forked from OSchip/llvm-project
678 lines
23 KiB
C++
678 lines
23 KiB
C++
//===- lib/MC/MCELFStreamer.cpp - ELF Object Output -----------------------===//
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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 assembles .s files and emits ELF .o object files.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/MC/MCELFStreamer.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/MC/MCAsmBackend.h"
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#include "llvm/MC/MCAsmLayout.h"
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#include "llvm/MC/MCAsmInfo.h"
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#include "llvm/MC/MCAssembler.h"
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#include "llvm/MC/MCCodeEmitter.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/MCInst.h"
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#include "llvm/MC/MCObjectFileInfo.h"
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#include "llvm/MC/MCObjectStreamer.h"
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#include "llvm/MC/MCSection.h"
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#include "llvm/MC/MCSectionELF.h"
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#include "llvm/MC/MCSymbolELF.h"
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#include "llvm/MC/MCSymbol.h"
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#include "llvm/MC/MCValue.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/ELF.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/TargetRegistry.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace llvm;
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bool MCELFStreamer::isBundleLocked() const {
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return getCurrentSectionOnly()->isBundleLocked();
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}
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MCELFStreamer::~MCELFStreamer() {
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}
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void MCELFStreamer::mergeFragment(MCDataFragment *DF,
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MCDataFragment *EF) {
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MCAssembler &Assembler = getAssembler();
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if (Assembler.isBundlingEnabled() && Assembler.getRelaxAll()) {
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uint64_t FSize = EF->getContents().size();
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if (FSize > Assembler.getBundleAlignSize())
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report_fatal_error("Fragment can't be larger than a bundle size");
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uint64_t RequiredBundlePadding = computeBundlePadding(
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Assembler, EF, DF->getContents().size(), FSize);
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if (RequiredBundlePadding > UINT8_MAX)
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report_fatal_error("Padding cannot exceed 255 bytes");
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if (RequiredBundlePadding > 0) {
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SmallString<256> Code;
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raw_svector_ostream VecOS(Code);
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MCObjectWriter *OW = Assembler.getBackend().createObjectWriter(VecOS);
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EF->setBundlePadding(static_cast<uint8_t>(RequiredBundlePadding));
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Assembler.writeFragmentPadding(*EF, FSize, OW);
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delete OW;
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DF->getContents().append(Code.begin(), Code.end());
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}
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}
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flushPendingLabels(DF, DF->getContents().size());
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for (unsigned i = 0, e = EF->getFixups().size(); i != e; ++i) {
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EF->getFixups()[i].setOffset(EF->getFixups()[i].getOffset() +
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DF->getContents().size());
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DF->getFixups().push_back(EF->getFixups()[i]);
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}
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DF->setHasInstructions(true);
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DF->getContents().append(EF->getContents().begin(), EF->getContents().end());
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}
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void MCELFStreamer::InitSections(bool NoExecStack) {
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MCContext &Ctx = getContext();
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SwitchSection(Ctx.getObjectFileInfo()->getTextSection());
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EmitCodeAlignment(4);
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if (NoExecStack)
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SwitchSection(Ctx.getAsmInfo()->getNonexecutableStackSection(Ctx));
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}
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void MCELFStreamer::EmitLabel(MCSymbol *S) {
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auto *Symbol = cast<MCSymbolELF>(S);
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assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
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MCObjectStreamer::EmitLabel(Symbol);
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const MCSectionELF &Section =
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static_cast<const MCSectionELF &>(*getCurrentSectionOnly());
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if (Section.getFlags() & ELF::SHF_TLS)
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Symbol->setType(ELF::STT_TLS);
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}
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void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
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// Let the target do whatever target specific stuff it needs to do.
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getAssembler().getBackend().handleAssemblerFlag(Flag);
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// Do any generic stuff we need to do.
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switch (Flag) {
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case MCAF_SyntaxUnified: return; // no-op here.
