stack.cc revision 5dc158e9b6635b6c5d3916ae4094e8886feb4580 
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 "base/hex_dump.h"
20#include "mirror/art_method-inl.h"
21#include "mirror/class-inl.h"
22#include "mirror/object.h"
23#include "mirror/object-inl.h"
24#include "mirror/object_array-inl.h"
25#include "object_utils.h"
26#include "quick/quick_method_frame_info.h"
27#include "runtime.h"
28#include "thread.h"
29#include "thread_list.h"
30#include "throw_location.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
59ThrowLocation ShadowFrame::GetCurrentLocationForThrow() const {
60  return ThrowLocation(GetThisObject(), GetMethod(), GetDexPC());
61}
62
63size_t ManagedStack::NumJniShadowFrameReferences() const {
64  size_t count = 0;
65  for (const ManagedStack* current_fragment = this; current_fragment != NULL;
66       current_fragment = current_fragment->GetLink()) {
67    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != NULL;
68         current_frame = current_frame->GetLink()) {
69      if (current_frame->GetMethod()->IsNative()) {
70        // The JNI ShadowFrame only contains references. (For indirect reference.)
71        count += current_frame->NumberOfVRegs();
72      }
73    }
74  }
75  return count;
76}
77
78bool ManagedStack::ShadowFramesContain(StackReference<mirror::Object>* shadow_frame_entry) const {
79  for (const ManagedStack* current_fragment = this; current_fragment != NULL;
80       current_fragment = current_fragment->GetLink()) {
81    for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != NULL;
82         current_frame = current_frame->GetLink()) {
83      if (current_frame->Contains(shadow_frame_entry)) {
84        return true;
85      }
86    }
87  }
88  return false;
89}
90
91StackVisitor::StackVisitor(Thread* thread, Context* context)
92    : thread_(thread), cur_shadow_frame_(NULL),
93      cur_quick_frame_(NULL), cur_quick_frame_pc_(0), num_frames_(0), cur_depth_(0),
94      context_(context) {
95  DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
96}
97
98StackVisitor::StackVisitor(Thread* thread, Context* context, size_t num_frames)
99    : thread_(thread), cur_shadow_frame_(NULL),
100      cur_quick_frame_(NULL), cur_quick_frame_pc_(0), num_frames_(num_frames), cur_depth_(0),
101      context_(context) {
102  DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
103}
104
105uint32_t StackVisitor::GetDexPc(bool abort_on_failure) const {
106  if (cur_shadow_frame_ != NULL) {
107    return cur_shadow_frame_->GetDexPC();
108  } else if (cur_quick_frame_ != NULL) {
109    return GetMethod()->ToDexPc(cur_quick_frame_pc_, abort_on_failure);
110  } else {
111    return 0;
112  }
113}
114
115mirror::Object* StackVisitor::GetThisObject() const {
116  mirror::ArtMethod* m = GetMethod();
117  if (m->IsStatic()) {
118    return NULL;
119  } else if (m->IsNative()) {
120    if (cur_quick_frame_ != NULL) {
121      HandleScope* hs = reinterpret_cast<HandleScope*>(
122          reinterpret_cast<char*>(cur_quick_frame_) + m->GetHandleScopeOffsetInBytes());
123      return hs->GetReference(0);
124    } else {
125      return cur_shadow_frame_->GetVRegReference(0);
126    }
127  } else {
128    const DexFile::CodeItem* code_item = m->GetCodeItem();
129    if (code_item == NULL) {
130      UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method: "
131          << PrettyMethod(m);
132      return nullptr;
133    } else {
134      uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
135      return reinterpret_cast<mirror::Object*>(GetVReg(m, reg, kReferenceVReg));
136    }
137  }
138}
139
140size_t StackVisitor::GetNativePcOffset() const {
141  DCHECK(!IsShadowFrame());
142  return GetMethod()->NativePcOffset(cur_quick_frame_pc_);
143}
144
145bool StackVisitor::GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind,
146                           uint32_t* val) const {
147  if (cur_quick_frame_ != nullptr) {
148    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
149    DCHECK(m == GetMethod());
150    const void* code_pointer = m->GetQuickOatCodePointer();
151    DCHECK(code_pointer != nullptr);
152    const VmapTable vmap_table(m->GetVmapTable(code_pointer));
153    QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
154    uint32_t vmap_offset;
155    // TODO: IsInContext stops before spotting floating point registers.
