Index: clang-tools-extra/trunk/clangd/ClangdServer.h
===================================================================
--- clang-tools-extra/trunk/clangd/ClangdServer.h
+++ clang-tools-extra/trunk/clangd/ClangdServer.h
@@ -126,10 +126,6 @@
 
     bool SuggestMissingIncludes = false;
 
-    /// Enable hidden features mostly useful to clangd developers.
-    /// e.g. tweaks to dump the AST.
-    bool HiddenFeatures = false;
-
     /// Clangd will execute compiler drivers matching one of these globs to
     /// fetch system include path.
     std::vector<std::string> QueryDriverGlobs;
@@ -137,9 +133,10 @@
     /// Enable semantic highlighting features.
     bool SemanticHighlighting = false;
 
-    /// Returns true if the StringRef is a tweak that should be enabled
-    std::function<bool(llvm::StringRef)> TweakFilter =
-        [](llvm::StringRef TweakToSearch) { return true; };
+    /// Returns true if the tweak should be enabled.
+    std::function<bool(const Tweak &)> TweakFilter = [](const Tweak &T) {
+      return !T.hidden(); // only enable non-hidden tweaks.
+    };
   };
   // Sensible default options for use in tests.
   // Features like indexing must be enabled if desired.
@@ -322,7 +319,7 @@
   bool SuggestMissingIncludes = false;
   bool EnableHiddenFeatures = false;
 
-  std::function<bool(llvm::StringRef)> TweakFilter;
+  std::function<bool(const Tweak &)> TweakFilter;
 
   // GUARDED_BY(CachedCompletionFuzzyFindRequestMutex)
   llvm::StringMap<llvm::Optional<FuzzyFindRequest>>
Index: clang-tools-extra/trunk/clangd/ClangdServer.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/ClangdServer.cpp
+++ clang-tools-extra/trunk/clangd/ClangdServer.cpp
@@ -101,7 +101,7 @@
                      : nullptr),
       GetClangTidyOptions(Opts.GetClangTidyOptions),
       SuggestMissingIncludes(Opts.SuggestMissingIncludes),
-      EnableHiddenFeatures(Opts.HiddenFeatures), TweakFilter(Opts.TweakFilter),
+      TweakFilter(Opts.TweakFilter),
       WorkspaceRoot(Opts.WorkspaceRoot),
       // Pass a callback into `WorkScheduler` to extract symbols from a newly
       // parsed file and rebuild the file index synchronously each time an AST
@@ -333,11 +333,9 @@
     if (!Selection)
       return CB(Selection.takeError());
     std::vector<TweakRef> Res;
-    for (auto &T : prepareTweaks(*Selection)) {
-      if (!TweakFilter(T->id()) || (T->hidden() && !EnableHiddenFeatures))
-        continue;
+    for (auto &T : prepareTweaks(*Selection, TweakFilter))
       Res.push_back({T->id(), T->title(), T->intent()});
-    }
+
     CB(std::move(Res));
   };
 
Index: clang-tools-extra/trunk/clangd/refactor/Tweak.h
===================================================================
--- clang-tools-extra/trunk/clangd/refactor/Tweak.h
+++ clang-tools-extra/trunk/clangd/refactor/Tweak.h
@@ -110,9 +110,11 @@
       TweakRegistrationFor##Subclass(#Subclass, /*Description=*/"");           \
   const char *Subclass::id() const { return #Subclass; }
 
-/// Calls prepare() on all tweaks, returning those that can run on the
-/// selection.
-std::vector<std::unique_ptr<Tweak>> prepareTweaks(const Tweak::Selection &S);
+/// Calls prepare() on all tweaks that satisfy the filter, returning those that
+/// can run on the selection.
+std::vector<std::unique_ptr<Tweak>>
+prepareTweaks(const Tweak::Selection &S,
+              llvm::function_ref<bool(const Tweak &)> Filter);
 
 // Calls prepare() on the tweak with a given ID.
 // If prepare() returns false, returns an error.
Index: clang-tools-extra/trunk/clangd/refactor/Tweak.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/refactor/Tweak.cpp
+++ clang-tools-extra/trunk/clangd/refactor/Tweak.cpp
@@ -46,13 +46,15 @@
   Cursor = SM.getComposedLoc(SM.getMainFileID(), RangeBegin);
 }
 
-std::vector<std::unique_ptr<Tweak>> prepareTweaks(const Tweak::Selection &S) {
+std::vector<std::unique_ptr<Tweak>>
+prepareTweaks(const Tweak::Selection &S,
+              llvm::function_ref<bool(const Tweak &)> Filter) {
   validateRegistry();
 
   std::vector<std::unique_ptr<Tweak>> Available;
   for (const auto &E : TweakRegistry::entries()) {
     std::unique_ptr<Tweak> T = E.instantiate();
-    if (!T->prepare(S))
+    if (!Filter(*T) || !T->prepare(S))
       continue;
     Available.push_back(std::move(T));
   }
Index: clang-tools-extra/trunk/clangd/tool/ClangdMain.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/tool/ClangdMain.cpp
+++ clang-tools-extra/trunk/clangd/tool/ClangdMain.cpp
@@ -472,7 +472,6 @@
   }
   Opts.StaticIndex = StaticIdx.get();
   Opts.AsyncThreadsCount = WorkerThreadsCount;
-  Opts.HiddenFeatures = HiddenFeatures;
 
   clangd::CodeCompleteOptions CCOpts;
   CCOpts.IncludeIneligibleResults = IncludeIneligibleResults;
@@ -531,11 +530,14 @@
   }
   Opts.SuggestMissingIncludes = SuggestMissingIncludes;
   Opts.QueryDriverGlobs = std::move(QueryDriverGlobs);
-  if (TweakList.getNumOccurrences())
-    Opts.TweakFilter = [&](llvm::StringRef TweakToSearch) {
-      // return true if any tweak matches the TweakToSearch
-      return llvm::find(TweakList, TweakToSearch) != TweakList.end();
-    };
+
+  Opts.TweakFilter = [&](const Tweak &T) {
+    if (T.hidden() && !HiddenFeatures)
+      return false;
+    if (TweakList.getNumOccurrences())
+      return llvm::is_contained(TweakList, T.id());
+    return true;
+  };
   llvm::Optional<OffsetEncoding> OffsetEncodingFromFlag;
   if (ForceOffsetEncoding != OffsetEncoding::UnsupportedEncoding)
     OffsetEncodingFromFlag = ForceOffsetEncoding;