dexlayout/dex_writer.h - platform/art - Gitiles

 /*
  * Copyright (C) 2016 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.
  *
  * Header file of an in-memory representation of DEX files.
  */

 #ifndef ART_DEXLAYOUT_DEX_WRITER_H_
 #define ART_DEXLAYOUT_DEX_WRITER_H_

 #include <functional>
 #include <memory>  // For unique_ptr

 #include "base/os.h"
 #include "base/unix_file/fd_file.h"
 #include "dex/compact_dex_level.h"
 #include "dex_container.h"
 #include "dex/dex_file.h"
 #include "dex_ir.h"

 #include <queue>

 namespace art {

 class DexLayout;
 class DexLayoutHotnessInfo;

 struct MapItem {
   // Not using DexFile::MapItemType since compact dex and standard dex file may have different
   // sections.
   MapItem() = default;
   MapItem(uint32_t type, uint32_t size, size_t offset)
       : type_(type), size_(size), offset_(offset) { }

   // Sort by decreasing order since the priority_queue puts largest elements first.
   bool operator>(const MapItem& other) const {
     return offset_ > other.offset_;
   }

   uint32_t type_ = 0u;
   uint32_t size_ = 0u;
   uint32_t offset_ = 0u;
 };

 class MapItemQueue : public
     std::priority_queue<MapItem, std::vector<MapItem>, std::greater<MapItem>> {
  public:
   void AddIfNotEmpty(const MapItem& item);
 };

 class DexWriter {
  public:
   static constexpr uint32_t kDataSectionAlignment = sizeof(uint32_t) * 2;
   static constexpr uint32_t kDexSectionWordAlignment = 4;

   // Stream that writes into a dex container section. Do not have two streams pointing to the same
   // backing storage as there may be invalidation of backing storage to resize the section.
   // Random access stream (consider refactoring).
   class Stream {
    public:
     explicit Stream(DexContainer::Section* section) : section_(section) {
       SyncWithSection();
     }

     const uint8_t* Begin() const {
       return data_;
     }

     // Functions are not virtual (yet) for speed.
     size_t Tell() const {
       return position_;
     }

     void Seek(size_t position) {
       position_ = position;
       EnsureStorage(0u);
     }

     // Does not allow overwriting for bug prevention purposes.
     ALWAYS_INLINE size_t Write(const void* buffer, size_t length) {
       EnsureStorage(length);
       for (size_t i = 0; i < length; ++i) {
         DCHECK_EQ(data_[position_ + i], 0u);
       }
       memcpy(&data_[position_], buffer, length);
       position_ += length;
       return length;
     }

     ALWAYS_INLINE size_t Overwrite(const void* buffer, size_t length) {
       EnsureStorage(length);
       memcpy(&data_[position_], buffer, length);
       position_ += length;
       return length;
     }

     ALWAYS_INLINE size_t Clear(size_t position, size_t length) {
       EnsureStorage(length);
       memset(&data_[position], 0, length);
       return length;
     }

     ALWAYS_INLINE size_t WriteSleb128(int32_t value) {
       EnsureStorage(8);
       uint8_t* ptr = &data_[position_];
       const size_t len = EncodeSignedLeb128(ptr, value) - ptr;
       position_ += len;
       return len;
     }

     ALWAYS_INLINE size_t WriteUleb128(uint32_t value) {
       EnsureStorage(8);
       uint8_t* ptr = &data_[position_];
       const size_t len = EncodeUnsignedLeb128(ptr, value) - ptr;
       position_ += len;
       return len;
     }

     ALWAYS_INLINE void AlignTo(const size_t alignment) {
       position_ = RoundUp(position_, alignment);
       EnsureStorage(0u);
     }

     ALWAYS_INLINE void Skip(const size_t count) {
       position_ += count;
       EnsureStorage(0u);
     }

     class ScopedSeek {
      public:
       ScopedSeek(Stream* stream, uint32_t offset) : stream_(stream), offset_(stream->Tell()) {
         stream->Seek(offset);
       }

       ~ScopedSeek() {
         stream_->Seek(offset_);
       }

      private:
       Stream* const stream_;
       const uint32_t offset_;
     };

    private:
     ALWAYS_INLINE void EnsureStorage(size_t length) {
       size_t end = position_ + length;
       while (UNLIKELY(end > data_size_)) {
         section_->Resize(data_size_ * 3 / 2 + 1);
         SyncWithSection();
       }
     }

     void SyncWithSection() {
       data_ = section_->Begin();
       data_size_ = section_->Size();
     }

