diff --git a/llvm/tools/llvm-objcopy/COFF/Object.cpp b/llvm/tools/llvm-objcopy/COFF/Object.cpp
new file mode 100644
index 0000000..315d3a7
--- /dev/null
+++ b/llvm/tools/llvm-objcopy/COFF/Object.cpp
@@ -0,0 +1,70 @@
+//===- Object.cpp ---------------------------------------------------------===//
+//
+//                      The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Object.h"
+#include <algorithm>
+
+namespace llvm {
+namespace objcopy {
+namespace coff {
+
+using namespace object;
+
+void Object::addSymbols(ArrayRef<Symbol> NewSymbols) {
+  for (Symbol S : NewSymbols) {
+    S.UniqueId = NextSymbolUniqueId++;
+    Symbols.emplace_back(S);
+  }
+  updateSymbols();
+}
+
+void Object::updateSymbols() {
+  SymbolMap = DenseMap<size_t, Symbol *>(Symbols.size());
+  size_t RawSymIndex = 0;
+  for (Symbol &Sym : Symbols) {
+    SymbolMap[Sym.UniqueId] = &Sym;
+    Sym.RawIndex = RawSymIndex;
+    RawSymIndex += 1 + Sym.Sym.NumberOfAuxSymbols;
+  }
+}
+
+const Symbol *Object::findSymbol(size_t UniqueId) const {
+  auto It = SymbolMap.find(UniqueId);
+  if (It == SymbolMap.end())
+    return nullptr;
+  return It->second;
+}
+
+void Object::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {
+  Symbols.erase(
+      std::remove_if(std::begin(Symbols), std::end(Symbols),
+                     [ToRemove](const Symbol &Sym) { return ToRemove(Sym); }),
+      std::end(Symbols));
+  updateSymbols();
+}
+
+Error Object::markSymbols() {
+  for (Symbol &Sym : Symbols)
+    Sym.Referenced = false;
+  for (const Section &Sec : Sections) {
+    for (const Relocation &R : Sec.Relocs) {
+      auto It = SymbolMap.find(R.Target);
+      if (It == SymbolMap.end())
+        return make_error<StringError>("Relocation target " + Twine(R.Target) +
+                                           " not found",
+                                       object_error::invalid_symbol_index);
+      It->second->Referenced = true;
+    }
+  }
+  return Error::success();
+}
+
+} // end namespace coff
+} // end namespace objcopy
+} // end namespace llvm