stack.cc revision 7cc56a1fe81475d5126785c45606dd491dec2d8c 
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 "base/hex_dump.h"
21#include "entrypoints/runtime_asm_entrypoints.h"
22#include "mirror/art_method-inl.h"
23#include "mirror/class-inl.h"
24#include "mirror/object.h"
25#include "mirror/object-inl.h"
26#include "mirror/object_array-inl.h"
27#include "quick/quick_method_frame_info.h"
28#include "runtime.h"
29#include "thread.h"
30#include "thread_list.h"
31#include "verify_object-inl.h"
32#include "vmap_table.h"
33
34namespace art {
35
36mirror::Object* ShadowFrame::GetThisObject() const {
37  mirror::ArtMethod* m = GetMethod();
38  if (m->IsStatic()) {
39    return nullptr;
40  } else if (m->IsNative()) {
41    return GetVRegReference(0);
42  } else {
43    const DexFile::CodeItem* code_item = m->GetCodeItem();
44    CHECK(code_item != nullptr) << PrettyMethod(m);
45    uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
46    return GetVRegReference(reg);
47  }
48}
49
50mirror::Object* ShadowFrame::GetThisObject(uint16_t num_ins) const {
51  mirror::ArtMethod* m = GetMethod();
52  if (m->IsStatic()) {
53    return nullptr;
54  } else {
55    return GetVRegReference(NumberOfVRegs() - num_ins);
56  }
57}
58
59size_t ManagedStack::NumJniShadowFrameReferences() const {
60  size_t count = 0;
61  for (const ManagedStack* current_fragment = this; current_fragment != nullptr;
62       current_fragment = current_fragment->GetLink()) {
63    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != nullptr;
64         current_frame = current_frame->GetLink()) {
65      if (current_frame->GetMethod()->IsNative()) {
66        // The JNI ShadowFrame only contains references. (For indirect reference.)
67        count += current_frame->NumberOfVRegs();
68      }
69    }
70  }
71  return count;
72}
73
74bool ManagedStack::ShadowFramesContain(StackReference<mirror::Object>* shadow_frame_entry) const {
75  for (const ManagedStack* current_fragment = this; current_fragment != nullptr;
76       current_fragment = current_fragment->GetLink()) {
77    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != nullptr;
78         current_frame = current_frame->GetLink()) {
79      if (current_frame->Contains(shadow_frame_entry)) {
80        return true;
81      }
82    }
83  }
84  return false;
85}
86
87StackVisitor::StackVisitor(Thread* thread, Context* context)
88    : thread_(thread), cur_shadow_frame_(nullptr),
89      cur_quick_frame_(nullptr), cur_quick_frame_pc_(0), num_frames_(0), cur_depth_(0),
90      context_(context) {
91  DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
92}
93
94StackVisitor::StackVisitor(Thread* thread, Context* context, size_t num_frames)
95    : thread_(thread), cur_shadow_frame_(nullptr),
96      cur_quick_frame_(nullptr), cur_quick_frame_pc_(0), num_frames_(num_frames), cur_depth_(0),
97      context_(context) {
98  DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
99}
100
101uint32_t StackVisitor::GetDexPc(bool abort_on_failure) const {
102  if (cur_shadow_frame_ != nullptr) {
103    return cur_shadow_frame_->GetDexPC();
104  } else if (cur_quick_frame_ != nullptr) {
105    return GetMethod()->ToDexPc(cur_quick_frame_pc_, abort_on_failure);
106  } else {
107    return 0;
108  }
109}
110
111extern "C" mirror::Object* artQuickGetProxyThisObject(StackReference<mirror::ArtMethod>* sp)
112    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
113
114mirror::Object* StackVisitor::GetThisObject() const {
115  mirror::ArtMethod* m = GetMethod();
116  if (m->IsStatic()) {
117    return nullptr;
118  } else if (m->IsNative()) {
119    if (cur_quick_frame_ != nullptr) {
120      HandleScope* hs = reinterpret_cast<HandleScope*>(
121          reinterpret_cast<char*>(cur_quick_frame_) + m->GetHandleScopeOffset().SizeValue());
122      return hs->GetReference(0);
123    } else {
124      return cur_shadow_frame_->GetVRegReference(0);
125    }
126  } else if (m->IsProxyMethod()) {
127    if (cur_quick_frame_ != nullptr) {
128      return artQuickGetProxyThisObject(cur_quick_frame_);
129    } else {
130      return cur_shadow_frame_->GetVRegReference(0);
131    }
132  } else {
133    const DexFile::CodeItem* code_item = m->GetCodeItem();
134    if (code_item == nullptr) {
135      UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method: "
136          << PrettyMethod(m);
137      return nullptr;
138    } else {
139      uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
140      uint32_t value = 0;
141      bool success = GetVReg(m, reg, kReferenceVReg, &value);
142      // We currently always guarantee the `this` object is live throughout the method.
