1//===-- AArch64TargetObjectFile.cpp - AArch64 Object Info -----------------===//
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 "AArch64TargetObjectFile.h"
10#include "AArch64TargetMachine.h"
11#include "llvm/BinaryFormat/Dwarf.h"
12#include "llvm/IR/Mangler.h"
13#include "llvm/MC/MCContext.h"
14#include "llvm/MC/MCExpr.h"
15#include "llvm/MC/MCStreamer.h"
16#include "llvm/MC/MCValue.h"
17using namespace llvm;
18using namespace dwarf;
19
20void AArch64_ELFTargetObjectFile::Initialize(MCContext &Ctx,
21 const TargetMachine &TM) {
22 TargetLoweringObjectFileELF::Initialize(Ctx, TM);
23 // AARCH64 ELF ABI does not define static relocation type for TLS offset
24 // within a module. Do not generate AT_location for TLS variables.
25 SupportDebugThreadLocalLocation = false;
26}
27
28const MCExpr *AArch64_ELFTargetObjectFile::getIndirectSymViaGOTPCRel(
29 const GlobalValue *GV, const MCSymbol *Sym, const MCValue &MV,
30 int64_t Offset, MachineModuleInfo *MMI, MCStreamer &Streamer) const {
31 int64_t FinalOffset = Offset + MV.getConstant();
32 const MCExpr *Res =
33 MCSymbolRefExpr::create(Symbol: Sym, Kind: MCSymbolRefExpr::VK_GOTPCREL, Ctx&: getContext());
34 const MCExpr *Off = MCConstantExpr::create(Value: FinalOffset, Ctx&: getContext());
35 return MCBinaryExpr::createAdd(LHS: Res, RHS: Off, Ctx&: getContext());
36}
37
38AArch64_MachoTargetObjectFile::AArch64_MachoTargetObjectFile() {
39 SupportGOTPCRelWithOffset = false;
40}
41
42const MCExpr *AArch64_MachoTargetObjectFile::getTTypeGlobalReference(
43 const GlobalValue *GV, unsigned Encoding, const TargetMachine &TM,
44 MachineModuleInfo *MMI, MCStreamer &Streamer) const {
45 // On Darwin, we can reference dwarf symbols with foo@GOT-., which
46 // is an indirect pc-relative reference. The default implementation
47 // won't reference using the GOT, so we need this target-specific
48 // version.
49 if (Encoding & (DW_EH_PE_indirect | DW_EH_PE_pcrel)) {
50 const MCSymbol *Sym = TM.getSymbol(GV);
51 const MCExpr *Res =
52 MCSymbolRefExpr::create(Symbol: Sym, Kind: MCSymbolRefExpr::VK_GOT, Ctx&: getContext());
53 MCSymbol *PCSym = getContext().createTempSymbol();
54 Streamer.emitLabel(Symbol: PCSym);
55 const MCExpr *PC = MCSymbolRefExpr::create(Symbol: PCSym, Ctx&: getContext());
56 return MCBinaryExpr::createSub(LHS: Res, RHS: PC, Ctx&: getContext());
57 }
58
59 return TargetLoweringObjectFileMachO::getTTypeGlobalReference(
60 GV, Encoding, TM, MMI, Streamer);
61}
62
63MCSymbol *AArch64_MachoTargetObjectFile::getCFIPersonalitySymbol(
64 const GlobalValue *GV, const TargetMachine &TM,
65 MachineModuleInfo *MMI) const {
66 return TM.getSymbol(GV);
67}
68
69const MCExpr *AArch64_MachoTargetObjectFile::getIndirectSymViaGOTPCRel(
70 const GlobalValue *GV, const MCSymbol *Sym, const MCValue &MV,
71 int64_t Offset, MachineModuleInfo *MMI, MCStreamer &Streamer) const {
72 assert((Offset+MV.getConstant() == 0) &&
73 "Arch64 does not support GOT PC rel with extra offset");
74 // On ARM64 Darwin, we can reference symbols with foo@GOT-., which
75 // is an indirect pc-relative reference.
76 const MCExpr *Res =
77 MCSymbolRefExpr::create(Symbol: Sym, Kind: MCSymbolRefExpr::VK_GOT, Ctx&: getContext());
78 MCSymbol *PCSym = getContext().createTempSymbol();
79 Streamer.emitLabel(Symbol: PCSym);
80 const MCExpr *PC = MCSymbolRefExpr::create(Symbol: PCSym, Ctx&: getContext());
81 return MCBinaryExpr::createSub(LHS: Res, RHS: PC, Ctx&: getContext());
82}
83
84void AArch64_MachoTargetObjectFile::getNameWithPrefix(
85 SmallVectorImpl<char> &OutName, const GlobalValue *GV,
86 const TargetMachine &TM) const {
87 // AArch64 does not use section-relative relocations so any global symbol must
88 // be accessed via at least a linker-private symbol.
89 getMangler().getNameWithPrefix(OutName, GV, /* CannotUsePrivateLabel */ true);
90}
91

source code of llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp