1 /* PR middle-end/79376 - wrong lower bound with %s and non-constant
2 strings in -Wformat-overflow
3 { dg-do compile }
4 { dg-options "-O2 -Wall -Wformat-overflow=1 -ftrack-macro-expansion=0" } */
5
6 typedef __SIZE_TYPE__ size_t;
7
8 #define INT_MAX __INT_MAX__
9 #define INT_MIN (-INT_MAX - 1)
10
11 /* When debugging, define LINE to the line number of the test case to exercise
12 and avoid exercising any of the others. The buffer and objsize macros
13 below make use of LINE to avoid warnings for other lines. */
14 #ifndef LINE
15 # define LINE 0
16 #endif
17
18 extern int int_value (void);
19
20 static int int_range (int min, int max)
21 {
22 int n = int_value ();
23 return n < min || max < n ? min : n;
24 }
25
26 static const char*
27 choose_string (const char *s1, const char *s2, const char *s3)
28 {
29 int i = int_value ();
30 return i < 0 ? s1 : 0 < i ? s3 : s2;
31 }
32
33 void sink (char*, char*);
34
35 int dummy_sprintf (char*, const char*, ...);
36
37 char buffer [256];
38 extern char *ptr;
39
40 const char s0[] = "";
41 const char s1[] = "1";
42 const char s2[] = "12";
43 const char s3[] = "123";
44 const char s4[] = "1234";
45 const char s5[] = "12345";
46 const char s6[] = "123456";
47 const char s7[] = "1234567";
48 const char s8[] = "12345678";
49 const char s9[] = "123456789";
50 extern const char sx[];
51 extern const char sy[];
52
53 /* Evaluate to an array of SIZE characters when non-negative, or to
54 a pointer to an unknown object otherwise. */
55 #define buffer(size) \
56 ((0 <= size) ? buffer + sizeof buffer - (size) : ptr)
57
58 /* Helper to expand function to either __builtin_f or dummy_f to
59 make debugging GCC easy. */
60 #define FUNC(f) \
61 ((!LINE || LINE == __LINE__) ? __builtin_ ## f : dummy_ ## f)
62
63 /* Macro to verify that calls to __builtin_sprintf (i.e., with no size
64 argument) issue diagnostics by correctly determining the size of
65 the destination buffer. */
66 #define T(size, ...) \
67 (FUNC (sprintf) (buffer (size), __VA_ARGS__), \
68 sink (buffer, ptr))
69
70 /* Return a value in the range [MIN, MAX]. */
71 #define R(min, max) int_range (min, max)
72
73 /* Return one of the strings S1, S2, S3. */
74 #define S(s1, s2, s3) choose_string (s1, s2, s3)
75
76 struct S {
77 char a1[1];
78 char a2[2];
79 char a3[3];
80 char a4[4];
81 char a5[5];
82 char ax[];
83 };
84
85 void test_strings (struct S *s)
86 {
87 T (0, "%-s", S (s->a1, s->a1, s1)); /* { dg-warning "writing up to 1 byte" } */
88 T (0, "%-s", S (s->a1, s->a2, s1)); /* { dg-warning "writing up to 1 byte" } */
89 T (0, "%-s", S (s->a2, s->a1, s1)); /* { dg-warning "writing up to 1 byte" } */
90
91 T (0, "%-s", S (s->a1, s1, s->a1)); /* { dg-warning "writing up to 1 byte" } */
92 T (0, "%-s", S (s->a1, s1, s->a2)); /* { dg-warning "writing up to 1 byte" } */
93 T (0, "%-s", S (s->a2, s1, s->a1)); /* { dg-warning "writing up to 1 byte" } */
94
95 T (0, "%-s", S (s1, s->a1, s1)); /* { dg-warning "writing up to 1 byte" } */
96 T (0, "%-s", S (s1, s->a1, s1)); /* { dg-warning "writing up to 1 byte" } */
97 T (0, "%-s", S (s1, s->a2, s1)); /* { dg-warning "writing up to 1 byte" } */
98
99 T (0, "%-s", S (s->a1, s->a1, s2)); /* { dg-warning "writing up to 2 bytes" } */
100 T (0, "%-s", S (s->a1, s->a2, s2)); /* { dg-warning "writing up to 2 bytes" } */
101 T (0, "%-s", S (s->a2, s->a1, s2)); /* { dg-warning "writing up to 2 bytes" } */
102
103 T (0, "%-s", S (s->a1, s2, s->a1)); /* { dg-warning "writing up to 2 bytes" } */
104 T (0, "%-s", S (s->a1, s2, s->a2)); /* { dg-warning "writing up to 2 bytes" } */
105 T (0, "%-s", S (s->a2, s2, s->a1)); /* { dg-warning "writing up to 2 bytes" } */
106
107 T (0, "%-s", S (s2, s->a1, s1)); /* { dg-warning "writing up to 2 bytes" } */
