Index: clangd/AST.h
===================================================================
--- clangd/AST.h
+++ clangd/AST.h
@@ -42,6 +42,11 @@
 /// Returns the first enclosing namespace scope starting from \p DC.
 std::string printNamespaceScope(const DeclContext &DC);
 
+/// Prints unqualified name of the decl for the purpose of displaying it to the
+/// user. Anonymous decls return names of the form "(anonymous {kind})", e.g.
+/// "(anonymous struct)" or "(anonymous namespace)".
+std::string printName(const ASTContext &Ctx, const NamedDecl &ND);
+
 /// Gets the symbol ID for a declaration, if possible.
 llvm::Optional<SymbolID> getSymbolID(const Decl *D);
 
Index: clangd/AST.cpp
===================================================================
--- clangd/AST.cpp
+++ clangd/AST.cpp
@@ -11,9 +11,12 @@
 
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Decl.h"
+#include "clang/AST/DeclTemplate.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Index/USRGeneration.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/ScopedPrinter.h"
 
 using namespace llvm;
 namespace clang {
@@ -61,6 +64,46 @@
   return QName;
 }
 
+static const TemplateArgumentList *
+getTemplateSpecializationArgs(const NamedDecl &ND) {
+  if (auto *Func = llvm::dyn_cast<FunctionDecl>(&ND))
+    return Func->getTemplateSpecializationArgs();
+  if (auto *Cls = llvm::dyn_cast<ClassTemplateSpecializationDecl>(&ND))
+    return &Cls->getTemplateInstantiationArgs();
+  if (auto *Var = llvm::dyn_cast<VarTemplateSpecializationDecl>(&ND))
+    return &Var->getTemplateInstantiationArgs();
+  return nullptr;
+}
+
+std::string printName(const ASTContext &Ctx, const NamedDecl &ND) {
+  std::string Name;
+  llvm::raw_string_ostream Out(Name);
+  PrintingPolicy PP(Ctx.getLangOpts());
+  // Handle 'using namespace'. They all have the same name - <using-directive>.
+  if (auto *UD = llvm::dyn_cast<UsingDirectiveDecl>(&ND)) {
+    Out << "using namespace ";
+    if (auto *Qual = UD->getQualifier())
+      Qual->print(Out, PP);
+    UD->getNominatedNamespaceAsWritten()->printName(Out);
+    return Out.str();
+  }
+  ND.getDeclName().print(Out, PP);
+  if (!Out.str().empty()) {
+    // FIXME(ibiryukov): do not show args not explicitly written by the user.
+    if (auto *ArgList = getTemplateSpecializationArgs(ND))
+      printTemplateArgumentList(Out, ArgList->asArray(), PP);
+    return Out.str();
+  }
+  // The name was empty, so present an anonymous entity.
+  if (auto *NS = llvm::dyn_cast<NamespaceDecl>(&ND))
+    return "(anonymous namespace)";
+  if (auto *Cls = llvm::dyn_cast<RecordDecl>(&ND))
+    return ("(anonymous " + Cls->getKindName() + ")").str();
+  if (auto *En = llvm::dyn_cast<EnumDecl>(&ND))
+    return "(anonymous enum)";
+  return "(anonymous)";
+}
+
 std::string printNamespaceScope(const DeclContext &DC) {
   for (const auto *Ctx = &DC; Ctx != nullptr; Ctx = Ctx->getParent())
     if (const auto *NS = dyn_cast<NamespaceDecl>(Ctx))
Index: clangd/ClangdLSPServer.h
===================================================================
--- clangd/ClangdLSPServer.h
+++ clangd/ClangdLSPServer.h
@@ -66,8 +66,11 @@
                                  Callback<std::vector<TextEdit>>);
   void onDocumentFormatting(const DocumentFormattingParams &,
                             Callback<std::vector<TextEdit>>);
+  // The results are serialized 'vector<DocumentSymbol>' if
+  // SupportsHierarchicalDocumentSymbol is true and 'vector<SymbolInformation>'
+  // otherwise.
   void onDocumentSymbol(const DocumentSymbolParams &,
-                        Callback<std::vector<SymbolInformation>>);
+                        Callback<llvm::json::Value>);
   void onCodeAction(const CodeActionParams &, Callback<llvm::json::Value>);
   void onCompletion(const TextDocumentPositionParams &,
                     Callback<CompletionList>);
@@ -128,6 +131,8 @@
   CompletionItemKindBitset SupportedCompletionItemKinds;
   // Whether the client supports CodeAction response objects.
   bool SupportsCodeAction = false;
+  /// From capabilities of textDocument/documentSymbol.
+  bool SupportsHierarchicalDocumentSymbol = false;
 
   // Store of the current versions of the open documents.
   DraftStore DraftMgr;
Index: clangd/ClangdLSPServer.cpp
===================================================================
--- clangd/ClangdLSPServer.cpp
+++ clangd/ClangdLSPServer.cpp
@@ -23,6 +23,14 @@
 namespace clangd {
 namespace {
 
+void adjustSymbolKinds(llvm::MutableArrayRef<DocumentSymbol> Syms,
+                       SymbolKindBitset Kinds) {
+  for (auto &S : Syms) {
+    S.kind = adjustKindToCapability(S.kind, Kinds);
+    adjustSymbolKinds(S.children, Kinds);
+  }
+}
+
 SymbolKindBitset defaultSymbolKinds() {
   SymbolKindBitset Defaults;
   for (size_t I = SymbolKindMin; I <= static_cast<size_t>(SymbolKind::Array);
@@ -284,6 +292,8 @@
   if (Params.capabilities.CompletionItemKinds)
     SupportedCompletionItemKinds |= *Params.capabilities.CompletionItemKinds;
   SupportsCodeAction = Params.capabilities.CodeActionStructure;
+  SupportsHierarchicalDocumentSymbol =
+      Params.capabilities.HierarchicalDocumentSymbol;
 
