libdexfile/dex/dex_file.cc - platform/art - Git at Google

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "dex_file.h"

 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <zlib.h>

 #include <memory>
 #include <ostream>
 #include <sstream>
 #include <type_traits>

 #include "android-base/stringprintf.h"

 #include "base/enums.h"
 #include "base/leb128.h"
 #include "base/stl_util.h"
 #include "class_accessor-inl.h"
 #include "descriptors_names.h"
 #include "dex_file-inl.h"
 #include "standard_dex_file.h"
 #include "utf-inl.h"

 namespace art {

 using android::base::StringPrintf;

 using dex::CallSiteIdItem;
 using dex::ClassDef;
 using dex::FieldId;
 using dex::MapList;
 using dex::MapItem;
 using dex::MethodHandleItem;
 using dex::MethodId;
 using dex::ProtoId;
 using dex::StringId;
 using dex::TryItem;
 using dex::TypeId;
 using dex::TypeList;

 static_assert(sizeof(dex::StringIndex) == sizeof(uint32_t), "StringIndex size is wrong");
 static_assert(std::is_trivially_copyable<dex::StringIndex>::value, "StringIndex not trivial");
 static_assert(sizeof(dex::TypeIndex) == sizeof(uint16_t), "TypeIndex size is wrong");
 static_assert(std::is_trivially_copyable<dex::TypeIndex>::value, "TypeIndex not trivial");

 uint32_t DexFile::CalculateChecksum() const {
   return CalculateChecksum(Begin(), Size());
 }

 uint32_t DexFile::CalculateChecksum(const uint8_t* begin, size_t size) {
   const uint32_t non_sum_bytes = OFFSETOF_MEMBER(DexFile::Header, signature_);
   return ChecksumMemoryRange(begin + non_sum_bytes, size - non_sum_bytes);
 }

 uint32_t DexFile::ChecksumMemoryRange(const uint8_t* begin, size_t size) {
   return adler32(adler32(0L, Z_NULL, 0), begin, size);
 }

 int DexFile::GetPermissions() const {
   CHECK(container_.get() != nullptr);
   return container_->GetPermissions();
 }

 bool DexFile::IsReadOnly() const {
   CHECK(container_.get() != nullptr);
   return container_->IsReadOnly();
 }

 bool DexFile::EnableWrite() const {
   CHECK(container_.get() != nullptr);
   return container_->EnableWrite();
 }

 bool DexFile::DisableWrite() const {
   CHECK(container_.get() != nullptr);
   return container_->DisableWrite();
 }

 DexFile::DexFile(const uint8_t* base,
                  size_t size,
                  const uint8_t* data_begin,
                  size_t data_size,
                  const std::string& location,
                  uint32_t location_checksum,
                  const OatDexFile* oat_dex_file,
                  std::unique_ptr<DexFileContainer> container,
                  bool is_compact_dex)
     : begin_(base),
       size_(size),
       data_begin_(data_begin),
       data_size_(data_size),
       location_(location),
       location_checksum_(location_checksum),
       header_(reinterpret_cast<const Header*>(base)),
       string_ids_(reinterpret_cast<const StringId*>(base + header_->string_ids_off_)),
       type_ids_(reinterpret_cast<const TypeId*>(base + header_->type_ids_off_)),
       field_ids_(reinterpret_cast<const FieldId*>(base + header_->field_ids_off_)),
       method_ids_(reinterpret_cast<const MethodId*>(base + header_->method_ids_off_)),
       proto_ids_(reinterpret_cast<const ProtoId*>(base + header_->proto_ids_off_)),
       class_defs_(reinterpret_cast<const ClassDef*>(base + header_->class_defs_off_)),
       method_handles_(nullptr),
       num_method_handles_(0),
       call_site_ids_(nullptr),
       num_call_site_ids_(0),
       hiddenapi_class_data_(nullptr),
       oat_dex_file_(oat_dex_file),
       container_(std::move(container)),
       is_compact_dex_(is_compact_dex),
       is_platform_dex_(false) {
   CHECK(begin_ != nullptr) << GetLocation();
   CHECK_GT(size_, 0U) << GetLocation();
   // Check base (=header) alignment.
   // Must be 4-byte aligned to avoid undefined behavior when accessing
   // any of the sections via a pointer.
   CHECK_ALIGNED(begin_, alignof(Header));

   InitializeSectionsFromMapList();
 }

 DexFile::~DexFile() {
   // We don't call DeleteGlobalRef on dex_object_ because we're only called by DestroyJavaVM, and
   // that's only called after DetachCurrentThread, which means there's no JNIEnv. We could
   // re-attach, but cleaning up these global references is not obviously useful. It's not as if
   // the global reference table is otherwise empty!
 }

 bool DexFile::Init(std::string* error_msg) {
   if (!CheckMagicAndVersion(error_msg)) {
     return false;
   }
   return true;
 }

 bool DexFile::CheckMagicAndVersion(std::string* error_msg) const {
   if (!IsMagicValid()) {
     std::ostringstream oss;
     oss << "Unrecognized magic number in "  << GetLocation() << ":"
             << " " << header_->magic_[0]
             << " " << header_->magic_[1]
             << " " << header_->magic_[2]
             << " " << header_->magic_[3];
     *error_msg = oss.str();
     return false;
   }
   if (!IsVersionValid()) {
     std::ostringstream oss;
     oss << "Unrecognized version number in "  << GetLocation() << ":"
             << " " << header_->magic_[4]
             << " " << header_->magic_[5]
             << " " << header_->magic_[6]
             << " " << header_->magic_[7];
     *error_msg = oss.str();
     return false;
   }
   return true;
 }

 void DexFile::InitializeSectionsFromMapList() {
   const MapList* map_list = reinterpret_cast<const MapList*>(DataBegin() + header_->map_off_);
   if (header_->map_off_ == 0 || header_->map_off_ > DataSize()) {
     // Bad offset. The dex file verifier runs after this method and will reject the file.
     return;
   }
   const size_t count = map_list->size_;

