stack.cc revision a2d8ec6876325e89e5d82f5dbeca59f96ced3ec1 
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 NULL;
40  } else if (m->IsNative()) {
41    return GetVRegReference(0);
42  } else {
43    const DexFile::CodeItem* code_item = m->GetCodeItem();
44    CHECK(code_item != NULL) << 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 NULL;
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 != NULL;
62       current_fragment = current_fragment->GetLink()) {
63    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != NULL;
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 != NULL;
76       current_fragment = current_fragment->GetLink()) {
77    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != NULL;
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_(NULL),
89      cur_quick_frame_(NULL), 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_(NULL),
96      cur_quick_frame_(NULL), 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_ != NULL) {
103    return cur_shadow_frame_->GetDexPC();
104  } else if (cur_quick_frame_ != NULL) {
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 if (m->IsOptimized(GetInstructionSetPointerSize(
133      Runtime::Current()->GetInstructionSet()))) {
134    // TODO: Implement, currently only used for exceptions when jdwp is enabled.
135    UNIMPLEMENTED(WARNING)
136        << "StackVisitor::GetThisObject is unimplemented with the optimizing compiler";
137    return nullptr;
138  } else {
139    const DexFile::CodeItem* code_item = m->GetCodeItem();
140    if (code_item == nullptr) {
141      UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method: "
142          << PrettyMethod(m);
143      return nullptr;
144    } else {
145      uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
146      return reinterpret_cast<mirror::Object*>(GetVReg(m, reg, kReferenceVReg));
147    }
148  }
149}
150
151size_t StackVisitor::GetNativePcOffset() const {
152  DCHECK(!IsShadowFrame());
153  return GetMethod()->NativeQuickPcOffset(cur_quick_frame_pc_);
154}
155
156bool StackVisitor::GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind,
157                           uint32_t* val) const {
158  if (cur_quick_frame_ != nullptr) {
159    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
160    DCHECK(m == GetMethod());
161    if (m->IsOptimized(sizeof(void*))) {
162      return GetVRegFromOptimizedCode(m, vreg, kind, val);
163    } else {
164      return GetVRegFromQuickCode(m, vreg, kind, val);
165    }
166  } else {
167    DCHECK(cur_shadow_frame_ != nullptr);
168    *val = cur_shadow_frame_->GetVReg(vreg);
169    return true;
170  }
171}
172
173bool StackVisitor::GetVRegFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind,
174                                        uint32_t* val) const {
175  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
176  DCHECK(code_pointer != nullptr);
177  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
178  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
179  uint32_t vmap_offset;
180  // TODO: IsInContext stops before spotting floating point registers.
181  if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
182    bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
183    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
184    uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
185    return GetRegisterIfAccessible(reg, kind, val);
186  } else {
187    const DexFile::CodeItem* code_item = m->GetCodeItem();
188    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
189                                                      // its instructions?
190    *val = *GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
191                        frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
192    return true;
193  }
194}
195
196bool StackVisitor::GetVRegFromOptimizedCode(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind,
197                                            uint32_t* val) const {
198  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
199  DCHECK(code_pointer != nullptr);
200  uint32_t native_pc_offset = m->NativeQuickPcOffset(cur_quick_frame_pc_);
201  CodeInfo code_info = m->GetOptimizedCodeInfo();
202  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset);
203  const DexFile::CodeItem* code_item = m->GetCodeItem();
204  DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
205                                                    // its instructions?
