libdexfile/dex/test_dex_file_builder.h - platform/art - Gitiles

 /*
  * Copyright (C) 2015 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.
  */

 #ifndef ART_LIBDEXFILE_DEX_TEST_DEX_FILE_BUILDER_H_
 #define ART_LIBDEXFILE_DEX_TEST_DEX_FILE_BUILDER_H_

 #include <zlib.h>

 #include <cstring>
 #include <map>
 #include <set>
 #include <vector>

 #include <android-base/logging.h>

 #include "base/bit_utils.h"
 #include "dex/dex_file_loader.h"
 #include "dex/standard_dex_file.h"

 namespace art {

 class TestDexFileBuilder {
  public:
   TestDexFileBuilder()
       : strings_(), types_(), fields_(), protos_(), dex_file_data_() {
   }

   void AddString(const std::string& str) {
     CHECK(dex_file_data_.empty());
     auto it = strings_.emplace(str, IdxAndDataOffset()).first;
     CHECK_LT(it->first.length(), 128u);  // Don't allow multi-byte length in uleb128.
   }

   void AddType(const std::string& descriptor) {
     CHECK(dex_file_data_.empty());
     AddString(descriptor);
     types_.emplace(descriptor, 0u);
   }

   void AddField(const std::string& class_descriptor, const std::string& type,
                 const std::string& name) {
     CHECK(dex_file_data_.empty());
     AddType(class_descriptor);
     AddType(type);
     AddString(name);
     FieldKey key = { class_descriptor, type, name };
     fields_.emplace(key, 0u);
   }

   void AddMethod(const std::string& class_descriptor, const std::string& signature,
                  const std::string& name) {
     CHECK(dex_file_data_.empty());
     AddType(class_descriptor);
     AddString(name);

     ProtoKey proto_key = CreateProtoKey(signature);
     AddString(proto_key.shorty);
     AddType(proto_key.return_type);
     for (const auto& arg_type : proto_key.args) {
       AddType(arg_type);
     }
     auto it = protos_.emplace(proto_key, IdxAndDataOffset()).first;
     const ProtoKey* proto = &it->first;  // Valid as long as the element remains in protos_.

     MethodKey method_key = {
         class_descriptor, name, proto
     };
     methods_.emplace(method_key, 0u);
   }

   // NOTE: The builder holds the actual data, so it must live as long as the dex file.
   std::unique_ptr<const DexFile> Build(const std::string& dex_location) {
     CHECK(dex_file_data_.empty());
     union {
       uint8_t data[sizeof(DexFile::Header)];
       uint64_t force_alignment;
     } header_data;
     std::memset(header_data.data, 0, sizeof(header_data.data));
     DexFile::Header* header = reinterpret_cast<DexFile::Header*>(&header_data.data);
     std::copy_n(StandardDexFile::kDexMagic, 4u, header->magic_);
     std::copy_n(StandardDexFile::kDexMagicVersions[0], 4u, header->magic_ + 4u);
     header->header_size_ = sizeof(DexFile::Header);
     header->endian_tag_ = DexFile::kDexEndianConstant;
     header->link_size_ = 0u;  // Unused.
     header->link_off_ = 0u;  // Unused.
     header->map_off_ = 0u;  // Unused. TODO: This is wrong. Dex files created by this builder
                             //               cannot be verified. b/26808512

     uint32_t data_section_size = 0u;

     uint32_t string_ids_offset = sizeof(DexFile::Header);
     uint32_t string_idx = 0u;
     for (auto& entry : strings_) {
       entry.second.idx = string_idx;
       string_idx += 1u;
       entry.second.data_offset = data_section_size;
       data_section_size += entry.first.length() + 1u /* length */ + 1u /* null-terminator */;
     }
     header->string_ids_size_ = strings_.size();
     header->string_ids_off_ = strings_.empty() ? 0u : string_ids_offset;

     uint32_t type_ids_offset = string_ids_offset + strings_.size() * sizeof(dex::StringId);
     uint32_t type_idx = 0u;
     for (auto& entry : types_) {
       entry.second = type_idx;
       type_idx += 1u;
     }
     header->type_ids_size_ = types_.size();
     header->type_ids_off_ = types_.empty() ? 0u : type_ids_offset;

