[clang-tidy] add check cppcoreguidelines-special-member-functions

Summary:
Check for classes that violate the rule of five and zero as specified in CppCoreGuidelines:

"If a class defines or deletes a default operation then it should define or delete them all."

https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#c21-if-you-define-or-delete-any-default-operation-define-or-delete-them-all.

Reviewers: alexfh, sbenza, aaron.ballman

Subscribers: Prazek, Eugene.Zelenko, cfe-commits, ericLemanissier, nemanjai

Projects: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D22513

llvm-svn: 277262

1 files changed, 101 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/SpecialMemberFunctionsCheck.h b/clang-tools-extra/clang-tidy/cppcoreguidelines/SpecialMemberFunctionsCheck.h
new file mode 100644
index 00000000000..62185354182
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/SpecialMemberFunctionsCheck.h
@@ -0,0 +1,101 @@
+//===--- SpecialMemberFunctionsCheck.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_CPPCOREGUIDELINES_SPECIAL_MEMBER_FUNCTIONS_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_SPECIAL_MEMBER_FUNCTIONS_H
+
+#include "../ClangTidy.h"
+
+#include "llvm/ADT/DenseMapInfo.h"
+
+namespace clang {
+namespace tidy {
+namespace cppcoreguidelines {
+
+/// Checks for classes where some, but not all, of the special member functions
+/// are defined.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines-special-member-functions.html
+class SpecialMemberFunctionsCheck : public ClangTidyCheck {
+public:
+  SpecialMemberFunctionsCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  void onEndOfTranslationUnit() override;
+  
+  enum class SpecialMemberFunctionKind {
+    Destructor,
+    CopyConstructor,
+    CopyAssignment,
+    MoveConstructor,
+    MoveAssignment
+  };
+
+  using ClassDefId = std::pair<SourceLocation, std::string>;
+
+  using ClassDefiningSpecialMembersMap = llvm::DenseMap<ClassDefId, llvm::SmallVector<SpecialMemberFunctionKind, 5>>;
+
+private:
+  
+  static llvm::StringRef toString(SpecialMemberFunctionKind K);
+
+  static std::string join(llvm::ArrayRef<SpecialMemberFunctionKind> SMFS,
+                          llvm::StringRef AndOr);
+  
+  ClassDefiningSpecialMembersMap ClassWithSpecialMembers;
+};
+
+} // namespace cppcoreguidelines
+} // namespace tidy
+} // namespace clang
+
+namespace llvm {
+/// Specialisation of DenseMapInfo to allow ClassDefId objects in DenseMaps
+/// FIXME: Move this to the corresponding cpp file as is done for
+/// clang-tidy/readability/IdentifierNamingCheck.cpp. 
+template <>
+struct DenseMapInfo<
+    clang::tidy::cppcoreguidelines::SpecialMemberFunctionsCheck::ClassDefId> {
+  using ClassDefId =
+    clang::tidy::cppcoreguidelines::SpecialMemberFunctionsCheck::ClassDefId;
+
+  static inline ClassDefId getEmptyKey() {
+    return ClassDefId(
+        clang::SourceLocation::getFromRawEncoding(static_cast<unsigned>(-1)),
+        "EMPTY");
+  }
+
+  static inline ClassDefId getTombstoneKey() {
+    return ClassDefId(
+        clang::SourceLocation::getFromRawEncoding(static_cast<unsigned>(-2)),
+        "TOMBSTONE");
+  }
+
+  static unsigned getHashValue(ClassDefId Val) {
+    assert(Val != getEmptyKey() && "Cannot hash the empty key!");
+    assert(Val != getTombstoneKey() && "Cannot hash the tombstone key!");
+
+    std::hash<ClassDefId::second_type> SecondHash;
+    return Val.first.getRawEncoding() + SecondHash(Val.second);
+  }
+
+  static bool isEqual(ClassDefId LHS, ClassDefId RHS) {
+    if (RHS == getEmptyKey())
+      return LHS == getEmptyKey();
+    if (RHS == getTombstoneKey())
+      return LHS == getTombstoneKey();
+    return LHS == RHS;
+  }
+};
+
+} // namespace llvm
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_SPECIAL_MEMBER_FUNCTIONS_H