xref: /llvm-project/clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.h (revision 4718da506091a37ca4863d979bc541e359b79b10)
1 //===--- ProTypeMemberInitCheck.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_CPPCOREGUIDELINES_PRO_TYPE_MEMBER_INIT_H
10 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_PRO_TYPE_MEMBER_INIT_H
11 
12 #include "../ClangTidyCheck.h"
13 #include "llvm/ADT/DenseSet.h"
14 
15 namespace clang::tidy::cppcoreguidelines {
16 
17 /// Implements C++ Core Guidelines Type.6.
18 ///
19 /// Checks that every user-provided constructor value-initializes all class
20 /// members and base classes that would have undefined behavior otherwise. Also
21 /// check that any record types without user-provided default constructors are
22 /// value-initialized where used.
23 ///
24 /// Members initialized through function calls in the body of the constructor
25 /// will result in false positives.
26 ///
27 /// For the user-facing documentation see:
28 /// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines/pro-type-member-init.html
29 /// TODO: See if 'fixes' for false positives are optimized away by the compiler.
30 /// TODO: For classes with multiple constructors, make sure that we don't offer
31 ///     multiple in-class initializer fixits for the same  member.
32 class ProTypeMemberInitCheck : public ClangTidyCheck {
33 public:
34   ProTypeMemberInitCheck(StringRef Name, ClangTidyContext *Context);
isLanguageVersionSupported(const LangOptions & LangOpts)35   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
36     return LangOpts.CPlusPlus;
37   }
38   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
39   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
40   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
41 
42 private:
43   // Checks Type.6 part 1:
44   // Issue a diagnostic for any constructor of a non-trivially-constructible
45   // type that does not initialize all member variables.
46   //
47   // To fix: Write a data member initializer, or mention it in the member
48   // initializer list.
49   void checkMissingMemberInitializer(ASTContext &Context,
50                                      const CXXRecordDecl &ClassDecl,
51                                      const CXXConstructorDecl *Ctor);
52 
53   // A subtle side effect of Type.6 part 2:
54   // Make sure to initialize trivially constructible base classes.
55   void checkMissingBaseClassInitializer(const ASTContext &Context,
56                                         const CXXRecordDecl &ClassDecl,
57                                         const CXXConstructorDecl *Ctor);
58 
59   // Checks Type.6 part 2:
60   // Issue a diagnostic when constructing an object of a trivially constructible
61   // type without () or {} to initialize its members.
62   //
63   // To fix: Add () or {}.
64   void checkUninitializedTrivialType(const ASTContext &Context,
65                                      const VarDecl *Var);
66 
67   // Whether arrays need to be initialized or not. Default is false.
68   bool IgnoreArrays;
69 
70   // Whether fix-its for initialization of fundamental type use assignment
71   // instead of brace initialization. Only effective in C++11 mode. Default is
72   // false.
73   bool UseAssignment;
74 
75   // Record the member variables that have been initialized to prevent repeated
76   // initialization.
77   llvm::DenseSet<const FieldDecl *> HasRecordClassMemberSet;
78 };
79 
80 } // namespace clang::tidy::cppcoreguidelines
81 
82 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_PRO_TYPE_MEMBER_INIT_H
83