lib/malloc/dynarray_finalize.c

   1 /* Copy the dynamically-allocated area to an explicitly-sized heap allocation.
   2    Copyright (C) 2017-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _LIBC
  20 # include <libc-config.h>
  21 #endif
  22
  23 #include <dynarray.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 bool
  28 __libc_dynarray_finalize (struct dynarray_header *list,
  29                           void *scratch, size_t element_size,
  30                           struct dynarray_finalize_result *result)
  31 {
  32   if (__dynarray_error (list))
  33     /* The caller will reported the deferred error.  */
  34     return false;
  35
  36   size_t used = list->used;
  37
  38   /* Empty list.  */
  39   if (used == 0)
  40     {
  41       /* An empty list could still be backed by a heap-allocated
  42          array.  Free it if necessary.  */
  43       if (list->array != scratch)
  44         free (list->array);
  45       *result = (struct dynarray_finalize_result) { NULL, 0 };
  46       return true;
  47     }
  48
  49   size_t allocation_size = used * element_size;
  50   void *heap_array = malloc (allocation_size);
  51   if (heap_array != NULL)
  52     {
  53       /* The new array takes ownership of the strings.  */
  54       if (list->array != NULL)
  55         memcpy (heap_array, list->array, allocation_size);
  56       if (list->array != scratch)
  57         free (list->array);
  58       *result = (struct dynarray_finalize_result)
  59         { .array = heap_array, .length = used };
  60       return true;
  61     }
  62   else
  63     /* The caller will perform the freeing operation.  */
  64     return false;
  65 }
  66 libc_hidden_def (__libc_dynarray_finalize)