1//===- CloneModule.cpp - Clone an entire module ---------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the CloneModule interface which makes a copy of an
11// entire module.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/Transforms/Utils/Cloning.h"
16#include "llvm/Module.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Constant.h"
19#include "llvm/Transforms/Utils/ValueMapper.h"
20using namespace llvm;
21
22/// CloneModule - Return an exact copy of the specified module.  This is not as
23/// easy as it might seem because we have to worry about making copies of global
24/// variables and functions, and making their (initializers and references,
25/// respectively) refer to the right globals.
26///
27Module *llvm::CloneModule(const Module *M) {
28  // Create the value map that maps things from the old module over to the new
29  // module.
30  ValueToValueMapTy VMap;
31  return CloneModule(M, VMap);
32}
33
34Module *llvm::CloneModule(const Module *M, ValueToValueMapTy &VMap) {
35  // First off, we need to create the new module.
36  Module *New = new Module(M->getModuleIdentifier(), M->getContext());
37  New->setDataLayout(M->getDataLayout());
38  New->setTargetTriple(M->getTargetTriple());
39  New->setModuleInlineAsm(M->getModuleInlineAsm());
40
41  // Copy all of the dependent libraries over.
42  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
43    New->addLibrary(*I);
44
45  // Loop over all of the global variables, making corresponding globals in the
46  // new module.  Here we add them to the VMap and to the new Module.  We
47  // don't worry about attributes or initializers, they will come later.
48  //
49  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
50       I != E; ++I) {
51    GlobalVariable *GV = new GlobalVariable(*New,
52                                            I->getType()->getElementType(),
53                                            I->isConstant(), I->getLinkage(),
54                                            (Constant*) 0, I->getName(),
55                                            (GlobalVariable*) 0,
56                                            I->isThreadLocal(),
57                                            I->getType()->getAddressSpace());
58    GV->copyAttributesFrom(I);
59    VMap[I] = GV;
60  }
61
62  // Loop over the functions in the module, making external functions as before
63  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
64    Function *NF =
65      Function::Create(cast<FunctionType>(I->getType()->getElementType()),
66                       I->getLinkage(), I->getName(), New);
67    NF->copyAttributesFrom(I);
68    VMap[I] = NF;
69  }
70
71  // Loop over the aliases in the module
72  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
73       I != E; ++I) {
74    GlobalAlias *GA = new GlobalAlias(I->getType(), I->getLinkage(),
75                                      I->getName(), NULL, New);
76    GA->copyAttributesFrom(I);
77    VMap[I] = GA;
78  }
79
80  // Now that all of the things that global variable initializer can refer to
81  // have been created, loop through and copy the global variable referrers
82  // over...  We also set the attributes on the global now.
83  //
84  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
85       I != E; ++I) {
86    GlobalVariable *GV = cast<GlobalVariable>(VMap[I]);
87    if (I->hasInitializer())
88      GV->setInitializer(MapValue(I->getInitializer(), VMap));
89  }
90
91  // Similarly, copy over function bodies now...
92  //
93  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
94    Function *F = cast<Function>(VMap[I]);
95    if (!I->isDeclaration()) {
96      Function::arg_iterator DestI = F->arg_begin();
97      for (Function::const_arg_iterator J = I->arg_begin(); J != I->arg_end();
98           ++J) {
99        DestI->setName(J->getName());
100        VMap[J] = DestI++;
101      }
102
103      SmallVector<ReturnInst*, 8> Returns;  // Ignore returns cloned.
104      CloneFunctionInto(F, I, VMap, /*ModuleLevelChanges=*/true, Returns);
105    }
106  }
107
108  // And aliases
109  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
110       I != E; ++I) {
111    GlobalAlias *GA = cast<GlobalAlias>(VMap[I]);
112    if (const Constant *C = I->getAliasee())
113      GA->setAliasee(MapValue(C, VMap));
114  }
115
116  // And named metadata....
117  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
118         E = M->named_metadata_end(); I != E; ++I) {
119    const NamedMDNode &NMD = *I;
120    NamedMDNode *NewNMD = New->getOrInsertNamedMetadata(NMD.getName());
121    for (unsigned i = 0, e = NMD.getNumOperands(); i != e; ++i)
122      NewNMD->addOperand(MapValue(NMD.getOperand(i), VMap));
123  }
124
125  return New;
126}
127