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case MCAF_Code16: return; // Change parsing mode; no-op here.
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case MCAF_Code32: return; // Change parsing mode; no-op here.
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case MCAF_Code64: return; // Change parsing mode; no-op here.
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case MCAF_SubsectionsViaSymbols:
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getAssembler().setSubsectionsViaSymbols(true);
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return;
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}
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llvm_unreachable("invalid assembler flag!");
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}
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// If bundle alignment is used and there are any instructions in the section, it
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// needs to be aligned to at least the bundle size.
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static void setSectionAlignmentForBundling(const MCAssembler &Assembler,
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MCSection *Section) {
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if (Section && Assembler.isBundlingEnabled() && Section->hasInstructions() &&
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Section->getAlignment() < Assembler.getBundleAlignSize())
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Section->setAlignment(Assembler.getBundleAlignSize());
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}
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void MCELFStreamer::ChangeSection(MCSection *Section,
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const MCExpr *Subsection) {
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MCSection *CurSection = getCurrentSectionOnly();
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if (CurSection && isBundleLocked())
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report_fatal_error("Unterminated .bundle_lock when changing a section");
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MCAssembler &Asm = getAssembler();
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// Ensure the previous section gets aligned if necessary.
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setSectionAlignmentForBundling(Asm, CurSection);
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auto *SectionELF = static_cast<const MCSectionELF *>(Section);
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const MCSymbol *Grp = SectionELF->getGroup();
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if (Grp)
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Asm.registerSymbol(*Grp);
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this->MCObjectStreamer::ChangeSection(Section, Subsection);
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MCContext &Ctx = getContext();
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auto *Begin = cast_or_null<MCSymbolELF>(Section->getBeginSymbol());
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if (!Begin) {
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Begin = Ctx.getOrCreateSectionSymbol(*SectionELF);
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Section->setBeginSymbol(Begin);
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}
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if (Begin->isUndefined()) {
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Asm.registerSymbol(*Begin);
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Begin->setType(ELF::STT_SECTION);
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}
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}
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void MCELFStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {
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getAssembler().registerSymbol(*Symbol);
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const MCExpr *Value = MCSymbolRefExpr::create(
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Symbol, MCSymbolRefExpr::VK_WEAKREF, getContext());
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Alias->setVariableValue(Value);
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}
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// When GNU as encounters more than one .type declaration for an object it seems
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// to use a mechanism similar to the one below to decide which type is actually
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// used in the object file. The greater of T1 and T2 is selected based on the
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// following ordering:
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// STT_NOTYPE < STT_OBJECT < STT_FUNC < STT_GNU_IFUNC < STT_TLS < anything else
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// If neither T1 < T2 nor T2 < T1 according to this ordering, use T2 (the user
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// provided type).
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static unsigned CombineSymbolTypes(unsigned T1, unsigned T2) {
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for (unsigned Type : {ELF::STT_NOTYPE, ELF::STT_OBJECT, ELF::STT_FUNC,
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ELF::STT_GNU_IFUNC, ELF::STT_TLS}) {
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if (T1 == Type)
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return T2;
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if (T2 == Type)
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return T1;
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}
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return T2;
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}
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bool MCELFStreamer::EmitSymbolAttribute(MCSymbol *S, MCSymbolAttr Attribute) {
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auto *Symbol = cast<MCSymbolELF>(S);
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// Indirect symbols are handled differently, to match how 'as' handles
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// them. This makes writing matching .o files easier.
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if (Attribute == MCSA_IndirectSymbol) {
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// Note that we intentionally cannot use the symbol data here; this is
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// important for matching the string table that 'as' generates.
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IndirectSymbolData ISD;
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ISD.Symbol = Symbol;
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ISD.Section = getCurrentSectionOnly();
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getAssembler().getIndirectSymbols().push_back(ISD);
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return true;
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}
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// Adding a symbol attribute always introduces the symbol, note that an
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// important side effect of calling registerSymbol here is to register
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// the symbol with the assembler.
