libcxx/test/tools/clang_tidy_checks/proper_version_checks.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 #include "proper_version_checks.hpp"
  10
  11 #include <clang/Lex/Lexer.h>
  12 #include <clang/Lex/PPCallbacks.h>
  13 #include <clang/Lex/Preprocessor.h>
  14
  15 namespace libcpp {
  16 namespace {
  17 class proper_version_checks_callbacks : public clang::PPCallbacks {
  18 public:
  19   proper_version_checks_callbacks(clang::Preprocessor& preprocessor, clang::tidy::ClangTidyCheck& check)
  20       : preprocessor_(preprocessor), check_(check) {}
  21
  22   void If(clang::SourceLocation location, clang::SourceRange condition_range, ConditionValueKind) override {
  23     check_condition(location, condition_range);
  24   }
  25
  26   void Elif(clang::SourceLocation location,
  27             clang::SourceRange condition_range,
  28             ConditionValueKind,
  29             clang::SourceLocation if_location) override {
  30     check_condition(location, condition_range);
  31   }
  32
  33 private:
  34   void check_condition(clang::SourceLocation location, clang::SourceRange condition_range) {
  35     std::string_view condition = clang::Lexer::getSourceText(
  36         clang::CharSourceRange::getTokenRange(condition_range),
  37         preprocessor_.getSourceManager(),
  38         preprocessor_.getLangOpts());
  39     if (preprocessor_.getSourceManager().isInMainFile(location))
  40       return;
  41
  42     if (condition.starts_with("_LIBCPP_STD_VER") && condition.find(">") != std::string_view::npos &&
  43         condition.find(">=") == std::string_view::npos)
  44       check_.diag(location, "_LIBCPP_STD_VER >= version should be used instead of _LIBCPP_STD_VER > prev_version");
  45
  46     else if (condition.starts_with("__cplusplus"))
  47       check_.diag(location, "Use _LIBCPP_STD_VER instead of __cplusplus to constrain based on the C++ version");
  48
  49     else if (condition == "_LIBCPP_STD_VER >= 11")
  50       check_.diag(location, "_LIBCPP_STD_VER >= 11 is always true. Did you mean '#ifndef _LIBCPP_CXX03_LANG'?");
  51
  52     else if (condition.starts_with("_LIBCPP_STD_VER >= ") &&
  53              std::ranges::none_of(std::array{"14", "17", "20", "23", "26"}, [&](auto val) {
  54                return condition.find(val) != std::string_view::npos;
  55              }))
  56       check_.diag(location, "Not a valid value for _LIBCPP_STD_VER. Use 14, 17, 20, 23, or 26");
  57   }
  58
  59   clang::Preprocessor& preprocessor_;
  60   clang::tidy::ClangTidyCheck& check_;
  61 };
  62 } // namespace
  63
  64 proper_version_checks::proper_version_checks(llvm::StringRef name, clang::tidy::ClangTidyContext* context)
  65     : clang::tidy::ClangTidyCheck(name, context) {}
  66
  67 void proper_version_checks::registerPPCallbacks(
  68     const clang::SourceManager& source_manager,
  69     clang::Preprocessor* preprocessor,
  70     clang::Preprocessor* module_expander) {
  71   preprocessor->addPPCallbacks(std::make_unique<proper_version_checks_callbacks>(*preprocessor, *this));
  72 }
  73
  74 } // namespace libcpp