diff options
Diffstat (limited to 'llvm/lib/MC')
-rw-r--r-- | llvm/lib/MC/ELFObjectWriter.cpp | 74 | ||||
-rw-r--r-- | llvm/lib/MC/MCContext.cpp | 17 | ||||
-rw-r--r-- | llvm/lib/MC/MCELFStreamer.cpp | 13 |
3 files changed, 54 insertions, 50 deletions
diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp index 4577f0130ed..d77f03f5281 100644 --- a/llvm/lib/MC/ELFObjectWriter.cpp +++ b/llvm/lib/MC/ELFObjectWriter.cpp @@ -81,23 +81,13 @@ public: struct ELFRelocationEntry { uint64_t Offset; // Where is the relocation. - bool UseSymbol; // Relocate with a symbol, not the section. - union { - const MCSymbol *Symbol; // The symbol to relocate with. - const MCSectionData *Section; // The section to relocate with. - }; + const MCSymbol *Symbol; // The symbol to relocate with. unsigned Type; // The type of the relocation. uint64_t Addend; // The addend to use. ELFRelocationEntry(uint64_t Offset, const MCSymbol *Symbol, unsigned Type, uint64_t Addend) - : Offset(Offset), UseSymbol(true), Symbol(Symbol), Type(Type), - Addend(Addend) {} - - ELFRelocationEntry(uint64_t Offset, const MCSectionData *Section, - unsigned Type, uint64_t Addend) - : Offset(Offset), UseSymbol(false), Section(Section), Type(Type), - Addend(Addend) {} + : Offset(Offset), Symbol(Symbol), Type(Type), Addend(Addend) {} }; class ELFObjectWriter : public MCObjectWriter { @@ -137,6 +127,14 @@ class ELFObjectWriter : public MCObjectWriter { // Support lexicographic sorting. bool operator<(const ELFSymbolData &RHS) const { + unsigned LHSType = MCELF::GetType(*SymbolData); + unsigned RHSType = MCELF::GetType(*RHS.SymbolData); + if (LHSType == ELF::STT_SECTION && RHSType != ELF::STT_SECTION) + return false; + if (LHSType != ELF::STT_SECTION && RHSType == ELF::STT_SECTION) + return true; + if (LHSType == ELF::STT_SECTION && RHSType == ELF::STT_SECTION) + return SectionIndex < RHS.SectionIndex; return Name < RHS.Name; } }; @@ -651,22 +649,6 @@ void ELFObjectWriter::WriteSymbolTable(MCDataFragment *SymtabF, WriteSymbol(Writer, MSD, Layout); } - // Write out a symbol table entry for each regular section. - for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; - ++i) { - const MCSectionELF &Section = - static_cast<const MCSectionELF&>(i->getSection()); - if (Section.getType() == ELF::SHT_RELA || - Section.getType() == ELF::SHT_REL || - Section.getType() == ELF::SHT_STRTAB || - Section.getType() == ELF::SHT_SYMTAB || - Section.getType() == ELF::SHT_SYMTAB_SHNDX) - continue; - Writer.writeSymbol(0, ELF::STT_SECTION, 0, 0, ELF::STV_DEFAULT, - SectionIndexMap.lookup(&Section), false); - LastLocalSymbolIndex++; - } - for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i) { ELFSymbolData &MSD = ExternalSymbolData[i]; MCSymbolData &Data = *MSD.SymbolData; @@ -882,8 +864,11 @@ void ELFObjectWriter::RecordRelocation(const MCAssembler &Asm, if (!RelocateWithSymbol) { const MCSection *SecA = (SymA && !SymA->isUndefined()) ? &SymA->getSection() : nullptr; - const MCSectionData *SecAD = SecA ? &Asm.getSectionData(*SecA) : nullptr; - ELFRelocationEntry Rec(FixupOffset, SecAD, Type, Addend); + auto *ELFSec = cast_or_null<MCSectionELF>(SecA); + MCSymbol *SectionSymbol = + ELFSec ? Asm.getContext().GetOrCreateSymbol(ELFSec->getSectionName()) + : nullptr; + ELFRelocationEntry Rec(FixupOffset, SectionSymbol, Type, Addend); Relocations[FixupSection].push_back(Rec); return; } @@ -1061,7 +1046,10 @@ ELFObjectWriter::computeSymbolTable(MCAssembler &Asm, const MCAsmLayout &Layout, Buf += Name.substr(Pos + Skip); Name = Buf; } - MSD.Name = StrTabBuilder.add(Name); + + // Sections have their own string table + if (MCELF::GetType(SD) != ELF::STT_SECTION) + MSD.Name = StrTabBuilder.add(Name); if (MSD.SectionIndex == ELF::SHN_UNDEF) UndefinedSymbolData.push_back(MSD); @@ -1079,9 +1067,11 @@ ELFObjectWriter::computeSymbolTable(MCAssembler &Asm, const MCAsmLayout &Layout, for (auto i = Asm.file_names_begin(), e = Asm.file_names_end(); i != e; ++i) FileSymbolData.push_back(StrTabBuilder.getOffset(*i)); - for (ELFSymbolData& MSD : LocalSymbolData) - MSD.StringIndex = StrTabBuilder.getOffset(MSD.Name); - for (ELFSymbolData& MSD : ExternalSymbolData) + for (ELFSymbolData &MSD : LocalSymbolData) + MSD.StringIndex = MCELF::GetType(*MSD.SymbolData) == ELF::STT_SECTION + ? 