   Reply(json::Object{
       {{"capabilities",
@@ -501,19 +511,48 @@
     Reply(ReplacementsOrError.takeError());
 }
 
-void ClangdLSPServer::onDocumentSymbol(
-    const DocumentSymbolParams &Params,
-    Callback<std::vector<SymbolInformation>> Reply) {
+/// The functions constructs a flattened view of the DocumentSymbol hierarchy.
+/// Used by the clients that do not support the hierarchical view.
+static std::vector<SymbolInformation>
+flattenSymbolHierarchy(llvm::ArrayRef<DocumentSymbol> Symbols,
+                       const URIForFile &FileURI) {
+
+  std::vector<SymbolInformation> Results;
+  std::function<void(const DocumentSymbol &, StringRef)> Process =
+      [&](const DocumentSymbol &S, Optional<StringRef> ParentName) {
+        SymbolInformation SI;
+        SI.containerName = ParentName ? "" : *ParentName;
+        SI.name = S.name;
+        SI.kind = S.kind;
+        SI.location.range = S.range;
+        SI.location.uri = FileURI;
+
+        Results.push_back(std::move(SI));
+        std::string FullName =
+            !ParentName ? S.name : (ParentName->str() + "::" + S.name);
+        for (auto &C : S.children)
+          Process(C, /*ParentName=*/FullName);
+      };
+  for (auto &S : Symbols)
+    Process(S, /*ParentName=*/"");
+  return Results;
+}
+
+void ClangdLSPServer::onDocumentSymbol(const DocumentSymbolParams &Params,
+                                       Callback<json::Value> Reply) {
+  URIForFile FileURI = Params.textDocument.uri;
   Server->documentSymbols(
       Params.textDocument.uri.file(),
       Bind(
-          [this](decltype(Reply) Reply,
-                 Expected<std::vector<SymbolInformation>> Items) {
+          [this, FileURI](decltype(Reply) Reply,
+                          Expected<std::vector<DocumentSymbol>> Items) {
             if (!Items)
               return Reply(Items.takeError());
-            for (auto &Sym : *Items)
-              Sym.kind = adjustKindToCapability(Sym.kind, SupportedSymbolKinds);
-            Reply(std::move(*Items));
+            adjustSymbolKinds(*Items, SupportedSymbolKinds);
+            if (SupportsHierarchicalDocumentSymbol)
+              return Reply(std::move(*Items));
+            else
+              return Reply(flattenSymbolHierarchy(*Items, FileURI));
           },
           std::move(Reply)));
 }
Index: clangd/ClangdServer.h
===================================================================
--- clangd/ClangdServer.h
+++ clangd/ClangdServer.h
@@ -167,7 +167,7 @@
 
   /// Retrieve the symbols within the specified file.
   void documentSymbols(StringRef File,
-                       Callback<std::vector<SymbolInformation>> CB);
+                       Callback<std::vector<DocumentSymbol>> CB);
 
   /// Retrieve locations for symbol references.
   void findReferences(PathRef File, Position Pos,
Index: clangd/ClangdServer.cpp
===================================================================
--- clangd/ClangdServer.cpp
+++ clangd/ClangdServer.cpp
@@ -470,10 +470,10 @@
           std::move(CB)));
 }
 
-void ClangdServer::documentSymbols(
-    StringRef File, Callback<std::vector<SymbolInformation>> CB) {
-  auto Action = [](Callback<std::vector<SymbolInformation>> CB,
-                   Expected<InputsAndAST> InpAST) {
+void ClangdServer::documentSymbols(StringRef File,
+                                   Callback<std::vector<DocumentSymbol>> CB) {
+  auto Action = [](Callback<std::vector<DocumentSymbol>> CB,
+                   llvm::Expected<InputsAndAST> InpAST) {
     if (!InpAST)
       return CB(InpAST.takeError());
     CB(clangd::getDocumentSymbols(InpAST->AST));
Index: clangd/FindSymbols.h
===================================================================
--- clangd/FindSymbols.h
+++ clangd/FindSymbols.h
@@ -36,8 +36,7 @@
 
 /// Retrieves the symbols contained in the "main file" section of an AST in the
 /// same order that they appear.
-llvm::Expected<std::vector<SymbolInformation>>
-getDocumentSymbols(ParsedAST &AST);
+llvm::Expected<std::vector<DocumentSymbol>> getDocumentSymbols(ParsedAST &AST);
 
 } // namespace clangd
 } // namespace clang
Index: clangd/FindSymbols.cpp
===================================================================
--- clangd/FindSymbols.cpp
+++ clangd/FindSymbols.cpp
@@ -15,11 +15,13 @@
 #include "Quality.h"
 #include "SourceCode.h"
 #include "index/Index.h"
+#include "clang/AST/DeclTemplate.h"
 #include "clang/Index/IndexDataConsumer.h"
 #include "clang/Index/IndexSymbol.h"
 #include "clang/Index/IndexingAction.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/ScopedPrinter.h"
 
 #define DEBUG_TYPE "FindSymbols"
 
