Index: include/llvm/CodeGen/AccelTable.h
===================================================================
--- include/llvm/CodeGen/AccelTable.h
+++ include/llvm/CodeGen/AccelTable.h
@@ -130,6 +130,9 @@
 #endif
 protected:
   virtual uint64_t order() const = 0;
+
+private:
+  virtual void anchor();
 };
 
 /// A base class holding non-template-dependant functionality of the AccelTable
@@ -244,6 +247,9 @@
   virtual void emit(AsmPrinter *Asm) const = 0;
 
   static uint32_t hash(StringRef Buffer) { return djbHash(Buffer); }
+
+private:
+  void anchor() override;
 };
 
 /// The Data class implementation for DWARF v5 accelerator table. Unlike the
Index: include/llvm/CodeGen/GCMetadata.h
===================================================================
--- include/llvm/CodeGen/GCMetadata.h
+++ include/llvm/CodeGen/GCMetadata.h
@@ -157,6 +157,8 @@
   /// A helper map to speedup lookups into the above list
   StringMap<GCStrategy*> GCStrategyMap;
 
+  virtual void anchor();
+
 public:
   /// Lookup the GCStrategy object associated with the given gc name.
   /// Objects are owned internally; No caller should attempt to delete the
Index: include/llvm/CodeGen/GCStrategy.h
===================================================================
--- include/llvm/CodeGen/GCStrategy.h
+++ include/llvm/CodeGen/GCStrategy.h
@@ -83,6 +83,8 @@
 
   std::string Name;
 
+  virtual void anchor();
+
 protected:
   bool UseStatepoints = false; /// Uses gc.statepoints as opposed to gc.roots,
                                /// if set, none of the other options can be
Index: include/llvm/CodeGen/SelectionDAG.h
===================================================================
--- include/llvm/CodeGen/SelectionDAG.h
+++ include/llvm/CodeGen/SelectionDAG.h
@@ -298,6 +298,9 @@
         : DAGUpdateListener(DAG), Callback(std::move(Callback)) {}
 
     void NodeDeleted(SDNode *N, SDNode *E) override { Callback(N, E); }
+
+  private:
+    virtual void anchor();
   };
 
   /// When true, additional steps are taken to
Index: include/llvm/DebugInfo/CodeView/TypeVisitorCallbacks.h
===================================================================
--- include/llvm/DebugInfo/CodeView/TypeVisitorCallbacks.h
+++ include/llvm/DebugInfo/CodeView/TypeVisitorCallbacks.h
@@ -17,6 +17,8 @@
 namespace codeview {
 
 class TypeVisitorCallbacks {
+  virtual void anchor();
+
 public:
   virtual ~TypeVisitorCallbacks() = default;
 
Index: include/llvm/DebugInfo/DIContext.h
===================================================================
--- include/llvm/DebugInfo/DIContext.h
+++ include/llvm/DebugInfo/DIContext.h
@@ -206,6 +206,7 @@
 
 private:
   const DIContextKind Kind;
+  virtual void anchor();
 };
 
 /// An inferface for inquiring the load address of a loaded object file
Index: include/llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h
===================================================================
--- include/llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h
+++ include/llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h
@@ -37,6 +37,9 @@
 public:
   /// An abstract class representing a single entry in the accelerator tables.
   class Entry {
+  private:
+    virtual void anchor();
+
   protected:
     SmallVector<DWARFFormValue, 3> Values;
 
Index: include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h
===================================================================
--- include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h
+++ include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h
@@ -155,6 +155,9 @@
   const uint64_t Length;
 
   CFIProgram CFIs;
+
+private:
+  virtual void anchor();
 };
 
