[clangd] Do not insert parentheses when completing a using declaration

[ilya-biryukov]

Summary

Would be nice to also fix this in clang, but that looks like more work
if we want to preserve signatures in informative chunks.

Fixes https://github.com/clangd/clangd/issues/118

[ilya-biryukov]

• Fix name of a constructor parameter

[merge_guards_bot]

Build result: fail - 59611 tests passed, 1 failed and 763 were skipped.

failed: libc++.libcxx/thread/thread_threads/thread_thread_this/sleep_for.pass.cpp

Log files: cmake-log.txt, ninja_check_all-log.txt, CMakeCache.txt

[merge_guards_bot]

Build result: fail - 59587 tests passed, 1 failed and 805 were skipped.

failed: LLVM.tools/llvm-ar/mri-utf8.test

Log files: cmake-log.txt, ninja_check_all-log.txt, CMakeCache.txt

[kadircet]

clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp

463

I believe AllScopes and this feature is orthogonal what exactly is this part of the test checking for?

clang/lib/Sema/SemaCodeComplete.cpp

5377–5378

CC in here and above(in the SS.isInvalid case) seems to be the same, why not use only a single one?

[ilya-biryukov]

clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp

463

There are two different code paths in code completion that trigger here:

1. one coming from ParseOptionalCXXScopeSpecifier, this is checked with using ns::^
2. one coming from ParseUsingDeclarator, this is checked with using ^.

I haven't checked, but the second one shouldn't provide completions from the same namespace, it's a bit more reliable long-term to assume we only provide results from other scopes.
Although maybe I'm overthinking, our index is definitely not smart enough to filter out results from the current scope in that situation (at least now)

clang/lib/Sema/SemaCodeComplete.cpp

5377–5378

Good point, thanks!

[ilya-biryukov]

• Use the same CodeCompletionContext

[merge_guards_bot]

Build result: pass - 59630 tests passed, 0 failed and 763 were skipped.
Log files: cmake-log.txt, ninja_check_all-log.txt, CMakeCache.txt

[kadircet]

clang-tools-extra/clangd/CodeComplete.cpp

1466

why not handle SnippetSuffix in here ?

instead of propagating IsUsingDeclaration, we can just drop Output.Completions.back().SnippetSuffix in here, which sounds like a more appropriate layering.
considering we don't really have context specific knowledge in CodeCompletionBuilder ?

[ilya-biryukov]

clang-tools-extra/clangd/CodeComplete.cpp

1466

I was trying to keep all processing of snippets in one place.
Code completion code is hard enough to navigate as it stands today...

Although I agree doing this when summarizing items in a bundles looks like the wrong layer, but this place is also after bundling, so I'm not sure if it's actually winning us much.

[kadircet]

clang-tools-extra/clangd/CodeComplete.cpp

482

maybe rather use GenerateSnippets? Since this doesn't generate completions for the snippets, but rather disables generation of any snippets at all.

also I think it makes sense to document this one, because of the field just above it.

1466

ah ok, that's also a good concern. feel free to choose one or the other then.

[ilya-biryukov]

• Rename flag to GenerateSnippets, document it

[merge_guards_bot]

Build result: pass - 59630 tests passed, 0 failed and 763 were skipped.
Log files: cmake-log.txt, ninja_check_all-log.txt, CMakeCache.txt

[kadircet]

oops, thought I've LGTM'd it on previous cycle :D

clang-tools-extra/clangd/CodeComplete.cpp

482

not just function, also template arguments.

[ilya-biryukov]

• Update the comment

clang-tools-extra/clangd/CodeComplete.cpp

482

Right... That was too specific.

[merge_guards_bot]

Build result: fail - 59587 tests passed, 1 failed and 805 were skipped.

