/*
* 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 "base/macros.h"
#include "base/mutex.h"
#include "quick/quick_method_frame_info.h"
namespace art {
namespace mirror {
class Object;
} // namespace mirror
class ArtMethod;
class Context;
class HandleScope;
class OatQuickMethodHeader;
class ShadowFrame;
class Thread;
union JValue;
// 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);
// Size in bytes of the should_deoptimize flag on stack.
// We just need 4 bytes for our purpose regardless of the architecture. Frame size
// calculation will automatically do alignment for the final frame size.
static constexpr size_t kShouldDeoptimizeFlagSize = 4;
/*
* Our current stack layout.
* 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.
*
* TODO: Update this documentation?
*
* +-------------------------------+
* | 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
* +===============================+
*/
class StackVisitor {
public:
// This enum defines a flag to control whether inlined frames are included
// when walking the stack.
enum class StackWalkKind {
kIncludeInlinedFrames,
kSkipInlinedFrames,
};
protected:
StackVisitor(Thread* thread,
Context* context,
StackWalkKind walk_kind,
bool check_suspended = true);
bool GetRegisterIfAccessible(uint32_t reg, VRegKind kind, uint32_t* val) const
REQUIRES_SHARED(Locks::mutator_lock_);
public:
virtual ~StackVisitor() {}
StackVisitor(const StackVisitor&) = default;
StackVisitor(StackVisitor&&) = default;
// Return 'true' if we should continue to visit more frames, 'false' to stop.
virtual bool VisitFrame() REQUIRES_SHARED(Locks::mutator_lock_) = 0;
enum class CountTransitions {
kYes,
kNo,
};
template <CountTransitions kCount = CountTransitions::kYes>
void WalkStack(bool include_transitions = false) REQUIRES_SHARED(Locks::mutator_lock_);
Thread* GetThread() const {
return thread_;
}
ArtMethod* GetMethod() const REQUIRES_SHARED(Locks::mutator_lock_);
// Sets this stack frame's method pointer. This requires a full lock of the MutatorLock. This
// doesn't work with inlined methods.
void SetMethod(ArtMethod* method) 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 REQUIRES_SHARED(Locks::mutator_lock_);
mirror::Object* GetThisObject() const REQUIRES_SHARED(Locks::mutator_lock_);
size_t GetNativePcOffset() const REQUIRES_SHARED(Locks::mutator_lock_);
// Returns the height of the stack in the managed stack frames, including transitions.
size_t GetFrameHeight() REQUIRES_SHARED(Locks::mutator_lock_) {
return GetNumFrames() - cur_depth_ - 1;
}
// Returns a frame ID for JDWP use, starting from 1.
size_t GetFrameId() REQUIRES_SHARED(Locks::mutator_lock_) {
return GetFrameHeight() + 1;
}
size_t GetNumFrames() REQUIRES_SHARED(Locks::mutator_lock_) {
if (num_frames_ == 0) {
num_frames_ = ComputeNumFrames(thread_, walk_kind_);
}
return num_frames_;
}
size_t GetFrameDepth() const REQUIRES_SHARED(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)
REQUIRES_SHARED(Locks::mutator_lock_);
bool GetVReg(ArtMethod* m, uint16_t vreg, VRegKind kind, uint32_t* val) const
REQUIRES_SHARED(Locks::mutator_lock_);
bool GetVRegPair(ArtMethod* m, uint16_t vreg, VRegKind kind_lo, VRegKind kind_hi,
uint64_t* val) const
REQUIRES_SHARED(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)
REQUIRES_SHARED(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)
REQUIRES_SHARED(Locks::mutator_lock_);
uintptr_t* GetGPRAddress(uint32_t reg) const;
uintptr_t GetReturnPc() const REQUIRES_SHARED(Locks::mutator_lock_);
void SetReturnPc(uintptr_t new_ret_pc) REQUIRES_SHARED(Locks::mutator_lock_);
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_;
}
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 REQUIRES_SHARED(Locks::mutator_lock_);
static size_t ComputeNumFrames(Thread* thread, StackWalkKind walk_kind)
REQUIRES_SHARED(Locks::mutator_lock_);
static void DescribeStack(Thread* thread) REQUIRES_SHARED(Locks::mutator_lock_);
const OatQuickMethodHeader* GetCurrentOatQuickMethodHeader() const {
return cur_oat_quick_method_header_;
}
QuickMethodFrameInfo GetCurrentQuickFrameInfo() const REQUIRES_SHARED(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,
bool check_suspended = true)
REQUIRES_SHARED(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
REQUIRES_SHARED(Locks::mutator_lock_);
bool GetVRegFromOptimizedCode(ArtMethod* m, uint16_t vreg, VRegKind kind,
uint32_t* val) const
REQUIRES_SHARED(Locks::mutator_lock_);
bool GetVRegPairFromDebuggerShadowFrame(uint16_t vreg, VRegKind kind_lo, VRegKind kind_hi,
uint64_t* val) const
REQUIRES_SHARED(Locks::mutator_lock_);
bool GetVRegPairFromOptimizedCode(ArtMethod* m, uint16_t vreg,
VRegKind kind_lo, VRegKind kind_hi,
uint64_t* val) const
REQUIRES_SHARED(Locks::mutator_lock_);
bool GetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi, VRegKind kind_lo,
uint64_t* val) const
REQUIRES_SHARED(Locks::mutator_lock_);
void SanityCheckFrame() const REQUIRES_SHARED(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_;
const bool check_suspended_;
};
} // namespace art
#endif // ART_RUNTIME_STACK_H_