| //===-- DataEncoder.h -------------------------------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef liblldb_DataEncoder_h_ |
| #define liblldb_DataEncoder_h_ |
| |
| #if defined(__cplusplus) |
| |
| #include "lldb/lldb-defines.h" |
| #include "lldb/lldb-enumerations.h" |
| #include "lldb/lldb-forward.h" |
| #include "lldb/lldb-types.h" |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| namespace lldb_private { |
| |
| /// \class DataEncoder DataEncoder.h "lldb/Core/DataEncoder.h" An binary data |
| /// encoding class. |
| /// |
| /// DataEncoder is a class that can encode binary data (swapping if needed) to |
| /// a data buffer. The data buffer can be caller owned, or can be shared data |
| /// that can be shared between multiple DataEncoder or DataEncoder instances. |
| /// |
| /// \see DataBuffer |
| class DataEncoder { |
| public: |
| /// Default constructor. |
| /// |
| /// Initialize all members to a default empty state. |
| DataEncoder(); |
| |
| /// Construct with a buffer that is owned by the caller. |
| /// |
| /// This constructor allows us to use data that is owned by the caller. The |
| /// data must stay around as long as this object is valid. |
| /// |
| /// \param[in] data |
| /// A pointer to caller owned data. |
| /// |
| /// \param[in] data_length |
| /// The length in bytes of \a data. |
| /// |
| /// \param[in] byte_order |
| /// A byte order of the data that we are extracting from. |
| /// |
| /// \param[in] addr_size |
| /// A new address byte size value. |
| DataEncoder(void *data, uint32_t data_length, lldb::ByteOrder byte_order, |
| uint8_t addr_size); |
| |
| /// Construct with shared data. |
| /// |
| /// Copies the data shared pointer which adds a reference to the contained |
| /// in \a data_sp. The shared data reference is reference counted to ensure |
| /// the data lives as long as anyone still has a valid shared pointer to the |
| /// data in \a data_sp. |
| /// |
| /// \param[in] data_sp |
| /// A shared pointer to data. |
| /// |
| /// \param[in] byte_order |
| /// A byte order of the data that we are extracting from. |
| /// |
| /// \param[in] addr_size |
| /// A new address byte size value. |
| DataEncoder(const lldb::DataBufferSP &data_sp, lldb::ByteOrder byte_order, |
| uint8_t addr_size); |
| |
| /// Destructor |
| /// |
| /// If this object contains a valid shared data reference, the reference |
| /// count on the data will be decremented, and if zero, the data will be |
| /// freed. |
| ~DataEncoder(); |
| |
| /// Clears the object state. |
| /// |
| /// Clears the object contents back to a default invalid state, and release |
| /// any references to shared data that this object may contain. |
| void Clear(); |
| |
| /// Get the current address size. |
| /// |
| /// Return the size in bytes of any address values this object will extract. |
| /// |
| /// \return |
| /// The size in bytes of address values that will be extracted. |
| uint8_t GetAddressByteSize() const { return m_addr_size; } |
| |
| /// Get the number of bytes contained in this object. |
| /// |
| /// \return |
| /// The total number of bytes of data this object refers to. |
| size_t GetByteSize() const { return m_end - m_start; } |
| |
| /// Get the data end pointer. |
| /// |
| /// \return |
| /// Returns a pointer to the next byte contained in this |
| /// object's data, or NULL of there is no data in this object. |
| uint8_t *GetDataEnd() { return m_end; } |
| |
| const uint8_t *GetDataEnd() const { return m_end; } |
| |
| /// Get the shared data offset. |
| /// |
| /// Get the offset of the first byte of data in the shared data (if any). |
| /// |
| /// \return |
| /// If this object contains shared data, this function returns |
| /// the offset in bytes into that shared data, zero otherwise. |
| size_t GetSharedDataOffset() const; |
| |
| /// Get the current byte order value. |
| /// |
| /// \return |
| /// The current byte order value from this object's internal |
| /// state. |
| lldb::ByteOrder GetByteOrder() const { return m_byte_order; } |
| |
| /// Get the data start pointer. |
| /// |
| /// \return |
| /// Returns a pointer to the first byte contained in this |
