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
| // RUN: %clang_cc1 -fsyntax-only -Wself-assign -verify %s
void f() {
int a = 42, b = 42;
a = a; // expected-warning{{explicitly assigning}}
b = b; // expected-warning{{explicitly assigning}}
a = b;
b = a = b;
a = a = a; // expected-warning{{explicitly assigning}}
a = b = b = a;
a *= a;
a /= a;
a %= a;
a += a;
a -= a;
a <<= a;
a >>= a;
a &= a; // expected-warning {{explicitly assigning}}
a |= a; // expected-warning {{explicitly assigning}}
a ^= a;
}
// Dummy type.
struct S {};
void false_positives() {
#define OP =
#define LHS a
#define RHS a
int a = 42;
// These shouldn't warn due to the use of the preprocessor.
a OP a;
LHS = a;
a = RHS;
LHS OP RHS;
#undef OP
#undef LHS
#undef RHS
// A way to silence the warning.
a = (int &)a;
// Volatile stores aren't side-effect free.
volatile int vol_a;
vol_a = vol_a;
volatile int &vol_a_ref = vol_a;
vol_a_ref = vol_a_ref;
}
// Do not diagnose self-assigment in an unevaluated context
void false_positives_unevaluated_ctx(int a) noexcept(noexcept(a = a)) // expected-warning {{expression with side effects has no effect in an unevaluated context}}
{
decltype(a = a) b = a; // expected-warning {{expression with side effects has no effect in an unevaluated context}}
static_assert(noexcept(a = a), ""); // expected-warning {{expression with side effects has no effect in an unevaluated context}}
static_assert(sizeof(a = a), ""); // expected-warning {{expression with side effects has no effect in an unevaluated context}}
}
template <typename T>
void g() {
T a;
a = a; // expected-warning{{explicitly assigning}}
}
void instantiate() {
g<int>();
g<S>();
}
|