src/oat_file.cc - platform/art - Gitiles

 /*
  * 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 "oat_file.h"

 #include <dlfcn.h>

 #include "base/stl_util.h"
 #include "base/unix_file/fd_file.h"
 #include "elf_file.h"
 #include "oat.h"
 #include "mirror/class.h"
 #include "mirror/abstract_method.h"
 #include "mirror/abstract_method-inl.h"
 #include "mirror/object-inl.h"
 #include "os.h"
 #include "utils.h"

 namespace art {

 std::string OatFile::DexFilenameToOatFilename(const std::string& location) {
   CHECK(IsValidDexFilename(location) || IsValidZipFilename(location));
   std::string oat_location(location);
   oat_location += ".oat";
   return oat_location;
 }

 void OatFile::CheckLocation(const std::string& location) {
   CHECK(!location.empty());
   if (!IsValidOatFilename(location)) {
     LOG(WARNING) << "Attempting to open oat file with unknown extension '" << location << "'";
   }
 }

 OatFile* OatFile::OpenMemory(std::vector<uint8_t>& oat_contents,
                              const std::string& location) {
   CHECK(!oat_contents.empty()) << location;
   CheckLocation(location);
   UniquePtr<OatFile> oat_file(new OatFile(location));
   oat_file->begin_ = &oat_contents[0];
   oat_file->end_ = &oat_contents[oat_contents.size()];
   return oat_file->Setup() ? oat_file.release() : NULL;
 }

 OatFile* OatFile::Open(const std::string& filename,
                        const std::string& location,
                        byte* requested_base) {
   CHECK(!filename.empty()) << location;
   CheckLocation(location);
   /*
    * TODO: Reenable dlopen when it works again on MIPS. It may have broken from this change:
    * commit 818d98eb563ad5d7293b8b5c40f3dabf745e611f
    * Author: Brian Carlstrom <bdc@google.com>
    * Date:   Sun Feb 10 21:38:12 2013 -0800
    *
    *    Fix MIPS to use standard kPageSize=0x1000 section alignment for ELF sections
    *
    *    Change-Id: I905f0c5f75921a65bd7426a54d6258c780d85d0e
    */
   OatFile* result = OpenDlopen(filename, location, requested_base);
   if (result != NULL) {
     return result;
   }
   // On target, only used dlopen to load.
   if (kIsTargetBuild) {
     return NULL;
   }
   // On host, dlopen is expected to fail when cross compiling, so fall back to OpenElfFile.
   // This won't work for portable runtime execution because it doesn't process relocations.
   UniquePtr<File> file(OS::OpenFile(filename.c_str(), false, false));
   if (file.get() == NULL) {
     return NULL;
   }
   return OpenElfFile(file.get(), location, requested_base, false);
 }

 OatFile* OatFile::OpenWritable(File* file, const std::string& location) {
   CheckLocation(location);
   return OpenElfFile(file, location, NULL, true);
 }

 OatFile* OatFile::OpenDlopen(const std::string& elf_filename,
                              const std::string& location,
                              byte* requested_base) {
   UniquePtr<OatFile> oat_file(new OatFile(location));
   bool success = oat_file->Dlopen(elf_filename, requested_base);
   if (!success) {
     return NULL;
   }
   return oat_file.release();
 }

 OatFile* OatFile::OpenElfFile(File* file,
                               const std::string& location,
                               byte* requested_base,
                               bool writable) {
   UniquePtr<OatFile> oat_file(new OatFile(location));
   bool success = oat_file->ElfFileOpen(file, requested_base, writable);
   if (!success) {
     return NULL;
   }
   return oat_file.release();
 }

 OatFile::OatFile(const std::string& location)
     : location_(location), begin_(NULL), end_(NULL), dlopen_handle_(NULL) {
   CHECK(!location_.empty());
 }

