src/system/libroot/posix/glibc/iconv/loop.c

   1 /* Conversion loop frame work.
   2    Copyright (C) 1998-2002, 2003 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      ONEBYTE_BODY       body of the specialized conversion function for a
  48                         single byte from the current character set to INTERNAL.
  49 */
  50
  51 #include <assert.h>
  52 #include <endian.h>
  53 #include <gconv.h>
  54 #include <stdint.h>
  55 #include <string.h>
  56 #include <wchar.h>
  57 #include <sys/param.h>          /* For MIN.  */
  58 #define __need_size_t
  59 #include <stddef.h>
  60
  61
  62 /* We have to provide support for machines which are not able to handled
  63    unaligned memory accesses.  Some of the character encodings have
  64    representations with a fixed width of 2 or 4 bytes.  But if we cannot
  65    access unaligned memory we still have to read byte-wise.  */
  66 #undef FCTNAME2
  67 #if defined _STRING_ARCH_unaligned || !defined DEFINE_UNALIGNED
  68 /* We can handle unaligned memory access.  */
  69 # define get16(addr) *((__const uint16_t *) (addr))
  70 # define get32(addr) *((__const uint32_t *) (addr))
  71
  72 /* We need no special support for writing values either.  */
  73 # define put16(addr, val) *((uint16_t *) (addr)) = (val)
  74 # define put32(addr, val) *((uint32_t *) (addr)) = (val)
  75
  76 # define FCTNAME2(name) name
  77 #else
  78 /* Distinguish between big endian and little endian.  */
  79 # if __BYTE_ORDER == __LITTLE_ENDIAN
  80 #  define get16(addr) \
  81      (((__const unsigned char *) (addr))[1] << 8                              \
  82       | ((__const unsigned char *) (addr))[0])
  83 #  define get32(addr) \
  84      (((((__const unsigned char *) (addr))[3] << 8                            \
  85         | ((__const unsigned char *) (addr))[2]) << 8                         \
  86        | ((__const unsigned char *) (addr))[1]) << 8                          \
  87       | ((__const unsigned char *) (addr))[0])
  88
  89 #  define put16(addr, val) \
  90      ({ uint16_t __val = (val);                                               \
  91         ((unsigned char *) (addr))[0] = __val;                                \
  92         ((unsigned char *) (addr))[1] = __val >> 8;                           \
  93         (void) 0; })
  94 #  define put32(addr, val) \
  95      ({ uint32_t __val = (val);                                               \
  96         ((unsigned char *) (addr))[0] = __val;                                \
  97         __val >>= 8;                                                          \
  98         ((unsigned char *) (addr))[1] = __val;                                \
  99         __val >>= 8;                                                          \
 100         ((unsigned char *) (addr))[2] = __val;                                \
 101         __val >>= 8;                                                          \
 102         ((unsigned char *) (addr))[3] = __val;                                \
 103         (void) 0; })
 104 # else
 105 #  define get16(addr) \
 106      (((__const unsigned char *) (addr))[0] << 8                              \
 107       | ((__const unsigned char *) (addr))[1])
 108 #  define get32(addr) \
 109      (((((__const unsigned char *) (addr))[0] << 8                            \
 110         | ((__const unsigned char *) (addr))[1]) << 8                         \
 111        | ((__const unsigned char *) (addr))[2]) << 8                          \
 112       | ((__const unsigned char *) (addr))[3])
 113
 114 #  define put16(addr, val) \
 115      ({ uint16_t __val = (val);                                               \
 116         ((unsigned char *) (addr))[1] = __val;                                \
 117         ((unsigned char *) (addr))[0] = __val >> 8;                           \
 118         (void) 0; })
 119 #  define put32(addr, val) \
 120      ({ uint32_t __val = (val);                                               \
 121         ((unsigned char *) (addr))[3] = __val;                                \
 122         __val >>= 8;                                                          \
 123         ((unsigned char *) (addr))[2] = __val;                                \
 124         __val >>= 8;                                                          \
 125         ((unsigned char *) (addr))[1] = __val;                                \
