| /* |
| * Copyright (C) 2018 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| |
| #pragma once |
| |
| #include "BytecodeIndex.h" |
| #include "Instruction.h" |
| #include <wtf/Vector.h> |
| |
| namespace JSC { |
| |
| class InstructionStream { |
| WTF_MAKE_FAST_ALLOCATED; |
| |
| using InstructionBuffer = Vector<uint8_t, 0, UnsafeVectorOverflow>; |
| |
| friend class InstructionStreamWriter; |
| friend class CachedInstructionStream; |
| public: |
| size_t sizeInBytes() const; |
| |
| using Offset = unsigned; |
| |
| private: |
| template<class InstructionBuffer> |
| class BaseRef { |
| WTF_MAKE_FAST_ALLOCATED; |
| |
| friend class InstructionStream; |
| |
| public: |
| BaseRef(const BaseRef<InstructionBuffer>& other) |
| : m_instructions(other.m_instructions) |
| , m_index(other.m_index) |
| { } |
| |
| void operator=(const BaseRef<InstructionBuffer>& other) |
| { |
| m_instructions = other.m_instructions; |
| m_index = other.m_index; |
| } |
| |
| inline const Instruction* operator->() const { return unwrap(); } |
| inline const Instruction* ptr() const { return unwrap(); } |
| |
| bool operator!=(const BaseRef<InstructionBuffer>& other) const |
| { |
| return &m_instructions != &other.m_instructions || m_index != other.m_index; |
| } |
| |
| BaseRef next() const |
| { |
| return BaseRef { m_instructions, m_index + ptr()->size() }; |
| } |
| |
| inline Offset offset() const { return m_index; } |
| inline BytecodeIndex index() const { return BytecodeIndex(offset()); } |
| |
| bool isValid() const |
| { |
| return m_index < m_instructions.size(); |
| } |
| |
| private: |
| inline const Instruction* unwrap() const { return reinterpret_cast<const Instruction*>(&m_instructions[m_index]); } |
| |
| protected: |
| BaseRef(InstructionBuffer& instructions, size_t index) |
| : m_instructions(instructions) |
| , m_index(index) |
| { } |
| |
| InstructionBuffer& m_instructions; |
| Offset m_index; |
| }; |
| |
| public: |
| using Ref = BaseRef<const InstructionBuffer>; |
| |
| class MutableRef : public BaseRef<InstructionBuffer> { |
| friend class InstructionStreamWriter; |
| |
| protected: |
| using BaseRef<InstructionBuffer>::BaseRef; |
| |
| public: |
| Ref freeze() const { return Ref { m_instructions, m_index }; } |
| inline Instruction* operator->() { return unwrap(); } |
| inline Instruction* ptr() { return unwrap(); } |
| inline operator Ref() |
| { |
| return Ref { m_instructions, m_index }; |
| } |
| |
| private: |
| inline Instruction* unwrap() { return reinterpret_cast<Instruction*>(&m_instructions[m_index]); } |
| }; |
| |
| private: |
| class iterator : public Ref { |
| friend class InstructionStream; |
| |
| public: |
| using Ref::Ref; |
| |
| Ref& operator*() |
| { |
| return *this; |
| } |
| |
| iterator& operator+=(size_t size) |
| { |
| m_index += size; |
| return *this; |
| } |
| |
| iterator& operator++() |
| { |
| return *this += ptr()->size(); |
| } |
| }; |
| |
| public: |
| inline iterator begin() const |
| { |
| return iterator { m_instructions, 0 }; |
| } |
| |
| inline iterator end() const |
| { |
| return iterator { m_instructions, m_instructions.size() }; |
| } |
| |
| inline const Ref at(BytecodeIndex index) const { return at(index.offset()); } |
| inline const Ref at(Offset offset) const |
| { |
| ASSERT(offset < m_instructions.size()); |
| return Ref { m_instructions, offset }; |
