diff --git a/lib/TBDGen/TBDGen.cpp b/lib/TBDGen/TBDGen.cpp
index 72ebab22e2b7d..67e6fbf8c5cec 100644
--- a/lib/TBDGen/TBDGen.cpp
+++ b/lib/TBDGen/TBDGen.cpp
@@ -636,8 +636,6 @@ static void enumeratePublicSymbolsAndWrite(ModuleDecl *M, FileUnit *singleFile,
   file.setTwoLevelNamespace();
   file.setSwiftABIVersion(irgen::getSwiftABIVersion());
   file.setInstallAPI(opts.IsInstallAPI);
-  llvm::MachO::Target target(triple);
-  file.addTarget(target);
 
   llvm::MachO::Target target(triple);
   file.addTarget(target);
diff --git a/lib/TBDGen/tapi/Registry.cpp b/lib/TBDGen/tapi/Registry.cpp
deleted file mode 100644
index aa3f38a4059ab..0000000000000
--- a/lib/TBDGen/tapi/Registry.cpp
+++ /dev/null
@@ -1,186 +0,0 @@
-//===- lib/Core/Registry.cpp - TAPI Registry --------------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-///
-/// \file
-/// Implements the TAPI Registry.
-///
-//===----------------------------------------------------------------------===//
-
-#include "Registry.h"
-/*#include "tapi/Core/MachODylibReader.h"
-#include "tapi/Core/ReexportFileWriter.h"
-#include "tapi/Core/TextAPI_v1.h"
-#include "tapi/Core/TextStub_v1.h"
-#include "tapi/Core/TextStub_v2.h"*/
-#include "TextStub_v3.h"
-#include "llvm/ADT/StringRef.h"
-#include "llvm/Support/FileSystem.h"
-#include "llvm/Support/raw_ostream.h"
-
-using namespace llvm;
-
-TAPI_NAMESPACE_INTERNAL_BEGIN
-
-namespace {
-
-// Diagnostic reader. It can read all the YAML file with !tapi tag and returns
-// proper error when started to read the file.
-class DiagnosticReader : public Reader {
-  bool canRead(file_magic fileType, MemoryBufferRef bufferRef,
-               FileType types = FileType::All) const override;
-  Expected<FileType> getFileType(file_magic magic,
-                                 MemoryBufferRef bufferRef) const override;
-  Expected<std::unique_ptr<File>>
-  readFile(std::unique_ptr<MemoryBuffer> memBuffer, ReadFlags readFlags,
-           ArchitectureSet arches) const override;
-};
-
-} // namespace
-
-bool DiagnosticReader::canRead(file_magic fileType, MemoryBufferRef bufferRef,
-                               FileType types) const {
-  auto str = bufferRef.getBuffer().trim();
-  if (!str.startswith("--- !tapi") || !str.endswith("..."))
-    return false;
-
-  return true;
-}
-
-Expected<FileType>
-DiagnosticReader::getFileType(file_magic magic,
-                              MemoryBufferRef bufferRef) const {
-  return Invalid;
-}
-
-Expected<std::unique_ptr<File>>
-DiagnosticReader::readFile(std::unique_ptr<MemoryBuffer> memBuffer,
-                           ReadFlags readFlags, ArchitectureSet arches) const {
-  auto str = memBuffer->getBuffer().trim();
-  auto tag = str.split('\n').first.drop_front(4);
-  return make_error<StringError>(
-      "unsupported tapi file type \'" + tag.str() + "\' in YAML",
-      std::make_error_code(std::errc::not_supported));
-}
-
-bool Registry::canRead(MemoryBufferRef memBuffer, FileType types) const {
-  auto data = memBuffer.getBuffer();
-  auto magic = identify_magic(data);
-
-  for (const auto &reader : _readers) {
-    if (reader->canRead(magic, memBuffer, types))
-      return true;
-  }
-
-  return false;
-}
-
-Expected<FileType> Registry::getFileType(MemoryBufferRef memBuffer) const {
-  auto data = memBuffer.getBuffer();
-  auto magic = identify_magic(data);
-
-  for (const auto &reader : _readers) {
-    auto fileType = reader->getFileType(magic, memBuffer);
-    if (!fileType)
-      return fileType.takeError();
-    if (fileType.get() != FileType::Invalid)
-      return fileType;
-  }
-
-  return FileType::Invalid;
-}
-
-bool Registry::canWrite(const File *file) const {
-  for (const auto &writer : _writers) {
-    if (writer->canWrite(file))
-      return true;
-  }
-
-  return false;
-}
-
-Expected<std::unique_ptr<File>>