156    if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
157      bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
158      uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
159      uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
160      uintptr_t ptr_val;
161      bool success = is_float ? GetFPR(reg, &ptr_val) : GetGPR(reg, &ptr_val);
162      if (!success) {
163        return false;
164      }
165      bool target64 = Is64BitInstructionSet(kRuntimeISA);
166      if (target64) {
167        bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
168        bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
169        int64_t value_long = static_cast<int64_t>(ptr_val);
170        if (wide_lo) {
171          ptr_val = static_cast<uintptr_t>(value_long & 0xFFFFFFFF);
172        } else if (wide_hi) {
173          ptr_val = static_cast<uintptr_t>(value_long >> 32);
174        }
175      }
176      *val = ptr_val;
177      return true;
178    } else {
179      const DexFile::CodeItem* code_item = m->GetCodeItem();
180      DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
181                                                        // its instructions?
182      *val = *GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
183                          frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
184      return true;
185    }
186  } else {
187    *val = cur_shadow_frame_->GetVReg(vreg);
188    return true;
189  }
190}
191
192bool StackVisitor::GetVRegPair(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
193                               VRegKind kind_hi, uint64_t* val) const {
194  if (kind_lo == kLongLoVReg) {
195    DCHECK_EQ(kind_hi, kLongHiVReg);
196  } else if (kind_lo == kDoubleLoVReg) {
197    DCHECK_EQ(kind_hi, kDoubleHiVReg);
198  } else {
199    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
200  }
201  if (cur_quick_frame_ != nullptr) {
202    DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
203    DCHECK(m == GetMethod());
204    const void* code_pointer = m->GetQuickOatCodePointer();
205    DCHECK(code_pointer != nullptr);
206    const VmapTable vmap_table(m->GetVmapTable(code_pointer));
207    QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
208    uint32_t vmap_offset_lo, vmap_offset_hi;
209    // TODO: IsInContext stops before spotting floating point registers.
210    if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
211        vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
212      bool is_float = (kind_lo == kDoubleLoVReg);
213      uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
214      uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
215      uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
216      uintptr_t ptr_val_lo, ptr_val_hi;
217      bool success = is_float ? GetFPR(reg_lo, &ptr_val_lo) : GetGPR(reg_lo, &ptr_val_lo);
218      success &= is_float ? GetFPR(reg_hi, &ptr_val_hi) : GetGPR(reg_hi, &ptr_val_hi);
219      if (!success) {
220        return false;
221      }
222      bool target64 = Is64BitInstructionSet(kRuntimeISA);
223      if (target64) {
224        int64_t value_long_lo = static_cast<int64_t>(ptr_val_lo);
225        int64_t value_long_hi = static_cast<int64_t>(ptr_val_hi);
226        ptr_val_lo = static_cast<uintptr_t>(value_long_lo & 0xFFFFFFFF);
227        ptr_val_hi = static_cast<uintptr_t>(value_long_hi >> 32);
228      }
229      *val = (static_cast<uint64_t>(ptr_val_hi) << 32) | static_cast<uint32_t>(ptr_val_lo);
230      return true;
231    } else {
232      const DexFile::CodeItem* code_item = m->GetCodeItem();
233      DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
234                                                        // its instructions?
235      uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
236                                   frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
237      *val = *reinterpret_cast<uint64_t*>(addr);
238      return true;
239    }
240  } else {
241    *val = cur_shadow_frame_->GetVRegLong(vreg);
242    return true;
243  }
244}
245
246bool StackVisitor::SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
247                           VRegKind kind) {
248  if (cur_quick_frame_ != nullptr) {
249    DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
250    DCHECK(m == GetMethod());
251    const void* code_pointer = m->GetQuickOatCodePointer();
252    DCHECK(code_pointer != nullptr);
253    const VmapTable vmap_table(m->GetVmapTable(code_pointer));
254    QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
255    uint32_t vmap_offset;
256    // TODO: IsInContext stops before spotting floating point registers.
257    if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
258      bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
259      uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
260      const uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
261      bool target64 = Is64BitInstructionSet(kRuntimeISA);
262      // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
263      if (target64) {
264        bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
265        bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
266        if (wide_lo || wide_hi) {
267          uintptr_t old_reg_val;
268          bool success = is_float ? GetFPR(reg, &old_reg_val) : GetGPR(reg, &old_reg_val);
269          if (!success) {
270            return false;
271          }
272          uint64_t new_vreg_portion = static_cast<uint64_t>(new_value);
273          uint64_t old_reg_val_as_wide = static_cast<uint64_t>(old_reg_val);
274          uint64_t mask = 0xffffffff;
275          if (wide_lo) {
276            mask = mask << 32;
277          } else {
278            new_vreg_portion = new_vreg_portion << 32;
279          }
280          new_value = static_cast<uintptr_t>((old_reg_val_as_wide & mask) | new_vreg_portion);
281        }
282      }
283      if (is_float) {
284        return SetFPR(reg, new_value);
285      } else {
286        return SetGPR(reg, new_value);
287      }
288    } else {
289      const DexFile::CodeItem* code_item = m->GetCodeItem();
290      DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
291                                                        // its instructions?
