1 /*
2 * Copyright (C) 2008-2021 Free Software Foundation, Inc.
3 * Written by Eric Blake and Bruno Haible
4 *
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 3 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 #include <config.h>
19
20 #include <string.h>
21
22 #include "signature.h"
23 SIGNATURE_CHECK (memchr, void *, (void const *, int, size_t));
24
25 #include <stdlib.h>
26
27 #include "zerosize-ptr.h"
28 #include "macros.h"
29
30 /* Calculating void * + int is not portable, so this wrapper converts
31 to char * to make the tests easier to write. */
32 #define MEMCHR (char *) memchr
33
34 int
main(void)35 main (void)
36 {
37 size_t n = 0x100000;
38 char *input = malloc (n);
39 ASSERT (input);
40
41 input[0] = 'a';
42 input[1] = 'b';
43 memset (input + 2, 'c', 1024);
44 memset (input + 1026, 'd', n - 1028);
45 input[n - 2] = 'e';
46 input[n - 1] = 'a';
47
48 /* Basic behavior tests. */
49 ASSERT (MEMCHR (input, 'a', n) == input);
50
51 ASSERT (MEMCHR (input, 'a', 0) == NULL);
52
53 {
54 void *page_boundary = zerosize_ptr ();
55 if (page_boundary)
56 ASSERT (MEMCHR (page_boundary, 'a', 0) == NULL);
57 }
58
59 ASSERT (MEMCHR (input, 'b', n) == input + 1);
60 ASSERT (MEMCHR (input, 'c', n) == input + 2);
61 ASSERT (MEMCHR (input, 'd', n) == input + 1026);
62
63 ASSERT (MEMCHR (input + 1, 'a', n - 1) == input + n - 1);
64 ASSERT (MEMCHR (input + 1, 'e', n - 1) == input + n - 2);
65 ASSERT (MEMCHR (input + 1, 0x789abc00 | 'e', n - 1) == input + n - 2);
66
67 ASSERT (MEMCHR (input, 'f', n) == NULL);
68 ASSERT (MEMCHR (input, '\0', n) == NULL);
69
70 /* Check that a very long haystack is handled quickly if the byte is
71 found near the beginning. */
72 {
73 size_t repeat = 10000;
74 for (; repeat > 0; repeat--)
75 {
76 ASSERT (MEMCHR (input, 'c', n) == input + 2);
77 }
78 }
79
80 /* Alignment tests. */
81 {
82 int i, j;
83 for (i = 0; i < 32; i++)
84 {
85 for (j = 0; j < 256; j++)
86 input[i + j] = j;
87 for (j = 0; j < 256; j++)
88 {
89 ASSERT (MEMCHR (input + i, j, 256) == input + i + j);
90 }
91 }
92 }
93
94 /* Check that memchr() does not read past the first occurrence of the
95 byte being searched. See the Austin Group's clarification
96 <https://www.opengroup.org/austin/docs/austin_454.txt>.
97 Test both '\0' and something else, since some implementations
98 special-case searching for NUL.
99 */
100 {
101 char *page_boundary = (char *) zerosize_ptr ();
102 /* Too small, and we miss cache line boundary tests; too large,
103 and the test takes cubically longer to complete. */
104 int limit = 257;
105
106 if (page_boundary != NULL)
107 {
108 for (n = 1; n <= limit; n++)
109 {
110 char *mem = page_boundary - n;
111 memset (mem, 'X', n);
112 ASSERT (MEMCHR (mem, 'U', n) == NULL);
113 ASSERT (MEMCHR (mem, 0, n) == NULL);
114
115 {
116 size_t i;
117 size_t k;
118
119 for (i = 0; i < n; i++)
120 {
121 mem[i] = 'U';
122 for (k = i + 1; k < n + limit; k++)
123 ASSERT (MEMCHR (mem, 'U', k) == mem + i);
124 mem[i] = 0;
125 for (k = i + 1; k < n + limit; k++)
126 ASSERT (MEMCHR (mem, 0, k) == mem + i);
127 mem[i] = 'X';
128 }
129 }
130 }
131 }
132 }
133
134 free (input);
135
136 return 0;
137 }
138