stack.cc revision 0aa50ce2fb75bfc2e815a0c33adf9b049561923b 
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 = code_info.GetDexRegisterMapOf(stack_map,
208                                                                  code_item->registers_size_);
209  DexRegisterMap::LocationKind location_kind = dex_register_map.GetLocationKind(vreg);
210  switch (location_kind) {
211    case DexRegisterMap::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 DexRegisterMap::kInRegister:
218    case DexRegisterMap::kInFpuRegister: {
219      uint32_t reg = dex_register_map.GetMachineRegister(vreg);
220      return GetRegisterIfAccessible(reg, kind, val);
221    }
222    case DexRegisterMap::kConstant:
223      *val = dex_register_map.GetConstant(vreg);
224      return true;
225    case DexRegisterMap::kNone:
226      return false;
227  }
228  UNREACHABLE();
229  return false;
230}
231
232bool StackVisitor::GetRegisterIfAccessible(uint32_t reg, VRegKind kind, uint32_t* val) const {
233  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
234  if (!IsAccessibleRegister(reg, is_float)) {
235    return false;
236  }
237  uintptr_t ptr_val = GetRegister(reg, is_float);
238  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
239  if (target64) {
240    const bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
241    const bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
242    int64_t value_long = static_cast<int64_t>(ptr_val);
243    if (wide_lo) {
244      ptr_val = static_cast<uintptr_t>(Low32Bits(value_long));
245    } else if (wide_hi) {
246      ptr_val = static_cast<uintptr_t>(High32Bits(value_long));
247    }
248  }
249  *val = ptr_val;
250  return true;
251}
252
253bool StackVisitor::GetVRegPair(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
254                               VRegKind kind_hi, uint64_t* val) const {
255  if (kind_lo == kLongLoVReg) {
256    DCHECK_EQ(kind_hi, kLongHiVReg);
257  } else if (kind_lo == kDoubleLoVReg) {
258    DCHECK_EQ(kind_hi, kDoubleHiVReg);
259  } else {
260    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
261    UNREACHABLE();
262  }
263  if (cur_quick_frame_ != nullptr) {
264    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
265    DCHECK(m == GetMethod());
266    if (m->IsOptimized(sizeof(void*))) {
267      return GetVRegPairFromOptimizedCode(m, vreg, kind_lo, kind_hi, val);
268    } else {
269      return GetVRegPairFromQuickCode(m, vreg, kind_lo, kind_hi, val);
270    }
271  } else {
272    DCHECK(cur_shadow_frame_ != nullptr);
273    *val = cur_shadow_frame_->GetVRegLong(vreg);
274    return true;
275  }
276}
277
278bool StackVisitor::GetVRegPairFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
279                                            VRegKind kind_hi, uint64_t* val) const {
280  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
281  DCHECK(code_pointer != nullptr);
282  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
283  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
284  uint32_t vmap_offset_lo, vmap_offset_hi;
285  // TODO: IsInContext stops before spotting floating point registers.
286  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
287      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
288    bool is_float = (kind_lo == kDoubleLoVReg);
289    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
290    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
291    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
292    return GetRegisterPairIfAccessible(reg_lo, reg_hi, kind_lo, val);
293  } else {
294    const DexFile::CodeItem* code_item = m->GetCodeItem();
295    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
296                                                      // its instructions?
