/// SplitLandingPadPreds - The landing pad needs to be extracted with the invoke
/// instruction. The critical edge breaker will refuse to break critical edges
/// to a landing pad. So do them here. After this method runs, all landing pads
/// should have only one predecessor.
void BlockExtractorPass::SplitLandingPadPreds(Function *F) {
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
InvokeInst *II = dyn_cast<InvokeInst>(I);
if (!II) continue;
BasicBlock *Parent = II->getParent();
BasicBlock *LPad = II->getUnwindDest();
// Look through the landing pad's predecessors. If one of them ends in an
// 'invoke', then we want to split the landing pad.
bool Split = false;
for (pred_iterator
PI = pred_begin(LPad), PE = pred_end(LPad); PI != PE; ++PI) {
BasicBlock *BB = *PI;
if (BB->isLandingPad() && BB != Parent &&
isa<InvokeInst>(Parent->getTerminator())) {
Split = true;
break;
}
}
if (!Split) continue;
SmallVector<BasicBlock*, 2> NewBBs;
SplitLandingPadPredecessors(LPad, Parent, ".1", ".2", NewBBs);
}
}
// visitCallInst - This converts all LLVM call instructions into invoke
// instructions. The except part of the invoke goes to the "LongJmpBlkPre"
// that grabs the exception and proceeds to determine if it's a longjmp
// exception or not.
void LowerSetJmp::visitCallInst(CallInst& CI)
{
if (CI.getCalledFunction())
if (!IsTransformableFunction(CI.getCalledFunction()->getName()) ||
CI.getCalledFunction()->isIntrinsic()) return;
BasicBlock* OldBB = CI.getParent();
// If not reachable from a setjmp call, don't transform.
if (!DFSBlocks.count(OldBB)) return;
BasicBlock* NewBB = OldBB->splitBasicBlock(CI);
assert(NewBB && "Couldn't split BB of \"call\" instruction!!");
DFSBlocks.insert(NewBB);
NewBB->setName("Call2Invoke");
Function* Func = OldBB->getParent();
// Construct the new "invoke" instruction.
TerminatorInst* Term = OldBB->getTerminator();
std::vector<Value*> Params(CI.op_begin() + 1, CI.op_end());
InvokeInst* II =
InvokeInst::Create(CI.getCalledValue(), NewBB, PrelimBBMap[Func],
Params.begin(), Params.end(), CI.getName(), Term);
II->setCallingConv(CI.getCallingConv());
II->setParamAttrs(CI.getParamAttrs());
// Replace the old call inst with the invoke inst and remove the call.
CI.replaceAllUsesWith(II);
CI.getParent()->getInstList().erase(&CI);
// The old terminator is useless now that we have the invoke inst.
Term->getParent()->getInstList().erase(Term);
++CallsTransformed;
}
void Preparer::expandCallSite(CallSite CS) {
if (!CS.getCalledFunction()) return;
Function *F = CS.getCalledFunction();
if (!F->isVarArg()) return;
vector<Value *> Args;
for (CallSite::arg_iterator ArgI = CS.arg_begin();
ArgI != CS.arg_end(); ArgI++) {
Args.push_back(*ArgI);
}
Args.push_back(ConstantInt::get(
IntegerType::get(CS.getInstruction()->getContext(), 8), 0));
string InstName = "";
if (CS.getInstruction()->getName() != "")
InstName = CS.getInstruction()->getName().str() + ".padded";
if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction())) {
CallInst *NewCI = CallInst::Create(F, Args, InstName, CI);
NewCI->setAttributes(CI->getAttributes());
CI->replaceAllUsesWith(NewCI);
CI->eraseFromParent();
} else if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) {
InvokeInst *NewII = InvokeInst::Create(F,
II->getNormalDest(), II->getUnwindDest(), Args, InstName, II);
NewII->setAttributes(II->getAttributes());
II->replaceAllUsesWith(NewII);
II->eraseFromParent();
}
}
/// Extracts the landing pads to make sure all of them have only one
/// predecessor.
void BlockExtractor::splitLandingPadPreds(Function &F) {
for (BasicBlock &BB : F) {
for (Instruction &I : BB) {
if (!isa<InvokeInst>(&I))
continue;
InvokeInst *II = cast<InvokeInst>(&I);
BasicBlock *Parent = II->getParent();
BasicBlock *LPad = II->getUnwindDest();
// Look through the landing pad's predecessors. If one of them ends in an
// 'invoke', then we want to split the landing pad.
bool Split = false;
for (auto PredBB : predecessors(LPad)) {
if (PredBB->isLandingPad() && PredBB != Parent &&
isa<InvokeInst>(Parent->getTerminator())) {
Split = true;
break;
}
}
if (!Split)
continue;
SmallVector<BasicBlock *, 2> NewBBs;
SplitLandingPadPredecessors(LPad, Parent, ".1", ".2", NewBBs);
}
}
}
/*
* Replace called function of a given call site.
*/
void DeadStoreEliminationPass::replaceCallingInst(Instruction* caller,
Function* fn) {
if (isa<CallInst>(caller)) {
CallInst *callInst = dyn_cast<CallInst>(caller);
callInst->setCalledFunction(fn);
} else if (isa<InvokeInst>(caller)) {
InvokeInst *invokeInst = dyn_cast<InvokeInst>(caller);
invokeInst->setCalledFunction(fn);
}
}
/// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
/// an invoke, we have to turn all of the calls that can throw into
/// invokes. This function analyze BB to see if there are any calls, and if so,
/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
/// nodes in that block with the values specified in InvokeDestPHIValues.
///
/// Returns true to indicate that the next block should be skipped.
static bool HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
InvokeInliningInfo &Invoke) {
LandingPadInst *LPI = Invoke.getLandingPadInst();
for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
Instruction *I = BBI++;
if (LandingPadInst *L = dyn_cast<LandingPadInst>(I)) {
unsigned NumClauses = LPI->getNumClauses();
L->reserveClauses(NumClauses);
for (unsigned i = 0; i != NumClauses; ++i)
L->addClause(LPI->getClause(i));
}
// We only need to check for function calls: inlined invoke
// instructions require no special handling.
CallInst *CI = dyn_cast<CallInst>(I);
// If this call cannot unwind, don't convert it to an invoke.
// Inline asm calls cannot throw.
if (!CI || CI->doesNotThrow() || isa<InlineAsm>(CI->getCalledValue()))
continue;
// Convert this function call into an invoke instruction. First, split the
// basic block.
BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
// Delete the unconditional branch inserted by splitBasicBlock
BB->getInstList().pop_back();
// Create the new invoke instruction.
ImmutableCallSite CS(CI);
SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end());
InvokeInst *II = InvokeInst::Create(CI->getCalledValue(), Split,
Invoke.getOuterResumeDest(),
InvokeArgs, CI->getName(), BB);
II->setCallingConv(CI->getCallingConv());
II->setAttributes(CI->getAttributes());
// Make sure that anything using the call now uses the invoke! This also
// updates the CallGraph if present, because it uses a WeakVH.
CI->replaceAllUsesWith(II);
// Delete the original call
Split->getInstList().pop_front();
// Update any PHI nodes in the exceptional block to indicate that there is
// now a new entry in them.