 /// DWARF Common Information Entry (CIE)
Index: include/llvm/DebugInfo/DWARF/DWARFUnit.h
===================================================================
--- include/llvm/DebugInfo/DWARF/DWARFUnit.h
+++ include/llvm/DebugInfo/DWARF/DWARFUnit.h
@@ -62,6 +62,9 @@
                          StringRef SS, const DWARFSection &SOS,
                          const DWARFSection *AOS, const DWARFSection &LS,
                          bool isLittleEndian, bool isDWO, bool Lazy) = 0;
+
+private:
+  virtual void anchor();
 };
 
 const DWARFUnitIndex &getDWARFUnitIndex(DWARFContext &Context,
Index: include/llvm/MC/MCCodePadder.h
===================================================================
--- include/llvm/MC/MCCodePadder.h
+++ include/llvm/MC/MCCodePadder.h
@@ -128,6 +128,7 @@
   MCCodePaddingPolicy() = delete;
   MCCodePaddingPolicy(const MCCodePaddingPolicy &) = delete;
   void operator=(const MCCodePaddingPolicy &) = delete;
+  virtual void anchor();
 
 protected:
   /// A mask holding the kind of this policy, i.e. only the i'th bit will be set
Index: include/llvm/MC/MCSection.h
===================================================================
--- include/llvm/MC/MCSection.h
+++ include/llvm/MC/MCSection.h
@@ -88,6 +88,8 @@
   /// below that number.
   SmallVector<std::pair<unsigned, MCFragment *>, 1> SubsectionFragmentMap;
 
+  virtual void anchor();
+
 protected:
   SectionVariant Variant;
   SectionKind Kind;
Index: include/llvm/MC/MCSubtargetInfo.h
===================================================================
--- include/llvm/MC/MCSubtargetInfo.h
+++ include/llvm/MC/MCSubtargetInfo.h
@@ -174,6 +174,8 @@
   virtual std::string getSchedInfoStr(MCInst const &MCI) const {
     return {};
   }
+private:
+  virtual void anchor();
 };
 
 } // end namespace llvm
Index: include/llvm/Object/Error.h
===================================================================
--- include/llvm/Object/Error.h
+++ include/llvm/Object/Error.h
@@ -56,6 +56,9 @@
     // Default to parse_failed, can be overridden with setErrorCode.
     setErrorCode(make_error_code(object_error::parse_failed));
   }
+
+private:
+  virtual void anchor();
 };
 
 /// Generic binary error.
Index: include/llvm/Support/BinaryByteStream.h
===================================================================
--- include/llvm/Support/BinaryByteStream.h
+++ include/llvm/Support/BinaryByteStream.h
@@ -67,6 +67,9 @@
 protected:
   llvm::support::endianness Endian;
   ArrayRef<uint8_t> Data;
+
+private:
+  virtual void anchor() override;
 };
 
 /// \brief An implementation of BinaryStream whose data is backed by an llvm
@@ -81,6 +84,9 @@
         MemBuffer(std::move(Buffer)) {}
 
   std::unique_ptr<MemoryBuffer> MemBuffer;
+
+private:
+  virtual void anchor() override;
 };
 
 /// \brief An implementation of BinaryStream which holds its entire data set
@@ -129,6 +135,7 @@
 private:
   MutableArrayRef<uint8_t> Data;
   BinaryByteStream ImmutableStream;
+  void anchor() override;
 };
 
 /// \brief An implementation of WritableBinaryStream which can write at its end
@@ -199,12 +206,16 @@
   }
 
   MutableArrayRef<uint8_t> data() { return Data; }
+
+private:
+  virtual void anchor() override;
 };
 
 /// \brief An implementation of WritableBinaryStream backed by an llvm
 /// FileOutputBuffer.
 class FileBufferByteStream : public WritableBinaryStream {
 private:
+  virtual void anchor() override;
   class StreamImpl : public MutableBinaryByteStream {
   public:
     StreamImpl(std::unique_ptr<FileOutputBuffer> Buffer,
@@ -224,6 +235,7 @@
 
   private:
     std::unique_ptr<FileOutputBuffer> FileBuffer;
+    void anchor() override;
   };
 
 public:
Index: include/llvm/Support/BinaryStream.h
===================================================================
--- include/llvm/Support/BinaryStream.h
+++ include/llvm/Support/BinaryStream.h
@@ -64,6 +64,9 @@
       return make_error<BinaryStreamError>(stream_error_code::stream_too_short);
     return Error::success();
   }
+
+private:
+  virtual void anchor();
 };
 