143      CHECK(success) << "Failed to read the this object in " << PrettyMethod(m);
144      return reinterpret_cast<mirror::Object*>(value);
145    }
146  }
147}
148
149size_t StackVisitor::GetNativePcOffset() const {
150  DCHECK(!IsShadowFrame());
151  return GetMethod()->NativeQuickPcOffset(cur_quick_frame_pc_);
152}
153
154bool StackVisitor::GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind,
155                           uint32_t* val) const {
156  if (cur_quick_frame_ != nullptr) {
157    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
158    DCHECK(m == GetMethod());
159    if (m->IsOptimized(sizeof(void*))) {
160      return GetVRegFromOptimizedCode(m, vreg, kind, val);
161    } else {
162      return GetVRegFromQuickCode(m, vreg, kind, val);
163    }
164  } else {
165    DCHECK(cur_shadow_frame_ != nullptr);
166    *val = cur_shadow_frame_->GetVReg(vreg);
167    return true;
168  }
169}
170
171bool StackVisitor::GetVRegFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind,
172                                        uint32_t* val) const {
173  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
174  DCHECK(code_pointer != nullptr);
175  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
176  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
177  uint32_t vmap_offset;
178  // TODO: IsInContext stops before spotting floating point registers.
179  if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
180    bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
181    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
182    uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
183    return GetRegisterIfAccessible(reg, kind, val);
184  } else {
185    const DexFile::CodeItem* code_item = m->GetCodeItem();
186    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
187                                                      // its instructions?
188    *val = *GetVRegAddrFromQuickCode(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
189                                     frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
190    return true;
191  }
192}
193
194bool StackVisitor::GetVRegFromOptimizedCode(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind,
195                                            uint32_t* val) const {
196  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
197  DCHECK(code_pointer != nullptr);
198  uint32_t native_pc_offset = m->NativeQuickPcOffset(cur_quick_frame_pc_);
199  CodeInfo code_info = m->GetOptimizedCodeInfo();
200  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset);
201  const DexFile::CodeItem* code_item = m->GetCodeItem();
202  DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
203                                                    // its instructions?
