llvm-6502/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
2014-05-27 14:58:51 +00:00

256 lines
7.7 KiB
C++

//===-- MipsELFObjectWriter.cpp - Mips ELF Writer -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/MipsBaseInfo.h"
#include "MCTargetDesc/MipsFixupKinds.h"
#include "MCTargetDesc/MipsMCTargetDesc.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/ErrorHandling.h"
#include <list>
using namespace llvm;
namespace {
class MipsELFObjectWriter : public MCELFObjectTargetWriter {
public:
MipsELFObjectWriter(bool _is64Bit, uint8_t OSABI,
bool _isN64, bool IsLittleEndian);
virtual ~MipsELFObjectWriter();
unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
bool IsPCRel) const override;
bool needsRelocateWithSymbol(unsigned Type) const override;
};
}
MipsELFObjectWriter::MipsELFObjectWriter(bool _is64Bit, uint8_t OSABI,
bool _isN64, bool IsLittleEndian)
: MCELFObjectTargetWriter(_is64Bit, OSABI, ELF::EM_MIPS,
/*HasRelocationAddend*/ (_isN64) ? true : false,
/*IsN64*/ _isN64) {}
MipsELFObjectWriter::~MipsELFObjectWriter() {}
unsigned MipsELFObjectWriter::GetRelocType(const MCValue &Target,
const MCFixup &Fixup,
bool IsPCRel) const {
// determine the type of the relocation
unsigned Type = (unsigned)ELF::R_MIPS_NONE;
unsigned Kind = (unsigned)Fixup.getKind();
switch (Kind) {
default:
llvm_unreachable("invalid fixup kind!");
case FK_Data_4:
Type = ELF::R_MIPS_32;
break;
case FK_Data_8:
Type = ELF::R_MIPS_64;
break;
case FK_GPRel_4:
if (isN64()) {
Type = setRType((unsigned)ELF::R_MIPS_GPREL32, Type);
Type = setRType2((unsigned)ELF::R_MIPS_64, Type);
Type = setRType3((unsigned)ELF::R_MIPS_NONE, Type);
}
else
Type = ELF::R_MIPS_GPREL32;
break;
case Mips::fixup_Mips_GPREL16:
Type = ELF::R_MIPS_GPREL16;
break;
case Mips::fixup_Mips_26:
Type = ELF::R_MIPS_26;
break;
case Mips::fixup_Mips_CALL16:
Type = ELF::R_MIPS_CALL16;
break;
case Mips::fixup_Mips_GOT_Global:
case Mips::fixup_Mips_GOT_Local:
Type = ELF::R_MIPS_GOT16;
break;
case Mips::fixup_Mips_HI16:
Type = ELF::R_MIPS_HI16;
break;
case Mips::fixup_Mips_LO16:
Type = ELF::R_MIPS_LO16;
break;
case Mips::fixup_Mips_TLSGD:
Type = ELF::R_MIPS_TLS_GD;
break;
case Mips::fixup_Mips_GOTTPREL:
Type = ELF::R_MIPS_TLS_GOTTPREL;
break;
case Mips::fixup_Mips_TPREL_HI:
Type = ELF::R_MIPS_TLS_TPREL_HI16;
break;
case Mips::fixup_Mips_TPREL_LO:
Type = ELF::R_MIPS_TLS_TPREL_LO16;
break;
case Mips::fixup_Mips_TLSLDM:
Type = ELF::R_MIPS_TLS_LDM;
break;
case Mips::fixup_Mips_DTPREL_HI:
Type = ELF::R_MIPS_TLS_DTPREL_HI16;
break;
case Mips::fixup_Mips_DTPREL_LO:
Type = ELF::R_MIPS_TLS_DTPREL_LO16;
break;
case Mips::fixup_Mips_Branch_PCRel:
case Mips::fixup_Mips_PC16:
Type = ELF::R_MIPS_PC16;
break;
case Mips::fixup_Mips_GOT_PAGE:
Type = ELF::R_MIPS_GOT_PAGE;
break;
case Mips::fixup_Mips_GOT_OFST:
Type = ELF::R_MIPS_GOT_OFST;
break;
case Mips::fixup_Mips_GOT_DISP:
Type = ELF::R_MIPS_GOT_DISP;
break;
case Mips::fixup_Mips_GPOFF_HI:
Type = setRType((unsigned)ELF::R_MIPS_GPREL16, Type);
Type = setRType2((unsigned)ELF::R_MIPS_SUB, Type);
Type = setRType3((unsigned)ELF::R_MIPS_HI16, Type);
break;
case Mips::fixup_Mips_GPOFF_LO:
Type = setRType((unsigned)ELF::R_MIPS_GPREL16, Type);
Type = setRType2((unsigned)ELF::R_MIPS_SUB, Type);