292      uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
293                                   frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
294      *addr = new_value;
295      return true;
296    }
297  } else {
298    cur_shadow_frame_->SetVReg(vreg, new_value);
299    return true;
300  }
301}
302
303bool StackVisitor::SetVRegPair(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
304                               VRegKind kind_lo, VRegKind kind_hi) {
305  if (kind_lo == kLongLoVReg) {
306    DCHECK_EQ(kind_hi, kLongHiVReg);
307  } else if (kind_lo == kDoubleLoVReg) {
308    DCHECK_EQ(kind_hi, kDoubleHiVReg);
309  } else {
310    LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
311  }
312  if (cur_quick_frame_ != nullptr) {
313    DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
314    DCHECK(m == GetMethod());
315    const void* code_pointer = m->GetQuickOatCodePointer();
316    DCHECK(code_pointer != nullptr);
317    const VmapTable vmap_table(m->GetVmapTable(code_pointer));
318    QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
319    uint32_t vmap_offset_lo, vmap_offset_hi;
320    // TODO: IsInContext stops before spotting floating point registers.
321    if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
322        vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
323      bool is_float = (kind_lo == kDoubleLoVReg);
324      uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
325      uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
326      uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
327      uintptr_t new_value_lo = static_cast<uintptr_t>(new_value & 0xFFFFFFFF);
328      uintptr_t new_value_hi = static_cast<uintptr_t>(new_value >> 32);
329      bool target64 = Is64BitInstructionSet(kRuntimeISA);
330      // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
331      if (target64) {
332        uintptr_t old_reg_val_lo, old_reg_val_hi;
333        bool success = is_float ? GetFPR(reg_lo, &old_reg_val_lo) : GetGPR(reg_lo, &old_reg_val_lo);
334        success &= is_float ? GetFPR(reg_hi, &old_reg_val_hi) : GetGPR(reg_hi, &old_reg_val_hi);
335        if (!success) {
336          return false;
337        }
338        uint64_t new_vreg_portion_lo = static_cast<uint64_t>(new_value_lo);
339        uint64_t new_vreg_portion_hi = static_cast<uint64_t>(new_value_hi) << 32;
340        uint64_t old_reg_val_lo_as_wide = static_cast<uint64_t>(old_reg_val_lo);
341        uint64_t old_reg_val_hi_as_wide = static_cast<uint64_t>(old_reg_val_hi);
342        uint64_t mask_lo = static_cast<uint64_t>(0xffffffff) << 32;
343        uint64_t mask_hi = 0xffffffff;
344        new_value_lo = static_cast<uintptr_t>((old_reg_val_lo_as_wide & mask_lo) | new_vreg_portion_lo);
345        new_value_hi = static_cast<uintptr_t>((old_reg_val_hi_as_wide & mask_hi) | new_vreg_portion_hi);
346      }
347      bool success = is_float ? SetFPR(reg_lo, new_value_lo) : SetGPR(reg_lo, new_value_lo);
348      success &= is_float ? SetFPR(reg_hi, new_value_hi) : SetGPR(reg_hi, new_value_hi);
349      return success;
350    } else {
351      const DexFile::CodeItem* code_item = m->GetCodeItem();
352      DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
353                                                        // its instructions?
