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[ELF] Make InStruct members unique_ptr and remove associate make<XXX> 

See D116143 for benefits. My lld executable (x86-64) is 24+KiB smaller.
This commit is contained in:
Fangrui Song 2021-12-22 21:11:25 -08:00
parent 5c75cc51b3
commit d019de23a1
6 changed files with 71 additions and 64 deletions
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8
lld/ELF/InputFiles.cpp
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@ -878,8 +878,8 @@ InputSectionBase *ObjFile<ELFT>::createInputSection(uint32_t idx,
// to work. In a full implementation we would merge all attribute
// sections.
if (in.attributes == nullptr) {
in.attributes = make<InputSection>(*this, sec, name);
return in.attributes;
in.attributes = std::make_unique<InputSection>(*this, sec, name);
return in.attributes.get();
}
return &InputSection::discarded;
}
@ -900,8 +900,8 @@ InputSectionBase *ObjFile<ELFT>::createInputSection(uint32_t idx,
// standard extensions to enable. In a full implementation we would merge
// all attribute sections.
if (in.attributes == nullptr) {
in.attributes = make<InputSection>(*this, sec, name);
return in.attributes;
in.attributes = std::make_unique<InputSection>(*this, sec, name);
return in.attributes.get();
}
return &InputSection::discarded;
}

2
lld/ELF/LinkerScript.cpp
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@ -561,7 +561,7 @@ LinkerScript::computeInputSections(const InputSectionDescription *cmd,
}
void LinkerScript::discard(InputSectionBase &s) {
if (&s == in.shStrTab || &s == mainPart->relrDyn)
if (&s == in.shStrTab.get() || &s == mainPart->relrDyn)
error("discarding " + s.name + " section is not allowed");
// You can discard .hash and .gnu.hash sections by linker scripts. Since

8
lld/ELF/Relocations.cpp
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@ -870,7 +870,7 @@ static void addGotEntry(Symbol &sym) {
// If preemptible, emit a GLOB_DAT relocation.
if (sym.isPreemptible) {
mainPart->relaDyn->addReloc({target->gotRel, in.got, off,
mainPart->relaDyn->addReloc({target->gotRel, in.got.get(), off,
DynamicReloc::AgainstSymbol, sym, 0, R_ABS});
return;
}
@ -1205,8 +1205,8 @@ handleTlsRelocation(RelType type, Symbol &sym, InputSectionBase &c,
in.got->relocations.push_back(
{R_ADDEND, target->symbolicRel, in.got->getTlsIndexOff(), 1, &sym});
else
mainPart->relaDyn->addReloc(
{target->tlsModuleIndexRel, in.got, in.got->getTlsIndexOff()});
mainPart->relaDyn->addReloc({target->tlsModuleIndexRel, in.got.get(),
in.got->getTlsIndexOff()});
}
c.relocations.push_back({expr, type, offset, addend, &sym});
return 1;
@ -1592,7 +1592,7 @@ static bool handleNonPreemptibleIfunc(Symbol &sym) {
if (sym.hasDirectReloc) {
// Change the value to the IPLT and redirect all references to it.
auto &d = cast<Defined>(sym);
d.section = in.iplt;
d.section = in.iplt.get();
d.value = sym.pltIndex * target->ipltEntrySize;
d.size = 0;
// It's important to set the symbol type here so that dynamic loaders

9
lld/ELF/SyntheticSections.cpp
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@ -1636,11 +1636,11 @@ void RelocationBaseSection::finalizeContents() {
else
getParent()->link = 0;
if (in.relaPlt == this && in.gotPlt->getParent()) {
if (in.relaPlt.get() == this && in.gotPlt->getParent()) {
getParent()->flags |= ELF::SHF_INFO_LINK;
getParent()->info = in.gotPlt->getParent()->sectionIndex;
}
if (in.relaIplt == this && in.igotPlt->getParent()) {
if (in.relaIplt.get() == this && in.igotPlt->getParent()) {
getParent()->flags |= ELF::SHF_INFO_LINK;
getParent()->info = in.igotPlt->getParent()->sectionIndex;
}
@ -3801,8 +3801,9 @@ void PartitionIndexSection::writeTo(uint8_t *buf) {
write32(buf, mainPart->dynStrTab->getVA() + partitions[i].nameStrTab - va);
write32(buf + 4, partitions[i].elfHeader->getVA() - (va + 4));
SyntheticSection *next =
i == partitions.size() - 1 ? in.partEnd : partitions[i + 1].elfHeader;
SyntheticSection *next = i == partitions.size() - 1
? in.partEnd.get()
: partitions[i + 1].elfHeader;
write32(buf + 8, next->getVA() - partitions[i].elfHeader->getVA());
va += 12;

