runtime/stack.cc

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "stack.h"
#include <limits>

#include "android-base/stringprintf.h"

#include "arch/context.h"
#include "art_method-inl.h"
#include "base/aborting.h"
#include "base/callee_save_type.h"
#include "base/enums.h"
#include "base/hex_dump.h"
#include "base/mutex.h"
#include "dex/dex_file_types.h"
#include "entrypoints/entrypoint_utils-inl.h"
#include "entrypoints/quick/callee_save_frame.h"
#include "entrypoints/runtime_asm_entrypoints.h"
#include "gc/space/image_space.h"
#include "gc/space/space-inl.h"
#include "interpreter/shadow_frame-inl.h"
#include "jit/jit.h"
#include "jit/jit_code_cache.h"
#include "linear_alloc.h"
#include "managed_stack.h"
#include "mirror/class-inl.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "nterp_helpers.h"
#include "oat_quick_method_header.h"
#include "obj_ptr-inl.h"
#include "quick/quick_method_frame_info.h"
#include "runtime.h"
#include "thread.h"
#include "thread_list.h"

namespace art {

using android::base::StringPrintf;

static constexpr bool kDebugStackWalk = false;

StackVisitor::StackVisitor(Thread* thread,
                           Context* context,
                           StackWalkKind walk_kind,
                           bool check_suspended)
    : StackVisitor(thread, context, walk_kind, 0, check_suspended) {}

StackVisitor::StackVisitor(Thread* thread,
                           Context* context,
                           StackWalkKind walk_kind,
                           size_t num_frames,
                           bool check_suspended)
    : thread_(thread),
      walk_kind_(walk_kind),
      cur_shadow_frame_(nullptr),
      cur_quick_frame_(nullptr),
      cur_quick_frame_pc_(0),
      cur_oat_quick_method_header_(nullptr),
      num_frames_(num_frames),
      cur_depth_(0),
      walk_started_(false),
      cur_inline_info_(nullptr, CodeInfo()),
      cur_stack_map_(0, StackMap()),
      context_(context),
      check_suspended_(check_suspended) {
  if (check_suspended_) {
    DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
  }
}

CodeInfo* StackVisitor::GetCurrentInlineInfo() const {
  DCHECK(!(*cur_quick_frame_)->IsNative());
  const OatQuickMethodHeader* header = GetCurrentOatQuickMethodHeader();
  if (cur_inline_info_.first != header) {
    cur_inline_info_ = std::make_pair(header, CodeInfo::DecodeInlineInfoOnly(header));
  }
  return &cur_inline_info_.second;
}

StackMap* StackVisitor::GetCurrentStackMap() const {
  DCHECK(!(*cur_quick_frame_)->IsNative());
  const OatQuickMethodHeader* header = GetCurrentOatQuickMethodHeader();
  if (cur_stack_map_.first != cur_quick_frame_pc_) {
    uint32_t pc = header->NativeQuickPcOffset(cur_quick_frame_pc_);
    cur_stack_map_ = std::make_pair(cur_quick_frame_pc_,
                                    GetCurrentInlineInfo()->GetStackMapForNativePcOffset(pc));
  }
  return &cur_stack_map_.second;
}

ArtMethod* StackVisitor::GetMethod() const {
  if (cur_shadow_frame_ != nullptr) {
    return cur_shadow_frame_->GetMethod();
  } else if (cur_quick_frame_ != nullptr) {
    if (IsInInlinedFrame()) {
      CodeInfo* code_info = GetCurrentInlineInfo();
      DCHECK(walk_kind_ != StackWalkKind::kSkipInlinedFrames);
      return GetResolvedMethod(*GetCurrentQuickFrame(), *code_info, current_inline_frames_);
    } else {
      return *cur_quick_frame_;
    }
  }
  return nullptr;
}

uint32_t StackVisitor::GetDexPc(bool abort_on_failure) const {
  if (cur_shadow_frame_ != nullptr) {
    return cur_shadow_frame_->GetDexPC();
  } else if (cur_quick_frame_ != nullptr) {
    if (IsInInlinedFrame()) {
      return current_inline_frames_.back().GetDexPc();
    } else if (cur_oat_quick_method_header_ == nullptr) {
      return dex::kDexNoIndex;
    } else if ((*GetCurrentQuickFrame())->IsNative()) {
      return cur_oat_quick_method_header_->ToDexPc(
          GetCurrentQuickFrame(), cur_quick_frame_pc_, abort_on_failure);
    } else if (cur_oat_quick_method_header_->IsOptimized()) {
      StackMap* stack_map = GetCurrentStackMap();
      DCHECK(stack_map->IsValid());
      return stack_map->GetDexPc();
    } else {
      DCHECK(cur_oat_quick_method_header_->IsNterpMethodHeader());
      return NterpGetDexPC(cur_quick_frame_);
    }
  } else {
    return 0;
  }
}

extern "C" mirror::Object* artQuickGetProxyThisObject(ArtMethod** sp)
    REQUIRES_SHARED(Locks::mutator_lock_);

