diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -1477,6 +1477,31 @@
   void printPostfixForExternalizedDecl(llvm::raw_ostream &OS,
                                        const Decl *D) const;
 
+  /// Move some lazily-emitted states to the NewBuilder. This is especially
+  /// essential for the incremental parsing environment like Clang Interpreter,
+  /// because we'll lose all important information after each repl.
+  void moveLazyEmissionStates(CodeGenModule *NewBuilder) {
+    assert(DeferredDeclsToEmit.empty() &&
+           "Should have emitted all decls deferred to emit.");
+    assert(NewBuilder->DeferredDecls.empty() &&
+           "Newly created module should not have deferred decls");
+    NewBuilder->DeferredDecls = std::move(DeferredDecls);
+
+    assert(NewBuilder->DeferredVTables.empty() &&
+           "Newly created module should not have deferred vtables");
+    NewBuilder->DeferredVTables = std::move(DeferredVTables);
+
+    assert(NewBuilder->MangledDeclNames.empty() &&
+           "Newly created module should not have mangled decl names");
+    assert(NewBuilder->Manglings.empty() &&
+           "Newly created module should not have manglings");
+    NewBuilder->Manglings = std::move(Manglings);
+
+    assert(WeakRefReferences.empty() &&
+           "Not all WeakRefRefs have been applied");
+    NewBuilder->TBAA = std::move(TBAA);
+  }
+
 private:
   llvm::Constant *GetOrCreateLLVMFunction(
       StringRef MangledName, llvm::Type *Ty, GlobalDecl D, bool ForVTable,
diff --git a/clang/lib/CodeGen/ModuleBuilder.cpp b/clang/lib/CodeGen/ModuleBuilder.cpp
--- a/clang/lib/CodeGen/ModuleBuilder.cpp
+++ b/clang/lib/CodeGen/ModuleBuilder.cpp
@@ -134,7 +134,14 @@
                               llvm::LLVMContext &C) {
       assert(!M && "Replacing existing Module?");
       M.reset(new llvm::Module(ExpandModuleName(ModuleName, CodeGenOpts), C));
+
+      std::unique_ptr<CodeGenModule> OldBuilder = std::move(Builder);
+
       Initialize(*Ctx);
+
+      if (OldBuilder)
+        OldBuilder->moveLazyEmissionStates(Builder.get());
+
       return M.get();
     }
 
diff --git a/clang/test/Interpreter/execute.cpp b/clang/test/Interpreter/execute.cpp
--- a/clang/test/Interpreter/execute.cpp
+++ b/clang/test/Interpreter/execute.cpp
@@ -13,4 +13,8 @@
 
 auto r2 = printf("S[f=%f, m=0x%llx]\n", s.f, reinterpret_cast<unsigned long long>(s.m));
 // CHECK-NEXT: S[f=1.000000, m=0x0]
+
+inline int foo() { return 42; }
+int r3 = foo();
+
 quit