| //===-- 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()); |
| } |
| |