1 //===- FaultMaps.h - The "FaultMaps" section --------------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #ifndef LLVM_CODEGEN_FAULTMAPS_H
10 #define LLVM_CODEGEN_FAULTMAPS_H
12 #include "llvm/MC/MCSymbol.h"
13 #include "llvm/Support/Endian.h"
35 explicit FaultMaps(AsmPrinter &AP);
37 static const char *faultTypeToString(FaultKind);
39 void recordFaultingOp(FaultKind FaultTy, const MCSymbol *FaultingLabel,
40 const MCSymbol *HandlerLabel);
41 void serializeToFaultMapSection();
43 FunctionInfos.clear();
47 static const char *WFMP;
50 FaultKind Kind = FaultKindMax;
51 const MCExpr *FaultingOffsetExpr = nullptr;
52 const MCExpr *HandlerOffsetExpr = nullptr;
54 FaultInfo() = default;
56 explicit FaultInfo(FaultMaps::FaultKind Kind, const MCExpr *FaultingOffset,
57 const MCExpr *HandlerOffset)
58 : Kind(Kind), FaultingOffsetExpr(FaultingOffset),
59 HandlerOffsetExpr(HandlerOffset) {}
62 using FunctionFaultInfos = std::vector<FaultInfo>;
64 // We'd like to keep a stable iteration order for FunctionInfos to help
65 // FileCheck based testing.
66 struct MCSymbolComparator {
67 bool operator()(const MCSymbol *LHS, const MCSymbol *RHS) const {
68 return LHS->getName() < RHS->getName();
72 std::map<const MCSymbol *, FunctionFaultInfos, MCSymbolComparator>
76 void emitFunctionInfo(const MCSymbol *FnLabel, const FunctionFaultInfos &FFI);
79 /// A parser for the __llvm_faultmaps section generated by the FaultMaps class
80 /// above. This parser is version locked with with the __llvm_faultmaps section
81 /// generated by the version of LLVM that includes it. No guarantees are made
82 /// with respect to forward or backward compatibility.
83 class FaultMapParser {
84 using FaultMapVersionType = uint8_t;
85 using Reserved0Type = uint8_t;
86 using Reserved1Type = uint16_t;
87 using NumFunctionsType = uint32_t;
89 static const size_t FaultMapVersionOffset = 0;
90 static const size_t Reserved0Offset =
91 FaultMapVersionOffset + sizeof(FaultMapVersionType);
92 static const size_t Reserved1Offset = Reserved0Offset + sizeof(Reserved0Type);
93 static const size_t NumFunctionsOffset =
94 Reserved1Offset + sizeof(Reserved1Type);
95 static const size_t FunctionInfosOffset =
96 NumFunctionsOffset + sizeof(NumFunctionsType);
101 template <typename T> static T read(const uint8_t *P, const uint8_t *E) {
102 assert(P + sizeof(T) <= E && "out of bounds read!");
103 return support::endian::read<T, support::little, 1>(P);
107 class FunctionFaultInfoAccessor {
108 using FaultKindType = uint32_t;
109 using FaultingPCOffsetType = uint32_t;
110 using HandlerPCOffsetType = uint32_t;
112 static const size_t FaultKindOffset = 0;
113 static const size_t FaultingPCOffsetOffset =
114 FaultKindOffset + sizeof(FaultKindType);
115 static const size_t HandlerPCOffsetOffset =
116 FaultingPCOffsetOffset + sizeof(FaultingPCOffsetType);
122 static const size_t Size =
123 HandlerPCOffsetOffset + sizeof(HandlerPCOffsetType);
125 explicit FunctionFaultInfoAccessor(const uint8_t *P, const uint8_t *E)
128 FaultKindType getFaultKind() const {
129 return read<FaultKindType>(P + FaultKindOffset, E);
132 FaultingPCOffsetType getFaultingPCOffset() const {
133 return read<FaultingPCOffsetType>(P + FaultingPCOffsetOffset, E);
136 HandlerPCOffsetType getHandlerPCOffset() const {
137 return read<HandlerPCOffsetType>(P + HandlerPCOffsetOffset, E);
141 class FunctionInfoAccessor {
142 using FunctionAddrType = uint64_t;
143 using NumFaultingPCsType = uint32_t;
144 using ReservedType = uint32_t;
146 static const size_t FunctionAddrOffset = 0;
147 static const size_t NumFaultingPCsOffset =
148 FunctionAddrOffset + sizeof(FunctionAddrType);
149 static const size_t ReservedOffset =
150 NumFaultingPCsOffset + sizeof(NumFaultingPCsType);
151 static const size_t FunctionFaultInfosOffset =
152 ReservedOffset + sizeof(ReservedType);
153 static const size_t FunctionInfoHeaderSize = FunctionFaultInfosOffset;
155 const uint8_t *P = nullptr;
156 const uint8_t *E = nullptr;
159 FunctionInfoAccessor() = default;
161 explicit FunctionInfoAccessor(const uint8_t *P, const uint8_t *E)
164 FunctionAddrType getFunctionAddr() const {
165 return read<FunctionAddrType>(P + FunctionAddrOffset, E);
168 NumFaultingPCsType getNumFaultingPCs() const {
169 return read<NumFaultingPCsType>(P + NumFaultingPCsOffset, E);
172 FunctionFaultInfoAccessor getFunctionFaultInfoAt(uint32_t Index) const {
173 assert(Index < getNumFaultingPCs() && "index out of bounds!");
174 const uint8_t *Begin = P + FunctionFaultInfosOffset +
175 FunctionFaultInfoAccessor::Size * Index;
176 return FunctionFaultInfoAccessor(Begin, E);
179 FunctionInfoAccessor getNextFunctionInfo() const {
180 size_t MySize = FunctionInfoHeaderSize +
181 getNumFaultingPCs() * FunctionFaultInfoAccessor::Size;
183 const uint8_t *Begin = P + MySize;
184 assert(Begin < E && "out of bounds!");
185 return FunctionInfoAccessor(Begin, E);
189 explicit FaultMapParser(const uint8_t *Begin, const uint8_t *End)
190 : P(Begin), E(End) {}
192 FaultMapVersionType getFaultMapVersion() const {
193 auto Version = read<FaultMapVersionType>(P + FaultMapVersionOffset, E);
194 assert(Version == 1 && "only version 1 supported!");
198 NumFunctionsType getNumFunctions() const {
199 return read<NumFunctionsType>(P + NumFunctionsOffset, E);
202 FunctionInfoAccessor getFirstFunctionInfo() const {
203 const uint8_t *Begin = P + FunctionInfosOffset;
204 return FunctionInfoAccessor(Begin, E);
209 operator<<(raw_ostream &OS, const FaultMapParser::FunctionFaultInfoAccessor &);
211 raw_ostream &operator<<(raw_ostream &OS,
212 const FaultMapParser::FunctionInfoAccessor &);
214 raw_ostream &operator<<(raw_ostream &OS, const FaultMapParser &);
216 } // end namespace llvm
218 #endif // LLVM_CODEGEN_FAULTMAPS_H