stack.cc revision 6bc4374e3fa00e3ee5e832e1761c43e0b8a71558 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "stack.h"
18
19#include "arch/context.h"
20#include "art_code.h"
21#include "art_method-inl.h"
22#include "base/hex_dump.h"
23#include "entrypoints/entrypoint_utils-inl.h"
24#include "entrypoints/runtime_asm_entrypoints.h"
25#include "gc_map.h"
26#include "gc/space/image_space.h"
27#include "gc/space/space-inl.h"
28#include "linear_alloc.h"
29#include "mirror/class-inl.h"
30#include "mirror/object-inl.h"
31#include "mirror/object_array-inl.h"
32#include "quick/quick_method_frame_info.h"
33#include "runtime.h"
34#include "thread.h"
35#include "thread_list.h"
36#include "verify_object-inl.h"
37#include "vmap_table.h"
38
39namespace art {
40
41static constexpr bool kDebugStackWalk = false;
42
43mirror::Object* ShadowFrame::GetThisObject() const {
44  ArtMethod* m = GetMethod();
45  if (m->IsStatic()) {
46    return nullptr;
47  } else if (m->IsNative()) {
48    return GetVRegReference(0);
49  } else {
50    const DexFile::CodeItem* code_item = m->GetCodeItem();
51    CHECK(code_item != nullptr) << PrettyMethod(m);
52    uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
53    return GetVRegReference(reg);
54  }
55}
56
57mirror::Object* ShadowFrame::GetThisObject(uint16_t num_ins) const {
58  ArtMethod* m = GetMethod();
59  if (m->IsStatic()) {
60    return nullptr;
61  } else {
62    return GetVRegReference(NumberOfVRegs() - num_ins);
63  }
64}
65
66size_t ManagedStack::NumJniShadowFrameReferences() const {
67  size_t count = 0;
68  for (const ManagedStack* current_fragment = this; current_fragment != nullptr;
69       current_fragment = current_fragment->GetLink()) {
70    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != nullptr;
71         current_frame = current_frame->GetLink()) {
72      if (current_frame->GetMethod()->IsNative()) {
73        // The JNI ShadowFrame only contains references. (For indirect reference.)
74        count += current_frame->NumberOfVRegs();
75      }
76    }
77  }
78  return count;
79}
80
81bool ManagedStack::ShadowFramesContain(StackReference<mirror::Object>* shadow_frame_entry) const {
82  for (const ManagedStack* current_fragment = this; current_fragment != nullptr;
83       current_fragment = current_fragment->GetLink()) {
84    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != nullptr;
85         current_frame = current_frame->GetLink()) {
86      if (current_frame->Contains(shadow_frame_entry)) {
87        return true;
88      }
89    }
90  }
91  return false;
92}
93
94StackVisitor::StackVisitor(Thread* thread, Context* context, StackWalkKind walk_kind)
95    : StackVisitor(thread, context, walk_kind, 0) {}
96
97StackVisitor::StackVisitor(Thread* thread,
98                           Context* context,
99                           StackWalkKind walk_kind,
100                           size_t num_frames)
101    : thread_(thread),
102      walk_kind_(walk_kind),
103      cur_shadow_frame_(nullptr),
104      cur_quick_frame_(nullptr),
105      cur_quick_frame_pc_(0),
106      num_frames_(num_frames),
107      cur_depth_(0),
108      current_inlining_depth_(0),
109      context_(context) {
110  DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
111}
112
113InlineInfo StackVisitor::GetCurrentInlineInfo() const {
114  ArtCode outer_code = GetCurrentCode();
115  uint32_t native_pc_offset = outer_code.NativeQuickPcOffset(cur_quick_frame_pc_);
116  CodeInfo code_info = outer_code.GetOptimizedCodeInfo();
117  StackMapEncoding encoding = code_info.ExtractEncoding();
118  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
119  DCHECK(stack_map.IsValid());
120  return code_info.GetInlineInfoOf(stack_map, encoding);
121}
122
123ArtMethod* StackVisitor::GetMethod() const {
124  if (cur_shadow_frame_ != nullptr) {
125    return cur_shadow_frame_->GetMethod();
126  } else if (cur_quick_frame_ != nullptr) {
127    if (IsInInlinedFrame()) {
128      size_t depth_in_stack_map = current_inlining_depth_ - 1;
129      InlineInfo inline_info = GetCurrentInlineInfo();
130      return GetResolvedMethod(*GetCurrentQuickFrame(), inline_info, depth_in_stack_map);
131    } else {
132      return *cur_quick_frame_;
133    }
134  }
135  return nullptr;
136}
137
138uint32_t StackVisitor::GetDexPc(bool abort_on_failure) const {
139  if (cur_shadow_frame_ != nullptr) {
140    return cur_shadow_frame_->GetDexPC();
141  } else if (cur_quick_frame_ != nullptr) {
142    if (IsInInlinedFrame()) {
143      size_t depth_in_stack_map = current_inlining_depth_ - 1;
144      return GetCurrentInlineInfo().GetDexPcAtDepth(depth_in_stack_map);
145    } else {
146      return GetCurrentCode().ToDexPc(cur_quick_frame_pc_, abort_on_failure);
147    }
148  } else {
149    return 0;
150  }
151}
152
153extern "C" mirror::Object* artQuickGetProxyThisObject(ArtMethod** sp)
154    SHARED_REQUIRES(Locks::mutator_lock_);
155
156mirror::Object* StackVisitor::GetThisObject() const {
157  DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), sizeof(void*));
158  ArtMethod* m = GetMethod();
159  if (m->IsStatic()) {
160    return nullptr;
161  } else if (m->IsNative()) {
162    if (cur_quick_frame_ != nullptr) {
163      HandleScope* hs = reinterpret_cast<HandleScope*>(
164          reinterpret_cast<char*>(cur_quick_frame_) +
165            GetCurrentCode().GetHandleScopeOffset().SizeValue());
166      return hs->GetReference(0);
167    } else {
168      return cur_shadow_frame_->GetVRegReference(0);
169    }
170  } else if (m->IsProxyMethod()) {
171    if (cur_quick_frame_ != nullptr) {
172      return artQuickGetProxyThisObject(cur_quick_frame_);
173    } else {
174      return cur_shadow_frame_->GetVRegReference(0);
175    }
176  } else {
177    const DexFile::CodeItem* code_item = m->GetCodeItem();
178    if (code_item == nullptr) {
179      UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method: "
180          << PrettyMethod(m);
181      return nullptr;
182    } else {
183      uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
184      uint32_t value = 0;
185      bool success = GetVReg(m, reg, kReferenceVReg, &value);
186      // We currently always guarantee the `this` object is live throughout the method.
