stack.cc revision b331febbab8e916680faba722cc84b66b84218a3 
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 "jit/jit.h"
28#include "jit/jit_code_cache.h"
29#include "linear_alloc.h"
30#include "mirror/class-inl.h"
31#include "mirror/object-inl.h"
32#include "mirror/object_array-inl.h"
33#include "oat_quick_method_header.h"
34#include "quick/quick_method_frame_info.h"
35#include "runtime.h"
36#include "thread.h"
37#include "thread_list.h"
38#include "verify_object-inl.h"
39#include "vmap_table.h"
40
41namespace art {
42
43static constexpr bool kDebugStackWalk = true;
44
45mirror::Object* ShadowFrame::GetThisObject() const {
46  ArtMethod* m = GetMethod();
47  if (m->IsStatic()) {
48    return nullptr;
49  } else if (m->IsNative()) {
50    return GetVRegReference(0);
51  } else {
52    const DexFile::CodeItem* code_item = m->GetCodeItem();
53    CHECK(code_item != nullptr) << PrettyMethod(m);
54    uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
55    return GetVRegReference(reg);
56  }
57}
58
59mirror::Object* ShadowFrame::GetThisObject(uint16_t num_ins) const {
60  ArtMethod* m = GetMethod();
61  if (m->IsStatic()) {
62    return nullptr;
63  } else {
64    return GetVRegReference(NumberOfVRegs() - num_ins);
65  }
66}
67
68size_t ManagedStack::NumJniShadowFrameReferences() const {
69  size_t count = 0;
70  for (const ManagedStack* current_fragment = this; current_fragment != nullptr;
71       current_fragment = current_fragment->GetLink()) {
72    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != nullptr;
73         current_frame = current_frame->GetLink()) {
74      if (current_frame->GetMethod()->IsNative()) {
75        // The JNI ShadowFrame only contains references. (For indirect reference.)
76        count += current_frame->NumberOfVRegs();
77      }
78    }
79  }
80  return count;
81}
82
83bool ManagedStack::ShadowFramesContain(StackReference<mirror::Object>* shadow_frame_entry) const {
84  for (const ManagedStack* current_fragment = this; current_fragment != nullptr;
85       current_fragment = current_fragment->GetLink()) {
86    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != nullptr;
87         current_frame = current_frame->GetLink()) {
88      if (current_frame->Contains(shadow_frame_entry)) {
89        return true;
90      }
91    }
92  }
93  return false;
94}
95
96StackVisitor::StackVisitor(Thread* thread, Context* context, StackWalkKind walk_kind)
97    : StackVisitor(thread, context, walk_kind, 0) {}
98
99StackVisitor::StackVisitor(Thread* thread,
100                           Context* context,
101                           StackWalkKind walk_kind,
102                           size_t num_frames)
103    : thread_(thread),
104      walk_kind_(walk_kind),
105      cur_shadow_frame_(nullptr),
106      cur_quick_frame_(nullptr),
107      cur_quick_frame_pc_(0),
108      cur_oat_quick_method_header_(nullptr),
109      num_frames_(num_frames),
110      cur_depth_(0),
111      current_inlining_depth_(0),
112      context_(context) {
113  DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
114}
115
116InlineInfo StackVisitor::GetCurrentInlineInfo() const {
117  const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
118  uint32_t native_pc_offset = method_header->NativeQuickPcOffset(cur_quick_frame_pc_);
119  CodeInfo code_info = method_header->GetOptimizedCodeInfo();
120  StackMapEncoding encoding = code_info.ExtractEncoding();
121  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
122  DCHECK(stack_map.IsValid());
123  return code_info.GetInlineInfoOf(stack_map, encoding);
124}
125
126ArtMethod* StackVisitor::GetMethod() const {
127  if (cur_shadow_frame_ != nullptr) {
128    return cur_shadow_frame_->GetMethod();
129  } else if (cur_quick_frame_ != nullptr) {
130    if (IsInInlinedFrame()) {
131      size_t depth_in_stack_map = current_inlining_depth_ - 1;
132      InlineInfo inline_info = GetCurrentInlineInfo();
133      return GetResolvedMethod(*GetCurrentQuickFrame(), inline_info, depth_in_stack_map);
134    } else {
135      return *cur_quick_frame_;
136    }
137  }
138  return nullptr;
139}
140
141uint32_t StackVisitor::GetDexPc(bool abort_on_failure) const {
142  if (cur_shadow_frame_ != nullptr) {
143    return cur_shadow_frame_->GetDexPC();
144  } else if (cur_quick_frame_ != nullptr) {
145    if (IsInInlinedFrame()) {
146      size_t depth_in_stack_map = current_inlining_depth_ - 1;
147      return GetCurrentInlineInfo().GetDexPcAtDepth(depth_in_stack_map);
148    } else if (cur_oat_quick_method_header_ == nullptr) {
149      return DexFile::kDexNoIndex;
150    } else {
151      return cur_oat_quick_method_header_->ToDexPc(
152          GetMethod(), cur_quick_frame_pc_, abort_on_failure);
153    }
154  } else {
155    return 0;
156  }
157}
158
159extern "C" mirror::Object* artQuickGetProxyThisObject(ArtMethod** sp)
160    SHARED_REQUIRES(Locks::mutator_lock_);
161
162mirror::Object* StackVisitor::GetThisObject() const {
163  DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), sizeof(void*));
164  ArtMethod* m = GetMethod();
165  if (m->IsStatic()) {
166    return nullptr;
167  } else if (m->IsNative()) {
168    if (cur_quick_frame_ != nullptr) {
169      HandleScope* hs = reinterpret_cast<HandleScope*>(
170          reinterpret_cast<char*>(cur_quick_frame_) + sizeof(ArtMethod*));
171      return hs->GetReference(0);
172    } else {
173      return cur_shadow_frame_->GetVRegReference(0);
174    }
175  } else if (m->IsProxyMethod()) {
176    if (cur_quick_frame_ != nullptr) {
177      return artQuickGetProxyThisObject(cur_quick_frame_);
178    } else {
179      return cur_shadow_frame_->GetVRegReference(0);
180    }
181  } else {
182    const DexFile::CodeItem* code_item = m->GetCodeItem();
183    if (code_item == nullptr) {
184      UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method: "
185          << PrettyMethod(m);
186      return nullptr;
187    } else {
188      uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
189      uint32_t value = 0;
190      bool success = GetVReg(m, reg, kReferenceVReg, &value);
191      // We currently always guarantee the `this` object is live throughout the method.
