iconv/skeleton.c

   1 /* Skeleton for a conversion module.
   2    Copyright (C) 1998, 1999, 2000 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 Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    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    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 /* This file can be included to provide definitions of several things
  22    many modules have in common.  It can be customized using the following
  23    macros:
  24
  25      DEFINE_INIT        define the default initializer.  This requires the
  26                         following symbol to be defined.
  27
  28      CHARSET_NAME       string with official name of the coded character
  29                         set (in all-caps)
  30
  31      DEFINE_FINI        define the default destructor function.
  32
  33      MIN_NEEDED_FROM    minimal number of bytes needed for the from-charset.
  34      MIN_NEEDED_TO      likewise for the to-charset.
  35
  36      MAX_NEEDED_FROM    maximal number of bytes needed for the from-charset.
  37                         This macro is optional, it defaults to MIN_NEEDED_FROM.
  38      MAX_NEEDED_TO      likewise for the to-charset.
  39
  40      DEFINE_DIRECTION_OBJECTS
  41                         two objects will be defined to be used when the
  42                         `gconv' function must only distinguish two
  43                         directions.  This is implied by DEFINE_INIT.
  44                         If this macro is not defined the following
  45                         macro must be available.
  46
  47      FROM_DIRECTION     this macro is supposed to return a value != 0
  48                         if we convert from the current character set,
  49                         otherwise it return 0.
  50
  51      EMIT_SHIFT_TO_INIT this symbol is optional.  If it is defined it
  52                         defines some code which writes out a sequence
  53                         of characters which bring the current state into
  54                         the initial state.
  55
  56      FROM_LOOP          name of the function implementing the conversion
  57                         from the current characters.
  58      TO_LOOP            likewise for the other direction
  59
  60      RESET_STATE        in case of an error we must reset the state for
  61                         the rerun so this macro must be defined for
  62                         stateful encodings.  It takes an argument which
  63                         is nonzero when saving.
  64
  65      RESET_INPUT_BUFFER If the input character sets allow this the macro
  66                         can be defined to reset the input buffer pointers
  67                         to cover only those characters up to the error.
  68
  69      FUNCTION_NAME      if not set the conversion function is named `gconv'.
  70
  71      PREPARE_LOOP       optional code preparing the conversion loop.  Can
  72                         contain variable definitions.
  73      END_LOOP           also optional, may be used to store information
  74
  75      EXTRA_LOOP_ARGS    optional macro specifying extra arguments passed
  76                         to loop function.
  77  */
  78
  79 #include <assert.h>
  80 #include <gconv.h>
  81 #include <string.h>
  82 #define __need_size_t
  83 #define __need_NULL
  84 #include <stddef.h>
  85
  86 #ifndef STATIC_GCONV
  87 # include <dlfcn.h>
  88 #endif
  89
  90 #ifndef DL_CALL_FCT
  91 # define DL_CALL_FCT(fct, args) fct args
  92 #endif
  93
  94 /* The direction objects.  */
  95 #if DEFINE_DIRECTION_OBJECTS || DEFINE_INIT
  96 static int from_object;
  97 static int to_object;
  98
  99 # ifndef FROM_DIRECTION
 100 #  define FROM_DIRECTION (step->__data == &from_object)
 101 # endif
 102 #else
 103 # ifndef FROM_DIRECTION
 104 #  error "FROM_DIRECTION must be provided if direction objects are not used"
 105 # endif
 106 #endif
 107
 108