 126         __val >>= 8;                                                          \
 127         ((unsigned char *) (addr))[0] = __val;                                \
 128         (void) 0; })
 129 # endif
 130
 131 # define FCTNAME2(name) name##_unaligned
 132 #endif
 133 #define FCTNAME(name) FCTNAME2(name)
 134
 135
 136 /* We need at least one byte for the next round.  */
 137 #ifndef MIN_NEEDED_INPUT
 138 # error "MIN_NEEDED_INPUT definition missing"
 139 #elif MIN_NEEDED_INPUT < 1
 140 # error "MIN_NEEDED_INPUT must be >= 1"
 141 #endif
 142
 143 /* Let's see how many bytes we produce.  */
 144 #ifndef MAX_NEEDED_INPUT
 145 # define MAX_NEEDED_INPUT       MIN_NEEDED_INPUT
 146 #endif
 147
 148 /* We produce at least one byte in the next round.  */
 149 #ifndef MIN_NEEDED_OUTPUT
 150 # error "MIN_NEEDED_OUTPUT definition missing"
 151 #elif MIN_NEEDED_OUTPUT < 1
 152 # error "MIN_NEEDED_OUTPUT must be >= 1"
 153 #endif
 154
 155 /* Let's see how many bytes we produce.  */
 156 #ifndef MAX_NEEDED_OUTPUT
 157 # define MAX_NEEDED_OUTPUT      MIN_NEEDED_OUTPUT
 158 #endif
 159
 160 /* Default name for the function.  */
 161 #ifndef LOOPFCT
 162 # define LOOPFCT                loop
 163 #endif
 164
 165 /* Make sure we have a loop body.  */
 166 #ifndef BODY
 167 # error "Definition of BODY missing for function" LOOPFCT
 168 #endif
 169
 170
 171 /* If no arguments have to passed to the loop function define the macro
 172    as empty.  */
 173 #ifndef EXTRA_LOOP_DECLS
 174 # define EXTRA_LOOP_DECLS
 175 #endif
 176
 177
 178 /* To make it easier for the writers of the modules, we define a macro
 179    to test whether we have to ignore errors.  */
 180 #define ignore_errors_p() \
 181   (irreversible != NULL && (flags & __GCONV_IGNORE_ERRORS))
 182
 183
 184 /* Error handling for the FROM_LOOP direction, with ignoring of errors.
 185    Note that we cannot use the do while (0) trick since `break' and
 186    `continue' must reach certain points.  */
 187 #define STANDARD_FROM_LOOP_ERR_HANDLER(Incr) \
 188   {                                                                           \
 189     result = __GCONV_ILLEGAL_INPUT;                                           \
 190                                                                               \
 191     if (! ignore_errors_p ())                                                 \
 192       break;                                                                  \
 193                                                                               \
 194     /* We ignore the invalid input byte sequence.  */                         \
 195     inptr += (Incr);                                                          \
 196     ++*irreversible;                                                          \
 197     /* But we keep result == __GCONV_ILLEGAL_INPUT, because of the constraint \
 198        that "iconv -c" must give the same exitcode as "iconv".  */            \
 199     continue;                                                                 \
 200   }
 201
 202 /* Error handling for the TO_LOOP direction, with use of transliteration/
 203    transcription functions and ignoring of errors.  Note that we cannot use
 204    the do while (0) trick since `break' and `continue' must reach certain
 205    points.  */
 206 #define STANDARD_TO_LOOP_ERR_HANDLER(Incr) \
 207   {                                                                           \
 208     result = __GCONV_ILLEGAL_INPUT;                                           \
 209                                                                               \
 210     if (irreversible == NULL)                                                 \
 211       /* This means we are in call from __gconv_transliterate.  In this       \
 212          case we are not doing any error recovery outself.  */                \
 213       break;                                                                  \
 214                                                                               \
 215     /* See whether we have to ignore the error.  If not, stop.  */            \
 216     if (! ignore_errors_p ())                                                 \
 217       break;                                                                  \
 218                                                                               \
 219     /* When we come here it means we ignore the character.  */                \
