00001 /* 00002 ******************************************************************************* 00003 * 00004 * Copyright (C) 1999-2000, 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 * This file defines macros to deal with UTF-8 code units and code points. 00017 * Signatures and semantics are the same as for the similarly named macros 00018 * in utf16.h. 00019 * utf8.h is included by utf.h after unicode/umachine.h 00020 * and some common definitions. 00021 */ 00022 00023 00024 /* utf.h must be included first. */ 00025 #ifndef __UTF_H__ 00026 # include "unicode/utf.h" 00027 #endif 00028 00029 #ifndef __UTF8_H__ 00030 #define __UTF8_H__ 00031 00032 /* internal definitions ----------------------------------------------------- */ 00033 00034 U_CAPI uint8_t U_EXPORT2 00035 utf8_countTrailBytes[256]; 00036 00037 /* 00038 * Count the trail bytes for a lead byte - 00039 * this macro should be used so that the assembler code 00040 * that is mentioned in utf_impl.c could be used here. 00041 */ 00042 #define UTF8_COUNT_TRAIL_BYTES(leadByte) (utf8_countTrailBytes[(uint8_t)leadByte]) 00043 00044 /* use a macro here, too - there may be a simpler way with some machines */ 00045 #define UTF8_MASK_LEAD_BYTE(leadByte, countTrailBytes) ((leadByte)&=(1<<(6-(countTrailBytes)))-1) 00046 00047 U_CAPI UChar32 U_EXPORT2 00048 utf8_nextCharSafeBody(const uint8_t *s, UTextOffset *pi, UTextOffset length, UChar32 c, UBool strict); 00049 00050 U_CAPI UTextOffset U_EXPORT2 00051 utf8_appendCharSafeBody(uint8_t *s, UTextOffset i, UTextOffset length, UChar32 c); 00052 00053 U_CAPI UChar32 U_EXPORT2 00054 utf8_prevCharSafeBody(const uint8_t *s, UTextOffset start, UTextOffset *pi, UChar32 c, UBool strict); 00055 00056 U_CAPI UTextOffset U_EXPORT2 00057 utf8_back1SafeBody(const uint8_t *s, UTextOffset start, UTextOffset i); 00058 00059 /* 00060 * For the semantics of all of these macros, see utf16.h. 00061 * The UTF-8 macros favor sequences more the shorter they are. 00062 * Sometimes, only the single-byte case is covered by a macro, 00063 * while longer sequences are handled by a function call. 00064 */ 00065 00066 /* single-code point definitions -------------------------------------------- */ 00067 00068 /* classes of code unit values */ 00069 #define UTF8_IS_SINGLE(uchar) ((uchar)&0x80==0) 00070 #define UTF8_IS_LEAD(uchar) ((uint8_t)((uchar)-0xc0)<0x3e) 00071 #define UTF8_IS_TRAIL(uchar) ((uchar)&0xc0==0x80) 00072 00073 /* number of code units per code point */ 00074 #define UTF8_NEED_MULTIPLE_UCHAR(c) ((uint32_t)(c)>0x7f) 00075 00076 /* 00077 * ICU does not deal with code points >0x10ffff 00078 * unless necessary for advancing in the byte stream. 00079 * 00080 * These length macros take into account that for values >0x10ffff 00081 * the "safe" append macros would write the error code point 0xffff 00082 * with 3 bytes. 00083 * Code point comparisons need to be in uint32_t because UChar32 00084 * may be a signed type, and negative values must be recognized. 00085 */ 00086 #if 1 00087 # define UTF8_CHAR_LENGTH(c) \ 00088 ((uint32_t)(c)<=0x7f ? 1 : \ 00089 ((uint32_t)(c)<=0x7ff ? 