LLVM 17.0.0git
MCAsmBackend.cpp
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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
19#include <cassert>
20#include <cstddef>
21#include <cstdint>
22
23using namespace llvm;
24
26
28
29std::unique_ptr<MCObjectWriter>
31 auto TW = createObjectTargetWriter();
32 switch (TW->getFormat()) {
33 case Triple::ELF:
34 return createELFObjectWriter(cast<MCELFObjectTargetWriter>(std::move(TW)), OS,
36 case Triple::MachO:
37 return createMachObjectWriter(cast<MCMachObjectTargetWriter>(std::move(TW)),
38 OS, Endian == support::little);
39 case Triple::COFF:
41 cast<MCWinCOFFObjectTargetWriter>(std::move(TW)), OS);
42 case Triple::SPIRV:
44 cast<MCSPIRVObjectTargetWriter>(std::move(TW)), OS);
45 case Triple::Wasm:
46 return createWasmObjectWriter(cast<MCWasmObjectTargetWriter>(std::move(TW)),
47 OS);
48 case Triple::XCOFF:
50 cast<MCXCOFFObjectTargetWriter>(std::move(TW)), OS);
53 cast<MCDXContainerTargetWriter>(std::move(TW)), OS);
54 default:
55 llvm_unreachable("unexpected object format");
56 }
57}
58
59std::unique_ptr<MCObjectWriter>
61 raw_pwrite_stream &DwoOS) const {
62 auto TW = createObjectTargetWriter();
63 switch (TW->getFormat()) {
64 case Triple::ELF:
66 cast<MCELFObjectTargetWriter>(std::move(TW)), OS, DwoOS,
68 case Triple::Wasm:
70 cast<MCWasmObjectTargetWriter>(std::move(TW)), OS, DwoOS);
71 default:
72 report_fatal_error("dwo only supported with ELF and Wasm");
73 }
74}
75
76std::optional<MCFixupKind> MCAsmBackend::getFixupKind(StringRef Name) const {
77 return std::nullopt;
78}
79
81 static const MCFixupKindInfo Builtins[] = {
82 {"FK_NONE", 0, 0, 0},
83 {"FK_Data_1", 0, 8, 0},
84 {"FK_Data_2", 0, 16, 0},
85 {"FK_Data_4", 0, 32, 0},
86 {"FK_Data_8", 0, 64, 0},
87 {"FK_Data_6b", 0, 6, 0},
88 {"FK_PCRel_1", 0, 8, MCFixupKindInfo::FKF_IsPCRel},
89 {"FK_PCRel_2", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
90 {"FK_PCRel_4", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
91 {"FK_PCRel_8", 0, 64, MCFixupKindInfo::FKF_IsPCRel},
92 {"FK_GPRel_1", 0, 8, 0},
93 {"FK_GPRel_2", 0, 16, 0},
94 {"FK_GPRel_4", 0, 32, 0},
95 {"FK_GPRel_8", 0, 64, 0},
96 {"FK_DTPRel_4", 0, 32, 0},
97 {"FK_DTPRel_8", 0, 64, 0},
98 {"FK_TPRel_4", 0, 32, 0},
99 {"FK_TPRel_8", 0, 64, 0},
100 {"FK_SecRel_1", 0, 8, 0},
101 {"FK_SecRel_2", 0, 16, 0},
102 {"FK_SecRel_4", 0, 32, 0},
103 {"FK_SecRel_8", 0, 64, 0},
104 };
105
106 assert((size_t)Kind <= std::size(Builtins) && "Unknown fixup kind");
107 return Builtins[Kind];
108}
109
111 const MCFixup &Fixup, bool Resolved, uint64_t Value,
112 const MCRelaxableFragment *DF, const MCAsmLayout &Layout,
113 const bool WasForced) const {
114 if (!Resolved)
115 return true;
116 return fixupNeedsRelaxation(Fixup, Value, DF, Layout);
117}
static RegisterPass< DebugifyFunctionPass > DF("debugify-function", "Attach debug info to a function")
std::string Name
PowerPC TLS Dynamic Call Fixup
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
virtual bool fixupNeedsRelaxationAdvanced(const MCFixup &Fixup, bool Resolved, uint64_t Value, const MCRelaxableFragment *DF, const MCAsmLayout &Layout, const bool WasForced) const
Target specific predicate for whether a given fixup requires the associated instruction to be relaxed...
