lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp

   1 //===-- RISCVELFObjectWriter.cpp - RISCV ELF Writer -----------------------===//
   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 #include "MCTargetDesc/RISCVFixupKinds.h"
  10 #include "MCTargetDesc/RISCVMCTargetDesc.h"
  11 #include "llvm/MC/MCELFObjectWriter.h"
  12 #include "llvm/MC/MCFixup.h"
  13 #include "llvm/MC/MCObjectWriter.h"
  14 #include "llvm/Support/ErrorHandling.h"
  15
  16 using namespace llvm;
  17
  18 namespace {
  19 class RISCVELFObjectWriter : public MCELFObjectTargetWriter {
  20 public:
  21   RISCVELFObjectWriter(uint8_t OSABI, bool Is64Bit);
  22
  23   ~RISCVELFObjectWriter() override;
  24
  25   // Return true if the given relocation must be with a symbol rather than
  26   // section plus offset.
  27   bool needsRelocateWithSymbol(const MCSymbol &Sym,
  28                                unsigned Type) const override {
  29     // TODO: this is very conservative, update once RISC-V psABI requirements
  30     //       are clarified.
  31     return true;
  32   }
  33
  34 protected:
  35   unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
  36                         const MCFixup &Fixup, bool IsPCRel) const override;
  37 };
  38 }
  39
  40 RISCVELFObjectWriter::RISCVELFObjectWriter(uint8_t OSABI, bool Is64Bit)
  41     : MCELFObjectTargetWriter(Is64Bit, OSABI, ELF::EM_RISCV,
  42                               /*HasRelocationAddend*/ true) {}
  43
  44 RISCVELFObjectWriter::~RISCVELFObjectWriter() {}
  45
  46 unsigned RISCVELFObjectWriter::getRelocType(MCContext &Ctx,
  47                                             const MCValue &Target,
  48                                             const MCFixup &Fixup,
  49                                             bool IsPCRel) const {
  50   // Determine the type of the relocation
  51   switch ((unsigned)Fixup.getKind()) {
  52   default:
  53     llvm_unreachable("invalid fixup kind!");
  54   case FK_Data_4:
  55     return ELF::R_RISCV_32;
  56   case FK_Data_8:
  57     return ELF::R_RISCV_64;
  58   case FK_Data_Add_1:
  59     return ELF::R_RISCV_ADD8;
  60   case FK_Data_Add_2:
  61     return ELF::R_RISCV_ADD16;
  62   case FK_Data_Add_4:
  63     return ELF::R_RISCV_ADD32;
  64   case FK_Data_Add_8:
  65     return ELF::R_RISCV_ADD64;
  66   case FK_Data_Sub_1:
  67     return ELF::R_RISCV_SUB8;
  68   case FK_Data_Sub_2:
  69     return ELF::R_RISCV_SUB16;
  70   case FK_Data_Sub_4:
  71     return ELF::R_RISCV_SUB32;
  72   case FK_Data_Sub_8:
  73     return ELF::R_RISCV_SUB64;
  74   case RISCV::fixup_riscv_hi20:
  75     return ELF::R_RISCV_HI20;
  76   case RISCV::fixup_riscv_lo12_i:
  77     return ELF::R_RISCV_LO12_I;
  78   case RISCV::fixup_riscv_lo12_s:
  79     return ELF::R_RISCV_LO12_S;
  80   case RISCV::fixup_riscv_pcrel_hi20:
  81     return ELF::R_RISCV_PCREL_HI20;
  82   case RISCV::fixup_riscv_pcrel_lo12_i:
  83     return ELF::R_RISCV_PCREL_LO12_I;
  84   case RISCV::fixup_riscv_pcrel_lo12_s:
  85     return ELF::R_RISCV_PCREL_LO12_S;
  86   case RISCV::fixup_riscv_got_hi20:
  87     return ELF::R_RISCV_GOT_HI20;
  88   case RISCV::fixup_riscv_jal:
  89     return ELF::R_RISCV_JAL;
  90   case RISCV::fixup_riscv_branch:
  91     return ELF::R_RISCV_BRANCH;
  92   case RISCV::fixup_riscv_rvc_jump:
  93     return ELF::R_RISCV_RVC_JUMP;
  94   case RISCV::fixup_riscv_rvc_branch:
  95     return ELF::R_RISCV_RVC_BRANCH;
  96   case RISCV::fixup_riscv_call:
  97     return ELF::R_RISCV_CALL;
  98   case RISCV::fixup_riscv_relax:
  99     return ELF::R_RISCV_RELAX;
 100   case RISCV::fixup_riscv_align:
 101     return ELF::R_RISCV_ALIGN;
 102   }
 103 }
 104
 105 std::unique_ptr<MCObjectTargetWriter>
 106 llvm::createRISCVELFObjectWriter(uint8_t OSABI, bool Is64Bit) {
 107   return llvm::make_unique<RISCVELFObjectWriter>(OSABI, Is64Bit);
 108 }