   size_t map_limit = header_->map_off_ + count * sizeof(MapItem);
   if (header_->map_off_ >= map_limit || map_limit > DataSize()) {
     // Overflow or out out of bounds. The dex file verifier runs after
     // this method and will reject the file as it is malformed.
     return;
   }

   for (size_t i = 0; i < count; ++i) {
     const MapItem& map_item = map_list->list_[i];
     if (map_item.type_ == kDexTypeMethodHandleItem) {
       method_handles_ = reinterpret_cast<const MethodHandleItem*>(Begin() + map_item.offset_);
       num_method_handles_ = map_item.size_;
     } else if (map_item.type_ == kDexTypeCallSiteIdItem) {
       call_site_ids_ = reinterpret_cast<const CallSiteIdItem*>(Begin() + map_item.offset_);
       num_call_site_ids_ = map_item.size_;
     } else if (map_item.type_ == kDexTypeHiddenapiClassData) {
       hiddenapi_class_data_ = GetHiddenapiClassDataAtOffset(map_item.offset_);
     } else {
       // Pointers to other sections are not necessary to retain in the DexFile struct.
       // Other items have pointers directly into their data.
     }
   }
 }

 uint32_t DexFile::Header::GetVersion() const {
   const char* version = reinterpret_cast<const char*>(&magic_[kDexMagicSize]);
   return atoi(version);
 }

 const ClassDef* DexFile::FindClassDef(dex::TypeIndex type_idx) const {
   size_t num_class_defs = NumClassDefs();
   // Fast path for rare no class defs case.
   if (num_class_defs == 0) {
     return nullptr;
   }
   for (size_t i = 0; i < num_class_defs; ++i) {
     const ClassDef& class_def = GetClassDef(i);
     if (class_def.class_idx_ == type_idx) {
       return &class_def;
     }
   }
   return nullptr;
 }

 uint32_t DexFile::FindCodeItemOffset(const ClassDef& class_def, uint32_t method_idx) const {
   ClassAccessor accessor(*this, class_def);
   CHECK(accessor.HasClassData());
   for (const ClassAccessor::Method& method : accessor.GetMethods()) {
     if (method.GetIndex() == method_idx) {
       return method.GetCodeItemOffset();
     }
   }
   LOG(FATAL) << "Unable to find method " << method_idx;
   UNREACHABLE();
 }

 const FieldId* DexFile::FindFieldId(const TypeId& declaring_klass,
                                     const StringId& name,
                                     const TypeId& type) const {
   // Binary search MethodIds knowing that they are sorted by class_idx, name_idx then proto_idx
   const dex::TypeIndex class_idx = GetIndexForTypeId(declaring_klass);
   const dex::StringIndex name_idx = GetIndexForStringId(name);
   const dex::TypeIndex type_idx = GetIndexForTypeId(type);
   int32_t lo = 0;
   int32_t hi = NumFieldIds() - 1;
   while (hi >= lo) {
     int32_t mid = (hi + lo) / 2;
     const FieldId& field = GetFieldId(mid);
     if (class_idx > field.class_idx_) {
       lo = mid + 1;
     } else if (class_idx < field.class_idx_) {
       hi = mid - 1;
     } else {
       if (name_idx > field.name_idx_) {
         lo = mid + 1;
       } else if (name_idx < field.name_idx_) {
         hi = mid - 1;
       } else {
         if (type_idx > field.type_idx_) {
           lo = mid + 1;
         } else if (type_idx < field.type_idx_) {
           hi = mid - 1;
         } else {
           return &field;
         }
       }
     }
   }
   return nullptr;
 }

 const MethodId* DexFile::FindMethodId(const TypeId& declaring_klass,
                                       const StringId& name,
                                       const ProtoId& signature) const {
   // Binary search MethodIds knowing that they are sorted by class_idx, name_idx then proto_idx
   const dex::TypeIndex class_idx = GetIndexForTypeId(declaring_klass);
   const dex::StringIndex name_idx = GetIndexForStringId(name);
   const dex::ProtoIndex proto_idx = GetIndexForProtoId(signature);
   int32_t lo = 0;
   int32_t hi = NumMethodIds() - 1;
   while (hi >= lo) {
     int32_t mid = (hi + lo) / 2;
     const MethodId& method = GetMethodId(mid);
     if (class_idx > method.class_idx_) {
       lo = mid + 1;
     } else if (class_idx < method.class_idx_) {
       hi = mid - 1;
     } else {
       if (name_idx > method.name_idx_) {
         lo = mid + 1;
       } else if (name_idx < method.name_idx_) {
         hi = mid - 1;
       } else {
         if (proto_idx > method.proto_idx_) {
           lo = mid + 1;
         } else if (proto_idx < method.proto_idx_) {
           hi = mid - 1;
         } else {
           return &method;
         }
       }
     }
   }
   return nullptr;
 }

 const StringId* DexFile::FindStringId(const char* string) const {
   int32_t lo = 0;
   int32_t hi = NumStringIds() - 1;
   while (hi >= lo) {
     int32_t mid = (hi + lo) / 2;
     const StringId& str_id = GetStringId(dex::StringIndex(mid));
     const char* str = GetStringData(str_id);
     int compare = CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(string, str);
     if (compare > 0) {
       lo = mid + 1;
     } else if (compare < 0) {
       hi = mid - 1;
     } else {
       return &str_id;
     }
   }
   return nullptr;
 }

 const TypeId* DexFile::FindTypeId(const char* string) const {
   int32_t lo = 0;
   int32_t hi = NumTypeIds() - 1;
   while (hi >= lo) {
     int32_t mid = (hi + lo) / 2;
     const TypeId& type_id = GetTypeId(dex::TypeIndex(mid));
     const StringId& str_id = GetStringId(type_id.descriptor_idx_);
     const char* str = GetStringData(str_id);
     int compare = CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(string, str);
     if (compare > 0) {
       lo = mid + 1;
     } else if (compare < 0) {
       hi = mid - 1;
     } else {
       return &type_id;
     }
   }
   return nullptr;
 }

