#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/ValueMapper.h"
#include <map>
using namespace llvm;
BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB,
ValueToValueMapTy &VMap,
const Twine &NameSuffix, Function *F,
ClonedCodeInfo *CodeInfo) {
BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), "", F);
if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);
bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end();
II != IE; ++II) {
Instruction *NewInst = II->clone();
if (II->hasName())
NewInst->setName(II->getName()+NameSuffix);
NewBB->getInstList().push_back(NewInst);
VMap[II] = NewInst;
hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
if (isa<ConstantInt>(AI->getArraySize()))
hasStaticAllocas = true;
else
hasDynamicAllocas = true;
}
}
if (CodeInfo) {
CodeInfo->ContainsCalls |= hasCalls;
CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
BB != &BB->getParent()->getEntryBlock();
}
return NewBB;
}
void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
ValueToValueMapTy &VMap,
bool ModuleLevelChanges,
SmallVectorImpl<ReturnInst*> &Returns,
const char *NameSuffix, ClonedCodeInfo *CodeInfo,
ValueMapTypeRemapper *TypeMapper,
ValueMaterializer *Materializer) {
assert(NameSuffix && "NameSuffix cannot be null!");
#ifndef NDEBUG
for (Function::const_arg_iterator I = OldFunc->arg_begin(),
E = OldFunc->arg_end(); I != E; ++I)
assert(VMap.count(I) && "No mapping from source argument specified!");
#endif
AttributeSet NewAttrs = NewFunc->getAttributes();
NewFunc->copyAttributesFrom(OldFunc);
NewFunc->setAttributes(NewAttrs);
AttributeSet OldAttrs = OldFunc->getAttributes();
for (const Argument &OldArg : OldFunc->args())
if (Argument *NewArg = dyn_cast<Argument>(VMap[&OldArg])) {
AttributeSet attrs =
OldAttrs.getParamAttributes(OldArg.getArgNo() + 1);
if (attrs.getNumSlots() > 0)
NewArg->addAttr(attrs);
}
NewFunc->setAttributes(
NewFunc->getAttributes()
.addAttributes(NewFunc->getContext(), AttributeSet::ReturnIndex,
OldAttrs.getRetAttributes())
.addAttributes(NewFunc->getContext(), AttributeSet::FunctionIndex,
OldAttrs.getFnAttributes()));
for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
BI != BE; ++BI) {
const BasicBlock &BB = *BI;
BasicBlock *CBB = CloneBasicBlock(&BB, VMap, NameSuffix, NewFunc, CodeInfo);
VMap[&BB] = CBB;
if (BB.hasAddressTaken()) {
Constant *OldBBAddr = BlockAddress::get(const_cast<Function*>(OldFunc),
const_cast<BasicBlock*>(&BB));
VMap[OldBBAddr] = BlockAddress::get(NewFunc, CBB);
}
if (ReturnInst *RI = dyn_cast<ReturnInst>(CBB->getTerminator()))
Returns.push_back(RI);
}
for (Function::iterator BB = cast<BasicBlock>(VMap[OldFunc->begin()]),
BE = NewFunc->end(); BB != BE; ++BB)
for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II)
RemapInstruction(II, VMap,
ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges,
TypeMapper, Materializer);
}
static DISubprogram *FindSubprogram(const Function *F,
DebugInfoFinder &Finder) {
for (DISubprogram *Subprogram : Finder.subprograms()) {
if (Subprogram->describes(F))
return Subprogram;
}
return nullptr;
}
static void AddOperand(DICompileUnit *CU, DISubprogramArray SPs,