Invoke.addIncomingPHIValuesFor(BB);
return false;
}
return false;
}
void DeadStoreEliminationPass::runOverwrittenDeadStoreAnalysisOnFn(Function &F) {
MDA = &getAnalysis<MemoryDependenceAnalysis>(F);
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
for (BasicBlock::iterator I = BB->begin(), IE = BB->end(); I != IE; ++I) {
Instruction *inst = I;
if (StoreInst* SI = dyn_cast<StoreInst>(inst)) {
Value *ptr = SI->getPointerOperand();
MemDepResult mdr = MDA->getDependency(inst);
Instruction *depInst = mdr.getInst();
if (depInst && (isa<CallInst>(depInst) || isa<InvokeInst>(depInst))) {
Function *calledFn;
if (CallInst* CI = dyn_cast<CallInst>(depInst)) {
calledFn = CI->getCalledFunction();
} else {
InvokeInst *II = dyn_cast<InvokeInst>(depInst);
calledFn = II->getCalledFunction();
}
if (!fnThatStoreOnArgs.count(calledFn)) continue;
CallSite CS(depInst);
CallSite::arg_iterator actualArgIter = CS.arg_begin();
Function::arg_iterator formalArgIter = calledFn->arg_begin();
int size = calledFn->arg_size();
std::set<Value*> storedArgs = fnThatStoreOnArgs[calledFn];
for (int i = 0; i < size; ++i, ++actualArgIter, ++formalArgIter) {
Value *formalArg = formalArgIter;
Value *actualArg = *actualArgIter;
if (ptr == actualArg && storedArgs.count(formalArg)) {
int64_t InstWriteOffset, DepWriteOffset;
DEBUG(errs() << " Verifying if store is completely overwritten.\n");
AliasAnalysis::Location Loc(ptr, getPointerSize(ptr, *AA), NULL);
AliasAnalysis::Location DepLoc(actualArg, getPointerSize(actualArg, *AA), NULL);
OverwriteResult OR = isOverwrite(Loc, DepLoc, *AA, DepWriteOffset, InstWriteOffset);
if (OR == OverwriteComplete) {
DEBUG(errs() << " Store on " << formalArg->getName() << " will be removed with cloning\n");
deadArguments[depInst].insert(formalArg);
}
}
}
if (deadArguments.count(depInst)) {
fn2Clone[calledFn].push_back(depInst);
}
}
}
}
}
}
CallSite GNUstep::IMPCacher::SplitSend(CallSite msgSend)
{
BasicBlock *lookupBB = msgSend->getParent();
Function *F = lookupBB->getParent();
Module *M = F->getParent();
Function *send = M->getFunction("objc_msgSend");
Function *send_stret = M->getFunction("objc_msgSend_stret");
Function *send_fpret = M->getFunction("objc_msgSend_fpret");
Value *self;
Value *cmd;
int selfIndex = 0;
if ((msgSend.getCalledFunction() == send) ||
(msgSend.getCalledFunction() == send_fpret)) {
self = msgSend.getArgument(0);
cmd = msgSend.getArgument(1);
} else if (msgSend.getCalledFunction() == send_stret) {
selfIndex = 1;
self = msgSend.getArgument(1);
cmd = msgSend.getArgument(2);
} else {
abort();
return CallSite();
}
CGBuilder B(&F->getEntryBlock(), F->getEntryBlock().begin());
Value *selfPtr = B.CreateAlloca(self->getType());
B.SetInsertPoint(msgSend.getInstruction());
B.CreateStore(self, selfPtr, true);
LLVMType *impTy = msgSend.getCalledValue()->getType();
LLVMType *slotTy = PointerType::getUnqual(StructType::get(PtrTy, PtrTy, PtrTy,
IntTy, impTy, PtrTy, NULL));
Value *slot;
Constant *lookupFn = M->getOrInsertFunction("objc_msg_lookup_sender",
slotTy, selfPtr->getType(), cmd->getType(), PtrTy, NULL);
if (msgSend.isCall()) {
slot = B.CreateCall3(lookupFn, selfPtr, cmd, Constant::getNullValue(PtrTy));
} else {
InvokeInst *inv = cast<InvokeInst>(msgSend.getInstruction());
BasicBlock *callBB = SplitBlock(lookupBB, msgSend.getInstruction(), Owner);
removeTerminator(lookupBB);
B.SetInsertPoint(lookupBB);
slot = B.CreateInvoke3(lookupFn, callBB, inv->getUnwindDest(), selfPtr, cmd,
Constant::getNullValue(PtrTy));
addPredecssor(inv->getUnwindDest(), msgSend->getParent(), lookupBB);
B.SetInsertPoint(msgSend.getInstruction());
}
Value *imp = B.CreateLoad(B.CreateStructGEP(slot, 4));
msgSend.setArgument(selfIndex, B.CreateLoad(selfPtr, true));
msgSend.setCalledFunction(imp);
return CallSite(slot);
}
/// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
/// an invoke, we have to turn all of the calls that can throw into
/// invokes. This function analyze BB to see if there are any calls, and if so,
/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
/// nodes in that block with the values specified in InvokeDestPHIValues.
///
static void HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
BasicBlock *InvokeDest,
const SmallVectorImpl<Value*> &InvokeDestPHIValues) {
for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
Instruction *I = BBI++;
// We only need to check for function calls: inlined invoke
// instructions require no special handling.
CallInst *CI = dyn_cast<CallInst>(I);
if (CI == 0) continue;
// If this call cannot unwind, don't convert it to an invoke.
if (CI->doesNotThrow())
continue;
// Convert this function call into an invoke instruction.
// First, split the basic block.
BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
// Next, create the new invoke instruction, inserting it at the end
// of the old basic block.
ImmutableCallSite CS(CI);
SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end());
InvokeInst *II =
InvokeInst::Create(CI->getCalledValue(), Split, InvokeDest,
InvokeArgs.begin(), InvokeArgs.end(),
CI->getName(), BB->getTerminator());
II->setCallingConv(CI->getCallingConv());
II->setAttributes(CI->getAttributes());
// Make sure that anything using the call now uses the invoke! This also
// updates the CallGraph if present, because it uses a WeakVH.
CI->replaceAllUsesWith(II);
// Delete the unconditional branch inserted by splitBasicBlock
BB->getInstList().pop_back();
Split->getInstList().pop_front(); // Delete the original call
// Update any PHI nodes in the exceptional block to indicate that
// there is now a new entry in them.
unsigned i = 0;
for (BasicBlock::iterator I = InvokeDest->begin();
isa<PHINode>(I); ++I, ++i)
cast<PHINode>(I)->addIncoming(InvokeDestPHIValues[i], BB);
// This basic block is now complete, the caller will continue scanning the
// next one.
return;
}
}
// visitInvokeInst - Converting the "invoke" instruction is fairly
// straight-forward. The old exception part is replaced by a query asking
// if this is a longjmp exception. If it is, then it goes to the longjmp
// exception blocks. Otherwise, control is passed the old exception.
void LowerSetJmp::visitInvokeInst(InvokeInst& II)
{
if (II.getCalledFunction())
if (!IsTransformableFunction(II.getCalledFunction()->getName()) ||
II.getCalledFunction()->isIntrinsic()) return;
BasicBlock* BB = II.getParent();
// If not reachable from a setjmp call, don't transform.
if (!DFSBlocks.count(BB)) return;
BasicBlock* ExceptBB = II.getUnwindDest();
Function* Func = BB->getParent();
BasicBlock* NewExceptBB = BasicBlock::Create(II.getContext(),
"InvokeExcept", Func);
// If this is a longjmp exception, then branch to the preliminary BB of
// the longjmp exception handling. Otherwise, go to the old exception.
CallInst* IsLJExcept = CallInst::Create(IsLJException, "IsLJExcept",
NewExceptBB);
BranchInst::Create(PrelimBBMap[Func], ExceptBB, IsLJExcept, NewExceptBB);
II.setUnwindDest(NewExceptBB);
++InvokesTransformed;
}
extern "C" void LLVMRustMarkAllFunctionsNounwind(LLVMModuleRef M) {
for (Module::iterator GV = unwrap(M)->begin(), E = unwrap(M)->end(); GV != E;
++GV) {
GV->setDoesNotThrow();
Function *F = dyn_cast<Function>(GV);
if (F == nullptr)
continue;
for (Function::iterator B = F->begin(), BE = F->end(); B != BE; ++B) {
for (BasicBlock::iterator I = B->begin(), IE = B->end(); I != IE; ++I) {
if (isa<InvokeInst>(I)) {
InvokeInst *CI = cast<InvokeInst>(I);
CI->setDoesNotThrow();
}
}
}
}
}
void MemoryInstrumenter::instrumentPointerInstruction(Instruction *I) {
BasicBlock::iterator Loc;
if (isa<PHINode>(I)) {
// Cannot insert hooks right after a PHI, because PHINodes have to be
// grouped together.
Loc = I->getParent()->getFirstNonPHI();
} else if (!I->isTerminator()) {
Loc = I;
++Loc;
} else {
assert(isa<InvokeInst>(I));
InvokeInst *II = cast<InvokeInst>(I);
BasicBlock *NormalDest = II->getNormalDest();
// It's not always OK to insert HookTopLevel simply at the beginning of the
// normal destination, because the normal destionation may be shared by
// multiple InvokeInsts. In that case, we will create a critical edge block,
// and add the HookTopLevel over there.
if (NormalDest->getUniquePredecessor()) {
Loc = NormalDest->getFirstNonPHI();
} else {
BasicBlock *CritEdge = BasicBlock::Create(I->getContext(),
"crit_edge",
I->getParent()->getParent());
Loc = BranchInst::Create(NormalDest, CritEdge);
// Now that CritEdge becomes the new predecessor of NormalDest, replace
// all phi uses of I->getParent() with CritEdge.
for (auto J = NormalDest->begin();
NormalDest->getFirstNonPHI() != J;
++J) {
PHINode *Phi = cast<PHINode>(J);
int i;
while ((i = Phi->getBasicBlockIndex(I->getParent())) >= 0)
Phi->setIncomingBlock(i, CritEdge);
}
II->setNormalDest(CritEdge);
}
}
if (LoadInst *LI = dyn_cast<LoadInst>(I))
instrumentPointer(I, LI->getPointerOperand(), Loc);
else
instrumentPointer(I, NULL, Loc);
}
void
visitInvokeInst(InvokeInst &I)
{
Function* target = I.getCalledFunction();
if (target == NULL) {
anyUnknown = true;
return;
}
if (isInternal(target)) {
if (used != NULL) used->push(target);
} else {
interface->call(target->getName(), arg_begin(I), arg_end(I));
}
this->visitInstruction(I);
}
void Preparer::expandCallSite(CallSite CS) {
// Skip the callsites that are not calling a va function.
Value *Callee = CS.getCalledValue();
FunctionType *CalleeType = cast<FunctionType>(
cast<PointerType>(Callee->getType())->getElementType());
if (!CalleeType->isVarArg()) {
return;
}
vector<Value *> Args;
for (CallSite::arg_iterator ArgI = CS.arg_begin();
ArgI != CS.arg_end(); ArgI++) {
Args.push_back(*ArgI);
}
Args.push_back(ConstantInt::get(
IntegerType::get(CS.getInstruction()->getContext(), 8), 0));
string InstName = "";
if (CS.getInstruction()->getName() != "")
InstName = CS.getInstruction()->getName().str() + ".padded";
if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction())) {
CallInst *NewCI = CallInst::Create(Callee, Args, InstName, CI);
NewCI->setAttributes(CI->getAttributes());
CI->replaceAllUsesWith(NewCI);
CI->eraseFromParent();
} else if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) {
InvokeInst *NewII = InvokeInst::Create(Callee,
II->getNormalDest(),
II->getUnwindDest(),
Args,
InstName,
II);
NewII->setAttributes(II->getAttributes());
II->replaceAllUsesWith(NewII);
II->eraseFromParent();
}
}
// First thing we need to do is scan the whole function for values that are
// live across unwind edges. Each value that is live across an unwind edge
// we spill into a stack location, guaranteeing that there is nothing live
// across the unwind edge. This process also splits all critical edges
// coming out of invoke's.
void LowerInvoke::
splitLiveRangesLiveAcrossInvokes(std::vector<InvokeInst*> &Invokes) {
// First step, split all critical edges from invoke instructions.
for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
InvokeInst *II = Invokes[i];
SplitCriticalEdge(II, 0, this);
SplitCriticalEdge(II, 1, this);
assert(!isa<PHINode>(II->getNormalDest()) &&
!isa<PHINode>(II->getUnwindDest()) &&
"critical edge splitting left single entry phi nodes?");
}
Function *F = Invokes.back()->getParent()->getParent();
// To avoid having to handle incoming arguments specially, we lower each arg
// to a copy instruction in the entry block. This ensures that the argument
// value itself cannot be live across the entry block.
BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin();
while (isa<AllocaInst>(AfterAllocaInsertPt) &&
isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsertPt)->getArraySize()))
++AfterAllocaInsertPt;
for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
AI != E; ++AI) {
// This is always a no-op cast because we're casting AI to AI->getType() so
// src and destination types are identical. BitCast is the only possibility.
CastInst *NC = new BitCastInst(
AI, AI->getType(), AI->getName()+".tmp", AfterAllocaInsertPt);
AI->replaceAllUsesWith(NC);
// Normally its is forbidden to replace a CastInst's operand because it
// could cause the opcode to reflect an illegal conversion. However, we're
// replacing it here with the same value it was constructed with to simply
// make NC its user.
NC->setOperand(0, AI);
}
// Finally, scan the code looking for instructions with bad live ranges.
for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E; ++II) {
// Ignore obvious cases we don't have to handle. In particular, most
// instructions either have no uses or only have a single use inside the
// current block. Ignore them quickly.
Instruction *Inst = II;
if (Inst->use_empty()) continue;
if (Inst->hasOneUse() &&
cast<Instruction>(Inst->use_back())->getParent() == BB &&
!isa<PHINode>(Inst->use_back())) continue;
// If this is an alloca in the entry block, it's not a real register
// value.
if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst))
if (isa<ConstantInt>(AI->getArraySize()) && BB == F->begin())
continue;
// Avoid iterator invalidation by copying users to a temporary vector.
std::vector<Instruction*> Users;
for (Value::use_iterator UI = Inst->use_begin(), E = Inst->use_end();
UI != E; ++UI) {
Instruction *User = cast<Instruction>(*UI);
if (User->getParent() != BB || isa<PHINode>(User))
Users.push_back(User);
}
// Scan all of the uses and see if the live range is live across an unwind
// edge. If we find a use live across an invoke edge, create an alloca
// and spill the value.
std::set<InvokeInst*> InvokesWithStoreInserted;
// Find all of the blocks that this value is live in.
std::set<BasicBlock*> LiveBBs;
LiveBBs.insert(Inst->getParent());
while (!Users.empty()) {
Instruction *U = Users.back();
Users.pop_back();
if (!isa<PHINode>(U)) {
MarkBlocksLiveIn(U->getParent(), LiveBBs);
} else {
// Uses for a PHI node occur in their predecessor block.
PHINode *PN = cast<PHINode>(U);
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
if (PN->getIncomingValue(i) == Inst)
MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs);
}
}
// Now that we know all of the blocks that this thing is live in, see if
// it includes any of the unwind locations.
bool NeedsSpill = false;
for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) {
NeedsSpill = true;
}
}
// If we decided we need a spill, do it.
if (NeedsSpill) {
++NumSpilled;
DemoteRegToStack(*Inst, true);
}
}
}
/// HandleInlinedInvoke - If we inlined an invoke site, we need to convert calls
/// in the body of the inlined function into invokes and turn unwind
/// instructions into branches to the invoke unwind dest.
///
/// II is the invoke instruction being inlined. FirstNewBlock is the first
/// block of the inlined code (the last block is the end of the function),
/// and InlineCodeInfo is information about the code that got inlined.
static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
ClonedCodeInfo &InlinedCodeInfo) {
BasicBlock *InvokeDest = II->getUnwindDest();
std::vector<Value*> InvokeDestPHIValues;
// If there are PHI nodes in the unwind destination block, we need to
// keep track of which values came into them from this invoke, then remove
// the entry for this block.
BasicBlock *InvokeBlock = II->getParent();
for (BasicBlock::iterator I = InvokeDest->begin(); isa<PHINode>(I); ++I) {
PHINode *PN = cast<PHINode>(I);
// Save the value to use for this edge.
InvokeDestPHIValues.push_back(PN->getIncomingValueForBlock(InvokeBlock));
}
Function *Caller = FirstNewBlock->getParent();
// The inlined code is currently at the end of the function, scan from the
// start of the inlined code to its end, checking for stuff we need to
// rewrite.
if (InlinedCodeInfo.ContainsCalls || InlinedCodeInfo.ContainsUnwinds) {
for (Function::iterator BB = FirstNewBlock, E = Caller->end();
BB != E; ++BB) {
if (InlinedCodeInfo.ContainsCalls) {
for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ){
Instruction *I = BBI++;
// We only need to check for function calls: inlined invoke
// instructions require no special handling.
if (!isa<CallInst>(I)) continue;
CallInst *CI = cast<CallInst>(I);
// If this call cannot unwind, don't convert it to an invoke.
if (CI->doesNotThrow())
continue;
// Convert this function call into an invoke instruction.
// First, split the basic block.
BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
// Next, create the new invoke instruction, inserting it at the end
// of the old basic block.
SmallVector<Value*, 8> InvokeArgs(CI->op_begin()+1, CI->op_end());
InvokeInst *II =
InvokeInst::Create(CI->getCalledValue(), Split, InvokeDest,
InvokeArgs.begin(), InvokeArgs.end(),
CI->getName(), BB->getTerminator());
II->setCallingConv(CI->getCallingConv());
II->setAttributes(CI->getAttributes());
// Make sure that anything using the call now uses the invoke!
CI->replaceAllUsesWith(II);
// Delete the unconditional branch inserted by splitBasicBlock
BB->getInstList().pop_back();
Split->getInstList().pop_front(); // Delete the original call
// Update any PHI nodes in the exceptional block to indicate that
// there is now a new entry in them.
unsigned i = 0;
for (BasicBlock::iterator I = InvokeDest->begin();
isa<PHINode>(I); ++I, ++i) {
PHINode *PN = cast<PHINode>(I);
PN->addIncoming(InvokeDestPHIValues[i], BB);
}
// This basic block is now complete, start scanning the next one.
break;
}
}
if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
// An UnwindInst requires special handling when it gets inlined into an
// invoke site. Once this happens, we know that the unwind would cause
// a control transfer to the invoke exception destination, so we can
// transform it into a direct branch to the exception destination.
BranchInst::Create(InvokeDest, UI);
// Delete the unwind instruction!
UI->eraseFromParent();
// Update any PHI nodes in the exceptional block to indicate that
// there is now a new entry in them.
unsigned i = 0;
for (BasicBlock::iterator I = InvokeDest->begin();
isa<PHINode>(I); ++I, ++i) {
PHINode *PN = cast<PHINode>(I);
PN->addIncoming(InvokeDestPHIValues[i], BB);
}
}
}
}
// Now that everything is happy, we have one final detail. The PHI nodes in
// the exception destination block still have entries due to the original
// invoke instruction. Eliminate these entries (which might even delete the
// PHI node) now.
InvokeDest->removePredecessor(II->getParent());
}
bool CSDataRando::processCallSite(CallSite CS, FuncInfo &FI, PointerEquivalenceAnalysis &P, DSGraph *G) {
bool IndirectCall = !isa<Function>(CS.getCalledValue()->stripPointerCasts());
if (IndirectCall) { NumIndirectCalls++; }
CallSite OriginalCS = originalCallSite(FI, CS);
if (!DSA->canEncryptCall(OriginalCS)) {
if (IndirectCall) { NumIndirectCantEncrypt++; }
return false;
}
DSCallSite DSCS = G->getDSCallSiteForCallSite(OriginalCS);
const Function *Callee = getEffectiveCallee(DSCS, FI, G);
if (!Callee) {
if (IndirectCall) { NumIndirectCantEncrypt++; }
return false;
}
FuncInfo &CalleeInfo = FunctionInfo[Callee];
Value *Clone = getCloneCalledValue(CS, CalleeInfo);
if (!Clone || CalleeInfo.ArgNodes.empty()) {
if (IndirectCall) { NumIndirectCantEncrypt++; }
return false;
}
// We create a mapping of the formal argument nodes in the callee function and
// actual argument nodes in the caller function's graph.
