glibc/malloc/tst-realloc.c

173 lines
4.3 KiB
C

/* Copyright (C) 2013-2023 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 <errno.h>
#include <malloc.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <libc-diag.h>
#include <support/check.h>
static int
do_test (void)
{
void *p;
unsigned char *c;
int save, i, ok;
errno = 0;
/* realloc (NULL, ...) behaves similarly to malloc (C89). */
DIAG_PUSH_NEEDS_COMMENT;
#if __GNUC_PREREQ (7, 0)
/* GCC 7 warns about too-large allocations; here we want to test
that they fail. */
DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
#endif
p = realloc (NULL, -1);
DIAG_POP_NEEDS_COMMENT;
save = errno;
if (p != NULL)
FAIL_EXIT1 ("realloc (NULL, -1) succeeded.");
/* errno should be set to ENOMEM on failure (POSIX). */
if (p == NULL && save != ENOMEM)
FAIL_EXIT1 ("errno is not set correctly");
errno = 0;
/* realloc (NULL, ...) behaves similarly to malloc (C89). */
p = realloc (NULL, 10);
save = errno;
if (p == NULL)
FAIL_EXIT1 ("realloc (NULL, 10) failed.");
free (p);
p = calloc (20, 1);
if (p == NULL)
FAIL_EXIT1 ("calloc (20, 1) failed.");
/* Check increasing size preserves contents (C89). */
p = realloc (p, 200);
if (p == NULL)
FAIL_EXIT1 ("realloc (p, 200) failed.");
c = p;
ok = 1;
for (i = 0; i < 20; i++)
{
if (c[i] != 0)
ok = 0;
}
if (ok == 0)
FAIL_EXIT1 ("first 20 bytes were not cleared");
free (p);
p = realloc (NULL, 100);
if (p == NULL)
FAIL_EXIT1 ("realloc (NULL, 100) failed.");
memset (p, 0xff, 100);
/* Check decreasing size preserves contents (C89). */
p = realloc (p, 16);
if (p == NULL)
FAIL_EXIT1 ("realloc (p, 16) failed.");
c = p;
ok = 1;
for (i = 0; i < 16; i++)
{
if (c[i] != 0xff)
ok = 0;
}
if (ok == 0)
FAIL_EXIT1 ("first 16 bytes were not correct");
/* Check failed realloc leaves original untouched (C89). */
DIAG_PUSH_NEEDS_COMMENT;
#if __GNUC_PREREQ (7, 0)
/* GCC 7 warns about too-large allocations; here we want to test
that they fail. */
DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
#endif
c = realloc (p, -1);
DIAG_POP_NEEDS_COMMENT;
if (c != NULL)
FAIL_EXIT1 ("realloc (p, -1) succeeded.");
c = p;
ok = 1;
for (i = 0; i < 16; i++)
{
if (c[i] != 0xff)
ok = 0;
}
if (ok == 0)
FAIL_EXIT1 ("first 16 bytes were not correct after failed realloc");
/* realloc (p, 0) frees p (C89) and returns NULL (glibc). */
p = realloc (p, 0);
if (p != NULL)
FAIL_EXIT1 ("realloc (p, 0) returned non-NULL.");
/* realloc (NULL, 0) acts like malloc (0) (glibc). */
p = realloc (NULL, 0);
if (p == NULL)
FAIL_EXIT1 ("realloc (NULL, 0) returned NULL.");
free (p);
/* Smoke test to make sure that allocations do not move if they have enough
space to expand in the chunk. */
for (size_t sz = 3; sz < 256 * 1024; sz += 2048)
{
p = realloc (NULL, sz);
if (p == NULL)
FAIL_EXIT1 ("realloc (NULL, %zu) returned NULL.", sz);
size_t newsz = malloc_usable_size (p);
printf ("size: %zu, usable size: %zu, extra: %zu\n",
sz, newsz, newsz - sz);
uintptr_t oldp = (uintptr_t) p;
void *new_p = realloc (p, newsz);
if ((uintptr_t) new_p != oldp)
FAIL_EXIT1 ("Expanding (%zu bytes) to usable size (%zu) moved block",
sz, newsz);
free (new_p);
/* We encountered a large enough extra size at least once. */
if (newsz - sz > 1024)
break;
}
return 0;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"