malloc/tst-realloc.c

   1 /* Copyright (C) 2013-2018 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 #include <libc-diag.h>
  23
  24 static int errors = 0;
  25
  26 static void
  27 merror (const char *msg)
  28 {
  29   ++errors;
  30   printf ("Error: %s\n", msg);
  31 }
  32
  33 static int
  34 do_test (void)
  35 {
  36   void *p;
  37   unsigned char *c;
  38   int save, i, ok;
  39
  40   errno = 0;
  41
  42   /* realloc (NULL, ...) behaves similarly to malloc (C89).  */
  43   DIAG_PUSH_NEEDS_COMMENT;
  44 #if __GNUC_PREREQ (7, 0)
  45   /* GCC 7 warns about too-large allocations; here we want to test
  46      that they fail.  */
  47   DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
  48 #endif
  49   p = realloc (NULL, -1);
  50   DIAG_POP_NEEDS_COMMENT;
  51   save = errno;
  52
  53   if (p != NULL)
  54     merror ("realloc (NULL, -1) succeeded.");
  55
  56   /* errno should be set to ENOMEM on failure (POSIX).  */
  57   if (p == NULL && save != ENOMEM)
  58     merror ("errno is not set correctly");
  59
  60   errno = 0;
  61
  62   /* realloc (NULL, ...) behaves similarly to malloc (C89).  */
  63   p = realloc (NULL, 10);
  64   save = errno;
  65
  66   if (p == NULL)
  67     merror ("realloc (NULL, 10) failed.");
  68
  69   free (p);
  70
  71   p = calloc (20, 1);
  72   if (p == NULL)
  73     merror ("calloc (20, 1) failed.");
  74
  75   /* Check increasing size preserves contents (C89).  */
  76   p = realloc (p, 200);
  77   if (p == NULL)
  78     merror ("realloc (p, 200) failed.");
  79
  80   c = p;
  81   ok = 1;
  82
  83   for (i = 0; i < 20; i++)
  84     {
  85       if (c[i] != 0)
  86         ok = 0;
  87     }
  88
  89   if (ok == 0)
  90     merror ("first 20 bytes were not cleared");
  91
  92   free (p);
  93
  94   p = realloc (NULL, 100);
  95   if (p == NULL)
  96     merror ("realloc (NULL, 100) failed.");
  97
  98   memset (p, 0xff, 100);
  99
 100   /* Check decreasing size preserves contents (C89).  */
 101   p = realloc (p, 16);
 102   if (p == NULL)
 103     merror ("realloc (p, 16) failed.");
 104
 105   c = p;
 106   ok = 1;
 107
 108   for (i = 0; i < 16; i++)
 109     {
 110       if (c[i] != 0xff)
 111         ok = 0;
 112     }
 113
 114   if (ok == 0)
 115     merror ("first 16 bytes were not correct");
 116
 117   /* Check failed realloc leaves original untouched (C89).  */
 118   DIAG_PUSH_NEEDS_COMMENT;
 119 #if __GNUC_PREREQ (7, 0)
 120   /* GCC 7 warns about too-large allocations; here we want to test
 121      that they fail.  */
 122   DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
 123 #endif
 124   c = realloc (p, -1);
 125   DIAG_POP_NEEDS_COMMENT;
 126   if (c != NULL)
 127     merror ("realloc (p, -1) succeeded.");
 128
 129   c = p;
 130   ok = 1;
 131
 132   for (i = 0; i < 16; i++)
 133     {
 134       if (c[i] != 0xff)
 135         ok = 0;
 136     }
 137
 138   if (ok == 0)
 139     merror ("first 16 bytes were not correct after failed realloc");
 140
 141   /* realloc (p, 0) frees p (C89) and returns NULL (glibc).  */
 142   p = realloc (p, 0);
 143   if (p != NULL)
 144     merror ("realloc (p, 0) returned non-NULL.");
 145
 146   /* realloc (NULL, 0) acts like malloc (0) (glibc).  */
 147   p = realloc (NULL, 0);
 148   if (p == NULL)
 149     merror ("realloc (NULL, 0) returned NULL.");
 150
 151   free (p);
 152
 153   return errors != 0;
 154 }
 155
 156 #define TEST_FUNCTION do_test ()
 157 #include "../test-skeleton.c"