Index: include/llvm/Support/DynamicLibrary.h
===================================================================
--- include/llvm/Support/DynamicLibrary.h
+++ include/llvm/Support/DynamicLibrary.h
@@ -108,7 +108,9 @@
     /// @brief Add searchable symbol/value pair.
     static void AddSymbol(StringRef symbolName, void *symbolValue);
 
+    // Force any ManagedStatics DynamicLibrary requires to be constructed.
     class HandleSet;
+    static HandleSet& init();
   };
 
 } // End sys namespace
Index: lib/Support/DynamicLibrary.cpp
===================================================================
--- lib/Support/DynamicLibrary.cpp
+++ lib/Support/DynamicLibrary.cpp
@@ -125,12 +125,21 @@
   (*ExplicitSymbols)[SymbolName] = SymbolValue;
 }
 
+DynamicLibrary::HandleSet& DynamicLibrary::init() {
+  return *OpenedHandles;
+}
+
 DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *FileName,
                                                    std::string *Err) {
-  SmartScopedLock<true> Lock(*SymbolsMutex);
+  // Force OpenedHandles to be added into the ManagedStatic list before any
+  // ManagedStatic can be added from static constructors in HandleSet::DLOpen.
+  HandleSet& HS = init();
+
   void *Handle = HandleSet::DLOpen(FileName, Err);
-  if (Handle != &Invalid)
-    OpenedHandles->AddLibrary(Handle, /*IsProcess*/ FileName == nullptr);
+  if (Handle != &Invalid) {
+    SmartScopedLock<true> Lock(*SymbolsMutex);
+    HS.AddLibrary(Handle, /*IsProcess*/ FileName == nullptr);
+  }
 
   return DynamicLibrary(Handle);
 }
Index: lib/Transforms/IPO/PassManagerBuilder.cpp
===================================================================
--- lib/Transforms/IPO/PassManagerBuilder.cpp
+++ lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -29,6 +29,7 @@
 #include "llvm/IR/ModuleSummaryIndex.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/DynamicLibrary.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Transforms/IPO.h"
@@ -197,6 +198,7 @@
 void PassManagerBuilder::addGlobalExtension(
     PassManagerBuilder::ExtensionPointTy Ty,
     PassManagerBuilder::ExtensionFn Fn) {
+  sys::DynamicLibrary::init();
   GlobalExtensions->push_back(std::make_pair(Ty, std::move(Fn)));
 }
 
Index: unittests/Support/DynamicLibrary/CMakeLists.txt
===================================================================
--- unittests/Support/DynamicLibrary/CMakeLists.txt
+++ unittests/Support/DynamicLibrary/CMakeLists.txt
@@ -1,4 +1,4 @@
-set(LLVM_LINK_COMPONENTS Support)
+set(LLVM_LINK_COMPONENTS Support IPO)
 
 add_llvm_unittest(DynamicLibraryTests DynamicLibraryTest.cpp)
 
Index: unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
===================================================================
--- unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
+++ unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
@@ -12,6 +12,7 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "gtest/gtest.h"
 
 #include "PipSqueak.h"
@@ -54,6 +55,28 @@
   return Tmp.P;
 }
 
+static void
+NoPassRegistration(const PassManagerBuilder &, legacy::PassManagerBase &) {
+}
+
+static RegisterStandardPasses TestOrder(PassManagerBuilder::EP_LoopOptimizerEnd,
+                                        NoPassRegistration);
+
+typedef void (*TestPassReg)(void (*)(PassManagerBuilder::ExtensionPointTy,
+                                     PassManagerBuilder::ExtensionFn));
+
+TEST(DynamicLibrary, PassRegistration) {
+  std::string Err;
+  llvm_shutdown_obj Shutdown;
+  DynamicLibrary DL =
+      DynamicLibrary::getPermanentLibrary(LibPath().c_str(), &Err);
+  EXPECT_TRUE(DL.isValid());
+  EXPECT_TRUE(Err.empty());
+
+  TestPassReg RP = FuncPtr<TestPassReg>(DL.getAddressOfSymbol("TestPassReg"));
+  RP(&PassManagerBuilder::addGlobalExtension);
+}
+
 static const char *OverloadTestA() { return "OverloadCall"; }
 
 std::string StdString(const char *Ptr) { return Ptr ? Ptr : ""; }
Index: unittests/Support/DynamicLibrary/PipSqueak.cxx
===================================================================
--- unittests/Support/DynamicLibrary/PipSqueak.cxx
+++ unittests/Support/DynamicLibrary/PipSqueak.cxx
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "PipSqueak.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
 
 #if defined(_WIN32) && !defined(__GNUC__)
 // Disable warnings from inclusion of xlocale & exception
@@ -44,3 +45,13 @@
 }
 
 extern "C" PIPSQUEAK_EXPORT const char *TestA() { return "LibCall"; }
+
+static void LibPassRegistration(const llvm::PassManagerBuilder &,
+                                llvm::legacy::PassManagerBase &) {}
+
+extern "C" PIPSQUEAK_EXPORT void TestPassReg(
+    void (*addGlobalExtension)(llvm::PassManagerBuilder::ExtensionPointTy,
+                               llvm::PassManagerBuilder::ExtensionFn)) {
+  addGlobalExtension(llvm::PassManagerBuilder::EP_EarlyAsPossible,
+                     LibPassRegistration);
+}