stack.cc revision 356412e2b7ba3fde164bc08a44fee0ddc19c54e1 
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_method-inl.h"
21#include "base/hex_dump.h"
22#include "entrypoints/entrypoint_utils-inl.h"
23#include "entrypoints/runtime_asm_entrypoints.h"
24#include "gc_map.h"
25#include "gc/space/image_space.h"
26#include "gc/space/space-inl.h"
27#include "linear_alloc.h"
28#include "mirror/class-inl.h"
29#include "mirror/object-inl.h"
30#include "mirror/object_array-inl.h"
31#include "quick/quick_method_frame_info.h"
32#include "runtime.h"
33#include "thread.h"
34#include "thread_list.h"
35#include "verify_object-inl.h"
36#include "vmap_table.h"
37
38namespace art {
39
40static constexpr bool kDebugStackWalk = false;
41
42mirror::Object* ShadowFrame::GetThisObject() const {
43  ArtMethod* m = GetMethod();
44  if (m->IsStatic()) {
45    return nullptr;
46  } else if (m->IsNative()) {
47    return GetVRegReference(0);
48  } else {
49    const DexFile::CodeItem* code_item = m->GetCodeItem();
50    CHECK(code_item != nullptr) << PrettyMethod(m);
51    uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
52    return GetVRegReference(reg);
53  }
54}
55
56mirror::Object* ShadowFrame::GetThisObject(uint16_t num_ins) const {
57  ArtMethod* m = GetMethod();
58  if (m->IsStatic()) {
59    return nullptr;
60  } else {
61    return GetVRegReference(NumberOfVRegs() - num_ins);
62  }
63}
64
65size_t ManagedStack::NumJniShadowFrameReferences() const {
66  size_t count = 0;
67  for (const ManagedStack* current_fragment = this; current_fragment != nullptr;
68       current_fragment = current_fragment->GetLink()) {
69    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != nullptr;
70         current_frame = current_frame->GetLink()) {
71      if (current_frame->GetMethod()->IsNative()) {
72        // The JNI ShadowFrame only contains references. (For indirect reference.)
73        count += current_frame->NumberOfVRegs();
74      }
75    }
76  }
77  return count;
78}
79
80bool ManagedStack::ShadowFramesContain(StackReference<mirror::Object>* shadow_frame_entry) const {
81  for (const ManagedStack* current_fragment = this; current_fragment != nullptr;
82       current_fragment = current_fragment->GetLink()) {
83    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != nullptr;
84         current_frame = current_frame->GetLink()) {
85      if (current_frame->Contains(shadow_frame_entry)) {
86        return true;
87      }
88    }
89  }
90  return false;
91}
92
93StackVisitor::StackVisitor(Thread* thread, Context* context, StackWalkKind walk_kind)
94    : StackVisitor(thread, context, walk_kind, 0) {}
95
96StackVisitor::StackVisitor(Thread* thread,
97                           Context* context,
98                           StackWalkKind walk_kind,
99                           size_t num_frames)
100    : thread_(thread),
101      walk_kind_(walk_kind),
102      cur_shadow_frame_(nullptr),
103      cur_quick_frame_(nullptr),
104      cur_quick_frame_pc_(0),
105      num_frames_(num_frames),
106      cur_depth_(0),
107      current_inlining_depth_(0),
108      context_(context) {
109  DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
110}
111
112InlineInfo StackVisitor::GetCurrentInlineInfo() const {
113  ArtMethod* outer_method = *GetCurrentQuickFrame();
114  uint32_t native_pc_offset = outer_method->NativeQuickPcOffset(cur_quick_frame_pc_);
115  CodeInfo code_info = outer_method->GetOptimizedCodeInfo();
116  StackMapEncoding encoding = code_info.ExtractEncoding();
117  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
118  DCHECK(stack_map.IsValid());
119  return code_info.GetInlineInfoOf(stack_map, encoding);
120}
121
122ArtMethod* StackVisitor::GetMethod() const {
123  if (cur_shadow_frame_ != nullptr) {
124    return cur_shadow_frame_->GetMethod();
125  } else if (cur_quick_frame_ != nullptr) {
126    if (IsInInlinedFrame()) {
127      size_t depth_in_stack_map = current_inlining_depth_ - 1;
128      InlineInfo inline_info = GetCurrentInlineInfo();
129      return GetResolvedMethod(*GetCurrentQuickFrame(), inline_info, depth_in_stack_map);
130    } else {
131      return *cur_quick_frame_;
132    }
133  }
134  return nullptr;
135}
136
137uint32_t StackVisitor::GetDexPc(bool abort_on_failure) const {
138  if (cur_shadow_frame_ != nullptr) {
139    return cur_shadow_frame_->GetDexPC();
140  } else if (cur_quick_frame_ != nullptr) {
141    if (IsInInlinedFrame()) {
142      size_t depth_in_stack_map = current_inlining_depth_ - 1;
143      return GetCurrentInlineInfo().GetDexPcAtDepth(depth_in_stack_map);
144    } else {
145      return GetMethod()->ToDexPc(cur_quick_frame_pc_, abort_on_failure);
146    }
147  } else {
148    return 0;
149  }
150}
151
152extern "C" mirror::Object* artQuickGetProxyThisObject(ArtMethod** sp)
153    SHARED_REQUIRES(Locks::mutator_lock_);
154
155mirror::Object* StackVisitor::GetThisObject() const {
156  DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), sizeof(void*));
157  ArtMethod* m = GetMethod();
158  if (m->IsStatic()) {
159    return nullptr;
160  } else if (m->IsNative()) {
161    if (cur_quick_frame_ != nullptr) {
162      HandleScope* hs = reinterpret_cast<HandleScope*>(
163          reinterpret_cast<char*>(cur_quick_frame_) + m->GetHandleScopeOffset().SizeValue());
164      return hs->GetReference(0);
165    } else {
166      return cur_shadow_frame_->GetVRegReference(0);
167    }
168  } else if (m->IsProxyMethod()) {
169    if (cur_quick_frame_ != nullptr) {
170      return artQuickGetProxyThisObject(cur_quick_frame_);
171    } else {
172      return cur_shadow_frame_->GetVRegReference(0);
173    }
174  } else {
175    const DexFile::CodeItem* code_item = m->GetCodeItem();
176    if (code_item == nullptr) {
177      UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method: "
178          << PrettyMethod(m);
179      return nullptr;
180    } else {
181      uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
182      uint32_t value = 0;
183      bool success = GetVReg(m, reg, kReferenceVReg, &value);
184      // We currently always guarantee the `this` object is live throughout the method.