DSGraph::NodeMapTy NodeMap;
DSGraph *CalleeG = DSA->getDSGraph(*Callee);
// getArgNodesForCall places the return node and the vanode in the
// first two slots of the vector, followed by the nodes for the regular
// pointer arguments.
std::vector<DSNodeHandle> ArgNodes;
getArgNodesForCall(CalleeG, DSCS, ArgNodes);
// First the return value
DSNodeHandle CalleeRetNode = ArgNodes[0];
DSGraph::computeNodeMapping(CalleeRetNode, DSCS.getRetVal(), NodeMap);
// Then VarArgs
DSNodeHandle CalleeVarArgNode = ArgNodes[1];
DSGraph::computeNodeMapping(CalleeVarArgNode, DSCS.getVAVal(), NodeMap);
// And last the regular arguments.
for (unsigned int i = 0; i < DSCS.getNumPtrArgs() && i + 2 < ArgNodes.size(); i++) {
DSGraph::computeNodeMapping(ArgNodes[i + 2], DSCS.getPtrArg(i), NodeMap);
}
// Collect the arguments and masks to pass to call
SmallVector<Value*, 8> Args;
unsigned int i = 0;
for (unsigned int e = CS.getFunctionType()->getNumParams(); i < e; i++) {
Args.push_back(CS.getArgOperand(i));
}
for (const DSNode *N : CalleeInfo.ArgNodes) {
Value *Mask = P.getMaskForNode(NodeMap[N]);
Args.push_back(Mask);
}
// VarArgs go after masks
for (unsigned int e = CS.arg_size(); i < e; i++) {
Args.push_back(CS.getArgOperand(i));
}
// Do replacement
Instruction *CI = CS.getInstruction();
Value *Call;
if (CS.isCall()) {
Call = CallInst::Create(Clone, Args, "", CI);
} else {
InvokeInst *II = cast<InvokeInst>(CI);
Call = InvokeInst::Create(Clone, II->getNormalDest(), II->getUnwindDest(), Args, "", II);
}
CallSite NewCS(Call);
NewCS.setCallingConv(CS.getCallingConv());
CI->replaceAllUsesWith(Call);
P.replace(CI, Call);
CI->eraseFromParent();
return true;
}
// Convert the given call to use normalized argument/return types.
template <class T> static bool ConvertCall(T *Call, Pass *P) {
// Don't try to change calls to intrinsics.
if (isa<IntrinsicInst>(Call))
return false;
FunctionType *FTy = cast<FunctionType>(
Call->getCalledValue()->getType()->getPointerElementType());
FunctionType *NFTy = NormalizeFunctionType(FTy);
if (NFTy == FTy)
return false; // No change needed.
// Convert arguments.
SmallVector<Value *, 8> Args;
for (unsigned I = 0; I < Call->getNumArgOperands(); ++I) {
Value *Arg = Call->getArgOperand(I);
if (NFTy->getParamType(I) != FTy->getParamType(I)) {
Instruction::CastOps CastType =
Call->getAttributes().hasAttribute(I + 1, Attribute::SExt) ?
Instruction::SExt : Instruction::ZExt;
Arg = CopyDebug(CastInst::Create(CastType, Arg, NFTy->getParamType(I),
"arg_ext", Call), Call);
}
Args.push_back(Arg);
}
Value *CastFunc =
CopyDebug(new BitCastInst(Call->getCalledValue(), NFTy->getPointerTo(),
Call->getName() + ".arg_cast", Call), Call);
Value *Result = NULL;
if (CallInst *OldCall = dyn_cast<CallInst>(Call)) {
CallInst *NewCall = CopyDebug(CallInst::Create(CastFunc, Args, "", OldCall),
OldCall);
NewCall->takeName(OldCall);
NewCall->setAttributes(OldCall->getAttributes());
NewCall->setCallingConv(OldCall->getCallingConv());
NewCall->setTailCall(OldCall->isTailCall());
Result = NewCall;
if (FTy->getReturnType() != NFTy->getReturnType()) {
Result = CopyDebug(new TruncInst(NewCall, FTy->getReturnType(),
NewCall->getName() + ".ret_trunc", Call),
Call);
}
} else if (InvokeInst *OldInvoke = dyn_cast<InvokeInst>(Call)) {
BasicBlock *Parent = OldInvoke->getParent();
BasicBlock *NormalDest = OldInvoke->getNormalDest();
BasicBlock *UnwindDest = OldInvoke->getUnwindDest();
if (FTy->getReturnType() != NFTy->getReturnType()) {
if (BasicBlock *SplitDest = SplitCriticalEdge(Parent, NormalDest)) {
NormalDest = SplitDest;
}
}
InvokeInst *New = CopyDebug(InvokeInst::Create(CastFunc, NormalDest,
UnwindDest, Args,
"", OldInvoke),
OldInvoke);
New->takeName(OldInvoke);
if (FTy->getReturnType() != NFTy->getReturnType()) {
Result = CopyDebug(new TruncInst(New, FTy->getReturnType(),
New->getName() + ".ret_trunc",
NormalDest->getTerminator()),
OldInvoke);
} else {
Result = New;
}
New->setAttributes(OldInvoke->getAttributes());
New->setCallingConv(OldInvoke->getCallingConv());
}
Call->replaceAllUsesWith(Result);
Call->eraseFromParent();
return true;
}
/// Replaces the given call site (Call or Invoke) with a gc.statepoint
/// intrinsic with an empty deoptimization arguments list. This does
/// NOT do explicit relocation for GC support.
static Value *ReplaceWithStatepoint(const CallSite &CS, /* to replace */
Pass *P) {
BasicBlock *BB = CS.getInstruction()->getParent();
Function *F = BB->getParent();
Module *M = F->getParent();
assert(M && "must be set");
// TODO: technically, a pass is not allowed to get functions from within a
// function pass since it might trigger a new function addition. Refactor
// this logic out to the initialization of the pass. Doesn't appear to
// matter in practice.
// Fill in the one generic type'd argument (the function is also vararg)
std::vector<Type *> argTypes;
argTypes.push_back(CS.getCalledValue()->getType());
Function *gc_statepoint_decl = Intrinsic::getDeclaration(
M, Intrinsic::experimental_gc_statepoint, argTypes);
// Then go ahead and use the builder do actually do the inserts. We insert
// immediately before the previous instruction under the assumption that all
// arguments will be available here. We can't insert afterwards since we may
// be replacing a terminator.
Instruction *insertBefore = CS.getInstruction();
IRBuilder<> Builder(insertBefore);
// First, create the statepoint (with all live ptrs as arguments).
std::vector<llvm::Value *> args;
// target, #args, unused, args
Value *Target = CS.getCalledValue();
args.push_back(Target);
int callArgSize = CS.arg_size();
args.push_back(
ConstantInt::get(Type::getInt32Ty(M->getContext()), callArgSize));
// TODO: add a 'Needs GC-rewrite' later flag
args.push_back(ConstantInt::get(Type::getInt32Ty(M->getContext()), 0));
// Copy all the arguments of the original call
args.insert(args.end(), CS.arg_begin(), CS.arg_end());
// Create the statepoint given all the arguments
Instruction *token = nullptr;
AttributeSet return_attributes;
if (CS.isCall()) {
CallInst *toReplace = cast<CallInst>(CS.getInstruction());
CallInst *call =
Builder.CreateCall(gc_statepoint_decl, args, "safepoint_token");
call->setTailCall(toReplace->isTailCall());
call->setCallingConv(toReplace->getCallingConv());
// Before we have to worry about GC semantics, all attributes are legal
AttributeSet new_attrs = toReplace->getAttributes();
// In case if we can handle this set of sttributes - set up function attrs
// directly on statepoint and return attrs later for gc_result intrinsic.
call->setAttributes(new_attrs.getFnAttributes());
return_attributes = new_attrs.getRetAttributes();
// TODO: handle param attributes
token = call;
// Put the following gc_result and gc_relocate calls immediately after the
// the old call (which we're about to delete)
BasicBlock::iterator next(toReplace);
assert(BB->end() != next && "not a terminator, must have next");
next++;
Instruction *IP = &*(next);
Builder.SetInsertPoint(IP);
Builder.SetCurrentDebugLocation(IP->getDebugLoc());
} else if (CS.isInvoke()) {
InvokeInst *toReplace = cast<InvokeInst>(CS.getInstruction());
// Insert the new invoke into the old block. We'll remove the old one in a
// moment at which point this will become the new terminator for the
// original block.
InvokeInst *invoke = InvokeInst::Create(
gc_statepoint_decl, toReplace->getNormalDest(),
toReplace->getUnwindDest(), args, "", toReplace->getParent());
invoke->setCallingConv(toReplace->getCallingConv());
// Currently we will fail on parameter attributes and on certain
// function attributes.
AttributeSet new_attrs = toReplace->getAttributes();
// In case if we can handle this set of sttributes - set up function attrs
// directly on statepoint and return attrs later for gc_result intrinsic.
invoke->setAttributes(new_attrs.getFnAttributes());
return_attributes = new_attrs.getRetAttributes();
token = invoke;
// We'll insert the gc.result into the normal block
BasicBlock *normalDest = normalizeBBForInvokeSafepoint(
toReplace->getNormalDest(), invoke->getParent());
Instruction *IP = &*(normalDest->getFirstInsertionPt());
Builder.SetInsertPoint(IP);
} else {
llvm_unreachable("unexpect type of CallSite");
}
assert(token);
// Handle the return value of the original call - update all uses to use a
// gc_result hanging off the statepoint node we just inserted
// Only add the gc_result iff there is actually a used result
if (!CS.getType()->isVoidTy() && !CS.getInstruction()->use_empty()) {
Instruction *gc_result = nullptr;
std::vector<Type *> types; // one per 'any' type
types.push_back(CS.getType()); // result type
auto get_gc_result_id = [&](Type &Ty) {
if (Ty.isIntegerTy()) {
return Intrinsic::experimental_gc_result_int;
} else if (Ty.isFloatingPointTy()) {
return Intrinsic::experimental_gc_result_float;
} else if (Ty.isPointerTy()) {
return Intrinsic::experimental_gc_result_ptr;
} else {
llvm_unreachable("non java type encountered");
}
};
Intrinsic::ID Id = get_gc_result_id(*CS.getType());
Value *gc_result_func = Intrinsic::getDeclaration(M, Id, types);
std::vector<Value *> args;
args.push_back(token);
gc_result = Builder.CreateCall(
gc_result_func, args,
CS.getInstruction()->hasName() ? CS.getInstruction()->getName() : "");
cast<CallInst>(gc_result)->setAttributes(return_attributes);
return gc_result;
} else {
// No return value for the call.
return nullptr;
}
}
// Specialize F by replacing the arguments (keys) in replacements with the
// constants (values). Replace all calls to F with those constants with
// a call to the specialized function. Returns the specialized function
static Function*
SpecializeFunction(Function* F,
ValueMap<const Value*, Value*>& replacements) {
// arg numbers of deleted arguments
DenseMap<unsigned, const Argument*> deleted;
for (ValueMap<const Value*, Value*>::iterator
repb = replacements.begin(), repe = replacements.end();
repb != repe; ++repb) {
Argument const *arg = cast<const Argument>(repb->first);
deleted[arg->getArgNo()] = arg;
}
Function* NF = CloneFunction(F, replacements,
/*ModuleLevelChanges=*/false);
NF->setLinkage(GlobalValue::InternalLinkage);
F->getParent()->getFunctionList().push_back(NF);
for (Value::use_iterator ii = F->use_begin(), ee = F->use_end();
ii != ee; ) {
Value::use_iterator i = ii;
++ii;
User *U = *i;
CallSite CS(U);
if (CS) {
if (CS.getCalledFunction() == F) {
SmallVector<Value*, 6> args;
// Assemble the non-specialized arguments for the updated callsite.
