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: [id, name] 76 }; 77 78 } // End bitc namespace 79 80 /// BitCodeAbbrevOp - This describes one or more operands in an abbreviation. 81 /// This is actually a union of two different things: 82 /// 1. It could be a literal integer value ("the operand is always 17"). 83 /// 2. It could be an encoding specification ("this operand encoded like so"). 84 /// 85 class BitCodeAbbrevOp { 86 uint64_t Val; // A literal value or data for an encoding. 87 bool IsLiteral : 1; // Indicate whether this is a literal value or not. 88 unsigned Enc : 3; // The encoding to use. 89 public: 90 enum Encoding { 91 Fixed = 1, // A fixed width field, Val specifies number of bits. 92 VBR = 2, // A VBR field where Val specifies the width of each chunk. 93 Array = 3, // A sequence of fields, next field species elt encoding. 94 Char6 = 4, // A 6-bit fixed field which maps to [a-zA-Z0-9._]. 95 Blob = 5 // 32-bit aligned array of 8-bit characters. 96 }; 97 98 explicit BitCodeAbbrevOp(uint64_t V) : Val(V), IsLiteral(true) {} 99 explicit BitCodeAbbrevOp(Encoding E, uint64_t Data = 0) 100 : Val(Data), IsLiteral(false), Enc(E) {} 101 102 bool isLiteral() const { return IsLiteral; } 103 bool isEncoding() const { return !IsLiteral; } 104 105 // Accessors for literals. 106 uint64_t getLiteralValue() const { assert(isLiteral()); return Val; } 107 108 // Accessors for encoding info. 109 Encoding getEncoding() const { assert(isEncoding()); return (Encoding)Enc; } 110 uint64_t getEncodingData() const { 111 assert(isEncoding() && hasEncodingData()); 112 return Val; 113 } 114 115 bool hasEncodingData() const { return hasEncodingData(getEncoding()); } 116 static bool hasEncodingData(Encoding E) { 117 switch (E) { 118 case Fixed: 119 case VBR: 120 return true; 121 case Array: 122 case Char6: 123 case Blob: 124 return false; 125 } 126 llvm_unreachable("Invalid encoding"); 127 } 128 129 /// isChar6 - Return true if this character is legal in the Char6 encoding. 130 static bool isChar6(char C) { 131 if (C >= 'a' && C <= 'z') return true; 132 if (C >= 'A' && C <= 'Z') return true; 133 if (C >= '0' && C <= '9') return true; 134 if (C == '.' || C == '_') return true; 135 return false; 136 } 137 static unsigned EncodeChar6(char C) { 138 if (C >= 'a' && C <= 'z') return C-'a'; 139 if (C >= 'A' && C <= 'Z') return C-'A'+26; 140 if (C >= '0' && C <= '9') return C-'0'+26+26; 141 if (C == '.') return 62; 142 if (C == '_') return 63; 143 llvm_unreachable("Not a value Char6 character!"); 144 } 145 146 static char DecodeChar6(unsigned V) { 147 assert((V & ~63) == 0 && "Not a Char6 encoded character!"); 148 if (V < 26) return V+'a'; 149 if (V < 26+26) return V-26+'A'; 150 if (V < 26+26+10) return V-26-26+'0'; 151 if (V == 62) return '.'; 152 if (V == 63) return '_'; 153 llvm_unreachable("Not a value Char6 character!"); 154 } 155 156 }; 157 158 template <> struct isPodLike<BitCodeAbbrevOp> { static const bool value=true; }; 159 160 /// BitCodeAbbrev - This class represents an abbreviation record. An 161 /// abbreviation allows a complex record that has redundancy to be stored in a 162 /// specialized format instead of the fully-general, fully-vbr, format. 163 class BitCodeAbbrev { 164 SmallVector<BitCodeAbbrevOp, 32> OperandList; 165 unsigned char RefCount; // Number of things using this. 166 ~BitCodeAbbrev() {} 167 public: 168 BitCodeAbbrev() : RefCount(1) {} 169 170 void addRef() { ++RefCount; } 171 void dropRef() { if (--RefCount == 0) delete this; } 172 173 unsigned getNumOperandInfos() const { 174 return static_cast<unsigned>(OperandList.size()); 175 } 176 const BitCodeAbbrevOp &getOperandInfo(unsigned N) const { 177 return OperandList[N]; 178 } 179 180 void Add(const BitCodeAbbrevOp &OpInfo) { 181 OperandList.push_back(OpInfo); 182 } 183 }; 184 } // End llvm namespace 185 186 #endif 187
