clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.h

   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::tidy::performance {
  17
  18 /// A check that flags value parameters of expensive to copy types that
  19 /// can safely be converted to const references.
  20 ///
  21 /// For the user-facing documentation see:
  22 /// http://clang.llvm.org/extra/clang-tidy/checks/performance/unnecessary-value-param.html
  23 class UnnecessaryValueParamCheck : public ClangTidyCheck {
  24 public:
  25   UnnecessaryValueParamCheck(StringRef Name, ClangTidyContext *Context);
  26   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
  27     return LangOpts.CPlusPlus;
  28   }
  29   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
  30   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
  31   void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
  32                            Preprocessor *ModuleExpanderPP) override;
  33   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
  34   void onEndOfTranslationUnit() override;
  35
  36 protected:
  37   // Create diagnostics. These are virtual so that derived classes can change
  38   // behaviour.
  39   virtual void handleMoveFix(const ParmVarDecl &Param,
  40                              const DeclRefExpr &CopyArgument,
  41                              ASTContext &Context);
  42   virtual void handleConstRefFix(const FunctionDecl &Function,
  43                                  const ParmVarDecl &Param, ASTContext &Context);
  44
  45 private:
  46   ExprMutationAnalyzer::Memoized MutationAnalyzerCache;
  47   utils::IncludeInserter Inserter;
  48   const std::vector<StringRef> AllowedTypes;
  49 };
  50
  51 } // namespace clang::tidy::performance
  52
  53 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PERFORMANCE_UNNECESSARY_VALUE_PARAM_H