@@ -178,104 +180,146 @@
 }
 
 namespace {
-/// Finds document symbols in the main file of the AST.
-class DocumentSymbolsConsumer : public index::IndexDataConsumer {
-  ASTContext &AST;
-  std::vector<SymbolInformation> Symbols;
-  // We are always list document for the same file, so cache the value.
-  Optional<URIForFile> MainFileUri;
+llvm::Optional<DocumentSymbol> declToSym(ASTContext &Ctx, const NamedDecl &ND) {
+  auto &SM = Ctx.getSourceManager();
 
-public:
-  DocumentSymbolsConsumer(ASTContext &AST) : AST(AST) {}
-  std::vector<SymbolInformation> takeSymbols() { return std::move(Symbols); }
+  SourceLocation NameLoc = findNameLoc(&ND);
+  // getFileLoc is a good choice for us, but we also need to make sure
+  // sourceLocToPosition won't switch files, so we call getSpellingLoc on top of
+  // that to make sure it does not switch files.
+  // FIXME: sourceLocToPosition should not switch files!
+  SourceLocation BeginLoc =  SM.getSpellingLoc(SM.getFileLoc(ND.getBeginLoc()));
+  SourceLocation EndLoc = SM.getSpellingLoc(SM.getFileLoc(ND.getEndLoc()));
+  if (NameLoc.isInvalid() || BeginLoc.isInvalid() || EndLoc.isInvalid())
+    return llvm::None;
 
-  void initialize(ASTContext &Ctx) override {
-    // Compute the absolute path of the main file which we will use for all
-    // results.
-    const SourceManager &SM = AST.getSourceManager();
-    const FileEntry *F = SM.getFileEntryForID(SM.getMainFileID());
-    if (!F)
-      return;
-    auto FilePath = getRealPath(F, SM);
-    if (FilePath)
-      MainFileUri = URIForFile(*FilePath);
+  if (!SM.isWrittenInMainFile(NameLoc) || !SM.isWrittenInMainFile(BeginLoc) ||
+      !SM.isWrittenInMainFile(EndLoc))
+    return llvm::None;
+
+  Position NameBegin = sourceLocToPosition(SM, NameLoc);
+  Position NameEnd = sourceLocToPosition(
+      SM, Lexer::getLocForEndOfToken(NameLoc, 0, SM, Ctx.getLangOpts()));
+
+  index::SymbolInfo SymInfo = index::getSymbolInfo(&ND);
+  // FIXME: this is not classifying constructors, destructors and operators
+  //        correctly (they're all "methods").
+  SymbolKind SK = indexSymbolKindToSymbolKind(SymInfo.Kind);
+
+  DocumentSymbol SI;
+  SI.name = printName(Ctx, ND);
+  SI.kind = SK;
+  SI.deprecated = ND.isDeprecated();
+  SI.range =
+      Range{sourceLocToPosition(SM, BeginLoc), sourceLocToPosition(SM, EndLoc)};
+  SI.selectionRange = Range{NameBegin, NameEnd};
+  if (!SI.range.contains(SI.selectionRange)) {
+    // 'selectionRange' must be contained in 'range', so in cases where clang
+    // reports unrelated ranges we need to reconcile somehow.
+    SI.range = SI.selectionRange;
   }
+  return SI;
+}
 
-  bool shouldIncludeSymbol(const NamedDecl *ND) {
-    if (!ND || ND->isImplicit())
-      return false;
-    // Skip anonymous declarations, e.g (anonymous enum/class/struct).
-    if (ND->getDeclName().isEmpty())
-      return false;
-    return true;
+/// A helper class to build an outline for the parse AST. It traverse the AST
+/// directly instead of using RecursiveASTVisitor (RAV) for three main reasons:
+///    - there is no way to keep RAV from traversing subtrees we're not
+///      interested in. E.g. not traversing function locals or implicit template
+///      instantiations.
+///    - it's easier to combine results of recursive passes, e.g.
+///    - visiting decls is actually simple, so we don't hit the complicated
+///      cases that RAV mostly helps with (types and expressions, etc.)
+class DocumentOutline {
+public:
+  DocumentOutline(ParsedAST &AST) : AST(AST) {}
+
+  /// Builds the document outline for the generated AST.
+  std::vector<DocumentSymbol> build() {
+    std::vector<DocumentSymbol> Results;
+    for (auto &TopLevel : AST.getLocalTopLevelDecls())
+      traverseDecl(TopLevel, Results);
+    return Results;
   }
 
-  bool
-  handleDeclOccurence(const Decl *, index::SymbolRoleSet Roles,
-                      ArrayRef<index::SymbolRelation> Relations,
-                      SourceLocation Loc,
-                      index::IndexDataConsumer::ASTNodeInfo ASTNode) override {
-    assert(ASTNode.OrigD);
-    // No point in continuing the index consumer if we could not get the
-    // absolute path of the main file.
-    if (!MainFileUri)
-      return false;
-    // We only want declarations and definitions, i.e. no references.
-    if (!(Roles & static_cast<unsigned>(index::SymbolRole::Declaration) ||
-          Roles & static_cast<unsigned>(index::SymbolRole::Definition)))
-      return true;
-    SourceLocation NameLoc = findNameLoc(ASTNode.OrigD);
-    const SourceManager &SourceMgr = AST.getSourceManager();
-    // We should be only be looking at "local" decls in the main file.
-    if (!SourceMgr.isWrittenInMainFile(NameLoc)) {
-      // Even thought we are visiting only local (non-preamble) decls,
-      // we can get here when in the presence of "extern" decls.
-      return true;
-    }
-    const NamedDecl *ND = dyn_cast<NamedDecl>(ASTNode.OrigD);
-    if (!shouldIncludeSymbol(ND))
-      return true;
+private:
+  enum class VisitKind { No, OnlyDecl, DeclAndChildren };
 