// In the process, make sure that the specialized arguments are
// constant and match the specialization. If that's not the case,
// this callsite needs to call the original or some other
// specialization; don't change it here.
CallSite::arg_iterator as = CS.arg_begin(), ae = CS.arg_end();
for (CallSite::arg_iterator ai = as; ai != ae; ++ai) {
DenseMap<unsigned, const Argument*>::iterator delit = deleted.find(
std::distance(as, ai));
if (delit == deleted.end())
args.push_back(cast<Value>(ai));
else {
Constant *ci = dyn_cast<Constant>(ai);
if (!(ci && ci == replacements[delit->second]))
goto next_use;
}
}
Value* NCall;
if (CallInst *CI = dyn_cast<CallInst>(U)) {
NCall = CallInst::Create(NF, args.begin(), args.end(),
CI->getName(), CI);
cast<CallInst>(NCall)->setTailCall(CI->isTailCall());
cast<CallInst>(NCall)->setCallingConv(CI->getCallingConv());
} else {
InvokeInst *II = cast<InvokeInst>(U);
NCall = InvokeInst::Create(NF, II->getNormalDest(),
II->getUnwindDest(),
args.begin(), args.end(),
II->getName(), II);
cast<InvokeInst>(NCall)->setCallingConv(II->getCallingConv());
}
CS.getInstruction()->replaceAllUsesWith(NCall);
CS.getInstruction()->eraseFromParent();
++numReplaced;
}
}
next_use:;
}
return NF;
}
void AAAnalyzer::handle_inst(Instruction *inst, FunctionWrapper * parent_func) {
//outs()<<*inst<<"\n"; outs().flush();
switch (inst->getOpcode()) {
// common/bitwise binary operations
// Terminator instructions
case Instruction::Ret:
{
ReturnInst* retInst = ((ReturnInst*) inst);
if (retInst->getNumOperands() > 0 && !retInst->getOperandUse(0)->getType()->isVoidTy()) {
parent_func->addRet(retInst->getOperandUse(0));
}
}
break;
case Instruction::Resume:
{
Value* resume = ((ResumeInst*) inst)->getOperand(0);
parent_func->addResume(resume);
}
break;
case Instruction::Switch:
case Instruction::Br:
case Instruction::IndirectBr:
case Instruction::Unreachable:
break;
// vector operations
case Instruction::ExtractElement:
{
}
break;
case Instruction::InsertElement:
{
}
break;
case Instruction::ShuffleVector:
{
}
break;
// aggregate operations
case Instruction::ExtractValue:
{
Value * agg = ((ExtractValueInst*) inst)->getAggregateOperand();
DyckVertex* aggV = wrapValue(agg);
Type* aggTy = agg->getType();
ArrayRef<unsigned> indices = ((ExtractValueInst*) inst)->getIndices();
DyckVertex* currentStruct = aggV;
for (unsigned int i = 0; i < indices.size(); i++) {
if (isa<CompositeType>(aggTy) && aggTy->isSized()) {
if (!aggTy->isStructTy()) {
aggTy = ((CompositeType*) aggTy)->getTypeAtIndex(indices[i]);
#ifndef ARRAY_SIMPLIFIED
current = addPtrOffset(current, (int) indices[i] * dl.getTypeAllocSize(aggTy), dgraph);
#endif
if (i == indices.size() - 1) {
this->makeAlias(currentStruct, wrapValue(inst));
}
} else {
aggTy = ((CompositeType*) aggTy)->getTypeAtIndex(indices[i]);
if (i != indices.size() - 1) {
currentStruct = this->addField(currentStruct, -2 - (int) indices[i], NULL);
} else {
currentStruct = this->addField(currentStruct, -2 - (int) indices[i], wrapValue(inst));
}
}
} else {
break;
}
}
}
break;
case Instruction::InsertValue:
{
DyckVertex* resultV = wrapValue(inst);
Value * agg = ((InsertValueInst*) inst)->getAggregateOperand();
if (!isa<UndefValue>(agg)) {
makeAlias(resultV, wrapValue(agg));
}
Value * val = ((InsertValueInst*) inst)->getInsertedValueOperand();
DyckVertex* insertedVal = wrapValue(val);
Type *aggTy = inst->getType();
ArrayRef<unsigned> indices = ((InsertValueInst*) inst)->getIndices();
DyckVertex* currentStruct = resultV;
for (unsigned int i = 0; i < indices.size(); i++) {
if (isa<CompositeType>(aggTy) && aggTy->isSized()) {
if (!aggTy->isStructTy()) {
aggTy = ((CompositeType*) aggTy)->getTypeAtIndex(indices[i]);
#ifndef ARRAY_SIMPLIFIED
current = addPtrOffset(current, (int) indices[i] * dl.getTypeAllocSize(aggTy), dgraph);
#endif
if (i == indices.size() - 1) {
this->makeAlias(currentStruct, insertedVal);
}
} else {
aggTy = ((CompositeType*) aggTy)->getTypeAtIndex(indices[i]);
if (i != indices.size() - 1) {
currentStruct = this->addField(currentStruct, -2 - (int) indices[i], NULL);
} else {
currentStruct = this->addField(currentStruct, -2 - (int) indices[i], insertedVal);
}
}
} else {
break;
}
}
}
break;
// memory accessing and addressing operations
case Instruction::Alloca:
{
}
break;
case Instruction::Fence:
{
}
break;
case Instruction::AtomicCmpXchg:
{
Value * retXchg = inst;
Value * ptrXchg = inst->getOperand(0);
Value * newXchg = inst->getOperand(2);
addPtrTo(wrapValue(ptrXchg), wrapValue(retXchg));
addPtrTo(wrapValue(ptrXchg), wrapValue(newXchg));
}
break;
case Instruction::AtomicRMW:
{
Value * retRmw = inst;
Value * ptrRmw = ((AtomicRMWInst*) inst)->getPointerOperand();
addPtrTo(wrapValue(ptrRmw), wrapValue(retRmw));
switch (((AtomicRMWInst*) inst)->getOperation()) {
case AtomicRMWInst::Max:
case AtomicRMWInst::Min:
case AtomicRMWInst::UMax:
case AtomicRMWInst::UMin:
case AtomicRMWInst::Xchg:
{
Value * newRmw = ((AtomicRMWInst*) inst)->getValOperand();
addPtrTo(wrapValue(ptrRmw), wrapValue(newRmw));
}
break;
default:
//others are binary ops like add/sub/...
///@TODO
break;
}
}
break;
case Instruction::Load:
{
Value *lval = inst;
Value *ladd = inst->getOperand(0);
addPtrTo(wrapValue(ladd), wrapValue(lval));
}
break;
case Instruction::Store:
{
Value * sval = inst->getOperand(0);
Value * sadd = inst->getOperand(1);
addPtrTo(wrapValue(sadd), wrapValue(sval));
}
break;
case Instruction::GetElementPtr:
{
makeAlias(wrapValue(inst), handle_gep((GEPOperator*) inst));
}
break;
// conversion operations
case Instruction::Trunc:
case Instruction::ZExt:
case Instruction::SExt:
case Instruction::FPTrunc:
case Instruction::FPExt:
case Instruction::FPToUI:
case Instruction::FPToSI:
case Instruction::UIToFP:
case Instruction::SIToFP:
case Instruction::BitCast:
case Instruction::PtrToInt:
case Instruction::IntToPtr:
{
Value * itpv = inst->getOperand(0);
makeAlias(wrapValue(inst), wrapValue(itpv));
}
break;
// other operations
case Instruction::Invoke: // invoke is a terminal operation
{
InvokeInst * invoke = (InvokeInst*) inst;
LandingPadInst* lpd = invoke->getLandingPadInst();
parent_func->addLandingPad(invoke, lpd);
Value * cv = invoke->getCalledValue();
vector<Value*> args;
for (unsigned i = 0; i < invoke->getNumArgOperands(); i++) {
args.push_back(invoke->getArgOperand(i));
}
this->handle_invoke_call_inst(invoke, cv, &args, parent_func);
}
break;
case Instruction::Call:
{
CallInst * callinst = (CallInst*) inst;
if (callinst->isInlineAsm()) {
break;
}
Value * cv = callinst->getCalledValue();
vector<Value*> args;
for (unsigned i = 0; i < callinst->getNumArgOperands(); i++) {
args.push_back(callinst->getArgOperand(i));
}
this->handle_invoke_call_inst(callinst, cv, &args, parent_func);
}
break;
case Instruction::PHI:
{
PHINode *phi = (PHINode *) inst;
int nums = phi->getNumIncomingValues();
for (int i = 0; i < nums; i++) {
Value * p = phi->getIncomingValue(i);
makeAlias(wrapValue(inst), wrapValue(p));
}
}
break;
case Instruction::Select:
{
Value *first = ((SelectInst*) inst)->getTrueValue();
Value *second = ((SelectInst*) inst)->getFalseValue();
makeAlias(wrapValue(inst), wrapValue(first));
makeAlias(wrapValue(inst), wrapValue(second));
}
break;
case Instruction::VAArg:
{
parent_func->addVAArg(inst);
DyckVertex* vaarg = wrapValue(inst);
Value * ptrVaarg = inst->getOperand(0);
addPtrTo(wrapValue(ptrVaarg), vaarg);
}
break;
case Instruction::LandingPad: // handled with invoke inst
case Instruction::ICmp:
case Instruction::FCmp:
default:
break;
}
}
/// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
/// an invoke, we have to turn all of the calls that can throw into
/// invokes. This function analyze BB to see if there are any calls, and if so,
/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
/// nodes in that block with the values specified in InvokeDestPHIValues.