 const TypeId* DexFile::FindTypeId(dex::StringIndex string_idx) const {
   int32_t lo = 0;
   int32_t hi = NumTypeIds() - 1;
   while (hi >= lo) {
     int32_t mid = (hi + lo) / 2;
     const TypeId& type_id = GetTypeId(dex::TypeIndex(mid));
     if (string_idx > type_id.descriptor_idx_) {
       lo = mid + 1;
     } else if (string_idx < type_id.descriptor_idx_) {
       hi = mid - 1;
     } else {
       return &type_id;
     }
   }
   return nullptr;
 }

 const ProtoId* DexFile::FindProtoId(dex::TypeIndex return_type_idx,
                                     const dex::TypeIndex* signature_type_idxs,
                                     uint32_t signature_length) const {
   int32_t lo = 0;
   int32_t hi = NumProtoIds() - 1;
   while (hi >= lo) {
     int32_t mid = (hi + lo) / 2;
     const dex::ProtoIndex proto_idx = static_cast<dex::ProtoIndex>(mid);
     const ProtoId& proto = GetProtoId(proto_idx);
     int compare = return_type_idx.index_ - proto.return_type_idx_.index_;
     if (compare == 0) {
       DexFileParameterIterator it(*this, proto);
       size_t i = 0;
       while (it.HasNext() && i < signature_length && compare == 0) {
         compare = signature_type_idxs[i].index_ - it.GetTypeIdx().index_;
         it.Next();
         i++;
       }
       if (compare == 0) {
         if (it.HasNext()) {
           compare = -1;
         } else if (i < signature_length) {
           compare = 1;
         }
       }
     }
     if (compare > 0) {
       lo = mid + 1;
     } else if (compare < 0) {
       hi = mid - 1;
     } else {
       return &proto;
     }
   }
   return nullptr;
 }

 // Given a signature place the type ids into the given vector
 bool DexFile::CreateTypeList(const StringPiece& signature,
                              dex::TypeIndex* return_type_idx,
                              std::vector<dex::TypeIndex>* param_type_idxs) const {
   if (signature[0] != '(') {
     return false;
   }
   size_t offset = 1;
   size_t end = signature.size();
   bool process_return = false;
   while (offset < end) {
     size_t start_offset = offset;
     char c = signature[offset];
     offset++;
     if (c == ')') {
       process_return = true;
       continue;
     }
     while (c == '[') {  // process array prefix
       if (offset >= end) {  // expect some descriptor following [
         return false;
       }
       c = signature[offset];
       offset++;
     }
     if (c == 'L') {  // process type descriptors
       do {
         if (offset >= end) {  // unexpected early termination of descriptor
           return false;
         }
         c = signature[offset];
         offset++;
       } while (c != ';');
     }
     // TODO: avoid creating a std::string just to get a 0-terminated char array
     std::string descriptor(signature.data() + start_offset, offset - start_offset);
     const TypeId* type_id = FindTypeId(descriptor.c_str());
     if (type_id == nullptr) {
       return false;
     }
     dex::TypeIndex type_idx = GetIndexForTypeId(*type_id);
     if (!process_return) {
       param_type_idxs->push_back(type_idx);
     } else {
       *return_type_idx = type_idx;
       return offset == end;  // return true if the signature had reached a sensible end
     }
   }
   return false;  // failed to correctly parse return type
 }

 const Signature DexFile::CreateSignature(const StringPiece& signature) const {
   dex::TypeIndex return_type_idx;
   std::vector<dex::TypeIndex> param_type_indices;
   bool success = CreateTypeList(signature, &return_type_idx, &param_type_indices);
   if (!success) {
     return Signature::NoSignature();
   }
   const ProtoId* proto_id = FindProtoId(return_type_idx, param_type_indices);
   if (proto_id == nullptr) {
     return Signature::NoSignature();
   }
   return Signature(this, *proto_id);
 }

 int32_t DexFile::FindTryItem(const TryItem* try_items, uint32_t tries_size, uint32_t address) {
   uint32_t min = 0;
   uint32_t max = tries_size;
   while (min < max) {
     const uint32_t mid = (min + max) / 2;

     const TryItem& ti = try_items[mid];
     const uint32_t start = ti.start_addr_;
     const uint32_t end = start + ti.insn_count_;

     if (address < start) {
       max = mid;
     } else if (address >= end) {
       min = mid + 1;
     } else {  // We have a winner!
       return mid;
     }
   }
   // No match.
   return -1;
 }

 // Read a signed integer.  "zwidth" is the zero-based byte count.
 int32_t DexFile::ReadSignedInt(const uint8_t* ptr, int zwidth) {
   int32_t val = 0;
   for (int i = zwidth; i >= 0; --i) {
     val = ((uint32_t)val >> 8) | (((int32_t)*ptr++) << 24);
   }
   val >>= (3 - zwidth) * 8;
   return val;
 }

 // Read an unsigned integer.  "zwidth" is the zero-based byte count,
 // "fill_on_right" indicates which side we want to zero-fill from.
 uint32_t DexFile::ReadUnsignedInt(const uint8_t* ptr, int zwidth, bool fill_on_right) {
   uint32_t val = 0;
   for (int i = zwidth; i >= 0; --i) {
     val = (val >> 8) | (((uint32_t)*ptr++) << 24);
   }
   if (!fill_on_right) {
     val >>= (3 - zwidth) * 8;
   }
   return val;
 }

 // Read a signed long.  "zwidth" is the zero-based byte count.
 int64_t DexFile::ReadSignedLong(const uint8_t* ptr, int zwidth) {
   int64_t val = 0;
   for (int i = zwidth; i >= 0; --i) {
     val = ((uint64_t)val >> 8) | (((int64_t)*ptr++) << 56);
   }
   val >>= (7 - zwidth) * 8;
   return val;
 }

