Commit 76817ab1 authored by Paul Robinson's avatar Paul Robinson Committed by Tom Stellard
Browse files

Merging r373219: 

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r373219 | probinson | 2019-09-30 08:08:38 -0700 (Mon, 30 Sep 2019) | 3 lines

[SSP] [2/3] Refactor an if/dyn_cast chain to switch on opcode. NFC

Differential Revision: https://reviews.llvm.org/D67844
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parent c1d76f45

llvm/lib/CodeGen/StackProtector.cpp

+24 −15
Original line number Diff line number Diff line
@@ -159,33 +159,42 @@ bool StackProtector::ContainsProtectableArray(Type *Ty, bool &IsLarge, 
bool StackProtector::HasAddressTaken(const Instruction *AI,

                                SmallPtrSetImpl<const PHINode *> &VisitedPHIs) {

  for (const User *U : AI->users()) {

    if (const StoreInst *SI = dyn_cast<StoreInst>(U)) {

      if (AI == SI->getValueOperand())

    const auto *I = cast<Instruction>(U);

    switch (I->getOpcode()) {

    case Instruction::Store:

      if (AI == cast<StoreInst>(I)->getValueOperand())

        return true;

    } else if (const PtrToIntInst *SI = dyn_cast<PtrToIntInst>(U)) {

      if (AI == SI->getOperand(0))

      break;

    case Instruction::PtrToInt:

      if (AI == cast<PtrToIntInst>(I)->getOperand(0))

        return true;

    } else if (const CallInst *CI = dyn_cast<CallInst>(U)) {

      break;

    case Instruction::Call: {

      // Ignore intrinsics that are not calls. TODO: Use isLoweredToCall().

      const auto *CI = cast<CallInst>(I);

      if (!isa<DbgInfoIntrinsic>(CI) && !CI->isLifetimeStartOrEnd())

        return true;

    } else if (isa<InvokeInst>(U)) {

      break;

    }

    case Instruction::Invoke:

      return true;

    } else if (const SelectInst *SI = dyn_cast<SelectInst>(U)) {

      if (HasAddressTaken(SI, VisitedPHIs))

    case Instruction::BitCast:

    case Instruction::GetElementPtr:

    case Instruction::Select:

      if (HasAddressTaken(I, VisitedPHIs))

        return true;

    } else if (const PHINode *PN = dyn_cast<PHINode>(U)) {

      break;

    case Instruction::PHI: {

      // Keep track of what PHI nodes we have already visited to ensure

      // they are only visited once.

      const auto *PN = cast<PHINode>(I);

      if (VisitedPHIs.insert(PN).second)

        if (HasAddressTaken(PN, VisitedPHIs))

          return true;

    } else if (const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(U)) {

      if (HasAddressTaken(GEP, VisitedPHIs))

        return true;

    } else if (const BitCastInst *BI = dyn_cast<BitCastInst>(U)) {

      if (HasAddressTaken(BI, VisitedPHIs))

        return true;

      break;

    }

    default:

      break;

    }

  }

  return false;