1 files changed, 0 insertions, 902 deletions

diff --git a/contrib/llvm/lib/CodeGen/SafeStack.cpp b/contrib/llvm/lib/CodeGen/SafeStack.cpp
deleted file mode 100644
index a6bc7330e2cc..000000000000
--- a/contrib/llvm/lib/CodeGen/SafeStack.cpp
+++ /dev/null
@@ -1,902 +0,0 @@
-//===- SafeStack.cpp - Safe Stack Insertion -------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass splits the stack into the safe stack (kept as-is for LLVM backend)
-// and the unsafe stack (explicitly allocated and managed through the runtime
-// support library).
-//
-// http://clang.llvm.org/docs/SafeStack.html
-//
-//===----------------------------------------------------------------------===//
-
-#include "SafeStackColoring.h"
-#include "SafeStackLayout.h"
-#include "llvm/ADT/APInt.h"
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/AssumptionCache.h"
-#include "llvm/Analysis/BranchProbabilityInfo.h"
-#include "llvm/Analysis/InlineCost.h"
-#include "llvm/Analysis/LoopInfo.h"
-#include "llvm/Analysis/ScalarEvolution.h"
-#include "llvm/Analysis/ScalarEvolutionExpressions.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/CodeGen/TargetLowering.h"
-#include "llvm/CodeGen/TargetPassConfig.h"
-#include "llvm/CodeGen/TargetSubtargetInfo.h"
-#include "llvm/IR/Argument.h"
-#include "llvm/IR/Attributes.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/ConstantRange.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DIBuilder.h"
-#include "llvm/IR/DataLayout.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/IRBuilder.h"
-#include "llvm/IR/InstIterator.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Intrinsics.h"
-#include "llvm/IR/MDBuilder.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/Use.h"
-#include "llvm/IR/User.h"
-#include "llvm/IR/Value.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/MathExtras.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/Cloning.h"
-#include <algorithm>
-#include <cassert>
-#include <cstdint>
-#include <string>
-#include <utility>
-
-using namespace llvm;
-using namespace llvm::safestack;
-
-#define DEBUG_TYPE "safe-stack"
-
-namespace llvm {
-
-STATISTIC(NumFunctions, "Total number of functions");
-STATISTIC(NumUnsafeStackFunctions, "Number of functions with unsafe stack");
-STATISTIC(NumUnsafeStackRestorePointsFunctions,
-          "Number of functions that use setjmp or exceptions");
-
-STATISTIC(NumAllocas, "Total number of allocas");
-STATISTIC(NumUnsafeStaticAllocas, "Number of unsafe static allocas");
-STATISTIC(NumUnsafeDynamicAllocas, "Number of unsafe dynamic allocas");
-STATISTIC(NumUnsafeByValArguments, "Number of unsafe byval arguments");
-STATISTIC(NumUnsafeStackRestorePoints, "Number of setjmps and landingpads");
-
-} // namespace llvm
-
-/// Use __safestack_pointer_address even if the platform has a faster way of
-/// access safe stack pointer.
-static cl::opt<bool>
-    SafeStackUsePointerAddress("safestack-use-pointer-address",
-                                  cl::init(false), cl::Hidden);
-
-
-namespace {
-
-/// Rewrite an SCEV expression for a memory access address to an expression that
-/// represents offset from the given alloca.
-///
-/// The implementation simply replaces all mentions of the alloca with zero.
-class AllocaOffsetRewriter : public SCEVRewriteVisitor<AllocaOffsetRewriter> {
-  const Value *AllocaPtr;
-
-public:
-  AllocaOffsetRewriter(ScalarEvolution &SE, const Value *AllocaPtr)
-      : SCEVRewriteVisitor(SE), AllocaPtr(AllocaPtr) {}
-
-  const SCEV *visitUnknown(const SCEVUnknown *Expr) {
-    if (Expr->getValue() == AllocaPtr)
-      return SE.getZero(Expr->getType());
-    return Expr;
-  }
-};
-
-/// The SafeStack pass splits the stack of each function into the safe
-/// stack, which is only accessed through memory safe dereferences (as
-/// determined statically), and the unsafe stack, which contains all
-/// local variables that are accessed in ways that we can't prove to
-/// be safe.
-class SafeStack {
-  Function &F;
-  const TargetLoweringBase &TL;
-  const DataLayout &DL;
-  ScalarEvolution &SE;
-
-  Type *StackPtrTy;
-  Type *IntPtrTy;
-  Type *Int32Ty;
-  Type *Int8Ty;
-
-  Value *UnsafeStackPtr = nullptr;
-
-  /// Unsafe stack alignment. Each stack frame must ensure that the stack is
-  /// aligned to this value. We need to re-align the unsafe stack if the
-  /// alignment of any object on the stack exceeds this value.
-  ///
-  /// 16 seems like a reasonable upper bound on the alignment of objects that we
-  /// might expect to appear on the stack on most common targets.
-  enum { StackAlignment = 16 };
-
-  /// Return the value of the stack canary.
