iconv/loop.c

   1 /* Conversion loop frame work.
   2    Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 /* This file provides a frame for the reader loop in all conversion modules.
  22    The actual code must (of course) be provided in the actual module source
  23    code but certain actions can be written down generically, with some
  24    customization options which are these:
  25
  26      MIN_NEEDED_INPUT   minimal number of input bytes needed for the next
  27                         conversion.
  28      MIN_NEEDED_OUTPUT  minimal number of bytes produced by the next round
  29                         of conversion.
  30
  31      MAX_NEEDED_INPUT   you guess it, this is the maximal number of input
  32                         bytes needed.  It defaults to MIN_NEEDED_INPUT
  33      MAX_NEEDED_OUTPUT  likewise for output bytes.
  34
  35      LOOPFCT            name of the function created.  If not specified
  36                         the name is `loop' but this prevents the use
  37                         of multiple functions in the same file.
  38
  39      BODY               this is supposed to expand to the body of the loop.
  40                         The user must provide this.
  41
  42      EXTRA_LOOP_DECLS   extra arguments passed from converion loop call.
  43
  44      INIT_PARAMS        code to define and initialize variables from params.
  45      UPDATE_PARAMS      code to store result in params.
  46 */
  47
  48 #include <assert.h>
  49 #include <endian.h>
  50 #include <gconv.h>
  51 #include <stdint.h>
  52 #include <string.h>
  53 #include <wchar.h>
  54 #include <sys/param.h>          /* For MIN.  */
  55 #define __need_size_t
  56 #include <stddef.h>
  57
  58
  59 /* We have to provide support for machines which are not able to handled
  60    unaligned memory accesses.  Some of the character encodings have
  61    representations with a fixed width of 2 or 4 bytes.  But if we cannot
  62    access unaligned memory we still have to read byte-wise.  */
  63 #undef FCTNAME2
  64 #if defined _STRING_ARCH_unaligned || !defined DEFINE_UNALIGNED
  65 /* We can handle unaligned memory access.  */
  66 # define get16(addr) *((__const uint16_t *) (addr))
  67 # define get32(addr) *((__const uint32_t *) (addr))
  68
  69 /* We need no special support for writing values either.  */
  70 # define put16(addr, val) *((uint16_t *) (addr)) = (val)
  71 # define put32(addr, val) *((uint32_t *) (addr)) = (val)
  72
  73 # define FCTNAME2(name) name
  74 #else
  75 /* Distinguish between big endian and little endian.  */
  76 # if __BYTE_ORDER == __LITTLE_ENDIAN
  77 #  define get16(addr) \
  78      (((__const unsigned char *) (addr))[1] << 8                              \
  79       | ((__const unsigned char *) (addr))[0])
  80 #  define get32(addr) \
  81      (((((__const unsigned char *) (addr))[3] << 8                            \
  82         | ((__const unsigned char *) (addr))[2]) << 8                         \
  83        | ((__const unsigned char *) (addr))[1]) << 8                          \
  84       | ((__const unsigned char *) (addr))[0])
  85
  86 #  define put16(addr, val) \
  87      ({ uint16_t __val = (val);                                               \
  88         ((unsigned char *) (addr))[0] = __val;                                \
  89         ((unsigned char *) (addr))[1] = __val >> 8;                           \
  90         (void) 0; })
  91 #  define put32(addr, val) \
  92      ({ uint32_t __val = (val);                                               \
  93         ((unsigned char *) (addr))[0] = __val;                                \
  94         __val >>= 8;                                                          \