 /// \brief A BinaryStream which can be read from as well as written to.  Note
@@ -95,6 +98,9 @@
       return make_error<BinaryStreamError>(stream_error_code::invalid_offset);
     return Error::success();
   }
+
+private:
+  virtual void anchor() override;
 };
 
 } // end namespace llvm
Index: include/llvm/Support/BinaryStreamReader.h
===================================================================
--- include/llvm/Support/BinaryStreamReader.h
+++ include/llvm/Support/BinaryStreamReader.h
@@ -264,6 +264,7 @@
 private:
   BinaryStreamRef Stream;
   uint32_t Offset = 0;
+  virtual void anchor();
 };
 } // namespace llvm
 
Index: include/llvm/Support/Error.h
===================================================================
--- include/llvm/Support/Error.h
+++ include/llvm/Support/Error.h
@@ -1045,6 +1045,7 @@
 /// std::error_codes.
 class ECError : public ErrorInfo<ECError> {
   friend Error errorCodeToError(std::error_code);
+  void anchor() override;
 
 public:
   void setErrorCode(std::error_code EC) { this->EC = EC; }
Index: include/llvm/Support/FileOutputBuffer.h
===================================================================
--- include/llvm/Support/FileOutputBuffer.h
+++ include/llvm/Support/FileOutputBuffer.h
@@ -68,6 +68,9 @@
   FileOutputBuffer(StringRef Path) : FinalPath(Path) {}
 
   std::string FinalPath;
+
+private:
+  virtual void anchor();
 };
 } // end namespace llvm
 
Index: include/llvm/Support/FormatVariadicDetails.h
===================================================================
--- include/llvm/Support/FormatVariadicDetails.h
+++ include/llvm/Support/FormatVariadicDetails.h
@@ -20,6 +20,8 @@
 
 namespace detail {
 class format_adapter {
+  virtual void anchor();
+
 protected:
   virtual ~format_adapter() {}
 
Index: include/llvm/Support/raw_ostream.h
===================================================================
--- include/llvm/Support/raw_ostream.h
+++ include/llvm/Support/raw_ostream.h
@@ -537,6 +537,7 @@
 class buffer_ostream : public raw_svector_ostream {
   raw_ostream &OS;
   SmallVector<char, 0> Buffer;
+  void anchor() override;
 
 public:
   buffer_ostream(raw_ostream &OS) : raw_svector_ostream(Buffer), OS(OS) {}
Index: include/llvm/TableGen/Record.h
===================================================================
--- include/llvm/TableGen/Record.h
+++ include/llvm/TableGen/Record.h
@@ -1798,6 +1798,7 @@
 public:
   explicit Resolver(Record *CurRec) : CurRec(CurRec) {}
   virtual ~Resolver() {}
+  virtual void anchor();
 
   Record *getCurrentRecord() const { return CurRec; }
 
@@ -1858,6 +1859,7 @@
 //       arguments simultaneously and get rid of this class.
 class RecordValResolver final : public Resolver {
   const RecordVal *RV;
+  void anchor() override;
 
 public:
   explicit RecordValResolver(Record &R, const RecordVal *RV)
@@ -1874,6 +1876,7 @@
 class ShadowResolver final : public Resolver {
   Resolver &R;
   DenseSet<Init *> Shadowed;
+  void anchor() override;
 
 public:
   explicit ShadowResolver(Resolver &R)
Index: lib/CodeGen/AsmPrinter/AccelTable.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AccelTable.cpp
+++ lib/CodeGen/AsmPrinter/AccelTable.cpp
@@ -566,6 +566,9 @@
   Asm->emitInt32(QualifiedNameHash);
 }
 