-Registry::readFile(std::unique_ptr<MemoryBuffer> memBuffer, ReadFlags readFlags,
-                   ArchitectureSet arches) const {
-  auto data = memBuffer->getBuffer();
-  auto fileType = identify_magic(data);
-
-  for (const auto &reader : _readers) {
-    if (!reader->canRead(fileType, memBuffer->getMemBufferRef()))
-      continue;
-    return reader->readFile(std::move(memBuffer), readFlags, arches);
-  }
-
-  return make_error<StringError>(
-      "unsupported file type", std::make_error_code(std::errc::not_supported));
-}
-
-Error Registry::writeFile(const File *file, const std::string &path) const {
-  std::error_code ec;
-  raw_fd_ostream os(path, ec, sys::fs::F_Text);
-  if (ec)
-    return errorCodeToError(ec);
-  auto error = writeFile(os, file);
-  if (error)
-    return error;
-  os.close();
-  if (ec)
-    return errorCodeToError(ec);
-  return Error::success();
-}
-
-Error Registry::writeFile(raw_ostream &os, const File *file) const {
-  for (const auto &writer : _writers) {
-    if (!writer->canWrite(file))
-      continue;
-    return writer->writeFile(os, file);
-  }
-
-  return make_error<StringError>(
-      "unsupported file type", std::make_error_code(std::errc::not_supported));
-}
-
-/*void Registry::addBinaryReaders() {
-  add(std::unique_ptr<Reader>(new MachODylibReader));
-  }*/
-
-void Registry::addYAMLReaders() {
-  auto reader =std::make_unique<YAMLReader>();
-  /*reader->add(
-      std::unique_ptr<DocumentHandler>(new stub::v1::YAMLDocumentHandler));
-  reader->add(
-  std::unique_ptr<DocumentHandler>(new stub::v2::YAMLDocumentHandler));*/
-  reader->add(
-      std::unique_ptr<DocumentHandler>(new stub::v3::YAMLDocumentHandler));
-/*reader->add(
-  std::unique_ptr<DocumentHandler>(new api::v1::YAMLDocumentHandler));*/
-  add(std::unique_ptr<Reader>(std::move(reader)));
-}
-
-void Registry::addYAMLWriters() {
-  auto writer =std::make_unique<YAMLWriter>();
-  /*writer->add(
-      std::unique_ptr<DocumentHandler>(new stub::v1::YAMLDocumentHandler));
-  writer->add(
-  std::unique_ptr<DocumentHandler>(new stub::v2::YAMLDocumentHandler));*/
-  writer->add(
-      std::unique_ptr<DocumentHandler>(new stub::v3::YAMLDocumentHandler));
-  /*writer->add(
-    std::unique_ptr<DocumentHandler>(new api::v1::YAMLDocumentHandler));*/
-  add(std::unique_ptr<Writer>(std::move(writer)));
-}
-
-void Registry::addReexportWriters() {
-  //add(std::unique_ptr<Writer>(new ReexportFileWriter));
-}
-
-void Registry::addDiagnosticReader() {
-  add(std::make_unique<DiagnosticReader>());
-}
-
-TAPI_NAMESPACE_INTERNAL_END
diff --git a/lib/TBDGen/tapi/YAML.cpp b/lib/TBDGen/tapi/YAML.cpp
deleted file mode 100644
index 2037759afe631..0000000000000
--- a/lib/TBDGen/tapi/YAML.cpp
+++ /dev/null
@@ -1,153 +0,0 @@
-//===- lib/Core/YAML.cpp - Common YAML Mappings------------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-///
-/// \file
-/// Implements common YAML mappings
-///
-//===----------------------------------------------------------------------===//
-
-#include "YAML.h"
-
-namespace llvm {
-namespace yaml {
-
-using tapi::ObjCConstraint;
-void ScalarEnumerationTraits<ObjCConstraint>::enumeration(
-    IO &io, ObjCConstraint &constraint) {
-  io.enumCase(constraint, "none", ObjCConstraint::None);
-  io.enumCase(constraint, "retain_release", ObjCConstraint::Retain_Release);
-  io.enumCase(constraint, "retain_release_for_simulator",
-              ObjCConstraint::Retain_Release_For_Simulator);
-  io.enumCase(constraint, "retain_release_or_gc",
-              ObjCConstraint::Retain_Release_Or_GC);
-  io.enumCase(constraint, "gc", ObjCConstraint::GC);
-}
-
-using TAPI_INTERNAL::Platform;
-void ScalarEnumerationTraits<Platform>::enumeration(IO &io,
-                                                    Platform &platform) {
-  io.enumCase(platform, "unknown", Platform::unknown);
