iconv/gconv_open.c

   1 /* Find matching transformation algorithms and initialize steps.
   2    Copyright (C) 1997, 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>, 1997.
   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 #include <errno.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include <gconv_int.h>
  26
  27
  28 int
  29 internal_function
  30 __gconv_open (const char *toset, const char *fromset, __gconv_t *handle,
  31               int flags)
  32 {
  33   struct __gconv_step *steps;
  34   size_t nsteps;
  35   __gconv_t result = NULL;
  36   size_t cnt = 0;
  37   int res;
  38   int conv_flags = 0;
  39   const char *errhand;
  40   const char *ignore;
  41   struct trans_struct *trans = NULL;
  42
  43   /* Find out whether any error handling method is specified.  */
  44   errhand = strchr (toset, '/');
  45   if (errhand != NULL)
  46     errhand = strchr (errhand + 1, '/');
  47   if (__builtin_expect (errhand != NULL, 1))
  48     {
  49       if (*++errhand == '\0')
  50         errhand = NULL;
  51       else
  52         {
  53           /* Make copy without the error handling description.  */
  54           char *newtoset = (char *) alloca (errhand - toset + 1);
  55           char *tok;
  56           char *ptr;
  57
  58           newtoset[errhand - toset] = '\0';
  59           toset = memcpy (newtoset, toset, errhand - toset);
  60
  61           /* Find the appropriate transliteration handlers.  */
  62           tok = strdupa (errhand);
  63
  64           tok = __strtok_r (tok, ",", &ptr);
  65           while (tok != NULL)
  66             {
  67               if (__strcasecmp (tok, "TRANSLIT") == 0)
  68                 {
  69                   /* It's the builtin transliteration handling.  We only
  70                      support it for working on the internal encoding.  */
  71                   static const char *internal_trans_names[1] = { "INTERNAL" };
  72                   struct trans_struct *lastp = NULL;
  73                   struct trans_struct *runp;
  74
  75                   for (runp = trans; runp != NULL; runp = runp->next)
  76                     if (runp->trans_fct == __gconv_transliterate)
  77                       break;
  78                     else
  79                       lastp = runp;
  80
  81                   if (runp == NULL)
  82                     {
  83                       struct trans_struct *newp;
  84
  85                       newp = (struct trans_struct *) alloca (sizeof (*newp));
  86                       memset (newp, '\0', sizeof (*newp));
  87
  88                       /* We leave the `name' field zero to signal that
  89                          this is an internal transliteration step.  */
  90                       newp->csnames = internal_trans_names;
  91                       newp->ncsnames = 1;
  92                       newp->trans_fct = __gconv_transliterate;
  93
  94                       if (lastp == NULL)
  95                         trans = newp;
  96                       else
  97                         lastp->next = newp;
  98                     }
  99                 }
 100               else if (__strcasecmp (tok, "IGNORE") == 0)
 101                 /* Set the flag to ignore all errors.  */
 102                 flags = __GCONV_IGNORE_ERRORS;
 103               else
 104                 {
 105                   /* `tok' is possibly a module name.  We'll see later
 106                      whether we can find it.  But first see that we do
 107                      not already a module of this name.  */
 108                   struct trans_struct *lastp = NULL;
 109                   struct trans_struct *runp;
 110
 111                   for (runp = trans; runp != NULL; runp = runp->next)
 112                     if (runp->name != NULL
 113                         && __strcasecmp (tok, runp->name) == 0)
 114                       break;
 115                     else
 116                       lastp = runp;
 117
 118                   if (runp == NULL)
 119                     {
 120                       struct trans_struct *newp;
 121
 122                       newp = (struct trans_struct *) alloca (sizeof (*newp));
 123                       memset (newp, '\0', sizeof (*newp));
 124                       newp->name = tok;
 125
 126                       if (lastp == NULL)
 127                         trans = newp;
 128                       else
 129                         lastp->next = newp;
 130                     }
 131                 }
 132
 133               tok = __strtok_r (NULL, ",", &ptr);
 134             }
 135         }
 136     }
 137
 138   /* For the source character set we ignore the error handler specification.