204  DCHECK_LT(vreg, code_item->registers_size_);
205  uint16_t number_of_dex_registers = code_item->registers_size_;
206  DexRegisterMap dex_register_map =
207      code_info.GetDexRegisterMapOf(stack_map, number_of_dex_registers);
208  DexRegisterLocation::Kind location_kind =
209      dex_register_map.GetLocationKind(vreg, number_of_dex_registers, code_info);
210  switch (location_kind) {
211    case DexRegisterLocation::Kind::kInStack: {
212      const int32_t offset =
213          dex_register_map.GetStackOffsetInBytes(vreg, number_of_dex_registers, code_info);
214      const uint8_t* addr = reinterpret_cast<const uint8_t*>(cur_quick_frame_) + offset;
215      *val = *reinterpret_cast<const uint32_t*>(addr);
216      return true;
217    }
218    case DexRegisterLocation::Kind::kInRegister:
219    case DexRegisterLocation::Kind::kInFpuRegister: {
220      uint32_t reg = dex_register_map.GetMachineRegister(vreg, number_of_dex_registers, code_info);
221      return GetRegisterIfAccessible(reg, kind, val);
222    }
223    case DexRegisterLocation::Kind::kConstant:
224      *val = dex_register_map.GetConstant(vreg, number_of_dex_registers, code_info);
225      return true;
226    case DexRegisterLocation::Kind::kNone:
227      return false;
228    default:
229      LOG(FATAL)
230          << "Unexpected location kind"
231          << DexRegisterLocation::PrettyDescriptor(
232                dex_register_map.GetLocationInternalKind(vreg, number_of_dex_registers, code_info));
233      UNREACHABLE();
234  }
235}
236
237bool StackVisitor::GetRegisterIfAccessible(uint32_t reg, VRegKind kind, uint32_t* val) const {
238  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
239  if (!IsAccessibleRegister(reg, is_float)) {
240    return false;
241  }
242  uintptr_t ptr_val = GetRegister(reg, is_float);
243  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
244  if (target64) {
245    const bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
246    const bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
247    int64_t value_long = static_cast<int64_t>(ptr_val);
248    if (wide_lo) {
249      ptr_val = static_cast<uintptr_t>(Low32Bits(value_long));
250    } else if (wide_hi) {
251      ptr_val = static_cast<uintptr_t>(High32Bits(value_long));
252    }
253  }
254  *val = ptr_val;
255  return true;
256}
257
258bool StackVisitor::GetVRegPair(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
259                               VRegKind kind_hi, uint64_t* val) const {
260  if (kind_lo == kLongLoVReg) {
261    DCHECK_EQ(kind_hi, kLongHiVReg);
262  } else if (kind_lo == kDoubleLoVReg) {
263    DCHECK_EQ(kind_hi, kDoubleHiVReg);
264  } else {
265    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
266    UNREACHABLE();
267  }
268  if (cur_quick_frame_ != nullptr) {
269    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
270    DCHECK(m == GetMethod());
271    if (m->IsOptimized(sizeof(void*))) {
272      return GetVRegPairFromOptimizedCode(m, vreg, kind_lo, kind_hi, val);
273    } else {
274      return GetVRegPairFromQuickCode(m, vreg, kind_lo, kind_hi, val);
275    }
276  } else {
277    DCHECK(cur_shadow_frame_ != nullptr);
278    *val = cur_shadow_frame_->GetVRegLong(vreg);
279    return true;
280  }
281}
282
283bool StackVisitor::GetVRegPairFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
284                                            VRegKind kind_hi, uint64_t* val) const {
285  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
286  DCHECK(code_pointer != nullptr);
287  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
288  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
289  uint32_t vmap_offset_lo, vmap_offset_hi;
290  // TODO: IsInContext stops before spotting floating point registers.
291  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
292      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
293    bool is_float = (kind_lo == kDoubleLoVReg);
294    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
295    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
296    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
297    return GetRegisterPairIfAccessible(reg_lo, reg_hi, kind_lo, val);
298  } else {
299    const DexFile::CodeItem* code_item = m->GetCodeItem();
300    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
301                                                      // its instructions?