     uint32_t proto_ids_offset = type_ids_offset + types_.size() * sizeof(dex::TypeId);
     uint32_t proto_idx = 0u;
     for (auto& entry : protos_) {
       entry.second.idx = proto_idx;
       proto_idx += 1u;
       size_t num_args = entry.first.args.size();
       if (num_args != 0u) {
         entry.second.data_offset = RoundUp(data_section_size, 4u);
         data_section_size = entry.second.data_offset + 4u + num_args * sizeof(dex::TypeItem);
       } else {
         entry.second.data_offset = 0u;
       }
     }
     header->proto_ids_size_ = protos_.size();
     header->proto_ids_off_ = protos_.empty() ? 0u : proto_ids_offset;

     uint32_t field_ids_offset = proto_ids_offset + protos_.size() * sizeof(dex::ProtoId);
     uint32_t field_idx = 0u;
     for (auto& entry : fields_) {
       entry.second = field_idx;
       field_idx += 1u;
     }
     header->field_ids_size_ = fields_.size();
     header->field_ids_off_ = fields_.empty() ? 0u : field_ids_offset;

     uint32_t method_ids_offset = field_ids_offset + fields_.size() * sizeof(dex::FieldId);
     uint32_t method_idx = 0u;
     for (auto& entry : methods_) {
       entry.second = method_idx;
       method_idx += 1u;
     }
     header->method_ids_size_ = methods_.size();
     header->method_ids_off_ = methods_.empty() ? 0u : method_ids_offset;

     // No class defs.
     header->class_defs_size_ = 0u;
     header->class_defs_off_ = 0u;

     uint32_t data_section_offset = method_ids_offset + methods_.size() * sizeof(dex::MethodId);
     header->data_size_ = data_section_size;
     header->data_off_ = (data_section_size != 0u) ? data_section_offset : 0u;

     uint32_t total_size = data_section_offset + data_section_size;

     dex_file_data_.resize(total_size);

     for (const auto& entry : strings_) {
       CHECK_LT(entry.first.size(), 128u);
       uint32_t raw_offset = data_section_offset + entry.second.data_offset;
       dex_file_data_[raw_offset] = static_cast<uint8_t>(entry.first.size());
       std::memcpy(&dex_file_data_[raw_offset + 1], entry.first.c_str(), entry.first.size() + 1);
       Write32(string_ids_offset + entry.second.idx * sizeof(dex::StringId), raw_offset);
     }

     for (const auto& entry : types_) {
       Write32(type_ids_offset + entry.second * sizeof(dex::TypeId), GetStringIdx(entry.first));
       ++type_idx;
     }

     for (const auto& entry : protos_) {
       size_t num_args = entry.first.args.size();
       uint32_t type_list_offset =
           (num_args != 0u) ? data_section_offset + entry.second.data_offset : 0u;
       uint32_t raw_offset = proto_ids_offset + entry.second.idx * sizeof(dex::ProtoId);
       Write32(raw_offset + 0u, GetStringIdx(entry.first.shorty));
       Write16(raw_offset + 4u, GetTypeIdx(entry.first.return_type));
       Write32(raw_offset + 8u, type_list_offset);
       if (num_args != 0u) {
         CHECK_NE(entry.second.data_offset, 0u);
         Write32(type_list_offset, num_args);
         for (size_t i = 0; i != num_args; ++i) {
           Write16(type_list_offset + 4u + i * sizeof(dex::TypeItem),
                   GetTypeIdx(entry.first.args[i]));
         }
       }
     }

     for (const auto& entry : fields_) {
       uint32_t raw_offset = field_ids_offset + entry.second * sizeof(dex::FieldId);
       Write16(raw_offset + 0u, GetTypeIdx(entry.first.class_descriptor));
       Write16(raw_offset + 2u, GetTypeIdx(entry.first.type));
       Write32(raw_offset + 4u, GetStringIdx(entry.first.name));
     }

     for (const auto& entry : methods_) {
       uint32_t raw_offset = method_ids_offset + entry.second * sizeof(dex::MethodId);
       Write16(raw_offset + 0u, GetTypeIdx(entry.first.class_descriptor));
       auto it = protos_.find(*entry.first.proto);
       CHECK(it != protos_.end());
       Write16(raw_offset + 2u, it->second.idx);
       Write32(raw_offset + 4u, GetStringIdx(entry.first.name));
     }

     // Leave signature as zeros.