354      uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
355                                   frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
356      *reinterpret_cast<uint64_t*>(addr) = new_value;
357      return true;
358    }
359  } else {
360    cur_shadow_frame_->SetVRegLong(vreg, new_value);
361    return true;
362  }
363}
364
365uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
366  DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
367  return context_->GetGPRAddress(reg);
368}
369
370bool StackVisitor::GetGPR(uint32_t reg, uintptr_t* val) const {
371  DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
372  return context_->GetGPR(reg, val);
373}
374
375bool StackVisitor::SetGPR(uint32_t reg, uintptr_t value) {
376  DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
377  return context_->SetGPR(reg, value);
378}
379
380bool StackVisitor::GetFPR(uint32_t reg, uintptr_t* val) const {
381  DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
382  return context_->GetFPR(reg, val);
383}
384
385bool StackVisitor::SetFPR(uint32_t reg, uintptr_t value) {
386  DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
387  return context_->SetFPR(reg, value);
388}
389
390uintptr_t StackVisitor::GetReturnPc() const {
391  byte* sp = reinterpret_cast<byte*>(GetCurrentQuickFrame());
392  DCHECK(sp != NULL);
393  byte* pc_addr = sp + GetMethod()->GetReturnPcOffsetInBytes();
394  return *reinterpret_cast<uintptr_t*>(pc_addr);
395}
396
397void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
398  byte* sp = reinterpret_cast<byte*>(GetCurrentQuickFrame());
399  CHECK(sp != NULL);
400  byte* pc_addr = sp + GetMethod()->GetReturnPcOffsetInBytes();
401  *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
402}
403
404size_t StackVisitor::ComputeNumFrames(Thread* thread) {
405  struct NumFramesVisitor : public StackVisitor {
406    explicit NumFramesVisitor(Thread* thread)
407        : StackVisitor(thread, NULL), frames(0) {}
408
409    bool VisitFrame() OVERRIDE {
410      frames++;
411      return true;
412    }
413
414    size_t frames;
415  };
416  NumFramesVisitor visitor(thread);
417  visitor.WalkStack(true);
418  return visitor.frames;
419}
420
421bool StackVisitor::GetNextMethodAndDexPc(mirror::ArtMethod** next_method, uint32_t* next_dex_pc) {
422  struct HasMoreFramesVisitor : public StackVisitor {
423    explicit HasMoreFramesVisitor(Thread* thread, size_t num_frames, size_t frame_height)
424        : StackVisitor(thread, nullptr, num_frames), frame_height_(frame_height),
425          found_frame_(false), has_more_frames_(false), next_method_(nullptr), next_dex_pc_(0) {
426    }
427
428    bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
429      if (found_frame_) {
430        mirror::ArtMethod* method = GetMethod();
431        if (method != nullptr && !method->IsRuntimeMethod()) {
432          has_more_frames_ = true;
433          next_method_ = method;
434          next_dex_pc_ = GetDexPc();
435          return false;  // End stack walk once next method is found.
436        }
437      } else if (GetFrameHeight() == frame_height_) {
438        found_frame_ = true;
439      }
440      return true;
441    }
442
443    size_t frame_height_;
444    bool found_frame_;
445    bool has_more_frames_;
446    mirror::ArtMethod* next_method_;
447    uint32_t next_dex_pc_;
448  };
449  HasMoreFramesVisitor visitor(thread_, GetNumFrames(), GetFrameHeight());
450  visitor.WalkStack(true);
451  *next_method = visitor.next_method_;
452  *next_dex_pc = visitor.next_dex_pc_;
453  return visitor.has_more_frames_;
454}
455
456void StackVisitor::DescribeStack(Thread* thread) {
457  struct DescribeStackVisitor : public StackVisitor {
458    explicit DescribeStackVisitor(Thread* thread)
459        : StackVisitor(thread, NULL) {}
460
461    bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
462      LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
463      return true;
464    }
465  };
466  DescribeStackVisitor visitor(thread);
467  visitor.WalkStack(true);
468}
469
470std::string StackVisitor::DescribeLocation() const {
471  std::string result("Visiting method '");
472  mirror::ArtMethod* m = GetMethod();
473  if (m == NULL) {
474    return "upcall";
475  }
476  result += PrettyMethod(m);
477  result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
478  if (!IsShadowFrame()) {
479    result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
480  }
481  return result;
482}
483
484instrumentation::InstrumentationStackFrame& StackVisitor::GetInstrumentationStackFrame(uint32_t depth) const {
485  CHECK_LT(depth, thread_->GetInstrumentationStack()->size());
486  return thread_->GetInstrumentationStack()->at(depth);
487}
488
489void StackVisitor::SanityCheckFrame() const {
490  if (kIsDebugBuild) {
491    mirror::ArtMethod* method = GetMethod();
492    CHECK_EQ(method->GetClass(), mirror::ArtMethod::GetJavaLangReflectArtMethod());
493    if (cur_quick_frame_ != nullptr) {
494      method->AssertPcIsWithinQuickCode(cur_quick_frame_pc_);
495      // Frame sanity.
496      size_t frame_size = method->GetFrameSizeInBytes();
497      CHECK_NE(frame_size, 0u);
498      // A rough guess at an upper size we expect to see for a frame.