-  io.enumCase(platform, "macosx", Platform::macOS);
-  io.enumCase(platform, "ios", Platform::iOS);
-  io.enumCase(platform, "ios", Platform::iOSSimulator);
-
-  io.enumCase(platform, "watchos", Platform::watchOS);
-  io.enumCase(platform, "watchos", Platform::watchOSSimulator);
-  io.enumCase(platform, "tvos", Platform::tvOS);
-  io.enumCase(platform, "tvos", Platform::tvOSSimulator);
-  io.enumCase(platform, "bridgeos", Platform::bridgeOS);
-}
-
-using TAPI_INTERNAL::Architecture;
-using TAPI_INTERNAL::ArchitectureSet;
-void ScalarBitSetTraits<ArchitectureSet>::bitset(IO &io,
-                                                 ArchitectureSet &archs) {
-#define ARCHINFO(arch, type, subtype)                                          \
-  io.bitSetCase(archs, #arch, 1U << static_cast<int>(Architecture::arch));
-#include "Architecture.def"
-#undef ARCHINFO
-}
-
-using TAPI_INTERNAL::getArchType;
-void ScalarTraits<Architecture>::output(const Architecture &value, void *,
-                                        raw_ostream &os) {
-  os << value;
-}
-StringRef ScalarTraits<Architecture>::input(StringRef scalar, void *,
-                                            Architecture &value) {
-  value = getArchType(scalar);
-  return {};
-}
-QuotingType ScalarTraits<Architecture>::mustQuote(StringRef) {
-  return QuotingType::None;
-}
-
-using TAPI_INTERNAL::PackedVersion;
-void ScalarTraits<PackedVersion>::output(const PackedVersion &value, void *,
-                                         raw_ostream &os) {
-  os << value;
-}
-StringRef ScalarTraits<PackedVersion>::input(StringRef scalar, void *,
-                                             PackedVersion &value) {
-  if (!value.parse32(scalar))
-    return "invalid packed version string.";
-  return {};
-}
-QuotingType ScalarTraits<PackedVersion>::mustQuote(StringRef) {
-  return QuotingType::None;
-}
-
-using TAPI_INTERNAL::AvailabilityInfo;
-void ScalarTraits<AvailabilityInfo>::output(const AvailabilityInfo &value,
-                                            void *, raw_ostream &os) {
-  if (value._unavailable) {
-    os << "n/a";
-    return;
-  }
-
-  os << value._introduced;
-  if (!value._obsoleted.empty())
-    os << ".." << value._obsoleted;
-}
-StringRef ScalarTraits<AvailabilityInfo>::input(StringRef scalar, void *,
-                                                AvailabilityInfo &value) {
-  if (scalar == "n/a") {
-    value._unavailable = true;
-    return {};
-  }
-
-  auto split = scalar.split("..");
-  auto introduced = split.first.trim();
-  auto obsoleted = split.second.trim();
-
-  if (!value._introduced.parse32(introduced))
-    return "invalid packed version string.";
-
-  if (obsoleted.empty())
-    return StringRef();
-
-  if (!value._obsoleted.parse32(obsoleted))
-    return "invalid packed version string.";
-
-  return StringRef();
-}
-QuotingType ScalarTraits<AvailabilityInfo>::mustQuote(StringRef) {
-  return QuotingType::None;
-}
-
-void ScalarTraits<UUID>::output(const UUID &value, void *, raw_ostream &os) {
-  os << value.first << ": " << value.second;
-}
-StringRef ScalarTraits<UUID>::input(StringRef scalar, void *, UUID &value) {
-  auto split = scalar.split(':');
-  auto arch = split.first.trim();
-  auto uuid = split.second.trim();
-  if (uuid.empty())
-    return "invalid uuid string pair";
-  value.first = getArchType(arch);
-  value.second = uuid;
-  return {};
-}
-QuotingType ScalarTraits<UUID>::mustQuote(StringRef) {
-  return QuotingType::Single;
-}
-
-using clang::Language;
-void ScalarEnumerationTraits<Language>::enumeration(IO &io, Language &kind) {
-  io.enumCase(kind, "c", Language::C);
-  io.enumCase(kind, "cxx", Language::CXX);
-  io.enumCase(kind, "objective-c", Language::ObjC);
-  io.enumCase(kind, "objc", Language::ObjC); // to keep old snapshots working.