-  Value *getStackGuard(IRBuilder<> &IRB, Function &F);
-
-  /// Load stack guard from the frame and check if it has changed.
-  void checkStackGuard(IRBuilder<> &IRB, Function &F, ReturnInst &RI,
-                       AllocaInst *StackGuardSlot, Value *StackGuard);
-
-  /// Find all static allocas, dynamic allocas, return instructions and
-  /// stack restore points (exception unwind blocks and setjmp calls) in the
-  /// given function and append them to the respective vectors.
-  void findInsts(Function &F, SmallVectorImpl<AllocaInst *> &StaticAllocas,
-                 SmallVectorImpl<AllocaInst *> &DynamicAllocas,
-                 SmallVectorImpl<Argument *> &ByValArguments,
-                 SmallVectorImpl<ReturnInst *> &Returns,
-                 SmallVectorImpl<Instruction *> &StackRestorePoints);
-
-  /// Calculate the allocation size of a given alloca. Returns 0 if the
-  /// size can not be statically determined.
-  uint64_t getStaticAllocaAllocationSize(const AllocaInst* AI);
-
-  /// Allocate space for all static allocas in \p StaticAllocas,
-  /// replace allocas with pointers into the unsafe stack and generate code to
-  /// restore the stack pointer before all return instructions in \p Returns.
-  ///
-  /// \returns A pointer to the top of the unsafe stack after all unsafe static
-  /// allocas are allocated.
-  Value *moveStaticAllocasToUnsafeStack(IRBuilder<> &IRB, Function &F,
-                                        ArrayRef<AllocaInst *> StaticAllocas,
-                                        ArrayRef<Argument *> ByValArguments,
-                                        ArrayRef<ReturnInst *> Returns,
-                                        Instruction *BasePointer,
-                                        AllocaInst *StackGuardSlot);
-
-  /// Generate code to restore the stack after all stack restore points
-  /// in \p StackRestorePoints.
-  ///
-  /// \returns A local variable in which to maintain the dynamic top of the
-  /// unsafe stack if needed.
-  AllocaInst *
-  createStackRestorePoints(IRBuilder<> &IRB, Function &F,
-                           ArrayRef<Instruction *> StackRestorePoints,
-                           Value *StaticTop, bool NeedDynamicTop);
-
-  /// Replace all allocas in \p DynamicAllocas with code to allocate
-  /// space dynamically on the unsafe stack and store the dynamic unsafe stack
-  /// top to \p DynamicTop if non-null.
-  void moveDynamicAllocasToUnsafeStack(Function &F, Value *UnsafeStackPtr,
-                                       AllocaInst *DynamicTop,
-                                       ArrayRef<AllocaInst *> DynamicAllocas);
-
-  bool IsSafeStackAlloca(const Value *AllocaPtr, uint64_t AllocaSize);
-
-  bool IsMemIntrinsicSafe(const MemIntrinsic *MI, const Use &U,
-                          const Value *AllocaPtr, uint64_t AllocaSize);
-  bool IsAccessSafe(Value *Addr, uint64_t Size, const Value *AllocaPtr,
-                    uint64_t AllocaSize);
-
-  bool ShouldInlinePointerAddress(CallSite &CS);
-  void TryInlinePointerAddress();
-
-public:
-  SafeStack(Function &F, const TargetLoweringBase &TL, const DataLayout &DL,
-            ScalarEvolution &SE)
-      : F(F), TL(TL), DL(DL), SE(SE),
-        StackPtrTy(Type::getInt8PtrTy(F.getContext())),
-        IntPtrTy(DL.getIntPtrType(F.getContext())),
-        Int32Ty(Type::getInt32Ty(F.getContext())),
-        Int8Ty(Type::getInt8Ty(F.getContext())) {}
-
-  // Run the transformation on the associated function.
-  // Returns whether the function was changed.
