Index: lld/trunk/lib/ReaderWriter/MachO/File.h
===================================================================
--- lld/trunk/lib/ReaderWriter/MachO/File.h
+++ lld/trunk/lib/ReaderWriter/MachO/File.h
@@ -197,6 +197,11 @@
   uint32_t swiftVersion() const { return _swiftVersion; }
   void setSwiftVersion(uint32_t v) { _swiftVersion = v; }
 
+  bool subsectionsViaSymbols() const {
+    return _flags & llvm::MachO::MH_SUBSECTIONS_VIA_SYMBOLS;
+  }
+  void setFlags(normalized::FileFlags v) { _flags = v; }
+
   /// Methods for support type inquiry through isa, cast, and dyn_cast:
   static inline bool classof(const File *F) {
     return F->kind() == File::kindMachObject;
@@ -238,6 +243,7 @@
   MachOLinkingContext::Arch      _arch = MachOLinkingContext::arch_unknown;
   MachOLinkingContext::OS        _os = MachOLinkingContext::OS::unknown;
   uint32_t                       _swiftVersion = 0;
+  normalized::FileFlags          _flags;
 };
 
 class MachODylibFile : public SharedLibraryFile {
Index: lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
===================================================================
--- lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
+++ lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
@@ -105,10 +105,12 @@
 public:
   Util(const MachOLinkingContext &ctxt)
       : _ctx(ctxt), _archHandler(ctxt.archHandler()), _entryAtom(nullptr),
-        _hasTLVDescriptors(false) {}
+        _hasTLVDescriptors(false), _subsectionsViaSymbols(true) {}
   ~Util();
 
-  void      assignAtomsToSections(const lld::File &atomFile);
+  void      processDefinedAtoms(const lld::File &atomFile);
+  void      processAtomAttributes(const DefinedAtom *atom);
+  void      assignAtomToSection(const DefinedAtom *atom);
   void      organizeSections();
   void      assignAddressesToSections(const NormalizedFile &file);
   uint32_t  fileFlags();
@@ -180,6 +182,7 @@
   AtomToIndex                   _atomToSymbolIndex;
   std::vector<const Atom *>     _machHeaderAliasAtoms;
   bool                          _hasTLVDescriptors;
+  bool                          _subsectionsViaSymbols;
 };
 
 Util::~Util() {
@@ -366,15 +369,28 @@
   sect->size = offset + atom->size();
 }
 
-void Util::assignAtomsToSections(const lld::File &atomFile) {
+void Util::processDefinedAtoms(const lld::File &atomFile) {
   for (const DefinedAtom *atom : atomFile.defined()) {
-    if (atom->contentType() == DefinedAtom::typeMachHeader)
-      _machHeaderAliasAtoms.push_back(atom);
-    else
-      appendAtom(sectionForAtom(atom), atom);
+    processAtomAttributes(atom);
+    assignAtomToSection(atom);
   }
 }
 
+void Util::processAtomAttributes(const DefinedAtom *atom) {
+  auto *machoFile = static_cast<const mach_o::MachOFile *>(&atom->file());
+  // If the file doesn't use subsections via symbols, then make sure we don't
+  // add that flag to the final output file if we have a relocatable file.
+  if (!machoFile->subsectionsViaSymbols())
+    _subsectionsViaSymbols = false;
+}
+
+void Util::assignAtomToSection(const DefinedAtom *atom) {
+  if (atom->contentType() == DefinedAtom::typeMachHeader)
+    _machHeaderAliasAtoms.push_back(atom);
+  else
+    appendAtom(sectionForAtom(atom), atom);
+}
+
 SegmentInfo *Util::segmentForName(StringRef segName) {
   for (SegmentInfo *si : _segmentInfos) {
     if ( si->name.equals(segName) )
@@ -1183,7 +1199,7 @@
 uint32_t Util::fileFlags() {
   // FIXME: these need to determined at runtime.
   if (_ctx.outputMachOType() == MH_OBJECT) {
-    return MH_SUBSECTIONS_VIA_SYMBOLS;
+    return _subsectionsViaSymbols ? MH_SUBSECTIONS_VIA_SYMBOLS : 0;
   } else {
     uint32_t flags = MH_DYLDLINK;
     if (!_ctx.useFlatNamespace())
@@ -1208,7 +1224,7 @@
                                            const MachOLinkingContext &context) {
   // The util object buffers info until the normalized file can be made.
   Util util(context);
-  util.assignAtomsToSections(atomFile);
+  util.processDefinedAtoms(atomFile);
   util.organizeSections();
 
   std::unique_ptr<NormalizedFile> f(new NormalizedFile());
Index: lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
===================================================================
--- lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
+++ lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
@@ -1056,6 +1056,7 @@
   }
 
   // Cache some attributes on the file for use later.
+  file->setFlags(normalizedFile.flags);
   file->setArch(normalizedFile.arch);
   file->setOS(normalizedFile.os);
 
Index: lld/trunk/test/mach-o/parse-data-relocs-x86_64.yaml
===================================================================
--- lld/trunk/test/mach-o/parse-data-relocs-x86_64.yaml
+++ lld/trunk/test/mach-o/parse-data-relocs-x86_64.yaml
@@ -323,4 +323,5 @@
 # CHECK:    content:         [ 00, 00, 00, 00, 00, 00, 00, 00 ]
 # CHECK:    section-choice:  custom-required
 # CHECK:    section-name:    __DATA/__custom
+# CHECK:    dead-strip:      never