  95         ((unsigned char *) (addr))[1] = __val;                                \
  96         __val >>= 8;                                                          \
  97         ((unsigned char *) (addr))[2] = __val;                                \
  98         __val >>= 8;                                                          \
  99         ((unsigned char *) (addr))[3] = __val;                                \
 100         (void) 0; })
 101 # else
 102 #  define get16(addr) \
 103      (((__const unsigned char *) (addr))[0] << 8                              \
 104       | ((__const unsigned char *) (addr))[1])
 105 #  define get32(addr) \
 106      (((((__const unsigned char *) (addr))[0] << 8                            \
 107         | ((__const unsigned char *) (addr))[1]) << 8                         \
 108        | ((__const unsigned char *) (addr))[2]) << 8                          \
 109       | ((__const unsigned char *) (addr))[3])
 110
 111 #  define put16(addr, val) \
 112      ({ uint16_t __val = (val);                                               \
 113         ((unsigned char *) (addr))[1] = __val;                                \
 114         ((unsigned char *) (addr))[0] = __val >> 8;                           \
 115         (void) 0; })
 116 #  define put32(addr, val) \
 117      ({ uint32_t __val = (val);                                               \
 118         ((unsigned char *) (addr))[3] = __val;                                \
 119         __val >>= 8;                                                          \
 120         ((unsigned char *) (addr))[2] = __val;                                \
 121         __val >>= 8;                                                          \
 122         ((unsigned char *) (addr))[1] = __val;                                \
 123         __val >>= 8;                                                          \
 124         ((unsigned char *) (addr))[0] = __val;                                \
 125         (void) 0; })
 126 # endif
 127
 128 # define FCTNAME2(name) name##_unaligned
 129 #endif
 130 #define FCTNAME(name) FCTNAME2(name)
 131
 132
 133 /* We need at least one byte for the next round.  */
 134 #ifndef MIN_NEEDED_INPUT
 135 # error "MIN_NEEDED_INPUT definition missing"
 136 #elif MIN_NEEDED_INPUT < 1
 137 # error "MIN_NEEDED_INPUT must be >= 1"
 138 #endif
 139
 140 /* Let's see how many bytes we produce.  */
 141 #ifndef MAX_NEEDED_INPUT
 142 # define MAX_NEEDED_INPUT       MIN_NEEDED_INPUT
 143 #endif
 144
 145 /* We produce at least one byte in the next round.  */
 146 #ifndef MIN_NEEDED_OUTPUT
 147 # error "MIN_NEEDED_OUTPUT definition missing"
 148 #elif MIN_NEEDED_OUTPUT < 1
 149 # error "MIN_NEEDED_OUTPUT must be >= 1"
 150 #endif
 151
 152 /* Let's see how many bytes we produce.  */
 153 #ifndef MAX_NEEDED_OUTPUT
 154 # define MAX_NEEDED_OUTPUT      MIN_NEEDED_OUTPUT
 155 #endif
 156
 157 /* Default name for the function.  */
 158 #ifndef LOOPFCT
 159 # define LOOPFCT                loop
 160 #endif
 161
 162 /* Make sure we have a loop body.  */
 163 #ifndef BODY
 164 # error "Definition of BODY missing for function" LOOPFCT
 165 #endif
 166
 167
 168 /* If no arguments have to passed to the loop function define the macro
 169    as empty.  */
 170 #ifndef EXTRA_LOOP_DECLS
 171 # define EXTRA_LOOP_DECLS
 172 #endif
 173
 174
 175 /* To make it easier for the writers of the modules, we define a macro
 176    to test whether we have to ignore errors.  */
 177 #define ignore_errors_p() \
 178   (irreversible != NULL && (flags & __GCONV_IGNORE_ERRORS))
 179
 180
 181 /* Error handling for the FROM_LOOP direction, with ignoring of errors.