297    uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
298                                 frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
299    *val = *reinterpret_cast<uint64_t*>(addr);
300    return true;
301  }
302}
303
304bool StackVisitor::GetVRegPairFromOptimizedCode(mirror::ArtMethod* m, uint16_t vreg,
305                                                VRegKind kind_lo, VRegKind kind_hi,
306                                                uint64_t* val) const {
307  uint32_t low_32bits;
308  uint32_t high_32bits;
309  bool success = GetVRegFromOptimizedCode(m, vreg, kind_lo, &low_32bits);
310  success &= GetVRegFromOptimizedCode(m, vreg + 1, kind_hi, &high_32bits);
311  if (success) {
312    *val = (static_cast<uint64_t>(high_32bits) << 32) | static_cast<uint64_t>(low_32bits);
313  }
314  return success;
315}
316
317bool StackVisitor::GetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
318                                               VRegKind kind_lo, uint64_t* val) const {
319  const bool is_float = (kind_lo == kDoubleLoVReg);
320  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
321    return false;
322  }
323  uintptr_t ptr_val_lo = GetRegister(reg_lo, is_float);
324  uintptr_t ptr_val_hi = GetRegister(reg_hi, is_float);
325  bool target64 = Is64BitInstructionSet(kRuntimeISA);
326  if (target64) {
327    int64_t value_long_lo = static_cast<int64_t>(ptr_val_lo);
328    int64_t value_long_hi = static_cast<int64_t>(ptr_val_hi);
329    ptr_val_lo = static_cast<uintptr_t>(Low32Bits(value_long_lo));
330    ptr_val_hi = static_cast<uintptr_t>(High32Bits(value_long_hi));
331  }
332  *val = (static_cast<uint64_t>(ptr_val_hi) << 32) | static_cast<uint32_t>(ptr_val_lo);
333  return true;
334}
335
336bool StackVisitor::SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
337                           VRegKind kind) {
338  if (cur_quick_frame_ != nullptr) {
339      DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
340      DCHECK(m == GetMethod());
341      if (m->IsOptimized(sizeof(void*))) {
342        return SetVRegFromOptimizedCode(m, vreg, new_value, kind);
343      } else {
344        return SetVRegFromQuickCode(m, vreg, new_value, kind);
345      }
346    } else {
347      cur_shadow_frame_->SetVReg(vreg, new_value);
348      return true;
349    }
350}
351
352bool StackVisitor::SetVRegFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
353                                        VRegKind kind) {
354  DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
355  DCHECK(m == GetMethod());
356  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
357  DCHECK(code_pointer != nullptr);
358  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
359  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
360  uint32_t vmap_offset;
361  // TODO: IsInContext stops before spotting floating point registers.
362  if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
363    bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
364    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
365    uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
366    return SetRegisterIfAccessible(reg, new_value, kind);
367  } else {
368    const DexFile::CodeItem* code_item = m->GetCodeItem();
369    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
370                                                      // its instructions?
371    uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
372                                 frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
373    *addr = new_value;
374    return true;
375  }
376}
377
378bool StackVisitor::SetVRegFromOptimizedCode(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
379                                            VRegKind kind) {
380  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
381  DCHECK(code_pointer != nullptr);
382  uint32_t native_pc_offset = m->NativeQuickPcOffset(cur_quick_frame_pc_);
383  CodeInfo code_info = m->GetOptimizedCodeInfo();
384  StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset);
385  const DexFile::CodeItem* code_item = m->GetCodeItem();
386  DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
387                                                    // its instructions?