 OatFile::~OatFile() {
   STLDeleteValues(&oat_dex_files_);
   if (dlopen_handle_ != NULL) {
     dlclose(dlopen_handle_);
   }
 }

 bool OatFile::Dlopen(const std::string& elf_filename, byte* requested_base) {

   char* absolute_path = realpath(elf_filename.c_str(), NULL);
   if (absolute_path == NULL) {
     return false;
   }
   dlopen_handle_ = dlopen(absolute_path, RTLD_NOW);
   free(absolute_path);
   if (dlopen_handle_ == NULL) {
     return false;
   }
   begin_ = reinterpret_cast<byte*>(dlsym(dlopen_handle_, "oatdata"));
   if (begin_ == NULL) {
     LOG(WARNING) << "Failed to find oatdata symbol in " << elf_filename << ": " << dlerror();
     return false;
   }
   if (requested_base != NULL && begin_ != requested_base) {
     std::string maps;
     ReadFileToString("/proc/self/maps", &maps);
     LOG(WARNING) << "Failed to find oatdata symbol at expected address: oatdata="
                  << reinterpret_cast<const void*>(begin_) << " != expected="
                  << reinterpret_cast<const void*>(requested_base)
                  << " /proc/self/maps:\n" << maps;
     return false;
   }
   end_ = reinterpret_cast<byte*>(dlsym(dlopen_handle_, "oatlastword"));
   if (end_ == NULL) {
     LOG(WARNING) << "Failed to find oatlastword symbol in " << elf_filename << ": " << dlerror();
     return false;
   }
   // Readjust to be non-inclusive upper bound.
   end_ += sizeof(uint32_t);
   return Setup();
 }

 bool OatFile::ElfFileOpen(File* file, byte* requested_base, bool writable) {
   elf_file_.reset(ElfFile::Open(file, writable, true));
   if (elf_file_.get() == NULL) {
     PLOG(WARNING) << "Failed to create ELF file for " << file->GetPath();
     return false;
   }
   bool loaded = elf_file_->Load();
   if (!loaded) {
     LOG(WARNING) << "Failed to load ELF file " << file->GetPath();
     return false;
   }
   begin_ = elf_file_->FindDynamicSymbolAddress("oatdata");
   if (begin_ == NULL) {
     LOG(WARNING) << "Failed to find oatdata symbol in " << file->GetPath();
     return false;
   }
   if (requested_base != NULL && begin_ != requested_base) {
     std::string maps;
     ReadFileToString("/proc/self/maps", &maps);
     LOG(WARNING) << "Failed to find oatdata symbol at expected address: oatdata="
                  << reinterpret_cast<const void*>(begin_) << " != expected="
                  << reinterpret_cast<const void*>(requested_base)
                  << " /proc/self/maps:\n" << maps;
     return false;
   }
   end_ = elf_file_->FindDynamicSymbolAddress("oatlastword");
   if (end_ == NULL) {
     LOG(WARNING) << "Failed to find oatlastword symbol in " << file->GetPath();
     return false;
   }
   // Readjust to be non-inclusive upper bound.
   end_ += sizeof(uint32_t);
   return Setup();
 }

 bool OatFile::Setup() {
   if (!GetOatHeader().IsValid()) {
     LOG(WARNING) << "Invalid oat magic for " << GetLocation();
     return false;
   }
   const byte* oat = Begin();
   oat += sizeof(OatHeader);
   oat += GetOatHeader().GetImageFileLocationSize();

   CHECK_LE(oat, End())
     << reinterpret_cast<const void*>(Begin())
     << "+" << sizeof(OatHeader)
     << "+" << GetOatHeader().GetImageFileLocationSize()
     << "<=" << reinterpret_cast<const void*>(End())
     << " " << GetLocation();
   for (size_t i = 0; i < GetOatHeader().GetDexFileCount(); i++) {
     size_t dex_file_location_size = *reinterpret_cast<const uint32_t*>(oat);
     CHECK_GT(dex_file_location_size, 0U) << GetLocation();
     oat += sizeof(dex_file_location_size);
     CHECK_LT(oat, End()) << GetLocation();

     const char* dex_file_location_data = reinterpret_cast<const char*>(oat);
     oat += dex_file_location_size;
     CHECK_LT(oat, End()) << GetLocation();

     std::string dex_file_location(dex_file_location_data, dex_file_location_size);

