lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp

   1 //===-- MipsELFObjectWriter.cpp - Mips ELF Writer ---------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "MCTargetDesc/MipsFixupKinds.h"
  11 #include "MCTargetDesc/MipsMCTargetDesc.h"
  12 #include "llvm/MC/MCELFObjectWriter.h"
  13 #include "llvm/MC/MCExpr.h"
  14 #include "llvm/MC/MCSection.h"
  15 #include "llvm/MC/MCValue.h"
  16 #include "llvm/Support/ErrorHandling.h"
  17
  18 using namespace llvm;
  19
  20 namespace {
  21   class MipsELFObjectWriter : public MCELFObjectTargetWriter {
  22   public:
  23     MipsELFObjectWriter(uint8_t OSABI);
  24
  25     virtual ~MipsELFObjectWriter();
  26
  27     virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
  28                                   bool IsPCRel, bool IsRelocWithSymbol,
  29                                   int64_t Addend) const;
  30     virtual unsigned getEFlags() const;
  31     virtual const MCSymbol *ExplicitRelSym(const MCAssembler &Asm,
  32                                            const MCValue &Target,
  33                                            const MCFragment &F,
  34                                            const MCFixup &Fixup,
  35                                            bool IsPCRel) const;
  36   };
  37 }
  38
  39 MipsELFObjectWriter::MipsELFObjectWriter(uint8_t OSABI)
  40   : MCELFObjectTargetWriter(/*Is64Bit*/ false, OSABI, ELF::EM_MIPS,
  41                             /*HasRelocationAddend*/ false) {}
  42
  43 MipsELFObjectWriter::~MipsELFObjectWriter() {}
  44
  45 // FIXME: get the real EABI Version from the Triple.
  46 unsigned MipsELFObjectWriter::getEFlags() const {
  47   return ELF::EF_MIPS_NOREORDER | ELF::EF_MIPS_ARCH_32R2;
  48 }
  49
  50 const MCSymbol *MipsELFObjectWriter::ExplicitRelSym(const MCAssembler &Asm,
  51                                                     const MCValue &Target,
  52                                                     const MCFragment &F,
  53                                                     const MCFixup &Fixup,
  54                                                     bool IsPCRel) const {
  55   assert(Target.getSymA() && "SymA cannot be 0.");
  56   const MCSymbol &Sym = Target.getSymA()->getSymbol();
  57
  58   if (Sym.getSection().getKind().isMergeableCString() ||
  59       Sym.getSection().getKind().isMergeableConst())
  60     return &Sym;
  61
  62   return NULL;
  63 }
  64
  65 unsigned MipsELFObjectWriter::GetRelocType(const MCValue &Target,
  66                                            const MCFixup &Fixup,
  67                                            bool IsPCRel,
  68                                            bool IsRelocWithSymbol,
  69                                            int64_t Addend) const {
  70   // determine the type of the relocation
  71   unsigned Type = (unsigned)ELF::R_MIPS_NONE;
  72   unsigned Kind = (unsigned)Fixup.getKind();
  73
  74   switch (Kind) {
  75   default:
  76     llvm_unreachable("invalid fixup kind!");
  77   case FK_Data_4:
  78     Type = ELF::R_MIPS_32;
  79     break;
  80   case FK_GPRel_4:
  81     Type = ELF::R_MIPS_GPREL32;
  82     break;
  83   case Mips::fixup_Mips_GPREL16:
  84     Type = ELF::R_MIPS_GPREL16;
  85     break;
  86   case Mips::fixup_Mips_26:
  87     Type = ELF::R_MIPS_26;
  88     break;
  89   case Mips::fixup_Mips_CALL16:
  90     Type = ELF::R_MIPS_CALL16;
  91     break;
  92   case Mips::fixup_Mips_GOT_Global:
  93   case Mips::fixup_Mips_GOT_Local:
  94     Type = ELF::R_MIPS_GOT16;
  95     break;
  96   case Mips::fixup_Mips_HI16:
  97     Type = ELF::R_MIPS_HI16;
  98     break;
  99   case Mips::fixup_Mips_LO16:
 100     Type = ELF::R_MIPS_LO16;
 101     break;
 102   case Mips::fixup_Mips_TLSGD:
 103     Type = ELF::R_MIPS_TLS_GD;
 104     break;
 105   case Mips::fixup_Mips_GOTTPREL:
 106     Type = ELF::R_MIPS_TLS_GOTTPREL;
 107     break;
 108   case Mips::fixup_Mips_TPREL_HI:
 109     Type = ELF::R_MIPS_TLS_TPREL_HI16;
 110     break;
 111   case Mips::fixup_Mips_TPREL_LO:
 112     Type = ELF::R_MIPS_TLS_TPREL_LO16;
 113     break;
 114   case Mips::fixup_Mips_TLSLDM:
 115     Type = ELF::R_MIPS_TLS_LDM;
 116     break;
 117   case Mips::fixup_Mips_DTPREL_HI:
 118     Type = ELF::R_MIPS_TLS_DTPREL_HI16;
 119     break;
 120   case Mips::fixup_Mips_DTPREL_LO:
 121     Type = ELF::R_MIPS_TLS_DTPREL_LO16;
 122     break;
 123   case Mips::fixup_Mips_Branch_PCRel:
 124   case Mips::fixup_Mips_PC16:
 125     Type = ELF::R_MIPS_PC16;
 126     break;
 127   }
 128
 129   return Type;
 130 }
 131
 132 MCObjectWriter *llvm::createMipsELFObjectWriter(raw_ostream &OS,
 133                                                bool IsLittleEndian,
 134                                                uint8_t OSABI) {
 135   MCELFObjectTargetWriter *MOTW = new MipsELFObjectWriter(OSABI);
 136   return createELFObjectWriter(MOTW, OS, IsLittleEndian);
 137 }