206  DCHECK_LT(vreg, code_item->registers_size_);
207  DexRegisterMap dex_register_map =
208      code_info.GetDexRegisterMapOf(stack_map, code_item->registers_size_);
209  DexRegisterLocation::Kind location_kind = dex_register_map.GetLocationKind(vreg);
210  switch (location_kind) {
211    case DexRegisterLocation::Kind::kInStack: {
212      const int32_t offset = dex_register_map.GetStackOffsetInBytes(vreg);
213      const uint8_t* addr = reinterpret_cast<const uint8_t*>(cur_quick_frame_) + offset;
214      *val = *reinterpret_cast<const uint32_t*>(addr);
215      return true;
216    }
217    case DexRegisterLocation::Kind::kInRegister:
218    case DexRegisterLocation::Kind::kInFpuRegister: {
219      uint32_t reg = dex_register_map.GetMachineRegister(vreg);
220      return GetRegisterIfAccessible(reg, kind, val);
221    }
222    case DexRegisterLocation::Kind::kConstant:
223      *val = dex_register_map.GetConstant(vreg);
224      return true;
225    case DexRegisterLocation::Kind::kNone:
226      return false;
227    default:
228      LOG(FATAL)
229          << "Unexpected location kind"
230          << DexRegisterLocation::PrettyDescriptor(dex_register_map.GetLocationInternalKind(vreg));
231      UNREACHABLE();
232  }
233}
234
235bool StackVisitor::GetRegisterIfAccessible(uint32_t reg, VRegKind kind, uint32_t* val) const {
236  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
237  if (!IsAccessibleRegister(reg, is_float)) {
238    return false;
239  }
240  uintptr_t ptr_val = GetRegister(reg, is_float);
241  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
242  if (target64) {
243    const bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
244    const bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
245    int64_t value_long = static_cast<int64_t>(ptr_val);
246    if (wide_lo) {
247      ptr_val = static_cast<uintptr_t>(Low32Bits(value_long));
248    } else if (wide_hi) {
249      ptr_val = static_cast<uintptr_t>(High32Bits(value_long));
250    }
251  }
252  *val = ptr_val;
253  return true;
254}
255
256bool StackVisitor::GetVRegPair(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
257                               VRegKind kind_hi, uint64_t* val) const {
258  if (kind_lo == kLongLoVReg) {
259    DCHECK_EQ(kind_hi, kLongHiVReg);
260  } else if (kind_lo == kDoubleLoVReg) {
261    DCHECK_EQ(kind_hi, kDoubleHiVReg);
262  } else {
263    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
264    UNREACHABLE();
265  }
266  if (cur_quick_frame_ != nullptr) {
267    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
268    DCHECK(m == GetMethod());
269    if (m->IsOptimized(sizeof(void*))) {
270      return GetVRegPairFromOptimizedCode(m, vreg, kind_lo, kind_hi, val);
271    } else {
272      return GetVRegPairFromQuickCode(m, vreg, kind_lo, kind_hi, val);
273    }
274  } else {
275    DCHECK(cur_shadow_frame_ != nullptr);
276    *val = cur_shadow_frame_->GetVRegLong(vreg);
277    return true;
278  }
279}
280
281bool StackVisitor::GetVRegPairFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
282                                            VRegKind kind_hi, uint64_t* val) const {
283  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
284  DCHECK(code_pointer != nullptr);
285  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
286  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
287  uint32_t vmap_offset_lo, vmap_offset_hi;
288  // TODO: IsInContext stops before spotting floating point registers.
289  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
290      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
291    bool is_float = (kind_lo == kDoubleLoVReg);
292    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
293    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
294    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
295    return GetRegisterPairIfAccessible(reg_lo, reg_hi, kind_lo, val);
296  } else {
297    const DexFile::CodeItem* code_item = m->GetCodeItem();
298    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
299                                                      // its instructions?
