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* 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
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
#include <list>
#include <string>
#include <string_view>
#include <vector>
#include "base/array_ref.h"
#include "base/mutex.h"
#include "base/os.h"
#include "base/safe_map.h"
#include "base/tracking_safe_map.h"
#include "class_status.h"
#include "compiler_filter.h"
#include "dex/dex_file_layout.h"
#include "dex/type_lookup_table.h"
#include "dex/utf.h"
#include "index_bss_mapping.h"
#include "mirror/object.h"
#include "oat.h"
namespace art {
class BitVector;
class DexFile;
class ElfFile;
class DexLayoutSections;
template <class MirrorType> class GcRoot;
class MemMap;
class OatDexFile;
class OatHeader;
class OatMethodOffsets;
class OatQuickMethodHeader;
class VdexFile;
namespace dex {
struct ClassDef;
} // namespace dex
namespace gc {
namespace collector {
class DummyOatFile;
} // namespace collector
} // namespace gc
// Runtime representation of the OAT file format which holds compiler output.
// The class opens an OAT file from storage and maps it to memory, typically with
// dlopen and provides access to its internal data structures (see OatWriter for
// for more details about the OAT format).
// In the process of loading OAT, the class also loads the associated VDEX file
// with the input DEX files (see VdexFile for details about the VDEX format).
// The raw DEX data are accessible transparently through the OatDexFile objects.
class OatFile {
// Special classpath that skips shared library check.
static constexpr const char* kSpecialSharedLibrary = "&";
// Opens an oat file contained within the given elf file. This is always opened as
// non-executable at the moment.
static OatFile* OpenWithElfFile(int zip_fd,
ElfFile* elf_file,
VdexFile* vdex_file,
const std::string& location,
const char* abs_dex_location,
std::string* error_msg);
// Open an oat file. Returns null on failure. Requested base can
// optionally be used to request where the file should be loaded.
// See the ResolveRelativeEncodedDexLocation for a description of how the
// abs_dex_location argument is used.
static OatFile* Open(int zip_fd,
const std::string& filename,
const std::string& location,
bool executable,
bool low_4gb,
const char* abs_dex_location,
/*inout*/MemMap* reservation, // Where to load if not null.
/*out*/std::string* error_msg);
// Similar to OatFile::Open(const std::string...), but accepts input vdex and
// odex files as file descriptors. We also take zip_fd in case the vdex does not
// contain the dex code, and we need to read it from the zip file.
static OatFile* Open(int zip_fd,
int vdex_fd,
int oat_fd,
const std::string& oat_location,
bool executable,
bool low_4gb,
const char* abs_dex_location,
/*inout*/MemMap* reservation, // Where to load if not null.
/*out*/std::string* error_msg);
// Open an oat file from an already opened File.
// Does not use dlopen underneath so cannot be used for runtime use
// where relocations may be required. Currently used from
// ImageWriter which wants to open a writable version from an existing
// file descriptor for patching.
static OatFile* OpenWritable(int zip_fd,
File* file,
const std::string& location,
const char* abs_dex_location,
std::string* error_msg);
// Open an oat file from an already opened File. Maps it PROT_READ, MAP_PRIVATE.
static OatFile* OpenReadable(int zip_fd,
File* file,
const std::string& location,
const char* abs_dex_location,
std::string* error_msg);
virtual ~OatFile();
bool IsExecutable() const {
return is_executable_;
// Indicates whether the oat file was compiled with full debugging capability.
bool IsDebuggable() const;
CompilerFilter::Filter GetCompilerFilter() const;
std::string GetClassLoaderContext() const;
const char* GetCompilationReason() const;
const std::string& GetLocation() const {
return location_;
const OatHeader& GetOatHeader() const;
class OatMethod final {
void LinkMethod(ArtMethod* method) const;
uint32_t GetCodeOffset() const;
const void* GetQuickCode() const;
// Returns size of quick code.
uint32_t GetQuickCodeSize() const;
uint32_t GetQuickCodeSizeOffset() const;
// Returns OatQuickMethodHeader for debugging. Most callers should
// use more specific methods such as GetQuickCodeSize.
const OatQuickMethodHeader* GetOatQuickMethodHeader() const;
uint32_t GetOatQuickMethodHeaderOffset() const;
size_t GetFrameSizeInBytes() const;
uint32_t GetCoreSpillMask() const;
uint32_t GetFpSpillMask() const;
const uint8_t* GetVmapTable() const;
uint32_t GetVmapTableOffset() const;
uint32_t GetVmapTableOffsetOffset() const;
// Create an OatMethod with offsets relative to the given base address
OatMethod(const uint8_t* base, const uint32_t code_offset)
: begin_(base), code_offset_(code_offset) {
OatMethod(const OatMethod&) = default;
~OatMethod() {}
OatMethod& operator=(const OatMethod&) = default;
// A representation of an invalid OatMethod, used when an OatMethod or OatClass can't be found.
