diff --git a/test/tools/gold/Inputs/drop-debug.bc b/test/tools/gold/Inputs/drop-debug.bc
new file mode 100644
index 00000000000..f9c471f8e0d
Binary files /dev/null and b/test/tools/gold/Inputs/drop-debug.bc differ
diff --git a/test/tools/gold/drop-debug.ll b/test/tools/gold/drop-debug.ll
new file mode 100644
index 00000000000..b8c4d8c62a9
--- /dev/null
+++ b/test/tools/gold/drop-debug.ll
@@ -0,0 +1,8 @@
+; RUN: %gold -plugin %llvmshlibdir/LLVMgold.so \
+; RUN:    --plugin-opt=emit-llvm -shared %p/Inputs/drop-debug.bc \
+; RUN:    -o t2.bc 2>&1 | FileCheck %s
+
+; drop-debug.bc was created from "void f(void) {}" with clang 3.5 and
+; -gline-tables-only, so it contains old debug info.
+
+; CHECK: warning: LLVM gold plugin: ignoring debug info with an invalid version (1) in {{.*}}/Inputs/drop-debug.bc
diff --git a/tools/gold/gold-plugin.cpp b/tools/gold/gold-plugin.cpp
index e654a1581f7..2aec4e21bc4 100644
--- a/tools/gold/gold-plugin.cpp
+++ b/tools/gold/gold-plugin.cpp
@@ -20,6 +20,7 @@
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/CodeGen/Analysis.h"
 #include "llvm/CodeGen/CommandFlags.h"
+#include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
@@ -273,11 +274,11 @@ static bool shouldSkip(uint32_t Symflags) {
 }
 
 static void diagnosticHandler(const DiagnosticInfo &DI, void *Context) {
-  assert(DI.getSeverity() == DS_Error && "Only expecting errors");
-  const auto &BDI = cast<BitcodeDiagnosticInfo>(DI);
-  std::error_code EC = BDI.getError();
-  if (EC == BitcodeError::InvalidBitcodeSignature)
-    return;
+  if (const auto *BDI = dyn_cast<BitcodeDiagnosticInfo>(&DI)) {
+    std::error_code EC = BDI->getError();
+    if (EC == BitcodeError::InvalidBitcodeSignature)
+      return;
+  }
 
   std::string ErrStorage;
   {
@@ -285,8 +286,24 @@ static void diagnosticHandler(const DiagnosticInfo &DI, void *Context) {
     DiagnosticPrinterRawOStream DP(OS);
     DI.print(DP);
   }
-  message(LDPL_FATAL, "LLVM gold plugin has failed to create LTO module: %s",
-          ErrStorage.c_str());
+  ld_plugin_level Level;
+  switch (DI.getSeverity()) {
+  case DS_Error:
+    message(LDPL_FATAL, "LLVM gold plugin has failed to create LTO module: %s",
+            ErrStorage.c_str());
+    llvm_unreachable("Fatal doesn't return.");
+  case DS_Warning:
+    Level = LDPL_WARNING;
+    break;
+  case DS_Note:
+    Level = LDPL_INFO;
+    break;
+    // FIXME: Just ignore remarks for now. They are always passed by
+    // if there is a custom diagnostic handler, so we get flooded.
+  case DS_Remark:
+    return;
+  }
+  message(Level, "LLVM gold plugin: %s",  ErrStorage.c_str());
 }
 
 /// Called by gold to see whether this file is one that our plugin can handle.
@@ -561,7 +578,7 @@ static void freeSymName(ld_plugin_symbol &Sym) {
 
 static std::unique_ptr<Module>
 getModuleForFile(LLVMContext &Context, claimed_file &F,
-                 off_t Filesize, raw_fd_ostream *ApiFile,
+                 ld_plugin_input_file &Info, raw_fd_ostream *ApiFile,
                  StringSet<> &Internalize, StringSet<> &Maybe) {
 
   if (get_symbols(F.handle, F.syms.size(), &F.syms[0]) != LDPS_OK)
@@ -571,7 +588,8 @@ getModuleForFile(LLVMContext &Context, claimed_file &F,
   if (get_view(F.handle, &View) != LDPS_OK)
     message(LDPL_FATAL, "Failed to get a view of file");
 
-  MemoryBufferRef BufferRef(StringRef((const char *)View, Filesize), "");
+  MemoryBufferRef BufferRef(StringRef((const char *)View, Info.filesize),
+                            Info.name);
   ErrorOr<std::unique_ptr<object::IRObjectFile>> ObjOrErr =
       object::IRObjectFile::create(BufferRef, Context);
 
@@ -583,6 +601,8 @@ getModuleForFile(LLVMContext &Context, claimed_file &F,
 
   Module &M = Obj.getModule();
 
+  UpgradeDebugInfo(M);
+
   SmallPtrSet<GlobalValue *, 8> Used;
   collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
 
@@ -792,6 +812,8 @@ static ld_plugin_status allSymbolsReadHook(raw_fd_ostream *ApiFile) {
     return LDPS_OK;
 
   LLVMContext Context;
+  Context.setDiagnosticHandler(diagnosticHandler);
+
   std::unique_ptr<Module> Combined(new Module("ld-temp.o", Context));
   Linker L(Combined.get());
 
@@ -804,8 +826,7 @@ static ld_plugin_status allSymbolsReadHook(raw_fd_ostream *ApiFile) {
     if (get_input_file(F.handle, &File) != LDPS_OK)
       message(LDPL_FATAL, "Failed to get file information");
     std::unique_ptr<Module> M =
-        getModuleForFile(Context, F, File.filesize, ApiFile,
-                         Internalize, Maybe);
+        getModuleForFile(Context, F, File, ApiFile, Internalize, Maybe);
     if (!options::triple.empty())
       M->setTargetTriple(options::triple.c_str());
     else if (M->getTargetTriple().empty()) {