/*
* 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.
*/
#ifndef ART_RUNTIME_STACK_H_
#define ART_RUNTIME_STACK_H_
#include <stdint.h>
#include <string>
#include "arch/instruction_set.h"
#include "base/macros.h"
#include "base/mutex.h"
#include "dex_file.h"
#include "gc_root.h"
#include "mirror/object_reference.h"
#include "quick/quick_method_frame_info.h"
#include "read_barrier.h"
#include "verify_object.h"
namespace art {
namespace mirror {
class Object;
} // namespace mirror
class ArtMethod;
class Context;
class HandleScope;
class InlineInfo;
class OatQuickMethodHeader;
class ScopedObjectAccess;
class ShadowFrame;
class StackVisitor;
class Thread;
// The kind of vreg being accessed in calls to Set/GetVReg.
enum VRegKind {
kReferenceVReg,
kIntVReg,
kFloatVReg,
kLongLoVReg,
kLongHiVReg,
kDoubleLoVReg,
kDoubleHiVReg,
kConstant,
kImpreciseConstant,
kUndefined,
};
std::ostream& operator<<(std::ostream& os, const VRegKind& rhs);
// A reference from the shadow stack to a MirrorType object within the Java heap.
template<class MirrorType>
class MANAGED StackReference : public mirror::CompressedReference<MirrorType> {
};
// Forward declaration. Just calls the destructor.
struct ShadowFrameDeleter;
using ShadowFrameAllocaUniquePtr = std::unique_ptr<ShadowFrame, ShadowFrameDeleter>;
// Counting locks by storing object pointers into a vector. Duplicate entries mark recursive locks.
// The vector will be visited with the ShadowFrame during GC (so all the locked-on objects are
// thread roots).
// Note: implementation is split so that the call sites may be optimized to no-ops in case no
// lock counting is necessary. The actual implementation is in the cc file to avoid
// dependencies.
class LockCountData {
public:
// Add the given object to the list of monitors, that is, objects that have been locked. This
// will not throw (but be skipped if there is an exception pending on entry).
void AddMonitor(Thread* self, mirror::Object* obj) SHARED_REQUIRES(Locks::mutator_lock_);
// Try to remove the given object from the monitor list, indicating an unlock operation.
// This will throw an IllegalMonitorStateException (clearing any already pending exception), in
// case that there wasn't a lock recorded for the object.
void RemoveMonitorOrThrow(Thread* self,
const mirror::Object* obj) SHARED_REQUIRES(Locks::mutator_lock_);
// Check whether all acquired monitors have been released. This will potentially throw an
// IllegalMonitorStateException, clearing any already pending exception. Returns true if the
// check shows that everything is OK wrt/ lock counting, false otherwise.
bool CheckAllMonitorsReleasedOrThrow(Thread* self) SHARED_REQUIRES(Locks::mutator_lock_);
template <typename T, typename... Args>
void VisitMonitors(T visitor, Args&&... args) SHARED_REQUIRES(Locks::mutator_lock_) {
if (monitors_ != nullptr) {
// Visitors may change the Object*. Be careful with the foreach loop.
for (mirror::Object*& obj : *monitors_) {
visitor(/* inout */ &obj, std::forward<Args>(args)...);
}
}
}
private:
// Stores references to the locked-on objects. As noted, this should be visited during thread
// marking.
std::unique_ptr<std::vector<mirror::Object*>> monitors_;
};
// ShadowFrame has 2 possible layouts:
// - interpreter - separate VRegs and reference arrays. References are in the reference array.
// - JNI - just VRegs, but where every VReg holds a reference.
class ShadowFrame {
public:
// Compute size of ShadowFrame in bytes assuming it has a reference array.
static size_t ComputeSize(uint32_t num_vregs) {
return sizeof(ShadowFrame) + (sizeof(uint32_t) * num_vregs) +
(sizeof(StackReference<mirror::Object>) * num_vregs);
}
// Create ShadowFrame in heap for deoptimization.
static ShadowFrame* CreateDeoptimizedFrame(uint32_t num_vregs, ShadowFrame* link,
ArtMethod* method, uint32_t dex_pc) {
uint8_t* memory = new uint8_t[ComputeSize(num_vregs)];
return CreateShadowFrameImpl(num_vregs, link, method, dex_pc, memory);
}
// Delete a ShadowFrame allocated on the heap for deoptimization.
static void DeleteDeoptimizedFrame(ShadowFrame* sf) {
sf->~ShadowFrame(); // Explicitly destruct.
uint8_t* memory = reinterpret_cast<uint8_t*>(sf);
delete[] memory;
}
// Create a shadow frame in a fresh alloca. This needs to be in the context of the caller.
