diff --git a/llvm/lib/LTO/LTOCodeGenerator.cpp b/llvm/lib/LTO/LTOCodeGenerator.cpp
--- a/llvm/lib/LTO/LTOCodeGenerator.cpp
+++ b/llvm/lib/LTO/LTOCodeGenerator.cpp
@@ -119,6 +119,10 @@
     cl::Hidden);
 }
 
+static cl::opt<bool> SaveTemps(
+    "save-temps", cl::init(false),
+    cl::desc("Save temporary LTO files in the current working directory."));
+
 LTOCodeGenerator::LTOCodeGenerator(LLVMContext &Context)
     : Context(Context), MergedModule(new Module("ld-temp.o", Context)),
       TheLinker(new Linker(*MergedModule)) {
@@ -545,6 +549,9 @@
   // Add an appropriate DataLayout instance for this module...
   MergedModule->setDataLayout(TargetMach->createDataLayout());
 
+  if (Config.PostImportModuleHook)
+    Config.PostImportModuleHook(0, *MergedModule);
+
   ModuleSummaryIndex CombinedIndex(false);
   TargetMach = createTargetMachine();
   if (!opt(Config, TargetMach.get(), 0, *MergedModule, /*IsThinLTO=*/false,
@@ -606,8 +613,13 @@
       CodegenArgv.push_back(Arg.c_str());
     cl::ParseCommandLineOptions(CodegenArgv.size(), CodegenArgv.data());
   }
-}
 
+  if (SaveTemps) {
+    if (Config.addSaveTemps("ld-temp.",
+                            /* UseInputModulePath */ true))
+      errs() << "Warning: failed to set up path to save temporary files\n";
+  }
+}
 
 void LTOCodeGenerator::DiagnosticHandler(const DiagnosticInfo &DI) {
   // Map the LLVM internal diagnostic severity to the LTO diagnostic severity.