1 //===- MCAsmBackend.cpp - Target MC Assembly Backend ----------------------===//
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 "llvm/MC/MCAsmBackend.h"
10 #include "llvm/ADT/None.h"
11 #include "llvm/ADT/STLArrayExtras.h"
12 #include "llvm/MC/MCDXContainerWriter.h"
13 #include "llvm/MC/MCELFObjectWriter.h"
14 #include "llvm/MC/MCFixupKindInfo.h"
15 #include "llvm/MC/MCMachObjectWriter.h"
16 #include "llvm/MC/MCObjectWriter.h"
17 #include "llvm/MC/MCSPIRVObjectWriter.h"
18 #include "llvm/MC/MCWasmObjectWriter.h"
19 #include "llvm/MC/MCWinCOFFObjectWriter.h"
20 #include "llvm/MC/MCXCOFFObjectWriter.h"
21 #include <cassert>
22 #include <cstddef>
23 #include <cstdint>
24
25 using namespace llvm;
26
MCAsmBackend(support::endianness Endian)27 MCAsmBackend::MCAsmBackend(support::endianness Endian) : Endian(Endian) {}
28
29 MCAsmBackend::~MCAsmBackend() = default;
30
31 std::unique_ptr<MCObjectWriter>
createObjectWriter(raw_pwrite_stream & OS) const32 MCAsmBackend::createObjectWriter(raw_pwrite_stream &OS) const {
33 auto TW = createObjectTargetWriter();
34 switch (TW->getFormat()) {
35 case Triple::ELF:
36 return createELFObjectWriter(cast<MCELFObjectTargetWriter>(std::move(TW)), OS,
37 Endian == support::little);
38 case Triple::MachO:
39 return createMachObjectWriter(cast<MCMachObjectTargetWriter>(std::move(TW)),
40 OS, Endian == support::little);
41 case Triple::COFF:
42 return createWinCOFFObjectWriter(
43 cast<MCWinCOFFObjectTargetWriter>(std::move(TW)), OS);
44 case Triple::SPIRV:
45 return createSPIRVObjectWriter(
46 cast<MCSPIRVObjectTargetWriter>(std::move(TW)), OS);
47 case Triple::Wasm:
48 return createWasmObjectWriter(cast<MCWasmObjectTargetWriter>(std::move(TW)),
49 OS);
50 case Triple::XCOFF:
51 return createXCOFFObjectWriter(
52 cast<MCXCOFFObjectTargetWriter>(std::move(TW)), OS);
53 case Triple::DXContainer:
54 return createDXContainerObjectWriter(
55 cast<MCDXContainerTargetWriter>(std::move(TW)), OS);
56 default:
57 llvm_unreachable("unexpected object format");
58 }
59 }
60
61 std::unique_ptr<MCObjectWriter>
createDwoObjectWriter(raw_pwrite_stream & OS,raw_pwrite_stream & DwoOS) const62 MCAsmBackend::createDwoObjectWriter(raw_pwrite_stream &OS,
63 raw_pwrite_stream &DwoOS) const {
64 auto TW = createObjectTargetWriter();
65 switch (TW->getFormat()) {
66 case Triple::ELF:
67 return createELFDwoObjectWriter(
68 cast<MCELFObjectTargetWriter>(std::move(TW)), OS, DwoOS,
69 Endian == support::little);
70 case Triple::Wasm:
71 return createWasmDwoObjectWriter(
72 cast<MCWasmObjectTargetWriter>(std::move(TW)), OS, DwoOS);
73 default:
74 report_fatal_error("dwo only supported with ELF and Wasm");
75 }
76 }
77
getFixupKind(StringRef Name) const78 Optional<MCFixupKind> MCAsmBackend::getFixupKind(StringRef Name) const {
79 return None;
80 }
81
getFixupKindInfo(MCFixupKind Kind) const82 const MCFixupKindInfo &MCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
83 static const MCFixupKindInfo Builtins[] = {
84 {"FK_NONE", 0, 0, 0},
85 {"FK_Data_1", 0, 8, 0},
86 {"FK_Data_2", 0, 16, 0},
87 {"FK_Data_4", 0, 32, 0},
88 {"FK_Data_8", 0, 64, 0},
89 {"FK_Data_6b", 0, 6, 0},
90 {"FK_PCRel_1", 0, 8, MCFixupKindInfo::FKF_IsPCRel},
91 {"FK_PCRel_2", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
92 {"FK_PCRel_4", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
93 {"FK_PCRel_8", 0, 64, MCFixupKindInfo::FKF_IsPCRel},
94 {"FK_GPRel_1", 0, 8, 0},
95 {"FK_GPRel_2", 0, 16, 0},
96 {"FK_GPRel_4", 0, 32, 0},
97 {"FK_GPRel_8", 0, 64, 0},
98 {"FK_DTPRel_4", 0, 32, 0},
99 {"FK_DTPRel_8", 0, 64, 0},
100 {"FK_TPRel_4", 0, 32, 0},
101 {"FK_TPRel_8", 0, 64, 0},
102 {"FK_SecRel_1", 0, 8, 0},
103 {"FK_SecRel_2", 0, 16, 0},
104 {"FK_SecRel_4", 0, 32, 0},
105 {"FK_SecRel_8", 0, 64, 0},
106 };
107
108 assert((size_t)Kind <= array_lengthof(Builtins) && "Unknown fixup kind");
109 return Builtins[Kind];
110 }
111
fixupNeedsRelaxationAdvanced(const MCFixup & Fixup,bool Resolved,uint64_t Value,const MCRelaxableFragment * DF,const MCAsmLayout & Layout,const bool WasForced) const112 bool MCAsmBackend::fixupNeedsRelaxationAdvanced(
113 const MCFixup &Fixup, bool Resolved, uint64_t Value,
114 const MCRelaxableFragment *DF, const MCAsmLayout &Layout,
115 const bool WasForced) const {
116 if (!Resolved)
117 return true;
118 return fixupNeedsRelaxation(Fixup, Value, DF, Layout);
119 }
120