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 namespace bitc { 28 enum StandardWidths { 29 BlockIDWidth = 8, // We use VBR-8 for block IDs. 30 CodeLenWidth = 4, // Codelen are VBR-4. 31 BlockSizeWidth = 32 // BlockSize up to 2^32 32-bit words = 16GB per block. 32 }; 33 34 // The standard abbrev namespace always has a way to exit a block, enter a 35 // nested block, define abbrevs, and define an unabbreviated record. 36 enum FixedAbbrevIDs { 37 END_BLOCK = 0, // Must be zero to guarantee termination for broken bitcode. 38 ENTER_SUBBLOCK = 1, 39 40 /// DEFINE_ABBREV - Defines an abbrev for the current block. It consists 41 /// of a vbr5 for # operand infos. Each operand info is emitted with a 42 /// single bit to indicate if it is a literal encoding. If so, the value is 43 /// emitted with a vbr8. If not, the encoding is emitted as 3 bits followed 44 /// by the info value as a vbr5 if needed. 45 DEFINE_ABBREV = 2, 46 47 // UNABBREV_RECORDs are emitted with a vbr6 for the record code, followed by 48 // a vbr6 for the # operands, followed by vbr6's for each operand. 49 UNABBREV_RECORD = 3, 50 51 // This is not a code, this is a marker for the first abbrev assignment. 52 FIRST_APPLICATION_ABBREV = 4 53 }; 54 55 /// StandardBlockIDs - All bitcode files can optionally include a BLOCKINFO 56 /// block, which contains metadata about other blocks in the file. 57 enum StandardBlockIDs { 58 /// BLOCKINFO_BLOCK is used to define metadata about blocks, for example, 59 /// standard abbrevs that should be available to all blocks of a specified 60 /// ID. 61 BLOCKINFO_BLOCK_ID = 0, 62 63 // Block IDs 1-7 are reserved for future expansion. 64 FIRST_APPLICATION_BLOCKID = 8 65 }; 66 67 /// BlockInfoCodes - The blockinfo block contains metadata about user-defined 68 /// blocks. 69 enum BlockInfoCodes { 70 // DEFINE_ABBREV has magic semantics here, applying to the current SETBID'd 71 // block, instead of the BlockInfo block. 72 73 BLOCKINFO_CODE_SETBID = 1, // SETBID: [blockid#] 74 BLOCKINFO_CODE_BLOCKNAME = 2, // BLOCKNAME: [name] 75 BLOCKINFO_CODE_SETRECORDNAME = 3 // BLOCKINFO_CODE_SETRECORDNAME: 76 // [id, name] 77 }; 78 79 } // End bitc namespace 80 81 /// BitCodeAbbrevOp - This describes one or more operands in an abbreviation. 82 /// This is actually a union of two different things: 83 /// 1. It could be a literal integer value ("the operand is always 17"). 84 /// 2. It could be an encoding specification ("this operand encoded like so"). 85 /// 86 class BitCodeAbbrevOp { 87 uint64_t Val; // A literal value or data for an encoding. 88 bool IsLiteral : 1; // Indicate whether this is a literal value or not. 89 unsigned Enc : 3; // The encoding to use. 90 public: 91 enum Encoding { 92 Fixed = 1, // A fixed width field, Val specifies number of bits. 93 VBR = 2, // A VBR field where Val specifies the width of each chunk. 94 Array = 3, // A sequence of fields, next field species elt encoding. 95 Char6 = 4, // A 6-bit fixed field which maps to [a-zA-Z0-9._]. 96 Blob = 5 // 32-bit aligned array of 8-bit characters. 97 }; 98 99 explicit BitCodeAbbrevOp(uint64_t V) : Val(V), IsLiteral(true) {} 100 explicit BitCodeAbbrevOp(Encoding E, uint64_t Data = 0) 101 : Val(Data), IsLiteral(false), Enc(E) {} 102 103 bool isLiteral() const { return IsLiteral; } 104 bool isEncoding() const { return !IsLiteral; } 105 106 // Accessors for literals. 107 uint64_t getLiteralValue() const { assert(isLiteral()); return Val; } 108 109 // Accessors for encoding info. 110 Encoding getEncoding() const { assert(isEncoding()); return (Encoding)Enc; } 111 uint64_t getEncodingData() const { 112 assert(isEncoding() && hasEncodingData()); 113 return Val; 114 } 115 116 bool hasEncodingData() const { return hasEncodingData(getEncoding()); } 117 static bool hasEncodingData(Encoding E) { 118 switch (E) { 119 case Fixed: 120 case VBR: 121 return true; 122 case Array: 123 case Char6: 124 case Blob: 125 return false; 126 } 127 llvm_unreachable("Invalid encoding"); 128 } 129 130 /// isChar6 - Return true if this character is legal in the Char6 encoding. 131 static bool isChar6(char C) { 132 if (C >= 'a' && C <= 'z') return true; 133 if (C >= 'A' && C <= 'Z') return true; 134 if (C >= '0' && C <= '9') return true; 135 if (C == '.' || C == '_') return true; 136 return false; 137 } 138 static unsigned EncodeChar6(char C) { 139 if (C >= 'a' && C <= 'z') return C-'a'; 140 if (C >= 'A' && C <= 'Z') return C-'A'+26; 141 if (C >= '0' && C <= '9') return C-'0'+26+26; 142 if (C == '.') return 62; 143 if (C == '_') return 63; 144 llvm_unreachable("Not a value Char6 character!"); 145 } 146 147 static char DecodeChar6(unsigned V) { 148 assert((V & ~63) == 0 && "Not a Char6 encoded character!"); 149 if (V < 26) return V+'a'; 150 if (V < 26+26) return V-26+'A'; 151 if (V < 26+26+10) return V-26-26+'0'; 152 if (V == 62) return '.'; 153 if (V == 63) return '_'; 154 llvm_unreachable("Not a value Char6 character!"); 155 } 156 157 }; 158 159 template <> struct isPodLike<BitCodeAbbrevOp> { static const bool value=true; }; 160 161 /// BitCodeAbbrev - This class represents an abbreviation record. An 162 /// abbreviation allows a complex record that has redundancy to be stored in a 163 /// specialized format instead of the fully-general, fully-vbr, format. 164 class BitCodeAbbrev { 165 SmallVector<BitCodeAbbrevOp, 32> OperandList; 166 unsigned char RefCount; // Number of things using this. 167 ~BitCodeAbbrev() {} 168 public: 169 BitCodeAbbrev() : RefCount(1) {} 170 171 void addRef() { ++RefCount; } 172 void dropRef() { if (--RefCount == 0) delete this; } 173 174 unsigned getNumOperandInfos() const { 175 return static_cast<unsigned>(OperandList.size()); 176 } 177 const BitCodeAbbrevOp &getOperandInfo(unsigned N) const { 178 return OperandList[N]; 179 } 180 181 void Add(const BitCodeAbbrevOp &OpInfo) { 182 OperandList.push_back(OpInfo); 183 } 184 }; 185 } // End llvm namespace 186 187 #endif 188