| /// object's data, or NULL of there is no data in this object. |
| uint8_t *GetDataStart() { return m_start; } |
| |
| const uint8_t *GetDataStart() const { return m_start; } |
| |
| /// Encode unsigned integer values into the data at \a offset. |
| /// |
| /// \param[in] offset |
| /// The offset within the contained data at which to put the |
| /// data. |
| /// |
| /// \param[in] value |
| /// The value to encode into the data. |
| /// |
| /// \return |
| /// The next offset in the bytes of this data if the data |
| /// was successfully encoded, UINT32_MAX if the encoding failed. |
| uint32_t PutU8(uint32_t offset, uint8_t value); |
| |
| uint32_t PutU16(uint32_t offset, uint16_t value); |
| |
| uint32_t PutU32(uint32_t offset, uint32_t value); |
| |
| uint32_t PutU64(uint32_t offset, uint64_t value); |
| |
| /// Encode an unsigned integer of size \a byte_size to \a offset. |
| /// |
| /// Encode a single integer value at \a offset and return the offset that |
| /// follows the newly encoded integer when the data is successfully encoded |
| /// into the existing data. There must be enough room in the data, else |
| /// UINT32_MAX will be returned to indicate that encoding failed. |
| /// |
| /// \param[in] offset |
| /// The offset within the contained data at which to put the |
| /// encoded integer. |
| /// |
| /// \param[in] byte_size |
| /// The size in byte of the integer to encode. |
| /// |
| /// \param[in] value |
| /// The integer value to write. The least significant bytes of |
| /// the integer value will be written if the size is less than |
| /// 8 bytes. |
| /// |
| /// \return |
| /// The next offset in the bytes of this data if the integer |
| /// was successfully encoded, UINT32_MAX if the encoding failed. |
| uint32_t PutMaxU64(uint32_t offset, uint32_t byte_size, uint64_t value); |
| |
| /// Encode an arbitrary number of bytes. |
| /// |
| /// \param[in] offset |
| /// The offset in bytes into the contained data at which to |
| /// start encoding. |
| /// |
| /// \param[in] src |
| /// The buffer that contains the bytes to encode. |
| /// |
| /// \param[in] src_len |
| /// The number of bytes to encode. |
| /// |
| /// \return |
| /// The next valid offset within data if the put operation |
| /// was successful, else UINT32_MAX to indicate the put failed. |
| uint32_t PutData(uint32_t offset, const void *src, uint32_t src_len); |
| |
| /// Encode an address in the existing buffer at \a offset bytes into the |
| /// buffer. |
| /// |
| /// Encode a single address (honoring the m_addr_size member) to the data |
| /// and return the next offset where subsequent data would go. pointed to by |
| /// \a offset_ptr. The size of the extracted address comes from the \a |
| /// m_addr_size member variable and should be set correctly prior to |
| /// extracting any address values. |
| /// |
| /// \param[in,out] offset_ptr |
| /// A pointer to an offset within the data that will be advanced |
| /// by the appropriate number of bytes if the value is extracted |
| /// correctly. If the offset is out of bounds or there are not |
| /// enough bytes to extract this value, the offset will be left |
| /// unmodified. |
| /// |
| /// \return |
| /// The next valid offset within data if the put operation |
| /// was successful, else UINT32_MAX to indicate the put failed. |
| uint32_t PutAddress(uint32_t offset, lldb::addr_t addr); |
| |
| /// Put a C string to \a offset. |
| /// |
| /// Encodes a C string into the existing data including the terminating |
| /// |
| /// \param[in,out] offset_ptr |
| /// A pointer to an offset within the data that will be advanced |
| /// by the appropriate number of bytes if the value is extracted |
| /// correctly. If the offset is out of bounds or there are not |
| /// enough bytes to extract this value, the offset will be left |
| /// unmodified. |
| /// |
| /// \return |
| /// A pointer to the C string value in the data. If the offset |
| /// pointed to by \a offset_ptr is out of bounds, or if the |
| /// offset plus the length of the C string is out of bounds, |
| /// NULL will be returned. |
| uint32_t PutCString(uint32_t offset_ptr, const char *cstr); |