 // Read an unsigned long.  "zwidth" is the zero-based byte count,
 // "fill_on_right" indicates which side we want to zero-fill from.
 uint64_t DexFile::ReadUnsignedLong(const uint8_t* ptr, int zwidth, bool fill_on_right) {
   uint64_t val = 0;
   for (int i = zwidth; i >= 0; --i) {
     val = (val >> 8) | (((uint64_t)*ptr++) << 56);
   }
   if (!fill_on_right) {
     val >>= (7 - zwidth) * 8;
   }
   return val;
 }

 std::string DexFile::PrettyMethod(uint32_t method_idx, bool with_signature) const {
   if (method_idx >= NumMethodIds()) {
     return StringPrintf("<<invalid-method-idx-%d>>", method_idx);
   }
   const MethodId& method_id = GetMethodId(method_idx);
   std::string result;
   const ProtoId* proto_id = with_signature ? &GetProtoId(method_id.proto_idx_) : nullptr;
   if (with_signature) {
     AppendPrettyDescriptor(StringByTypeIdx(proto_id->return_type_idx_), &result);
     result += ' ';
   }
   AppendPrettyDescriptor(GetMethodDeclaringClassDescriptor(method_id), &result);
   result += '.';
   result += GetMethodName(method_id);
   if (with_signature) {
     result += '(';
     const TypeList* params = GetProtoParameters(*proto_id);
     if (params != nullptr) {
       const char* separator = "";
       for (uint32_t i = 0u, size = params->Size(); i != size; ++i) {
         result += separator;
         separator = ", ";
         AppendPrettyDescriptor(StringByTypeIdx(params->GetTypeItem(i).type_idx_), &result);
       }
     }
     result += ')';
   }
   return result;
 }

 std::string DexFile::PrettyField(uint32_t field_idx, bool with_type) const {
   if (field_idx >= NumFieldIds()) {
     return StringPrintf("<<invalid-field-idx-%d>>", field_idx);
   }
   const FieldId& field_id = GetFieldId(field_idx);
   std::string result;
   if (with_type) {
     result += GetFieldTypeDescriptor(field_id);
     result += ' ';
   }
   AppendPrettyDescriptor(GetFieldDeclaringClassDescriptor(field_id), &result);
   result += '.';
   result += GetFieldName(field_id);
   return result;
 }

 std::string DexFile::PrettyType(dex::TypeIndex type_idx) const {
   if (type_idx.index_ >= NumTypeIds()) {
     return StringPrintf("<<invalid-type-idx-%d>>", type_idx.index_);
   }
   const TypeId& type_id = GetTypeId(type_idx);
   return PrettyDescriptor(GetTypeDescriptor(type_id));
 }

 dex::ProtoIndex DexFile::GetProtoIndexForCallSite(uint32_t call_site_idx) const {
   const CallSiteIdItem& csi = GetCallSiteId(call_site_idx);
   CallSiteArrayValueIterator it(*this, csi);
   it.Next();
   it.Next();
   DCHECK_EQ(EncodedArrayValueIterator::ValueType::kMethodType, it.GetValueType());
   return dex::ProtoIndex(it.GetJavaValue().i);
 }

 // Checks that visibility is as expected. Includes special behavior for M and
 // before to allow runtime and build visibility when expecting runtime.
 std::ostream& operator<<(std::ostream& os, const DexFile& dex_file) {
   os << StringPrintf("[DexFile: %s dex-checksum=%08x location-checksum=%08x %p-%p]",
                      dex_file.GetLocation().c_str(),
                      dex_file.GetHeader().checksum_, dex_file.GetLocationChecksum(),
                      dex_file.Begin(), dex_file.Begin() + dex_file.Size());
   return os;
 }

 EncodedArrayValueIterator::EncodedArrayValueIterator(const DexFile& dex_file,
                                                      const uint8_t* array_data)
     : dex_file_(dex_file),
       array_size_(),
       pos_(-1),
       ptr_(array_data),
       type_(kByte) {
   array_size_ = (ptr_ != nullptr) ? DecodeUnsignedLeb128(&ptr_) : 0;
   if (array_size_ > 0) {
     Next();
   }
 }

 void EncodedArrayValueIterator::Next() {
   pos_++;
   if (pos_ >= array_size_) {
     return;
   }
   uint8_t value_type = *ptr_++;
   uint8_t value_arg = value_type >> kEncodedValueArgShift;
   size_t width = value_arg + 1;  // assume and correct later
   type_ = static_cast<ValueType>(value_type & kEncodedValueTypeMask);
   switch (type_) {
   case kBoolean:
     jval_.i = (value_arg != 0) ? 1 : 0;
     width = 0;
     break;
   case kByte:
     jval_.i = DexFile::ReadSignedInt(ptr_, value_arg);
     CHECK(IsInt<8>(jval_.i));
     break;
   case kShort:
     jval_.i = DexFile::ReadSignedInt(ptr_, value_arg);
     CHECK(IsInt<16>(jval_.i));
     break;
   case kChar:
     jval_.i = DexFile::ReadUnsignedInt(ptr_, value_arg, false);
     CHECK(IsUint<16>(jval_.i));
     break;
   case kInt:
     jval_.i = DexFile::ReadSignedInt(ptr_, value_arg);
     break;
   case kLong:
     jval_.j = DexFile::ReadSignedLong(ptr_, value_arg);
     break;
   case kFloat:
     jval_.i = DexFile::ReadUnsignedInt(ptr_, value_arg, true);
     break;
   case kDouble:
     jval_.j = DexFile::ReadUnsignedLong(ptr_, value_arg, true);
     break;
   case kString:
   case kType:
   case kMethodType:
   case kMethodHandle:
     jval_.i = DexFile::ReadUnsignedInt(ptr_, value_arg, false);
     break;
   case kField:
   case kMethod:
   case kEnum:
   case kArray:
   case kAnnotation:
     UNIMPLEMENTED(FATAL) << ": type " << type_;
     UNREACHABLE();
   case kNull:
     jval_.l = nullptr;
     width = 0;
     break;
   default:
     LOG(FATAL) << "Unreached";
     UNREACHABLE();
   }
   ptr_ += width;
 }

 namespace dex {

 std::ostream& operator<<(std::ostream& os, const ProtoIndex& index) {
   os << "ProtoIndex[" << index.index_ << "]";
   return os;
 }

 std::ostream& operator<<(std::ostream& os, const StringIndex& index) {
   os << "StringIndex[" << index.index_ << "]";
   return os;
 }

 std::ostream& operator<<(std::ostream& os, const TypeIndex& index) {
   os << "TypeIndex[" << index.index_ << "]";
   return os;
 }

