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 "dex_file.h"
18
19#include <fcntl.h>
20#include <limits.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <sys/file.h>
25#include <sys/stat.h>
26#include <memory>
27
28#include "base/logging.h"
29#include "base/stringprintf.h"
30#include "class_linker.h"
31#include "dex_file-inl.h"
32#include "dex_file_verifier.h"
33#include "globals.h"
34#include "leb128.h"
35#include "mirror/art_field-inl.h"
36#include "mirror/art_method-inl.h"
37#include "mirror/string.h"
38#include "os.h"
39#include "safe_map.h"
40#include "ScopedFd.h"
41#include "handle_scope-inl.h"
42#include "thread.h"
43#include "utf-inl.h"
44#include "utils.h"
45#include "well_known_classes.h"
46#include "zip_archive.h"
47
48namespace art {
49
50const byte DexFile::kDexMagic[] = { 'd', 'e', 'x', '\n' };
51const byte DexFile::kDexMagicVersion[] = { '0', '3', '5', '\0' };
52
53static int OpenAndReadMagic(const char* filename, uint32_t* magic, std::string* error_msg) {
54  CHECK(magic != NULL);
55  ScopedFd fd(open(filename, O_RDONLY, 0));
56  if (fd.get() == -1) {
57    *error_msg = StringPrintf("Unable to open '%s' : %s", filename, strerror(errno));
58    return -1;
59  }
60  int n = TEMP_FAILURE_RETRY(read(fd.get(), magic, sizeof(*magic)));
61  if (n != sizeof(*magic)) {
62    *error_msg = StringPrintf("Failed to find magic in '%s'", filename);
63    return -1;
64  }
65  if (lseek(fd.get(), 0, SEEK_SET) != 0) {
66    *error_msg = StringPrintf("Failed to seek to beginning of file '%s' : %s", filename,
67                              strerror(errno));
68    return -1;
69  }
70  return fd.release();
71}
72
73bool DexFile::GetChecksum(const char* filename, uint32_t* checksum, std::string* error_msg) {
74  CHECK(checksum != NULL);
75  uint32_t magic;
76
77  // Strip ":...", which is the location
78  const char* zip_entry_name = kClassesDex;
79  const char* file_part = filename;
80  std::string file_part_storage;
81
82  if (DexFile::IsMultiDexLocation(filename)) {
83    file_part_storage = GetBaseLocation(filename);
84    file_part = file_part_storage.c_str();
85    zip_entry_name = filename + file_part_storage.size() + 1;
86    DCHECK_EQ(zip_entry_name[-1], kMultiDexSeparator);
87  }
88
89  ScopedFd fd(OpenAndReadMagic(file_part, &magic, error_msg));
90  if (fd.get() == -1) {
91    DCHECK(!error_msg->empty());
92    return false;
93  }
94  if (IsZipMagic(magic)) {
95    std::unique_ptr<ZipArchive> zip_archive(ZipArchive::OpenFromFd(fd.release(), filename, error_msg));
96    if (zip_archive.get() == NULL) {
97      *error_msg = StringPrintf("Failed to open zip archive '%s'", file_part);
98      return false;
99    }
100    std::unique_ptr<ZipEntry> zip_entry(zip_archive->Find(zip_entry_name, error_msg));
101    if (zip_entry.get() == NULL) {
102      *error_msg = StringPrintf("Zip archive '%s' doesn't contain %s (error msg: %s)", file_part,
103                                zip_entry_name, error_msg->c_str());
104      return false;
105    }
106    *checksum = zip_entry->GetCrc32();
107    return true;
108  }
109  if (IsDexMagic(magic)) {
110    std::unique_ptr<const DexFile> dex_file(DexFile::OpenFile(fd.release(), filename, false, error_msg));
111    if (dex_file.get() == NULL) {
112      return false;
113    }
114    *checksum = dex_file->GetHeader().checksum_;
115    return true;
116  }
117  *error_msg = StringPrintf("Expected valid zip or dex file: '%s'", filename);
118  return false;
119}
120
121bool DexFile::Open(const char* filename, const char* location, std::string* error_msg,
122                   std::vector<const DexFile*>* dex_files) {
123  uint32_t magic;
124  ScopedFd fd(OpenAndReadMagic(filename, &magic, error_msg));
125  if (fd.get() == -1) {
126    DCHECK(!error_msg->empty());
127    return false;
128  }
129  if (IsZipMagic(magic)) {
130    return DexFile::OpenZip(fd.release(), location, error_msg, dex_files);
131  }
132  if (IsDexMagic(magic)) {
133    std::unique_ptr<const DexFile> dex_file(DexFile::OpenFile(fd.release(), location, true,
134                                                              error_msg));
135    if (dex_file.get() != nullptr) {
136      dex_files->push_back(dex_file.release());
137      return true;
138    } else {
139      return false;
140    }
141  }
142  *error_msg = StringPrintf("Expected valid zip or dex file: '%s'", filename);
143  return false;
144}
145
146int DexFile::GetPermissions() const {
147  if (mem_map_.get() == NULL) {
148    return 0;
149  } else {
150    return mem_map_->GetProtect();
151  }
152}
153
154bool DexFile::IsReadOnly() const {
155  return GetPermissions() == PROT_READ;
156}
157
158bool DexFile::EnableWrite() const {
159  CHECK(IsReadOnly());
160  if (mem_map_.get() == NULL) {
161    return false;
162  } else {
163    return mem_map_->Protect(PROT_READ | PROT_WRITE);
164  }
165}
166
167bool DexFile::DisableWrite() const {
168  CHECK(!IsReadOnly());
169  if (mem_map_.get() == NULL) {
170    return false;
171  } else {
172    return mem_map_->Protect(PROT_READ);
173  }
174}
175
176const DexFile* DexFile::OpenFile(int fd, const char* location, bool verify,
177                                 std::string* error_msg) {
178  CHECK(location != nullptr);
179  std::unique_ptr<MemMap> map;
180  {
181    ScopedFd delayed_close(fd);
182    struct stat sbuf;
183    memset(&sbuf, 0, sizeof(sbuf));
184    if (fstat(fd, &sbuf) == -1) {
185      *error_msg = StringPrintf("DexFile: fstat '%s' failed: %s", location, strerror(errno));
186      return nullptr;
187    }
188    if (S_ISDIR(sbuf.st_mode)) {
189      *error_msg = StringPrintf("Attempt to mmap directory '%s'", location);
190      return nullptr;
191    }
192    size_t length = sbuf.st_size;
193    map.reset(MemMap::MapFile(length, PROT_READ, MAP_PRIVATE, fd, 0, location, error_msg));
194    if (map.get() == nullptr) {
195      DCHECK(!error_msg->empty());
196      return nullptr;
197    }
198  }
199
200  if (map->Size() < sizeof(DexFile::Header)) {
201    *error_msg = StringPrintf(
202        "DexFile: failed to open dex file '%s' that is too short to have a header", location);
203    return nullptr;
204  }
205
206  const Header* dex_header = reinterpret_cast<const Header*>(map->Begin());
207
208  const DexFile* dex_file = OpenMemory(location, dex_header->checksum_, map.release(), error_msg);
209  if (dex_file == nullptr) {
210    *error_msg = StringPrintf("Failed to open dex file '%s' from memory: %s", location,
211                              error_msg->c_str());
212    return nullptr;
213  }
214
215  if (verify && !DexFileVerifier::Verify(dex_file, dex_file->Begin(), dex_file->Size(), location,
216                                         error_msg)) {
217    return nullptr;
218  }
219
220  return dex_file;