42
lld/ELF/SyntheticSections.h
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@ -1235,27 +1235,27 @@ inline Partition &SectionBase::getPartition() const {
// Linker generated sections which can be used as inputs and are not specific to
// a partition.
struct InStruct {
InputSection *attributes;
BssSection *bss;
BssSection *bssRelRo;
GotSection *got;
GotPltSection *gotPlt;
IgotPltSection *igotPlt;
PPC64LongBranchTargetSection *ppc64LongBranchTarget;
MipsGotSection *mipsGot;
MipsRldMapSection *mipsRldMap;
SyntheticSection *partEnd;
SyntheticSection *partIndex;
PltSection *plt;
IpltSection *iplt;
PPC32Got2Section *ppc32Got2;
IBTPltSection *ibtPlt;
RelocationBaseSection *relaPlt;
RelocationBaseSection *relaIplt;
StringTableSection *shStrTab;
StringTableSection *strTab;
SymbolTableBaseSection *symTab;
SymtabShndxSection *symTabShndx;
std::unique_ptr<InputSection> attributes;
std::unique_ptr<BssSection> bss;
std::unique_ptr<BssSection> bssRelRo;
std::unique_ptr<GotSection> got;
std::unique_ptr<GotPltSection> gotPlt;
std::unique_ptr<IgotPltSection> igotPlt;
std::unique_ptr<PPC64LongBranchTargetSection> ppc64LongBranchTarget;
std::unique_ptr<MipsGotSection> mipsGot;
std::unique_ptr<MipsRldMapSection> mipsRldMap;
std::unique_ptr<SyntheticSection> partEnd;
std::unique_ptr<SyntheticSection> partIndex;
std::unique_ptr<PltSection> plt;
std::unique_ptr<IpltSection> iplt;
std::unique_ptr<PPC32Got2Section> ppc32Got2;
std::unique_ptr<IBTPltSection> ibtPlt;
std::unique_ptr<RelocationBaseSection> relaPlt;
std::unique_ptr<RelocationBaseSection> relaIplt;
std::unique_ptr<StringTableSection> shStrTab;
std::unique_ptr<StringTableSection> strTab;
std::unique_ptr<SymbolTableBaseSection> symTab;
std::unique_ptr<SymtabShndxSection> symTabShndx;
};
extern InStruct in;