192      CHECK(success) << "Failed to read the this object in " << PrettyMethod(m);
193      return reinterpret_cast<mirror::Object*>(value);
194    }
195  }
196}
197
198size_t StackVisitor::GetNativePcOffset() const {
199  DCHECK(!IsShadowFrame());
200  return GetCurrentOatQuickMethodHeader()->NativeQuickPcOffset(cur_quick_frame_pc_);
201}
202
203bool StackVisitor::IsReferenceVReg(ArtMethod* m, uint16_t vreg) {
204  DCHECK_EQ(m, GetMethod());
205  // Process register map (which native and runtime methods don't have)
206  if (m->IsNative() || m->IsRuntimeMethod() || m->IsProxyMethod()) {
207    return false;
208  }
209  const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
210  if (method_header->IsOptimized()) {
211    return true;  // TODO: Implement.
212  }
213  const uint8_t* native_gc_map = method_header->GetNativeGcMap();
214  CHECK(native_gc_map != nullptr) << PrettyMethod(m);
215  const DexFile::CodeItem* code_item = m->GetCodeItem();
216  // Can't be null or how would we compile its instructions?
217  DCHECK(code_item != nullptr) << PrettyMethod(m);
218  NativePcOffsetToReferenceMap map(native_gc_map);
219  size_t num_regs = std::min(map.RegWidth() * 8, static_cast<size_t>(code_item->registers_size_));
220  const uint8_t* reg_bitmap = nullptr;
221  if (num_regs > 0) {
222    uintptr_t native_pc_offset = method_header->NativeQuickPcOffset(GetCurrentQuickFramePc());
223    reg_bitmap = map.FindBitMap(native_pc_offset);
224    DCHECK(reg_bitmap != nullptr);
225  }
226  // Does this register hold a reference?
227  return vreg < num_regs && TestBitmap(vreg, reg_bitmap);
228}
229
230bool StackVisitor::GetVRegFromDebuggerShadowFrame(uint16_t vreg,
231                                                  VRegKind kind,
232                                                  uint32_t* val) const {
233  size_t frame_id = const_cast<StackVisitor*>(this)->GetFrameId();
234  ShadowFrame* shadow_frame = thread_->FindDebuggerShadowFrame(frame_id);
235  if (shadow_frame != nullptr) {
236    bool* updated_vreg_flags = thread_->GetUpdatedVRegFlags(frame_id);
237    DCHECK(updated_vreg_flags != nullptr);
238    if (updated_vreg_flags[vreg]) {
239      // Value is set by the debugger.
240      if (kind == kReferenceVReg) {
241        *val = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(
242            shadow_frame->GetVRegReference(vreg)));
243      } else {
244        *val = shadow_frame->GetVReg(vreg);
245      }
246      return true;
247    }
248  }
249  // No value is set by the debugger.
250  return false;
251}
252
253bool StackVisitor::GetVReg(ArtMethod* m, uint16_t vreg, VRegKind kind, uint32_t* val) const {
254  if (cur_quick_frame_ != nullptr) {
255    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
256    DCHECK(m == GetMethod());
257    // Check if there is value set by the debugger.
258    if (GetVRegFromDebuggerShadowFrame(vreg, kind, val)) {
259      return true;
260    }
261    if (cur_oat_quick_method_header_->IsOptimized()) {
262      return GetVRegFromOptimizedCode(m, vreg, kind, val);
263    } else {
264      return GetVRegFromQuickCode(m, vreg, kind, val);
265    }
266  } else {
267    DCHECK(cur_shadow_frame_ != nullptr);
268    if (kind == kReferenceVReg) {
269      *val = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(
270          cur_shadow_frame_->GetVRegReference(vreg)));
271    } else {
272      *val = cur_shadow_frame_->GetVReg(vreg);
273    }
274    return true;
275  }
276}
277
278bool StackVisitor::GetVRegFromQuickCode(ArtMethod* m, uint16_t vreg, VRegKind kind,
279                                        uint32_t* val) const {
280  DCHECK_EQ(m, GetMethod());
281  const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
282  QuickMethodFrameInfo frame_info = method_header->GetFrameInfo();
283  const VmapTable vmap_table(method_header->GetVmapTable());
284  uint32_t vmap_offset;
285  // TODO: IsInContext stops before spotting floating point registers.
286  if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
287    bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
288    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
289    uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
290    return GetRegisterIfAccessible(reg, kind, val);
291  } else {
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    *val = *GetVRegAddrFromQuickCode(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
296                                     frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
297    return true;
298  }
299}
300
301bool StackVisitor::GetVRegFromOptimizedCode(ArtMethod* m, uint16_t vreg, VRegKind kind,
302                                            uint32_t* val) const {
303  DCHECK_EQ(m, GetMethod());
304  const DexFile::CodeItem* code_item = m->GetCodeItem();
305  DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
306                                                    // its instructions?
