/*
* 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 "dex_file.h"
#include "instruction_set.h"
#include "mirror/object_reference.h"
#include "throw_location.h"
#include "utils.h"
#include "verify_object.h"
namespace art {
namespace mirror {
class ArtMethod;
class Object;
} // namespace mirror
class Context;
class ShadowFrame;
class HandleScope;
class ScopedObjectAccess;
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,
};
/**
* @brief Represents the virtual register numbers that denote special meaning.
* @details This is used to make some virtual register numbers to have specific
* semantic meaning. This is done so that the compiler can treat all virtual
* registers the same way and only special case when needed. For example,
* calculating SSA does not care whether a virtual register is a normal one or
* a compiler temporary, so it can deal with them in a consistent manner. But,
* for example if backend cares about temporaries because it has custom spill
* location, then it can special case them only then.
*/
enum VRegBaseRegNum : int {
/**
* @brief Virtual registers originating from dex have number >= 0.
*/
kVRegBaseReg = 0,
/**
* @brief Invalid virtual register number.
*/
kVRegInvalid = -1,
/**
* @brief Used to denote the base register for compiler temporaries.
* @details Compiler temporaries are virtual registers not originating
* from dex but that are created by compiler. All virtual register numbers
* that are <= kVRegTempBaseReg are categorized as compiler temporaries.
*/
kVRegTempBaseReg = -2,
/**
* @brief Base register of temporary that holds the method pointer.
* @details This is a special compiler temporary because it has a specific
* location on stack.
*/
kVRegMethodPtrBaseReg = kVRegTempBaseReg,
/**
* @brief Base register of non-special compiler temporary.
* @details A non-special compiler temporary is one whose spill location
* is flexible.
*/
kVRegNonSpecialTempBaseReg = -3,
};
// A reference from the shadow stack to a MirrorType object within the Java heap.
template<class MirrorType>
class MANAGED StackReference : public mirror::ObjectReference<false, MirrorType> {
public:
StackReference<MirrorType>() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
: mirror::ObjectReference<false, MirrorType>(nullptr) {}
static StackReference<MirrorType> FromMirrorPtr(MirrorType* p)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
return StackReference<MirrorType>(p);
}
private:
StackReference<MirrorType>(MirrorType* p) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
: mirror::ObjectReference<false, MirrorType>(p) {}
};
// ShadowFrame has 3 possible layouts:
// - portable - a unified array of VRegs and references. Precise references need GC maps.
// - 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* Create(uint32_t num_vregs, ShadowFrame* link,
mirror::ArtMethod* method, uint32_t dex_pc) {
uint8_t* memory = new uint8_t[ComputeSize(num_vregs)];
return Create(num_vregs, link, method, dex_pc, memory);
}
// Create ShadowFrame for interpreter using provided memory.
static ShadowFrame* Create(uint32_t num_vregs, ShadowFrame* link,
mirror::ArtMethod* method, uint32_t dex_pc, void* memory) {
ShadowFrame* sf = new (memory) ShadowFrame(num_vregs, link, method, dex_pc, true);
return sf;
}
~ShadowFrame() {}
bool HasReferenceArray() const {
#if defined(ART_USE_PORTABLE_COMPILER)
return (number_of_vregs_ & kHasReferenceArray) != 0;
#else
return true;
#endif
}
uint32_t NumberOfVRegs() const {
#if defined(ART_USE_PORTABLE_COMPILER)
return number_of_vregs_ & ~kHasReferenceArray;
#else
return number_of_vregs_;
#endif
}
void SetNumberOfVRegs(uint32_t number_of_vregs) {
#if defined(ART_USE_PORTABLE_COMPILER)
number_of_vregs_ = number_of_vregs | (number_of_vregs_ & kHasReferenceArray);
#else
UNUSED(number_of_vregs);
UNIMPLEMENTED(FATAL) << "Should only be called when portable is enabled";
#endif
}
uint32_t GetDexPC() const {
return dex_pc_;
}
void SetDexPC(uint32_t dex_pc) {
dex_pc_ = dex_pc;
}
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);
}