221}
222
223const char* DexFile::kClassesDex = "classes.dex";
224
225bool DexFile::OpenZip(int fd, const std::string& location, std::string* error_msg,
226                      std::vector<const  DexFile*>* dex_files) {
227  std::unique_ptr<ZipArchive> zip_archive(ZipArchive::OpenFromFd(fd, location.c_str(), error_msg));
228  if (zip_archive.get() == nullptr) {
229    DCHECK(!error_msg->empty());
230    return false;
231  }
232  return DexFile::OpenFromZip(*zip_archive, location, error_msg, dex_files);
233}
234
235const DexFile* DexFile::OpenMemory(const std::string& location,
236                                   uint32_t location_checksum,
237                                   MemMap* mem_map,
238                                   std::string* error_msg) {
239  return OpenMemory(mem_map->Begin(),
240                    mem_map->Size(),
241                    location,
242                    location_checksum,
243                    mem_map,
244                    nullptr,
245                    error_msg);
246}
247
248const DexFile* DexFile::Open(const ZipArchive& zip_archive, const char* entry_name,
249                             const std::string& location, std::string* error_msg,
250                             ZipOpenErrorCode* error_code) {
251  CHECK(!location.empty());
252  std::unique_ptr<ZipEntry> zip_entry(zip_archive.Find(entry_name, error_msg));
253  if (zip_entry.get() == NULL) {
254    *error_code = ZipOpenErrorCode::kEntryNotFound;
255    return nullptr;
256  }
257  std::unique_ptr<MemMap> map(zip_entry->ExtractToMemMap(location.c_str(), entry_name, error_msg));
258  if (map.get() == NULL) {
259    *error_msg = StringPrintf("Failed to extract '%s' from '%s': %s", entry_name, location.c_str(),
260                              error_msg->c_str());
261    *error_code = ZipOpenErrorCode::kExtractToMemoryError;
262    return nullptr;
263  }
264  std::unique_ptr<const DexFile> dex_file(OpenMemory(location, zip_entry->GetCrc32(), map.release(),
265                                               error_msg));
266  if (dex_file.get() == nullptr) {
267    *error_msg = StringPrintf("Failed to open dex file '%s' from memory: %s", location.c_str(),
268                              error_msg->c_str());
269    *error_code = ZipOpenErrorCode::kDexFileError;
270    return nullptr;
271  }
272  if (!dex_file->DisableWrite()) {
273    *error_msg = StringPrintf("Failed to make dex file '%s' read only", location.c_str());
274    *error_code = ZipOpenErrorCode::kMakeReadOnlyError;
275    return nullptr;
276  }
277  CHECK(dex_file->IsReadOnly()) << location;
278  if (!DexFileVerifier::Verify(dex_file.get(), dex_file->Begin(), dex_file->Size(),
279                               location.c_str(), error_msg)) {
280    *error_code = ZipOpenErrorCode::kVerifyError;
281    return nullptr;
282  }
283  *error_code = ZipOpenErrorCode::kNoError;
284  return dex_file.release();
285}
286
287bool DexFile::OpenFromZip(const ZipArchive& zip_archive, const std::string& location,
288                          std::string* error_msg, std::vector<const DexFile*>* dex_files) {
289  ZipOpenErrorCode error_code;
290  std::unique_ptr<const DexFile> dex_file(Open(zip_archive, kClassesDex, location, error_msg,
291                                               &error_code));
292  if (dex_file.get() == nullptr) {
293    return false;
294  } else {
295    // Had at least classes.dex.
296    dex_files->push_back(dex_file.release());
297
298    // Now try some more.
299    size_t i = 2;
300
301    // We could try to avoid std::string allocations by working on a char array directly. As we
302    // do not expect a lot of iterations, this seems too involved and brittle.
303
304    while (i < 100) {
305      std::string name = StringPrintf("classes%zu.dex", i);
306      std::string fake_location = location + kMultiDexSeparator + name;
307      std::unique_ptr<const DexFile> next_dex_file(Open(zip_archive, name.c_str(), fake_location,
308                                                        error_msg, &error_code));
309      if (next_dex_file.get() == nullptr) {
310        if (error_code != ZipOpenErrorCode::kEntryNotFound) {
311          LOG(WARNING) << error_msg;
312        }
313        break;
314      } else {
315        dex_files->push_back(next_dex_file.release());
316      }
317
318      i++;
319    }
320
321    return true;
322  }
323}
324
325
326const DexFile* DexFile::OpenMemory(const byte* base,
327                                   size_t size,
328                                   const std::string& location,
329                                   uint32_t location_checksum,
330                                   MemMap* mem_map,
331                                   const OatFile* oat_file,
332                                   std::string* error_msg) {
333  CHECK_ALIGNED(base, 4);  // various dex file structures must be word aligned
334  std::unique_ptr<DexFile> dex_file(
335      new DexFile(base, size, location, location_checksum, mem_map, oat_file));
336  if (!dex_file->Init(error_msg)) {
337    return nullptr;
338  } else {
339    return dex_file.release();
340  }
341}
342
343DexFile::DexFile(const byte* base, size_t size,
344                 const std::string& location,
345                 uint32_t location_checksum,
346                 MemMap* mem_map,
347                 const OatFile* oat_file)
348    : begin_(base),
349      size_(size),
350      location_(location),
351      location_checksum_(location_checksum),
352      mem_map_(mem_map),
353      header_(reinterpret_cast<const Header*>(base)),
354      string_ids_(reinterpret_cast<const StringId*>(base + header_->string_ids_off_)),
355      type_ids_(reinterpret_cast<const TypeId*>(base + header_->type_ids_off_)),
356      field_ids_(reinterpret_cast<const FieldId*>(base + header_->field_ids_off_)),
357      method_ids_(reinterpret_cast<const MethodId*>(base + header_->method_ids_off_)),
358      proto_ids_(reinterpret_cast<const ProtoId*>(base + header_->proto_ids_off_)),
359      class_defs_(reinterpret_cast<const ClassDef*>(base + header_->class_defs_off_)),
360      find_class_def_misses_(0),
361      class_def_index_(nullptr),
362      build_class_def_index_mutex_("DexFile index creation mutex"),
363      oat_file_(oat_file) {
364  CHECK(begin_ != NULL) << GetLocation();
365  CHECK_GT(size_, 0U) << GetLocation();
366}
367
368DexFile::~DexFile() {
369  // We don't call DeleteGlobalRef on dex_object_ because we're only called by DestroyJavaVM, and
370  // that's only called after DetachCurrentThread, which means there's no JNIEnv. We could
371  // re-attach, but cleaning up these global references is not obviously useful. It's not as if
372  // the global reference table is otherwise empty!