ObjPtr<mirror::Object> StackVisitor::GetThisObject() const {
  DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), kRuntimePointerSize);
  ArtMethod* m = GetMethod();
  if (m->IsStatic()) {
    return nullptr;
  } else if (m->IsNative()) {
    if (cur_quick_frame_ != nullptr) {
      HandleScope* hs = reinterpret_cast<HandleScope*>(
          reinterpret_cast<char*>(cur_quick_frame_) + sizeof(ArtMethod*));
      return hs->GetReference(0);
    } else {
      return cur_shadow_frame_->GetVRegReference(0);
    }
  } else if (m->IsProxyMethod()) {
    if (cur_quick_frame_ != nullptr) {
      return artQuickGetProxyThisObject(cur_quick_frame_);
    } else {
      return cur_shadow_frame_->GetVRegReference(0);
    }
  } else {
    CodeItemDataAccessor accessor(m->DexInstructionData());
    if (!accessor.HasCodeItem()) {
      UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method: "
          << ArtMethod::PrettyMethod(m);
      return nullptr;
    } else {
      uint16_t reg = accessor.RegistersSize() - accessor.InsSize();
      uint32_t value = 0;
      if (!GetVReg(m, reg, kReferenceVReg, &value)) {
        return nullptr;
      }
      return reinterpret_cast<mirror::Object*>(value);
    }
  }
}

size_t StackVisitor::GetNativePcOffset() const {
  DCHECK(!IsShadowFrame());
  return GetCurrentOatQuickMethodHeader()->NativeQuickPcOffset(cur_quick_frame_pc_);
}

bool StackVisitor::GetVRegFromDebuggerShadowFrame(uint16_t vreg,
                                                  VRegKind kind,
                                                  uint32_t* val) const {
  size_t frame_id = const_cast<StackVisitor*>(this)->GetFrameId();
  ShadowFrame* shadow_frame = thread_->FindDebuggerShadowFrame(frame_id);
  if (shadow_frame != nullptr) {
    bool* updated_vreg_flags = thread_->GetUpdatedVRegFlags(frame_id);
    DCHECK(updated_vreg_flags != nullptr);
    if (updated_vreg_flags[vreg]) {
      // Value is set by the debugger.
      if (kind == kReferenceVReg) {
        *val = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(
            shadow_frame->GetVRegReference(vreg)));
      } else {
        *val = shadow_frame->GetVReg(vreg);
      }
      return true;
    }
  }
  // No value is set by the debugger.
  return false;
}

bool StackVisitor::GetVReg(ArtMethod* m,
                           uint16_t vreg,
                           VRegKind kind,
                           uint32_t* val,
                           std::optional<DexRegisterLocation> location) const {
  if (cur_quick_frame_ != nullptr) {
    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
    DCHECK(m == GetMethod());
    // Check if there is value set by the debugger.
    if (GetVRegFromDebuggerShadowFrame(vreg, kind, val)) {
      return true;
    }
    bool result = false;
    if (cur_oat_quick_method_header_->IsNterpMethodHeader()) {
      result = true;
      *val = (kind == kReferenceVReg)
          ? NterpGetVRegReference(cur_quick_frame_, vreg)
          : NterpGetVReg(cur_quick_frame_, vreg);
    } else {
      DCHECK(cur_oat_quick_method_header_->IsOptimized());
      if (location.has_value() && kind != kReferenceVReg) {
        uint32_t val2 = *val;
        // The caller already known the register location, so we can use the faster overload
        // which does not decode the stack maps.
        result = GetVRegFromOptimizedCode(location.value(), kind, val);
        // Compare to the slower overload.
        DCHECK_EQ(result, GetVRegFromOptimizedCode(m, vreg, kind, &val2));
        DCHECK_EQ(*val, val2);
      } else {
        result = GetVRegFromOptimizedCode(m, vreg, kind, val);
      }
    }
    if (kind == kReferenceVReg) {
      // Perform a read barrier in case we are in a different thread and GC is ongoing.
      mirror::Object* out = reinterpret_cast<mirror::Object*>(static_cast<uintptr_t>(*val));
      uintptr_t ptr_out = reinterpret_cast<uintptr_t>(GcRoot<mirror::Object>(out).Read());
      DCHECK_LT(ptr_out, std::numeric_limits<uint32_t>::max());
      *val = static_cast<uint32_t>(ptr_out);
    }
    return result;
  } else {
    DCHECK(cur_shadow_frame_ != nullptr);
    if (kind == kReferenceVReg) {
      *val = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(
          cur_shadow_frame_->GetVRegReference(vreg)));
    } else {
      *val = cur_shadow_frame_->GetVReg(vreg);
    }
    return true;
  }
}

bool StackVisitor::GetVRegFromOptimizedCode(ArtMethod* m, uint16_t vreg, VRegKind kind,
                                            uint32_t* val) const {
  DCHECK_EQ(m, GetMethod());
  // Can't be null or how would we compile its instructions?
  DCHECK(m->GetCodeItem() != nullptr) << m->PrettyMethod();
  CodeItemDataAccessor accessor(m->DexInstructionData());
  uint16_t number_of_dex_registers = accessor.RegistersSize();
  DCHECK_LT(vreg, number_of_dex_registers);
  const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
  CodeInfo code_info(method_header);

  uint32_t native_pc_offset = method_header->NativeQuickPcOffset(cur_quick_frame_pc_);
  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset);
  DCHECK(stack_map.IsValid());

  DexRegisterMap dex_register_map = IsInInlinedFrame()
      ? code_info.GetInlineDexRegisterMapOf(stack_map, current_inline_frames_.back())
      : code_info.GetDexRegisterMapOf(stack_map);
  if (dex_register_map.empty()) {
    return false;
  }
  DCHECK_EQ(dex_register_map.size(), number_of_dex_registers);
  DexRegisterLocation::Kind location_kind = dex_register_map[vreg].GetKind();
  switch (location_kind) {
    case DexRegisterLocation::Kind::kInStack: {
      const int32_t offset = dex_register_map[vreg].GetStackOffsetInBytes();
      BitMemoryRegion stack_mask = code_info.GetStackMaskOf(stack_map);
      if (kind == kReferenceVReg && !stack_mask.LoadBit(offset / kFrameSlotSize)) {
        return false;
      }
      const uint8_t* addr = reinterpret_cast<const uint8_t*>(cur_quick_frame_) + offset;
      *val = *reinterpret_cast<const uint32_t*>(addr);
      return true;
    }
    case DexRegisterLocation::Kind::kInRegister: {
      uint32_t register_mask = code_info.GetRegisterMaskOf(stack_map);
      uint32_t reg = dex_register_map[vreg].GetMachineRegister();
      if (kind == kReferenceVReg && !(register_mask & (1 << reg))) {
        return false;
      }
      return GetRegisterIfAccessible(reg, kind, val);
    }
    case DexRegisterLocation::Kind::kInRegisterHigh:
    case DexRegisterLocation::Kind::kInFpuRegister:
    case DexRegisterLocation::Kind::kInFpuRegisterHigh: {
      if (kind == kReferenceVReg) {
        return false;
      }
      uint32_t reg = dex_register_map[vreg].GetMachineRegister();
      return GetRegisterIfAccessible(reg, kind, val);
    }
    case DexRegisterLocation::Kind::kConstant: {
      uint32_t result = dex_register_map[vreg].GetConstant();
      if (kind == kReferenceVReg && result != 0) {
        return false;
      }
      *val = result;
      return true;
    }
    case DexRegisterLocation::Kind::kNone:
      return false;
    default:
      LOG(FATAL) << "Unexpected location kind " << dex_register_map[vreg].GetKind();
      UNREACHABLE();
  }
}