300    uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
301                                 frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
302    *val = *reinterpret_cast<uint64_t*>(addr);
303    return true;
304  }
305}
306
307bool StackVisitor::GetVRegPairFromOptimizedCode(mirror::ArtMethod* m, uint16_t vreg,
308                                                VRegKind kind_lo, VRegKind kind_hi,
309                                                uint64_t* val) const {
310  uint32_t low_32bits;
311  uint32_t high_32bits;
312  bool success = GetVRegFromOptimizedCode(m, vreg, kind_lo, &low_32bits);
313  success &= GetVRegFromOptimizedCode(m, vreg + 1, kind_hi, &high_32bits);
314  if (success) {
315    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
316  }
317  return success;
318}
319
320bool StackVisitor::GetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
321                                               VRegKind kind_lo, uint64_t* val) const {
322  const bool is_float = (kind_lo == kDoubleLoVReg);
323  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
324    return false;
325  }
326  uintptr_t ptr_val_lo = GetRegister(reg_lo, is_float);
327  uintptr_t ptr_val_hi = GetRegister(reg_hi, is_float);
328  bool target64 = Is64BitInstructionSet(kRuntimeISA);
329  if (target64) {
330    int64_t value_long_lo = static_cast<int64_t>(ptr_val_lo);
331    int64_t value_long_hi = static_cast<int64_t>(ptr_val_hi);
332    ptr_val_lo = static_cast<uintptr_t>(Low32Bits(value_long_lo));
333    ptr_val_hi = static_cast<uintptr_t>(High32Bits(value_long_hi));
334  }
335  *val = (static_cast<uint64_t>(ptr_val_hi) << 32) | static_cast<uint32_t>(ptr_val_lo);
336  return true;
337}
338
339bool StackVisitor::SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
340                           VRegKind kind) {
341  if (cur_quick_frame_ != nullptr) {
342      DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
343      DCHECK(m == GetMethod());
344      if (m->IsOptimized(sizeof(void*))) {
345        return SetVRegFromOptimizedCode(m, vreg, new_value, kind);
346      } else {
347        return SetVRegFromQuickCode(m, vreg, new_value, kind);
348      }
349    } else {
350      cur_shadow_frame_->SetVReg(vreg, new_value);
351      return true;
352    }
353}
354
355bool StackVisitor::SetVRegFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
356                                        VRegKind kind) {
357  DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
358  DCHECK(m == GetMethod());
359  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
360  DCHECK(code_pointer != nullptr);
361  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
362  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
363  uint32_t vmap_offset;
364  // TODO: IsInContext stops before spotting floating point registers.
365  if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
366    bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
367    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
368    uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
369    return SetRegisterIfAccessible(reg, new_value, kind);
370  } else {
371    const DexFile::CodeItem* code_item = m->GetCodeItem();
372    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
373                                                      // its instructions?
374    uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
375                                 frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
376    *addr = new_value;
377    return true;
378  }
379}
380
381bool StackVisitor::SetVRegFromOptimizedCode(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
382                                            VRegKind kind) {
383  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
384  DCHECK(code_pointer != nullptr);
385  uint32_t native_pc_offset = m->NativeQuickPcOffset(cur_quick_frame_pc_);
386  CodeInfo code_info = m->GetOptimizedCodeInfo();
387  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset);
388  const DexFile::CodeItem* code_item = m->GetCodeItem();
389  DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
390                                                    // its instructions?
