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"
17 using namespace llvm;
18 using namespace dwarf;
19
Initialize(MCContext & Ctx,const TargetMachine & TM)20 void AArch64_ELFTargetObjectFile::Initialize(MCContext &Ctx,
21 const TargetMachine &TM) {
22 TargetLoweringObjectFileELF::Initialize(Ctx, TM);
23 InitializeELF(TM.Options.UseInitArray);
24 // AARCH64 ELF ABI does not define static relocation type for TLS offset
25 // within a module. Do not generate AT_location for TLS variables.
26 SupportDebugThreadLocalLocation = false;
27 }
28
AArch64_MachoTargetObjectFile()29 AArch64_MachoTargetObjectFile::AArch64_MachoTargetObjectFile()
30 : TargetLoweringObjectFileMachO() {
31 SupportGOTPCRelWithOffset = false;
32 }
33
getTTypeGlobalReference(const GlobalValue * GV,unsigned Encoding,const TargetMachine & TM,MachineModuleInfo * MMI,MCStreamer & Streamer) const34 const MCExpr *AArch64_MachoTargetObjectFile::getTTypeGlobalReference(
35 const GlobalValue *GV, unsigned Encoding, const TargetMachine &TM,
36 MachineModuleInfo *MMI, MCStreamer &Streamer) const {
37 // On Darwin, we can reference dwarf symbols with foo@GOT-., which
38 // is an indirect pc-relative reference. The default implementation
39 // won't reference using the GOT, so we need this target-specific
40 // version.
41 if (Encoding & (DW_EH_PE_indirect | DW_EH_PE_pcrel)) {
42 const MCSymbol *Sym = TM.getSymbol(GV);
43 const MCExpr *Res =
44 MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOT, getContext());
45 MCSymbol *PCSym = getContext().createTempSymbol();
46 Streamer.EmitLabel(PCSym);
47 const MCExpr *PC = MCSymbolRefExpr::create(PCSym, getContext());
48 return MCBinaryExpr::createSub(Res, PC, getContext());
49 }
50
51 return TargetLoweringObjectFileMachO::getTTypeGlobalReference(
52 GV, Encoding, TM, MMI, Streamer);
53 }
54
getCFIPersonalitySymbol(const GlobalValue * GV,const TargetMachine & TM,MachineModuleInfo * MMI) const55 MCSymbol *AArch64_MachoTargetObjectFile::getCFIPersonalitySymbol(
56 const GlobalValue *GV, const TargetMachine &TM,
57 MachineModuleInfo *MMI) const {
58 return TM.getSymbol(GV);
59 }
60
getIndirectSymViaGOTPCRel(const GlobalValue * GV,const MCSymbol * Sym,const MCValue & MV,int64_t Offset,MachineModuleInfo * MMI,MCStreamer & Streamer) const61 const MCExpr *AArch64_MachoTargetObjectFile::getIndirectSymViaGOTPCRel(
62 const GlobalValue *GV, const MCSymbol *Sym, const MCValue &MV,
63 int64_t Offset, MachineModuleInfo *MMI, MCStreamer &Streamer) const {
64 assert((Offset+MV.getConstant() == 0) &&
65 "Arch64 does not support GOT PC rel with extra offset");
66 // On ARM64 Darwin, we can reference symbols with foo@GOT-., which
67 // is an indirect pc-relative reference.
68 const MCExpr *Res =
69 MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOT, getContext());
70 MCSymbol *PCSym = getContext().createTempSymbol();
71 Streamer.EmitLabel(PCSym);
72 const MCExpr *PC = MCSymbolRefExpr::create(PCSym, getContext());
73 return MCBinaryExpr::createSub(Res, PC, getContext());
74 }
75
getNameWithPrefix(SmallVectorImpl<char> & OutName,const GlobalValue * GV,const TargetMachine & TM) const76 void AArch64_MachoTargetObjectFile::getNameWithPrefix(
77 SmallVectorImpl<char> &OutName, const GlobalValue *GV,
78 const TargetMachine &TM) const {
79 // AArch64 does not use section-relative relocations so any global symbol must
80 // be accessed via at least a linker-private symbol.
81 getMangler().getNameWithPrefix(OutName, GV, /* CannotUsePrivateLabel */ true);
82 }
83