malloc/tst-realloc.c

   1 /* Copyright (C) 2013-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <malloc.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <libc-diag.h>
  23 #include <support/check.h>
  24
  25 static int
  26 do_test (void)
  27 {
  28   void *p;
  29   unsigned char *c;
  30   int save, i, ok;
  31
  32   errno = 0;
  33
  34   /* realloc (NULL, ...) behaves similarly to malloc (C89).  */
  35   DIAG_PUSH_NEEDS_COMMENT;
  36 #if __GNUC_PREREQ (7, 0)
  37   /* GCC 7 warns about too-large allocations; here we want to test
  38      that they fail.  */
  39   DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
  40 #endif
  41   p = realloc (NULL, -1);
  42   DIAG_POP_NEEDS_COMMENT;
  43   save = errno;
  44
  45   if (p != NULL)
  46     FAIL_EXIT1 ("realloc (NULL, -1) succeeded.");
  47
  48   /* errno should be set to ENOMEM on failure (POSIX).  */
  49   if (p == NULL && save != ENOMEM)
  50     FAIL_EXIT1 ("errno is not set correctly");
  51
  52   errno = 0;
  53
  54   /* realloc (NULL, ...) behaves similarly to malloc (C89).  */
  55   p = realloc (NULL, 10);
  56   save = errno;
  57
  58   if (p == NULL)
  59     FAIL_EXIT1 ("realloc (NULL, 10) failed.");
  60
  61   free (p);
  62
  63   p = calloc (20, 1);
  64   if (p == NULL)
  65     FAIL_EXIT1 ("calloc (20, 1) failed.");
  66
  67   /* Check increasing size preserves contents (C89).  */
  68   p = realloc (p, 200);
  69   if (p == NULL)
  70     FAIL_EXIT1 ("realloc (p, 200) failed.");
  71
  72   c = p;
  73   ok = 1;
  74
  75   for (i = 0; i < 20; i++)
  76     {
  77       if (c[i] != 0)
  78         ok = 0;
  79     }
  80
  81   if (ok == 0)
  82     FAIL_EXIT1 ("first 20 bytes were not cleared");
  83
  84   free (p);
  85
  86   p = realloc (NULL, 100);
  87   if (p == NULL)
  88     FAIL_EXIT1 ("realloc (NULL, 100) failed.");
  89
  90   memset (p, 0xff, 100);
  91
  92   /* Check decreasing size preserves contents (C89).  */
  93   p = realloc (p, 16);
  94   if (p == NULL)
  95     FAIL_EXIT1 ("realloc (p, 16) failed.");
  96
  97   c = p;
  98   ok = 1;
  99
 100   for (i = 0; i < 16; i++)
 101     {
 102       if (c[i] != 0xff)
 103         ok = 0;
 104     }
 105
 106   if (ok == 0)
 107     FAIL_EXIT1 ("first 16 bytes were not correct");
 108
 109   /* Check failed realloc leaves original untouched (C89).  */
 110   DIAG_PUSH_NEEDS_COMMENT;
 111 #if __GNUC_PREREQ (7, 0)
 112   /* GCC 7 warns about too-large allocations; here we want to test
 113      that they fail.  */
 114   DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
 115 #endif
 116   c = realloc (p, -1);
 117   DIAG_POP_NEEDS_COMMENT;
 118   if (c != NULL)
 119     FAIL_EXIT1 ("realloc (p, -1) succeeded.");
 120
 121   c = p;
 122   ok = 1;
 123
 124   for (i = 0; i < 16; i++)
 125     {
 126       if (c[i] != 0xff)
 127         ok = 0;
 128     }
 129
 130   if (ok == 0)
 131     FAIL_EXIT1 ("first 16 bytes were not correct after failed realloc");
 132
 133   /* realloc (p, 0) frees p (C89) and returns NULL (glibc).  */
 134   p = realloc (p, 0);
 135   if (p != NULL)
 136     FAIL_EXIT1 ("realloc (p, 0) returned non-NULL.");
 137
 138   /* realloc (NULL, 0) acts like malloc (0) (glibc).  */
 139   p = realloc (NULL, 0);
 140   if (p == NULL)
 141     FAIL_EXIT1 ("realloc (NULL, 0) returned NULL.");
 142
 143   free (p);
 144
 145   return 0;
 146 }
 147
 148 #define TEST_FUNCTION do_test ()
 149 #include "../test-skeleton.c"