391  DCHECK_LT(vreg, code_item->registers_size_);
392  DexRegisterMap dex_register_map =
393      code_info.GetDexRegisterMapOf(stack_map, code_item->registers_size_);
394  DexRegisterLocation::Kind location_kind = dex_register_map.GetLocationKind(vreg);
395  uint32_t dex_pc = m->ToDexPc(cur_quick_frame_pc_, false);
396  switch (location_kind) {
397    case DexRegisterLocation::Kind::kInStack: {
398      const int32_t offset = dex_register_map.GetStackOffsetInBytes(vreg);
399      uint8_t* addr = reinterpret_cast<uint8_t*>(cur_quick_frame_) + offset;
400      *reinterpret_cast<uint32_t*>(addr) = new_value;
401      return true;
402    }
403    case DexRegisterLocation::Kind::kInRegister:
404    case DexRegisterLocation::Kind::kInFpuRegister: {
405      uint32_t reg = dex_register_map.GetMachineRegister(vreg);
406      return SetRegisterIfAccessible(reg, new_value, kind);
407    }
408    case DexRegisterLocation::Kind::kConstant:
409      LOG(ERROR) << StringPrintf("Cannot change value of DEX register v%u used as a constant at "
410                                 "DEX pc 0x%x (native pc 0x%x) of method %s",
411                                 vreg, dex_pc, native_pc_offset,
412                                 PrettyMethod(cur_quick_frame_->AsMirrorPtr()).c_str());
413      return false;
414    case DexRegisterLocation::Kind::kNone:
415      LOG(ERROR) << StringPrintf("No location for DEX register v%u at DEX pc 0x%x "
416                                 "(native pc 0x%x) of method %s",
417                                 vreg, dex_pc, native_pc_offset,
418                                 PrettyMethod(cur_quick_frame_->AsMirrorPtr()).c_str());
419      return false;
420    default:
421      LOG(FATAL) << StringPrintf("Unknown location for DEX register v%u at DEX pc 0x%x "
422                                 "(native pc 0x%x) of method %s",
423                                 vreg, dex_pc, native_pc_offset,
424                                 PrettyMethod(cur_quick_frame_->AsMirrorPtr()).c_str());
425      UNREACHABLE();
426  }
427}
428
429bool StackVisitor::SetRegisterIfAccessible(uint32_t reg, uint32_t new_value, VRegKind kind) {
430  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
431  if (!IsAccessibleRegister(reg, is_float)) {
432    return false;
433  }
434  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
435
436  // Create a new value that can hold both low 32 and high 32 bits, in
437  // case we are running 64 bits.
438  uintptr_t full_new_value = new_value;
439  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
440  if (target64) {
441    bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
442    bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
443    if (wide_lo || wide_hi) {
444      uintptr_t old_reg_val = GetRegister(reg, is_float);
445      uint64_t new_vreg_portion = static_cast<uint64_t>(new_value);
446      uint64_t old_reg_val_as_wide = static_cast<uint64_t>(old_reg_val);
447      uint64_t mask = 0xffffffff;
448      if (wide_lo) {
449        mask = mask << 32;
450      } else {
451        new_vreg_portion = new_vreg_portion << 32;
452      }
453      full_new_value = static_cast<uintptr_t>((old_reg_val_as_wide & mask) | new_vreg_portion);
454    }
455  }
456  SetRegister(reg, full_new_value, is_float);
457  return true;
458}
459
460bool StackVisitor::SetVRegPair(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
461                               VRegKind kind_lo, VRegKind kind_hi) {
462  if (kind_lo == kLongLoVReg) {
463    DCHECK_EQ(kind_hi, kLongHiVReg);
464  } else if (kind_lo == kDoubleLoVReg) {
465    DCHECK_EQ(kind_hi, kDoubleHiVReg);
466  } else {
467    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
468  }
469  if (cur_quick_frame_ != nullptr) {
470    DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
471    DCHECK(m == GetMethod());
472    if (m->IsOptimized(sizeof(void*))) {
473      return SetVRegPairFromOptimizedCode(m, vreg, new_value, kind_lo, kind_hi);
474    } else {
475      return SetVRegPairFromQuickCode(m, vreg, new_value, kind_lo, kind_hi);
476    }
477  } else {
478    DCHECK(cur_shadow_frame_ != nullptr);
479    cur_shadow_frame_->SetVRegLong(vreg, new_value);
480    return true;
481  }
482}
483
484bool StackVisitor::SetVRegPairFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
485                                            VRegKind kind_lo, VRegKind kind_hi) {
486  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
487  DCHECK(code_pointer != nullptr);
488  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
489  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
490  uint32_t vmap_offset_lo, vmap_offset_hi;
491  // TODO: IsInContext stops before spotting floating point registers.
492  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
493      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
494    bool is_float = (kind_lo == kDoubleLoVReg);
495    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
496    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
497    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
498    return SetRegisterPairIfAccessible(reg_lo, reg_hi, new_value, is_float);
499  } else {
500    const DexFile::CodeItem* code_item = m->GetCodeItem();
501    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
502                                                      // its instructions?
