xref: /llvm-project/libcxx/test/tools/clang_tidy_checks/proper_version_checks.cpp (revision b9a2658a3e8bd13b0f9e7a8a440832a95b377216)
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 == "__cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)")
43       return;
44 
45     if (condition.starts_with("_LIBCPP_STD_VER") && condition.find(">") != std::string_view::npos &&
46         condition.find(">=") == std::string_view::npos)
47       check_.diag(location, "_LIBCPP_STD_VER >= version should be used instead of _LIBCPP_STD_VER > prev_version");
48 
49     else if (condition.starts_with("__cplusplus"))
50       check_.diag(location, "Use _LIBCPP_STD_VER instead of __cplusplus to constrain based on the C++ version");
51 
52     else if (condition == "_LIBCPP_STD_VER >= 11")
53       check_.diag(location, "_LIBCPP_STD_VER >= 11 is always true. Did you mean '#ifndef _LIBCPP_CXX03_LANG'?");
54 
55     else if (condition.starts_with("_LIBCPP_STD_VER >= ") &&
56              std::ranges::none_of(std::array{"14", "17", "20", "23", "26"}, [&](auto val) {
57                return condition.find(val) != std::string_view::npos;
58              }))
59       check_.diag(location, "Not a valid value for _LIBCPP_STD_VER. Use 14, 17, 20, 23, or 26");
60   }
61 
62   clang::Preprocessor& preprocessor_;
63   clang::tidy::ClangTidyCheck& check_;
64 };
65 } // namespace
66 
67 proper_version_checks::proper_version_checks(llvm::StringRef name, clang::tidy::ClangTidyContext* context)
68     : clang::tidy::ClangTidyCheck(name, context) {}
69 
70 void proper_version_checks::registerPPCallbacks(
71     const clang::SourceManager& source_manager,
72     clang::Preprocessor* preprocessor,
73     clang::Preprocessor* module_expander) {
74   preprocessor->addPPCallbacks(std::make_unique<proper_version_checks_callbacks>(*preprocessor, *this));
75 }
76 
77 } // namespace libcpp
78