[clang-tools-extra] [clang-tidy] Add new check: `readability-use-concise-preprocessor-directives` (PR #146830)

[Victor Chernyakin via cfe-commits]

================
@@ -0,0 +1,40 @@
+//===--- UseConcisePreprocessorDirectivesCheck.h - clang-tidy ---*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_USECONCISEPREPROCESSORDIRECTIVESCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_USECONCISEPREPROCESSORDIRECTIVESCHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::readability {
+
+/// Shortens `#if` preprocessor conditions:
+///
+/// #if  defined(MEOW) -> #ifdef  MEOW
+/// #if !defined(MEOW) -> #ifndef MEOW
+///
+/// And, since C23 and C++23, shortens `#elif` conditions too:
+///
+/// #elif  defined(MEOW) -> #elifdef  MEOW
+/// #elif !defined(MEOW) -> #elifndef MEOW
+///
+/// User-facing documentation:
+/// https://clang.llvm.org/extra/clang-tidy/checks/readability/use-concise-preprocessor-directives.html
+class UseConcisePreprocessorDirectivesCheck : public ClangTidyCheck {
+public:
+  using ClangTidyCheck::ClangTidyCheck;
+  void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
+                           Preprocessor *ModuleExpanderPP) override;
+  bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+    return LangOpts.CPlusPlus || LangOpts.C99;
----------------
localspook wrote:

Changed to `return true`

https://github.com/llvm/llvm-project/pull/146830