307  uint16_t number_of_dex_registers = code_item->registers_size_;
308  DCHECK_LT(vreg, code_item->registers_size_);
309  const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
310  CodeInfo code_info = method_header->GetOptimizedCodeInfo();
311  StackMapEncoding encoding = code_info.ExtractEncoding();
312
313  uint32_t native_pc_offset = method_header->NativeQuickPcOffset(cur_quick_frame_pc_);
314  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
315  DCHECK(stack_map.IsValid());
316  size_t depth_in_stack_map = current_inlining_depth_ - 1;
317
318  DexRegisterMap dex_register_map = IsInInlinedFrame()
319      ? code_info.GetDexRegisterMapAtDepth(depth_in_stack_map,
320                                           code_info.GetInlineInfoOf(stack_map, encoding),
321                                           encoding,
322                                           number_of_dex_registers)
323      : code_info.GetDexRegisterMapOf(stack_map, encoding, number_of_dex_registers);
324
325  if (!dex_register_map.IsValid()) {
326    return false;
327  }
328  DexRegisterLocation::Kind location_kind =
329      dex_register_map.GetLocationKind(vreg, number_of_dex_registers, code_info, encoding);
330  switch (location_kind) {
331    case DexRegisterLocation::Kind::kInStack: {
332      const int32_t offset = dex_register_map.GetStackOffsetInBytes(vreg,
333                                                                    number_of_dex_registers,
334                                                                    code_info,
335                                                                    encoding);
336      const uint8_t* addr = reinterpret_cast<const uint8_t*>(cur_quick_frame_) + offset;
337      *val = *reinterpret_cast<const uint32_t*>(addr);
338      return true;
339    }
340    case DexRegisterLocation::Kind::kInRegister:
341    case DexRegisterLocation::Kind::kInRegisterHigh:
342    case DexRegisterLocation::Kind::kInFpuRegister:
343    case DexRegisterLocation::Kind::kInFpuRegisterHigh: {
344      uint32_t reg =
345          dex_register_map.GetMachineRegister(vreg, number_of_dex_registers, code_info, encoding);
346      return GetRegisterIfAccessible(reg, kind, val);
347    }
348    case DexRegisterLocation::Kind::kConstant:
349      *val = dex_register_map.GetConstant(vreg, number_of_dex_registers, code_info, encoding);
350      return true;
351    case DexRegisterLocation::Kind::kNone:
352      return false;
353    default:
354      LOG(FATAL)
355          << "Unexpected location kind"
356          << DexRegisterLocation::PrettyDescriptor(
357                dex_register_map.GetLocationInternalKind(vreg,
358                                                         number_of_dex_registers,
359                                                         code_info,
360                                                         encoding));
361      UNREACHABLE();
362  }
363}
364
365bool StackVisitor::GetRegisterIfAccessible(uint32_t reg, VRegKind kind, uint32_t* val) const {
366  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
367
368  // X86 float registers are 64-bit and the logic below does not apply.
369  DCHECK(!is_float || kRuntimeISA != InstructionSet::kX86);
370
371  if (!IsAccessibleRegister(reg, is_float)) {
372    return false;
373  }
374  uintptr_t ptr_val = GetRegister(reg, is_float);
375  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
376  if (target64) {
377    const bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
378    const bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
379    int64_t value_long = static_cast<int64_t>(ptr_val);
380    if (wide_lo) {
381      ptr_val = static_cast<uintptr_t>(Low32Bits(value_long));
382    } else if (wide_hi) {
383      ptr_val = static_cast<uintptr_t>(High32Bits(value_long));
384    }
385  }
386  *val = ptr_val;
387  return true;
388}
389
390bool StackVisitor::GetVRegPairFromDebuggerShadowFrame(uint16_t vreg,
391                                                      VRegKind kind_lo,
392                                                      VRegKind kind_hi,
393                                                      uint64_t* val) const {
394  uint32_t low_32bits;
395  uint32_t high_32bits;
396  bool success = GetVRegFromDebuggerShadowFrame(vreg, kind_lo, &low_32bits);
397  success &= GetVRegFromDebuggerShadowFrame(vreg + 1, kind_hi, &high_32bits);
398  if (success) {
399    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
400  }
401  return success;
402}
403
404bool StackVisitor::GetVRegPair(ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
405                               VRegKind kind_hi, uint64_t* val) const {
406  if (kind_lo == kLongLoVReg) {
407    DCHECK_EQ(kind_hi, kLongHiVReg);
408  } else if (kind_lo == kDoubleLoVReg) {
409    DCHECK_EQ(kind_hi, kDoubleHiVReg);
410  } else {
411    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
412    UNREACHABLE();
413  }
414  // Check if there is value set by the debugger.
415  if (GetVRegPairFromDebuggerShadowFrame(vreg, kind_lo, kind_hi, val)) {
416    return true;
417  }
418  if (cur_quick_frame_ != nullptr) {
419    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
420    DCHECK(m == GetMethod());
421    if (cur_oat_quick_method_header_->IsOptimized()) {
422      return GetVRegPairFromOptimizedCode(m, vreg, kind_lo, kind_hi, val);
423    } else {
424      return GetVRegPairFromQuickCode(m, vreg, kind_lo, kind_hi, val);
425    }
426  } else {
427    DCHECK(cur_shadow_frame_ != nullptr);
428    *val = cur_shadow_frame_->GetVRegLong(vreg);
429    return true;
430  }
431}
432
433bool StackVisitor::GetVRegPairFromQuickCode(ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
434                                            VRegKind kind_hi, uint64_t* val) const {
435  DCHECK_EQ(m, GetMethod());
436  const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
437  QuickMethodFrameInfo frame_info = method_header->GetFrameInfo();
438  const VmapTable vmap_table(method_header->GetVmapTable());
439  uint32_t vmap_offset_lo, vmap_offset_hi;
440  // TODO: IsInContext stops before spotting floating point registers.