-  bool run();
-};
-
-uint64_t SafeStack::getStaticAllocaAllocationSize(const AllocaInst* AI) {
-  uint64_t Size = DL.getTypeAllocSize(AI->getAllocatedType());
-  if (AI->isArrayAllocation()) {
-    auto C = dyn_cast<ConstantInt>(AI->getArraySize());
-    if (!C)
-      return 0;
-    Size *= C->getZExtValue();
-  }
-  return Size;
-}
-
-bool SafeStack::IsAccessSafe(Value *Addr, uint64_t AccessSize,
-                             const Value *AllocaPtr, uint64_t AllocaSize) {
-  AllocaOffsetRewriter Rewriter(SE, AllocaPtr);
-  const SCEV *Expr = Rewriter.visit(SE.getSCEV(Addr));
-
-  uint64_t BitWidth = SE.getTypeSizeInBits(Expr->getType());
-  ConstantRange AccessStartRange = SE.getUnsignedRange(Expr);
-  ConstantRange SizeRange =
-      ConstantRange(APInt(BitWidth, 0), APInt(BitWidth, AccessSize));
-  ConstantRange AccessRange = AccessStartRange.add(SizeRange);
-  ConstantRange AllocaRange =
-      ConstantRange(APInt(BitWidth, 0), APInt(BitWidth, AllocaSize));
-  bool Safe = AllocaRange.contains(AccessRange);
-
-  LLVM_DEBUG(
-      dbgs() << "[SafeStack] "
-             << (isa<AllocaInst>(AllocaPtr) ? "Alloca " : "ByValArgument ")
-             << *AllocaPtr << "\n"
-             << "            Access " << *Addr << "\n"
-             << "            SCEV " << *Expr
-             << " U: " << SE.getUnsignedRange(Expr)
-             << ", S: " << SE.getSignedRange(Expr) << "\n"
-             << "            Range " << AccessRange << "\n"
-             << "            AllocaRange " << AllocaRange << "\n"
-             << "            " << (Safe ? "safe" : "unsafe") << "\n");
-
-  return Safe;
-}
-
-bool SafeStack::IsMemIntrinsicSafe(const MemIntrinsic *MI, const Use &U,
-                                   const Value *AllocaPtr,
-                                   uint64_t AllocaSize) {
-  if (auto MTI = dyn_cast<MemTransferInst>(MI)) {
-    if (MTI->getRawSource() != U && MTI->getRawDest() != U)
-      return true;
-  } else {
-    if (MI->getRawDest() != U)
-      return true;
-  }
-
-  const auto *Len = dyn_cast<ConstantInt>(MI->getLength());
-  // Non-constant size => unsafe. FIXME: try SCEV getRange.
-  if (!Len) return false;
-  return IsAccessSafe(U, Len->getZExtValue(), AllocaPtr, AllocaSize);
-}
-
-/// Check whether a given allocation must be put on the safe
-/// stack or not. The function analyzes all uses of AI and checks whether it is
-/// only accessed in a memory safe way (as decided statically).
-bool SafeStack::IsSafeStackAlloca(const Value *AllocaPtr, uint64_t AllocaSize) {
-  // Go through all uses of this alloca and check whether all accesses to the
-  // allocated object are statically known to be memory safe and, hence, the
-  // object can be placed on the safe stack.
-  SmallPtrSet<const Value *, 16> Visited;
-  SmallVector<const Value *, 8> WorkList;
-  WorkList.push_back(AllocaPtr);
-
-  // A DFS search through all uses of the alloca in bitcasts/PHI/GEPs/etc.
-  while (!WorkList.empty()) {
-    const Value *V = WorkList.pop_back_val();
-    for (const Use &UI : V->uses()) {
-      auto I = cast<const Instruction>(UI.getUser());
-      assert(V == UI.get());
-
-      switch (I->getOpcode()) {
-      case Instruction::Load:
-        if (!IsAccessSafe(UI, DL.getTypeStoreSize(I->getType()), AllocaPtr,
-                          AllocaSize))
-          return false;
-        break;
-
-      case Instruction::VAArg:
-        // "va-arg" from a pointer is safe.
-        break;
-      case Instruction::Store:
-        if (V == I->getOperand(0)) {
-          // Stored the pointer - conservatively assume it may be unsafe.
-          LLVM_DEBUG(dbgs()
-                     << "[SafeStack] Unsafe alloca: " << *AllocaPtr
-                     << "\n            store of address: " << *I << "\n");
-          return false;
-        }
-
-        if (!IsAccessSafe(UI, DL.getTypeStoreSize(I->getOperand(0)->getType()),
-                          AllocaPtr, AllocaSize))
-          return false;
-        break;
-
-      case Instruction::Ret:
-        // Information leak.
-        return false;
-
-      case Instruction::Call:
-      case Instruction::Invoke: {
-        ImmutableCallSite CS(I);
-
-        if (I->isLifetimeStartOrEnd())
-          continue;
-
-        if (const MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I)) {
-          if (!IsMemIntrinsicSafe(MI, UI, AllocaPtr, AllocaSize)) {
-            LLVM_DEBUG(dbgs()
-                       << "[SafeStack] Unsafe alloca: " << *AllocaPtr
-                       << "\n            unsafe memintrinsic: " << *I << "\n");
-            return false;
-          }
-          continue;
-        }
-
-        // LLVM 'nocapture' attribute is only set for arguments whose address
-        // is not stored, passed around, or used in any other non-trivial way.
-        // We assume that passing a pointer to an object as a 'nocapture
-        // readnone' argument is safe.
-        // FIXME: a more precise solution would require an interprocedural
-        // analysis here, which would look at all uses of an argument inside
-        // the function being called.
-        ImmutableCallSite::arg_iterator B = CS.arg_begin(), E = CS.arg_end();
-        for (ImmutableCallSite::arg_iterator A = B; A != E; ++A)
-          if (A->get() == V)
-            if (!(CS.doesNotCapture(A - B) && (CS.doesNotAccessMemory(A - B) ||
-                                               CS.doesNotAccessMemory()))) {
-              LLVM_DEBUG(dbgs() << "[SafeStack] Unsafe alloca: " << *AllocaPtr
-                                << "\n            unsafe call: " << *I << "\n");
-              return false;
-            }
-        continue;
-      }
-
-      default:
-        if (Visited.insert(I).second)
-          WorkList.push_back(cast<const Instruction>(I));
-      }
-    }
-  }
-
-  // All uses of the alloca are safe, we can place it on the safe stack.
