forked from OSchip/llvm-project
60 lines
2.5 KiB
C++
60 lines
2.5 KiB
C++
//===-- PPCTargetObjectFile.cpp - PPC Object Info -------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "PPCTargetObjectFile.h"
|
|
#include "llvm/IR/GlobalVariable.h"
|
|
#include "llvm/IR/Mangler.h"
|
|
#include "llvm/MC/MCContext.h"
|
|
#include "llvm/MC/MCExpr.h"
|
|
#include "llvm/MC/MCSectionELF.h"
|
|
|
|
using namespace llvm;
|
|
|
|
void
|
|
PPC64LinuxTargetObjectFile::
|
|
Initialize(MCContext &Ctx, const TargetMachine &TM) {
|
|
TargetLoweringObjectFileELF::Initialize(Ctx, TM);
|
|
}
|
|
|
|
MCSection *PPC64LinuxTargetObjectFile::SelectSectionForGlobal(
|
|
const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
|
|
// Here override ReadOnlySection to DataRelROSection for PPC64 SVR4 ABI
|
|
// when we have a constant that contains global relocations. This is
|
|
// necessary because of this ABI's handling of pointers to functions in
|
|
// a shared library. The address of a function is actually the address
|
|
// of a function descriptor, which resides in the .opd section. Generated
|
|
// code uses the descriptor directly rather than going via the GOT as some
|
|
// other ABIs do, which means that initialized function pointers must
|
|
// reference the descriptor. The linker must convert copy relocs of
|
|
// pointers to functions in shared libraries into dynamic relocations,
|
|
// because of an ordering problem with initialization of copy relocs and
|
|
// PLT entries. The dynamic relocation will be initialized by the dynamic
|
|
// linker, so we must use DataRelROSection instead of ReadOnlySection.
|
|
// For more information, see the description of ELIMINATE_COPY_RELOCS in
|
|
// GNU ld.
|
|
if (Kind.isReadOnly()) {
|
|
const auto *GVar = dyn_cast<GlobalVariable>(GO);
|
|
|
|
if (GVar && GVar->isConstant() &&
|
|
GVar->getInitializer()->needsDynamicRelocation())
|
|
Kind = SectionKind::getReadOnlyWithRel();
|
|
}
|
|
|
|
return TargetLoweringObjectFileELF::SelectSectionForGlobal(GO, Kind, TM);
|
|
}
|
|
|
|
const MCExpr *PPC64LinuxTargetObjectFile::
|
|
getDebugThreadLocalSymbol(const MCSymbol *Sym) const {
|
|
const MCExpr *Expr =
|
|
MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_DTPREL, getContext());
|
|
return MCBinaryExpr::createAdd(Expr,
|
|
MCConstantExpr::create(0x8000, getContext()),
|
|
getContext());
|
|
}
|
|
|