test/clang-tidy/performance-unnecessary-copy-initialization.cpp


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
149
150
151
152
153
154
155
156

// RUN: %check_clang_tidy %s performance-unnecessary-copy-initialization %t

struct ExpensiveToCopyType {
  ExpensiveToCopyType() {}
  virtual ~ExpensiveToCopyType() {}
  const ExpensiveToCopyType &reference() const { return *this; }
};

struct TrivialToCopyType {
  const TrivialToCopyType &reference() const { return *this; }
};

const ExpensiveToCopyType &ExpensiveTypeReference() {
  static const ExpensiveToCopyType *Type = new ExpensiveToCopyType();
  return *Type;
}

const TrivialToCopyType &TrivialTypeReference() {
  static const TrivialToCopyType *Type = new TrivialToCopyType();
  return *Type;
}

void PositiveFunctionCall() {
  const auto AutoAssigned = ExpensiveTypeReference();
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable 'AutoAssigned' is copy-constructed from a const reference; consider making it a const reference [performance-unnecessary-copy-initialization]
  // CHECK-FIXES: const auto& AutoAssigned = ExpensiveTypeReference();
  const auto AutoCopyConstructed(ExpensiveTypeReference());
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& AutoCopyConstructed(ExpensiveTypeReference());
  const ExpensiveToCopyType VarAssigned = ExpensiveTypeReference();
  // CHECK-MESSAGES: [[@LINE-1]]:29: warning: the const qualified variable
  // CHECK-FIXES:   const ExpensiveToCopyType& VarAssigned = ExpensiveTypeReference();
  const ExpensiveToCopyType VarCopyConstructed(ExpensiveTypeReference());
  // CHECK-MESSAGES: [[@LINE-1]]:29: warning: the const qualified variable
  // CHECK-FIXES: const ExpensiveToCopyType& VarCopyConstructed(ExpensiveTypeReference());
}

void PositiveMethodCallConstReferenceParam(const ExpensiveToCopyType &Obj) {
  const auto AutoAssigned = Obj.reference();
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& AutoAssigned = Obj.reference();
  const auto AutoCopyConstructed(Obj.reference());
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& AutoCopyConstructed(Obj.reference());
  const ExpensiveToCopyType VarAssigned = Obj.reference();
  // CHECK-MESSAGES: [[@LINE-1]]:29: warning: the const qualified variable
  // CHECK-FIXES: const ExpensiveToCopyType& VarAssigned = Obj.reference();
  const ExpensiveToCopyType VarCopyConstructed(Obj.reference());
  // CHECK-MESSAGES: [[@LINE-1]]:29: warning: the const qualified variable
  // CHECK-FIXES: const ExpensiveToCopyType& VarCopyConstructed(Obj.reference());
}

void PositiveMethodCallConstParam(const ExpensiveToCopyType Obj) {
  const auto AutoAssigned = Obj.reference();
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& AutoAssigned = Obj.reference();
  const auto AutoCopyConstructed(Obj.reference());
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& AutoCopyConstructed(Obj.reference());
  const ExpensiveToCopyType VarAssigned = Obj.reference();
  // CHECK-MESSAGES: [[@LINE-1]]:29: warning: the const qualified variable
  // CHECK-FIXES: const ExpensiveToCopyType& VarAssigned = Obj.reference();
  const ExpensiveToCopyType VarCopyConstructed(Obj.reference());
  // CHECK-MESSAGES: [[@LINE-1]]:29: warning: the const qualified variable
  // CHECK-FIXES: const ExpensiveToCopyType& VarCopyConstructed(Obj.reference());
}

