clang-tools-extra/clang-tidy/bugprone/ForwardDeclarationNamespaceCheck.h

   1 //===--- ForwardDeclarationNamespaceCheck.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_BUGPRONE_FORWARDDECLARATIONNAMESPACECHECK_H
  10 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_FORWARDDECLARATIONNAMESPACECHECK_H
  11
  12 #include "../ClangTidyCheck.h"
  13 #include "llvm/ADT/SmallPtrSet.h"
  14 #include <set>
  15 #include <vector>
  16
  17 namespace clang::tidy::bugprone {
  18
  19 /// Checks if an unused forward declaration is in a wrong namespace.
  20 ///
  21 /// The check inspects all unused forward declarations and checks if there is
  22 /// any declaration/definition with the same name, which could indicate
  23 /// that the forward declaration is potentially in a wrong namespace.
  24 ///
  25 /// \code
  26 ///   namespace na { struct A; }
  27 ///   namespace nb { struct A {} };
  28 ///   nb::A a;
  29 ///   // warning : no definition found for 'A', but a definition with the same
  30 ///   name 'A' found in another namespace 'nb::'
  31 /// \endcode
  32 ///
  33 /// This check can only generate warnings, but it can't suggest fixes at this
  34 /// point.
  35 ///
  36 /// For the user-facing documentation see:
  37 /// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/forward-declaration-namespace.html
  38 class ForwardDeclarationNamespaceCheck : public ClangTidyCheck {
  39 public:
  40   ForwardDeclarationNamespaceCheck(StringRef Name, ClangTidyContext *Context)
  41       : ClangTidyCheck(Name, Context) {}
  42   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
  43   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
  44   void onEndOfTranslationUnit() override;
  45
  46 private:
  47   llvm::StringMap<std::vector<const CXXRecordDecl *>> DeclNameToDefinitions;
  48   llvm::StringMap<std::vector<const CXXRecordDecl *>> DeclNameToDeclarations;
  49   llvm::SmallPtrSet<const Type *, 16> FriendTypes;
  50 };
  51
  52 } // namespace clang::tidy::bugprone
  53
  54 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_FORWARDDECLARATIONNAMESPACECHECK_H