diff --git a/lld/lib/ReaderWriter/PECOFF/CMakeLists.txt b/lld/lib/ReaderWriter/PECOFF/CMakeLists.txt
index d0fde5f4e7aa..d6112462d1ad 100644
--- a/lld/lib/ReaderWriter/PECOFF/CMakeLists.txt
+++ b/lld/lib/ReaderWriter/PECOFF/CMakeLists.txt
@@ -1,6 +1,7 @@
 add_lld_library(lldPECOFF
   EdataPass.cpp
   IdataPass.cpp
+  LinkerGeneratedSymbolFile.cpp
   LoadConfigPass.cpp
   PECOFFLinkingContext.cpp
   Pass.cpp
diff --git a/lld/lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.cpp b/lld/lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.cpp
new file mode 100644
index 000000000000..9825912a2ae7
--- /dev/null
+++ b/lld/lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.cpp
@@ -0,0 +1,48 @@
+//===- lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.cpp --------------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LinkerGeneratedSymbolFile.h"
+
+namespace lld {
+namespace pecoff {
+
+// Find decorated symbol, namely /sym@[0-9]+/ or /\?sym@@.+/.
+bool findDecoratedSymbol(PECOFFLinkingContext *ctx, ResolvableSymbols *syms,
+                         std::string sym, std::string &res) {
+  const std::set<std::string> &defined = syms->defined();
+  // Search for /sym@[0-9]+/
+  {
+    std::string s = sym + '@';
+    auto it = defined.lower_bound(s);
+    for (auto e = defined.end(); it != e; ++it) {
+      if (!StringRef(*it).startswith(s))
+        break;
+      if (it->size() == s.size())
+        continue;
+      StringRef suffix = StringRef(*it).substr(s.size());
+      if (suffix.find_first_not_of("0123456789") != StringRef::npos)
+        continue;
+      res = *it;
+      return true;
+    }
+  }
+  // Search for /\?sym@@.+/
+  {
+    std::string s = "?" + ctx->undecorateSymbol(sym).str() + "@@";
+    auto it = defined.lower_bound(s);
+    if (it != defined.end() && StringRef(*it).startswith(s)) {
+      res = *it;
+      return true;
+    }
+  }
+  return false;
+}
+
+} // namespace pecoff
+} // namespace lld
diff --git a/lld/lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.h b/lld/lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.h
index 0b02b8ef1fb5..33667ad2b200 100644
--- a/lld/lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.h
+++ b/lld/lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.h
@@ -1,4 +1,4 @@
-//===- lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.cpp --------------===//
+//===- lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.h ----------------===//
 //
 //                             The LLVM Linker
 //
@@ -21,6 +21,10 @@ using llvm::COFF::WindowsSubsystem;
 namespace lld {
 namespace pecoff {
 
+class ResolvableSymbols;
+bool findDecoratedSymbol(PECOFFLinkingContext *ctx, ResolvableSymbols *syms,
+                         std::string sym, std::string &res);
+
 namespace impl {
 
 /// The defined atom for dllexported symbols with __imp_ prefix.
@@ -255,7 +259,7 @@ public:
     if (it == _exportedSyms.end())
       return nullptr;
     std::string replace;
-    if (!findDecoratedSymbol(sym.str(), replace))
+    if (!findDecoratedSymbol(_ctx, _syms.get(), sym.str(), replace))
       return nullptr;
     it->second->name = replace;
     if (_ctx->deadStrip())
@@ -264,37 +268,6 @@ public:
   }
 
 private:
-  // Find decorated symbol, namely /sym@[0-9]+/ or /\?sym@@.+/.
-  bool findDecoratedSymbol(std::string sym, std::string &res) const {
-    const std::set<std::string> &defined = _syms->defined();
-    // Search for /sym@[0-9]+/
-    {
-      std::string s = sym + '@';
-      auto it = defined.lower_bound(s);
-      for (auto e = defined.end(); it != e; ++it) {
-        if (!StringRef(*it).startswith(s))
-          break;
-        if (it->size() == s.size())
-          continue;
-        StringRef suffix = StringRef(*it).substr(s.size());
-        if (suffix.find_first_not_of("0123456789") != StringRef::npos)
-          continue;
-        res = *it;
-        return true;
-      }
-    }
-    // Search for /\?sym@@.+/
-    {
-      std::string s = "?" + _ctx->undecorateSymbol(sym).str() + "@@";
-      auto it = defined.lower_bound(s);
-      if (it != defined.end() && StringRef(*it).startswith(s)) {
-        res = *it;
-        return true;
-      }
-    }
-    return false;
-  }
-
   std::map<std::string, PECOFFLinkingContext::ExportDesc *> _exportedSyms;
   std::shared_ptr<ResolvableSymbols> _syms;
   mutable llvm::BumpPtrAllocator _alloc;