499      // 256 registers
500      // 2 words HandleScope overhead
501      // 3+3 register spills
502      // TODO: this seems architecture specific for the case of JNI frames.
503      // TODO: 083-compiler-regressions ManyFloatArgs shows this estimate is wrong.
504      // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
505      const size_t kMaxExpectedFrameSize = 2 * KB;
506      CHECK_LE(frame_size, kMaxExpectedFrameSize);
507      size_t return_pc_offset = method->GetReturnPcOffsetInBytes();
508      CHECK_LT(return_pc_offset, frame_size);
509    }
510  }
511}
512
513void StackVisitor::WalkStack(bool include_transitions) {
514  DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
515  CHECK_EQ(cur_depth_, 0U);
516  bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
517  uint32_t instrumentation_stack_depth = 0;
518
519  for (const ManagedStack* current_fragment = thread_->GetManagedStack(); current_fragment != NULL;
520       current_fragment = current_fragment->GetLink()) {
521    cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
522    cur_quick_frame_ = current_fragment->GetTopQuickFrame();
523    cur_quick_frame_pc_ = current_fragment->GetTopQuickFramePc();
524
525    if (cur_quick_frame_ != NULL) {  // Handle quick stack frames.
526      // Can't be both a shadow and a quick fragment.
527      DCHECK(current_fragment->GetTopShadowFrame() == NULL);
528      mirror::ArtMethod* method = cur_quick_frame_->AsMirrorPtr();
529      while (method != NULL) {
530        SanityCheckFrame();
531        bool should_continue = VisitFrame();
532        if (UNLIKELY(!should_continue)) {
533          return;
534        }
535
536        if (context_ != NULL) {
537          context_->FillCalleeSaves(*this);
538        }
539        size_t frame_size = method->GetFrameSizeInBytes();
540        // Compute PC for next stack frame from return PC.
541        size_t return_pc_offset = method->GetReturnPcOffsetInBytes(frame_size);
542        byte* return_pc_addr = reinterpret_cast<byte*>(cur_quick_frame_) + return_pc_offset;
543        uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
544        if (UNLIKELY(exit_stubs_installed)) {
545          // While profiling, the return pc is restored from the side stack, except when walking
546          // the stack for an exception where the side stack will be unwound in VisitFrame.
547          if (GetQuickInstrumentationExitPc() == return_pc) {
548            const instrumentation::InstrumentationStackFrame& instrumentation_frame =
549                GetInstrumentationStackFrame(instrumentation_stack_depth);
550            instrumentation_stack_depth++;
551            if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
552              // Skip runtime save all callee frames which are used to deliver exceptions.
553            } else if (instrumentation_frame.interpreter_entry_) {
554              mirror::ArtMethod* callee = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
555              CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
556                                            << PrettyMethod(GetMethod());
557            } else if (instrumentation_frame.method_ != GetMethod()) {
558              LOG(FATAL)  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
559                          << " Found: " << PrettyMethod(GetMethod());
560            }
561            if (num_frames_ != 0) {
562              // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
563              // recursion.
564              CHECK(instrumentation_frame.frame_id_ == GetFrameId())
565                    << "Expected: " << instrumentation_frame.frame_id_
566                    << " Found: " << GetFrameId();
567            }
568            return_pc = instrumentation_frame.return_pc_;
569          }
570        }
571        cur_quick_frame_pc_ = return_pc;
572        byte* next_frame = reinterpret_cast<byte*>(cur_quick_frame_) + frame_size;
573        cur_quick_frame_ = reinterpret_cast<StackReference<mirror::ArtMethod>*>(next_frame);
574        cur_depth_++;
575        method = cur_quick_frame_->AsMirrorPtr();
576      }
577    } else if (cur_shadow_frame_ != NULL) {
578      do {
579        SanityCheckFrame();
580        bool should_continue = VisitFrame();
581        if (UNLIKELY(!should_continue)) {
582          return;
583        }
584        cur_depth_++;
585        cur_shadow_frame_ = cur_shadow_frame_->GetLink();
586      } while (cur_shadow_frame_ != NULL);
587    }
588    if (include_transitions) {
589      bool should_continue = VisitFrame();
590      if (!should_continue) {
591        return;
592      }
593    }
594    cur_depth_++;
595  }
596  if (num_frames_ != 0) {
597    CHECK_EQ(cur_depth_, num_frames_);
598  }
599}
600
601}  // namespace art
602