root/lib/malloc/dynarray_resize.c

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DEFINITIONS

This source file includes following definitions.
  1. __libc_dynarray_resize

     1 /* Increase the size of a dynamic array.
     2    Copyright (C) 2017-2023 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 <errno.h>
    25 #include <stdckdint.h>
    26 #include <stdlib.h>
    27 #include <string.h>
    28 
    29 bool
    30 __libc_dynarray_resize (struct dynarray_header *list, size_t size,
    31                         void *scratch, size_t element_size)
    32 {
    33   /* The existing allocation provides sufficient room.  */
    34   if (size <= list->allocated)
    35     {
    36       list->used = size;
    37       return true;
    38     }
    39 
    40   /* Otherwise, use size as the new allocation size.  The caller is
    41      expected to provide the final size of the array, so there is no
    42      over-allocation here.  */
    43 
    44   size_t new_size_bytes;
    45   if (ckd_mul (&new_size_bytes, size, element_size))
    46     {
    47       /* Overflow.  */
    48       __set_errno (ENOMEM);
    49       return false;
    50     }
    51   void *new_array;
    52   if (list->array == scratch)
    53     {
    54       /* The previous array was not heap-allocated.  */
    55       new_array = malloc (new_size_bytes);
    56       if (new_array != NULL && list->array != NULL)
    57         memcpy (new_array, list->array, list->used * element_size);
    58     }
    59   else
    60     new_array = realloc (list->array, new_size_bytes);
    61   if (new_array == NULL)
    62     return false;
    63   list->array = new_array;
    64   list->allocated = size;
    65   list->used = size;
    66   return true;
    67 }
    68 libc_hidden_def (__libc_dynarray_resize)

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