failed: LLVM.tools/llvm-ar/mri-utf8.test

Log files: cmake-log.txt, ninja_check_all-log.txt, CMakeCache.txt

clang-tools-extra/clangd/CodeComplete.cpp

 // Others vary per candidate, so add() must be called for remaining candidates.
 struct CodeCompletionBuilder {
   CodeCompletionBuilder(ASTContext *ASTCtx, const CompletionCandidate &C,
                         CodeCompletionString *SemaCCS,
                         llvm::ArrayRef<std::string> QueryScopes,
                         const IncludeInserter &Includes,
                         llvm::StringRef FileName,
                         CodeCompletionContext::Kind ContextKind,
-                        const CodeCompleteOptions &Opts)
+                        const CodeCompleteOptions &Opts, bool GenerateSnippets)
       : ASTCtx(ASTCtx), ExtractDocumentation(Opts.IncludeComments),
-        EnableFunctionArgSnippets(Opts.EnableFunctionArgSnippets) {
+        EnableFunctionArgSnippets(Opts.EnableFunctionArgSnippets),
+        GenerateSnippets(GenerateSnippets) {
     add(C, SemaCCS);
     if (C.SemaResult) {
       assert(ASTCtx);
       Completion.Origin |= SymbolOrigin::AST;
       Completion.Name = llvm::StringRef(SemaCCS->getTypedText());
       if (Completion.Scope.empty()) {
         if ((C.SemaResult->Kind == CodeCompletionResult::RK_Declaration) ||
             (C.SemaResult->Kind == CodeCompletionResult::RK_Pattern))
private:
 
   std::string summarizeReturnType() const {
     if (auto *RT = onlyValue<&BundledEntry::ReturnType>())
       return *RT;
     return "";
   }
 
   std::string summarizeSnippet() const {
+    if (!GenerateSnippets)
+      return "";
     auto *Snippet = onlyValue<&BundledEntry::SnippetSuffix>();
     if (!Snippet)
       // All bundles are function calls.
       // FIXME(ibiryukov): sometimes add template arguments to a snippet, e.g.
       // we need to complete 'forward<$1>($0)'.
       return "($0)";
     if (EnableFunctionArgSnippets)
       return *Snippet;
private:
   }
 
   // ASTCtx can be nullptr if not run with sema.
   ASTContext *ASTCtx;
   CodeCompletion Completion;
   llvm::SmallVector<BundledEntry, 1> Bundled;
   bool ExtractDocumentation;
   bool EnableFunctionArgSnippets;
+  /// When false, no snippets are generated argument lists.
+  bool GenerateSnippets;
 };
 
 // Determine the symbol ID for a Sema code completion result, if possible.
 llvm::Optional<SymbolID> getSymbolID(const CodeCompletionResult &R,
                                      const SourceManager &SM) {
   switch (R.Kind) {
   case CodeCompletionResult::RK_Declaration:
   case CodeCompletionResult::RK_Pattern: {
class CodeCompleteFlow {
   PathRef FileName;
   IncludeStructure Includes;           // Complete once the compiler runs.
   SpeculativeFuzzyFind *SpecFuzzyFind; // Can be nullptr.
   const CodeCompleteOptions &Opts;
 
   // Sema takes ownership of Recorder. Recorder is valid until Sema cleanup.
   CompletionRecorder *Recorder = nullptr;
   CodeCompletionContext::Kind CCContextKind = CodeCompletionContext::CCC_Other;
+  bool IsUsingDeclaration = false;
   // Counters for logging.
   int NSema = 0, NIndex = 0, NSemaAndIndex = 0, NIdent = 0;
   bool Incomplete = false; // Would more be available with a higher limit?
   CompletionPrefix HeuristicPrefix;
   llvm::Optional<FuzzyMatcher> Filter; // Initialized once Sema runs.
   Range ReplacedRange;
   std::vector<std::string> QueryScopes; // Initialized once Sema runs.
   // Initialized once QueryScopes is initialized, if there are scopes.
CodeCompleteResult run(const SemaCompleteInput &SemaCCInput) && {
 
     // We run Sema code completion first. It builds an AST and calculates:
     //   - completion results based on the AST.
     //   - partial identifier and context. We need these for the index query.
     CodeCompleteResult Output;
     auto RecorderOwner = std::make_unique<CompletionRecorder>(Opts, [&]() {
       assert(Recorder && "Recorder is not set");
       CCContextKind = Recorder->CCContext.getKind();
+      IsUsingDeclaration = Recorder->CCContext.isUsingDeclaration();
       auto Style = getFormatStyleForFile(
           SemaCCInput.FileName, SemaCCInput.Contents, SemaCCInput.VFS.get());
       // If preprocessor was run, inclusions from preprocessor callback should
       // already be added to Includes.
       Inserter.emplace(
           SemaCCInput.FileName, SemaCCInput.Contents, Style,
           SemaCCInput.Command.Directory,
           &Recorder->CCSema->getPreprocessor().getHeaderSearchInfo());
auto RecorderOwner = std::make_unique<CompletionRecorder>(Opts, [&]() {
       }
       FileProximity.emplace(ProxSources, ProxOpts);
 