 182    Note that we cannot use the do while (0) trick since `break' and
 183    `continue' must reach certain points.  */
 184 #define STANDARD_FROM_LOOP_ERR_HANDLER(Incr) \
 185   {                                                                           \
 186     result = __GCONV_ILLEGAL_INPUT;                                           \
 187                                                                               \
 188     if (! ignore_errors_p ())                                                 \
 189       break;                                                                  \
 190                                                                               \
 191     /* We ignore the invalid input byte sequence.  */                         \
 192     inptr += (Incr);                                                          \
 193     ++*irreversible;                                                          \
 194     /* But we keep result == __GCONV_ILLEGAL_INPUT, because of the constraint \
 195        that "iconv -c" must give the same exitcode as "iconv".  */            \
 196     continue;                                                                 \
 197   }
 198
 199 /* Error handling for the TO_LOOP direction, with use of transliteration/
 200    transcription functions and ignoring of errors.  Note that we cannot use
 201    the do while (0) trick since `break' and `continue' must reach certain
 202    points.  */
 203 #define STANDARD_TO_LOOP_ERR_HANDLER(Incr) \
 204   {                                                                           \
 205     struct __gconv_trans_data *trans;                                         \
 206                                                                               \
 207     result = __GCONV_ILLEGAL_INPUT;                                           \
 208                                                                               \
 209     if (irreversible == NULL)                                                 \
 210       /* This means we are in call from __gconv_transliterate.  In this       \
 211          case we are not doing any error recovery outself.  */                \
 212       break;                                                                  \
 213                                                                               \
 214     /* First try the transliteration methods.  */                             \
 215     for (trans = step_data->__trans; trans != NULL; trans = trans->__next)    \
 216       {                                                                       \
 217         result = DL_CALL_FCT (trans->__trans_fct,                             \
 218                               (step, step_data, trans->__data, *inptrp,       \
 219                                &inptr, inend, &outptr, irreversible));        \
 220         if (result != __GCONV_ILLEGAL_INPUT)                                  \
 221           break;                                                              \
 222       }                                                                       \
 223     /* If any of them recognized the input continue with the loop.  */        \
 224     if (result != __GCONV_ILLEGAL_INPUT)                                      \
 225       continue;                                                               \
 226                                                                               \
 227     /* Next see whether we have to ignore the error.  If not, stop.  */       \
 228     if (! ignore_errors_p ())                                                 \
 229       break;                                                                  \
 230                                                                               \
 231     /* When we come here it means we ignore the character.  */                \
 232     ++*irreversible;                                                          \
 233     inptr += Incr;                                                            \
 234     /* But we keep result == __GCONV_ILLEGAL_INPUT, because of the constraint \