 }  // namespace dex

 }  // namespace art
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "dex_file.h"

	#include <limits.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <zlib.h>

	#include <memory>
	#include <ostream>
	#include <sstream>
	#include <type_traits>

	#include "android-base/stringprintf.h"

	#include "base/enums.h"
	#include "base/leb128.h"
	#include "base/stl_util.h"
	#include "class_accessor-inl.h"
	#include "descriptors_names.h"
	#include "dex_file-inl.h"
	#include "standard_dex_file.h"
	#include "utf-inl.h"

	namespace art {

	using android::base::StringPrintf;

	using dex::CallSiteIdItem;
	using dex::ClassDef;
	using dex::FieldId;
	using dex::MapList;
	using dex::MapItem;
	using dex::MethodHandleItem;
	using dex::MethodId;
	using dex::ProtoId;
	using dex::StringId;
	using dex::TryItem;
	using dex::TypeId;
	using dex::TypeList;

	static_assert(sizeof(dex::StringIndex) == sizeof(uint32_t), "StringIndex size is wrong");
	static_assert(std::is_trivially_copyable<dex::StringIndex>::value, "StringIndex not trivial");
	static_assert(sizeof(dex::TypeIndex) == sizeof(uint16_t), "TypeIndex size is wrong");
	static_assert(std::is_trivially_copyable<dex::TypeIndex>::value, "TypeIndex not trivial");

	uint32_t DexFile::CalculateChecksum() const {
	return CalculateChecksum(Begin(), Size());
	}

	uint32_t DexFile::CalculateChecksum(const uint8_t* begin, size_t size) {
	const uint32_t non_sum_bytes = OFFSETOF_MEMBER(DexFile::Header, signature_);
	return ChecksumMemoryRange(begin + non_sum_bytes, size - non_sum_bytes);
	}

	uint32_t DexFile::ChecksumMemoryRange(const uint8_t* begin, size_t size) {
	return adler32(adler32(0L, Z_NULL, 0), begin, size);
	}

	int DexFile::GetPermissions() const {
	CHECK(container_.get() != nullptr);
	return container_->GetPermissions();
	}

	bool DexFile::IsReadOnly() const {
	CHECK(container_.get() != nullptr);
	return container_->IsReadOnly();
	}

	bool DexFile::EnableWrite() const {
	CHECK(container_.get() != nullptr);
	return container_->EnableWrite();
	}

	bool DexFile::DisableWrite() const {
	CHECK(container_.get() != nullptr);
	return container_->DisableWrite();
	}

	DexFile::DexFile(const uint8_t* base,
	size_t size,
	const uint8_t* data_begin,
	size_t data_size,
	const std::string& location,
	uint32_t location_checksum,
	const OatDexFile* oat_dex_file,
	std::unique_ptr<DexFileContainer> container,
	bool is_compact_dex)
	: begin_(base),
	size_(size),
	data_begin_(data_begin),
	data_size_(data_size),
	location_(location),
	location_checksum_(location_checksum),
	header_(reinterpret_cast<const Header*>(base)),
	string_ids_(reinterpret_cast<const StringId*>(base + header_->string_ids_off_)),
	type_ids_(reinterpret_cast<const TypeId*>(base + header_->type_ids_off_)),
	field_ids_(reinterpret_cast<const FieldId*>(base + header_->field_ids_off_)),
	method_ids_(reinterpret_cast<const MethodId*>(base + header_->method_ids_off_)),
	proto_ids_(reinterpret_cast<const ProtoId*>(base + header_->proto_ids_off_)),
	class_defs_(reinterpret_cast<const ClassDef*>(base + header_->class_defs_off_)),
	method_handles_(nullptr),
	num_method_handles_(0),
	call_site_ids_(nullptr),
	num_call_site_ids_(0),
	hiddenapi_class_data_(nullptr),
	oat_dex_file_(oat_dex_file),
	container_(std::move(container)),
	is_compact_dex_(is_compact_dex),
	is_platform_dex_(false) {
	CHECK(begin_ != nullptr) << GetLocation();
	CHECK_GT(size_, 0U) << GetLocation();
	// Check base (=header) alignment.
	// Must be 4-byte aligned to avoid undefined behavior when accessing
	// any of the sections via a pointer.
	CHECK_ALIGNED(begin_, alignof(Header));

	InitializeSectionsFromMapList();
	}

	DexFile::~DexFile() {
	// We don't call DeleteGlobalRef on dex_object_ because we're only called by DestroyJavaVM, and
	// that's only called after DetachCurrentThread, which means there's no JNIEnv. We could
	// re-attach, but cleaning up these global references is not obviously useful. It's not as if
	// the global reference table is otherwise empty!
	}

	bool DexFile::Init(std::string* error_msg) {
	if (!CheckMagicAndVersion(error_msg)) {
	return false;
	}
	return true;
	}

	bool DexFile::CheckMagicAndVersion(std::string* error_msg) const {
	if (!IsMagicValid()) {
	std::ostringstream oss;
	oss << "Unrecognized magic number in " << GetLocation() << ":"
	<< " " << header_->magic_[0]
	<< " " << header_->magic_[1]
	<< " " << header_->magic_[2]
	<< " " << header_->magic_[3];
	*error_msg = oss.str();
	return false;
	}
	if (!IsVersionValid()) {
	std::ostringstream oss;
	oss << "Unrecognized version number in " << GetLocation() << ":"
	<< " " << header_->magic_[4]
	<< " " << header_->magic_[5]
	<< " " << header_->magic_[6]
	<< " " << header_->magic_[7];
	*error_msg = oss.str();
	return false;
	}
	return true;
	}

	void DexFile::InitializeSectionsFromMapList() {
	const MapList* map_list = reinterpret_cast<const MapList*>(DataBegin() + header_->map_off_);
	if (header_->map_off_ == 0 \|\| header_->map_off_ > DataSize()) {
	// Bad offset. The dex file verifier runs after this method and will reject the file.
	return;
	}
	const size_t count = map_list->size_;