     // Current position of the stream.
     size_t position_ = 0u;
     DexContainer::Section* const section_ = nullptr;
     // Cached Begin() from the container to provide faster accesses.
     uint8_t* data_ = nullptr;
     // Cached Size from the container to provide faster accesses.
     size_t data_size_ = 0u;
   };

   static inline constexpr uint32_t SectionAlignment(DexFile::MapItemType type) {
     switch (type) {
       case DexFile::kDexTypeClassDataItem:
       case DexFile::kDexTypeStringDataItem:
       case DexFile::kDexTypeDebugInfoItem:
       case DexFile::kDexTypeAnnotationItem:
       case DexFile::kDexTypeEncodedArrayItem:
         return alignof(uint8_t);

       default:
         // All other sections are kDexAlignedSection.
         return DexWriter::kDexSectionWordAlignment;
     }
   }

   class Container : public DexContainer {
    public:
     Section* GetMainSection() override {
       return &main_section_;
     }

     Section* GetDataSection() override {
       return &data_section_;
     }

     bool IsCompactDexContainer() const override {
       return false;
     }

    private:
     VectorSection main_section_;
     VectorSection data_section_;

     friend class CompactDexWriter;
   };

   DexWriter(DexLayout* dex_layout, bool compute_offsets);

   static bool Output(DexLayout* dex_layout,
                      std::unique_ptr<DexContainer>* container,
                      bool compute_offsets,
                      std::string* error_msg) WARN_UNUSED;

   virtual ~DexWriter() {}

  protected:
   virtual bool Write(DexContainer* output, std::string* error_msg);
   virtual std::unique_ptr<DexContainer> CreateDexContainer() const;

   void WriteEncodedValue(Stream* stream, dex_ir::EncodedValue* encoded_value);
   void WriteEncodedValueHeader(Stream* stream, int8_t value_type, size_t value_arg);
   void WriteEncodedArray(Stream* stream, dex_ir::EncodedValueVector* values);
   void WriteEncodedAnnotation(Stream* stream, dex_ir::EncodedAnnotation* annotation);
   void WriteEncodedFields(Stream* stream, dex_ir::FieldItemVector* fields);
   void WriteEncodedMethods(Stream* stream, dex_ir::MethodItemVector* methods);

   // Header and id section
   virtual void WriteHeader(Stream* stream);
   virtual size_t GetHeaderSize() const;
   // reserve_only means don't write, only reserve space. This is required since the string data
   // offsets must be assigned.
   void WriteStringIds(Stream* stream, bool reserve_only);
   void WriteTypeIds(Stream* stream);
   void WriteProtoIds(Stream* stream, bool reserve_only);
   void WriteFieldIds(Stream* stream);
   void WriteMethodIds(Stream* stream);
   void WriteClassDefs(Stream* stream, bool reserve_only);
   void WriteCallSiteIds(Stream* stream, bool reserve_only);

   void WriteEncodedArrays(Stream* stream);
   void WriteAnnotations(Stream* stream);
   void WriteAnnotationSets(Stream* stream);
   void WriteAnnotationSetRefs(Stream* stream);
   void WriteAnnotationsDirectories(Stream* stream);

   // Data section.
   void WriteDebugInfoItems(Stream* stream);
   void WriteCodeItems(Stream* stream, bool reserve_only);
   void WriteTypeLists(Stream* stream);
   void WriteStringDatas(Stream* stream);
   void WriteClassDatas(Stream* stream);
   void WriteMethodHandles(Stream* stream);
   void WriteHiddenapiClassData(Stream* stream);
   void WriteMapItems(Stream* stream, MapItemQueue* queue);
   void GenerateAndWriteMapItems(Stream* stream);

   virtual void WriteCodeItemPostInstructionData(Stream* stream,
                                                     dex_ir::CodeItem* item,
                                                     bool reserve_only);
   virtual void WriteCodeItem(Stream* stream, dex_ir::CodeItem* item, bool reserve_only);
   virtual void WriteDebugInfoItem(Stream* stream, dex_ir::DebugInfoItem* debug_info);
   virtual void WriteStringData(Stream* stream, dex_ir::StringData* string_data);

   // Process an offset, if compute_offset is set, write into the dex ir item, otherwise read the
   // existing offset and use that for writing.
   void ProcessOffset(Stream* stream, dex_ir::Item* item);
   void ProcessOffset(Stream* stream, dex_ir::CollectionBase* item);

   dex_ir::Header* const header_;
   DexLayout* const dex_layout_;
   bool compute_offsets_;

  private:
   DISALLOW_COPY_AND_ASSIGN(DexWriter);
 };

