/*
* 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 "mirror/art_method-inl.h"
#include "mirror/class-inl.h"
#include "mirror/object.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "object_utils.h"
#include "thread_list.h"
#include "throw_location.h"
#include "vmap_table.h"
namespace art {
mirror::Object* ShadowFrame::GetThisObject() const {
mirror::ArtMethod* m = GetMethod();
if (m->IsStatic()) {
return NULL;
} else if (m->IsNative()) {
return GetVRegReference(0);
} else {
const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
CHECK(code_item != NULL) << PrettyMethod(m);
uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
return GetVRegReference(reg);
}
}
mirror::Object* ShadowFrame::GetThisObject(uint16_t num_ins) const {
mirror::ArtMethod* m = GetMethod();
if (m->IsStatic()) {
return NULL;
} else {
return GetVRegReference(NumberOfVRegs() - num_ins);
}
}
ThrowLocation ShadowFrame::GetCurrentLocationForThrow() const {
return ThrowLocation(GetThisObject(), GetMethod(), GetDexPC());
}
size_t ManagedStack::NumJniShadowFrameReferences() const {
size_t count = 0;
for (const ManagedStack* current_fragment = this; current_fragment != NULL;
current_fragment = current_fragment->GetLink()) {
for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != NULL;
current_frame = current_frame->GetLink()) {
if (current_frame->GetMethod()->IsNative()) {
// The JNI ShadowFrame only contains references. (For indirect reference.)
count += current_frame->NumberOfVRegs();
}
}
}
return count;
}
bool ManagedStack::ShadowFramesContain(mirror::Object** shadow_frame_entry) const {
for (const ManagedStack* current_fragment = this; current_fragment != NULL;
current_fragment = current_fragment->GetLink()) {
for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != NULL;
current_frame = current_frame->GetLink()) {
if (current_frame->Contains(shadow_frame_entry)) {
return true;
}
}
}
return false;
}
StackVisitor::StackVisitor(Thread* thread, Context* context)
: thread_(thread), cur_shadow_frame_(NULL),
cur_quick_frame_(NULL), cur_quick_frame_pc_(0), num_frames_(0), cur_depth_(0),
context_(context) {
DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
}
uint32_t StackVisitor::GetDexPc() const {
if (cur_shadow_frame_ != NULL) {
return cur_shadow_frame_->GetDexPC();
} else if (cur_quick_frame_ != NULL) {
return GetMethod()->ToDexPc(cur_quick_frame_pc_);
} else {
return 0;
}
}
mirror::Object* StackVisitor::GetThisObject() const {
mirror::ArtMethod* m = GetMethod();
if (m->IsStatic()) {
return NULL;
} else if (m->IsNative()) {
if (cur_quick_frame_ != NULL) {
StackIndirectReferenceTable* sirt =
reinterpret_cast<StackIndirectReferenceTable*>(
reinterpret_cast<char*>(cur_quick_frame_) +
m->GetSirtOffsetInBytes());
return sirt->GetReference(0);
} else {
return cur_shadow_frame_->GetVRegReference(0);
}
} else {
const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
if (code_item == NULL) {
UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method"
<< PrettyMethod(m);
return NULL;
} else {
uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
return reinterpret_cast<mirror::Object*>(GetVReg(m, reg, kReferenceVReg));
}
}
}
size_t StackVisitor::GetNativePcOffset() const {
DCHECK(!IsShadowFrame());
return GetMethod()->NativePcOffset(cur_quick_frame_pc_);
}
uint32_t StackVisitor::GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind) const {
if (cur_quick_frame_ != NULL) {
DCHECK(context_ != NULL); // You can't reliably read registers without a context.