-    SourceLocation EndLoc =
-        Lexer::getLocForEndOfToken(NameLoc, 0, SourceMgr, AST.getLangOpts());
-    Position Begin = sourceLocToPosition(SourceMgr, NameLoc);
-    Position End = sourceLocToPosition(SourceMgr, EndLoc);
-    Range R = {Begin, End};
-    Location L;
-    L.uri = *MainFileUri;
-    L.range = R;
+  void traverseDecl(Decl *D, std::vector<DocumentSymbol> &Results) {
+    if (auto *Templ = llvm::dyn_cast<TemplateDecl>(D))
+      D = Templ->getTemplatedDecl();
+    auto *ND = llvm::dyn_cast<NamedDecl>(D);
+    if (!ND)
+      return;
+    VisitKind Visit = shouldVisit(ND);
+    if (Visit == VisitKind::No)
+      return;
+    llvm::Optional<DocumentSymbol> Sym = declToSym(AST.getASTContext(), *ND);
+    if (!Sym)
+      return;
+    if (Visit == VisitKind::DeclAndChildren)
+      traverseChildren(D, Sym->children);
+    Results.push_back(std::move(*Sym));
+  }
 
-    std::string QName = printQualifiedName(*ND);
-    StringRef Scope, Name;
-    std::tie(Scope, Name) = splitQualifiedName(QName);
-    Scope.consume_back("::");
+  void traverseChildren(Decl *D, std::vector<DocumentSymbol> &Results) {
+    auto *Scope = llvm::dyn_cast<DeclContext>(D);
+    if (!Scope)
+      return;
+    for (auto *C : Scope->decls())
+      traverseDecl(C, Results);
+  }
 
-    index::SymbolInfo SymInfo = index::getSymbolInfo(ND);
-    SymbolKind SK = indexSymbolKindToSymbolKind(SymInfo.Kind);
+  VisitKind shouldVisit(NamedDecl *D) {
+    if (D->isImplicit())
+      return VisitKind::No;
 
-    SymbolInformation SI;
-    SI.name = Name;
-    SI.kind = SK;
-    SI.location = L;
-    SI.containerName = Scope;
-    Symbols.push_back(std::move(SI));
-    return true;
+    if (auto Func = llvm::dyn_cast<FunctionDecl>(D)) {
+      // Some functions are implicit template instantiations, those should be
+      // ignored.
+      if (auto *Info = Func->getTemplateSpecializationInfo()) {
+        if (!Info->isExplicitInstantiationOrSpecialization())
+          return VisitKind::No;
+      }
+      // Only visit the function itself, do not visit the children (i.e.
+      // function parameters, etc.)
+      return VisitKind::OnlyDecl;
+    }
+    // Handle template instantiations. We have three cases to consider:
+    //   - explicit instantiations, e.g. 'template class std::vector<int>;'
+    //     Visit the decl itself (it's present in the code), but not the
+    //     children.
+    //   - implicit instantiations, i.e. not written by the user.
+    //     Do not visit at all, they are not present in the code.
+    //   - explicit specialization, e.g. 'template <> class vector<bool> {};'
+    //     Visit both the decl and its children, both are written in the code.
+    if (auto *TemplSpec = llvm::dyn_cast<ClassTemplateSpecializationDecl>(D)) {
+      if (TemplSpec->isExplicitInstantiationOrSpecialization())
+        return TemplSpec->isExplicitSpecialization()
+                   ? VisitKind::DeclAndChildren
+                   : VisitKind::OnlyDecl;
+      return VisitKind::No;
+    }
+    if (auto *TemplSpec = llvm::dyn_cast<VarTemplateSpecializationDecl>(D)) {
+      if (TemplSpec->isExplicitInstantiationOrSpecialization())
+        return TemplSpec->isExplicitSpecialization()
+                   ? VisitKind::DeclAndChildren
+                   : VisitKind::OnlyDecl;
+      return VisitKind::No;
+    }
+    // For all other cases, visit both the children and the decl.
+    return VisitKind::DeclAndChildren;
   }
-};
-} // namespace
 
-Expected<std::vector<SymbolInformation>> getDocumentSymbols(ParsedAST &AST) {
-  DocumentSymbolsConsumer DocumentSymbolsCons(AST.getASTContext());
+  ParsedAST &AST;
+};
 
-  index::IndexingOptions IndexOpts;
-  IndexOpts.SystemSymbolFilter =
-      index::IndexingOptions::SystemSymbolFilterKind::DeclarationsOnly;
-  IndexOpts.IndexFunctionLocals = false;
-  indexTopLevelDecls(AST.getASTContext(), AST.getPreprocessor(),
-                     AST.getLocalTopLevelDecls(), DocumentSymbolsCons,
-                     IndexOpts);
+std::vector<DocumentSymbol> collectDocSymbols(ParsedAST &AST) {
+  return DocumentOutline(AST).build();
+}
+} // namespace
 
-  return DocumentSymbolsCons.takeSymbols();
+llvm::Expected<std::vector<DocumentSymbol>> getDocumentSymbols(ParsedAST &AST) {
+  return collectDocSymbols(AST);
 }
 
