Revert "Fix nested namespaces in google-readability-nested-namespace-comments."

This reverts r315057. The revision introduces assertion failures:
assertion failed at llvm/tools/clang/include/clang/Basic/SourceManager.h:428 in
const clang::SrcMgr::ExpansionInfo &clang::SrcMgr::SLocEntry::getExpansion()
const: isExpansion() && "Not a macro expansion SLocEntry!"
Stack trace:
    __assert_fail
    clang::SrcMgr::SLocEntry::getExpansion()
    clang::SourceManager::getExpansionLocSlowCase()
    clang::SourceManager::getExpansionLoc()
    clang::Lexer::getRawToken()
    clang::tidy::readability::NamespaceCommentCheck::check()
    clang::ast_matchers::internal::(anonymous namespace)::MatchASTVisitor::MatchVisitor::visitMatch()
    clang::ast_matchers::internal::BoundNodesTreeBuilder::visitMatches()
    clang::ast_matchers::internal::(anonymous namespace)::MatchASTVisitor::matchWithFilter()
    clang::ast_matchers::internal::(anonymous namespace)::MatchASTVisitor::matchDispatch()
    clang::ast_matchers::internal::(anonymous namespace)::MatchASTVisitor::TraverseDecl()
    clang::RecursiveASTVisitor<>::TraverseDeclContextHelper()
    clang::RecursiveASTVisitor<>::TraverseDecl()
    clang::RecursiveASTVisitor<>::TraverseDeclContextHelper()
    clang::RecursiveASTVisitor<>::TraverseDecl()
    clang::RecursiveASTVisitor<>::TraverseDeclContextHelper()
    clang::RecursiveASTVisitor<>::TraverseDecl()
    clang::ast_matchers::MatchFinder::matchAST()
    clang::MultiplexConsumer::HandleTranslationUnit()
    clang::ParseAST()
    clang::FrontendAction::Execute()
    clang::CompilerInstance::ExecuteAction()
    clang::tooling::FrontendActionFactory::runInvocation()
    clang::tooling::ToolInvocation::runInvocation()
    clang::tooling::ToolInvocation::run()

Still working on an isolated test case.

llvm-svn: 315580

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

@@ -23,7 +23,7 @@ NamespaceCommentCheck::NamespaceCommentCheck(StringRef Name,
                                              ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       NamespaceCommentPattern("^/[/*] *(end (of )?)? *(anonymous|unnamed)? *"
-                              "namespace( +([a-zA-Z0-9_:]+))?\\.? *(\\*/)?$",
+                              "namespace( +([a-zA-Z0-9_]+))?\\.? *(\\*/)?$",
                               llvm::Regex::IgnoreCase),
       ShortNamespaceLines(Options.get("ShortNamespaceLines", 1u)),
       SpacesBeforeComments(Options.get("SpacesBeforeComments", 1u)) {}
@@ -56,15 +56,6 @@ static std::string getNamespaceComment(const NamespaceDecl *ND,
   return Fix;
 }
 
-static std::string getNamespaceComment(const std::string &NameSpaceName,
-                                       bool InsertLineBreak) {
-  std::string Fix = "// namespace ";
-  Fix.append(NameSpaceName);
-  if (InsertLineBreak)
-    Fix.append("\n");
-  return Fix;
-}
-
 void NamespaceCommentCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *ND = Result.Nodes.getNodeAs<NamespaceDecl>("namespace");
   const SourceManager &Sources = *Result.SourceManager;
@@ -83,38 +74,11 @@ void NamespaceCommentCheck::check(const MatchFinder::MatchResult &Result) {
   SourceLocation AfterRBrace = ND->getRBraceLoc().getLocWithOffset(1);
   SourceLocation Loc = AfterRBrace;
   Token Tok;
-  SourceLocation LBracketLocation = ND->getLocation();
-  SourceLocation NestedNamespaceBegin = LBracketLocation;
-
-  // Currently for nested namepsace (n1::n2::...) the AST matcher will match foo
-  // then bar instead of a single match. So if we got a nested namespace we have
-  // to skip the next ones.
-  for (const auto &EndOfNameLocation : Ends) {
-    if (Sources.isBeforeInTranslationUnit(NestedNamespaceBegin,
-                                          EndOfNameLocation))
-      return;
-  }
-  while (Lexer::getRawToken(LBracketLocation, Tok, Sources, getLangOpts()) ||
-         !Tok.is(tok::l_brace)) {
-    LBracketLocation = LBracketLocation.getLocWithOffset(1);
-  }
-
-  auto TextRange =
-      Lexer::getAsCharRange(SourceRange(NestedNamespaceBegin, LBracketLocation),
-                            Sources, getLangOpts());
-  auto NestedNamespaceName =
-      Lexer::getSourceText(TextRange, Sources, getLangOpts()).rtrim();
-  bool IsNested = NestedNamespaceName.contains(':');
-
-  if (IsNested)
-    Ends.push_back(LBracketLocation);
-
   // Skip whitespace until we find the next token.
   while (Lexer::getRawToken(Loc, Tok, Sources, getLangOpts()) ||
          Tok.is(tok::semi)) {
     Loc = Loc.getLocWithOffset(1);
   }
-
   if (!locationsInSameFile(Sources, ND->getRBraceLoc(), Loc))
     return;
 