2 : \ 00090 ((uint32_t)((c)-0x10000)>0xfffff ? 3 : 4) \ 00091 ) \ 00092 ) 00093 #else 00094 # define UTF8_CHAR_LENGTH(c) \ 00095 ((uint32_t)(c)<=0x7f ? 1 : \ 00096 ((uint32_t)(c)<=0x7ff ? 2 : \ 00097 ((uint32_t)(c)<=0xffff ? 3 : \ 00098 ((uint32_t)(c)<=0x10ffff ? 4 : \ 00099 ((uint32_t)(c)<=0x3ffffff ? 5 : \ 00100 ((uint32_t)(c)<=0x7fffffff ? 6 : 3) \ 00101 ) \ 00102 ) \ 00103 ) \ 00104 ) \ 00105 ) 00106 #endif 00107 00108 #define UTF8_MAX_CHAR_LENGTH 4 00109 00110 /* average number of code units compared to UTF-16 */ 00111 #define UTF8_ARRAY_SIZE(size) ((5*(size))/2) 00112 00113 #define UTF8_GET_CHAR_UNSAFE(s, i, c) { \ 00114 UTextOffset __I=(UTextOffset)(i); \ 00115 UTF8_SET_CHAR_START_UNSAFE(s, __I); \ 00116 UTF8_NEXT_CHAR_UNSAFE(s, __I, c); \ 00117 } 00118 00119 #define UTF8_GET_CHAR_SAFE(s, start, i, length, c, strict) { \ 00120 UTextOffset __I=(UTextOffset)(i); \ 00121 UTF8_SET_CHAR_START_SAFE(s, start, __I); \ 00122 UTF8_NEXT_CHAR_SAFE(s, __I, length, c, strict); \ 00123 } 00124 00125 /* definitions with forward iteration --------------------------------------- */ 00126 00127 /* 00128 * Read a Unicode scalar value from an array of UTF-8 bytes. 00129 * Only values <=0x10ffff are accepted, and if an error occurs, 00130 * then c will be set such that UTF_IS_ERROR(c). 00131 * The _UNSAFE macro is fast and does not check for errors. 00132 * The _SAFE macro checks for errors and optionally for 00133 * irregular sequences, too, i.e., for sequences that 00134 * are longer than necessary, such as <c0 80> instead of <0>. 00135 * The strict checks also check for surrogates and 00136 * for 0xXXXXfffe and 0xXXXXffff. 00137 */ 00138 #define UTF8_NEXT_CHAR_UNSAFE(s, i, c) { \ 00139 (c)=(s)[(i)++]; \ 00140 if((uint8_t)((c)-0xc0)<0x35) { \ 00141 uint8_t __count=UTF8_COUNT_TRAIL_BYTES(c); \ 00142 UTF8_MASK_LEAD_BYTE(c, __count); \ 00143 switch(__count) { \ 00144 /* each following branch falls through to the next one */ \ 00145 case 3: \ 00146 (c)=((c)<<6)|((s)[(i)++]&0x3f); \ 00147 case 2: \ 00148 (c)=((c)<<6)|((s)[(i)++]&0x3f); \ 00149 case 1: \ 00150 (c)=((c)<<6)|((s)[(i)++]&0x3f); \ 00151 /* no other branches to optimize switch() */ \ 00152 break; \ 00153 } \ 00154 } \ 00155 } 00156 00157 #define UTF8_APPEND_CHAR_UNSAFE(s, i, c) { \ 00158 if((uint32_t)(c)<=0x7f) { \ 00159 (s)[(i)++]=(uint8_t)(c); \ 00160 } else { \ 00161 if((uint32_t)(c)<=0x7ff) { \ 00162 (s)[(i)++]=(uint8_t)((c)>>6)|0xc0; \ 00163 } else { \ 00164 if((uint32_t)(c)<=0xffff) { \ 00165 (s)[(i)++]=(uint8_t)((c)>>12)|0xe0; \ 00166 } else { \ 00167 (s)[(i)++]=(uint8_t)((c)>>18)|0xf0; \ 00168 (s)[(i)++]=(uint8_t)((c)>>12)&0x3f|0x80; \ 00169 } \ 00170 (s)[(i)++]=(uint8_t)((c)>>6)&0x3f|0x80; \ 00171 } \ 00172 (s)[(i)++]=(uint8_t)(c)&0x3f|0x80; \ 00173 } \ 00174 } 00175 00176 #define UTF8_FWD_1_UNSAFE(s, i) { \ 00177 (i)+=1+UTF8_COUNT_TRAIL_BYTES((s)[i]); \ 00178 } 00179 00180 #define UTF8_FWD_N_UNSAFE(s, i, n) { \ 00181 UTextOffset __N=(n); \ 00182 while(__N>0) { \ 00183 UTF8_FWD_1_UNSAFE(s, i); \ 00184 --__N; \ 00185 } \ 00186 } 00187 00188 #define UTF8_SET_CHAR_START_UNSAFE(s, i) { \ 00189 