Index: ELF/Config.h
===================================================================
--- ELF/Config.h
+++ ELF/Config.h
@@ -48,6 +48,7 @@
   llvm::StringRef SoName;
   llvm::StringRef Sysroot;
   std::string RPath;
+  std::string ReproduceDir = "";
   std::vector<llvm::StringRef> DynamicList;
   std::vector<llvm::StringRef> SearchPaths;
   std::vector<llvm::StringRef> Undefined;
Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -19,6 +19,7 @@
 #include "Writer.h"
 #include "lld/Driver/Driver.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/raw_ostream.h"
 #include <utility>
@@ -97,12 +98,42 @@
   return V;
 }
 
+// Should this be moved to LLVM/Support ?
+static std::string getFullPath(StringRef FileName) {
+  SmallString<128> CurPath;
+  sys::fs::current_path(CurPath);
+  sys::path::append(CurPath, FileName);
+  return CurPath.str();
+}
+
+static void dumpFile(StringRef SrcPath) {
+  if (Config->ReproduceDir.empty())
+    return;
+
+  std::error_code EC;
+  EC = llvm::sys::fs::create_directories(
+    Config->ReproduceDir + "/" + llvm::sys::path::parent_path(SrcPath));
+  if (EC) {
+    error("--reproduce: can't create directory " +
+        Config->ReproduceDir + "/" + SrcPath
+        + ": " + EC.message());
+    return;
+  }
+
+  EC = llvm::sys::fs::copy_file(SrcPath,
+    Config->ReproduceDir + "/" + SrcPath);
+  if (EC)
+    error("--reproduce: can't copy file " + SrcPath + ": " + EC.message());
+}
+
 // Opens and parses a file. Path has to be resolved already.
 // Newly created memory buffers are owned by this driver.
 void LinkerDriver::addFile(StringRef Path) {
   using namespace llvm::sys::fs;
   if (Config->Verbose)
     llvm::outs() << Path << "\n";
+  dumpFile(Path);
+
   Optional<MemoryBufferRef> Buffer = readFile(Path);
   if (!Buffer.hasValue())
     return;
@@ -223,6 +254,23 @@
   return false;
 }
 
+static void dumpLinkerInvocation(ArrayRef<const char *> Args) {
+  if (Config->ReproduceDir.empty())
+    return;
+
+  std::error_code EC = llvm::sys::fs::create_directories(Config->ReproduceDir);
+  if (EC) {
+    error("--reproduce: can't create directory: " + EC.message());
+    return;
+  }
+
+  raw_fd_ostream OS(Config->ReproduceDir + "/invocation.txt", EC,
+    sys::fs::OpenFlags::F_None);
+  check(EC);
+  for (auto Arg: Args)
+    OS << Arg << " ";
+}
+
 void LinkerDriver::main(ArrayRef<const char *> ArgsArr) {
   ELFOptTable Parser;
   opt::InputArgList Args = Parser.parse(ArgsArr.slice(1));
@@ -237,6 +285,7 @@
 
   initLLVM(Args);
   readConfigs(Args);
+  dumpLinkerInvocation(ArgsArr);
   createFiles(Args);
   checkOptions(Args);
   if (HasError)
@@ -378,6 +427,15 @@
     if (Optional<MemoryBufferRef> Buffer =
             readFile(getString(Args, OPT_version_script)))
       parseVersionScript(*Buffer);
+
+  if (auto *Arg = Args.getLastArg(OPT_reproduce)) {
+    if (llvm::sys::path::is_relative(Arg->getValue()))
+      Config->ReproduceDir = getFullPath(Arg->getValue());
+    else
+      Config->ReproduceDir = Arg->getValue();
+    if (llvm::sys::fs::exists(Config->ReproduceDir))
+      error("--reproduce: directory " + Config->ReproduceDir + " already exists.");
+  }
 }
 
 void LinkerDriver::createFiles(opt::InputArgList &Args) {
Index: ELF/Options.td
===================================================================
--- ELF/Options.td
+++ ELF/Options.td
@@ -120,6 +120,9 @@
 def print_gc_sections: Flag<["--"], "print-gc-sections">,
   HelpText<"List removed unused sections">;
 
+def reproduce : Separate<["--"], "reproduce">,
+  HelpText<"Dump linker invocation and input files for debugging">;
+
 def rpath : Separate<["-"], "rpath">,
   HelpText<"Add a DT_RUNPATH to the output">;
 
Index: test/ELF/reproduce.s
===================================================================
--- /dev/null
+++ test/ELF/reproduce.s
@@ -0,0 +1,26 @@
+# REQUIRES: x86
+
+# RUN: rm -rf %S/repro
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: ld.lld %t -o %t2 -shared --as-needed --reproduce %S/repro
+# RUN: llvm-objdump -d %S/repro/%t | FileCheck %s --check-prefix=DUMP
+# RUN: cat %S/repro/invocation.txt | FileCheck %s --check-prefix=INVOCATION
+
+.globl _start;
+_start:
+  mov $60, %rax
+  mov $42, %rdi
+  syscall
+
+# DUMP: Disassembly of section .text:
+# DUMP: _start:
+# DUMP:        0:       48 c7 c0 3c 00 00 00    movq    $60, %rax
+# DUMP:        7:       48 c7 c7 2a 00 00 00    movq    $42, %rdi
+# DUMP:        e:       0f 05   syscall
+
+# INVOCATION: lld {{.*}}reproduce.s{{.*}} -o {{.*}} -shared --as-needed --reproduce
+
+# RUN: rm -rf %S/repro2
+# RUN: mkdir %S/repro2
+# RUN: not ld.lld %t -o %t2 --reproduce %S/repro2 2>&1 | FileCheck --check-prefix=EDIR %s
+# EDIR: --reproduce: directory {{.*}}repro2 already exists.