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/*
* Copyright (C) 2014 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_MAP_H_
#define ART_RUNTIME_STACK_MAP_H_
#include "base/bit_vector.h"
#include "memory_region.h"
#include "utils.h"
namespace art {
// Size of a frame slot, in bytes. This constant is a signed value,
// to please the compiler in arithmetic operations involving int32_t
// (signed) values.
static ssize_t constexpr kFrameSlotSize = 4;
// Word alignment required on ARM, in bytes.
static constexpr size_t kWordAlignment = 4;
// Size of Dex virtual registers.
static size_t constexpr kVRegSize = 4;
/**
* Classes in the following file are wrapper on stack map information backed
* by a MemoryRegion. As such they read and write to the region, they don't have
* their own fields.
*/
/**
* Inline information for a specific PC. The information is of the form:
* [inlining_depth, [method_dex reference]+]
*/
class InlineInfo {
public:
explicit InlineInfo(MemoryRegion region) : region_(region) {}
uint8_t GetDepth() const {
return region_.LoadUnaligned<uint8_t>(kDepthOffset);
}
void SetDepth(uint8_t depth) {
region_.StoreUnaligned<uint8_t>(kDepthOffset, depth);
}
uint32_t GetMethodReferenceIndexAtDepth(uint8_t depth) const {
return region_.LoadUnaligned<uint32_t>(kFixedSize + depth * SingleEntrySize());
}
void SetMethodReferenceIndexAtDepth(uint8_t depth, uint32_t index) {
region_.StoreUnaligned<uint32_t>(kFixedSize + depth * SingleEntrySize(), index);
}
static size_t SingleEntrySize() {
return sizeof(uint32_t);
}
private:
// TODO: Instead of plain types such as "uint8_t", introduce
// typedefs (and document the memory layout of InlineInfo).
static constexpr int kDepthOffset = 0;
static constexpr int kFixedSize = kDepthOffset + sizeof(uint8_t);
MemoryRegion region_;
friend class CodeInfo;
friend class StackMap;
friend class StackMapStream;
};
// Dex register location container used by DexRegisterMap and StackMapStream.
class DexRegisterLocation {
public:
/*
* The location kind used to populate the Dex register information in a
* StackMapStream can either be:
* - kNone: the register has no location yet, meaning it has not been set;
* - kConstant: value holds the constant;
* - kStack: value holds the stack offset;
* - kRegister: value holds the physical register number;
* - kFpuRegister: value holds the physical register number.
*
* In addition, DexRegisterMap also uses these values:
* - kInStackLargeOffset: value holds a "large" stack offset (greater than
* 128 bytes);
* - kConstantLargeValue: value holds a "large" constant (lower than or
* equal to -16, or greater than 16).
*/
enum class Kind : uint8_t {
// Short location kinds, for entries fitting on one byte (3 bits
// for the kind, 5 bits for the value) in a DexRegisterMap.
kNone = 0, // 0b000
kInStack = 1, // 0b001
kInRegister = 2, // 0b010
kInFpuRegister = 3, // 0b011
kConstant = 4, // 0b100
// Large location kinds, requiring a 5-byte encoding (1 byte for the
// kind, 4 bytes for the value).
// Stack location at a large offset, meaning that the offset value
// divided by the stack frame slot size (4 bytes) cannot fit on a
// 5-bit unsigned integer (i.e., this offset value is greater than
// or equal to 2^5 * 4 = 128 bytes).
kInStackLargeOffset = 5, // 0b101
// Large constant, that cannot fit on a 5-bit signed integer (i.e.,
// lower than -2^(5-1) = -16, or greater than or equal to
// 2^(5-1) - 1 = 15).
