1 /* PR middle-end/78476 - snprintf(0, 0, ...) with known arguments not
2 optimized away
3 PR middle-end/78512 - r242674 miscompiles Linux kernel
4 A negative test complementing builtin-sprintf-5.c to verify that calls
5 to the function that do not return a constant are not optimized away.
6 Test also verifies that unknown directives prevent the optimization.
7 { dg-do compile }
8 { dg-options "-O2 -Wformat -fdump-tree-optimized" }
9 { dg-require-effective-target int32plus } */
10
11 typedef __SIZE_TYPE__ size_t;
12
13 #define CONCAT(a, b) a ## b
14 #define CAT(a, b) CONCAT (a, b)
15
16 #define T(...) \
17 do { \
18 int CAT (n, __LINE__) = __builtin_snprintf (0, 0, __VA_ARGS__); \
19 sink (CAT (n, __LINE__)); \
20 } while (0)
21
22 void sink (int);
23
24 static int
int_range(int min,int max)25 int_range (int min, int max)
26 {
27 extern int int_value (void);
28 int val = int_value ();
29 if (val < min || max < val)
30 val = min;
31 return val;
32 }
33
34 #define R(min, max) int_range (min, max)
35
test_arg_int(int width,int prec,int i,int n)36 void test_arg_int (int width, int prec, int i, int n)
37 {
38 T ("%i", i);
39 T ("%1i", i);
40 T ("%2i", i);
41 T ("%3i", i);
42 T ("%4i", i);
43
44 T ("%*i", width, 0);
45 T ("%*i", width, 1);
46 T ("%*i", width, i);
47
48 T ("%.*i", prec, 0);
49 T ("%.*i", prec, 1);
50 T ("%.*i", prec, i);
51 T ("%.*i", 0, i);
52
53 T ("%i", R (1, 10));
54
55 /* Each of the bounds of the ranges below results in just one byte
56 on output because they convert to the value 9 in type char, yet
57 other values in those ranges can result in up to four bytes.
58 For example, 4240 converts to -112. Verify that the output
59 isn't folded into a constant. This assumes __CHAR_BIT__ of 8. */
60 T ("%hhi", R (4104, 4360) + 1);
61 T ("%hhu", R (4104, 4360) + 1);
62
63 /* Here, the range includes all possible lengths of output for
64 a 16-bit short and 32-bit int. */
65 T ("%hi", R (65536, 65536 * 2));
66 T ("%hu", R (65536, 65536 * 2));
67
68 T ("%'i", 1234567);
69
70 for (i = -n; i != n; ++i)
71 T ("%*x", n, i);
72 }
73
74 /* Support for %p was removed in response to PR middle-end/78512 due
75 to the Linux kernel relying on GCC builtins while at the same time
76 providing a large number of extensions to the %p directive that
77 interfere with the optimization. Verify that %p disables it. */
78
test_arg_ptr(int width,int prec,int i)79 void test_arg_ptr (int width, int prec, int i)
80 {
81 T ("%p", (void*)0);
82 T ("p=%p", (void*)0);
83 T ("%s=%p", "p=", (void*)0);
84 T ("%i%p", 123, (void*)0);
85 }
86
test_arg_string(int width,int prec,const char * s)87 void test_arg_string (int width, int prec, const char *s)
88 {
89 T ("%-s", s);
90 T ("%1s", s);
91 T ("%.1s", s);
92 T ("%*s", width, s);
93 T ("%.*s", prec, s);
94 T ("%1.*s", prec, s);
95 T ("%*.1s", width, s);
96 T ("%*.*s", width, prec, s);
97 T ("%*s", width, "123");
98 T ("%.*s", prec, "123");
99 T ("%1.*s", prec, "123");
100 T ("%*.1s", width, "123");
101 T ("%*.*s", width, prec, "123");
102 }
103
test_invalid_directive(void)104 void test_invalid_directive (void)
105 {
106 T ("%"); /* { dg-warning "spurious trailing .%." } */
107 T ("abc%"); /* { dg-warning "spurious trailing .%." } */
108
109 T ("%2$i"); /* { dg-warning "operand number out of range" } */
110 T ("abc%2$i"); /* { dg-warning "operand number out of range" } */
111
112 T ("%=i", 0); /* { dg-warning "unknown conversion type character .=." } */
113 /* { dg-warning "too many arguments" "" { target *-*-* } .-1 } */
114
115 T ("%*i", "", 0); /* { dg-warning "field width specifier .\\*. expects argument of type .int." } */
116 T ("%.*i", "", 0); /* { dg-warning "field precision specifier .\\.\\*. expects argument of type .int." } */
117 T ("%.*.i", 0); /* { dg-warning "unknown conversion type character .\\.." } */
118 T ("%Q"); /* { dg-warning "unknown conversion type character .Q." } */
119 T ("abc%Q"); /* { dg-warning "unknown conversion type character .Q." } */
120 }
121
122
123 /* Use 'grep "^ *T (" builtin-sprintf-6.c | wc -l' to determine
124 the count for the directive below.
125 { dg-final { scan-tree-dump-times "snprintf" 46 "optimized"} } */
126