// See ClassLinker::FindOatMethodFor.
static const OatMethod Invalid() {
return OatMethod(nullptr, -1);
template<class T>
T GetOatPointer(uint32_t offset) const {
if (offset == 0) {
return nullptr;
return reinterpret_cast<T>(begin_ + offset);
const uint8_t* begin_;
uint32_t code_offset_;
friend class OatClass;
class OatClass final {
ClassStatus GetStatus() const {
return status_;
OatClassType GetType() const {
return type_;
// Get the OatMethod entry based on its index into the class
// defintion. Direct methods come first, followed by virtual
// methods. Note that runtime created methods such as miranda
// methods are not included.
const OatMethod GetOatMethod(uint32_t method_index) const;
// Return a pointer to the OatMethodOffsets for the requested
// method_index, or null if none is present. Note that most
// callers should use GetOatMethod.
const OatMethodOffsets* GetOatMethodOffsets(uint32_t method_index) const;
// Return the offset from the start of the OatFile to the
// OatMethodOffsets for the requested method_index, or 0 if none
// is present. Note that most callers should use GetOatMethod.
uint32_t GetOatMethodOffsetsOffset(uint32_t method_index) const;
// A representation of an invalid OatClass, used when an OatClass can't be found.
// See FindOatClass().
static OatClass Invalid() {
return OatClass(/* oat_file= */ nullptr,
/* bitmap_size= */ 0,
/* bitmap_pointer= */ nullptr,
/* methods_pointer= */ nullptr);
OatClass(const OatFile* oat_file,
ClassStatus status,
OatClassType type,
uint32_t bitmap_size,
const uint32_t* bitmap_pointer,
const OatMethodOffsets* methods_pointer);
const OatFile* const oat_file_;
const ClassStatus status_;
const OatClassType type_;
const uint32_t* const bitmap_;
const OatMethodOffsets* const methods_pointer_;
friend class art::OatDexFile;
// Get the OatDexFile for the given dex_location within this oat file.
// If dex_location_checksum is non-null, the OatDexFile will only be
// returned if it has a matching checksum.
// If error_msg is non-null and no OatDexFile is returned, error_msg will
// be updated with a description of why no OatDexFile was returned.
const OatDexFile* GetOatDexFile(const char* dex_location,
const uint32_t* const dex_location_checksum,
/*out*/std::string* error_msg = nullptr) const
const std::vector<const OatDexFile*>& GetOatDexFiles() const {
return oat_dex_files_storage_;
size_t Size() const {
return End() - Begin();
bool Contains(const void* p) const {
return p >= Begin() && p < End();
size_t DataBimgRelRoSize() const {
return DataBimgRelRoEnd() - DataBimgRelRoBegin();
size_t BssSize() const {
return BssEnd() - BssBegin();
size_t VdexSize() const {
return VdexEnd() - VdexBegin();
size_t BssMethodsOffset() const {
// Note: This is used only for symbolizer and needs to return a valid .bss offset.
return (bss_methods_ != nullptr) ? bss_methods_ - BssBegin() : BssRootsOffset();
size_t BssRootsOffset() const {
// Note: This is used only for symbolizer and needs to return a valid .bss offset.
return (bss_roots_ != nullptr) ? bss_roots_ - BssBegin() : BssSize();
size_t DexSize() const {
return DexEnd() - DexBegin();
const uint8_t* Begin() const;
const uint8_t* End() const;
const uint8_t* DataBimgRelRoBegin() const { return data_bimg_rel_ro_begin_; }
const uint8_t* DataBimgRelRoEnd() const { return data_bimg_rel_ro_end_; }
const uint8_t* BssBegin() const { return bss_begin_; }
const uint8_t* BssEnd() const { return bss_end_; }
const uint8_t* VdexBegin() const { return vdex_begin_; }
const uint8_t* VdexEnd() const { return vdex_end_; }
const uint8_t* DexBegin() const;
const uint8_t* DexEnd() const;
ArrayRef<const uint32_t> GetBootImageRelocations() const;
ArrayRef<ArtMethod*> GetBssMethods() const;
ArrayRef<GcRoot<mirror::Object>> GetBssGcRoots() const;
// Initialize relocation sections ( and .bss).
void InitializeRelocations() const;
// Returns the absolute dex location for the encoded relative dex location.