// Inlining doesn't work, the compiler will still undo the alloca. So this needs to be a macro.
#define CREATE_SHADOW_FRAME(num_vregs, link, method, dex_pc) ({ \
size_t frame_size = ShadowFrame::ComputeSize(num_vregs); \
void* alloca_mem = alloca(frame_size); \
ShadowFrameAllocaUniquePtr( \
ShadowFrame::CreateShadowFrameImpl((num_vregs), (link), (method), (dex_pc), \
(alloca_mem))); \
})
~ShadowFrame() {}
// TODO(iam): Clean references array up since they're always there,
// we don't need to do conditionals.
bool HasReferenceArray() const {
return true;
}
uint32_t NumberOfVRegs() const {
return number_of_vregs_;
}
uint32_t GetDexPC() const {
return (dex_pc_ptr_ == nullptr) ? dex_pc_ : dex_pc_ptr_ - code_item_->insns_;
}
int16_t GetCachedHotnessCountdown() const {
return cached_hotness_countdown_;
}
void SetCachedHotnessCountdown(int16_t cached_hotness_countdown) {
cached_hotness_countdown_ = cached_hotness_countdown;
}
int16_t GetHotnessCountdown() const {
return hotness_countdown_;
}
void SetHotnessCountdown(int16_t hotness_countdown) {
hotness_countdown_ = hotness_countdown;
}
void SetDexPC(uint32_t dex_pc) {
dex_pc_ = dex_pc;
dex_pc_ptr_ = nullptr;
}
ShadowFrame* GetLink() const {
return link_;
}
void SetLink(ShadowFrame* frame) {
DCHECK_NE(this, frame);
link_ = frame;
}
int32_t GetVReg(size_t i) const {
DCHECK_LT(i, NumberOfVRegs());
const uint32_t* vreg = &vregs_[i];
return *reinterpret_cast<const int32_t*>(vreg);
}
uint32_t* GetVRegAddr(size_t i) {
return &vregs_[i];
}
uint32_t* GetShadowRefAddr(size_t i) {
DCHECK(HasReferenceArray());
DCHECK_LT(i, NumberOfVRegs());
return &vregs_[i + NumberOfVRegs()];
}
void SetCodeItem(const DexFile::CodeItem* code_item) {
code_item_ = code_item;
}
float GetVRegFloat(size_t i) const {
DCHECK_LT(i, NumberOfVRegs());
// NOTE: Strict-aliasing?
const uint32_t* vreg = &vregs_[i];
return *reinterpret_cast<const float*>(vreg);
}
int64_t GetVRegLong(size_t i) const {
DCHECK_LT(i, NumberOfVRegs());
const uint32_t* vreg = &vregs_[i];
// Alignment attribute required for GCC 4.8
typedef const int64_t unaligned_int64 __attribute__ ((aligned (4)));
return *reinterpret_cast<unaligned_int64*>(vreg);
}
double GetVRegDouble(size_t i) const {
DCHECK_LT(i, NumberOfVRegs());
const uint32_t* vreg = &vregs_[i];
// Alignment attribute required for GCC 4.8
typedef const double unaligned_double __attribute__ ((aligned (4)));
return *reinterpret_cast<unaligned_double*>(vreg);
}
// Look up the reference given its virtual register number.
// If this returns non-null then this does not mean the vreg is currently a reference
// on non-moving collectors. Check that the raw reg with GetVReg is equal to this if not certain.
template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
mirror::Object* GetVRegReference(size_t i) const SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK_LT(i, NumberOfVRegs());
mirror::Object* ref;
if (HasReferenceArray()) {
ref = References()[i].AsMirrorPtr();
} else {
const uint32_t* vreg_ptr = &vregs_[i];
ref = reinterpret_cast<const StackReference<mirror::Object>*>(vreg_ptr)->AsMirrorPtr();
}
if (kUseReadBarrier) {
ReadBarrier::AssertToSpaceInvariant(ref);
}
if (kVerifyFlags & kVerifyReads) {
VerifyObject(ref);
}
return ref;
}
// Get view of vregs as range of consecutive arguments starting at i.