     header->file_size_ = dex_file_data_.size();

     // Write the complete header early, as part of it needs to be checksummed.
     std::memcpy(&dex_file_data_[0], header_data.data, sizeof(DexFile::Header));

     // Checksum starts after the checksum field.
     size_t skip = sizeof(header->magic_) + sizeof(header->checksum_);
     header->checksum_ = adler32(adler32(0L, Z_NULL, 0),
                                 dex_file_data_.data() + skip,
                                 dex_file_data_.size() - skip);

     // Write the complete header again, just simpler that way.
     std::memcpy(&dex_file_data_[0], header_data.data, sizeof(DexFile::Header));

     static constexpr bool kVerify = false;
     static constexpr bool kVerifyChecksum = false;
     std::string error_msg;
     const DexFileLoader dex_file_loader;
     std::unique_ptr<const DexFile> dex_file(dex_file_loader.Open(
         &dex_file_data_[0],
         dex_file_data_.size(),
         dex_location,
         0u,
         nullptr,
         kVerify,
         kVerifyChecksum,
         &error_msg));
     CHECK(dex_file != nullptr) << error_msg;
     return dex_file;
   }

   uint32_t GetStringIdx(const std::string& type) {
     auto it = strings_.find(type);
     CHECK(it != strings_.end());
     return it->second.idx;
   }

   uint32_t GetTypeIdx(const std::string& type) {
     auto it = types_.find(type);
     CHECK(it != types_.end());
     return it->second;
   }

   uint32_t GetFieldIdx(const std::string& class_descriptor, const std::string& type,
                        const std::string& name) {
     FieldKey key = { class_descriptor, type, name };
     auto it = fields_.find(key);
     CHECK(it != fields_.end());
     return it->second;
   }

   uint32_t GetMethodIdx(const std::string& class_descriptor, const std::string& signature,
                         const std::string& name) {
     ProtoKey proto_key = CreateProtoKey(signature);
     MethodKey method_key = { class_descriptor, name, &proto_key };
     auto it = methods_.find(method_key);
     CHECK(it != methods_.end());
     return it->second;
   }

  private:
   struct IdxAndDataOffset {
     uint32_t idx;
     uint32_t data_offset;
   };

   struct FieldKey {
     const std::string class_descriptor;
     const std::string type;
     const std::string name;
   };
   struct FieldKeyComparator {
     bool operator()(const FieldKey& lhs, const FieldKey& rhs) const {
       if (lhs.class_descriptor != rhs.class_descriptor) {
         return lhs.class_descriptor < rhs.class_descriptor;
       }
       if (lhs.name != rhs.name) {
         return lhs.name < rhs.name;
       }
       return lhs.type < rhs.type;
     }
   };

   struct ProtoKey {
     std::string shorty;
     std::string return_type;
     std::vector<std::string> args;
   };
   struct ProtoKeyComparator {
     bool operator()(const ProtoKey& lhs, const ProtoKey& rhs) const {
       if (lhs.return_type != rhs.return_type) {
         return lhs.return_type < rhs.return_type;
       }
       size_t min_args = std::min(lhs.args.size(), rhs.args.size());
       for (size_t i = 0; i != min_args; ++i) {
         if (lhs.args[i] != rhs.args[i]) {
           return lhs.args[i] < rhs.args[i];
         }
       }
       return lhs.args.size() < rhs.args.size();
     }
   };

   struct MethodKey {
     std::string class_descriptor;
     std::string name;
     const ProtoKey* proto;
   };
   struct MethodKeyComparator {
     bool operator()(const MethodKey& lhs, const MethodKey& rhs) const {
       if (lhs.class_descriptor != rhs.class_descriptor) {
         return lhs.class_descriptor < rhs.class_descriptor;
       }
       if (lhs.name != rhs.name) {
         return lhs.name < rhs.name;
       }
       return ProtoKeyComparator()(*lhs.proto, *rhs.proto);
     }
   };

   ProtoKey CreateProtoKey(const std::string& signature) {
     CHECK_EQ(signature[0], '(');
     const char* args = signature.c_str() + 1;
     const char* args_end = std::strchr(args, ')');
     CHECK(args_end != nullptr);
     const char* return_type = args_end + 1;