 109 /* How many bytes are needed at most for the from-charset.  */
 110 #ifndef MAX_NEEDED_FROM
 111 # define MAX_NEEDED_FROM        MIN_NEEDED_FROM
 112 #endif
 113
 114 /* Same for the to-charset.  */
 115 #ifndef MAX_NEEDED_TO
 116 # define MAX_NEEDED_TO          MIN_NEEDED_TO
 117 #endif
 118
 119
 120 /* Define macros which can access unaligned buffers.  These macros are
 121    supposed to be used only in code outside the inner loops.  For the inner
 122    loops we have other definitions which allow optimized access.  */
 123 #ifdef _STRING_ARCH_unaligned
 124 /* We can handle unaligned memory access.  */
 125 # define get16u(addr) *((uint16_t *) (addr))
 126 # define get32u(addr) *((uint32_t *) (addr))
 127
 128 /* We need no special support for writing values either.  */
 129 # define put16u(addr, val) *((uint16_t *) (addr)) = (val)
 130 # define put32u(addr, val) *((uint32_t *) (addr)) = (val)
 131 #else
 132 /* Distinguish between big endian and little endian.  */
 133 # if __BYTE_ORDER == __LITTLE_ENDIAN
 134 #  define get16u(addr) \
 135      (((__const unsigned char *) (addr))[1] << 8                              \
 136       | ((__const unsigned char *) (addr))[0])
 137 #  define get32u(addr) \
 138      (((((__const unsigned char *) (addr))[3] << 8                            \
 139         | ((__const unsigned char *) (addr))[2]) << 8                         \
 140        | ((__const unsigned char *) (addr))[1]) << 8                          \
 141       | ((__const unsigned char *) (addr))[0])
 142
 143 #  define put16u(addr, val) \
 144      ({ uint16_t __val = (val);                                               \
 145         ((unsigned char *) (addr))[0] = __val;                                \
 146         ((unsigned char *) (addr))[1] = __val >> 8;                           \
 147         (void) 0; })
 148 #  define put32u(addr, val) \
 149      ({ uint32_t __val = (val);                                               \
 150         ((unsigned char *) (addr))[0] = __val;                                \
 151         __val >>= 8;                                                          \
 152         ((unsigned char *) (addr))[1] = __val;                                \
 153         __val >>= 8;                                                          \
 154         ((unsigned char *) (addr))[2] = __val;                                \
 155         __val >>= 8;                                                          \
 156         ((unsigned char *) (addr))[3] = __val;                                \
 157         (void) 0; })
 158 # else
 159 #  define get16u(addr) \
 160      (((__const unsigned char *) (addr))[0] << 8                              \
 161       | ((__const unsigned char *) (addr))[1])
 162 #  define get32u(addr) \
 163      (((((__const unsigned char *) (addr))[0] << 8                            \
 164         | ((__const unsigned char *) (addr))[1]) << 8                         \
 165        | ((__const unsigned char *) (addr))[2]) << 8                          \
 166       | ((__const unsigned char *) (addr))[3])
 167
 168 #  define put16u(addr, val) \
 169      ({ uint16_t __val = (val);                                               \
 170         ((unsigned char *) (addr))[1] = __val;                                \
 171         ((unsigned char *) (addr))[0] = __val >> 8;                           \
 172         (void) 0; })
 173 #  define put32u(addr, val) \
 174      ({ uint32_t __val = (val);                                               \
 175         ((unsigned char *) (addr))[3] = __val;                                \
 176         __val >>= 8;                                                          \
 177         ((unsigned char *) (addr))[2] = __val;                                \
 178         __val >>= 8;                                                          \
 179         ((unsigned char *) (addr))[1] = __val;                                \
 180         __val >>= 8;                                                          \
 181         ((unsigned char *) (addr))[0] = __val;                                \
 182         (void) 0; })
 183 # endif
 184 #endif
 185
 186
 187 /* For conversions from a fixed width character sets to another fixed width
 188    character set we we can define RESET_INPUT_BUFFER is necessary.  */
 189 #if !defined RESET_INPUT_BUFFER && !defined SAVE_RESET_STATE
 190 # if MIN_NEEDED_FROM == MAX_NEEDED_FROM && MIN_NEEDED_TO == MAX_NEEDED_TO
 191 /* We have to use these `if's here since the compiler cannot know that
 192    (outbuf - outerr) is always divisible by MIN_NEEDED_TO.  */
 193 #  define RESET_INPUT_BUFFER \
 194   if (MIN_NEEDED_FROM % MIN_NEEDED_TO == 0)                                   \
 195     *inptrp -= (outbuf - outerr) * (MIN_NEEDED_FROM / MIN_NEEDED_TO);         \
 196   else if (MIN_NEEDED_TO % MIN_NEEDED_FROM == 0)                              \
 197     *inptrp -= (outbuf - outerr) / (MIN_NEEDED_TO / MIN_NEEDED_FROM);         \
 198   else                                                                        \
 199     *inptrp -= ((outbuf - outerr) / MIN_NEEDED_TO) * MIN_NEEDED_FROM
 200 # endif
 201 #endif
 202
 203
 204 /* The default init function.  It simply matches the name and initializes
 205    the step data to point to one of the objects above.  */
 206 #if DEFINE_INIT
 207 # ifndef CHARSET_NAME
 208 #  error "CHARSET_NAME not defined"
 209 # endif
 210
 211 int
 212 gconv_init (struct __gconv_step *step)
 213 {
 214   /* Determine which direction.  */
 215   if (strcmp (step->__from_name, CHARSET_NAME) == 0)
 216     {
 217       step->__data = &from_object;
 218
 219       step->__min_needed_from = MIN_NEEDED_FROM;
 220       step->__max_needed_from = MAX_NEEDED_FROM;
 221       step->__min_needed_to = MIN_NEEDED_TO;
 222       step->__max_needed_to = MAX_NEEDED_TO;
 223     }
 224   else if (__builtin_expect (strcmp (step->__to_name, CHARSET_NAME), 0) == 0)
 225     {
 226       step->__data = &to_object;
 227
 228       step->__min_needed_from = MIN_NEEDED_TO;
 229       step->__max_needed_from = MAX_NEEDED_TO;
 230       step->__min_needed_to = MIN_NEEDED_FROM;
 231       step->__max_needed_to = MAX_NEEDED_FROM;
 232     }
 233   else
 234     return __GCONV_NOCONV;
 235
 236 #ifdef RESET_STATE
 237   step->__stateful = 1;
 238 #else
 239   step->__stateful = 0;
 240 #endif
 241
 242   return __GCONV_OK;
 243 }
 244 #endif
 245
 246
 247 /* The default destructor function does nothing in the moment and so
 248    be define it at all.  But we still provide the macro just in case
 249    we need it some day.  */
 250 #if DEFINE_FINI
 251 #endif
 252
 253
 254 /* If no arguments have to passed to the loop function define the macro
 255    as empty.  */
 256 #ifndef EXTRA_LOOP_ARGS
 257 # define EXTRA_LOOP_ARGS
 258 #endif
 259
 260
 261 /* This is the actual conversion function.  */
 262 #ifndef FUNCTION_NAME
 263 # define FUNCTION_NAME  gconv
 264 #endif
 265
 266 /* The macros are used to access the function to convert single characters.  */
 267 #define SINGLE(fct) SINGLE2 (fct)
 268 #define SINGLE2(fct) fct##_single
 269
 270
 271 int
 272 FUNCTION_NAME (struct __gconv_step *step, struct __gconv_step_data *data,
 273                const unsigned char **inptrp, const unsigned char *inend,
 274                size_t *written, int do_flush, int consume_incomplete)
 275 {
 276   struct __gconv_step *next_step = step + 1;
 277   struct __gconv_step_data *next_data = data + 1;
 278   __gconv_fct fct;
 279   int status;
 280
 281   fct = (data->__flags & __GCONV_IS_LAST) ? NULL : next_step->__fct;
 282
 283   /* If the function is called with no input this means we have to reset
 284      to the initial state.  The possibly partly converted input is
 285      dropped.  */
 286   if (__builtin_expect (do_flush, 0))
 287     {
 288       status = __GCONV_OK;
 289
 290 #ifdef EMIT_SHIFT_TO_INIT