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getAssembler().registerSymbol(*Symbol);
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// The implementation of symbol attributes is designed to match 'as', but it
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// leaves much to desired. It doesn't really make sense to arbitrarily add and
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// remove flags, but 'as' allows this (in particular, see .desc).
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//
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// In the future it might be worth trying to make these operations more well
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// defined.
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switch (Attribute) {
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case MCSA_LazyReference:
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case MCSA_Reference:
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case MCSA_SymbolResolver:
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case MCSA_PrivateExtern:
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case MCSA_WeakDefinition:
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case MCSA_WeakDefAutoPrivate:
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case MCSA_Invalid:
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case MCSA_IndirectSymbol:
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return false;
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case MCSA_NoDeadStrip:
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// Ignore for now.
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break;
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case MCSA_ELF_TypeGnuUniqueObject:
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Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_OBJECT));
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Symbol->setBinding(ELF::STB_GNU_UNIQUE);
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Symbol->setExternal(true);
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break;
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case MCSA_Global:
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Symbol->setBinding(ELF::STB_GLOBAL);
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Symbol->setExternal(true);
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break;
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case MCSA_WeakReference:
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case MCSA_Weak:
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Symbol->setBinding(ELF::STB_WEAK);
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Symbol->setExternal(true);
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break;
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case MCSA_Local:
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Symbol->setBinding(ELF::STB_LOCAL);
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Symbol->setExternal(false);
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break;
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case MCSA_ELF_TypeFunction:
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Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_FUNC));
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break;
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case MCSA_ELF_TypeIndFunction:
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Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_GNU_IFUNC));
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break;
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case MCSA_ELF_TypeObject:
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Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_OBJECT));
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break;
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case MCSA_ELF_TypeTLS:
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Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_TLS));
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break;
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case MCSA_ELF_TypeCommon:
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// TODO: Emit these as a common symbol.
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Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_OBJECT));
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break;
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case MCSA_ELF_TypeNoType:
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Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_NOTYPE));
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break;
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case MCSA_Protected:
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Symbol->setVisibility(ELF::STV_PROTECTED);
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break;
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case MCSA_Hidden:
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Symbol->setVisibility(ELF::STV_HIDDEN);
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break;
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case MCSA_Internal:
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Symbol->setVisibility(ELF::STV_INTERNAL);
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break;
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case MCSA_AltEntry:
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llvm_unreachable("ELF doesn't support the .alt_entry attribute");
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}
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return true;
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}
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void MCELFStreamer::EmitCommonSymbol(MCSymbol *S, uint64_t Size,
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unsigned ByteAlignment) {
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auto *Symbol = cast<MCSymbolELF>(S);
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getAssembler().registerSymbol(*Symbol);
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if (!Symbol->isBindingSet()) {
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Symbol->setBinding(ELF::STB_GLOBAL);
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Symbol->setExternal(true);
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}
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Symbol->setType(ELF::STT_OBJECT);
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if (Symbol->getBinding() == ELF::STB_LOCAL) {
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MCSection &Section = *getAssembler().getContext().getELFSection(
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".bss", ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
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MCSectionSubPair P = getCurrentSection();
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SwitchSection(&Section);
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EmitValueToAlignment(ByteAlignment, 0, 1, 0);
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EmitLabel(Symbol);
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EmitZeros(Size);
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// Update the maximum alignment of the section if necessary.
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if (ByteAlignment > Section.getAlignment())
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Section.setAlignment(ByteAlignment);
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SwitchSection(P.first, P.second);
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} else {
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if(Symbol->declareCommon(Size, ByteAlignment))
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report_fatal_error("Symbol: " + Symbol->getName() +
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" redeclared as different type");
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}
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cast<MCSymbolELF>(Symbol)
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->setSize(MCConstantExpr::create(Size, getContext()));
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}
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void MCELFStreamer::emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) {
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Symbol->setSize(Value);
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}
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void MCELFStreamer::EmitLocalCommonSymbol(MCSymbol *S, uint64_t Size,
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unsigned ByteAlignment) {
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auto *Symbol = cast<MCSymbolELF>(S);
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// FIXME: Should this be caught and done earlier?
