Index: include/llvm-c/lto.h
===================================================================
--- include/llvm-c/lto.h
+++ include/llvm-c/lto.h
@@ -40,7 +40,7 @@
  * @{
  */
 
-#define LTO_API_VERSION 17
+#define LTO_API_VERSION 18
 
 /**
  * \since prior to LTO_API_VERSION=3
@@ -374,8 +374,7 @@
 lto_codegen_add_module(lto_code_gen_t cg, lto_module_t mod);
 
 /**
- * Sets the object module for code generation. This will transfer the ownship of
- * the module to code generator.
+ * Sets the object module for code generation. This will destroy the module.
  *
  * \c cg and \c mod must both be in the same context.
  *
Index: include/llvm/LTO/LTOCodeGenerator.h
===================================================================
--- include/llvm/LTO/LTOCodeGenerator.h
+++ include/llvm/LTO/LTOCodeGenerator.h
@@ -69,7 +69,7 @@
   bool addModule(struct LTOModule *);
 
   // Set the destination module.
-  void setModule(struct LTOModule *);
+  void setModule(std::unique_ptr<LTOModule> M);
 
   void setTargetOptions(TargetOptions options);
   void setDebugInfo(lto_debug_model);
@@ -155,9 +155,9 @@
 
   typedef StringMap<uint8_t> StringSet;
 
-  void destroyMergedModule();
   std::unique_ptr<LLVMContext> OwnedContext;
   LLVMContext &Context;
+  std::unique_ptr<Module> OwnedModule;
   Linker IRLinker;
   TargetMachine *TargetMach = nullptr;
   bool EmitDwarfDebugInfo = false;
@@ -173,7 +173,6 @@
   unsigned OptLevel = 2;
   lto_diagnostic_handler_t DiagHandler = nullptr;
   void *DiagContext = nullptr;
-  LTOModule *OwnedModule = nullptr;
   bool ShouldInternalize = true;
   bool ShouldEmbedUselists = false;
 };
Index: include/llvm/LTO/LTOModule.h
===================================================================
--- include/llvm/LTO/LTOModule.h
+++ include/llvm/LTO/LTOModule.h
@@ -113,6 +113,10 @@
     return IRFile->getModule();
   }
 
+  std::unique_ptr<Module> takeModule() {
+    return IRFile->takeModule();
+  }
+
   /// Return the Module's target triple.
   const std::string &getTargetTriple() {
     return getModule().getTargetTriple();
Index: include/llvm/Linker/Linker.h
===================================================================
--- include/llvm/Linker/Linker.h
+++ include/llvm/Linker/Linker.h
@@ -62,7 +62,6 @@
 
   Linker(Module *M, DiagnosticHandlerFunction DiagnosticHandler);
   Linker(Module *M);
-  ~Linker();
 
   Module *getModule() const { return Composite; }
   void deleteModule();
Index: lib/LTO/LTOCodeGenerator.cpp
===================================================================
--- lib/LTO/LTOCodeGenerator.cpp
+++ lib/LTO/LTOCodeGenerator.cpp
@@ -64,29 +64,20 @@
 }
 
 LTOCodeGenerator::LTOCodeGenerator()
-    : Context(getGlobalContext()), IRLinker(new Module("ld-temp.o", Context)) {
+    : Context(getGlobalContext()),
+      OwnedModule(new Module("ld-temp.o", Context)),
+      IRLinker(OwnedModule.get()) {
   initializeLTOPasses();
 }
 
 LTOCodeGenerator::LTOCodeGenerator(std::unique_ptr<LLVMContext> Context)
     : OwnedContext(std::move(Context)), Context(*OwnedContext),
-      IRLinker(new Module("ld-temp.o", *OwnedContext)) {
+      OwnedModule(new Module("ld-temp.o", *OwnedContext)),
+      IRLinker(OwnedModule.get()) {
   initializeLTOPasses();
 }
 
-void LTOCodeGenerator::destroyMergedModule() {
-  if (OwnedModule) {
-    assert(IRLinker.getModule() == &OwnedModule->getModule() &&
-           "The linker's module should be the same as the owned module");
-    delete OwnedModule;
-    OwnedModule = nullptr;
-  } else if (IRLinker.getModule())
-    IRLinker.deleteModule();
-}
-
 LTOCodeGenerator::~LTOCodeGenerator() {
-  destroyMergedModule();
-
   delete TargetMach;
   TargetMach = nullptr;
 