187      CHECK(success) << "Failed to read the this object in " << PrettyMethod(m);
188      return reinterpret_cast<mirror::Object*>(value);
189    }
190  }
191}
192
193size_t StackVisitor::GetNativePcOffset() const {
194  DCHECK(!IsShadowFrame());
195  return GetCurrentCode().NativeQuickPcOffset(cur_quick_frame_pc_);
196}
197
198bool StackVisitor::IsReferenceVReg(ArtMethod* m, uint16_t vreg) {
199  DCHECK_EQ(m, GetMethod());
200  // Process register map (which native and runtime methods don't have)
201  if (m->IsNative() || m->IsRuntimeMethod() || m->IsProxyMethod()) {
202    return false;
203  }
204  if (GetCurrentCode().IsOptimized(sizeof(void*))) {
205    return true;  // TODO: Implement.
206  }
207  const uint8_t* native_gc_map = GetCurrentCode().GetNativeGcMap(sizeof(void*));
208  CHECK(native_gc_map != nullptr) << PrettyMethod(m);
209  const DexFile::CodeItem* code_item = m->GetCodeItem();
210  // Can't be null or how would we compile its instructions?
211  DCHECK(code_item != nullptr) << PrettyMethod(m);
212  NativePcOffsetToReferenceMap map(native_gc_map);
213  size_t num_regs = std::min(map.RegWidth() * 8, static_cast<size_t>(code_item->registers_size_));
214  const uint8_t* reg_bitmap = nullptr;
215  if (num_regs > 0) {
216    uintptr_t native_pc_offset = GetCurrentCode().NativeQuickPcOffset(GetCurrentQuickFramePc());
217    reg_bitmap = map.FindBitMap(native_pc_offset);
218    DCHECK(reg_bitmap != nullptr);
219  }
220  // Does this register hold a reference?
221  return vreg < num_regs && TestBitmap(vreg, reg_bitmap);
222}
223
224bool StackVisitor::GetVRegFromDebuggerShadowFrame(uint16_t vreg,
225                                                  VRegKind kind,
226                                                  uint32_t* val) const {
227  size_t frame_id = const_cast<StackVisitor*>(this)->GetFrameId();
228  ShadowFrame* shadow_frame = thread_->FindDebuggerShadowFrame(frame_id);
229  if (shadow_frame != nullptr) {
230    bool* updated_vreg_flags = thread_->GetUpdatedVRegFlags(frame_id);
231    DCHECK(updated_vreg_flags != nullptr);
232    if (updated_vreg_flags[vreg]) {
233      // Value is set by the debugger.
234      if (kind == kReferenceVReg) {
235        *val = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(
236            shadow_frame->GetVRegReference(vreg)));
237      } else {
238        *val = shadow_frame->GetVReg(vreg);
239      }
240      return true;
241    }
242  }
243  // No value is set by the debugger.
244  return false;
245}
246
247bool StackVisitor::GetVReg(ArtMethod* m, uint16_t vreg, VRegKind kind, uint32_t* val) const {
248  if (cur_quick_frame_ != nullptr) {
249    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
250    DCHECK(m == GetMethod());
251    // Check if there is value set by the debugger.
252    if (GetVRegFromDebuggerShadowFrame(vreg, kind, val)) {
253      return true;
254    }
255    if (GetCurrentCode().IsOptimized(sizeof(void*))) {
256      return GetVRegFromOptimizedCode(m, vreg, kind, val);
257    } else {
258      return GetVRegFromQuickCode(m, vreg, kind, val);
259    }
260  } else {
261    DCHECK(cur_shadow_frame_ != nullptr);
262    *val = cur_shadow_frame_->GetVReg(vreg);
263    return true;
264  }
265}
266
267bool StackVisitor::GetVRegFromQuickCode(ArtMethod* m, uint16_t vreg, VRegKind kind,
268                                        uint32_t* val) const {
269  DCHECK_EQ(m, GetMethod());
270  const VmapTable vmap_table(GetCurrentCode().GetVmapTable(sizeof(void*)));
271  QuickMethodFrameInfo frame_info = GetCurrentCode().GetQuickFrameInfo();
272  uint32_t vmap_offset;
273  // TODO: IsInContext stops before spotting floating point registers.
274  if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
275    bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
276    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
277    uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
278    return GetRegisterIfAccessible(reg, kind, val);
279  } else {
280    const DexFile::CodeItem* code_item = m->GetCodeItem();
281    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
282                                                      // its instructions?
283    *val = *GetVRegAddrFromQuickCode(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
284                                     frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
285    return true;
286  }
287}
288
289bool StackVisitor::GetVRegFromOptimizedCode(ArtMethod* m, uint16_t vreg, VRegKind kind,
290                                            uint32_t* val) const {
291  DCHECK_EQ(m, GetMethod());
292  const DexFile::CodeItem* code_item = m->GetCodeItem();
293  DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
294                                                    // its instructions?
