LLVM 19.0.0git
PPCTargetObjectFile.cpp
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1//===-- PPCTargetObjectFile.cpp - PPC 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
11#include "llvm/IR/Mangler.h"
12#include "llvm/MC/MCContext.h"
13#include "llvm/MC/MCExpr.h"
15
16using namespace llvm;
17
18void
19PPC64LinuxTargetObjectFile::
20Initialize(MCContext &Ctx, const TargetMachine &TM) {
22}
23
24MCSection *PPC64LinuxTargetObjectFile::SelectSectionForGlobal(
25 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
26 // Here override ReadOnlySection to DataRelROSection for PPC64 SVR4 ABI
27 // when we have a constant that contains global relocations. This is
28 // necessary because of this ABI's handling of pointers to functions in
29 // a shared library. The address of a function is actually the address
30 // of a function descriptor, which resides in the .opd section. Generated
31 // code uses the descriptor directly rather than going via the GOT as some
32 // other ABIs do, which means that initialized function pointers must
33 // reference the descriptor. The linker must convert copy relocs of
34 // pointers to functions in shared libraries into dynamic relocations,
35 // because of an ordering problem with initialization of copy relocs and
36 // PLT entries. The dynamic relocation will be initialized by the dynamic
37 // linker, so we must use DataRelROSection instead of ReadOnlySection.
38 // For more information, see the description of ELIMINATE_COPY_RELOCS in
39 // GNU ld.
40 if (Kind.isReadOnly()) {
41 const auto *GVar = dyn_cast<GlobalVariable>(GO);
42
43 if (GVar && GVar->isConstant() &&
44 GVar->getInitializer()->needsDynamicRelocation())
46 }
47
49}
50
51const MCExpr *PPC64LinuxTargetObjectFile::
52getDebugThreadLocalSymbol(const MCSymbol *Sym) const {
53 const MCExpr *Expr =
55 return MCBinaryExpr::createAdd(Expr,
57 getContext());
58}
59
Symbol * Sym
Definition: ELF_riscv.cpp:479
const char LLVMTargetMachineRef TM
static const MCBinaryExpr * createAdd(const MCExpr *LHS, const MCExpr *RHS, MCContext &Ctx)
Definition: MCExpr.h:536
static const MCConstantExpr * create(int64_t Value, MCContext &Ctx, bool PrintInHex=false, unsigned SizeInBytes=0)
Definition: MCExpr.cpp:194
Context object for machine code objects.
Definition: MCContext.h:82
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:35
MCContext & getContext() const
Instances of this class represent a uniqued identifier for a section in the current translation unit.
Definition: MCSection.h:35
static const MCSymbolRefExpr * create(const MCSymbol *Symbol, MCContext &Ctx)
Definition: MCExpr.h:397
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:40
SectionKind - This is a simple POD value that classifies the properties of a section.
Definition: SectionKind.h:22
static SectionKind getReadOnlyWithRel()
Definition: SectionKind.h:214
void Initialize(MCContext &Ctx, const TargetMachine &TM) override
This method must be called before any actual lowering is done.
MCSection * SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const override
Primary interface to the complete machine description for the target machine.
Definition: TargetMachine.h:76
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18