diff --git a/llvm/include/llvm/Linker/IRMover.h b/llvm/include/llvm/Linker/IRMover.h
--- a/llvm/include/llvm/Linker/IRMover.h
+++ b/llvm/include/llvm/Linker/IRMover.h
@@ -11,6 +11,7 @@
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/FunctionExtras.h"
 #include <functional>
 
 namespace llvm {
@@ -62,6 +63,8 @@
   IRMover(Module &M);
 
   typedef std::function<void(GlobalValue &)> ValueAdder;
+  using LazyCallback =
+      llvm::unique_function<void(GlobalValue &GV, ValueAdder Add)>;
 
   /// Move in the provide values in \p ValuesToLink from \p Src.
   ///
@@ -70,11 +73,11 @@
   ///   not present in ValuesToLink. The GlobalValue and a ValueAdder callback
   ///   are passed as an argument, and the callback is expected to be called
   ///   if the GlobalValue needs to be added to the \p ValuesToLink and linked.
+  ///   Pass nullptr if there's no work to be done in such cases.
   /// - \p IsPerformingImport is true when this IR link is to perform ThinLTO
   ///   function importing from Src.
   Error move(std::unique_ptr<Module> Src, ArrayRef<GlobalValue *> ValuesToLink,
-             std::function<void(GlobalValue &GV, ValueAdder Add)> AddLazyFor,
-             bool IsPerformingImport);
+             LazyCallback AddLazyFor, bool IsPerformingImport);
   Module &getModule() { return Composite; }
 
 private:
diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -885,8 +885,7 @@
     Keep.push_back(GV);
   }
 
-  return RegularLTO.Mover->move(std::move(Mod.M), Keep,
-                                [](GlobalValue &, IRMover::ValueAdder) {},
+  return RegularLTO.Mover->move(std::move(Mod.M), Keep, nullptr,
                                 /* IsPerformingImport */ false);
 }
 
diff --git a/llvm/lib/Linker/IRMover.cpp b/llvm/lib/Linker/IRMover.cpp
--- a/llvm/lib/Linker/IRMover.cpp
+++ b/llvm/lib/Linker/IRMover.cpp
@@ -381,7 +381,7 @@
   std::unique_ptr<Module> SrcM;
 
   /// See IRMover::move().
-  std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor;
+  IRMover::LazyCallback AddLazyFor;
 
   TypeMapTy TypeMap;
   GlobalValueMaterializer GValMaterializer;
@@ -524,8 +524,7 @@
   IRLinker(Module &DstM, MDMapT &SharedMDs,
            IRMover::IdentifiedStructTypeSet &Set, std::unique_ptr<Module> SrcM,
            ArrayRef<GlobalValue *> ValuesToLink,
-           std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor,
-           bool IsPerformingImport)
+           IRMover::LazyCallback AddLazyFor, bool IsPerformingImport)
       : DstM(DstM), SrcM(std::move(SrcM)), AddLazyFor(std::move(AddLazyFor)),
         TypeMap(Set), GValMaterializer(*this), LValMaterializer(*this),
         SharedMDs(SharedMDs), IsPerformingImport(IsPerformingImport),
@@ -987,10 +986,11 @@
   // Callback to the client to give a chance to lazily add the Global to the
   // list of value to link.
   bool LazilyAdded = false;
-  AddLazyFor(SGV, [this, &LazilyAdded](GlobalValue &GV) {
-    maybeAdd(&GV);
-    LazilyAdded = true;
-  });
+  if (AddLazyFor)
+    AddLazyFor(SGV, [this, &LazilyAdded](GlobalValue &GV) {
+      maybeAdd(&GV);
+      LazilyAdded = true;
+    });
   return LazilyAdded;
 }
 
@@ -1673,10 +1673,9 @@
   }
 }
 
-Error IRMover::move(
-    std::unique_ptr<Module> Src, ArrayRef<GlobalValue *> ValuesToLink,
-    std::function<void(GlobalValue &, ValueAdder Add)> AddLazyFor,
-    bool IsPerformingImport) {
+Error IRMover::move(std::unique_ptr<Module> Src,
+                    ArrayRef<GlobalValue *> ValuesToLink,
+                    LazyCallback AddLazyFor, bool IsPerformingImport) {
   IRLinker TheIRLinker(Composite, SharedMDs, IdentifiedStructTypes,
                        std::move(Src), ValuesToLink, std::move(AddLazyFor),
                        IsPerformingImport);
diff --git a/llvm/lib/Linker/LinkModules.cpp b/llvm/lib/Linker/LinkModules.cpp
--- a/llvm/lib/Linker/LinkModules.cpp
+++ b/llvm/lib/Linker/LinkModules.cpp
@@ -573,11 +573,13 @@
   // FIXME: Propagate Errors through to the caller instead of emitting
   // diagnostics.
   bool HasErrors = false;
-  if (Error E = Mover.move(std::move(SrcM), ValuesToLink.getArrayRef(),
-                           [this](GlobalValue &GV, IRMover::ValueAdder Add) {
-                             addLazyFor(GV, Add);
-                           },
-                           /* IsPerformingImport */ false)) {
+  if (Error E =
+          Mover.move(std::move(SrcM), ValuesToLink.getArrayRef(),
+                     IRMover::LazyCallback(
+                         [this](GlobalValue &GV, IRMover::ValueAdder Add) {
+                           addLazyFor(GV, Add);
+                         }),
+                     /* IsPerformingImport */ false)) {
     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
       DstM.getContext().diagnose(LinkDiagnosticInfo(DS_Error, EIB.message()));
       HasErrors = true;
diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -1331,10 +1331,9 @@
                << " from " << SrcModule->getSourceFileName() << "\n";
     }
 
-    if (Error Err = Mover.move(
-            std::move(SrcModule), GlobalsToImport.getArrayRef(),
-            [](GlobalValue &, IRMover::ValueAdder) {},
-            /*IsPerformingImport=*/true))
+    if (Error Err = Mover.move(std::move(SrcModule),
+                               GlobalsToImport.getArrayRef(), nullptr,
+                               /*IsPerformingImport=*/true))
       report_fatal_error(Twine("Function Import: link error: ") +
                          toString(std::move(Err)));