kConstantLargeValue = 6, // 0b110
kLastLocationKind = kConstantLargeValue
};
static_assert(
sizeof(Kind) == 1u,
"art::DexRegisterLocation::Kind has a size different from one byte.");
static const char* PrettyDescriptor(Kind kind) {
switch (kind) {
case Kind::kNone:
return "none";
case Kind::kInStack:
return "in stack";
case Kind::kInRegister:
return "in register";
case Kind::kInFpuRegister:
return "in fpu register";
case Kind::kConstant:
return "as constant";
case Kind::kInStackLargeOffset:
return "in stack (large offset)";
case Kind::kConstantLargeValue:
return "as constant (large value)";
default:
UNREACHABLE();
}
}
static bool IsShortLocationKind(Kind kind) {
switch (kind) {
case Kind::kNone:
case Kind::kInStack:
case Kind::kInRegister:
case Kind::kInFpuRegister:
case Kind::kConstant:
return true;
case Kind::kInStackLargeOffset:
case Kind::kConstantLargeValue:
return false;
default:
UNREACHABLE();
}
}
// Convert `kind` to a "surface" kind, i.e. one that doesn't include
// any value with a "large" qualifier.
// TODO: Introduce another enum type for the surface kind?
static Kind ConvertToSurfaceKind(Kind kind) {
switch (kind) {
case Kind::kNone:
case Kind::kInStack:
case Kind::kInRegister:
case Kind::kInFpuRegister:
case Kind::kConstant:
return kind;
case Kind::kInStackLargeOffset:
return Kind::kInStack;
case Kind::kConstantLargeValue:
return Kind::kConstant;
default:
UNREACHABLE();
}
}
DexRegisterLocation(Kind kind, int32_t value)
: kind_(kind), value_(value) {}
static DexRegisterLocation None() {
return DexRegisterLocation(Kind::kNone, 0);
}
// Get the "surface" kind of the location, i.e., the one that doesn't
// include any value with a "large" qualifier.
Kind GetKind() const {
return ConvertToSurfaceKind(kind_);
}
// Get the value of the location.
int32_t GetValue() const { return value_; }
// Get the actual kind of the location.
Kind GetInternalKind() const { return kind_; }
private:
Kind kind_;
int32_t value_;
};
/**
* Information on dex register values for a specific PC. The information is
* of the form:
* [live_bit_mask, DexRegisterLocation+].
* DexRegisterLocations are either 1- or 5-byte wide (see art::DexRegisterLocation::Kind).
*/
class DexRegisterMap {
public:
explicit DexRegisterMap(MemoryRegion region) : region_(region) {}
// Short (compressed) location, fitting on one byte.
typedef uint8_t ShortLocation;
static size_t LiveBitMaskSize(uint16_t number_of_dex_registers) {
return RoundUp(number_of_dex_registers, kBitsPerByte) / kBitsPerByte;
}
void SetLiveBitMask(size_t offset,
uint16_t number_of_dex_registers,
const BitVector& live_dex_registers_mask) {
for (uint16_t i = 0; i < number_of_dex_registers; i++) {
region_.StoreBit(offset + i, live_dex_registers_mask.IsBitSet(i));
}
}
void SetRegisterInfo(size_t offset, const DexRegisterLocation& dex_register_location) {
DexRegisterLocation::Kind kind = ComputeCompressedKind(dex_register_location);
int32_t value = dex_register_location.GetValue();
if (DexRegisterLocation::IsShortLocationKind(kind)) {
// Short location. Compress the kind and the value as a single byte.
if (kind == DexRegisterLocation::Kind::kInStack) {
// Instead of storing stack offsets expressed in bytes for
// short stack locations, store slot offsets. A stack offset
// is a multiple of 4 (kFrameSlotSize). This means that by
// dividing it by 4, we can fit values from the [0, 128)
// interval in a short stack location, and not just values
// from the [0, 32) interval.
DCHECK_EQ(value % kFrameSlotSize, 0);
value /= kFrameSlotSize;
}
DCHECK(IsUint<kValueBits>(value)) << value;
region_.StoreUnaligned<ShortLocation>(offset, MakeShortLocation(kind, value));
} else {
// Large location. Write the location on one byte and the value
// on 4 bytes.
DCHECK(!IsUint<kValueBits>(value)) << value;
if (kind == DexRegisterLocation::Kind::kInStackLargeOffset) {
// Also divide large stack offsets by 4 for the sake of consistency.