uint32_t* GetVRegArgs(size_t i) {
return &vregs_[i];
}
void SetVReg(size_t i, int32_t val) {
DCHECK_LT(i, NumberOfVRegs());
uint32_t* vreg = &vregs_[i];
*reinterpret_cast<int32_t*>(vreg) = val;
// This is needed for moving collectors since these can update the vreg references if they
// happen to agree with references in the reference array.
if (kMovingCollector && HasReferenceArray()) {
References()[i].Clear();
}
}
void SetVRegFloat(size_t i, float val) {
DCHECK_LT(i, NumberOfVRegs());
uint32_t* vreg = &vregs_[i];
*reinterpret_cast<float*>(vreg) = val;
// This is needed for moving collectors since these can update the vreg references if they
// happen to agree with references in the reference array.
if (kMovingCollector && HasReferenceArray()) {
References()[i].Clear();
}
}
void SetVRegLong(size_t i, int64_t val) {
DCHECK_LT(i, NumberOfVRegs());
uint32_t* vreg = &vregs_[i];
// Alignment attribute required for GCC 4.8
typedef int64_t unaligned_int64 __attribute__ ((aligned (4)));
*reinterpret_cast<unaligned_int64*>(vreg) = val;
// This is needed for moving collectors since these can update the vreg references if they
// happen to agree with references in the reference array.
if (kMovingCollector && HasReferenceArray()) {
References()[i].Clear();
References()[i + 1].Clear();
}
}
void SetVRegDouble(size_t i, double val) {
DCHECK_LT(i, NumberOfVRegs());
uint32_t* vreg = &vregs_[i];
// Alignment attribute required for GCC 4.8
typedef double unaligned_double __attribute__ ((aligned (4)));
*reinterpret_cast<unaligned_double*>(vreg) = val;
// This is needed for moving collectors since these can update the vreg references if they
// happen to agree with references in the reference array.
if (kMovingCollector && HasReferenceArray()) {
References()[i].Clear();
References()[i + 1].Clear();
}
}
template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
void SetVRegReference(size_t i, mirror::Object* val) SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK_LT(i, NumberOfVRegs());
if (kVerifyFlags & kVerifyWrites) {
VerifyObject(val);
}
if (kUseReadBarrier) {
ReadBarrier::AssertToSpaceInvariant(val);
}
uint32_t* vreg = &vregs_[i];
reinterpret_cast<StackReference<mirror::Object>*>(vreg)->Assign(val);
if (HasReferenceArray()) {
References()[i].Assign(val);
}
}
ArtMethod* GetMethod() const SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK(method_ != nullptr);
return method_;
}
mirror::Object* GetThisObject() const SHARED_REQUIRES(Locks::mutator_lock_);
mirror::Object* GetThisObject(uint16_t num_ins) const SHARED_REQUIRES(Locks::mutator_lock_);
bool Contains(StackReference<mirror::Object>* shadow_frame_entry_obj) const {
if (HasReferenceArray()) {
return ((&References()[0] <= shadow_frame_entry_obj) &&
(shadow_frame_entry_obj <= (&References()[NumberOfVRegs() - 1])));
} else {
uint32_t* shadow_frame_entry = reinterpret_cast<uint32_t*>(shadow_frame_entry_obj);
return ((&vregs_[0] <= shadow_frame_entry) &&
(shadow_frame_entry <= (&vregs_[NumberOfVRegs() - 1])));
}
}
LockCountData& GetLockCountData() {
return lock_count_data_;
}
static size_t LockCountDataOffset() {
return OFFSETOF_MEMBER(ShadowFrame, lock_count_data_);
}
static size_t LinkOffset() {
return OFFSETOF_MEMBER(ShadowFrame, link_);
}
static size_t MethodOffset() {
return OFFSETOF_MEMBER(ShadowFrame, method_);
}
static size_t DexPCOffset() {
return OFFSETOF_MEMBER(ShadowFrame, dex_pc_);
}
static size_t NumberOfVRegsOffset() {
return OFFSETOF_MEMBER(ShadowFrame, number_of_vregs_);
}
static size_t VRegsOffset() {
return OFFSETOF_MEMBER(ShadowFrame, vregs_);
}
static size_t ResultRegisterOffset() {
return OFFSETOF_MEMBER(ShadowFrame, result_register_);
}
static size_t DexPCPtrOffset() {
return OFFSETOF_MEMBER(ShadowFrame, dex_pc_ptr_);
}
static size_t CodeItemOffset() {
return OFFSETOF_MEMBER(ShadowFrame, code_item_);
}
static size_t CachedHotnessCountdownOffset() {
return OFFSETOF_MEMBER(ShadowFrame, cached_hotness_countdown_);
}
static size_t HotnessCountdownOffset() {
return OFFSETOF_MEMBER(ShadowFrame, hotness_countdown_);
}
// Create ShadowFrame for interpreter using provided memory.
