mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-27 07:20:11 +00:00
47 lines
1.8 KiB
C
47 lines
1.8 KiB
C
/* Array allocation from a fixed-size buffer.
|
|
Copyright (C) 2017-2024 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library 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 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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 the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <alloc_buffer.h>
|
|
#include <libc-pointer-arith.h>
|
|
|
|
void *
|
|
__libc_alloc_buffer_alloc_array (struct alloc_buffer *buf, size_t element_size,
|
|
size_t align, size_t count)
|
|
{
|
|
uintptr_t current = buf->__alloc_buffer_current;
|
|
/* The caller asserts that align is a power of two. */
|
|
uintptr_t aligned = ALIGN_UP (current, align);
|
|
size_t size;
|
|
bool overflow = __builtin_mul_overflow (element_size, count, &size);
|
|
uintptr_t new_current = aligned + size;
|
|
if (!overflow /* Multiplication did not overflow. */
|
|
&& aligned >= current /* No overflow in align step. */
|
|
&& new_current >= size /* No overflow in size computation. */
|
|
&& new_current <= buf->__alloc_buffer_end) /* Room in buffer. */
|
|
{
|
|
buf->__alloc_buffer_current = new_current;
|
|
return (void *) aligned;
|
|
}
|
|
else
|
|
{
|
|
alloc_buffer_mark_failed (buf);
|
|
return NULL;
|
|
}
|
|
}
|
|
libc_hidden_def (__libc_alloc_buffer_alloc_array)
|