185      CHECK(success) << "Failed to read the this object in " << PrettyMethod(m);
186      return reinterpret_cast<mirror::Object*>(value);
187    }
188  }
189}
190
191size_t StackVisitor::GetNativePcOffset() const {
192  DCHECK(!IsShadowFrame());
193  return GetMethod()->NativeQuickPcOffset(cur_quick_frame_pc_);
194}
195
196bool StackVisitor::IsReferenceVReg(ArtMethod* m, uint16_t vreg) {
197  // Process register map (which native and runtime methods don't have)
198  if (m->IsNative() || m->IsRuntimeMethod() || m->IsProxyMethod()) {
199    return false;
200  }
201  if (m->IsOptimized(sizeof(void*))) {
202    return true;  // TODO: Implement.
203  }
204  const uint8_t* native_gc_map = m->GetNativeGcMap(sizeof(void*));
205  CHECK(native_gc_map != nullptr) << PrettyMethod(m);
206  const DexFile::CodeItem* code_item = m->GetCodeItem();
207  // Can't be null or how would we compile its instructions?
208  DCHECK(code_item != nullptr) << PrettyMethod(m);
209  NativePcOffsetToReferenceMap map(native_gc_map);
210  size_t num_regs = std::min(map.RegWidth() * 8, static_cast<size_t>(code_item->registers_size_));
211  const uint8_t* reg_bitmap = nullptr;
212  if (num_regs > 0) {
213    Runtime* runtime = Runtime::Current();
214    const void* entry_point = runtime->GetInstrumentation()->GetQuickCodeFor(m, sizeof(void*));
215    uintptr_t native_pc_offset = m->NativeQuickPcOffset(GetCurrentQuickFramePc(), entry_point);
216    reg_bitmap = map.FindBitMap(native_pc_offset);
217    DCHECK(reg_bitmap != nullptr);
218  }
219  // Does this register hold a reference?
220  return vreg < num_regs && TestBitmap(vreg, reg_bitmap);
221}
222
223bool StackVisitor::GetVRegFromDebuggerShadowFrame(uint16_t vreg,
224                                                  VRegKind kind,
225                                                  uint32_t* val) const {
226  size_t frame_id = const_cast<StackVisitor*>(this)->GetFrameId();
227  ShadowFrame* shadow_frame = thread_->FindDebuggerShadowFrame(frame_id);
228  if (shadow_frame != nullptr) {
229    bool* updated_vreg_flags = thread_->GetUpdatedVRegFlags(frame_id);
230    DCHECK(updated_vreg_flags != nullptr);
231    if (updated_vreg_flags[vreg]) {
232      // Value is set by the debugger.
233      if (kind == kReferenceVReg) {
234        *val = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(
235            shadow_frame->GetVRegReference(vreg)));
236      } else {
237        *val = shadow_frame->GetVReg(vreg);
238      }
239      return true;
240    }
241  }
242  // No value is set by the debugger.
243  return false;
244}
245
246bool StackVisitor::GetVReg(ArtMethod* m, uint16_t vreg, VRegKind kind, uint32_t* val) const {
247  if (cur_quick_frame_ != nullptr) {
248    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
249    DCHECK(m == GetMethod());
250    // Check if there is value set by the debugger.
