1 //===-- AArch64TargetObjectFile.cpp - AArch64 Object Info -----------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "AArch64TargetObjectFile.h"
11 #include "AArch64TargetMachine.h"
12 #include "llvm/BinaryFormat/Dwarf.h"
13 #include "llvm/IR/Mangler.h"
14 #include "llvm/MC/MCContext.h"
15 #include "llvm/MC/MCExpr.h"
16 #include "llvm/MC/MCStreamer.h"
17 #include "llvm/MC/MCValue.h"
18 using namespace llvm;
19 using namespace dwarf;
20
Initialize(MCContext & Ctx,const TargetMachine & TM)21 void AArch64_ELFTargetObjectFile::Initialize(MCContext &Ctx,
22 const TargetMachine &TM) {
23 TargetLoweringObjectFileELF::Initialize(Ctx, TM);
24 InitializeELF(TM.Options.UseInitArray);
25 // AARCH64 ELF ABI does not define static relocation type for TLS offset
26 // within a module. Do not generate AT_location for TLS variables.
27 SupportDebugThreadLocalLocation = false;
28 }
29
AArch64_MachoTargetObjectFile()30 AArch64_MachoTargetObjectFile::AArch64_MachoTargetObjectFile()
31 : TargetLoweringObjectFileMachO() {
32 SupportGOTPCRelWithOffset = false;
33 }
34
getTTypeGlobalReference(const GlobalValue * GV,unsigned Encoding,const TargetMachine & TM,MachineModuleInfo * MMI,MCStreamer & Streamer) const35 const MCExpr *AArch64_MachoTargetObjectFile::getTTypeGlobalReference(
36 const GlobalValue *GV, unsigned Encoding, const TargetMachine &TM,
37 MachineModuleInfo *MMI, MCStreamer &Streamer) const {
38 // On Darwin, we can reference dwarf symbols with foo@GOT-., which
39 // is an indirect pc-relative reference. The default implementation
40 // won't reference using the GOT, so we need this target-specific
41 // version.
42 if (Encoding & (DW_EH_PE_indirect | DW_EH_PE_pcrel)) {
43 const MCSymbol *Sym = TM.getSymbol(GV);
44 const MCExpr *Res =
45 MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOT, getContext());
46 MCSymbol *PCSym = getContext().createTempSymbol();
47 Streamer.EmitLabel(PCSym);
48 const MCExpr *PC = MCSymbolRefExpr::create(PCSym, getContext());
49 return MCBinaryExpr::createSub(Res, PC, getContext());
50 }
51
52 return TargetLoweringObjectFileMachO::getTTypeGlobalReference(
53 GV, Encoding, TM, MMI, Streamer);
54 }
55
getCFIPersonalitySymbol(const GlobalValue * GV,const TargetMachine & TM,MachineModuleInfo * MMI) const56 MCSymbol *AArch64_MachoTargetObjectFile::getCFIPersonalitySymbol(
57 const GlobalValue *GV, const TargetMachine &TM,
58 MachineModuleInfo *MMI) const {
59 return TM.getSymbol(GV);
60 }
61
getIndirectSymViaGOTPCRel(const MCSymbol * Sym,const MCValue & MV,int64_t Offset,MachineModuleInfo * MMI,MCStreamer & Streamer) const62 const MCExpr *AArch64_MachoTargetObjectFile::getIndirectSymViaGOTPCRel(
63 const MCSymbol *Sym, const MCValue &MV, int64_t Offset,
64 MachineModuleInfo *MMI, MCStreamer &Streamer) const {
65 assert((Offset+MV.getConstant() == 0) &&
66 "Arch64 does not support GOT PC rel with extra offset");
67 // On ARM64 Darwin, we can reference symbols with foo@GOT-., which
68 // is an indirect pc-relative reference.
69 const MCExpr *Res =
70 MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOT, getContext());
71 MCSymbol *PCSym = getContext().createTempSymbol();
72 Streamer.EmitLabel(PCSym);
73 const MCExpr *PC = MCSymbolRefExpr::create(PCSym, getContext());
74 return MCBinaryExpr::createSub(Res, PC, getContext());
75 }
76
getNameWithPrefix(SmallVectorImpl<char> & OutName,const GlobalValue * GV,const TargetMachine & TM) const77 void AArch64_MachoTargetObjectFile::getNameWithPrefix(
78 SmallVectorImpl<char> &OutName, const GlobalValue *GV,
79 const TargetMachine &TM) const {
80 // AArch64 does not use section-relative relocations so any global symbol must
81 // be accessed via at least a linker-private symbol.
82 getMangler().getNameWithPrefix(OutName, GV, /* CannotUsePrivateLabel */ true);
83 }
84