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"
21 using 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 ///
CloneModule(const Module * M)28 Module *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
CloneModule(const Module * M,ValueToValueMapTy & VMap)35 Module *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
127 extern "C" {
128
LLVMCloneModule(LLVMModuleRef M)129 LLVMModuleRef LLVMCloneModule(LLVMModuleRef M) {
130 return wrap(CloneModule(unwrap(M)));
131 }
132
133 }
134