//===- FaultMaps.h - The "FaultMaps" section --------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_FAULTMAPS_H
#define LLVM_CODEGEN_FAULTMAPS_H
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/Endian.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <map>
#include <vector>
namespace llvm {
class AsmPrinter;
class MCExpr;
class raw_ostream;
class FaultMaps {
public:
enum FaultKind {
FaultingLoad = 1,
FaultingLoadStore,
FaultingStore,
FaultKindMax
};
explicit FaultMaps(AsmPrinter &AP);
static const char *faultTypeToString(FaultKind);
void recordFaultingOp(FaultKind FaultTy, const MCSymbol *HandlerLabel);
void serializeToFaultMapSection();
private:
static const char *WFMP;
struct FaultInfo {
FaultKind Kind = FaultKindMax;
const MCExpr *FaultingOffsetExpr = nullptr;
const MCExpr *HandlerOffsetExpr = nullptr;
FaultInfo() = default;
explicit FaultInfo(FaultMaps::FaultKind Kind, const MCExpr *FaultingOffset,
const MCExpr *HandlerOffset)
: Kind(Kind), FaultingOffsetExpr(FaultingOffset),
HandlerOffsetExpr(HandlerOffset) {}
};
using FunctionFaultInfos = std::vector<FaultInfo>;
// We'd like to keep a stable iteration order for FunctionInfos to help
// FileCheck based testing.
struct MCSymbolComparator {
bool operator()(const MCSymbol *LHS, const MCSymbol *RHS) const {
return LHS->getName() < RHS->getName();
}
};
std::map<const MCSymbol *, FunctionFaultInfos, MCSymbolComparator>
FunctionInfos;
AsmPrinter &AP;
void emitFunctionInfo(const MCSymbol *FnLabel, const FunctionFaultInfos &FFI);
};
/// A parser for the __llvm_faultmaps section generated by the FaultMaps class
/// above. This parser is version locked with with the __llvm_faultmaps section
/// generated by the version of LLVM that includes it. No guarantees are made
/// with respect to forward or backward compatibility.
class FaultMapParser {
using FaultMapVersionType = uint8_t;
using Reserved0Type = uint8_t;
using Reserved1Type = uint16_t;
using NumFunctionsType = uint32_t;
static const size_t FaultMapVersionOffset = 0;
static const size_t Reserved0Offset =
FaultMapVersionOffset + sizeof(FaultMapVersionType);
static const size_t Reserved1Offset = Reserved0Offset + sizeof(Reserved0Type);
static const size_t NumFunctionsOffset =
Reserved1Offset + sizeof(Reserved1Type);
static const size_t FunctionInfosOffset =
NumFunctionsOffset + sizeof(NumFunctionsType);
const uint8_t *P;
const uint8_t *E;
template <typename T> static T read(const uint8_t *P, const uint8_t *E) {
assert(P + sizeof(T) <= E && "out of bounds read!");
return support::endian::read<T, support::little, 1>(P);
}
public:
class FunctionFaultInfoAccessor {
using FaultKindType = uint32_t;
using FaultingPCOffsetType = uint32_t;
using HandlerPCOffsetType = uint32_t;
static const size_t FaultKindOffset = 0;
static const size_t FaultingPCOffsetOffset =
FaultKindOffset + sizeof(FaultKindType);
static const size_t HandlerPCOffsetOffset =
FaultingPCOffsetOffset + sizeof(FaultingPCOffsetType);
const uint8_t *P;
const uint8_t *E;
public:
static const size_t Size =
HandlerPCOffsetOffset + sizeof(HandlerPCOffsetType);
explicit FunctionFaultInfoAccessor(const uint8_t *P, const uint8_t *E)
: P(P), E(E) {}
FaultKindType getFaultKind() const {
return read<FaultKindType>(P + FaultKindOffset, E);
}
FaultingPCOffsetType getFaultingPCOffset() const {
return read<FaultingPCOffsetType>(P + FaultingPCOffsetOffset, E);
}
HandlerPCOffsetType getHandlerPCOffset() const {
return read<HandlerPCOffsetType>(P + HandlerPCOffsetOffset, E);
}
};
class FunctionInfoAccessor {
using FunctionAddrType = uint64_t;
using NumFaultingPCsType = uint32_t;
using ReservedType = uint32_t;
static const size_t FunctionAddrOffset = 0;
static const size_t NumFaultingPCsOffset =
FunctionAddrOffset + sizeof(FunctionAddrType);
static const size_t ReservedOffset =
NumFaultingPCsOffset + sizeof(NumFaultingPCsType);
static const size_t FunctionFaultInfosOffset =
ReservedOffset + sizeof(ReservedType);
static const size_t FunctionInfoHeaderSize = FunctionFaultInfosOffset;
const uint8_t *P = nullptr;
const uint8_t *E = nullptr;
public:
FunctionInfoAccessor() = default;
explicit FunctionInfoAccessor(const uint8_t *P, const uint8_t *E)
: P(P), E(E) {}
FunctionAddrType getFunctionAddr() const {
return read<FunctionAddrType>(P + FunctionAddrOffset, E);
}
NumFaultingPCsType getNumFaultingPCs() const {
return read<NumFaultingPCsType>(P + NumFaultingPCsOffset, E);
}
FunctionFaultInfoAccessor getFunctionFaultInfoAt(uint32_t Index) const {
assert(Index < getNumFaultingPCs() && "index out of bounds!");
const uint8_t *Begin = P + FunctionFaultInfosOffset +
FunctionFaultInfoAccessor::Size * Index;
return FunctionFaultInfoAccessor(Begin, E);
}
FunctionInfoAccessor getNextFunctionInfo() const {
size_t MySize = FunctionInfoHeaderSize +
getNumFaultingPCs() * FunctionFaultInfoAccessor::Size;
const uint8_t *Begin = P + MySize;
assert(Begin < E && "out of bounds!");
return FunctionInfoAccessor(Begin, E);
}
};
explicit FaultMapParser(const uint8_t *Begin, const uint8_t *End)
: P(Begin), E(End) {}
FaultMapVersionType getFaultMapVersion() const {
auto Version = read<FaultMapVersionType>(P + FaultMapVersionOffset, E);
assert(Version == 1 && "only version 1 supported!");
return Version;
}
NumFunctionsType getNumFunctions() const {
return read<NumFunctionsType>(P + NumFunctionsOffset, E);
}
FunctionInfoAccessor getFirstFunctionInfo() const {
const uint8_t *Begin = P + FunctionInfosOffset;
return FunctionInfoAccessor(Begin, E);
}
};
raw_ostream &
operator<<(raw_ostream &OS, const FaultMapParser::FunctionFaultInfoAccessor &);
raw_ostream &operator<<(raw_ostream &OS,
const FaultMapParser::FunctionInfoAccessor &);
raw_ostream &operator<<(raw_ostream &OS, const FaultMapParser &);
} // end namespace llvm
#endif // LLVM_CODEGEN_FAULTMAPS_H