clang-tools-extra/clang-tidy/readability/NonConstParameterCheck.h

   1 //===--- NonConstParameterCheck.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_NON_CONST_PARAMETER_H
  10 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_NON_CONST_PARAMETER_H
  11
  12 #include "../ClangTidyCheck.h"
  13
  14 namespace clang::tidy::readability {
  15
  16 /// Warn when a pointer function parameter can be const.
  17 ///
  18 /// For the user-facing documentation see:
  19 /// http://clang.llvm.org/extra/clang-tidy/checks/readability/non-const-parameter.html
  20 class NonConstParameterCheck : public ClangTidyCheck {
  21 public:
  22   NonConstParameterCheck(StringRef Name, ClangTidyContext *Context)
  23       : ClangTidyCheck(Name, Context) {}
  24   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
  25   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
  26   void onEndOfTranslationUnit() override;
  27   std::optional<TraversalKind> getCheckTraversalKind() const override {
  28     return TK_IgnoreUnlessSpelledInSource;
  29   }
  30
  31 private:
  32   /// Parameter info.
  33   struct ParmInfo {
  34     /// Is function parameter referenced?
  35     bool IsReferenced;
  36
  37     /// Can function parameter be const?
  38     bool CanBeConst;
  39   };
  40
  41   /// Track all nonconst integer/float parameters.
  42   std::map<const ParmVarDecl *, ParmInfo> Parameters;
  43
  44   /// Add function parameter.
  45   void addParm(const ParmVarDecl *Parm);
  46
  47   /// Set IsReferenced.
  48   void setReferenced(const DeclRefExpr *Ref);
  49
  50   /// Set CanNotBeConst.
  51   /// Visits sub expressions recursively. If a DeclRefExpr is found
  52   /// and CanNotBeConst is true the Parameter is marked as not-const.
  53   /// The CanNotBeConst is updated as sub expressions are visited.
  54   void markCanNotBeConst(const Expr *E, bool CanNotBeConst);
  55
  56   /// Diagnose non const parameters.
  57   void diagnoseNonConstParameters();
  58 };
  59
  60 } // namespace clang::tidy::readability
  61
  62 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_NON_CONST_PARAMETER_H