251    if (GetVRegFromDebuggerShadowFrame(vreg, kind, val)) {
252      return true;
253    }
254    if (m->IsOptimized(sizeof(void*))) {
255      return GetVRegFromOptimizedCode(m, vreg, kind, val);
256    } else {
257      return GetVRegFromQuickCode(m, vreg, kind, val);
258    }
259  } else {
260    DCHECK(cur_shadow_frame_ != nullptr);
261    *val = cur_shadow_frame_->GetVReg(vreg);
262    return true;
263  }
264}
265
266bool StackVisitor::GetVRegFromQuickCode(ArtMethod* m, uint16_t vreg, VRegKind kind,
267                                        uint32_t* val) const {
268  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
269  DCHECK(code_pointer != nullptr);
270  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
271  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
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  ArtMethod* outer_method = *GetCurrentQuickFrame();
298  const void* code_pointer = outer_method->GetQuickOatCodePointer(sizeof(void*));
299  DCHECK(code_pointer != nullptr);
300  CodeInfo code_info = outer_method->GetOptimizedCodeInfo();
301  StackMapEncoding encoding = code_info.ExtractEncoding();
302
303  uint32_t native_pc_offset = outer_method->NativeQuickPcOffset(cur_quick_frame_pc_);
304  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
305  DCHECK(stack_map.IsValid());
306  size_t depth_in_stack_map = current_inlining_depth_ - 1;
307
308  DexRegisterMap dex_register_map = IsInInlinedFrame()
309      ? code_info.GetDexRegisterMapAtDepth(depth_in_stack_map,
310                                           code_info.GetInlineInfoOf(stack_map, encoding),
311                                           encoding,
312                                           number_of_dex_registers)
313      : code_info.GetDexRegisterMapOf(stack_map, encoding, number_of_dex_registers);
314
315  DexRegisterLocation::Kind location_kind =
316      dex_register_map.GetLocationKind(vreg, number_of_dex_registers, code_info, encoding);
317  switch (location_kind) {
318    case DexRegisterLocation::Kind::kInStack: {
319      const int32_t offset = dex_register_map.GetStackOffsetInBytes(vreg,
320                                                                    number_of_dex_registers,
321                                                                    code_info,
322                                                                    encoding);
323      const uint8_t* addr = reinterpret_cast<const uint8_t*>(cur_quick_frame_) + offset;
324      *val = *reinterpret_cast<const uint32_t*>(addr);
325      return true;
326    }
327    case DexRegisterLocation::Kind::kInRegister:
328    case DexRegisterLocation::Kind::kInRegisterHigh:
329    case DexRegisterLocation::Kind::kInFpuRegister:
330    case DexRegisterLocation::Kind::kInFpuRegisterHigh: {
331      uint32_t reg =
332          dex_register_map.GetMachineRegister(vreg, number_of_dex_registers, code_info, encoding);
333      return GetRegisterIfAccessible(reg, kind, val);
334    }
335    case DexRegisterLocation::Kind::kConstant:
336      *val = dex_register_map.GetConstant(vreg, number_of_dex_registers, code_info, encoding);
337      return true;
338    case DexRegisterLocation::Kind::kNone:
339      return false;
340    default:
341      LOG(FATAL)
342          << "Unexpected location kind"
343          << DexRegisterLocation::PrettyDescriptor(
344                dex_register_map.GetLocationInternalKind(vreg,
345                                                         number_of_dex_registers,
346                                                         code_info,
347                                                         encoding));
348      UNREACHABLE();
349  }
350}
351
352bool StackVisitor::GetRegisterIfAccessible(uint32_t reg, VRegKind kind, uint32_t* val) const {
353  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
354
355  // X86 float registers are 64-bit and the logic below does not apply.
356  DCHECK(!is_float || kRuntimeISA != InstructionSet::kX86);
357
358  if (!IsAccessibleRegister(reg, is_float)) {
359    return false;
360  }
361  uintptr_t ptr_val = GetRegister(reg, is_float);
362  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
363  if (target64) {
364    const bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
365    const bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
366    int64_t value_long = static_cast<int64_t>(ptr_val);
367    if (wide_lo) {
368      ptr_val = static_cast<uintptr_t>(Low32Bits(value_long));
369    } else if (wide_hi) {
370      ptr_val = static_cast<uintptr_t>(High32Bits(value_long));
371    }
372  }
373  *val = ptr_val;
374  return true;
375}
376
377bool StackVisitor::GetVRegPairFromDebuggerShadowFrame(uint16_t vreg,
378                                                      VRegKind kind_lo,
379                                                      VRegKind kind_hi,
380                                                      uint64_t* val) const {
381  uint32_t low_32bits;
382  uint32_t high_32bits;
383  bool success = GetVRegFromDebuggerShadowFrame(vreg, kind_lo, &low_32bits);
384  success &= GetVRegFromDebuggerShadowFrame(vreg + 1, kind_hi, &high_32bits);
385  if (success) {
386    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
387  }
388  return success;
389}
390
391bool StackVisitor::GetVRegPair(ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
392                               VRegKind kind_hi, uint64_t* val) const {
393  if (kind_lo == kLongLoVReg) {
394    DCHECK_EQ(kind_hi, kLongHiVReg);
395  } else if (kind_lo == kDoubleLoVReg) {
396    DCHECK_EQ(kind_hi, kDoubleHiVReg);
397  } else {
398    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
399    UNREACHABLE();
400  }
401  // Check if there is value set by the debugger.
