Index: ELF/Config.h
===================================================================
--- ELF/Config.h
+++ ELF/Config.h
@@ -84,6 +84,7 @@
   uint8_t OSABI = 0;
   llvm::CachePruningPolicy ThinLTOCachePolicy;
   llvm::StringMap<uint64_t> SectionStartMap;
+  llvm::StringRef BuildIdLinkDir;
   llvm::StringRef Chroot;
   llvm::StringRef DynamicLinker;
   llvm::StringRef DwoDir;
Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -730,6 +730,7 @@
   Config->AuxiliaryList = args::getStrings(Args, OPT_auxiliary);
   Config->Bsymbolic = Args.hasArg(OPT_Bsymbolic);
   Config->BsymbolicFunctions = Args.hasArg(OPT_Bsymbolic_functions);
+  Config->BuildIdLinkDir = Args.getLastArgValue(OPT_build_id_link_dir);
   Config->CheckSections =
       Args.hasFlag(OPT_check_sections, OPT_no_check_sections, true);
   Config->Chroot = Args.getLastArgValue(OPT_chroot);
Index: ELF/Options.td
===================================================================
--- ELF/Options.td
+++ ELF/Options.td
@@ -32,6 +32,11 @@
 def build_id_eq: J<"build-id=">, HelpText<"Generate build ID note">,
   MetaVarName<"[fast,md5,sha,uuid,0x<hexstring>]">;
 
+defm build_id_link_dir:
+  Eq<"build-id-link-dir",
+     "Hard-link output to <dir>/xx/xxx name derived from hex build ID">,
+  MetaVarName<"<dir>">;
+
 defm check_sections: B<"check-sections",
     "Check section addresses for overlaps (default)",
     "Do not check section addresses for overlaps">;
Index: ELF/SyntheticSections.h
===================================================================
--- ELF/SyntheticSections.h
+++ ELF/SyntheticSections.h
@@ -153,7 +153,7 @@
   BuildIdSection();
   void writeTo(uint8_t *Buf) override;
   size_t getSize() const override { return HeaderSize + HashSize; }
-  void writeBuildId(llvm::ArrayRef<uint8_t> Buf);
+  llvm::SmallVector<uint8_t, 32> writeBuildId(llvm::ArrayRef<uint8_t> Buf);
 
 private:
   void computeHash(llvm::ArrayRef<uint8_t> Buf,
Index: ELF/SyntheticSections.cpp
===================================================================
--- ELF/SyntheticSections.cpp
+++ ELF/SyntheticSections.cpp
@@ -331,7 +331,8 @@
   this->Size = Size;
 }
 
-void BuildIdSection::writeBuildId(ArrayRef<uint8_t> Buf) {
+llvm::SmallVector<uint8_t, 32>
+BuildIdSection::writeBuildId(ArrayRef<uint8_t> Buf) {
   switch (Config->BuildId) {
   case BuildIdKind::Fast:
     computeHash(Buf, [](uint8_t *Dest, ArrayRef<uint8_t> Arr) {
@@ -358,6 +359,7 @@
   default:
     llvm_unreachable("unknown BuildIdKind");
   }
+  return {HashBuf, HashBuf + HashSize};
 }
 
 EhFrameSection::EhFrameSection()
Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -25,6 +25,7 @@
 #include "lld/Common/Threads.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/Path.h"
 #include <climits>
 
 using namespace llvm;
@@ -71,6 +72,7 @@
   void writeSections();
   void writeSectionsBinary();
   void writeBuildId();
+  void writeBuildIdLink();
 
   std::unique_ptr<FileOutputBuffer> &Buffer;
 
@@ -83,6 +85,8 @@
 
   uint64_t FileSize;
   uint64_t SectionHeaderOff;
+
+  SmallVector<uint8_t, 32> BuildIdBytes;
 };
 } // anonymous namespace
 
@@ -522,6 +526,8 @@
 
   if (auto E = Buffer->commit())
     error("failed to write to the output file: " + toString(std::move(E)));
+
+  writeBuildIdLink();
 }
 
 static bool shouldKeepInSymtab(SectionBase *Sec, StringRef SymName,
@@ -2411,7 +2417,42 @@
   // Compute a hash of all sections of the output file.
   uint8_t *Start = Buffer->getBufferStart();
   uint8_t *End = Start + FileSize;
-  InX::BuildId->writeBuildId({Start, End});
+  BuildIdBytes = InX::BuildId->writeBuildId({Start, End});
+}
+
+template <class ELFT> void Writer<ELFT>::writeBuildIdLink() {
+  if (Config->BuildIdLinkDir.empty() ||
+      !InX::BuildId || !InX::BuildId->getParent())
+    return;
+
+  if (BuildIdBytes.size() < 2) {
+    error("build ID too small for --build-id-link-dir");
+    return;
+  }
+
+  char HexByteStrBuf[3];
+  const auto HexDigit = "0123456789abcdef";
+  auto HexByteStr = [&](uint8_t x) -> char* {
+    HexByteStrBuf[0] = HexDigit[x >> 4];
+    HexByteStrBuf[1] = HexDigit[x & 0xf];
+    HexByteStrBuf[2] = '\0';
+    return HexByteStrBuf;
+  };
+
+  SmallString<128> Path(Config->BuildIdLinkDir);
+  llvm::sys::path::append(Path, HexByteStr(BuildIdBytes[0]));
+  if (auto EC = sys::fs::create_directories(Path)) {
+    error("cannot create build ID link directory " +
+          Path + ": " + EC.message());
+    return;
+  }
+
+  llvm::sys::path::append(Path, HexByteStr(BuildIdBytes[1]));
+  for (auto It = BuildIdBytes.begin() + 2; It != BuildIdBytes.end(); ++It)
+    Path.append(HexByteStr(*It));
+
+  if (auto EC = sys::fs::create_hard_link(Config->OutputFile, Path))
+    error("cannot link " + Path + ": " + EC.message());
 }
 
 template void elf::writeResult<ELF32LE>();