 235        that "iconv -c" must give the same exitcode as "iconv".  */            \
 236     continue;                                                                 \
 237   }
 238
 239
 240 /* Handling of Unicode 3.1 TAG characters.  Unicode recommends
 241    "If language codes are not relevant to the particular processing
 242     operation, then they should be ignored."  This macro is usually
 243    called right before  STANDARD_TO_LOOP_ERR_HANDLER (Incr).  */
 244 #define UNICODE_TAG_HANDLER(Character, Incr) \
 245   {                                                                           \
 246     /* TAG characters are those in the range U+E0000..U+E007F.  */            \
 247     if (((Character) >> 7) == (0xe0000 >> 7))                                 \
 248       {                                                                       \
 249         inptr += Incr;                                                        \
 250         continue;                                                             \
 251       }                                                                       \
 252   }
 253
 254
 255 /* The function returns the status, as defined in gconv.h.  */
 256 static inline int
 257 FCTNAME (LOOPFCT) (struct __gconv_step *step,
 258                    struct __gconv_step_data *step_data,
 259                    const unsigned char **inptrp, const unsigned char *inend,
 260                    unsigned char **outptrp, const unsigned char *outend,
 261                    size_t *irreversible EXTRA_LOOP_DECLS)
 262 {
 263 #ifdef LOOP_NEED_STATE
 264   mbstate_t *state = step_data->__statep;
 265 #endif
 266 #ifdef LOOP_NEED_FLAGS
 267   int flags = step_data->__flags;
 268 #endif
 269 #ifdef LOOP_NEED_DATA
 270   void *data = step->__data;
 271 #endif
 272   int result = __GCONV_EMPTY_INPUT;
 273   const unsigned char *inptr = *inptrp;
 274   unsigned char *outptr = *outptrp;
 275
 276 #ifdef INIT_PARAMS
 277   INIT_PARAMS;
 278 #endif
 279
 280   while (inptr != inend)
 281     {
 282       /* `if' cases for MIN_NEEDED_OUTPUT ==/!= 1 is made to help the
 283          compiler generating better code.  They will be optimized away
 284          since MIN_NEEDED_OUTPUT is always a constant.  */
 285       if ((MIN_NEEDED_OUTPUT != 1
 286            && __builtin_expect (outptr + MIN_NEEDED_OUTPUT > outend, 0))
 287           || (MIN_NEEDED_OUTPUT == 1
 288               && __builtin_expect (outptr >= outend, 0)))
 289         {
 290           /* Overflow in the output buffer.  */
 291           result = __GCONV_FULL_OUTPUT;
 292           break;
 293         }
 294       if (MIN_NEEDED_INPUT > 1
 295           && __builtin_expect (inptr + MIN_NEEDED_INPUT > inend, 0))
 296         {
 297           /* We don't have enough input for another complete input
 298              character.  */
 299           result = __GCONV_INCOMPLETE_INPUT;
 300           break;
 301         }
 302
 303       /* Here comes the body the user provides.  It can stop with
 304          RESULT set to GCONV_INCOMPLETE_INPUT (if the size of the
 305          input characters vary in size), GCONV_ILLEGAL_INPUT, or
 306          GCONV_FULL_OUTPUT (if the output characters vary in size).  */
 307       BODY
 308     }
 309
 310   /* Update the pointers pointed to by the parameters.  */
 311   *inptrp = inptr;
 312   *outptrp = outptr;
 313 #ifdef UPDATE_PARAMS
 314   UPDATE_PARAMS;
 315 #endif
 316
 317   return result;
 318 }
 319
 320
 321 /* Include the file a second time to define the function to handle
 322    unaligned access.  */
 323 #if !defined DEFINE_UNALIGNED && !defined _STRING_ARCH_unaligned \
 324     && MIN_NEEDED_INPUT != 1 && MAX_NEEDED_INPUT % MIN_NEEDED_INPUT == 0 \
 325     && MIN_NEEDED_OUTPUT != 1 && MAX_NEEDED_OUTPUT % MIN_NEEDED_OUTPUT == 0
 326 # undef get16
 327 # undef get32
 328 # undef put16
 329 # undef put32
 330 # undef unaligned
 331
 332 # define DEFINE_UNALIGNED
 333 # include "loop.c"
 334 # undef DEFINE_UNALIGNED
 335 #endif
 336
 337
 338 #if MAX_NEEDED_INPUT > 1
 339 # define SINGLE(fct) SINGLE2 (fct)
 340 # define SINGLE2(fct) fct##_single
 341 static inline int