| |
| lldb::DataBufferSP &GetSharedDataBuffer() { return m_data_sp; } |
| |
| /// Set the address byte size. |
| /// |
| /// Set the size in bytes that will be used when extracting any address and |
| /// pointer values from data contained in this object. |
| /// |
| /// \param[in] addr_size |
| /// The size in bytes to use when extracting addresses. |
| void SetAddressByteSize(uint8_t addr_size) { m_addr_size = addr_size; } |
| |
| /// Set data with a buffer that is caller owned. |
| /// |
| /// Use data that is owned by the caller when extracting values. The data |
| /// must stay around as long as this object, or any object that copies a |
| /// subset of this object's data, is valid. If \a bytes is NULL, or \a |
| /// length is zero, this object will contain no data. |
| /// |
| /// \param[in] bytes |
| /// A pointer to caller owned data. |
| /// |
| /// \param[in] length |
| /// The length in bytes of \a bytes. |
| /// |
| /// \param[in] byte_order |
| /// A byte order of the data that we are extracting from. |
| /// |
| /// \return |
| /// The number of bytes that this object now contains. |
| uint32_t SetData(void *bytes, uint32_t length, lldb::ByteOrder byte_order); |
| |
| /// Adopt a subset of shared data in \a data_sp. |
| /// |
| /// Copies the data shared pointer which adds a reference to the contained |
| /// in \a data_sp. The shared data reference is reference counted to ensure |
| /// the data lives as long as anyone still has a valid shared pointer to the |
| /// data in \a data_sp. The byte order and address byte size settings remain |
| /// the same. If \a offset is not a valid offset in \a data_sp, then no |
| /// reference to the shared data will be added. If there are not \a length |
| /// bytes available in \a data starting at \a offset, the length will be |
| /// truncated to contains as many bytes as possible. |
| /// |
| /// \param[in] data_sp |
| /// A shared pointer to data. |
| /// |
| /// \param[in] offset |
| /// The offset into \a data_sp at which the subset starts. |
| /// |
| /// \param[in] length |
| /// The length in bytes of the subset of \a data_sp. |
| /// |
| /// \return |
| /// The number of bytes that this object now contains. |
| uint32_t SetData(const lldb::DataBufferSP &data_sp, uint32_t offset = 0, |
| uint32_t length = UINT32_MAX); |
| |
| /// Set the byte_order value. |
| /// |
| /// Sets the byte order of the data to extract. Extracted values will be |
| /// swapped if necessary when decoding. |
| /// |
| /// \param[in] byte_order |
| /// The byte order value to use when extracting data. |
| void SetByteOrder(lldb::ByteOrder byte_order) { m_byte_order = byte_order; } |
| |
| /// Test the validity of \a offset. |
| /// |
| /// \return |
| /// \b true if \a offset is a valid offset into the data in this |
| /// object, \b false otherwise. |
| bool ValidOffset(uint32_t offset) const { return offset < GetByteSize(); } |
| |
| /// Test the availability of \a length bytes of data from \a offset. |
| /// |
| /// \return |
| /// \b true if \a offset is a valid offset and there are \a |
| /// length bytes available at that offset, \b false otherwise. |
| bool ValidOffsetForDataOfSize(uint32_t offset, uint32_t length) const { |
| return length <= BytesLeft(offset); |
| } |
| |
| uint32_t BytesLeft(uint32_t offset) const { |
| const uint32_t size = GetByteSize(); |
| if (size > offset) |
| return size - offset; |
| return 0; |
| } |
| |
| protected: |
| // Member variables |
| uint8_t *m_start; ///< A pointer to the first byte of data. |
| uint8_t *m_end; ///< A pointer to the byte that is past the end of the data. |
| lldb::ByteOrder |
| m_byte_order; ///< The byte order of the data we are extracting from. |
| uint8_t m_addr_size; ///< The address size to use when extracting pointers or |
| /// addresses |
| mutable lldb::DataBufferSP m_data_sp; ///< The shared pointer to data that can |
| /// be shared among multiple instances |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(DataEncoder); |
| }; |
| |
| } // namespace lldb_private |
| |
| #endif // #if defined (__cplusplus) |
| #endif // #ifndef liblldb_DataEncoder_h_ |