+void AccelTableData::anchor() {}
+void AppleAccelTableData::anchor() {}
+
 #ifndef _MSC_VER
 // The lines below are rejected by older versions (TBD) of MSVC.
 constexpr AppleAccelTableData::Atom AppleAccelTableTypeData::Atoms[];
Index: lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
+++ lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
@@ -269,3 +269,5 @@
   // Emit the abbreviations data.
   Abbrev.Emit(this);
 }
+
+void ByteStreamer::anchor() {}
Index: lib/CodeGen/AsmPrinter/ByteStreamer.h
===================================================================
--- lib/CodeGen/AsmPrinter/ByteStreamer.h
+++ lib/CodeGen/AsmPrinter/ByteStreamer.h
@@ -33,6 +33,9 @@
   virtual void EmitInt8(uint8_t Byte, const Twine &Comment = "") = 0;
   virtual void EmitSLEB128(uint64_t DWord, const Twine &Comment = "") = 0;
   virtual void EmitULEB128(uint64_t DWord, const Twine &Comment = "") = 0;
+
+private:
+  virtual void anchor();
 };
 
 class APByteStreamer final : public ByteStreamer {
Index: lib/CodeGen/GCMetadata.cpp
===================================================================
--- lib/CodeGen/GCMetadata.cpp
+++ lib/CodeGen/GCMetadata.cpp
@@ -181,3 +181,5 @@
   } else
     report_fatal_error(std::string("unsupported GC: ") + Name);
 }
+
+void GCModuleInfo::anchor() {}
Index: lib/CodeGen/GCStrategy.cpp
===================================================================
--- lib/CodeGen/GCStrategy.cpp
+++ lib/CodeGen/GCStrategy.cpp
@@ -19,3 +19,5 @@
 LLVM_INSTANTIATE_REGISTRY(GCRegistry)
 
 GCStrategy::GCStrategy() = default;
+
+void GCStrategy::anchor() {}
Index: lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -87,6 +87,8 @@
 void SelectionDAG::DAGUpdateListener::NodeDeleted(SDNode*, SDNode*) {}
 void SelectionDAG::DAGUpdateListener::NodeUpdated(SDNode*) {}
 
+void SelectionDAG::DAGNodeDeletedListener::anchor() {}
+
 #define DEBUG_TYPE "selectiondag"
 
 static void NewSDValueDbgMsg(SDValue V, StringRef Msg, SelectionDAG *G) {
Index: lib/DebugInfo/CodeView/RecordName.cpp
===================================================================
--- lib/DebugInfo/CodeView/RecordName.cpp
+++ lib/DebugInfo/CodeView/RecordName.cpp
@@ -331,3 +331,5 @@
   StringRef StringData = toStringRef(Sym.content()).drop_front(Offset);
   return StringData.split('\0').first;
 }
+
+void TypeVisitorCallbacks::anchor() {}
Index: lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
===================================================================
--- lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
+++ lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
@@ -861,3 +861,5 @@
     return make_range(ValueIterator(), ValueIterator());
   return make_range(ValueIterator(*this, Key), ValueIterator());
 }
+
+void DWARFAcceleratorTable::Entry::anchor() {}
Index: lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
===================================================================
--- lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
+++ lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
@@ -543,3 +543,5 @@
   for (const auto &Entry : Entries)
     Entry->dump(OS, MRI, IsEH);
 }
+
+void FrameEntry::anchor() {}
Index: lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
===================================================================
--- lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
+++ lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
@@ -59,3 +59,5 @@
   else
     OS << "<type unit can't be parsed!>\n\n";
 }
+
+void DIContext::anchor() {}
Index: lib/DebugInfo/DWARF/DWARFUnit.cpp
===================================================================
--- lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -571,3 +571,5 @@
       //StrOffsetsContributionDescriptor(Offset, Size, 4, DWARF32));
   return StrOffsetsContributionDescriptor(Offset, Size, 4, DWARF32);
 }
+
+void DWARFUnitSectionBase::anchor() {}
Index: lib/MC/MCCodePadder.cpp
===================================================================
--- lib/MC/MCCodePadder.cpp
+++ lib/MC/MCCodePadder.cpp
@@ -369,3 +369,5 @@
          "More fragments necessarily means bigger weight");
   return FullWindowWeight - FullWindowFirstPartWeight;
 }
+
+void MCCodePaddingPolicy::anchor() {}
Index: lib/MC/MCSection.cpp
===================================================================
--- lib/MC/MCSection.cpp
+++ lib/MC/MCSection.cpp
@@ -99,3 +99,5 @@
   OS << "]>";
 }
 #endif
+
+void MCSection::anchor() {}
Index: lib/MC/MCSubtargetInfo.cpp
===================================================================
--- lib/MC/MCSubtargetInfo.cpp
+++ lib/MC/MCSubtargetInfo.cpp
@@ -118,3 +118,5 @@
   InstrItins = InstrItineraryData(getSchedModel(), Stages, OperandCycles,
                                   ForwardingPaths);
 }
+
+void MCSubtargetInfo::anchor() {}
Index: lib/Object/Binary.cpp
===================================================================
--- lib/Object/Binary.cpp
+++ lib/Object/Binary.cpp
@@ -101,3 +101,5 @@
 
