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The new metadata is easier to manipulate than module flags. Differential Revision: https://reviews.llvm.org/D31349 llvm-svn: 305227
1337 lines
47 KiB
C++
1337 lines
47 KiB
C++
//===- llvm/CodeGen/TargetLoweringObjectFileImpl.cpp - Object File 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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//
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// This file implements classes used to handle lowerings specific to common
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// object file formats.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/ADT/Triple.h"
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#include "llvm/BinaryFormat/COFF.h"
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#include "llvm/BinaryFormat/Dwarf.h"
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#include "llvm/BinaryFormat/ELF.h"
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#include "llvm/BinaryFormat/MachO.h"
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#include "llvm/CodeGen/MachineModuleInfo.h"
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#include "llvm/CodeGen/MachineModuleInfoImpls.h"
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#include "llvm/IR/Comdat.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/DerivedTypes.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/GlobalAlias.h"
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#include "llvm/IR/GlobalObject.h"
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#include "llvm/IR/GlobalValue.h"
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#include "llvm/IR/GlobalVariable.h"
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#include "llvm/IR/Mangler.h"
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#include "llvm/IR/Metadata.h"
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#include "llvm/IR/Module.h"
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#include "llvm/IR/Type.h"
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#include "llvm/MC/MCAsmInfo.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/MCSectionCOFF.h"
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#include "llvm/MC/MCSectionELF.h"
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#include "llvm/MC/MCSectionMachO.h"
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#include "llvm/MC/MCSectionWasm.h"
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#include "llvm/MC/MCStreamer.h"
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#include "llvm/MC/MCSymbol.h"
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#include "llvm/MC/MCSymbolELF.h"
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#include "llvm/MC/MCValue.h"
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#include "llvm/MC/SectionKind.h"
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#include "llvm/ProfileData/InstrProf.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/CodeGen.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Target/TargetMachine.h"
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#include <cassert>
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#include <string>
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using namespace llvm;
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using namespace dwarf;
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static void GetObjCImageInfo(Module &M, unsigned &Version, unsigned &Flags,
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StringRef &Section) {
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SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
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M.getModuleFlagsMetadata(ModuleFlags);
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for (const auto &MFE: ModuleFlags) {
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// Ignore flags with 'Require' behaviour.
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if (MFE.Behavior == Module::Require)
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continue;
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StringRef Key = MFE.Key->getString();
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if (Key == "Objective-C Image Info Version") {
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Version = mdconst::extract<ConstantInt>(MFE.Val)->getZExtValue();
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} else if (Key == "Objective-C Garbage Collection" ||
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Key == "Objective-C GC Only" ||
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Key == "Objective-C Is Simulated" ||
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Key == "Objective-C Class Properties" ||
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Key == "Objective-C Image Swift Version") {
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Flags |= mdconst::extract<ConstantInt>(MFE.Val)->getZExtValue();
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} else if (Key == "Objective-C Image Info Section") {
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Section = cast<MDString>(MFE.Val)->getString();
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}
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}
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}
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//===----------------------------------------------------------------------===//
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// ELF
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//===----------------------------------------------------------------------===//
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void TargetLoweringObjectFileELF::emitModuleMetadata(
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MCStreamer &Streamer, Module &M, const TargetMachine &TM) const {
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unsigned Version = 0;
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unsigned Flags = 0;
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StringRef Section;
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GetObjCImageInfo(M, Version, Flags, Section);
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if (Section.empty())
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return;
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auto &C = getContext();
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auto *S = C.getELFSection(Section, ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
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Streamer.SwitchSection(S);
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Streamer.EmitLabel(C.getOrCreateSymbol(StringRef("OBJC_IMAGE_INFO")));
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Streamer.EmitIntValue(Version, 4);
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Streamer.EmitIntValue(Flags, 4);
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Streamer.AddBlankLine();
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}
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MCSymbol *TargetLoweringObjectFileELF::getCFIPersonalitySymbol(
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const GlobalValue *GV, const TargetMachine &TM,
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MachineModuleInfo *MMI) const {
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unsigned Encoding = getPersonalityEncoding();
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if ((Encoding & 0x80) == DW_EH_PE_indirect)
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return getContext().getOrCreateSymbol(StringRef("DW.ref.") +
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TM.getSymbol(GV)->getName());
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if ((Encoding & 0x70) == DW_EH_PE_absptr)
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return TM.getSymbol(GV);
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report_fatal_error("We do not support this DWARF encoding yet!");
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}
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void TargetLoweringObjectFileELF::emitPersonalityValue(
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MCStreamer &Streamer, const DataLayout &DL, const MCSymbol *Sym) const {
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SmallString<64> NameData("DW.ref.");
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NameData += Sym->getName();
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MCSymbolELF *Label =
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cast<MCSymbolELF>(getContext().getOrCreateSymbol(NameData));
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Streamer.EmitSymbolAttribute(Label, MCSA_Hidden);
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Streamer.EmitSymbolAttribute(Label, MCSA_Weak);
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unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_WRITE | ELF::SHF_GROUP;
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MCSection *Sec = getContext().getELFNamedSection(".data", Label->getName(),
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ELF::SHT_PROGBITS, Flags, 0);
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unsigned Size = DL.getPointerSize();
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Streamer.SwitchSection(Sec);
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Streamer.EmitValueToAlignment(DL.getPointerABIAlignment());
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Streamer.EmitSymbolAttribute(Label, MCSA_ELF_TypeObject);
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const MCExpr *E = MCConstantExpr::create(Size, getContext());
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Streamer.emitELFSize(Label, E);
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Streamer.EmitLabel(Label);
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Streamer.EmitSymbolValue(Sym, Size);
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}
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const MCExpr *TargetLoweringObjectFileELF::getTTypeGlobalReference(
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const GlobalValue *GV, unsigned Encoding, const TargetMachine &TM,
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MachineModuleInfo *MMI, MCStreamer &Streamer) const {
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if (Encoding & DW_EH_PE_indirect) {
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MachineModuleInfoELF &ELFMMI = MMI->getObjFileInfo<MachineModuleInfoELF>();
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MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, ".DW.stub", TM);
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// Add information about the stub reference to ELFMMI so that the stub
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// gets emitted by the asmprinter.
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MachineModuleInfoImpl::StubValueTy &StubSym = ELFMMI.getGVStubEntry(SSym);
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if (!StubSym.getPointer()) {
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MCSymbol *Sym = TM.getSymbol(GV);
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StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
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}
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return TargetLoweringObjectFile::
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getTTypeReference(MCSymbolRefExpr::create(SSym, getContext()),
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Encoding & ~DW_EH_PE_indirect, Streamer);
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}
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return TargetLoweringObjectFile::getTTypeGlobalReference(GV, Encoding, TM,
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MMI, Streamer);
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}
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static SectionKind
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getELFKindForNamedSection(StringRef Name, SectionKind K) {
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// N.B.: The defaults used in here are no the same ones used in MC.