bool StackVisitor::GetVRegFromOptimizedCode(DexRegisterLocation location,
                                            VRegKind kind,
                                            uint32_t* val) const {
  switch (location.GetKind()) {
    case DexRegisterLocation::Kind::kInvalid:
      break;
    case DexRegisterLocation::Kind::kInStack: {
      const uint8_t* sp = reinterpret_cast<const uint8_t*>(cur_quick_frame_);
      *val = *reinterpret_cast<const uint32_t*>(sp + location.GetStackOffsetInBytes());
      return true;
    }
    case DexRegisterLocation::Kind::kInRegister:
    case DexRegisterLocation::Kind::kInRegisterHigh:
    case DexRegisterLocation::Kind::kInFpuRegister:
    case DexRegisterLocation::Kind::kInFpuRegisterHigh:
      return GetRegisterIfAccessible(location.GetMachineRegister(), kind, val);
    case DexRegisterLocation::Kind::kConstant:
      *val = location.GetConstant();
      return true;
    case DexRegisterLocation::Kind::kNone:
      return false;
  }
  LOG(FATAL) << "Unexpected location kind " << location.GetKind();
  UNREACHABLE();
}

bool StackVisitor::GetRegisterIfAccessible(uint32_t reg, VRegKind kind, uint32_t* val) const {
  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);

  if (kRuntimeISA == InstructionSet::kX86 && is_float) {
    // X86 float registers are 64-bit and each XMM register is provided as two separate
    // 32-bit registers by the context.
    reg = (kind == kDoubleHiVReg) ? (2 * reg + 1) : (2 * reg);
  }

  // MIPS32 float registers are used as 64-bit (for MIPS32r2 it is pair
  // F(2n)-F(2n+1), and for MIPS32r6 it is 64-bit register F(2n)). When
  // accessing upper 32-bits from double, reg + 1 should be used.
  if ((kRuntimeISA == InstructionSet::kMips) && (kind == kDoubleHiVReg)) {
    DCHECK_ALIGNED(reg, 2);
    reg++;
  }

  if (!IsAccessibleRegister(reg, is_float)) {
    return false;
  }
  uintptr_t ptr_val = GetRegister(reg, is_float);
  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
  if (target64) {
    const bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
    const bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
    int64_t value_long = static_cast<int64_t>(ptr_val);
    if (wide_lo) {
      ptr_val = static_cast<uintptr_t>(Low32Bits(value_long));
    } else if (wide_hi) {
      ptr_val = static_cast<uintptr_t>(High32Bits(value_long));
    }
  }
  *val = ptr_val;
  return true;
}

bool StackVisitor::GetVRegPairFromDebuggerShadowFrame(uint16_t vreg,
                                                      VRegKind kind_lo,
                                                      VRegKind kind_hi,
                                                      uint64_t* val) const {
  uint32_t low_32bits;
  uint32_t high_32bits;
  bool success = GetVRegFromDebuggerShadowFrame(vreg, kind_lo, &low_32bits);
  success &= GetVRegFromDebuggerShadowFrame(vreg + 1, kind_hi, &high_32bits);
  if (success) {
    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
  }
  return success;
}

bool StackVisitor::GetVRegPair(ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
                               VRegKind kind_hi, uint64_t* val) const {
  if (kind_lo == kLongLoVReg) {
    DCHECK_EQ(kind_hi, kLongHiVReg);
  } else if (kind_lo == kDoubleLoVReg) {
    DCHECK_EQ(kind_hi, kDoubleHiVReg);
  } else {
    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
    UNREACHABLE();
  }
  // Check if there is value set by the debugger.
  if (GetVRegPairFromDebuggerShadowFrame(vreg, kind_lo, kind_hi, val)) {
    return true;
  }
  if (cur_quick_frame_ != nullptr) {
    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
    DCHECK(m == GetMethod());
    DCHECK(cur_oat_quick_method_header_->IsOptimized());
    return GetVRegPairFromOptimizedCode(m, vreg, kind_lo, kind_hi, val);
  } else {
    DCHECK(cur_shadow_frame_ != nullptr);
    *val = cur_shadow_frame_->GetVRegLong(vreg);
    return true;
  }
}

bool StackVisitor::GetVRegPairFromOptimizedCode(ArtMethod* m, uint16_t vreg,
                                                VRegKind kind_lo, VRegKind kind_hi,
                                                uint64_t* val) const {
  uint32_t low_32bits;
  uint32_t high_32bits;
  bool success = GetVRegFromOptimizedCode(m, vreg, kind_lo, &low_32bits);
  success &= GetVRegFromOptimizedCode(m, vreg + 1, kind_hi, &high_32bits);
  if (success) {
    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
  }
  return success;
}

bool StackVisitor::GetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
                                               VRegKind kind_lo, uint64_t* val) const {
  const bool is_float = (kind_lo == kDoubleLoVReg);
  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
    return false;
  }
  uintptr_t ptr_val_lo = GetRegister(reg_lo, is_float);
  uintptr_t ptr_val_hi = GetRegister(reg_hi, is_float);
  bool target64 = Is64BitInstructionSet(kRuntimeISA);
  if (target64) {
    int64_t value_long_lo = static_cast<int64_t>(ptr_val_lo);
    int64_t value_long_hi = static_cast<int64_t>(ptr_val_hi);
    ptr_val_lo = static_cast<uintptr_t>(Low32Bits(value_long_lo));
    ptr_val_hi = static_cast<uintptr_t>(High32Bits(value_long_hi));
  }
  *val = (static_cast<uint64_t>(ptr_val_hi) << 32) | static_cast<uint32_t>(ptr_val_lo);
  return true;
}