295  uint16_t number_of_dex_registers = code_item->registers_size_;
296  DCHECK_LT(vreg, code_item->registers_size_);
297  CodeInfo code_info = GetCurrentCode().GetOptimizedCodeInfo();
298  StackMapEncoding encoding = code_info.ExtractEncoding();
299
300  uint32_t native_pc_offset = GetCurrentCode().NativeQuickPcOffset(cur_quick_frame_pc_);
301  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
302  DCHECK(stack_map.IsValid());
303  size_t depth_in_stack_map = current_inlining_depth_ - 1;
304
305  DexRegisterMap dex_register_map = IsInInlinedFrame()
306      ? code_info.GetDexRegisterMapAtDepth(depth_in_stack_map,
307                                           code_info.GetInlineInfoOf(stack_map, encoding),
308                                           encoding,
309                                           number_of_dex_registers)
310      : code_info.GetDexRegisterMapOf(stack_map, encoding, number_of_dex_registers);
311
312  DexRegisterLocation::Kind location_kind =
313      dex_register_map.GetLocationKind(vreg, number_of_dex_registers, code_info, encoding);
314  switch (location_kind) {
315    case DexRegisterLocation::Kind::kInStack: {
316      const int32_t offset = dex_register_map.GetStackOffsetInBytes(vreg,
317                                                                    number_of_dex_registers,
318                                                                    code_info,
319                                                                    encoding);
320      const uint8_t* addr = reinterpret_cast<const uint8_t*>(cur_quick_frame_) + offset;
321      *val = *reinterpret_cast<const uint32_t*>(addr);
322      return true;
323    }
324    case DexRegisterLocation::Kind::kInRegister:
325    case DexRegisterLocation::Kind::kInRegisterHigh:
326    case DexRegisterLocation::Kind::kInFpuRegister:
327    case DexRegisterLocation::Kind::kInFpuRegisterHigh: {
328      uint32_t reg =
329          dex_register_map.GetMachineRegister(vreg, number_of_dex_registers, code_info, encoding);
330      return GetRegisterIfAccessible(reg, kind, val);
331    }
332    case DexRegisterLocation::Kind::kConstant:
333      *val = dex_register_map.GetConstant(vreg, number_of_dex_registers, code_info, encoding);
334      return true;
335    case DexRegisterLocation::Kind::kNone:
336      return false;
337    default:
338      LOG(FATAL)
339          << "Unexpected location kind"
340          << DexRegisterLocation::PrettyDescriptor(
341                dex_register_map.GetLocationInternalKind(vreg,
342                                                         number_of_dex_registers,
343                                                         code_info,
344                                                         encoding));
345      UNREACHABLE();
346  }
347}
348
349bool StackVisitor::GetRegisterIfAccessible(uint32_t reg, VRegKind kind, uint32_t* val) const {
350  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
351
352  // X86 float registers are 64-bit and the logic below does not apply.
353  DCHECK(!is_float || kRuntimeISA != InstructionSet::kX86);
354
355  if (!IsAccessibleRegister(reg, is_float)) {
356    return false;
357  }
358  uintptr_t ptr_val = GetRegister(reg, is_float);
359  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
360  if (target64) {
361    const bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
362    const bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
363    int64_t value_long = static_cast<int64_t>(ptr_val);
364    if (wide_lo) {
365      ptr_val = static_cast<uintptr_t>(Low32Bits(value_long));
366    } else if (wide_hi) {
367      ptr_val = static_cast<uintptr_t>(High32Bits(value_long));
368    }
369  }
370  *val = ptr_val;
371  return true;
372}
373
374bool StackVisitor::GetVRegPairFromDebuggerShadowFrame(uint16_t vreg,
375                                                      VRegKind kind_lo,
376                                                      VRegKind kind_hi,
377                                                      uint64_t* val) const {
378  uint32_t low_32bits;
379  uint32_t high_32bits;
380  bool success = GetVRegFromDebuggerShadowFrame(vreg, kind_lo, &low_32bits);
381  success &= GetVRegFromDebuggerShadowFrame(vreg + 1, kind_hi, &high_32bits);
382  if (success) {
383    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
384  }
385  return success;
386}
387
388bool StackVisitor::GetVRegPair(ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
389                               VRegKind kind_hi, uint64_t* val) const {
390  if (kind_lo == kLongLoVReg) {
391    DCHECK_EQ(kind_hi, kLongHiVReg);
392  } else if (kind_lo == kDoubleLoVReg) {
393    DCHECK_EQ(kind_hi, kDoubleHiVReg);
394  } else {
395    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
396    UNREACHABLE();
397  }
398  // Check if there is value set by the debugger.
399  if (GetVRegPairFromDebuggerShadowFrame(vreg, kind_lo, kind_hi, val)) {
400    return true;
401  }
402  if (cur_quick_frame_ != nullptr) {
403    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
404    DCHECK(m == GetMethod());
405    if (GetCurrentCode().IsOptimized(sizeof(void*))) {
406      return GetVRegPairFromOptimizedCode(m, vreg, kind_lo, kind_hi, val);
407    } else {
408      return GetVRegPairFromQuickCode(m, vreg, kind_lo, kind_hi, val);
409    }
410  } else {
411    DCHECK(cur_shadow_frame_ != nullptr);
412    *val = cur_shadow_frame_->GetVRegLong(vreg);
413    return true;
414  }
415}
416
417bool StackVisitor::GetVRegPairFromQuickCode(ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
418                                            VRegKind kind_hi, uint64_t* val) const {
419  DCHECK_EQ(m, GetMethod());
420  const VmapTable vmap_table(GetCurrentCode().GetVmapTable(sizeof(void*)));
421  QuickMethodFrameInfo frame_info = GetCurrentCode().GetQuickFrameInfo();
422  uint32_t vmap_offset_lo, vmap_offset_hi;
423  // TODO: IsInContext stops before spotting floating point registers.
424  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
425      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
426    bool is_float = (kind_lo == kDoubleLoVReg);
427    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
428    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
429    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
430    return GetRegisterPairIfAccessible(reg_lo, reg_hi, kind_lo, val);
431  } else {
432    const DexFile::CodeItem* code_item = m->GetCodeItem();
433    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
434                                                      // its instructions?
