libcxx/test/tools/clang_tidy_checks/header_exportable_declarations.hpp

   1 //===----------------------------------------------------------------------===//
   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 #include "clang-tidy/ClangTidyCheck.h"
  10
  11 #include "llvm/ADT/StringRef.h"
  12
  13 #include <fstream>
  14 #include <set>
  15 #include <string>
  16
  17 namespace libcpp {
  18 class header_exportable_declarations : public clang::tidy::ClangTidyCheck {
  19 public:
  20   explicit header_exportable_declarations(llvm::StringRef, clang::tidy::ClangTidyContext*);
  21   ~header_exportable_declarations();
  22   void registerMatchers(clang::ast_matchers::MatchFinder*) override;
  23   void check(const clang::ast_matchers::MatchFinder::MatchResult&) override;
  24
  25   enum class FileType {
  26     // std module specific
  27     Header,
  28     CompatModulePartition,
  29     Module,
  30     // std.compat module specific
  31     CHeader,
  32     ModulePartition,
  33     CompatModule,
  34     // invalid value
  35     Unknown
  36   };
  37
  38 private:
  39   llvm::StringRef filename_;
  40   FileType file_type_;
  41   llvm::StringRef extra_header_;
  42   std::set<std::string> decls_;
  43   std::set<std::string> global_decls_;
  44
  45   // The named declarations in .h C headers are "tricky". On POSIX
  46   // systems these headers contain POSIX specific functions that do not
  47   // use a reserved name. For example, fmemopen is provided by stdio.h.
  48   // We filter the names that should be provided by the headers as follows:
  49   // - record all named declarations the global namespace
  50   // - wait until the header is completely processed
  51   // - every named declaration in the global namespace that has a matching
  52   //   "export" in the std namespace is exported.
  53   //
  54   // The only place where we can do the above while ensuring that all
  55   // the declarations in the header have been seen is in the clang tidy
  56   // plugin's destructor.
  57   //
  58   // It is possible to skip some declarations in the std namespace,
  59   // these are added to decls_ before processing. To differentiate
  60   // between a skipped declaration and a real declaration the skipped
  61   // declarations are recorded in an extra variable.
  62   std::set<std::string> skip_decls_;
  63 };
  64 } // namespace libcpp