DCHECK_EQ(value % kFrameSlotSize, 0);
value /= kFrameSlotSize;
}
// Data can be unaligned as the written Dex register locations can
// either be 1-byte or 5-byte wide. Use
// art::MemoryRegion::StoreUnaligned instead of
// art::MemoryRegion::Store to prevent unligned word accesses on ARM.
region_.StoreUnaligned<DexRegisterLocation::Kind>(offset, kind);
region_.StoreUnaligned<int32_t>(offset + sizeof(DexRegisterLocation::Kind), value);
}
}
bool IsDexRegisterLive(uint16_t dex_register_index) const {
size_t offset = kFixedSize;
return region_.LoadBit(offset + dex_register_index);
}
static constexpr size_t kNoDexRegisterLocationOffset = -1;
static size_t GetDexRegisterMapLocationsOffset(uint16_t number_of_dex_registers) {
return kLiveBitMaskOffset + LiveBitMaskSize(number_of_dex_registers);
}
// Find the offset of the Dex register location number `dex_register_index`.
size_t FindLocationOffset(uint16_t dex_register_index, uint16_t number_of_dex_registers) const {
if (!IsDexRegisterLive(dex_register_index)) return kNoDexRegisterLocationOffset;
size_t offset = GetDexRegisterMapLocationsOffset(number_of_dex_registers);
// Skip the first `dex_register_index - 1` entries.
for (uint16_t i = 0; i < dex_register_index; ++i) {
if (IsDexRegisterLive(i)) {
// Read the first next byte and inspect its first 3 bits to decide
// whether it is a short or a large location.
DexRegisterLocation::Kind kind = ExtractKindAtOffset(offset);
if (DexRegisterLocation::IsShortLocationKind(kind)) {
// Short location. Skip the current byte.
offset += SingleShortEntrySize();
} else {
// Large location. Skip the 5 next bytes.
offset += SingleLargeEntrySize();
}
}
}
return offset;
}
// Get the surface kind.
DexRegisterLocation::Kind GetLocationKind(uint16_t dex_register_index,
uint16_t number_of_dex_registers) const {
return IsDexRegisterLive(dex_register_index)
? DexRegisterLocation::ConvertToSurfaceKind(
GetLocationInternalKind(dex_register_index, number_of_dex_registers))
: DexRegisterLocation::Kind::kNone;
}
// Get the internal kind.
DexRegisterLocation::Kind GetLocationInternalKind(uint16_t dex_register_index,
uint16_t number_of_dex_registers) const {
return IsDexRegisterLive(dex_register_index)
? ExtractKindAtOffset(FindLocationOffset(dex_register_index, number_of_dex_registers))
: DexRegisterLocation::Kind::kNone;
}
// TODO: Rename as GetDexRegisterLocation?
DexRegisterLocation GetLocationKindAndValue(uint16_t dex_register_index,
uint16_t number_of_dex_registers) const {
if (!IsDexRegisterLive(dex_register_index)) {
return DexRegisterLocation::None();
}
size_t offset = FindLocationOffset(dex_register_index, number_of_dex_registers);
// Read the first byte and inspect its first 3 bits to get the location.
ShortLocation first_byte = region_.LoadUnaligned<ShortLocation>(offset);
DexRegisterLocation::Kind kind = ExtractKindFromShortLocation(first_byte);
if (DexRegisterLocation::IsShortLocationKind(kind)) {
// Short location. Extract the value from the remaining 5 bits.
int32_t value = ExtractValueFromShortLocation(first_byte);
if (kind == DexRegisterLocation::Kind::kInStack) {
// Convert the stack slot (short) offset to a byte offset value.
value *= kFrameSlotSize;
}
return DexRegisterLocation(kind, value);
} else {
// Large location. Read the four next bytes to get the value.
int32_t value = region_.LoadUnaligned<int32_t>(offset + sizeof(DexRegisterLocation::Kind));
if (kind == DexRegisterLocation::Kind::kInStackLargeOffset) {
// Convert the stack slot (large) offset to a byte offset value.
