1 /* PR tree-optimization/84468 - Inconsistent -Wstringop-truncation warnings
2 with -O2
3 { dg-do compile }
4 { dg-options "-O2 -Wstringop-truncation -ftrack-macro-expansion=0 -g" } */
5
6 #define strncpy __builtin_strncpy
7
8 struct A
9 {
10 char a[4];
11 };
12
no_pred_succ_lit(struct A * p)13 void no_pred_succ_lit (struct A *p)
14 {
15 /* The following is folded early on, before the strncpy statement
16 has a basic block. Verify that the case is handled gracefully
17 (i.e., there's no assumption that the statement does have
18 a basic block). */
19 strncpy (p->a, "1234", sizeof p->a - 1); /* { dg-warning "\\\[-Wstringop-truncation" } */
20 }
21
22 /* Verify a strncpy call in a basic block with no predecessor or
23 successor. */
no_pred_succ(struct A * p,const struct A * q)24 void no_pred_succ (struct A *p, const struct A *q)
25 {
26 strncpy (p->a, q->a, sizeof p->a - 1); /* { dg-warning "\\\[-Wstringop-truncation" } */
27 }
28
29
30 /* Verify a strncpy call in a basic block with no successor. */
no_succ(struct A * p,const struct A * q)31 void no_succ (struct A *p, const struct A *q)
32 {
33 if (q->a)
34 strncpy (p->a, q->a, sizeof p->a - 1); /* { dg-warning "\\\[-Wstringop-truncation" } */
35 }
36
37 /* Verify a strncpy call in a basic block with nul assignment in
38 a successor block. */
succ(struct A * p,const struct A * q)39 void succ (struct A *p, const struct A *q)
40 {
41 /* Verify that the assignment suppresses the warning for the conditional
42 strcnpy call. The conditional should be folded to true since the
43 address of an array can never be null (see bug 84470). */
44 if (q->a)
45 strncpy (p->a, q->a, sizeof p->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation" } */
46
47 p->a[sizeof p->a - 1] = 0;
48 }
49
50
succ_2(struct A * p,const struct A * q,int i)51 void succ_2 (struct A *p, const struct A *q, int i)
52 {
53 /* Same as above but with a conditional that cannot be eliminated. */
54 if (i < 0)
55 strncpy (p->a, q->a, sizeof p->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation" } */
56
57 p->a[sizeof p->a - 1] = 0;
58 }
59
60
61 /* Verify a strncpy call in a basic block with nul assignment in
62 the next successor block. */
next_succ(struct A * p,const struct A * q,int i,int j)63 int next_succ (struct A *p, const struct A *q, int i, int j)
64 {
65 /* Same as above but with a nested conditionals with else clauses. */
66 if (i < 0)
67 {
68 if (j < 0)
69 strncpy (p->a, q->a, sizeof p->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation" } */
70 }
71 else
72 __builtin_strcpy (p->a, q->a);
73
74 p->a[sizeof p->a - 1] = 0;
75 return 0;
76 }
77
78
next_succ_1(struct A * p,const struct A * q,int i,int j)79 int next_succ_1 (struct A *p, const struct A *q, int i, int j)
80 {
81 /* Same as above but with a nested conditionals with else clauses. */
82 if (i < 0)
83 {
84 if (j < 0)
85 strncpy (p->a, q->a, sizeof p->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation" } */
86 else
87 strncpy (p->a, q->a, sizeof p->a - 2); /* { dg-bogus "\\\[-Wstringop-truncation" } */
88 }
89
90 p->a[sizeof p->a - 2] = 0;
91 return 1;
92 }
93
94
next_succ_2(struct A * p,const struct A * q,int i,int j)95 int next_succ_2 (struct A *p, const struct A *q, int i, int j)
96 {
97 /* Same as above but with a nested conditionals with else clauses. */
98 if (i < 0)
99 {
100 if (j < 0)
101 strncpy (p->a, q->a, sizeof p->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation" } */
102 else
103 strncpy (p->a, q->a, sizeof p->a - 2); /* { dg-bogus "\\\[-Wstringop-truncation" } */
104 }
105 else
106 __builtin_strcpy (p->a, q->a);
107
108 p->a[sizeof p->a - 2] = 0;
109 return 2;
110 }
111
112
cond_succ_warn(struct A * p,const struct A * q,int i)113 void cond_succ_warn (struct A *p, const struct A *q, int i)
114 {
115 /* Verify that a conditional assignment doesn't suppress the warning. */
116 strncpy (p->a, q->a, sizeof p->a - 1); /* { dg-warning "\\\[-Wstringop-truncation" } */
117
118 if (i < 0)
119 p->a[sizeof p->a - 1] = 0;
120 }
121
cond_succ_nowarn(struct A * p,const struct A * q)122 void cond_succ_nowarn (struct A *p, const struct A *q)
123 {
124 /* Verify that distinct but provably equivalent conditionals are
125 recognized and don't trigger the warning. */
126 if (p != q)
127 strncpy (p->a, q->a, sizeof p->a - 1);
128
129 if (p->a != q->a)
130 p->a[sizeof p->a - 1] = 0;
131 }
132