 } // namespace clangd
Index: clangd/Protocol.h
===================================================================
--- clangd/Protocol.h
+++ clangd/Protocol.h
@@ -150,6 +150,9 @@
   }
 
   bool contains(Position Pos) const { return start <= Pos && Pos < end; }
+  bool contains(Range Rng) const {
+    return start <= Rng.start && Rng.end <= end;
+  }
 };
 bool fromJSON(const llvm::json::Value &, Range &);
 llvm::json::Value toJSON(const Range &);
@@ -331,6 +334,9 @@
   /// textDocument.completion.completionItem.snippetSupport
   bool CompletionSnippets = false;
 
+  /// Client supports hierarchical document symbols.
+  bool HierarchicalDocumentSymbol = false;
+
   /// The supported set of CompletionItemKinds for textDocument/completion.
   /// textDocument.completion.completionItemKind.valueSet
   llvm::Optional<CompletionItemKindBitset> CompletionItemKinds;
@@ -655,6 +661,39 @@
 };
 llvm::json::Value toJSON(const CodeAction &);
 
+/// Represents programming constructs like variables, classes, interfaces etc.
+/// that appear in a document. Document symbols can be hierarchical and they
+/// have two ranges: one that encloses its definition and one that points to its
+/// most interesting range, e.g. the range of an identifier.
+struct DocumentSymbol {
+  /// The name of this symbol.
+  std::string name;
+
+  /// More detail for this symbol, e.g the signature of a function.
+  std::string detail;
+
+  /// The kind of this symbol.
+  SymbolKind kind;
+
+  /// Indicates if this symbol is deprecated.
+  bool deprecated;
+
+  /// The range enclosing this symbol not including leading/trailing whitespace
+  /// but everything else like comments. This information is typically used to
+  /// determine if the clients cursor is inside the symbol to reveal in the
+  /// symbol in the UI.
+  Range range;
+
+  /// The range that should be selected and revealed when this symbol is being
+  /// picked, e.g the name of a function. Must be contained by the `range`.
+  Range selectionRange;
+
+  /// Children of this symbol, e.g. properties of a class.
+  std::vector<DocumentSymbol> children;
+};
+llvm::raw_ostream &operator<<(llvm::raw_ostream &O, const DocumentSymbol &S);
+llvm::json::Value toJSON(const DocumentSymbol &S);
+
 /// Represents information about programming constructs like variables, classes,
 /// interfaces etc.
 struct SymbolInformation {
Index: clangd/Protocol.cpp
===================================================================
--- clangd/Protocol.cpp
+++ clangd/Protocol.cpp
@@ -18,6 +18,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/JSON.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
 
@@ -222,6 +223,11 @@
       if (CodeAction->getObject("codeActionLiteralSupport"))
         R.CodeActionStructure = true;
     }
+    if (auto *DocumentSymbol = TextDocument->getObject("documentSymbol")) {
+      if (auto HierarchicalSupport =
+              DocumentSymbol->getBoolean("hierarchicalDocumentSymbolSupport"))
+        R.HierarchicalDocumentSymbol = *HierarchicalSupport;
+    }
   }
   if (auto *Workspace = O->getObject("workspace")) {
     if (auto *Symbol = Workspace->getObject("symbol")) {
@@ -449,6 +455,25 @@
   return std::move(CodeAction);
 }
 
+llvm::raw_ostream &operator<<(llvm::raw_ostream &O, const DocumentSymbol &S) {
+  return O << S.name << " - " << toJSON(S);
+}
+
+llvm::json::Value toJSON(const DocumentSymbol &S) {
+  json::Object Result{{"name", S.name},
+                      {"kind", static_cast<int>(S.kind)},
+                      {"range", S.range},
+                      {"selectionRange", S.selectionRange}};
+
+  if (!S.detail.empty())
+    Result["detail"] = S.detail;
+  if (!S.children.empty())
+    Result["children"] = S.children;
+  if (S.deprecated)
+    Result["deprecated"] = true;
+  return Result;
+}
+
 json::Value toJSON(const WorkspaceEdit &WE) {
   if (!WE.changes)
     return json::Object{};
Index: clangd/clients/clangd-vscode/package.json
===================================================================
--- clangd/clients/clangd-vscode/package.json
+++ clangd/clients/clangd-vscode/package.json
@@ -6,7 +6,7 @@
     "publisher": "llvm-vs-code-extensions",
     "homepage": "https://clang.llvm.org/extra/clangd.html",
     "engines": {
-        "vscode": "^1.18.0"
+        "vscode": "^1.27.0"
     },
     "categories": [
         "Programming Languages",
@@ -32,8 +32,8 @@
         "test": "node ./node_modules/vscode/bin/test"
     },
     "dependencies": {
-        "vscode-languageclient": "^4.0.0",
-        "vscode-languageserver": "^4.0.0"
+        "vscode-languageclient": "^5.1.0",
+        "vscode-languageserver": "^5.1.0"
     },
     "devDependencies": {
         "typescript": "^2.0.3",
Index: unittests/clangd/FindSymbolsTests.cpp
===================================================================
--- unittests/clangd/FindSymbolsTests.cpp
+++ unittests/clangd/FindSymbolsTests.cpp
@@ -14,6 +14,8 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+using namespace llvm;
+
 namespace clang {
 namespace clangd {
 
