1 //===--- ForRangeCopyCheck.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_PERFORMANCE_FORRANGECOPYCHECK_H
10 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PERFORMANCE_FORRANGECOPYCHECK_H
11 
12 #include "../ClangTidyCheck.h"
13 
14 namespace clang {
15 namespace tidy {
16 namespace performance {
17 
18 /// A check that detects copied loop variables and suggests using const
19 /// references.
20 /// For the user-facing documentation see:
21 /// http://clang.llvm.org/extra/clang-tidy/checks/performance-for-range-copy.html
22 class ForRangeCopyCheck : public ClangTidyCheck {
23 public:
24   ForRangeCopyCheck(StringRef Name, ClangTidyContext *Context);
isLanguageVersionSupported(const LangOptions & LangOpts)25   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override{
26     return LangOpts.CPlusPlus11;
27   }
28   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
29   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
30   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
31 
32 private:
33   // Checks if the loop variable is a const value and expensive to copy. If so
34   // suggests it be converted to a const reference.
35   bool handleConstValueCopy(const VarDecl &LoopVar, ASTContext &Context);
36 
37   // Checks if the loop variable is a non-const value and whether only
38   // const methods are invoked on it or whether it is only used as a const
39   // reference argument. If so it suggests it be made a const reference.
40   bool handleCopyIsOnlyConstReferenced(const VarDecl &LoopVar,
41                                        const CXXForRangeStmt &ForRange,
42                                        ASTContext &Context);
43 
44   const bool WarnOnAllAutoCopies;
45   const std::vector<std::string> AllowedTypes;
46 };
47 
48 } // namespace performance
49 } // namespace tidy
50 } // namespace clang
51 
52 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PERFORMANCE_FORRANGECOPYCHECK_H
53