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// We follow gcc, MC follows gas. For example, given ".section .eh_frame",
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// both gas and MC will produce a section with no flags. Given
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// section(".eh_frame") gcc will produce:
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//
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// .section .eh_frame,"a",@progbits
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if (Name == getInstrProfSectionName(IPSK_covmap, Triple::ELF,
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/*AddSegmentInfo=*/false))
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return SectionKind::getMetadata();
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if (Name.empty() || Name[0] != '.') return K;
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// Some lame default implementation based on some magic section names.
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if (Name == ".bss" ||
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Name.startswith(".bss.") ||
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Name.startswith(".gnu.linkonce.b.") ||
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Name.startswith(".llvm.linkonce.b.") ||
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Name == ".sbss" ||
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Name.startswith(".sbss.") ||
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Name.startswith(".gnu.linkonce.sb.") ||
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Name.startswith(".llvm.linkonce.sb."))
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return SectionKind::getBSS();
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if (Name == ".tdata" ||
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Name.startswith(".tdata.") ||
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Name.startswith(".gnu.linkonce.td.") ||
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Name.startswith(".llvm.linkonce.td."))
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return SectionKind::getThreadData();
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if (Name == ".tbss" ||
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Name.startswith(".tbss.") ||
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Name.startswith(".gnu.linkonce.tb.") ||
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Name.startswith(".llvm.linkonce.tb."))
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return SectionKind::getThreadBSS();
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return K;
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}
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static unsigned getELFSectionType(StringRef Name, SectionKind K) {
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// Use SHT_NOTE for section whose name starts with ".note" to allow
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// emitting ELF notes from C variable declaration.
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// See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77609
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if (Name.startswith(".note"))
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return ELF::SHT_NOTE;
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if (Name == ".init_array")
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return ELF::SHT_INIT_ARRAY;
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if (Name == ".fini_array")
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return ELF::SHT_FINI_ARRAY;
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if (Name == ".preinit_array")
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return ELF::SHT_PREINIT_ARRAY;
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if (K.isBSS() || K.isThreadBSS())
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return ELF::SHT_NOBITS;
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return ELF::SHT_PROGBITS;
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}
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static unsigned getELFSectionFlags(SectionKind K) {
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unsigned Flags = 0;
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if (!K.isMetadata())
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Flags |= ELF::SHF_ALLOC;
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if (K.isText())
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Flags |= ELF::SHF_EXECINSTR;
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if (K.isExecuteOnly())
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Flags |= ELF::SHF_ARM_PURECODE;
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if (K.isWriteable())
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Flags |= ELF::SHF_WRITE;
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if (K.isThreadLocal())
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Flags |= ELF::SHF_TLS;
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if (K.isMergeableCString() || K.isMergeableConst())
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Flags |= ELF::SHF_MERGE;
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if (K.isMergeableCString())
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Flags |= ELF::SHF_STRINGS;
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return Flags;
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}
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static const Comdat *getELFComdat(const GlobalValue *GV) {
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const Comdat *C = GV->getComdat();
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if (!C)
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return nullptr;
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if (C->getSelectionKind() != Comdat::Any)
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report_fatal_error("ELF COMDATs only support SelectionKind::Any, '" +
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C->getName() + "' cannot be lowered.");
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return C;
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}
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static const MCSymbolELF *getAssociatedSymbol(const GlobalObject *GO,
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const TargetMachine &TM) {
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MDNode *MD = GO->getMetadata(LLVMContext::MD_associated);
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if (!MD)
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return nullptr;
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const MDOperand &Op = MD->getOperand(0);
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if (!Op.get())
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return nullptr;
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auto *VM = dyn_cast<ValueAsMetadata>(Op);
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if (!VM)
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report_fatal_error("MD_associated operand is not ValueAsMetadata");
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GlobalObject *OtherGO = dyn_cast<GlobalObject>(VM->getValue());
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return OtherGO ? dyn_cast<MCSymbolELF>(TM.getSymbol(OtherGO)) : nullptr;
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}
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MCSection *TargetLoweringObjectFileELF::getExplicitSectionGlobal(
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const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
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StringRef SectionName = GO->getSection();
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// Check if '#pragma clang section' name is applicable.
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// Note that pragma directive overrides -ffunction-section, -fdata-section
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// and so section name is exactly as user specified and not uniqued.
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const GlobalVariable *GV = dyn_cast<GlobalVariable>(GO);
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if (GV && GV->hasImplicitSection()) {
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auto Attrs = GV->getAttributes();
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if (Attrs.hasAttribute("bss-section") && Kind.isBSS()) {
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SectionName = Attrs.getAttribute("bss-section").getValueAsString();
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} else if (Attrs.hasAttribute("rodata-section") && Kind.isReadOnly()) {
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SectionName = Attrs.getAttribute("rodata-section").getValueAsString();
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} else if (Attrs.hasAttribute("data-section") && Kind.isData()) {
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SectionName = Attrs.getAttribute("data-section").getValueAsString();
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}
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}
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const Function *F = dyn_cast<Function>(GO);
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if (F && F->hasFnAttribute("implicit-section-name")) {
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SectionName = F->getFnAttribute("implicit-section-name").getValueAsString();
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}
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// Infer section flags from the section name if we can.
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Kind = getELFKindForNamedSection(SectionName, Kind);
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StringRef Group = "";
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unsigned Flags = getELFSectionFlags(Kind);
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if (const Comdat *C = getELFComdat(GO)) {
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Group = C->getName();
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Flags |= ELF::SHF_GROUP;
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}
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// A section can have at most one associated section. Put each global with
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// MD_associated in a unique section.
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unsigned UniqueID = MCContext::GenericSectionID;
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const MCSymbolELF *AssociatedSymbol = getAssociatedSymbol(GO, TM);
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if (AssociatedSymbol) {
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UniqueID = NextUniqueID++;
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Flags |= ELF::SHF_LINK_ORDER;
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}
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MCSectionELF *Section = getContext().getELFSection(
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SectionName, getELFSectionType(SectionName, Kind), Flags,
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/*EntrySize=*/0, Group, UniqueID, AssociatedSymbol);
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// Make sure that we did not get some other section with incompatible sh_link.
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// This should not be possible due to UniqueID code above.
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assert(Section->getAssociatedSymbol() == AssociatedSymbol);
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return Section;
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}
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/// Return the section prefix name used by options FunctionsSections and
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/// DataSections.
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static StringRef getSectionPrefixForGlobal(SectionKind Kind) {
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if (Kind.isText())
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return ".text";
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if (Kind.isReadOnly())
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return ".rodata";
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if (Kind.isBSS())
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return ".bss";
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if (Kind.isThreadData())
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return ".tdata";
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if (Kind.isThreadBSS())
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return ".tbss";
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if (Kind.isData())
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return ".data";
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assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
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return ".data.rel.ro";
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}
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static MCSectionELF *selectELFSectionForGlobal(
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MCContext &Ctx, const GlobalObject *GO, SectionKind Kind, Mangler &Mang,
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const TargetMachine &TM, bool EmitUniqueSection, unsigned Flags,
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unsigned *NextUniqueID, const MCSymbolELF *AssociatedSymbol) {
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unsigned EntrySize = 0;
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if (Kind.isMergeableCString()) {
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if (Kind.isMergeable2ByteCString()) {
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EntrySize = 2;
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} else if (Kind.isMergeable4ByteCString()) {
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EntrySize = 4;
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} else {
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EntrySize = 1;
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assert(Kind.isMergeable1ByteCString() && "unknown string width");
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}
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} else if (Kind.isMergeableConst()) {
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if (Kind.isMergeableConst4()) {
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EntrySize = 4;
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} else if (Kind.isMergeableConst8()) {
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EntrySize = 8;
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} else if (Kind.isMergeableConst16()) {
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EntrySize = 16;
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} else {
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assert(Kind.isMergeableConst32() && "unknown data width");
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EntrySize = 32;
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}
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}
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StringRef Group = "";
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if (const Comdat *C = getELFComdat(GO)) {
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Flags |= ELF::SHF_GROUP;
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Group = C->getName();
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}
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bool UniqueSectionNames = TM.getUniqueSectionNames();
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SmallString<128> Name;
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if (Kind.isMergeableCString()) {
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// We also need alignment here.