66
lld/ELF/Writer.cpp
View File

@ -299,18 +299,18 @@ template <class ELFT> void elf::createSyntheticSections() {
auto add = [](SyntheticSection &sec) { inputSections.push_back(&sec); };
in.shStrTab = make<StringTableSection>(".shstrtab", false);
in.shStrTab = std::make_unique<StringTableSection>(".shstrtab", false);
Out::programHeaders = make<OutputSection>("", 0, SHF_ALLOC);
Out::programHeaders->alignment = config->wordsize;
if (config->strip != StripPolicy::All) {
in.strTab = make<StringTableSection>(".strtab", false);
in.symTab = make<SymbolTableSection<ELFT>>(*in.strTab);
in.symTabShndx = make<SymtabShndxSection>();
in.strTab = std::make_unique<StringTableSection>(".strtab", false);
in.symTab = std::make_unique<SymbolTableSection<ELFT>>(*in.strTab);
in.symTabShndx = std::make_unique<SymtabShndxSection>();
}
in.bss = make<BssSection>(".bss", 0, 1);
in.bss = std::make_unique<BssSection>(".bss", 0, 1);
add(*in.bss);
// If there is a SECTIONS command and a .data.rel.ro section name use name
@ -318,14 +318,14 @@ template <class ELFT> void elf::createSyntheticSections() {
// This makes sure our relro is contiguous.
bool hasDataRelRo =
script->hasSectionsCommand && findSection(".data.rel.ro", 0);
in.bssRelRo =
make<BssSection>(hasDataRelRo ? ".data.rel.ro.bss" : ".bss.rel.ro", 0, 1);
in.bssRelRo = std::make_unique<BssSection>(
hasDataRelRo ? ".data.rel.ro.bss" : ".bss.rel.ro", 0, 1);
add(*in.bssRelRo);
// Add MIPS-specific sections.
if (config->emachine == EM_MIPS) {
if (!config->shared && config->hasDynSymTab) {
in.mipsRldMap = make<MipsRldMapSection>();
in.mipsRldMap = std::make_unique<MipsRldMapSection>();
add(*in.mipsRldMap);
}
if (auto *sec = MipsAbiFlagsSection<ELFT>::create())
@ -422,13 +422,14 @@ template <class ELFT> void elf::createSyntheticSections() {
// Create the partition end marker. This needs to be in partition number 255
// so that it is sorted after all other partitions. It also has other
// special handling (see createPhdrs() and combineEhSections()).
in.partEnd = make<BssSection>(".part.end", config->maxPageSize, 1);
in.partEnd =
std::make_unique<BssSection>(".part.end", config->maxPageSize, 1);
in.partEnd->partition = 255;
add(*in.partEnd);
in.partIndex = make<PartitionIndexSection>();
addOptionalRegular("__part_index_begin", in.partIndex, 0);
addOptionalRegular("__part_index_end", in.partIndex,
in.partIndex = std::make_unique<PartitionIndexSection>();
addOptionalRegular("__part_index_begin", in.partIndex.get(), 0);
addOptionalRegular("__part_index_end", in.partIndex.get(),
in.partIndex->getSize());
add(*in.partIndex);
}
@ -436,26 +437,26 @@ template <class ELFT> void elf::createSyntheticSections() {
// Add .got. MIPS' .got is so different from the other archs,
// it has its own class.
if (config->emachine == EM_MIPS) {
in.mipsGot = make<MipsGotSection>();
in.mipsGot = std::make_unique<MipsGotSection>();
add(*in.mipsGot);
} else {
in.got = make<GotSection>();
in.got = std::make_unique<GotSection>();
add(*in.got);
}
if (config->emachine == EM_PPC) {
in.ppc32Got2 = make<PPC32Got2Section>();
in.ppc32Got2 = std::make_unique<PPC32Got2Section>();
add(*in.ppc32Got2);
}
if (config->emachine == EM_PPC64) {
in.ppc64LongBranchTarget = make<PPC64LongBranchTargetSection>();
in.ppc64LongBranchTarget = std::make_unique<PPC64LongBranchTargetSection>();
add(*in.ppc64LongBranchTarget);
}
in.gotPlt = make<GotPltSection>();
in.gotPlt = std::make_unique<GotPltSection>();
add(*in.gotPlt);
in.igotPlt = make<IgotPltSection>();
in.igotPlt = std::make_unique<IgotPltSection>();
add(*in.igotPlt);
// _GLOBAL_OFFSET_TABLE_ is defined relative to either .got.plt or .got. Treat
@ -472,7 +473,7 @@ template <class ELFT> void elf::createSyntheticSections() {
// We always need to add rel[a].plt to output if it has entries.
// Even for static linking it can contain R_[*]_IRELATIVE relocations.
in.relaPlt = make<RelocationSection<ELFT>>(
in.relaPlt = std::make_unique<RelocationSection<ELFT>>(
config->isRela ? ".rela.plt" : ".rel.plt", /*sort=*/false);
add(*in.relaPlt);
@ -482,21 +483,23 @@ template <class ELFT> void elf::createSyntheticSections() {
// that would cause a section type mismatch. However, because the Android
// dynamic loader reads .rel.plt after .rel.dyn, we can get the desired
// behaviour by placing the iplt section in .rel.plt.
in.relaIplt = make<RelocationSection<ELFT>>(
in.relaIplt = std::make_unique<RelocationSection<ELFT>>(
config->androidPackDynRelocs ? in.relaPlt->name : relaDynName,
/*sort=*/false);
add(*in.relaIplt);
if ((config->emachine == EM_386 || config->emachine == EM_X86_64) &&
(config->andFeatures & GNU_PROPERTY_X86_FEATURE_1_IBT)) {
in.ibtPlt = make<IBTPltSection>();
in.ibtPlt = std::make_unique<IBTPltSection>();
add(*in.ibtPlt);
}
in.plt = config->emachine == EM_PPC ? make<PPC32GlinkSection>()
: make<PltSection>();
if (config->emachine == EM_PPC)
in.plt = std::make_unique<PPC32GlinkSection>();
else
in.plt = std::make_unique<PltSection>();
add(*in.plt);
in.iplt = make<IpltSection>();
in.iplt = std::make_unique<IpltSection>();
add(*in.iplt);
if (config->andFeatures)
@ -1066,17 +1069,17 @@ template <class ELFT> void Writer<ELFT>::setReservedSymbolSections() {
if (ElfSym::globalOffsetTable) {
// The _GLOBAL_OFFSET_TABLE_ symbol is defined by target convention usually
// to the start of the .got or .got.plt section.
InputSection *gotSection = in.gotPlt;
InputSection *sec = in.gotPlt.get();
if (!target->gotBaseSymInGotPlt)
gotSection = in.mipsGot ? cast<InputSection>(in.mipsGot)
: cast<InputSection>(in.got);
ElfSym::globalOffsetTable->section = gotSection;
sec = in.mipsGot.get() ? cast<InputSection>(in.mipsGot.get())
: cast<InputSection>(in.got.get());
ElfSym::globalOffsetTable->section = sec;
}
// .rela_iplt_{start,end} mark the start and the end of in.relaIplt.
if (ElfSym::relaIpltStart && in.relaIplt->isNeeded()) {
ElfSym::relaIpltStart->section = in.relaIplt;
ElfSym::relaIpltEnd->section = in.relaIplt;
ElfSym::relaIpltStart->section = in.relaIplt.get();
ElfSym::relaIpltEnd->section = in.relaIplt.get();
ElfSym::relaIpltEnd->value = in.relaIplt->getSize();
}
@ -1644,6 +1647,9 @@ static void finalizeSynthetic(SyntheticSection *sec) {
sec->finalizeContents();
}
}
template <typename T> static void finalizeSynthetic(std::unique_ptr<T> &sec) {
finalizeSynthetic(sec.get());
}
// We need to generate and finalize the content that depends on the address of
// InputSections. As the generation of the content may also alter InputSection