441  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
442      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
443    bool is_float = (kind_lo == kDoubleLoVReg);
444    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
445    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
446    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
447    return GetRegisterPairIfAccessible(reg_lo, reg_hi, kind_lo, val);
448  } else {
449    const DexFile::CodeItem* code_item = m->GetCodeItem();
450    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
451                                                      // its instructions?
452    uint32_t* addr = GetVRegAddrFromQuickCode(
453        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
454        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
455    *val = *reinterpret_cast<uint64_t*>(addr);
456    return true;
457  }
458}
459
460bool StackVisitor::GetVRegPairFromOptimizedCode(ArtMethod* m, uint16_t vreg,
461                                                VRegKind kind_lo, VRegKind kind_hi,
462                                                uint64_t* val) const {
463  uint32_t low_32bits;
464  uint32_t high_32bits;
465  bool success = GetVRegFromOptimizedCode(m, vreg, kind_lo, &low_32bits);
466  success &= GetVRegFromOptimizedCode(m, vreg + 1, kind_hi, &high_32bits);
467  if (success) {
468    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
469  }
470  return success;
471}
472
473bool StackVisitor::GetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
474                                               VRegKind kind_lo, uint64_t* val) const {
475  const bool is_float = (kind_lo == kDoubleLoVReg);
476  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
477    return false;
478  }
479  uintptr_t ptr_val_lo = GetRegister(reg_lo, is_float);
480  uintptr_t ptr_val_hi = GetRegister(reg_hi, is_float);
481  bool target64 = Is64BitInstructionSet(kRuntimeISA);
482  if (target64) {
483    int64_t value_long_lo = static_cast<int64_t>(ptr_val_lo);
484    int64_t value_long_hi = static_cast<int64_t>(ptr_val_hi);
485    ptr_val_lo = static_cast<uintptr_t>(Low32Bits(value_long_lo));
486    ptr_val_hi = static_cast<uintptr_t>(High32Bits(value_long_hi));
487  }
488  *val = (static_cast<uint64_t>(ptr_val_hi) << 32) | static_cast<uint32_t>(ptr_val_lo);
489  return true;
490}
491
492bool StackVisitor::SetVReg(ArtMethod* m,
493                           uint16_t vreg,
494                           uint32_t new_value,
495                           VRegKind kind) {
496  const DexFile::CodeItem* code_item = m->GetCodeItem();
497  if (code_item == nullptr) {
498    return false;
499  }
500  ShadowFrame* shadow_frame = GetCurrentShadowFrame();
501  if (shadow_frame == nullptr) {
502    // This is a compiled frame: we must prepare and update a shadow frame that will
503    // be executed by the interpreter after deoptimization of the stack.
504    const size_t frame_id = GetFrameId();
505    const uint16_t num_regs = code_item->registers_size_;
506    shadow_frame = thread_->FindOrCreateDebuggerShadowFrame(frame_id, num_regs, m, GetDexPc());
507    CHECK(shadow_frame != nullptr);
508    // Remember the vreg has been set for debugging and must not be overwritten by the
509    // original value during deoptimization of the stack.
510    thread_->GetUpdatedVRegFlags(frame_id)[vreg] = true;
511  }
512  if (kind == kReferenceVReg) {
513    shadow_frame->SetVRegReference(vreg, reinterpret_cast<mirror::Object*>(new_value));
514  } else {
515    shadow_frame->SetVReg(vreg, new_value);
516  }
517  return true;
518}
519
520bool StackVisitor::SetVRegPair(ArtMethod* m,
521                               uint16_t vreg,
522                               uint64_t new_value,
523                               VRegKind kind_lo,
524                               VRegKind kind_hi) {
525  if (kind_lo == kLongLoVReg) {
526    DCHECK_EQ(kind_hi, kLongHiVReg);
527  } else if (kind_lo == kDoubleLoVReg) {
528    DCHECK_EQ(kind_hi, kDoubleHiVReg);
529  } else {
530    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
531    UNREACHABLE();
532  }
533  const DexFile::CodeItem* code_item = m->GetCodeItem();
534  if (code_item == nullptr) {
535    return false;
536  }
537  ShadowFrame* shadow_frame = GetCurrentShadowFrame();
538  if (shadow_frame == nullptr) {
539    // This is a compiled frame: we must prepare for deoptimization (see SetVRegFromDebugger).
540    const size_t frame_id = GetFrameId();
541    const uint16_t num_regs = code_item->registers_size_;
542    shadow_frame = thread_->FindOrCreateDebuggerShadowFrame(frame_id, num_regs, m, GetDexPc());
543    CHECK(shadow_frame != nullptr);
544    // Remember the vreg pair has been set for debugging and must not be overwritten by the
545    // original value during deoptimization of the stack.