@@ -134,14 +98,10 @@ void NamespaceCommentCheck::check(const MatchFinder::MatchResult &Result) {
       StringRef NamespaceNameInComment = Groups.size() > 5 ? Groups[5] : "";
       StringRef Anonymous = Groups.size() > 3 ? Groups[3] : "";
 
-      if (IsNested && NestedNamespaceName == NamespaceNameInComment) {
-        // C++17 nested namespace.
-        return;
-      } else if ((ND->isAnonymousNamespace() &&
-                  NamespaceNameInComment.empty()) ||
-                 (ND->getNameAsString() == NamespaceNameInComment &&
-                  Anonymous.empty())) {
-        // Check if the namespace in the comment is the same.
+      // Check if the namespace in the comment is the same.
+      if ((ND->isAnonymousNamespace() && NamespaceNameInComment.empty()) ||
+          (ND->getNameAsString() == NamespaceNameInComment &&
+           Anonymous.empty())) {
         // FIXME: Maybe we need a strict mode, where we always fix namespace
         // comments with different format.
         return;
@@ -171,16 +131,13 @@ void NamespaceCommentCheck::check(const MatchFinder::MatchResult &Result) {
   std::string NamespaceName =
       ND->isAnonymousNamespace()
           ? "anonymous namespace"
-          : ("namespace '" + NestedNamespaceName.str() + "'");
+          : ("namespace '" + ND->getNameAsString() + "'");
 
   diag(AfterRBrace, Message)
-      << NamespaceName
-      << FixItHint::CreateReplacement(
-             CharSourceRange::getCharRange(OldCommentRange),
-             std::string(SpacesBeforeComments, ' ') +
-                 (IsNested
-                      ? getNamespaceComment(NestedNamespaceName, NeedLineBreak)
-                      : getNamespaceComment(ND, NeedLineBreak)));
+      << NamespaceName << FixItHint::CreateReplacement(
+                              CharSourceRange::getCharRange(OldCommentRange),
+                              std::string(SpacesBeforeComments, ' ') +
+                                  getNamespaceComment(ND, NeedLineBreak));
   diag(ND->getLocation(), "%0 starts here", DiagnosticIDs::Note)
       << NamespaceName;
 }

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

@@ -34,7 +34,6 @@ private:
   llvm::Regex NamespaceCommentPattern;
   const unsigned ShortNamespaceLines;
   const unsigned SpacesBeforeComments;
-  llvm::SmallVector<SourceLocation, 4> Ends;
 };
 
 } // namespace readability

clang-tools-extra/test/clang-tidy/google-readability-namespace-comments-cxx17.cpp

@@ -1,23 +0,0 @@
-// RUN: %check_clang_tidy %s google-readability-namespace-comments %t -- -- -std=c++17
-
-namespace n1::n2 {
-namespace n3 {
-  // So that namespace is not empty and has at least 10 lines.
-  // 1
-  // 2
-  // 3
-  // 3
-  // 4
-  // 5
-  // 6
-  // 7
-  // 8
-  void f();
-}}
-// CHECK-MESSAGES: :[[@LINE-1]]:2: warning: namespace 'n3' not terminated with
-// CHECK-MESSAGES: :[[@LINE-14]]:11: note: namespace 'n3' starts here
-// CHECK-MESSAGES: :[[@LINE-3]]:3: warning: namespace 'n1::n2' not terminated with a closing comment [google-readability-namespace-comments]
-// CHECK-MESSAGES: :[[@LINE-17]]:11: note: namespace 'n1::n2' starts here
-// CHECK-FIXES: }  // namespace n3
-// CHECK-FIXES: }  // namespace n1::n2
-