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
23 using namespace llvm;
24
25 namespace {
26
27 class ARMWinCOFFObjectWriter : public MCWinCOFFObjectTargetWriter {
28 public:
ARMWinCOFFObjectWriter()29 ARMWinCOFFObjectWriter()
30 : MCWinCOFFObjectTargetWriter(COFF::IMAGE_FILE_MACHINE_ARMNT) {
31 }
32
33 ~ARMWinCOFFObjectWriter() override = default;
34
35 unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
36 const MCFixup &Fixup, bool IsCrossSection,
37 const MCAsmBackend &MAB) const override;
38
39 bool recordRelocation(const MCFixup &) const override;
40 };
41
42 } // end anonymous namespace
43
getRelocType(MCContext & Ctx,const MCValue & Target,const MCFixup & Fixup,bool IsCrossSection,const MCAsmBackend & MAB) const44 unsigned ARMWinCOFFObjectWriter::getRelocType(MCContext &Ctx,
45 const MCValue &Target,
46 const MCFixup &Fixup,
47 bool IsCrossSection,
48 const MCAsmBackend &MAB) const {
49 MCSymbolRefExpr::VariantKind Modifier =
50 Target.isAbsolute() ? MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
51
52 unsigned FixupKind = Fixup.getKind();
53 if (IsCrossSection) {
54 if (FixupKind != FK_Data_4) {
55 Ctx.reportError(Fixup.getLoc(), "Cannot represent this expression");
56 return COFF::IMAGE_REL_ARM_ADDR32;
57 }
58 FixupKind = FK_PCRel_4;
59 }
60
61
62 switch (FixupKind) {
63 default: {
64 const MCFixupKindInfo &Info = MAB.getFixupKindInfo(Fixup.getKind());
65 report_fatal_error(Twine("unsupported relocation type: ") + Info.Name);
66 }
67 case FK_Data_4:
68 switch (Modifier) {
69 case MCSymbolRefExpr::VK_COFF_IMGREL32:
70 return COFF::IMAGE_REL_ARM_ADDR32NB;
71 case MCSymbolRefExpr::VK_SECREL:
72 return COFF::IMAGE_REL_ARM_SECREL;
73 default:
74 return COFF::IMAGE_REL_ARM_ADDR32;
75 }
76 case FK_PCRel_4:
77 return COFF::IMAGE_REL_ARM_REL32;
78 case FK_SecRel_2:
79 return COFF::IMAGE_REL_ARM_SECTION;
80 case FK_SecRel_4:
81 return COFF::IMAGE_REL_ARM_SECREL;
82 case ARM::fixup_t2_condbranch:
83 return COFF::IMAGE_REL_ARM_BRANCH20T;
84 case ARM::fixup_t2_uncondbranch:
85 case ARM::fixup_arm_thumb_bl:
86 return COFF::IMAGE_REL_ARM_BRANCH24T;
87 case ARM::fixup_arm_thumb_blx:
88 return COFF::IMAGE_REL_ARM_BLX23T;
89 case ARM::fixup_t2_movw_lo16:
90 case ARM::fixup_t2_movt_hi16:
91 return COFF::IMAGE_REL_ARM_MOV32T;
92 }
93 }
94
recordRelocation(const MCFixup & Fixup) const95 bool ARMWinCOFFObjectWriter::recordRelocation(const MCFixup &Fixup) const {
96 return static_cast<unsigned>(Fixup.getKind()) != ARM::fixup_t2_movt_hi16;
97 }
98
99 namespace llvm {
100
101 std::unique_ptr<MCObjectTargetWriter>
createARMWinCOFFObjectWriter()102 createARMWinCOFFObjectWriter() {
103 return std::make_unique<ARMWinCOFFObjectWriter>();
104 }
105
106 } // end namespace llvm
107