402  if (GetVRegPairFromDebuggerShadowFrame(vreg, kind_lo, kind_hi, val)) {
403    return true;
404  }
405  if (cur_quick_frame_ != nullptr) {
406    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
407    DCHECK(m == GetMethod());
408    if (m->IsOptimized(sizeof(void*))) {
409      return GetVRegPairFromOptimizedCode(m, vreg, kind_lo, kind_hi, val);
410    } else {
411      return GetVRegPairFromQuickCode(m, vreg, kind_lo, kind_hi, val);
412    }
413  } else {
414    DCHECK(cur_shadow_frame_ != nullptr);
415    *val = cur_shadow_frame_->GetVRegLong(vreg);
416    return true;
417  }
418}
419
420bool StackVisitor::GetVRegPairFromQuickCode(ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
421                                            VRegKind kind_hi, uint64_t* val) const {
422  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
423  DCHECK(code_pointer != nullptr);
424  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
425  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
426  uint32_t vmap_offset_lo, vmap_offset_hi;
427  // TODO: IsInContext stops before spotting floating point registers.
428  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
429      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
430    bool is_float = (kind_lo == kDoubleLoVReg);
431    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
432    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
433    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
434    return GetRegisterPairIfAccessible(reg_lo, reg_hi, kind_lo, val);
435  } else {
436    const DexFile::CodeItem* code_item = m->GetCodeItem();
437    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
438                                                      // its instructions?
439    uint32_t* addr = GetVRegAddrFromQuickCode(
440        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
441        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
442    *val = *reinterpret_cast<uint64_t*>(addr);
443    return true;
444  }
445}
446
447bool StackVisitor::GetVRegPairFromOptimizedCode(ArtMethod* m, uint16_t vreg,
448                                                VRegKind kind_lo, VRegKind kind_hi,
449                                                uint64_t* val) const {
450  uint32_t low_32bits;
451  uint32_t high_32bits;
452  bool success = GetVRegFromOptimizedCode(m, vreg, kind_lo, &low_32bits);
453  success &= GetVRegFromOptimizedCode(m, vreg + 1, kind_hi, &high_32bits);
454  if (success) {
455    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
456  }
457  return success;
458}
459
460bool StackVisitor::GetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
461                                               VRegKind kind_lo, uint64_t* val) const {
462  const bool is_float = (kind_lo == kDoubleLoVReg);
463  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
464    return false;
465  }
466  uintptr_t ptr_val_lo = GetRegister(reg_lo, is_float);
467  uintptr_t ptr_val_hi = GetRegister(reg_hi, is_float);
468  bool target64 = Is64BitInstructionSet(kRuntimeISA);
469  if (target64) {
470    int64_t value_long_lo = static_cast<int64_t>(ptr_val_lo);
471    int64_t value_long_hi = static_cast<int64_t>(ptr_val_hi);
472    ptr_val_lo = static_cast<uintptr_t>(Low32Bits(value_long_lo));
473    ptr_val_hi = static_cast<uintptr_t>(High32Bits(value_long_hi));
474  }
475  *val = (static_cast<uint64_t>(ptr_val_hi) << 32) | static_cast<uint32_t>(ptr_val_lo);
476  return true;
477}
478
479bool StackVisitor::SetVReg(ArtMethod* m, uint16_t vreg, uint32_t new_value,
480                           VRegKind kind) {
481  if (cur_quick_frame_ != nullptr) {
482    DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
483    DCHECK(m == GetMethod());
484    if (m->IsOptimized(sizeof(void*))) {
485      return false;
486    } else {
487      return SetVRegFromQuickCode(m, vreg, new_value, kind);
488    }
489  } else {
490    cur_shadow_frame_->SetVReg(vreg, new_value);
491    return true;
492  }
493}
494
495bool StackVisitor::SetVRegFromQuickCode(ArtMethod* m, uint16_t vreg, uint32_t new_value,
496                                        VRegKind kind) {
497  DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
498  DCHECK(m == GetMethod());
499  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
500  DCHECK(code_pointer != nullptr);
501  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
502  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
503  uint32_t vmap_offset;
504  // TODO: IsInContext stops before spotting floating point registers.
505  if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
506    bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
507    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
508    uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
509    return SetRegisterIfAccessible(reg, new_value, kind);
510  } else {
511    const DexFile::CodeItem* code_item = m->GetCodeItem();
512    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
513                                                      // its instructions?
514    uint32_t* addr = GetVRegAddrFromQuickCode(
515        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
516        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
517    *addr = new_value;
518    return true;
519  }
520}
521
522bool StackVisitor::SetVRegFromDebugger(ArtMethod* m,
523                                       uint16_t vreg,
524                                       uint32_t new_value,
525                                       VRegKind kind) {
526  const DexFile::CodeItem* code_item = m->GetCodeItem();
527  if (code_item == nullptr) {
528    return false;
529  }
530  ShadowFrame* shadow_frame = GetCurrentShadowFrame();
531  if (shadow_frame == nullptr) {
532    // This is a compiled frame: we must prepare and update a shadow frame that will
533    // be executed by the interpreter after deoptimization of the stack.
534    const size_t frame_id = GetFrameId();
535    const uint16_t num_regs = code_item->registers_size_;
536    shadow_frame = thread_->FindOrCreateDebuggerShadowFrame(frame_id, num_regs, m, GetDexPc());
537    CHECK(shadow_frame != nullptr);
538    // Remember the vreg has been set for debugging and must not be overwritten by the
539    // original value during deoptimization of the stack.