static ShadowFrame* CreateShadowFrameImpl(uint32_t num_vregs,
ShadowFrame* link,
ArtMethod* method,
uint32_t dex_pc,
void* memory) {
return new (memory) ShadowFrame(num_vregs, link, method, dex_pc, true);
}
const uint16_t* GetDexPCPtr() {
return dex_pc_ptr_;
}
JValue* GetResultRegister() {
return result_register_;
}
private:
ShadowFrame(uint32_t num_vregs, ShadowFrame* link, ArtMethod* method,
uint32_t dex_pc, bool has_reference_array)
: link_(link), method_(method), result_register_(nullptr), dex_pc_ptr_(nullptr),
code_item_(nullptr), number_of_vregs_(num_vregs), dex_pc_(dex_pc) {
// TODO(iam): Remove this parameter, it's an an artifact of portable removal
DCHECK(has_reference_array);
if (has_reference_array) {
memset(vregs_, 0, num_vregs * (sizeof(uint32_t) + sizeof(StackReference<mirror::Object>)));
} else {
memset(vregs_, 0, num_vregs * sizeof(uint32_t));
}
}
const StackReference<mirror::Object>* References() const {
DCHECK(HasReferenceArray());
const uint32_t* vreg_end = &vregs_[NumberOfVRegs()];
return reinterpret_cast<const StackReference<mirror::Object>*>(vreg_end);
}
StackReference<mirror::Object>* References() {
return const_cast<StackReference<mirror::Object>*>(
const_cast<const ShadowFrame*>(this)->References());
}
// Link to previous shadow frame or null.
ShadowFrame* link_;
ArtMethod* method_;
JValue* result_register_;
const uint16_t* dex_pc_ptr_;
const DexFile::CodeItem* code_item_;
LockCountData lock_count_data_; // This may contain GC roots when lock counting is active.
const uint32_t number_of_vregs_;
uint32_t dex_pc_;
int16_t cached_hotness_countdown_;
int16_t hotness_countdown_;
// This is a two-part array:
// - [0..number_of_vregs) holds the raw virtual registers, and each element here is always 4
// bytes.
// - [number_of_vregs..number_of_vregs*2) holds only reference registers. Each element here is
// ptr-sized.
// In other words when a primitive is stored in vX, the second (reference) part of the array will
// be null. When a reference is stored in vX, the second (reference) part of the array will be a
// copy of vX.
uint32_t vregs_[0];
DISALLOW_IMPLICIT_CONSTRUCTORS(ShadowFrame);
};
struct ShadowFrameDeleter {
inline void operator()(ShadowFrame* frame) {
if (frame != nullptr) {
frame->~ShadowFrame();
}
}
};
class JavaFrameRootInfo : public RootInfo {
public:
JavaFrameRootInfo(uint32_t thread_id, const StackVisitor* stack_visitor, size_t vreg)
: RootInfo(kRootJavaFrame, thread_id), stack_visitor_(stack_visitor), vreg_(vreg) {
}
virtual void Describe(std::ostream& os) const OVERRIDE
SHARED_REQUIRES(Locks::mutator_lock_);
private:
const StackVisitor* const stack_visitor_;
const size_t vreg_;
};
// The managed stack is used to record fragments of managed code stacks. Managed code stacks
// may either be shadow frames or lists of frames using fixed frame sizes. Transition records are
// necessary for transitions between code using different frame layouts and transitions into native
// code.
class PACKED(4) ManagedStack {
public:
ManagedStack()
: top_quick_frame_(nullptr), link_(nullptr), top_shadow_frame_(nullptr) {}
void PushManagedStackFragment(ManagedStack* fragment) {
// Copy this top fragment into given fragment.
memcpy(fragment, this, sizeof(ManagedStack));
// Clear this fragment, which has become the top.