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getAssembler().registerSymbol(*Symbol);
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Symbol->setBinding(ELF::STB_LOCAL);
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Symbol->setExternal(false);
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EmitCommonSymbol(Symbol, Size, ByteAlignment);
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}
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void MCELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
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SMLoc Loc) {
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if (isBundleLocked())
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report_fatal_error("Emitting values inside a locked bundle is forbidden");
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fixSymbolsInTLSFixups(Value);
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MCObjectStreamer::EmitValueImpl(Value, Size, Loc);
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}
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void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
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int64_t Value,
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unsigned ValueSize,
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unsigned MaxBytesToEmit) {
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if (isBundleLocked())
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report_fatal_error("Emitting values inside a locked bundle is forbidden");
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MCObjectStreamer::EmitValueToAlignment(ByteAlignment, Value,
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ValueSize, MaxBytesToEmit);
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}
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// Add a symbol for the file name of this module. They start after the
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// null symbol and don't count as normal symbol, i.e. a non-STT_FILE symbol
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// with the same name may appear.
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void MCELFStreamer::EmitFileDirective(StringRef Filename) {
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getAssembler().addFileName(Filename);
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}
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void MCELFStreamer::EmitIdent(StringRef IdentString) {
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MCSection *Comment = getAssembler().getContext().getELFSection(
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".comment", ELF::SHT_PROGBITS, ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
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PushSection();
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SwitchSection(Comment);
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if (!SeenIdent) {
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EmitIntValue(0, 1);
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SeenIdent = true;
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}
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EmitBytes(IdentString);
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EmitIntValue(0, 1);
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PopSection();
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}
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void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
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switch (expr->getKind()) {
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case MCExpr::Target:
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cast<MCTargetExpr>(expr)->fixELFSymbolsInTLSFixups(getAssembler());
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break;
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case MCExpr::Constant:
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break;
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case MCExpr::Binary: {
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const MCBinaryExpr *be = cast<MCBinaryExpr>(expr);
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fixSymbolsInTLSFixups(be->getLHS());
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fixSymbolsInTLSFixups(be->getRHS());
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break;
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}
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case MCExpr::SymbolRef: {
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const MCSymbolRefExpr &symRef = *cast<MCSymbolRefExpr>(expr);
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switch (symRef.getKind()) {
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default:
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return;
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case MCSymbolRefExpr::VK_GOTTPOFF:
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case MCSymbolRefExpr::VK_INDNTPOFF:
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case MCSymbolRefExpr::VK_NTPOFF:
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case MCSymbolRefExpr::VK_GOTNTPOFF:
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case MCSymbolRefExpr::VK_TLSGD:
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case MCSymbolRefExpr::VK_TLSLD:
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case MCSymbolRefExpr::VK_TLSLDM:
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case MCSymbolRefExpr::VK_TPOFF:
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case MCSymbolRefExpr::VK_TPREL:
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case MCSymbolRefExpr::VK_DTPOFF:
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case MCSymbolRefExpr::VK_DTPREL:
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case MCSymbolRefExpr::VK_Mips_TLSGD:
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case MCSymbolRefExpr::VK_Mips_GOTTPREL:
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case MCSymbolRefExpr::VK_Mips_TPREL_HI:
