Andrew Scull | 0372a57 | 2018-11-16 15:47:06 +0000 | [diff] [blame] | 1 | //===-- MsgPack.h - MessagePack Constants -----------------------*- C++ -*-===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | /// |
| 10 | /// \file |
| 11 | /// This file contains constants used for implementing MessagePack support. |
| 12 | /// |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #ifndef LLVM_BINARYFORMAT_MSGPACK_H |
| 16 | #define LLVM_BINARYFORMAT_MSGPACK_H |
| 17 | |
| 18 | #include "llvm/Support/DataTypes.h" |
| 19 | #include "llvm/Support/Endian.h" |
| 20 | |
| 21 | namespace llvm { |
| 22 | namespace msgpack { |
| 23 | |
| 24 | /// The endianness of all multi-byte encoded values in MessagePack. |
| 25 | constexpr support::endianness Endianness = support::big; |
| 26 | |
| 27 | /// The first byte identifiers of MessagePack object formats. |
| 28 | namespace FirstByte { |
| 29 | #define HANDLE_MP_FIRST_BYTE(ID, NAME) constexpr uint8_t NAME = ID; |
| 30 | #include "llvm/BinaryFormat/MsgPack.def" |
| 31 | } |
| 32 | |
| 33 | /// Most significant bits used to identify "Fix" variants in MessagePack. |
| 34 | /// |
| 35 | /// For example, FixStr objects encode their size in the five least significant |
| 36 | /// bits of their first byte, which is identified by the bit pattern "101" in |
| 37 | /// the three most significant bits. So FixBits::String contains 0b10100000. |
| 38 | /// |
| 39 | /// A corresponding mask of the bit pattern is found in \c FixBitsMask. |
| 40 | namespace FixBits { |
| 41 | #define HANDLE_MP_FIX_BITS(ID, NAME) constexpr uint8_t NAME = ID; |
| 42 | #include "llvm/BinaryFormat/MsgPack.def" |
| 43 | } |
| 44 | |
| 45 | /// Mask of bits used to identify "Fix" variants in MessagePack. |
| 46 | /// |
| 47 | /// For example, FixStr objects encode their size in the five least significant |
| 48 | /// bits of their first byte, which is identified by the bit pattern "101" in |
| 49 | /// the three most significant bits. So FixBitsMask::String contains |
| 50 | /// 0b11100000. |
| 51 | /// |
| 52 | /// The corresponding bit pattern to mask for is found in FixBits. |
| 53 | namespace FixBitsMask { |
| 54 | #define HANDLE_MP_FIX_BITS_MASK(ID, NAME) constexpr uint8_t NAME = ID; |
| 55 | #include "llvm/BinaryFormat/MsgPack.def" |
| 56 | } |
| 57 | |
| 58 | /// The maximum value or size encodable in "Fix" variants of formats. |
| 59 | /// |
| 60 | /// For example, FixStr objects encode their size in the five least significant |
| 61 | /// bits of their first byte, so the largest encodable size is 0b00011111. |
| 62 | namespace FixMax { |
| 63 | #define HANDLE_MP_FIX_MAX(ID, NAME) constexpr uint8_t NAME = ID; |
| 64 | #include "llvm/BinaryFormat/MsgPack.def" |
| 65 | } |
| 66 | |
| 67 | /// The exact size encodable in "Fix" variants of formats. |
| 68 | /// |
| 69 | /// The only objects for which an exact size makes sense are of Extension type. |
| 70 | /// |
| 71 | /// For example, FixExt4 stores an extension type containing exactly four bytes. |
| 72 | namespace FixLen { |
| 73 | #define HANDLE_MP_FIX_LEN(ID, NAME) constexpr uint8_t NAME = ID; |
| 74 | #include "llvm/BinaryFormat/MsgPack.def" |
| 75 | } |
| 76 | |
| 77 | /// The minimum value or size encodable in "Fix" variants of formats. |
| 78 | /// |
| 79 | /// The only object for which a minimum makes sense is a negative FixNum. |
| 80 | /// |
| 81 | /// Negative FixNum objects encode their signed integer value in one byte, but |
| 82 | /// they must have the pattern "111" as their three most significant bits. This |
| 83 | /// means all values are negative, and the smallest representable value is |
| 84 | /// 0b11100000. |
| 85 | namespace FixMin { |
| 86 | #define HANDLE_MP_FIX_MIN(ID, NAME) constexpr int8_t NAME = ID; |
| 87 | #include "llvm/BinaryFormat/MsgPack.def" |
| 88 | } |
| 89 | |
| 90 | } // end namespace msgpack |
| 91 | } // end namespace llvm |
| 92 | |
| 93 | #endif // LLVM_BINARYFORMAT_MSGPACK_H |