540    thread_->GetUpdatedVRegFlags(frame_id)[vreg] = true;
541  }
542  if (kind == kReferenceVReg) {
543    shadow_frame->SetVRegReference(vreg, reinterpret_cast<mirror::Object*>(new_value));
544  } else {
545    shadow_frame->SetVReg(vreg, new_value);
546  }
547  return true;
548}
549
550bool StackVisitor::SetRegisterIfAccessible(uint32_t reg, uint32_t new_value, VRegKind kind) {
551  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
552  if (!IsAccessibleRegister(reg, is_float)) {
553    return false;
554  }
555  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
556
557  // Create a new value that can hold both low 32 and high 32 bits, in
558  // case we are running 64 bits.
559  uintptr_t full_new_value = new_value;
560  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
561  if (target64) {
562    bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
563    bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
564    if (wide_lo || wide_hi) {
565      uintptr_t old_reg_val = GetRegister(reg, is_float);
566      uint64_t new_vreg_portion = static_cast<uint64_t>(new_value);
567      uint64_t old_reg_val_as_wide = static_cast<uint64_t>(old_reg_val);
568      uint64_t mask = 0xffffffff;
569      if (wide_lo) {
570        mask = mask << 32;
571      } else {
572        new_vreg_portion = new_vreg_portion << 32;
573      }
574      full_new_value = static_cast<uintptr_t>((old_reg_val_as_wide & mask) | new_vreg_portion);
575    }
576  }
577  SetRegister(reg, full_new_value, is_float);
578  return true;
579}
580
581bool StackVisitor::SetVRegPair(ArtMethod* m, uint16_t vreg, uint64_t new_value,
582                               VRegKind kind_lo, VRegKind kind_hi) {
583  if (kind_lo == kLongLoVReg) {
584    DCHECK_EQ(kind_hi, kLongHiVReg);
585  } else if (kind_lo == kDoubleLoVReg) {
586    DCHECK_EQ(kind_hi, kDoubleHiVReg);
587  } else {
588    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
589  }
590  if (cur_quick_frame_ != nullptr) {
591    DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
592    DCHECK(m == GetMethod());
593    if (m->IsOptimized(sizeof(void*))) {
594      return false;
595    } else {
596      return SetVRegPairFromQuickCode(m, vreg, new_value, kind_lo, kind_hi);
597    }
598  } else {
599    DCHECK(cur_shadow_frame_ != nullptr);
600    cur_shadow_frame_->SetVRegLong(vreg, new_value);
601    return true;
602  }
603}
604
605bool StackVisitor::SetVRegPairFromQuickCode(
606    ArtMethod* m, uint16_t vreg, uint64_t new_value, VRegKind kind_lo, VRegKind kind_hi) {
607  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
608  DCHECK(code_pointer != nullptr);
609  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
610  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
611  uint32_t vmap_offset_lo, vmap_offset_hi;
612  // TODO: IsInContext stops before spotting floating point registers.
613  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
614      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
615    bool is_float = (kind_lo == kDoubleLoVReg);
616    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
617    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
618    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
619    return SetRegisterPairIfAccessible(reg_lo, reg_hi, new_value, is_float);
620  } else {
621    const DexFile::CodeItem* code_item = m->GetCodeItem();
622    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
623                                                      // its instructions?
624    uint32_t* addr = GetVRegAddrFromQuickCode(
625        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
626        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
627    *reinterpret_cast<uint64_t*>(addr) = new_value;
628    return true;
629  }
630}
631
632bool StackVisitor::SetVRegPairFromDebugger(ArtMethod* m,
633                                           uint16_t vreg,
634                                           uint64_t new_value,
635                                           VRegKind kind_lo,
636                                           VRegKind kind_hi) {
637  if (kind_lo == kLongLoVReg) {
638    DCHECK_EQ(kind_hi, kLongHiVReg);
639  } else if (kind_lo == kDoubleLoVReg) {
640    DCHECK_EQ(kind_hi, kDoubleHiVReg);
641  } else {
642    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
643    UNREACHABLE();
644  }
645  const DexFile::CodeItem* code_item = m->GetCodeItem();
646  if (code_item == nullptr) {
647    return false;
648  }
649  ShadowFrame* shadow_frame = GetCurrentShadowFrame();
650  if (shadow_frame == nullptr) {
651    // This is a compiled frame: we must prepare for deoptimization (see SetVRegFromDebugger).
652    const size_t frame_id = GetFrameId();
653    const uint16_t num_regs = code_item->registers_size_;
654    shadow_frame = thread_->FindOrCreateDebuggerShadowFrame(frame_id, num_regs, m, GetDexPc());
655    CHECK(shadow_frame != nullptr);
656    // Remember the vreg pair has been set for debugging and must not be overwritten by the
657    // original value during deoptimization of the stack.
