llvm-project/llvm/lib/Transforms/Utils/CloneModule.cpp

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//===- 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/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/TypeSymbolTable.h"
#include "llvm/Constant.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.
DenseMap<const Value*, Value*> ValueMap;
return CloneModule(M, ValueMap);
}
Module *llvm::CloneModule(const Module *M,
DenseMap<const Value*, Value*> &ValueMap) {
// 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());
// Copy all of the type symbol table entries over.
const TypeSymbolTable &TST = M->getTypeSymbolTable();
for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
TI != TE; ++TI)
New->addTypeName(TI->first, TI->second);
// Copy all of the dependent libraries over.
for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
New->addLibrary(*I);
// Loop over all of the global variables, making corresponding globals in the
// new module. Here we add them to the ValueMap 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(),
false,
GlobalValue::ExternalLinkage, 0,
I->getName());
GV->setAlignment(I->getAlignment());
ValueMap[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()),
GlobalValue::ExternalLinkage, I->getName(), New);
NF->copyAttributesFrom(I);
ValueMap[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)
ValueMap[I] = new GlobalAlias(I->getType(), GlobalAlias::ExternalLinkage,
I->getName(), NULL, New);
// 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>(ValueMap[I]);
if (I->hasInitializer())
GV->setInitializer(cast<Constant>(MapValue(I->getInitializer(),
ValueMap,
M->getContext())));
GV->setLinkage(I->getLinkage());
GV->setThreadLocal(I->isThreadLocal());
GV->setConstant(I->isConstant());
}
// Similarly, copy over function bodies now...
//
for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
Function *F = cast<Function>(ValueMap[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());
ValueMap[J] = DestI++;
}
std::vector<ReturnInst*> Returns; // Ignore returns cloned...
CloneFunctionInto(F, I, ValueMap, Returns);
}
F->setLinkage(I->getLinkage());
}
// And aliases
for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
I != E; ++I) {
GlobalAlias *GA = cast<GlobalAlias>(ValueMap[I]);
GA->setLinkage(I->getLinkage());
if (const Constant* C = I->getAliasee())
GA->setAliasee(cast<Constant>(MapValue(C, ValueMap, M->getContext())));
}
return New;
}