1 //===-- ARMWinCOFFObjectWriter.cpp - ARM Windows COFF Object 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 #include "MCTargetDesc/ARMFixupKinds.h" 10 #include "llvm/ADT/Twine.h" 11 #include "llvm/BinaryFormat/COFF.h" 12 #include "llvm/MC/MCAsmBackend.h" 13 #include "llvm/MC/MCContext.h" 14 #include "llvm/MC/MCExpr.h" 15 #include "llvm/MC/MCFixup.h" 16 #include "llvm/MC/MCFixupKindInfo.h" 17 #include "llvm/MC/MCObjectWriter.h" 18 #include "llvm/MC/MCValue.h" 19 #include "llvm/MC/MCWinCOFFObjectWriter.h" 20 #include "llvm/Support/ErrorHandling.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include <cassert> 23 24 using namespace llvm; 25 26 namespace { 27 28 class ARMWinCOFFObjectWriter : public MCWinCOFFObjectTargetWriter { 29 public: 30 ARMWinCOFFObjectWriter() 31 : MCWinCOFFObjectTargetWriter(COFF::IMAGE_FILE_MACHINE_ARMNT) { 32 } 33 34 ~ARMWinCOFFObjectWriter() override = default; 35 36 unsigned getRelocType(MCContext &Ctx, const MCValue &Target, 37 const MCFixup &Fixup, bool IsCrossSection, 38 const MCAsmBackend &MAB) const override; 39 40 bool recordRelocation(const MCFixup &) const override; 41 }; 42 43 } // end anonymous namespace 44 45 unsigned ARMWinCOFFObjectWriter::getRelocType(MCContext &Ctx, 46 const MCValue &Target, 47 const MCFixup &Fixup, 48 bool IsCrossSection, 49 const MCAsmBackend &MAB) const { 50 MCSymbolRefExpr::VariantKind Modifier = 51 Target.isAbsolute() ? MCSymbolRefExpr::VK_None : Target.getSymA()->getKind(); 52 53 unsigned FixupKind = Fixup.getKind(); 54 if (IsCrossSection) { 55 if (FixupKind != FK_Data_4) { 56 Ctx.reportError(Fixup.getLoc(), "Cannot represent this expression"); 57 return COFF::IMAGE_REL_ARM_ADDR32; 58 } 59 FixupKind = FK_PCRel_4; 60 } 61 62 63 switch (FixupKind) { 64 default: { 65 const MCFixupKindInfo &Info = MAB.getFixupKindInfo(Fixup.getKind()); 66 report_fatal_error(Twine("unsupported relocation type: ") + Info.Name); 67 } 68 case FK_Data_4: 69 switch (Modifier) { 70 case MCSymbolRefExpr::VK_COFF_IMGREL32: 71 return COFF::IMAGE_REL_ARM_ADDR32NB; 72 case MCSymbolRefExpr::VK_SECREL: 73 return COFF::IMAGE_REL_ARM_SECREL; 74 default: 75 return COFF::IMAGE_REL_ARM_ADDR32; 76 } 77 case FK_PCRel_4: 78 return COFF::IMAGE_REL_ARM_REL32; 79 case FK_SecRel_2: 80 return COFF::IMAGE_REL_ARM_SECTION; 81 case FK_SecRel_4: 82 return COFF::IMAGE_REL_ARM_SECREL; 83 case ARM::fixup_t2_condbranch: 84 return COFF::IMAGE_REL_ARM_BRANCH20T; 85 case ARM::fixup_t2_uncondbranch: 86 case ARM::fixup_arm_thumb_bl: 87 return COFF::IMAGE_REL_ARM_BRANCH24T; 88 case ARM::fixup_arm_thumb_blx: 89 return COFF::IMAGE_REL_ARM_BLX23T; 90 case ARM::fixup_t2_movw_lo16: 91 case ARM::fixup_t2_movt_hi16: 92 return COFF::IMAGE_REL_ARM_MOV32T; 93 } 94 } 95 96 bool ARMWinCOFFObjectWriter::recordRelocation(const MCFixup &Fixup) const { 97 return static_cast<unsigned>(Fixup.getKind()) != ARM::fixup_t2_movt_hi16; 98 } 99 100 namespace llvm { 101 102 std::unique_ptr<MCObjectTargetWriter> 103 createARMWinCOFFObjectWriter() { 104 return std::make_unique<ARMWinCOFFObjectWriter>(); 105 } 106 107 } // end namespace llvm 108