-  return true;
-}
-
-Value *SafeStack::getStackGuard(IRBuilder<> &IRB, Function &F) {
-  Value *StackGuardVar = TL.getIRStackGuard(IRB);
-  if (!StackGuardVar)
-    StackGuardVar =
-        F.getParent()->getOrInsertGlobal("__stack_chk_guard", StackPtrTy);
-  return IRB.CreateLoad(StackPtrTy, StackGuardVar, "StackGuard");
-}
-
-void SafeStack::findInsts(Function &F,
-                          SmallVectorImpl<AllocaInst *> &StaticAllocas,
-                          SmallVectorImpl<AllocaInst *> &DynamicAllocas,
-                          SmallVectorImpl<Argument *> &ByValArguments,
-                          SmallVectorImpl<ReturnInst *> &Returns,
-                          SmallVectorImpl<Instruction *> &StackRestorePoints) {
-  for (Instruction &I : instructions(&F)) {
-    if (auto AI = dyn_cast<AllocaInst>(&I)) {
-      ++NumAllocas;
-
-      uint64_t Size = getStaticAllocaAllocationSize(AI);
-      if (IsSafeStackAlloca(AI, Size))
-        continue;
-
-      if (AI->isStaticAlloca()) {
-        ++NumUnsafeStaticAllocas;
-        StaticAllocas.push_back(AI);
-      } else {
-        ++NumUnsafeDynamicAllocas;
-        DynamicAllocas.push_back(AI);
-      }
-    } else if (auto RI = dyn_cast<ReturnInst>(&I)) {
-      Returns.push_back(RI);
-    } else if (auto CI = dyn_cast<CallInst>(&I)) {
-      // setjmps require stack restore.
-      if (CI->getCalledFunction() && CI->canReturnTwice())
-        StackRestorePoints.push_back(CI);
-    } else if (auto LP = dyn_cast<LandingPadInst>(&I)) {
-      // Exception landing pads require stack restore.
-      StackRestorePoints.push_back(LP);
-    } else if (auto II = dyn_cast<IntrinsicInst>(&I)) {
-      if (II->getIntrinsicID() == Intrinsic::gcroot)
-        report_fatal_error(
-            "gcroot intrinsic not compatible with safestack attribute");
-    }
-  }
-  for (Argument &Arg : F.args()) {
-    if (!Arg.hasByValAttr())
-      continue;
-    uint64_t Size =
-        DL.getTypeStoreSize(Arg.getType()->getPointerElementType());
-    if (IsSafeStackAlloca(&Arg, Size))
-      continue;
-
-    ++NumUnsafeByValArguments;
-    ByValArguments.push_back(&Arg);
-  }
-}
-
-AllocaInst *
-SafeStack::createStackRestorePoints(IRBuilder<> &IRB, Function &F,
-                                    ArrayRef<Instruction *> StackRestorePoints,
-                                    Value *StaticTop, bool NeedDynamicTop) {
-  assert(StaticTop && "The stack top isn't set.");
-
-  if (StackRestorePoints.empty())
-    return nullptr;
-
-  // We need the current value of the shadow stack pointer to restore
-  // after longjmp or exception catching.
-
-  // FIXME: On some platforms this could be handled by the longjmp/exception
-  // runtime itself.
-
-  AllocaInst *DynamicTop = nullptr;
-  if (NeedDynamicTop) {
-    // If we also have dynamic alloca's, the stack pointer value changes
-    // throughout the function. For now we store it in an alloca.
-    DynamicTop = IRB.CreateAlloca(StackPtrTy, /*ArraySize=*/nullptr,
-                                  "unsafe_stack_dynamic_ptr");
-    IRB.CreateStore(StaticTop, DynamicTop);
-  }
-
-  // Restore current stack pointer after longjmp/exception catch.
-  for (Instruction *I : StackRestorePoints) {
-    ++NumUnsafeStackRestorePoints;
-
-    IRB.SetInsertPoint(I->getNextNode());
-    Value *CurrentTop =
-        DynamicTop ? IRB.CreateLoad(StackPtrTy, DynamicTop) : StaticTop;
-    IRB.CreateStore(CurrentTop, UnsafeStackPtr);
-  }
-
-  return DynamicTop;
-}
-
-void SafeStack::checkStackGuard(IRBuilder<> &IRB, Function &F, ReturnInst &RI,
-                                AllocaInst *StackGuardSlot, Value *StackGuard) {
-  Value *V = IRB.CreateLoad(StackPtrTy, StackGuardSlot);
-  Value *Cmp = IRB.CreateICmpNE(StackGuard, V);
-
-  auto SuccessProb = BranchProbabilityInfo::getBranchProbStackProtector(true);
-  auto FailureProb = BranchProbabilityInfo::getBranchProbStackProtector(false);
-  MDNode *Weights = MDBuilder(F.getContext())
-                        .createBranchWeights(SuccessProb.getNumerator(),
-                                             FailureProb.getNumerator());
-  Instruction *CheckTerm =
-      SplitBlockAndInsertIfThen(Cmp, &RI,
-                                /* Unreachable */ true, Weights);
-  IRBuilder<> IRBFail(CheckTerm);
-  // FIXME: respect -fsanitize-trap / -ftrap-function here?
