kc3-lang/gnulib/lib/astrxfrm.c

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• Hash : 281b825e
  Author :
  Date : 2018-01-01T00:57:25
  

  maint: Run 'make update-copyright'
  

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• lib/astrxfrm.c

• /* Locale dependent string transformation for comparison.
     Copyright (C) 2010-2018 Free Software Foundation, Inc.
     Written by Bruno Haible <bruno@clisp.org>, 2010.
  
     This program is free software: you can redistribute it and/or modify it
     under the terms of the GNU Lesser General Public License as published
     by the Free Software Foundation; either version 3 of the License, or
     (at your option) any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.
  
     You should have received a copy of the GNU Lesser General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  
  #include <config.h>
  
  /* Specification.  */
  #include "astrxfrm.h"
  
  #include <errno.h>
  #include <stdlib.h>
  #include <string.h>
  
  char *
  astrxfrm (const char *s, char *resultbuf, size_t *lengthp)
  {
    char tmpbuf[4000];
    char *result;      /* either == resultbuf or == tmpbuf or freshly allocated
                          or NULL.  */
    size_t allocated;  /* number of bytes allocated at result */
    size_t length;
  
    if (resultbuf != NULL)
      {
        result = resultbuf;
        allocated = *lengthp;
      }
    else
      {
        result = NULL;
        allocated = 0;
      }
  
    {
      size_t l = strlen (s);
      size_t k;
  
      /* A call to strxfrm costs about 20 times more than a call to strdup of
         the result.  Therefore it is worth to try to avoid calling strxfrm
         more than once on a given string, by making enough room before calling
         strxfrm.  The size of the strxfrm result, k, is likely to be between
         l and 3 * l.  */
      if (3 * l + 1 > allocated)
        {
          /* Grow the result buffer.  */
          if (3 * l + 1 <= sizeof (tmpbuf))
            {
              result = tmpbuf;
              allocated = sizeof (tmpbuf);
            }
          else
            {
              size_t new_allocated;
              char *new_result;
  
              new_allocated = 3 * l + 1;
              if (new_allocated < 2 * allocated)
                new_allocated = 2 * allocated;
              new_result = (char *) malloc (new_allocated);
              if (new_result != NULL)
                {
                  allocated = new_allocated;
                  result = new_result;
                }
            }
        }
  
      errno = 0;
      k = strxfrm (result, s, allocated);
      if (errno != 0)
        goto fail;
      if (k >= allocated)
        {
          /* Grow the result buffer.  */
          if (result != resultbuf && result != tmpbuf)
            free (result);
          if (k + 1 <= sizeof (tmpbuf))
            {
              result = tmpbuf;
              allocated = sizeof (tmpbuf);
            }
          else
            {
              size_t new_allocated;
              char *new_result;
  
              new_allocated = k + 1;
              new_result = (char *) malloc (new_allocated);
              if (new_result == NULL)
                goto out_of_memory;
              allocated = new_allocated;
              result = new_result;
            }
          /* Here k < allocated.  */
  
          /* Try again.  */
          errno = 0;
          if (strxfrm (result, s, allocated) != k)
            /* strxfrm() is not producing reproducible results.  */
            abort ();
          if (errno != 0)
            goto fail;
        }
  
      /* Verify that strxfrm() has NUL-terminated the result.  */
      if (result[k] != '\0')
        abort ();
      length = k + 1;
    }
  
    /* Here length > 0.  */
  
    if (result == tmpbuf)
      {
        if (resultbuf != NULL && length <= *lengthp)
          {
            memcpy (resultbuf, result, length);
            result = resultbuf;
          }
        else
          {
            char *memory = (char *) malloc (length);
  
            if (memory == NULL)
              goto out_of_memory;
            memcpy (memory, result, length);
            result = memory;
          }
      }
    else
      {
        /* Shrink the allocated memory if possible.  */
        if (result != resultbuf && length < allocated)
          {
            if (length <= *lengthp)
              {
                memcpy (resultbuf, result, length);
                free (result);
                result = resultbuf;
              }
            else
              {
                char *memory = (char *) realloc (result, length);
                if (memory != NULL)
                  {
                    memcpy (memory, result, length);
                    result = memory;
                  }
              }
          }
      }
  
    *lengthp = length;
    return result;
  
   fail:
    {
      int saved_errno = errno;
      if (result != resultbuf && result != tmpbuf)
        free (result);
      errno = saved_errno;
      return NULL;
    }
  
   out_of_memory:
    errno = ENOMEM;
    return NULL;
  }
  

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