546    thread_->GetUpdatedVRegFlags(frame_id)[vreg] = true;
547    thread_->GetUpdatedVRegFlags(frame_id)[vreg + 1] = true;
548  }
549  shadow_frame->SetVRegLong(vreg, new_value);
550  return true;
551}
552
553bool StackVisitor::IsAccessibleGPR(uint32_t reg) const {
554  DCHECK(context_ != nullptr);
555  return context_->IsAccessibleGPR(reg);
556}
557
558uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
559  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
560  DCHECK(context_ != nullptr);
561  return context_->GetGPRAddress(reg);
562}
563
564uintptr_t StackVisitor::GetGPR(uint32_t reg) const {
565  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
566  DCHECK(context_ != nullptr);
567  return context_->GetGPR(reg);
568}
569
570bool StackVisitor::IsAccessibleFPR(uint32_t reg) const {
571  DCHECK(context_ != nullptr);
572  return context_->IsAccessibleFPR(reg);
573}
574
575uintptr_t StackVisitor::GetFPR(uint32_t reg) const {
576  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
577  DCHECK(context_ != nullptr);
578  return context_->GetFPR(reg);
579}
580
581uintptr_t StackVisitor::GetReturnPc() const {
582  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
583  DCHECK(sp != nullptr);
584  uint8_t* pc_addr = sp + GetCurrentQuickFrameInfo().GetReturnPcOffset();
585  return *reinterpret_cast<uintptr_t*>(pc_addr);
586}
587
588void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
589  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
590  CHECK(sp != nullptr);
591  uint8_t* pc_addr = sp + GetCurrentQuickFrameInfo().GetReturnPcOffset();
592  *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
593}
594
595size_t StackVisitor::ComputeNumFrames(Thread* thread, StackWalkKind walk_kind) {
596  struct NumFramesVisitor : public StackVisitor {
597    NumFramesVisitor(Thread* thread_in, StackWalkKind walk_kind_in)
598        : StackVisitor(thread_in, nullptr, walk_kind_in), frames(0) {}
599
600    bool VisitFrame() OVERRIDE {
601      frames++;
602      return true;
603    }
604
605    size_t frames;
606  };
607  NumFramesVisitor visitor(thread, walk_kind);
608  visitor.WalkStack(true);
609  return visitor.frames;
610}
611
612bool StackVisitor::GetNextMethodAndDexPc(ArtMethod** next_method, uint32_t* next_dex_pc) {
613  struct HasMoreFramesVisitor : public StackVisitor {
614    HasMoreFramesVisitor(Thread* thread,
615                         StackWalkKind walk_kind,
616                         size_t num_frames,
617                         size_t frame_height)
618        : StackVisitor(thread, nullptr, walk_kind, num_frames),
619          frame_height_(frame_height),
620          found_frame_(false),
621          has_more_frames_(false),
622          next_method_(nullptr),
623          next_dex_pc_(0) {
624    }
625
626    bool VisitFrame() OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
627      if (found_frame_) {
628        ArtMethod* method = GetMethod();
629        if (method != nullptr && !method->IsRuntimeMethod()) {
630          has_more_frames_ = true;
631          next_method_ = method;
632          next_dex_pc_ = GetDexPc();
633          return false;  // End stack walk once next method is found.
634        }
635      } else if (GetFrameHeight() == frame_height_) {
636        found_frame_ = true;
637      }
638      return true;
639    }
640
641    size_t frame_height_;
642    bool found_frame_;
643    bool has_more_frames_;
644    ArtMethod* next_method_;
645    uint32_t next_dex_pc_;
646  };
647  HasMoreFramesVisitor visitor(thread_, walk_kind_, GetNumFrames(), GetFrameHeight());
648  visitor.WalkStack(true);
649  *next_method = visitor.next_method_;
650  *next_dex_pc = visitor.next_dex_pc_;
651  return visitor.has_more_frames_;
652}
653
654void StackVisitor::DescribeStack(Thread* thread) {
655  struct DescribeStackVisitor : public StackVisitor {
656    explicit DescribeStackVisitor(Thread* thread_in)
657        : StackVisitor(thread_in, nullptr, StackVisitor::StackWalkKind::kIncludeInlinedFrames) {}
658
659    bool VisitFrame() OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
660      LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
661      return true;
662    }
663  };
664  DescribeStackVisitor visitor(thread);
665  visitor.WalkStack(true);
666}
667
668std::string StackVisitor::DescribeLocation() const {
669  std::string result("Visiting method '");
670  ArtMethod* m = GetMethod();
671  if (m == nullptr) {
672    return "upcall";
673  }
674  result += PrettyMethod(m);
675  result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
676  if (!IsShadowFrame()) {
677    result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
678  }
679  return result;
680}
681
682static instrumentation::InstrumentationStackFrame& GetInstrumentationStackFrame(Thread* thread,
683                                                                                uint32_t depth) {
684  CHECK_LT(depth, thread->GetInstrumentationStack()->size());
685  return thread->GetInstrumentationStack()->at(depth);
686}
687
688static void AssertPcIsWithinQuickCode(ArtMethod* method, uintptr_t pc)
689    SHARED_REQUIRES(Locks::mutator_lock_) {
690  if (method->IsNative() || method->IsRuntimeMethod() || method->IsProxyMethod()) {
691    return;
692  }
693
694  if (pc == reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc())) {
695    return;
696  }
697
698  const void* code = method->GetEntryPointFromQuickCompiledCode();
699  if (code == GetQuickInstrumentationEntryPoint()) {
700    return;
701  }
702
703  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
704  if (class_linker->IsQuickToInterpreterBridge(code) ||
705      class_linker->IsQuickResolutionStub(code)) {
706    return;
707  }
708
709  // If we are the JIT then we may have just compiled the method after the
710  // IsQuickToInterpreterBridge check.
711  jit::Jit* const jit = Runtime::Current()->GetJit();
712  if (jit != nullptr && jit->GetCodeCache()->ContainsPc(code)) {
713    return;
714  }
715
716  uint32_t code_size = OatQuickMethodHeader::FromEntryPoint(code)->code_size_;
717  uintptr_t code_start = reinterpret_cast<uintptr_t>(code);
718  CHECK(code_start <= pc && pc <= (code_start + code_size))
719      << PrettyMethod(method)
720      << " pc=" << std::hex << pc
721      << " code_start=" << code_start
722      << " code_size=" << code_size;
723}
724
725void StackVisitor::SanityCheckFrame() const {
726  if (kIsDebugBuild) {
727    ArtMethod* method = GetMethod();
728    auto* declaring_class = method->GetDeclaringClass();
729    // Runtime methods have null declaring class.