-  FunctionCallee StackChkFail =
-      F.getParent()->getOrInsertFunction("__stack_chk_fail", IRB.getVoidTy());
-  IRBFail.CreateCall(StackChkFail, {});
-}
-
-/// We explicitly compute and set the unsafe stack layout for all unsafe
-/// static alloca instructions. We save the unsafe "base pointer" in the
-/// prologue into a local variable and restore it in the epilogue.
-Value *SafeStack::moveStaticAllocasToUnsafeStack(
-    IRBuilder<> &IRB, Function &F, ArrayRef<AllocaInst *> StaticAllocas,
-    ArrayRef<Argument *> ByValArguments, ArrayRef<ReturnInst *> Returns,
-    Instruction *BasePointer, AllocaInst *StackGuardSlot) {
-  if (StaticAllocas.empty() && ByValArguments.empty())
-    return BasePointer;
-
-  DIBuilder DIB(*F.getParent());
-
-  StackColoring SSC(F, StaticAllocas);
-  SSC.run();
-  SSC.removeAllMarkers();
-
-  // Unsafe stack always grows down.
-  StackLayout SSL(StackAlignment);
-  if (StackGuardSlot) {
-    Type *Ty = StackGuardSlot->getAllocatedType();
-    unsigned Align =
-        std::max(DL.getPrefTypeAlignment(Ty), StackGuardSlot->getAlignment());
-    SSL.addObject(StackGuardSlot, getStaticAllocaAllocationSize(StackGuardSlot),
-                  Align, SSC.getFullLiveRange());
-  }
-
-  for (Argument *Arg : ByValArguments) {
-    Type *Ty = Arg->getType()->getPointerElementType();
-    uint64_t Size = DL.getTypeStoreSize(Ty);
-    if (Size == 0)
-      Size = 1; // Don't create zero-sized stack objects.
-
-    // Ensure the object is properly aligned.
-    unsigned Align = std::max((unsigned)DL.getPrefTypeAlignment(Ty),
-                              Arg->getParamAlignment());
-    SSL.addObject(Arg, Size, Align, SSC.getFullLiveRange());
-  }
-
-  for (AllocaInst *AI : StaticAllocas) {
-    Type *Ty = AI->getAllocatedType();
-    uint64_t Size = getStaticAllocaAllocationSize(AI);
-    if (Size == 0)
-      Size = 1; // Don't create zero-sized stack objects.
-
-    // Ensure the object is properly aligned.
-    unsigned Align =
-        std::max((unsigned)DL.getPrefTypeAlignment(Ty), AI->getAlignment());
-
-    SSL.addObject(AI, Size, Align, SSC.getLiveRange(AI));
-  }
-
-  SSL.computeLayout();
-  unsigned FrameAlignment = SSL.getFrameAlignment();
-
-  // FIXME: tell SSL that we start at a less-then-MaxAlignment aligned location
-  // (AlignmentSkew).
-  if (FrameAlignment > StackAlignment) {
-    // Re-align the base pointer according to the max requested alignment.
-    assert(isPowerOf2_32(FrameAlignment));
-    IRB.SetInsertPoint(BasePointer->getNextNode());
-    BasePointer = cast<Instruction>(IRB.CreateIntToPtr(
-        IRB.CreateAnd(IRB.CreatePtrToInt(BasePointer, IntPtrTy),
-                      ConstantInt::get(IntPtrTy, ~uint64_t(FrameAlignment - 1))),
-        StackPtrTy));
-  }
-
-  IRB.SetInsertPoint(BasePointer->getNextNode());
-
-  if (StackGuardSlot) {
-    unsigned Offset = SSL.getObjectOffset(StackGuardSlot);
-    Value *Off = IRB.CreateGEP(Int8Ty, BasePointer, // BasePointer is i8*
-                               ConstantInt::get(Int32Ty, -Offset));
-    Value *NewAI =
-        IRB.CreateBitCast(Off, StackGuardSlot->getType(), "StackGuardSlot");
-
-    // Replace alloc with the new location.
-    StackGuardSlot->replaceAllUsesWith(NewAI);
-    StackGuardSlot->eraseFromParent();
-  }
-
-  for (Argument *Arg : ByValArguments) {
-    unsigned Offset = SSL.getObjectOffset(Arg);
-    unsigned Align = SSL.getObjectAlignment(Arg);
-    Type *Ty = Arg->getType()->getPointerElementType();
-
-    uint64_t Size = DL.getTypeStoreSize(Ty);
-    if (Size == 0)
-      Size = 1; // Don't create zero-sized stack objects.
