1 /* PR tree-optimization/79376 - wrong lower bound with %s and non-constant
2 strings in -Wformat-overflow
3 { dg-do compile }
4 { dg-options "-O2 -fdump-tree-optimized" } */
5
6 #define CAT(s, n) s ## n
7 #define FAIL(line) CAT (failure_on_line_, line)
8
9 /* Emit a call to a function named failure_on_line_NNN when EXPR is false. */
10 #define ASSERT(expr) \
11 do { \
12 extern void FAIL (__LINE__)(void); \
13 if (!(expr)) FAIL (__LINE__)(); \
14 } while (0)
15
16 #define KEEP(line) CAT (keep_call_on_line_, line)
17
18 /* Emit a call to a function named keep_call_on_line_NNN when EXPR is true.
19 Used to verify that the expression need not be the only one that holds. */
20 #define ASSERT_MAYBE(expr) \
21 do { \
22 extern void KEEP (__LINE__)(void); \
23 if (expr) KEEP (__LINE__)(); \
24 } while (0)
25
26 struct Arrays
27 {
28 char a1[1];
29 char a2[2];
30 char a3[3];
31 char a4[4];
32 char a5[5];
33 char ax[];
34 };
35
test_arrays(int i,struct Arrays * a)36 void test_arrays (int i, struct Arrays *a)
37 {
38 {
39 const char *s = i < 0 ? a->a3 : a->a1;
40
41 int n = __builtin_snprintf (0, 0, "%-s", s);
42
43 /* Since it's undefined to pass an unterminated array to a %s
44 directive it would be valid to assume that S above is not
45 longer than sizeof (A->A3) but the optimization isn't done
46 because the GIMPLE representation of the %s argument isn't
47 suffficiently reliable not to confuse it for some other
48 array. The argument length is therefore assumed to be in
49 the range [0, PTRDIFF_MAX - 2] and the sprintf result to be
50 as big as INT_MAX and possibly even negative if the function
51 were to fail due to a single directive resulting in more than
52 the 4,095 byte maximum required to be supported.
53 ASSERT (0 <= n && n < 3);
54 */
55
56 ASSERT_MAYBE (0 == n);
57 ASSERT_MAYBE (1 == n);
58 ASSERT_MAYBE (2 == n);
59 }
60
61 {
62 const char *s = i < 0 ? a->a3 : a->a5;
63
64 int n = __builtin_snprintf (0, 0, "%-s", s);
65
66 /* ASSERT (0 <= n && n < 5); */
67
68 ASSERT_MAYBE (0 == n);
69 ASSERT_MAYBE (1 == n);
70 ASSERT_MAYBE (2 == n);
71 ASSERT_MAYBE (3 == n);
72 ASSERT_MAYBE (4 == n);
73 }
74 }
75
test_string_and_array(int i,struct Arrays * a)76 void test_string_and_array (int i, struct Arrays *a)
77 {
78 {
79 const char *s = i < 0 ? a->a3 : "1";
80
81 int n = __builtin_snprintf (0, 0, "%-s", s);
82
83 /* ASSERT (0 <= n && n < 3); */
84
85 ASSERT_MAYBE (0 == n);
86 ASSERT_MAYBE (1 == n);
87 ASSERT_MAYBE (2 == n);
88 }
89
90 {
91 const char *s = i < 0 ? "12" : a->a5;
92
93 int n = __builtin_snprintf (0, 0, "%-s", s);
94
95 /* ASSERT (0 <= n && n < 5); */
96
97 ASSERT_MAYBE (0 == n);
98 ASSERT_MAYBE (1 == n);
99 ASSERT_MAYBE (2 == n);
100 ASSERT_MAYBE (3 == n);
101 ASSERT_MAYBE (4 == n);
102 }
103
104 {
105 const char *s = i < 0 ? a->a4 : 0 < i ? "12" : a->a5;
106
107 int n = __builtin_snprintf (0, 0, "%-s", s);
108
109 /* ASSERT (0 <= n && n < 5); */
110
111 ASSERT_MAYBE (0 == n);
112 ASSERT_MAYBE (1 == n);
113 ASSERT_MAYBE (2 == n);
114 ASSERT_MAYBE (3 == n);
115 ASSERT_MAYBE (4 == n);
116 }
117 }
118
119 /* { dg-final { scan-tree-dump-not "failure_on_line" "optimized"} }
120 { dg-final { scan-tree-dump-times "keep_call_on_line" 21 "optimized"} } */
121