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// FIXME: this is getting the alignment of the character, not the
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// alignment of the global!
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unsigned Align = GO->getParent()->getDataLayout().getPreferredAlignment(
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cast<GlobalVariable>(GO));
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std::string SizeSpec = ".rodata.str" + utostr(EntrySize) + ".";
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Name = SizeSpec + utostr(Align);
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} else if (Kind.isMergeableConst()) {
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Name = ".rodata.cst";
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Name += utostr(EntrySize);
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} else {
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Name = getSectionPrefixForGlobal(Kind);
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}
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if (const auto *F = dyn_cast<Function>(GO)) {
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const auto &OptionalPrefix = F->getSectionPrefix();
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if (OptionalPrefix)
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Name += *OptionalPrefix;
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}
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if (EmitUniqueSection && UniqueSectionNames) {
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Name.push_back('.');
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TM.getNameWithPrefix(Name, GO, Mang, true);
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}
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unsigned UniqueID = MCContext::GenericSectionID;
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if (EmitUniqueSection && !UniqueSectionNames) {
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UniqueID = *NextUniqueID;
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(*NextUniqueID)++;
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}
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// Use 0 as the unique ID for execute-only text
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if (Kind.isExecuteOnly())
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UniqueID = 0;
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return Ctx.getELFSection(Name, getELFSectionType(Name, Kind), Flags,
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EntrySize, Group, UniqueID, AssociatedSymbol);
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}
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MCSection *TargetLoweringObjectFileELF::SelectSectionForGlobal(
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const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
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unsigned Flags = getELFSectionFlags(Kind);
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// If we have -ffunction-section or -fdata-section then we should emit the
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// global value to a uniqued section specifically for it.
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bool EmitUniqueSection = false;
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if (!(Flags & ELF::SHF_MERGE) && !Kind.isCommon()) {
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if (Kind.isText())
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EmitUniqueSection = TM.getFunctionSections();
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else
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EmitUniqueSection = TM.getDataSections();
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}
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EmitUniqueSection |= GO->hasComdat();
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const MCSymbolELF *AssociatedSymbol = getAssociatedSymbol(GO, TM);
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if (AssociatedSymbol) {
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EmitUniqueSection = true;
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Flags |= ELF::SHF_LINK_ORDER;
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}
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MCSectionELF *Section = selectELFSectionForGlobal(
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getContext(), GO, Kind, getMangler(), TM, EmitUniqueSection, Flags,
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&NextUniqueID, AssociatedSymbol);
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assert(Section->getAssociatedSymbol() == AssociatedSymbol);
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return Section;
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}
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MCSection *TargetLoweringObjectFileELF::getSectionForJumpTable(
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const Function &F, const TargetMachine &TM) const {
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// If the function can be removed, produce a unique section so that
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// the table doesn't prevent the removal.
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const Comdat *C = F.getComdat();
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bool EmitUniqueSection = TM.getFunctionSections() || C;
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if (!EmitUniqueSection)
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return ReadOnlySection;
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|
|
return selectELFSectionForGlobal(getContext(), &F, SectionKind::getReadOnly(),
|
|
getMangler(), TM, EmitUniqueSection,
|
|
ELF::SHF_ALLOC, &NextUniqueID,
|
|
/* AssociatedSymbol */ nullptr);
|
|
}
|
|
|
|
bool TargetLoweringObjectFileELF::shouldPutJumpTableInFunctionSection(
|
|
bool UsesLabelDifference, const Function &F) const {
|
|
// We can always create relative relocations, so use another section
|
|
// that can be marked non-executable.
|
|
return false;
|
|
}
|
|
|
|
/// Given a mergeable constant with the specified size and relocation
|
|
/// information, return a section that it should be placed in.
|
|
MCSection *TargetLoweringObjectFileELF::getSectionForConstant(
|
|
const DataLayout &DL, SectionKind Kind, const Constant *C,
|
|
unsigned &Align) const {
|
|
if (Kind.isMergeableConst4() && MergeableConst4Section)
|
|
return MergeableConst4Section;
|
|
if (Kind.isMergeableConst8() && MergeableConst8Section)
|
|
return MergeableConst8Section;
|
|
if (Kind.isMergeableConst16() && MergeableConst16Section)
|
|
return MergeableConst16Section;
|
|
if (Kind.isMergeableConst32() && MergeableConst32Section)
|
|
return MergeableConst32Section;
|
|
if (Kind.isReadOnly())
|
|
return ReadOnlySection;
|
|
|
|
assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
|
|
return DataRelROSection;
|
|
}
|
|
|
|
static MCSectionELF *getStaticStructorSection(MCContext &Ctx, bool UseInitArray,
|
|
bool IsCtor, unsigned Priority,
|
|
const MCSymbol *KeySym) {
|
|
std::string Name;
|
|
unsigned Type;
|
|
unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_WRITE;
|
|
StringRef COMDAT = KeySym ? KeySym->getName() : "";
|
|
|
|
if (KeySym)
|
|
Flags |= ELF::SHF_GROUP;
|
|
|
|
if (UseInitArray) {
|
|
if (IsCtor) {
|
|
Type = ELF::SHT_INIT_ARRAY;
|
|
Name = ".init_array";
|
|
} else {
|
|
Type = ELF::SHT_FINI_ARRAY;
|
|
Name = ".fini_array";
|
|
}
|
|
if (Priority != 65535) {
|
|
Name += '.';
|
|
Name += utostr(Priority);
|
|
}
|
|
} else {
|
|
// The default scheme is .ctor / .dtor, so we have to invert the priority
|
|
// numbering.
|
|
if (IsCtor)
|
|
Name = ".ctors";
|
|
else
|
|
Name = ".dtors";
|
|
if (Priority != 65535) {
|
|
Name += '.';
|
|
Name += utostr(65535 - Priority);
|
|
}
|
|
Type = ELF::SHT_PROGBITS;
|
|
}
|
|
|
|
return Ctx.getELFSection(Name, Type, Flags, 0, COMDAT);
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileELF::getStaticCtorSection(
|
|
unsigned Priority, const MCSymbol *KeySym) const {
|
|
return getStaticStructorSection(getContext(), UseInitArray, true, Priority,
|
|
KeySym);
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileELF::getStaticDtorSection(
|
|
unsigned Priority, const MCSymbol *KeySym) const {
|
|
return getStaticStructorSection(getContext(), UseInitArray, false, Priority,
|
|
KeySym);
|
|
}
|
|
|
|
const MCExpr *TargetLoweringObjectFileELF::lowerRelativeReference(
|
|
const GlobalValue *LHS, const GlobalValue *RHS,
|
|
const TargetMachine &TM) const {
|
|
// We may only use a PLT-relative relocation to refer to unnamed_addr
|
|
// functions.