-
-    Value *Off = IRB.CreateGEP(Int8Ty, BasePointer, // BasePointer is i8*
-                               ConstantInt::get(Int32Ty, -Offset));
-    Value *NewArg = IRB.CreateBitCast(Off, Arg->getType(),
-                                     Arg->getName() + ".unsafe-byval");
-
-    // Replace alloc with the new location.
-    replaceDbgDeclare(Arg, BasePointer, BasePointer->getNextNode(), DIB,
-                      DIExpression::ApplyOffset, -Offset);
-    Arg->replaceAllUsesWith(NewArg);
-    IRB.SetInsertPoint(cast<Instruction>(NewArg)->getNextNode());
-    IRB.CreateMemCpy(Off, Align, Arg, Arg->getParamAlignment(), Size);
-  }
-
-  // Allocate space for every unsafe static AllocaInst on the unsafe stack.
-  for (AllocaInst *AI : StaticAllocas) {
-    IRB.SetInsertPoint(AI);
-    unsigned Offset = SSL.getObjectOffset(AI);
-
-    replaceDbgDeclareForAlloca(AI, BasePointer, DIB, DIExpression::ApplyOffset,
-                               -Offset);
-    replaceDbgValueForAlloca(AI, BasePointer, DIB, -Offset);
-
-    // Replace uses of the alloca with the new location.
-    // Insert address calculation close to each use to work around PR27844.
-    std::string Name = std::string(AI->getName()) + ".unsafe";
-    while (!AI->use_empty()) {
-      Use &U = *AI->use_begin();
-      Instruction *User = cast<Instruction>(U.getUser());
-
-      Instruction *InsertBefore;
-      if (auto *PHI = dyn_cast<PHINode>(User))
-        InsertBefore = PHI->getIncomingBlock(U)->getTerminator();
-      else
-        InsertBefore = User;
-
-      IRBuilder<> IRBUser(InsertBefore);
-      Value *Off = IRBUser.CreateGEP(Int8Ty, BasePointer, // BasePointer is i8*
-                                     ConstantInt::get(Int32Ty, -Offset));
-      Value *Replacement = IRBUser.CreateBitCast(Off, AI->getType(), Name);
-
-      if (auto *PHI = dyn_cast<PHINode>(User))
-        // PHI nodes may have multiple incoming edges from the same BB (why??),
-        // all must be updated at once with the same incoming value.
-        PHI->setIncomingValueForBlock(PHI->getIncomingBlock(U), Replacement);
-      else
-        U.set(Replacement);
-    }
-
-    AI->eraseFromParent();
-  }
-
-  // Re-align BasePointer so that our callees would see it aligned as
-  // expected.
-  // FIXME: no need to update BasePointer in leaf functions.
-  unsigned FrameSize = alignTo(SSL.getFrameSize(), StackAlignment);
-
-  // Update shadow stack pointer in the function epilogue.
-  IRB.SetInsertPoint(BasePointer->getNextNode());
-
-  Value *StaticTop =
-      IRB.CreateGEP(Int8Ty, BasePointer, ConstantInt::get(Int32Ty, -FrameSize),
-                    "unsafe_stack_static_top");
-  IRB.CreateStore(StaticTop, UnsafeStackPtr);
-  return StaticTop;
-}
-
-void SafeStack::moveDynamicAllocasToUnsafeStack(
-    Function &F, Value *UnsafeStackPtr, AllocaInst *DynamicTop,
-    ArrayRef<AllocaInst *> DynamicAllocas) {
-  DIBuilder DIB(*F.getParent());
-
-  for (AllocaInst *AI : DynamicAllocas) {
-    IRBuilder<> IRB(AI);
-
-    // Compute the new SP value (after AI).
-    Value *ArraySize = AI->getArraySize();
-    if (ArraySize->getType() != IntPtrTy)
-      ArraySize = IRB.CreateIntCast(ArraySize, IntPtrTy, false);
-
-    Type *Ty = AI->getAllocatedType();
-    uint64_t TySize = DL.getTypeAllocSize(Ty);
-    Value *Size = IRB.CreateMul(ArraySize, ConstantInt::get(IntPtrTy, TySize));
-
-    Value *SP = IRB.CreatePtrToInt(IRB.CreateLoad(StackPtrTy, UnsafeStackPtr),
-                                   IntPtrTy);
-    SP = IRB.CreateSub(SP, Size);
-
-    // Align the SP value to satisfy the AllocaInst, type and stack alignments.
-    unsigned Align = std::max(
-        std::max((unsigned)DL.getPrefTypeAlignment(Ty), AI->getAlignment()),
-        (unsigned)StackAlignment);
-
-    assert(isPowerOf2_32(Align));
-    Value *NewTop = IRB.CreateIntToPtr(
-        IRB.CreateAnd(SP, ConstantInt::get(IntPtrTy, ~uint64_t(Align - 1))),
-        StackPtrTy);
-
-    // Save the stack pointer.