435    uint32_t* addr = GetVRegAddrFromQuickCode(
436        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
437        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
438    *val = *reinterpret_cast<uint64_t*>(addr);
439    return true;
440  }
441}
442
443bool StackVisitor::GetVRegPairFromOptimizedCode(ArtMethod* m, uint16_t vreg,
444                                                VRegKind kind_lo, VRegKind kind_hi,
445                                                uint64_t* val) const {
446  uint32_t low_32bits;
447  uint32_t high_32bits;
448  bool success = GetVRegFromOptimizedCode(m, vreg, kind_lo, &low_32bits);
449  success &= GetVRegFromOptimizedCode(m, vreg + 1, kind_hi, &high_32bits);
450  if (success) {
451    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
452  }
453  return success;
454}
455
456bool StackVisitor::GetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
457                                               VRegKind kind_lo, uint64_t* val) const {
458  const bool is_float = (kind_lo == kDoubleLoVReg);
459  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
460    return false;
461  }
462  uintptr_t ptr_val_lo = GetRegister(reg_lo, is_float);
463  uintptr_t ptr_val_hi = GetRegister(reg_hi, is_float);
464  bool target64 = Is64BitInstructionSet(kRuntimeISA);
465  if (target64) {
466    int64_t value_long_lo = static_cast<int64_t>(ptr_val_lo);
467    int64_t value_long_hi = static_cast<int64_t>(ptr_val_hi);
468    ptr_val_lo = static_cast<uintptr_t>(Low32Bits(value_long_lo));
469    ptr_val_hi = static_cast<uintptr_t>(High32Bits(value_long_hi));
470  }
471  *val = (static_cast<uint64_t>(ptr_val_hi) << 32) | static_cast<uint32_t>(ptr_val_lo);
472  return true;
473}
474
475bool StackVisitor::SetVReg(ArtMethod* m, uint16_t vreg, uint32_t new_value,
476                           VRegKind kind) {
477  if (cur_quick_frame_ != nullptr) {
478    DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
479    DCHECK(m == GetMethod());
480    if (GetCurrentCode().IsOptimized(sizeof(void*))) {
481      return false;
482    } else {
483      return SetVRegFromQuickCode(m, vreg, new_value, kind);
484    }
485  } else {
486    cur_shadow_frame_->SetVReg(vreg, new_value);
487    return true;
488  }
489}
490
491bool StackVisitor::SetVRegFromQuickCode(ArtMethod* m, uint16_t vreg, uint32_t new_value,
492                                        VRegKind kind) {
493  DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
494  DCHECK(m == GetMethod());
495  const VmapTable vmap_table(GetCurrentCode().GetVmapTable(sizeof(void*)));
496  QuickMethodFrameInfo frame_info = GetCurrentCode().GetQuickFrameInfo();
497  uint32_t vmap_offset;
498  // TODO: IsInContext stops before spotting floating point registers.
499  if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
500    bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
501    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
502    uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
503    return SetRegisterIfAccessible(reg, new_value, kind);
504  } else {
505    const DexFile::CodeItem* code_item = m->GetCodeItem();
506    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
507                                                      // its instructions?
508    uint32_t* addr = GetVRegAddrFromQuickCode(
509        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
510        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
511    *addr = new_value;
512    return true;
513  }
514}
515
516bool StackVisitor::SetVRegFromDebugger(ArtMethod* m,
517                                       uint16_t vreg,
518                                       uint32_t new_value,
519                                       VRegKind kind) {
520  const DexFile::CodeItem* code_item = m->GetCodeItem();
521  if (code_item == nullptr) {
522    return false;
523  }
524  ShadowFrame* shadow_frame = GetCurrentShadowFrame();
525  if (shadow_frame == nullptr) {
526    // This is a compiled frame: we must prepare and update a shadow frame that will
527    // be executed by the interpreter after deoptimization of the stack.
528    const size_t frame_id = GetFrameId();
529    const uint16_t num_regs = code_item->registers_size_;
530    shadow_frame = thread_->FindOrCreateDebuggerShadowFrame(frame_id, num_regs, m, GetDexPc());
531    CHECK(shadow_frame != nullptr);
532    // Remember the vreg has been set for debugging and must not be overwritten by the
533    // original value during deoptimization of the stack.
534    thread_->GetUpdatedVRegFlags(frame_id)[vreg] = true;
535  }
536  if (kind == kReferenceVReg) {
537    shadow_frame->SetVRegReference(vreg, reinterpret_cast<mirror::Object*>(new_value));
538  } else {
539    shadow_frame->SetVReg(vreg, new_value);
540  }
541  return true;
542}
543
544bool StackVisitor::SetRegisterIfAccessible(uint32_t reg, uint32_t new_value, VRegKind kind) {
545  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
546  if (!IsAccessibleRegister(reg, is_float)) {
547    return false;
548  }
549  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
550
551  // Create a new value that can hold both low 32 and high 32 bits, in
552  // case we are running 64 bits.