value *= kFrameSlotSize;
}
return DexRegisterLocation(kind, value);
}
}
int32_t GetStackOffsetInBytes(uint16_t dex_register_index,
uint16_t number_of_dex_registers) const {
DexRegisterLocation location =
GetLocationKindAndValue(dex_register_index, number_of_dex_registers);
DCHECK(location.GetKind() == DexRegisterLocation::Kind::kInStack);
// GetLocationKindAndValue returns the offset in bytes.
return location.GetValue();
}
int32_t GetConstant(uint16_t dex_register_index, uint16_t number_of_dex_registers) const {
DexRegisterLocation location =
GetLocationKindAndValue(dex_register_index, number_of_dex_registers);
DCHECK(location.GetKind() == DexRegisterLocation::Kind::kConstant);
return location.GetValue();
}
int32_t GetMachineRegister(uint16_t dex_register_index, uint16_t number_of_dex_registers) const {
DexRegisterLocation location =
GetLocationKindAndValue(dex_register_index, number_of_dex_registers);
DCHECK(location.GetInternalKind() == DexRegisterLocation::Kind::kInRegister
|| location.GetInternalKind() == DexRegisterLocation::Kind::kInFpuRegister)
<< DexRegisterLocation::PrettyDescriptor(location.GetInternalKind());
return location.GetValue();
}
// Compute the compressed kind of `location`.
static DexRegisterLocation::Kind ComputeCompressedKind(const DexRegisterLocation& location) {
switch (location.GetInternalKind()) {
case DexRegisterLocation::Kind::kNone:
DCHECK_EQ(location.GetValue(), 0);
return DexRegisterLocation::Kind::kNone;
case DexRegisterLocation::Kind::kInRegister:
DCHECK_GE(location.GetValue(), 0);
DCHECK_LT(location.GetValue(), 1 << DexRegisterMap::kValueBits);
return DexRegisterLocation::Kind::kInRegister;
case DexRegisterLocation::Kind::kInFpuRegister:
DCHECK_GE(location.GetValue(), 0);
DCHECK_LT(location.GetValue(), 1 << DexRegisterMap::kValueBits);
return DexRegisterLocation::Kind::kInFpuRegister;
case DexRegisterLocation::Kind::kInStack:
DCHECK_EQ(location.GetValue() % kFrameSlotSize, 0);
return IsUint<DexRegisterMap::kValueBits>(location.GetValue() / kFrameSlotSize)
? DexRegisterLocation::Kind::kInStack
: DexRegisterLocation::Kind::kInStackLargeOffset;
case DexRegisterLocation::Kind::kConstant:
return IsUint<DexRegisterMap::kValueBits>(location.GetValue())
? DexRegisterLocation::Kind::kConstant
: DexRegisterLocation::Kind::kConstantLargeValue;
default:
LOG(FATAL) << "Unexpected location kind"
<< DexRegisterLocation::PrettyDescriptor(location.GetInternalKind());
UNREACHABLE();
}
}
// Can `location` be turned into a short location?
static bool CanBeEncodedAsShortLocation(const DexRegisterLocation& location) {
switch (location.GetInternalKind()) {
case DexRegisterLocation::Kind::kNone:
case DexRegisterLocation::Kind::kInRegister:
case DexRegisterLocation::Kind::kInFpuRegister:
return true;
case DexRegisterLocation::Kind::kInStack:
DCHECK_EQ(location.GetValue() % kFrameSlotSize, 0);
return IsUint<kValueBits>(location.GetValue() / kFrameSlotSize);
case DexRegisterLocation::Kind::kConstant:
return IsUint<kValueBits>(location.GetValue());
default:
UNREACHABLE();
}
}
static size_t EntrySize(const DexRegisterLocation& location) {
return CanBeEncodedAsShortLocation(location)
? DexRegisterMap::SingleShortEntrySize()
: DexRegisterMap::SingleLargeEntrySize();
}
static size_t SingleShortEntrySize() {
return sizeof(ShortLocation);
}
static size_t SingleLargeEntrySize() {
return sizeof(DexRegisterLocation::Kind) + sizeof(int32_t);
}
size_t Size() const {
return region_.size();
}
static constexpr int kLiveBitMaskOffset = 0;
static constexpr int kFixedSize = kLiveBitMaskOffset;
private:
// Width of the kind "field" in a short location, in bits.