Metadata *NewSP) {
SmallVector<Metadata *, 16> NewSPs;
NewSPs.reserve(SPs.size() + 1);
for (auto *SP : SPs)
NewSPs.push_back(SP);
NewSPs.push_back(NewSP);
CU->replaceSubprograms(MDTuple::get(CU->getContext(), NewSPs));
}
static void CloneDebugInfoMetadata(Function *NewFunc, const Function *OldFunc,
ValueToValueMapTy &VMap) {
DebugInfoFinder Finder;
Finder.processModule(*OldFunc->getParent());
const DISubprogram *OldSubprogramMDNode = FindSubprogram(OldFunc, Finder);
if (!OldSubprogramMDNode) return;
VMap[OldFunc] = NewFunc;
auto *NewSubprogram =
cast<DISubprogram>(MapMetadata(OldSubprogramMDNode, VMap));
for (auto *CU : Finder.compile_units()) {
auto Subprograms = CU->getSubprograms();
for (auto *SP : Subprograms) {
if (SP == OldSubprogramMDNode) {
AddOperand(CU, Subprograms, NewSubprogram);
break;
}
}
}
}
Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &VMap,
bool ModuleLevelChanges,
ClonedCodeInfo *CodeInfo) {
std::vector<Type*> ArgTypes;
for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
I != E; ++I)
if (VMap.count(I) == 0) ArgTypes.push_back(I->getType());
FunctionType *FTy = FunctionType::get(F->getFunctionType()->getReturnType(),
ArgTypes, F->getFunctionType()->isVarArg());
Function *NewF = Function::Create(FTy, F->getLinkage(), F->getName());
Function::arg_iterator DestI = NewF->arg_begin();
for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
I != E; ++I)
if (VMap.count(I) == 0) { DestI->setName(I->getName()); VMap[I] = DestI++; }
if (ModuleLevelChanges)
CloneDebugInfoMetadata(NewF, F, VMap);
SmallVector<ReturnInst*, 8> Returns; CloneFunctionInto(NewF, F, VMap, ModuleLevelChanges, Returns, "", CodeInfo);
return NewF;
}
namespace {
struct PruningFunctionCloner {
Function *NewFunc;
const Function *OldFunc;
ValueToValueMapTy &VMap;
bool ModuleLevelChanges;
const char *NameSuffix;
ClonedCodeInfo *CodeInfo;
public:
PruningFunctionCloner(Function *newFunc, const Function *oldFunc,
ValueToValueMapTy &valueMap,
bool moduleLevelChanges,
const char *nameSuffix,
ClonedCodeInfo *codeInfo)
: NewFunc(newFunc), OldFunc(oldFunc),
VMap(valueMap), ModuleLevelChanges(moduleLevelChanges),
NameSuffix(nameSuffix), CodeInfo(codeInfo) {
}
void CloneBlock(const BasicBlock *BB,
std::vector<const BasicBlock*> &ToClone);
};
}
void PruningFunctionCloner::CloneBlock(const BasicBlock *BB,
std::vector<const BasicBlock*> &ToClone){
WeakVH &BBEntry = VMap[BB];
if (BBEntry) return;
BasicBlock *NewBB;
BBEntry = NewBB = BasicBlock::Create(BB->getContext());
if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);
if (BB->hasAddressTaken()) {
Constant *OldBBAddr = BlockAddress::get(const_cast<Function*>(OldFunc),
const_cast<BasicBlock*>(BB));
VMap[OldBBAddr] = BlockAddress::get(NewFunc, NewBB);
}
bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
for (BasicBlock::const_iterator II = BB->begin(), IE = --BB->end();
II != IE; ++II) {
Instruction *NewInst = II->clone();
if (!isa<PHINode>(NewInst)) {
RemapInstruction(NewInst, VMap,
ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
if (Value *V =
SimplifyInstruction(NewInst, BB->getModule()->getDataLayout())) {
