Index: include/llvm/Linker/Linker.h
===================================================================
--- include/llvm/Linker/Linker.h
+++ include/llvm/Linker/Linker.h
@@ -83,7 +83,7 @@
   /// Returns true on error.
   bool linkInModule(Module *Src, unsigned Flags = Flags::None,
                     const FunctionInfoIndex *Index = nullptr,
-                    Function *FuncToImport = nullptr);
+                    DenseSet<const GlobalValue *> *FuncToImport = nullptr);
 
   /// \brief Set the composite to the passed-in module.
   void setModule(Module *Dst);
Index: lib/Linker/LinkModules.cpp
===================================================================
--- lib/Linker/LinkModules.cpp
+++ lib/Linker/LinkModules.cpp
@@ -423,7 +423,7 @@
 
   /// Function to import from source module, all other functions are
   /// imported as declarations instead of definitions.
-  Function *ImportFunction;
+  DenseSet<const GlobalValue *> *ImportFunction;
 
   /// Set to true if the given FunctionInfoIndex contains any functions
   /// from this source module, in which case we must conservatively assume
@@ -442,7 +442,7 @@
   ModuleLinker(Module *dstM, Linker::IdentifiedStructTypeSet &Set, Module *srcM,
                DiagnosticHandlerFunction DiagnosticHandler, unsigned Flags,
                const FunctionInfoIndex *Index = nullptr,
-               Function *FuncToImport = nullptr)
+               DenseSet<const GlobalValue *> *FuncToImport = nullptr)
       : DstM(dstM), SrcM(srcM), TypeMap(Set), ValMaterializer(this),
         DiagnosticHandler(DiagnosticHandler), Flags(Flags), ImportIndex(Index),
         ImportFunction(FuncToImport), HasExportedFunctions(false),
@@ -655,7 +655,7 @@
     return true;
   // Only import the function requested for importing.
   auto *SF = dyn_cast<Function>(SGV);
-  if (SF && SF == ImportFunction)
+  if (SF && ImportFunction->count(SF))
     return true;
   // Otherwise no.
   return false;
@@ -1081,7 +1081,7 @@
     if (isa<Function>(&Src)) {
       // For functions, LinkFromSrc iff this is the function requested
       // for importing. For variables, decide below normally.
-      LinkFromSrc = (&Src == ImportFunction);
+      LinkFromSrc = ImportFunction->count(&Src);
       return false;
     }
 
@@ -2102,7 +2102,7 @@
 
 bool Linker::linkInModule(Module *Src, unsigned Flags,
                           const FunctionInfoIndex *Index,
-                          Function *FuncToImport) {
+                          DenseSet<const GlobalValue *> *FuncToImport) {
   ModuleLinker TheLinker(Composite, IdentifiedStructTypes, Src,
                          DiagnosticHandler, Flags, Index, FuncToImport);
   bool RetCode = TheLinker.run();
Index: lib/Transforms/IPO/FunctionImport.cpp
===================================================================
--- lib/Transforms/IPO/FunctionImport.cpp
+++ lib/Transforms/IPO/FunctionImport.cpp
@@ -185,8 +185,10 @@
       continue;
     }
 
-    // Link in the specified function.
-    if (L.linkInModule(&Module, Linker::Flags::None, &Index, F))
+    DenseSet<const GlobalValue *> FunctionsToImport;
+    FunctionsToImport.insert(F);
+    if (L.linkInModule(&Module, Linker::Flags::None, &Index,
+                       &FunctionsToImport))
       report_fatal_error("Function Import: link error");
 
     // Process the newly imported function and add callees to the worklist.
@@ -198,6 +200,7 @@
 
     Changed = true;
   }
+
   return Changed;
 }
 
Index: tools/llvm-link/llvm-link.cpp
===================================================================
--- tools/llvm-link/llvm-link.cpp
+++ tools/llvm-link/llvm-link.cpp
@@ -198,7 +198,10 @@
     }
 
     // Link in the specified function.
-    if (L.linkInModule(M.get(), Linker::Flags::None, Index.get(), F))
+    DenseSet<const GlobalValue *> FunctionToImport;
+    FunctionToImport.insert(F);
+    if (L.linkInModule(M.get(), Linker::Flags::None, Index.get(),
+                       &FunctionToImport))
       return false;
   }
   return true;