     uint32_t dex_file_checksum = *reinterpret_cast<const uint32_t*>(oat);
     oat += sizeof(dex_file_checksum);
     CHECK_LT(oat, End()) << GetLocation();

     uint32_t dex_file_offset = *reinterpret_cast<const uint32_t*>(oat);
     CHECK_GT(dex_file_offset, 0U) << GetLocation();
     CHECK_LT(dex_file_offset, Size()) << GetLocation();
     oat += sizeof(dex_file_offset);
     CHECK_LT(oat, End()) << GetLocation();

     const uint8_t* dex_file_pointer = Begin() + dex_file_offset;
     CHECK(DexFile::IsMagicValid(dex_file_pointer))
         << GetLocation() << " " << dex_file_pointer;
     CHECK(DexFile::IsVersionValid(dex_file_pointer))
         << GetLocation() << " "  << dex_file_pointer;
     const DexFile::Header* header = reinterpret_cast<const DexFile::Header*>(dex_file_pointer);
     const uint32_t* methods_offsets_pointer = reinterpret_cast<const uint32_t*>(oat);

     oat += (sizeof(*methods_offsets_pointer) * header->class_defs_size_);
     CHECK_LE(oat, End()) << GetLocation();

     oat_dex_files_.Put(dex_file_location, new OatDexFile(this,
                                                          dex_file_location,
                                                          dex_file_checksum,
                                                          dex_file_pointer,
                                                          methods_offsets_pointer));
   }
   return true;
 }

 const OatHeader& OatFile::GetOatHeader() const {
   return *reinterpret_cast<const OatHeader*>(Begin());
 }

 const byte* OatFile::Begin() const {
   CHECK(begin_ != NULL);
   return begin_;
 }

 const byte* OatFile::End() const {
   CHECK(end_ != NULL);
   return end_;
 }

 const OatFile::OatDexFile* OatFile::GetOatDexFile(const std::string& dex_file_location,
                                                   bool warn_if_not_found) const {
   Table::const_iterator it = oat_dex_files_.find(dex_file_location);
   if (it == oat_dex_files_.end()) {
     if (warn_if_not_found) {
       LOG(WARNING) << "Failed to find OatDexFile for DexFile " << dex_file_location;
     }
     return NULL;
   }
   return it->second;
 }

 std::vector<const OatFile::OatDexFile*> OatFile::GetOatDexFiles() const {
   std::vector<const OatFile::OatDexFile*> result;
   for (Table::const_iterator it = oat_dex_files_.begin(); it != oat_dex_files_.end(); ++it) {
     result.push_back(it->second);
   }
   return result;
 }

 OatFile::OatDexFile::OatDexFile(const OatFile* oat_file,
                                 const std::string& dex_file_location,
                                 uint32_t dex_file_location_checksum,
                                 const byte* dex_file_pointer,
                                 const uint32_t* oat_class_offsets_pointer)
     : oat_file_(oat_file),
       dex_file_location_(dex_file_location),
       dex_file_location_checksum_(dex_file_location_checksum),
       dex_file_pointer_(dex_file_pointer),
       oat_class_offsets_pointer_(oat_class_offsets_pointer) {}

 OatFile::OatDexFile::~OatDexFile() {}

 size_t OatFile::OatDexFile::FileSize() const {
   return reinterpret_cast<const DexFile::Header*>(dex_file_pointer_)->file_size_;
 }

 const DexFile* OatFile::OatDexFile::OpenDexFile() const {
   return DexFile::Open(dex_file_pointer_, FileSize(), dex_file_location_,
                        dex_file_location_checksum_);
 }

 const OatFile::OatClass* OatFile::OatDexFile::GetOatClass(uint32_t class_def_index) const {
   uint32_t oat_class_offset = oat_class_offsets_pointer_[class_def_index];

   const byte* oat_class_pointer = oat_file_->Begin() + oat_class_offset;
   CHECK_LT(oat_class_pointer, oat_file_->End());
   mirror::Class::Status status = *reinterpret_cast<const mirror::Class::Status*>(oat_class_pointer);

   const byte* methods_pointer = oat_class_pointer + sizeof(status);
   CHECK_LT(methods_pointer, oat_file_->End());

   return new OatClass(oat_file_,
                       status,
                       reinterpret_cast<const OatMethodOffsets*>(methods_pointer));
 }

