[clang-tidy] Non-private member variables in classes (MISRA, CppCoreGuidelines, HICPP)

Summary:
Finds classes that not only contain the data (non-static member variables),
but also have logic (non-static member functions), and diagnoses all member
variables that have any other scope other than `private`. They should be
made `private`, and manipulated exclusively via the member functions.

Optionally, classes with all member variables being `public` could be
ignored, and optionally all `public` member variables could be ignored.

Options
-------

* IgnoreClassesWithAllMemberVariablesBeingPublic

  Allows to completely ignore classes if **all** the member variables in that
  class have `public` visibility.

* IgnorePublicMemberVariables

  Allows to ignore (not diagnose) **all** the member variables with `public`
  visibility scope.

References:
* MISRA 11-0-1 Member data in non-POD class types shall be private.
* https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#c2-use-class-if-the-class-has-an-invariant-use-struct-if-the-data-members-can-vary-independently
* https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#Rc-private
* https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#Rh-protected

Reviewers: JonasToth, aaron.ballman, alexfh, hokein, xazax.hun

Reviewed By: aaron.ballman

Subscribers: Eugene.Zelenko, zinovy.nis, cfe-commits, rnkovacs, nemanjai, mgorny, xazax.hun, kbarton

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D52771

llvm-svn: 344757

1 files changed, 46 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/misc/NonPrivateMemberVariablesInClassesCheck.h b/clang-tools-extra/clang-tidy/misc/NonPrivateMemberVariablesInClassesCheck.h
new file mode 100644
index 00000000000..c39e356c96d
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/misc/NonPrivateMemberVariablesInClassesCheck.h
@@ -0,0 +1,46 @@
+//===--- NonPrivateMemberVariablesInClassesCheck.h - clang-tidy -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_NONPRIVATEMEMBERVARIABLESINCLASSESCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_NONPRIVATEMEMBERVARIABLESINCLASSESCHECK_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace misc {
+
+/// This checker finds classes that not only contain the data
+/// (non-static member variables), but also have logic (non-static member
+/// functions), and diagnoses all member variables that have any other scope
+/// other than `private`. They should be made `private`, and manipulated
+/// exclusively via the member functions.
+///
+/// Optionally, classes with all member variables being `public` could be
+/// ignored and optionally all `public` member variables could be ignored.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/misc-non-private-member-variables-in-classes.html
+class NonPrivateMemberVariablesInClassesCheck : public ClangTidyCheck {
+public:
+  NonPrivateMemberVariablesInClassesCheck(StringRef Name,
+                                          ClangTidyContext *Context);
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+private:
+  const bool IgnoreClassesWithAllMemberVariablesBeingPublic;
+  const bool IgnorePublicMemberVariables;
+};
+
+} // namespace misc
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_NONPRIVATEMEMBERVARIABLESINCLASSESCHECK_H