|
|
if (!LHS->hasGlobalUnnamedAddr() || !LHS->getValueType()->isFunctionTy())
|
|
return nullptr;
|
|
|
|
// Basic sanity checks.
|
|
if (LHS->getType()->getPointerAddressSpace() != 0 ||
|
|
RHS->getType()->getPointerAddressSpace() != 0 || LHS->isThreadLocal() ||
|
|
RHS->isThreadLocal())
|
|
return nullptr;
|
|
|
|
return MCBinaryExpr::createSub(
|
|
MCSymbolRefExpr::create(TM.getSymbol(LHS), PLTRelativeVariantKind,
|
|
getContext()),
|
|
MCSymbolRefExpr::create(TM.getSymbol(RHS), getContext()), getContext());
|
|
}
|
|
|
|
void
|
|
TargetLoweringObjectFileELF::InitializeELF(bool UseInitArray_) {
|
|
UseInitArray = UseInitArray_;
|
|
MCContext &Ctx = getContext();
|
|
if (!UseInitArray) {
|
|
StaticCtorSection = Ctx.getELFSection(".ctors", ELF::SHT_PROGBITS,
|
|
ELF::SHF_ALLOC | ELF::SHF_WRITE);
|
|
|
|
StaticDtorSection = Ctx.getELFSection(".dtors", ELF::SHT_PROGBITS,
|
|
ELF::SHF_ALLOC | ELF::SHF_WRITE);
|
|
return;
|
|
}
|
|
|
|
StaticCtorSection = Ctx.getELFSection(".init_array", ELF::SHT_INIT_ARRAY,
|
|
ELF::SHF_WRITE | ELF::SHF_ALLOC);
|
|
StaticDtorSection = Ctx.getELFSection(".fini_array", ELF::SHT_FINI_ARRAY,
|
|
ELF::SHF_WRITE | ELF::SHF_ALLOC);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// MachO
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
TargetLoweringObjectFileMachO::TargetLoweringObjectFileMachO()
|
|
: TargetLoweringObjectFile() {
|
|
SupportIndirectSymViaGOTPCRel = true;
|
|
}
|
|
|
|
void TargetLoweringObjectFileMachO::Initialize(MCContext &Ctx,
|
|
const TargetMachine &TM) {
|
|
TargetLoweringObjectFile::Initialize(Ctx, TM);
|
|
if (TM.getRelocationModel() == Reloc::Static) {
|
|
StaticCtorSection = Ctx.getMachOSection("__TEXT", "__constructor", 0,
|
|
SectionKind::getData());
|
|
StaticDtorSection = Ctx.getMachOSection("__TEXT", "__destructor", 0,
|
|
SectionKind::getData());
|
|
} else {
|
|
StaticCtorSection = Ctx.getMachOSection("__DATA", "__mod_init_func",
|
|
MachO::S_MOD_INIT_FUNC_POINTERS,
|
|
SectionKind::getData());
|
|
StaticDtorSection = Ctx.getMachOSection("__DATA", "__mod_term_func",
|
|
MachO::S_MOD_TERM_FUNC_POINTERS,
|
|
SectionKind::getData());
|
|
}
|
|
}
|
|
|
|
void TargetLoweringObjectFileMachO::emitModuleMetadata(
|
|
MCStreamer &Streamer, Module &M, const TargetMachine &TM) const {
|
|
// Emit the linker options if present.
|
|
if (auto *LinkerOptions = M.getNamedMetadata("llvm.linker.options")) {
|
|
for (const auto &Option : LinkerOptions->operands()) {
|
|
SmallVector<std::string, 4> StrOptions;
|
|
for (const auto &Piece : cast<MDNode>(Option)->operands())
|
|
StrOptions.push_back(cast<MDString>(Piece)->getString());
|
|
Streamer.EmitLinkerOptions(StrOptions);
|
|
}
|
|
}
|
|
|
|
unsigned VersionVal = 0;
|
|
unsigned ImageInfoFlags = 0;
|
|
StringRef SectionVal;
|
|
|
|
GetObjCImageInfo(M, VersionVal, ImageInfoFlags, SectionVal);
|
|
|
|
// The section is mandatory. If we don't have it, then we don't have GC info.
|
|
if (SectionVal.empty())
|
|
return;
|
|
|
|
StringRef Segment, Section;
|
|
unsigned TAA = 0, StubSize = 0;
|
|
bool TAAParsed;
|
|
std::string ErrorCode =
|
|
MCSectionMachO::ParseSectionSpecifier(SectionVal, Segment, Section,
|
|
TAA, TAAParsed, StubSize);
|
|
if (!ErrorCode.empty())
|
|
// If invalid, report the error with report_fatal_error.
|
|
report_fatal_error("Invalid section specifier '" + Section + "': " +
|
|
ErrorCode + ".");
|
|
|
|
// Get the section.
|
|
MCSectionMachO *S = getContext().getMachOSection(
|
|
Segment, Section, TAA, StubSize, SectionKind::getData());
|
|
Streamer.SwitchSection(S);
|
|
Streamer.EmitLabel(getContext().
|
|
getOrCreateSymbol(StringRef("L_OBJC_IMAGE_INFO")));
|
|
Streamer.EmitIntValue(VersionVal, 4);
|
|
Streamer.EmitIntValue(ImageInfoFlags, 4);
|
|
Streamer.AddBlankLine();
|
|
}
|
|
|
|
static void checkMachOComdat(const GlobalValue *GV) {
|
|
const Comdat *C = GV->getComdat();
|
|
if (!C)
|
|
return;
|
|
|
|
report_fatal_error("MachO doesn't support COMDATs, '" + C->getName() +
|
|
"' cannot be lowered.");
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileMachO::getExplicitSectionGlobal(
|
|
const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
|
|
// Parse the section specifier and create it if valid.
|
|
StringRef Segment, Section;
|
|
unsigned TAA = 0, StubSize = 0;
|
|
bool TAAParsed;
|
|
|
|
checkMachOComdat(GO);
|
|
|
|
std::string ErrorCode =
|
|
MCSectionMachO::ParseSectionSpecifier(GO->getSection(), Segment, Section,
|
|
TAA, TAAParsed, StubSize);
|
|
if (!ErrorCode.empty()) {
|
|
// If invalid, report the error with report_fatal_error.
|
|
report_fatal_error("Global variable '" + GO->getName() +
|
|
"' has an invalid section specifier '" +
|
|
GO->getSection() + "': " + ErrorCode + ".");
|
|
}
|
|
|
|
// Get the section.