static constexpr size_t kKindBits = 3;
// Width of the value "field" in a short location, in bits.
static constexpr size_t kValueBits = 5;
static constexpr uint8_t kKindMask = (1 << kKindBits) - 1;
static constexpr int32_t kValueMask = (1 << kValueBits) - 1;
static constexpr size_t kKindOffset = 0;
static constexpr size_t kValueOffset = kKindBits;
static ShortLocation MakeShortLocation(DexRegisterLocation::Kind kind, int32_t value) {
DCHECK(IsUint<kKindBits>(static_cast<uint8_t>(kind))) << static_cast<uint8_t>(kind);
DCHECK(IsUint<kValueBits>(value)) << value;
return (static_cast<uint8_t>(kind) & kKindMask) << kKindOffset
| (value & kValueMask) << kValueOffset;
}
static DexRegisterLocation::Kind ExtractKindFromShortLocation(ShortLocation location) {
uint8_t kind = (location >> kKindOffset) & kKindMask;
DCHECK_LE(kind, static_cast<uint8_t>(DexRegisterLocation::Kind::kLastLocationKind));
// We do not encode kNone locations in the stack map.
DCHECK_NE(kind, static_cast<uint8_t>(DexRegisterLocation::Kind::kNone));
return static_cast<DexRegisterLocation::Kind>(kind);
}
static int32_t ExtractValueFromShortLocation(ShortLocation location) {
return (location >> kValueOffset) & kValueMask;
}
// Extract a location kind from the byte at position `offset`.
DexRegisterLocation::Kind ExtractKindAtOffset(size_t offset) const {
ShortLocation first_byte = region_.LoadUnaligned<ShortLocation>(offset);
return ExtractKindFromShortLocation(first_byte);
}
MemoryRegion region_;
friend class CodeInfo;
friend class StackMapStream;
};
/**
* A Stack Map holds compilation information for a specific PC necessary for:
* - Mapping it to a dex PC,
* - Knowing which stack entries are objects,
* - Knowing which registers hold objects,
* - Knowing the inlining information,
* - Knowing the values of dex registers.
*
* The information is of the form:
* [dex_pc, native_pc_offset, dex_register_map_offset, inlining_info_offset, register_mask, stack_mask].
*
* Note that register_mask is fixed size, but stack_mask is variable size, depending on the
* stack size of a method.
*/
class StackMap {
public:
explicit StackMap(MemoryRegion region) : region_(region) {}
uint32_t GetDexPc() const {
return region_.LoadUnaligned<uint32_t>(kDexPcOffset);
}
void SetDexPc(uint32_t dex_pc) {
region_.StoreUnaligned<uint32_t>(kDexPcOffset, dex_pc);
}
uint32_t GetNativePcOffset() const {
return region_.LoadUnaligned<uint32_t>(kNativePcOffsetOffset);
}
void SetNativePcOffset(uint32_t native_pc_offset) {
region_.StoreUnaligned<uint32_t>(kNativePcOffsetOffset, native_pc_offset);
}
uint32_t GetDexRegisterMapOffset() const {
return region_.LoadUnaligned<uint32_t>(kDexRegisterMapOffsetOffset);
}
void SetDexRegisterMapOffset(uint32_t offset) {
region_.StoreUnaligned<uint32_t>(kDexRegisterMapOffsetOffset, offset);
}
uint32_t GetInlineDescriptorOffset() const {
return region_.LoadUnaligned<uint32_t>(kInlineDescriptorOffsetOffset);
}
void SetInlineDescriptorOffset(uint32_t offset) {
region_.StoreUnaligned<uint32_t>(kInlineDescriptorOffsetOffset, offset);
}
uint32_t GetRegisterMask() const {
return region_.LoadUnaligned<uint32_t>(kRegisterMaskOffset);
}
void SetRegisterMask(uint32_t mask) {
region_.StoreUnaligned<uint32_t>(kRegisterMaskOffset, mask);
}
MemoryRegion GetStackMask() const {
return region_.Subregion(kStackMaskOffset, StackMaskSize());
}
void SetStackMask(const BitVector& sp_map) {
MemoryRegion region = GetStackMask();
for (size_t i = 0; i < region.size_in_bits(); i++) {
region.StoreBit(i, sp_map.IsBitSet(i));
}
}
bool HasDexRegisterMap() const {
return GetDexRegisterMapOffset() != kNoDexRegisterMap;
}
bool HasInlineInfo() const {
return GetInlineDescriptorOffset() != kNoInlineInfo;
}
bool Equals(const StackMap& other) const {
return region_.pointer() == other.region_.pointer()
&& region_.size() == other.region_.size();
}
static size_t ComputeStackMapSize(size_t stack_mask_size) {
return StackMap::kFixedSize + stack_mask_size;
}
// Special (invalid) offset for the DexRegisterMapOffset field meaning
// that there is no Dex register map for this stack map.