       Output = runWithSema();
       Inserter.reset(); // Make sure this doesn't out-live Clang.
       SPAN_ATTACH(Tracer, "sema_completion_kind",
                   getCompletionKindString(CCContextKind));
       log("Code complete: sema context {0}, query scopes [{1}] (AnyScope={2}), "
-          "expected type {3}",
+          "expected type {3}{4}",
           getCompletionKindString(CCContextKind),
           llvm::join(QueryScopes.begin(), QueryScopes.end(), ","), AllScopes,
           PreferredType ? Recorder->CCContext.getPreferredType().getAsString()
-                        : "<none>");
+                        : "<none>",
+          IsUsingDeclaration ? ", inside using declaration" : "");
     });
 
     Recorder = RecorderOwner.get();
 
     semaCodeComplete(std::move(RecorderOwner), Opts.getClangCompleteOpts(),
                      SemaCCInput, &Includes);
     logResults(Output, Tracer);
     return Output;
public:
   CodeCompleteResult
   runWithoutSema(llvm::StringRef Content, size_t Offset,
                  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) && {
     trace::Span Tracer("CodeCompleteWithoutSema");
     // Fill in fields normally set by runWithSema()
     HeuristicPrefix = guessCompletionPrefix(Content, Offset);
     populateContextWords(Content);
     CCContextKind = CodeCompletionContext::CCC_Recovery;
+    IsUsingDeclaration = false;
     Filter = FuzzyMatcher(HeuristicPrefix.Name);
     auto Pos = offsetToPosition(Content, Offset);
     ReplacedRange.start = ReplacedRange.end = Pos;
     ReplacedRange.start.character -= HeuristicPrefix.Name.size();
 
     llvm::StringMap<SourceParams> ProxSources;
     ProxSources[FileName].Cost = 0;
     FileProximity.emplace(ProxSources);
private:
   CodeCompleteResult
   toCodeCompleteResult(const std::vector<ScoredBundle> &Scored) {
     CodeCompleteResult Output;
 
     // Convert the results to final form, assembling the expensive strings.
     for (auto &C : Scored) {
       Output.Completions.push_back(toCodeCompletion(C.first));
       Output.Completions.back().Score = C.second;
       Output.Completions.back().CompletionTokenRange = ReplacedRange;
     }
     Output.HasMore = Incomplete;
     Output.Context = CCContextKind;
     return Output;
   }
 
   SymbolSlab queryIndex() {
     trace::Span Tracer("Query index");
CodeCompletion toCodeCompletion(const CompletionCandidate::Bundle &Bundle) {
     llvm::Optional<CodeCompletionBuilder> Builder;
     for (const auto &Item : Bundle) {
       CodeCompletionString *SemaCCS =
           Item.SemaResult ? Recorder->codeCompletionString(*Item.SemaResult)
                           : nullptr;
       if (!Builder)
         Builder.emplace(Recorder ? &Recorder->CCSema->getASTContext() : nullptr,
                         Item, SemaCCS, QueryScopes, *Inserter, FileName,
-                        CCContextKind, Opts);
+                        CCContextKind, Opts,
+                        /*GenerateSnippets=*/!IsUsingDeclaration);
       else
         Builder->add(Item, SemaCCS);
     }
     return Builder->build();
   }
 };
 
 } // namespace

clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp

auto Results = completions(
       )cpp",
       /*IndexSymbols=*/{}, Opts);
   EXPECT_THAT(
       Results.Completions,
       HasSubsequence(Named("a"),
                      SnippetSuffix("(${1:int i}, ${2:const float f})")));
 }
 
+TEST(CompletionTest, NoSnippetsInUsings) {
+  clangd::CodeCompleteOptions Opts;
+  Opts.EnableSnippets = true;
+  auto Results = completions(
+      R"cpp(
+      namespace ns {
+        int func(int a, int b);
+      }
+
+      using ns::^;
+      )cpp",
+      /*IndexSymbols=*/{}, Opts);
+  EXPECT_THAT(Results.Completions,
+              ElementsAre(AllOf(Named("func"), Labeled("func(int a, int b)"),
+                                SnippetSuffix(""))));
+
+  // Check index completions too.
+  auto Func = func("ns::func");
+  Func.CompletionSnippetSuffix = "(${1:int a}, ${2: int b})";
+  Func.Signature = "(int a, int b)";
+  Func.ReturnType = "void";
+
+  Results = completions(R"cpp(
+      namespace ns {}
+      using ns::^;
+  )cpp",
+                        /*IndexSymbols=*/{Func}, Opts);
+  EXPECT_THAT(Results.Completions,
+              ElementsAre(AllOf(Named("func"), Labeled("func(int a, int b)"),
+                                SnippetSuffix(""))));
+
+  // Check all-scopes completions too.
+  Opts.AllScopes = true;
+  Results = completions(R"cpp(
+      using ^;
+  )cpp",
+                        /*IndexSymbols=*/{Func}, Opts);
+  EXPECT_THAT(Results.Completions,
+              Contains(AllOf(Named("func"), Labeled("ns::func(int a, int b)"),
+                             SnippetSuffix(""))));
+}
+
 TEST(CompletionTest, Kinds) {
   auto Results = completions(
       R"cpp(
           int variable;
           struct Struct {};
           int function();
           // make sure MACRO is not included in preamble.
           #define MACRO 10

