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91b6eb1140
This is intended as a type-safe alternative to obstacks and hand-written realloc constructs. The implementation avoids writing function pointers to the heap.
60 lines
2.0 KiB
C
60 lines
2.0 KiB
C
/* Increase the size of a dynamic array.
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Copyright (C) 2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <dynarray.h>
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#include <malloc-internal.h>
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#include <stdlib.h>
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#include <string.h>
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bool
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__libc_dynarray_resize (struct dynarray_header *list, size_t size,
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void *scratch, size_t element_size)
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{
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/* The existing allocation provides sufficient room. */
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if (size <= list->allocated)
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{
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list->used = size;
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return true;
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}
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/* Otherwise, use size as the new allocation size. The caller is
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expected to provide the final size of the array, so there is no
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over-allocation here. */
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size_t new_size_bytes;
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if (check_mul_overflow_size_t (size, element_size, &new_size_bytes))
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return false;
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void *new_array;
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if (list->array == scratch)
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{
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/* The previous array was not heap-allocated. */
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new_array = malloc (new_size_bytes);
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if (new_array != NULL && list->array != NULL)
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memcpy (new_array, list->array, list->used * element_size);
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}
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else
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new_array = realloc (list->array, new_size_bytes);
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if (new_array == NULL)
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return false;
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list->array = new_array;
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list->allocated = size;
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list->used = size;
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return true;
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}
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libc_hidden_def (__libc_dynarray_resize)
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