1 //===- FaultMaps.h - The "FaultMaps" section --------------------*- 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 #ifndef LLVM_CODEGEN_FAULTMAPS_H 11 #define LLVM_CODEGEN_FAULTMAPS_H 12 13 #include "llvm/MC/MCSymbol.h" 14 #include "llvm/Support/Endian.h" 15 #include <cassert> 16 #include <cstddef> 17 #include <cstdint> 18 #include <map> 19 #include <vector> 20 21 namespace llvm { 22 23 class AsmPrinter; 24 class MCExpr; 25 class raw_ostream; 26 27 class FaultMaps { 28 public: 29 enum FaultKind { 30 FaultingLoad = 1, 31 FaultingLoadStore, 32 FaultingStore, 33 FaultKindMax 34 }; 35 36 explicit FaultMaps(AsmPrinter &AP); 37 38 static const char *faultTypeToString(FaultKind); 39 40 void recordFaultingOp(FaultKind FaultTy, const MCSymbol *HandlerLabel); 41 void serializeToFaultMapSection(); 42 43 private: 44 static const char *WFMP; 45 46 struct FaultInfo { 47 FaultKind Kind = FaultKindMax; 48 const MCExpr *FaultingOffsetExpr = nullptr; 49 const MCExpr *HandlerOffsetExpr = nullptr; 50 51 FaultInfo() = default; 52 53 explicit FaultInfo(FaultMaps::FaultKind Kind, const MCExpr *FaultingOffset, 54 const MCExpr *HandlerOffset) 55 : Kind(Kind), FaultingOffsetExpr(FaultingOffset), 56 HandlerOffsetExpr(HandlerOffset) {} 57 }; 58 59 using FunctionFaultInfos = std::vector<FaultInfo>; 60 61 // We'd like to keep a stable iteration order for FunctionInfos to help 62 // FileCheck based testing. 63 struct MCSymbolComparator { 64 bool operator()(const MCSymbol *LHS, const MCSymbol *RHS) const { 65 return LHS->getName() < RHS->getName(); 66 } 67 }; 68 69 std::map<const MCSymbol *, FunctionFaultInfos, MCSymbolComparator> 70 FunctionInfos; 71 AsmPrinter &AP; 72 73 void emitFunctionInfo(const MCSymbol *FnLabel, const FunctionFaultInfos &FFI); 74 }; 75 76 /// A parser for the __llvm_faultmaps section generated by the FaultMaps class 77 /// above. This parser is version locked with with the __llvm_faultmaps section 78 /// generated by the version of LLVM that includes it. No guarantees are made 79 /// with respect to forward or backward compatibility. 80 class FaultMapParser { 81 using FaultMapVersionType = uint8_t; 82 using Reserved0Type = uint8_t; 83 using Reserved1Type = uint16_t; 84 using NumFunctionsType = uint32_t; 85 86 static const size_t FaultMapVersionOffset = 0; 87 static const size_t Reserved0Offset = 88 FaultMapVersionOffset + sizeof(FaultMapVersionType); 89 static const size_t Reserved1Offset = Reserved0Offset + sizeof(Reserved0Type); 90 static const size_t NumFunctionsOffset = 91 Reserved1Offset + sizeof(Reserved1Type); 92 static const size_t FunctionInfosOffset = 93 NumFunctionsOffset + sizeof(NumFunctionsType); 94 95 const uint8_t *P; 96 const uint8_t *E; 97 98 template <typename T> static T read(const uint8_t *P, const uint8_t *E) { 99 assert(P + sizeof(T) <= E && "out of bounds read!"); 100 return support::endian::read<T, support::little, 1>(P); 101 } 102 103 public: 104 class FunctionFaultInfoAccessor { 105 using FaultKindType = uint32_t; 106 using FaultingPCOffsetType = uint32_t; 107 using HandlerPCOffsetType = uint32_t; 108 109 static const size_t FaultKindOffset = 0; 110 static const size_t FaultingPCOffsetOffset = 111 FaultKindOffset + sizeof(FaultKindType); 112 static const size_t HandlerPCOffsetOffset = 113 