730    if (!method->IsRuntimeMethod()) {
731      CHECK(declaring_class != nullptr);
732      CHECK_EQ(declaring_class->GetClass(), declaring_class->GetClass()->GetClass())
733          << declaring_class;
734    } else {
735      CHECK(declaring_class == nullptr);
736    }
737    Runtime* const runtime = Runtime::Current();
738    LinearAlloc* const linear_alloc = runtime->GetLinearAlloc();
739    if (!linear_alloc->Contains(method)) {
740      // Check class linker linear allocs.
741      mirror::Class* klass = method->GetDeclaringClass();
742      LinearAlloc* const class_linear_alloc = (klass != nullptr)
743          ? ClassLinker::GetAllocatorForClassLoader(klass->GetClassLoader())
744          : linear_alloc;
745      if (!class_linear_alloc->Contains(method)) {
746        // Check image space.
747        bool in_image = false;
748        for (auto& space : runtime->GetHeap()->GetContinuousSpaces()) {
749          if (space->IsImageSpace()) {
750            auto* image_space = space->AsImageSpace();
751            const auto& header = image_space->GetImageHeader();
752            const auto* methods = &header.GetMethodsSection();
753            if (methods->Contains(reinterpret_cast<const uint8_t*>(method) - image_space->Begin())) {
754              in_image = true;
755              break;
756            }
757          }
758        }
759        CHECK(in_image) << PrettyMethod(method) << " not in linear alloc or image";
760      }
761    }
762    if (cur_quick_frame_ != nullptr) {
763      AssertPcIsWithinQuickCode(method, cur_quick_frame_pc_);
764      // Frame sanity.
765      size_t frame_size = GetCurrentQuickFrameInfo().FrameSizeInBytes();
766      CHECK_NE(frame_size, 0u);
767      // A rough guess at an upper size we expect to see for a frame.
768      // 256 registers
769      // 2 words HandleScope overhead
770      // 3+3 register spills
771      // TODO: this seems architecture specific for the case of JNI frames.
772      // TODO: 083-compiler-regressions ManyFloatArgs shows this estimate is wrong.
773      // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
774      const size_t kMaxExpectedFrameSize = 2 * KB;
775      CHECK_LE(frame_size, kMaxExpectedFrameSize) << PrettyMethod(method);
776      size_t return_pc_offset = GetCurrentQuickFrameInfo().GetReturnPcOffset();
777      CHECK_LT(return_pc_offset, frame_size);
778    }
779  }
780}
781
782// Counts the number of references in the parameter list of the corresponding method.
783// Note: Thus does _not_ include "this" for non-static methods.
784static uint32_t GetNumberOfReferenceArgsWithoutReceiver(ArtMethod* method)
785    SHARED_REQUIRES(Locks::mutator_lock_) {
786  uint32_t shorty_len;
787  const char* shorty = method->GetShorty(&shorty_len);
788  uint32_t refs = 0;
789  for (uint32_t i = 1; i < shorty_len ; ++i) {
790    if (shorty[i] == 'L') {
791      refs++;
792    }
793  }
794  return refs;
795}
796
797QuickMethodFrameInfo StackVisitor::GetCurrentQuickFrameInfo() const {
798  if (cur_oat_quick_method_header_ != nullptr) {
799    return cur_oat_quick_method_header_->GetFrameInfo();
800  }
801
802  ArtMethod* method = GetMethod();
803  Runtime* runtime = Runtime::Current();
804
805  if (method->IsAbstract()) {
806    return runtime->GetCalleeSaveMethodFrameInfo(Runtime::kRefsAndArgs);
807  }
808
809  // This goes before IsProxyMethod since runtime methods have a null declaring class.
810  if (method->IsRuntimeMethod()) {
811    return runtime->GetRuntimeMethodFrameInfo(method);
812  }
813
814  if (method->IsProxyMethod()) {
815    // There is only one direct method of a proxy class: the constructor. A direct method is
816    // cloned from the original java.lang.reflect.Proxy and is executed as usual quick
817    // compiled method without any stubs. Therefore the method must have a OatQuickMethodHeader.
818    DCHECK(!method->IsDirect() && !method->IsConstructor())
819        << "Constructors of proxy classes must have a OatQuickMethodHeader";
820    return runtime->GetCalleeSaveMethodFrameInfo(Runtime::kRefsAndArgs);
821  }
822
823  // The only remaining case is if the method is native and uses the generic JNI stub.
824  DCHECK(method->IsNative());
825  ClassLinker* class_linker = runtime->GetClassLinker();
826  const void* entry_point = runtime->GetInstrumentation()->GetQuickCodeFor(method, sizeof(void*));
827  DCHECK(class_linker->IsQuickGenericJniStub(entry_point)) << PrettyMethod(method);
828  // Generic JNI frame.
829  uint32_t handle_refs = GetNumberOfReferenceArgsWithoutReceiver(method) + 1;
830  size_t scope_size = HandleScope::SizeOf(handle_refs);
831  QuickMethodFrameInfo callee_info = runtime->GetCalleeSaveMethodFrameInfo(Runtime::kRefsAndArgs);
832
833  // Callee saves + handle scope + method ref + alignment
834  // Note: -sizeof(void*) since callee-save frame stores a whole method pointer.
835  size_t frame_size = RoundUp(
836      callee_info.FrameSizeInBytes() - sizeof(void*) + sizeof(ArtMethod*) + scope_size,
837      kStackAlignment);
838  return QuickMethodFrameInfo(frame_size, callee_info.CoreSpillMask(), callee_info.FpSpillMask());
839}
840
841void StackVisitor::WalkStack(bool include_transitions) {
842  DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
843  CHECK_EQ(cur_depth_, 0U);
844  bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
845  uint32_t instrumentation_stack_depth = 0;
846  size_t inlined_frames_count = 0;
847
848  for (const ManagedStack* current_fragment = thread_->GetManagedStack();
849       current_fragment != nullptr; current_fragment = current_fragment->GetLink()) {
850    cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
851    cur_quick_frame_ = current_fragment->GetTopQuickFrame();
852    cur_quick_frame_pc_ = 0;
853    cur_oat_quick_method_header_ = nullptr;
854
855    if (cur_quick_frame_ != nullptr) {  // Handle quick stack frames.