@@ -23,6 +25,7 @@
 using ::testing::AnyOf;
 using ::testing::ElementsAre;
 using ::testing::ElementsAreArray;
+using ::testing::Field;
 using ::testing::IsEmpty;
 using ::testing::UnorderedElementsAre;
 
@@ -37,9 +40,17 @@
     return arg.name == Name;
   return (arg.containerName + "::" + arg.name) == Name;
 }
+MATCHER_P(WithName, N, "") { return arg.name == N; }
 MATCHER_P(WithKind, Kind, "") { return arg.kind == Kind; }
 MATCHER_P(SymRange, Range, "") { return arg.location.range == Range; }
 
+// GMock helpers for matching DocumentSymbol.
+MATCHER_P(SymNameRange, Range, "") { return arg.selectionRange == Range; }
+template <class... ChildMatchers>
+testing::Matcher<DocumentSymbol> Children(ChildMatchers... ChildrenM) {
+  return Field(&DocumentSymbol::children, ElementsAre(ChildrenM...));
+}
+
 ClangdServer::Options optsForTests() {
   auto ServerOpts = ClangdServer::optsForTest();
   ServerOpts.WorkspaceRoot = testRoot();
@@ -300,7 +311,7 @@
   IgnoreDiagnostics DiagConsumer;
   ClangdServer Server;
 
-  std::vector<SymbolInformation> getSymbols(PathRef File) {
+  std::vector<DocumentSymbol> getSymbols(PathRef File) {
     EXPECT_TRUE(Server.blockUntilIdleForTest()) << "Waiting for preamble";
     auto SymbolInfos = runDocumentSymbols(Server, File);
     EXPECT_TRUE(bool(SymbolInfos)) << "documentSymbols returned an error";
@@ -363,31 +374,46 @@
     )");
 
   addFile(FilePath, Main.code());
-  EXPECT_THAT(getSymbols(FilePath),
-              ElementsAreArray(
-                  {AllOf(QName("Foo"), WithKind(SymbolKind::Class)),
-                   AllOf(QName("Foo"), WithKind(SymbolKind::Class)),
-                   AllOf(QName("Foo::Foo"), WithKind(SymbolKind::Method)),
-                   AllOf(QName("Foo::Foo"), WithKind(SymbolKind::Method)),
-                   AllOf(QName("Foo::f"), WithKind(SymbolKind::Method)),
-                   AllOf(QName("f1"), WithKind(SymbolKind::Function)),
-                   AllOf(QName("Foo::operator="), WithKind(SymbolKind::Method)),
-                   AllOf(QName("Foo::~Foo"), WithKind(SymbolKind::Method)),
-                   AllOf(QName("Foo::Nested"), WithKind(SymbolKind::Class)),
-                   AllOf(QName("Foo::Nested::f"), WithKind(SymbolKind::Method)),
-                   AllOf(QName("Friend"), WithKind(SymbolKind::Class)),
-                   AllOf(QName("f1"), WithKind(SymbolKind::Function)),
-                   AllOf(QName("f2"), WithKind(SymbolKind::Function)),
-                   AllOf(QName("KInt"), WithKind(SymbolKind::Variable)),
-                   AllOf(QName("kStr"), WithKind(SymbolKind::Variable)),
-                   AllOf(QName("f1"), WithKind(SymbolKind::Function)),
-                   AllOf(QName("foo"), WithKind(SymbolKind::Namespace)),
-                   AllOf(QName("foo::int32"), WithKind(SymbolKind::Class)),
-                   AllOf(QName("foo::int32_t"), WithKind(SymbolKind::Class)),
-                   AllOf(QName("foo::v1"), WithKind(SymbolKind::Variable)),
-                   AllOf(QName("foo::bar"), WithKind(SymbolKind::Namespace)),
-                   AllOf(QName("foo::bar::v2"), WithKind(SymbolKind::Variable)),
-                   AllOf(QName("foo::baz"), WithKind(SymbolKind::Namespace))}));
+  EXPECT_THAT(
+      getSymbols(FilePath),
+      ElementsAreArray(
+          {AllOf(WithName("Foo"), WithKind(SymbolKind::Class), Children()),
+           AllOf(WithName("Foo"), WithKind(SymbolKind::Class),
+                 Children(AllOf(WithName("Foo"), WithKind(SymbolKind::Method),
+                                Children()),
+                          AllOf(WithName("Foo"), WithKind(SymbolKind::Method),
+                                Children()),
+                          AllOf(WithName("f"), WithKind(SymbolKind::Method),
+                                Children()),
+                          AllOf(WithName("operator="),
+                                WithKind(SymbolKind::Method), Children()),
+                          AllOf(WithName("~Foo"), WithKind(SymbolKind::Method),
+                                Children()),
+                          AllOf(WithName("Nested"), WithKind(SymbolKind::Class),
+                                Children(AllOf(WithName("f"),
+                                               WithKind(SymbolKind::Method),
+                                               Children()))))),
+           AllOf(WithName("Friend"), WithKind(SymbolKind::Class), Children()),
+           AllOf(WithName("f1"), WithKind(SymbolKind::Function), Children()),
+           AllOf(WithName("f2"), WithKind(SymbolKind::Function), Children()),
+           AllOf(WithName("KInt"), WithKind(SymbolKind::Variable), Children()),
+           AllOf(WithName("kStr"), WithKind(SymbolKind::Variable), Children()),
+           AllOf(WithName("f1"), WithKind(SymbolKind::Function), Children()),
+           AllOf(WithName("foo"), WithKind(SymbolKind::Namespace),
+                 Children(
+                     AllOf(WithName("int32"), WithKind(SymbolKind::Class),
+                           Children()),
+                     AllOf(WithName("int32_t"), WithKind(SymbolKind::Class),
+                           Children()),
+                     AllOf(WithName("v1"), WithKind(SymbolKind::Variable),
+                           Children()),
+                     AllOf(WithName("bar"), WithKind(SymbolKind::Namespace),
+                           Children(AllOf(WithName("v2"),
+                                          WithKind(SymbolKind::Variable),
+                                          Children()))),
+                     AllOf(WithName("baz"), WithKind(SymbolKind::Namespace),
+                           Children()),
+                     AllOf(WithName("v2"), WithKind(SymbolKind::Variable))))}));
 }
 