 }  // namespace art

 #endif  // ART_DEXLAYOUT_DEX_WRITER_H_
	/*
	* Copyright (C) 2016 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.
	*
	* Header file of an in-memory representation of DEX files.
	*/

	#ifndef ART_DEXLAYOUT_DEX_WRITER_H_
	#define ART_DEXLAYOUT_DEX_WRITER_H_

	#include <functional>
	#include <memory> // For unique_ptr

	#include "base/os.h"
	#include "base/unix_file/fd_file.h"
	#include "dex/compact_dex_level.h"
	#include "dex_container.h"
	#include "dex/dex_file.h"
	#include "dex_ir.h"

	#include <queue>

	namespace art {

	class DexLayout;
	class DexLayoutHotnessInfo;

	struct MapItem {
	// Not using DexFile::MapItemType since compact dex and standard dex file may have different
	// sections.
	MapItem() = default;
	MapItem(uint32_t type, uint32_t size, size_t offset)
	: type_(type), size_(size), offset_(offset) { }

	// Sort by decreasing order since the priority_queue puts largest elements first.
	bool operator>(const MapItem& other) const {
	return offset_ > other.offset_;
	}

	uint32_t type_ = 0u;
	uint32_t size_ = 0u;
	uint32_t offset_ = 0u;
	};

	class MapItemQueue : public
	std::priority_queue<MapItem, std::vector<MapItem>, std::greater<MapItem>> {
	public:
	void AddIfNotEmpty(const MapItem& item);
	};

	class DexWriter {
	public:
	static constexpr uint32_t kDataSectionAlignment = sizeof(uint32_t) * 2;
	static constexpr uint32_t kDexSectionWordAlignment = 4;

	// Stream that writes into a dex container section. Do not have two streams pointing to the same
	// backing storage as there may be invalidation of backing storage to resize the section.
	// Random access stream (consider refactoring).
	class Stream {
	public:
	explicit Stream(DexContainer::Section* section) : section_(section) {
	SyncWithSection();
	}

	const uint8_t* Begin() const {
	return data_;
	}

	// Functions are not virtual (yet) for speed.
	size_t Tell() const {
	return position_;
	}

	void Seek(size_t position) {
	position_ = position;
	EnsureStorage(0u);
	}

	// Does not allow overwriting for bug prevention purposes.
	ALWAYS_INLINE size_t Write(const void* buffer, size_t length) {
	EnsureStorage(length);
	for (size_t i = 0; i < length; ++i) {
	DCHECK_EQ(data_[position_ + i], 0u);
	}
	memcpy(&data_[position_], buffer, length);
	position_ += length;
	return length;
	}

	ALWAYS_INLINE size_t Overwrite(const void* buffer, size_t length) {
	EnsureStorage(length);
	memcpy(&data_[position_], buffer, length);
	position_ += length;
	return length;
	}

	ALWAYS_INLINE size_t Clear(size_t position, size_t length) {
	EnsureStorage(length);
	memset(&data_[position], 0, length);
	return length;
	}

	ALWAYS_INLINE size_t WriteSleb128(int32_t value) {
	EnsureStorage(8);
	uint8_t* ptr = &data_[position_];
	const size_t len = EncodeSignedLeb128(ptr, value) - ptr;
	position_ += len;
	return len;
	}

	ALWAYS_INLINE size_t WriteUleb128(uint32_t value) {
	EnsureStorage(8);
	uint8_t* ptr = &data_[position_];
	const size_t len = EncodeUnsignedLeb128(ptr, value) - ptr;
	position_ += len;
	return len;
	}

	ALWAYS_INLINE void AlignTo(const size_t alignment) {
	position_ = RoundUp(position_, alignment);
	EnsureStorage(0u);
	}

	ALWAYS_INLINE void Skip(const size_t count) {
	position_ += count;
	EnsureStorage(0u);
	}

	class ScopedSeek {
	public:
	ScopedSeek(Stream* stream, uint32_t offset) : stream_(stream), offset_(stream->Tell()) {
	stream->Seek(offset);
	}

	~ScopedSeek() {
	stream_->Seek(offset_);
	}

	private:
	Stream* const stream_;
	const uint32_t offset_;
	};

	private:
	ALWAYS_INLINE void EnsureStorage(size_t length) {
	size_t end = position_ + length;
	while (UNLIKELY(end > data_size_)) {
	section_->Resize(data_size_ * 3 / 2 + 1);
	SyncWithSection();
	}
	}

	void SyncWithSection() {
	data_ = section_->Begin();
	data_size_ = section_->Size();
	}