	size_t map_limit = header_->map_off_ + count * sizeof(MapItem);
	if (header_->map_off_ >= map_limit \|\| map_limit > DataSize()) {
	// Overflow or out out of bounds. The dex file verifier runs after
	// this method and will reject the file as it is malformed.
	return;
	}

	for (size_t i = 0; i < count; ++i) {
	const MapItem& map_item = map_list->list_[i];
	if (map_item.type_ == kDexTypeMethodHandleItem) {
	method_handles_ = reinterpret_cast<const MethodHandleItem*>(Begin() + map_item.offset_);
	num_method_handles_ = map_item.size_;
	} else if (map_item.type_ == kDexTypeCallSiteIdItem) {
	call_site_ids_ = reinterpret_cast<const CallSiteIdItem*>(Begin() + map_item.offset_);
	num_call_site_ids_ = map_item.size_;
	} else if (map_item.type_ == kDexTypeHiddenapiClassData) {
	hiddenapi_class_data_ = GetHiddenapiClassDataAtOffset(map_item.offset_);
	} else {
	// Pointers to other sections are not necessary to retain in the DexFile struct.
	// Other items have pointers directly into their data.
	}
	}
	}

	uint32_t DexFile::Header::GetVersion() const {
	const char* version = reinterpret_cast<const char*>(&magic_[kDexMagicSize]);
	return atoi(version);
	}

	const ClassDef* DexFile::FindClassDef(dex::TypeIndex type_idx) const {
	size_t num_class_defs = NumClassDefs();
	// Fast path for rare no class defs case.
	if (num_class_defs == 0) {
	return nullptr;
	}
	for (size_t i = 0; i < num_class_defs; ++i) {
	const ClassDef& class_def = GetClassDef(i);
	if (class_def.class_idx_ == type_idx) {
	return &class_def;
	}
	}
	return nullptr;
	}

	uint32_t DexFile::FindCodeItemOffset(const ClassDef& class_def, uint32_t method_idx) const {
	ClassAccessor accessor(*this, class_def);
	CHECK(accessor.HasClassData());
	for (const ClassAccessor::Method& method : accessor.GetMethods()) {
	if (method.GetIndex() == method_idx) {
	return method.GetCodeItemOffset();
	}
	}
	LOG(FATAL) << "Unable to find method " << method_idx;
	UNREACHABLE();
	}

	const FieldId* DexFile::FindFieldId(const TypeId& declaring_klass,
	const StringId& name,
	const TypeId& type) const {
	// Binary search MethodIds knowing that they are sorted by class_idx, name_idx then proto_idx
	const dex::TypeIndex class_idx = GetIndexForTypeId(declaring_klass);
	const dex::StringIndex name_idx = GetIndexForStringId(name);
	const dex::TypeIndex type_idx = GetIndexForTypeId(type);
	int32_t lo = 0;
	int32_t hi = NumFieldIds() - 1;
	while (hi >= lo) {
	int32_t mid = (hi + lo) / 2;
	const FieldId& field = GetFieldId(mid);
	if (class_idx > field.class_idx_) {
	lo = mid + 1;
	} else if (class_idx < field.class_idx_) {
	hi = mid - 1;
	} else {
	if (name_idx > field.name_idx_) {
	lo = mid + 1;
	} else if (name_idx < field.name_idx_) {
	hi = mid - 1;
	} else {
	if (type_idx > field.type_idx_) {
	lo = mid + 1;
	} else if (type_idx < field.type_idx_) {
	hi = mid - 1;
	} else {
	return &field;
	}
	}
	}
	}
	return nullptr;
	}

	const MethodId* DexFile::FindMethodId(const TypeId& declaring_klass,
	const StringId& name,
	const ProtoId& signature) const {
	// Binary search MethodIds knowing that they are sorted by class_idx, name_idx then proto_idx
	const dex::TypeIndex class_idx = GetIndexForTypeId(declaring_klass);
	const dex::StringIndex name_idx = GetIndexForStringId(name);
	const dex::ProtoIndex proto_idx = GetIndexForProtoId(signature);
	int32_t lo = 0;
	int32_t hi = NumMethodIds() - 1;
	while (hi >= lo) {
	int32_t mid = (hi + lo) / 2;
	const MethodId& method = GetMethodId(mid);
	if (class_idx > method.class_idx_) {
	lo = mid + 1;
	} else if (class_idx < method.class_idx_) {
	hi = mid - 1;
	} else {
	if (name_idx > method.name_idx_) {
	lo = mid + 1;
	} else if (name_idx < method.name_idx_) {
	hi = mid - 1;
	} else {
	if (proto_idx > method.proto_idx_) {
	lo = mid + 1;
	} else if (proto_idx < method.proto_idx_) {
	hi = mid - 1;
	} else {
	return &method;
	}
	}
	}
	}
	return nullptr;
	}

	const StringId* DexFile::FindStringId(const char* string) const {
	int32_t lo = 0;
	int32_t hi = NumStringIds() - 1;
	while (hi >= lo) {
	int32_t mid = (hi + lo) / 2;
	const StringId& str_id = GetStringId(dex::StringIndex(mid));
	const char* str = GetStringData(str_id);
	int compare = CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(string, str);
	if (compare > 0) {
	lo = mid + 1;
	} else if (compare < 0) {
	hi = mid - 1;
	} else {
	return &str_id;
	}
	}
	return nullptr;
	}

	const TypeId* DexFile::FindTypeId(const char* string) const {
	int32_t lo = 0;
	int32_t hi = NumTypeIds() - 1;
	while (hi >= lo) {
	int32_t mid = (hi + lo) / 2;
	const TypeId& type_id = GetTypeId(dex::TypeIndex(mid));
	const StringId& str_id = GetStringId(type_id.descriptor_idx_);
	const char* str = GetStringData(str_id);
	int compare = CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(string, str);
	if (compare > 0) {
	lo = mid + 1;
	} else if (compare < 0) {
	hi = mid - 1;
	} else {
	return &type_id;
	}
	}
	return nullptr;
	}