     ProtoKey key = {
         std::string() + ((*return_type == '[') ? 'L' : *return_type),
         return_type,
         std::vector<std::string>()
     };
     while (args != args_end) {
       key.shorty += (*args == '[') ? 'L' : *args;
       const char* arg_start = args;
       while (*args == '[') {
         ++args;
       }
       if (*args == 'L') {
         do {
           ++args;
           CHECK_NE(args, args_end);
         } while (*args != ';');
       }
       ++args;
       key.args.emplace_back(arg_start, args);
     }
     return key;
   }

   void Write32(size_t offset, uint32_t value) {
     CHECK_LE(offset + 4u, dex_file_data_.size());
     CHECK_EQ(dex_file_data_[offset + 0], 0u);
     CHECK_EQ(dex_file_data_[offset + 1], 0u);
     CHECK_EQ(dex_file_data_[offset + 2], 0u);
     CHECK_EQ(dex_file_data_[offset + 3], 0u);
     dex_file_data_[offset + 0] = static_cast<uint8_t>(value >> 0);
     dex_file_data_[offset + 1] = static_cast<uint8_t>(value >> 8);
     dex_file_data_[offset + 2] = static_cast<uint8_t>(value >> 16);
     dex_file_data_[offset + 3] = static_cast<uint8_t>(value >> 24);
   }

   void Write16(size_t offset, uint32_t value) {
     CHECK_LE(value, 0xffffu);
     CHECK_LE(offset + 2u, dex_file_data_.size());
     CHECK_EQ(dex_file_data_[offset + 0], 0u);
     CHECK_EQ(dex_file_data_[offset + 1], 0u);
     dex_file_data_[offset + 0] = static_cast<uint8_t>(value >> 0);
     dex_file_data_[offset + 1] = static_cast<uint8_t>(value >> 8);
   }

   std::map<std::string, IdxAndDataOffset> strings_;
   std::map<std::string, uint32_t> types_;
   std::map<FieldKey, uint32_t, FieldKeyComparator> fields_;
   std::map<ProtoKey, IdxAndDataOffset, ProtoKeyComparator> protos_;
   std::map<MethodKey, uint32_t, MethodKeyComparator> methods_;

   std::vector<uint8_t> dex_file_data_;
 };

 }  // namespace art

 #endif  // ART_LIBDEXFILE_DEX_TEST_DEX_FILE_BUILDER_H_
	/*
	* Copyright (C) 2015 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.
	*/

	#ifndef ART_LIBDEXFILE_DEX_TEST_DEX_FILE_BUILDER_H_
	#define ART_LIBDEXFILE_DEX_TEST_DEX_FILE_BUILDER_H_

	#include <zlib.h>

	#include <cstring>
	#include <map>
	#include <set>
	#include <vector>

	#include <android-base/logging.h>

	#include "base/bit_utils.h"
	#include "dex/dex_file_loader.h"
	#include "dex/standard_dex_file.h"

	namespace art {

	class TestDexFileBuilder {
	public:
	TestDexFileBuilder()
	: strings_(), types_(), fields_(), protos_(), dex_file_data_() {
	}

	void AddString(const std::string& str) {
	CHECK(dex_file_data_.empty());
	auto it = strings_.emplace(str, IdxAndDataOffset()).first;
	CHECK_LT(it->first.length(), 128u); // Don't allow multi-byte length in uleb128.
	}

	void AddType(const std::string& descriptor) {
	CHECK(dex_file_data_.empty());
	AddString(descriptor);
	types_.emplace(descriptor, 0u);
	}

	void AddField(const std::string& class_descriptor, const std::string& type,
	const std::string& name) {
	CHECK(dex_file_data_.empty());
	AddType(class_descriptor);
	AddType(type);
	AddString(name);
	FieldKey key = { class_descriptor, type, name };
	fields_.emplace(key, 0u);
	}

	void AddMethod(const std::string& class_descriptor, const std::string& signature,
	const std::string& name) {
	CHECK(dex_file_data_.empty());
	AddType(class_descriptor);
	AddString(name);

	ProtoKey proto_key = CreateProtoKey(signature);
	AddString(proto_key.shorty);
	AddType(proto_key.return_type);
	for (const auto& arg_type : proto_key.args) {
	AddType(arg_type);
	}
	auto it = protos_.emplace(proto_key, IdxAndDataOffset()).first;
	const ProtoKey* proto = &it->first; // Valid as long as the element remains in protos_.

