iconv/iconv_open.c

   1 /* Get descriptor for character set conversion.
   2    Copyright (C) 1997,1998,1999,2000,2001,2007 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 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 #include <alloca.h>
  22 #include <errno.h>
  23 #include <iconv.h>
  24 #include <stdbool.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #include <gconv_int.h>
  29 #include "gconv_charset.h"
  30
  31
  32 iconv_t
  33 iconv_open (const char *tocode, const char *fromcode)
  34 {
  35   /* Normalize the name.  We remove all characters beside alpha-numeric,
  36      '_', '-', '/', '.', and ':'.  */
  37   size_t tocode_len = strlen (tocode) + 3;
  38   char *tocode_conv;
  39   bool tocode_usealloca = __libc_use_alloca (tocode_len);
  40   if (tocode_usealloca)
  41     tocode_conv = (char *) alloca (tocode_len);
  42   else
  43     {
  44       tocode_conv = (char *) malloc (tocode_len);
  45       if (tocode_conv == NULL)
  46         return (iconv_t) -1;
  47     }
  48   strip (tocode_conv, tocode);
  49   tocode = (tocode_conv[2] == '\0' && tocode[0] != '\0'
  50             ? upstr (tocode_conv, tocode) : tocode_conv);
  51
  52   size_t fromcode_len = strlen (fromcode) + 3;
  53   char *fromcode_conv;
  54   bool fromcode_usealloca = __libc_use_alloca (fromcode_len);
  55   if (fromcode_usealloca)
  56     fromcode_conv = (char *) alloca (fromcode_len);
  57   else
  58     {
  59       fromcode_conv = (char *) malloc (fromcode_len);
  60       if (fromcode_conv == NULL)
  61         {
  62           if (! tocode_usealloca)
  63             free (tocode_conv);
  64           return (iconv_t) -1;
  65         }
  66     }
  67   strip (fromcode_conv, fromcode);
  68   fromcode = (fromcode_conv[2] == '\0' && fromcode[0] != '\0'
  69               ? upstr (fromcode_conv, fromcode) : fromcode_conv);
  70
  71   __gconv_t cd;
  72   int res = __gconv_open (tocode, fromcode, &cd, 0);
  73
  74   if (! fromcode_usealloca)
  75     free (fromcode_conv);
  76   if (! tocode_usealloca)
  77     free (tocode_conv);
  78
  79   if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
  80     {
  81       /* We must set the error number according to the specs.  */
  82       if (res == __GCONV_NOCONV || res == __GCONV_NODB)
  83         __set_errno (EINVAL);
  84
  85       cd = (iconv_t) -1;
  86     }
  87
  88   return (iconv_t) cd;
  89 }