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 {
16 namespace tidy {
17 namespace cppcoreguidelines {
18 
19 /// Implements C++ Core Guidelines Type.6.
20 ///
21 /// Checks that every user-provided constructor value-initializes all class
22 /// members and base classes that would have undefined behavior otherwise. Also
23 /// check that any record types without user-provided default constructors are
24 /// value-initialized where used.
25 ///
26 /// Members initialized through function calls in the body of the constructor
27 /// will result in false positives.
28 ///
29 /// For the user-facing documentation see:
30 /// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines/pro-type-member-init.html
31 /// TODO: See if 'fixes' for false positives are optimized away by the compiler.
32 /// TODO: For classes with multiple constructors, make sure that we don't offer
33 ///     multiple in-class initializer fixits for the same  member.
34 class ProTypeMemberInitCheck : public ClangTidyCheck {
35 public:
36   ProTypeMemberInitCheck(StringRef Name, ClangTidyContext *Context);
isLanguageVersionSupported(const LangOptions & LangOpts)37   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
38     return LangOpts.CPlusPlus;
39   }
40   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
41   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
42   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
43 
44 private:
45   // Checks Type.6 part 1:
46   // Issue a diagnostic for any constructor of a non-trivially-constructible
47   // type that does not initialize all member variables.
48   //
49   // To fix: Write a data member initializer, or mention it in the member
50   // initializer list.
51   void checkMissingMemberInitializer(ASTContext &Context,
52                                      const CXXRecordDecl &ClassDecl,
53                                      const CXXConstructorDecl *Ctor);
54 
55   // A subtle side effect of Type.6 part 2:
56   // Make sure to initialize trivially constructible base classes.
57   void checkMissingBaseClassInitializer(const ASTContext &Context,
58                                         const CXXRecordDecl &ClassDecl,
59                                         const CXXConstructorDecl *Ctor);
60 
61   // Checks Type.6 part 2:
62   // Issue a diagnostic when constructing an object of a trivially constructible
63   // type without () or {} to initialize its members.
64   //
65   // To fix: Add () or {}.
66   void checkUninitializedTrivialType(const ASTContext &Context,
67                                      const VarDecl *Var);
68 
69   // Whether arrays need to be initialized or not. Default is false.
70   bool IgnoreArrays;
71 
72   // Whether fix-its for initialization of fundamental type use assignment
73   // instead of brace initialization. Only effective in C++11 mode. Default is
74   // false.
75   bool UseAssignment;
76 
77   // Record the member variables that have been initialized to prevent repeated
78   // initialization.
79   llvm::DenseSet<const FieldDecl *> HasRecordClassMemberSet;
80 };
81 
82 } // namespace cppcoreguidelines
83 } // namespace tidy
84 } // namespace clang
85 
86 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_PRO_TYPE_MEMBER_INIT_H
87