 OatFile::OatClass::OatClass(const OatFile* oat_file,
                             mirror::Class::Status status,
                             const OatMethodOffsets* methods_pointer)
     : oat_file_(oat_file), status_(status), methods_pointer_(methods_pointer) {}

 OatFile::OatClass::~OatClass() {}

 mirror::Class::Status OatFile::OatClass::GetStatus() const {
   return status_;
 }

 const OatFile::OatMethod OatFile::OatClass::GetOatMethod(uint32_t method_index) const {
   const OatMethodOffsets& oat_method_offsets = methods_pointer_[method_index];
   return OatMethod(
       oat_file_->Begin(),
       oat_method_offsets.code_offset_,
       oat_method_offsets.frame_size_in_bytes_,
       oat_method_offsets.core_spill_mask_,
       oat_method_offsets.fp_spill_mask_,
       oat_method_offsets.mapping_table_offset_,
       oat_method_offsets.vmap_table_offset_,
       oat_method_offsets.gc_map_offset_);
 }

 OatFile::OatMethod::OatMethod(const byte* base,
                               const uint32_t code_offset,
                               const size_t frame_size_in_bytes,
                               const uint32_t core_spill_mask,
                               const uint32_t fp_spill_mask,
                               const uint32_t mapping_table_offset,
                               const uint32_t vmap_table_offset,
                               const uint32_t gc_map_offset)
   : begin_(base),
     code_offset_(code_offset),
     frame_size_in_bytes_(frame_size_in_bytes),
     core_spill_mask_(core_spill_mask),
     fp_spill_mask_(fp_spill_mask),
     mapping_table_offset_(mapping_table_offset),
     vmap_table_offset_(vmap_table_offset),
     native_gc_map_offset_(gc_map_offset)
 {
 #ifndef NDEBUG
   if (mapping_table_offset_ != 0) {  // implies non-native, non-stub code
     if (vmap_table_offset_ == 0) {
       DCHECK_EQ(0U, static_cast<uint32_t>(__builtin_popcount(core_spill_mask_) + __builtin_popcount(fp_spill_mask_)));
     } else {
       const uint16_t* vmap_table_ = reinterpret_cast<const uint16_t*>(begin_ + vmap_table_offset_);
       DCHECK_EQ(vmap_table_[0], static_cast<uint32_t>(__builtin_popcount(core_spill_mask_) + __builtin_popcount(fp_spill_mask_)));
     }
   } else {
     DCHECK_EQ(vmap_table_offset_, 0U);
   }
 #endif
 }

 OatFile::OatMethod::~OatMethod() {}

 const void* OatFile::OatMethod::GetCode() const {
   return GetOatPointer<const void*>(code_offset_);
 }

 uint32_t OatFile::OatMethod::GetCodeSize() const {
 #if defined(ART_USE_PORTABLE_COMPILER)
   // TODO: With Quick, we store the size before the code. With
   // Portable, the code is in a .o file we don't manage ourselves. ELF
   // symbols do have a concept of size, so we could capture that and
   // store it somewhere, such as the OatMethod.
   return 0;
 #else
   uintptr_t code = reinterpret_cast<uint32_t>(GetCode());

   if (code == 0) {
     return 0;
   }
   // TODO: make this Thumb2 specific
   code &= ~0x1;
   return reinterpret_cast<uint32_t*>(code)[-1];
 #endif
 }

 void OatFile::OatMethod::LinkMethod(mirror::AbstractMethod* method) const {
   CHECK(method != NULL);
   method->SetEntryPointFromCompiledCode(GetCode());
   method->SetFrameSizeInBytes(frame_size_in_bytes_);
   method->SetCoreSpillMask(core_spill_mask_);
   method->SetFpSpillMask(fp_spill_mask_);
   method->SetMappingTable(GetMappingTable());
   method->SetVmapTable(GetVmapTable());
   method->SetNativeGcMap(GetNativeGcMap());  // Note, used by native methods in work around JNI mode.
 }

