1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
/* PR middle-end/103215 - bogus -Wstringop-overflow with two pointers with
different offsets each
Test for accesses into distinct arrays through pointers with different
offsets each.
If/when -Wstringop-overflow is enhanced to issue "maybe" kinds of
warnings some of the accesses here will trigger those and will need
updating.
{ dg-do compile }
{ dg-options "-O2 -Wall -ftrack-macro-expansion=0" } */
#define NOIPA __attribute__ ((noipa))
void sink (int[1]);
#define A(p, off) sink (p + off)
extern int a4[4], a8[8];
NOIPA void a4_p1_a8_p3 (int i)
{
int *a4_p1 = a4 + 1;
int *a8_p3 = a8 + 3;
int *q = i ? a4_p1 : a8_p3;
A (q, -4); // { dg-warning "-Wstringop-overflow" }
/* Because -3 is a valid offset into a8 but not a4, q must point
to the former and so subscripts between -3 and +4 refer to its
elements. */
A (q, -3); A (q, -2); A (q, -1); A (q, 0);
A (q, 1); A (q, 2); A (q, 3); A (q, 4);
A (q, 5); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
/* Both of the following are definitely out of bounds but the first isn't
diagnosed because the code conservatively merges the offsets into A4
and A8. */
A (q, 7); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void a4_p1_a8_p5 (int i)
{
int *a4_p1 = a4 + 1;
int *a8_p5 = a8 + 5;
int *q = i ? a4_p1 : a8_p5;
A (q, -6); // { dg-warning "-Wstringop-overflow" }
/* Similarly to the above, because -5 is a valid offset into a8 but
not a4, q must point to the former and so subscripts between -5
and +2 refer to its elements. */
A (q, -5); A (q, -4); A (q, -3); A (q, -2);
A (q, -1); A (q, 0); A (q, 1); A (q, 2);
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 7); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void a4_p1_a8_p7 (int i)
{
int *a4_p1 = a4 + 1;
int *a8_p7 = a8 + 7;
int *q = i ? a4_p1 : a8_p7;
A (q, -8); // { dg-warning "-Wstringop-overflow" }
A (q, -7); A (q, -6); A (q, -5); A (q, -4);
A (q, -3); A (q, -2); A (q, -1); A (q, 0);
/* Since -7 is valid, q must point to a8 and the last valid subscript
must be 0. */
A (q, 1); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 2); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 7); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void mp_1_a4_p1_a8_p7 (int i, int j)
{
int *a4_p1 = a4 + 1;
int *a8_p7 = a8 + 7;
int *p = i ? a4_p1 : a8_p7;
int *q = j ? p + 1 : p - 1;
A (q, -9); // { dg-warning "-Wstringop-overflow" }
/* q points either to a8 + [6, 8] or a4 + [0, 2]. */
A (q, -8); A (q, -7); A (q, -6); A (q, -5);
A (q, -4); A (q, -3); A (q, -2); A (q, -1);
/* Since all the above are valid, q must point to a8 + 8. But as
mentioned above, the warning for each subscript is independent
of prior subscripts into the same object so the access below
aren't diagnosed. */
A (q, 0); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 1); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 2); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 4); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 8); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void mp1_a4_p1_a8_p5 (int i, int j)
{
int *a4_p1 = a4 + 1;
int *a8_p5 = a8 + 5;
int *p = i ? a4_p1 : a8_p5;
int *q = j ? p + 1 : p - 1;
// q is assumed to point to a8 + 6
A (q, -7); // { dg-warning "-Wstringop-overflow" }
A (q, -6); A (q, -5); A (q, -4); A (q, -3);
A (q, -2); A (q, -1); A (q, 0); A (q, 1);
/* Even though the above accesses rule it out, q is now assumed
to point to either a4 + [0, 2] or a8 + [4, 5]. */
A (q, 2);
/* q is now assumed to point tp a4. Given that, only the first store
is valid. */
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 4); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 5); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 6); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 7); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 8); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void mp1_a4_p1_a8_p4 (int i, int j)
{
int *a4_p1 = a4 + 1;
int *a8_p4 = a8 + 4;
int *p = i ? a4_p1 : a8_p4;
int *q = j ? p + 1 : p - 1;
// q is assumed to point to a8 + 5
A (q, -6); // { dg-warning "-Wstringop-overflow" }
A (q, -5);
A (q, -4);
A (q, -3);
A (q, -2);
A (q, -1);
A (q, 0);
A (q, 1);
A (q, 2);
/* Even though the above accesses rule it out, q is now assumed
to point tp a4. Given that, only the first store is valid. */
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 4); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 5); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 6); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 7); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 8); // { dg-warning "-Wstringop-overflow" }
}
|