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);
}
template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
mirror::Object* GetVRegReference(size_t i) const SHARED_LOCKS_REQUIRED(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 (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_LOCKS_REQUIRED(Locks::mutator_lock_) {
DCHECK_LT(i, NumberOfVRegs());
if (kVerifyFlags & kVerifyWrites) {
VerifyObject(val);
}
uint32_t* vreg = &vregs_[i];
reinterpret_cast<StackReference<mirror::Object>*>(vreg)->Assign(val);
if (HasReferenceArray()) {
References()[i].Assign(val);
}
}
mirror::ArtMethod* GetMethod() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
DCHECK(method_ != nullptr);
return method_;
}
mirror::ArtMethod** GetMethodAddress() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
DCHECK(method_ != nullptr);
return &method_;
}
mirror::Object* GetThisObject() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
mirror::Object* GetThisObject(uint16_t num_ins) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
ThrowLocation GetCurrentLocationForThrow() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void SetMethod(mirror::ArtMethod* method) {
#if defined(ART_USE_PORTABLE_COMPILER)
DCHECK(method != nullptr);
method_ = method;
#else
UNUSED(method);
UNIMPLEMENTED(FATAL) << "Should only be called when portable is enabled";
#endif
}
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])));
}
}
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_);
}
private:
ShadowFrame(uint32_t num_vregs, ShadowFrame* link, mirror::ArtMethod* method,
uint32_t dex_pc, bool has_reference_array)
: number_of_vregs_(num_vregs), link_(link), method_(method), dex_pc_(dex_pc) {
if (has_reference_array) {
#if defined(ART_USE_PORTABLE_COMPILER)
CHECK_LT(num_vregs, static_cast<uint32_t>(kHasReferenceArray));
number_of_vregs_ |= kHasReferenceArray;
#endif
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());
}
#if defined(ART_USE_PORTABLE_COMPILER)
enum ShadowFrameFlag {
kHasReferenceArray = 1ul << 31
};
// TODO: make const in the portable case.
uint32_t number_of_vregs_;
#else
const uint32_t number_of_vregs_;
#endif
// Link to previous shadow frame or NULL.
ShadowFrame* link_;
mirror::ArtMethod* method_;
uint32_t dex_pc_;
uint32_t vregs_[0];
DISALLOW_IMPLICIT_CONSTRUCTORS(ShadowFrame);
};
// 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()
: link_(NULL), top_shadow_frame_(NULL), top_quick_frame_(NULL), top_quick_frame_pc_(0) {}
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_;
}
StackReference<mirror::ArtMethod>* GetTopQuickFrame() const {
return top_quick_frame_;
}
void SetTopQuickFrame(StackReference<mirror::ArtMethod>* top) {
DCHECK(top_shadow_frame_ == NULL);
top_quick_frame_ = top;
}
uintptr_t GetTopQuickFramePc() const {
return top_quick_frame_pc_;
}
void SetTopQuickFramePc(uintptr_t pc) {
DCHECK(top_shadow_frame_ == NULL);
top_quick_frame_pc_ = pc;
}
static size_t TopQuickFrameOffset() {
return OFFSETOF_MEMBER(ManagedStack, top_quick_frame_);
}
static size_t TopQuickFramePcOffset() {
return OFFSETOF_MEMBER(ManagedStack, top_quick_frame_pc_);
}
ShadowFrame* PushShadowFrame(ShadowFrame* new_top_frame) {
DCHECK(top_quick_frame_ == NULL);
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_ == NULL);
CHECK(top_shadow_frame_ != NULL);
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_ == NULL);
top_shadow_frame_ = top;
}
static size_t TopShadowFrameOffset() {
return OFFSETOF_MEMBER(ManagedStack, top_shadow_frame_);
}
size_t NumJniShadowFrameReferences() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
bool ShadowFramesContain(StackReference<mirror::Object>* shadow_frame_entry) const;
private:
ManagedStack* link_;
ShadowFrame* top_shadow_frame_;
StackReference<mirror::ArtMethod>* top_quick_frame_;
uintptr_t top_quick_frame_pc_;
};
class StackVisitor {
protected:
StackVisitor(Thread* thread, Context* context) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
public:
virtual ~StackVisitor() {}
// Return 'true' if we should continue to visit more frames, 'false' to stop.
virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) = 0;
void WalkStack(bool include_transitions = false)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
mirror::ArtMethod* GetMethod() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
if (cur_shadow_frame_ != nullptr) {
return cur_shadow_frame_->GetMethod();
} else if (cur_quick_frame_ != nullptr) {
return cur_quick_frame_->AsMirrorPtr();
} else {
return nullptr;
}
}
bool IsShadowFrame() const {
return cur_shadow_frame_ != nullptr;
}
uint32_t GetDexPc(bool abort_on_failure = true) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
mirror::Object* GetThisObject() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
size_t GetNativePcOffset() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
uintptr_t* CalleeSaveAddress(int num, size_t frame_size) const
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
// Callee saves are held at the top of the frame
DCHECK(GetMethod() != nullptr);
byte* save_addr =
reinterpret_cast<byte*>(cur_quick_frame_) + frame_size - ((num + 1) * kPointerSize);
#if defined(__i386__) || defined(__x86_64__)
save_addr -= kPointerSize; // account for return address
#endif
return reinterpret_cast<uintptr_t*>(save_addr);
}
// Returns the height of the stack in the managed stack frames, including transitions.
size_t GetFrameHeight() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
return GetNumFrames() - cur_depth_ - 1;
}
// Returns a frame ID for JDWP use, starting from 1.
size_t GetFrameId() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
return GetFrameHeight() + 1;
}
size_t GetNumFrames() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
if (num_frames_ == 0) {
num_frames_ = ComputeNumFrames(thread_);
}
return num_frames_;
}
size_t GetFrameDepth() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
return cur_depth_;
}
// Get the method and dex pc immediately after the one that's currently being visited.
bool GetNextMethodAndDexPc(mirror::ArtMethod** next_method, uint32_t* next_dex_pc)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
bool GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind, uint32_t* val) const
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
uint32_t GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind) const
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
uint32_t val;
bool success = GetVReg(m, vreg, kind, &val);
CHECK(success) << "Failed to read vreg " << vreg << " of kind " << kind;
return val;
}
bool GetVRegPair(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo, VRegKind kind_hi,
uint64_t* val) const
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
uint64_t GetVRegPair(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
VRegKind kind_hi) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
uint64_t val;
bool success = GetVRegPair(m, vreg, kind_lo, kind_hi, &val);
CHECK(success) << "Failed to read vreg pair " << vreg
<< " of kind [" << kind_lo << "," << kind_hi << "]";
return val;
}
bool SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value, VRegKind kind)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
bool SetVRegPair(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
VRegKind kind_lo, VRegKind kind_hi)
SHARED_LOCKS_REQUIRED(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* GetVRegAddr(StackReference<mirror::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 = GetVRegOffset(code_item, core_spills, fp_spills, frame_size, vreg, kRuntimeISA);
DCHECK_EQ(cur_quick_frame, GetCurrentQuickFrame());
byte* vreg_addr = reinterpret_cast<byte*>(cur_quick_frame) + offset;
return reinterpret_cast<uint32_t*>(vreg_addr);
}
uintptr_t GetReturnPc() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void SetReturnPc(uintptr_t new_ret_pc) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
/*
* Return sp-relative offset for a Dalvik virtual register, compiler
* spill or Method* in bytes using Method*.
