| // Copyright 2018 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_SNAPSHOT_EMBEDDED_EMBEDDED_DATA_H_ |
| #define V8_SNAPSHOT_EMBEDDED_EMBEDDED_DATA_H_ |
| |
| #include "src/base/macros.h" |
| #include "src/builtins/builtins.h" |
| #include "src/common/globals.h" |
| #include "src/execution/isolate.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| class Code; |
| class Isolate; |
| |
| // Wraps an off-heap instruction stream. |
| // TODO(jgruber,v8:6666): Remove this class. |
| class InstructionStream final : public AllStatic { |
| public: |
| // Returns true, iff the given pc points into an off-heap instruction stream. |
| static bool PcIsOffHeap(Isolate* isolate, Address pc); |
| |
| // Returns the corresponding Code object if it exists, and nullptr otherwise. |
| static Code TryLookupCode(Isolate* isolate, Address address); |
| |
| // During snapshot creation, we first create an executable off-heap area |
| // containing all off-heap code. The area is guaranteed to be contiguous. |
| // Note that this only applies when building the snapshot, e.g. for |
| // mksnapshot. Otherwise, off-heap code is embedded directly into the binary. |
| static void CreateOffHeapInstructionStream(Isolate* isolate, uint8_t** code, |
| uint32_t* code_size, |
| uint8_t** metadata, |
| uint32_t* metadata_size); |
| static void FreeOffHeapInstructionStream(uint8_t* code, uint32_t code_size, |
| uint8_t* metadata, |
| uint32_t metadata_size); |
| }; |
| |
| class EmbeddedData final { |
| public: |
| static EmbeddedData FromIsolate(Isolate* isolate); |
| |
| static EmbeddedData FromBlob() { |
| return EmbeddedData(Isolate::CurrentEmbeddedBlobCode(), |
| Isolate::CurrentEmbeddedBlobCodeSize(), |
| Isolate::CurrentEmbeddedBlobMetadata(), |
| Isolate::CurrentEmbeddedBlobMetadataSize()); |
| } |
| |
| static EmbeddedData FromBlob(Isolate* isolate) { |
| return EmbeddedData(isolate->embedded_blob_code(), |
| isolate->embedded_blob_code_size(), |
| isolate->embedded_blob_metadata(), |
| isolate->embedded_blob_metadata_size()); |
| } |
| |
| const uint8_t* code() const { return code_; } |
| uint32_t code_size() const { return code_size_; } |
| const uint8_t* metadata() const { return metadata_; } |
| uint32_t metadata_size() const { return metadata_size_; } |
| |
| void Dispose() { |
| delete[] code_; |
| code_ = nullptr; |
| delete[] metadata_; |
| metadata_ = nullptr; |
| } |
| |
| Address InstructionStartOfBuiltin(int i) const; |
| uint32_t InstructionSizeOfBuiltin(int i) const; |
| |
| Address InstructionStartOfBytecodeHandlers() const; |
| Address InstructionEndOfBytecodeHandlers() const; |
| |
| bool ContainsBuiltin(int i) const { return InstructionSizeOfBuiltin(i) > 0; } |
| |
| uint32_t AddressForHashing(Address addr) { |
| Address start = reinterpret_cast<Address>(code_); |
| DCHECK(IsInRange(addr, start, start + code_size_)); |
| return static_cast<uint32_t>(addr - start); |
| } |
| |
| // Padded with kCodeAlignment. |
| uint32_t PaddedInstructionSizeOfBuiltin(int i) const { |
| uint32_t size = InstructionSizeOfBuiltin(i); |
| return (size == 0) ? 0 : PadAndAlign(size); |
| } |
| |
| size_t CreateEmbeddedBlobHash() const; |
| size_t EmbeddedBlobHash() const { |
| return *reinterpret_cast<const size_t*>(metadata_ + |
| EmbeddedBlobHashOffset()); |
| } |
| |
| size_t IsolateHash() const { |
| return *reinterpret_cast<const size_t*>(metadata_ + IsolateHashOffset()); |
| } |
| |
| struct Metadata { |
| // Blob layout information. |
| uint32_t instructions_offset; |
| uint32_t instructions_length; |
| }; |
| STATIC_ASSERT(offsetof(Metadata, instructions_offset) == 0); |
| STATIC_ASSERT(offsetof(Metadata, instructions_length) == kUInt32Size); |
| STATIC_ASSERT(sizeof(Metadata) == kUInt32Size + kUInt32Size); |
| |
| // The layout of the blob is as follows: |
| // |
| // metadata: |
| // [0] hash of the remaining blob |
| // [1] hash of embedded-blob-relevant heap objects |
| // [2] metadata of instruction stream 0 |
| // ... metadata |
| // |
| // code: |
| // [0] instruction streams 0 |
| // ... instruction streams |
| |
| static constexpr uint32_t kTableSize = Builtins::builtin_count; |
| static constexpr uint32_t EmbeddedBlobHashOffset() { return 0; } |
| static constexpr uint32_t EmbeddedBlobHashSize() { return kSizetSize; } |
| static constexpr uint32_t IsolateHashOffset() { |
| return EmbeddedBlobHashOffset() + EmbeddedBlobHashSize(); |
| } |
| static constexpr uint32_t IsolateHashSize() { return kSizetSize; } |
| static constexpr uint32_t MetadataTableOffset() { |
| return IsolateHashOffset() + IsolateHashSize(); |
| } |
| static constexpr uint32_t MetadataTableSize() { |
| return sizeof(struct Metadata) * kTableSize; |
| } |
| static constexpr uint32_t RawCodeOffset() { return 0; } |
| |
| private: |
| EmbeddedData(const uint8_t* code, uint32_t code_size, const uint8_t* metadata, |
| uint32_t metadata_size) |
| : code_(code), |
| code_size_(code_size), |
| metadata_(metadata), |
| metadata_size_(metadata_size) { |
| DCHECK_NOT_NULL(code); |
| DCHECK_LT(0, code_size); |
| DCHECK_NOT_NULL(metadata); |
| DCHECK_LT(0, metadata_size); |
| } |
| |
| const Metadata* Metadata() const { |
| return reinterpret_cast<const struct Metadata*>(metadata_ + |
| MetadataTableOffset()); |
| } |
| const uint8_t* RawCode() const { return code_ + RawCodeOffset(); } |
| |
| static constexpr int PadAndAlign(int size) { |
| // Ensure we have at least one byte trailing the actual builtin |
| // instructions which we can later fill with int3. |
| return RoundUp<kCodeAlignment>(size + 1); |
| } |
| |
| void PrintStatistics() const; |
| |
| // This points to code for builtins. The contents are potentially unreadable |
| // on platforms that disallow reads from the .text section. |
| const uint8_t* code_; |
| uint32_t code_size_; |
| |
| // This is metadata for the code. |
| const uint8_t* metadata_; |
| uint32_t metadata_size_; |
| }; |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_SNAPSHOT_EMBEDDED_EMBEDDED_DATA_H_ |