-  io.enumCase(kind, "objective-cxx", Language::ObjCXX);
-  io.enumCase(kind, "objcxx",
-              Language::ObjCXX); // to keep old snapshots working.
-}
-
-} // end namespace yaml.
-} // end namespace llvm.
diff --git a/lib/TBDGen/tapi/YAML.h b/lib/TBDGen/tapi/YAML.h
deleted file mode 100644
index cbacb33db4e01..0000000000000
--- a/lib/TBDGen/tapi/YAML.h
+++ /dev/null
@@ -1,101 +0,0 @@
-//===- tapi/Core/YAML.h - YAML ----------------------------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-///
-/// \file
-/// Defines common YAML mappings
-///
-//===----------------------------------------------------------------------===//
-
-#ifndef TAPI_CORE_YAML_H
-#define TAPI_CORE_YAML_H
-
-#include "Architecture.h"
-#include "ArchitectureSet.h"
-#include "ArchitectureSupport.h"
-#include "AvailabilityInfo.h"
-#include "Platform.h"
-#include "YAMLReaderWriter.h"
-#include "clang/Frontend/FrontendOptions.h"
-#include "llvm/ADT/StringSwitch.h"
-#include "llvm/Support/YAMLTraits.h"
-
-using UUID = std::pair<TAPI_INTERNAL::Architecture, std::string>;
-
-LLVM_YAML_STRONG_TYPEDEF(llvm::StringRef, FlowStringRef)
-LLVM_YAML_STRONG_TYPEDEF(uint8_t, SwiftVersion)
-LLVM_YAML_IS_FLOW_SEQUENCE_VECTOR(UUID)
-LLVM_YAML_IS_FLOW_SEQUENCE_VECTOR(FlowStringRef)
-
-namespace llvm {
-namespace yaml {
-
-template <> struct ScalarTraits<FlowStringRef> {
-  static void output(const FlowStringRef &value, void *ctx, raw_ostream &os);
-  static StringRef input(StringRef value, void *ctx, FlowStringRef &out);
-  static QuotingType mustQuote(StringRef name);
-};
-
-using tapi::ObjCConstraint;
-template <> struct ScalarEnumerationTraits<ObjCConstraint> {
-  static void enumeration(IO &io, ObjCConstraint &constraint);
-};
-
-using TAPI_INTERNAL::Platform;
-template <> struct ScalarEnumerationTraits<Platform> {
-  static void enumeration(IO &io, Platform &platform);
-};
-
-using TAPI_INTERNAL::Architecture;
-using TAPI_INTERNAL::ArchitectureSet;
-template <> struct ScalarBitSetTraits<ArchitectureSet> {
-  static void bitset(IO &io, ArchitectureSet &archs);
-};
-
-using TAPI_INTERNAL::getArchType;
-template <> struct ScalarTraits<Architecture> {
-  static void output(const Architecture &value, void *, raw_ostream &os);
-  static StringRef input(StringRef scalar, void *, Architecture &value);
-  static QuotingType mustQuote(StringRef);
-};
-
-using TAPI_INTERNAL::PackedVersion;
-template <> struct ScalarTraits<PackedVersion> {
-  static void output(const PackedVersion &value, void *, raw_ostream &os);
-  static StringRef input(StringRef scalar, void *, PackedVersion &value);
-  static QuotingType mustQuote(StringRef);
-};
-
-template <> struct ScalarTraits<SwiftVersion> {
-  static void output(const SwiftVersion &value, void *, raw_ostream &os);
-  static StringRef input(StringRef scalar, void *, SwiftVersion &value);
-  static QuotingType mustQuote(StringRef);
-};
-
-using TAPI_INTERNAL::AvailabilityInfo;
-template <> struct ScalarTraits<AvailabilityInfo> {
-  static void output(const AvailabilityInfo &value, void *, raw_ostream &os);
-  static StringRef input(StringRef scalar, void *, AvailabilityInfo &value);
-  static QuotingType mustQuote(StringRef);
-};
-
-template <> struct ScalarTraits<UUID> {
-  static void output(const UUID &value, void *, raw_ostream &os);
-  static StringRef input(StringRef scalar, void *, UUID &value);
-  static QuotingType mustQuote(StringRef);
-};
-
-using clang::InputKind;
-template <> struct ScalarEnumerationTraits<clang::Language> {
-  static void enumeration(IO &io, clang::Language &kind);
-};
-
-} // end namespace yaml.
-} // end namespace llvm.
-
-#endif // TAPI_CORE_YAML_H