-    IRB.CreateStore(NewTop, UnsafeStackPtr);
-    if (DynamicTop)
-      IRB.CreateStore(NewTop, DynamicTop);
-
-    Value *NewAI = IRB.CreatePointerCast(NewTop, AI->getType());
-    if (AI->hasName() && isa<Instruction>(NewAI))
-      NewAI->takeName(AI);
-
-    replaceDbgDeclareForAlloca(AI, NewAI, DIB, DIExpression::ApplyOffset, 0);
-    AI->replaceAllUsesWith(NewAI);
-    AI->eraseFromParent();
-  }
-
-  if (!DynamicAllocas.empty()) {
-    // Now go through the instructions again, replacing stacksave/stackrestore.
-    for (inst_iterator It = inst_begin(&F), Ie = inst_end(&F); It != Ie;) {
-      Instruction *I = &*(It++);
-      auto II = dyn_cast<IntrinsicInst>(I);
-      if (!II)
-        continue;
-
-      if (II->getIntrinsicID() == Intrinsic::stacksave) {
-        IRBuilder<> IRB(II);
-        Instruction *LI = IRB.CreateLoad(StackPtrTy, UnsafeStackPtr);
-        LI->takeName(II);
-        II->replaceAllUsesWith(LI);
-        II->eraseFromParent();
-      } else if (II->getIntrinsicID() == Intrinsic::stackrestore) {
-        IRBuilder<> IRB(II);
-        Instruction *SI = IRB.CreateStore(II->getArgOperand(0), UnsafeStackPtr);
-        SI->takeName(II);
-        assert(II->use_empty());
-        II->eraseFromParent();
-      }
-    }
-  }
-}
-
-bool SafeStack::ShouldInlinePointerAddress(CallSite &CS) {
-  Function *Callee = CS.getCalledFunction();
-  if (CS.hasFnAttr(Attribute::AlwaysInline) && isInlineViable(*Callee))
-    return true;
-  if (Callee->isInterposable() || Callee->hasFnAttribute(Attribute::NoInline) ||
-      CS.isNoInline())
-    return false;
-  return true;
-}
-
-void SafeStack::TryInlinePointerAddress() {
-  if (!isa<CallInst>(UnsafeStackPtr))
-    return;
-
-  if(F.hasOptNone())
-    return;
-
-  CallSite CS(UnsafeStackPtr);
-  Function *Callee = CS.getCalledFunction();
-  if (!Callee || Callee->isDeclaration())
-    return;
-
-  if (!ShouldInlinePointerAddress(CS))
-    return;
-
-  InlineFunctionInfo IFI;
-  InlineFunction(CS, IFI);
-}
-
-bool SafeStack::run() {
-  assert(F.hasFnAttribute(Attribute::SafeStack) &&
-         "Can't run SafeStack on a function without the attribute");
-  assert(!F.isDeclaration() && "Can't run SafeStack on a function declaration");
-
-  ++NumFunctions;
-
-  SmallVector<AllocaInst *, 16> StaticAllocas;
-  SmallVector<AllocaInst *, 4> DynamicAllocas;
-  SmallVector<Argument *, 4> ByValArguments;
-  SmallVector<ReturnInst *, 4> Returns;
-
-  // Collect all points where stack gets unwound and needs to be restored
-  // This is only necessary because the runtime (setjmp and unwind code) is
-  // not aware of the unsafe stack and won't unwind/restore it properly.
-  // To work around this problem without changing the runtime, we insert
-  // instrumentation to restore the unsafe stack pointer when necessary.
-  SmallVector<Instruction *, 4> StackRestorePoints;
-
-  // Find all static and dynamic alloca instructions that must be moved to the
-  // unsafe stack, all return instructions and stack restore points.
-  findInsts(F, StaticAllocas, DynamicAllocas, ByValArguments, Returns,
-            StackRestorePoints);
-
-  if (StaticAllocas.empty() && DynamicAllocas.empty() &&
-      ByValArguments.empty() && StackRestorePoints.empty())
-    return false; // Nothing to do in this function.
-
-  if (!StaticAllocas.empty() || !DynamicAllocas.empty() ||
-      !ByValArguments.empty())
-    ++NumUnsafeStackFunctions; // This function has the unsafe stack.
-
-  if (!StackRestorePoints.empty())
-    ++NumUnsafeStackRestorePointsFunctions;
-
-  IRBuilder<> IRB(&F.front(), F.begin()->getFirstInsertionPt());
-  // Calls must always have a debug location, or else inlining breaks. So
-  // we explicitly set a artificial debug location here.
-  if (DISubprogram *SP = F.getSubprogram())
-    IRB.SetCurrentDebugLocation(DebugLoc::get(SP->getScopeLine(), 0, SP));
-  if (SafeStackUsePointerAddress) {
-    FunctionCallee Fn = F.getParent()->getOrInsertFunction(
-        "__safestack_pointer_address", StackPtrTy->getPointerTo(0));
-    UnsafeStackPtr = IRB.CreateCall(Fn);
-  } else {
-    UnsafeStackPtr = TL.getSafeStackPointerLocation(IRB);
-  }
-
-  // Load the current stack pointer (we'll also use it as a base pointer).
