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