| //===-- X86ELFObjectWriter.cpp - X86 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/X86FixupKinds.h" |
| #include "MCTargetDesc/X86MCTargetDesc.h" |
| #include "llvm/MC/MCELFObjectWriter.h" |
| #include "llvm/MC/MCExpr.h" |
| #include "llvm/MC/MCValue.h" |
| #include "llvm/Support/ELF.h" |
| #include "llvm/Support/ErrorHandling.h" |
| |
| using namespace llvm; |
| |
| namespace { |
| class X86ELFObjectWriter : public MCELFObjectTargetWriter { |
| public: |
| X86ELFObjectWriter(bool IsELF64, uint8_t OSABI, uint16_t EMachine); |
| |
| ~X86ELFObjectWriter() override; |
| |
| protected: |
| unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, |
| bool IsPCRel) const override; |
| }; |
| } |
| |
| X86ELFObjectWriter::X86ELFObjectWriter(bool IsELF64, uint8_t OSABI, |
| uint16_t EMachine) |
| : MCELFObjectTargetWriter(IsELF64, OSABI, EMachine, |
| // Only i386 and IAMCU use Rel instead of RelA. |
| /*HasRelocationAddend*/ |
| (EMachine != ELF::EM_386) && |
| (EMachine != ELF::EM_IAMCU)) {} |
| |
| X86ELFObjectWriter::~X86ELFObjectWriter() |
| {} |
| |
| enum X86_64RelType { RT64_64, RT64_32, RT64_32S, RT64_16, RT64_8 }; |
| |
| static X86_64RelType getType64(unsigned Kind, |
| MCSymbolRefExpr::VariantKind &Modifier, |
| bool &IsPCRel) { |
| switch (Kind) { |
| default: |
| llvm_unreachable("Unimplemented"); |
| case X86::reloc_global_offset_table8: |
| Modifier = MCSymbolRefExpr::VK_GOT; |
| IsPCRel = true; |
| return RT64_64; |
| case FK_Data_8: |
| return RT64_64; |
| case X86::reloc_signed_4byte: |
| if (Modifier == MCSymbolRefExpr::VK_None && !IsPCRel) |
| return RT64_32S; |
| return RT64_32; |
| case X86::reloc_global_offset_table: |
| Modifier = MCSymbolRefExpr::VK_GOT; |
| IsPCRel = true; |
| return RT64_32; |
| case FK_Data_4: |
| case FK_PCRel_4: |
| case X86::reloc_riprel_4byte: |
| case X86::reloc_riprel_4byte_movq_load: |
| return RT64_32; |
| case FK_PCRel_2: |
| case FK_Data_2: |
| return RT64_16; |
| case FK_PCRel_1: |
| case FK_Data_1: |
| return RT64_8; |
| } |
| } |
| |
| static unsigned getRelocType64(MCSymbolRefExpr::VariantKind Modifier, |
| X86_64RelType Type, bool IsPCRel) { |
| switch (Modifier) { |
| default: |
| llvm_unreachable("Unimplemented"); |
| case MCSymbolRefExpr::VK_None: |
| switch (Type) { |
| case RT64_64: |
| return IsPCRel ? ELF::R_X86_64_PC64 : ELF::R_X86_64_64; |
| case RT64_32: |
| return IsPCRel ? ELF::R_X86_64_PC32 : ELF::R_X86_64_32; |
| case RT64_32S: |
| return ELF::R_X86_64_32S; |
| case RT64_16: |
| return IsPCRel ? ELF::R_X86_64_PC16 : ELF::R_X86_64_16; |
| case RT64_8: |
| return IsPCRel ? ELF::R_X86_64_PC8 : ELF::R_X86_64_8; |
| } |
| case MCSymbolRefExpr::VK_GOT: |
| switch (Type) { |
| case RT64_64: |
| return IsPCRel ? ELF::R_X86_64_GOTPC64 : ELF::R_X86_64_GOT64; |
| case RT64_32: |
| return IsPCRel ? ELF::R_X86_64_GOTPC32 : ELF::R_X86_64_GOT32; |
| case RT64_32S: |
| case RT64_16: |
| case RT64_8: |
| llvm_unreachable("Unimplemented"); |
| } |
| case MCSymbolRefExpr::VK_GOTOFF: |
| assert(Type == RT64_64); |
| assert(!IsPCRel); |
| return ELF::R_X86_64_GOTOFF64; |
| case MCSymbolRefExpr::VK_TPOFF: |
| assert(!IsPCRel); |
| switch (Type) { |
| case RT64_64: |
| return ELF::R_X86_64_TPOFF64; |
| case RT64_32: |
| return ELF::R_X86_64_TPOFF32; |
| case RT64_32S: |
| case RT64_16: |
| case RT64_8: |
| llvm_unreachable("Unimplemented"); |
| } |
| case MCSymbolRefExpr::VK_DTPOFF: |
| assert(!IsPCRel); |
| switch (Type) { |
| case RT64_64: |
| return ELF::R_X86_64_DTPOFF64; |
| case RT64_32: |
| return ELF::R_X86_64_DTPOFF32; |
| case RT64_32S: |
| case RT64_16: |
| case RT64_8: |
| llvm_unreachable("Unimplemented"); |
| } |
| case MCSymbolRefExpr::VK_SIZE: |
| assert(!IsPCRel); |
| switch (Type) { |
