llvm-6502/lib/Target/AArch64/AArch64TargetObjectFile.cpp
Bruno Cardoso Lopes dfc6383227 [AsmPrinter][TLOF] 32-bit MachO support for replacing GOT equivalents
Add MachO 32-bit (i.e. arm and x86) support for replacing global GOT equivalent
symbol accesses. Unlike 64-bit targets, there's no GOTPCREL relocation, and
access through a non_lazy_symbol_pointers section is used instead.

-- before

    _extgotequiv:
       .long _extfoo

    _delta:
       .long _extgotequiv-_delta

-- after

    _delta:
       .long L_extfoo$non_lazy_ptr-_delta

       .section __IMPORT,__pointers,non_lazy_symbol_pointers
    L_extfoo$non_lazy_ptr:
       .indirect_symbol _extfoo
       .long 0

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231475 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 13:49:05 +00:00

74 lines
2.8 KiB
C++

//===-- AArch64TargetObjectFile.cpp - AArch64 Object Info -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "AArch64TargetObjectFile.h"
#include "AArch64TargetMachine.h"
#include "llvm/IR/Mangler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/Dwarf.h"
using namespace llvm;
using namespace dwarf;
void AArch64_ELFTargetObjectFile::Initialize(MCContext &Ctx,
const TargetMachine &TM) {
TargetLoweringObjectFileELF::Initialize(Ctx, TM);
InitializeELF(TM.Options.UseInitArray);
}
AArch64_MachoTargetObjectFile::AArch64_MachoTargetObjectFile()
: TargetLoweringObjectFileMachO() {
SupportGOTPCRelWithOffset = false;
}
const MCExpr *AArch64_MachoTargetObjectFile::getTTypeGlobalReference(
const GlobalValue *GV, unsigned Encoding, Mangler &Mang,
const TargetMachine &TM, MachineModuleInfo *MMI,
MCStreamer &Streamer) const {
// On Darwin, we can reference dwarf symbols with foo@GOT-., which
// is an indirect pc-relative reference. The default implementation
// won't reference using the GOT, so we need this target-specific
// version.
if (Encoding & (DW_EH_PE_indirect | DW_EH_PE_pcrel)) {
const MCSymbol *Sym = TM.getSymbol(GV, Mang);
const MCExpr *Res =
MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOT, getContext());
MCSymbol *PCSym = getContext().CreateTempSymbol();
Streamer.EmitLabel(PCSym);
const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, getContext());
return MCBinaryExpr::CreateSub(Res, PC, getContext());
}
return TargetLoweringObjectFileMachO::getTTypeGlobalReference(
GV, Encoding, Mang, TM, MMI, Streamer);
}
MCSymbol *AArch64_MachoTargetObjectFile::getCFIPersonalitySymbol(
const GlobalValue *GV, Mangler &Mang, const TargetMachine &TM,
MachineModuleInfo *MMI) const {
return TM.getSymbol(GV, Mang);
}
const MCExpr *AArch64_MachoTargetObjectFile::getIndirectSymViaGOTPCRel(
const MCSymbol *Sym, const MCValue &MV, int64_t Offset,
MachineModuleInfo *MMI, MCStreamer &Streamer) const {
assert((Offset+MV.getConstant() == 0) &&
"Arch64 does not support GOT PC rel with extra offset");
// On ARM64 Darwin, we can reference symbols with foo@GOT-., which
// is an indirect pc-relative reference.
const MCExpr *Res =
MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOT, getContext());
MCSymbol *PCSym = getContext().CreateTempSymbol();
Streamer.EmitLabel(PCSym);
const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, getContext());
return MCBinaryExpr::CreateSub(Res, PC, getContext());
}