clang/include/clang/Parse/Parser.h

private:
   ExprResult ParseCXXIdExpression(bool isAddressOfOperand = false);
 
   bool areTokensAdjacent(const Token &A, const Token &B);
 
   void CheckForTemplateAndDigraph(Token &Next, ParsedType ObjectTypePtr,
                                   bool EnteringContext, IdentifierInfo &II,
                                   CXXScopeSpec &SS);
 
-  bool ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
-                                      ParsedType ObjectType,
+  bool ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS, ParsedType ObjectType,
                                       bool EnteringContext,
                                       bool *MayBePseudoDestructor = nullptr,
                                       bool IsTypename = false,
                                       IdentifierInfo **LastII = nullptr,
-                                      bool OnlyNamespace = false);
+                                      bool OnlyNamespace = false,
+                                      bool InUsingDeclaration = false);
 
   //===--------------------------------------------------------------------===//
   // C++11 5.1.2: Lambda expressions
 
   /// Result of tentatively parsing a lambda-introducer.
   enum class LambdaIntroducerTentativeParse {
     /// This appears to be a lambda-introducer, which has been fully parsed.
     Success,

clang/include/clang/Sema/CodeCompleteConsumer.h

enum Kind {
     CCC_Recovery
   };
 
   using VisitedContextSet = llvm::SmallPtrSet<DeclContext *, 8>;
 
 private:
   Kind CCKind;
 
+  /// Indicates whether we are completing a name of a using declaration, e.g.
+  ///     using ^;
+  ///     using a::^;
+  bool IsUsingDeclaration;
+
   /// The type that would prefer to see at this point (e.g., the type
   /// of an initializer or function parameter).
   QualType PreferredType;
 
   /// The type of the base object in a member access expression.
   QualType BaseType;
 
   /// The identifiers for Objective-C selector parts.
   ArrayRef<IdentifierInfo *> SelIdents;
 
   /// The scope specifier that comes before the completion token e.g.
   /// "a::b::"
   llvm::Optional<CXXScopeSpec> ScopeSpecifier;
 
   /// A set of declaration contexts visited by Sema when doing lookup for
   /// code completion.
   VisitedContextSet VisitedContexts;
 
 public:
   /// Construct a new code-completion context of the given kind.
-  CodeCompletionContext(Kind CCKind) : CCKind(CCKind), SelIdents(None) {}
+  CodeCompletionContext(Kind CCKind)
+      : CCKind(CCKind), IsUsingDeclaration(false), SelIdents(None) {}
 
   /// Construct a new code-completion context of the given kind.
   CodeCompletionContext(Kind CCKind, QualType T,
                         ArrayRef<IdentifierInfo *> SelIdents = None)
-      : CCKind(CCKind), SelIdents(SelIdents) {
+      : CCKind(CCKind), IsUsingDeclaration(false), SelIdents(SelIdents) {
     if (CCKind == CCC_DotMemberAccess || CCKind == CCC_ArrowMemberAccess ||
         CCKind == CCC_ObjCPropertyAccess || CCKind == CCC_ObjCClassMessage ||
         CCKind == CCC_ObjCInstanceMessage)
       BaseType = T;
     else
       PreferredType = T;
   }
 
+  bool isUsingDeclaration() const { return IsUsingDeclaration; }
+  void setIsUsingDeclaration(bool V) { IsUsingDeclaration = V; }
+
   /// Retrieve the kind of code-completion context.
   Kind getKind() const { return CCKind; }
 