|
|
MCSectionMachO *S =
|
|
getContext().getMachOSection(Segment, Section, TAA, StubSize, Kind);
|
|
|
|
// If TAA wasn't set by ParseSectionSpecifier() above,
|
|
// use the value returned by getMachOSection() as a default.
|
|
if (!TAAParsed)
|
|
TAA = S->getTypeAndAttributes();
|
|
|
|
// Okay, now that we got the section, verify that the TAA & StubSize agree.
|
|
// If the user declared multiple globals with different section flags, we need
|
|
// to reject it here.
|
|
if (S->getTypeAndAttributes() != TAA || S->getStubSize() != StubSize) {
|
|
// If invalid, report the error with report_fatal_error.
|
|
report_fatal_error("Global variable '" + GO->getName() +
|
|
"' section type or attributes does not match previous"
|
|
" section specifier");
|
|
}
|
|
|
|
return S;
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileMachO::SelectSectionForGlobal(
|
|
const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
|
|
checkMachOComdat(GO);
|
|
|
|
// Handle thread local data.
|
|
if (Kind.isThreadBSS()) return TLSBSSSection;
|
|
if (Kind.isThreadData()) return TLSDataSection;
|
|
|
|
if (Kind.isText())
|
|
return GO->isWeakForLinker() ? TextCoalSection : TextSection;
|
|
|
|
// If this is weak/linkonce, put this in a coalescable section, either in text
|
|
// or data depending on if it is writable.
|
|
if (GO->isWeakForLinker()) {
|
|
if (Kind.isReadOnly())
|
|
return ConstTextCoalSection;
|
|
return DataCoalSection;
|
|
}
|
|
|
|
// FIXME: Alignment check should be handled by section classifier.
|
|
if (Kind.isMergeable1ByteCString() &&
|
|
GO->getParent()->getDataLayout().getPreferredAlignment(
|
|
cast<GlobalVariable>(GO)) < 32)
|
|
return CStringSection;
|
|
|
|
// Do not put 16-bit arrays in the UString section if they have an
|
|
// externally visible label, this runs into issues with certain linker
|
|
// versions.
|
|
if (Kind.isMergeable2ByteCString() && !GO->hasExternalLinkage() &&
|
|
GO->getParent()->getDataLayout().getPreferredAlignment(
|
|
cast<GlobalVariable>(GO)) < 32)
|
|
return UStringSection;
|
|
|
|
// With MachO only variables whose corresponding symbol starts with 'l' or
|
|
// 'L' can be merged, so we only try merging GVs with private linkage.
|
|
if (GO->hasPrivateLinkage() && Kind.isMergeableConst()) {
|
|
if (Kind.isMergeableConst4())
|
|
return FourByteConstantSection;
|
|
if (Kind.isMergeableConst8())
|
|
return EightByteConstantSection;
|
|
if (Kind.isMergeableConst16())
|
|
return SixteenByteConstantSection;
|
|
}
|
|
|
|
// Otherwise, if it is readonly, but not something we can specially optimize,
|
|
// just drop it in .const.
|
|
if (Kind.isReadOnly())
|
|
return ReadOnlySection;
|
|
|
|
// If this is marked const, put it into a const section. But if the dynamic
|
|
// linker needs to write to it, put it in the data segment.
|
|
if (Kind.isReadOnlyWithRel())
|
|
return ConstDataSection;
|
|
|
|
// Put zero initialized globals with strong external linkage in the
|
|
// DATA, __common section with the .zerofill directive.
|
|
if (Kind.isBSSExtern())
|
|
return DataCommonSection;
|
|
|
|
// Put zero initialized globals with local linkage in __DATA,__bss directive
|
|
// with the .zerofill directive (aka .lcomm).
|
|
if (Kind.isBSSLocal())
|
|
return DataBSSSection;
|
|
|
|
// Otherwise, just drop the variable in the normal data section.
|
|
return DataSection;
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileMachO::getSectionForConstant(
|
|
const DataLayout &DL, SectionKind Kind, const Constant *C,
|
|
unsigned &Align) const {
|
|
// If this constant requires a relocation, we have to put it in the data
|
|
// segment, not in the text segment.
|
|
if (Kind.isData() || Kind.isReadOnlyWithRel())
|
|
return ConstDataSection;
|
|
|
|
if (Kind.isMergeableConst4())
|
|
return FourByteConstantSection;
|
|
if (Kind.isMergeableConst8())
|
|
return EightByteConstantSection;
|
|
if (Kind.isMergeableConst16())
|
|
return SixteenByteConstantSection;
|
|
return ReadOnlySection; // .const
|
|
}
|
|
|
|
const MCExpr *TargetLoweringObjectFileMachO::getTTypeGlobalReference(
|
|
const GlobalValue *GV, unsigned Encoding, const TargetMachine &TM,
|
|
MachineModuleInfo *MMI, MCStreamer &Streamer) const {
|
|
// The mach-o version of this method defaults to returning a stub reference.
|
|
|
|
if (Encoding & DW_EH_PE_indirect) {
|
|
MachineModuleInfoMachO &MachOMMI =
|
|
MMI->getObjFileInfo<MachineModuleInfoMachO>();
|
|
|
|
MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr", TM);
|
|
|
|
// Add information about the stub reference to MachOMMI so that the stub
|
|
// gets emitted by the asmprinter.
|
|
MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(SSym);
|
|
if (!StubSym.getPointer()) {
|
|
MCSymbol *Sym = TM.getSymbol(GV);
|
|
StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
|
|
}
|
|
|
|
return TargetLoweringObjectFile::
|
|
getTTypeReference(MCSymbolRefExpr::create(SSym, getContext()),
|
|
Encoding & ~DW_EH_PE_indirect, Streamer);
|
|
}
|
|
|
|
return TargetLoweringObjectFile::getTTypeGlobalReference(GV, Encoding, TM,
|
|
MMI, Streamer);
|
|
}
|
|
|
|
MCSymbol *TargetLoweringObjectFileMachO::getCFIPersonalitySymbol(
|
|
const GlobalValue *GV, const TargetMachine &TM,
|
|
MachineModuleInfo *MMI) const {
|
|
// The mach-o version of this method defaults to returning a stub reference.
|
|
MachineModuleInfoMachO &MachOMMI =
|
|
MMI->getObjFileInfo<MachineModuleInfoMachO>();
|
|
|
|
MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr", TM);
|
|
|
|
// Add information about the stub reference to MachOMMI so that the stub
|
|
// gets emitted by the asmprinter.
