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 {
15 namespace tidy {
16 namespace readability {
17 
18 /// Warn when a pointer function parameter can be const.
19 ///
20 /// For the user-facing documentation see:
21 /// http://clang.llvm.org/extra/clang-tidy/checks/readability-non-const-parameter.html
22 class NonConstParameterCheck : public ClangTidyCheck {
23 public:
NonConstParameterCheck(StringRef Name,ClangTidyContext * Context)24   NonConstParameterCheck(StringRef Name, ClangTidyContext *Context)
25       : ClangTidyCheck(Name, Context) {}
26   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
27   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
28   void onEndOfTranslationUnit() override;
29 
30 private:
31   /// Parameter info.
32   struct ParmInfo {
33     /// Is function parameter referenced?
34     bool IsReferenced;
35 
36     /// Can function parameter be const?
37     bool CanBeConst;
38   };
39 
40   /// Track all nonconst integer/float parameters.
41   std::map<const ParmVarDecl *, ParmInfo> Parameters;
42 
43   /// Add function parameter.
44   void addParm(const ParmVarDecl *Parm);
45 
46   /// Set IsReferenced.
47   void setReferenced(const DeclRefExpr *Ref);
48 
49   /// Set CanNotBeConst.
50   /// Visits sub expressions recursively. If a DeclRefExpr is found
51   /// and CanNotBeConst is true the Parameter is marked as not-const.
52   /// The CanNotBeConst is updated as sub expressions are visited.
53   void markCanNotBeConst(const Expr *E, bool CanNotBeConst);
54 
55   /// Diagnose non const parameters.
56   void diagnoseNonConstParameters();
57 };
58 
59 } // namespace readability
60 } // namespace tidy
61 } // namespace clang
62 
63 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_NON_CONST_PARAMETER_H
64