diff options
Diffstat (limited to 'lld/ELF/MarkLive.cpp')
-rw-r--r-- | lld/ELF/MarkLive.cpp | 242 |
1 files changed, 121 insertions, 121 deletions
diff --git a/lld/ELF/MarkLive.cpp b/lld/ELF/MarkLive.cpp index ef85075e4a3..1058c97cecc 100644 --- a/lld/ELF/MarkLive.cpp +++ b/lld/ELF/MarkLive.cpp @@ -45,76 +45,76 @@ using namespace lld::elf; namespace { template <class ELFT> class MarkLive { public: - MarkLive(unsigned Partition) : Partition(Partition) {} + MarkLive(unsigned partition) : partition(partition) {} void run(); void moveToMain(); private: - void enqueue(InputSectionBase *Sec, uint64_t Offset); - void markSymbol(Symbol *Sym); + void enqueue(InputSectionBase *sec, uint64_t offset); + void markSymbol(Symbol *sym); void mark(); template <class RelTy> - void resolveReloc(InputSectionBase &Sec, RelTy &Rel, bool IsLSDA); + void resolveReloc(InputSectionBase &sec, RelTy &rel, bool isLSDA); template <class RelTy> - void scanEhFrameSection(EhInputSection &EH, ArrayRef<RelTy> Rels); + void scanEhFrameSection(EhInputSection &eh, ArrayRef<RelTy> rels); // The index of the partition that we are currently processing. - unsigned Partition; + unsigned partition; // A list of sections to visit. - SmallVector<InputSection *, 256> Queue; + SmallVector<InputSection *, 256> queue; // There are normally few input sections whose names are valid C // identifiers, so we just store a std::vector instead of a multimap. - DenseMap<StringRef, std::vector<InputSectionBase *>> CNamedSections; + DenseMap<StringRef, std::vector<InputSectionBase *>> cNamedSections; }; } // namespace template <class ELFT> -static uint64_t getAddend(InputSectionBase &Sec, - const typename ELFT::Rel &Rel) { - return Target->getImplicitAddend(Sec.data().begin() + Rel.r_offset, - Rel.getType(Config->IsMips64EL)); +static uint64_t getAddend(InputSectionBase &sec, + const typename ELFT::Rel &rel) { + return target->getImplicitAddend(sec.data().begin() + rel.r_offset, + rel.getType(config->isMips64EL)); } template <class ELFT> -static uint64_t getAddend(InputSectionBase &Sec, - const typename ELFT::Rela &Rel) { - return Rel.r_addend; +static uint64_t getAddend(InputSectionBase &sec, + const typename ELFT::Rela &rel) { + return rel.r_addend; } template <class ELFT> template <class RelTy> -void MarkLive<ELFT>::resolveReloc(InputSectionBase &Sec, RelTy &Rel, - bool IsLSDA) { - Symbol &Sym = Sec.getFile<ELFT>()->getRelocTargetSym(Rel); +void MarkLive<ELFT>::resolveReloc(InputSectionBase &sec, RelTy &rel, + bool isLSDA) { + Symbol &sym = sec.getFile<ELFT>()->getRelocTargetSym(rel); // If a symbol is referenced in a live section, it is used. - Sym.Used = true; + sym.used = true; - if (auto *D = dyn_cast<Defined>(&Sym)) { - auto *RelSec = dyn_cast_or_null<InputSectionBase>(D->Section); - if (!RelSec) + if (auto *d = dyn_cast<Defined>(&sym)) { + auto *relSec = dyn_cast_or_null<InputSectionBase>(d->section); + if (!relSec) return; - uint64_t Offset = D->Value; - if (D->isSection()) - Offset += getAddend<ELFT>(Sec, Rel); + uint64_t offset = d->value; + if (d->isSection()) + offset += getAddend<ELFT>(sec, rel); - if (!IsLSDA || !(RelSec->Flags & SHF_EXECINSTR)) - enqueue(RelSec, Offset); + if (!isLSDA || !