553  uintptr_t full_new_value = new_value;
554  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
555  if (target64) {
556    bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
557    bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
558    if (wide_lo || wide_hi) {
559      uintptr_t old_reg_val = GetRegister(reg, is_float);
560      uint64_t new_vreg_portion = static_cast<uint64_t>(new_value);
561      uint64_t old_reg_val_as_wide = static_cast<uint64_t>(old_reg_val);
562      uint64_t mask = 0xffffffff;
563      if (wide_lo) {
564        mask = mask << 32;
565      } else {
566        new_vreg_portion = new_vreg_portion << 32;
567      }
568      full_new_value = static_cast<uintptr_t>((old_reg_val_as_wide & mask) | new_vreg_portion);
569    }
570  }
571  SetRegister(reg, full_new_value, is_float);
572  return true;
573}
574
575bool StackVisitor::SetVRegPair(ArtMethod* m, uint16_t vreg, uint64_t new_value,
576                               VRegKind kind_lo, VRegKind kind_hi) {
577  if (kind_lo == kLongLoVReg) {
578    DCHECK_EQ(kind_hi, kLongHiVReg);
579  } else if (kind_lo == kDoubleLoVReg) {
580    DCHECK_EQ(kind_hi, kDoubleHiVReg);
581  } else {
582    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
583  }
584  if (cur_quick_frame_ != nullptr) {
585    DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
586    DCHECK(m == GetMethod());
587    if (GetCurrentCode().IsOptimized(sizeof(void*))) {
588      return false;
589    } else {
590      return SetVRegPairFromQuickCode(m, vreg, new_value, kind_lo, kind_hi);
591    }
592  } else {
593    DCHECK(cur_shadow_frame_ != nullptr);
594    cur_shadow_frame_->SetVRegLong(vreg, new_value);
595    return true;
596  }
597}
598
599bool StackVisitor::SetVRegPairFromQuickCode(
600    ArtMethod* m, uint16_t vreg, uint64_t new_value, VRegKind kind_lo, VRegKind kind_hi) {
601  DCHECK_EQ(m, GetMethod());
602  const VmapTable vmap_table(GetCurrentCode().GetVmapTable(sizeof(void*)));
603  QuickMethodFrameInfo frame_info = GetCurrentCode().GetQuickFrameInfo();
604  uint32_t vmap_offset_lo, vmap_offset_hi;
605  // TODO: IsInContext stops before spotting floating point registers.
606  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
607      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
608    bool is_float = (kind_lo == kDoubleLoVReg);
609    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
610    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
611    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
612    return SetRegisterPairIfAccessible(reg_lo, reg_hi, new_value, is_float);
613  } else {
614    const DexFile::CodeItem* code_item = m->GetCodeItem();
615    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
616                                                      // its instructions?
617    uint32_t* addr = GetVRegAddrFromQuickCode(
618        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
619        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
620    *reinterpret_cast<uint64_t*>(addr) = new_value;
621    return true;
622  }
623}
624
625bool StackVisitor::SetVRegPairFromDebugger(ArtMethod* m,
626                                           uint16_t vreg,
627                                           uint64_t new_value,
628                                           VRegKind kind_lo,
629                                           VRegKind kind_hi) {
630  if (kind_lo == kLongLoVReg) {
631    DCHECK_EQ(kind_hi, kLongHiVReg);
632  } else if (kind_lo == kDoubleLoVReg) {
633    DCHECK_EQ(kind_hi, kDoubleHiVReg);
634  } else {
635    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
636    UNREACHABLE();
637  }
638  const DexFile::CodeItem* code_item = m->GetCodeItem();
639  if (code_item == nullptr) {
640    return false;
641  }
642  ShadowFrame* shadow_frame = GetCurrentShadowFrame();
643  if (shadow_frame == nullptr) {
644    // This is a compiled frame: we must prepare for deoptimization (see SetVRegFromDebugger).
645    const size_t frame_id = GetFrameId();
646    const uint16_t num_regs = code_item->registers_size_;
647    shadow_frame = thread_->FindOrCreateDebuggerShadowFrame(frame_id, num_regs, m, GetDexPc());
648    CHECK(shadow_frame != nullptr);
649    // Remember the vreg pair has been set for debugging and must not be overwritten by the
650    // original value during deoptimization of the stack.
651    thread_->GetUpdatedVRegFlags(frame_id)[vreg] = true;
652    thread_->GetUpdatedVRegFlags(frame_id)[vreg + 1] = true;
653  }
654  shadow_frame->SetVRegLong(vreg, new_value);
655  return true;
656}
657
658bool StackVisitor::SetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
659                                               uint64_t new_value, bool is_float) {
660  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
661    return false;
662  }
663  uintptr_t new_value_lo = static_cast<uintptr_t>(new_value & 0xFFFFFFFF);
664  uintptr_t new_value_hi = static_cast<uintptr_t>(new_value >> 32);
665  bool target64 = Is64BitInstructionSet(kRuntimeISA);
666  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
667  if (target64) {
668    DCHECK_EQ(reg_lo, reg_hi);
669    SetRegister(reg_lo, new_value, is_float);
670  } else {
671    SetRegister(reg_lo, new_value_lo, is_float);
672    SetRegister(reg_hi, new_value_hi, is_float);
673  }
674  return true;
675}
676
677bool StackVisitor::IsAccessibleGPR(uint32_t reg) const {
678  DCHECK(context_ != nullptr);
679  return context_->IsAccessibleGPR(reg);
680}
681
682uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
683  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
684  DCHECK(context_ != nullptr);
685  return context_->GetGPRAddress(reg);
686}
687
688uintptr_t StackVisitor::GetGPR(uint32_t reg) const {
689  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
690  DCHECK(context_ != nullptr);
691  return context_->GetGPR(reg);
692}
693
694void StackVisitor::SetGPR(uint32_t reg, uintptr_t value) {
695  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
696  DCHECK(context_ != nullptr);
697  context_->SetGPR(reg, value);
698}
699
700bool StackVisitor::IsAccessibleFPR(uint32_t reg) const {
701  DCHECK(context_ != nullptr);
702  return context_->IsAccessibleFPR(reg);
703}
704
705uintptr_t StackVisitor::GetFPR(uint32_t reg) const {
706  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
707  DCHECK(context_ != nullptr);
