1 /* PR middle-end/95667 - unintended warning for memset writing across multiple
2 members
3 { dg-do compile }
4 { dg-options "-O2 -Wall" }
5 { dg-require-effective-target alloca } */
6
7 extern void sink (void*);
8
9 struct S1 { char a[3], b[5]; };
10
warn_strcpy_s1(void)11 void warn_strcpy_s1 (void)
12 {
13 struct S1 *p = __builtin_malloc (sizeof *p);
14 char s[] = "1234567";
15 __builtin_strcpy (p->a, s); // { dg-warning "\\\[-Wstringop-overflow" }
16 sink (p);
17 }
18
nowarn_memset_s1(void)19 void nowarn_memset_s1 (void)
20 {
21 struct S1 *p = __builtin_malloc (sizeof *p);
22 __builtin_memset (p->a, 0, 8); // { dg-bogus "\\\[-Wstringop-overflow" }
23 sink (p);
24 }
25
26 struct S2 { char a[2], b[2][2], c[3]; };
27
nowarn_memset_s2(void)28 void nowarn_memset_s2 (void)
29 {
30 struct S2 *p = __builtin_malloc (sizeof *p);
31
32 __builtin_memset (p->a, 0, sizeof *p);
33 sink (p);
34
35 __builtin_memset (p->b, 0, 7);
36 sink (p);
37
38 __builtin_memset (&p->b[0], 0, 7);
39 sink (p);
40
41 __builtin_memset (&p->b[1], 0, 5);
42 sink (p);
43
44 __builtin_memset (&p->b[0][0], 0, 7);
45 sink (p);
46
47 __builtin_memset (&p->b[0][1], 0, 6);
48 sink (p);
49
50 __builtin_memset (&p->b[1][0], 0, 5);
51 sink (p);
52
53 __builtin_memset (&p->b[1][1], 0, 4);
54 sink (p);
55 }
56
warn_memset_s2(void)57 void warn_memset_s2 (void)
58 {
59 const unsigned n = sizeof (struct S2);
60 struct S2 *p = __builtin_malloc (n);
61
62 /* These should trigger -Wstringop-overflow rather than -Warray-bounds
63 but the main purpose of the test is to verify the absence of warnings
64 above so the exact warning for these overflwing calls isn't important
65 here. */
66
67 __builtin_memset (p->a, 0, n + 1); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
68 sink (p);
69
70 __builtin_memset (p->b, 0, 8); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
71 sink (p);
72
73 __builtin_memset (&p->b[0], 0, 8); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
74 sink (p);
75
76 __builtin_memset (&p->b[0][0], 0, 8); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
77 sink (p);
78
79 __builtin_memset (&p->b[1], 0, 6); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
80 sink (p);
81
82 __builtin_memset (&p->b[0][1], 0, 7); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
83 sink (p);
84 }
85
nowarn_vl_struct(unsigned n)86 void nowarn_vl_struct (unsigned n)
87 {
88 if (n < 3 || 5 < n)
89 n = 3;
90
91 struct V { char a[3], b[n], c[7]; } v;
92
93 __builtin_memset (v.a, 0, 15);
94 sink (&v);
95
96 __builtin_memset (v.b, 0, 12);
97 sink (&v);
98
99 __builtin_memset (v.c, 0, 7);
100 sink (&v);
101
102 __builtin_memset (v.a, 0, 16); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
103 sink (&v);
104
105 __builtin_memset (v.b, 0, 13); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
106 sink (&v);
107
108 /* The &V.C argument is represented as a variable offset from
109 the beginning of the allocated object and there's no good
110 way to figure out from its variable offset that it's base
111 is the C member:
112 s.1_12 = __builtin_alloca_with_align (prephitmp_24, 8);
113 _9 = s.1_12 + prephitmp_27;
114 __builtin_memset (_9, 0, 2);
115 */
116
117 __builtin_memset (v.c, 0, 8); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" "pr?????" { xfail *-*-* } }
118 sink (&v);
119 }
120