lib/Target/ARM/MCTargetDesc/ARMWinCOFFObjectWriter.cpp

   1 //===-- ARMWinCOFFObjectWriter.cpp - ARM Windows COFF Object Writer -- C++ -==//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "MCTargetDesc/ARMFixupKinds.h"
  11 #include "llvm/ADT/Twine.h"
  12 #include "llvm/BinaryFormat/COFF.h"
  13 #include "llvm/MC/MCAsmBackend.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(bool Is64Bit)
  31     : MCWinCOFFObjectTargetWriter(COFF::IMAGE_FILE_MACHINE_ARMNT) {
  32     assert(!Is64Bit && "AArch64 support not yet implemented");
  33   }
  34
  35   ~ARMWinCOFFObjectWriter() override = default;
  36
  37   unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
  38                         const MCFixup &Fixup, bool IsCrossSection,
  39                         const MCAsmBackend &MAB) const override;
  40
  41   bool recordRelocation(const MCFixup &) const override;
  42 };
  43
  44 } // end anonymous namespace
  45
  46 unsigned ARMWinCOFFObjectWriter::getRelocType(MCContext &Ctx,
  47                                               const MCValue &Target,
  48                                               const MCFixup &Fixup,
  49                                               bool IsCrossSection,
  50                                               const MCAsmBackend &MAB) const {
  51   assert(getMachine() == COFF::IMAGE_FILE_MACHINE_ARMNT &&
  52          "AArch64 support not yet implemented");
  53
  54   MCSymbolRefExpr::VariantKind Modifier =
  55     Target.isAbsolute() ? MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
  56
  57   switch (static_cast<unsigned>(Fixup.getKind())) {
  58   default: {
  59     const MCFixupKindInfo &Info = MAB.getFixupKindInfo(Fixup.getKind());
  60     report_fatal_error(Twine("unsupported relocation type: ") + Info.Name);
  61   }
  62   case FK_Data_4:
  63     switch (Modifier) {
  64     case MCSymbolRefExpr::VK_COFF_IMGREL32:
  65       return COFF::IMAGE_REL_ARM_ADDR32NB;
  66     case MCSymbolRefExpr::VK_SECREL:
  67       return COFF::IMAGE_REL_ARM_SECREL;
  68     default:
  69       return COFF::IMAGE_REL_ARM_ADDR32;
  70     }
  71   case FK_SecRel_2:
  72     return COFF::IMAGE_REL_ARM_SECTION;
  73   case FK_SecRel_4:
  74     return COFF::IMAGE_REL_ARM_SECREL;
  75   case ARM::fixup_t2_condbranch:
  76     return COFF::IMAGE_REL_ARM_BRANCH20T;
  77   case ARM::fixup_t2_uncondbranch:
  78   case ARM::fixup_arm_thumb_bl:
  79     return COFF::IMAGE_REL_ARM_BRANCH24T;
  80   case ARM::fixup_arm_thumb_blx:
  81     return COFF::IMAGE_REL_ARM_BLX23T;
  82   case ARM::fixup_t2_movw_lo16:
  83   case ARM::fixup_t2_movt_hi16:
  84     return COFF::IMAGE_REL_ARM_MOV32T;
  85   }
  86 }
  87
  88 bool ARMWinCOFFObjectWriter::recordRelocation(const MCFixup &Fixup) const {
  89   return static_cast<unsigned>(Fixup.getKind()) != ARM::fixup_t2_movt_hi16;
  90 }
  91
  92 namespace llvm {
  93
  94 std::unique_ptr<MCObjectTargetWriter>
  95 createARMWinCOFFObjectWriter(bool Is64Bit) {
  96   return llvm::make_unique<ARMWinCOFFObjectWriter>(Is64Bit);
  97 }
  98
  99 } // end namespace llvm