503    uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
504                                 frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
505    *reinterpret_cast<uint64_t*>(addr) = new_value;
506    return true;
507  }
508}
509
510bool StackVisitor::SetVRegPairFromOptimizedCode(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
511                                                VRegKind kind_lo, VRegKind kind_hi) {
512  uint32_t low_32bits = Low32Bits(new_value);
513  uint32_t high_32bits = High32Bits(new_value);
514  bool success = SetVRegFromOptimizedCode(m, vreg, low_32bits, kind_lo);
515  success &= SetVRegFromOptimizedCode(m, vreg + 1, high_32bits, kind_hi);
516  return success;
517}
518
519bool StackVisitor::SetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
520                                               uint64_t new_value, bool is_float) {
521  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
522    return false;
523  }
524  uintptr_t new_value_lo = static_cast<uintptr_t>(new_value & 0xFFFFFFFF);
525  uintptr_t new_value_hi = static_cast<uintptr_t>(new_value >> 32);
526  bool target64 = Is64BitInstructionSet(kRuntimeISA);
527  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
528  if (target64) {
529    DCHECK_EQ(reg_lo, reg_hi);
530    SetRegister(reg_lo, new_value, is_float);
531  } else {
532    SetRegister(reg_lo, new_value_lo, is_float);
533    SetRegister(reg_hi, new_value_hi, is_float);
534  }
535  return true;
536}
537
538bool StackVisitor::IsAccessibleGPR(uint32_t reg) const {
539  DCHECK(context_ != nullptr);
540  return context_->IsAccessibleGPR(reg);
541}
542
543uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
544  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
545  DCHECK(context_ != nullptr);
546  return context_->GetGPRAddress(reg);
547}
548
549uintptr_t StackVisitor::GetGPR(uint32_t reg) const {
550  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
551  DCHECK(context_ != nullptr);
552  return context_->GetGPR(reg);
553}
554
555void StackVisitor::SetGPR(uint32_t reg, uintptr_t value) {
556  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
557  DCHECK(context_ != nullptr);
558  context_->SetGPR(reg, value);
559}
560
561bool StackVisitor::IsAccessibleFPR(uint32_t reg) const {
562  DCHECK(context_ != nullptr);
563  return context_->IsAccessibleFPR(reg);
564}
565
566uintptr_t StackVisitor::GetFPR(uint32_t reg) const {
567  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
568  DCHECK(context_ != nullptr);
569  return context_->GetFPR(reg);
570}
571
572void StackVisitor::SetFPR(uint32_t reg, uintptr_t value) {
573  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
574  DCHECK(context_ != nullptr);
575  context_->SetFPR(reg, value);
576}
577
578uintptr_t StackVisitor::GetReturnPc() const {
579  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
580  DCHECK(sp != NULL);
581  uint8_t* pc_addr = sp + GetMethod()->GetReturnPcOffset().SizeValue();
582  return *reinterpret_cast<uintptr_t*>(pc_addr);
583}
584
585void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
586  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
587  CHECK(sp != NULL);
588  uint8_t* pc_addr = sp + GetMethod()->GetReturnPcOffset().SizeValue();
589  *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
590}
591
592size_t StackVisitor::ComputeNumFrames(Thread* thread) {
593  struct NumFramesVisitor : public StackVisitor {
594    explicit NumFramesVisitor(Thread* thread_in)
595        : StackVisitor(thread_in, NULL), frames(0) {}
596
597    bool VisitFrame() OVERRIDE {
598      frames++;
599      return true;
600    }
601
602    size_t frames;
603  };
604  NumFramesVisitor visitor(thread);
605  visitor.WalkStack(true);
606  return visitor.frames;
607}
608
609bool StackVisitor::GetNextMethodAndDexPc(mirror::ArtMethod** next_method, uint32_t* next_dex_pc) {
610  struct HasMoreFramesVisitor : public StackVisitor {
611    explicit HasMoreFramesVisitor(Thread* thread, size_t num_frames, size_t frame_height)
612        : StackVisitor(thread, nullptr, num_frames), frame_height_(frame_height),
613          found_frame_(false), has_more_frames_(false), next_method_(nullptr), next_dex_pc_(0) {
614    }
615
616    bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
617      if (found_frame_) {
618        mirror::ArtMethod* method = GetMethod();
619        if (method != nullptr && !method->IsRuntimeMethod()) {
620          has_more_frames_ = true;
621          next_method_ = method;
622          next_dex_pc_ = GetDexPc();
623          return false;  // End stack walk once next method is found.