   /// Retrieve the type that this expression would prefer to have, e.g.,
   /// if the expression is a variable initializer or a function argument, the
   /// type of the corresponding variable or function parameter.
   QualType getPreferredType() const { return PreferredType; }
   void setPreferredType(QualType T) { PreferredType = T; }

clang/include/clang/Sema/Sema.h

QualType ProduceCtorInitMemberSignatureHelp(Scope *S, Decl *ConstructorDecl,
                                               ParsedType TemplateTypeTy,
                                               ArrayRef<Expr *> ArgExprs,
                                               IdentifierInfo *II,
                                               SourceLocation OpenParLoc);
   void CodeCompleteInitializer(Scope *S, Decl *D);
   void CodeCompleteAfterIf(Scope *S);
 
   void CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS, bool EnteringContext,
-                               QualType BaseType, QualType PreferredType);
+                               bool IsUsingDeclaration, QualType BaseType,
+                               QualType PreferredType);
   void CodeCompleteUsing(Scope *S);
   void CodeCompleteUsingDirective(Scope *S);
   void CodeCompleteNamespaceDecl(Scope *S);
   void CodeCompleteNamespaceAliasDecl(Scope *S);
   void CodeCompleteOperatorName(Scope *S);
   void CodeCompleteConstructorInitializer(
                                 Decl *Constructor,
                                 ArrayRef<CXXCtorInitializer *> Initializers);

clang/lib/Parse/ParseDeclCXX.cpp

if (Tok.is(tok::kw___super)) {
     return true;
   }
 
   // Parse nested-name-specifier.
   IdentifierInfo *LastII = nullptr;
   if (ParseOptionalCXXScopeSpecifier(D.SS, nullptr, /*EnteringContext=*/false,
                                      /*MayBePseudoDtor=*/nullptr,
                                      /*IsTypename=*/false,
-                                     /*LastII=*/&LastII))
+                                     /*LastII=*/&LastII,
+                                     /*OnlyNamespace=*/false,
+                                     /*InUsingDeclaration=*/true))
+
     return true;
   if (D.SS.isInvalid())
     return true;
 
   // Parse the unqualified-id. We allow parsing of both constructor and
   // destructor names and allow the action module to diagnose any semantic
   // errors.
   //

clang/lib/Parse/ParseExprCXX.cpp

 ///
 /// \param LastII When non-NULL, points to an IdentifierInfo* that will be
 /// filled in with the leading identifier in the last component of the
 /// nested-name-specifier, if any.
 ///
 /// \param OnlyNamespace If true, only considers namespaces in lookup.
 ///
 /// \returns true if there was an error parsing a scope specifier
-bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
-                                            ParsedType ObjectType,
-                                            bool EnteringContext,
-                                            bool *MayBePseudoDestructor,
-                                            bool IsTypename,
-                                            IdentifierInfo **LastII,
-                                            bool OnlyNamespace) {
+bool Parser::ParseOptionalCXXScopeSpecifier(
+    CXXScopeSpec &SS, ParsedType ObjectType, bool EnteringContext,
+    bool *MayBePseudoDestructor, bool IsTypename, IdentifierInfo **LastII,
+    bool OnlyNamespace, bool InUsingDeclaration) {
   assert(getLangOpts().CPlusPlus &&
          "Call sites of this function should be guarded by checking for C++");
 
   if (Tok.is(tok::annot_cxxscope)) {
     assert(!LastII && "want last identifier but have already annotated scope");
     assert(!MayBePseudoDestructor && "unexpected annot_cxxscope");
     Actions.RestoreNestedNameSpecifierAnnotation(Tok.getAnnotationValue(),
                                                  Tok.getAnnotationRange(),
bool Parser::ParseOptionalCXXScopeSpecifier(
   // Preferred type might change when parsing qualifiers, we need the original.
   auto SavedType = PreferredType;
   while (true) {
     if (HasScopeSpecifier) {
       if (Tok.is(tok::code_completion)) {
         // Code completion for a nested-name-specifier, where the code
         // completion token follows the '::'.
         Actions.CodeCompleteQualifiedId(getCurScope(), SS, EnteringContext,
-                                        ObjectType.get(),
+                                        InUsingDeclaration, ObjectType.get(),
                                         SavedType.get(SS.getBeginLoc()));
         // Include code completion token into the range of the scope otherwise
         // when we try to annotate the scope tokens the dangling code completion
         // token will cause assertion in
         // Preprocessor::AnnotatePreviousCachedTokens.
         SS.setEndLoc(Tok.getLocation());
         cutOffParsing();
         return true;

clang/lib/Sema/SemaCodeComplete.cpp

void Sema::CodeCompleteAfterIf(Scope *S) {
   if (CodeCompleter->includeMacros())
     AddMacroResults(PP, Results, CodeCompleter->loadExternal(), false);
 