| } |
| |
| inline size_t size() const |
| { |
| return m_instructions.size(); |
| } |
| |
| const void* rawPointer() const |
| { |
| return m_instructions.data(); |
| } |
| |
| bool contains(Instruction *) const; |
| |
| protected: |
| explicit InstructionStream(InstructionBuffer&&); |
| |
| InstructionBuffer m_instructions; |
| }; |
| |
| class InstructionStreamWriter : public InstructionStream { |
| friend class BytecodeRewriter; |
| public: |
| InstructionStreamWriter() |
| : InstructionStream({ }) |
| { } |
| |
| inline MutableRef ref(Offset offset) |
| { |
| ASSERT(offset < m_instructions.size()); |
| return MutableRef { m_instructions, offset }; |
| } |
| |
| void seek(unsigned position) |
| { |
| ASSERT(position <= m_instructions.size()); |
| m_position = position; |
| } |
| |
| unsigned position() |
| { |
| return m_position; |
| } |
| |
| void write(uint8_t byte) |
| { |
| ASSERT(!m_finalized); |
| if (m_position < m_instructions.size()) |
| m_instructions[m_position++] = byte; |
| else { |
| m_instructions.append(byte); |
| m_position++; |
| } |
| } |
| |
| void write(uint16_t h) |
| { |
| ASSERT(!m_finalized); |
| uint8_t bytes[2]; |
| std::memcpy(bytes, &h, sizeof(h)); |
| |
| // Though not always obvious, we don't have to invert the order of the |
| // bytes written here for CPU(BIG_ENDIAN). This is because the incoming |
| // i value is already ordered in big endian on CPU(BIG_EDNDIAN) platforms. |
| write(bytes[0]); |
| write(bytes[1]); |
| } |
| |
| void write(uint32_t i) |
| { |
| ASSERT(!m_finalized); |
| uint8_t bytes[4]; |
| std::memcpy(bytes, &i, sizeof(i)); |
| |
| // Though not always obvious, we don't have to invert the order of the |
| // bytes written here for CPU(BIG_ENDIAN). This is because the incoming |
| // i value is already ordered in big endian on CPU(BIG_EDNDIAN) platforms. |
| write(bytes[0]); |
| write(bytes[1]); |
| write(bytes[2]); |
| write(bytes[3]); |
| } |
| |
| void rewind(MutableRef& ref) |
| { |
| ASSERT(ref.offset() < m_instructions.size()); |
| m_instructions.shrink(ref.offset()); |
| m_position = ref.offset(); |
| } |
| |
| std::unique_ptr<InstructionStream> finalize() |
| { |
| m_finalized = true; |
| m_instructions.shrinkToFit(); |
| return std::unique_ptr<InstructionStream> { new InstructionStream(WTFMove(m_instructions)) }; |
| } |
| |
| MutableRef ref() |
| { |
| return MutableRef { m_instructions, m_position }; |
| } |
| |
| void swap(InstructionStreamWriter& other) |
| { |
| std::swap(m_finalized, other.m_finalized); |
| std::swap(m_position, other.m_position); |
| m_instructions.swap(other.m_instructions); |
| } |
| |
| private: |
| class iterator : public MutableRef { |
| friend class InstructionStreamWriter; |
| |
| protected: |
| using MutableRef::MutableRef; |
| |
| public: |
| MutableRef& operator*() |
| { |
| return *this; |
| } |
| |
| iterator& operator+=(size_t size) |
| { |
| m_index += size; |
| return *this; |
| } |
| |
| iterator& operator++() |
| { |
| return *this += ptr()->size(); |
| } |
| }; |
| |
| public: |
| iterator begin() |
| { |
| return iterator { m_instructions, 0 }; |
| } |
| |
| iterator end() |
| { |
| return iterator { m_instructions, m_instructions.size() }; |
| } |
| |
| private: |
| unsigned m_position { 0 }; |
| bool m_finalized { false }; |
| }; |
| |
| |
| } // namespace JSC |