373  // Remove the index if one were created.
374  delete class_def_index_.LoadRelaxed();
375}
376
377bool DexFile::Init(std::string* error_msg) {
378  if (!CheckMagicAndVersion(error_msg)) {
379    return false;
380  }
381  return true;
382}
383
384bool DexFile::CheckMagicAndVersion(std::string* error_msg) const {
385  if (!IsMagicValid(header_->magic_)) {
386    std::ostringstream oss;
387    oss << "Unrecognized magic number in "  << GetLocation() << ":"
388            << " " << header_->magic_[0]
389            << " " << header_->magic_[1]
390            << " " << header_->magic_[2]
391            << " " << header_->magic_[3];
392    *error_msg = oss.str();
393    return false;
394  }
395  if (!IsVersionValid(header_->magic_)) {
396    std::ostringstream oss;
397    oss << "Unrecognized version number in "  << GetLocation() << ":"
398            << " " << header_->magic_[4]
399            << " " << header_->magic_[5]
400            << " " << header_->magic_[6]
401            << " " << header_->magic_[7];
402    *error_msg = oss.str();
403    return false;
404  }
405  return true;
406}
407
408bool DexFile::IsMagicValid(const byte* magic) {
409  return (memcmp(magic, kDexMagic, sizeof(kDexMagic)) == 0);
410}
411
412bool DexFile::IsVersionValid(const byte* magic) {
413  const byte* version = &magic[sizeof(kDexMagic)];
414  return (memcmp(version, kDexMagicVersion, sizeof(kDexMagicVersion)) == 0);
415}
416
417uint32_t DexFile::GetVersion() const {
418  const char* version = reinterpret_cast<const char*>(&GetHeader().magic_[sizeof(kDexMagic)]);
419  return atoi(version);
420}
421
422const DexFile::ClassDef* DexFile::FindClassDef(const char* descriptor, size_t hash) const {
423  DCHECK_EQ(ComputeModifiedUtf8Hash(descriptor), hash);
424  // If we have an index lookup the descriptor via that as its constant time to search.
425  Index* index = class_def_index_.LoadSequentiallyConsistent();
426  if (index != nullptr) {
427    auto it = index->FindWithHash(descriptor, hash);
428    return (it == index->end()) ? nullptr : it->second;
429  }
430  // Fast path for rate no class defs case.
431  uint32_t num_class_defs = NumClassDefs();
432  if (num_class_defs == 0) {
433    return nullptr;
434  }
435  // Search for class def with 2 binary searches and then a linear search.
436  const StringId* string_id = FindStringId(descriptor);
437  if (string_id != nullptr) {
438    const TypeId* type_id = FindTypeId(GetIndexForStringId(*string_id));
439    if (type_id != nullptr) {
440      uint16_t type_idx = GetIndexForTypeId(*type_id);
441      for (size_t i = 0; i < num_class_defs; ++i) {
442        const ClassDef& class_def = GetClassDef(i);
443        if (class_def.class_idx_ == type_idx) {
444          return &class_def;
445        }
446      }
447    }
448  }
449  // A miss. If we've had kMaxFailedDexClassDefLookups misses then build an index to speed things
450  // up. This isn't done eagerly at construction as construction is not performed in multi-threaded
451  // sections of tools like dex2oat. If we're lazy we hopefully increase the chance of balancing
452  // out which thread builds the index.
453  find_class_def_misses_++;
454  const uint32_t kMaxFailedDexClassDefLookups = 100;
455  if (find_class_def_misses_ > kMaxFailedDexClassDefLookups) {
456    MutexLock mu(Thread::Current(), build_class_def_index_mutex_);
457    // Are we the first ones building the index?
