1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
// RUN: %clang_cc1 -fsyntax-only -verify %s -Wno-unreachable-code
int foo(int X, int Y);
double sqrt(double X); // implicitly const because of no -fmath-errno!
void bar(volatile int *VP, int *P, int A,
_Complex double C, volatile _Complex double VC) {
VP == P; // expected-warning {{expression result unused}}
(void)A;
(void)foo(1,2); // no warning.
A == foo(1, 2); // expected-warning {{expression result unused}}
foo(1,2)+foo(4,3); // expected-warning {{expression result unused}}
*P; // expected-warning {{expression result unused}}
*VP; // no warning.
P[4]; // expected-warning {{expression result unused}}
VP[4]; // no warning.
__real__ C; // expected-warning {{expression result unused}}
__real__ VC;
// We know this can't change errno because of no -fmath-errno.
sqrt(A); // expected-warning {{ignoring return value of function declared with const attribute}}
}
extern void t1();
extern void t2();
void t3(int c) {
c ? t1() : t2();
}
// This shouldn't warn: the expr at the end of the stmtexpr really is used.
int stmt_expr(int x, int y) {
return ({int _a = x, _b = y; _a > _b ? _a : _b; });
}
void nowarn(unsigned char* a, unsigned char* b)
{
unsigned char c = 1;
*a |= c, *b += c;
// PR4633
int y, x;
((void)0), y = x;
}
void t4(int a) {
int b = 0;
if (a)
b == 1; // expected-warning{{expression result unused}}
else
b == 2; // expected-warning{{expression result unused}}
while (1)
b == 3; // expected-warning{{expression result unused}}
do
b == 4; // expected-warning{{expression result unused}}
while (1);
for (;;)
b == 5; // expected-warning{{expression result unused}}
for (b == 1;;) {} // expected-warning{{expression result unused}}
for (;b == 1;) {}
for (;;b == 1) {} // expected-warning{{expression result unused}}
}
// rdar://7186119
int t5f(void) __attribute__((warn_unused_result));
void t5() {
t5f(); // expected-warning {{ignoring return value of function declared with warn_unused_result}}
}
int fn1() __attribute__ ((warn_unused_result));
int fn2() __attribute__ ((pure));
int fn3() __attribute__ ((const));
// rdar://6587766
int t6() {
if (fn1() < 0 || fn2(2,1) < 0 || fn3(2) < 0) // no warnings
return -1;
fn1(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}}
fn2(92, 21); // expected-warning {{ignoring return value of function declared with pure attribute}}
fn3(42); // expected-warning {{ignoring return value of function declared with const attribute}}
__builtin_fabsf(0); // expected-warning {{ignoring return value of function declared with const attribute}}
return 0;
}
int t7 __attribute__ ((warn_unused_result)); // expected-warning {{'warn_unused_result' attribute only applies to function types}}
// PR4010
int (*fn4)(void) __attribute__ ((warn_unused_result));
void t8() {
fn4(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}}
}
void t9() __attribute__((warn_unused_result)); // expected-warning {{attribute 'warn_unused_result' cannot be applied to functions without return value}}
|