 }  // 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 "oat_file.h"

	#include <dlfcn.h>

	#include "base/stl_util.h"
	#include "base/unix_file/fd_file.h"
	#include "elf_file.h"
	#include "oat.h"
	#include "mirror/class.h"
	#include "mirror/abstract_method.h"
	#include "mirror/abstract_method-inl.h"
	#include "mirror/object-inl.h"
	#include "os.h"
	#include "utils.h"

	namespace art {

	std::string OatFile::DexFilenameToOatFilename(const std::string& location) {
	CHECK(IsValidDexFilename(location) \|\| IsValidZipFilename(location));
	std::string oat_location(location);
	oat_location += ".oat";
	return oat_location;
	}

	void OatFile::CheckLocation(const std::string& location) {
	CHECK(!location.empty());
	if (!IsValidOatFilename(location)) {
	LOG(WARNING) << "Attempting to open oat file with unknown extension '" << location << "'";
	}
	}

	OatFile* OatFile::OpenMemory(std::vector<uint8_t>& oat_contents,
	const std::string& location) {
	CHECK(!oat_contents.empty()) << location;
	CheckLocation(location);
	UniquePtr<OatFile> oat_file(new OatFile(location));
	oat_file->begin_ = &oat_contents[0];
	oat_file->end_ = &oat_contents[oat_contents.size()];
	return oat_file->Setup() ? oat_file.release() : NULL;
	}

	OatFile* OatFile::Open(const std::string& filename,
	const std::string& location,
	byte* requested_base) {
	CHECK(!filename.empty()) << location;
	CheckLocation(location);
	/*
	* TODO: Reenable dlopen when it works again on MIPS. It may have broken from this change:
	* commit 818d98eb563ad5d7293b8b5c40f3dabf745e611f
	* Author: Brian Carlstrom <bdc@google.com>
	* Date: Sun Feb 10 21:38:12 2013 -0800
	*
	* Fix MIPS to use standard kPageSize=0x1000 section alignment for ELF sections
	*
	* Change-Id: I905f0c5f75921a65bd7426a54d6258c780d85d0e
	*/
	OatFile* result = OpenDlopen(filename, location, requested_base);
	if (result != NULL) {
	return result;
	}
	// On target, only used dlopen to load.
	if (kIsTargetBuild) {
	return NULL;
	}
	// On host, dlopen is expected to fail when cross compiling, so fall back to OpenElfFile.
	// This won't work for portable runtime execution because it doesn't process relocations.
	UniquePtr<File> file(OS::OpenFile(filename.c_str(), false, false));
	if (file.get() == NULL) {
	return NULL;
	}
	return OpenElfFile(file.get(), location, requested_base, false);
	}

	OatFile* OatFile::OpenWritable(File* file, const std::string& location) {
	CheckLocation(location);
	return OpenElfFile(file, location, NULL, true);
	}

	OatFile* OatFile::OpenDlopen(const std::string& elf_filename,
	const std::string& location,
	byte* requested_base) {
	UniquePtr<OatFile> oat_file(new OatFile(location));
	bool success = oat_file->Dlopen(elf_filename, requested_base);
	if (!success) {
	return NULL;
	}
	return oat_file.release();
	}

	OatFile* OatFile::OpenElfFile(File* file,
	const std::string& location,
	byte* requested_base,
	bool writable) {
	UniquePtr<OatFile> oat_file(new OatFile(location));
	bool success = oat_file->ElfFileOpen(file, requested_base, writable);
	if (!success) {
	return NULL;
	}
	return oat_file.release();
	}

	OatFile::OatFile(const std::string& location)
	: location_(location), begin_(NULL), end_(NULL), dlopen_handle_(NULL) {
	CHECK(!location_.empty());
	}