 139      XXX Is this really always the best?  */
 140   ignore = strchr (fromset, '/');
 141   if (ignore != NULL && (ignore = strchr (ignore + 1, '/')) != NULL
 142       && *++ignore != '\0')
 143     {
 144       char *newfromset = (char *) alloca (ignore - fromset + 1);
 145
 146       newfromset[ignore - fromset] = '\0';
 147       fromset = memcpy (newfromset, fromset, ignore - fromset);
 148     }
 149
 150   res = __gconv_find_transform (toset, fromset, &steps, &nsteps, flags);
 151   if (res == __GCONV_OK)
 152     {
 153       /* Find the modules.  */
 154       struct trans_struct *lastp = NULL;
 155       struct trans_struct *runp;
 156
 157       for (runp = trans; runp != NULL; runp = runp->next)
 158         {
 159           if (runp->name == NULL
 160               || __builtin_expect (__gconv_translit_find (runp), 0) == 0)
 161             lastp = runp;
 162           else
 163             /* This means we haven't found the module.  Remove it.  */
 164             (lastp == NULL ? trans : lastp->next) = runp->next;
 165         }
 166
 167       /* Allocate room for handle.  */
 168       result = (__gconv_t) malloc (sizeof (struct __gconv_info)
 169                                    + (nsteps
 170                                       * sizeof (struct __gconv_step_data)));
 171       if (result == NULL)
 172         res = __GCONV_NOMEM;
 173       else
 174         {
 175           size_t n;
 176
 177           /* Remember the list of steps.  */
 178           result->__steps = steps;
 179           result->__nsteps = nsteps;
 180
 181           /* Clear the array for the step data.  */
 182           memset (result->__data, '\0',
 183                   nsteps * sizeof (struct __gconv_step_data));
 184
 185           /* Call all initialization functions for the transformation
 186              step implementations.  */
 187           for (cnt = 0; cnt < nsteps; ++cnt)
 188             {
 189               size_t size;
 190
 191               /* Would have to be done if we would not clear the whole
 192                  array above.  */
 193 #if 0
 194               /* Reset the counter.  */
 195               result->__data[cnt].__invocation_counter = 0;
 196
 197               /* It's a regular use.  */
 198               result->__data[cnt].__internal_use = 0;
 199 #endif
 200
 201               /* We use the `mbstate_t' member in DATA.  */
 202               result->__data[cnt].__statep = &result->__data[cnt].__state;
 203
 204               /* Now see whether we can use any of the transliteration
 205                  modules for this step.  */
 206               for (runp = trans; runp != NULL; runp = runp->next)
 207                 for (n = 0; n < runp->ncsnames; ++n)
 208                   if (__strcasecmp (steps[cnt].__from_name,
 209                                     runp->csnames[n]) == 0)
 210                     {
 211                       void *data = NULL;
 212
 213                       /* Match!  Now try the initializer.  */
 214                       if (runp->trans_init_fct == NULL
 215                           || (runp->trans_init_fct (&data,
 216                                                     steps[cnt].__to_name)
 217                               == __GCONV_OK))
 218                         {
 219                           /* Append at the end of the list.  */
 220                           struct __gconv_trans_data *newp;
 221                           struct __gconv_trans_data **lastp;
 222
 223                           newp = (struct __gconv_trans_data *)
 224                             malloc (sizeof (struct __gconv_trans_data));
 225                           if (newp == NULL)
 226                             goto bail;
 227
 228                           newp->__trans_fct = runp->trans_fct;
 229                           newp->__trans_context_fct = runp->trans_context_fct;
 230                           newp->__trans_end_fct = runp->trans_end_fct;
 231                           newp->__data = data;
 232                           newp->__next = NULL;
 233
 234                           lastp = &result->__data[cnt].__trans;
 235                           while (*lastp != NULL)
 236                             lastp = &(*lastp)->__next;
 237
 238                           *lastp = newp;
 239                         }
 240                       break;
 241                     }
 242
 243               /* If this is the last step we must not allocate an
 244                  output buffer.  */
 245               if (cnt < nsteps - 1)
 246                 {
 247                   result->__data[cnt].__flags = conv_flags;
 248
 249                   /* Allocate the buffer.  */
 250                   size = (GCONV_NCHAR_GOAL * steps[cnt].__max_needed_to);
 251
 252                   result->__data[cnt].__outbuf = (char *) malloc (size);
 253                   if (result->__data[cnt].__outbuf == NULL)
 254                     goto bail;
 255
 256                   result->__data[cnt].__outbufend =
 257                     result->__data[cnt].__outbuf + size;
 258                 }
 259               else
 260                 {
 261                   /* Handle the last entry.  */
 262                   result->__data[cnt].__flags = conv_flags | __GCONV_IS_LAST;
 263
 264                   break;
 265                 }
 266             }
 267         }
 268
 269       if (res != __GCONV_OK)
 270         {
 271           /* Something went wrong.  Free all the resources.  */
 272           int serrno;
 273         bail:
 274           serrno = errno;
 275
 276           if (result != NULL)
 277             {
 278               while (cnt-- > 0)
 279                 {
 280                   struct __gconv_trans_data *transp;
 281
 282                   transp = result->__data[cnt].__trans;
 283                   while (transp != NULL)
 284                     {
 285                       struct __gconv_trans_data *curp = transp;
 286                       transp = transp->__next;
 287
 288                       if (__builtin_expect (curp->__trans_end_fct != NULL, 0))
 289                         curp->__trans_end_fct (curp->__data);
 290
 291                       free (curp);
 292                     }
 293
 294                   free (result->__data[cnt].__outbuf);
 295                 }
 296
 297               free (result);
 298               result = NULL;
 299             }
 300
 301           __gconv_close_transform (steps, nsteps);
 302
 303           __set_errno (serrno);
 304         }
 305     }
 306
 307   *handle = result;
 308   return res;
 309 }