856      // Can't be both a shadow and a quick fragment.
857      DCHECK(current_fragment->GetTopShadowFrame() == nullptr);
858      ArtMethod* method = *cur_quick_frame_;
859      while (method != nullptr) {
860        cur_oat_quick_method_header_ = method->GetOatQuickMethodHeader(cur_quick_frame_pc_);
861        SanityCheckFrame();
862
863        if ((walk_kind_ == StackWalkKind::kIncludeInlinedFrames)
864            && (cur_oat_quick_method_header_ != nullptr)
865            && cur_oat_quick_method_header_->IsOptimized()) {
866          CodeInfo code_info = cur_oat_quick_method_header_->GetOptimizedCodeInfo();
867          StackMapEncoding encoding = code_info.ExtractEncoding();
868          uint32_t native_pc_offset =
869              cur_oat_quick_method_header_->NativeQuickPcOffset(cur_quick_frame_pc_);
870          StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
871          if (stack_map.IsValid() && stack_map.HasInlineInfo(encoding)) {
872            InlineInfo inline_info = code_info.GetInlineInfoOf(stack_map, encoding);
873            DCHECK_EQ(current_inlining_depth_, 0u);
874            for (current_inlining_depth_ = inline_info.GetDepth();
875                 current_inlining_depth_ != 0;
876                 --current_inlining_depth_) {
877              bool should_continue = VisitFrame();
878              if (UNLIKELY(!should_continue)) {
879                return;
880              }
881              cur_depth_++;
882              inlined_frames_count++;
883            }
884          }
885        }
886
887        bool should_continue = VisitFrame();
888        if (UNLIKELY(!should_continue)) {
889          return;
890        }
891
892        QuickMethodFrameInfo frame_info = GetCurrentQuickFrameInfo();
893        if (context_ != nullptr) {
894          context_->FillCalleeSaves(reinterpret_cast<uint8_t*>(cur_quick_frame_), frame_info);
895        }
896        // Compute PC for next stack frame from return PC.
897        size_t frame_size = frame_info.FrameSizeInBytes();
898        size_t return_pc_offset = frame_size - sizeof(void*);
899        uint8_t* return_pc_addr = reinterpret_cast<uint8_t*>(cur_quick_frame_) + return_pc_offset;
900        uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
901
902        if (UNLIKELY(exit_stubs_installed)) {
903          // While profiling, the return pc is restored from the side stack, except when walking
904          // the stack for an exception where the side stack will be unwound in VisitFrame.
905          if (reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc()) == return_pc) {
906            const instrumentation::InstrumentationStackFrame& instrumentation_frame =
907                GetInstrumentationStackFrame(thread_, instrumentation_stack_depth);
908            instrumentation_stack_depth++;
909            if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
910              // Skip runtime save all callee frames which are used to deliver exceptions.
911            } else if (instrumentation_frame.interpreter_entry_) {
912              ArtMethod* callee = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
913              CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
914                                            << PrettyMethod(GetMethod());
915            } else {
916              CHECK_EQ(instrumentation_frame.method_, GetMethod())
917                  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
918                  << " Found: " << PrettyMethod(GetMethod());
919            }
920            if (num_frames_ != 0) {
921              // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
922              // recursion.
923              size_t frame_id = instrumentation::Instrumentation::ComputeFrameId(
924                  thread_,
925                  cur_depth_,
926                  inlined_frames_count);
927              CHECK_EQ(instrumentation_frame.frame_id_, frame_id);
928            }
929            return_pc = instrumentation_frame.return_pc_;
930          }
931        }
932
933        cur_quick_frame_pc_ = return_pc;
934        uint8_t* next_frame = reinterpret_cast<uint8_t*>(cur_quick_frame_) + frame_size;
935        cur_quick_frame_ = reinterpret_cast<ArtMethod**>(next_frame);
936
937        if (kDebugStackWalk) {
938          LOG(INFO) << PrettyMethod(method) << "@" << method << " size=" << frame_size
939              << std::boolalpha
940              << " optimized=" << (cur_oat_quick_method_header_ != nullptr &&
941                                   cur_oat_quick_method_header_->IsOptimized())
942              << " native=" << method->IsNative()
943              << std::noboolalpha
944              << " entrypoints=" << method->GetEntryPointFromQuickCompiledCode()
945              << "," << method->GetEntryPointFromJni()
946              << " next=" << *cur_quick_frame_;
947        }
948
949        cur_depth_++;
950        method = *cur_quick_frame_;
951      }
952    } else if (cur_shadow_frame_ != nullptr) {
953      do {
954        SanityCheckFrame();
955        bool should_continue = VisitFrame();
956        if (UNLIKELY(!should_continue)) {
957          return;
958        }
959        cur_depth_++;
960        cur_shadow_frame_ = cur_shadow_frame_->GetLink();
961      } while (cur_shadow_frame_ != nullptr);
962    }
963    if (include_transitions) {
964      bool should_continue = VisitFrame();
965      if (!should_continue) {
966        return;
967      }
968    }
969    cur_depth_++;
970  }
971  if (num_frames_ != 0) {
972    CHECK_EQ(cur_depth_, num_frames_);
973  }
974}
975
976void JavaFrameRootInfo::Describe(std::ostream& os) const {
977  const StackVisitor* visitor = stack_visitor_;
978  CHECK(visitor != nullptr);
979  os << "Type=" << GetType() << " thread_id=" << GetThreadId() << " location=" <<
980      visitor->DescribeLocation() << " vreg=" << vreg_;
981}
982
983int StackVisitor::GetVRegOffsetFromQuickCode(const DexFile::CodeItem* code_item,
984                                             uint32_t core_spills, uint32_t fp_spills,
985                                             size_t frame_size, int reg, InstructionSet isa) {
986  size_t pointer_size = InstructionSetPointerSize(isa);
987  if (kIsDebugBuild) {
988    auto* runtime = Runtime::Current();
989    if (runtime != nullptr) {
990      CHECK_EQ(runtime->GetClassLinker()->GetImagePointerSize(), pointer_size);
991    }
992  }
993  DCHECK_ALIGNED(frame_size, kStackAlignment);
994  DCHECK_NE(reg, -1);
995  int spill_size = POPCOUNT(core_spills) * GetBytesPerGprSpillLocation(isa)
996      + POPCOUNT(fp_spills) * GetBytesPerFprSpillLocation(isa)
997      + sizeof(uint32_t);  // Filler.