458    if (class_def_index_.LoadSequentiallyConsistent() == nullptr) {
459      index = new Index;
460      for (uint32_t i = 0; i < num_class_defs;  ++i) {
461        const ClassDef& class_def = GetClassDef(i);
462        const char* descriptor = GetClassDescriptor(class_def);
463        index->Insert(std::make_pair(descriptor, &class_def));
464      }
465      class_def_index_.StoreSequentiallyConsistent(index);
466    }
467  }
468  return nullptr;
469}
470
471const DexFile::ClassDef* DexFile::FindClassDef(uint16_t type_idx) const {
472  size_t num_class_defs = NumClassDefs();
473  for (size_t i = 0; i < num_class_defs; ++i) {
474    const ClassDef& class_def = GetClassDef(i);
475    if (class_def.class_idx_ == type_idx) {
476      return &class_def;
477    }
478  }
479  return NULL;
480}
481
482const DexFile::FieldId* DexFile::FindFieldId(const DexFile::TypeId& declaring_klass,
483                                              const DexFile::StringId& name,
484                                              const DexFile::TypeId& type) const {
485  // Binary search MethodIds knowing that they are sorted by class_idx, name_idx then proto_idx
486  const uint16_t class_idx = GetIndexForTypeId(declaring_klass);
487  const uint32_t name_idx = GetIndexForStringId(name);
488  const uint16_t type_idx = GetIndexForTypeId(type);
489  int32_t lo = 0;
490  int32_t hi = NumFieldIds() - 1;
491  while (hi >= lo) {
492    int32_t mid = (hi + lo) / 2;
493    const DexFile::FieldId& field = GetFieldId(mid);
494    if (class_idx > field.class_idx_) {
495      lo = mid + 1;
496    } else if (class_idx < field.class_idx_) {
497      hi = mid - 1;
498    } else {
499      if (name_idx > field.name_idx_) {
500        lo = mid + 1;
501      } else if (name_idx < field.name_idx_) {
502        hi = mid - 1;
503      } else {
504        if (type_idx > field.type_idx_) {
505          lo = mid + 1;
506        } else if (type_idx < field.type_idx_) {
507          hi = mid - 1;
508        } else {
509          return &field;
510        }
511      }
512    }
513  }
514  return NULL;
515}
516
517const DexFile::MethodId* DexFile::FindMethodId(const DexFile::TypeId& declaring_klass,
518                                               const DexFile::StringId& name,
519                                               const DexFile::ProtoId& signature) const {
520  // Binary search MethodIds knowing that they are sorted by class_idx, name_idx then proto_idx
521  const uint16_t class_idx = GetIndexForTypeId(declaring_klass);
522  const uint32_t name_idx = GetIndexForStringId(name);
523  const uint16_t proto_idx = GetIndexForProtoId(signature);
524  int32_t lo = 0;
525  int32_t hi = NumMethodIds() - 1;
526  while (hi >= lo) {
527    int32_t mid = (hi + lo) / 2;
528    const DexFile::MethodId& method = GetMethodId(mid);
529    if (class_idx > method.class_idx_) {
530      lo = mid + 1;
531    } else if (class_idx < method.class_idx_) {
532      hi = mid - 1;
533    } else {
534      if (name_idx > method.name_idx_) {
535        lo = mid + 1;
536      } else if (name_idx < method.name_idx_) {
537        hi = mid - 1;
538      } else {
539        if (proto_idx > method.proto_idx_) {
540          lo = mid + 1;
541        } else if (proto_idx < method.proto_idx_) {
542          hi = mid - 1;
543        } else {
544          return &method;
545        }
546      }
547    }
548  }
549  return NULL;
550}
551
552const DexFile::StringId* DexFile::FindStringId(const char* string) const {
553  int32_t lo = 0;
554  int32_t hi = NumStringIds() - 1;
555  while (hi >= lo) {
556    int32_t mid = (hi + lo) / 2;
557    const DexFile::StringId& str_id = GetStringId(mid);
558    const char* str = GetStringData(str_id);
559    int compare = CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(string, str);
560    if (compare > 0) {
561      lo = mid + 1;
562    } else if (compare < 0) {
563      hi = mid - 1;
564    } else {
565      return &str_id;
566    }
567  }
568  return NULL;
569}
570
571const DexFile::StringId* DexFile::FindStringId(const uint16_t* string) const {
572  int32_t lo = 0;
573  int32_t hi = NumStringIds() - 1;
574  while (hi >= lo) {
575    int32_t mid = (hi + lo) / 2;
576    const DexFile::StringId& str_id = GetStringId(mid);
577    const char* str = GetStringData(str_id);
578    int compare = CompareModifiedUtf8ToUtf16AsCodePointValues(str, string);
579    if (compare > 0) {
580      lo = mid + 1;
581    } else if (compare < 0) {
582      hi = mid - 1;
583    } else {
584      return &str_id;
585    }
586  }
587  return NULL;
588}
589
590const DexFile::TypeId* DexFile::FindTypeId(uint32_t string_idx) const {
591  int32_t lo = 0;
592  int32_t hi = NumTypeIds() - 1;
593  while (hi >= lo) {
594    int32_t mid = (hi + lo) / 2;
595    const TypeId& type_id = GetTypeId(mid);
596    if (string_idx > type_id.descriptor_idx_) {
597      lo = mid + 1;
598    } else if (string_idx < type_id.descriptor_idx_) {
599      hi = mid - 1;
600    } else {
601      return &type_id;
602    }
603  }
604  return NULL;
605}
606
607const DexFile::ProtoId* DexFile::FindProtoId(uint16_t return_type_idx,
608                                             const uint16_t* signature_type_idxs,
609                                             uint32_t signature_length) const {
610  int32_t lo = 0;
611  int32_t hi = NumProtoIds() - 1;
612  while (hi >= lo) {
613    int32_t mid = (hi + lo) / 2;
614    const DexFile::ProtoId& proto = GetProtoId(mid);
615    int compare = return_type_idx - proto.return_type_idx_;
616    if (compare == 0) {
617      DexFileParameterIterator it(*this, proto);
618      size_t i = 0;
619      while (it.HasNext() && i < signature_length && compare == 0) {
620        compare = signature_type_idxs[i] - it.GetTypeIdx();
621        it.Next();
622        i++;
623      }
624      if (compare == 0) {
625        if (it.HasNext()) {
626          compare = -1;
627        } else if (i < signature_length) {
628          compare = 1;
629        }
630      }
631    }
632    if (compare > 0) {
633      lo = mid + 1;
634    } else if (compare < 0) {
635      hi = mid - 1;
636    } else {
637      return &proto;
638    }
639  }
640  return NULL;
641}
642
643// Given a signature place the type ids into the given vector
644bool DexFile::CreateTypeList(const StringPiece& signature, uint16_t* return_type_idx,
645                             std::vector<uint16_t>* param_type_idxs) const {
646  if (signature[0] != '(') {
647    return false;
648  }
649  size_t offset = 1;
650  size_t end = signature.size();
651  bool process_return = false;
652  while (offset < end) {
653    size_t start_offset = offset;
654    char c = signature[offset];
655    offset++;
656    if (c == ')') {
657      process_return = true;
658      continue;
659    }
660    while (c == '[') {  // process array prefix
661      if (offset >= end) {  // expect some descriptor following [
662        return false;
663      }
664      c = signature[offset];
665      offset++;
666    }
667    if (c == 'L') {  // process type descriptors
668      do {
669        if (offset >= end) {  // unexpected early termination of descriptor
670          return false;
671        }
672        c = signature[offset];
673        offset++;
674      } while (c != ';');
675    }
676    // TODO: avoid creating a std::string just to get a 0-terminated char array
677    std::string descriptor(signature.data() + start_offset, offset - start_offset);
678    const DexFile::StringId* string_id = FindStringId(descriptor.c_str());
679    if (string_id == NULL) {
680      return false;
681    }
682    const DexFile::TypeId* type_id = FindTypeId(GetIndexForStringId(*string_id));
683    if (type_id == NULL) {
684      return false;
685    }
686    uint16_t type_idx = GetIndexForTypeId(*type_id);
687    if (!process_return) {
688      param_type_idxs->push_back(type_idx);
689    } else {
690      *return_type_idx = type_idx;
691      return offset == end;  // return true if the signature had reached a sensible end
692    }
693  }
694  return false;  // failed to correctly parse return type
695}
696
697const Signature DexFile::CreateSignature(const StringPiece& signature) const {
698  uint16_t return_type_idx;
699  std::vector<uint16_t> param_type_indices;
700  bool success = CreateTypeList(signature, &return_type_idx, &param_type_indices);
701  if (!success) {
702    return Signature::NoSignature();
703  }
704  const ProtoId* proto_id = FindProtoId(return_type_idx, param_type_indices);
705  if (proto_id == NULL) {
706    return Signature::NoSignature();
707  }
708  return Signature(this, *proto_id);
709}
710
711int32_t DexFile::GetLineNumFromPC(mirror::ArtMethod* method, uint32_t rel_pc) const {
712  // For native method, lineno should be -2 to indicate it is native. Note that
713  // "line number == -2" is how libcore tells from StackTraceElement.