 TEST_F(DocumentSymbolsTest, DeclarationDefinition) {
@@ -402,11 +428,12 @@
 
   addFile(FilePath, Main.code());
   EXPECT_THAT(getSymbols(FilePath),
-              ElementsAre(AllOf(QName("Foo"), WithKind(SymbolKind::Class)),
-                          AllOf(QName("Foo::f"), WithKind(SymbolKind::Method),
-                                SymRange(Main.range("decl"))),
-                          AllOf(QName("Foo::f"), WithKind(SymbolKind::Method),
-                                SymRange(Main.range("def")))));
+              ElementsAre(AllOf(WithName("Foo"), WithKind(SymbolKind::Class),
+                                Children(AllOf(
+                                    WithName("f"), WithKind(SymbolKind::Method),
+                                    SymNameRange(Main.range("decl"))))),
+                          AllOf(WithName("f"), WithKind(SymbolKind::Method),
+                                SymNameRange(Main.range("def")))));
 }
 
 TEST_F(DocumentSymbolsTest, ExternSymbol) {
@@ -429,7 +456,7 @@
         struct LocalClass {};
         int local_var;
       })cpp");
-  EXPECT_THAT(getSymbols(FilePath), ElementsAre(QName("test")));
+  EXPECT_THAT(getSymbols(FilePath), ElementsAre(WithName("test")));
 }
 
 TEST_F(DocumentSymbolsTest, Unnamed) {
@@ -442,9 +469,12 @@
       )cpp");
   EXPECT_THAT(
       getSymbols(FilePath),
-      ElementsAre(AllOf(QName("UnnamedStruct"), WithKind(SymbolKind::Variable)),
-                  AllOf(QName("(anonymous struct)::InUnnamed"),
-                        WithKind(SymbolKind::Field))));
+      ElementsAre(
+          AllOf(WithName("(anonymous struct)"), WithKind(SymbolKind::Struct),
+                Children(AllOf(WithName("InUnnamed"),
+                               WithKind(SymbolKind::Field), Children()))),
+          AllOf(WithName("UnnamedStruct"), WithKind(SymbolKind::Variable),
+                Children())));
 }
 
 TEST_F(DocumentSymbolsTest, InHeaderFile) {
@@ -461,23 +491,46 @@
   addFile("foo.cpp", R"cpp(
       #include "foo.h"
       )cpp");
-  EXPECT_THAT(getSymbols(FilePath), ElementsAre(QName("test")));
+  EXPECT_THAT(getSymbols(FilePath), ElementsAre(WithName("test")));
 }
 
 TEST_F(DocumentSymbolsTest, Template) {
   std::string FilePath = testPath("foo.cpp");
   addFile(FilePath, R"(
-    // Primary templates and specializations are included but instantiations
-    // are not.
     template <class T> struct Tmpl {T x = 0;};
-    template <> struct Tmpl<int> {};
+    template <> struct Tmpl<int> {
+      int y = 0;
+    };
     extern template struct Tmpl<float>;
     template struct Tmpl<double>;
+
+    template <class T, class U, class Z = float>
+    int funcTmpl(U a);
+    template <>
+    int funcTmpl<int>(double a);
+
+    template <class T, class U = double>
+    int varTmpl = T();
+    template <>
+    double varTmpl<int> = 10.0;
   )");
-  EXPECT_THAT(getSymbols(FilePath),
-              ElementsAre(AllOf(QName("Tmpl"), WithKind(SymbolKind::Struct)),
-                          AllOf(QName("Tmpl::x"), WithKind(SymbolKind::Field)),
-                          AllOf(QName("Tmpl"), WithKind(SymbolKind::Struct))));
+  EXPECT_THAT(
+      getSymbols(FilePath),
+      ElementsAre(
+          AllOf(WithName("Tmpl"), WithKind(SymbolKind::Struct),
+                Children(AllOf(WithName("x"), WithKind(SymbolKind::Field)))),
+          AllOf(WithName("Tmpl<int>"), WithKind(SymbolKind::Struct),
+                Children(WithName("y"))),
+          AllOf(WithName("Tmpl<float>"), WithKind(SymbolKind::Struct),
+                Children()),
+          AllOf(WithName("Tmpl<double>"), WithKind(SymbolKind::Struct),
+                Children()),
+          AllOf(WithName("funcTmpl"), Children()),
+          // FIXME(ibiryukov): template args should be <int> to match the code.
+          AllOf(WithName("funcTmpl<int, double, float>"), Children()),
+          AllOf(WithName("varTmpl"), Children()),
+          // FIXME(ibiryukov): template args should be <int> to match the code.
+          AllOf(WithName("varTmpl<int, double>"), Children())));
 }
 