///
/// Returns true to indicate that the next block should be skipped.
static bool HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
InvokeInliningInfo &Invoke) {
for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
Instruction *I = BBI++;
// We only need to check for function calls: inlined invoke
// instructions require no special handling.
CallInst *CI = dyn_cast<CallInst>(I);
if (CI == 0) continue;
// LIBUNWIND: merge selector instructions.
if (EHSelectorInst *Inner = dyn_cast<EHSelectorInst>(CI)) {
EHSelectorInst *Outer = Invoke.getOuterSelector();
if (!Outer) continue;
bool innerIsOnlyCleanup = isCleanupOnlySelector(Inner);
bool outerIsOnlyCleanup = isCleanupOnlySelector(Outer);
// If both selectors contain only cleanups, we don't need to do
// anything. TODO: this is really just a very specific instance
// of a much more general optimization.
if (innerIsOnlyCleanup && outerIsOnlyCleanup) continue;
// Otherwise, we just append the outer selector to the inner selector.
SmallVector<Value*, 16> NewSelector;
for (unsigned i = 0, e = Inner->getNumArgOperands(); i != e; ++i)
NewSelector.push_back(Inner->getArgOperand(i));
for (unsigned i = 2, e = Outer->getNumArgOperands(); i != e; ++i)
NewSelector.push_back(Outer->getArgOperand(i));
CallInst *NewInner =
IRBuilder<>(Inner).CreateCall(Inner->getCalledValue(), NewSelector);
// No need to copy attributes, calling convention, etc.
NewInner->takeName(Inner);
Inner->replaceAllUsesWith(NewInner);
Inner->eraseFromParent();
continue;
}
// If this call cannot unwind, don't convert it to an invoke.
if (CI->doesNotThrow())
continue;
// Convert this function call into an invoke instruction.
// First, split the basic block.
BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
// Delete the unconditional branch inserted by splitBasicBlock
BB->getInstList().pop_back();
// LIBUNWIND: If this is a call to @llvm.eh.resume, just branch
// directly to the new landing pad.
if (Invoke.forwardEHResume(CI, BB)) {
// TODO: 'Split' is now unreachable; clean it up.
// We want to leave the original call intact so that the call
// graph and other structures won't get misled. We also have to
// avoid processing the next block, or we'll iterate here forever.
return true;
}
// Otherwise, create the new invoke instruction.
ImmutableCallSite CS(CI);
SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end());
InvokeInst *II =
InvokeInst::Create(CI->getCalledValue(), Split,
Invoke.getOuterUnwindDest(),
InvokeArgs, CI->getName(), BB);
II->setCallingConv(CI->getCallingConv());
II->setAttributes(CI->getAttributes());
// Make sure that anything using the call now uses the invoke! This also
// updates the CallGraph if present, because it uses a WeakVH.
CI->replaceAllUsesWith(II);
Split->getInstList().pop_front(); // Delete the original call
// Update any PHI nodes in the exceptional block to indicate that
// there is now a new entry in them.
Invoke.addIncomingPHIValuesFor(BB);
return false;
}
return false;
}
/// splitLiveRangesAcrossInvokes - Each value that is live across an unwind edge
/// we spill into a stack location, guaranteeing that there is nothing live
/// across the unwind edge. This process also splits all critical edges
/// coming out of invoke's.
/// FIXME: Move this function to a common utility file (Local.cpp?) so
/// both SjLj and LowerInvoke can use it.
void SjLjEHPass::
splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes) {
// First step, split all critical edges from invoke instructions.
for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
InvokeInst *II = Invokes[i];
SplitCriticalEdge(II, 0, this);
// FIXME: New EH - This if-condition will be always true in the new scheme.
if (II->getUnwindDest()->isLandingPad()) {
SmallVector<BasicBlock*, 2> NewBBs;
SplitLandingPadPredecessors(II->getUnwindDest(), II->getParent(),
".1", ".2", this, NewBBs);
LPadSuccMap[II] = *succ_begin(NewBBs[0]);
} else {
SplitCriticalEdge(II, 1, this);
}
assert(!isa<PHINode>(II->getNormalDest()) &&
!isa<PHINode>(II->getUnwindDest()) &&
"Critical edge splitting left single entry phi nodes?");
}
Function *F = Invokes.back()->getParent()->getParent();
// To avoid having to handle incoming arguments specially, we lower each arg
// to a copy instruction in the entry block. This ensures that the argument
// value itself cannot be live across the entry block.
BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin();
while (isa<AllocaInst>(AfterAllocaInsertPt) &&
isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsertPt)->getArraySize()))
++AfterAllocaInsertPt;
for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
AI != E; ++AI) {
Type *Ty = AI->getType();
// Aggregate types can't be cast, but are legal argument types, so we have
// to handle them differently. We use an extract/insert pair as a
// lightweight method to achieve the same goal.
if (isa<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(Ty)) {
Instruction *EI = ExtractValueInst::Create(AI, 0, "",AfterAllocaInsertPt);
Instruction *NI = InsertValueInst::Create(AI, EI, 0);
NI->insertAfter(EI);
AI->replaceAllUsesWith(NI);
// Set the operand of the instructions back to the AllocaInst.
EI->setOperand(0, AI);
NI->setOperand(0, AI);
} else {
// This is always a no-op cast because we're casting AI to AI->getType()
// so src and destination types are identical. BitCast is the only
// possibility.
CastInst *NC = new BitCastInst(
AI, AI->getType(), AI->getName()+".tmp", AfterAllocaInsertPt);
AI->replaceAllUsesWith(NC);
// Set the operand of the cast instruction back to the AllocaInst.
// Normally it's forbidden to replace a CastInst's operand because it
// could cause the opcode to reflect an illegal conversion. However,
// we're replacing it here with the same value it was constructed with.
// We do this because the above replaceAllUsesWith() clobbered the
// operand, but we want this one to remain.
NC->setOperand(0, AI);
}
}
// Finally, scan the code looking for instructions with bad live ranges.
for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E; ++II) {
// Ignore obvious cases we don't have to handle. In particular, most
// instructions either have no uses or only have a single use inside the
// current block. Ignore them quickly.
Instruction *Inst = II;
if (Inst->use_empty()) continue;
if (Inst->hasOneUse() &&
cast<Instruction>(Inst->use_back())->getParent() == BB &&
!isa<PHINode>(Inst->use_back())) continue;
// If this is an alloca in the entry block, it's not a real register
// value.
if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst))
if (isa<ConstantInt>(AI->getArraySize()) && BB == F->begin())
continue;
// Avoid iterator invalidation by copying users to a temporary vector.
SmallVector<Instruction*,16> Users;
for (Value::use_iterator UI = Inst->use_begin(), E = Inst->use_end();
UI != E; ++UI) {
Instruction *User = cast<Instruction>(*UI);
if (User->getParent() != BB || isa<PHINode>(User))
Users.push_back(User);
}
// Find all of the blocks that this value is live in.
std::set<BasicBlock*> LiveBBs;
LiveBBs.insert(Inst->getParent());
while (!Users.empty()) {
Instruction *U = Users.back();
Users.pop_back();
if (!isa<PHINode>(U)) {
MarkBlocksLiveIn(U->getParent(), LiveBBs);
} else {
// Uses for a PHI node occur in their predecessor block.
PHINode *PN = cast<PHINode>(U);
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
if (PN->getIncomingValue(i) == Inst)
MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs);
}
}
// Now that we know all of the blocks that this thing is live in, see if
// it includes any of the unwind locations.
bool NeedsSpill = false;
for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) {
NeedsSpill = true;
}
}
// If we decided we need a spill, do it.
// FIXME: Spilling this way is overkill, as it forces all uses of
// the value to be reloaded from the stack slot, even those that aren't
// in the unwind blocks. We should be more selective.
if (NeedsSpill) {
++NumSpilled;
DemoteRegToStack(*Inst, true);
}
}
}
/// Replaces the given call site (Call or Invoke) with a gc.statepoint
/// intrinsic with an empty deoptimization arguments list. This does
/// NOT do explicit relocation for GC support.
static Value *ReplaceWithStatepoint(const CallSite &CS, /* to replace */
Pass *P) {
assert(CS.getInstruction()->getParent()->getParent()->getParent() &&
"must be set");
// TODO: technically, a pass is not allowed to get functions from within a
// function pass since it might trigger a new function addition. Refactor
// this logic out to the initialization of the pass. Doesn't appear to
// matter in practice.
// Then go ahead and use the builder do actually do the inserts. We insert
// immediately before the previous instruction under the assumption that all
// arguments will be available here. We can't insert afterwards since we may
// be replacing a terminator.