ShadowFrame* StackVisitor::PrepareSetVReg(ArtMethod* m, uint16_t vreg, bool wide) {
  CodeItemDataAccessor accessor(m->DexInstructionData());
  if (!accessor.HasCodeItem()) {
    return nullptr;
  }
  ShadowFrame* shadow_frame = GetCurrentShadowFrame();
  if (shadow_frame == nullptr) {
    // This is a compiled frame: we must prepare and update a shadow frame that will
    // be executed by the interpreter after deoptimization of the stack.
    const size_t frame_id = GetFrameId();
    const uint16_t num_regs = accessor.RegistersSize();
    shadow_frame = thread_->FindOrCreateDebuggerShadowFrame(frame_id, num_regs, m, GetDexPc());
    CHECK(shadow_frame != nullptr);
    // Remember the vreg(s) has been set for debugging and must not be overwritten by the
    // original value during deoptimization of the stack.
    thread_->GetUpdatedVRegFlags(frame_id)[vreg] = true;
    if (wide) {
      thread_->GetUpdatedVRegFlags(frame_id)[vreg + 1] = true;
    }
  }
  return shadow_frame;
}

bool StackVisitor::SetVReg(ArtMethod* m, uint16_t vreg, uint32_t new_value, VRegKind kind) {
  DCHECK(kind == kIntVReg || kind == kFloatVReg);
  ShadowFrame* shadow_frame = PrepareSetVReg(m, vreg, /* wide= */ false);
  if (shadow_frame == nullptr) {
    return false;
  }
  shadow_frame->SetVReg(vreg, new_value);
  return true;
}

bool StackVisitor::SetVRegReference(ArtMethod* m, uint16_t vreg, ObjPtr<mirror::Object> new_value) {
  ShadowFrame* shadow_frame = PrepareSetVReg(m, vreg, /* wide= */ false);
  if (shadow_frame == nullptr) {
    return false;
  }
  shadow_frame->SetVRegReference(vreg, new_value);
  return true;
}

bool StackVisitor::SetVRegPair(ArtMethod* m,
                               uint16_t vreg,
                               uint64_t new_value,
                               VRegKind kind_lo,
                               VRegKind kind_hi) {
  if (kind_lo == kLongLoVReg) {
    DCHECK_EQ(kind_hi, kLongHiVReg);
  } else if (kind_lo == kDoubleLoVReg) {
    DCHECK_EQ(kind_hi, kDoubleHiVReg);
  } else {
    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
    UNREACHABLE();
  }
  ShadowFrame* shadow_frame = PrepareSetVReg(m, vreg, /* wide= */ true);
  if (shadow_frame == nullptr) {
    return false;
  }
  shadow_frame->SetVRegLong(vreg, new_value);
  return true;
}

bool StackVisitor::IsAccessibleGPR(uint32_t reg) const {
  DCHECK(context_ != nullptr);
  return context_->IsAccessibleGPR(reg);
}

uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
  DCHECK(context_ != nullptr);
  return context_->GetGPRAddress(reg);
}

uintptr_t StackVisitor::GetGPR(uint32_t reg) const {
  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
  DCHECK(context_ != nullptr);
  return context_->GetGPR(reg);
}

bool StackVisitor::IsAccessibleFPR(uint32_t reg) const {
  DCHECK(context_ != nullptr);
  return context_->IsAccessibleFPR(reg);
}

uintptr_t StackVisitor::GetFPR(uint32_t reg) const {
  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
  DCHECK(context_ != nullptr);
  return context_->GetFPR(reg);
}

uintptr_t StackVisitor::GetReturnPc() const {
  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
  DCHECK(sp != nullptr);
  uint8_t* pc_addr = sp + GetCurrentQuickFrameInfo().GetReturnPcOffset();
  return *reinterpret_cast<uintptr_t*>(pc_addr);
}

void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
  CHECK(sp != nullptr);
  uint8_t* pc_addr = sp + GetCurrentQuickFrameInfo().GetReturnPcOffset();
  *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
}

size_t StackVisitor::ComputeNumFrames(Thread* thread, StackWalkKind walk_kind) {
  struct NumFramesVisitor : public StackVisitor {
    NumFramesVisitor(Thread* thread_in, StackWalkKind walk_kind_in)
        : StackVisitor(thread_in, nullptr, walk_kind_in), frames(0) {}

    bool VisitFrame() override {
      frames++;
      return true;
    }

    size_t frames;
  };
  NumFramesVisitor visitor(thread, walk_kind);
  visitor.WalkStack(true);
  return visitor.frames;
}

bool StackVisitor::GetNextMethodAndDexPc(ArtMethod** next_method, uint32_t* next_dex_pc) {
  struct HasMoreFramesVisitor : public StackVisitor {
    HasMoreFramesVisitor(Thread* thread,
                         StackWalkKind walk_kind,
                         size_t num_frames,
                         size_t frame_height)
        : StackVisitor(thread, nullptr, walk_kind, num_frames),
          frame_height_(frame_height),
          found_frame_(false),
          has_more_frames_(false),
          next_method_(nullptr),
          next_dex_pc_(0) {
    }

    bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
      if (found_frame_) {
        ArtMethod* method = GetMethod();
        if (method != nullptr && !method->IsRuntimeMethod()) {
          has_more_frames_ = true;
          next_method_ = method;
          next_dex_pc_ = GetDexPc();
          return false;  // End stack walk once next method is found.
        }
      } else if (GetFrameHeight() == frame_height_) {
        found_frame_ = true;
      }
      return true;
    }

    size_t frame_height_;
    bool found_frame_;
    bool has_more_frames_;
    ArtMethod* next_method_;
    uint32_t next_dex_pc_;
  };
  HasMoreFramesVisitor visitor(thread_, walk_kind_, GetNumFrames(), GetFrameHeight());
  visitor.WalkStack(true);
  *next_method = visitor.next_method_;
  *next_dex_pc = visitor.next_dex_pc_;
  return visitor.has_more_frames_;
}

void StackVisitor::DescribeStack(Thread* thread) {
  struct DescribeStackVisitor : public StackVisitor {
    explicit DescribeStackVisitor(Thread* thread_in)
        : StackVisitor(thread_in, nullptr, StackVisitor::StackWalkKind::kIncludeInlinedFrames) {}

    bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
      LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
      return true;
    }
  };
  DescribeStackVisitor visitor(thread);
  visitor.WalkStack(true);
}

std::string StackVisitor::DescribeLocation() const {
  std::string result("Visiting method '");
  ArtMethod* m = GetMethod();
  if (m == nullptr) {
    return "upcall";
  }
  result += m->PrettyMethod();
  result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
  if (!IsShadowFrame()) {
    result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
  }
  return result;
}

void StackVisitor::SetMethod(ArtMethod* method) {
  DCHECK(GetMethod() != nullptr);
  if (cur_shadow_frame_ != nullptr) {
    cur_shadow_frame_->SetMethod(method);
  } else {
    DCHECK(cur_quick_frame_ != nullptr);
    CHECK(!IsInInlinedFrame()) << "We do not support setting inlined method's ArtMethod: "
                               << GetMethod()->PrettyMethod() << " is inlined into "
                               << GetOuterMethod()->PrettyMethod();
    *cur_quick_frame_ = method;
  }
}

static void AssertPcIsWithinQuickCode(ArtMethod* method, uintptr_t pc)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  if (method->IsNative() || method->IsRuntimeMethod() || method->IsProxyMethod()) {
    return;
  }

  if (pc == reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc())) {
    return;
  }

  Runtime* runtime = Runtime::Current();
  if (runtime->UseJitCompilation() &&
      runtime->GetJit()->GetCodeCache()->ContainsPc(reinterpret_cast<const void*>(pc))) {
    return;
  }

  const void* code = method->GetEntryPointFromQuickCompiledCode();
  if (code == GetQuickInstrumentationEntryPoint() || code == GetInvokeObsoleteMethodStub()) {
    return;
  }

  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
  if (class_linker->IsQuickToInterpreterBridge(code) ||
      class_linker->IsQuickResolutionStub(code)) {
    return;
  }

  if (runtime->UseJitCompilation() && runtime->GetJit()->GetCodeCache()->ContainsPc(code)) {
    return;
  }

  uint32_t code_size = OatQuickMethodHeader::FromEntryPoint(code)->GetCodeSize();
  uintptr_t code_start = reinterpret_cast<uintptr_t>(code);
  CHECK(code_start <= pc && pc <= (code_start + code_size))
      << method->PrettyMethod()
      << " pc=" << std::hex << pc
      << " code_start=" << code_start
      << " code_size=" << code_size;
}

void StackVisitor::SanityCheckFrame() const {
  if (kIsDebugBuild) {
    ArtMethod* method = GetMethod();
    ObjPtr<mirror::Class> declaring_class = method->GetDeclaringClass();
    // Runtime methods have null declaring class.
    if (!method->IsRuntimeMethod()) {
      CHECK(declaring_class != nullptr);
      CHECK_EQ(declaring_class->GetClass(), declaring_class->GetClass()->GetClass())
          << declaring_class;
    } else {
      CHECK(declaring_class == nullptr);
    }
    Runtime* const runtime = Runtime::Current();
    LinearAlloc* const linear_alloc = runtime->GetLinearAlloc();
    if (!linear_alloc->Contains(method)) {
      // Check class linker linear allocs.
      // We get the canonical method as copied methods may have their declaring
      // class from another class loader.
      const PointerSize ptrSize = runtime->GetClassLinker()->GetImagePointerSize();
      ArtMethod* canonical = method->GetCanonicalMethod(ptrSize);
      ObjPtr<mirror::Class> klass = canonical->GetDeclaringClass();
      LinearAlloc* const class_linear_alloc = (klass != nullptr)
          ? runtime->GetClassLinker()->GetAllocatorForClassLoader(klass->GetClassLoader())
          : linear_alloc;
      if (!class_linear_alloc->Contains(canonical)) {
        // Check image space.
        bool in_image = false;
        for (auto& space : runtime->GetHeap()->GetContinuousSpaces()) {
          if (space->IsImageSpace()) {
            auto* image_space = space->AsImageSpace();
            const auto& header = image_space->GetImageHeader();
            const ImageSection& methods = header.GetMethodsSection();
            const ImageSection& runtime_methods = header.GetRuntimeMethodsSection();
            const size_t offset =  reinterpret_cast<const uint8_t*>(canonical) - image_space->Begin();
            if (methods.Contains(offset) || runtime_methods.Contains(offset)) {
              in_image = true;
              break;
            }
          }
        }
        CHECK(in_image) << canonical->PrettyMethod() << " not in linear alloc or image";
      }
    }
    if (cur_quick_frame_ != nullptr) {
      AssertPcIsWithinQuickCode(method, cur_quick_frame_pc_);
      // Frame sanity.
      size_t frame_size = GetCurrentQuickFrameInfo().FrameSizeInBytes();
      CHECK_NE(frame_size, 0u);
      // For compiled code, we could try to have a rough guess at an upper size we expect
      // to see for a frame:
      // 256 registers
      // 2 words HandleScope overhead
      // 3+3 register spills
      // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
      const size_t kMaxExpectedFrameSize = interpreter::kMaxNterpFrame;
      CHECK_LE(frame_size, kMaxExpectedFrameSize) << method->PrettyMethod();
      size_t return_pc_offset = GetCurrentQuickFrameInfo().GetReturnPcOffset();
      CHECK_LT(return_pc_offset, frame_size);
    }
  }
}