714  if (method->GetCodeItemOffset() == 0) {
715    return -2;
716  }
717
718  const CodeItem* code_item = GetCodeItem(method->GetCodeItemOffset());
719  DCHECK(code_item != NULL) << PrettyMethod(method) << " " << GetLocation();
720
721  // A method with no line number info should return -1
722  LineNumFromPcContext context(rel_pc, -1);
723  DecodeDebugInfo(code_item, method->IsStatic(), method->GetDexMethodIndex(), LineNumForPcCb,
724                  NULL, &context);
725  return context.line_num_;
726}
727
728int32_t DexFile::FindTryItem(const CodeItem &code_item, uint32_t address) {
729  // Note: Signed type is important for max and min.
730  int32_t min = 0;
731  int32_t max = code_item.tries_size_ - 1;
732
733  while (min <= max) {
734    int32_t mid = min + ((max - min) / 2);
735
736    const art::DexFile::TryItem* ti = GetTryItems(code_item, mid);
737    uint32_t start = ti->start_addr_;
738    uint32_t end = start + ti->insn_count_;
739
740    if (address < start) {
741      max = mid - 1;
742    } else if (address >= end) {
743      min = mid + 1;
744    } else {  // We have a winner!
745      return mid;
746    }
747  }
748  // No match.
749  return -1;
750}
751
752int32_t DexFile::FindCatchHandlerOffset(const CodeItem &code_item, uint32_t address) {
753  int32_t try_item = FindTryItem(code_item, address);
754  if (try_item == -1) {
755    return -1;
756  } else {
757    return DexFile::GetTryItems(code_item, try_item)->handler_off_;
758  }
759}
760
761void DexFile::DecodeDebugInfo0(const CodeItem* code_item, bool is_static, uint32_t method_idx,
762                               DexDebugNewPositionCb position_cb, DexDebugNewLocalCb local_cb,
763                               void* context, const byte* stream, LocalInfo* local_in_reg) const {
764  uint32_t line = DecodeUnsignedLeb128(&stream);
765  uint32_t parameters_size = DecodeUnsignedLeb128(&stream);
766  uint16_t arg_reg = code_item->registers_size_ - code_item->ins_size_;
767  uint32_t address = 0;
768  bool need_locals = (local_cb != NULL);
769
770  if (!is_static) {
771    if (need_locals) {
772      const char* descriptor = GetMethodDeclaringClassDescriptor(GetMethodId(method_idx));
773      local_in_reg[arg_reg].name_ = "this";
774      local_in_reg[arg_reg].descriptor_ = descriptor;
775      local_in_reg[arg_reg].signature_ = NULL;
776      local_in_reg[arg_reg].start_address_ = 0;
777      local_in_reg[arg_reg].is_live_ = true;
778    }
779    arg_reg++;
780  }
781
782  DexFileParameterIterator it(*this, GetMethodPrototype(GetMethodId(method_idx)));
783  for (uint32_t i = 0; i < parameters_size && it.HasNext(); ++i, it.Next()) {
784    if (arg_reg >= code_item->registers_size_) {
785      LOG(ERROR) << "invalid stream - arg reg >= reg size (" << arg_reg
786                 << " >= " << code_item->registers_size_ << ") in " << GetLocation();
787      return;
788    }
789    uint32_t id = DecodeUnsignedLeb128P1(&stream);
790    const char* descriptor = it.GetDescriptor();
791    if (need_locals && id != kDexNoIndex) {
792      const char* name = StringDataByIdx(id);
793      local_in_reg[arg_reg].name_ = name;
794      local_in_reg[arg_reg].descriptor_ = descriptor;
795      local_in_reg[arg_reg].signature_ = NULL;
796      local_in_reg[arg_reg].start_address_ = address;
797      local_in_reg[arg_reg].is_live_ = true;
798    }
799    switch (*descriptor) {
800      case 'D':
801      case 'J':
802        arg_reg += 2;
803        break;
804      default:
805        arg_reg += 1;
806        break;
807    }
808  }
809
810  if (it.HasNext()) {
811    LOG(ERROR) << "invalid stream - problem with parameter iterator in " << GetLocation()
812               << " for method " << PrettyMethod(method_idx, *this);
813    return;
814  }
815
816  for (;;)  {
817    uint8_t opcode = *stream++;
818    uint16_t reg;
819    uint32_t name_idx;
820    uint32_t descriptor_idx;
821    uint32_t signature_idx = 0;
822
823    switch (opcode) {
824      case DBG_END_SEQUENCE:
825        return;
826
827      case DBG_ADVANCE_PC:
828        address += DecodeUnsignedLeb128(&stream);
829        break;
830
831      case DBG_ADVANCE_LINE:
832        line += DecodeSignedLeb128(&stream);
833        break;
834
835      case DBG_START_LOCAL:
836      case DBG_START_LOCAL_EXTENDED:
837        reg = DecodeUnsignedLeb128(&stream);
838        if (reg > code_item->registers_size_) {
839          LOG(ERROR) << "invalid stream - reg > reg size (" << reg << " > "
840                     << code_item->registers_size_ << ") in " << GetLocation();
841          return;
842        }
843
844        name_idx = DecodeUnsignedLeb128P1(&stream);
845        descriptor_idx = DecodeUnsignedLeb128P1(&stream);
846        if (opcode == DBG_START_LOCAL_EXTENDED) {
847          signature_idx = DecodeUnsignedLeb128P1(&stream);
848        }
849
850        // Emit what was previously there, if anything
851        if (need_locals) {
852          InvokeLocalCbIfLive(context, reg, address, local_in_reg, local_cb);
853
854          local_in_reg[reg].name_ = StringDataByIdx(name_idx);
855          local_in_reg[reg].descriptor_ = StringByTypeIdx(descriptor_idx);
856          if (opcode == DBG_START_LOCAL_EXTENDED) {
857            local_in_reg[reg].signature_ = StringDataByIdx(signature_idx);
858          }
859          local_in_reg[reg].start_address_ = address;
860          local_in_reg[reg].is_live_ = true;
861        }
862        break;
863
864      case DBG_END_LOCAL:
865        reg = DecodeUnsignedLeb128(&stream);
866        if (reg > code_item->registers_size_) {
867          LOG(ERROR) << "invalid stream - reg > reg size (" << reg << " > "
868                     << code_item->registers_size_ << ") in " << GetLocation();
869          return;
870        }
871
872        if (need_locals) {
873          InvokeLocalCbIfLive(context, reg, address, local_in_reg, local_cb);
874          local_in_reg[reg].is_live_ = false;
875        }
876        break;
877
878      case DBG_RESTART_LOCAL:
879        reg = DecodeUnsignedLeb128(&stream);
880        if (reg > code_item->registers_size_) {
881          LOG(ERROR) << "invalid stream - reg > reg size (" << reg << " > "
882                     << code_item->registers_size_ << ") in " << GetLocation();
883          return;
884        }
885
886        if (need_locals) {
887          if (local_in_reg[reg].name_ == NULL || local_in_reg[reg].descriptor_ == NULL) {
888            LOG(ERROR) << "invalid stream - no name or descriptor in " << GetLocation();
889            return;
890          }
891
892          // If the register is live, the "restart" is superfluous,
893          // and we don't want to mess with the existing start address.