108 T (0, "%-s", S (s2, s->a1, s1)); /* { dg-warning "writing up to 2 bytes" } */
109 T (0, "%-s", S (s2, s->a2, s1)); /* { dg-warning "writing up to 2 bytes" } */
110
111 T (0, "%-s", S (s->a1, s->a1, s2)); /* { dg-warning "writing up to 2 bytes" } */
112 T (0, "%-s", S (s->a1, s->a2, s2)); /* { dg-warning "writing up to 2 bytes" } */
113 T (0, "%-s", S (s->a2, s->a1, s2)); /* { dg-warning "writing up to 2 bytes" } */
114
115 T (0, "%-s", S (s->a1, s2, s->a1)); /* { dg-warning "writing up to 2 bytes" } */
116 T (0, "%-s", S (s->a1, s2, s->a2)); /* { dg-warning "writing up to 2 bytes" } */
117 T (0, "%-s", S (s->a2, s2, s->a1)); /* { dg-warning "writing up to 2 bytes" } */
118
119 T (0, "%-s", S (s2, s->a1, s1)); /* { dg-warning "writing up to 2 bytes" } */
120 T (0, "%-s", S (s3, s->a1, s2)); /* { dg-warning "writing up to 3 bytes" } */
121 T (0, "%-s", S (s4, s->a2, s3)); /* { dg-warning "writing up to 4 bytes" } */
122
123 T (0, "%-s", S (s->a3, s->a5, s3)); /* { dg-warning "writing up to 4 bytes" } */
124 T (0, "%-s", S (s->a3, s->a5, s3)); /* { dg-warning "writing up to 4 bytes" } */
125 T (0, "%-s", S (s->a3, s->a5, s3)); /* { dg-warning "writing up to 4 bytes" } */
126
127 T (0, "%-s", S (s->a3, s3, s->a5)); /* { dg-warning "writing up to 4 bytes" } */
128 T (0, "%-s", S (s->a5, s3, s->a3)); /* { dg-warning "writing up to 4 bytes" } */
129 T (0, "%-s", S (s->a3, s3, s->a5)); /* { dg-warning "writing up to 4 bytes" } */
130
131 T (0, "%-s", S (s3, s->a1, s4)); /* { dg-warning "writing up to 4 bytes" } */
132 T (0, "%-s", S (s4, s->a2, s3)); /* { dg-warning "writing up to 4 bytes" } */
133 }
134
135 void test_strings_with_width (struct S *s)
136 {
137 T (0, "%*s", /* { dg-warning "writing up to 4 bytes" } */
138 R (0, 1),
139 S (s->a3, s->a5, s3));
140
141 T (0, "%*s", /* { dg-warning "writing up to 4 bytes" } */
142 R (0, 4),
143 S (s->a3, s->a5, s3));
144
145 T (0, "%*s", /* { dg-warning "writing between 1 and 4 bytes" } */
146 R (1, 4),
147 S (s->a3, s->a5, s3));
148
149 T (0, "%*s", /* { dg-warning "writing between 2 and 4 bytes" } */
150 R (2, 4),
151 S (s->a3, s->a5, s3));
152
153 T (0, "%*s", /* { dg-warning "writing between 3 and 4 bytes" } */
154 R (3, 4),
155 S (s->a3, s->a5, s3));
156
157 T (0, "%*s", /* { dg-warning "writing between 3 and 5 bytes" } */
158 R (3, 5),
159 S (s->a3, s->a5, s3));
160
161 T (0, "%*s", /* { dg-warning "writing between 3 and 9 bytes" } */
162 R (3, 9),
163 S (s->a3, s->a5, s3));
164
165 T (3, "%*s", /* { dg-warning "writing between 3 and 9 bytes" } */
166 R (3, 9),
167 S (s->a3, s->a5, s3));
168
169 /* The longest string fits but the terminating nul will overflow. Since
170 the null won't overflow with the shorter strings the warning is a "may
171 write." */
172 T (4, "%*s", /* { dg-warning "may write a terminating nul" } */
173 R (3, 9),
174 S (s->a3, s->a5, s3));
175 }
176
177 void test_strings_with_width_and_precisin (struct S *s)
178 {
179 T (0, "%*.*s", /* { dg-warning "writing up to 1 byte" } */
180 R (0, 1),
181 R (0, 1),
182 S (s->a3, s->a5, s3));
183
184 T (0, "%*.*s", /* { dg-warning "writing up to 2 bytes" } */
185 R (0, 2),
186 R (0, 1),
187 S (s->a3, s->a5, s3));
188
189 T (0, "%*.*s", /* { dg-warning "writing up to 9 bytes" } */
190 R (0, 9),
191 R (0, 1),
192 S (s->a3, s->a5, s3));
193
194 /* Since the longest string/array fits there is no warning even if
195 the maximum width would cause overflow. */
196 T (6, "%*.*s",
197 R (0, 9),
198 R (0, 1),
199 S (s->a3, s->a5, s3));
200
201 T (0, "%*.*s", /* { dg-warning "writing up to 2 bytes" } */
202 R (0, 2),
203 R (0, 2),
204 S (s->a3, s->a5, s3));
205
206 T (0, "%*.*s", /* { dg-warning "writing up to 3 bytes" } */
207 R (0, 3),
208 R (0, 2),
209 S (s->a3, s->a5, s3));
210 }