void PositiveMethodCallConstPointerParam(const ExpensiveToCopyType *const Obj) {
  const auto AutoAssigned = Obj->reference();
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& AutoAssigned = Obj->reference();
  const auto AutoCopyConstructed(Obj->reference());
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& AutoCopyConstructed(Obj->reference());
  const ExpensiveToCopyType VarAssigned = Obj->reference();
  // CHECK-MESSAGES: [[@LINE-1]]:29: warning: the const qualified variable
  // CHECK-FIXES: const ExpensiveToCopyType& VarAssigned = Obj->reference();
  const ExpensiveToCopyType VarCopyConstructed(Obj->reference());
  // CHECK-MESSAGES: [[@LINE-1]]:29: warning: the const qualified variable
  // CHECK-FIXES: const ExpensiveToCopyType& VarCopyConstructed(Obj->reference());
}

void PositiveLocalConstValue() {
  const ExpensiveToCopyType Obj;
  const auto UnnecessaryCopy = Obj.reference();
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& UnnecessaryCopy = Obj.reference();
}

void PositiveLocalConstRef() {
  const ExpensiveToCopyType Obj;
  const ExpensiveToCopyType &ConstReference = Obj.reference();
  const auto UnnecessaryCopy = ConstReference.reference();
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& UnnecessaryCopy = ConstReference.reference();
}

void PositiveLocalConstPointer() {
  const ExpensiveToCopyType Obj;
  const ExpensiveToCopyType *const ConstPointer = &Obj;
  const auto UnnecessaryCopy = ConstPointer->reference();
  // CHECK-MESSAGES: [[@LINE-1]]:14: warning: the const qualified variable
  // CHECK-FIXES: const auto& UnnecessaryCopy = ConstPointer->reference();
}

void NegativeFunctionCallTrivialType() {
  const auto AutoAssigned = TrivialTypeReference();
  const auto AutoCopyConstructed(TrivialTypeReference());
  const TrivialToCopyType VarAssigned = TrivialTypeReference();
  const TrivialToCopyType VarCopyConstructed(TrivialTypeReference());
}

void NegativeStaticLocalVar(const ExpensiveToCopyType &Obj) {
  static const auto StaticVar = Obj.reference();
}

void NegativeFunctionCallExpensiveTypeNonConstVariable() {
  auto AutoAssigned = ExpensiveTypeReference();
  auto AutoCopyConstructed(ExpensiveTypeReference());
  ExpensiveToCopyType VarAssigned = ExpensiveTypeReference();
  ExpensiveToCopyType VarCopyConstructed(ExpensiveTypeReference());
}

void NegativeMethodCallNonConstRef(ExpensiveToCopyType &Obj) {
  const auto AutoAssigned = Obj.reference();
  const auto AutoCopyConstructed(Obj.reference());
  const ExpensiveToCopyType VarAssigned = Obj.reference();
  const ExpensiveToCopyType VarCopyConstructed(Obj.reference());
}

void NegativeMethodCallNonConst(ExpensiveToCopyType Obj) {
  const auto AutoAssigned = Obj.reference();
  const auto AutoCopyConstructed(Obj.reference());
  const ExpensiveToCopyType VarAssigned = Obj.reference();
  const ExpensiveToCopyType VarCopyConstructed(Obj.reference());
}

void NegativeMethodCallNonConstPointer(ExpensiveToCopyType *const Obj) {
  const auto AutoAssigned = Obj->reference();
  const auto AutoCopyConstructed(Obj->reference());
  const ExpensiveToCopyType VarAssigned = Obj->reference();
  const ExpensiveToCopyType VarCopyConstructed(Obj->reference());
}

void NegativeObjIsNotParam() {
  ExpensiveToCopyType Obj;
  const auto AutoAssigned = Obj.reference();
  const auto AutoCopyConstructed(Obj.reference());
  const ExpensiveToCopyType VarAssigned = Obj.reference();
  const ExpensiveToCopyType VarCopyConstructed(Obj.reference());
}

struct NegativeConstructor {
  NegativeConstructor(const ExpensiveToCopyType &Obj) : Obj(Obj) {}
  ExpensiveToCopyType Obj;
};