Index: lib/IR/Verifier.cpp
===================================================================
--- lib/IR/Verifier.cpp
+++ lib/IR/Verifier.cpp
@@ -217,6 +217,12 @@
   /// Cache of constants visited in search of ConstantExprs.
   SmallPtrSet<const Constant *, 32> ConstantExprVisited;
 
+  // Verify that this GlobalValue is only used in this module.
+  // This map is used to avoid visiting uses twice. We can arrive at a user
+  // twice, if they have multiple operands. In particular for very large
+  // constant expressions, we can arrive at a particular user many times.
+  SmallPtrSet<const Value *, 32> GlobalValueVisited;
+
   void checkAtomicMemAccessSize(const Module *M, Type *Ty,
                                 const Instruction *I);
 public:
@@ -310,6 +316,10 @@
 private:
   // Verification methods...
   void visitGlobalValue(const GlobalValue &GV);
+  bool doVisitGlobalValue(const GlobalValue &GV, const Value *V);
+  void forEachUserGlobalValue(const Value *User,
+                              const GlobalValue &GV);
+
   void visitGlobalVariable(const GlobalVariable &GV);
   void visitGlobalAlias(const GlobalAlias &GA);
   void visitAliaseeSubExpr(const GlobalAlias &A, const Constant &C);
@@ -462,17 +472,35 @@
   InstVisitor<Verifier>::visit(I);
 }
 
-// Helper to recursively iterate over indirect users. By
-// returning false, the callback can ask to stop recursing
-// further.
-static void forEachUser(const Value *User,
-                        SmallPtrSet<const Value *, 32> &Visited,
-                        llvm::function_ref<bool(const Value *)> Callback) {
-  if (!Visited.insert(User).second)
+bool Verifier::doVisitGlobalValue(const GlobalValue &GV, const Value *V) {
+  if (const Instruction *I = dyn_cast<Instruction>(V)) {
+    if (!I->getParent() || !I->getParent()->getParent())
+      CheckFailed("Global is referenced by parentless instruction!", &GV,
+                  M, I);
+    else if (I->getParent()->getParent()->getParent() != M)
+      CheckFailed("Global is referenced in a different module!", &GV,
+                  M, I, I->getParent()->getParent(),
+                  I->getParent()->getParent()->getParent());
+    return false;
+  } else if (const Function *F = dyn_cast<Function>(V)) {
+    if (F->getParent() != M)
+      CheckFailed("Global is used by function in a different module", &GV,
+                  M, F, F->getParent());
+    return false;
+  }
+  return true;
+}
+
+// Helper to recursively iterate over indirect users of
+// a global value. By returning false, doVisitGlobalValue
+// can ask to stop recursing further.
+void Verifier::forEachUserGlobalValue(const Value *User,
+                                      const GlobalValue &GV) {
+  if (!GlobalValueVisited.insert(User).second)
     return;
   for (const Value *TheNextUser : User->materialized_users())
-    if (Callback(TheNextUser))
-      forEachUser(TheNextUser, Visited, Callback);
+    if (doVisitGlobalValue(GV, TheNextUser))
+      forEachUserGlobalValue(TheNextUser, GV);
 }
 
 void Verifier::visitGlobalValue(const GlobalValue &GV) {
@@ -494,29 +522,7 @@
   if (GV.isDeclarationForLinker())
     Assert(!GV.hasComdat(), "Declaration may not be in a Comdat!", &GV);
 
-  // Verify that this GlobalValue is only used in this module.
-  // This map is used to avoid visiting uses twice. We can arrive at a user
-  // twice, if they have multiple operands. In particular for very large
-  // constant expressions, we can arrive at a particular user many times.
-  SmallPtrSet<const Value *, 32> Visited;
-  forEachUser(&GV, Visited, [&](const Value *V) -> bool {
-    if (const Instruction *I = dyn_cast<Instruction>(V)) {
-      if (!I->getParent() || !I->getParent()->getParent())
-        CheckFailed("Global is referenced by parentless instruction!", &GV,
-                    M, I);
-      else if (I->getParent()->getParent()->getParent() != M)
-        CheckFailed("Global is referenced in a different module!", &GV,
-                    M, I, I->getParent()->getParent(),
-                    I->getParent()->getParent()->getParent());
-      return false;
-    } else if (const Function *F = dyn_cast<Function>(V)) {
-      if (F->getParent() != M)
-        CheckFailed("Global is used by function in a different module", &GV,
-                    M, F, F->getParent());
-      return false;
-    }
-    return true;
-  });
+  forEachUserGlobalValue(&GV, GV);
 }
 
 void Verifier::visitGlobalVariable(const GlobalVariable &GV) {