624        }
625      } else if (GetFrameHeight() == frame_height_) {
626        found_frame_ = true;
627      }
628      return true;
629    }
630
631    size_t frame_height_;
632    bool found_frame_;
633    bool has_more_frames_;
634    mirror::ArtMethod* next_method_;
635    uint32_t next_dex_pc_;
636  };
637  HasMoreFramesVisitor visitor(thread_, GetNumFrames(), GetFrameHeight());
638  visitor.WalkStack(true);
639  *next_method = visitor.next_method_;
640  *next_dex_pc = visitor.next_dex_pc_;
641  return visitor.has_more_frames_;
642}
643
644void StackVisitor::DescribeStack(Thread* thread) {
645  struct DescribeStackVisitor : public StackVisitor {
646    explicit DescribeStackVisitor(Thread* thread_in)
647        : StackVisitor(thread_in, NULL) {}
648
649    bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
650      LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
651      return true;
652    }
653  };
654  DescribeStackVisitor visitor(thread);
655  visitor.WalkStack(true);
656}
657
658std::string StackVisitor::DescribeLocation() const {
659  std::string result("Visiting method '");
660  mirror::ArtMethod* m = GetMethod();
661  if (m == NULL) {
662    return "upcall";
663  }
664  result += PrettyMethod(m);
665  result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
666  if (!IsShadowFrame()) {
667    result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
668  }
669  return result;
670}
671
672static instrumentation::InstrumentationStackFrame& GetInstrumentationStackFrame(Thread* thread,
673                                                                                uint32_t depth) {
674  CHECK_LT(depth, thread->GetInstrumentationStack()->size());
675  return thread->GetInstrumentationStack()->at(depth);
676}
677
678void StackVisitor::SanityCheckFrame() const {
679  if (kIsDebugBuild) {
680    mirror::ArtMethod* method = GetMethod();
681    CHECK_EQ(method->GetClass(), mirror::ArtMethod::GetJavaLangReflectArtMethod());
682    if (cur_quick_frame_ != nullptr) {
683      method->AssertPcIsWithinQuickCode(cur_quick_frame_pc_);
684      // Frame sanity.
685      size_t frame_size = method->GetFrameSizeInBytes();
686      CHECK_NE(frame_size, 0u);
687      // A rough guess at an upper size we expect to see for a frame.
688      // 256 registers
689      // 2 words HandleScope overhead
690      // 3+3 register spills
691      // TODO: this seems architecture specific for the case of JNI frames.
692      // TODO: 083-compiler-regressions ManyFloatArgs shows this estimate is wrong.
693      // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
694      const size_t kMaxExpectedFrameSize = 2 * KB;
695      CHECK_LE(frame_size, kMaxExpectedFrameSize);
696      size_t return_pc_offset = method->GetReturnPcOffset().SizeValue();
697      CHECK_LT(return_pc_offset, frame_size);
698    }
699  }
700}
701
702void StackVisitor::WalkStack(bool include_transitions) {
703  DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
704  CHECK_EQ(cur_depth_, 0U);
705  bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
706  uint32_t instrumentation_stack_depth = 0;
707
708  for (const ManagedStack* current_fragment = thread_->GetManagedStack(); current_fragment != NULL;
709       current_fragment = current_fragment->GetLink()) {
710    cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
711    cur_quick_frame_ = current_fragment->GetTopQuickFrame();
712    cur_quick_frame_pc_ = 0;
713
714    if (cur_quick_frame_ != NULL) {  // Handle quick stack frames.