|
|
MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(SSym);
|
|
if (!StubSym.getPointer()) {
|
|
MCSymbol *Sym = TM.getSymbol(GV);
|
|
StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
|
|
}
|
|
|
|
return SSym;
|
|
}
|
|
|
|
const MCExpr *TargetLoweringObjectFileMachO::getIndirectSymViaGOTPCRel(
|
|
const MCSymbol *Sym, const MCValue &MV, int64_t Offset,
|
|
MachineModuleInfo *MMI, MCStreamer &Streamer) const {
|
|
// Although MachO 32-bit targets do not explicitly have a GOTPCREL relocation
|
|
// as 64-bit do, we replace the GOT equivalent by accessing the final symbol
|
|
// through a non_lazy_ptr stub instead. One advantage is that it allows the
|
|
// computation of deltas to final external symbols. Example:
|
|
//
|
|
// _extgotequiv:
|
|
// .long _extfoo
|
|
//
|
|
// _delta:
|
|
// .long _extgotequiv-_delta
|
|
//
|
|
// is transformed to:
|
|
//
|
|
// _delta:
|
|
// .long L_extfoo$non_lazy_ptr-(_delta+0)
|
|
//
|
|
// .section __IMPORT,__pointers,non_lazy_symbol_pointers
|
|
// L_extfoo$non_lazy_ptr:
|
|
// .indirect_symbol _extfoo
|
|
// .long 0
|
|
//
|
|
MachineModuleInfoMachO &MachOMMI =
|
|
MMI->getObjFileInfo<MachineModuleInfoMachO>();
|
|
MCContext &Ctx = getContext();
|
|
|
|
// The offset must consider the original displacement from the base symbol
|
|
// since 32-bit targets don't have a GOTPCREL to fold the PC displacement.
|
|
Offset = -MV.getConstant();
|
|
const MCSymbol *BaseSym = &MV.getSymB()->getSymbol();
|
|
|
|
// Access the final symbol via sym$non_lazy_ptr and generate the appropriated
|
|
// non_lazy_ptr stubs.
|
|
SmallString<128> Name;
|
|
StringRef Suffix = "$non_lazy_ptr";
|
|
Name += MMI->getModule()->getDataLayout().getPrivateGlobalPrefix();
|
|
Name += Sym->getName();
|
|
Name += Suffix;
|
|
MCSymbol *Stub = Ctx.getOrCreateSymbol(Name);
|
|
|
|
MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(Stub);
|
|
if (!StubSym.getPointer())
|
|
StubSym = MachineModuleInfoImpl::
|
|
StubValueTy(const_cast<MCSymbol *>(Sym), true /* access indirectly */);
|
|
|
|
const MCExpr *BSymExpr =
|
|
MCSymbolRefExpr::create(BaseSym, MCSymbolRefExpr::VK_None, Ctx);
|
|
const MCExpr *LHS =
|
|
MCSymbolRefExpr::create(Stub, MCSymbolRefExpr::VK_None, Ctx);
|
|
|
|
if (!Offset)
|
|
return MCBinaryExpr::createSub(LHS, BSymExpr, Ctx);
|
|
|
|
const MCExpr *RHS =
|
|
MCBinaryExpr::createAdd(BSymExpr, MCConstantExpr::create(Offset, Ctx), Ctx);
|
|
return MCBinaryExpr::createSub(LHS, RHS, Ctx);
|
|
}
|
|
|
|
static bool canUsePrivateLabel(const MCAsmInfo &AsmInfo,
|
|
const MCSection &Section) {
|
|
if (!AsmInfo.isSectionAtomizableBySymbols(Section))
|
|
return true;
|
|
|
|
// If it is not dead stripped, it is safe to use private labels.
|
|
const MCSectionMachO &SMO = cast<MCSectionMachO>(Section);
|
|
if (SMO.hasAttribute(MachO::S_ATTR_NO_DEAD_STRIP))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
void TargetLoweringObjectFileMachO::getNameWithPrefix(
|
|
SmallVectorImpl<char> &OutName, const GlobalValue *GV,
|
|
const TargetMachine &TM) const {
|
|
bool CannotUsePrivateLabel = true;
|
|
if (auto *GO = GV->getBaseObject()) {
|
|
SectionKind GOKind = TargetLoweringObjectFile::getKindForGlobal(GO, TM);
|
|
const MCSection *TheSection = SectionForGlobal(GO, GOKind, TM);
|
|
CannotUsePrivateLabel =
|
|
!canUsePrivateLabel(*TM.getMCAsmInfo(), *TheSection);
|
|
}
|
|
getMangler().getNameWithPrefix(OutName, GV, CannotUsePrivateLabel);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// COFF
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
static unsigned
|
|
getCOFFSectionFlags(SectionKind K, const TargetMachine &TM) {
|
|
unsigned Flags = 0;
|
|
bool isThumb = TM.getTargetTriple().getArch() == Triple::thumb;
|
|
|
|
if (K.isMetadata())
|
|
Flags |=
|
|
COFF::IMAGE_SCN_MEM_DISCARDABLE;
|
|
else if (K.isText())
|
|
Flags |=
|
|
COFF::IMAGE_SCN_MEM_EXECUTE |
|
|
COFF::IMAGE_SCN_MEM_READ |
|
|
COFF::IMAGE_SCN_CNT_CODE |
|
|
(isThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0);
|
|
else if (K.isBSS())
|
|
Flags |=
|
|
COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
|
|
COFF::IMAGE_SCN_MEM_READ |
|
|
COFF::IMAGE_SCN_MEM_WRITE;
|
|
else if (K.isThreadLocal())
|
|
Flags |=
|
|
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
|
|
COFF::IMAGE_SCN_MEM_READ |
|
|
COFF::IMAGE_SCN_MEM_WRITE;
|
|
else if (K.isReadOnly() || K.isReadOnlyWithRel())
|
|
Flags |=
|
|
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
|
|
COFF::IMAGE_SCN_MEM_READ;
|
|
else if (K.isWriteable())
|
|
Flags |=
|
|
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
|
|
COFF::IMAGE_SCN_MEM_READ |
|
|
COFF::IMAGE_SCN_MEM_WRITE;
|
|
|
|
return Flags;
|
|
}
|
|
|
|
static const GlobalValue *getComdatGVForCOFF(const GlobalValue *GV) {
|
|
const Comdat *C = GV->getComdat();
|
|
assert(C && "expected GV to have a Comdat!");
|
|
|
|
StringRef ComdatGVName = C->getName();
|
|
const GlobalValue *ComdatGV = GV->getParent()->getNamedValue(ComdatGVName);
|
|
if (!ComdatGV)
|
|
report_fatal_error("Associative COMDAT symbol '" + ComdatGVName +
|
|
"' does not exist.");
|
|
|
|
if (ComdatGV->getComdat() != C)
|
|
report_fatal_error("Associative COMDAT symbol '" + ComdatGVName +
|
|
"' is not a key for its COMDAT.");
|
|
|
|
return ComdatGV;
|
|
}
|
|
|
|
static int getSelectionForCOFF(const GlobalValue *GV) {
|
|
if (const Comdat *C = GV->getComdat()) {
|
|
const GlobalValue *ComdatKey = getComdatGVForCOFF(GV);
|
|
if (const auto *GA = dyn_cast<GlobalAlias>(ComdatKey))
|
|
ComdatKey = GA->getBaseObject();
|
|
if (ComdatKey == GV) {
|
|
switch (C->getSelectionKind()) {
|
|
case Comdat::Any:
|
|
return COFF::IMAGE_COMDAT_SELECT_ANY;
|
|
case Comdat::ExactMatch:
|
|
return COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH;
|
|
case Comdat::Largest:
|
|
return COFF::IMAGE_COMDAT_SELECT_LARGEST;
|
|
case Comdat::NoDuplicates:
|
|
return COFF::IMAGE_COMDAT_SELECT_NODUPLICATES;
|
|
case Comdat::SameSize:
|
|
return COFF::IMAGE_COMDAT_SELECT_SAME_SIZE;
|
|
}
|
|
} else {
|
|
return COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileCOFF::getExplicitSectionGlobal(
|
|
const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
|
|
int Selection = 0;
|
|
unsigned Characteristics = getCOFFSectionFlags(Kind, TM);
|
|
StringRef Name = GO->getSection();
|
|
StringRef COMDATSymName = "";
|
|
if (GO->hasComdat()) {
|
|
Selection = getSelectionForCOFF(GO);
|
|
const GlobalValue *ComdatGV;
|
|
if (Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE)
|
|
ComdatGV = getComdatGVForCOFF(GO);
|
|
else
|
|
ComdatGV = GO;
|
|
|
|
if (!ComdatGV->hasPrivateLinkage()) {
|
|
MCSymbol *Sym = TM.getSymbol(ComdatGV);
|
|
COMDATSymName = Sym->getName();
|
|
Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
|
|
} else {
|
|
Selection = 0;
|
|
}
|
|
}
|
|
|
|
return getContext().getCOFFSection(Name, Characteristics, Kind, COMDATSymName,
|
|
Selection);
|
|
}
|
|
|
|
static const char *getCOFFSectionNameForUniqueGlobal(SectionKind Kind) {
|
|
if (Kind.isText())
|
|
return ".text";
|
|
if (Kind.isBSS())
|
|
return ".bss";
|
|
if (Kind.isThreadLocal())
|
|
return ".tls$";
|
|
if (Kind.isReadOnly() || Kind.isReadOnlyWithRel())
|
|
return ".rdata";
|
|
return ".data";
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileCOFF::SelectSectionForGlobal(
|
|
const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
|
|
// If we have -ffunction-sections then we should emit the global value to a
|
|
// uniqued section specifically for it.