| case RT64_64: |
| return ELF::R_X86_64_SIZE64; |
| case RT64_32: |
| return ELF::R_X86_64_SIZE32; |
| case RT64_32S: |
| case RT64_16: |
| case RT64_8: |
| llvm_unreachable("Unimplemented"); |
| } |
| case MCSymbolRefExpr::VK_TLSGD: |
| assert(Type == RT64_32); |
| return ELF::R_X86_64_TLSGD; |
| case MCSymbolRefExpr::VK_GOTTPOFF: |
| assert(Type == RT64_32); |
| return ELF::R_X86_64_GOTTPOFF; |
| case MCSymbolRefExpr::VK_TLSLD: |
| assert(Type == RT64_32); |
| return ELF::R_X86_64_TLSLD; |
| case MCSymbolRefExpr::VK_PLT: |
| assert(Type == RT64_32); |
| return ELF::R_X86_64_PLT32; |
| case MCSymbolRefExpr::VK_GOTPCREL: |
| assert(Type == RT64_32); |
| return ELF::R_X86_64_GOTPCREL; |
| } |
| } |
| |
| enum X86_32RelType { RT32_32, RT32_16, RT32_8 }; |
| |
| static X86_32RelType getType32(X86_64RelType T) { |
| switch (T) { |
| case RT64_64: |
| llvm_unreachable("Unimplemented"); |
| case RT64_32: |
| case RT64_32S: |
| return RT32_32; |
| case RT64_16: |
| return RT32_16; |
| case RT64_8: |
| return RT32_8; |
| } |
| llvm_unreachable("unexpected relocation type!"); |
| } |
| |
| static unsigned getRelocType32(MCSymbolRefExpr::VariantKind Modifier, |
| X86_32RelType Type, bool IsPCRel) { |
| switch (Modifier) { |
| default: |
| llvm_unreachable("Unimplemented"); |
| case MCSymbolRefExpr::VK_None: |
| switch (Type) { |
| case RT32_32: |
| return IsPCRel ? ELF::R_386_PC32 : ELF::R_386_32; |
| case RT32_16: |
| return IsPCRel ? ELF::R_386_PC16 : ELF::R_386_16; |
| case RT32_8: |
| return IsPCRel ? ELF::R_386_PC8 : ELF::R_386_8; |
| } |
| case MCSymbolRefExpr::VK_GOT: |
| assert(Type == RT32_32); |
| return IsPCRel ? ELF::R_386_GOTPC : ELF::R_386_GOT32; |
| case MCSymbolRefExpr::VK_GOTOFF: |
| assert(Type == RT32_32); |
| assert(!IsPCRel); |
| return ELF::R_386_GOTOFF; |
| case MCSymbolRefExpr::VK_TPOFF: |
| assert(Type == RT32_32); |
| assert(!IsPCRel); |
| return ELF::R_386_TLS_LE_32; |
| case MCSymbolRefExpr::VK_DTPOFF: |
| assert(Type == RT32_32); |
| assert(!IsPCRel); |
| return ELF::R_386_TLS_LDO_32; |
| case MCSymbolRefExpr::VK_TLSGD: |
| assert(Type == RT32_32); |
| assert(!IsPCRel); |
| return ELF::R_386_TLS_GD; |
| case MCSymbolRefExpr::VK_GOTTPOFF: |
| assert(Type == RT32_32); |
| assert(!IsPCRel); |
| return ELF::R_386_TLS_IE_32; |
| case MCSymbolRefExpr::VK_PLT: |
| assert(Type == RT32_32); |
| return ELF::R_386_PLT32; |
| case MCSymbolRefExpr::VK_INDNTPOFF: |
| assert(Type == RT32_32); |
| assert(!IsPCRel); |
| return ELF::R_386_TLS_IE; |
| case MCSymbolRefExpr::VK_NTPOFF: |
| assert(Type == RT32_32); |
| assert(!IsPCRel); |
| return ELF::R_386_TLS_LE; |
| case MCSymbolRefExpr::VK_GOTNTPOFF: |
| assert(Type == RT32_32); |
| assert(!IsPCRel); |
| return ELF::R_386_TLS_GOTIE; |
| case MCSymbolRefExpr::VK_TLSLDM: |
| assert(Type == RT32_32); |
| assert(!IsPCRel); |
| return ELF::R_386_TLS_LDM; |
| } |
| } |
| |
| unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target, |
| const MCFixup &Fixup, |
| bool IsPCRel) const { |
| MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant(); |
| X86_64RelType Type = getType64(Fixup.getKind(), Modifier, IsPCRel); |
| if (getEMachine() == ELF::EM_X86_64) |
| return getRelocType64(Modifier, Type, IsPCRel); |
| |
| assert((getEMachine() == ELF::EM_386 || getEMachine() == ELF::EM_IAMCU) && |
| "Unsupported ELF machine type."); |
| return getRelocType32(Modifier, getType32(Type), IsPCRel); |
| } |
| |
| MCObjectWriter *llvm::createX86ELFObjectWriter(raw_pwrite_stream &OS, |
| bool IsELF64, uint8_t OSABI, |
| uint16_t EMachine) { |
| MCELFObjectTargetWriter *MOTW = |
| new X86ELFObjectWriter(IsELF64, OSABI, EMachine); |
| return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/true); |
| } |