	MethodKey method_key = {
	class_descriptor, name, proto
	};
	methods_.emplace(method_key, 0u);
	}

	// NOTE: The builder holds the actual data, so it must live as long as the dex file.
	std::unique_ptr<const DexFile> Build(const std::string& dex_location) {
	CHECK(dex_file_data_.empty());
	union {
	uint8_t data[sizeof(DexFile::Header)];
	uint64_t force_alignment;
	} header_data;
	std::memset(header_data.data, 0, sizeof(header_data.data));
	DexFile::Header* header = reinterpret_cast<DexFile::Header*>(&header_data.data);
	std::copy_n(StandardDexFile::kDexMagic, 4u, header->magic_);
	std::copy_n(StandardDexFile::kDexMagicVersions[0], 4u, header->magic_ + 4u);
	header->header_size_ = sizeof(DexFile::Header);
	header->endian_tag_ = DexFile::kDexEndianConstant;
	header->link_size_ = 0u; // Unused.
	header->link_off_ = 0u; // Unused.
	header->map_off_ = 0u; // Unused. TODO: This is wrong. Dex files created by this builder
	// cannot be verified. b/26808512

	uint32_t data_section_size = 0u;

	uint32_t string_ids_offset = sizeof(DexFile::Header);
	uint32_t string_idx = 0u;
	for (auto& entry : strings_) {
	entry.second.idx = string_idx;
	string_idx += 1u;
	entry.second.data_offset = data_section_size;
	data_section_size += entry.first.length() + 1u /* length / + 1u / null-terminator */;
	}
	header->string_ids_size_ = strings_.size();
	header->string_ids_off_ = strings_.empty() ? 0u : string_ids_offset;

	uint32_t type_ids_offset = string_ids_offset + strings_.size() * sizeof(dex::StringId);
	uint32_t type_idx = 0u;
	for (auto& entry : types_) {
	entry.second = type_idx;
	type_idx += 1u;
	}
	header->type_ids_size_ = types_.size();
	header->type_ids_off_ = types_.empty() ? 0u : type_ids_offset;

	uint32_t proto_ids_offset = type_ids_offset + types_.size() * sizeof(dex::TypeId);
	uint32_t proto_idx = 0u;
	for (auto& entry : protos_) {
	entry.second.idx = proto_idx;
	proto_idx += 1u;
	size_t num_args = entry.first.args.size();
	if (num_args != 0u) {
	entry.second.data_offset = RoundUp(data_section_size, 4u);
	data_section_size = entry.second.data_offset + 4u + num_args * sizeof(dex::TypeItem);
	} else {
	entry.second.data_offset = 0u;
	}
	}
	header->proto_ids_size_ = protos_.size();
	header->proto_ids_off_ = protos_.empty() ? 0u : proto_ids_offset;

	uint32_t field_ids_offset = proto_ids_offset + protos_.size() * sizeof(dex::ProtoId);
	uint32_t field_idx = 0u;
	for (auto& entry : fields_) {
	entry.second = field_idx;
	field_idx += 1u;
	}
	header->field_ids_size_ = fields_.size();
	header->field_ids_off_ = fields_.empty() ? 0u : field_ids_offset;

	uint32_t method_ids_offset = field_ids_offset + fields_.size() * sizeof(dex::FieldId);
	uint32_t method_idx = 0u;
	for (auto& entry : methods_) {
	entry.second = method_idx;
	method_idx += 1u;
	}
	header->method_ids_size_ = methods_.size();
	header->method_ids_off_ = methods_.empty() ? 0u : method_ids_offset;

	// No class defs.
	header->class_defs_size_ = 0u;
	header->class_defs_off_ = 0u;

	uint32_t data_section_offset = method_ids_offset + methods_.size() * sizeof(dex::MethodId);
	header->data_size_ = data_section_size;
	header->data_off_ = (data_section_size != 0u) ? data_section_offset : 0u;

	uint32_t total_size = data_section_offset + data_section_size;

	dex_file_data_.resize(total_size);

	for (const auto& entry : strings_) {
	CHECK_LT(entry.first.size(), 128u);
	uint32_t raw_offset = data_section_offset + entry.second.data_offset;
	dex_file_data_[raw_offset] = static_cast<uint8_t>(entry.first.size());
	std::memcpy(&dex_file_data_[raw_offset + 1], entry.first.c_str(), entry.first.size() + 1);
	Write32(string_ids_offset + entry.second.idx * sizeof(dex::StringId), raw_offset);
	}