388  DCHECK_LT(vreg, code_item->registers_size_);
389  DexRegisterMap dex_register_map = code_info.GetDexRegisterMapOf(stack_map,
390                                                                  code_item->registers_size_);
391  DexRegisterMap::LocationKind location_kind = dex_register_map.GetLocationKind(vreg);
392  uint32_t dex_pc = m->ToDexPc(cur_quick_frame_pc_, false);
393  switch (location_kind) {
394    case DexRegisterMap::kInStack: {
395      const int32_t offset = dex_register_map.GetStackOffsetInBytes(vreg);
396      uint8_t* addr = reinterpret_cast<uint8_t*>(cur_quick_frame_) + offset;
397      *reinterpret_cast<uint32_t*>(addr) = new_value;
398      return true;
399    }
400    case DexRegisterMap::kInRegister:
401    case DexRegisterMap::kInFpuRegister: {
402      uint32_t reg = dex_register_map.GetMachineRegister(vreg);
403      return SetRegisterIfAccessible(reg, new_value, kind);
404    }
405    case DexRegisterMap::kConstant:
406      LOG(ERROR) << StringPrintf("Cannot change value of DEX register v%u used as a constant at "
407                                 "DEX pc 0x%x (native pc 0x%x) of method %s",
408                                 vreg, dex_pc, native_pc_offset,
409                                 PrettyMethod(cur_quick_frame_->AsMirrorPtr()).c_str());
410      return false;
411    case DexRegisterMap::kNone:
412      LOG(ERROR) << StringPrintf("No location for DEX register v%u at DEX pc 0x%x "
413                                 "(native pc 0x%x) of method %s",
414                                 vreg, dex_pc, native_pc_offset,
415                                 PrettyMethod(cur_quick_frame_->AsMirrorPtr()).c_str());
416      return false;
417    default:
418      LOG(FATAL) << StringPrintf("Unknown location for DEX register v%u at DEX pc 0x%x "
419                                 "(native pc 0x%x) of method %s",
420                                 vreg, dex_pc, native_pc_offset,
421                                 PrettyMethod(cur_quick_frame_->AsMirrorPtr()).c_str());
422      UNREACHABLE();
423  }
424}
425
426bool StackVisitor::SetRegisterIfAccessible(uint32_t reg, uint32_t new_value, VRegKind kind) {
427  const bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
428  if (!IsAccessibleRegister(reg, is_float)) {
429    return false;
430  }
431  const bool target64 = Is64BitInstructionSet(kRuntimeISA);
432
433  // Create a new value that can hold both low 32 and high 32 bits, in
434  // case we are running 64 bits.
435  uintptr_t full_new_value = new_value;
436  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
437  if (target64) {
438    bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
439    bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
440    if (wide_lo || wide_hi) {
441      uintptr_t old_reg_val = GetRegister(reg, is_float);
442      uint64_t new_vreg_portion = static_cast<uint64_t>(new_value);
443      uint64_t old_reg_val_as_wide = static_cast<uint64_t>(old_reg_val);
444      uint64_t mask = 0xffffffff;
445      if (wide_lo) {
446        mask = mask << 32;
447      } else {
448        new_vreg_portion = new_vreg_portion << 32;
449      }
450      full_new_value = static_cast<uintptr_t>((old_reg_val_as_wide & mask) | new_vreg_portion);
451    }
452  }
453  SetRegister(reg, full_new_value, is_float);
454  return true;
455}
456
457bool StackVisitor::SetVRegPair(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
458                               VRegKind kind_lo, VRegKind kind_hi) {
459  if (kind_lo == kLongLoVReg) {
460    DCHECK_EQ(kind_hi, kLongHiVReg);
461  } else if (kind_lo == kDoubleLoVReg) {
462    DCHECK_EQ(kind_hi, kDoubleHiVReg);
463  } else {
464    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
465  }
466  if (cur_quick_frame_ != nullptr) {
467    DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
468    DCHECK(m == GetMethod());
469    if (m->IsOptimized(sizeof(void*))) {
470      return SetVRegPairFromOptimizedCode(m, vreg, new_value, kind_lo, kind_hi);
471    } else {
472      return SetVRegPairFromQuickCode(m, vreg, new_value, kind_lo, kind_hi);
473    }
474  } else {
475    DCHECK(cur_shadow_frame_ != nullptr);
476    cur_shadow_frame_->SetVRegLong(vreg, new_value);
477    return true;
478  }
479}
480
481bool StackVisitor::SetVRegPairFromQuickCode(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
482                                            VRegKind kind_lo, VRegKind kind_hi) {
483  const void* code_pointer = m->GetQuickOatCodePointer(sizeof(void*));
484  DCHECK(code_pointer != nullptr);
485  const VmapTable vmap_table(m->GetVmapTable(code_pointer, sizeof(void*)));
486  QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
487  uint32_t vmap_offset_lo, vmap_offset_hi;
488  // TODO: IsInContext stops before spotting floating point registers.
489  if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
490      vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
491    bool is_float = (kind_lo == kDoubleLoVReg);
492    uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
493    uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
494    uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
495    return SetRegisterPairIfAccessible(reg_lo, reg_hi, new_value, is_float);
496  } else {
497    const DexFile::CodeItem* code_item = m->GetCodeItem();
498    DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
499                                                      // its instructions?