   HandleCodeCompleteResults(this, CodeCompleter, Results.getCompletionContext(),
                             Results.data(), Results.size());
 }
 
 void Sema::CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS,
-                                   bool EnteringContext, QualType BaseType,
+                                   bool EnteringContext,
+                                   bool IsUsingDeclaration, QualType BaseType,
                                    QualType PreferredType) {
   if (SS.isEmpty() || !CodeCompleter)
     return;
 
+  CodeCompletionContext CC(CodeCompletionContext::CCC_Symbol, PreferredType);
+  CC.setIsUsingDeclaration(IsUsingDeclaration);
+  CC.setCXXScopeSpecifier(SS);
+
   // We want to keep the scope specifier even if it's invalid (e.g. the scope
   // "a::b::" is not corresponding to any context/namespace in the AST), since
   // it can be useful for global code completion which have information about
   // contexts/symbols that are not in the AST.
   if (SS.isInvalid()) {
-    CodeCompletionContext CC(CodeCompletionContext::CCC_Symbol, PreferredType);
-    CC.setCXXScopeSpecifier(SS);
     // As SS is invalid, we try to collect accessible contexts from the current
     // scope with a dummy lookup so that the completion consumer can try to
     // guess what the specified scope is.
     ResultBuilder DummyResults(*this, CodeCompleter->getAllocator(),
                                CodeCompleter->getCodeCompletionTUInfo(), CC);
     if (!PreferredType.isNull())
       DummyResults.setPreferredType(PreferredType);
     if (S->getEntity()) {
void Sema::CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS,
   if (!Ctx)
     return;
 
   // Try to instantiate any non-dependent declaration contexts before
   // we look in them.
   if (!isDependentScopeSpecifier(SS) && RequireCompleteDeclContext(SS, Ctx))
     return;
 
-  ResultBuilder Results(
-      *this, CodeCompleter->getAllocator(),
-      CodeCompleter->getCodeCompletionTUInfo(),
-      CodeCompletionContext(CodeCompletionContext::CCC_Symbol, PreferredType));
+  ResultBuilder Results(*this, CodeCompleter->getAllocator(),
+                        CodeCompleter->getCodeCompletionTUInfo(), CC);
   if (!PreferredType.isNull())
     Results.setPreferredType(PreferredType);
   Results.EnterNewScope();
 
   // The "template" keyword can follow "::" in the grammar, but only
   // put it into the grammar if the nested-name-specifier is dependent.
   NestedNameSpecifier *NNS = SS.getScopeRep();
   if (!Results.empty() && NNS->isDependent())
if (CodeCompleter->includeNamespaceLevelDecls() ||
       (!Ctx->isNamespace() && !Ctx->isTranslationUnit())) {
     CodeCompletionDeclConsumer Consumer(Results, Ctx, BaseType);
     LookupVisibleDecls(Ctx, LookupOrdinaryName, Consumer,
                        /*IncludeGlobalScope=*/true,
                        /*IncludeDependentBases=*/true,
                        CodeCompleter->loadExternal());
   }
 
-  auto CC = Results.getCompletionContext();
-  CC.setCXXScopeSpecifier(SS);
-
-  HandleCodeCompleteResults(this, CodeCompleter, CC, Results.data(),
-                            Results.size());
+  HandleCodeCompleteResults(this, CodeCompleter, Results.getCompletionContext(),
+                            Results.data(), Results.size());
 }
 
 void Sema::CodeCompleteUsing(Scope *S) {
   if (!CodeCompleter)
     return;
 
+  // This can be both a using alias or using declaration, in the former we
+  // expect a new name and a symbol in the latter case.
+  CodeCompletionContext Context(CodeCompletionContext::CCC_SymbolOrNewName);
+  Context.setIsUsingDeclaration(true);
+
   ResultBuilder Results(*this, CodeCompleter->getAllocator(),
-                        CodeCompleter->getCodeCompletionTUInfo(),
-                        // This can be both a using alias or using
-                        // declaration, in the former we expect a new name and a
-                        // symbol in the latter case.
-                        CodeCompletionContext::CCC_SymbolOrNewName,
+                        CodeCompleter->getCodeCompletionTUInfo(), Context,
                         &ResultBuilder::IsNestedNameSpecifier);
   Results.EnterNewScope();
 
   // If we aren't in class scope, we could see the "namespace" keyword.
   if (!S->isClassScope())
     Results.AddResult(CodeCompletionResult("namespace"));
 
   // After "using", we can see anything that would start a