further improvements as suggested

Author: 4m4n-x-B4w4ne

clang-tools-extra/clang-tidy/readability/CMakeLists.txt

@@ -57,6 +57,7 @@ add_clang_library(clangTidyReadabilityModule STATIC
   UniqueptrDeleteReleaseCheck.cpp
   UppercaseLiteralSuffixCheck.cpp
   UseAnyOfAllOfCheck.cpp
+  UseCppStyleCommentsCheck.cpp
   UseStdMinMaxCheck.cpp
 
   LINK_LIBS

clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp

@@ -60,6 +60,7 @@
 #include "UniqueptrDeleteReleaseCheck.h"
 #include "UppercaseLiteralSuffixCheck.h"
 #include "UseAnyOfAllOfCheck.h"
+#include "UseCppStyleCommentsCheck.h"
 #include "UseStdMinMaxCheck.h"
 
 namespace clang::tidy {
@@ -146,6 +147,8 @@ class ReadabilityModule : public ClangTidyModule {
         "readability-static-definition-in-anonymous-namespace");
     CheckFactories.registerCheck<StringCompareCheck>(
         "readability-string-compare");
+    CheckFactories.registerCheck<UseCppStyleCommentsCheck>(
+        "readability-use-cpp-style-comments");
     CheckFactories.registerCheck<readability::NamedParameterCheck>(
         "readability-named-parameter");
     CheckFactories.registerCheck<NonConstParameterCheck>(

clang-tools-extra/clang-tidy/readability/UseCppStyleCommentsCheck.cpp

@@ -0,0 +1,136 @@
+//===--- 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"
+#include <sstream.h>
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+class UseCppStyleCommentsCheck::CStyleCommentHandler : public CommentHandler {
+public:
+  CStyleCommentHandler(UseCppStyleCommentsCheck &Check)
+      : Check(Check),
+        CStyleCommentMatch(
+            "^[ \t]*/\\*+[ \t\r\n]*(.*[ \t\r\n]*)*[ \t\r\n]*\\*+/[ \t\r\n]*$") {
+  }
+
+  std::string convertToCppStyleComment(const SourceManager &SM,
+                                       const SourceRange &Range) {
+    const StringRef CommentText = Lexer::getSourceText(
+        CharSourceRange::getTokenRange(Range), SM, LangOptions());
+
+    std::string InnerText = CommentText.str();
+    InnerText.erase(0, 2);
+    InnerText.erase(InnerText.size() - 2, 2);
+
+    std::string Result;
+    std::istringstream Stream(InnerText);
+    std::string Line;
+
+    if (std::getline(Stream, Line)) {
+      const size_t StartPos = Line.find_first_not_of(" \t");
+      if (StartPos != std::string::npos) {
+        Line = Line.substr(StartPos);
+      } else {
+        Line.clear();
+      }
+      Result += "// " + Line;
+    }
+
+    while (std::getline(Stream, Line)) {
+      const size_t StartPos = Line.find_first_not_of(" \t");
+      if (StartPos != std::string::npos) {
+        Line = Line.substr(StartPos);
+      } else {
+        Line.clear();
+      }
+      Result += "\n// " + Line;
+    }
+    return Result;
+  }
+
+  bool CheckForInlineComments(Preprocessor &PP, SourceRange Range) {
+    const SourceManager &SM = PP.getSourceManager();
+    const SourceLocation CommentStart = Range.getBegin();
+    const SourceLocation CommentEnd = Range.getEnd();
+
+    unsigned StartLine = SM.getSpellingLineNumber(CommentStart);
+    unsigned EndLine = SM.getSpellingLineNumber(CommentEnd);
+
+    if (StartLine == EndLine) {
+      SourceLocation LineBegin =
+          SM.translateLineCol(SM.getFileID(CommentStart), StartLine, 1);
+      SourceLocation LineEnd =
+          SM.translateLineCol(SM.getFileID(CommentEnd), EndLine,
+                              std::numeric_limits<unsigned>::max());
+      StringRef LineContent = Lexer::getSourceText(
+          CharSourceRange::getCharRange(LineBegin, LineEnd), SM,
+          PP.getLangOpts());
+      size_t CommentStartOffset = SM.getSpellingColumnNumber(CommentStart) - 1;
+      StringRef AfterComment =
+          LineContent.drop_front(CommentStartOffset + Text.size());
+
+      if (!AfterComment.trim().empty()) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  bool HandleComment(Preprocessor &PP, SourceRange Range) override {
+    const SourceManager &SM = PP.getSourceManager();
+
+    if (Range.getBegin().isMacroID() || SM.isInSystemHeader(Range.getBegin())) {
+      return false;
+    }
+
+    const StringRef Text = Lexer::getSourceText(
+        CharSourceRange::getCharRange(Range), SM, PP.getLangOpts());
+
+    SmallVector<StringRef> Matches;
+    if (!CStyleCommentMatch.match(Text, &Matches)) {
+      return false;
+    }
+
+    if (CheckForInlineComments(PP, Range)) {
+      return false;
+    }
+
+    Check.diag(
+        Range.getBegin(),
+        "use C++ style comments '//' instead of C style comments '/*...*/'")
+        << clang::FixItHint::CreateReplacement(
+               Range, convertToCppStyleComment(SM, Range));
+
+    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::readability

clang-tools-extra/clang-tidy/readability/UseCppStyleCommentsCheck.h

@@ -0,0 +1,40 @@
+//===--- UseCppStyleCommentsCheck.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_USECPPSTYLECOMMENTSCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_USECPPSTYLECOMMENTSCHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::readability {
+/// 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/readability/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::readability
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_USECPPSTYLECOMMENTSCHECK_H