500    uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
501                                 frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
502    *reinterpret_cast<uint64_t*>(addr) = new_value;
503    return true;
504  }
505}
506
507bool StackVisitor::SetVRegPairFromOptimizedCode(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
508                                                VRegKind kind_lo, VRegKind kind_hi) {
509  uint32_t low_32bits = Low32Bits(new_value);
510  uint32_t high_32bits = High32Bits(new_value);
511  bool success = SetVRegFromOptimizedCode(m, vreg, low_32bits, kind_lo);
512  success &= SetVRegFromOptimizedCode(m, vreg + 1, high_32bits, kind_hi);
513  return success;
514}
515
516bool StackVisitor::SetRegisterPairIfAccessible(uint32_t reg_lo, uint32_t reg_hi,
517                                               uint64_t new_value, bool is_float) {
518  if (!IsAccessibleRegister(reg_lo, is_float) || !IsAccessibleRegister(reg_hi, is_float)) {
519    return false;
520  }
521  uintptr_t new_value_lo = static_cast<uintptr_t>(new_value & 0xFFFFFFFF);
522  uintptr_t new_value_hi = static_cast<uintptr_t>(new_value >> 32);
523  bool target64 = Is64BitInstructionSet(kRuntimeISA);
524  // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
525  if (target64) {
526    DCHECK_EQ(reg_lo, reg_hi);
527    SetRegister(reg_lo, new_value, is_float);
528  } else {
529    SetRegister(reg_lo, new_value_lo, is_float);
530    SetRegister(reg_hi, new_value_hi, is_float);
531  }
532  return true;
533}
534
535bool StackVisitor::IsAccessibleGPR(uint32_t reg) const {
536  DCHECK(context_ != nullptr);
537  return context_->IsAccessibleGPR(reg);
538}
539
540uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
541  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
542  DCHECK(context_ != nullptr);
543  return context_->GetGPRAddress(reg);
544}
545
546uintptr_t StackVisitor::GetGPR(uint32_t reg) const {
547  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
548  DCHECK(context_ != nullptr);
549  return context_->GetGPR(reg);
550}
551
552void StackVisitor::SetGPR(uint32_t reg, uintptr_t value) {
553  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
554  DCHECK(context_ != nullptr);
555  context_->SetGPR(reg, value);
556}
557
558bool StackVisitor::IsAccessibleFPR(uint32_t reg) const {
559  DCHECK(context_ != nullptr);
560  return context_->IsAccessibleFPR(reg);
561}
562
563uintptr_t StackVisitor::GetFPR(uint32_t reg) const {
564  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
565  DCHECK(context_ != nullptr);
566  return context_->GetFPR(reg);
567}
568
569void StackVisitor::SetFPR(uint32_t reg, uintptr_t value) {
570  DCHECK(cur_quick_frame_ != nullptr) << "This is a quick frame routine";
571  DCHECK(context_ != nullptr);
572  context_->SetFPR(reg, value);
573}
574
575uintptr_t StackVisitor::GetReturnPc() const {
576  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
577  DCHECK(sp != NULL);
578  uint8_t* pc_addr = sp + GetMethod()->GetReturnPcOffset().SizeValue();
579  return *reinterpret_cast<uintptr_t*>(pc_addr);
580}
581
582void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
583  uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
584  CHECK(sp != NULL);
585  uint8_t* pc_addr = sp + GetMethod()->GetReturnPcOffset().SizeValue();
586  *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
587}
588
589size_t StackVisitor::ComputeNumFrames(Thread* thread) {
590  struct NumFramesVisitor : public StackVisitor {
591    explicit NumFramesVisitor(Thread* thread_in)
592        : StackVisitor(thread_in, NULL), frames(0) {}
593
594    bool VisitFrame() OVERRIDE {
595      frames++;
596      return true;
597    }
598
599    size_t frames;
600  };
601  NumFramesVisitor visitor(thread);
602  visitor.WalkStack(true);
603  return visitor.frames;
604}
605
606bool StackVisitor::GetNextMethodAndDexPc(mirror::ArtMethod** next_method, uint32_t* next_dex_pc) {
607  struct HasMoreFramesVisitor : public StackVisitor {
608    explicit HasMoreFramesVisitor(Thread* thread, size_t num_frames, size_t frame_height)
609        : StackVisitor(thread, nullptr, num_frames), frame_height_(frame_height),
610          found_frame_(false), has_more_frames_(false), next_method_(nullptr), next_dex_pc_(0) {
611    }
612
613    bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
614      if (found_frame_) {
615        mirror::ArtMethod* method = GetMethod();
616        if (method != nullptr && !method->IsRuntimeMethod()) {
617          has_more_frames_ = true;
618          next_method_ = method;
619          next_dex_pc_ = GetDexPc();
620          return false;  // End stack walk once next method is found.