 291       /* Emit the escape sequence to reset the state.  */
 292       EMIT_SHIFT_TO_INIT;
 293 #endif
 294       /* Call the steps down the chain if there are any but only if we
 295          successfully emitted the escape sequence.  */
 296       if (status == __GCONV_OK && ! (data->__flags & __GCONV_IS_LAST))
 297         status = DL_CALL_FCT (fct, (next_step, next_data, NULL, NULL,
 298                                     written, 1, consume_incomplete));
 299     }
 300   else
 301     {
 302       /* We preserve the initial values of the pointer variables.  */
 303       const unsigned char *inptr = *inptrp;
 304       unsigned char *outbuf = data->__outbuf;
 305       unsigned char *outend = data->__outbufend;
 306       unsigned char *outstart;
 307       /* This variable is used to count the number of characters we
 308          actually converted.  */
 309       size_t converted = 0;
 310 #if defined _STRING_ARCH_unaligned \
 311     || MIN_NEEDED_FROM == 1 || MAX_NEEDED_FROM % MIN_NEEDED_FROM != 0 \
 312     || MIN_NEEDED_TO == 1 || MAX_NEEDED_TO % MIN_NEEDED_TO != 0
 313 # define unaligned 0
 314 #else
 315       int unaligned;
 316 # define GEN_unaligned(name) GEN_unaligned2 (name)
 317 # define GEN_unaligned2(name) name##_unaligned
 318 #endif
 319
 320 #ifdef PREPARE_LOOP
 321       PREPARE_LOOP
 322 #endif
 323
 324 #if MAX_NEEDED_FROM > 1 || MAX_NEEDED_TO > 1
 325       /* If the function is used to implement the mb*towc*() or wc*tomb*()
 326          functions we must test whether any bytes from the last call are
 327          stored in the `state' object.  */
 328       if (((MAX_NEEDED_FROM > 1 && FROM_DIRECTION)
 329            || (MAX_NEEDED_TO > 1 && !FROM_DIRECTION))
 330           && consume_incomplete && (data->__statep->__count & 7) != 0)
 331         {
 332           /* Yep, we have some bytes left over.  Process them now.  */
 333
 334 # if MAX_NEEDED_FROM > 1
 335           if (MAX_NEEDED_TO == 1 || FROM_DIRECTION)
 336             status = SINGLE(FROM_LOOP) (inptrp, inend, &outbuf, outend,
 337                                         data->__statep, data->__flags,
 338                                         step->__data, &converted
 339                                         EXTRA_LOOP_ARGS);
 340 # endif
 341 # if MAX_NEEDED_FROM > 1 && MAX_NEEDED_TO > 1 && !ONE_DIRECTION
 342           else
 343 # endif
 344 # if MAX_NEEDED_TO > 1 && !ONE_DIRECTION
 345             status = SINGLE(TO_LOOP) (inptrp, inend, &outbuf, outend,
 346                                       data->__statep, data->__flags,
 347                                       step->__data, &converted
 348                                       EXTRA_LOOP_ARGS);
 349 # endif
 350
 351           if (__builtin_expect (status, __GCONV_OK) != __GCONV_OK)
 352             return status;
 353         }
 354 #endif
 355
 356 #if !defined _STRING_ARCH_unaligned \
 357     && MIN_NEEDED_FROM != 1 && MAX_NEEDED_FROM % MIN_NEEDED_FROM == 0 \
 358     && MIN_NEEDED_TO != 1 && MAX_NEEDED_TO % MIN_NEEDED_TO == 0
 359       /* The following assumes that encodings, which have a variable length
 360          what might unalign a buffer even though it is a aligned in the
 361          beginning, either don't have the minimal number of bytes as a divisor
 362          of the maximum length or have a minimum length of 1.  This is true
 363          for all known and supported encodings.  */
 364       unaligned = ((FROM_DIRECTION
 365                     && ((uintptr_t) inptr % MIN_NEEDED_FROM != 0
 366                         || ((data->__flags & __GCONV_IS_LAST)
 367                             && (uintptr_t) outbuf % MIN_NEEDED_TO != 0)))
 368                    || (!FROM_DIRECTION
 369                        && (((data->__flags & __GCONV_IS_LAST)
 370                             && (uintptr_t) outbuf % MIN_NEEDED_FROM != 0)
 371                            || (uintptr_t) inptr % MIN_NEEDED_TO != 0)));
 372 #endif
 373
 374       do
 375         {
