1 /* PR tree-optimization/101397 - spurious warning writing to the result
2 of stpcpy minus 1
3 Verify warnings for indexing into a pointer returned from mempcpy.
4 The call mempcpy(S1, S2, N) returns &S1[N].
5 { dg-do compile }
6 { dg-options "-O2 -Wall" } */
7
8 typedef __SIZE_TYPE__ size_t;
9
10 void* mempcpy (void*, const void*, size_t);
11
12 extern char ax[], a3[3], a5[5], a7[7], *s;
13
14 volatile int x;
15
16 /* Verify warnings for indexing into the result of mempcpy with a source
17 pointing to an array of unknown bound. */
18
19 void test_mempcpy_from_ptr (int i)
20 {
21 {
22 char *p = mempcpy (ax, s, 5);
23 x = p[-6]; // { dg-warning "\\\[-Warray-bounds" }
24 x = p[-5];
25 x = p[-1];
26 x = p[ 0];
27 x = p[ 9];
28 }
29
30 {
31 char *p = mempcpy (a5, s, 3);
32 x = p[-4]; // { dg-warning "\\\[-Warray-bounds" }
33 x = p[-3];
34 x = p[-2];
35 x = p[-1];
36 x = p[ 0];
37 x = p[ 1];
38 x = p[ 2]; // { dg-warning "\\\[-Warray-bounds" }
39 }
40
41 {
42 char *p = mempcpy (a5, s, 4);
43 x = p[-5]; // { dg-warning "\\\[-Warray-bounds" }
44 x = p[-4];
45 x = p[-3];
46 x = p[-2];
47 x = p[-1];
48 x = p[ 0];
49 x = p[ 1]; // { dg-warning "\\\[-Warray-bounds" }
50 }
51
52 {
53 char *p = mempcpy (a5, s, 4);
54
55 if (i > -1) i = -1;
56 x = p[i];
57
58 if (i > -2) i = -2;
59 x = p[i];
60
61 if (i > -3) i = -3;
62 x = p[i];
63
64 if (i > -4) i = -4;
65 x = p[i];
66
67 if (i > -5) i = -5;
68 x = p[i]; // { dg-warning "\\\[-Warray-bounds" }
69 }
70 }
71
72 /* Verify warnings for indexing into the result of mempcpy with a source
73 an array of size 5. */
74
75 void test_mempcpy_from_a5 (int i, int n, int n3_9)
76 {
77 {
78 // The returned pointer is ax + 3 as specified by the bound.
79 char *p = mempcpy (ax, a5, 3);
80 x = p[-4]; // { dg-warning "\\\[-Warray-bounds" }
81 x = p[-3];
82 x = p[-2];
83 x = p[ 0];
84 x = p[ 1];
85 x = p[ 2];
86 }
87
88 {
89 // The returned pointer is ax + 5.
90 char *p = mempcpy (ax, a5, 5);
91 x = p[-6]; // { dg-warning "\\\[-Warray-bounds" }
92 x = p[-5];
93 x = p[-1];
94 x = p[ 0];
95 x = p[ 9];
96 }
97
98 {
99 //The returned pointer is in [ax, ax + 5] even though n is not known.
100 char *p = mempcpy (ax, a5, n);
101 x = p[-6]; // { dg-warning "\\\[-Warray-bounds" }
102 x = p[-5];
103 x = p[-1];
104 x = p[ 0];
105 x = p[ 9];
106 }
107
108
109 {
110 // The returned pointer is a3 + 3.
111 char *p = mempcpy (a3, a5, 3);
112 x = p[-4]; // { dg-warning "\\\[-Warray-bounds" }
113 x = p[-3];
114 x = p[-1];
115 x = p[ 0]; // { dg-warning "\\\[-Warray-bounds" }
116 x = p[ 1]; // { dg-warning "\\\[-Warray-bounds" }
117 }
118
119 {
120 // The returned pointer is in [a3, a3 + 3].
121 char *p = mempcpy (a3, a5, n);
122 x = p[-4]; // { dg-warning "\\\[-Warray-bounds" }
123 x = p[-3];
124 x = p[-2];
125 x = p[-1];
126 x = p[ 0];
127 x = p[ 2];
128 x = p[ 3]; // { dg-warning "\\\[-Warray-bounds" }
129 }
130
131 {
132 if (n3_9 < 3 || 9 < n3_9)
133 n3_9 = 3;
134
135 // The returned pointer is a3.