IRBuilder<> Builder(CS.getInstruction());
// Note: The gc args are not filled in at this time, that's handled by
// RewriteStatepointsForGC (which is currently under review).
// Create the statepoint given all the arguments
Instruction *Token = nullptr;
AttributeSet OriginalAttrs;
if (CS.isCall()) {
CallInst *ToReplace = cast<CallInst>(CS.getInstruction());
CallInst *Call = Builder.CreateGCStatepointCall(
CS.getCalledValue(), makeArrayRef(CS.arg_begin(), CS.arg_end()), None,
None, "safepoint_token");
Call->setTailCall(ToReplace->isTailCall());
Call->setCallingConv(ToReplace->getCallingConv());
// Before we have to worry about GC semantics, all attributes are legal
// TODO: handle param attributes
OriginalAttrs = ToReplace->getAttributes();
// In case if we can handle this set of attributes - set up function
// attributes directly on statepoint and return attributes later for
// gc_result intrinsic.
Call->setAttributes(OriginalAttrs.getFnAttributes());
Token = Call;
// Put the following gc_result and gc_relocate calls immediately after the
// the old call (which we're about to delete).
assert(ToReplace->getNextNode() && "not a terminator, must have next");
Builder.SetInsertPoint(ToReplace->getNextNode());
Builder.SetCurrentDebugLocation(ToReplace->getNextNode()->getDebugLoc());
} else if (CS.isInvoke()) {
InvokeInst *ToReplace = cast<InvokeInst>(CS.getInstruction());
// Insert the new invoke into the old block. We'll remove the old one in a
// moment at which point this will become the new terminator for the
// original block.
Builder.SetInsertPoint(ToReplace->getParent());
InvokeInst *Invoke = Builder.CreateGCStatepointInvoke(
CS.getCalledValue(), ToReplace->getNormalDest(),
ToReplace->getUnwindDest(), makeArrayRef(CS.arg_begin(), CS.arg_end()),
Builder.getInt32(0), None, "safepoint_token");
// Currently we will fail on parameter attributes and on certain
// function attributes.
OriginalAttrs = ToReplace->getAttributes();
// In case if we can handle this set of attributes - set up function
// attributes directly on statepoint and return attributes later for
// gc_result intrinsic.
Invoke->setAttributes(OriginalAttrs.getFnAttributes());
Token = Invoke;
// We'll insert the gc.result into the normal block
BasicBlock *NormalDest = normalizeBBForInvokeSafepoint(
ToReplace->getNormalDest(), Invoke->getParent());
Builder.SetInsertPoint(NormalDest->getFirstInsertionPt());
} else {
llvm_unreachable("unexpect type of CallSite");
}
assert(Token);
// Handle the return value of the original call - update all uses to use a
// gc_result hanging off the statepoint node we just inserted
// Only add the gc_result iff there is actually a used result
if (!CS.getType()->isVoidTy() && !CS.getInstruction()->use_empty()) {
std::string TakenName =
CS.getInstruction()->hasName() ? CS.getInstruction()->getName() : "";
CallInst *GCResult = Builder.CreateGCResult(Token, CS.getType(), TakenName);
GCResult->setAttributes(OriginalAttrs.getRetAttributes());
return GCResult;
} else {
// No return value for the call.
return nullptr;
}
}
/// Replaces the given call site (Call or Invoke) with a gc.statepoint
/// intrinsic with an empty deoptimization arguments list. This does
/// NOT do explicit relocation for GC support.
static Value *ReplaceWithStatepoint(const CallSite &CS /* to replace */) {
assert(CS.getInstruction()->getModule() && "must be set");
// TODO: technically, a pass is not allowed to get functions from within a
// function pass since it might trigger a new function addition. Refactor
// this logic out to the initialization of the pass. Doesn't appear to
// matter in practice.
// Then go ahead and use the builder do actually do the inserts. We insert
// immediately before the previous instruction under the assumption that all
// arguments will be available here. We can't insert afterwards since we may
// be replacing a terminator.
IRBuilder<> Builder(CS.getInstruction());
// Note: The gc args are not filled in at this time, that's handled by
// RewriteStatepointsForGC (which is currently under review).
// Create the statepoint given all the arguments
Instruction *Token = nullptr;
uint64_t ID;
uint32_t NumPatchBytes;
AttributeSet OriginalAttrs = CS.getAttributes();
Attribute AttrID =
OriginalAttrs.getAttribute(AttributeSet::FunctionIndex, "statepoint-id");
Attribute AttrNumPatchBytes = OriginalAttrs.getAttribute(
AttributeSet::FunctionIndex, "statepoint-num-patch-bytes");
AttrBuilder AttrsToRemove;
bool HasID = AttrID.isStringAttribute() &&
!AttrID.getValueAsString().getAsInteger(10, ID);
if (HasID)
AttrsToRemove.addAttribute("statepoint-id");
else
ID = 0xABCDEF00;
bool HasNumPatchBytes =
AttrNumPatchBytes.isStringAttribute() &&
!AttrNumPatchBytes.getValueAsString().getAsInteger(10, NumPatchBytes);
if (HasNumPatchBytes)
AttrsToRemove.addAttribute("statepoint-num-patch-bytes");
else
NumPatchBytes = 0;
OriginalAttrs = OriginalAttrs.removeAttributes(
CS.getInstruction()->getContext(), AttributeSet::FunctionIndex,
AttrsToRemove);
if (CS.isCall()) {
CallInst *ToReplace = cast<CallInst>(CS.getInstruction());
CallInst *Call = Builder.CreateGCStatepointCall(
ID, NumPatchBytes, CS.getCalledValue(),
makeArrayRef(CS.arg_begin(), CS.arg_end()), None, None,
"safepoint_token");
Call->setTailCall(ToReplace->isTailCall());
Call->setCallingConv(ToReplace->getCallingConv());
// In case if we can handle this set of attributes - set up function
// attributes directly on statepoint and return attributes later for
// gc_result intrinsic.
Call->setAttributes(OriginalAttrs.getFnAttributes());
Token = Call;
// Put the following gc_result and gc_relocate calls immediately after
// the old call (which we're about to delete).
assert(ToReplace->getNextNode() && "not a terminator, must have next");
Builder.SetInsertPoint(ToReplace->getNextNode());
Builder.SetCurrentDebugLocation(ToReplace->getNextNode()->getDebugLoc());
} else if (CS.isInvoke()) {
InvokeInst *ToReplace = cast<InvokeInst>(CS.getInstruction());
// Insert the new invoke into the old block. We'll remove the old one in a
// moment at which point this will become the new terminator for the
// original block.
Builder.SetInsertPoint(ToReplace->getParent());
InvokeInst *Invoke = Builder.CreateGCStatepointInvoke(
ID, NumPatchBytes, CS.getCalledValue(), ToReplace->getNormalDest(),
ToReplace->getUnwindDest(), makeArrayRef(CS.arg_begin(), CS.arg_end()),
None, None, "safepoint_token");
Invoke->setCallingConv(ToReplace->getCallingConv());
// In case if we can handle this set of attributes - set up function
// attributes directly on statepoint and return attributes later for
// gc_result intrinsic.
Invoke->setAttributes(OriginalAttrs.getFnAttributes());
Token = Invoke;
// We'll insert the gc.result into the normal block
BasicBlock *NormalDest = ToReplace->getNormalDest();
// Can not insert gc.result in case of phi nodes preset.
// Should have removed this cases prior to running this function
assert(!isa<PHINode>(NormalDest->begin()));
Instruction *IP = &*(NormalDest->getFirstInsertionPt());
Builder.SetInsertPoint(IP);
} else {
llvm_unreachable("unexpect type of CallSite");
}
assert(Token);
// Handle the return value of the original call - update all uses to use a
// gc_result hanging off the statepoint node we just inserted
// Only add the gc_result iff there is actually a used result
if (!CS.getType()->isVoidTy() && !CS.getInstruction()->use_empty()) {
std::string TakenName =
CS.getInstruction()->hasName() ? CS.getInstruction()->getName() : "";
CallInst *GCResult = Builder.CreateGCResult(Token, CS.getType(), TakenName);
GCResult->setAttributes(OriginalAttrs.getRetAttributes());
return GCResult;
} else {
// No return value for the call.
return nullptr;
}
}
void MemoryInstrumenter::instrumentMalloc(const CallSite &CS) {
DataLayout &TD = getAnalysis<DataLayout>();
TargetLibraryInfo& TLI = getAnalysis<TargetLibraryInfo>();
Function *Callee = CS.getCalledFunction();
assert(DynAAUtils::IsMalloc(Callee));
Instruction *Ins = CS.getInstruction();
// Calculate where to insert.
// <Loc> will be the next instruction executed.
BasicBlock::iterator Loc;
if (!Ins->isTerminator()) {
Loc = Ins;
++Loc;
} else {
assert(isa<InvokeInst>(Ins));
InvokeInst *II = cast<InvokeInst>(Ins);
assert(II->getNormalDest()->getUniquePredecessor());
Loc = II->getNormalDest()->getFirstInsertionPt();
}
IRBuilder<> Builder(Loc);
Value *Start = NULL;
Value *Size = NULL;
Value *Success = NULL; // Indicate whether the allocation succeeded.
StringRef CalleeName = Callee->getName();
if (CalleeName == "malloc" || CalleeName == "valloc") {
Start = Ins;
Size = UndefValue::get(LongType);
Success = Builder.CreateICmpNE(Ins, ConstantPointerNull::get(CharStarType));
} else if (CalleeName.startswith("_Zn")) {
Start = Ins;
Size = CS.getArgument(0);
} else if (CalleeName == "calloc") {
// calloc() takes two size_t, i.e. i64.