 376           /* Remember the start value for this round.  */
 377           inptr = *inptrp;
 378           /* The outbuf buffer is empty.  */
 379           outstart = outbuf;
 380
 381 #ifdef SAVE_RESET_STATE
 382           SAVE_RESET_STATE (1);
 383 #endif
 384
 385           if (__builtin_expect (!unaligned, 1))
 386             {
 387               if (FROM_DIRECTION)
 388                 /* Run the conversion loop.  */
 389                 status = FROM_LOOP (inptrp, inend, &outbuf, outend,
 390                                     data->__statep, data->__flags,
 391                                     step->__data, &converted EXTRA_LOOP_ARGS);
 392               else
 393                 /* Run the conversion loop.  */
 394                 status = TO_LOOP (inptrp, inend, &outbuf, outend,
 395                                   data->__statep, data->__flags,
 396                                   step->__data, &converted EXTRA_LOOP_ARGS);
 397             }
 398 #if !defined _STRING_ARCH_unaligned \
 399     && MIN_NEEDED_FROM != 1 && MAX_NEEDED_FROM % MIN_NEEDED_FROM == 0 \
 400     && MIN_NEEDED_TO != 1 && MAX_NEEDED_TO % MIN_NEEDED_TO == 0
 401           else
 402             {
 403               if (FROM_DIRECTION)
 404                 /* Run the conversion loop.  */
 405                 status = GEN_unaligned (FROM_LOOP) (inptrp, inend, &outbuf,
 406                                                     outend, data->__statep,
 407                                                     data->__flags,
 408                                                     step->__data, &converted
 409                                                     EXTRA_LOOP_ARGS);
 410               else
 411                 /* Run the conversion loop.  */
 412                 status = GEN_unaligned (TO_LOOP) (inptrp, inend, &outbuf,
 413                                                   outend, data->__statep,
 414                                                   data->__flags,
 415                                                   step->__data, &converted
 416                                                   EXTRA_LOOP_ARGS);
 417             }
 418 #endif
 419
 420           /* We finished one use of the loops.  */
 421           ++data->__invocation_counter;
 422
 423           /* If this is the last step leave the loop, there is nothing
 424              we can do.  */
 425           if (__builtin_expect (data->__flags & __GCONV_IS_LAST, 0))
 426             {
 427               /* Store information about how many bytes are available.  */
 428               data->__outbuf = outbuf;
 429
 430               /* Remember how many non-identical characters we converted.  */
 431               *written += converted;
 432
 433               break;
 434             }
 435
 436           /* Write out all output which was produced.  */
 437           if (__builtin_expect (outbuf > outstart, 1))
 438             {
 439               const unsigned char *outerr = data->__outbuf;
 440               int result;
 441
 442               result = DL_CALL_FCT (fct, (next_step, next_data, &outerr,
 443                                           outbuf, written, 0,
 444                                           consume_incomplete));
 445
 446               if (result != __GCONV_EMPTY_INPUT)
 447                 {
 448                   if (__builtin_expect (outerr != outbuf, 0))
 449                     {
 450 #ifdef RESET_INPUT_BUFFER
 451                       RESET_INPUT_BUFFER;
 452 #else
 453                       /* We have a problem with the in on of the functions
 454                          below.  Undo the conversion upto the error point.  */
 455                       size_t nstatus;
 456
 457                       /* Reload the pointers.  */
 458                       *inptrp = inptr;
 459                       outbuf = outstart;
 460
 461                       /* Reset the state.  */
 462 # ifdef SAVE_RESET_STATE
 463                       SAVE_RESET_STATE (0);