while(UTF8_IS_TRAIL((s)[i])) { --(i); } \ 00190 } 00191 00192 #define UTF8_NEXT_CHAR_SAFE(s, i, length, c, strict) { \ 00193 (c)=(s)[(i)++]; \ 00194 if(UTF8_IS_LEAD(c)) { \ 00195 (c)=utf8_nextCharSafeBody(s, &(i), (UTextOffset)(length), c, strict); \ 00196 } \ 00197 } 00198 00199 #define UTF8_APPEND_CHAR_SAFE(s, i, length, c) { \ 00200 if((uint32_t)(c)<=0x7f) { \ 00201 (s)[(i)++]=(uint8_t)(c); \ 00202 } else { \ 00203 (i)=utf8_appendCharSafeBody(s, (UTextOffset)(i), (UTextOffset)(length), c); \ 00204 } \ 00205 } 00206 00207 #define UTF8_FWD_1_SAFE(s, i, length) { \ 00208 uint8_t __b=(s)[(i)++]; \ 00209 if(UTF8_IS_LEAD(__b)) { \ 00210 uint8_t __count=UTF8_COUNT_TRAIL_BYTES(__b); \ 00211 if((i)+__count>(length)) { \ 00212 __count=(length)-(i); \ 00213 } \ 00214 while(__count>0 && UTF8_IS_TRAIL((s)[i])) { \ 00215 ++(i); \ 00216 --__count; \ 00217 } \ 00218 } \ 00219 } 00220 00221 #define UTF8_FWD_N_SAFE(s, i, length, n) { \ 00222 UTextOffset __N=(n); \ 00223 while(__N>0 && (i)<(length)) { \ 00224 UTF8_FWD_1_SAFE(s, i, length); \ 00225 --__N; \ 00226 } \ 00227 } 00228 00229 #define UTF8_SET_CHAR_START_SAFE(s, start, i) { \ 00230 if(UTF8_IS_TRAIL((s)[(i)])) { \ 00231 (i)=utf8_back1SafeBody(s, start, (UTextOffset)(i)); \ 00232 } \ 00233 } 00234 00235 /* definitions with backward iteration -------------------------------------- */ 00236 00237 #define UTF8_PREV_CHAR_UNSAFE(s, i, c) { \ 00238 (c)=(s)[--(i)]; \ 00239 if(UTF8_IS_TRAIL(c)) { \ 00240 uint8_t __b, __count=1, __shift=6; \ 00241 \ 00242 /* c is a trail byte */ \ 00243 (c)&=0x3f; \ 00244 for(;;) { \ 00245 __b=(s)[--(i)]; \ 00246 if(__b>=0xc0) { \ 00247 UTF8_MASK_LEAD_BYTE(__b, __count); \ 00248 (c)|=(UChar32)__b<<__shift; \ 00249 break; \ 00250 } else { \ 00251 (c)|=(UChar32)(__b&0x3f)<<__shift; \ 00252 ++__count; \ 00253 __shift+=6; \ 00254 } \ 00255 } \ 00256 } \ 00257 } 00258 00259 #define UTF8_BACK_1_UNSAFE(s, i) { \ 00260 while(UTF8_IS_TRAIL((s)[--(i)])) {} \ 00261 } 00262 00263 #define UTF8_BACK_N_UNSAFE(s, i, n) { \ 00264 UTextOffset __N=(n); \ 00265 while(__N>0) { \ 00266 UTF8_BACK_1_UNSAFE(s, i); \ 00267 --__N; \ 00268 } \ 00269 } 00270 00271 #define UTF8_SET_CHAR_LIMIT_UNSAFE(s, i) { \ 00272 UTF8_BACK_1_UNSAFE(s, i); \ 00273 UTF8_FWD_1_UNSAFE(s, i); \ 00274 } 00275 00276 #define UTF8_PREV_CHAR_SAFE(s, start, i, c, strict) { \ 00277 (c)=(s)[--(i)]; \ 00278 if(UTF8_IS_TRAIL((c))) { \ 00279 (c)=utf8_prevCharSafeBody(s, start, &(i), c, strict); \ 00280 } \ 00281 } 00282 00283 #define UTF8_BACK_1_SAFE(s, start, i) { \ 00284 if(UTF8_IS_TRAIL((s)[--(i)])) { \ 00285 (i)=utf8_back1SafeBody(s, start, (UTextOffset)(i)); \ 00286 } \ 00287 } 00288 00289 #define UTF8_BACK_N_SAFE(s, start, i, n) { \ 00290 UTextOffset __N=(n); \ 00291 while(__N>0 && (i)>(start)) { \ 00292 UTF8_BACK_1_SAFE(s, start, i); \ 00293 --__N; \ 00294 } \ 00295 } 00296 00297 #define UTF8_SET_CHAR_LIMIT_SAFE(s, start, i, length) { \ 00298 if((start)<(i) && (i)<(length)) { \ 00299 UTF8_BACK_1_SAFE(s, start, i); \ 00300 (i)+=1+UTF8_COUNT_TRAIL_BYTES((s)[i]); \ 00301 if((i)>(length)) { \ 00302 (i)=(length); \ 00303 } \ 00304 } \ 00305 } 00306 00307 #endif