1//===- BitCodes.h - Enum values for the bitstream format --------*- 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// This header defines bitstream enum values.
10//
11// The enum values defined in this file should be considered permanent. If
12// new features are added, they should have values added at the end of the
13// respective lists.
14//
15//===----------------------------------------------------------------------===//
16
17#ifndef LLVM_BITSTREAM_BITCODES_H
18#define LLVM_BITSTREAM_BITCODES_H
19
20#include "llvm/ADT/SmallVector.h"
21#include "llvm/ADT/StringExtras.h"
22#include "llvm/Bitstream/BitCodeEnums.h"
23#include "llvm/Support/DataTypes.h"
24#include "llvm/Support/ErrorHandling.h"
25#include <cassert>
26
27namespace llvm {
28/// BitCodeAbbrevOp - This describes one or more operands in an abbreviation.
29/// This is actually a union of two different things:
30/// 1. It could be a literal integer value ("the operand is always 17").
31/// 2. It could be an encoding specification ("this operand encoded like so").
32///
33class BitCodeAbbrevOp {
34 uint64_t Val; // A literal value or data for an encoding.
35 bool IsLiteral : 1; // Indicate whether this is a literal value or not.
36 unsigned Enc : 3; // The encoding to use.
37public:
38 enum Encoding {
39 Fixed = 1, // A fixed width field, Val specifies number of bits.
40 VBR = 2, // A VBR field where Val specifies the width of each chunk.
41 Array = 3, // A sequence of fields, next field species elt encoding.
42 Char6 = 4, // A 6-bit fixed field which maps to [a-zA-Z0-9._].
43 Blob = 5 // 32-bit aligned array of 8-bit characters.
44 };
45
46 static bool isValidEncoding(uint64_t E) {
47 return E >= 1 && E <= 5;
48 }
49
50 explicit BitCodeAbbrevOp(uint64_t V) : Val(V), IsLiteral(true) {}
51 explicit BitCodeAbbrevOp(Encoding E, uint64_t Data = 0)
52 : Val(Data), IsLiteral(false), Enc(E) {}
53
54 bool isLiteral() const { return IsLiteral; }
55 bool isEncoding() const { return !IsLiteral; }
56
57 // Accessors for literals.
58 uint64_t getLiteralValue() const { assert(isLiteral()); return Val; }
59
60 // Accessors for encoding info.
61 Encoding getEncoding() const { assert(isEncoding()); return (Encoding)Enc; }
62 uint64_t getEncodingData() const {
63 assert(isEncoding() && hasEncodingData());
64 return Val;
65 }
66
67 bool hasEncodingData() const { return hasEncodingData(E: getEncoding()); }
68 static bool hasEncodingData(Encoding E) {
69 switch (E) {
70 case Fixed:
71 case VBR:
72 return true;
73 case Array:
74 case Char6:
75 case Blob:
76 return false;
77 }
78 report_fatal_error(reason: "Invalid encoding");
79 }
80
81 /// isChar6 - Return true if this character is legal in the Char6 encoding.
82 static bool isChar6(char C) { return isAlnum(C) || C == '.' || C == '_'; }
83 static unsigned EncodeChar6(char C) {
84 if (C >= 'a' && C <= 'z') return C-'a';
85 if (C >= 'A' && C <= 'Z') return C-'A'+26;
86 if (C >= '0' && C <= '9') return C-'0'+26+26;
87 if (C == '.') return 62;
88 if (C == '_') return 63;
89 llvm_unreachable("Not a value Char6 character!");
90 }
91
92 static char DecodeChar6(unsigned V) {
93 assert((V & ~63) == 0 && "Not a Char6 encoded character!");
94 return "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789._"
95 [V];
96 }
97
98};
99
100/// BitCodeAbbrev - This class represents an abbreviation record. An
101/// abbreviation allows a complex record that has redundancy to be stored in a
102/// specialized format instead of the fully-general, fully-vbr, format.
103class BitCodeAbbrev {
104 SmallVector<BitCodeAbbrevOp, 32> OperandList;
105
106public:
107 BitCodeAbbrev() = default;
108
109 explicit BitCodeAbbrev(std::initializer_list<BitCodeAbbrevOp> OperandList)
110 : OperandList(OperandList) {}
111
112 unsigned getNumOperandInfos() const {
113 return static_cast<unsigned>(OperandList.size());
114 }
115 const BitCodeAbbrevOp &getOperandInfo(unsigned N) const {
116 return OperandList[N];
117 }
118
119 void Add(const BitCodeAbbrevOp &OpInfo) {
120 OperandList.push_back(Elt: OpInfo);
121 }
122};
123} // namespace llvm
124
125#endif
126

source code of include/llvm-17/llvm/Bitstream/BitCodes.h