTF8_PREV_CHAR_UNSAFE(s, i, c) { \ 00254 (c)=(s)[--(i)]; \ 00255 if(UTF8_IS_TRAIL(c)) { \ 00256 uint8_t __b, __count=1, __shift=6; \ 00257 \ 00258 /* c is a trail byte */ \ 00259 (c)&=0x3f; \ 00260 for(;;) { \ 00261 __b=(s)[--(i)]; \ 00262 if(__b>=0xc0) { \ 00263 UTF8_MASK_LEAD_BYTE(__b, __count); \ 00264 (c)|=(UChar32)__b<<__shift; \ 00265 break; \ 00266 } else { \ 00267 (c)|=(UChar32)(__b&0x3f)<<__shift; \ 00268 ++__count; \ 00269 __shift+=6; \ 00270 } \ 00271 } \ 00272 } \ 00273 } 00274 00275 #define UTF8_BACK_1_UNSAFE(s, i) { \ 00276 while(UTF8_IS_TRAIL((s)[--(i)])) {} \ 00277 } 00278 00279 #define UTF8_BACK_N_UNSAFE(s, i, n) { \ 00280 int32_t __N=(n); \ 00281 while(__N>0) { \ 00282 UTF8_BACK_1_UNSAFE(s, i); \ 00283 --__N; \ 00284 } \ 00285 } 00286 00287 #define UTF8_SET_CHAR_LIMIT_UNSAFE(s, i) { \ 00288 UTF8_BACK_1_UNSAFE(s, i); \ 00289 UTF8_FWD_1_UNSAFE(s, i); \ 00290 } 00291 00292 #define UTF8_PREV_CHAR_SAFE(s, start, i, c, strict) { \ 00293 (c)=(s)[--(i)]; \ 00294 if((c)>=0x80) { \ 00295 if((c)<=0xbf) { \ 00296 (c)=utf8_prevCharSafeBody(s, start, &(i), c, strict); \ 00297 } else { \ 00298 (c)=UTF8_ERROR_VALUE_1; \ 00299 } \ 00300 } \ 00301 } 00302 00303 #define UTF8_BACK_1_SAFE(s, start, i) { \ 00304 if(UTF8_IS_TRAIL((s)[--(i)])) { \ 00305 (i)=utf8_back1SafeBody(s, start, (int32_t)(i)); \ 00306 } \ 00307 } 00308 00309 #define UTF8_BACK_N_SAFE(s, start, i, n) { \ 00310 int32_t __N=(n); \ 00311 while(__N>0 && (i)>(start)) { \ 00312 UTF8_BACK_1_SAFE(s, start, i); \ 00313 --__N; \ 00314 } \ 00315 } 00316 00317 /* 00318 * Need to use UTF8_FWD_1_SAFE() because UTF8_BACK_1_SAFE() 00319 * may have started from the middle of the sequence and not checked 00320 * all trail bytes. 00321 */ 00322 #define UTF8_SET_CHAR_LIMIT_SAFE(s, start, i, length) { \ 00323 if((start)<(i) && (i)<(length)) { \ 00324 UTF8_BACK_1_SAFE(s, start, i); \ 00325 UTF8_FWD_1_SAFE(s, i, length); \ 00326 } \ 00327 } 00328 00329 #endif

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