1 // RUN: %check_clang_tidy %s abseil-redundant-strcat-calls %t -- -- -isystem %clang_tidy_headers
2 #include <string>
3
4 namespace absl {
5
6 class string_view {
7 public:
8 typedef std::char_traits<char> traits_type;
9
10 string_view();
11 string_view(const char *);
12 string_view(const std::string &);
13 string_view(const char *, int);
14 string_view(string_view, int);
15
16 template <typename A>
17 explicit operator std::basic_string<char, traits_type, A>() const;
18
19 const char *data() const;
20 int size() const;
21 int length() const;
22 };
23
24 bool operator==(string_view A, string_view B);
25
26 struct AlphaNum {
27 AlphaNum(int i);
28 AlphaNum(double f);
29 AlphaNum(const char *c_str);
30 AlphaNum(const std::string &str);
31 AlphaNum(const string_view &pc);
32
33 private:
34 AlphaNum(const AlphaNum &);
35 AlphaNum &operator=(const AlphaNum &);
36 };
37
38 std::string StrCat();
39 std::string StrCat(const AlphaNum &A);
40 std::string StrCat(const AlphaNum &A, const AlphaNum &B);
41 std::string StrCat(const AlphaNum &A, const AlphaNum &B, const AlphaNum &C);
42 std::string StrCat(const AlphaNum &A, const AlphaNum &B, const AlphaNum &C,
43 const AlphaNum &D);
44
45 // Support 5 or more arguments
46 template <typename... AV>
47 std::string StrCat(const AlphaNum &A, const AlphaNum &B, const AlphaNum &C,
48 const AlphaNum &D, const AlphaNum &E, const AV &... args);
49
50 void StrAppend(std::string *Dest, const AlphaNum &A);
51 void StrAppend(std::string *Dest, const AlphaNum &A, const AlphaNum &B);
52 void StrAppend(std::string *Dest, const AlphaNum &A, const AlphaNum &B,
53 const AlphaNum &C);
54 void StrAppend(std::string *Dest, const AlphaNum &A, const AlphaNum &B,
55 const AlphaNum &C, const AlphaNum &D);
56
57 // Support 5 or more arguments
58 template <typename... AV>
59 void StrAppend(std::string *Dest, const AlphaNum &A, const AlphaNum &B,
60 const AlphaNum &C, const AlphaNum &D, const AlphaNum &E,
61 const AV &... args);
62
63 } // namespace absl
64
65 using absl::AlphaNum;
66 using absl::StrAppend;
67 using absl::StrCat;
68
Positives()69 void Positives() {
70 std::string S = StrCat(1, StrCat("A", StrCat(1.1)));
71 // CHECK-MESSAGES: [[@LINE-1]]:19: warning: multiple calls to 'absl::StrCat' can be flattened into a single call
72 // CHECK-FIXES: string S = StrCat(1, "A", 1.1);
73
74 S = StrCat(StrCat(StrCat(StrCat(StrCat(1)))));
75 // CHECK-MESSAGES: [[@LINE-1]]:7: warning: multiple calls to 'absl::StrCat' can be flattened into a single call
76 // CHECK-FIXES: S = StrCat(1);
77
78 // TODO: should trigger. The issue here is that in the current
79 // implementation we ignore any StrCat with StrCat ancestors. Therefore
80 // inserting anything in between calls will disable triggering the deepest
81 // ones.
82 // s = StrCat(Identity(StrCat(StrCat(1, 2), StrCat(3, 4))));
83
84 StrAppend(&S, 001, StrCat(1, 2, "3"), StrCat("FOO"));
85 // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple calls to 'absl::StrCat' can be flattened into a single call
86 // CHECK-FIXES: StrAppend(&S, 001, 1, 2, "3", "FOO");
87
88 StrAppend(&S, 001, StrCat(StrCat(1, 2), "3"), StrCat("FOO"));
89 // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple calls to 'absl::StrCat' can be flattened into a single call
90 // CHECK-FIXES: StrAppend(&S, 001, 1, 2, "3", "FOO");
91
92 // Too many args. Ignore for now.
93 S = StrCat(1, 2, StrCat(3, 4, 5, 6, 7), 8, 9, 10,
94 StrCat(11, 12, 13, 14, 15, 16, 17, 18), 19, 20, 21, 22, 23, 24, 25,
95 26, 27);
96 // CHECK-MESSAGES: :[[@LINE-3]]:7: warning: multiple calls to 'absl::StrCat' can be flattened into a single call
97 StrAppend(&S, StrCat(1, 2, 3, 4, 5), StrCat(6, 7, 8, 9, 10));
98 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: multiple calls to 'absl::StrCat' can be flattened into a single call
99 // CHECK-FIXES: StrAppend(&S, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
100
101 StrCat(1, StrCat());
102 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: multiple calls to 'absl::StrCat' can be flattened into a single call
103 }
104
Negatives()105 void Negatives() {
106 // One arg. It is used for conversion. Ignore.
107 std::string S = StrCat(1);
108
109 #define A_MACRO(x, y, z) StrCat(x, y, z)
110 S = A_MACRO(1, 2, StrCat("A", "B"));
111 }
112