[clang-tools-extra] [clang-tidy] Add modernize-use-cpp-style-comments check (PR #99713)

NagaChaitanya Vellanki via cfe-commits cfe-commits at lists.llvm.org
Sun Jul 21 00:12:31 PDT 2024


https://github.com/chaitanyav updated https://github.com/llvm/llvm-project/pull/99713

>From 2d45f8196e99c3b6f5a75db6e5e3df7ce1fd8aef Mon Sep 17 00:00:00 2001
From: NagaChaitanya Vellanki <pnagato at protonmail.com>
Date: Fri, 19 Jul 2024 14:26:23 -0700
Subject: [PATCH] [clang-tidy] Add modernize-use-cpp-style-comments check

  modernize-use-cpp-style-comments check finds C style comments
  and suggests to use C++ style comments

  Fixes #24841
---
 .../clang-tidy/modernize/CMakeLists.txt       |  1 +
 .../modernize/ModernizeTidyModule.cpp         |  3 +
 .../modernize/UseCppStyleCommentsCheck.cpp    | 67 +++++++++++++++++++
 .../modernize/UseCppStyleCommentsCheck.h      | 40 +++++++++++
 clang-tools-extra/docs/ReleaseNotes.rst       |  5 ++
 .../modernize/use-cpp-style-comments.rst      |  6 ++
 .../modernize/use-cpp-style-comments.cpp      |  7 ++
 7 files changed, 129 insertions(+)
 create mode 100644 clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.cpp
 create mode 100644 clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.h
 create mode 100644 clang-tools-extra/docs/clang-tidy/checks/modernize/use-cpp-style-comments.rst
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/modernize/use-cpp-style-comments.cpp

