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/IR/Constant.h"
17#include "llvm/IR/DerivedTypes.h"
18#include "llvm/IR/Module.h"
19#include "llvm/Transforms/Utils/ValueMapper.h"
20#include "llvm-c/Core.h"
21using namespace llvm;
22
23/// CloneModule - Return an exact copy of the specified module.  This is not as
24/// easy as it might seem because we have to worry about making copies of global
25/// variables and functions, and making their (initializers and references,
26/// respectively) refer to the right globals.
27///
28Module *llvm::CloneModule(const Module *M) {
29  // Create the value map that maps things from the old module over to the new
30  // module.
31  ValueToValueMapTy VMap;
32  return CloneModule(M, VMap);
33}
34
35Module *llvm::CloneModule(const Module *M, ValueToValueMapTy &VMap) {
36  // First off, we need to create the new module.
37  Module *New = new Module(M->getModuleIdentifier(), M->getContext());
38  New->setDataLayout(M->getDataLayout());
39  New->setTargetTriple(M->getTargetTriple());
40  New->setModuleInlineAsm(M->getModuleInlineAsm());
41
42  // Loop over all of the global variables, making corresponding globals in the
43  // new module.  Here we add them to the VMap and to the new Module.  We
44  // don't worry about attributes or initializers, they will come later.
45  //
46  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
47       I != E; ++I) {
48    GlobalVariable *GV = new GlobalVariable(*New,
49                                            I->getType()->getElementType(),
50                                            I->isConstant(), I->getLinkage(),
51                                            (Constant*) nullptr, I->getName(),
52                                            (GlobalVariable*) nullptr,
53                                            I->getThreadLocalMode(),
54                                            I->getType()->getAddressSpace());
55    GV->copyAttributesFrom(I);
56    VMap[I] = GV;
57  }
58
59  // Loop over the functions in the module, making external functions as before
60  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
61    Function *NF =
62      Function::Create(cast<FunctionType>(I->getType()->getElementType()),
63                       I->getLinkage(), I->getName(), New);
64    NF->copyAttributesFrom(I);
65    VMap[I] = NF;
66  }
67
68  // Loop over the aliases in the module
69  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
70       I != E; ++I) {
71    auto *PTy = cast<PointerType>(I->getType());
72    auto *GA =
73        GlobalAlias::create(PTy->getElementType(), PTy->getAddressSpace(),
74                            I->getLinkage(), I->getName(), New);
75    GA->copyAttributesFrom(I);
76    VMap[I] = GA;
77  }
78
79  // Now that all of the things that global variable initializer can refer to
80  // have been created, loop through and copy the global variable referrers
81  // over...  We also set the attributes on the global now.
82  //
83  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
84       I != E; ++I) {
85    GlobalVariable *GV = cast<GlobalVariable>(VMap[I]);
86    if (I->hasInitializer())
87      GV->setInitializer(MapValue(I->getInitializer(), VMap));
88  }
89
90  // Similarly, copy over function bodies now...
91  //
92  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
93    Function *F = cast<Function>(VMap[I]);
94    if (!I->isDeclaration()) {
95      Function::arg_iterator DestI = F->arg_begin();
96      for (Function::const_arg_iterator J = I->arg_begin(); J != I->arg_end();
97           ++J) {
98        DestI->setName(J->getName());
99        VMap[J] = DestI++;
100      }
101
102      SmallVector<ReturnInst*, 8> Returns;  // Ignore returns cloned.
103      CloneFunctionInto(F, I, VMap, /*ModuleLevelChanges=*/true, Returns);
104    }
105  }
106
107  // And aliases
108  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
109       I != E; ++I) {
110    GlobalAlias *GA = cast<GlobalAlias>(VMap[I]);
111    if (const Constant *C = I->getAliasee())
112      GA->setAliasee(MapValue(C, VMap));
113  }
114
115  // And named metadata....
116  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
117         E = M->named_metadata_end(); I != E; ++I) {
118    const NamedMDNode &NMD = *I;
119    NamedMDNode *NewNMD = New->getOrInsertNamedMetadata(NMD.getName());
120    for (unsigned i = 0, e = NMD.getNumOperands(); i != e; ++i)
121      NewNMD->addOperand(MapMetadata(NMD.getOperand(i), VMap));
122  }
123
124  return New;
125}
126
127extern "C" {
128
129LLVMModuleRef LLVMCloneModule(LLVMModuleRef M) {
130  return wrap(CloneModule(unwrap(M)));
131}
132
133}
134