memset(this, 0, sizeof(ManagedStack));
// Link our top fragment onto the given fragment.
link_ = fragment;
}
void PopManagedStackFragment(const ManagedStack& fragment) {
DCHECK(&fragment == link_);
// Copy this given fragment back to the top.
memcpy(this, &fragment, sizeof(ManagedStack));
}
ManagedStack* GetLink() const {
return link_;
}
ArtMethod** GetTopQuickFrame() const {
return top_quick_frame_;
}
void SetTopQuickFrame(ArtMethod** top) {
DCHECK(top_shadow_frame_ == nullptr);
top_quick_frame_ = top;
}
static size_t TopQuickFrameOffset() {
return OFFSETOF_MEMBER(ManagedStack, top_quick_frame_);
}
ShadowFrame* PushShadowFrame(ShadowFrame* new_top_frame) {
DCHECK(top_quick_frame_ == nullptr);
ShadowFrame* old_frame = top_shadow_frame_;
top_shadow_frame_ = new_top_frame;
new_top_frame->SetLink(old_frame);
return old_frame;
}
ShadowFrame* PopShadowFrame() {
DCHECK(top_quick_frame_ == nullptr);
CHECK(top_shadow_frame_ != nullptr);
ShadowFrame* frame = top_shadow_frame_;
top_shadow_frame_ = frame->GetLink();
return frame;
}
ShadowFrame* GetTopShadowFrame() const {
return top_shadow_frame_;
}
void SetTopShadowFrame(ShadowFrame* top) {
DCHECK(top_quick_frame_ == nullptr);
top_shadow_frame_ = top;
}
static size_t TopShadowFrameOffset() {
return OFFSETOF_MEMBER(ManagedStack, top_shadow_frame_);
}
size_t NumJniShadowFrameReferences() const SHARED_REQUIRES(Locks::mutator_lock_);
bool ShadowFramesContain(StackReference<mirror::Object>* shadow_frame_entry) const;
private:
ArtMethod** top_quick_frame_;
ManagedStack* link_;
ShadowFrame* top_shadow_frame_;
};
class StackVisitor {
public:
// This enum defines a flag to control whether inlined frames are included
// when walking the stack.
enum class StackWalkKind {
kIncludeInlinedFrames,
kIncludeInlinedFramesNoResolve,
kSkipInlinedFrames,
};
protected:
StackVisitor(Thread* thread, Context* context, StackWalkKind walk_kind)
SHARED_REQUIRES(Locks::mutator_lock_);
bool GetRegisterIfAccessible(uint32_t reg, VRegKind kind, uint32_t* val) const
SHARED_REQUIRES(Locks::mutator_lock_);
public:
virtual ~StackVisitor() {}
// Return 'true' if we should continue to visit more frames, 'false' to stop.
virtual bool VisitFrame() SHARED_REQUIRES(Locks::mutator_lock_) = 0;
void WalkStack(bool include_transitions = false)
SHARED_REQUIRES(Locks::mutator_lock_);
Thread* GetThread() const {
return thread_;
}
ArtMethod* GetMethod() const SHARED_REQUIRES(Locks::mutator_lock_);
ArtMethod* GetOuterMethod() const {
return *GetCurrentQuickFrame();
}
bool IsShadowFrame() const {
return cur_shadow_frame_ != nullptr;
}
uint32_t GetDexPc(bool abort_on_failure = true) const SHARED_REQUIRES(Locks::mutator_lock_);
mirror::Object* GetThisObject() const SHARED_REQUIRES(Locks::mutator_lock_);
size_t GetNativePcOffset() const SHARED_REQUIRES(Locks::mutator_lock_);
// Returns the height of the stack in the managed stack frames, including transitions.
size_t GetFrameHeight() SHARED_REQUIRES(Locks::mutator_lock_) {
return GetNumFrames() - cur_depth_ - 1;
}
// Returns a frame ID for JDWP use, starting from 1.
size_t GetFrameId() SHARED_REQUIRES(Locks::mutator_lock_) {
return GetFrameHeight() + 1;
}
size_t GetNumFrames() SHARED_REQUIRES(Locks::mutator_lock_) {
if (num_frames_ == 0) {
num_frames_ = ComputeNumFrames(thread_, walk_kind_);
}
return num_frames_;
}
size_t GetFrameDepth() SHARED_REQUIRES(Locks::mutator_lock_) {
return cur_depth_;
}
// Get the method and dex pc immediately after the one that's currently being visited.