708  return context_->GetFPR(reg);
709}
710
711void StackVisitor::SetFPR(uint32_t reg, uintptr_t value) {
712  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
713  DCHECK(context_ != nullptr);
714  context_->SetFPR(reg, value);
715}
716
717uintptr_t StackVisitor::GetReturnPc() const {
718  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
719  DCHECK(sp != nullptr);
720  uint8_t* pc_addr = sp + GetCurrentCode().GetReturnPcOffset().SizeValue();
721  return *reinterpret_cast<uintptr_t*>(pc_addr);
722}
723
724void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
725  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
726  CHECK(sp != nullptr);
727  uint8_t* pc_addr = sp + GetCurrentCode().GetReturnPcOffset().SizeValue();
728  *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
729}
730
731size_t StackVisitor::ComputeNumFrames(Thread* thread, StackWalkKind walk_kind) {
732  struct NumFramesVisitor : public StackVisitor {
733    NumFramesVisitor(Thread* thread_in, StackWalkKind walk_kind_in)
734        : StackVisitor(thread_in, nullptr, walk_kind_in), frames(0) {}
735
736    bool VisitFrame() OVERRIDE {
737      frames++;
738      return true;
739    }
740
741    size_t frames;
742  };
743  NumFramesVisitor visitor(thread, walk_kind);
744  visitor.WalkStack(true);
745  return visitor.frames;
746}
747
748bool StackVisitor::GetNextMethodAndDexPc(ArtMethod** next_method, uint32_t* next_dex_pc) {
749  struct HasMoreFramesVisitor : public StackVisitor {
750    HasMoreFramesVisitor(Thread* thread,
751                         StackWalkKind walk_kind,
752                         size_t num_frames,
753                         size_t frame_height)
754        : StackVisitor(thread, nullptr, walk_kind, num_frames),
755          frame_height_(frame_height),
756          found_frame_(false),
757          has_more_frames_(false),
758          next_method_(nullptr),
759          next_dex_pc_(0) {
760    }
761
762    bool VisitFrame() OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
763      if (found_frame_) {
764        ArtMethod* method = GetMethod();
765        if (method != nullptr && !method->IsRuntimeMethod()) {
766          has_more_frames_ = true;
767          next_method_ = method;
768          next_dex_pc_ = GetDexPc();
769          return false;  // End stack walk once next method is found.
770        }
771      } else if (GetFrameHeight() == frame_height_) {
772        found_frame_ = true;
773      }
774      return true;
775    }
776
777    size_t frame_height_;
778    bool found_frame_;
779    bool has_more_frames_;
780    ArtMethod* next_method_;
781    uint32_t next_dex_pc_;
782  };
783  HasMoreFramesVisitor visitor(thread_, walk_kind_, GetNumFrames(), GetFrameHeight());
784  visitor.WalkStack(true);
785  *next_method = visitor.next_method_;
786  *next_dex_pc = visitor.next_dex_pc_;
787  return visitor.has_more_frames_;
788}
789
790void StackVisitor::DescribeStack(Thread* thread) {
791  struct DescribeStackVisitor : public StackVisitor {
792    explicit DescribeStackVisitor(Thread* thread_in)
793        : StackVisitor(thread_in, nullptr, StackVisitor::StackWalkKind::kIncludeInlinedFrames) {}
794
795    bool VisitFrame() OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
796      LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
797      return true;
798    }
799  };
800  DescribeStackVisitor visitor(thread);
801  visitor.WalkStack(true);
802}
803
804std::string StackVisitor::DescribeLocation() const {
805  std::string result("Visiting method '");
806  ArtMethod* m = GetMethod();
807  if (m == nullptr) {
808    return "upcall";
809  }
810  result += PrettyMethod(m);
811  result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
812  if (!IsShadowFrame()) {
813    result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
814  }
815  return result;
816}
817
818static instrumentation::InstrumentationStackFrame& GetInstrumentationStackFrame(Thread* thread,
819                                                                                uint32_t depth) {
820  CHECK_LT(depth, thread->GetInstrumentationStack()->size());
821  return thread->GetInstrumentationStack()->at(depth);
822}
823
824void StackVisitor::SanityCheckFrame() const {
825  if (kIsDebugBuild) {
826    ArtMethod* method = GetMethod();
827    auto* declaring_class = method->GetDeclaringClass();
828    // Runtime methods have null declaring class.
829    if (!method->IsRuntimeMethod()) {
830      CHECK(declaring_class != nullptr);
831      CHECK_EQ(declaring_class->GetClass(), declaring_class->GetClass()->GetClass())
832          << declaring_class;
833    } else {
834      CHECK(declaring_class == nullptr);
835    }
836    Runtime* const runtime = Runtime::Current();
837    LinearAlloc* const linear_alloc = runtime->GetLinearAlloc();
838    if (!linear_alloc->Contains(method)) {
839      // Check class linker linear allocs.
840      mirror::Class* klass = method->GetDeclaringClass();
841      LinearAlloc* const class_linear_alloc = (klass != nullptr)
842          ? ClassLinker::GetAllocatorForClassLoader(klass->GetClassLoader())
843          : linear_alloc;
844      if (!class_linear_alloc->Contains(method)) {
845        // Check image space.
846        bool in_image = false;
847        for (auto& space : runtime->GetHeap()->GetContinuousSpaces()) {
848          if (space->IsImageSpace()) {
849            auto* image_space = space->AsImageSpace();
850            const auto& header = image_space->GetImageHeader();
851            const auto* methods = &header.GetMethodsSection();
852            if (methods->Contains(reinterpret_cast<const uint8_t*>(method) - image_space->Begin())) {
853              in_image = true;
854              break;
855            }
856          }
857        }
858        CHECK(in_image) << PrettyMethod(method) << " not in linear alloc or image";
859      }
860    }
861    if (cur_quick_frame_ != nullptr) {
862      GetCurrentCode().AssertPcIsWithinQuickCode(cur_quick_frame_pc_);
863      // Frame sanity.
864      size_t frame_size = GetCurrentCode().GetFrameSizeInBytes();
865      CHECK_NE(frame_size, 0u);
866      // A rough guess at an upper size we expect to see for a frame.
867      // 256 registers
868      // 2 words HandleScope overhead
869      // 3+3 register spills
870      // TODO: this seems architecture specific for the case of JNI frames.