 TEST_F(DocumentSymbolsTest, Namespaces) {
@@ -507,10 +560,15 @@
       )cpp");
   EXPECT_THAT(
       getSymbols(FilePath),
-      ElementsAreArray({QName("ans1"), QName("ans1::ai1"), QName("ans1::ans2"),
-                        QName("ans1::ans2::ai2"), QName("test"), QName("na"),
-                        QName("na::nb"), QName("na::Foo"), QName("na"),
-                        QName("na::nb"), QName("na::Bar")}));
+      ElementsAreArray<testing::Matcher<DocumentSymbol>>(
+          {AllOf(WithName("ans1"),
+                 Children(AllOf(WithName("ai1"), Children()),
+                          AllOf(WithName("ans2"), Children(WithName("ai2"))))),
+           AllOf(WithName("(anonymous namespace)"), Children(WithName("test"))),
+           AllOf(WithName("na"),
+                 Children(AllOf(WithName("nb"), Children(WithName("Foo"))))),
+           AllOf(WithName("na"),
+                 Children(AllOf(WithName("nb"), Children(WithName("Bar")))))}));
 }
 
 TEST_F(DocumentSymbolsTest, Enums) {
@@ -531,10 +589,14 @@
       };
       }
     )");
-  EXPECT_THAT(getSymbols(FilePath),
-              ElementsAre(QName("Red"), QName("Color"), QName("Green"),
-                          QName("Color2"), QName("Color2::Yellow"), QName("ns"),
-                          QName("ns::Black")));
+  EXPECT_THAT(
+      getSymbols(FilePath),
+      ElementsAre(
+          AllOf(WithName("(anonymous enum)"), Children(WithName("Red"))),
+          AllOf(WithName("Color"), Children(WithName("Green"))),
+          AllOf(WithName("Color2"), Children(WithName("Yellow"))),
+          AllOf(WithName("ns"), Children(AllOf(WithName("(anonymous enum)"),
+                                               Children(WithName("Black")))))));
 }
 
 TEST_F(DocumentSymbolsTest, FromMacro) {
@@ -553,8 +615,43 @@
   addFile(FilePath, Main.code());
   EXPECT_THAT(
       getSymbols(FilePath),
-      ElementsAre(AllOf(QName("abc_Test"), SymRange(Main.range("expansion"))),
-                  AllOf(QName("Test"), SymRange(Main.range("spelling")))));
+      ElementsAre(
+          AllOf(WithName("abc_Test"), SymNameRange(Main.range("expansion"))),
+          AllOf(WithName("Test"), SymNameRange(Main.range("spelling")))));
+}
+
+TEST_F(DocumentSymbolsTest, FuncTemplates) {
+  std::string FilePath = testPath("foo.cpp");
+  Annotations Source(R"cpp(
+    template <class T>
+    T foo() {}
+
+    auto x = foo<int>();
+    auto y = foo<double>()
+  )cpp");
+  addFile(FilePath, Source.code());
+  // Make sure we only see the template declaration, not instantiations.
+  EXPECT_THAT(getSymbols(FilePath),
+              ElementsAre(WithName("foo"), WithName("x"), WithName("y")));
+}
+
+TEST_F(DocumentSymbolsTest, UsingDirectives) {
+  std::string FilePath = testPath("foo.cpp");
+  Annotations Source(R"cpp(
+    namespace ns {
+      int foo;
+    }
+
+    namespace ns_alias = ns;
+
+    using namespace ::ns;     // check we don't loose qualifiers.
+    using namespace ns_alias; // and namespace aliases.
+  )cpp");
+  addFile(FilePath, Source.code());
+  EXPECT_THAT(getSymbols(FilePath),
+              ElementsAre(WithName("ns"), WithName("ns_alias"),
+                          WithName("using namespace ::ns"),
+                          WithName("using namespace ns_alias")));
 }
 
 } // namespace clangd
Index: unittests/clangd/SyncAPI.h
===================================================================
--- unittests/clangd/SyncAPI.h
+++ unittests/clangd/SyncAPI.h
@@ -47,8 +47,8 @@
 llvm::Expected<std::vector<SymbolInformation>>
 runWorkspaceSymbols(ClangdServer &Server, StringRef Query, int Limit);
 
-llvm::Expected<std::vector<SymbolInformation>>
-runDocumentSymbols(ClangdServer &Server, PathRef File);
+Expected<std::vector<DocumentSymbol>> runDocumentSymbols(ClangdServer &Server,
+                                                         PathRef File);
 
 SymbolSlab runFuzzyFind(const SymbolIndex &Index, StringRef Query);
 SymbolSlab runFuzzyFind(const SymbolIndex &Index, const FuzzyFindRequest &Req);
Index: unittests/clangd/SyncAPI.cpp
===================================================================
--- unittests/clangd/SyncAPI.cpp
+++ unittests/clangd/SyncAPI.cpp
@@ -120,9 +120,9 @@
   return std::move(*Result);
 }
 
-Expected<std::vector<SymbolInformation>>
-runDocumentSymbols(ClangdServer &Server, PathRef File) {
-  Optional<Expected<std::vector<SymbolInformation>>> Result;
+Expected<std::vector<DocumentSymbol>> runDocumentSymbols(ClangdServer &Server,
+                                                         PathRef File) {
+  Optional<Expected<std::vector<DocumentSymbol>>> Result;
   Server.documentSymbols(File, capture(Result));
   return std::move(*Result);
 }