Type = setRType3((unsigned)ELF::R_MIPS_LO16, Type);
break;
case Mips::fixup_Mips_HIGHER:
Type = ELF::R_MIPS_HIGHER;
break;
case Mips::fixup_Mips_HIGHEST:
Type = ELF::R_MIPS_HIGHEST;
break;
case Mips::fixup_Mips_GOT_HI16:
Type = ELF::R_MIPS_GOT_HI16;
break;
case Mips::fixup_Mips_GOT_LO16:
Type = ELF::R_MIPS_GOT_LO16;
break;
case Mips::fixup_Mips_CALL_HI16:
Type = ELF::R_MIPS_CALL_HI16;
break;
case Mips::fixup_Mips_CALL_LO16:
Type = ELF::R_MIPS_CALL_LO16;
break;
case Mips::fixup_MICROMIPS_26_S1:
Type = ELF::R_MICROMIPS_26_S1;
break;
case Mips::fixup_MICROMIPS_HI16:
Type = ELF::R_MICROMIPS_HI16;
break;
case Mips::fixup_MICROMIPS_LO16:
Type = ELF::R_MICROMIPS_LO16;
break;
case Mips::fixup_MICROMIPS_GOT16:
Type = ELF::R_MICROMIPS_GOT16;
break;
case Mips::fixup_MICROMIPS_PC16_S1:
Type = ELF::R_MICROMIPS_PC16_S1;
break;
case Mips::fixup_MICROMIPS_CALL16:
Type = ELF::R_MICROMIPS_CALL16;
break;
case Mips::fixup_MICROMIPS_GOT_DISP:
Type = ELF::R_MICROMIPS_GOT_DISP;
break;
case Mips::fixup_MICROMIPS_GOT_PAGE:
Type = ELF::R_MICROMIPS_GOT_PAGE;
break;
case Mips::fixup_MICROMIPS_GOT_OFST:
Type = ELF::R_MICROMIPS_GOT_OFST;
break;
case Mips::fixup_MICROMIPS_TLS_GD:
Type = ELF::R_MICROMIPS_TLS_GD;
break;
case Mips::fixup_MICROMIPS_TLS_LDM:
Type = ELF::R_MICROMIPS_TLS_LDM;
break;
case Mips::fixup_MICROMIPS_TLS_DTPREL_HI16:
Type = ELF::R_MICROMIPS_TLS_DTPREL_HI16;
break;
case Mips::fixup_MICROMIPS_TLS_DTPREL_LO16:
Type = ELF::R_MICROMIPS_TLS_DTPREL_LO16;
break;
case Mips::fixup_MICROMIPS_TLS_TPREL_HI16:
Type = ELF::R_MICROMIPS_TLS_TPREL_HI16;
break;
case Mips::fixup_MICROMIPS_TLS_TPREL_LO16:
Type = ELF::R_MICROMIPS_TLS_TPREL_LO16;
break;
case Mips::fixup_MIPS_PC21_S2:
Type = ELF::R_MIPS_PC21_S2;
break;
case Mips::fixup_MIPS_PC26_S2:
Type = ELF::R_MIPS_PC26_S2;
break;
case Mips::fixup_MIPS_PCHI16:
Type = ELF::R_MIPS_PCHI16;
break;
case Mips::fixup_MIPS_PCLO16:
Type = ELF::R_MIPS_PCLO16;
break;
}
return Type;
}
bool
MipsELFObjectWriter::needsRelocateWithSymbol(unsigned Type) const {
// FIXME: This is extremelly conservative. This really needs to use a
// whitelist with a clear explanation for why each realocation needs to
// point to the symbol, not to the section.
switch (Type) {
default:
return true;
case ELF::R_MIPS_GOT16:
case ELF::R_MIPS16_GOT16:
case ELF::R_MICROMIPS_GOT16:
llvm_unreachable("Should have been handled already");
// These relocations might be paired with another relocation. The pairing is
// done by the static linker by matching the symbol. Since we only see one
// relocation at a time, we have to force them to relocate with a symbol to
// avoid ending up with a pair where one points to a section and another
// points to a symbol.
case ELF::R_MIPS_HI16:
case ELF::R_MIPS16_HI16:
case ELF::R_MICROMIPS_HI16:
case ELF::R_MIPS_LO16:
case ELF::R_MIPS16_LO16:
case ELF::R_MICROMIPS_LO16:
return true;
case ELF::R_MIPS_26:
case ELF::R_MIPS_32:
case ELF::R_MIPS_64:
case ELF::R_MIPS_GPREL16:
return false;
}
}
MCObjectWriter *llvm::createMipsELFObjectWriter(raw_ostream &OS,
uint8_t OSABI,
bool IsLittleEndian,
bool Is64Bit) {
MCELFObjectTargetWriter *MOTW = new MipsELFObjectWriter(Is64Bit, OSABI,
(Is64Bit) ? true : false,
IsLittleEndian);
return createELFObjectWriter(MOTW, OS, IsLittleEndian);
}