 342 SINGLE(LOOPFCT) (struct __gconv_step *step,
 343                  struct __gconv_step_data *step_data,
 344                  const unsigned char **inptrp, const unsigned char *inend,
 345                  unsigned char **outptrp, unsigned char *outend,
 346                  size_t *irreversible EXTRA_LOOP_DECLS)
 347 {
 348   mbstate_t *state = step_data->__statep;
 349 #ifdef LOOP_NEED_FLAGS
 350   int flags = step_data->__flags;
 351 #endif
 352 #ifdef LOOP_NEED_DATA
 353   void *data = step->__data;
 354 #endif
 355   int result = __GCONV_OK;
 356   unsigned char bytebuf[MAX_NEEDED_INPUT];
 357   const unsigned char *inptr = *inptrp;
 358   unsigned char *outptr = *outptrp;
 359   size_t inlen;
 360
 361 #ifdef INIT_PARAMS
 362   INIT_PARAMS;
 363 #endif
 364
 365 #ifdef UNPACK_BYTES
 366   UNPACK_BYTES
 367 #else
 368   /* Add the bytes from the state to the input buffer.  */
 369   for (inlen = 0; inlen < (size_t) (state->__count & 7); ++inlen)
 370     bytebuf[inlen] = state->__value.__wchb[inlen];
 371 #endif
 372
 373   /* Are there enough bytes in the input buffer?  */
 374   if (__builtin_expect (inptr + (MIN_NEEDED_INPUT - inlen) > inend, 0))
 375     {
 376       *inptrp = inend;
 377 #ifdef STORE_REST
 378       inptr = bytebuf;
 379       inptrp = &inptr;
 380       inend = &bytebuf[inlen];
 381
 382       STORE_REST
 383 #else
 384       /* We don't have enough input for another complete input
 385          character.  */
 386       while (inptr < inend)
 387         state->__value.__wchb[inlen++] = *inptr++;
 388 #endif
 389
 390       return __GCONV_INCOMPLETE_INPUT;
 391     }
 392
 393   /* Enough space in output buffer.  */
 394   if ((MIN_NEEDED_OUTPUT != 1 && outptr + MIN_NEEDED_OUTPUT > outend)
 395       || (MIN_NEEDED_OUTPUT == 1 && outptr >= outend))
 396     /* Overflow in the output buffer.  */
 397     return __GCONV_FULL_OUTPUT;
 398
 399   /*  Now add characters from the normal input buffer.  */
 400   do
 401     bytebuf[inlen++] = *inptr++;
 402   while (inlen < MAX_NEEDED_INPUT && inptr < inend);
 403
 404   inptr = bytebuf;
 405   inend = &bytebuf[inlen];
 406
 407   do
 408     {
 409       BODY
 410     }
 411   while (0);
 412
 413   /* Now we either have produced an output character and consumed all the
 414      bytes from the state and at least one more, or the character is still
 415      incomplete, or we have some other error (like illegal input character,
 416      no space in output buffer).  */
 417   if (__builtin_expect (inptr != bytebuf, 1))
 418     {
 419       /* We found a new character.  */
 420       assert (inptr - bytebuf > (state->__count & 7));
 421
 422       *inptrp += inptr - bytebuf - (state->__count & 7);
 423       *outptrp = outptr;
 424
 425       result = __GCONV_OK;
 426
 427       /* Clear the state buffer.  */
 428       state->__count &= ~7;
 429     }
 430   else if (result == __GCONV_INCOMPLETE_INPUT)
 431     {
 432       /* This can only happen if we have less than MAX_NEEDED_INPUT bytes
 433          available.  */
 434       assert (inend != &bytebuf[MAX_NEEDED_INPUT]);
 435
 436       *inptrp += inend - bytebuf - (state->__count & 7);
 437 #ifdef STORE_REST
 438       inptrp = &inptr;
 439
 440       STORE_REST
 441 #else
 442       /* We don't have enough input for another complete input
 443          character.  */
 444       while (inptr < inend)
 445         state->__value.__wchb[inlen++] = *inptr++;
 446 #endif
 447     }
 448
 449   return result;
 450 }
 451 # undef SINGLE
 452 # undef SINGLE2
 453 #endif
 454
 455
 456 /* We remove the macro definitions so that we can include this file again
 457    for the definition of another function.  */
 458 #undef MIN_NEEDED_INPUT
 459 #undef MAX_NEEDED_INPUT
 460 #undef MIN_NEEDED_OUTPUT
 461 #undef MAX_NEEDED_OUTPUT
 462 #undef LOOPFCT
 463 #undef BODY
 464 #undef LOOPFCT
 465 #undef EXTRA_LOOP_DECLS
 466 #undef INIT_PARAMS
 467 #undef UPDATE_PARAMS
 468 #undef UNPACK_BYTES
 469 #undef LOOP_NEED_STATE
 470 #undef LOOP_NEED_FLAGS
 471 #undef LOOP_NEED_DATA
 472 #undef get16
 473 #undef get32
 474 #undef put16
 475 #undef put32
 476 #undef unaligned