xref: /freebsd/contrib/llvm-project/llvm/lib/MC/MCAsmBackend.cpp (revision 5ffd83dbcc34f10e07f6d3e968ae6365869615f4)
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/STLExtras.h"
12 #include "llvm/MC/MCELFObjectWriter.h"
13 #include "llvm/MC/MCFixupKindInfo.h"
14 #include "llvm/MC/MCMachObjectWriter.h"
15 #include "llvm/MC/MCObjectWriter.h"
16 #include "llvm/MC/MCWasmObjectWriter.h"
17 #include "llvm/MC/MCWinCOFFObjectWriter.h"
18 #include "llvm/MC/MCXCOFFObjectWriter.h"
19 #include <cassert>
20 #include <cstddef>
21 #include <cstdint>
22 
23 using namespace llvm;
24 
25 MCAsmBackend::MCAsmBackend(support::endianness Endian) : Endian(Endian) {}
26 
27 MCAsmBackend::~MCAsmBackend() = default;
28 
29 std::unique_ptr<MCObjectWriter>
30 MCAsmBackend::createObjectWriter(raw_pwrite_stream &OS) const {
31   auto TW = createObjectTargetWriter();
32   switch (TW->getFormat()) {
33   case Triple::ELF:
34     return createELFObjectWriter(cast<MCELFObjectTargetWriter>(std::move(TW)), OS,
35                                  Endian == support::little);
36   case Triple::MachO:
37     return createMachObjectWriter(cast<MCMachObjectTargetWriter>(std::move(TW)),
38                                   OS, Endian == support::little);
39   case Triple::COFF:
40     return createWinCOFFObjectWriter(
41         cast<MCWinCOFFObjectTargetWriter>(std::move(TW)), OS);
42   case Triple::Wasm:
43     return createWasmObjectWriter(cast<MCWasmObjectTargetWriter>(std::move(TW)),
44                                   OS);
45   case Triple::XCOFF:
46     return createXCOFFObjectWriter(
47         cast<MCXCOFFObjectTargetWriter>(std::move(TW)), OS);
48   default:
49     llvm_unreachable("unexpected object format");
50   }
51 }
52 
53 std::unique_ptr<MCObjectWriter>
54 MCAsmBackend::createDwoObjectWriter(raw_pwrite_stream &OS,
55                                     raw_pwrite_stream &DwoOS) const {
56   auto TW = createObjectTargetWriter();
57   if (TW->getFormat() != Triple::ELF)
58     report_fatal_error("dwo only supported with ELF");
59   return createELFDwoObjectWriter(cast<MCELFObjectTargetWriter>(std::move(TW)),
60                                   OS, DwoOS, Endian == support::little);
61 }
62 
63 Optional<MCFixupKind> MCAsmBackend::getFixupKind(StringRef Name) const {
64   return None;
65 }
66 
67 const MCFixupKindInfo &MCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
68   static const MCFixupKindInfo Builtins[] = {
69       {"FK_NONE", 0, 0, 0},
70       {"FK_Data_1", 0, 8, 0},
71       {"FK_Data_2", 0, 16, 0},
72       {"FK_Data_4", 0, 32, 0},
73       {"FK_Data_8", 0, 64, 0},
74       {"FK_Data_6b", 0, 6, 0},
75       {"FK_PCRel_1", 0, 8, MCFixupKindInfo::FKF_IsPCRel},
76       {"FK_PCRel_2", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
77       {"FK_PCRel_4", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
78       {"FK_PCRel_8", 0, 64, MCFixupKindInfo::FKF_IsPCRel},
79       {"FK_GPRel_1", 0, 8, 0},
80       {"FK_GPRel_2", 0, 16, 0},
81       {"FK_GPRel_4", 0, 32, 0},
82       {"FK_GPRel_8", 0, 64, 0},
83       {"FK_DTPRel_4", 0, 32, 0},
84       {"FK_DTPRel_8", 0, 64, 0},
85       {"FK_TPRel_4", 0, 32, 0},
86       {"FK_TPRel_8", 0, 64, 0},
87       {"FK_SecRel_1", 0, 8, 0},
88       {"FK_SecRel_2", 0, 16, 0},
89       {"FK_SecRel_4", 0, 32, 0},
90       {"FK_SecRel_8", 0, 64, 0},
91       {"FK_Data_Add_1", 0, 8, 0},
92       {"FK_Data_Add_2", 0, 16, 0},
93       {"FK_Data_Add_4", 0, 32, 0},
94       {"FK_Data_Add_8", 0, 64, 0},
95       {"FK_Data_Add_6b", 0, 6, 0},
96       {"FK_Data_Sub_1", 0, 8, 0},
97       {"FK_Data_Sub_2", 0, 16, 0},
98       {"FK_Data_Sub_4", 0, 32, 0},
99       {"FK_Data_Sub_8", 0, 64, 0},
100       {"FK_Data_Sub_6b", 0, 6, 0}};
101 
102   assert((size_t)Kind <= array_lengthof(Builtins) && "Unknown fixup kind");
103   return Builtins[Kind];
104 }
105 
106 bool MCAsmBackend::fixupNeedsRelaxationAdvanced(
107     const MCFixup &Fixup, bool Resolved, uint64_t Value,
108     const MCRelaxableFragment *DF, const MCAsmLayout &Layout,
109     const bool WasForced) const {
110   if (!Resolved)
111     return true;
112   return fixupNeedsRelaxation(Fixup, Value, DF, Layout);
113 }
114