658    thread_->GetUpdatedVRegFlags(frame_id)[vreg] = true;
659    thread_->GetUpdatedVRegFlags(frame_id)[vreg + 1] = true;
660  }
661  shadow_frame->SetVRegLong(vreg, new_value);
662  return true;
663}
664
665bool StackVisitor::SetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
666                                               uint64_t new_value, bool is_float) {
667  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
668    return false;
669  }
670  uintptr_t new_value_lo = static_cast<uintptr_t>(new_value & 0xFFFFFFFF);
671  uintptr_t new_value_hi = static_cast<uintptr_t>(new_value >> 32);
672  bool target64 = Is64BitInstructionSet(kRuntimeISA);
673  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
674  if (target64) {
675    DCHECK_EQ(reg_lo, reg_hi);
676    SetRegister(reg_lo, new_value, is_float);
677  } else {
678    SetRegister(reg_lo, new_value_lo, is_float);
679    SetRegister(reg_hi, new_value_hi, is_float);
680  }
681  return true;
682}
683
684bool StackVisitor::IsAccessibleGPR(uint32_t reg) const {
685  DCHECK(context_ != nullptr);
686  return context_->IsAccessibleGPR(reg);
687}
688
689uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
690  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
691  DCHECK(context_ != nullptr);
692  return context_->GetGPRAddress(reg);
693}
694
695uintptr_t StackVisitor::GetGPR(uint32_t reg) const {
696  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
697  DCHECK(context_ != nullptr);
698  return context_->GetGPR(reg);
699}
700
701void StackVisitor::SetGPR(uint32_t reg, uintptr_t value) {
702  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
703  DCHECK(context_ != nullptr);
704  context_->SetGPR(reg, value);
705}
706
707bool StackVisitor::IsAccessibleFPR(uint32_t reg) const {
708  DCHECK(context_ != nullptr);
709  return context_->IsAccessibleFPR(reg);
710}
711
712uintptr_t StackVisitor::GetFPR(uint32_t reg) const {
713  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
714  DCHECK(context_ != nullptr);
715  return context_->GetFPR(reg);
716}
717
718void StackVisitor::SetFPR(uint32_t reg, uintptr_t value) {
719  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
720  DCHECK(context_ != nullptr);
721  context_->SetFPR(reg, value);
722}
723
724uintptr_t StackVisitor::GetReturnPc() const {
725  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
726  DCHECK(sp != nullptr);
727  uint8_t* pc_addr = sp + GetMethod()->GetReturnPcOffset().SizeValue();
728  return *reinterpret_cast<uintptr_t*>(pc_addr);
729}
730
731void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
732  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
733  CHECK(sp != nullptr);
734  uint8_t* pc_addr = sp + GetMethod()->GetReturnPcOffset().SizeValue();
735  *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
736}
737
738size_t StackVisitor::ComputeNumFrames(Thread* thread, StackWalkKind walk_kind) {
739  struct NumFramesVisitor : public StackVisitor {
740    NumFramesVisitor(Thread* thread_in, StackWalkKind walk_kind_in)
741        : StackVisitor(thread_in, nullptr, walk_kind_in), frames(0) {}
742
743    bool VisitFrame() OVERRIDE {
744      frames++;
745      return true;
746    }
747
748    size_t frames;
749  };
750  NumFramesVisitor visitor(thread, walk_kind);
751  visitor.WalkStack(true);
752  return visitor.frames;
753}
754
755bool StackVisitor::GetNextMethodAndDexPc(ArtMethod** next_method, uint32_t* next_dex_pc) {
756  struct HasMoreFramesVisitor : public StackVisitor {
757    HasMoreFramesVisitor(Thread* thread,
758                         StackWalkKind walk_kind,
759                         size_t num_frames,
760                         size_t frame_height)
761        : StackVisitor(thread, nullptr, walk_kind, num_frames),
762          frame_height_(frame_height),
763          found_frame_(false),
764          has_more_frames_(false),
765          next_method_(nullptr),
766          next_dex_pc_(0) {
767    }
768
769    bool VisitFrame() OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
770      if (found_frame_) {
771        ArtMethod* method = GetMethod();
772        if (method != nullptr && !method->IsRuntimeMethod()) {
773          has_more_frames_ = true;
774          next_method_ = method;
775          next_dex_pc_ = GetDexPc();
776          return false;  // End stack walk once next method is found.
777        }
778      } else if (GetFrameHeight() == frame_height_) {
779        found_frame_ = true;
780      }
781      return true;
782    }
783
784    size_t frame_height_;
785    bool found_frame_;
786    bool has_more_frames_;
787    ArtMethod* next_method_;
788    uint32_t next_dex_pc_;
789  };
790  HasMoreFramesVisitor visitor(thread_, walk_kind_, GetNumFrames(), GetFrameHeight());
791  visitor.WalkStack(true);
792  *next_method = visitor.next_method_;
793  *next_dex_pc = visitor.next_dex_pc_;
794  return visitor.has_more_frames_;
795}
796
797void StackVisitor::DescribeStack(Thread* thread) {
798  struct DescribeStackVisitor : public StackVisitor {
799    explicit DescribeStackVisitor(Thread* thread_in)
800        : StackVisitor(thread_in, nullptr, StackVisitor::StackWalkKind::kIncludeInlinedFrames) {}
801
802    bool VisitFrame() OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
803      LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
804      return true;
805    }
806  };
807  DescribeStackVisitor visitor(thread);
808  visitor.WalkStack(true);
809}
810
811std::string StackVisitor::DescribeLocation() const {
812  std::string result("Visiting method '");
813  ArtMethod* m = GetMethod();
814  if (m == nullptr) {
815    return "upcall";
816  }
817  result += PrettyMethod(m);
818  result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
819  if (!IsShadowFrame()) {
820    result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
821  }
822  return result;
823}
824
825static instrumentation::InstrumentationStackFrame& GetInstrumentationStackFrame(Thread* thread,
826                                                                                uint32_t depth) {
827  CHECK_LT(depth, thread->GetInstrumentationStack()->size());
828  return thread->GetInstrumentationStack()->at(depth);
829}
830
831void StackVisitor::SanityCheckFrame() const {
832  if (kIsDebugBuild) {
833    ArtMethod* method = GetMethod();
834    auto* declaring_class = method->GetDeclaringClass();
835    // Runtime methods have null declaring class.
