libcxx/test/tools/clang_tidy_checks/internal_ftm_use.cpp

   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 // This clang-tidy check ensures that we don't use any _LIBCPP_HAS_FOO macro
  10 // inside `#ifdef`, `#ifndef` & friends, since the intent is to always use `#if` instead.
  11
  12 #include "internal_ftm_use.hpp"
  13
  14 #include <clang/Lex/Lexer.h>
  15 #include <clang/Lex/PPCallbacks.h>
  16 #include <clang/Lex/Preprocessor.h>
  17
  18 #include <string>
  19
  20 namespace libcpp {
  21 namespace {
  22 std::array valid_macros{
  23     // Public API macros
  24     "_LIBCPP_HAS_ASAN_CONTAINER_ANNOTATIONS_FOR_ALL_ALLOCATORS",
  25
  26     // Testing macros
  27     "_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER",
  28
  29     // TODO: Why does this macro even exist?
  30     "_LIBCPP_HAS_NO_TREE_BARRIER",
  31
  32     // Experimental features
  33     "_LIBCPP_HAS_NO_EXPERIMENTAL_TZDB",
  34     "_LIBCPP_HAS_NO_EXPERIMENTAL_SYNCSTREAM",
  35     "_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN",
  36     "_LIBCPP_HAS_NO_INCOMPLETE_PSTL",
  37 };
  38
  39 class internal_ftm_use_callbacks : public clang::PPCallbacks {
  40 public:
  41   internal_ftm_use_callbacks(clang::tidy::ClangTidyCheck& check) : check_(check) {}
  42
  43   void Defined(const clang::Token& token,
  44                const clang::MacroDefinition& macro_definition,
  45                clang::SourceRange location) override {
  46     check_macro(token.getIdentifierInfo()->getName(), location.getBegin());
  47   }
  48
  49   void Ifdef(clang::SourceLocation location, const clang::Token& token, const clang::MacroDefinition&) override {
  50     check_macro(token.getIdentifierInfo()->getName(), location);
  51   }
  52
  53   void Elifdef(clang::SourceLocation location, const clang::Token& token, const clang::MacroDefinition&) override {
  54     check_macro(token.getIdentifierInfo()->getName(), location);
  55   }
  56
  57   void Ifndef(clang::SourceLocation location, const clang::Token& token, const clang::MacroDefinition&) override {
  58     check_macro(token.getIdentifierInfo()->getName(), location);
  59   }
  60
  61   void Elifndef(clang::SourceLocation location, const clang::Token& token, const clang::MacroDefinition&) override {
  62     check_macro(token.getIdentifierInfo()->getName(), location);
  63   }
  64
  65 private:
  66   void check_macro(std::string_view macro, clang::SourceLocation location) {
  67     if (macro.starts_with("_LIBCPP_HAS_") && std::ranges::find(valid_macros, macro) == valid_macros.end()) {
  68       check_.diag(location, std::string("\'") + std::string{macro} + "' is always defined to 1 or 0.");
  69     }
  70   }
  71
  72   clang::tidy::ClangTidyCheck& check_;
  73 };
  74 } // namespace
  75
  76 internal_ftm_use::internal_ftm_use(llvm::StringRef name, clang::tidy::ClangTidyContext* context)
  77     : clang::tidy::ClangTidyCheck(name, context) {}
  78
  79 void internal_ftm_use::registerPPCallbacks(const clang::SourceManager& source_manager,
  80                                            clang::Preprocessor* preprocessor,
  81                                            clang::Preprocessor* module_expander) {
  82   preprocessor->addPPCallbacks(std::make_unique<internal_ftm_use_callbacks>(*this));
  83 }
  84
  85 } // namespace libcpp