bool GetNextMethodAndDexPc(ArtMethod** next_method, uint32_t* next_dex_pc)
SHARED_REQUIRES(Locks::mutator_lock_);
bool GetVReg(ArtMethod* m, uint16_t vreg, VRegKind kind, uint32_t* val) const
SHARED_REQUIRES(Locks::mutator_lock_);
bool GetVRegPair(ArtMethod* m, uint16_t vreg, VRegKind kind_lo, VRegKind kind_hi,
uint64_t* val) const
SHARED_REQUIRES(Locks::mutator_lock_);
// Values will be set in debugger shadow frames. Debugger will make sure deoptimization
// is triggered to make the values effective.
bool SetVReg(ArtMethod* m, uint16_t vreg, uint32_t new_value, VRegKind kind)
SHARED_REQUIRES(Locks::mutator_lock_);
// Values will be set in debugger shadow frames. Debugger will make sure deoptimization
// is triggered to make the values effective.
bool SetVRegPair(ArtMethod* m,
uint16_t vreg,
uint64_t new_value,
VRegKind kind_lo,
VRegKind kind_hi)
SHARED_REQUIRES(Locks::mutator_lock_);
uintptr_t* GetGPRAddress(uint32_t reg) const;
// This is a fast-path for getting/setting values in a quick frame.
uint32_t* GetVRegAddrFromQuickCode(ArtMethod** cur_quick_frame,
const DexFile::CodeItem* code_item,
uint32_t core_spills, uint32_t fp_spills, size_t frame_size,
uint16_t vreg) const {
int offset = GetVRegOffsetFromQuickCode(
code_item, core_spills, fp_spills, frame_size, vreg, kRuntimeISA);
DCHECK_EQ(cur_quick_frame, GetCurrentQuickFrame());
uint8_t* vreg_addr = reinterpret_cast<uint8_t*>(cur_quick_frame) + offset;
return reinterpret_cast<uint32_t*>(vreg_addr);
}
uintptr_t GetReturnPc() const SHARED_REQUIRES(Locks::mutator_lock_);
void SetReturnPc(uintptr_t new_ret_pc) SHARED_REQUIRES(Locks::mutator_lock_);
/*
* Return sp-relative offset for a Dalvik virtual register, compiler
* spill or Method* in bytes using Method*.
* Note that (reg == -1) denotes an invalid Dalvik register. For the
* positive values, the Dalvik registers come first, followed by the
* Method*, followed by other special temporaries if any, followed by
* regular compiler temporary. As of now we only have the Method* as
* as a special compiler temporary.
* A compiler temporary can be thought of as a virtual register that
* does not exist in the dex but holds intermediate values to help
* optimizations and code generation. A special compiler temporary is
* one whose location in frame is well known while non-special ones
* do not have a requirement on location in frame as long as code
* generator itself knows how to access them.
*
* +-------------------------------+
* | IN[ins-1] | {Note: resides in caller's frame}
* | . |
* | IN[0] |
* | caller's ArtMethod | ... ArtMethod*
* +===============================+ {Note: start of callee's frame}
* | core callee-save spill | {variable sized}
* +-------------------------------+
* | fp callee-save spill |
* +-------------------------------+
* | filler word | {For compatibility, if V[locals-1] used as wide
* +-------------------------------+
* | V[locals-1] |
* | V[locals-2] |
* | . |
* | . | ... (reg == 2)
* | V[1] | ... (reg == 1)
* | V[0] | ... (reg == 0) <---- "locals_start"
* +-------------------------------+
* | stack alignment padding | {0 to (kStackAlignWords-1) of padding}
* +-------------------------------+
* | Compiler temp region | ... (reg >= max_num_special_temps)
* | . |
* | . |
* | V[max_num_special_temps + 1] |
* | V[max_num_special_temps + 0] |
* +-------------------------------+
* | OUT[outs-1] |
* | OUT[outs-2] |
* | . |
* | OUT[0] |
* | ArtMethod* | ... (reg == num_total_code_regs == special_temp_value) <<== sp, 16-byte aligned
* +===============================+
*/
static int GetVRegOffsetFromQuickCode(const DexFile::CodeItem* code_item,
uint32_t core_spills, uint32_t fp_spills,
size_t frame_size, int reg, InstructionSet isa);
static int GetOutVROffset(uint16_t out_num, InstructionSet isa) {
// According to stack model, the first out is above the Method referernce.