	// Current position of the stream.
	size_t position_ = 0u;
	DexContainer::Section* const section_ = nullptr;
	// Cached Begin() from the container to provide faster accesses.
	uint8_t* data_ = nullptr;
	// Cached Size from the container to provide faster accesses.
	size_t data_size_ = 0u;
	};

	static inline constexpr uint32_t SectionAlignment(DexFile::MapItemType type) {
	switch (type) {
	case DexFile::kDexTypeClassDataItem:
	case DexFile::kDexTypeStringDataItem:
	case DexFile::kDexTypeDebugInfoItem:
	case DexFile::kDexTypeAnnotationItem:
	case DexFile::kDexTypeEncodedArrayItem:
	return alignof(uint8_t);

	default:
	// All other sections are kDexAlignedSection.
	return DexWriter::kDexSectionWordAlignment;
	}
	}

	class Container : public DexContainer {
	public:
	Section* GetMainSection() override {
	return &main_section_;
	}

	Section* GetDataSection() override {
	return &data_section_;
	}

	bool IsCompactDexContainer() const override {
	return false;
	}

	private:
	VectorSection main_section_;
	VectorSection data_section_;

	friend class CompactDexWriter;
	};

	DexWriter(DexLayout* dex_layout, bool compute_offsets);

	static bool Output(DexLayout* dex_layout,
	std::unique_ptr<DexContainer>* container,
	bool compute_offsets,
	std::string* error_msg) WARN_UNUSED;

	virtual ~DexWriter() {}

	protected:
	virtual bool Write(DexContainer* output, std::string* error_msg);
	virtual std::unique_ptr<DexContainer> CreateDexContainer() const;

	void WriteEncodedValue(Stream* stream, dex_ir::EncodedValue* encoded_value);
	void WriteEncodedValueHeader(Stream* stream, int8_t value_type, size_t value_arg);
	void WriteEncodedArray(Stream* stream, dex_ir::EncodedValueVector* values);
	void WriteEncodedAnnotation(Stream* stream, dex_ir::EncodedAnnotation* annotation);
	void WriteEncodedFields(Stream* stream, dex_ir::FieldItemVector* fields);
	void WriteEncodedMethods(Stream* stream, dex_ir::MethodItemVector* methods);

	// Header and id section
	virtual void WriteHeader(Stream* stream);
	virtual size_t GetHeaderSize() const;
	// reserve_only means don't write, only reserve space. This is required since the string data
	// offsets must be assigned.
	void WriteStringIds(Stream* stream, bool reserve_only);
	void WriteTypeIds(Stream* stream);
	void WriteProtoIds(Stream* stream, bool reserve_only);
	void WriteFieldIds(Stream* stream);
	void WriteMethodIds(Stream* stream);
	void WriteClassDefs(Stream* stream, bool reserve_only);
	void WriteCallSiteIds(Stream* stream, bool reserve_only);

	void WriteEncodedArrays(Stream* stream);
	void WriteAnnotations(Stream* stream);
	void WriteAnnotationSets(Stream* stream);
	void WriteAnnotationSetRefs(Stream* stream);
	void WriteAnnotationsDirectories(Stream* stream);

	// Data section.
	void WriteDebugInfoItems(Stream* stream);
	void WriteCodeItems(Stream* stream, bool reserve_only);
	void WriteTypeLists(Stream* stream);
	void WriteStringDatas(Stream* stream);
	void WriteClassDatas(Stream* stream);
	void WriteMethodHandles(Stream* stream);
	void WriteHiddenapiClassData(Stream* stream);
	void WriteMapItems(Stream* stream, MapItemQueue* queue);
	void GenerateAndWriteMapItems(Stream* stream);

	virtual void WriteCodeItemPostInstructionData(Stream* stream,
	dex_ir::CodeItem* item,
	bool reserve_only);
	virtual void WriteCodeItem(Stream* stream, dex_ir::CodeItem* item, bool reserve_only);
	virtual void WriteDebugInfoItem(Stream* stream, dex_ir::DebugInfoItem* debug_info);
	virtual void WriteStringData(Stream* stream, dex_ir::StringData* string_data);

	// Process an offset, if compute_offset is set, write into the dex ir item, otherwise read the
	// existing offset and use that for writing.
	void ProcessOffset(Stream* stream, dex_ir::Item* item);
	void ProcessOffset(Stream* stream, dex_ir::CollectionBase* item);

	dex_ir::Header* const header_;
	DexLayout* const dex_layout_;
	bool compute_offsets_;

	private:
	DISALLOW_COPY_AND_ASSIGN(DexWriter);
	};

	} // namespace art

	#endif // ART_DEXLAYOUT_DEX_WRITER_H_