	for (const auto& entry : types_) {
	Write32(type_ids_offset + entry.second * sizeof(dex::TypeId), GetStringIdx(entry.first));
	++type_idx;
	}

	for (const auto& entry : protos_) {
	size_t num_args = entry.first.args.size();
	uint32_t type_list_offset =
	(num_args != 0u) ? data_section_offset + entry.second.data_offset : 0u;
	uint32_t raw_offset = proto_ids_offset + entry.second.idx * sizeof(dex::ProtoId);
	Write32(raw_offset + 0u, GetStringIdx(entry.first.shorty));
	Write16(raw_offset + 4u, GetTypeIdx(entry.first.return_type));
	Write32(raw_offset + 8u, type_list_offset);
	if (num_args != 0u) {
	CHECK_NE(entry.second.data_offset, 0u);
	Write32(type_list_offset, num_args);
	for (size_t i = 0; i != num_args; ++i) {
	Write16(type_list_offset + 4u + i * sizeof(dex::TypeItem),
	GetTypeIdx(entry.first.args[i]));
	}
	}
	}

	for (const auto& entry : fields_) {
	uint32_t raw_offset = field_ids_offset + entry.second * sizeof(dex::FieldId);
	Write16(raw_offset + 0u, GetTypeIdx(entry.first.class_descriptor));
	Write16(raw_offset + 2u, GetTypeIdx(entry.first.type));
	Write32(raw_offset + 4u, GetStringIdx(entry.first.name));
	}

	for (const auto& entry : methods_) {
	uint32_t raw_offset = method_ids_offset + entry.second * sizeof(dex::MethodId);
	Write16(raw_offset + 0u, GetTypeIdx(entry.first.class_descriptor));
	auto it = protos_.find(*entry.first.proto);
	CHECK(it != protos_.end());
	Write16(raw_offset + 2u, it->second.idx);
	Write32(raw_offset + 4u, GetStringIdx(entry.first.name));
	}

	// Leave signature as zeros.

	header->file_size_ = dex_file_data_.size();

	// Write the complete header early, as part of it needs to be checksummed.
	std::memcpy(&dex_file_data_[0], header_data.data, sizeof(DexFile::Header));

	// Checksum starts after the checksum field.
	size_t skip = sizeof(header->magic_) + sizeof(header->checksum_);
	header->checksum_ = adler32(adler32(0L, Z_NULL, 0),
	dex_file_data_.data() + skip,
	dex_file_data_.size() - skip);

	// Write the complete header again, just simpler that way.
	std::memcpy(&dex_file_data_[0], header_data.data, sizeof(DexFile::Header));

	static constexpr bool kVerify = false;
	static constexpr bool kVerifyChecksum = false;
	std::string error_msg;
	const DexFileLoader dex_file_loader;
	std::unique_ptr<const DexFile> dex_file(dex_file_loader.Open(
	&dex_file_data_[0],
	dex_file_data_.size(),
	dex_location,
	0u,
	nullptr,
	kVerify,
	kVerifyChecksum,
	&error_msg));
	CHECK(dex_file != nullptr) << error_msg;
	return dex_file;
	}

	uint32_t GetStringIdx(const std::string& type) {
	auto it = strings_.find(type);
	CHECK(it != strings_.end());
	return it->second.idx;
	}

	uint32_t GetTypeIdx(const std::string& type) {
	auto it = types_.find(type);
	CHECK(it != types_.end());
	return it->second;
	}

	uint32_t GetFieldIdx(const std::string& class_descriptor, const std::string& type,
	const std::string& name) {
	FieldKey key = { class_descriptor, type, name };
	auto it = fields_.find(key);
	CHECK(it != fields_.end());
	return it->second;
	}

	uint32_t GetMethodIdx(const std::string& class_descriptor, const std::string& signature,
	const std::string& name) {
	ProtoKey proto_key = CreateProtoKey(signature);
	MethodKey method_key = { class_descriptor, name, &proto_key };
	auto it = methods_.find(method_key);
	CHECK(it != methods_.end());
	return it->second;
	}

	private:
	struct IdxAndDataOffset {
	uint32_t idx;
	uint32_t data_offset;
	};

