malloc/tst-realloc.c

   1 /* Copyright (C) 2013-2016 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    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <malloc.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22
  23 static int errors = 0;
  24
  25 static void
  26 merror (const char *msg)
  27 {
  28   ++errors;
  29   printf ("Error: %s\n", msg);
  30 }
  31
  32 static int
  33 do_test (void)
  34 {
  35   void *p;
  36   unsigned char *c;
  37   int save, i, ok;
  38
  39   errno = 0;
  40
  41   /* realloc (NULL, ...) behaves similarly to malloc (C89).  */
  42   p = realloc (NULL, -1);
  43   save = errno;
  44
  45   if (p != NULL)
  46     merror ("realloc (NULL, -1) succeeded.");
  47
  48   /* errno should be set to ENOMEM on failure (POSIX).  */
  49   if (p == NULL && save != ENOMEM)
  50     merror ("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     merror ("realloc (NULL, 10) failed.");
  60
  61   /* errno should be clear on success (POSIX).  */
  62   if (p != NULL && save != 0)
  63     merror ("errno is set but should not be");
  64
  65   free (p);
  66
  67   p = calloc (20, 1);
  68   if (p == NULL)
  69     merror ("calloc (20, 1) failed.");
  70
  71   /* Check increasing size preserves contents (C89).  */
  72   p = realloc (p, 200);
  73   if (p == NULL)
  74     merror ("realloc (p, 200) failed.");
  75
  76   c = p;
  77   ok = 1;
  78
  79   for (i = 0; i < 20; i++)
  80     {
  81       if (c[i] != 0)
  82         ok = 0;
  83     }
  84
  85   if (ok == 0)
  86     merror ("first 20 bytes were not cleared");
  87
  88   free (p);
  89
  90   p = realloc (NULL, 100);
  91   if (p == NULL)
  92     merror ("realloc (NULL, 100) failed.");
  93
  94   memset (p, 0xff, 100);
  95
  96   /* Check decreasing size preserves contents (C89).  */
  97   p = realloc (p, 16);
  98   if (p == NULL)
  99     merror ("realloc (p, 16) failed.");
 100
 101   c = p;
 102   ok = 1;
 103
 104   for (i = 0; i < 16; i++)
 105     {
 106       if (c[i] != 0xff)
 107         ok = 0;
 108     }
 109
 110   if (ok == 0)
 111     merror ("first 16 bytes were not correct");
 112
 113   /* Check failed realloc leaves original untouched (C89).  */
 114   c = realloc (p, -1);
 115   if (c != NULL)
 116     merror ("realloc (p, -1) succeeded.");
 117
 118   c = p;
 119   ok = 1;
 120
 121   for (i = 0; i < 16; i++)
 122     {
 123       if (c[i] != 0xff)
 124         ok = 0;
 125     }
 126
 127   if (ok == 0)
 128     merror ("first 16 bytes were not correct after failed realloc");
 129
 130   /* realloc (p, 0) frees p (C89) and returns NULL (glibc).  */
 131   p = realloc (p, 0);
 132   if (p != NULL)
 133     merror ("realloc (p, 0) returned non-NULL.");
 134
 135   /* realloc (NULL, 0) acts like malloc (0) (glibc).  */
 136   p = realloc (NULL, 0);
 137   if (p == NULL)
 138     merror ("realloc (NULL, 0) returned NULL.");
 139
 140   free (p);
 141
 142   return errors != 0;
 143 }
 144
 145 #define TEST_FUNCTION do_test ()
 146 #include "../test-skeleton.c"