	OatFile::~OatFile() {
	STLDeleteValues(&oat_dex_files_);
	if (dlopen_handle_ != NULL) {
	dlclose(dlopen_handle_);
	}
	}

	bool OatFile::Dlopen(const std::string& elf_filename, byte* requested_base) {

	char* absolute_path = realpath(elf_filename.c_str(), NULL);
	if (absolute_path == NULL) {
	return false;
	}
	dlopen_handle_ = dlopen(absolute_path, RTLD_NOW);
	free(absolute_path);
	if (dlopen_handle_ == NULL) {
	return false;
	}
	begin_ = reinterpret_cast<byte*>(dlsym(dlopen_handle_, "oatdata"));
	if (begin_ == NULL) {
	LOG(WARNING) << "Failed to find oatdata symbol in " << elf_filename << ": " << dlerror();
	return false;
	}
	if (requested_base != NULL && begin_ != requested_base) {
	std::string maps;
	ReadFileToString("/proc/self/maps", &maps);
	LOG(WARNING) << "Failed to find oatdata symbol at expected address: oatdata="
	<< reinterpret_cast<const void*>(begin_) << " != expected="
	<< reinterpret_cast<const void*>(requested_base)
	<< " /proc/self/maps:\n" << maps;
	return false;
	}
	end_ = reinterpret_cast<byte*>(dlsym(dlopen_handle_, "oatlastword"));
	if (end_ == NULL) {
	LOG(WARNING) << "Failed to find oatlastword symbol in " << elf_filename << ": " << dlerror();
	return false;
	}
	// Readjust to be non-inclusive upper bound.
	end_ += sizeof(uint32_t);
	return Setup();
	}

	bool OatFile::ElfFileOpen(File* file, byte* requested_base, bool writable) {
	elf_file_.reset(ElfFile::Open(file, writable, true));
	if (elf_file_.get() == NULL) {
	PLOG(WARNING) << "Failed to create ELF file for " << file->GetPath();
	return false;
	}
	bool loaded = elf_file_->Load();
	if (!loaded) {
	LOG(WARNING) << "Failed to load ELF file " << file->GetPath();
	return false;
	}
	begin_ = elf_file_->FindDynamicSymbolAddress("oatdata");
	if (begin_ == NULL) {
	LOG(WARNING) << "Failed to find oatdata symbol in " << file->GetPath();
	return false;
	}
	if (requested_base != NULL && begin_ != requested_base) {
	std::string maps;
	ReadFileToString("/proc/self/maps", &maps);
	LOG(WARNING) << "Failed to find oatdata symbol at expected address: oatdata="
	<< reinterpret_cast<const void*>(begin_) << " != expected="
	<< reinterpret_cast<const void*>(requested_base)
	<< " /proc/self/maps:\n" << maps;
	return false;
	}
	end_ = elf_file_->FindDynamicSymbolAddress("oatlastword");
	if (end_ == NULL) {
	LOG(WARNING) << "Failed to find oatlastword symbol in " << file->GetPath();
	return false;
	}
	// Readjust to be non-inclusive upper bound.
	end_ += sizeof(uint32_t);
	return Setup();
	}

	bool OatFile::Setup() {
	if (!GetOatHeader().IsValid()) {
	LOG(WARNING) << "Invalid oat magic for " << GetLocation();
	return false;
	}
	const byte* oat = Begin();
	oat += sizeof(OatHeader);
	oat += GetOatHeader().GetImageFileLocationSize();

	CHECK_LE(oat, End())
	<< reinterpret_cast<const void*>(Begin())
	<< "+" << sizeof(OatHeader)
	<< "+" << GetOatHeader().GetImageFileLocationSize()
	<< "<=" << reinterpret_cast<const void*>(End())
	<< " " << GetLocation();
	for (size_t i = 0; i < GetOatHeader().GetDexFileCount(); i++) {
	size_t dex_file_location_size = reinterpret_cast<const uint32_t>(oat);
	CHECK_GT(dex_file_location_size, 0U) << GetLocation();
	oat += sizeof(dex_file_location_size);
	CHECK_LT(oat, End()) << GetLocation();

	const char* dex_file_location_data = reinterpret_cast<const char*>(oat);
	oat += dex_file_location_size;
	CHECK_LT(oat, End()) << GetLocation();

	std::string dex_file_location(dex_file_location_data, dex_file_location_size);