DCHECK(m == GetMethod());
const VmapTable vmap_table(m->GetVmapTable());
uint32_t vmap_offset;
// TODO: IsInContext stops before spotting floating point registers.
if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
uint32_t spill_mask = is_float ? m->GetFpSpillMask()
: m->GetCoreSpillMask();
return GetGPR(vmap_table.ComputeRegister(spill_mask, vmap_offset, kind));
} else {
const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
DCHECK(code_item != NULL) << PrettyMethod(m); // Can't be NULL or how would we compile its instructions?
size_t frame_size = m->GetFrameSizeInBytes();
return GetVReg(cur_quick_frame_, code_item, m->GetCoreSpillMask(), m->GetFpSpillMask(),
frame_size, vreg);
}
} else {
return cur_shadow_frame_->GetVReg(vreg);
}
}
void StackVisitor::SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
VRegKind kind) {
if (cur_quick_frame_ != NULL) {
DCHECK(context_ != NULL); // You can't reliably write registers without a context.
DCHECK(m == GetMethod());
const VmapTable vmap_table(m->GetVmapTable());
uint32_t vmap_offset;
// TODO: IsInContext stops before spotting floating point registers.
if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
uint32_t spill_mask = is_float ? m->GetFpSpillMask() : m->GetCoreSpillMask();
const uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kReferenceVReg);
SetGPR(reg, new_value);
} else {
const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
DCHECK(code_item != NULL) << PrettyMethod(m); // Can't be NULL or how would we compile its instructions?
uint32_t core_spills = m->GetCoreSpillMask();
uint32_t fp_spills = m->GetFpSpillMask();
size_t frame_size = m->GetFrameSizeInBytes();
int offset = GetVRegOffset(code_item, core_spills, fp_spills, frame_size, vreg);
byte* vreg_addr = reinterpret_cast<byte*>(GetCurrentQuickFrame()) + offset;
*reinterpret_cast<uint32_t*>(vreg_addr) = new_value;
}
} else {
return cur_shadow_frame_->SetVReg(vreg, new_value);
}
}
uintptr_t StackVisitor::GetGPR(uint32_t reg) const {
DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
return context_->GetGPR(reg);
}
void StackVisitor::SetGPR(uint32_t reg, uintptr_t value) {
DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
context_->SetGPR(reg, value);
}
uintptr_t StackVisitor::GetReturnPc() const {
mirror::ArtMethod** sp = GetCurrentQuickFrame();
DCHECK(sp != NULL);
byte* pc_addr = reinterpret_cast<byte*>(sp) + GetMethod()->GetReturnPcOffsetInBytes();
return *reinterpret_cast<uintptr_t*>(pc_addr);
}
void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
mirror::ArtMethod** sp = GetCurrentQuickFrame();
CHECK(sp != NULL);
byte* pc_addr = reinterpret_cast<byte*>(sp) + GetMethod()->GetReturnPcOffsetInBytes();
*reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
}
size_t StackVisitor::ComputeNumFrames(Thread* thread) {
struct NumFramesVisitor : public StackVisitor {
explicit NumFramesVisitor(Thread* thread)
: StackVisitor(thread, NULL), frames(0) {}
virtual bool VisitFrame() {
frames++;
return true;
}
size_t frames;
};
NumFramesVisitor visitor(thread);
visitor.WalkStack(true);
return visitor.frames;
}
void StackVisitor::DescribeStack(Thread* thread) {
struct DescribeStackVisitor : public StackVisitor {
explicit DescribeStackVisitor(Thread* thread)
: StackVisitor(thread, NULL) {}
virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(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 '");
mirror::ArtMethod* m = GetMethod();
if (m == NULL) {
return "upcall";
}
result += PrettyMethod(m);
result += StringPrintf("' at dex PC 0x%04zx", GetDexPc());
if (!IsShadowFrame()) {
result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
}
return result;
}
instrumentation::InstrumentationStackFrame StackVisitor::GetInstrumentationStackFrame(uint32_t depth) const {
return thread_->GetInstrumentationStack()->at(depth);
}
void StackVisitor::SanityCheckFrame() const {
#ifndef NDEBUG
mirror::ArtMethod* method = GetMethod();
CHECK(method->GetClass() == mirror::ArtMethod::GetJavaLangReflectArtMethod());
if (cur_quick_frame_ != NULL) {
method->AssertPcIsWithinCode(cur_quick_frame_pc_);
// Frame sanity.
