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| //===- llvm/MC/MCELFObjectWriter.h - ELF Object Writer ----------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_MCELFOBJECTWRITER_H
#define LLVM_MC_MCELFOBJECTWRITER_H
#include "llvm/ADT/Triple.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdint>
#include <vector>
namespace llvm {
class MCAssembler;
class MCContext;
class MCFixup;
class MCObjectWriter;
class MCSymbol;
class MCSymbolELF;
class MCValue;
struct ELFRelocationEntry {
uint64_t Offset; // Where is the relocation.
const MCSymbolELF *Symbol; // The symbol to relocate with.
unsigned Type; // The type of the relocation.
uint64_t Addend; // The addend to use.
const MCSymbolELF *OriginalSymbol; // The original value of Symbol if we changed it.
uint64_t OriginalAddend; // The original value of addend.
ELFRelocationEntry(uint64_t Offset, const MCSymbolELF *Symbol, unsigned Type,
uint64_t Addend, const MCSymbolELF *OriginalSymbol,
uint64_t OriginalAddend)
: Offset(Offset), Symbol(Symbol), Type(Type), Addend(Addend),
OriginalSymbol(OriginalSymbol), OriginalAddend(OriginalAddend) {}
void print(raw_ostream &Out) const {
Out << "Off=" << Offset << ", Sym=" << Symbol << ", Type=" << Type
<< ", Addend=" << Addend << ", OriginalSymbol=" << OriginalSymbol
<< ", OriginalAddend=" << OriginalAddend;
}
void dump() const { print(errs()); }
};
class MCELFObjectTargetWriter : public MCObjectTargetWriter {
const uint8_t OSABI;
const uint8_t ABIVersion;
const uint16_t EMachine;
const unsigned HasRelocationAddend : 1;
const unsigned Is64Bit : 1;
protected:
MCELFObjectTargetWriter(bool Is64Bit_, uint8_t OSABI_, uint16_t EMachine_,
bool HasRelocationAddend_, uint8_t ABIVersion_ = 0);
public:
virtual ~MCELFObjectTargetWriter() = default;
virtual Triple::ObjectFormatType getFormat() const { return Triple::ELF; }
static bool classof(const MCObjectTargetWriter *W) {
return W->getFormat() == Triple::ELF;
}
static uint8_t getOSABI(Triple::OSType OSType) {
switch (OSType) {
case Triple::CloudABI:
return ELF::ELFOSABI_CLOUDABI;
case Triple::HermitCore:
return ELF::ELFOSABI_STANDALONE;
case Triple::PS4:
case Triple::FreeBSD:
return ELF::ELFOSABI_FREEBSD;
default:
return ELF::ELFOSABI_NONE;
}
}
virtual unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
const MCFixup &Fixup, bool IsPCRel) const = 0;
virtual bool needsRelocateWithSymbol(const MCSymbol &Sym,
unsigned Type) const;
virtual void sortRelocs(const MCAssembler &Asm,
std::vector<ELFRelocationEntry> &Relocs);
virtual void addTargetSectionFlags(MCContext &Ctx, MCSectionELF &Sec);
/// \name Accessors
/// @{
uint8_t getOSABI() const { return OSABI; }
uint8_t getABIVersion() const { return ABIVersion; }
uint16_t getEMachine() const { return EMachine; }
bool hasRelocationAddend() const { return HasRelocationAddend; }
bool is64Bit() const { return Is64Bit; }
/// @}
// Instead of changing everyone's API we pack the N64 Type fields
// into the existing 32 bit data unsigned.
#define R_TYPE_SHIFT 0
#define R_TYPE_MASK 0xffffff00
#define R_TYPE2_SHIFT 8
#define R_TYPE2_MASK 0xffff00ff
#define R_TYPE3_SHIFT 16
#define R_TYPE3_MASK 0xff00ffff
#define R_SSYM_SHIFT 24
#define R_SSYM_MASK 0x00ffffff
// N64 relocation type accessors
uint8_t getRType(uint32_t Type) const {
return (unsigned)((Type >> R_TYPE_SHIFT) & 0xff);
}
uint8_t getRType2(uint32_t Type) const {
return (unsigned)((Type >> R_TYPE2_SHIFT) & 0xff);
}
uint8_t getRType3(uint32_t Type) const {
return (unsigned)((Type >> R_TYPE3_SHIFT) & 0xff);
}
uint8_t getRSsym(uint32_t Type) const {
return (unsigned)((Type >> R_SSYM_SHIFT) & 0xff);
}
// N64 relocation type setting
unsigned setRType(unsigned Value, unsigned Type) const {
return ((Type & R_TYPE_MASK) | ((Value & 0xff) << R_TYPE_SHIFT));
}
unsigned setRType2(unsigned Value, unsigned Type) const {
return (Type & R_TYPE2_MASK) | ((Value & 0xff) << R_TYPE2_SHIFT);
}
unsigned setRType3(unsigned Value, unsigned Type) const {
return (Type & R_TYPE3_MASK) | ((Value & 0xff) << R_TYPE3_SHIFT);
}
unsigned setRSsym(unsigned Value, unsigned Type) const {
return (Type & R_SSYM_MASK) | ((Value & 0xff) << R_SSYM_SHIFT);
}
};
/// Construct a new ELF writer instance.
///
/// \param MOTW - The target specific ELF writer subclass.
/// \param OS - The stream to write to.
/// \returns The constructed object writer.
std::unique_ptr<MCObjectWriter>
createELFObjectWriter(std::unique_ptr<MCELFObjectTargetWriter> MOTW,
raw_pwrite_stream &OS, bool IsLittleEndian);
std::unique_ptr<MCObjectWriter>
createELFDwoObjectWriter(std::unique_ptr<MCELFObjectTargetWriter> MOTW,
raw_pwrite_stream &OS, raw_pwrite_stream &DwoOS,
bool IsLittleEndian);
} // end namespace llvm
#endif // LLVM_MC_MCELFOBJECTWRITER_H
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