871      // TODO: 083-compiler-regressions ManyFloatArgs shows this estimate is wrong.
872      // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
873      const size_t kMaxExpectedFrameSize = 2 * KB;
874      CHECK_LE(frame_size, kMaxExpectedFrameSize);
875      size_t return_pc_offset = GetCurrentCode().GetReturnPcOffset().SizeValue();
876      CHECK_LT(return_pc_offset, frame_size);
877    }
878  }
879}
880
881void StackVisitor::WalkStack(bool include_transitions) {
882  DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
883  CHECK_EQ(cur_depth_, 0U);
884  bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
885  uint32_t instrumentation_stack_depth = 0;
886
887  for (const ManagedStack* current_fragment = thread_->GetManagedStack();
888       current_fragment != nullptr; current_fragment = current_fragment->GetLink()) {
889    cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
890    cur_quick_frame_ = current_fragment->GetTopQuickFrame();
891    cur_quick_frame_pc_ = 0;
892
893    if (cur_quick_frame_ != nullptr) {  // Handle quick stack frames.
894      // Can't be both a shadow and a quick fragment.
895      DCHECK(current_fragment->GetTopShadowFrame() == nullptr);
896      ArtMethod* method = *cur_quick_frame_;
897      while (method != nullptr) {
898        SanityCheckFrame();
899
900        if ((walk_kind_ == StackWalkKind::kIncludeInlinedFrames)
901            && GetCurrentCode().IsOptimized(sizeof(void*))) {
902          CodeInfo code_info = GetCurrentCode().GetOptimizedCodeInfo();
903          StackMapEncoding encoding = code_info.ExtractEncoding();
904          uint32_t native_pc_offset = GetCurrentCode().NativeQuickPcOffset(cur_quick_frame_pc_);
905          StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
906          if (stack_map.IsValid() && stack_map.HasInlineInfo(encoding)) {
907            InlineInfo inline_info = code_info.GetInlineInfoOf(stack_map, encoding);
908            DCHECK_EQ(current_inlining_depth_, 0u);
909            for (current_inlining_depth_ = inline_info.GetDepth();
910                 current_inlining_depth_ != 0;
911                 --current_inlining_depth_) {
912              bool should_continue = VisitFrame();
913              if (UNLIKELY(!should_continue)) {
914                return;
915              }
916              cur_depth_++;
917            }
918          }
919        }
920
921        bool should_continue = VisitFrame();
922        if (UNLIKELY(!should_continue)) {
923          return;
924        }
925
926        if (context_ != nullptr) {
927          context_->FillCalleeSaves(*this);
928        }
929        size_t frame_size = GetCurrentCode().GetFrameSizeInBytes();
930        // Compute PC for next stack frame from return PC.
931        size_t return_pc_offset = GetCurrentCode().GetReturnPcOffset().SizeValue();
932        uint8_t* return_pc_addr = reinterpret_cast<uint8_t*>(cur_quick_frame_) + return_pc_offset;
933        uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
934        if (UNLIKELY(exit_stubs_installed)) {
935          // While profiling, the return pc is restored from the side stack, except when walking
936          // the stack for an exception where the side stack will be unwound in VisitFrame.
937          if (reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc()) == return_pc) {
938            const instrumentation::InstrumentationStackFrame& instrumentation_frame =
939                GetInstrumentationStackFrame(thread_, instrumentation_stack_depth);
940            instrumentation_stack_depth++;
941            if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
942              // Skip runtime save all callee frames which are used to deliver exceptions.
943            } else if (instrumentation_frame.interpreter_entry_) {
944              ArtMethod* callee = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
945              CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
946                                            << PrettyMethod(GetMethod());
947            } else if (instrumentation_frame.method_ != GetMethod()) {
948              LOG(FATAL)  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
949                          << " Found: " << PrettyMethod(GetMethod());
950            }
951            if (num_frames_ != 0) {
952              // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
953              // recursion.
954              CHECK(instrumentation_frame.frame_id_ == GetFrameId())
955                    << "Expected: " << instrumentation_frame.frame_id_
956                    << " Found: " << GetFrameId();
957            }
958            return_pc = instrumentation_frame.return_pc_;
959          }
960        }
961        ArtCode code = GetCurrentCode();
962
963        cur_quick_frame_pc_ = return_pc;
964        uint8_t* next_frame = reinterpret_cast<uint8_t*>(cur_quick_frame_) + frame_size;
965        cur_quick_frame_ = reinterpret_cast<ArtMethod**>(next_frame);
966
967        if (kDebugStackWalk) {
968          LOG(INFO) << PrettyMethod(method) << "@" << method << " size=" << frame_size
969              << " optimized=" << code.IsOptimized(sizeof(void*))
970              << " native=" << method->IsNative()
971              << " entrypoints=" << method->GetEntryPointFromQuickCompiledCode()
972              << "," << method->GetEntryPointFromJni()
973              << " next=" << *cur_quick_frame_;
974        }
975
976        cur_depth_++;
977        method = *cur_quick_frame_;
978      }
979    } else if (cur_shadow_frame_ != nullptr) {
980      do {
981        SanityCheckFrame();
982        bool should_continue = VisitFrame();
983        if (UNLIKELY(!should_continue)) {
984          return;
985        }
986        cur_depth_++;
987        cur_shadow_frame_ = cur_shadow_frame_->GetLink();
988      } while (cur_shadow_frame_ != nullptr);
989    }
990    if (include_transitions) {
991      bool should_continue = VisitFrame();
992      if (!should_continue) {
993        return;
994      }
995    }
996    cur_depth_++;
997  }
998  if (num_frames_ != 0) {
999    CHECK_EQ(cur_depth_, num_frames_);
1000  }
1001}
1002
1003void JavaFrameRootInfo::Describe(std::ostream& os) const {
1004  const StackVisitor* visitor = stack_visitor_;
1005  CHECK(visitor != nullptr);
1006  os << "Type=" << GetType() << " thread_id=" << GetThreadId() << " location=" <<
1007      visitor->DescribeLocation() << " vreg=" << vreg_;
1008}
1009
1010int StackVisitor::GetVRegOffsetFromQuickCode(const DexFile::CodeItem* code_item,
1011                                             uint32_t core_spills, uint32_t fp_spills,
1012                                             size_t frame_size, int reg, InstructionSet isa) {
1013  size_t pointer_size = InstructionSetPointerSize(isa);
1014  if (kIsDebugBuild) {
1015    auto* runtime = Runtime::Current();
1016    if (runtime != nullptr) {
1017      CHECK_EQ(runtime->GetClassLinker()->GetImagePointerSize(), pointer_size);
1018    }
1019  }
1020  DCHECK_ALIGNED(frame_size, kStackAlignment);
1021  DCHECK_NE(reg, -1);
1022  int spill_size = POPCOUNT(core_spills) * GetBytesPerGprSpillLocation(isa)
1023      + POPCOUNT(fp_spills) * GetBytesPerFprSpillLocation(isa)
1024      + sizeof(uint32_t);  // Filler.
