1 /* PR tree-optimization/90879 - fold zero-equality of strcmp between
2 a longer string and a smaller array
3 Test for a warning for strcmp of a longer string against smaller
4 array.
5 { dg-do compile }
6 { dg-options "-O2 -Wall -Wstring-compare -Wno-stringop-truncation -ftrack-macro-expansion=0" } */
7
8 typedef __SIZE_TYPE__ size_t;
9
10 extern void* memcpy (void*, const void*, size_t);
11
12 extern int strcmp (const char*, const char*);
13 extern size_t strlen (const char*);
14 extern char* strcpy (char*, const char*);
15 extern char* strncpy (char*, const char*, size_t);
16 extern int strncmp (const char*, const char*, size_t);
17
18 void sink (int, ...);
19 #define sink(...) sink (__LINE__, __VA_ARGS__)
20
21
22 extern char a1[1], a2[2], a3[3], a4[4], a5[5], a6[6], a7[7], a8[8], a9[9];
23
24 #define T(a, b) sink (0 == strcmp (a, b))
25
26
27 void test_string_cst (void)
28 {
29 const char *s1 = "1", *s2 = "12";
30
31 T (s1, a1); // { dg-warning ".strcmp. of a string of length 1 and an array of size 1 evaluates to nonzero" }
32 T (s1, a2);
33 T (s1, a3);
34
35 T (a1, s1); // { dg-warning ".strcmp. of a string of length 1 and an array of size 1 evaluates to nonzero" }
36 T (a2, s1);
37 T (a3, s1);
38
39 T (s2, a1); // { dg-warning ".strcmp. of a string of length 2 and an array of size 1 evaluates to nonzero" }
40 T (s2, a2); // { dg-warning ".strcmp. of a string of length 2 and an array of size 2 evaluates to nonzero" }
41 T (s2, a3);
42
43 T (a1, s2); // { dg-warning ".strcmp. of a string of length 2 and an array of size 1 evaluates to nonzero" }
44 T (a2, s2); // { dg-warning ".strcmp. of a string of length 2 and an array of size 2 evaluates to nonzero" }
45 T (a3, s2);
46 }
47
48
49 void test_string_cst_off_cst (void)
50 {
51 const char *s1 = "1", *s2 = "12", *s3 = "123", *s4 = "1234";
52
53 T (s1, a2 + 1); // { dg-warning ".strcmp. of a string of length 1 and an array of size 1 evaluates to nonzero" }
54 T (a2 + 1, s1); // { dg-warning ".strcmp. of a string of length 1 and an array of size 1 evaluates to nonzero" }
55
56
57 T (s3 + 1, a2); // { dg-warning ".strcmp. of a string of length 2 and an array of size 2 evaluates to nonzero" }
58 T (s3 + 1, a3);
59
60 T (s2, a4 + 1);
61 T (s2, a4 + 2); // { dg-warning ".strcmp. of a string of length 2 and an array of size 2 evaluates to nonzero" }
62
63 T (s4, a4 + 1); // { dg-warning ".strcmp. of a string of length 4 and an array of size 3 evaluates to nonzero" }
64 T (s3, a5 + 1);
65 }
66
67
68 /* Use strncpy below rather than memcpy until PR 91183 is resolved. */
69
70 #undef T
71 #define T(s, n, a) \
72 do { \
73 char arr[32]; \
74 sink (arr); \
75 strncpy (arr, s, n < 0 ? strlen (s) + 1: n); \
76 sink (0 == strcmp (arr, a)); \
77 } while (0)
78
79 void test_string_exact_length (void)
80 {
81 const char *s1 = "1", *s2 = "12";
82
83 T (s1, -1, a1); // { dg-warning ".strcmp. of a string of length 1 and an array of size 1 evaluates to nonzero" }
84 T (s1, -1, a2);
85 T (s1, -1, a3);
86
87 T (s2, -1, a1); // { dg-warning ".strcmp. of a string of length 2 and an array of size 1 evaluates to nonzero" }
88 T (s2, -1, a2); // { dg-warning ".strcmp. of a string of length 2 and an array of size 2 evaluates to nonzero" }
89 T (s2, -1, a3);
90 }
91
92
93 void test_string_min_length (void)
94 {
95 const char *s1 = "1", *s2 = "12";
96
97 T (s1, 1, a1); // { dg-warning ".strcmp. of a string of length 1 or more and an array of size 1 evaluates to nonzero" }
98 T (s1, 1, a2);
99 T (s1, 1, a3);
100
101 T (s2, 2, a1); // { dg-warning ".strcmp. of a string of length 2 or more and an array of size 1 evaluates to nonzero" }
102 T (s2, 2, a2); // { dg-warning ".strcmp. of a string of length 2 or more and an array of size 2 evaluates to nonzero" }
103 T (s2, 2, a3);
104 }
105
106
107 int test_strncmp_str_lit_var (const char *s, long n)
108 {
109 if (strncmp (s, "123456", n) == 0) // { dg-bogus "\\\[-Wstring-compare" }
110 return 1;
111
112 return 0;
113 }
114
115 int test_strlen_strncmp_str_lit_var (const char *s, long n)
116 {
117 if (__builtin_strlen (s) < n)
118 return -1;
119
120 if (n == 6)
121 if (strncmp (s, "123456", n) == 0) // { dg-bogus "\\\[-Wstring-compare" }
122 return 1;
123
124 return 0;
125 }
126
127