-  // FIXME: use a dedicated register for it ?
-  Instruction *BasePointer =
-      IRB.CreateLoad(StackPtrTy, UnsafeStackPtr, false, "unsafe_stack_ptr");
-  assert(BasePointer->getType() == StackPtrTy);
-
-  AllocaInst *StackGuardSlot = nullptr;
-  // FIXME: implement weaker forms of stack protector.
-  if (F.hasFnAttribute(Attribute::StackProtect) ||
-      F.hasFnAttribute(Attribute::StackProtectStrong) ||
-      F.hasFnAttribute(Attribute::StackProtectReq)) {
-    Value *StackGuard = getStackGuard(IRB, F);
-    StackGuardSlot = IRB.CreateAlloca(StackPtrTy, nullptr);
-    IRB.CreateStore(StackGuard, StackGuardSlot);
-
-    for (ReturnInst *RI : Returns) {
-      IRBuilder<> IRBRet(RI);
-      checkStackGuard(IRBRet, F, *RI, StackGuardSlot, StackGuard);
-    }
-  }
-
-  // The top of the unsafe stack after all unsafe static allocas are
-  // allocated.
-  Value *StaticTop =
-      moveStaticAllocasToUnsafeStack(IRB, F, StaticAllocas, ByValArguments,
-                                     Returns, BasePointer, StackGuardSlot);
-
-  // Safe stack object that stores the current unsafe stack top. It is updated
-  // as unsafe dynamic (non-constant-sized) allocas are allocated and freed.
-  // This is only needed if we need to restore stack pointer after longjmp
-  // or exceptions, and we have dynamic allocations.
-  // FIXME: a better alternative might be to store the unsafe stack pointer
-  // before setjmp / invoke instructions.
-  AllocaInst *DynamicTop = createStackRestorePoints(
-      IRB, F, StackRestorePoints, StaticTop, !DynamicAllocas.empty());
-
-  // Handle dynamic allocas.
-  moveDynamicAllocasToUnsafeStack(F, UnsafeStackPtr, DynamicTop,
-                                  DynamicAllocas);
-
-  // Restore the unsafe stack pointer before each return.
-  for (ReturnInst *RI : Returns) {
-    IRB.SetInsertPoint(RI);
-    IRB.CreateStore(BasePointer, UnsafeStackPtr);
-  }
-
-  TryInlinePointerAddress();
-
-  LLVM_DEBUG(dbgs() << "[SafeStack]     safestack applied\n");
-  return true;
-}
-
-class SafeStackLegacyPass : public FunctionPass {
-  const TargetMachine *TM = nullptr;
-
-public:
-  static char ID; // Pass identification, replacement for typeid..
-
-  SafeStackLegacyPass() : FunctionPass(ID) {
-    initializeSafeStackLegacyPassPass(*PassRegistry::getPassRegistry());
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<TargetPassConfig>();
-    AU.addRequired<TargetLibraryInfoWrapperPass>();
-    AU.addRequired<AssumptionCacheTracker>();
-  }
-
-  bool runOnFunction(Function &F) override {
-    LLVM_DEBUG(dbgs() << "[SafeStack] Function: " << F.getName() << "\n");
-
-    if (!F.hasFnAttribute(Attribute::SafeStack)) {
-      LLVM_DEBUG(dbgs() << "[SafeStack]     safestack is not requested"
-                           " for this function\n");
-      return false;
-    }
-
-    if (F.isDeclaration()) {
-      LLVM_DEBUG(dbgs() << "[SafeStack]     function definition"
-                           " is not available\n");
-      return false;
-    }
-
-    TM = &getAnalysis<TargetPassConfig>().getTM<TargetMachine>();
-    auto *TL = TM->getSubtargetImpl(F)->getTargetLowering();
-    if (!TL)
-      report_fatal_error("TargetLowering instance is required");
-
-    auto *DL = &F.getParent()->getDataLayout();
-    auto &TLI = getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
-    auto &ACT = getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
-
-    // Compute DT and LI only for functions that have the attribute.
-    // This is only useful because the legacy pass manager doesn't let us
-    // compute analyzes lazily.
-    // In the backend pipeline, nothing preserves DT before SafeStack, so we
-    // would otherwise always compute it wastefully, even if there is no
-    // function with the safestack attribute.
-    DominatorTree DT(F);
-    LoopInfo LI(DT);
-
-    ScalarEvolution SE(F, TLI, ACT, DT, LI);
-
-    return SafeStack(F, *TL, *DL, SE).run();
-  }
-};
-
-} // end anonymous namespace
-
-char SafeStackLegacyPass::ID = 0;
-
-INITIALIZE_PASS_BEGIN(SafeStackLegacyPass, DEBUG_TYPE,
-                      "Safe Stack instrumentation pass", false, false)
-INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
-INITIALIZE_PASS_END(SafeStackLegacyPass, DEBUG_TYPE,
-                    "Safe Stack instrumentation pass", false, false)
-
-FunctionPass *llvm::createSafeStackPass() { return new SafeStackLegacyPass(); }