1025  int num_regs = code_item->registers_size_ - code_item->ins_size_;
1026  int temp_threshold = code_item->registers_size_;
1027  const int max_num_special_temps = 1;
1028  if (reg == temp_threshold) {
1029    // The current method pointer corresponds to special location on stack.
1030    return 0;
1031  } else if (reg >= temp_threshold + max_num_special_temps) {
1032    /*
1033     * Special temporaries may have custom locations and the logic above deals with that.
1034     * However, non-special temporaries are placed relative to the outs.
1035     */
1036    int temps_start = code_item->outs_size_ * sizeof(uint32_t) + pointer_size /* art method */;
1037    int relative_offset = (reg - (temp_threshold + max_num_special_temps)) * sizeof(uint32_t);
1038    return temps_start + relative_offset;
1039  }  else if (reg < num_regs) {
1040    int locals_start = frame_size - spill_size - num_regs * sizeof(uint32_t);
1041    return locals_start + (reg * sizeof(uint32_t));
1042  } else {
1043    // Handle ins.
1044    return frame_size + ((reg - num_regs) * sizeof(uint32_t)) + pointer_size /* art method */;
1045  }
1046}
1047
1048void LockCountData::AddMonitorInternal(Thread* self, mirror::Object* obj) {
1049  if (obj == nullptr) {
1050    return;
1051  }
1052
1053  // If there's an error during enter, we won't have locked the monitor. So check there's no
1054  // exception.
1055  if (self->IsExceptionPending()) {
1056    return;
1057  }
1058
1059  if (monitors_ == nullptr) {
1060    monitors_.reset(new std::vector<mirror::Object*>());
1061  }
1062  monitors_->push_back(obj);
1063}
1064
1065void LockCountData::RemoveMonitorInternal(Thread* self, const mirror::Object* obj) {
1066  if (obj == nullptr) {
1067    return;
1068  }
1069  bool found_object = false;
1070  if (monitors_ != nullptr) {
1071    // We need to remove one pointer to ref, as duplicates are used for counting recursive locks.
1072    // We arbitrarily choose the first one.
1073    auto it = std::find(monitors_->begin(), monitors_->end(), obj);
1074    if (it != monitors_->end()) {
1075      monitors_->erase(it);
1076      found_object = true;
1077    }
1078  }
1079  if (!found_object) {
1080    // The object wasn't found. Time for an IllegalMonitorStateException.
1081    // The order here isn't fully clear. Assume that any other pending exception is swallowed.
1082    // TODO: Maybe make already pending exception a suppressed exception.
1083    self->ClearException();
1084    self->ThrowNewExceptionF("Ljava/lang/IllegalMonitorStateException;",
1085                             "did not lock monitor on object of type '%s' before unlocking",
1086                             PrettyTypeOf(const_cast<mirror::Object*>(obj)).c_str());
1087  }
1088}
1089
1090// Helper to unlock a monitor. Must be NO_THREAD_SAFETY_ANALYSIS, as we can't statically show
1091// that the object was locked.
1092void MonitorExitHelper(Thread* self, mirror::Object* obj) NO_THREAD_SAFETY_ANALYSIS {
1093  DCHECK(self != nullptr);
1094  DCHECK(obj != nullptr);
1095  obj->MonitorExit(self);
1096}
1097
1098bool LockCountData::CheckAllMonitorsReleasedInternal(Thread* self) {
1099  DCHECK(self != nullptr);
1100  if (monitors_ != nullptr) {
1101    if (!monitors_->empty()) {
1102      // There may be an exception pending, if the method is terminating abruptly. Clear it.
1103      // TODO: Should we add this as a suppressed exception?
1104      self->ClearException();
1105
1106      // OK, there are monitors that are still locked. To enforce structured locking (and avoid
1107      // deadlocks) we unlock all of them before we raise the IllegalMonitorState exception.
1108      for (mirror::Object* obj : *monitors_) {
1109        MonitorExitHelper(self, obj);
1110        // If this raised an exception, ignore. TODO: Should we add this as suppressed
1111        // exceptions?
1112        if (self->IsExceptionPending()) {
1113          self->ClearException();
1114        }
1115      }
1116      // Raise an exception, just give the first object as the sample.
1117      mirror::Object* first = (*monitors_)[0];
1118      self->ThrowNewExceptionF("Ljava/lang/IllegalMonitorStateException;",
1119                               "did not unlock monitor on object of type '%s'",
1120                               PrettyTypeOf(first).c_str());
1121
1122      // To make sure this path is not triggered again, clean out the monitors.
1123      monitors_->clear();
1124
1125      return false;
1126    }
1127  }
1128  return true;
1129}
1130
1131}  // namespace art
1132