894          if (!local_in_reg[reg].is_live_) {
895            local_in_reg[reg].start_address_ = address;
896            local_in_reg[reg].is_live_ = true;
897          }
898        }
899        break;
900
901      case DBG_SET_PROLOGUE_END:
902      case DBG_SET_EPILOGUE_BEGIN:
903      case DBG_SET_FILE:
904        break;
905
906      default: {
907        int adjopcode = opcode - DBG_FIRST_SPECIAL;
908
909        address += adjopcode / DBG_LINE_RANGE;
910        line += DBG_LINE_BASE + (adjopcode % DBG_LINE_RANGE);
911
912        if (position_cb != NULL) {
913          if (position_cb(context, address, line)) {
914            // early exit
915            return;
916          }
917        }
918        break;
919      }
920    }
921  }
922}
923
924void DexFile::DecodeDebugInfo(const CodeItem* code_item, bool is_static, uint32_t method_idx,
925                              DexDebugNewPositionCb position_cb, DexDebugNewLocalCb local_cb,
926                              void* context) const {
927  DCHECK(code_item != nullptr);
928  const byte* stream = GetDebugInfoStream(code_item);
929  std::unique_ptr<LocalInfo[]> local_in_reg(local_cb != NULL ?
930                                      new LocalInfo[code_item->registers_size_] :
931                                      NULL);
932  if (stream != NULL) {
933    DecodeDebugInfo0(code_item, is_static, method_idx, position_cb, local_cb, context, stream, &local_in_reg[0]);
934  }
935  for (int reg = 0; reg < code_item->registers_size_; reg++) {
936    InvokeLocalCbIfLive(context, reg, code_item->insns_size_in_code_units_, &local_in_reg[0], local_cb);
937  }
938}
939
940bool DexFile::LineNumForPcCb(void* raw_context, uint32_t address, uint32_t line_num) {
941  LineNumFromPcContext* context = reinterpret_cast<LineNumFromPcContext*>(raw_context);
942
943  // We know that this callback will be called in
944  // ascending address order, so keep going until we find
945  // a match or we've just gone past it.
946  if (address > context->address_) {
947    // The line number from the previous positions callback
948    // wil be the final result.
949    return true;
950  } else {
951    context->line_num_ = line_num;
952    return address == context->address_;
953  }
954}
955
956bool DexFile::IsMultiDexLocation(const char* location) {
957  return strrchr(location, kMultiDexSeparator) != nullptr;
958}
959
960std::string DexFile::GetMultiDexClassesDexName(size_t number, const char* dex_location) {
961  if (number == 0) {
962    return dex_location;
963  } else {
964    return StringPrintf("%s" kMultiDexSeparatorString "classes%zu.dex", dex_location, number + 1);
965  }
966}
967
968std::string DexFile::GetDexCanonicalLocation(const char* dex_location) {
969  CHECK_NE(dex_location, static_cast<const char*>(nullptr));
970  std::string base_location = GetBaseLocation(dex_location);
971  const char* suffix = dex_location + base_location.size();
972  DCHECK(suffix[0] == 0 || suffix[0] == kMultiDexSeparator);
973  UniqueCPtr<const char[]> path(realpath(base_location.c_str(), nullptr));
974  if (path != nullptr && path.get() != base_location) {
975    return std::string(path.get()) + suffix;
976  } else if (suffix[0] == 0) {
977    return base_location;
978  } else {
979    return dex_location;
980  }
981}
982
983std::ostream& operator<<(std::ostream& os, const DexFile& dex_file) {
984  os << StringPrintf("[DexFile: %s dex-checksum=%08x location-checksum=%08x %p-%p]",
985                     dex_file.GetLocation().c_str(),
986                     dex_file.GetHeader().checksum_, dex_file.GetLocationChecksum(),
987                     dex_file.Begin(), dex_file.Begin() + dex_file.Size());
988  return os;
989}
990
991std::string Signature::ToString() const {
992  if (dex_file_ == nullptr) {
993    CHECK(proto_id_ == nullptr);
994    return "<no signature>";
995  }
996  const DexFile::TypeList* params = dex_file_->GetProtoParameters(*proto_id_);
997  std::string result;
998  if (params == nullptr) {
999    result += "()";
1000  } else {
1001    result += "(";
1002    for (uint32_t i = 0; i < params->Size(); ++i) {
1003      result += dex_file_->StringByTypeIdx(params->GetTypeItem(i).type_idx_);
1004    }
1005    result += ")";
1006  }
1007  result += dex_file_->StringByTypeIdx(proto_id_->return_type_idx_);
1008  return result;
1009}
1010
1011bool Signature::operator==(const StringPiece& rhs) const {
1012  if (dex_file_ == nullptr) {
1013    return false;
1014  }
1015  StringPiece tail(rhs);
1016  if (!tail.starts_with("(")) {
1017    return false;  // Invalid signature
1018  }
1019  tail.remove_prefix(1);  // "(";
1020  const DexFile::TypeList* params = dex_file_->GetProtoParameters(*proto_id_);
1021  if (params != nullptr) {
1022    for (uint32_t i = 0; i < params->Size(); ++i) {
1023      StringPiece param(dex_file_->StringByTypeIdx(params->GetTypeItem(i).type_idx_));
1024      if (!tail.starts_with(param)) {
1025        return false;
1026      }
1027      tail.remove_prefix(param.length());
1028    }
1029  }
1030  if (!tail.starts_with(")")) {
1031    return false;
1032  }
1033  tail.remove_prefix(1);  // ")";
1034  return tail == dex_file_->StringByTypeIdx(proto_id_->return_type_idx_);
1035}
1036
1037std::ostream& operator<<(std::ostream& os, const Signature& sig) {
1038  return os << sig.ToString();
1039}
1040
1041// Decodes the header section from the class data bytes.