size_t frame_size = method->GetFrameSizeInBytes();
CHECK_NE(frame_size, 0u);
// A rough guess at an upper size we expect to see for a frame. The 256 is
// a dex register limit. The 16 incorporates callee save spills and
// outgoing argument set up.
const size_t kMaxExpectedFrameSize = 256 * sizeof(word) + 16;
CHECK_LE(frame_size, kMaxExpectedFrameSize);
size_t return_pc_offset = method->GetReturnPcOffsetInBytes();
CHECK_LT(return_pc_offset, frame_size);
}
#endif
}
void StackVisitor::WalkStack(bool include_transitions) {
DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
CHECK_EQ(cur_depth_, 0U);
bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
uint32_t instrumentation_stack_depth = 0;
for (const ManagedStack* current_fragment = thread_->GetManagedStack(); current_fragment != NULL;
current_fragment = current_fragment->GetLink()) {
cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
cur_quick_frame_ = current_fragment->GetTopQuickFrame();
cur_quick_frame_pc_ = current_fragment->GetTopQuickFramePc();
if (cur_quick_frame_ != NULL) { // Handle quick stack frames.
// Can't be both a shadow and a quick fragment.
DCHECK(current_fragment->GetTopShadowFrame() == NULL);
mirror::ArtMethod* method = *cur_quick_frame_;
while (method != NULL) {
SanityCheckFrame();
bool should_continue = VisitFrame();
if (UNLIKELY(!should_continue)) {
return;
}
if (context_ != NULL) {
context_->FillCalleeSaves(*this);
}
size_t frame_size = method->GetFrameSizeInBytes();
// Compute PC for next stack frame from return PC.
size_t return_pc_offset = method->GetReturnPcOffsetInBytes();
byte* return_pc_addr = reinterpret_cast<byte*>(cur_quick_frame_) + return_pc_offset;
uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
if (UNLIKELY(exit_stubs_installed)) {
// 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 (GetQuickInstrumentationExitPc() == return_pc) {
instrumentation::InstrumentationStackFrame instrumentation_frame =
GetInstrumentationStackFrame(instrumentation_stack_depth);
instrumentation_stack_depth++;
if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
// Skip runtime save all callee frames which are used to deliver exceptions.
} else if (instrumentation_frame.interpreter_entry_) {
mirror::ArtMethod* callee = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
<< PrettyMethod(GetMethod());
} else if (instrumentation_frame.method_ != GetMethod()) {
LOG(FATAL) << "Expected: " << PrettyMethod(instrumentation_frame.method_)
<< " Found: " << PrettyMethod(GetMethod());
}
if (num_frames_ != 0) {
// Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
// recursion.
CHECK(instrumentation_frame.frame_id_ == GetFrameId())
<< "Expected: " << instrumentation_frame.frame_id_
<< " Found: " << GetFrameId();
}
return_pc = instrumentation_frame.return_pc_;
}
}
cur_quick_frame_pc_ = return_pc;
byte* next_frame = reinterpret_cast<byte*>(cur_quick_frame_) + frame_size;
cur_quick_frame_ = reinterpret_cast<mirror::ArtMethod**>(next_frame);
cur_depth_++;
method = *cur_quick_frame_;
}
} else if (cur_shadow_frame_ != NULL) {
do {
SanityCheckFrame();
bool should_continue = VisitFrame();
if (UNLIKELY(!should_continue)) {
return;
}
cur_depth_++;
cur_shadow_frame_ = cur_shadow_frame_->GetLink();
} while (cur_shadow_frame_ != NULL);
}
if (include_transitions) {
bool should_continue = VisitFrame();
if (!should_continue) {
return;
}
}
cur_depth_++;
}
if (num_frames_ != 0) {
CHECK_EQ(cur_depth_, num_frames_);
}
}
} // namespace art