std::unique_ptr< MCObjectWriter > createObjectWriter(raw_pwrite_stream &OS) const
Create a new MCObjectWriter instance for use by the assembler backend to emit the final object file.
std::unique_ptr< MCObjectWriter > createDwoObjectWriter(raw_pwrite_stream &OS, raw_pwrite_stream &DwoOS) const
Create an MCObjectWriter that writes two object files: a .o file which is linked into the final progr...
virtual bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value, const MCRelaxableFragment *DF, const MCAsmLayout &Layout) const =0
Simple predicate for targets where !Resolved implies requiring relaxation.
virtual std::unique_ptr< MCObjectTargetWriter > createObjectTargetWriter() const =0
MCAsmBackend(support::endianness Endian)
virtual const MCFixupKindInfo & getFixupKindInfo(MCFixupKind Kind) const
Get information on a fixup kind.
virtual std::optional< MCFixupKind > getFixupKind(StringRef Name) const
Map a relocation name used in .reloc to a fixup kind.
const support::endianness Endian
Definition: MCAsmBackend.h:50
virtual ~MCAsmBackend()
Encapsulates the layout of an assembly file at a particular point in time.
Definition: MCAsmLayout.h:28
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:71
A relaxable fragment holds on to its MCInst, since it may need to be relaxed during the assembler lay...
Definition: MCFragment.h:270
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
@ DXContainer
Definition: Triple.h:283
LLVM Value Representation.
Definition: Value.h:74
An abstract base class for streams implementations that also support a pwrite operation.
Definition: raw_ostream.h:428
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
std::unique_ptr< MCObjectWriter > createELFObjectWriter(std::unique_ptr< MCELFObjectTargetWriter > MOTW, raw_pwrite_stream &OS, bool IsLittleEndian)
Construct a new ELF writer instance.
std::unique_ptr< MCObjectWriter > createMachObjectWriter(std::unique_ptr< MCMachObjectTargetWriter > MOTW, raw_pwrite_stream &OS, bool IsLittleEndian)
Construct a new Mach-O writer instance.
std::unique_ptr< MCObjectWriter > createDXContainerObjectWriter(std::unique_ptr< MCDXContainerTargetWriter > MOTW, raw_pwrite_stream &OS)
Construct a new DXContainer writer instance.
std::unique_ptr< MCObjectWriter > createELFDwoObjectWriter(std::unique_ptr< MCELFObjectTargetWriter > MOTW, raw_pwrite_stream &OS, raw_pwrite_stream &DwoOS, bool IsLittleEndian)
std::unique_ptr< MCObjectWriter > createWasmObjectWriter(std::unique_ptr< MCWasmObjectTargetWriter > MOTW, raw_pwrite_stream &OS)
Construct a new Wasm writer instance.
void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:145
MCFixupKind
Extensible enumeration to represent the type of a fixup.
Definition: MCFixup.h:21
std::unique_ptr< MCObjectWriter > createWinCOFFObjectWriter(std::unique_ptr< MCWinCOFFObjectTargetWriter > MOTW, raw_pwrite_stream &OS)
Construct a new Win COFF writer instance.
std::unique_ptr< MCObjectWriter > createSPIRVObjectWriter(std::unique_ptr< MCSPIRVObjectTargetWriter > MOTW, raw_pwrite_stream &OS)
Construct a new SPIR-V writer instance.
std::unique_ptr< MCObjectWriter > createXCOFFObjectWriter(std::unique_ptr< MCXCOFFObjectTargetWriter > MOTW, raw_pwrite_stream &OS)
std::unique_ptr< MCObjectWriter > createWasmDwoObjectWriter(std::unique_ptr< MCWasmObjectTargetWriter > MOTW, raw_pwrite_stream &OS, raw_pwrite_stream &DwoOS)
Target independent information on a fixup kind.
@ FKF_IsPCRel
Is this fixup kind PCrelative? This is used by the assembler backend to evaluate fixup values in a ta...