621        }
622      } else if (GetFrameHeight() == frame_height_) {
623        found_frame_ = true;
624      }
625      return true;
626    }
627
628    size_t frame_height_;
629    bool found_frame_;
630    bool has_more_frames_;
631    mirror::ArtMethod* next_method_;
632    uint32_t next_dex_pc_;
633  };
634  HasMoreFramesVisitor visitor(thread_, GetNumFrames(), GetFrameHeight());
635  visitor.WalkStack(true);
636  *next_method = visitor.next_method_;
637  *next_dex_pc = visitor.next_dex_pc_;
638  return visitor.has_more_frames_;
639}
640
641void StackVisitor::DescribeStack(Thread* thread) {
642  struct DescribeStackVisitor : public StackVisitor {
643    explicit DescribeStackVisitor(Thread* thread_in)
644        : StackVisitor(thread_in, NULL) {}
645
646    bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
647      LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
648      return true;
649    }
650  };
651  DescribeStackVisitor visitor(thread);
652  visitor.WalkStack(true);
653}
654
655std::string StackVisitor::DescribeLocation() const {
656  std::string result("Visiting method '");
657  mirror::ArtMethod* m = GetMethod();
658  if (m == NULL) {
659    return "upcall";
660  }
661  result += PrettyMethod(m);
662  result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
663  if (!IsShadowFrame()) {
664    result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
665  }
666  return result;
667}
668
669static instrumentation::InstrumentationStackFrame& GetInstrumentationStackFrame(Thread* thread,
670                                                                                uint32_t depth) {
671  CHECK_LT(depth, thread->GetInstrumentationStack()->size());
672  return thread->GetInstrumentationStack()->at(depth);
673}
674
675void StackVisitor::SanityCheckFrame() const {
676  if (kIsDebugBuild) {
677    mirror::ArtMethod* method = GetMethod();
678    CHECK_EQ(method->GetClass(), mirror::ArtMethod::GetJavaLangReflectArtMethod());
679    if (cur_quick_frame_ != nullptr) {
680      method->AssertPcIsWithinQuickCode(cur_quick_frame_pc_);
681      // Frame sanity.
682      size_t frame_size = method->GetFrameSizeInBytes();
683      CHECK_NE(frame_size, 0u);
684      // A rough guess at an upper size we expect to see for a frame.
685      // 256 registers
686      // 2 words HandleScope overhead
687      // 3+3 register spills
688      // TODO: this seems architecture specific for the case of JNI frames.
689      // TODO: 083-compiler-regressions ManyFloatArgs shows this estimate is wrong.
690      // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
691      const size_t kMaxExpectedFrameSize = 2 * KB;
692      CHECK_LE(frame_size, kMaxExpectedFrameSize);
693      size_t return_pc_offset = method->GetReturnPcOffset().SizeValue();
694      CHECK_LT(return_pc_offset, frame_size);
695    }
696  }
697}
698
699void StackVisitor::WalkStack(bool include_transitions) {
700  DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
701  CHECK_EQ(cur_depth_, 0U);
702  bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
703  uint32_t instrumentation_stack_depth = 0;
704
705  for (const ManagedStack* current_fragment = thread_->GetManagedStack(); current_fragment != NULL;
706       current_fragment = current_fragment->GetLink()) {
707    cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
708    cur_quick_frame_ = current_fragment->GetTopQuickFrame();
709    cur_quick_frame_pc_ = 0;
710
711    if (cur_quick_frame_ != NULL) {  // Handle quick stack frames.
