llvm/lib/Target/M68k/MCTargetDesc/M68kELFObjectWriter.cpp

   1 //===---------- M68kELFObjectWriter.cpp - M68k ELF Writer ---*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 ///
   9 /// \file
  10 /// This file contains definitions for M68k ELF Writers
  11 ///
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "MCTargetDesc/M68kFixupKinds.h"
  15 #include "MCTargetDesc/M68kMCTargetDesc.h"
  16
  17 #include "llvm/BinaryFormat/ELF.h"
  18 #include "llvm/MC/MCAsmInfo.h"
  19 #include "llvm/MC/MCContext.h"
  20 #include "llvm/MC/MCELFObjectWriter.h"
  21 #include "llvm/MC/MCExpr.h"
  22 #include "llvm/MC/MCValue.h"
  23 #include "llvm/Support/ErrorHandling.h"
  24
  25 using namespace llvm;
  26
  27 namespace {
  28 class M68kELFObjectWriter : public MCELFObjectTargetWriter {
  29 public:
  30   M68kELFObjectWriter(uint8_t OSABI);
  31
  32   ~M68kELFObjectWriter() override;
  33
  34 protected:
  35   unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
  36                         const MCFixup &Fixup, bool IsPCRel) const override;
  37 };
  38 } // namespace
  39
  40 M68kELFObjectWriter::M68kELFObjectWriter(uint8_t OSABI)
  41     : MCELFObjectTargetWriter(false, OSABI, ELF::EM_68K, /* RELA */ true) {}
  42
  43 M68kELFObjectWriter::~M68kELFObjectWriter() {}
  44
  45 enum M68kRelType { RT_32, RT_16, RT_8 };
  46
  47 static M68kRelType
  48 getType(unsigned Kind, MCSymbolRefExpr::VariantKind &Modifier, bool &IsPCRel) {
  49   switch (Kind) {
  50   case FK_Data_4:
  51   case FK_PCRel_4:
  52     return RT_32;
  53   case FK_PCRel_2:
  54   case FK_Data_2:
  55     return RT_16;
  56   case FK_PCRel_1:
  57   case FK_Data_1:
  58     return RT_8;
  59   }
  60   llvm_unreachable("Unimplemented");
  61 }
  62
  63 unsigned M68kELFObjectWriter::getRelocType(MCContext &Ctx,
  64                                            const MCValue &Target,
  65                                            const MCFixup &Fixup,
  66                                            bool IsPCRel) const {
  67   MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
  68   unsigned Kind = Fixup.getKind();
  69   M68kRelType Type = getType(Kind, Modifier, IsPCRel);
  70   switch (Modifier) {
  71   default:
  72     llvm_unreachable("Unimplemented");
  73   case MCSymbolRefExpr::VK_None:
  74     switch (Type) {
  75     case RT_32:
  76       return IsPCRel ? ELF::R_68K_PC32 : ELF::R_68K_32;
  77     case RT_16:
  78       return IsPCRel ? ELF::R_68K_PC16 : ELF::R_68K_16;
  79     case RT_8:
  80       return IsPCRel ? ELF::R_68K_PC8 : ELF::R_68K_8;
  81     }
  82     llvm_unreachable("Unrecognized size");
  83   case MCSymbolRefExpr::VK_GOTPCREL:
  84     switch (Type) {
  85     case RT_32:
  86       return ELF::R_68K_GOTPCREL32;
  87     case RT_16:
  88       return ELF::R_68K_GOTPCREL16;
  89     case RT_8:
  90       return ELF::R_68K_GOTPCREL8;
  91     }
  92     llvm_unreachable("Unrecognized size");
  93   case MCSymbolRefExpr::VK_GOTOFF:
  94     assert(!IsPCRel);
  95     switch (Type) {
  96     case RT_32:
  97       return ELF::R_68K_GOTOFF32;
  98     case RT_16:
  99       return ELF::R_68K_GOTOFF16;
 100     case RT_8:
 101       return ELF::R_68K_GOTOFF8;
 102     }
 103     llvm_unreachable("Unrecognized size");
 104   case MCSymbolRefExpr::VK_PLT:
 105     switch (Type) {
 106     case RT_32:
 107       return ELF::R_68K_PLT32;
 108     case RT_16:
 109       return ELF::R_68K_PLT16;
 110     case RT_8:
 111       return ELF::R_68K_PLT8;
 112     }
 113     llvm_unreachable("Unrecognized size");
 114   }
 115 }
 116
 117 std::unique_ptr<MCObjectTargetWriter>
 118 llvm::createM68kELFObjectWriter(uint8_t OSABI) {
 119   return std::make_unique<M68kELFObjectWriter>(OSABI);
 120 }