performance-faster-string-find.cpp
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// RUN: %check_clang_tidy %s performance-faster-string-find %t -- \
// RUN: -config="{CheckOptions: \
// RUN: [{key: performance-faster-string-find.StringLikeClasses, \
// RUN: value: 'std::basic_string; ::llvm::StringRef;'}]}" --
namespace std {
template <typename Char>
struct basic_string {
int find(const Char *, int = 0) const;
int find(const Char *, int, int) const;
int rfind(const Char *) const;
int find_first_of(const Char *) const;
int find_first_not_of(const Char *) const;
int find_last_of(const Char *) const;
int find_last_not_of(const Char *) const;
};
typedef basic_string<char> string;
typedef basic_string<wchar_t> wstring;
} // namespace std
namespace llvm {
struct StringRef {
int find(const char *) const;
};
} // namespace llvm
struct NotStringRef {
int find(const char *);
};
void StringFind() {
std::string Str;
Str.find("a");
// CHECK-MESSAGES: [[@LINE-1]]:12: warning: 'find' called with a string literal consisting of a single character; consider using the more effective overload accepting a character [performance-faster-string-find]
// CHECK-FIXES: Str.find('a');
// Works with the pos argument.
Str.find("a", 1);
// CHECK-MESSAGES: [[@LINE-1]]:12: warning: 'find' called with a string literal
// CHECK-FIXES: Str.find('a', 1);
// Doens't work with strings smaller or larger than 1 char.
Str.find("");
Str.find("ab");
// Doesn't do anything with the 3 argument overload.
Str.find("a", 1, 1);
// Other methods that can also be replaced
Str.rfind("a");
// CHECK-MESSAGES: [[@LINE-1]]:13: warning: 'rfind' called with a string literal
// CHECK-FIXES: Str.rfind('a');
Str.find_first_of("a");
// CHECK-MESSAGES: [[@LINE-1]]:21: warning: 'find_first_of' called with a string
// CHECK-FIXES: Str.find_first_of('a');
Str.find_first_not_of("a");
// CHECK-MESSAGES: [[@LINE-1]]:25: warning: 'find_first_not_of' called with a
// CHECK-FIXES: Str.find_first_not_of('a');
Str.find_last_of("a");
// CHECK-MESSAGES: [[@LINE-1]]:20: warning: 'find_last_of' called with a string
// CHECK-FIXES: Str.find_last_of('a');
Str.find_last_not_of("a");
// CHECK-MESSAGES: [[@LINE-1]]:24: warning: 'find_last_not_of' called with a
// CHECK-FIXES: Str.find_last_not_of('a');
// std::wstring should work.
std::wstring WStr;
WStr.find(L"n");
// CHECK-MESSAGES: [[@LINE-1]]:13: warning: 'find' called with a string literal
// CHECK-FIXES: Str.find(L'n');
// Even with unicode that fits in one wide char.
WStr.find(L"\x3A9");
// CHECK-MESSAGES: [[@LINE-1]]:13: warning: 'find' called with a string literal
// CHECK-FIXES: Str.find(L'\x3A9');
// Also with other types, but only if it was specified in the options.
llvm::StringRef sr;
sr.find("x");
// CHECK-MESSAGES: [[@LINE-1]]:11: warning: 'find' called with a string literal
// CHECK-FIXES: sr.find('x');
NotStringRef nsr;
nsr.find("x");
}
template <typename T>
int FindTemplateDependant(T value) {
return value.find("A");
}
template <typename T>
int FindTemplateNotDependant(T pos) {
return std::string().find("A", pos);
// CHECK-MESSAGES: [[@LINE-1]]:29: warning: 'find' called with a string literal
// CHECK-FIXES: return std::string().find('A', pos);
}
int FindStr() {
return FindTemplateDependant(std::string()) + FindTemplateNotDependant(1);
}
#define STR_MACRO(str) str.find("A")
#define POS_MACRO(pos) std::string().find("A",pos)
int Macros() {
return STR_MACRO(std::string()) + POS_MACRO(1);
// CHECK-MESSAGES: [[@LINE-1]]:10: warning: 'find' called with a string literal
// CHECK-MESSAGES: [[@LINE-2]]:37: warning: 'find' called with a string literal
}