136 char *p = mempcpy (a3, a5, n3_9);
137 x = p[-4]; // { dg-warning "\\\[-Warray-bounds" }
138 x = p[-3];
139 x = p[-2];
140 x = p[-1];
141 x = p[ 0]; // { dg-warning "\\\[-Warray-bounds" }
142 }
143
144 {
145 char *p = mempcpy (a3, a5, 3);
146
147 if (i > -1) i = -1;
148 x = p[i];
149
150 if (i > -2) i = -2;
151 x = p[i];
152
153 if (i > -3) i = -3;
154 x = p[i];
155
156 if (i > -4) i = -4;
157 x = p[i]; // { dg-warning "\\\[-Warray-bounds" }
158 }
159 }
160
161
162 /* Verify warnings for indexing into the result of mempcpy with a source
163 an array of size 7. */
164
165 void test_mempcpy_from_a7 (int i, int n, int n3_9)
166 {
167 {
168 // The returned pointer is ax + 5.
169 char *p = mempcpy (ax, a7, 5);
170 x = p[-6]; // { dg-warning "\\\[-Warray-bounds" }
171 x = p[-5];
172 x = p[-1];
173 x = p[ 0];
174 x = p[ 9];
175 }
176
177 {
178 //The returned pointer is in [ax, ax + 7] even though n is not known.
179 char *p = mempcpy (ax, a7, n);
180 x = p[-8]; // { dg-warning "\\\[-Warray-bounds" }
181 x = p[-7];
182 x = p[-1];
183 x = p[ 0];
184 x = p[ 9];
185 }
186
187
188 {
189 // The returned pointer is a5 + 3 as specified by the bound.
190 char *p = mempcpy (a5, a7, 3);
191 x = p[-4]; // { dg-warning "\\\[-Warray-bounds" }
192 x = p[-3];
193 x = p[-2];
194 x = p[ 0];
195 x = p[ 1];
196 x = p[ 2]; // { dg-warning "\\\[-Warray-bounds" }
197 }
198
199 {
200 // The returned pointer is a5 + 4.
201 char *p = mempcpy (a5, a7, 4);
202 x = p[-5]; // { dg-warning "\\\[-Warray-bounds" }
203 x = p[-4];
204 x = p[-3];
205 x = p[-2];
206 x = p[-1];
207 x = p[ 0];
208 x = p[ 1]; // { dg-warning "\\\[-Warray-bounds" }
209 }
210
211 {
212 // The returned pointer is in [a5, a5 + 5].
213 char *p = mempcpy (a5, a7, n);
214 x = p[-6]; // { dg-warning "\\\[-Warray-bounds" }
215 x = p[-5];
216 x = p[-3];
217 x = p[-2];
218 x = p[-1];
219 x = p[ 0];
220 x = p[ 4];
221 x = p[ 5]; // { dg-warning "\\\[-Warray-bounds" }
222 }
223
224 {
225 if (n3_9 < 3 || 9 < n3_9)
226 n3_9 = 3;
227
228 // The returned pointer is in [a5 + 3, a5 + 5].
229 char *p = mempcpy (a5, a7, n3_9);
230 x = p[-6]; // { dg-warning "\\\[-Warray-bounds" }
231 x = p[-5];
232 x = p[-3];
233 x = p[-2];
234 x = p[-1];
235 x = p[ 0];
236 x = p[ 1];
237 x = p[ 2]; // { dg-warning "\\\[-Warray-bounds" }
238 }
239
240 {
241 char *p = mempcpy (a5, a7, 4);
242
243 if (i > -1) i = -1;
244 x = p[i];
245
246 if (i > -2) i = -2;
247 x = p[i];
248
249 if (i > -3) i = -3;
250 x = p[i];
251
252 if (i > -4) i = -4;
253 x = p[i];
254
255 if (i > -5) i = -5;
256 x = p[i]; // { dg-warning "\\\[-Warray-bounds" }
257 }
258 }