if (Value *MappedV = VMap.lookup(V))
V = MappedV;
VMap[II] = V;
delete NewInst;
continue;
}
}
if (II->hasName())
NewInst->setName(II->getName()+NameSuffix);
VMap[II] = NewInst; NewBB->getInstList().push_back(NewInst);
hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
if (isa<ConstantInt>(AI->getArraySize()))
hasStaticAllocas = true;
else
hasDynamicAllocas = true;
}
}
const TerminatorInst *OldTI = BB->getTerminator();
bool TerminatorDone = false;
if (const BranchInst *BI = dyn_cast<BranchInst>(OldTI)) {
if (BI->isConditional()) {
ConstantInt *Cond = dyn_cast<ConstantInt>(BI->getCondition());
if (!Cond) {
Value *V = VMap[BI->getCondition()];
Cond = dyn_cast_or_null<ConstantInt>(V);
}
if (Cond) {
BasicBlock *Dest = BI->getSuccessor(!Cond->getZExtValue());
VMap[OldTI] = BranchInst::Create(Dest, NewBB);
ToClone.push_back(Dest);
TerminatorDone = true;
}
}
} else if (const SwitchInst *SI = dyn_cast<SwitchInst>(OldTI)) {
ConstantInt *Cond = dyn_cast<ConstantInt>(SI->getCondition());
if (!Cond) { Value *V = VMap[SI->getCondition()];
Cond = dyn_cast_or_null<ConstantInt>(V);
}
if (Cond) { SwitchInst::ConstCaseIt Case = SI->findCaseValue(Cond);
BasicBlock *Dest = const_cast<BasicBlock*>(Case.getCaseSuccessor());
VMap[OldTI] = BranchInst::Create(Dest, NewBB);
ToClone.push_back(Dest);
TerminatorDone = true;
}
}
if (!TerminatorDone) {
Instruction *NewInst = OldTI->clone();
if (OldTI->hasName())
NewInst->setName(OldTI->getName()+NameSuffix);
NewBB->getInstList().push_back(NewInst);
VMap[OldTI] = NewInst;
const TerminatorInst *TI = BB->getTerminator();
for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
ToClone.push_back(TI->getSuccessor(i));
}
if (CodeInfo) {
CodeInfo->ContainsCalls |= hasCalls;
CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
BB != &BB->getParent()->front();
}
}
void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
ValueToValueMapTy &VMap,
bool ModuleLevelChanges,
SmallVectorImpl<ReturnInst*> &Returns,
const char *NameSuffix,
ClonedCodeInfo *CodeInfo,
Instruction *TheCall) {
assert(NameSuffix && "NameSuffix cannot be null!");
#ifndef NDEBUG
for (Function::const_arg_iterator II = OldFunc->arg_begin(),
E = OldFunc->arg_end(); II != E; ++II)
assert(VMap.count(II) && "No mapping from source argument specified!");
#endif
PruningFunctionCloner PFC(NewFunc, OldFunc, VMap, ModuleLevelChanges,
NameSuffix, CodeInfo);
std::vector<const BasicBlock*> CloneWorklist;
CloneWorklist.push_back(&OldFunc->getEntryBlock());
while (!CloneWorklist.empty()) {
const BasicBlock *BB = CloneWorklist.back();
CloneWorklist.pop_back();
PFC.CloneBlock(BB, CloneWorklist);
}
SmallVector<const PHINode*, 16> PHIToResolve;
for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
BI != BE; ++BI) {
Value *V = VMap[BI];
BasicBlock *NewBB = cast_or_null<BasicBlock>(V);
if (!NewBB) continue;
NewFunc->getBasicBlockList().push_back(NewBB);
for (BasicBlock::const_iterator I = BI->begin(), E = BI->end(); I != E; ++I)
if (const PHINode *PN = dyn_cast<PHINode>(I))
PHIToResolve.push_back(PN);
else
break;
RemapInstruction(NewBB->getTerminator(), VMap,
ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
}
for (unsigned phino = 0, e = PHIToResolve.size(); phino != e; ) {
const PHINode *OPN = PHIToResolve[phino];
unsigned NumPreds = OPN->getNumIncomingValues();
const BasicBlock *OldBB = OPN->getParent();
BasicBlock *NewBB = cast<BasicBlock>(VMap[OldBB]);
for (; phino != PHIToResolve.size() &&
PHIToResolve[phino]->getParent() == OldBB; ++phino) {
OPN = PHIToResolve[phino];
PHINode *PN = cast<PHINode>(VMap[OPN]);
for (unsigned pred = 0, e = NumPreds; pred != e; ++pred) {
Value *V = VMap[PN->getIncomingBlock(pred)];
if (BasicBlock *MappedBlock = cast_or_null<BasicBlock>(V)) {
Value *InVal = MapValue(PN->getIncomingValue(pred),
VMap,
ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
assert(InVal && "Unknown input value?");
PN->setIncomingValue(pred, InVal);
PN->setIncomingBlock(pred, MappedBlock);
} else {
PN->removeIncomingValue(pred, false);
--pred, --e; }
}
}
PHINode *PN = cast<PHINode>(NewBB->begin());
NumPreds = std::distance(pred_begin(NewBB), pred_end(NewBB));
if (NumPreds != PN->getNumIncomingValues()) {
assert(NumPreds < PN->getNumIncomingValues());
std::map<BasicBlock*, unsigned> PredCount;
for (pred_iterator PI = pred_begin(NewBB), E = pred_end(NewBB);
PI != E; ++PI)
--PredCount[*PI];
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
++PredCount[PN->getIncomingBlock(i)];
BasicBlock::iterator I = NewBB->begin();
for (; (PN = dyn_cast<PHINode>(I)); ++I) {
for (std::map<BasicBlock*, unsigned>::iterator PCI =PredCount.begin(),
E = PredCount.end(); PCI != E; ++PCI) {
BasicBlock *Pred = PCI->first;
for (unsigned NumToRemove = PCI->second; NumToRemove; --NumToRemove)
PN->removeIncomingValue(Pred, false);
}
}
}
PN = cast<PHINode>(NewBB->begin());
if (PN->getNumIncomingValues() == 0) {
BasicBlock::iterator I = NewBB->begin();
BasicBlock::const_iterator OldI = OldBB->begin();
while ((PN = dyn_cast<PHINode>(I++))) {
Value *NV = UndefValue::get(PN->getType());
PN->replaceAllUsesWith(NV);
assert(VMap[OldI] == PN && "VMap mismatch");
VMap[OldI] = NV;
PN->eraseFromParent();
++OldI;
}
}
}
for (unsigned Idx = 0, Size = PHIToResolve.size(); Idx != Size; ++Idx)
if (PHINode *PN = dyn_cast<PHINode>(VMap[PHIToResolve[Idx]]))
recursivelySimplifyInstruction(PN);
Function::iterator Begin = cast<BasicBlock>(VMap[&OldFunc->getEntryBlock()]);
Function::iterator I = Begin;
while (I != NewFunc->end()) {
if (I != Begin && (pred_begin(I) == pred_end(I) ||
I->getSinglePredecessor() == I)) {
BasicBlock *DeadBB = I++;
DeleteDeadBlock(DeadBB);
continue;
}
ConstantFoldTerminator(I);
BranchInst *BI = dyn_cast<BranchInst>(I->getTerminator());
if (!BI || BI->isConditional()) { ++I; continue; }
BasicBlock *Dest = BI->getSuccessor(0);
if (!Dest->getSinglePredecessor()) {
++I; continue;
}
assert(!isa<PHINode>(Dest->begin()));
BI->eraseFromParent();
Dest->replaceAllUsesWith(I);
I->getInstList().splice(I->end(), Dest->getInstList());
Dest->eraseFromParent();
}
for (Function::iterator I = cast<BasicBlock>(VMap[&OldFunc->getEntryBlock()]),
E = NewFunc->end();
I != E; ++I)
if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator()))
Returns.push_back(RI);
}