1 //===--- ContainerSizeEmptyCheck.h - clang-tidy -----------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_CONTAINERSIZEEMPTYCHECK_H 10 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_CONTAINERSIZEEMPTYCHECK_H 11 12 #include "../ClangTidyCheck.h" 13 #include <vector> 14 15 namespace clang::tidy::readability { 16 17 /// Checks whether a call to the `size()`/`length()` method can be replaced with 18 /// a call to `empty()`. 19 /// 20 /// The emptiness of a container should be checked using the `empty()` method 21 /// instead of the `size()` method. It is not guaranteed that `size()` is a 22 /// constant-time function, and it is generally more efficient and also shows 23 /// clearer intent to use `empty()`. Furthermore some containers may implement 24 /// the `empty()` method but not implement the `size()` method. Using `empty()` 25 /// whenever possible makes it easier to switch to another container in the 26 /// future. 27 class ContainerSizeEmptyCheck : public ClangTidyCheck { 28 public: 29 ContainerSizeEmptyCheck(StringRef Name, ClangTidyContext *Context); isLanguageVersionSupported(const LangOptions & LangOpts)30 bool isLanguageVersionSupported(const LangOptions &LangOpts) const override { 31 return LangOpts.CPlusPlus; 32 } 33 void registerMatchers(ast_matchers::MatchFinder *Finder) override; 34 void check(const ast_matchers::MatchFinder::MatchResult &Result) override; 35 void storeOptions(ClangTidyOptions::OptionMap &Opts) override; getCheckTraversalKind()36 std::optional<TraversalKind> getCheckTraversalKind() const override { 37 return TK_IgnoreUnlessSpelledInSource; 38 } 39 40 private: 41 std::vector<llvm::StringRef> ExcludedComparisonTypes; 42 }; 43 44 } // namespace clang::tidy::readability 45 46 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_CONTAINERSIZEEMPTYCHECK_H 47