|
|
bool EmitUniquedSection;
|
|
if (Kind.isText())
|
|
EmitUniquedSection = TM.getFunctionSections();
|
|
else
|
|
EmitUniquedSection = TM.getDataSections();
|
|
|
|
if ((EmitUniquedSection && !Kind.isCommon()) || GO->hasComdat()) {
|
|
const char *Name = getCOFFSectionNameForUniqueGlobal(Kind);
|
|
unsigned Characteristics = getCOFFSectionFlags(Kind, TM);
|
|
|
|
Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
|
|
int Selection = getSelectionForCOFF(GO);
|
|
if (!Selection)
|
|
Selection = COFF::IMAGE_COMDAT_SELECT_NODUPLICATES;
|
|
const GlobalValue *ComdatGV;
|
|
if (GO->hasComdat())
|
|
ComdatGV = getComdatGVForCOFF(GO);
|
|
else
|
|
ComdatGV = GO;
|
|
|
|
unsigned UniqueID = MCContext::GenericSectionID;
|
|
if (EmitUniquedSection)
|
|
UniqueID = NextUniqueID++;
|
|
|
|
if (!ComdatGV->hasPrivateLinkage()) {
|
|
MCSymbol *Sym = TM.getSymbol(ComdatGV);
|
|
StringRef COMDATSymName = Sym->getName();
|
|
return getContext().getCOFFSection(Name, Characteristics, Kind,
|
|
COMDATSymName, Selection, UniqueID);
|
|
} else {
|
|
SmallString<256> TmpData;
|
|
getMangler().getNameWithPrefix(TmpData, GO, /*CannotUsePrivateLabel=*/true);
|
|
return getContext().getCOFFSection(Name, Characteristics, Kind, TmpData,
|
|
Selection, UniqueID);
|
|
}
|
|
}
|
|
|
|
if (Kind.isText())
|
|
return TextSection;
|
|
|
|
if (Kind.isThreadLocal())
|
|
return TLSDataSection;
|
|
|
|
if (Kind.isReadOnly() || Kind.isReadOnlyWithRel())
|
|
return ReadOnlySection;
|
|
|
|
// Note: we claim that common symbols are put in BSSSection, but they are
|
|
// really emitted with the magic .comm directive, which creates a symbol table
|
|
// entry but not a section.
|
|
if (Kind.isBSS() || Kind.isCommon())
|
|
return BSSSection;
|
|
|
|
return DataSection;
|
|
}
|
|
|
|
void TargetLoweringObjectFileCOFF::getNameWithPrefix(
|
|
SmallVectorImpl<char> &OutName, const GlobalValue *GV,
|
|
const TargetMachine &TM) const {
|
|
bool CannotUsePrivateLabel = false;
|
|
if (GV->hasPrivateLinkage() &&
|
|
((isa<Function>(GV) && TM.getFunctionSections()) ||
|
|
(isa<GlobalVariable>(GV) && TM.getDataSections())))
|
|
CannotUsePrivateLabel = true;
|
|
|
|
getMangler().getNameWithPrefix(OutName, GV, CannotUsePrivateLabel);
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileCOFF::getSectionForJumpTable(
|
|
const Function &F, const TargetMachine &TM) const {
|
|
// If the function can be removed, produce a unique section so that
|
|
// the table doesn't prevent the removal.
|
|
const Comdat *C = F.getComdat();
|
|
bool EmitUniqueSection = TM.getFunctionSections() || C;
|
|
if (!EmitUniqueSection)
|
|
return ReadOnlySection;
|
|
|
|
// FIXME: we should produce a symbol for F instead.
|
|
if (F.hasPrivateLinkage())
|
|
return ReadOnlySection;
|
|
|
|
MCSymbol *Sym = TM.getSymbol(&F);
|
|
StringRef COMDATSymName = Sym->getName();
|
|
|
|
SectionKind Kind = SectionKind::getReadOnly();
|
|
const char *Name = getCOFFSectionNameForUniqueGlobal(Kind);
|
|
unsigned Characteristics = getCOFFSectionFlags(Kind, TM);
|
|
Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
|
|
unsigned UniqueID = NextUniqueID++;
|
|
|
|
return getContext().getCOFFSection(Name, Characteristics, Kind, COMDATSymName,
|
|
COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE, UniqueID);
|
|
}
|
|
|
|
void TargetLoweringObjectFileCOFF::emitModuleMetadata(
|
|
MCStreamer &Streamer, Module &M, const TargetMachine &TM) const {
|
|
if (NamedMDNode *LinkerOptions = M.getNamedMetadata("llvm.linker.options")) {
|
|
// Emit the linker options to the linker .drectve section. According to the
|
|
// spec, this section is a space-separated string containing flags for
|
|
// linker.
|
|
MCSection *Sec = getDrectveSection();
|
|
Streamer.SwitchSection(Sec);
|
|
for (const auto &Option : LinkerOptions->operands()) {
|
|
for (const auto &Piece : cast<MDNode>(Option)->operands()) {
|
|
// Lead with a space for consistency with our dllexport implementation.