(relSec->flags & SHF_EXECINSTR)) + enqueue(relSec, offset); return; } - if (auto *SS = dyn_cast<SharedSymbol>(&Sym)) - if (!SS->isWeak()) - SS->getFile().IsNeeded = true; + if (auto *ss = dyn_cast<SharedSymbol>(&sym)) + if (!ss->isWeak()) + ss->getFile().isNeeded = true; - for (InputSectionBase *Sec : CNamedSections.lookup(Sym.getName())) - enqueue(Sec, 0); + for (InputSectionBase *sec : cNamedSections.lookup(sym.getName())) + enqueue(sec, 0); } // The .eh_frame section is an unfortunate special case. @@ -133,80 +133,80 @@ void MarkLive<ELFT>::resolveReloc(InputSectionBase &Sec, RelTy &Rel, // LSDAs and personality functions if we found that they were unused. template <class ELFT> template <class RelTy> -void MarkLive<ELFT>::scanEhFrameSection(EhInputSection &EH, - ArrayRef<RelTy> Rels) { - for (size_t I = 0, End = EH.Pieces.size(); I < End; ++I) { - EhSectionPiece &Piece = EH.Pieces[I]; - size_t FirstRelI = Piece.FirstRelocation; - if (FirstRelI == (unsigned)-1) +void MarkLive<ELFT>::scanEhFrameSection(EhInputSection &eh, + ArrayRef<RelTy> rels) { + for (size_t i = 0, end = eh.pieces.size(); i < end; ++i) { + EhSectionPiece &piece = eh.pieces[i]; + size_t firstRelI = piece.firstRelocation; + if (firstRelI == (unsigned)-1) continue; - if (read32<ELFT::TargetEndianness>(Piece.data().data() + 4) == 0) { + if (read32<ELFT::TargetEndianness>(piece.data().data() + 4) == 0) { // This is a CIE, we only need to worry about the first relocation. It is // known to point to the personality function. - resolveReloc(EH, Rels[FirstRelI], false); + resolveReloc(eh, rels[firstRelI], false); continue; } // This is a FDE. The relocations point to the described function or to // a LSDA. We only need to keep the LSDA alive, so ignore anything that // points to executable sections. - uint64_t PieceEnd = Piece.InputOff + Piece.Size; - for (size_t J = FirstRelI, End2 = Rels.size(); J < End2; ++J) - if (Rels[J].r_offset < PieceEnd) - resolveReloc(EH, Rels[J], true); + uint64_t pieceEnd = piece.inputOff + piece.size; + for (size_t j = firstRelI, end2 = rels.size(); j < end2; ++j) + if (rels[j].r_offset < pieceEnd) + resolveReloc(eh, rels[j], true); } } // Some sections are used directly by the loader, so they should never be // garbage-collected. This function returns true if a given section is such // section. -static bool isReserved(InputSectionBase *Sec) { - switch (Sec->Type) { +static bool isReserved(InputSectionBase *sec) { + switch (sec->type) { case SHT_FINI_ARRAY: case SHT_INIT_ARRAY: case SHT_NOTE: case SHT_PREINIT_ARRAY: return true; default: - StringRef S = Sec->Name; - return S.startswith(".ctors") || S.startswith(".dtors") || - S.startswith(".init") || S.startswith(".fini") || - S.startswith(".jcr"); + StringRef s = sec->name; + return s.startswith(".ctors") || s.startswith(".dtors") || + s.startswith(".init") || s.startswith(".fini") || + s.startswith(".jcr"); } } template <class ELFT> -void MarkLive<ELFT>::enqueue(InputSectionBase *Sec, uint64_t Offset) { +void MarkLive<ELFT>::enqueue(InputSectionBase *sec, uint64_t offset) { // Skip over discarded sections. This in theory shouldn't happen, because // the ELF spec doesn't allow a relocation to point to a deduplicated // COMDAT section directly. Unfortunately this happens in practice (e.g. // .eh_frame) so we need to add a check. - if (Sec == &InputSection::Discarded) + if (sec == &InputSection::discarded) return; // Usually, a whole section is marked as live or dead, but in mergeable // (splittable) sections, each piece of data has independent liveness bit. // So we explicitly tell it which offset is in use. - if (auto *MS = dyn_cast<MergeInputSection>(Sec)) - MS->getSectionPiece(Offset)->Live = true; + if (auto *ms = dyn_cast<MergeInputSection>(sec)) + ms->getSectionPiece(offset)->live = true; // Set Sec->Partition to the meet (i.e. the "minimum") of Partition and // Sec->Partition in the following lattice: 1 < other < 0. If Sec->Partition // doesn't change, we don't need to do anything. - if (Sec->Partition == 1 || Sec->Partition == Partition) + if (sec->partition == 1 || sec->partition == partition) return; - Sec->Partition = Sec->Partition ? 1 : Partition; + sec->partition = sec->partition ? 