FaultingPCOffsetOffset + sizeof(FaultingPCOffsetType); 114 115 const uint8_t *P; 116 const uint8_t *E; 117 118 public: 119 static const size_t Size = 120 HandlerPCOffsetOffset + sizeof(HandlerPCOffsetType); 121 122 explicit FunctionFaultInfoAccessor(const uint8_t *P, const uint8_t *E) 123 : P(P), E(E) {} 124 125 FaultKindType getFaultKind() const { 126 return read<FaultKindType>(P + FaultKindOffset, E); 127 } 128 129 FaultingPCOffsetType getFaultingPCOffset() const { 130 return read<FaultingPCOffsetType>(P + FaultingPCOffsetOffset, E); 131 } 132 133 HandlerPCOffsetType getHandlerPCOffset() const { 134 return read<HandlerPCOffsetType>(P + HandlerPCOffsetOffset, E); 135 } 136 }; 137 138 class FunctionInfoAccessor { 139 using FunctionAddrType = uint64_t; 140 using NumFaultingPCsType = uint32_t; 141 using ReservedType = uint32_t; 142 143 static const size_t FunctionAddrOffset = 0; 144 static const size_t NumFaultingPCsOffset = 145 FunctionAddrOffset + sizeof(FunctionAddrType); 146 static const size_t ReservedOffset = 147 NumFaultingPCsOffset + sizeof(NumFaultingPCsType); 148 static const size_t FunctionFaultInfosOffset = 149 ReservedOffset + sizeof(ReservedType); 150 static const size_t FunctionInfoHeaderSize = FunctionFaultInfosOffset; 151 152 const uint8_t *P = nullptr; 153 const uint8_t *E = nullptr; 154 155 public: 156 FunctionInfoAccessor() = default; 157 158 explicit FunctionInfoAccessor(const uint8_t *P, const uint8_t *E) 159 : P(P), E(E) {} 160 161 FunctionAddrType getFunctionAddr() const { 162 return read<FunctionAddrType>(P + FunctionAddrOffset, E); 163 } 164 165 NumFaultingPCsType getNumFaultingPCs() const { 166 return read<NumFaultingPCsType>(P + NumFaultingPCsOffset, E); 167 } 168 169 FunctionFaultInfoAccessor getFunctionFaultInfoAt(uint32_t Index) const { 170 assert(Index < getNumFaultingPCs() && "index out of bounds!"); 171 const uint8_t *Begin = P + FunctionFaultInfosOffset + 172 FunctionFaultInfoAccessor::Size * Index; 173 return FunctionFaultInfoAccessor(Begin, E); 174 } 175 176 FunctionInfoAccessor getNextFunctionInfo() const { 177 size_t MySize = FunctionInfoHeaderSize + 178 getNumFaultingPCs() * FunctionFaultInfoAccessor::Size; 179 180 const uint8_t *Begin = P + MySize; 181 assert(Begin < E && "out of bounds!"); 182 return FunctionInfoAccessor(Begin, E); 183 } 184 }; 185 186 explicit FaultMapParser(const uint8_t *Begin, const uint8_t *End) 187 : P(Begin), E(End) {} 188 189 FaultMapVersionType getFaultMapVersion() const { 190 auto Version = read<FaultMapVersionType>(P + FaultMapVersionOffset, E); 191 assert(Version == 1 && "only version 1 supported!"); 192 return Version; 193 } 194 195 NumFunctionsType getNumFunctions() const { 196 return read<NumFunctionsType>(P + NumFunctionsOffset, E); 197 } 198 199 FunctionInfoAccessor getFirstFunctionInfo() const { 200 const uint8_t *Begin = P + FunctionInfosOffset; 201 return FunctionInfoAccessor(Begin, E); 202 } 203 }; 204 205 raw_ostream & 206 operator<<(raw_ostream &OS, const FaultMapParser::FunctionFaultInfoAccessor &); 207 208 raw_ostream &operator<<(raw_ostream &OS, 209 const FaultMapParser::FunctionInfoAccessor &); 210 211 raw_ostream &operator<<(raw_ostream &OS, const FaultMapParser &); 212 213 } // end namespace llvm 214 215 #endif // LLVM_CODEGEN_FAULTMAPS_H 216
