1 //===--- UnnecessaryValueParamCheck.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_UNNECESSARY_VALUE_PARAM_H
10 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PERFORMANCE_UNNECESSARY_VALUE_PARAM_H
11 
12 #include "../ClangTidyCheck.h"
13 #include "../utils/IncludeInserter.h"
14 #include "clang/Analysis/Analyses/ExprMutationAnalyzer.h"
15 
16 namespace clang {
17 namespace tidy {
18 namespace performance {
19 
20 /// A check that flags value parameters of expensive to copy types that
21 /// can safely be converted to const references.
22 ///
23 /// For the user-facing documentation see:
24 /// http://clang.llvm.org/extra/clang-tidy/checks/performance-unnecessary-value-param.html
25 class UnnecessaryValueParamCheck : public ClangTidyCheck {
26 public:
27   UnnecessaryValueParamCheck(StringRef Name, ClangTidyContext *Context);
isLanguageVersionSupported(const LangOptions & LangOpts)28   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
29     return LangOpts.CPlusPlus;
30   }
31   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
32   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
33   void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
34                            Preprocessor *ModuleExpanderPP) override;
35   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
36   void onEndOfTranslationUnit() override;
37 
38 private:
39   void handleMoveFix(const ParmVarDecl &Var, const DeclRefExpr &CopyArgument,
40                      const ASTContext &Context);
41 
42   llvm::DenseMap<const FunctionDecl *, FunctionParmMutationAnalyzer>
43       MutationAnalyzers;
44   utils::IncludeInserter Inserter;
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_UNNECESSARY_VALUE_PARAM_H
53