1042void ClassDataItemIterator::ReadClassDataHeader() {
1043  CHECK(ptr_pos_ != NULL);
1044  header_.static_fields_size_ = DecodeUnsignedLeb128(&ptr_pos_);
1045  header_.instance_fields_size_ = DecodeUnsignedLeb128(&ptr_pos_);
1046  header_.direct_methods_size_ = DecodeUnsignedLeb128(&ptr_pos_);
1047  header_.virtual_methods_size_ = DecodeUnsignedLeb128(&ptr_pos_);
1048}
1049
1050void ClassDataItemIterator::ReadClassDataField() {
1051  field_.field_idx_delta_ = DecodeUnsignedLeb128(&ptr_pos_);
1052  field_.access_flags_ = DecodeUnsignedLeb128(&ptr_pos_);
1053  if (last_idx_ != 0 && field_.field_idx_delta_ == 0) {
1054    LOG(WARNING) << "Duplicate field in " << dex_file_.GetLocation();
1055  }
1056}
1057
1058void ClassDataItemIterator::ReadClassDataMethod() {
1059  method_.method_idx_delta_ = DecodeUnsignedLeb128(&ptr_pos_);
1060  method_.access_flags_ = DecodeUnsignedLeb128(&ptr_pos_);
1061  method_.code_off_ = DecodeUnsignedLeb128(&ptr_pos_);
1062  if (last_idx_ != 0 && method_.method_idx_delta_ == 0) {
1063    LOG(WARNING) << "Duplicate method in " << dex_file_.GetLocation();
1064  }
1065}
1066
1067// Read a signed integer.  "zwidth" is the zero-based byte count.
1068static int32_t ReadSignedInt(const byte* ptr, int zwidth) {
1069  int32_t val = 0;
1070  for (int i = zwidth; i >= 0; --i) {
1071    val = ((uint32_t)val >> 8) | (((int32_t)*ptr++) << 24);
1072  }
1073  val >>= (3 - zwidth) * 8;
1074  return val;
1075}
1076
1077// Read an unsigned integer.  "zwidth" is the zero-based byte count,
1078// "fill_on_right" indicates which side we want to zero-fill from.
1079static uint32_t ReadUnsignedInt(const byte* ptr, int zwidth, bool fill_on_right) {
1080  uint32_t val = 0;
1081  if (!fill_on_right) {
1082    for (int i = zwidth; i >= 0; --i) {
1083      val = (val >> 8) | (((uint32_t)*ptr++) << 24);
1084    }
1085    val >>= (3 - zwidth) * 8;
1086  } else {
1087    for (int i = zwidth; i >= 0; --i) {
1088      val = (val >> 8) | (((uint32_t)*ptr++) << 24);
1089    }
1090  }
1091  return val;
1092}
1093
1094// Read a signed long.  "zwidth" is the zero-based byte count.
1095static int64_t ReadSignedLong(const byte* ptr, int zwidth) {
1096  int64_t val = 0;
1097  for (int i = zwidth; i >= 0; --i) {
1098    val = ((uint64_t)val >> 8) | (((int64_t)*ptr++) << 56);
1099  }
1100  val >>= (7 - zwidth) * 8;
1101  return val;
1102}
1103
1104// Read an unsigned long.  "zwidth" is the zero-based byte count,
1105// "fill_on_right" indicates which side we want to zero-fill from.
1106static uint64_t ReadUnsignedLong(const byte* ptr, int zwidth, bool fill_on_right) {
1107  uint64_t val = 0;
1108  if (!fill_on_right) {
1109    for (int i = zwidth; i >= 0; --i) {
1110      val = (val >> 8) | (((uint64_t)*ptr++) << 56);
1111    }
1112    val >>= (7 - zwidth) * 8;
1113  } else {
1114    for (int i = zwidth; i >= 0; --i) {
1115      val = (val >> 8) | (((uint64_t)*ptr++) << 56);
1116    }
1117  }
1118  return val;
1119}
1120
1121EncodedStaticFieldValueIterator::EncodedStaticFieldValueIterator(const DexFile& dex_file,
1122                                                                 Handle<mirror::DexCache>* dex_cache,
1123                                                                 Handle<mirror::ClassLoader>* class_loader,
1124                                                                 ClassLinker* linker,
1125                                                                 const DexFile::ClassDef& class_def)
1126    : dex_file_(dex_file), dex_cache_(dex_cache), class_loader_(class_loader), linker_(linker),
1127      array_size_(), pos_(-1), type_(kByte) {
1128  DCHECK(dex_cache != nullptr);
1129  DCHECK(class_loader != nullptr);
1130  ptr_ = dex_file.GetEncodedStaticFieldValuesArray(class_def);
1131  if (ptr_ == NULL) {
1132    array_size_ = 0;
1133  } else {
1134    array_size_ = DecodeUnsignedLeb128(&ptr_);
1135  }
1136  if (array_size_ > 0) {
1137    Next();
1138  }
1139}
1140
1141void EncodedStaticFieldValueIterator::Next() {
1142  pos_++;
1143  if (pos_ >= array_size_) {
1144    return;
1145  }
1146  byte value_type = *ptr_++;
1147  byte value_arg = value_type >> kEncodedValueArgShift;
1148  size_t width = value_arg + 1;  // assume and correct later
1149  type_ = static_cast<ValueType>(value_type & kEncodedValueTypeMask);
1150  switch (type_) {
1151  case kBoolean:
1152    jval_.i = (value_arg != 0) ? 1 : 0;
1153    width = 0;
1154    break;
1155  case kByte:
1156    jval_.i = ReadSignedInt(ptr_, value_arg);
1157    CHECK(IsInt(8, jval_.i));
1158    break;
1159  case kShort:
1160    jval_.i = ReadSignedInt(ptr_, value_arg);
1161    CHECK(IsInt(16, jval_.i));
1162    break;
1163  case kChar:
1164    jval_.i = ReadUnsignedInt(ptr_, value_arg, false);
1165    CHECK(IsUint(16, jval_.i));
1166    break;
1167  case kInt:
1168    jval_.i = ReadSignedInt(ptr_, value_arg);
1169    break;
1170  case kLong:
1171    jval_.j = ReadSignedLong(ptr_, value_arg);
1172    break;
1173  case kFloat:
1174    jval_.i = ReadUnsignedInt(ptr_, value_arg, true);
1175    break;