// If not null, abs_dex_location is used to resolve the absolute dex
// location of relative dex locations encoded in the oat file.
// For example, given absolute location "/data/app/foo/base.apk", encoded
// dex locations "base.apk", "base.apk!classes2.dex", etc. would be resolved
// to "/data/app/foo/base.apk", "/data/app/foo/base.apk!classes2.dex", etc.
// Relative encoded dex locations that don't match the given abs_dex_location
// are left unchanged.
static std::string ResolveRelativeEncodedDexLocation(
const char* abs_dex_location, const std::string& rel_dex_location);
// Finds the associated oat class for a dex_file and descriptor. Returns an invalid OatClass on
// error and sets found to false.
static OatClass FindOatClass(const DexFile& dex_file, uint16_t class_def_idx, bool* found);
VdexFile* GetVdexFile() const {
return vdex_.get();
// Whether the OatFile embeds the Dex code.
bool ContainsDexCode() const {
return uncompressed_dex_files_ == nullptr;
OatFile(const std::string& filename, bool executable);
// The oat file name.
// The image will embed this to link its associated oat file.
const std::string location_;
// Pointer to the Vdex file with the Dex files for this Oat file.
std::unique_ptr<VdexFile> vdex_;
// Pointer to OatHeader.
const uint8_t* begin_;
// Pointer to end of oat region for bounds checking.
const uint8_t* end_;
// Pointer to the section, if present, otherwise null.
const uint8_t* data_bimg_rel_ro_begin_;
// Pointer to the end of the section, if present, otherwise null.
const uint8_t* data_bimg_rel_ro_end_;
// Pointer to the .bss section, if present, otherwise null.
uint8_t* bss_begin_;
// Pointer to the end of the .bss section, if present, otherwise null.
uint8_t* bss_end_;
// Pointer to the beginning of the ArtMethod*s in .bss section, if present, otherwise null.
uint8_t* bss_methods_;
// Pointer to the beginning of the GC roots in .bss section, if present, otherwise null.
uint8_t* bss_roots_;
// Was this oat_file loaded executable?
const bool is_executable_;
// Pointer to the .vdex section, if present, otherwise null.
uint8_t* vdex_begin_;
// Pointer to the end of the .vdex section, if present, otherwise null.
uint8_t* vdex_end_;
// Owning storage for the OatDexFile objects.
std::vector<const OatDexFile*> oat_dex_files_storage_;
// NOTE: We use a std::string_view as the key type to avoid a memory allocation on every
// lookup with a const char* key. The std::string_view doesn't own its backing storage,
// therefore we're using the OatFile's stored dex location as the backing storage
// for keys in oat_dex_files_ and the string_cache_ entries for the backing storage
// of keys in secondary_oat_dex_files_ and oat_dex_files_by_canonical_location_.
using Table =
AllocationTrackingSafeMap<std::string_view, const OatDexFile*, kAllocatorTagOatFile>;
// Map each location and canonical location (if different) retrieved from the
// oat file to its OatDexFile. This map doesn't change after it's constructed in Setup()
// and therefore doesn't need any locking and provides the cheapest dex file lookup
// for GetOatDexFile() for a very frequent use case. Never contains a null value.
Table oat_dex_files_;
// Lock guarding all members needed for secondary lookup in GetOatDexFile().
mutable Mutex secondary_lookup_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
// If the primary oat_dex_files_ lookup fails, use a secondary map. This map stores
// the results of all previous secondary lookups, whether successful (non-null) or
// failed (null). If it doesn't contain an entry we need to calculate the canonical
// location and use oat_dex_files_by_canonical_location_.
mutable Table secondary_oat_dex_files_ GUARDED_BY(secondary_lookup_lock_);
// Cache of strings. Contains the backing storage for keys in the secondary_oat_dex_files_
// and the lazily initialized oat_dex_files_by_canonical_location_.