715      // Can't be both a shadow and a quick fragment.
716      DCHECK(current_fragment->GetTopShadowFrame() == NULL);
717      mirror::ArtMethod* method = cur_quick_frame_->AsMirrorPtr();
718      while (method != NULL) {
719        SanityCheckFrame();
720        bool should_continue = VisitFrame();
721        if (UNLIKELY(!should_continue)) {
722          return;
723        }
724
725        if (context_ != NULL) {
726          context_->FillCalleeSaves(*this);
727        }
728        size_t frame_size = method->GetFrameSizeInBytes();
729        // Compute PC for next stack frame from return PC.
730        size_t return_pc_offset = method->GetReturnPcOffset(frame_size).SizeValue();
731        uint8_t* return_pc_addr = reinterpret_cast<uint8_t*>(cur_quick_frame_) + return_pc_offset;
732        uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
733        if (UNLIKELY(exit_stubs_installed)) {
734          // While profiling, the return pc is restored from the side stack, except when walking
735          // the stack for an exception where the side stack will be unwound in VisitFrame.
736          if (reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc()) == return_pc) {
737            const instrumentation::InstrumentationStackFrame& instrumentation_frame =
738                GetInstrumentationStackFrame(thread_, instrumentation_stack_depth);
739            instrumentation_stack_depth++;
740            if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
741              // Skip runtime save all callee frames which are used to deliver exceptions.
742            } else if (instrumentation_frame.interpreter_entry_) {
743              mirror::ArtMethod* callee = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
744              CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
745                                            << PrettyMethod(GetMethod());
746            } else if (instrumentation_frame.method_ != GetMethod()) {
747              LOG(FATAL)  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
748                          << " Found: " << PrettyMethod(GetMethod());
749            }
750            if (num_frames_ != 0) {
751              // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
752              // recursion.
753              CHECK(instrumentation_frame.frame_id_ == GetFrameId())
754                    << "Expected: " << instrumentation_frame.frame_id_
755                    << " Found: " << GetFrameId();
756            }
757            return_pc = instrumentation_frame.return_pc_;
758          }
759        }
760        cur_quick_frame_pc_ = return_pc;
761        uint8_t* next_frame = reinterpret_cast<uint8_t*>(cur_quick_frame_) + frame_size;
762        cur_quick_frame_ = reinterpret_cast<StackReference<mirror::ArtMethod>*>(next_frame);
763        cur_depth_++;
764        method = cur_quick_frame_->AsMirrorPtr();
765      }
766    } else if (cur_shadow_frame_ != NULL) {
767      do {
768        SanityCheckFrame();
769        bool should_continue = VisitFrame();
770        if (UNLIKELY(!should_continue)) {
771          return;
772        }
773        cur_depth_++;
774        cur_shadow_frame_ = cur_shadow_frame_->GetLink();
775      } while (cur_shadow_frame_ != NULL);
776    }
777    if (include_transitions) {
778      bool should_continue = VisitFrame();
779      if (!should_continue) {
780        return;
781      }
782    }
783    cur_depth_++;
784  }
785  if (num_frames_ != 0) {
786    CHECK_EQ(cur_depth_, num_frames_);
787  }
788}
789
790void JavaFrameRootInfo::Describe(std::ostream& os) const {
791  const StackVisitor* visitor = stack_visitor_;
792  CHECK(visitor != nullptr);
793  os << "Type=" << GetType() << " thread_id=" << GetThreadId() << " location=" <<
794      visitor->DescribeLocation() << " vreg=" << vreg_;
795}
796
797}  // namespace art
798