302    uint32_t* addr = GetVRegAddrFromQuickCode(
303        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
304        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
305    *val = *reinterpret_cast<uint64_t*>(addr);
306    return true;
307  }
308}
309
310bool StackVisitor::GetVRegPairFromOptimizedCode(mirror::ArtMethod* m, uint16_t vreg,
311                                                VRegKind kind_lo, VRegKind kind_hi,
312                                                uint64_t* val) const {
313  uint32_t low_32bits;
314  uint32_t high_32bits;
315  bool success = GetVRegFromOptimizedCode(m, vreg, kind_lo, &low_32bits);
316  success &= GetVRegFromOptimizedCode(m, vreg + 1, kind_hi, &high_32bits);
317  if (success) {
318    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
319  }
320  return success;
321}
322
323bool StackVisitor::GetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
324                                               VRegKind kind_lo, uint64_t* val) const {
325  const bool is_float = (kind_lo == kDoubleLoVReg);
326  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
327    return false;
328  }
329  uintptr_t ptr_val_lo = GetRegister(reg_lo, is_float);
330  uintptr_t ptr_val_hi = GetRegister(reg_hi, is_float);
331  bool target64 = Is64BitInstructionSet(kRuntimeISA);
332  if (target64) {
333    int64_t value_long_lo = static_cast<int64_t>(ptr_val_lo);
334    int64_t value_long_hi = static_cast<int64_t>(ptr_val_hi);
335    ptr_val_lo = static_cast<uintptr_t>(Low32Bits(value_long_lo));
336    ptr_val_hi = static_cast<uintptr_t>(High32Bits(value_long_hi));
337  }
338  *val = (static_cast<uint64_t>(ptr_val_hi) << 32) | static_cast<uint32_t>(ptr_val_lo);
339  return true;
340}
341
342bool StackVisitor::SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
343                           VRegKind kind) {
344  if (cur_quick_frame_ != nullptr) {
345      DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
346      DCHECK(m == GetMethod());
347      if (m->IsOptimized(sizeof(void*))) {
348        return false;
349      } else {
350        return SetVRegFromQuickCode(m, vreg, new_value, kind);
351      }
352    } else {
353      cur_shadow_frame_->SetVReg(vreg, new_value);
354      return true;
355    }
356}
357
358bool StackVisitor::SetVRegFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
359                                        VRegKind kind) {
360  DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
361  DCHECK(m == GetMethod());
362  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
363  DCHECK(code_pointer != nullptr);
364  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
365  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
366  uint32_t vmap_offset;
367  // TODO: IsInContext stops before spotting floating point registers.
368  if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
369    bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
370    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
371    uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
372    return SetRegisterIfAccessible(reg, new_value, kind);
373  } else {
374    const DexFile::CodeItem* code_item = m->GetCodeItem();
375    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
376                                                      // its instructions?
377    uint32_t* addr = GetVRegAddrFromQuickCode(
378        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
379        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
380    *addr = new_value;
381    return true;
382  }
383}
384
385bool StackVisitor::SetRegisterIfAccessible(uint32_t reg, uint32_t new_value, VRegKind kind) {
386  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
387  if (!IsAccessibleRegister(reg, is_float)) {
388    return false;
389  }
390  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
391
392  // Create a new value that can hold both low 32 and high 32 bits, in
393  // case we are running 64 bits.
394  uintptr_t full_new_value = new_value;
395  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
396  if (target64) {
397    bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
398    bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
399    if (wide_lo || wide_hi) {
400      uintptr_t old_reg_val = GetRegister(reg, is_float);
401      uint64_t new_vreg_portion = static_cast<uint64_t>(new_value);
402      uint64_t old_reg_val_as_wide = static_cast<uint64_t>(old_reg_val);
403      uint64_t mask = 0xffffffff;
404      if (wide_lo) {
405        mask = mask << 32;
406      } else {
407        new_vreg_portion = new_vreg_portion << 32;
408      }
409      full_new_value = static_cast<uintptr_t>((old_reg_val_as_wide & mask) | new_vreg_portion);
410    }
411  }
412  SetRegister(reg, full_new_value, is_float);
413  return true;
414}
415
416bool StackVisitor::SetVRegPair(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
417                               VRegKind kind_lo, VRegKind kind_hi) {
418  if (kind_lo == kLongLoVReg) {
419    DCHECK_EQ(kind_hi, kLongHiVReg);
420  } else if (kind_lo == kDoubleLoVReg) {
421    DCHECK_EQ(kind_hi, kDoubleHiVReg);
422  } else {
423    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
424  }
425  if (cur_quick_frame_ != nullptr) {
426    DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
427    DCHECK(m == GetMethod());
428    if (m->IsOptimized(sizeof(void*))) {
429      return false;
430    } else {
431      return SetVRegPairFromQuickCode(m, vreg, new_value, kind_lo, kind_hi);
432    }
433  } else {
434    DCHECK(cur_shadow_frame_ != nullptr);
435    cur_shadow_frame_->SetVRegLong(vreg, new_value);
436    return true;
437  }
438}
439
440bool StackVisitor::SetVRegPairFromQuickCode(
441    mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value, VRegKind kind_lo, VRegKind kind_hi) {
442  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
443  DCHECK(code_pointer != nullptr);
444  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
445  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
446  uint32_t vmap_offset_lo, vmap_offset_hi;
447  // TODO: IsInContext stops before spotting floating point registers.
