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
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
| // RUN: %clang_cc1 -std=c++14 -verify -fsyntax-only -Wshadow -D AVOID %s
// RUN: %clang_cc1 -std=c++14 -verify -fsyntax-only -Wshadow -Wshadow-uncaptured-local %s
// RUN: %clang_cc1 -std=c++14 -verify -fsyntax-only -Wshadow-all %s
// RUN: %clang_cc1 -std=c++17 -verify -fsyntax-only -Wshadow-all %s
void foo(int param) { // expected-note 1+ {{previous declaration is here}}
int var = 0; // expected-note 1+ {{previous declaration is here}}
// Avoid warnings for variables that aren't implicitly captured.
{
#ifdef AVOID
auto f1 = [=] { int var = 1; }; // no warning
auto f2 = [&] { int var = 2; }; // no warning
auto f3 = [=] (int param) { ; }; // no warning
auto f4 = [&] (int param) { ; }; // no warning
#else
auto f1 = [=] { int var = 1; }; // expected-warning {{declaration shadows a local variable}}
auto f2 = [&] { int var = 2; }; // expected-warning {{declaration shadows a local variable}}
auto f3 = [=] (int param) { ; }; // expected-warning {{declaration shadows a local variable}}
auto f4 = [&] (int param) { ; }; // expected-warning {{declaration shadows a local variable}}
#endif
}
// Warn for variables that are implicitly captured.
{
auto f1 = [=] () {
{
int var = 1; // expected-warning {{declaration shadows a local variable}}
}
int x = var; // expected-note {{variable 'var' is captured here}}
};
auto f2 = [&]
#ifdef AVOID
(int param) {
#else
(int param) { // expected-warning {{declaration shadows a local variable}}
#endif
int x = var; // expected-note {{variable 'var' is captured here}}
int var = param; // expected-warning {{declaration shadows a local variable}}
};
}
// Warn for variables that are explicitly captured when a lambda has a default
// capture specifier.
{
auto f1 = [=, &var] () { // expected-note {{variable 'var' is captured here}}
int x = param; // expected-note {{variable 'param' is captured here}}
int var = 0; // expected-warning {{declaration shadows a local variable}}
int param = 0; // expected-warning {{declaration shadows a local variable}}
};
}
// Warn normally inside of lambdas.
auto l1 = [] { // expected-note {{previous declaration is here}}
int x = 1; // expected-note {{previous declaration is here}}
{ int x = 2; } // expected-warning {{declaration shadows a local variable}}
};
auto l2 = [] (int x) { // expected-note {{previous declaration is here}}
{ int x = 1; } // expected-warning {{declaration shadows a local variable}}
};
// Avoid warnings for variables that aren't explicitly captured.
{
#ifdef AVOID
auto f1 = [] { int var = 1; }; // no warning
auto f2 = [] (int param) { ; }; // no warning
auto f3 = [param] () { int var = 1; }; // no warning
auto f4 = [var] (int param) { ; }; // no warning
#else
auto f1 = [] { int var = 1; }; // expected-warning {{declaration shadows a local variable}}
auto f2 = [] (int param) { ; }; // expected-warning {{declaration shadows a local variable}}
auto f3 = [param] () { int var = 1; }; // expected-warning {{declaration shadows a local variable}}
auto f4 = [var] (int param) { ; }; // expected-warning {{declaration shadows a local variable}}
#endif
};
// Warn for variables that are explicitly captured.
{
auto f1 = [var] () { // expected-note {{variable 'var' is explicitly captured here}}
int var = 1; // expected-warning {{declaration shadows a local variable}}
};
auto f2 = [param] // expected-note {{variable 'param' is explicitly captured here}}
(int param) { ; }; // expected-error {{a lambda parameter cannot shadow an explicitly captured entity}}
}
// Warn for variables defined in the capture list.
auto l3 = [z = var] { // expected-note {{previous declaration is here}}
#ifdef AVOID
int var = 1; // no warning
#else
int var = 1; // expected-warning {{declaration shadows a local variable}}
#endif
{ int z = 1; } // expected-warning {{declaration shadows a local variable}}
};
#ifdef AVOID
auto l4 = [var = param] (int param) { ; }; // no warning
#else
auto l4 = [var = param] (int param) { ; }; // expected-warning {{declaration shadows a local variable}}
#endif
// Make sure that inner lambdas work as well.
auto l5 = [var, l1] { // expected-note {{variable 'l1' is explicitly captured here}}
auto l1 = [] { // expected-warning {{declaration shadows a local variable}}
#ifdef AVOID
int var = 1; // no warning
#else
int var = 1; // expected-warning {{declaration shadows a local variable}}
#endif
};
#ifdef AVOID
auto f1 = [] { int var = 1; }; // no warning
auto f2 = [=] { int var = 1; }; // no warning
#else
auto f1 = [] { int var = 1; }; // expected-warning {{declaration shadows a local variable}}
auto f2 = [=] { int var = 1; }; // expected-warning {{declaration shadows a local variable}}
#endif
auto f3 = [var] // expected-note {{variable 'var' is explicitly captured here}}
{ int var = 1; }; // expected-warning {{declaration shadows a local variable}}
auto f4 = [&] {
int x = var; // expected-note {{variable 'var' is captured here}}
int var = 2; // expected-warning {{declaration shadows a local variable}}
};
};
auto l6 = [&] {
auto f1 = [param] { // expected-note {{variable 'param' is explicitly captured here}}
int param = 0; // expected-warning {{declaration shadows a local variable}}
};
};
// Generic lambda arguments should work.
#ifdef AVOID
auto g1 = [](auto param) { ; }; // no warning
auto g2 = [=](auto param) { ; }; // no warning
#else
auto g1 = [](auto param) { ; }; // expected-warning {{declaration shadows a local variable}}
auto g2 = [=](auto param) { ; }; // expected-warning {{declaration shadows a local variable}}
#endif
auto g3 = [param] // expected-note {{variable 'param' is explicitly captured here}}
(auto param) { ; }; // expected-error {{a lambda parameter cannot shadow an explicitly captured entity}}
}
void avoidWarningWhenRedefining() {
int a = 1;
auto l = [b = a] { // expected-note {{previous definition is here}}
// Don't warn on redefinitions.
int b = 0; // expected-error {{redefinition of 'b'}}
};
}
|