	const TypeId* DexFile::FindTypeId(dex::StringIndex string_idx) const {
	int32_t lo = 0;
	int32_t hi = NumTypeIds() - 1;
	while (hi >= lo) {
	int32_t mid = (hi + lo) / 2;
	const TypeId& type_id = GetTypeId(dex::TypeIndex(mid));
	if (string_idx > type_id.descriptor_idx_) {
	lo = mid + 1;
	} else if (string_idx < type_id.descriptor_idx_) {
	hi = mid - 1;
	} else {
	return &type_id;
	}
	}
	return nullptr;
	}

	const ProtoId* DexFile::FindProtoId(dex::TypeIndex return_type_idx,
	const dex::TypeIndex* signature_type_idxs,
	uint32_t signature_length) const {
	int32_t lo = 0;
	int32_t hi = NumProtoIds() - 1;
	while (hi >= lo) {
	int32_t mid = (hi + lo) / 2;
	const dex::ProtoIndex proto_idx = static_cast<dex::ProtoIndex>(mid);
	const ProtoId& proto = GetProtoId(proto_idx);
	int compare = return_type_idx.index_ - proto.return_type_idx_.index_;
	if (compare == 0) {
	DexFileParameterIterator it(*this, proto);
	size_t i = 0;
	while (it.HasNext() && i < signature_length && compare == 0) {
	compare = signature_type_idxs[i].index_ - it.GetTypeIdx().index_;
	it.Next();
	i++;
	}
	if (compare == 0) {
	if (it.HasNext()) {
	compare = -1;
	} else if (i < signature_length) {
	compare = 1;
	}
	}
	}
	if (compare > 0) {
	lo = mid + 1;
	} else if (compare < 0) {
	hi = mid - 1;
	} else {
	return &proto;
	}
	}
	return nullptr;
	}

	// Given a signature place the type ids into the given vector
	bool DexFile::CreateTypeList(const StringPiece& signature,
	dex::TypeIndex* return_type_idx,
	std::vector<dex::TypeIndex>* param_type_idxs) const {
	if (signature[0] != '(') {
	return false;
	}
	size_t offset = 1;
	size_t end = signature.size();
	bool process_return = false;
	while (offset < end) {
	size_t start_offset = offset;
	char c = signature[offset];
	offset++;
	if (c == ')') {
	process_return = true;
	continue;
	}
	while (c == '[') { // process array prefix
	if (offset >= end) { // expect some descriptor following [
	return false;
	}
	c = signature[offset];
	offset++;
	}
	if (c == 'L') { // process type descriptors
	do {
	if (offset >= end) { // unexpected early termination of descriptor
	return false;
	}
	c = signature[offset];
	offset++;
	} while (c != ';');
	}
	// TODO: avoid creating a std::string just to get a 0-terminated char array
	std::string descriptor(signature.data() + start_offset, offset - start_offset);
	const TypeId* type_id = FindTypeId(descriptor.c_str());
	if (type_id == nullptr) {
	return false;
	}
	dex::TypeIndex type_idx = GetIndexForTypeId(*type_id);
	if (!process_return) {
	param_type_idxs->push_back(type_idx);
	} else {
	*return_type_idx = type_idx;
	return offset == end; // return true if the signature had reached a sensible end
	}
	}
	return false; // failed to correctly parse return type
	}

	const Signature DexFile::CreateSignature(const StringPiece& signature) const {
	dex::TypeIndex return_type_idx;
	std::vector<dex::TypeIndex> param_type_indices;
	bool success = CreateTypeList(signature, &return_type_idx, &param_type_indices);
	if (!success) {
	return Signature::NoSignature();
	}
	const ProtoId* proto_id = FindProtoId(return_type_idx, param_type_indices);
	if (proto_id == nullptr) {
	return Signature::NoSignature();
	}
	return Signature(this, *proto_id);
	}

	int32_t DexFile::FindTryItem(const TryItem* try_items, uint32_t tries_size, uint32_t address) {
	uint32_t min = 0;
	uint32_t max = tries_size;
	while (min < max) {
	const uint32_t mid = (min + max) / 2;

	const TryItem& ti = try_items[mid];
	const uint32_t start = ti.start_addr_;
	const uint32_t end = start + ti.insn_count_;

	if (address < start) {
	max = mid;
	} else if (address >= end) {
	min = mid + 1;
	} else { // We have a winner!
	return mid;
	}
	}
	// No match.
	return -1;
	}

	// Read a signed integer. "zwidth" is the zero-based byte count.
	int32_t DexFile::ReadSignedInt(const uint8_t* ptr, int zwidth) {
	int32_t val = 0;
	for (int i = zwidth; i >= 0; --i) {
	val = ((uint32_t)val >> 8) \| (((int32_t)*ptr++) << 24);
	}
	val >>= (3 - zwidth) * 8;
	return val;
	}

	// Read an unsigned integer. "zwidth" is the zero-based byte count,
	// "fill_on_right" indicates which side we want to zero-fill from.
	uint32_t DexFile::ReadUnsignedInt(const uint8_t* ptr, int zwidth, bool fill_on_right) {
	uint32_t val = 0;
	for (int i = zwidth; i >= 0; --i) {
	val = (val >> 8) \| (((uint32_t)*ptr++) << 24);
	}
	if (!fill_on_right) {
	val >>= (3 - zwidth) * 8;
	}
	return val;
	}

	// Read a signed long. "zwidth" is the zero-based byte count.
	int64_t DexFile::ReadSignedLong(const uint8_t* ptr, int zwidth) {
	int64_t val = 0;
	for (int i = zwidth; i >= 0; --i) {
	val = ((uint64_t)val >> 8) \| (((int64_t)*ptr++) << 56);
	}
	val >>= (7 - zwidth) * 8;
	return val;
	}