static constexpr uint32_t kNoDexRegisterMap = -1;
// Special (invalid) offset for the InlineDescriptorOffset field meaning
// that there is no inline info for this stack map.
static constexpr uint32_t kNoInlineInfo = -1;
private:
// TODO: Instead of plain types such as "uint32_t", introduce
// typedefs (and document the memory layout of StackMap).
static constexpr int kDexPcOffset = 0;
static constexpr int kNativePcOffsetOffset = kDexPcOffset + sizeof(uint32_t);
static constexpr int kDexRegisterMapOffsetOffset = kNativePcOffsetOffset + sizeof(uint32_t);
static constexpr int kInlineDescriptorOffsetOffset =
kDexRegisterMapOffsetOffset + sizeof(uint32_t);
static constexpr int kRegisterMaskOffset = kInlineDescriptorOffsetOffset + sizeof(uint32_t);
static constexpr int kFixedSize = kRegisterMaskOffset + sizeof(uint32_t);
static constexpr int kStackMaskOffset = kFixedSize;
size_t StackMaskSize() const { return region_.size() - kFixedSize; }
MemoryRegion region_;
friend class CodeInfo;
friend class StackMapStream;
};
/**
* Wrapper around all compiler information collected for a method.
* The information is of the form:
* [overall_size, number_of_stack_maps, stack_mask_size, StackMap+, DexRegisterInfo+, InlineInfo*].
*/
class CodeInfo {
public:
explicit CodeInfo(MemoryRegion region) : region_(region) {}
explicit CodeInfo(const void* data) {
uint32_t size = reinterpret_cast<const uint32_t*>(data)[0];
region_ = MemoryRegion(const_cast<void*>(data), size);
}
StackMap GetStackMapAt(size_t i) const {
size_t size = StackMapSize();
return StackMap(GetStackMaps().Subregion(i * size, size));
}
uint32_t GetOverallSize() const {
return region_.Load<uint32_t>(kOverallSizeOffset);
}
void SetOverallSize(uint32_t size) {
region_.Store<uint32_t>(kOverallSizeOffset, size);
}
uint32_t GetStackMaskSize() const {
return region_.Load<uint32_t>(kStackMaskSizeOffset);
}
void SetStackMaskSize(uint32_t size) {
region_.Store<uint32_t>(kStackMaskSizeOffset, size);
}
size_t GetNumberOfStackMaps() const {
return region_.Load<uint32_t>(kNumberOfStackMapsOffset);
}
void SetNumberOfStackMaps(uint32_t number_of_stack_maps) {
region_.Store<uint32_t>(kNumberOfStackMapsOffset, number_of_stack_maps);
}
// Get the size of one stack map of this CodeInfo object, in bytes.