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case MCSymbolRefExpr::VK_Mips_TPREL_LO:
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case MCSymbolRefExpr::VK_PPC_DTPMOD:
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case MCSymbolRefExpr::VK_PPC_TPREL_LO:
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case MCSymbolRefExpr::VK_PPC_TPREL_HI:
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case MCSymbolRefExpr::VK_PPC_TPREL_HA:
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case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER:
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case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA:
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case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST:
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case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA:
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case MCSymbolRefExpr::VK_PPC_DTPREL_LO:
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case MCSymbolRefExpr::VK_PPC_DTPREL_HI:
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case MCSymbolRefExpr::VK_PPC_DTPREL_HA:
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case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER:
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case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA:
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case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST:
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case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA:
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case MCSymbolRefExpr::VK_PPC_GOT_TPREL:
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case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO:
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case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI:
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case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA:
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case MCSymbolRefExpr::VK_PPC_GOT_DTPREL:
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case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO:
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case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI:
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case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA:
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case MCSymbolRefExpr::VK_PPC_TLS:
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case MCSymbolRefExpr::VK_PPC_GOT_TLSGD:
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case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO:
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case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI:
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case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA:
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case MCSymbolRefExpr::VK_PPC_TLSGD:
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case MCSymbolRefExpr::VK_PPC_GOT_TLSLD:
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case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO:
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case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI:
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case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA:
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case MCSymbolRefExpr::VK_PPC_TLSLD:
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break;
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}
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getAssembler().registerSymbol(symRef.getSymbol());
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cast<MCSymbolELF>(symRef.getSymbol()).setType(ELF::STT_TLS);
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break;
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}
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case MCExpr::Unary:
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fixSymbolsInTLSFixups(cast<MCUnaryExpr>(expr)->getSubExpr());
|
|
break;
|
|
}
|
|
}
|
|
|
|
void MCELFStreamer::EmitInstToFragment(const MCInst &Inst,
|
|
const MCSubtargetInfo &STI) {
|
|
this->MCObjectStreamer::EmitInstToFragment(Inst, STI);
|
|
MCRelaxableFragment &F = *cast<MCRelaxableFragment>(getCurrentFragment());
|
|
|
|
for (unsigned i = 0, e = F.getFixups().size(); i != e; ++i)
|
|
fixSymbolsInTLSFixups(F.getFixups()[i].getValue());
|
|
}
|
|
|
|
void MCELFStreamer::EmitInstToData(const MCInst &Inst,
|
|
const MCSubtargetInfo &STI) {
|
|
MCAssembler &Assembler = getAssembler();
|
|
SmallVector<MCFixup, 4> Fixups;
|
|
SmallString<256> Code;
|
|
raw_svector_ostream VecOS(Code);
|
|
Assembler.getEmitter().encodeInstruction(Inst, VecOS, Fixups, STI);
|
|
|
|
for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
|
|
fixSymbolsInTLSFixups(Fixups[i].getValue());
|
|
|
|
// There are several possibilities here:
|
|
//
|
|
// If bundling is disabled, append the encoded instruction to the current data
|
|
// fragment (or create a new such fragment if the current fragment is not a
|
|
// data fragment).
|
|
//
|
|
// If bundling is enabled:
|
|
// - If we're not in a bundle-locked group, emit the instruction into a
|
|
// fragment of its own. If there are no fixups registered for the
|
|
// instruction, emit a MCCompactEncodedInstFragment. Otherwise, emit a
|
|
// MCDataFragment.
|
|
// - If we're in a bundle-locked group, append the instruction to the current
|
|
// data fragment because we want all the instructions in a group to get into
|
|
// the same fragment. Be careful not to do that for the first instruction in
|
|
// the group, though.
|
|
MCDataFragment *DF;
|
|
|
|
if (Assembler.isBundlingEnabled()) {
|
|
MCSection &Sec = *getCurrentSectionOnly();
|
|
if (Assembler.getRelaxAll() && isBundleLocked())
|
|
// If the -mc-relax-all flag is used and we are bundle-locked, we re-use
|
|
// the current bundle group.