1 : partition; // Add input section to the queue. - if (InputSection *S = dyn_cast<InputSection>(Sec)) - Queue.push_back(S); + if (InputSection *s = dyn_cast<InputSection>(sec)) + queue.push_back(s); } -template <class ELFT> void MarkLive<ELFT>::markSymbol(Symbol *Sym) { - if (auto *D = dyn_cast_or_null<Defined>(Sym)) - if (auto *IS = dyn_cast_or_null<InputSectionBase>(D->Section)) - enqueue(IS, D->Value); +template <class ELFT> void MarkLive<ELFT>::markSymbol(Symbol *sym) { + if (auto *d = dyn_cast_or_null<Defined>(sym)) + if (auto *isec = dyn_cast_or_null<InputSectionBase>(d->section)) + enqueue(isec, d->value); } // This is the main function of the garbage collector. @@ -217,51 +217,51 @@ template <class ELFT> void MarkLive<ELFT>::run() { // Preserve externally-visible symbols if the symbols defined by this // file can interrupt other ELF file's symbols at runtime. - Symtab->forEachSymbol([&](Symbol *Sym) { - if (Sym->includeInDynsym() && Sym->Partition == Partition) - markSymbol(Sym); + symtab->forEachSymbol([&](Symbol *sym) { + if (sym->includeInDynsym() && sym->partition == partition) + markSymbol(sym); }); // If this isn't the main partition, that's all that we need to preserve. - if (Partition != 1) { + if (partition != 1) { mark(); return; } - markSymbol(Symtab->find(Config->Entry)); - markSymbol(Symtab->find(Config->Init)); - markSymbol(Symtab->find(Config->Fini)); - for (StringRef S : Config->Undefined) - markSymbol(Symtab->find(S)); - for (StringRef S : Script->ReferencedSymbols) - markSymbol(Symtab->find(S)); + markSymbol(symtab->find(config->entry)); + markSymbol(symtab->find(config->init)); + markSymbol(symtab->find(config->fini)); + for (StringRef s : config->undefined) + markSymbol(symtab->find(s)); + for (StringRef s : script->referencedSymbols) + markSymbol(symtab->find(s)); // Preserve special sections and those which are specified in linker // script KEEP command. - for (InputSectionBase *Sec : InputSections) { + for (InputSectionBase *sec : inputSections) { // Mark .eh_frame sections as live because there are usually no relocations // that point to .eh_frames. Otherwise, the garbage collector would drop // all of them. We also want to preserve personality routines and LSDA // referenced by .eh_frame sections, so we scan them for that here. - if (auto *EH = dyn_cast<EhInputSection>(Sec)) { - EH->markLive(); - if (!EH->NumRelocations) + if (auto *eh = dyn_cast<EhInputSection>(sec)) { + eh->markLive(); + if (!eh->numRelocations) continue; - if (EH->AreRelocsRela) - scanEhFrameSection(*EH, EH->template relas<ELFT>()); + if (eh->areRelocsRela) + scanEhFrameSection(*eh, eh->template relas<ELFT>()); else - scanEhFrameSection(*EH, EH->template rels<ELFT>()); + scanEhFrameSection(*eh, eh->template rels<ELFT>()); } - if (Sec->Flags & SHF_LINK_ORDER) + if (sec->flags & SHF_LINK_ORDER) continue; - if (isReserved(Sec) || Script->shouldKeep(Sec)) { - enqueue(Sec, 0); - } else if (isValidCIdentifier(Sec->Name)) { - CNamedSections[Saver.save("__start_" + Sec->Name)].push_back(Sec); - CNamedSections[Saver.save("__stop_" + Sec->Name)].push_back(Sec); + if (isReserved(sec) || script->shouldKeep(sec)) { + enqueue(sec, 0); + } else if (isValidCIdentifier(sec->name)) { + cNamedSections[Saver.save("__start_" + sec->name)].push_back(sec); + cNamedSections[Saver.save("__stop_" + sec->name)].push_back(sec); } } @@ -270,19 +270,19 @@ template <class ELFT> void MarkLive<ELFT>::run() { template <class ELFT> void MarkLive<ELFT>::mark() { // Mark all reachable sections. - while (!Queue.empty()) { - InputSectionBase &Sec = *Queue.pop_back_val(); + while (!queue.empty()) { + InputSectionBase &sec = *queue.pop_back_val(); - if (Sec.AreRelocsRela) { - for (const typename ELFT::Rela &Rel : Sec.template