|
|
std::string Directive(" ");
|
|
Directive.append(cast<MDString>(Piece)->getString());
|
|
Streamer.EmitBytes(Directive);
|
|
}
|
|
}
|
|
}
|
|
|
|
unsigned Version = 0;
|
|
unsigned Flags = 0;
|
|
StringRef Section;
|
|
|
|
GetObjCImageInfo(M, Version, Flags, Section);
|
|
if (Section.empty())
|
|
return;
|
|
|
|
auto &C = getContext();
|
|
auto *S = C.getCOFFSection(
|
|
Section, COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
|
|
SectionKind::getReadOnly());
|
|
Streamer.SwitchSection(S);
|
|
Streamer.EmitLabel(C.getOrCreateSymbol(StringRef("OBJC_IMAGE_INFO")));
|
|
Streamer.EmitIntValue(Version, 4);
|
|
Streamer.EmitIntValue(Flags, 4);
|
|
Streamer.AddBlankLine();
|
|
}
|
|
|
|
void TargetLoweringObjectFileCOFF::Initialize(MCContext &Ctx,
|
|
const TargetMachine &TM) {
|
|
TargetLoweringObjectFile::Initialize(Ctx, TM);
|
|
const Triple &T = TM.getTargetTriple();
|
|
if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
|
|
StaticCtorSection =
|
|
Ctx.getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
|
|
COFF::IMAGE_SCN_MEM_READ,
|
|
SectionKind::getReadOnly());
|
|
StaticDtorSection =
|
|
Ctx.getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
|
|
COFF::IMAGE_SCN_MEM_READ,
|
|
SectionKind::getReadOnly());
|
|
} else {
|
|
StaticCtorSection = Ctx.getCOFFSection(
|
|
".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
|
|
COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
|
|
SectionKind::getData());
|
|
StaticDtorSection = Ctx.getCOFFSection(
|
|
".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
|
|
COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
|
|
SectionKind::getData());
|
|
}
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileCOFF::getStaticCtorSection(
|
|
unsigned Priority, const MCSymbol *KeySym) const {
|
|
return getContext().getAssociativeCOFFSection(
|
|
cast<MCSectionCOFF>(StaticCtorSection), KeySym, 0);
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileCOFF::getStaticDtorSection(
|
|
unsigned Priority, const MCSymbol *KeySym) const {
|
|
return getContext().getAssociativeCOFFSection(
|
|
cast<MCSectionCOFF>(StaticDtorSection), KeySym, 0);
|
|
}
|
|
|
|
void TargetLoweringObjectFileCOFF::emitLinkerFlagsForGlobal(
|
|
raw_ostream &OS, const GlobalValue *GV) const {
|
|
emitLinkerFlagsForGlobalCOFF(OS, GV, getTargetTriple(), getMangler());
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Wasm
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
static const Comdat *getWasmComdat(const GlobalValue *GV) {
|
|
const Comdat *C = GV->getComdat();
|
|
if (!C)
|
|
return nullptr;
|
|
|
|
if (C->getSelectionKind() != Comdat::Any)
|
|
report_fatal_error("Wasm COMDATs only support SelectionKind::Any, '" +
|
|
C->getName() + "' cannot be lowered.");
|
|
|
|
return C;
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileWasm::getExplicitSectionGlobal(
|
|
const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
|
|
llvm_unreachable("getExplicitSectionGlobal not yet implemented");
|
|
return nullptr;
|
|
}
|
|
|
|
static MCSectionWasm *
|
|
selectWasmSectionForGlobal(MCContext &Ctx, const GlobalObject *GO,
|
|
SectionKind Kind, Mangler &Mang,
|
|
const TargetMachine &TM, bool EmitUniqueSection,
|
|
unsigned Flags, unsigned *NextUniqueID) {
|
|
StringRef Group = "";
|
|
if (getWasmComdat(GO))
|
|
llvm_unreachable("comdat not yet supported for wasm");
|
|
|
|
bool UniqueSectionNames = TM.getUniqueSectionNames();
|
|
SmallString<128> Name = getSectionPrefixForGlobal(Kind);
|
|
|
|
if (const auto *F = dyn_cast<Function>(GO)) {
|
|
const auto &OptionalPrefix = F->getSectionPrefix();
|
|
if (OptionalPrefix)
|
|
Name += *OptionalPrefix;
|
|
}
|
|
|
|
if (EmitUniqueSection && UniqueSectionNames) {
|
|
Name.push_back('.');
|
|
TM.getNameWithPrefix(Name, GO, Mang, true);
|
|
}
|
|
unsigned UniqueID = MCContext::GenericSectionID;
|
|
if (EmitUniqueSection && !UniqueSectionNames) {
|
|
UniqueID = *NextUniqueID;
|
|
(*NextUniqueID)++;
|
|
}
|
|
return Ctx.getWasmSection(Name, /*Type=*/0, Flags,
|
|
Group, UniqueID);
|
|
}
|
|
|
|
MCSection *TargetLoweringObjectFileWasm::SelectSectionForGlobal(
|
|
const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
|
|
|
|
if (Kind.isCommon())
|
|
report_fatal_error("mergable sections not supported yet on wasm");
|
|
|
|
// If we have -ffunction-section or -fdata-section then we should emit the
|
|
// global value to a uniqued section specifically for it.
|
|
bool EmitUniqueSection = false;
|
|
if (Kind.isText())
|
|
EmitUniqueSection = TM.getFunctionSections();
|
|
else
|
|
EmitUniqueSection = TM.getDataSections();
|
|
EmitUniqueSection |= GO->hasComdat();
|
|
|
|
return selectWasmSectionForGlobal(getContext(), GO, Kind, getMangler(), TM,
|
|
EmitUniqueSection, /*Flags=*/0,
|
|
&NextUniqueID);
|
|
}
|
|
|
|
bool TargetLoweringObjectFileWasm::shouldPutJumpTableInFunctionSection(
|
|
bool UsesLabelDifference, const Function &F) const {
|
|
// We can always create relative relocations, so use another section
|
|
// that can be marked non-executable.
|
|
return false;
|
|
}
|
|
|
|
const MCExpr *TargetLoweringObjectFileWasm::lowerRelativeReference(
|
|
const GlobalValue *LHS, const GlobalValue *RHS,
|
|
const TargetMachine &TM) const {
|
|
// We may only use a PLT-relative relocation to refer to unnamed_addr
|
|
// functions.
|
|
if (!LHS->hasGlobalUnnamedAddr() || !LHS->getValueType()->isFunctionTy())
|
|
return nullptr;
|
|
|
|
// Basic sanity checks.
|
|
if (LHS->getType()->getPointerAddressSpace() != 0 ||
|
|
RHS->getType()->getPointerAddressSpace() != 0 || LHS->isThreadLocal() ||
|
|
RHS->isThreadLocal())
|
|
return nullptr;
|
|
|
|
return MCBinaryExpr::createSub(
|
|
MCSymbolRefExpr::create(TM.getSymbol(LHS), MCSymbolRefExpr::VK_None,
|
|
getContext()),
|
|
MCSymbolRefExpr::create(TM.getSymbol(RHS), getContext()), getContext());
|
|
}
|
|
|
|
void
|
|
TargetLoweringObjectFileWasm::InitializeWasm() {
|
|
// TODO: Initialize StaticCtorSection and StaticDtorSection.
|
|
}
|