|
|
DF = BundleGroups.back();
|
|
else if (Assembler.getRelaxAll() && !isBundleLocked())
|
|
// When not in a bundle-locked group and the -mc-relax-all flag is used,
|
|
// we create a new temporary fragment which will be later merged into
|
|
// the current fragment.
|
|
DF = new MCDataFragment();
|
|
else if (isBundleLocked() && !Sec.isBundleGroupBeforeFirstInst())
|
|
// If we are bundle-locked, we re-use the current fragment.
|
|
// The bundle-locking directive ensures this is a new data fragment.
|
|
DF = cast<MCDataFragment>(getCurrentFragment());
|
|
else if (!isBundleLocked() && Fixups.size() == 0) {
|
|
// Optimize memory usage by emitting the instruction to a
|
|
// MCCompactEncodedInstFragment when not in a bundle-locked group and
|
|
// there are no fixups registered.
|
|
MCCompactEncodedInstFragment *CEIF = new MCCompactEncodedInstFragment();
|
|
insert(CEIF);
|
|
CEIF->getContents().append(Code.begin(), Code.end());
|
|
return;
|
|
} else {
|
|
DF = new MCDataFragment();
|
|
insert(DF);
|
|
}
|
|
if (Sec.getBundleLockState() == MCSection::BundleLockedAlignToEnd) {
|
|
// If this fragment is for a group marked "align_to_end", set a flag
|
|
// in the fragment. This can happen after the fragment has already been
|
|
// created if there are nested bundle_align groups and an inner one
|
|
// is the one marked align_to_end.
|
|
DF->setAlignToBundleEnd(true);
|
|
}
|
|
|
|
// We're now emitting an instruction in a bundle group, so this flag has
|
|
// to be turned off.
|
|
Sec.setBundleGroupBeforeFirstInst(false);
|
|
} else {
|
|
DF = getOrCreateDataFragment();
|
|
}
|
|
|
|
// Add the fixups and data.
|
|
for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
|
|
Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
|
|
DF->getFixups().push_back(Fixups[i]);
|
|
}
|
|
DF->setHasInstructions(true);
|
|
DF->getContents().append(Code.begin(), Code.end());
|
|
|
|
if (Assembler.isBundlingEnabled() && Assembler.getRelaxAll()) {
|
|
if (!isBundleLocked()) {
|
|
mergeFragment(getOrCreateDataFragment(), DF);
|
|
delete DF;
|
|
}
|
|
}
|
|
}
|
|
|
|
void MCELFStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
|
|
assert(AlignPow2 <= 30 && "Invalid bundle alignment");
|
|
MCAssembler &Assembler = getAssembler();
|
|
if (AlignPow2 > 0 && (Assembler.getBundleAlignSize() == 0 ||
|
|
Assembler.getBundleAlignSize() == 1U << AlignPow2))
|
|
Assembler.setBundleAlignSize(1U << AlignPow2);
|
|
else
|
|
report_fatal_error(".bundle_align_mode cannot be changed once set");
|
|
}
|
|
|
|
void MCELFStreamer::EmitBundleLock(bool AlignToEnd) {
|
|
MCSection &Sec = *getCurrentSectionOnly();
|
|
|
|
// Sanity checks
|
|
//
|
|
if (!getAssembler().isBundlingEnabled())
|
|
report_fatal_error(".bundle_lock forbidden when bundling is disabled");
|
|
|
|
if (!isBundleLocked())
|
|
Sec.setBundleGroupBeforeFirstInst(true);
|
|
|
|
if (getAssembler().getRelaxAll() && !isBundleLocked()) {
|
|
// TODO: drop the lock state and set directly in the fragment
|
|
MCDataFragment *DF = new MCDataFragment();
|
|
BundleGroups.push_back(DF);
|
|
}
|
|
|
|
Sec.setBundleLockState(AlignToEnd ? MCSection::BundleLockedAlignToEnd
|
|
: MCSection::BundleLocked);
|
|
}
|
|
|
|
void MCELFStreamer::EmitBundleUnlock() {
|
|
MCSection &Sec = *getCurrentSectionOnly();
|
|
|
|
// Sanity checks
|
|
if (!getAssembler().isBundlingEnabled())
|
|
report_fatal_error(".bundle_unlock forbidden when bundling is disabled");
|
|
else if (!isBundleLocked())
|
|
report_fatal_error(".bundle_unlock without matching lock");
|
|
else if (Sec.isBundleGroupBeforeFirstInst())
|
|
report_fatal_error("Empty bundle-locked group is forbidden");
|
|
|
|
// When the -mc-relax-all flag is used, we emit instructions to fragments
|
|
// stored on a stack. When the bundle unlock is emitted, we pop a fragment
|
|
// from the stack a merge it to the one below.
