mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-12 09:28:24 +00:00
68 lines
2.0 KiB
C
68 lines
2.0 KiB
C
/* Variable-sized buffer with on-stack default allocation.
|
|
Copyright (C) 2015-2021 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 General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 3 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
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#ifndef _LIBC
|
|
# include <libc-config.h>
|
|
#endif
|
|
|
|
#include <scratch_buffer.h>
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
|
|
bool
|
|
__libc_scratch_buffer_grow_preserve (struct scratch_buffer *buffer)
|
|
{
|
|
size_t new_length = 2 * buffer->length;
|
|
void *new_ptr;
|
|
|
|
if (buffer->data == buffer->__space.__c)
|
|
{
|
|
/* Move buffer to the heap. No overflow is possible because
|
|
buffer->length describes a small buffer on the stack. */
|
|
new_ptr = malloc (new_length);
|
|
if (new_ptr == NULL)
|
|
return false;
|
|
memcpy (new_ptr, buffer->__space.__c, buffer->length);
|
|
}
|
|
else
|
|
{
|
|
/* Buffer was already on the heap. Check for overflow. */
|
|
if (__glibc_likely (new_length >= buffer->length))
|
|
new_ptr = realloc (buffer->data, new_length);
|
|
else
|
|
{
|
|
__set_errno (ENOMEM);
|
|
new_ptr = NULL;
|
|
}
|
|
|
|
if (__glibc_unlikely (new_ptr == NULL))
|
|
{
|
|
/* Deallocate, but buffer must remain valid to free. */
|
|
free (buffer->data);
|
|
scratch_buffer_init (buffer);
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/* Install new heap-based buffer. */
|
|
buffer->data = new_ptr;
|
|
buffer->length = new_length;
|
|
return true;
|
|
}
|
|
libc_hidden_def (__libc_scratch_buffer_grow_preserve)
|