asm/strfunc.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 1996-2009 The NASM Authors - All Rights Reserved
   4  *   See the file AUTHORS included with the NASM distribution for
   5  *   the specific copyright holders.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following
   9  *   conditions are met:
  10  *
  11  *   * Redistributions of source code must retain the above copyright
  12  *     notice, this list of conditions and the following disclaimer.
  13  *   * Redistributions in binary form must reproduce the above
  14  *     copyright notice, this list of conditions and the following
  15  *     disclaimer in the documentation and/or other materials provided
  16  *     with the distribution.
  17  *
  18  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  19  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  21  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  23  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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  29  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  30  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * ----------------------------------------------------------------------- */
  33
  34 /*
  35  * strfunc.c
  36  *
  37  * String transformation functions
  38  */
  39
  40 #include "nasmlib.h"
  41 #include "nasm.h"
  42
  43 /*
  44  * Convert a string in UTF-8 format to UTF-16LE
  45  */
  46 static size_t utf8_to_16le(uint8_t *str, size_t len, char *op)
  47 {
  48 #define EMIT(x) do { if (op) { WRITESHORT(op,x); } outlen++; } while(0)
  49
  50     size_t outlen = 0;
  51     int expect = 0;
  52     uint8_t c;
  53     uint32_t v = 0, vmin = 0;
  54
  55     while (len--) {
  56         c = *str++;
  57
  58         if (expect) {
  59             if ((c & 0xc0) != 0x80) {
  60                 expect = 0;
  61                 return -1;
  62             } else {
  63                 v = (v << 6) | (c & 0x3f);
  64                 if (!--expect) {
  65                     if (v < vmin || v > 0x10ffff ||
  66                         (v >= 0xd800 && v <= 0xdfff)) {
  67                         return -1;
  68                     } else if (v > 0xffff) {
  69                         v -= 0x10000;
  70                         EMIT(0xd800 | (v >> 10));
  71                         EMIT(0xdc00 | (v & 0x3ff));
  72                     } else {
  73                         EMIT(v);
  74                     }
  75                 }
  76                 continue;
  77             }
  78         }
  79
  80         if (c < 0x80) {
  81             EMIT(c);
  82         } else if (c < 0xc0 || c >= 0xfe) {
  83             /* Invalid UTF-8 */
  84             return -1;
  85         } else if (c < 0xe0) {
  86             v = c & 0x1f;
  87             expect = 1;
  88             vmin = 0x80;
  89         } else if (c < 0xf0) {
  90             v = c & 0x0f;
  91             expect = 2;
  92             vmin = 0x800;
  93         } else if (c < 0xf8) {
  94             v = c & 0x07;
  95             expect = 3;
  96             vmin = 0x10000;
  97         } else if (c < 0xfc) {
  98             v = c & 0x03;
  99             expect = 4;
 100             vmin = 0x200000;
 101         } else {
 102             v = c & 0x01;
 103             expect = 5;
 104             vmin = 0x4000000;
 105         }
 106     }
 107
 108     return expect ? (size_t)-1 : outlen << 1;
 109
 110 #undef EMIT
 111 }
 112
 113 /*
 114  * Convert a string in UTF-8 format to UTF-16BE
 115  */
 116 static size_t utf8_to_16be(uint8_t *str, size_t len, char *op)
 117 {
 118 #define EMIT(x)                                 \
 119     do {                                        \
 120         uint16_t _y = (x);                      \
 121         if (op) {                               \
 122             WRITECHAR(op, _y >> 8);             \
 123             WRITECHAR(op, _y);                  \
 124         }                                       \
 125         outlen++;                               \
 126     } while (0)                                 \
 127
 128     size_t outlen = 0;
 129     int expect = 0;
 130     uint8_t c;
 131     uint32_t v = 0, vmin = 0;
 132
 133     while (len--) {
 134         c = *str++;
 135
 136         if (expect) {
 137             if ((c & 0xc0) != 0x80) {
 138                 expect = 0;
 139                 return -1;
 140             } else {
 141                 v = (v << 6) | (c & 0x3f);
 142                 if (!--expect) {
 143                     if (v < vmin || v > 0x10ffff ||
 144                         (v >= 0xd800 && v <= 0xdfff)) {
 145                         return -1;
 146                     } else if (v > 0xffff) {
 147                         v -= 0x10000;
 148                         EMIT(0xdc00 | (v & 0x3ff));
 149                         EMIT(0xd800 | (v >> 10));
 150                     } else {
 151                         EMIT(v);
 152                     }
 153                 }
 154                 continue;
 155             }
 156         }
 157
 158         if (c < 0x80) {
 159             EMIT(c);
 160         } else if (c < 0xc0 || c >= 0xfe) {
 161             /* Invalid UTF-8 */
 162             return -1;
 163         } else if (c < 0xe0) {
 164             v = c & 0x1f;
 165             expect = 1;
 166             vmin = 0x80;
 167         } else if (c < 0xf0) {
 168             v = c & 0x0f;
 169             expect = 2;
 170             vmin = 0x800;
 171         } else if (c < 0xf8) {
 172             v = c & 0x07;
 173             expect = 3;
 174             vmin = 0x10000;