diff --git a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
index 4f68c487cac9d..04a1d04cc333e 100644
--- a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
@@ -31,6 +31,7 @@ add_clang_library(clangTidyModernizeModule
   UseAutoCheck.cpp
   UseBoolLiteralsCheck.cpp
   UseConstraintsCheck.cpp
+  UseCppStyleCommentsCheck.cpp
   UseDefaultMemberInitCheck.cpp
   UseDesignatedInitializersCheck.cpp
   UseEmplaceCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
index 1860759332063..39995a32133b3 100644
--- a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
@@ -32,6 +32,7 @@
 #include "UseAutoCheck.h"
 #include "UseBoolLiteralsCheck.h"
 #include "UseConstraintsCheck.h"
+#include "UseCppStyleCommentsCheck.h"
 #include "UseDefaultMemberInitCheck.h"
 #include "UseDesignatedInitializersCheck.h"
 #include "UseEmplaceCheck.h"
@@ -104,6 +105,8 @@ class ModernizeModule : public ClangTidyModule {
         "modernize-use-bool-literals");
     CheckFactories.registerCheck<UseConstraintsCheck>(
         "modernize-use-constraints");
+    CheckFactories.registerCheck<UseCppStyleCommentsCheck>(
+        "modernize-use-cpp-style-comments");
     CheckFactories.registerCheck<UseDefaultMemberInitCheck>(
         "modernize-use-default-member-init");
     CheckFactories.registerCheck<UseEmplaceCheck>("modernize-use-emplace");
diff --git a/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.cpp
new file mode 100644
index 0000000000000..ed57d36644fb6
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.cpp
@@ -0,0 +1,67 @@
+//===--- UseCppStyleCommentsCheck.cpp - clang-tidy-------------------------===//
+
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "UseCppStyleCommentsCheck.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Lex/Preprocessor.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::modernize {
+  class UseCppStyleCommentsCheck::CStyleCommentHandler : public CommentHandler {
+  public:
+    CStyleCommentHandler(UseCppStyleCommentsCheck &Check)
+      : Check(Check),
+        CStyleCommentMatch(
+          "^[ \t]*/\\*+[ \t\n]*(.*[ \t\n]*)*[ \t\n]*\\*+/[ \t\n]*$") {
+    }
+
+    bool HandleComment(Preprocessor &PP, SourceRange Range) override {
+      if (Range.getBegin().isMacroID() ||
+          PP.getSourceManager().isInSystemHeader(Range.getBegin()))
+        return false;
+
+      const StringRef Text =
+          Lexer::getSourceText(CharSourceRange::getCharRange(Range),
+                               PP.getSourceManager(), PP.getLangOpts());
+
+      SmallVector<StringRef> Matches;
+      if (!CStyleCommentMatch.match(Text, &Matches)) {
+        return false;
+      }
+
+      Check.diag(
+        Range.getBegin(),
+        "use C++ style comments '//' instead of C style comments '/*...*/'");
+
+      return false;
+    }
+
+  private:
+    UseCppStyleCommentsCheck &Check;
+    llvm::Regex CStyleCommentMatch;
+  };
+
+  UseCppStyleCommentsCheck::UseCppStyleCommentsCheck(StringRef Name,
+                                                     ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      Handler(std::make_unique<CStyleCommentHandler>(*this)) {
+  }
+
+  void UseCppStyleCommentsCheck::registerPPCallbacks(
+    const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
+    PP->addCommentHandler(Handler.get());
+  }
+
+  void UseCppStyleCommentsCheck::check(const MatchFinder::MatchResult &Result) {
+  }
+
+  UseCppStyleCommentsCheck::~UseCppStyleCommentsCheck() = default;
+} // namespace clang::tidy::modernize
diff --git a/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.h b/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.h
new file mode 100644
index 0000000000000..a0f51b943b9c1
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.h
@@ -0,0 +1,40 @@
+//===--- UseCppStyleCommentsCheck.h - clang-tidy---------------------------===//
+//
+// 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_MODERNIZE_USE_CPP_STYLE_COMMENTS_CHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USE_CPP_STYLE_COMMENTS_CHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::modernize {
+    /// Detects C Style comments and suggests to use C++ style comments instead.
+    ///
+    /// For the user-facing documentation see:
+    /// http://clang.llvm.org/extra/clang-tidy/checks/modernize/use-cpp-style-comments.html
+    class UseCppStyleCommentsCheck : public ClangTidyCheck {
+    public:
+        UseCppStyleCommentsCheck(StringRef Name, ClangTidyContext *Context);
+
+        ~UseCppStyleCommentsCheck() override;
+
+        bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+            return LangOpts.CPlusPlus;
+        }
+
+        void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
+                                 Preprocessor *ModuleExpanderPP) override;
+
+        void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+    private:
+        class CStyleCommentHandler;
+        std::unique_ptr<CStyleCommentHandler> Handler;
+    };
+} // namespace clang::tidy::modernize
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USE_CPP_STYLE_COMMENTS_CHECK_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index a23483e6df6d2..c191d42285263 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -178,6 +178,11 @@ New checks
   Replaces nested ``std::min`` and ``std::max`` calls with an initializer list
   where applicable.
 
+- New :doc:`modernize-use-cpp-style-comments
+  <clang-tidy/checks/modernize/use-cpp-style-comments>` check.
+
+  Detects C Style comments and suggests to use C++ style comments instead.
+
 - New :doc:`modernize-use-designated-initializers
   <clang-tidy/checks/modernize/use-designated-initializers>` check.
 
diff --git a/clang-tools-extra/docs/clang-tidy/checks/modernize/use-cpp-style-comments.rst b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-cpp-style-comments.rst
new file mode 100644
index 0000000000000..ea97e02e28c23
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-cpp-style-comments.rst
@@ -0,0 +1,6 @@
+.. title:: clang-tidy - modernize-use-cpp-style-comments
+
+modernize-use-cpp-style-comments
+================================
+
+Detects C Style comments and suggests to use C++ style comments instead.
\ No newline at end of file
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-cpp-style-comments.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-cpp-style-comments.cpp
new file mode 100644
index 0000000000000..4b566b74171e7
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-cpp-style-comments.cpp
@@ -0,0 +1,7 @@
+// RUN: %check_clang_tidy -std=c++11 %s modernize-use-cpp-style-comments %t
+
+static auto PI = 3.14159265; /* value of pi upto 8 decimal places */
+// CHECK-MESSAGES: :[[@LINE-1]]:30: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
+
+int a = /*some value */ 5;
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
\ No newline at end of file



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