836    if (!method->IsRuntimeMethod()) {
837      CHECK(declaring_class != nullptr);
838      CHECK_EQ(declaring_class->GetClass(), declaring_class->GetClass()->GetClass())
839          << declaring_class;
840    } else {
841      CHECK(declaring_class == nullptr);
842    }
843    Runtime* const runtime = Runtime::Current();
844    LinearAlloc* const linear_alloc = runtime->GetLinearAlloc();
845    if (!linear_alloc->Contains(method)) {
846      // Check class linker linear allocs.
847      mirror::Class* klass = method->GetDeclaringClass();
848      LinearAlloc* const class_linear_alloc = (klass != nullptr)
849          ? ClassLinker::GetAllocatorForClassLoader(klass->GetClassLoader())
850          : linear_alloc;
851      if (!class_linear_alloc->Contains(method)) {
852        // Check image space.
853        bool in_image = false;
854        for (auto& space : runtime->GetHeap()->GetContinuousSpaces()) {
855          if (space->IsImageSpace()) {
856            auto* image_space = space->AsImageSpace();
857            const auto& header = image_space->GetImageHeader();
858            const auto* methods = &header.GetMethodsSection();
859            if (methods->Contains(reinterpret_cast<const uint8_t*>(method) - image_space->Begin())) {
860              in_image = true;
861              break;
862            }
863          }
864        }
865        CHECK(in_image) << PrettyMethod(method) << " not in linear alloc or image";
866      }
867    }
868    if (cur_quick_frame_ != nullptr) {
869      method->AssertPcIsWithinQuickCode(cur_quick_frame_pc_);
870      // Frame sanity.
871      size_t frame_size = method->GetFrameSizeInBytes();
872      CHECK_NE(frame_size, 0u);
873      // A rough guess at an upper size we expect to see for a frame.
874      // 256 registers
875      // 2 words HandleScope overhead
876      // 3+3 register spills
877      // TODO: this seems architecture specific for the case of JNI frames.
878      // TODO: 083-compiler-regressions ManyFloatArgs shows this estimate is wrong.
879      // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
880      const size_t kMaxExpectedFrameSize = 2 * KB;
881      CHECK_LE(frame_size, kMaxExpectedFrameSize);
882      size_t return_pc_offset = method->GetReturnPcOffset().SizeValue();
883      CHECK_LT(return_pc_offset, frame_size);
884    }
885  }
886}
887
888void StackVisitor::WalkStack(bool include_transitions) {
889  DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
890  CHECK_EQ(cur_depth_, 0U);
891  bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
892  uint32_t instrumentation_stack_depth = 0;
893
894  for (const ManagedStack* current_fragment = thread_->GetManagedStack();
895       current_fragment != nullptr; current_fragment = current_fragment->GetLink()) {
896    cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
897    cur_quick_frame_ = current_fragment->GetTopQuickFrame();
898    cur_quick_frame_pc_ = 0;
899
900    if (cur_quick_frame_ != nullptr) {  // Handle quick stack frames.
901      // Can't be both a shadow and a quick fragment.
902      DCHECK(current_fragment->GetTopShadowFrame() == nullptr);
903      ArtMethod* method = *cur_quick_frame_;
904      while (method != nullptr) {
905        SanityCheckFrame();
906
907        if ((walk_kind_ == StackWalkKind::kIncludeInlinedFrames)
908            && method->IsOptimized(sizeof(void*))) {
909          CodeInfo code_info = method->GetOptimizedCodeInfo();
910          StackMapEncoding encoding = code_info.ExtractEncoding();
911          uint32_t native_pc_offset = method->NativeQuickPcOffset(cur_quick_frame_pc_);
912          StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
913          if (stack_map.IsValid() && stack_map.HasInlineInfo(encoding)) {
914            InlineInfo inline_info = code_info.GetInlineInfoOf(stack_map, encoding);
915            DCHECK_EQ(current_inlining_depth_, 0u);
916            for (current_inlining_depth_ = inline_info.GetDepth();
917                 current_inlining_depth_ != 0;
918                 --current_inlining_depth_) {
919              bool should_continue = VisitFrame();
920              if (UNLIKELY(!should_continue)) {
921                return;
922              }
923              cur_depth_++;
924            }
925          }
926        }
927
928        bool should_continue = VisitFrame();
929        if (UNLIKELY(!should_continue)) {
930          return;
931        }
932
933        if (context_ != nullptr) {
934          context_->FillCalleeSaves(*this);
935        }
936        size_t frame_size = method->GetFrameSizeInBytes();
937        // Compute PC for next stack frame from return PC.
938        size_t return_pc_offset = method->GetReturnPcOffset(frame_size).SizeValue();
939        uint8_t* return_pc_addr = reinterpret_cast<uint8_t*>(cur_quick_frame_) + return_pc_offset;
940        uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
941        if (UNLIKELY(exit_stubs_installed)) {
942          // While profiling, the return pc is restored from the side stack, except when walking
943          // the stack for an exception where the side stack will be unwound in VisitFrame.