@@ -139,16 +130,14 @@
   return !ret;
 }
 
-void LTOCodeGenerator::setModule(LTOModule *Mod) {
+void LTOCodeGenerator::setModule(std::unique_ptr<LTOModule> Mod) {
   assert(&Mod->getModule().getContext() == &Context &&
          "Expected module in same context");
 
-  // Delete the old merged module.
-  destroyMergedModule();
   AsmUndefinedRefs.clear();
 
-  OwnedModule = Mod;
-  IRLinker.setModule(&Mod->getModule());
+  OwnedModule = Mod->takeModule();
+  IRLinker.setModule(OwnedModule.get());
 
   const std::vector<const char*> &Undefs = Mod->getAsmUndefinedRefs();
   for (int I = 0, E = Undefs.size(); I != E; ++I)
@@ -551,8 +540,6 @@
   if (!this->determineTarget(errMsg))
     return false;
 
-  Module *mergedModule = IRLinker.getModule();
-
   legacy::PassManager codeGenPasses;
 
   // If the bitcode files contain ARC code and were compiled with optimization,
@@ -566,7 +553,10 @@
   }
 
   // Run the code generator, and write assembly file
-  codeGenPasses.run(*mergedModule);
+  codeGenPasses.run(*OwnedModule.get());
+
+  // Finally destroy the module as we no longer need it
+  OwnedModule.reset();
 
   return true;
 }
Index: lib/Linker/LinkModules.cpp
===================================================================
--- lib/Linker/LinkModules.cpp
+++ lib/Linker/LinkModules.cpp
@@ -1754,9 +1754,6 @@
   });
 }
 
-Linker::~Linker() {
-}
-
 void Linker::deleteModule() {
   delete Composite;
   Composite = nullptr;
Index: tools/llvm-lto/llvm-lto.cpp
===================================================================
--- tools/llvm-lto/llvm-lto.cpp
+++ tools/llvm-lto/llvm-lto.cpp
@@ -207,26 +207,24 @@
       return 1;
     }
 
-    LTOModule *LTOMod = Module.get();
-
-    // We use the first input module as the destination module when
-    // SetMergedModule is true.
-    if (SetMergedModule && i == BaseArg) {
-      // Transfer ownership to the code generator.
-      CodeGen.setModule(Module.release());
-    } else if (!CodeGen.addModule(Module.get()))
-      return 1;
-
-    unsigned NumSyms = LTOMod->getSymbolCount();
+    unsigned NumSyms = Module->getSymbolCount();
     for (unsigned I = 0; I < NumSyms; ++I) {
-      StringRef Name = LTOMod->getSymbolName(I);
+      StringRef Name = Module->getSymbolName(I);
       if (!DSOSymbolsSet.count(Name))
         continue;
-      lto_symbol_attributes Attrs = LTOMod->getSymbolAttributes(I);
+      lto_symbol_attributes Attrs = Module->getSymbolAttributes(I);
       unsigned Scope = Attrs & LTO_SYMBOL_SCOPE_MASK;
       if (Scope != LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN)
         KeptDSOSyms.push_back(Name);
     }
+
+    // We use the first input module as the destination module when
+    // SetMergedModule is true.
+    if (SetMergedModule && i == BaseArg) {
+      // Transfer ownership to the code generator.
+      CodeGen.setModule(std::move(Module));
+    } else if (!CodeGen.addModule(Module.get()))
+      return 1;
   }
 
   // Add all the exported symbols to the table of symbols to preserve.
Index: tools/lto/lto.cpp
===================================================================
--- tools/lto/lto.cpp
+++ tools/lto/lto.cpp
@@ -260,7 +260,7 @@
 }
 
 void lto_codegen_set_module(lto_code_gen_t cg, lto_module_t mod) {
-  unwrap(cg)->setModule(unwrap(mod));
+  unwrap(cg)->setModule(std::unique_ptr<LTOModule>(unwrap(mod)));
 }
 
 bool lto_codegen_set_debug_model(lto_code_gen_t cg, lto_debug_model debug) {