1//===- BitCodes.h - Enum values for the bitcode format ----------*- 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// This header Bitcode enum values.
11//
12// The enum values defined in this file should be considered permanent. If
13// new features are added, they should have values added at the end of the
14// respective lists.
15//
16//===----------------------------------------------------------------------===//
17
18#ifndef LLVM_BITCODE_BITCODES_H
19#define LLVM_BITCODE_BITCODES_H
20
21#include "llvm/ADT/SmallVector.h"
22#include "llvm/Support/DataTypes.h"
23#include "llvm/Support/ErrorHandling.h"
24#include <cassert>
25
26namespace llvm {
27/// Offsets of the 32-bit fields of bitcode wrapper header.
28static const unsigned BWH_MagicField = 0 * 4;
29static const unsigned BWH_VersionField = 1 * 4;
30static const unsigned BWH_OffsetField = 2 * 4;
31static const unsigned BWH_SizeField = 3 * 4;
32static const unsigned BWH_CPUTypeField = 4 * 4;
33static const unsigned BWH_HeaderSize = 5 * 4;
34
35namespace bitc {
36 enum StandardWidths {
37 BlockIDWidth = 8, // We use VBR-8 for block IDs.
38 CodeLenWidth = 4, // Codelen are VBR-4.
39 BlockSizeWidth = 32 // BlockSize up to 2^32 32-bit words = 16GB per block.
40 };
41
42 // The standard abbrev namespace always has a way to exit a block, enter a
43 // nested block, define abbrevs, and define an unabbreviated record.
44 enum FixedAbbrevIDs {
45 END_BLOCK = 0, // Must be zero to guarantee termination for broken bitcode.
46 ENTER_SUBBLOCK = 1,
47
48 /// DEFINE_ABBREV - Defines an abbrev for the current block. It consists
49 /// of a vbr5 for # operand infos. Each operand info is emitted with a
50 /// single bit to indicate if it is a literal encoding. If so, the value is
51 /// emitted with a vbr8. If not, the encoding is emitted as 3 bits followed
52 /// by the info value as a vbr5 if needed.
53 DEFINE_ABBREV = 2,
54
55 // UNABBREV_RECORDs are emitted with a vbr6 for the record code, followed by
56 // a vbr6 for the # operands, followed by vbr6's for each operand.
57 UNABBREV_RECORD = 3,
58
59 // This is not a code, this is a marker for the first abbrev assignment.
60 FIRST_APPLICATION_ABBREV = 4
61 };
62
63 /// StandardBlockIDs - All bitcode files can optionally include a BLOCKINFO
64 /// block, which contains metadata about other blocks in the file.
65 enum StandardBlockIDs {
66 /// BLOCKINFO_BLOCK is used to define metadata about blocks, for example,
67 /// standard abbrevs that should be available to all blocks of a specified
68 /// ID.
69 BLOCKINFO_BLOCK_ID = 0,
70
71 // Block IDs 1-7 are reserved for future expansion.
72 FIRST_APPLICATION_BLOCKID = 8
73 };
74
75 /// BlockInfoCodes - The blockinfo block contains metadata about user-defined
76 /// blocks.
77 enum BlockInfoCodes {
78 // DEFINE_ABBREV has magic semantics here, applying to the current SETBID'd
79 // block, instead of the BlockInfo block.
80
81 BLOCKINFO_CODE_SETBID = 1, // SETBID: [blockid#]
82 BLOCKINFO_CODE_BLOCKNAME = 2, // BLOCKNAME: [name]
83 BLOCKINFO_CODE_SETRECORDNAME = 3 // BLOCKINFO_CODE_SETRECORDNAME:
84 // [id, name]
85 };
86
87} // End bitc namespace
88
89/// BitCodeAbbrevOp - This describes one or more operands in an abbreviation.
90/// This is actually a union of two different things:
91/// 1. It could be a literal integer value ("the operand is always 17").
92/// 2. It could be an encoding specification ("this operand encoded like so").
93///
94class BitCodeAbbrevOp {
95 uint64_t Val; // A literal value or data for an encoding.
96 bool IsLiteral : 1; // Indicate whether this is a literal value or not.
97 unsigned Enc : 3; // The encoding to use.
98public:
99 enum Encoding {
100 Fixed = 1, // A fixed width field, Val specifies number of bits.
101 VBR = 2, // A VBR field where Val specifies the width of each chunk.
102 Array = 3, // A sequence of fields, next field species elt encoding.
103 Char6 = 4, // A 6-bit fixed field which maps to [a-zA-Z0-9._].
104 Blob = 5 // 32-bit aligned array of 8-bit characters.
105 };
106
107 explicit BitCodeAbbrevOp(uint64_t V) : Val(V), IsLiteral(true) {}
108 explicit BitCodeAbbrevOp(Encoding E, uint64_t Data = 0)
109 : Val(Data), IsLiteral(false), Enc(E) {}
110
111 bool isLiteral() const { return IsLiteral; }
112 bool isEncoding() const { return !IsLiteral; }
113
114 // Accessors for literals.
115 uint64_t getLiteralValue() const { assert(isLiteral()); return Val; }
116
117 // Accessors for encoding info.
118 Encoding getEncoding() const { assert(isEncoding()); return (Encoding)Enc; }
119 uint64_t getEncodingData() const {
120 assert(isEncoding() && hasEncodingData());
121 return Val;
122 }
123
124 bool hasEncodingData() const { return hasEncodingData(getEncoding()); }
125 static bool hasEncodingData(Encoding E) {
126 switch (E) {
127 case Fixed:
128 case VBR:
129 return true;
130 case Array:
131 case Char6:
132 case Blob:
133 return false;
134 }
135 report_fatal_error("Invalid encoding");
136 }
137
138 /// isChar6 - Return true if this character is legal in the Char6 encoding.
139 static bool isChar6(char C) {
140 if (C >= 'a' && C <= 'z') return true;
141 if (C >= 'A' && C <= 'Z') return true;
142 if (C >= '0' && C <= '9') return true;
143 if (C == '.' || C == '_') return true;
144 return false;
145 }
146 static unsigned EncodeChar6(char C) {
147 if (C >= 'a' && C <= 'z') return C-'a';
148 if (C >= 'A' && C <= 'Z') return C-'A'+26;
149 if (C >= '0' && C <= '9') return C-'0'+26+26;
150 if (C == '.') return 62;
151 if (C == '_') return 63;
152 llvm_unreachable("Not a value Char6 character!");
153 }
154
155 static char DecodeChar6(unsigned V) {
156 assert((V & ~63) == 0 && "Not a Char6 encoded character!");
157 return "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789._"
158 [V];
159 }
160
161};
162
163template <> struct isPodLike<BitCodeAbbrevOp> { static const bool value=true; };
164
165/// BitCodeAbbrev - This class represents an abbreviation record. An
166/// abbreviation allows a complex record that has redundancy to be stored in a
167/// specialized format instead of the fully-general, fully-vbr, format.
168class BitCodeAbbrev {
169 SmallVector<BitCodeAbbrevOp, 32> OperandList;
170
171public:
172 unsigned getNumOperandInfos() const {
173 return static_cast<unsigned>(OperandList.size());
174 }
175 const BitCodeAbbrevOp &getOperandInfo(unsigned N) const {
176 return OperandList[N];
177 }
178
179 void Add(const BitCodeAbbrevOp &OpInfo) {
180 OperandList.push_back(OpInfo);
181 }
182};
183} // End llvm namespace
184
185#endif
186