// All stack maps of a CodeInfo have the same size.
size_t StackMapSize() const {
return StackMap::ComputeStackMapSize(GetStackMaskSize());
}
// Get the size all the stack maps of this CodeInfo object, in bytes.
size_t StackMapsSize() const {
return StackMapSize() * GetNumberOfStackMaps();
}
uint32_t GetStackMapsOffset() const {
return kFixedSize;
}
DexRegisterMap GetDexRegisterMapOf(StackMap stack_map, uint32_t number_of_dex_registers) const {
DCHECK(stack_map.HasDexRegisterMap());
uint32_t offset = stack_map.GetDexRegisterMapOffset();
size_t size = ComputeDexRegisterMapSize(offset, number_of_dex_registers);
return DexRegisterMap(region_.Subregion(offset, size));
}
InlineInfo GetInlineInfoOf(StackMap stack_map) const {
DCHECK(stack_map.HasInlineInfo());
uint32_t offset = stack_map.GetInlineDescriptorOffset();
uint8_t depth = region_.Load<uint8_t>(offset);
return InlineInfo(region_.Subregion(offset,
InlineInfo::kFixedSize + depth * InlineInfo::SingleEntrySize()));
}
StackMap GetStackMapForDexPc(uint32_t dex_pc) const {
for (size_t i = 0, e = GetNumberOfStackMaps(); i < e; ++i) {
StackMap stack_map = GetStackMapAt(i);
if (stack_map.GetDexPc() == dex_pc) {
return stack_map;
}
}
LOG(FATAL) << "Unreachable";
UNREACHABLE();
}
StackMap GetStackMapForNativePcOffset(uint32_t native_pc_offset) const {
// TODO: stack maps are sorted by native pc, we can do a binary search.
for (size_t i = 0, e = GetNumberOfStackMaps(); i < e; ++i) {
StackMap stack_map = GetStackMapAt(i);
if (stack_map.GetNativePcOffset() == native_pc_offset) {
return stack_map;
}
}
LOG(FATAL) << "Unreachable";
UNREACHABLE();
}
private:
// TODO: Instead of plain types such as "uint32_t", introduce
// typedefs (and document the memory layout of CodeInfo).
static constexpr int kOverallSizeOffset = 0;
static constexpr int kNumberOfStackMapsOffset = kOverallSizeOffset + sizeof(uint32_t);
static constexpr int kStackMaskSizeOffset = kNumberOfStackMapsOffset + sizeof(uint32_t);
static constexpr int kFixedSize = kStackMaskSizeOffset + sizeof(uint32_t);
MemoryRegion GetStackMaps() const {
return region_.size() == 0
? MemoryRegion()
: region_.Subregion(kFixedSize, StackMapsSize());
}
// Compute the size of a Dex register map starting at offset `origin` in
// `region_` and containing `number_of_dex_registers` locations.
size_t ComputeDexRegisterMapSize(uint32_t origin, uint32_t number_of_dex_registers) const {
// TODO: Ideally, we would like to use art::DexRegisterMap::Size or
// art::DexRegisterMap::FindLocationOffset, but the DexRegisterMap is not
// yet built. Try to factor common code.
size_t offset =
origin + DexRegisterMap::GetDexRegisterMapLocationsOffset(number_of_dex_registers);
// Create a temporary DexRegisterMap to be able to call DexRegisterMap.IsDexRegisterLive.
DexRegisterMap only_live_mask(MemoryRegion(region_.Subregion(origin, offset - origin)));
// Skip the first `number_of_dex_registers - 1` entries.
for (uint16_t i = 0; i < number_of_dex_registers; ++i) {
if (only_live_mask.IsDexRegisterLive(i)) {
// Read the first next byte and inspect its first 3 bits to decide
// whether it is a short or a large location.
DexRegisterMap::ShortLocation first_byte =
region_.LoadUnaligned<DexRegisterMap::ShortLocation>(offset);
DexRegisterLocation::Kind kind =
DexRegisterMap::ExtractKindFromShortLocation(first_byte);
if (DexRegisterLocation::IsShortLocationKind(kind)) {
// Short location. Skip the current byte.
offset += DexRegisterMap::SingleShortEntrySize();
} else {
// Large location. Skip the 5 next bytes.
offset += DexRegisterMap::SingleLargeEntrySize();
}
}
}
size_t size = offset - origin;
return size;
}
MemoryRegion region_;
friend class StackMapStream;
};
} // namespace art
#endif // ART_RUNTIME_STACK_MAP_H_