Index: llvm/trunk/lib/ExecutionEngine/ExecutionEngine.cpp
===================================================================
--- llvm/trunk/lib/ExecutionEngine/ExecutionEngine.cpp
+++ llvm/trunk/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -142,7 +142,8 @@
 
 Function *ExecutionEngine::FindFunctionNamed(const char *FnName) {
   for (unsigned i = 0, e = Modules.size(); i != e; ++i) {
-    if (Function *F = Modules[i]->getFunction(FnName))
+    Function *F = Modules[i]->getFunction(FnName);
+    if (F && !F->isDeclaration())
       return F;
   }
   return nullptr;
Index: llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.cpp
===================================================================
--- llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.cpp
+++ llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.cpp
@@ -408,7 +408,8 @@
                                                  ModulePtrSet::iterator I,
                                                  ModulePtrSet::iterator E) {
   for (; I != E; ++I) {
-    if (Function *F = (*I)->getFunction(FnName))
+    Function *F = (*I)->getFunction(FnName);
+    if (F && !F->isDeclaration())
       return F;
   }
   return nullptr;
Index: llvm/trunk/unittests/ExecutionEngine/MCJIT/MCJITMultipleModuleTest.cpp
===================================================================
--- llvm/trunk/unittests/ExecutionEngine/MCJIT/MCJITMultipleModuleTest.cpp
+++ llvm/trunk/unittests/ExecutionEngine/MCJIT/MCJITMultipleModuleTest.cpp
@@ -392,4 +392,23 @@
   ptr = TheJIT->getFunctionAddress(FB2->getName().str());
   checkAccumulate(ptr);
 }
+
+// Test that FindFunctionNamed finds the definition of
+// a function in the correct module. We check two functions
+// in two different modules, to make sure that for at least
+// one of them MCJIT had to ignore the extern declaration.
+TEST_F(MCJITMultipleModuleTest, FindFunctionNamed_test) {
+  SKIP_UNSUPPORTED_PLATFORM;
+
+  std::unique_ptr<Module> A, B;
+  Function *FA, *FB1, *FB2;
+  createCrossModuleRecursiveCase(A, FA, B, FB1, FB2);
+
+  createJIT(std::move(A));
+  TheJIT->addModule(std::move(B));
+
+  EXPECT_EQ(FA, TheJIT->FindFunctionNamed(FA->getName().data()));
+  EXPECT_EQ(FB1, TheJIT->FindFunctionNamed(FB1->getName().data()));
+}
+
 }