448  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
449      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
450    bool is_float = (kind_lo == kDoubleLoVReg);
451    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
452    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
453    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
454    return SetRegisterPairIfAccessible(reg_lo, reg_hi, new_value, is_float);
455  } else {
456    const DexFile::CodeItem* code_item = m->GetCodeItem();
457    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be null or how would we compile
458                                                      // its instructions?
459    uint32_t* addr = GetVRegAddrFromQuickCode(
460        cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
461        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
462    *reinterpret_cast<uint64_t*>(addr) = new_value;
463    return true;
464  }
465}
466
467bool StackVisitor::SetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
468                                               uint64_t new_value, bool is_float) {
469  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
470    return false;
471  }
472  uintptr_t new_value_lo = static_cast<uintptr_t>(new_value & 0xFFFFFFFF);
473  uintptr_t new_value_hi = static_cast<uintptr_t>(new_value >> 32);
474  bool target64 = Is64BitInstructionSet(kRuntimeISA);
475  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
476  if (target64) {
477    DCHECK_EQ(reg_lo, reg_hi);
478    SetRegister(reg_lo, new_value, is_float);
479  } else {
480    SetRegister(reg_lo, new_value_lo, is_float);
481    SetRegister(reg_hi, new_value_hi, is_float);
482  }
483  return true;
484}
485
486bool StackVisitor::IsAccessibleGPR(uint32_t reg) const {
487  DCHECK(context_ != nullptr);
488  return context_->IsAccessibleGPR(reg);
489}
490
491uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
492  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
493  DCHECK(context_ != nullptr);
494  return context_->GetGPRAddress(reg);
495}
496
497uintptr_t StackVisitor::GetGPR(uint32_t reg) const {
498  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
499  DCHECK(context_ != nullptr);
500  return context_->GetGPR(reg);
501}
502
503void StackVisitor::SetGPR(uint32_t reg, uintptr_t value) {
504  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
505  DCHECK(context_ != nullptr);
506  context_->SetGPR(reg, value);
507}
508
509bool StackVisitor::IsAccessibleFPR(uint32_t reg) const {
510  DCHECK(context_ != nullptr);
511  return context_->IsAccessibleFPR(reg);
512}
513
514uintptr_t StackVisitor::GetFPR(uint32_t reg) const {
515  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
516  DCHECK(context_ != nullptr);
517  return context_->GetFPR(reg);
518}
519
520void StackVisitor::SetFPR(uint32_t reg, uintptr_t value) {
521  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
522  DCHECK(context_ != nullptr);
523  context_->SetFPR(reg, value);
524}
525
526uintptr_t StackVisitor::GetReturnPc() const {
527  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
528  DCHECK(sp != nullptr);
529  uint8_t* pc_addr = sp + GetMethod()->GetReturnPcOffset().SizeValue();
530  return *reinterpret_cast<uintptr_t*>(pc_addr);
531}
532
533void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
534  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
535  CHECK(sp != nullptr);
536  uint8_t* pc_addr = sp + GetMethod()->GetReturnPcOffset().SizeValue();
537  *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
538}
539
540size_t StackVisitor::ComputeNumFrames(Thread* thread) {
541  struct NumFramesVisitor : public StackVisitor {
542    explicit NumFramesVisitor(Thread* thread_in)
543        : StackVisitor(thread_in, nullptr), frames(0) {}
544
545    bool VisitFrame() OVERRIDE {
546      frames++;
547      return true;
548    }
549
550    size_t frames;
551  };
552  NumFramesVisitor visitor(thread);
553  visitor.WalkStack(true);
554  return visitor.frames;
555}
556
557bool StackVisitor::GetNextMethodAndDexPc(mirror::ArtMethod** next_method, uint32_t* next_dex_pc) {
558  struct HasMoreFramesVisitor : public StackVisitor {
559    explicit HasMoreFramesVisitor(Thread* thread, size_t num_frames, size_t frame_height)
560        : StackVisitor(thread, nullptr, num_frames), frame_height_(frame_height),
561          found_frame_(false), has_more_frames_(false), next_method_(nullptr), next_dex_pc_(0) {
562    }
563
564    bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
565      if (found_frame_) {
566        mirror::ArtMethod* method = GetMethod();
567        if (method != nullptr && !method->IsRuntimeMethod()) {
568          has_more_frames_ = true;
569          next_method_ = method;
570          next_dex_pc_ = GetDexPc();
571          return false;  // End stack walk once next method is found.