// Counts the number of references in the parameter list of the corresponding method.
// Note: Thus does _not_ include "this" for non-static methods.
static uint32_t GetNumberOfReferenceArgsWithoutReceiver(ArtMethod* method)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  uint32_t shorty_len;
  const char* shorty = method->GetShorty(&shorty_len);
  uint32_t refs = 0;
  for (uint32_t i = 1; i < shorty_len ; ++i) {
    if (shorty[i] == 'L') {
      refs++;
    }
  }
  return refs;
}

QuickMethodFrameInfo StackVisitor::GetCurrentQuickFrameInfo() const {
  if (cur_oat_quick_method_header_ != nullptr) {
    if (cur_oat_quick_method_header_->IsOptimized()) {
      return cur_oat_quick_method_header_->GetFrameInfo();
    } else {
      DCHECK(cur_oat_quick_method_header_->IsNterpMethodHeader());
      return NterpFrameInfo(cur_quick_frame_);
    }
  }

  ArtMethod* method = GetMethod();
  Runtime* runtime = Runtime::Current();

  if (method->IsAbstract()) {
    return RuntimeCalleeSaveFrame::GetMethodFrameInfo(CalleeSaveType::kSaveRefsAndArgs);
  }

  // This goes before IsProxyMethod since runtime methods have a null declaring class.
  if (method->IsRuntimeMethod()) {
    return runtime->GetRuntimeMethodFrameInfo(method);
  }

  if (method->IsProxyMethod()) {
    // There is only one direct method of a proxy class: the constructor. A direct method is
    // cloned from the original java.lang.reflect.Proxy and is executed as usual quick
    // compiled method without any stubs. Therefore the method must have a OatQuickMethodHeader.
    DCHECK(!method->IsDirect() && !method->IsConstructor())
        << "Constructors of proxy classes must have a OatQuickMethodHeader";
    return RuntimeCalleeSaveFrame::GetMethodFrameInfo(CalleeSaveType::kSaveRefsAndArgs);
  }

  // The only remaining case is if the method is native and uses the generic JNI stub,
  // called either directly or through some (resolution, instrumentation) trampoline.
  DCHECK(method->IsNative());
  if (kIsDebugBuild) {
    ClassLinker* class_linker = runtime->GetClassLinker();
    const void* entry_point = runtime->GetInstrumentation()->GetQuickCodeFor(method,
                                                                             kRuntimePointerSize);
    CHECK(class_linker->IsQuickGenericJniStub(entry_point) ||
          // The current entrypoint (after filtering out trampolines) may have changed
          // from GenericJNI to JIT-compiled stub since we have entered this frame.
          (runtime->GetJit() != nullptr &&
           runtime->GetJit()->GetCodeCache()->ContainsPc(entry_point))) << method->PrettyMethod();
  }
  // Generic JNI frame.
  uint32_t handle_refs = GetNumberOfReferenceArgsWithoutReceiver(method) + 1;
  size_t scope_size = HandleScope::SizeOf(handle_refs);
  constexpr QuickMethodFrameInfo callee_info =
      RuntimeCalleeSaveFrame::GetMethodFrameInfo(CalleeSaveType::kSaveRefsAndArgs);

  // Callee saves + handle scope + method ref + alignment
  // Note: -sizeof(void*) since callee-save frame stores a whole method pointer.
  size_t frame_size = RoundUp(
      callee_info.FrameSizeInBytes() - sizeof(void*) + sizeof(ArtMethod*) + scope_size,
      kStackAlignment);
  return QuickMethodFrameInfo(frame_size, callee_info.CoreSpillMask(), callee_info.FpSpillMask());
}

template <StackVisitor::CountTransitions kCount>
void StackVisitor::WalkStack(bool include_transitions) {
  if (check_suspended_) {
    DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
  }
  CHECK_EQ(cur_depth_, 0U);
  CHECK(!walk_started_);
  walk_started_ = true;
  bool retry = false;
  size_t depth;
  bool skip_to_depth = false;
  uint64_t current_sequence_number;
  Thread* self = Thread::Current();
  // If the instrumentation stack changes due to DeoptimizeThreadStack or similar while we are
  // running this stack-walk we need to restart and try again.
  //
  // This is because when we perform DeoptimizeThreadStack we replace the return-pc of the threads
  // stack-frames with a trampoline, the actual return-address is placed in the threads
  // InstrumentationStack. The instrumentation code will fill up this stack as it goes. Since there
  // is no good way to map instrumentation stack frames to real ones (or vice versa) and we need to
  // know which instrumentation stack frame we are on in order to find the real return-pc using that
  // the next stack-frame's size we instead simply keep track of how many instrumentation frames we
  // have used (as instrumentation_stack_depth). Each time we need a new instrumentation frame we
  // simply increment this value. This works well enough but if InstrumentationInstallStack is
  // called concurrently the InstrumentationStack might have frames inserted prior to the point this
  // StackVisitor is currently at. This would cause the visitor to get the incorrect
  // instrumentation_frame and start incorrectly walking the stack.
  //
  // To prevent this we keep track of when the last update that changes the indexs of
  // instrumentation frames occurs and restart the stack walk if that changes. To simplify the
  // process of building stack walkers we also keep track of how many times we have called
  // VisitFrame and skip that many calls. This prevents any frames from being visited more than once
  // per 'WalkStack' call.
  do {
    retry = false;
    depth = 0;
    // Keep track of how far in the stack-walk we are, making sure to also keep track of whether
    // we've skipped enough to resume calling 'VisitFrame' after a retry.
    auto increment_depth = [&]() {
      DCHECK_LE(depth, cur_depth_);
      ++depth;
      if (skip_to_depth && depth == cur_depth_) {
        skip_to_depth = false;
      } else if (!skip_to_depth) {
        ++cur_depth_;
      }
    };
    // Wait for any current instrumentation installs to finish, Skip this if we are aborting.
    if (LIKELY(gAborting == 0)) {
      MutexLock mu(self, *GetThread()->GetInstrumentationInstallMutex());
    }
    // Get Current install state id.
    {
      MutexLock mu(self, *GetThread()->GetInstrumentationInstallSequenceNumberMutex());
      current_sequence_number = GetThread()->GetInstrumentationInstallSequenceNumber();
    }
    bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
    uint32_t instrumentation_stack_depth = 0;
    size_t inlined_frames_count = 0;