   return OwningBinary<Binary>(std::move(Bin), std::move(Buffer));
 }
+
+void BinaryError::anchor() {}
Index: lib/Support/BinaryStreamReader.cpp
===================================================================
--- lib/Support/BinaryStreamReader.cpp
+++ lib/Support/BinaryStreamReader.cpp
@@ -146,4 +146,6 @@
   BinaryStreamReader W1{First};
   BinaryStreamReader W2{Second};
   return std::make_pair(W1, W2);
-}
\ No newline at end of file
+}
+
+void BinaryStreamReader::anchor() {}
Index: lib/Support/BinaryStreamRef.cpp
===================================================================
--- lib/Support/BinaryStreamRef.cpp
+++ lib/Support/BinaryStreamRef.cpp
@@ -129,3 +129,12 @@
 
 /// \brief For buffered streams, commits changes to the backing store.
 Error WritableBinaryStreamRef::commit() { return BorrowedImpl->commit(); }
+
+void WritableBinaryStream::anchor() {}
+void FileBufferByteStream::anchor() {}
+void FileBufferByteStream::StreamImpl::anchor() {}
+void MutableBinaryByteStream ::anchor() {}
+void AppendingBinaryByteStream::anchor() {}
+void BinaryByteStream::anchor() {}
+void MemoryBufferByteStream::anchor() {}
+void BinaryStream::anchor() {}
Index: lib/Support/Error.cpp
===================================================================
--- lib/Support/Error.cpp
+++ lib/Support/Error.cpp
@@ -49,6 +49,7 @@
 namespace llvm {
 
 void ErrorInfoBase::anchor() {}
+void ECError::anchor() {}
 char ErrorInfoBase::ID = 0;
 char ErrorList::ID = 0;
 char ECError::ID = 0;
Index: lib/Support/FileOutputBuffer.cpp
===================================================================
--- lib/Support/FileOutputBuffer.cpp
+++ lib/Support/FileOutputBuffer.cpp
@@ -168,3 +168,5 @@
     return createInMemoryBuffer(Path, Size, Mode);
   }
 }
+
+void FileOutputBuffer::anchor() {}
Index: lib/Support/FormatVariadic.cpp
===================================================================
--- lib/Support/FormatVariadic.cpp
+++ lib/Support/FormatVariadic.cpp
@@ -152,3 +152,5 @@
   }
   return Replacements;
 }
+
+void detail::format_adapter::anchor() {}
Index: lib/Support/raw_ostream.cpp
===================================================================
--- lib/Support/raw_ostream.cpp
+++ lib/Support/raw_ostream.cpp
@@ -475,6 +475,7 @@
 }
 
 void raw_ostream::anchor() {}
+void buffer_ostream::anchor() {}
 
 //===----------------------------------------------------------------------===//
 //  Formatted Output
Index: lib/TableGen/Record.cpp
===================================================================
--- lib/TableGen/Record.cpp
+++ lib/TableGen/Record.cpp
@@ -2257,3 +2257,7 @@
     FoundUnresolved = true;
   return I;
 }
+
+void Resolver::anchor() {}
+void ShadowResolver::anchor() {}
+void RecordValResolver::anchor() {}