	uint32_t dex_file_checksum = reinterpret_cast<const uint32_t>(oat);
	oat += sizeof(dex_file_checksum);
	CHECK_LT(oat, End()) << GetLocation();

	uint32_t dex_file_offset = reinterpret_cast<const uint32_t>(oat);
	CHECK_GT(dex_file_offset, 0U) << GetLocation();
	CHECK_LT(dex_file_offset, Size()) << GetLocation();
	oat += sizeof(dex_file_offset);
	CHECK_LT(oat, End()) << GetLocation();

	const uint8_t* dex_file_pointer = Begin() + dex_file_offset;
	CHECK(DexFile::IsMagicValid(dex_file_pointer))
	<< GetLocation() << " " << dex_file_pointer;
	CHECK(DexFile::IsVersionValid(dex_file_pointer))
	<< GetLocation() << " " << dex_file_pointer;
	const DexFile::Header* header = reinterpret_cast<const DexFile::Header*>(dex_file_pointer);
	const uint32_t* methods_offsets_pointer = reinterpret_cast<const uint32_t*>(oat);

	oat += (sizeof(methods_offsets_pointer) header->class_defs_size_);
	CHECK_LE(oat, End()) << GetLocation();

	oat_dex_files_.Put(dex_file_location, new OatDexFile(this,
	dex_file_location,
	dex_file_checksum,
	dex_file_pointer,
	methods_offsets_pointer));
	}
	return true;
	}

	const OatHeader& OatFile::GetOatHeader() const {
	return reinterpret_cast<const OatHeader>(Begin());
	}

	const byte* OatFile::Begin() const {
	CHECK(begin_ != NULL);
	return begin_;
	}

	const byte* OatFile::End() const {
	CHECK(end_ != NULL);
	return end_;
	}

	const OatFile::OatDexFile* OatFile::GetOatDexFile(const std::string& dex_file_location,
	bool warn_if_not_found) const {
	Table::const_iterator it = oat_dex_files_.find(dex_file_location);
	if (it == oat_dex_files_.end()) {
	if (warn_if_not_found) {
	LOG(WARNING) << "Failed to find OatDexFile for DexFile " << dex_file_location;
	}
	return NULL;
	}
	return it->second;
	}

	std::vector<const OatFile::OatDexFile*> OatFile::GetOatDexFiles() const {
	std::vector<const OatFile::OatDexFile*> result;
	for (Table::const_iterator it = oat_dex_files_.begin(); it != oat_dex_files_.end(); ++it) {
	result.push_back(it->second);
	}
	return result;
	}

	OatFile::OatDexFile::OatDexFile(const OatFile* oat_file,
	const std::string& dex_file_location,
	uint32_t dex_file_location_checksum,
	const byte* dex_file_pointer,
	const uint32_t* oat_class_offsets_pointer)
	: oat_file_(oat_file),
	dex_file_location_(dex_file_location),
	dex_file_location_checksum_(dex_file_location_checksum),
	dex_file_pointer_(dex_file_pointer),
	oat_class_offsets_pointer_(oat_class_offsets_pointer) {}

	OatFile::OatDexFile::~OatDexFile() {}

	size_t OatFile::OatDexFile::FileSize() const {
	return reinterpret_cast<const DexFile::Header*>(dex_file_pointer_)->file_size_;
	}

	const DexFile* OatFile::OatDexFile::OpenDexFile() const {
	return DexFile::Open(dex_file_pointer_, FileSize(), dex_file_location_,
	dex_file_location_checksum_);
	}

	const OatFile::OatClass* OatFile::OatDexFile::GetOatClass(uint32_t class_def_index) const {
	uint32_t oat_class_offset = oat_class_offsets_pointer_[class_def_index];

	const byte* oat_class_pointer = oat_file_->Begin() + oat_class_offset;
	CHECK_LT(oat_class_pointer, oat_file_->End());
	mirror::Class::Status status = reinterpret_cast<const mirror::Class::Status>(oat_class_pointer);

	const byte* methods_pointer = oat_class_pointer + sizeof(status);
	CHECK_LT(methods_pointer, oat_file_->End());

	return new OatClass(oat_file_,
	status,
	reinterpret_cast<const OatMethodOffsets*>(methods_pointer));
	}

