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 26 namespace llvm { 27 /// Offsets of the 32-bit fields of bitcode wrapper header. 28 static const unsigned BWH_MagicField = 0 * 4; 29 static const unsigned BWH_VersionField = 1 * 4; 30 static const unsigned BWH_OffsetField = 2 * 4; 31 static const unsigned BWH_SizeField = 3 * 4; 32 static const unsigned BWH_CPUTypeField = 4 * 4; 33 static const unsigned BWH_HeaderSize = 5 * 4; 34 35 namespace 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 /// 94 class 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. 98 public: 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 }; 162 163 template <> 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. 168 class BitCodeAbbrev { 169 SmallVector<BitCodeAbbrevOp, 32> OperandList; 170 171 public: 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