// NOTE: We're keeping references to contained strings in form of std::string_view and adding
// new strings to the end. The adding of a new element must not touch any previously stored
// elements. std::list<> and std::deque<> satisfy this requirement, std::vector<> doesn't.
mutable std::list<std::string> string_cache_ GUARDED_BY(secondary_lookup_lock_);
// Cache of dex files mapped directly from a location, in case the OatFile does
// not embed the dex code.
std::unique_ptr<std::vector<std::unique_ptr<const DexFile>>> uncompressed_dex_files_;
friend class gc::collector::DummyOatFile; // For modifying begin_ and end_.
friend class OatClass;
friend class art::OatDexFile;
friend class OatDumper; // For GetBase and GetLimit
friend class OatFileBase;
// OatDexFile should be an inner class of OatFile. Unfortunately, C++ doesn't
// support forward declarations of inner classes, and we want to
// forward-declare OatDexFile so that we can store an opaque pointer to an
// OatDexFile in DexFile.
class OatDexFile final {
// Opens the DexFile referred to by this OatDexFile from within the containing OatFile.
std::unique_ptr<const DexFile> OpenDexFile(std::string* error_msg) const;
// May return null if the OatDexFile only contains a type lookup table. This case only happens
// for the compiler to speed up compilation.
const OatFile* GetOatFile() const {
// Avoid pulling in runtime.h in the header file.
if (kIsDebugBuild && oat_file_ == nullptr) {
return oat_file_;
// Returns the size of the DexFile refered to by this OatDexFile.
size_t FileSize() const;
// Returns original path of DexFile that was the source of this OatDexFile.
const std::string& GetDexFileLocation() const {
return dex_file_location_;
// Returns the canonical location of DexFile that was the source of this OatDexFile.
const std::string& GetCanonicalDexFileLocation() const {
return canonical_dex_file_location_;
// Returns checksum of original DexFile that was the source of this OatDexFile;
uint32_t GetDexFileLocationChecksum() const {
return dex_file_location_checksum_;
// Returns the OatClass for the class specified by the given DexFile class_def_index.
OatFile::OatClass GetOatClass(uint16_t class_def_index) const;
// Returns the offset to the OatClass information. Most callers should use GetOatClass.
uint32_t GetOatClassOffset(uint16_t class_def_index) const;
const uint8_t* GetLookupTableData() const {
return lookup_table_data_;
const IndexBssMapping* GetMethodBssMapping() const {
return method_bss_mapping_;
const IndexBssMapping* GetTypeBssMapping() const {
return type_bss_mapping_;
const IndexBssMapping* GetStringBssMapping() const {
return string_bss_mapping_;
const uint8_t* GetDexFilePointer() const {
return dex_file_pointer_;
ArrayRef<const uint8_t> GetQuickenedInfoOf(const DexFile& dex_file,
uint32_t dex_method_idx) const;
// Looks up a class definition by its class descriptor. Hash must be
// ComputeModifiedUtf8Hash(descriptor).
static const dex::ClassDef* FindClassDef(const DexFile& dex_file,
const char* descriptor,
size_t hash);
// Madvise the dex file based on the state we are moving to.
static void MadviseDexFile(const DexFile& dex_file, MadviseState state);
const TypeLookupTable& GetTypeLookupTable() const {
return lookup_table_;
// Create only with a type lookup table, used by the compiler to speed up compilation.
explicit OatDexFile(TypeLookupTable&& lookup_table);
// Return the dex layout sections.
const DexLayoutSections* GetDexLayoutSections() const {
return dex_layout_sections_;
OatDexFile(const OatFile* oat_file,
const std::string& dex_file_location,
const std::string& canonical_dex_file_location,
uint32_t dex_file_checksum,
const uint8_t* dex_file_pointer,
const uint8_t* lookup_table_data,
const IndexBssMapping* method_bss_mapping,
const IndexBssMapping* type_bss_mapping,
const IndexBssMapping* string_bss_mapping,
const uint32_t* oat_class_offsets_pointer,
const DexLayoutSections* dex_layout_sections);
static void AssertAotCompiler();
const OatFile* const oat_file_ = nullptr;
const std::string dex_file_location_;
const std::string canonical_dex_file_location_;
const uint32_t dex_file_location_checksum_ = 0u;
const uint8_t* const dex_file_pointer_ = nullptr;
const uint8_t* const lookup_table_data_ = nullptr;
const IndexBssMapping* const method_bss_mapping_ = nullptr;
const IndexBssMapping* const type_bss_mapping_ = nullptr;
const IndexBssMapping* const string_bss_mapping_ = nullptr;
const uint32_t* const oat_class_offsets_pointer_ = nullptr;
TypeLookupTable lookup_table_;
const DexLayoutSections* const dex_layout_sections_ = nullptr;
friend class OatFile;
friend class OatFileBase;
} // namespace art