	OatFile::OatClass::OatClass(const OatFile* oat_file,
	mirror::Class::Status status,
	const OatMethodOffsets* methods_pointer)
	: oat_file_(oat_file), status_(status), methods_pointer_(methods_pointer) {}

	OatFile::OatClass::~OatClass() {}

	mirror::Class::Status OatFile::OatClass::GetStatus() const {
	return status_;
	}

	const OatFile::OatMethod OatFile::OatClass::GetOatMethod(uint32_t method_index) const {
	const OatMethodOffsets& oat_method_offsets = methods_pointer_[method_index];
	return OatMethod(
	oat_file_->Begin(),
	oat_method_offsets.code_offset_,
	oat_method_offsets.frame_size_in_bytes_,
	oat_method_offsets.core_spill_mask_,
	oat_method_offsets.fp_spill_mask_,
	oat_method_offsets.mapping_table_offset_,
	oat_method_offsets.vmap_table_offset_,
	oat_method_offsets.gc_map_offset_);
	}

	OatFile::OatMethod::OatMethod(const byte* base,
	const uint32_t code_offset,
	const size_t frame_size_in_bytes,
	const uint32_t core_spill_mask,
	const uint32_t fp_spill_mask,
	const uint32_t mapping_table_offset,
	const uint32_t vmap_table_offset,
	const uint32_t gc_map_offset)
	: begin_(base),
	code_offset_(code_offset),
	frame_size_in_bytes_(frame_size_in_bytes),
	core_spill_mask_(core_spill_mask),
	fp_spill_mask_(fp_spill_mask),
	mapping_table_offset_(mapping_table_offset),
	vmap_table_offset_(vmap_table_offset),
	native_gc_map_offset_(gc_map_offset)
	{
	#ifndef NDEBUG
	if (mapping_table_offset_ != 0) { // implies non-native, non-stub code
	if (vmap_table_offset_ == 0) {
	DCHECK_EQ(0U, static_cast<uint32_t>(__builtin_popcount(core_spill_mask_) + __builtin_popcount(fp_spill_mask_)));
	} else {
	const uint16_t* vmap_table_ = reinterpret_cast<const uint16_t*>(begin_ + vmap_table_offset_);
	DCHECK_EQ(vmap_table_[0], static_cast<uint32_t>(__builtin_popcount(core_spill_mask_) + __builtin_popcount(fp_spill_mask_)));
	}
	} else {
	DCHECK_EQ(vmap_table_offset_, 0U);
	}
	#endif
	}

	OatFile::OatMethod::~OatMethod() {}

	const void* OatFile::OatMethod::GetCode() const {
	return GetOatPointer<const void*>(code_offset_);
	}

	uint32_t OatFile::OatMethod::GetCodeSize() const {
	#if defined(ART_USE_PORTABLE_COMPILER)
	// TODO: With Quick, we store the size before the code. With
	// Portable, the code is in a .o file we don't manage ourselves. ELF
	// symbols do have a concept of size, so we could capture that and
	// store it somewhere, such as the OatMethod.
	return 0;
	#else
	uintptr_t code = reinterpret_cast<uint32_t>(GetCode());

	if (code == 0) {
	return 0;
	}
	// TODO: make this Thumb2 specific
	code &= ~0x1;
	return reinterpret_cast<uint32_t*>(code)[-1];
	#endif
	}

	void OatFile::OatMethod::LinkMethod(mirror::AbstractMethod* method) const {
	CHECK(method != NULL);
	method->SetEntryPointFromCompiledCode(GetCode());
	method->SetFrameSizeInBytes(frame_size_in_bytes_);
	method->SetCoreSpillMask(core_spill_mask_);
	method->SetFpSpillMask(fp_spill_mask_);
	method->SetMappingTable(GetMappingTable());
	method->SetVmapTable(GetVmapTable());
	method->SetNativeGcMap(GetNativeGcMap()); // Note, used by native methods in work around JNI mode.
	}

	} // namespace art