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

84 lines
3.4 KiB
C++

//===- CloneModule.cpp - Clone an entire module ---------------------------===//
//
// 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/SymbolTable.h"
#include "llvm/Constant.h"
#include "ValueMapper.h"
/// 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 (intializers and references,
/// respectively) refer to the right globals.
///
Module *CloneModule(const Module *M) {
// First off, we need to create the new module...
Module *New = new Module(M->getModuleIdentifier());
New->setEndianness(M->getEndianness());
New->setPointerSize(M->getPointerSize());
// Copy all of the type symbol table entries over...
const SymbolTable &SymTab = M->getSymbolTable();
SymbolTable::const_iterator TypeI = SymTab.find(Type::TypeTy);
if (TypeI != SymTab.end())
for (SymbolTable::VarMap::const_iterator I = TypeI->second.begin(),
E = TypeI->second.end(); I != E; ++I)
New->addTypeName(I->first, cast<Type>(I->second));
// Create the value map that maps things from the old module over to the new
// module.
std::map<const Value*, Value*> ValueMap;
// 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_giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
ValueMap[I] = new GlobalVariable(I->getType()->getElementType(), false,
GlobalValue::ExternalLinkage, 0,
I->getName(), New);
// 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)
ValueMap[I]=new Function(cast<FunctionType>(I->getType()->getElementType()),
GlobalValue::ExternalLinkage, I->getName(), 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_giterator I = M->gbegin(), E = M->gend(); I != E; ++I) {
GlobalVariable *GV = cast<GlobalVariable>(ValueMap[I]);
if (I->hasInitializer())
GV->setInitializer(cast<Constant>(MapValue(I->getInitializer(),
ValueMap)));
GV->setLinkage(I->getLinkage());
}
// 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->isExternal()) {
Function::aiterator DestI = F->abegin();
for (Function::const_aiterator J = I->abegin(); J != I->aend(); ++J) {
DestI->setName(J->getName());
ValueMap[J] = DestI++;
}
std::vector<ReturnInst*> Returns; // Ignore returns cloned...
CloneFunctionInto(F, I, ValueMap, Returns);
}
F->setLinkage(I->getLinkage());
}
return New;
}