712      // Can't be both a shadow and a quick fragment.
713      DCHECK(current_fragment->GetTopShadowFrame() == NULL);
714      mirror::ArtMethod* method = cur_quick_frame_->AsMirrorPtr();
715      while (method != NULL) {
716        SanityCheckFrame();
717        bool should_continue = VisitFrame();
718        if (UNLIKELY(!should_continue)) {
719          return;
720        }
721
722        if (context_ != NULL) {
723          context_->FillCalleeSaves(*this);
724        }
725        size_t frame_size = method->GetFrameSizeInBytes();
726        // Compute PC for next stack frame from return PC.
727        size_t return_pc_offset = method->GetReturnPcOffset(frame_size).SizeValue();
728        uint8_t* return_pc_addr = reinterpret_cast<uint8_t*>(cur_quick_frame_) + return_pc_offset;
729        uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
730        if (UNLIKELY(exit_stubs_installed)) {
731          // While profiling, the return pc is restored from the side stack, except when walking
732          // the stack for an exception where the side stack will be unwound in VisitFrame.
733          if (reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc()) == return_pc) {
734            const instrumentation::InstrumentationStackFrame& instrumentation_frame =
735                GetInstrumentationStackFrame(thread_, instrumentation_stack_depth);
736            instrumentation_stack_depth++;
737            if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
738              // Skip runtime save all callee frames which are used to deliver exceptions.
739            } else if (instrumentation_frame.interpreter_entry_) {
740              mirror::ArtMethod* callee = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
741              CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
742                                            << PrettyMethod(GetMethod());
743            } else if (instrumentation_frame.method_ != GetMethod()) {
744              LOG(FATAL)  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
745                          << " Found: " << PrettyMethod(GetMethod());
746            }
747            if (num_frames_ != 0) {
748              // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
749              // recursion.
750              CHECK(instrumentation_frame.frame_id_ == GetFrameId())
751                    << "Expected: " << instrumentation_frame.frame_id_
752                    << " Found: " << GetFrameId();
753            }
754            return_pc = instrumentation_frame.return_pc_;
755          }
756        }
757        cur_quick_frame_pc_ = return_pc;
758        uint8_t* next_frame = reinterpret_cast<uint8_t*>(cur_quick_frame_) + frame_size;
759        cur_quick_frame_ = reinterpret_cast<StackReference<mirror::ArtMethod>*>(next_frame);
760        cur_depth_++;
761        method = cur_quick_frame_->AsMirrorPtr();
762      }
763    } else if (cur_shadow_frame_ != NULL) {
764      do {
765        SanityCheckFrame();
766        bool should_continue = VisitFrame();
767        if (UNLIKELY(!should_continue)) {
768          return;
769        }
770        cur_depth_++;
771        cur_shadow_frame_ = cur_shadow_frame_->GetLink();
772      } while (cur_shadow_frame_ != NULL);
773    }
774    if (include_transitions) {
775      bool should_continue = VisitFrame();
776      if (!should_continue) {
777        return;
778      }
779    }
780    cur_depth_++;
781  }
782  if (num_frames_ != 0) {
783    CHECK_EQ(cur_depth_, num_frames_);
784  }
785}
786
787void JavaFrameRootInfo::Describe(std::ostream& os) const {
788  const StackVisitor* visitor = stack_visitor_;
789  CHECK(visitor != nullptr);
790  os << "Type=" << GetType() << " thread_id=" << GetThreadId() << " location=" <<
791      visitor->DescribeLocation() << " vreg=" << vreg_;
792}
793
794}  // namespace art
795