 220     ++*irreversible;                                                          \
 221     inptr += Incr;                                                            \
 222     /* But we keep result == __GCONV_ILLEGAL_INPUT, because of the constraint \
 223        that "iconv -c" must give the same exitcode as "iconv".  */            \
 224     continue;                                                                 \
 225   }
 226
 227
 228 /* Handling of Unicode 3.1 TAG characters.  Unicode recommends
 229    "If language codes are not relevant to the particular processing
 230     operation, then they should be ignored."  This macro is usually
 231    called right before  STANDARD_TO_LOOP_ERR_HANDLER (Incr).  */
 232 #define UNICODE_TAG_HANDLER(Character, Incr) \
 233   {                                                                           \
 234     /* TAG characters are those in the range U+E0000..U+E007F.  */            \
 235     if (((Character) >> 7) == (0xe0000 >> 7))                                 \
 236       {                                                                       \
 237         inptr += Incr;                                                        \
 238         continue;                                                             \
 239       }                                                                       \
 240   }
 241
 242
 243 /* The function returns the status, as defined in gconv.h.  */
 244 static inline int
 245 FCTNAME (LOOPFCT) (struct __gconv_step *step,
 246                    struct __gconv_step_data *step_data,
 247                    const unsigned char **inptrp, const unsigned char *inend,
 248                    unsigned char **outptrp, const unsigned char *outend,
 249                    size_t *irreversible EXTRA_LOOP_DECLS)
 250 {
 251 #ifdef LOOP_NEED_STATE
 252   mbstate_t *state = step_data->__statep;
 253 #endif
 254 #ifdef LOOP_NEED_FLAGS
 255   int flags = step_data->__flags;
 256 #endif
 257 #ifdef LOOP_NEED_DATA
 258   void *data = step->__data;
 259 #endif
 260   int result = __GCONV_EMPTY_INPUT;
 261   const unsigned char *inptr = *inptrp;
 262   unsigned char *outptr = *outptrp;
 263
 264 #ifdef INIT_PARAMS
 265   INIT_PARAMS;
 266 #endif
 267
 268   while (inptr != inend)
 269     {
 270       /* `if' cases for MIN_NEEDED_OUTPUT ==/!= 1 is made to help the
 271          compiler generating better code.  They will be optimized away
 272          since MIN_NEEDED_OUTPUT is always a constant.  */
 273       if (MIN_NEEDED_INPUT > 1
 274           && __builtin_expect (inptr + MIN_NEEDED_INPUT > inend, 0))
 275         {
 276           /* We don't have enough input for another complete input
 277              character.  */
 278           result = __GCONV_INCOMPLETE_INPUT;
 279           break;
 280         }
 281       if ((MIN_NEEDED_OUTPUT != 1
 282            && __builtin_expect (outptr + MIN_NEEDED_OUTPUT > outend, 0))
 283           || (MIN_NEEDED_OUTPUT == 1
 284               && __builtin_expect (outptr >= outend, 0)))
 285         {
 286           /* Overflow in the output buffer.  */
 287           result = __GCONV_FULL_OUTPUT;
 288           break;
 289         }
 290
 291       /* Here comes the body the user provides.  It can stop with
 292          RESULT set to GCONV_INCOMPLETE_INPUT (if the size of the
 293          input characters vary in size), GCONV_ILLEGAL_INPUT, or
 294          GCONV_FULL_OUTPUT (if the output characters vary in size).  */
 295       BODY
 296     }
 297
 298   /* Update the pointers pointed to by the parameters.  */
 299   *inptrp = inptr;
 300   *outptrp = outptr;
 301 #ifdef UPDATE_PARAMS
 302   UPDATE_PARAMS;
 303 #endif
 304
 305   return result;
 306 }
 307
 308
 309 /* Include the file a second time to define the function to handle
 310    unaligned access.  */
 311 #if !defined DEFINE_UNALIGNED && !defined _STRING_ARCH_unaligned \
 312     && MIN_NEEDED_INPUT != 1 && MAX_NEEDED_INPUT % MIN_NEEDED_INPUT == 0 \
 313     && MIN_NEEDED_OUTPUT != 1 && MAX_NEEDED_OUTPUT % MIN_NEEDED_OUTPUT == 0
 314 # undef get16
 315 # undef get32
 316 # undef put16
 317 # undef put32
 318 # undef unaligned
 319
 320 # define DEFINE_UNALIGNED
 321 # include "loop.c"
 322 # undef DEFINE_UNALIGNED
 323 #endif
 324
 325
 326 #if MAX_NEEDED_INPUT > 1
 327 # define SINGLE(fct) SINGLE2 (fct)
 328 # define SINGLE2(fct) fct##_single
 329 static inline int
 330 SINGLE(LOOPFCT) (struct __gconv_step *step,