    for (const ManagedStack* current_fragment = thread_->GetManagedStack();
         current_fragment != nullptr;
         current_fragment = current_fragment->GetLink()) {
      cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
      cur_quick_frame_ = current_fragment->GetTopQuickFrame();
      cur_quick_frame_pc_ = 0;
      cur_oat_quick_method_header_ = nullptr;
      if (cur_quick_frame_ != nullptr) {  // Handle quick stack frames.
        // Can't be both a shadow and a quick fragment.
        DCHECK(current_fragment->GetTopShadowFrame() == nullptr);
        ArtMethod* method = *cur_quick_frame_;
        DCHECK(method != nullptr);
        bool header_retrieved = false;
        if (method->IsNative()) {
          // We do not have a PC for the first frame, so we cannot simply use
          // ArtMethod::GetOatQuickMethodHeader() as we're unable to distinguish there
          // between GenericJNI frame and JIT-compiled JNI stub; the entrypoint may have
          // changed since the frame was entered. The top quick frame tag indicates
          // GenericJNI here, otherwise it's either AOT-compiled or JNI-compiled JNI stub.
          if (UNLIKELY(current_fragment->GetTopQuickFrameTag())) {
            // The generic JNI does not have any method header.
            cur_oat_quick_method_header_ = nullptr;
          } else {
            const void* existing_entry_point = method->GetEntryPointFromQuickCompiledCode();
            CHECK(existing_entry_point != nullptr);
            Runtime* runtime = Runtime::Current();
            ClassLinker* class_linker = runtime->GetClassLinker();
            // Check whether we can quickly get the header from the current entrypoint.
            if (!class_linker->IsQuickGenericJniStub(existing_entry_point) &&
                !class_linker->IsQuickResolutionStub(existing_entry_point) &&
                existing_entry_point != GetQuickInstrumentationEntryPoint()) {
              cur_oat_quick_method_header_ =
                  OatQuickMethodHeader::FromEntryPoint(existing_entry_point);
            } else {
              const void* code = method->GetOatMethodQuickCode(class_linker->GetImagePointerSize());
              if (code != nullptr) {
                cur_oat_quick_method_header_ = OatQuickMethodHeader::FromEntryPoint(code);
              } else {
                // This must be a JITted JNI stub frame.
                CHECK(runtime->GetJit() != nullptr);
                code = runtime->GetJit()->GetCodeCache()->GetJniStubCode(method);
                CHECK(code != nullptr) << method->PrettyMethod();
                cur_oat_quick_method_header_ = OatQuickMethodHeader::FromCodePointer(code);
              }
            }
          }
          header_retrieved = true;
        }
        while (method != nullptr) {
          if (!header_retrieved) {
            cur_oat_quick_method_header_ = method->GetOatQuickMethodHeader(cur_quick_frame_pc_);
          }
          header_retrieved = false;  // Force header retrieval in next iteration.
          SanityCheckFrame();

          if ((walk_kind_ == StackWalkKind::kIncludeInlinedFrames) &&
              (cur_oat_quick_method_header_ != nullptr) &&
              cur_oat_quick_method_header_->IsOptimized() &&
              !method->IsNative()  // JNI methods cannot have any inlined frames.
              && CodeInfo::HasInlineInfo(cur_oat_quick_method_header_->GetOptimizedCodeInfoPtr())) {
            DCHECK_NE(cur_quick_frame_pc_, 0u);
            CodeInfo* code_info = GetCurrentInlineInfo();
            StackMap* stack_map = GetCurrentStackMap();
            if (stack_map->IsValid() && stack_map->HasInlineInfo()) {
              DCHECK_EQ(current_inline_frames_.size(), 0u);
              for (current_inline_frames_ = code_info->GetInlineInfosOf(*stack_map);
                   !current_inline_frames_.empty();
                   current_inline_frames_.pop_back()) {
                if (!skip_to_depth) {
                  bool should_continue = VisitFrame();
                  if (UNLIKELY(!should_continue)) {
                    return;
                  }
                }
                increment_depth();
                inlined_frames_count++;
              }
            }
          }

          if (!skip_to_depth) {
            bool should_continue = VisitFrame();
            if (UNLIKELY(!should_continue)) {
              return;
            }
          }
          if (kCount == CountTransitions::kYes || !method->IsRuntimeMethod()) {
            increment_depth();
          }

