forked from OSchip/llvm-project
68 lines
2.6 KiB
C++
68 lines
2.6 KiB
C++
//===-- PPCTargetObjectFile.cpp - PPC Object Info -------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "PPCTargetObjectFile.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCExpr.h"
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#include "llvm/MC/MCSectionELF.h"
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#include "llvm/Target/Mangler.h"
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using namespace llvm;
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void
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PPC64LinuxTargetObjectFile::
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Initialize(MCContext &Ctx, const TargetMachine &TM) {
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TargetLoweringObjectFileELF::Initialize(Ctx, TM);
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InitializeELF(TM.Options.UseInitArray);
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}
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const MCSection * PPC64LinuxTargetObjectFile::
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SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
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Mangler *Mang, const TargetMachine &TM) const {
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const MCSection *DefaultSection =
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TargetLoweringObjectFileELF::SelectSectionForGlobal(GV, Kind, Mang, TM);
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if (DefaultSection != ReadOnlySection)
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return DefaultSection;
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// Here override ReadOnlySection to DataRelROSection for PPC64 SVR4 ABI
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// when we have a constant that contains global relocations. This is
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// necessary because of this ABI's handling of pointers to functions in
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// a shared library. The address of a function is actually the address
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// of a function descriptor, which resides in the .opd section. Generated
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// code uses the descriptor directly rather than going via the GOT as some
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// other ABIs do, which means that initialized function pointers must
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// reference the descriptor. The linker must convert copy relocs of
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// pointers to functions in shared libraries into dynamic relocations,
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// because of an ordering problem with initialization of copy relocs and
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// PLT entries. The dynamic relocation will be initialized by the dynamic
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// linker, so we must use DataRelROSection instead of ReadOnlySection.
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// For more information, see the description of ELIMINATE_COPY_RELOCS in
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// GNU ld.
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const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
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if (GVar && GVar->isConstant() &&
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(GVar->getInitializer()->getRelocationInfo() ==
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Constant::GlobalRelocations))
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return DataRelROSection;
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return DefaultSection;
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}
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const MCExpr *PPC64LinuxTargetObjectFile::
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getDebugThreadLocalSymbol(const MCSymbol *Sym) const {
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const MCExpr *Expr =
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MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_PPC_DTPREL, getContext());
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return MCBinaryExpr::CreateAdd(Expr,
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MCConstantExpr::Create(0x8000, getContext()),
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getContext());
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}
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