944          if (reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc()) == return_pc) {
945            const instrumentation::InstrumentationStackFrame& instrumentation_frame =
946                GetInstrumentationStackFrame(thread_, instrumentation_stack_depth);
947            instrumentation_stack_depth++;
948            if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
949              // Skip runtime save all callee frames which are used to deliver exceptions.
950            } else if (instrumentation_frame.interpreter_entry_) {
951              ArtMethod* callee = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
952              CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
953                                            << PrettyMethod(GetMethod());
954            } else if (instrumentation_frame.method_ != GetMethod()) {
955              LOG(FATAL)  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
956                          << " Found: " << PrettyMethod(GetMethod());
957            }
958            if (num_frames_ != 0) {
959              // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
960              // recursion.
961              CHECK(instrumentation_frame.frame_id_ == GetFrameId())
962                    << "Expected: " << instrumentation_frame.frame_id_
963                    << " Found: " << GetFrameId();
964            }
965            return_pc = instrumentation_frame.return_pc_;
966          }
967        }
968        cur_quick_frame_pc_ = return_pc;
969        uint8_t* next_frame = reinterpret_cast<uint8_t*>(cur_quick_frame_) + frame_size;
970        cur_quick_frame_ = reinterpret_cast<ArtMethod**>(next_frame);
971
972        if (kDebugStackWalk) {
973          LOG(INFO) << PrettyMethod(method) << "@" << method << " size=" << frame_size
974              << " optimized=" << method->IsOptimized(sizeof(void*))
975              << " native=" << method->IsNative()
976              << " entrypoints=" << method->GetEntryPointFromQuickCompiledCode()
977              << "," << method->GetEntryPointFromJni()
978              << " next=" << *cur_quick_frame_;
979        }
980
981        cur_depth_++;
982        method = *cur_quick_frame_;
983      }
984    } else if (cur_shadow_frame_ != nullptr) {
985      do {
986        SanityCheckFrame();
987        bool should_continue = VisitFrame();
988        if (UNLIKELY(!should_continue)) {
989          return;
990        }
991        cur_depth_++;
992        cur_shadow_frame_ = cur_shadow_frame_->GetLink();
993      } while (cur_shadow_frame_ != nullptr);
994    }
995    if (include_transitions) {
996      bool should_continue = VisitFrame();
997      if (!should_continue) {
998        return;
999      }
1000    }
1001    cur_depth_++;
1002  }
1003  if (num_frames_ != 0) {
1004    CHECK_EQ(cur_depth_, num_frames_);
1005  }
1006}
1007
1008void JavaFrameRootInfo::Describe(std::ostream& os) const {
1009  const StackVisitor* visitor = stack_visitor_;
1010  CHECK(visitor != nullptr);
1011  os << "Type=" << GetType() << " thread_id=" << GetThreadId() << " location=" <<
1012      visitor->DescribeLocation() << " vreg=" << vreg_;
1013}
1014
1015int StackVisitor::GetVRegOffsetFromQuickCode(const DexFile::CodeItem* code_item,
1016                                             uint32_t core_spills, uint32_t fp_spills,
1017                                             size_t frame_size, int reg, InstructionSet isa) {
1018  size_t pointer_size = InstructionSetPointerSize(isa);
1019  if (kIsDebugBuild) {
1020    auto* runtime = Runtime::Current();
1021    if (runtime != nullptr) {
1022      CHECK_EQ(runtime->GetClassLinker()->GetImagePointerSize(), pointer_size);
1023    }
1024  }
1025  DCHECK_ALIGNED(frame_size, kStackAlignment);
1026  DCHECK_NE(reg, -1);
1027  int spill_size = POPCOUNT(core_spills) * GetBytesPerGprSpillLocation(isa)
1028      + POPCOUNT(fp_spills) * GetBytesPerFprSpillLocation(isa)
1029      + sizeof(uint32_t);  // Filler.
1030  int num_regs = code_item->registers_size_ - code_item->ins_size_;
1031  int temp_threshold = code_item->registers_size_;
1032  const int max_num_special_temps = 1;
1033  if (reg == temp_threshold) {
1034    // The current method pointer corresponds to special location on stack.
1035    return 0;
1036  } else if (reg >= temp_threshold + max_num_special_temps) {
1037    /*
1038     * Special temporaries may have custom locations and the logic above deals with that.
1039     * However, non-special temporaries are placed relative to the outs.
1040     */
1041    int temps_start = code_item->outs_size_ * sizeof(uint32_t) + pointer_size /* art method */;
1042    int relative_offset = (reg - (temp_threshold + max_num_special_temps)) * sizeof(uint32_t);
1043    return temps_start + relative_offset;
1044  }  else if (reg < num_regs) {
1045    int locals_start = frame_size - spill_size - num_regs * sizeof(uint32_t);
1046    return locals_start + (reg * sizeof(uint32_t));
1047  } else {
1048    // Handle ins.
1049    return frame_size + ((reg - num_regs) * sizeof(uint32_t)) + pointer_size /* art method */;
1050  }
1051}
1052
1053}  // namespace art
1054