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  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
29AArch64_MachoTargetObjectFile::AArch64_MachoTargetObjectFile()
30  : TargetLoweringObjectFileMachO() {
31  SupportGOTPCRelWithOffset = false;
32}
33
34const 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
55MCSymbol *AArch64_MachoTargetObjectFile::getCFIPersonalitySymbol(
56    const GlobalValue *GV, const TargetMachine &TM,
57    MachineModuleInfo *MMI) const {
58  return TM.getSymbol(GV);
59}
60
61const 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
76void 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