1 /* Test of calloc function.
2    Copyright (C) 2010-2021 Free Software Foundation, Inc.
3 
4    This program is free software: you can redistribute it and/or modify
5    it under the terms of the GNU General Public License as published by
6    the Free Software Foundation; either version 3 of the License, or
7    (at your option) any later version.
8 
9    This program 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
12    GNU General Public License for more details.
13 
14    You should have received a copy of the GNU General Public License
15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
16 
17 #include <config.h>
18 
19 /* Specification.  */
20 #include <stdlib.h>
21 
22 #include <errno.h>
23 #include <stdint.h>
24 
25 #include "macros.h"
26 
27 /* Return N.
28    Usual compilers are not able to infer something about the return value.  */
29 static size_t
identity(size_t n)30 identity (size_t n)
31 {
32   unsigned int x = rand ();
33   unsigned int y = x * x * x * x;
34   x++; y |= x * x * x * x;
35   x++; y |= x * x * x * x;
36   x++; y |= x * x * x * x;
37   y = y >> 1;
38   y &= -y;
39   y -= 8;
40   /* At this point Y is zero but GCC doesn't infer this.  */
41   return n + y;
42 }
43 
44 int
main()45 main ()
46 {
47   /* Check that calloc (0, 0) is not a NULL pointer.  */
48   {
49     void * volatile p = calloc (0, 0);
50     ASSERT (p != NULL);
51     free (p);
52   }
53 
54   /* Check that calloc fails when requested to allocate a block of memory
55      larger than PTRDIFF_MAX or SIZE_MAX bytes.
56      Use 'identity' to avoid a compiler warning from GCC 7.
57      'volatile' is needed to defeat an incorrect optimization by clang 10,
58      see <https://bugs.llvm.org/show_bug.cgi?id=46055>.  */
59   {
60     for (size_t n = 2; n != 0; n <<= 1)
61       {
62         void *volatile p = calloc (PTRDIFF_MAX / n + 1, identity (n));
63         ASSERT (p == NULL);
64         ASSERT (errno == ENOMEM);
65 
66 	p = calloc (SIZE_MAX / n + 1, identity (n));
67         ASSERT (p == NULL);
68         ASSERT (errno == ENOMEM);
69       }
70   }
71 
72   return 0;
73 }
74