1 | //===-- MsgPack.h - MessagePack Constants -----------------------*- C++ -*-===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | /// |
9 | /// \file |
10 | /// This file contains constants used for implementing MessagePack support. |
11 | /// |
12 | //===----------------------------------------------------------------------===// |
13 | |
14 | #ifndef LLVM_BINARYFORMAT_MSGPACK_H |
15 | #define LLVM_BINARYFORMAT_MSGPACK_H |
16 | |
17 | #include "llvm/Support/DataTypes.h" |
18 | #include "llvm/Support/Endian.h" |
19 | |
20 | namespace llvm { |
21 | namespace msgpack { |
22 | |
23 | /// The endianness of all multi-byte encoded values in MessagePack. |
24 | constexpr llvm::endianness Endianness = llvm::endianness::big; |
25 | |
26 | /// The first byte identifiers of MessagePack object formats. |
27 | namespace FirstByte { |
28 | #define HANDLE_MP_FIRST_BYTE(ID, NAME) constexpr uint8_t NAME = ID; |
29 | #include "llvm/BinaryFormat/MsgPack.def" |
30 | } |
31 | |
32 | /// Most significant bits used to identify "Fix" variants in MessagePack. |
33 | /// |
34 | /// For example, FixStr objects encode their size in the five least significant |
35 | /// bits of their first byte, which is identified by the bit pattern "101" in |
36 | /// the three most significant bits. So FixBits::String contains 0b10100000. |
37 | /// |
38 | /// A corresponding mask of the bit pattern is found in \c FixBitsMask. |
39 | namespace FixBits { |
40 | #define HANDLE_MP_FIX_BITS(ID, NAME) constexpr uint8_t NAME = ID; |
41 | #include "llvm/BinaryFormat/MsgPack.def" |
42 | } |
43 | |
44 | /// Mask of bits used to identify "Fix" variants in MessagePack. |
45 | /// |
46 | /// For example, FixStr objects encode their size in the five least significant |
47 | /// bits of their first byte, which is identified by the bit pattern "101" in |
48 | /// the three most significant bits. So FixBitsMask::String contains |
49 | /// 0b11100000. |
50 | /// |
51 | /// The corresponding bit pattern to mask for is found in FixBits. |
52 | namespace FixBitsMask { |
53 | #define HANDLE_MP_FIX_BITS_MASK(ID, NAME) constexpr uint8_t NAME = ID; |
54 | #include "llvm/BinaryFormat/MsgPack.def" |
55 | } |
56 | |
57 | /// The maximum value or size encodable in "Fix" variants of formats. |
58 | /// |
59 | /// For example, FixStr objects encode their size in the five least significant |
60 | /// bits of their first byte, so the largest encodable size is 0b00011111. |
61 | namespace FixMax { |
62 | #define HANDLE_MP_FIX_MAX(ID, NAME) constexpr uint8_t NAME = ID; |
63 | #include "llvm/BinaryFormat/MsgPack.def" |
64 | } |
65 | |
66 | /// The exact size encodable in "Fix" variants of formats. |
67 | /// |
68 | /// The only objects for which an exact size makes sense are of Extension type. |
69 | /// |
70 | /// For example, FixExt4 stores an extension type containing exactly four bytes. |
71 | namespace FixLen { |
72 | #define HANDLE_MP_FIX_LEN(ID, NAME) constexpr uint8_t NAME = ID; |
73 | #include "llvm/BinaryFormat/MsgPack.def" |
74 | } |
75 | |
76 | /// The minimum value or size encodable in "Fix" variants of formats. |
77 | /// |
78 | /// The only object for which a minimum makes sense is a negative FixNum. |
79 | /// |
80 | /// Negative FixNum objects encode their signed integer value in one byte, but |
81 | /// they must have the pattern "111" as their three most significant bits. This |
82 | /// means all values are negative, and the smallest representable value is |
83 | /// 0b11100000. |
84 | namespace FixMin { |
85 | #define HANDLE_MP_FIX_MIN(ID, NAME) constexpr int8_t NAME = ID; |
86 | #include "llvm/BinaryFormat/MsgPack.def" |
87 | } |
88 | |
89 | } // end namespace msgpack |
90 | } // end namespace llvm |
91 | |
92 | #endif // LLVM_BINARYFORMAT_MSGPACK_H |
93 | |