572        }
573      } else if (GetFrameHeight() == frame_height_) {
574        found_frame_ = true;
575      }
576      return true;
577    }
578
579    size_t frame_height_;
580    bool found_frame_;
581    bool has_more_frames_;
582    mirror::ArtMethod* next_method_;
583    uint32_t next_dex_pc_;
584  };
585  HasMoreFramesVisitor visitor(thread_, GetNumFrames(), GetFrameHeight());
586  visitor.WalkStack(true);
587  *next_method = visitor.next_method_;
588  *next_dex_pc = visitor.next_dex_pc_;
589  return visitor.has_more_frames_;
590}
591
592void StackVisitor::DescribeStack(Thread* thread) {
593  struct DescribeStackVisitor : public StackVisitor {
594    explicit DescribeStackVisitor(Thread* thread_in)
595        : StackVisitor(thread_in, nullptr) {}
596
597    bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
598      LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
599      return true;
600    }
601  };
602  DescribeStackVisitor visitor(thread);
603  visitor.WalkStack(true);
604}
605
606std::string StackVisitor::DescribeLocation() const {
607  std::string result("Visiting method '");
608  mirror::ArtMethod* m = GetMethod();
609  if (m == nullptr) {
610    return "upcall";
611  }
612  result += PrettyMethod(m);
613  result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
614  if (!IsShadowFrame()) {
615    result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
616  }
617  return result;
618}
619
620static instrumentation::InstrumentationStackFrame& GetInstrumentationStackFrame(Thread* thread,
621                                                                                uint32_t depth) {
622  CHECK_LT(depth, thread->GetInstrumentationStack()->size());
623  return thread->GetInstrumentationStack()->at(depth);
624}
625
626void StackVisitor::SanityCheckFrame() const {
627  if (kIsDebugBuild) {
628    mirror::ArtMethod* method = GetMethod();
629    CHECK_EQ(method->GetClass(), mirror::ArtMethod::GetJavaLangReflectArtMethod());
630    if (cur_quick_frame_ != nullptr) {
631      method->AssertPcIsWithinQuickCode(cur_quick_frame_pc_);
632      // Frame sanity.
633      size_t frame_size = method->GetFrameSizeInBytes();
634      CHECK_NE(frame_size, 0u);
635      // A rough guess at an upper size we expect to see for a frame.
636      // 256 registers
637      // 2 words HandleScope overhead
638      // 3+3 register spills
639      // TODO: this seems architecture specific for the case of JNI frames.
640      // TODO: 083-compiler-regressions ManyFloatArgs shows this estimate is wrong.
641      // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
642      const size_t kMaxExpectedFrameSize = 2 * KB;
643      CHECK_LE(frame_size, kMaxExpectedFrameSize);
644      size_t return_pc_offset = method->GetReturnPcOffset().SizeValue();
645      CHECK_LT(return_pc_offset, frame_size);
646    }
647  }
648}
649
650void StackVisitor::WalkStack(bool include_transitions) {
651  DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
652  CHECK_EQ(cur_depth_, 0U);
653  bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
654  uint32_t instrumentation_stack_depth = 0;
655
656  for (const ManagedStack* current_fragment = thread_->GetManagedStack();
657       current_fragment != nullptr; current_fragment = current_fragment->GetLink()) {
658    cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
659    cur_quick_frame_ = current_fragment->GetTopQuickFrame();
660    cur_quick_frame_pc_ = 0;
661
662    if (cur_quick_frame_ != nullptr) {  // Handle quick stack frames.
