llvm-6502/include/llvm/MC/MCELFObjectWriter.h
2012-10-25 18:35:04 +00:00

156 lines
5.0 KiB
C++

//===-- llvm/MC/MCELFObjectWriter.h - ELF Object Writer ---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_MCELFOBJECTWRITER_H
#define LLVM_MC_MCELFOBJECTWRITER_H
#include "llvm/ADT/Triple.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/ELF.h"
#include <vector>
namespace llvm {
class MCAssembler;
class MCFixup;
class MCFragment;
class MCObjectWriter;
class MCSymbol;
class MCValue;
/// @name Relocation Data
/// @{
struct ELFRelocationEntry {
// Make these big enough for both 32-bit and 64-bit
uint64_t r_offset;
int Index;
unsigned Type;
const MCSymbol *Symbol;
uint64_t r_addend;
const MCFixup *Fixup;
ELFRelocationEntry()
: r_offset(0), Index(0), Type(0), Symbol(0), r_addend(0), Fixup(0) {}
ELFRelocationEntry(uint64_t RelocOffset, int Idx, unsigned RelType,
const MCSymbol *Sym, uint64_t Addend, const MCFixup &Fixup)
: r_offset(RelocOffset), Index(Idx), Type(RelType), Symbol(Sym),
r_addend(Addend), Fixup(&Fixup) {}
// Support lexicographic sorting.
bool operator<(const ELFRelocationEntry &RE) const {
return RE.r_offset < r_offset;
}
};
class MCELFObjectTargetWriter {
const uint8_t OSABI;
const uint16_t EMachine;
const unsigned HasRelocationAddend : 1;
const unsigned Is64Bit : 1;
const unsigned IsN64 : 1;
protected:
MCELFObjectTargetWriter(bool Is64Bit_, uint8_t OSABI_,
uint16_t EMachine_, bool HasRelocationAddend,
bool IsN64=false);
public:
static uint8_t getOSABI(Triple::OSType OSType) {
switch (OSType) {
case Triple::FreeBSD:
return ELF::ELFOSABI_FREEBSD;
case Triple::Linux:
return ELF::ELFOSABI_LINUX;
default:
return ELF::ELFOSABI_NONE;
}
}
virtual ~MCELFObjectTargetWriter() {}
virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
bool IsPCRel, bool IsRelocWithSymbol,
int64_t Addend) const = 0;
virtual unsigned getEFlags() const;
virtual const MCSymbol *ExplicitRelSym(const MCAssembler &Asm,
const MCValue &Target,
const MCFragment &F,
const MCFixup &Fixup,
bool IsPCRel) const;
virtual const MCSymbol *undefinedExplicitRelSym(const MCValue &Target,
const MCFixup &Fixup,
bool IsPCRel) const;
virtual void adjustFixupOffset(const MCFixup &Fixup,
uint64_t &RelocOffset);
virtual void sortRelocs(const MCAssembler &Asm,
std::vector<ELFRelocationEntry> &Relocs);
/// @name Accessors
/// @{
uint8_t getOSABI() const { return OSABI; }
uint16_t getEMachine() const { return EMachine; }
bool hasRelocationAddend() const { return HasRelocationAddend; }
bool is64Bit() const { return Is64Bit; }
bool isN64() const { return IsN64; }
/// @}
// 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
unsigned getRType(uint32_t Type) const {
return (unsigned)((Type >> R_TYPE_SHIFT) & 0xff);
}
unsigned getRType2(uint32_t Type) const {
return (unsigned)((Type >> R_TYPE2_SHIFT) & 0xff);
}
unsigned getRType3(uint32_t Type) const {
return (unsigned)((Type >> R_TYPE3_SHIFT) & 0xff);
}
unsigned 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);
}
};
/// \brief 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.
MCObjectWriter *createELFObjectWriter(MCELFObjectTargetWriter *MOTW,
raw_ostream &OS, bool IsLittleEndian);
} // End llvm namespace
#endif