|
|
if (getAssembler().getRelaxAll()) {
|
|
assert(!BundleGroups.empty() && "There are no bundle groups");
|
|
MCDataFragment *DF = BundleGroups.back();
|
|
|
|
// FIXME: Use BundleGroups to track the lock state instead.
|
|
Sec.setBundleLockState(MCSection::NotBundleLocked);
|
|
|
|
// FIXME: Use more separate fragments for nested groups.
|
|
if (!isBundleLocked()) {
|
|
mergeFragment(getOrCreateDataFragment(), DF);
|
|
BundleGroups.pop_back();
|
|
delete DF;
|
|
}
|
|
|
|
if (Sec.getBundleLockState() != MCSection::BundleLockedAlignToEnd)
|
|
getOrCreateDataFragment()->setAlignToBundleEnd(false);
|
|
} else
|
|
Sec.setBundleLockState(MCSection::NotBundleLocked);
|
|
}
|
|
|
|
void MCELFStreamer::FinishImpl() {
|
|
// Ensure the last section gets aligned if necessary.
|
|
MCSection *CurSection = getCurrentSectionOnly();
|
|
setSectionAlignmentForBundling(getAssembler(), CurSection);
|
|
|
|
EmitFrames(nullptr);
|
|
|
|
this->MCObjectStreamer::FinishImpl();
|
|
}
|
|
|
|
MCStreamer *llvm::createELFStreamer(MCContext &Context, MCAsmBackend &MAB,
|
|
raw_pwrite_stream &OS, MCCodeEmitter *CE,
|
|
bool RelaxAll) {
|
|
MCELFStreamer *S = new MCELFStreamer(Context, MAB, OS, CE);
|
|
if (RelaxAll)
|
|
S->getAssembler().setRelaxAll(true);
|
|
return S;
|
|
}
|
|
|
|
void MCELFStreamer::EmitThumbFunc(MCSymbol *Func) {
|
|
llvm_unreachable("Generic ELF doesn't support this directive");
|
|
}
|
|
|
|
void MCELFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
|
|
llvm_unreachable("ELF doesn't support this directive");
|
|
}
|
|
|
|
void MCELFStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
|
|
llvm_unreachable("ELF doesn't support this directive");
|
|
}
|
|
|
|
void MCELFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
|
|
llvm_unreachable("ELF doesn't support this directive");
|
|
}
|
|
|
|
void MCELFStreamer::EmitCOFFSymbolType(int Type) {
|
|
llvm_unreachable("ELF doesn't support this directive");
|
|
}
|
|
|
|
void MCELFStreamer::EndCOFFSymbolDef() {
|
|
llvm_unreachable("ELF doesn't support this directive");
|
|
}
|
|
|
|
void MCELFStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
|
|
uint64_t Size, unsigned ByteAlignment) {
|
|
llvm_unreachable("ELF doesn't support this directive");
|
|
}
|
|
|
|
void MCELFStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
|
|
uint64_t Size, unsigned ByteAlignment) {
|
|
llvm_unreachable("ELF doesn't support this directive");
|
|
}
|