// Therefore, no need to worry Mul will have two operands with different
// types. Also, Size will always be of type i64.
Start = Ins;
assert(CS.getArgument(0)->getType() == LongType);
assert(CS.getArgument(1)->getType() == LongType);
Size = BinaryOperator::Create(Instruction::Mul,
CS.getArgument(0),
CS.getArgument(1),
"",
Loc);
Success = Builder.CreateICmpNE(Ins, ConstantPointerNull::get(CharStarType));
} else if (CalleeName == "memalign" || CalleeName == "realloc") {
Start = Ins;
Size = CS.getArgument(1);
Success = Builder.CreateICmpNE(Ins, ConstantPointerNull::get(CharStarType));
} else if (CalleeName == "strdup" || CalleeName == "__strdup") {
Start = Ins;
// Use strlen to compute the length of the allocated memory.
Value *StrLen = EmitStrLen(Ins, Builder, &TD, &TLI);
// size = strlen(result) + 1
Size = Builder.CreateAdd(StrLen, ConstantInt::get(LongType, 1));
Success = Builder.CreateICmpNE(Ins, ConstantPointerNull::get(CharStarType));
} else if (CalleeName == "getline") {
// getline(char **lineptr, size_t *n, FILE *stream)
// start = *lineptr
// size = *n
// succ = (<rv> != -1)
Start = Builder.CreateLoad(CS.getArgument(0));
Size = Builder.CreateLoad(CS.getArgument(1));
Success = Builder.CreateICmpNE(Ins, ConstantInt::get(Ins->getType(), -1));
} else {
assert(false && "Unhandled malloc function call");
}
// start = malloc(size)
// if (success)
// HookMemAlloc
// Loc:
instrumentMemoryAllocation(Start, Size, Success, Loc);
}
bool FuncAddrTaken::runOnModule(Module &M) {
bool Changed = false;
// add declaration of function __patch_at
// declare void @__patch_at(void)
FunctionType *FT = FunctionType::get(Type::getVoidTy(M.getContext()),
false);
Function* PatchAt = Function::Create(FT, Function::ExternalLinkage, "__patch_at", &M);
if (PatchAt->getName() != "__patch_at") {
PatchAt->eraseFromParent();
return false;
}
Changed = true;
// Simple optimization so that no function address will be taken twice
// in the same basic block.
std::map<BasicBlock*, std::set<std::string> > UniqPatchAt;
// before each store instruction that manipulates a function, create a call
// to __patch_at
for (auto F = M.getFunctionList().begin(); F != M.getFunctionList().end(); F++) {
for (auto BB = F->begin(); BB != F->end(); BB++) {
for (auto MI = BB->begin(); MI != BB->end(); MI++) {
if (isa<StoreInst>(MI)) {
// check if the store inst moves a function to a variable
Value *V = InnerMost(cast<StoreInst>(MI)->getValueOperand());
addPatchAt(M, FT, V, MI, UniqPatchAt);
if (isa<ConstantVector>(V)) {
std::set<Value*> patched;
for (unsigned i = 0; i < cast<ConstantVector>(V)->getNumOperands(); i++) {
Value *VV = InnerMost(cast<ConstantVector>(V)->getOperand(i));
if (patched.find(VV) == patched.end()) {
addPatchAt(M, FT, VV, MI, UniqPatchAt);
patched.insert(VV);
}
}
} else if (isa<ConstantStruct>(V)) {
std::set<Value*> patched;
for (unsigned i = 0; i < cast<ConstantStruct>(V)->getNumOperands(); i++) {
Value *VV = InnerMost(cast<ConstantStruct>(V)->getOperand(i));
if (patched.find(VV) == patched.end()) {
addPatchAt(M, FT, VV, MI, UniqPatchAt);
patched.insert(VV);
}
}
} else if (isa<ConstantArray>(V)) {
std::set<Value*> patched;
for (unsigned i = 0; i < cast<ConstantArray>(V)->getNumOperands(); i++) {
Value *VV = InnerMost(cast<ConstantArray>(V)->getOperand(i));
if (patched.find(VV) == patched.end()) {
addPatchAt(M, FT, VV, MI, UniqPatchAt);
patched.insert(VV);
}
}
}
} else if (isa<SelectInst>(MI)) {
Value *V = InnerMost(cast<SelectInst>(MI)->getTrueValue());
addPatchAt(M, FT, V, MI, UniqPatchAt);
V = InnerMost(cast<SelectInst>(MI)->getFalseValue());
addPatchAt(M, FT, V, MI, UniqPatchAt);
} else if (isa<CallInst>(MI)) {
CallInst* CI = cast<CallInst>(MI);
for (unsigned i = 0; i < CI->getNumArgOperands(); i++) {
Value *V = InnerMost(CI->getArgOperand(i));
addPatchAt(M, FT, V, MI, UniqPatchAt);
}
} else if (isa<InvokeInst>(MI)) {
InvokeInst* CI = cast<InvokeInst>(MI);
for (unsigned i = 0; i < CI->getNumArgOperands(); i++) {
Value *V = InnerMost(CI->getArgOperand(i));
addPatchAt(M, FT, V, MI, UniqPatchAt);
}
} else if (isa<ReturnInst>(MI)) {
Value *V = cast<ReturnInst>(MI)->getReturnValue();
if (V) {
V = InnerMost(V);
addPatchAt(M, FT, V, MI, UniqPatchAt);
}
} else if (isa<PHINode>(MI)) {
for (unsigned i = 0; i < cast<PHINode>(MI)->getNumIncomingValues(); i++) {
Value *V = InnerMost(cast<PHINode>(MI)->getIncomingValue(i));
BasicBlock* BB = cast<PHINode>(MI)->getIncomingBlock(i);
// right before the last (maybe terminator) instruction.
addPatchAt(M, FT, V, &(BB->back()), UniqPatchAt);
}
}
}
}
}
// TODO: separate the following virtual table traversal code into another pass
for (auto G = M.getGlobalList().begin(); G != M.getGlobalList().end(); G++) {
if (isa<GlobalVariable>(G) &&
cast<GlobalVariable>(G)->hasInitializer()) {
const GlobalVariable *GV = cast<GlobalVariable>(G);
const Constant *C = GV->getInitializer();
if (GV->hasName() && isa<ConstantArray>(C) && GV->getName().startswith("_ZTV")) {
std::string VTName = CXXDemangledName(GV->getName().data());
if (VTName.size() && VTName.find("vtable") == 0) {
//llvm::errs() << VTName << "\n";
VTName = VTName.substr(11); // get pass "vtable for "
llvm::NamedMDNode* MD = M.getOrInsertNamedMetadata("MCFIVtable");
std::string info = VTName;
for (unsigned i = 0; i < cast<ConstantArray>(C)->getNumOperands(); i++) {
Value *V = InnerMost(cast<ConstantArray>(C)->getOperand(i));
if (isa<Function>(V) && cast<Function>(V)->hasName()) {
//llvm::errs() << cast<Function>(V)->getName() << "\n";
info += std::string("#") + cast<Function>(V)->getName().str();
}
}
MD->addOperand(llvm::MDNode::get(M.getContext(),
llvm::MDString::get(
M.getContext(), info.c_str())));
}
}
}
}
return Changed;
}
bool ICFGBuilder::runOnModule(Module &M) {
MicroBasicBlockBuilder &MBBB = getAnalysis<MicroBasicBlockBuilder>();
forallbb(M, bb) {
for (mbb_iterator mi = MBBB.begin(bb), E = MBBB.end(bb); mi != E; ++mi)
getOrInsertMBB(mi);
}
forallbb(M, bb) {
for (mbb_iterator mi = MBBB.begin(bb), E = MBBB.end(bb); mi != E; ++mi) {
// The ICFG will not contain any inter-thread edge.
// It's also difficult to handle them. How to deal with the return
// edges? They are supposed to go to the pthread_join sites.
if (mi->end() != bb->end() && !is_pthread_create(mi->end())) {
FPCallGraph &CG = getAnalysis<FPCallGraph>();
FuncList callees = CG.getCalledFunctions(mi->end());
bool calls_decl = false;
for (size_t i = 0; i < callees.size(); ++i) {
Function *callee = callees[i];
if (callee->isDeclaration()) {
calls_decl = true;
} else {
MicroBasicBlock *entry_mbb = MBBB.begin(callee->begin());
addEdge(mi, entry_mbb);
}
}
if (calls_decl) {
mbb_iterator next_mbb = mi; ++next_mbb;
addEdge(mi, next_mbb);
}
} else {
for (succ_iterator si = succ_begin(bb); si != succ_end(bb); ++si) {
MicroBasicBlock *succ_mbb = MBBB.begin(*si);
addEdge(mi, succ_mbb);
}
TerminatorInst *ti = bb->getTerminator();
if (is_ret(ti)) {
FPCallGraph &CG = getAnalysis<FPCallGraph>();
InstList call_sites = CG.getCallSites(bb->getParent());
for (size_t i = 0; i < call_sites.size(); ++i) {
Instruction *call_site = call_sites[i];
// Ignore inter-thread edges.
if (is_pthread_create(call_site))
continue;
MicroBasicBlock *next_mbb;
if (isa<CallInst>(call_site)) {
BasicBlock::iterator next = call_site;
++next;
next_mbb = MBBB.parent(next);
} else {
assert(isa<InvokeInst>(call_site));
InvokeInst *inv = dyn_cast<InvokeInst>(call_site);
if (isa<ReturnInst>(ti)) {
next_mbb = MBBB.begin(inv->getNormalDest());
} else {
next_mbb = MBBB.begin(inv->getUnwindDest());
}
}
addEdge(mi, next_mbb);
}
}
}
}
}
return false;
}