	struct FieldKey {
	const std::string class_descriptor;
	const std::string type;
	const std::string name;
	};
	struct FieldKeyComparator {
	bool operator()(const FieldKey& lhs, const FieldKey& rhs) const {
	if (lhs.class_descriptor != rhs.class_descriptor) {
	return lhs.class_descriptor < rhs.class_descriptor;
	}
	if (lhs.name != rhs.name) {
	return lhs.name < rhs.name;
	}
	return lhs.type < rhs.type;
	}
	};

	struct ProtoKey {
	std::string shorty;
	std::string return_type;
	std::vector<std::string> args;
	};
	struct ProtoKeyComparator {
	bool operator()(const ProtoKey& lhs, const ProtoKey& rhs) const {
	if (lhs.return_type != rhs.return_type) {
	return lhs.return_type < rhs.return_type;
	}
	size_t min_args = std::min(lhs.args.size(), rhs.args.size());
	for (size_t i = 0; i != min_args; ++i) {
	if (lhs.args[i] != rhs.args[i]) {
	return lhs.args[i] < rhs.args[i];
	}
	}
	return lhs.args.size() < rhs.args.size();
	}
	};

	struct MethodKey {
	std::string class_descriptor;
	std::string name;
	const ProtoKey* proto;
	};
	struct MethodKeyComparator {
	bool operator()(const MethodKey& lhs, const MethodKey& rhs) const {
	if (lhs.class_descriptor != rhs.class_descriptor) {
	return lhs.class_descriptor < rhs.class_descriptor;
	}
	if (lhs.name != rhs.name) {
	return lhs.name < rhs.name;
	}
	return ProtoKeyComparator()(lhs.proto, rhs.proto);
	}
	};

	ProtoKey CreateProtoKey(const std::string& signature) {
	CHECK_EQ(signature[0], '(');
	const char* args = signature.c_str() + 1;
	const char* args_end = std::strchr(args, ')');
	CHECK(args_end != nullptr);
	const char* return_type = args_end + 1;

	ProtoKey key = {
	std::string() + ((return_type == '[') ? 'L' : return_type),
	return_type,
	std::vector<std::string>()
	};
	while (args != args_end) {
	key.shorty += (args == '[') ? 'L' : args;
	const char* arg_start = args;
	while (*args == '[') {
	++args;
	}
	if (*args == 'L') {
	do {
	++args;
	CHECK_NE(args, args_end);
	} while (*args != ';');
	}
	++args;
	key.args.emplace_back(arg_start, args);
	}
	return key;
	}

	void Write32(size_t offset, uint32_t value) {
	CHECK_LE(offset + 4u, dex_file_data_.size());
	CHECK_EQ(dex_file_data_[offset + 0], 0u);
	CHECK_EQ(dex_file_data_[offset + 1], 0u);
	CHECK_EQ(dex_file_data_[offset + 2], 0u);
	CHECK_EQ(dex_file_data_[offset + 3], 0u);
	dex_file_data_[offset + 0] = static_cast<uint8_t>(value >> 0);
	dex_file_data_[offset + 1] = static_cast<uint8_t>(value >> 8);
	dex_file_data_[offset + 2] = static_cast<uint8_t>(value >> 16);
	dex_file_data_[offset + 3] = static_cast<uint8_t>(value >> 24);
	}

	void Write16(size_t offset, uint32_t value) {
	CHECK_LE(value, 0xffffu);
	CHECK_LE(offset + 2u, dex_file_data_.size());
	CHECK_EQ(dex_file_data_[offset + 0], 0u);
	CHECK_EQ(dex_file_data_[offset + 1], 0u);
	dex_file_data_[offset + 0] = static_cast<uint8_t>(value >> 0);
	dex_file_data_[offset + 1] = static_cast<uint8_t>(value >> 8);
	}

	std::map<std::string, IdxAndDataOffset> strings_;
	std::map<std::string, uint32_t> types_;
	std::map<FieldKey, uint32_t, FieldKeyComparator> fields_;
	std::map<ProtoKey, IdxAndDataOffset, ProtoKeyComparator> protos_;
	std::map<MethodKey, uint32_t, MethodKeyComparator> methods_;

	std::vector<uint8_t> dex_file_data_;
	};

	} // namespace art

	#endif // ART_LIBDEXFILE_DEX_TEST_DEX_FILE_BUILDER_H_