relas<ELFT>()) - resolveReloc(Sec, Rel, false); + if (sec.areRelocsRela) { + for (const typename ELFT::Rela &rel : sec.template relas<ELFT>()) + resolveReloc(sec, rel, false); } else { - for (const typename ELFT::Rel &Rel : Sec.template rels<ELFT>()) - resolveReloc(Sec, Rel, false); + for (const typename ELFT::Rel &rel : sec.template rels<ELFT>()) + resolveReloc(sec, rel, false); } - for (InputSectionBase *IS : Sec.DependentSections) - enqueue(IS, 0); + for (InputSectionBase *isec : sec.dependentSections) + enqueue(isec, 0); } } @@ -292,12 +292,12 @@ template <class ELFT> void MarkLive<ELFT>::mark() { // loaded) and TLS symbols (because we only know how to correctly process TLS // relocations for the main partition). template <class ELFT> void MarkLive<ELFT>::moveToMain() { - for (InputFile *File : ObjectFiles) - for (Symbol *S : File->getSymbols()) - if (auto *D = dyn_cast<Defined>(S)) - if ((D->Type == STT_GNU_IFUNC || D->Type == STT_TLS) && D->Section && - D->Section->isLive()) - markSymbol(S); + for (InputFile *file : objectFiles) + for (Symbol *s : file->getSymbols()) + if (auto *d = dyn_cast<Defined>(s)) + if ((d->type == STT_GNU_IFUNC || d->type == STT_TLS) && d->section && + d->section->isLive()) + markSymbol(s); mark(); } @@ -307,15 +307,15 @@ template <class ELFT> void MarkLive<ELFT>::moveToMain() { // so that they are emitted to the output file. template <class ELFT> void elf::markLive() { // If -gc-sections is not given, no sections are removed. - if (!Config->GcSections) { - for (InputSectionBase *Sec : InputSections) - Sec->markLive(); + if (!config->gcSections) { + for (InputSectionBase *sec : inputSections) + sec->markLive(); // If a DSO defines a symbol referenced in a regular object, it is needed. - Symtab->forEachSymbol([](Symbol *Sym) { - if (auto *S = dyn_cast<SharedSymbol>(Sym)) - if (S->IsUsedInRegularObj && !S->isWeak()) - S->getFile().IsNeeded = true; + symtab->forEachSymbol([](Symbol *sym) { + if (auto *s = dyn_cast<SharedSymbol>(sym)) + if (s->isUsedInRegularObj && !s->isWeak()) + s->getFile().isNeeded = true; }); return; } @@ -341,30 +341,30 @@ template <class ELFT> void elf::markLive() { // or -emit-reloc were given. And they are subject of garbage // collection because, if we remove a text section, we also // remove its relocation section. - for (InputSectionBase *Sec : InputSections) { - bool IsAlloc = (Sec->Flags & SHF_ALLOC); - bool IsLinkOrder = (Sec->Flags & SHF_LINK_ORDER); - bool IsRel = (Sec->Type == SHT_REL || Sec->Type == SHT_RELA); + for (InputSectionBase *sec : inputSections) { + bool isAlloc = (sec->flags & SHF_ALLOC); + bool isLinkOrder = (sec->flags & SHF_LINK_ORDER); + bool isRel = (sec->type == SHT_REL || sec->type == SHT_RELA); - if (!IsAlloc && !IsLinkOrder && !IsRel) - Sec->markLive(); + if (!isAlloc && !isLinkOrder && !isRel) + sec->markLive(); } // Follow the graph to mark all live sections. - for (unsigned CurPart = 1; CurPart <= Partitions.size(); ++CurPart) - MarkLive<ELFT>(CurPart).run(); + for (unsigned curPart = 1; curPart <= partitions.size(); ++curPart) + MarkLive<ELFT>(curPart).run(); // If we have multiple partitions, some sections need to live in the main // partition even if they were allocated to a loadable partition. Move them // there now. - if (Partitions.size() != 1) + if (partitions.size() != 1) MarkLive<ELFT>(1).moveToMain(); // Report garbage-collected sections. - if (Config->PrintGcSections) - for (InputSectionBase *Sec : InputSections) - if (!Sec->isLive()) - message("removing unused section " + toString(Sec)); + if (config->printGcSections) + for (InputSectionBase *sec : inputSections) + if (!sec->isLive()) + message("removing unused section " + toString(sec)); } template void elf::markLive<ELF32LE>(); |