0 + : StrTabBuilder.getOffset(MSD.Name); + for (ELFSymbolData &MSD : ExternalSymbolData) MSD.StringIndex = StrTabBuilder.getOffset(MSD.Name); for (ELFSymbolData& MSD : UndefinedSymbolData) MSD.StringIndex = StrTabBuilder.getOffset(MSD.Name); @@ -1097,8 +1087,6 @@ ELFObjectWriter::computeSymbolTable(MCAssembler &Asm, const MCAsmLayout &Layout, for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i) LocalSymbolData[i].SymbolData->setIndex(Index++); - Index += NumRegularSections; - for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i) ExternalSymbolData[i].SymbolData->setIndex(Index++); for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i) @@ -1354,18 +1342,8 @@ void ELFObjectWriter::WriteRelocationsFragment(const MCAssembler &Asm, for (unsigned i = 0, e = Relocs.size(); i != e; ++i) { const ELFRelocationEntry &Entry = Relocs[e - i - 1]; - - unsigned Index; - if (Entry.UseSymbol) { - Index = getSymbolIndexInSymbolTable(Asm, Entry.Symbol); - } else { - const MCSectionData *Sec = Entry.Section; - if (Sec) - Index = Sec->getOrdinal() + FileSymbolData.size() + - LocalSymbolData.size() + 1; - else - Index = 0; - } + unsigned Index = + Entry.Symbol ? getSymbolIndexInSymbolTable(Asm, Entry.Symbol) : 0; if (is64Bit()) { write(*F, Entry.Offset); diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp index 9d8a57e55f6..3ac8d658873 100644 --- a/llvm/lib/MC/MCContext.cpp +++ b/llvm/lib/MC/MCContext.cpp @@ -113,6 +113,23 @@ MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) { return Sym; } +MCSymbol *MCContext::getOrCreateSectionSymbol(const MCSectionELF &Section) { + MCSymbol *&Sym = SectionSymbols[&Section]; + if (Sym) + return Sym; + + StringRef Name = Section.getSectionName(); + StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name); + NameEntry->setValue(true); + Sym = new (*this) MCSymbol(NameEntry->getKey(), /*isTemporary*/ false); + + StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name); + if (!Entry.getValue()) + Entry.setValue(Sym); + + return Sym; +} + MCSymbol *MCContext::CreateSymbol(StringRef Name) { // Determine whether this is an assembler temporary or normal label, if used. bool isTemporary = false; diff --git a/llvm/lib/MC/MCELFStreamer.cpp b/llvm/lib/MC/MCELFStreamer.cpp index 4ef22d00224..bdc4a8410fb 100644 --- a/llvm/lib/MC/MCELFStreamer.cpp +++ b/llvm/lib/MC/MCELFStreamer.cpp @@ -92,10 +92,19 @@ void MCELFStreamer::ChangeSection(const MCSection *Section, MCSectionData *CurSection = getCurrentSectionData(); if (CurSection && CurSection->isBundleLocked()) report_fatal_error("Unterminated .bundle_lock when changing a section"); - const MCSymbol *Grp = static_cast<const MCSectionELF *>(Section)->getGroup(); + + MCAssembler &Asm = getAssembler(); + auto *SectionELF = static_cast<const MCSectionELF *>(Section); + const MCSymbol *Grp = SectionELF->getGroup(); if (Grp) - getAssembler().getOrCreateSymbolData(*Grp); + Asm.getOrCreateSymbolData(*Grp); + this->MCObjectStreamer::ChangeSection(Section, Subsection); + MCSymbol *SectionSymbol = getContext().getOrCreateSectionSymbol(*SectionELF); + if (SectionSymbol->isUndefined()) { + EmitLabel(SectionSymbol); + MCELF::SetType(Asm.getSymbolData(*SectionSymbol), ELF::STT_SECTION); + } } void MCELFStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) { |