          // NB This uses cur_oat_quick_frame_info_ (and hence cur_quick_frame_pc_ & the previous
          // return_pc_) to determine the frame information.
          QuickMethodFrameInfo frame_info = GetCurrentQuickFrameInfo();
          if (context_ != nullptr) {
            context_->FillCalleeSaves(reinterpret_cast<uint8_t*>(cur_quick_frame_), frame_info);
          }
          // Compute PC for next stack frame from return PC.
          size_t frame_size = frame_info.FrameSizeInBytes();
          size_t return_pc_offset = frame_size - sizeof(void*);
          uint8_t* return_pc_addr = reinterpret_cast<uint8_t*>(cur_quick_frame_) + return_pc_offset;
          uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);

          if (UNLIKELY(exit_stubs_installed ||
                       reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc()) == return_pc)) {
            // While profiling, the return pc is restored from the side stack, except when walking
            // the stack for an exception where the side stack will be unwound in VisitFrame.
            if (reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc()) == return_pc) {
              MutexLock mu(self, *GetThread()->GetInstrumentationInstallSequenceNumberMutex());
              // Instrument-install walks will change the instrumentation-stack but only put things
              // at the end, so we can continue regardless. We hold the InstrumentationInstallMutex
              // so we know nothing can mess up the stack.
              if (!IsStackInstrumentWalk() &&
                  GetThread()->GetInstrumentationInstallSequenceNumber() !=
                      current_sequence_number) {
                if (kDebugStackWalk) {
                  LOG(INFO) << "Retrying walk from begining due to instrumentation change. "
                            << "Skipping to depth " << cur_depth_;
                }
                skip_to_depth = true;
                retry = true;
                // Annoyingly c++ doesn't have a labled continue. If they respected RAII this would
                // be a good time to use goto but as is we'll just break twice.
                break;  // From while (method != nullptr)
              } else if (kIsDebugBuild && IsStackInstrumentWalk()) {
                GetThread()->GetInstrumentationInstallMutex()->AssertExclusiveHeld(self);
              }
              CHECK_LT(instrumentation_stack_depth, thread_->GetInstrumentationStack()->size());
              const instrumentation::InstrumentationStackFrame& instrumentation_frame =
                  (*thread_->GetInstrumentationStack())[instrumentation_stack_depth];
              instrumentation_stack_depth++;
              if (GetMethod() ==
                  Runtime::Current()->GetCalleeSaveMethod(CalleeSaveType::kSaveAllCalleeSaves)) {
                // Skip runtime save all callee frames which are used to deliver exceptions.
              } else if (instrumentation_frame.interpreter_entry_) {
                ArtMethod* callee =
                    Runtime::Current()->GetCalleeSaveMethod(CalleeSaveType::kSaveRefsAndArgs);
                CHECK_EQ(GetMethod(), callee)
                    << "Expected: " << ArtMethod::PrettyMethod(callee)
                    << " Found: " << ArtMethod::PrettyMethod(GetMethod());
              } else {
                // Instrumentation generally doesn't distinguish between a method's obsolete and
                // non-obsolete version.
                CHECK_EQ(instrumentation_frame.method_->GetNonObsoleteMethod(),
                          GetMethod()->GetNonObsoleteMethod())
                    << "Expected: "
                    << ArtMethod::PrettyMethod(
                            instrumentation_frame.method_->GetNonObsoleteMethod())
                    << " Found: " << ArtMethod::PrettyMethod(GetMethod()->GetNonObsoleteMethod());
              }
              return_pc = instrumentation_frame.return_pc_;
              // TODO It would be nice to do this check but unfortunately it leads to a race since
              // we need to perform a recursive stack-walk to calculate the frame-id.
              // size_t expected_id = instrumentation_frame.frame_id_;
              // if (num_frames_ != 0) {
              //   // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
              //   // recursion.
              //   size_t frame_id = instrumentation::Instrumentation::ComputeFrameId(
              //       thread_,
              //       // We already incremented depth but we want to get the last visited frame.
              //       depth - 1,
              //       inlined_frames_count);
              //   CHECK_EQ(expected_id, frame_id);
              // }
            }
          }

          cur_quick_frame_pc_ = return_pc;
          uint8_t* next_frame = reinterpret_cast<uint8_t*>(cur_quick_frame_) + frame_size;
          cur_quick_frame_ = reinterpret_cast<ArtMethod**>(next_frame);

          if (kDebugStackWalk) {
            LOG(INFO) << ArtMethod::PrettyMethod(method) << "@" << method << " size=" << frame_size
                      << std::boolalpha << " optimized="
                      << (cur_oat_quick_method_header_ != nullptr &&
                          cur_oat_quick_method_header_->IsOptimized())
                      << " native=" << method->IsNative() << std::noboolalpha
                      << " entrypoints=" << method->GetEntryPointFromQuickCompiledCode() << ","
                      << (method->IsNative() ? method->GetEntryPointFromJni() : nullptr)
                      << " next=" << *cur_quick_frame_;
          }

          method = *cur_quick_frame_;
        }
        // We want to start again. Break right now.
        if (retry) {
          break;  // From for (const ManagedStack* current_fragment = thread_->GetManagedStack();
        }
      } else if (cur_shadow_frame_ != nullptr) {
        do {
          SanityCheckFrame();
          if (!skip_to_depth) {
            bool should_continue = VisitFrame();
            if (UNLIKELY(!should_continue)) {
              return;
            }
          }
          increment_depth();
          cur_shadow_frame_ = cur_shadow_frame_->GetLink();
        } while (cur_shadow_frame_ != nullptr);
      }
      if (!skip_to_depth && include_transitions) {
        bool should_continue = VisitFrame();
        if (!should_continue) {
          return;
        }
      }
      if (kCount == CountTransitions::kYes) {
        increment_depth();
      }
    }
    if (retry) {
      continue;  // Real retry.
    }
    if (num_frames_ != 0) {
      CHECK_EQ(cur_depth_, num_frames_);
    }
  } while (retry);
}

template void StackVisitor::WalkStack<StackVisitor::CountTransitions::kYes>(bool);
template void StackVisitor::WalkStack<StackVisitor::CountTransitions::kNo>(bool);

}  // namespace art