 331                  struct __gconv_step_data *step_data,
 332                  const unsigned char **inptrp, const unsigned char *inend,
 333                  unsigned char **outptrp, unsigned char *outend,
 334                  size_t *irreversible EXTRA_LOOP_DECLS)
 335 {
 336   mbstate_t *state = step_data->__statep;
 337 #ifdef LOOP_NEED_FLAGS
 338   int flags = step_data->__flags;
 339 #endif
 340 #ifdef LOOP_NEED_DATA
 341   void *data = step->__data;
 342 #endif
 343   int result = __GCONV_OK;
 344   unsigned char bytebuf[MAX_NEEDED_INPUT];
 345   const unsigned char *inptr = *inptrp;
 346   unsigned char *outptr = *outptrp;
 347   size_t inlen;
 348
 349 #ifdef INIT_PARAMS
 350   INIT_PARAMS;
 351 #endif
 352
 353 #ifdef UNPACK_BYTES
 354   UNPACK_BYTES
 355 #else
 356   /* Add the bytes from the state to the input buffer.  */
 357   for (inlen = 0; inlen < (size_t) (state->__count & 7); ++inlen)
 358     bytebuf[inlen] = state->__value.__wchb[inlen];
 359 #endif
 360
 361   /* Are there enough bytes in the input buffer?  */
 362   if (__builtin_expect (inptr + (MIN_NEEDED_INPUT - inlen) > inend, 0))
 363     {
 364       *inptrp = inend;
 365 #ifdef STORE_REST
 366       inptr = bytebuf;
 367       inptrp = &inptr;
 368       inend = &bytebuf[inlen];
 369
 370       STORE_REST
 371 #else
 372       /* We don't have enough input for another complete input
 373          character.  */
 374       while (inptr < inend)
 375         state->__value.__wchb[inlen++] = *inptr++;
 376 #endif
 377
 378       return __GCONV_INCOMPLETE_INPUT;
 379     }
 380
 381   /* Enough space in output buffer.  */
 382   if ((MIN_NEEDED_OUTPUT != 1 && outptr + MIN_NEEDED_OUTPUT > outend)
 383       || (MIN_NEEDED_OUTPUT == 1 && outptr >= outend))
 384     /* Overflow in the output buffer.  */
 385     return __GCONV_FULL_OUTPUT;
 386
 387   /*  Now add characters from the normal input buffer.  */
 388   do
 389     bytebuf[inlen++] = *inptr++;
 390   while (inlen < MAX_NEEDED_INPUT && inptr < inend);
 391
 392   inptr = bytebuf;
 393   inend = &bytebuf[inlen];
 394
 395   do
 396     {
 397       BODY
 398     }
 399   while (0);
 400
 401   /* Now we either have produced an output character and consumed all the
 402      bytes from the state and at least one more, or the character is still
 403      incomplete, or we have some other error (like illegal input character,
 404      no space in output buffer).  */
 405   if (__builtin_expect (inptr != bytebuf, 1))
 406     {
 407       /* We found a new character.  */
 408       assert (inptr - bytebuf > (state->__count & 7));
 409
 410       *inptrp += inptr - bytebuf - (state->__count & 7);
 411       *outptrp = outptr;
 412
 413       result = __GCONV_OK;
 414
 415       /* Clear the state buffer.  */
 416 #ifdef CLEAR_STATE
 417       CLEAR_STATE;
 418 #else
 419       state->__count &= ~7;
 420 #endif
 421     }
 422   else if (result == __GCONV_INCOMPLETE_INPUT)
 423     {
 424       /* This can only happen if we have less than MAX_NEEDED_INPUT bytes
 425          available.  */
 426       assert (inend != &bytebuf[MAX_NEEDED_INPUT]);
 427
 428       *inptrp += inend - bytebuf - (state->__count & 7);
 429 #ifdef STORE_REST
 430       inptrp = &inptr;
 431
 432       STORE_REST
 433 #else
 434       /* We don't have enough input for another complete input
 435          character.  */
 436       while (inptr < inend)
 437         state->__value.__wchb[inlen++] = *inptr++;
 438 #endif
 439     }
 440
 441   return result;
 442 }
 443 # undef SINGLE
 444 # undef SINGLE2
 445 #endif
 446
 447
 448 #ifdef ONEBYTE_BODY
 449 /* Define the shortcut function for btowc.  */
 450 static wint_t
 451 gconv_btowc (struct __gconv_step *step, unsigned char c)
 452   ONEBYTE_BODY
 453 # define FROM_ONEBYTE gconv_btowc
 454 #endif
 455
 456
 457 /* We remove the macro definitions so that we can include this file again
 458    for the definition of another function.  */
 459 #undef MIN_NEEDED_INPUT
 460 #undef MAX_NEEDED_INPUT
 461 #undef MIN_NEEDED_OUTPUT
 462 #undef MAX_NEEDED_OUTPUT
 463 #undef LOOPFCT
 464 #undef BODY
 465 #undef LOOPFCT
 466 #undef EXTRA_LOOP_DECLS
 467 #undef INIT_PARAMS
 468 #undef UPDATE_PARAMS
 469 #undef ONEBYTE_BODY
 470 #undef UNPACK_BYTES
 471 #undef CLEAR_STATE
 472 #undef LOOP_NEED_STATE
 473 #undef LOOP_NEED_FLAGS
 474 #undef LOOP_NEED_DATA
 475 #undef get16
 476 #undef get32
 477 #undef put16
 478 #undef put32
 479 #undef unaligned