return InstructionSetPointerSize(isa) + out_num * sizeof(uint32_t);
}
bool IsInInlinedFrame() const {
return current_inlining_depth_ != 0;
}
size_t GetCurrentInliningDepth() const {
return current_inlining_depth_;
}
uintptr_t GetCurrentQuickFramePc() const {
return cur_quick_frame_pc_;
}
ArtMethod** GetCurrentQuickFrame() const {
return cur_quick_frame_;
}
ShadowFrame* GetCurrentShadowFrame() const {
return cur_shadow_frame_;
}
bool IsCurrentFrameInInterpreter() const {
return cur_shadow_frame_ != nullptr;
}
HandleScope* GetCurrentHandleScope(size_t pointer_size) const {
ArtMethod** sp = GetCurrentQuickFrame();
// Skip ArtMethod*; handle scope comes next;
return reinterpret_cast<HandleScope*>(reinterpret_cast<uintptr_t>(sp) + pointer_size);
}
std::string DescribeLocation() const SHARED_REQUIRES(Locks::mutator_lock_);
static size_t ComputeNumFrames(Thread* thread, StackWalkKind walk_kind)
SHARED_REQUIRES(Locks::mutator_lock_);
static void DescribeStack(Thread* thread) SHARED_REQUIRES(Locks::mutator_lock_);
const OatQuickMethodHeader* GetCurrentOatQuickMethodHeader() const {
return cur_oat_quick_method_header_;
}
QuickMethodFrameInfo GetCurrentQuickFrameInfo() const SHARED_REQUIRES(Locks::mutator_lock_);
private:
// Private constructor known in the case that num_frames_ has already been computed.
StackVisitor(Thread* thread, Context* context, StackWalkKind walk_kind, size_t num_frames)
SHARED_REQUIRES(Locks::mutator_lock_);
bool IsAccessibleRegister(uint32_t reg, bool is_float) const {
return is_float ? IsAccessibleFPR(reg) : IsAccessibleGPR(reg);
}
uintptr_t GetRegister(uint32_t reg, bool is_float) const {
DCHECK(IsAccessibleRegister(reg, is_float));
return is_float ? GetFPR(reg) : GetGPR(reg);
}
bool IsAccessibleGPR(uint32_t reg) const;
uintptr_t GetGPR(uint32_t reg) const;
bool IsAccessibleFPR(uint32_t reg) const;
uintptr_t GetFPR(uint32_t reg) const;
bool GetVRegFromDebuggerShadowFrame(uint16_t vreg, VRegKind kind, uint32_t* val) const
SHARED_REQUIRES(Locks::mutator_lock_);
bool GetVRegFromOptimizedCode(ArtMethod* m, uint16_t vreg, VRegKind kind,
uint32_t* val) const
SHARED_REQUIRES(Locks::mutator_lock_);
bool GetVRegPairFromDebuggerShadowFrame(uint16_t vreg, VRegKind kind_lo, VRegKind kind_hi,
uint64_t* val) const
SHARED_REQUIRES(Locks::mutator_lock_);
bool GetVRegPairFromOptimizedCode(ArtMethod* m, uint16_t vreg,
VRegKind kind_lo, VRegKind kind_hi,
uint64_t* val) const
SHARED_REQUIRES(Locks::mutator_lock_);
bool GetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi, VRegKind kind_lo,
uint64_t* val) const
SHARED_REQUIRES(Locks::mutator_lock_);
void SanityCheckFrame() const SHARED_REQUIRES(Locks::mutator_lock_);
InlineInfo GetCurrentInlineInfo() const SHARED_REQUIRES(Locks::mutator_lock_);
Thread* const thread_;
const StackWalkKind walk_kind_;
ShadowFrame* cur_shadow_frame_;
ArtMethod** cur_quick_frame_;
uintptr_t cur_quick_frame_pc_;
const OatQuickMethodHeader* cur_oat_quick_method_header_;
// Lazily computed, number of frames in the stack.
size_t num_frames_;
// Depth of the frame we're currently at.
size_t cur_depth_;
// Current inlining depth of the method we are currently at.
// 0 if there is no inlined frame.
size_t current_inlining_depth_;
protected:
Context* const context_;
};
} // namespace art
#endif // ART_RUNTIME_STACK_H_