	// Read an unsigned long. "zwidth" is the zero-based byte count,
	// "fill_on_right" indicates which side we want to zero-fill from.
	uint64_t DexFile::ReadUnsignedLong(const uint8_t* ptr, int zwidth, bool fill_on_right) {
	uint64_t val = 0;
	for (int i = zwidth; i >= 0; --i) {
	val = (val >> 8) \| (((uint64_t)*ptr++) << 56);
	}
	if (!fill_on_right) {
	val >>= (7 - zwidth) * 8;
	}
	return val;
	}

	std::string DexFile::PrettyMethod(uint32_t method_idx, bool with_signature) const {
	if (method_idx >= NumMethodIds()) {
	return StringPrintf("<<invalid-method-idx-%d>>", method_idx);
	}
	const MethodId& method_id = GetMethodId(method_idx);
	std::string result;
	const ProtoId* proto_id = with_signature ? &GetProtoId(method_id.proto_idx_) : nullptr;
	if (with_signature) {
	AppendPrettyDescriptor(StringByTypeIdx(proto_id->return_type_idx_), &result);
	result += ' ';
	}
	AppendPrettyDescriptor(GetMethodDeclaringClassDescriptor(method_id), &result);
	result += '.';
	result += GetMethodName(method_id);
	if (with_signature) {
	result += '(';
	const TypeList* params = GetProtoParameters(*proto_id);
	if (params != nullptr) {
	const char* separator = "";
	for (uint32_t i = 0u, size = params->Size(); i != size; ++i) {
	result += separator;
	separator = ", ";
	AppendPrettyDescriptor(StringByTypeIdx(params->GetTypeItem(i).type_idx_), &result);
	}
	}
	result += ')';
	}
	return result;
	}

	std::string DexFile::PrettyField(uint32_t field_idx, bool with_type) const {
	if (field_idx >= NumFieldIds()) {
	return StringPrintf("<<invalid-field-idx-%d>>", field_idx);
	}
	const FieldId& field_id = GetFieldId(field_idx);
	std::string result;
	if (with_type) {
	result += GetFieldTypeDescriptor(field_id);
	result += ' ';
	}
	AppendPrettyDescriptor(GetFieldDeclaringClassDescriptor(field_id), &result);
	result += '.';
	result += GetFieldName(field_id);
	return result;
	}

	std::string DexFile::PrettyType(dex::TypeIndex type_idx) const {
	if (type_idx.index_ >= NumTypeIds()) {
	return StringPrintf("<<invalid-type-idx-%d>>", type_idx.index_);
	}
	const TypeId& type_id = GetTypeId(type_idx);
	return PrettyDescriptor(GetTypeDescriptor(type_id));
	}

	dex::ProtoIndex DexFile::GetProtoIndexForCallSite(uint32_t call_site_idx) const {
	const CallSiteIdItem& csi = GetCallSiteId(call_site_idx);
	CallSiteArrayValueIterator it(*this, csi);
	it.Next();
	it.Next();
	DCHECK_EQ(EncodedArrayValueIterator::ValueType::kMethodType, it.GetValueType());
	return dex::ProtoIndex(it.GetJavaValue().i);
	}

	// Checks that visibility is as expected. Includes special behavior for M and
	// before to allow runtime and build visibility when expecting runtime.
	std::ostream& operator<<(std::ostream& os, const DexFile& dex_file) {
	os << StringPrintf("[DexFile: %s dex-checksum=%08x location-checksum=%08x %p-%p]",
	dex_file.GetLocation().c_str(),
	dex_file.GetHeader().checksum_, dex_file.GetLocationChecksum(),
	dex_file.Begin(), dex_file.Begin() + dex_file.Size());
	return os;
	}

	EncodedArrayValueIterator::EncodedArrayValueIterator(const DexFile& dex_file,
	const uint8_t* array_data)
	: dex_file_(dex_file),
	array_size_(),
	pos_(-1),
	ptr_(array_data),
	type_(kByte) {
	array_size_ = (ptr_ != nullptr) ? DecodeUnsignedLeb128(&ptr_) : 0;
	if (array_size_ > 0) {
	Next();
	}
	}

	void EncodedArrayValueIterator::Next() {
	pos_++;
	if (pos_ >= array_size_) {
	return;
	}
	uint8_t value_type = *ptr_++;
	uint8_t value_arg = value_type >> kEncodedValueArgShift;
	size_t width = value_arg + 1; // assume and correct later
	type_ = static_cast<ValueType>(value_type & kEncodedValueTypeMask);
	switch (type_) {
	case kBoolean:
	jval_.i = (value_arg != 0) ? 1 : 0;
	width = 0;
	break;
	case kByte:
	jval_.i = DexFile::ReadSignedInt(ptr_, value_arg);
	CHECK(IsInt<8>(jval_.i));
	break;
	case kShort:
	jval_.i = DexFile::ReadSignedInt(ptr_, value_arg);
	CHECK(IsInt<16>(jval_.i));
	break;
	case kChar:
	jval_.i = DexFile::ReadUnsignedInt(ptr_, value_arg, false);
	CHECK(IsUint<16>(jval_.i));
	break;
	case kInt:
	jval_.i = DexFile::ReadSignedInt(ptr_, value_arg);
	break;
	case kLong:
	jval_.j = DexFile::ReadSignedLong(ptr_, value_arg);
	break;
	case kFloat:
	jval_.i = DexFile::ReadUnsignedInt(ptr_, value_arg, true);
	break;
	case kDouble:
	jval_.j = DexFile::ReadUnsignedLong(ptr_, value_arg, true);
	break;
	case kString:
	case kType:
	case kMethodType:
	case kMethodHandle:
	jval_.i = DexFile::ReadUnsignedInt(ptr_, value_arg, false);
	break;
	case kField:
	case kMethod:
	case kEnum:
	case kArray:
	case kAnnotation:
	UNIMPLEMENTED(FATAL) << ": type " << type_;
	UNREACHABLE();
	case kNull:
	jval_.l = nullptr;
	width = 0;
	break;
	default:
	LOG(FATAL) << "Unreached";
	UNREACHABLE();
	}
	ptr_ += width;
	}

	namespace dex {

	std::ostream& operator<<(std::ostream& os, const ProtoIndex& index) {
	os << "ProtoIndex[" << index.index_ << "]";
	return os;
	}

	std::ostream& operator<<(std::ostream& os, const StringIndex& index) {
	os << "StringIndex[" << index.index_ << "]";
	return os;
	}

	std::ostream& operator<<(std::ostream& os, const TypeIndex& index) {
	os << "TypeIndex[" << index.index_ << "]";
	return os;
	}

	} // namespace dex

	} // namespace art