--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/Transforms/Utils/CloneModule.cpp	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,122 @@
+//===- CloneModule.cpp - Clone an entire module ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the CloneModule interface which makes a copy of an
+// entire module.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/IR/Constant.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Transforms/Utils/ValueMapper.h"
+using namespace llvm;
+
+/// CloneModule - Return an exact copy of the specified module.  This is not as
+/// easy as it might seem because we have to worry about making copies of global
+/// variables and functions, and making their (initializers and references,
+/// respectively) refer to the right globals.
+///
+Module *llvm::CloneModule(const Module *M) {
+  // Create the value map that maps things from the old module over to the new
+  // module.
+  ValueToValueMapTy VMap;
+  return CloneModule(M, VMap);
+}
+
+Module *llvm::CloneModule(const Module *M, ValueToValueMapTy &VMap) {
+  // First off, we need to create the new module.
+  Module *New = new Module(M->getModuleIdentifier(), M->getContext());
+  New->setDataLayout(M->getDataLayout());
+  New->setTargetTriple(M->getTargetTriple());
+  New->setModuleInlineAsm(M->getModuleInlineAsm());
+   
+  // Loop over all of the global variables, making corresponding globals in the
+  // new module.  Here we add them to the VMap and to the new Module.  We
+  // don't worry about attributes or initializers, they will come later.
+  //
+  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
+       I != E; ++I) {
+    GlobalVariable *GV = new GlobalVariable(*New, 
+                                            I->getType()->getElementType(),
+                                            I->isConstant(), I->getLinkage(),
+                                            (Constant*) 0, I->getName(),
+                                            (GlobalVariable*) 0,
+                                            I->getThreadLocalMode(),
+                                            I->getType()->getAddressSpace());
+    GV->copyAttributesFrom(I);
+    VMap[I] = GV;
+  }
+
+  // Loop over the functions in the module, making external functions as before
+  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
+    Function *NF =
+      Function::Create(cast<FunctionType>(I->getType()->getElementType()),
+                       I->getLinkage(), I->getName(), New);
+    NF->copyAttributesFrom(I);
+    VMap[I] = NF;
+  }
+
+  // Loop over the aliases in the module
+  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
+       I != E; ++I) {
+    GlobalAlias *GA = new GlobalAlias(I->getType(), I->getLinkage(),
+                                      I->getName(), NULL, New);
+    GA->copyAttributesFrom(I);
+    VMap[I] = GA;
+  }
+  
+  // Now that all of the things that global variable initializer can refer to
+  // have been created, loop through and copy the global variable referrers
+  // over...  We also set the attributes on the global now.
+  //
+  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
+       I != E; ++I) {
+    GlobalVariable *GV = cast<GlobalVariable>(VMap[I]);
+    if (I->hasInitializer())
+      GV->setInitializer(MapValue(I->getInitializer(), VMap));
+  }
+
+  // Similarly, copy over function bodies now...
+  //
+  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
+    Function *F = cast<Function>(VMap[I]);
+    if (!I->isDeclaration()) {
+      Function::arg_iterator DestI = F->arg_begin();
+      for (Function::const_arg_iterator J = I->arg_begin(); J != I->arg_end();
+           ++J) {
+        DestI->setName(J->getName());
+        VMap[J] = DestI++;
+      }
+
+      SmallVector<ReturnInst*, 8> Returns;  // Ignore returns cloned.
+      CloneFunctionInto(F, I, VMap, /*ModuleLevelChanges=*/true, Returns);
+    }
+  }
+
+  // And aliases
+  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
+       I != E; ++I) {
+    GlobalAlias *GA = cast<GlobalAlias>(VMap[I]);
+    if (const Constant *C = I->getAliasee())
+      GA->setAliasee(MapValue(C, VMap));
+  }
+
+  // And named metadata....
+  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
+         E = M->named_metadata_end(); I != E; ++I) {
+    const NamedMDNode &NMD = *I;
+    NamedMDNode *NewNMD = New->getOrInsertNamedMetadata(NMD.getName());
+    for (unsigned i = 0, e = NMD.getNumOperands(); i != e; ++i)
+      NewNMD->addOperand(MapValue(NMD.getOperand(i), VMap));
+  }
+
+  return New;
+}