1176  case kDouble:
1177    jval_.j = ReadUnsignedLong(ptr_, value_arg, true);
1178    break;
1179  case kString:
1180  case kType:
1181    jval_.i = ReadUnsignedInt(ptr_, value_arg, false);
1182    break;
1183  case kField:
1184  case kMethod:
1185  case kEnum:
1186  case kArray:
1187  case kAnnotation:
1188    UNIMPLEMENTED(FATAL) << ": type " << type_;
1189    break;
1190  case kNull:
1191    jval_.l = NULL;
1192    width = 0;
1193    break;
1194  default:
1195    LOG(FATAL) << "Unreached";
1196  }
1197  ptr_ += width;
1198}
1199
1200template<bool kTransactionActive>
1201void EncodedStaticFieldValueIterator::ReadValueToField(mirror::ArtField* field) const {
1202  switch (type_) {
1203    case kBoolean: field->SetBoolean<kTransactionActive>(field->GetDeclaringClass(), jval_.z); break;
1204    case kByte:    field->SetByte<kTransactionActive>(field->GetDeclaringClass(), jval_.b); break;
1205    case kShort:   field->SetShort<kTransactionActive>(field->GetDeclaringClass(), jval_.s); break;
1206    case kChar:    field->SetChar<kTransactionActive>(field->GetDeclaringClass(), jval_.c); break;
1207    case kInt:     field->SetInt<kTransactionActive>(field->GetDeclaringClass(), jval_.i); break;
1208    case kLong:    field->SetLong<kTransactionActive>(field->GetDeclaringClass(), jval_.j); break;
1209    case kFloat:   field->SetFloat<kTransactionActive>(field->GetDeclaringClass(), jval_.f); break;
1210    case kDouble:  field->SetDouble<kTransactionActive>(field->GetDeclaringClass(), jval_.d); break;
1211    case kNull:    field->SetObject<kTransactionActive>(field->GetDeclaringClass(), NULL); break;
1212    case kString: {
1213      CHECK(!kMovingFields);
1214      mirror::String* resolved = linker_->ResolveString(dex_file_, jval_.i, *dex_cache_);
1215      field->SetObject<kTransactionActive>(field->GetDeclaringClass(), resolved);
1216      break;
1217    }
1218    case kType: {
1219      CHECK(!kMovingFields);
1220      mirror::Class* resolved = linker_->ResolveType(dex_file_, jval_.i, *dex_cache_,
1221                                                     *class_loader_);
1222      field->SetObject<kTransactionActive>(field->GetDeclaringClass(), resolved);
1223      break;
1224    }
1225    default: UNIMPLEMENTED(FATAL) << ": type " << type_;
1226  }
1227}
1228template void EncodedStaticFieldValueIterator::ReadValueToField<true>(mirror::ArtField* field) const;
1229template void EncodedStaticFieldValueIterator::ReadValueToField<false>(mirror::ArtField* field) const;
1230
1231CatchHandlerIterator::CatchHandlerIterator(const DexFile::CodeItem& code_item, uint32_t address) {
1232  handler_.address_ = -1;
1233  int32_t offset = -1;
1234
1235  // Short-circuit the overwhelmingly common cases.
1236  switch (code_item.tries_size_) {
1237    case 0:
1238      break;
1239    case 1: {
1240      const DexFile::TryItem* tries = DexFile::GetTryItems(code_item, 0);
1241      uint32_t start = tries->start_addr_;
1242      if (address >= start) {
1243        uint32_t end = start + tries->insn_count_;
1244        if (address < end) {
1245          offset = tries->handler_off_;
1246        }
1247      }
1248      break;
1249    }
1250    default:
1251      offset = DexFile::FindCatchHandlerOffset(code_item, address);
1252  }
1253  Init(code_item, offset);
1254}
1255
1256CatchHandlerIterator::CatchHandlerIterator(const DexFile::CodeItem& code_item,
1257                                           const DexFile::TryItem& try_item) {
1258  handler_.address_ = -1;
1259  Init(code_item, try_item.handler_off_);
1260}
1261
1262void CatchHandlerIterator::Init(const DexFile::CodeItem& code_item,
1263                                int32_t offset) {
1264  if (offset >= 0) {
1265    Init(DexFile::GetCatchHandlerData(code_item, offset));
1266  } else {
1267    // Not found, initialize as empty
1268    current_data_ = NULL;
1269    remaining_count_ = -1;
1270    catch_all_ = false;
1271    DCHECK(!HasNext());
1272  }
1273}
1274
1275void CatchHandlerIterator::Init(const byte* handler_data) {
1276  current_data_ = handler_data;
1277  remaining_count_ = DecodeSignedLeb128(&current_data_);
1278
1279  // If remaining_count_ is non-positive, then it is the negative of
1280  // the number of catch types, and the catches are followed by a
1281  // catch-all handler.
1282  if (remaining_count_ <= 0) {
1283    catch_all_ = true;
1284    remaining_count_ = -remaining_count_;
1285  } else {
1286    catch_all_ = false;
1287  }
1288  Next();
1289}
1290
1291void CatchHandlerIterator::Next() {
1292  if (remaining_count_ > 0) {
1293    handler_.type_idx_ = DecodeUnsignedLeb128(&current_data_);
1294    handler_.address_  = DecodeUnsignedLeb128(&current_data_);
1295    remaining_count_--;
1296    return;
1297  }
1298
1299  if (catch_all_) {
1300    handler_.type_idx_ = DexFile::kDexNoIndex16;
1301    handler_.address_  = DecodeUnsignedLeb128(&current_data_);
1302    catch_all_ = false;
1303    return;
1304  }
1305
1306  // no more handler
1307  remaining_count_ = -1;
1308}
1309
1310}  // namespace art
1311