663      // Can't be both a shadow and a quick fragment.
664      DCHECK(current_fragment->GetTopShadowFrame() == nullptr);
665      mirror::ArtMethod* method = cur_quick_frame_->AsMirrorPtr();
666      while (method != nullptr) {
667        SanityCheckFrame();
668        bool should_continue = VisitFrame();
669        if (UNLIKELY(!should_continue)) {
670          return;
671        }
672
673        if (context_ != nullptr) {
674          context_->FillCalleeSaves(*this);
675        }
676        size_t frame_size = method->GetFrameSizeInBytes();
677        // Compute PC for next stack frame from return PC.
678        size_t return_pc_offset = method->GetReturnPcOffset(frame_size).SizeValue();
679        uint8_t* return_pc_addr = reinterpret_cast<uint8_t*>(cur_quick_frame_) + return_pc_offset;
680        uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
681        if (UNLIKELY(exit_stubs_installed)) {
682          // While profiling, the return pc is restored from the side stack, except when walking
683          // the stack for an exception where the side stack will be unwound in VisitFrame.
684          if (reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc()) == return_pc) {
685            const instrumentation::InstrumentationStackFrame& instrumentation_frame =
686                GetInstrumentationStackFrame(thread_, instrumentation_stack_depth);
687            instrumentation_stack_depth++;
688            if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
689              // Skip runtime save all callee frames which are used to deliver exceptions.
690            } else if (instrumentation_frame.interpreter_entry_) {
691              mirror::ArtMethod* callee =
692                  Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
693              CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
694                                            << PrettyMethod(GetMethod());
695            } else if (instrumentation_frame.method_ != GetMethod()) {
696              LOG(FATAL)  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
697                          << " Found: " << PrettyMethod(GetMethod());
698            }
699            if (num_frames_ != 0) {
700              // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
701              // recursion.
702              CHECK(instrumentation_frame.frame_id_ == GetFrameId())
703                    << "Expected: " << instrumentation_frame.frame_id_
704                    << " Found: " << GetFrameId();
705            }
706            return_pc = instrumentation_frame.return_pc_;
707          }
708        }
709        cur_quick_frame_pc_ = return_pc;
710        uint8_t* next_frame = reinterpret_cast<uint8_t*>(cur_quick_frame_) + frame_size;
711        cur_quick_frame_ = reinterpret_cast<StackReference<mirror::ArtMethod>*>(next_frame);
712        cur_depth_++;
713        method = cur_quick_frame_->AsMirrorPtr();
714      }
715    } else if (cur_shadow_frame_ != nullptr) {
716      do {
717        SanityCheckFrame();
718        bool should_continue = VisitFrame();
719        if (UNLIKELY(!should_continue)) {
720          return;
721        }
722        cur_depth_++;
723        cur_shadow_frame_ = cur_shadow_frame_->GetLink();
724      } while (cur_shadow_frame_ != nullptr);
725    }
726    if (include_transitions) {
727      bool should_continue = VisitFrame();
728      if (!should_continue) {
729        return;
730      }
731    }
732    cur_depth_++;
733  }
734  if (num_frames_ != 0) {
735    CHECK_EQ(cur_depth_, num_frames_);
736  }
737}
738
739void JavaFrameRootInfo::Describe(std::ostream& os) const {
740  const StackVisitor* visitor = stack_visitor_;
741  CHECK(visitor != nullptr);
742  os << "Type=" << GetType() << " thread_id=" << GetThreadId() << " location=" <<
743      visitor->DescribeLocation() << " vreg=" << vreg_;
744}
745
746}  // namespace art
747