998  int num_regs = code_item->registers_size_ - code_item->ins_size_;
999  int temp_threshold = code_item->registers_size_;
1000  const int max_num_special_temps = 1;
1001  if (reg == temp_threshold) {
1002    // The current method pointer corresponds to special location on stack.
1003    return 0;
1004  } else if (reg >= temp_threshold + max_num_special_temps) {
1005    /*
1006     * Special temporaries may have custom locations and the logic above deals with that.
1007     * However, non-special temporaries are placed relative to the outs.
1008     */
1009    int temps_start = code_item->outs_size_ * sizeof(uint32_t) + pointer_size /* art method */;
1010    int relative_offset = (reg - (temp_threshold + max_num_special_temps)) * sizeof(uint32_t);
1011    return temps_start + relative_offset;
1012  }  else if (reg < num_regs) {
1013    int locals_start = frame_size - spill_size - num_regs * sizeof(uint32_t);
1014    return locals_start + (reg * sizeof(uint32_t));
1015  } else {
1016    // Handle ins.
1017    return frame_size + ((reg - num_regs) * sizeof(uint32_t)) + pointer_size /* art method */;
1018  }
1019}
1020
1021void LockCountData::AddMonitorInternal(Thread* self, mirror::Object* obj) {
1022  if (obj == nullptr) {
1023    return;
1024  }
1025
1026  // If there's an error during enter, we won't have locked the monitor. So check there's no
1027  // exception.
1028  if (self->IsExceptionPending()) {
1029    return;
1030  }
1031
1032  if (monitors_ == nullptr) {
1033    monitors_.reset(new std::vector<mirror::Object*>());
1034  }
1035  monitors_->push_back(obj);
1036}
1037
1038void LockCountData::RemoveMonitorInternal(Thread* self, const mirror::Object* obj) {
1039  if (obj == nullptr) {
1040    return;
1041  }
1042  bool found_object = false;
1043  if (monitors_ != nullptr) {
1044    // We need to remove one pointer to ref, as duplicates are used for counting recursive locks.
1045    // We arbitrarily choose the first one.
1046    auto it = std::find(monitors_->begin(), monitors_->end(), obj);
1047    if (it != monitors_->end()) {
1048      monitors_->erase(it);
1049      found_object = true;
1050    }
1051  }
1052  if (!found_object) {
1053    // The object wasn't found. Time for an IllegalMonitorStateException.
1054    // The order here isn't fully clear. Assume that any other pending exception is swallowed.
1055    // TODO: Maybe make already pending exception a suppressed exception.
1056    self->ClearException();
1057    self->ThrowNewExceptionF("Ljava/lang/IllegalMonitorStateException;",
1058                             "did not lock monitor on object of type '%s' before unlocking",
1059                             PrettyTypeOf(const_cast<mirror::Object*>(obj)).c_str());
1060  }
1061}
1062
1063// Helper to unlock a monitor. Must be NO_THREAD_SAFETY_ANALYSIS, as we can't statically show
1064// that the object was locked.
1065void MonitorExitHelper(Thread* self, mirror::Object* obj) NO_THREAD_SAFETY_ANALYSIS {
1066  DCHECK(self != nullptr);
1067  DCHECK(obj != nullptr);
1068  obj->MonitorExit(self);
1069}
1070
1071bool LockCountData::CheckAllMonitorsReleasedInternal(Thread* self) {
1072  DCHECK(self != nullptr);
1073  if (monitors_ != nullptr) {
1074    if (!monitors_->empty()) {
1075      // There may be an exception pending, if the method is terminating abruptly. Clear it.
1076      // TODO: Should we add this as a suppressed exception?
1077      self->ClearException();
1078
1079      // OK, there are monitors that are still locked. To enforce structured locking (and avoid
1080      // deadlocks) we unlock all of them before we raise the IllegalMonitorState exception.
1081      for (mirror::Object* obj : *monitors_) {
1082        MonitorExitHelper(self, obj);
1083        // If this raised an exception, ignore. TODO: Should we add this as suppressed
1084        // exceptions?
1085        if (self->IsExceptionPending()) {
1086          self->ClearException();
1087        }
1088      }
1089      // Raise an exception, just give the first object as the sample.
1090      mirror::Object* first = (*monitors_)[0];
1091      self->ThrowNewExceptionF("Ljava/lang/IllegalMonitorStateException;",
1092                               "did not unlock monitor on object of type '%s'",
1093                               PrettyTypeOf(first).c_str());
1094
1095      // To make sure this path is not triggered again, clean out the monitors.
1096      monitors_->clear();
1097
1098      return false;
1099    }
1100  }
1101  return true;
1102}
1103
1104}  // namespace art
1105