 175         } else if (c < 0xfc) {
 176             v = c & 0x03;
 177             expect = 4;
 178             vmin = 0x200000;
 179         } else {
 180             v = c & 0x01;
 181             expect = 5;
 182             vmin = 0x4000000;
 183         }
 184     }
 185
 186     return expect ? (size_t)-1 : outlen << 1;
 187
 188 #undef EMIT
 189 }
 190
 191 /*
 192  * Convert a string in UTF-8 format to UTF-32LE
 193  */
 194 static size_t utf8_to_32le(uint8_t *str, size_t len, char *op)
 195 {
 196 #define EMIT(x) do { if (op) { WRITELONG(op,x); } outlen++; } while(0)
 197
 198     size_t outlen = 0;
 199     int expect = 0;
 200     uint8_t c;
 201     uint32_t v = 0, vmin = 0;
 202
 203     while (len--) {
 204         c = *str++;
 205
 206         if (expect) {
 207             if ((c & 0xc0) != 0x80) {
 208                 return -1;
 209             } else {
 210                 v = (v << 6) | (c & 0x3f);
 211                 if (!--expect) {
 212                     if (v < vmin || (v >= 0xd800 && v <= 0xdfff)) {
 213                         return -1;
 214                     } else {
 215                         EMIT(v);
 216                     }
 217                 }
 218                 continue;
 219             }
 220         }
 221
 222         if (c < 0x80) {
 223             EMIT(c);
 224         } else if (c < 0xc0 || c >= 0xfe) {
 225             /* Invalid UTF-8 */
 226             return -1;
 227         } else if (c < 0xe0) {
 228             v = c & 0x1f;
 229             expect = 1;
 230             vmin = 0x80;
 231         } else if (c < 0xf0) {
 232             v = c & 0x0f;
 233             expect = 2;
 234             vmin = 0x800;
 235         } else if (c < 0xf8) {
 236             v = c & 0x07;
 237             expect = 3;
 238             vmin = 0x10000;
 239         } else if (c < 0xfc) {
 240             v = c & 0x03;
 241             expect = 4;
 242             vmin = 0x200000;
 243         } else {
 244             v = c & 0x01;
 245             expect = 5;
 246             vmin = 0x4000000;
 247         }
 248     }
 249
 250     return expect ? (size_t)-1 : outlen << 2;
 251
 252 #undef EMIT
 253 }
 254
 255 /*
 256  * Convert a string in UTF-8 format to UTF-32BE
 257  */
 258 static size_t utf8_to_32be(uint8_t *str, size_t len, char *op)
 259 {
 260 #define EMIT(x)                                         \
 261     do {                                                \
 262         uint32_t _y = (x);                              \
 263         if (op) {                                       \
 264             WRITECHAR(op,_y >> 24);                     \
 265             WRITECHAR(op,_y >> 16);                     \
 266             WRITECHAR(op,_y >> 8);                      \
 267             WRITECHAR(op,_y);                           \
 268         }                                               \
 269         outlen++;                                       \
 270     } while (0)
 271
 272     size_t outlen = 0;
 273     int expect = 0;
 274     uint8_t c;
 275     uint32_t v = 0, vmin = 0;
 276
 277     while (len--) {
 278         c = *str++;
 279
 280         if (expect) {
 281             if ((c & 0xc0) != 0x80) {
 282                 return -1;
 283             } else {
 284                 v = (v << 6) | (c & 0x3f);
 285                 if (!--expect) {
 286                     if (v < vmin || (v >= 0xd800 && v <= 0xdfff)) {
 287                         return -1;
 288                     } else {
 289                         EMIT(v);
 290                     }
 291                 }
 292                 continue;
 293             }
 294         }
 295
 296         if (c < 0x80) {
 297             EMIT(c);
 298         } else if (c < 0xc0 || c >= 0xfe) {
 299             /* Invalid UTF-8 */
 300             return -1;
 301         } else if (c < 0xe0) {
 302             v = c & 0x1f;
 303             expect = 1;
 304             vmin = 0x80;
 305         } else if (c < 0xf0) {
 306             v = c & 0x0f;
 307             expect = 2;
 308             vmin = 0x800;
 309         } else if (c < 0xf8) {
 310             v = c & 0x07;
 311             expect = 3;
 312             vmin = 0x10000;
 313         } else if (c < 0xfc) {
 314             v = c & 0x03;
 315             expect = 4;
 316             vmin = 0x200000;
 317         } else {
 318             v = c & 0x01;
 319             expect = 5;
 320             vmin = 0x4000000;
 321         }
 322     }
 323
 324     return expect ? (size_t)-1 : outlen << 2;
 325
 326 #undef EMIT
 327 }
 328
 329 typedef size_t (*transform_func)(uint8_t *, size_t, char *);
 330
 331 /*
 332  * Apply a specific string transform and return it in a nasm_malloc'd
 333  * buffer, returning the length.  On error, returns (size_t)-1 and no
 334  * buffer is allocated.
 335  */
 336 size_t string_transform(char *str, size_t len, char **out, enum strfunc func)
 337 {
 338     /* This should match enum strfunc in nasm.h */
 339     static const transform_func str_transforms[] = {
 340         utf8_to_16le,
 341         utf8_to_16le,
 342         utf8_to_16be,
 343         utf8_to_32le,
 344         utf8_to_32le,
 345         utf8_to_32be,
 346     };
 347     transform_func transform = str_transforms[func];
 348     size_t outlen;
 349     uint8_t *s = (uint8_t *)str;
 350     char *buf;
 351
 352     outlen = transform(s, len, NULL);
 353     if (outlen == (size_t)-1)
 354         return -1;
 355
 356     *out = buf = nasm_malloc(outlen+1);
 357     buf[outlen] = '\0'; /* Forcibly null-terminate the buffer */
 358     return transform(s, len, buf);
 359 }