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/* xmalloc.c -- malloc with out of memory checking
Copyright (C) 1990-2000, 2002-2006, 2008-2021 Free Software Foundation, Inc.
This program 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.
This program 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 this program. If not, see <https://www.gnu.org/licenses/>. */
#include <config.h>
#define XALLOC_INLINE _GL_EXTERN_INLINE
#include "xalloc.h"
#include "intprops.h"
#include "minmax.h"
#include <stdlib.h>
#include <string.h>
/* Allocate N bytes of memory dynamically, with error checking. */
void *
xmalloc (size_t n)
{
void *p = malloc (n);
if (!p)
xalloc_die ();
return p;
}
/* Change the size of an allocated block of memory P to N bytes,
with error checking. */
void *
xrealloc (void *p, size_t n)
{
void *r = realloc (p, n);
if (!r && (!p || n))
xalloc_die ();
return r;
}
/* Change the size of an allocated block of memory P to an array of N
objects each of S bytes, with error checking. */
void *
xreallocarray (void *p, size_t n, size_t s)
{
void *r = reallocarray (p, n, s);
if (!r && (!p || (n && s)))
xalloc_die ();
return r;
}
/* If P is null, allocate a block of at least *PN bytes; otherwise,
reallocate P so that it contains more than *PN bytes. *PN must be
nonzero unless P is null. Set *PN to the new block's size, and
return the pointer to the new block. *PN is never set to zero, and
the returned pointer is never null. */
void *
x2realloc (void *p, size_t *pn)
{
return x2nrealloc (p, pn, 1);
}
/* Grow PA, which points to an array of *NITEMS items, and return the
location of the reallocated array, updating *NITEMS to reflect its
new size. The new array will contain at least NITEMS_INCR_MIN more
items, but will not contain more than NITEMS_MAX items total.
ITEM_SIZE is the size of each item, in bytes.
ITEM_SIZE and NITEMS_INCR_MIN must be positive. *NITEMS must be
nonnegative. If NITEMS_MAX is -1, it is treated as if it were
infinity.
If PA is null, then allocate a new array instead of reallocating
the old one.
Thus, to grow an array A without saving its old contents, do
{ free (A); A = xpalloc (NULL, &AITEMS, ...); }. */
void *
xpalloc (void *pa, idx_t *nitems, idx_t nitems_incr_min,
ptrdiff_t nitems_max, idx_t item_size)
{
idx_t n0 = *nitems;
/* The approximate size to use for initial small allocation
requests. This is the largest "small" request for the GNU C
library malloc. */
enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 };
/* If the array is tiny, grow it to about (but no greater than)
DEFAULT_MXFAST bytes. Otherwise, grow it by about 50%.
Adjust the growth according to three constraints: NITEMS_INCR_MIN,
NITEMS_MAX, and what the C language can represent safely. */
idx_t n;
if (INT_ADD_WRAPV (n0, n0 >> 1, &n))
n = IDX_MAX;
if (0 <= nitems_max && nitems_max < n)
n = nitems_max;
/* NBYTES is of a type suitable for holding the count of bytes in an object.
This is typically idx_t, but it should be size_t on (theoretical?)
platforms where SIZE_MAX < IDX_MAX so xpalloc does not pass
values greater than SIZE_MAX to xrealloc. */
#if IDX_MAX <= SIZE_MAX
idx_t nbytes;
#else
size_t nbytes;
#endif
idx_t adjusted_nbytes
= (INT_MULTIPLY_WRAPV (n, item_size, &nbytes)
? MIN (IDX_MAX, SIZE_MAX)
: nbytes < DEFAULT_MXFAST ? DEFAULT_MXFAST : 0);
if (adjusted_nbytes)
{
n = adjusted_nbytes / item_size;
nbytes = adjusted_nbytes - adjusted_nbytes % item_size;
}
if (! pa)
*nitems = 0;
if (n - n0 < nitems_incr_min
&& (INT_ADD_WRAPV (n0, nitems_incr_min, &n)
|| (0 <= nitems_max && nitems_max < n)
|| INT_MULTIPLY_WRAPV (n, item_size, &nbytes)))
xalloc_die ();
pa = xrealloc (pa, nbytes);
*nitems = n;
return pa;
}
/* Allocate N bytes of zeroed memory dynamically, with error checking.
There's no need for xnzalloc (N, S), since it would be equivalent
to xcalloc (N, S). */
void *
xzalloc (size_t n)
{
return xcalloc (n, 1);
}
/* Allocate zeroed memory for N elements of S bytes, with error
checking. S must be nonzero. */
void *
xcalloc (size_t n, size_t s)
{
void *p = calloc (n, s);
if (!p)
xalloc_die ();
return p;
}
/* Clone an object P of size S, with error checking. There's no need
for xnmemdup (P, N, S), since xmemdup (P, N * S) works without any
need for an arithmetic overflow check. */
void *
xmemdup (void const *p, size_t s)
{
return memcpy (xmalloc (s), p, s);
}
/* Clone STRING. */
char *
xstrdup (char const *string)
{
return xmemdup (string, strlen (string) + 1);
}
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