 464 # endif
 465
 466                       /* XXX Handle unaligned access here as well.  */
 467                       if (FROM_DIRECTION)
 468                         /* Run the conversion loop.  */
 469                         nstatus = FROM_LOOP ((const unsigned char **) inptrp,
 470                                              (const unsigned char *) inend,
 471                                              (unsigned char **) &outbuf,
 472                                              (unsigned char *) outerr,
 473                                              data->__statep, data->__flags,
 474                                              step->__data, &converted
 475                                              EXTRA_LOOP_ARGS);
 476                       else
 477                         /* Run the conversion loop.  */
 478                         nstatus = TO_LOOP ((const unsigned char **) inptrp,
 479                                            (const unsigned char *) inend,
 480                                            (unsigned char **) &outbuf,
 481                                            (unsigned char *) outerr,
 482                                            data->__statep, data->__flags,
 483                                            step->__data, &converted
 484                                            EXTRA_LOOP_ARGS);
 485
 486                       /* We must run out of output buffer space in this
 487                          rerun.  */
 488                       assert (outbuf == outerr);
 489                       assert (nstatus == __GCONV_FULL_OUTPUT);
 490
 491                       /* If we haven't consumed a single byte decrement
 492                          the invocation counter.  */
 493                       if (__builtin_expect (outbuf == outstart, 0))
 494                         --data->__invocation_counter;
 495 #endif  /* reset input buffer */
 496                     }
 497
 498                   /* Change the status.  */
 499                   status = result;
 500                 }
 501               else
 502                 /* All the output is consumed, we can make another run
 503                    if everything was ok.  */
 504                 if (status == __GCONV_FULL_OUTPUT)
 505                   status = __GCONV_OK;
 506             }
 507         }
 508       while (status == __GCONV_OK);
 509
 510 #ifdef END_LOOP
 511       END_LOOP
 512 #endif
 513
 514       /* If we are supposed to consume all character store now all of the
 515          remaining characters in the `state' object.  */
 516 #if MAX_NEEDED_FROM > 1 || MAX_NEEDED_TO > 1
 517       if (((MAX_NEEDED_FROM > 1 && FROM_DIRECTION)
 518            || (MAX_NEEDED_TO > 1 && !FROM_DIRECTION))
 519           && __builtin_expect (consume_incomplete, 0)
 520           && status == __GCONV_INCOMPLETE_INPUT)
 521         {
 522 # ifdef STORE_REST
 523           mbstate_t *state = data->__statep;
 524
 525           STORE_REST
 526 # else
 527           size_t cnt;
 528
 529           /* Make sure the remaining bytes fit into the state objects
 530              buffer.  */
 531           assert (inend - *inptrp < 4);
 532
 533           for (cnt = 0; *inptrp < inend; ++cnt)
 534             data->__statep->__value.__wchb[cnt] = *(*inptrp)++;
 535           data->__statep->__count &= ~7;
 536           data->__statep->__count |= cnt;
 537 # endif
 538         }
 539 #endif
 540     }
 541
 542   return status;
 543 }
 544
 545 #undef DEFINE_INIT
 546 #undef CHARSET_NAME
 547 #undef DEFINE_FINI
 548 #undef MIN_NEEDED_FROM
 549 #undef MIN_NEEDED_TO
 550 #undef MAX_NEEDED_FROM
 551 #undef MAX_NEEDED_TO
 552 #undef DEFINE_DIRECTION_OBJECTS
 553 #undef FROM_DIRECTION
 554 #undef EMIT_SHIFT_TO_INIT
 555 #undef FROM_LOOP
 556 #undef TO_LOOP
 557 #undef RESET_STATE
 558 #undef RESET_INPUT_BUFFER
 559 #undef FUNCTION_NAME
 560 #undef PREPARE_LOOP
 561 #undef END_LOOP
 562 #undef ONE_DIRECTION
 563 #undef STORE_REST