* Note that (reg >= 0) refers to a Dalvik register, (reg == -1)
* denotes an invalid Dalvik register, (reg == -2) denotes Method*
* and (reg <= -3) denotes a 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 | ... StackReference<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"
* +---------------------------+
* | Compiler temp region | ... (reg <= -3)
* | |
* | |
* +---------------------------+
* | stack alignment padding | {0 to (kStackAlignWords-1) of padding}
* +---------------------------+
* | OUT[outs-1] |
* | OUT[outs-2] |
* | . |
* | OUT[0] |
* | StackReference<ArtMethod> | ... (reg == -2) <<== sp, 16-byte aligned
* +===========================+
*/
static int GetVRegOffset(const DexFile::CodeItem* code_item,
uint32_t core_spills, uint32_t fp_spills,
size_t frame_size, int reg, InstructionSet isa) {
DCHECK_EQ(frame_size & (kStackAlignment - 1), 0U);
DCHECK_NE(reg, static_cast<int>(kVRegInvalid));
int spill_size = POPCOUNT(core_spills) * GetBytesPerGprSpillLocation(isa)
+ POPCOUNT(fp_spills) * GetBytesPerFprSpillLocation(isa)
+ sizeof(uint32_t); // Filler.
int num_ins = code_item->ins_size_;
int num_regs = code_item->registers_size_ - num_ins;
int locals_start = frame_size - spill_size - num_regs * sizeof(uint32_t);
if (reg == static_cast<int>(kVRegMethodPtrBaseReg)) {
// The current method pointer corresponds to special location on stack.
return 0;
} else if (reg <= static_cast<int>(kVRegNonSpecialTempBaseReg)) {
/*
* Special temporaries may have custom locations and the logic above deals with that.
* However, non-special temporaries are placed relative to the locals. Since the
* virtual register numbers for temporaries "grow" in negative direction, reg number
* will always be <= to the temp base reg. Thus, the logic ensures that the first
* temp is at offset -4 bytes from locals, the second is at -8 bytes from locals,
* and so on.
*/
int relative_offset =
(reg + std::abs(static_cast<int>(kVRegNonSpecialTempBaseReg)) - 1) * sizeof(uint32_t);
return locals_start + relative_offset;
} else if (reg < num_regs) {
return locals_start + (reg * sizeof(uint32_t));
} else {
// Handle ins.
return frame_size + ((reg - num_regs) * sizeof(uint32_t)) +
sizeof(StackReference<mirror::ArtMethod>);
}
}
static int GetOutVROffset(uint16_t out_num, InstructionSet isa) {
// According to stack model, the first out is above the Method referernce.
return sizeof(StackReference<mirror::ArtMethod>) + (out_num * sizeof(uint32_t));
}
uintptr_t GetCurrentQuickFramePc() const {
return cur_quick_frame_pc_;
}
StackReference<mirror::ArtMethod>* GetCurrentQuickFrame() const {
return cur_quick_frame_;
}
ShadowFrame* GetCurrentShadowFrame() const {
return cur_shadow_frame_;
}
HandleScope* GetCurrentHandleScope() const {
StackReference<mirror::ArtMethod>* sp = GetCurrentQuickFrame();
++sp; // Skip Method*; handle scope comes next;
return reinterpret_cast<HandleScope*>(sp);
}
std::string DescribeLocation() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
static size_t ComputeNumFrames(Thread* thread) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
static void DescribeStack(Thread* thread) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
private:
// Private constructor known in the case that num_frames_ has already been computed.
StackVisitor(Thread* thread, Context* context, size_t num_frames)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
bool GetGPR(uint32_t reg, uintptr_t* val) const;
bool SetGPR(uint32_t reg, uintptr_t value);
bool GetFPR(uint32_t reg, uintptr_t* val) const;
bool SetFPR(uint32_t reg, uintptr_t value);
void SanityCheckFrame() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
Thread* const thread_;
ShadowFrame* cur_shadow_frame_;
StackReference<mirror::ArtMethod>* cur_quick_frame_;
uintptr_t cur_quick_frame_pc_;
// Lazily computed, number of frames in the stack.
size_t num_frames_;
// Depth of the frame we're currently at.
size_t cur_depth_;
protected:
Context* const context_;
};
} // namespace art
#endif // ART_RUNTIME_STACK_H_