[clang-tidy] fix false positve for namespace with attrs in modernize-concat-nested-namespaces

[HerrCai0907]

Summary

Fixed https://github.com/llvm/llvm-project/issues/57530
Add pre check to avoid false positive for namespace with attributes like

namespace [[deprecated]] ns {}

[HerrCai0907]

It should fix https://github.com/llvm/llvm-project/issues/57530 due to side effect instead of root cause.\

[PiotrZSL]

clang-tools-extra/docs/ReleaseNotes.rst

303–309

Merge those 2 into one if possible.

[PiotrZSL]

Reference issue in commit message, so it could auto-close, or close it manualy later.

[HerrCai0907]

merge items in release note

clang-tools-extra/clang-tidy/modernize/ConcatNestedNamespacesCheck.cpp

 
 static StringRef getRawStringRef(const SourceRange &Range,
                                  const SourceManager &Sources,
                                  const LangOptions &LangOpts) {
   CharSourceRange TextRange = Lexer::getAsCharRange(Range, Sources, LangOpts);
   return Lexer::getSourceText(TextRange, Sources, LangOpts);
 }
 
-static bool anonymousOrInlineNamespace(const NamespaceDecl &ND) {
-  return ND.isAnonymousNamespace() || ND.isInlineNamespace();
+static bool unsupportedNamespace(const NamespaceDecl &ND) {
+  return ND.isAnonymousNamespace() || ND.isInlineNamespace() ||
+         !ND.attrs().empty();
 }
 
 static bool singleNamedNamespaceChild(const NamespaceDecl &ND) {
   NamespaceDecl::decl_range Decls = ND.decls();
   if (std::distance(Decls.begin(), Decls.end()) != 1)
     return false;
 
   const auto *ChildNamespace = dyn_cast<const NamespaceDecl>(*Decls.begin());
-  return ChildNamespace && !anonymousOrInlineNamespace(*ChildNamespace);
+  return ChildNamespace && !unsupportedNamespace(*ChildNamespace);
 }
 
 static bool alreadyConcatenated(std::size_t NumCandidates,
                                 const SourceRange &ReplacementRange,
                                 const SourceManager &Sources,
                                 const LangOptions &LangOpts) {
   // FIXME: This logic breaks when there is a comment with ':'s in the middle.
   return getRawStringRef(ReplacementRange, Sources, LangOpts).count(':') ==

 void ConcatNestedNamespacesCheck::check(
     const ast_matchers::MatchFinder::MatchResult &Result) {
   const NamespaceDecl &ND = *Result.Nodes.getNodeAs<NamespaceDecl>("namespace");
   const SourceManager &Sources = *Result.SourceManager;
 
   if (!locationsInSameFile(Sources, ND.getBeginLoc(), ND.getRBraceLoc()))
     return;
 
-  if (anonymousOrInlineNamespace(ND))
+  if (unsupportedNamespace(ND))
     return;
 
   Namespaces.push_back(&ND);
 
   if (singleNamedNamespaceChild(ND))
     return;
 
   SourceRange FrontReplacement(Namespaces.front()->getBeginLoc(),

clang-tools-extra/docs/ReleaseNotes.rst

 - Fixed an issue in :doc:`readability-identifier-naming
   <clang-tidy/checks/readability/identifier-naming>` when specifying an empty
   string for ``Prefix`` or ``Suffix`` options could result in the style not
   being used.
 
 - Fixed an issue in :doc:`google-readability-avoid-underscore-in-googletest-name
   <clang-tidy/checks/google/readability-avoid-underscore-in-googletest-name>` when using
   ``DISABLED_`` in the test suite name.
 
-- Fixed an issue in :doc:`modernize-concat-nested-namespaces
-  <clang-tidy/checks/modernize/concat-nested-namespaces>` when using macro between
-  namespace declarations could result incorrect fix.
+- Improved :doc:`modernize-concat-nested-namespaces
+  <clang-tidy/checks/modernize/concat-nested-namespaces>` to fix incorrect fixes when 
+  using macro between namespace declarations and false positive when using namespace 
+  with attributes.
 
 - Fixed a false positive in :doc:`performance-no-automatic-move
   <clang-tidy/checks/performance/no-automatic-move>` when warning would be
   emitted for a const local variable to which NRVO is applied.
 
 Removed checks
 ^^^^^^^^^^^^^^
 
 Improvements to include-fixer
 -----------------------------

clang-tools-extra/test/clang-tidy/checkers/modernize/concat-nested-namespaces.cpp

 void t();
 }
 namespace n4 {
 void t();
 }
 } // namespace n2
 
 namespace n5 {
-inline namespace n6 {
+inline namespace inline_ns {
 void t();
-}
+} // namespace inline_ns
 } // namespace n5
 
+namespace n6 {
+namespace [[deprecated]] attr_ns {
+void t();
+} // namespace attr_ns
+} // namespace n6
+
 namespace n7 {
 void t();
 
 namespace n8 {
 void t();
 }
 } // namespace n7