1 //===-- X86WinCOFFObjectWriter.cpp - X86 Win COFF 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/X86FixupKinds.h" 10 #include "MCTargetDesc/X86MCTargetDesc.h" 11 #include "llvm/BinaryFormat/COFF.h" 12 #include "llvm/MC/MCContext.h" 13 #include "llvm/MC/MCExpr.h" 14 #include "llvm/MC/MCFixup.h" 15 #include "llvm/MC/MCObjectWriter.h" 16 #include "llvm/MC/MCValue.h" 17 #include "llvm/MC/MCWinCOFFObjectWriter.h" 18 #include "llvm/Support/ErrorHandling.h" 19 20 using namespace llvm; 21 22 namespace { 23 24 class X86WinCOFFObjectWriter : public MCWinCOFFObjectTargetWriter { 25 public: 26 X86WinCOFFObjectWriter(bool Is64Bit); 27 ~X86WinCOFFObjectWriter() override = default; 28 29 unsigned getRelocType(MCContext &Ctx, const MCValue &Target, 30 const MCFixup &Fixup, bool IsCrossSection, 31 const MCAsmBackend &MAB) const override; 32 }; 33 34 } // end anonymous namespace 35 36 X86WinCOFFObjectWriter::X86WinCOFFObjectWriter(bool Is64Bit) 37 : MCWinCOFFObjectTargetWriter(Is64Bit ? COFF::IMAGE_FILE_MACHINE_AMD64 38 : COFF::IMAGE_FILE_MACHINE_I386) {} 39 40 unsigned X86WinCOFFObjectWriter::getRelocType(MCContext &Ctx, 41 const MCValue &Target, 42 const MCFixup &Fixup, 43 bool IsCrossSection, 44 const MCAsmBackend &MAB) const { 45 unsigned FixupKind = Fixup.getKind(); 46 if (IsCrossSection) { 47 if (FixupKind != FK_Data_4 && FixupKind != llvm::X86::reloc_signed_4byte) { 48 Ctx.reportError(Fixup.getLoc(), "Cannot represent this expression"); 49 return COFF::IMAGE_REL_AMD64_ADDR32; 50 } 51 FixupKind = FK_PCRel_4; 52 } 53 54 MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ? 55 MCSymbolRefExpr::VK_None : Target.getSymA()->getKind(); 56 57 if (getMachine() == COFF::IMAGE_FILE_MACHINE_AMD64) { 58 switch (FixupKind) { 59 case FK_PCRel_4: 60 case X86::reloc_riprel_4byte: 61 case X86::reloc_riprel_4byte_movq_load: 62 case X86::reloc_riprel_4byte_relax: 63 case X86::reloc_riprel_4byte_relax_rex: 64 case X86::reloc_branch_4byte_pcrel: 65 return COFF::IMAGE_REL_AMD64_REL32; 66 case FK_Data_4: 67 case X86::reloc_signed_4byte: 68 case X86::reloc_signed_4byte_relax: 69 if (Modifier == MCSymbolRefExpr::VK_COFF_IMGREL32) 70 return COFF::IMAGE_REL_AMD64_ADDR32NB; 71 if (Modifier == MCSymbolRefExpr::VK_SECREL) 72 return COFF::IMAGE_REL_AMD64_SECREL; 73 return COFF::IMAGE_REL_AMD64_ADDR32; 74 case FK_Data_8: 75 return COFF::IMAGE_REL_AMD64_ADDR64; 76 case FK_SecRel_2: 77 return COFF::IMAGE_REL_AMD64_SECTION; 78 case FK_SecRel_4: 79 return COFF::IMAGE_REL_AMD64_SECREL; 80 default: 81 Ctx.reportError(Fixup.getLoc(), "unsupported relocation type"); 82 return COFF::IMAGE_REL_AMD64_ADDR32; 83 } 84 } else if (getMachine() == COFF::IMAGE_FILE_MACHINE_I386) { 85 switch (FixupKind) { 86 case FK_PCRel_4: 87 case X86::reloc_riprel_4byte: 88 case X86::reloc_riprel_4byte_movq_load: 89 return COFF::IMAGE_REL_I386_REL32; 90 case FK_Data_4: 91 case X86::reloc_signed_4byte: 92 case X86::reloc_signed_4byte_relax: 93 if (Modifier == MCSymbolRefExpr::VK_COFF_IMGREL32) 94 return COFF::IMAGE_REL_I386_DIR32NB; 95 if (Modifier == MCSymbolRefExpr::VK_SECREL) 96 return COFF::IMAGE_REL_AMD64_SECREL; 97 return COFF::IMAGE_REL_I386_DIR32; 98 case FK_SecRel_2: 99 return COFF::IMAGE_REL_I386_SECTION; 100 case FK_SecRel_4: 101 return COFF::IMAGE_REL_I386_SECREL; 102 default: 103 Ctx.reportError(Fixup.getLoc(), "unsupported relocation type"); 104 return COFF::IMAGE_REL_I386_DIR32; 105 } 106 } else 107 llvm_unreachable("Unsupported COFF machine type."); 108 } 109 110 std::unique_ptr<MCObjectTargetWriter> 111 llvm::createX86WinCOFFObjectWriter(bool Is64Bit) { 112 return std::make_unique<X86WinCOFFObjectWriter>(Is64Bit); 113 } 114