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Diffstat (limited to 'gnu/llvm/tools/lld/ELF/InputFiles.cpp')
| -rw-r--r-- | gnu/llvm/tools/lld/ELF/InputFiles.cpp | 829 |
1 files changed, 829 insertions, 0 deletions
diff --git a/gnu/llvm/tools/lld/ELF/InputFiles.cpp b/gnu/llvm/tools/lld/ELF/InputFiles.cpp new file mode 100644 index 00000000000..426d9c39715 --- /dev/null +++ b/gnu/llvm/tools/lld/ELF/InputFiles.cpp @@ -0,0 +1,829 @@ +//===- InputFiles.cpp -----------------------------------------------------===// +// +// The LLVM Linker +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "InputFiles.h" +#include "Driver.h" +#include "Error.h" +#include "InputSection.h" +#include "SymbolTable.h" +#include "Symbols.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/Bitcode/ReaderWriter.h" +#include "llvm/CodeGen/Analysis.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/Module.h" +#include "llvm/Support/Path.h" +#include "llvm/Support/raw_ostream.h" + +using namespace llvm; +using namespace llvm::ELF; +using namespace llvm::object; +using namespace llvm::sys::fs; + +using namespace lld; +using namespace lld::elf; + +// Returns "(internal)", "foo.a(bar.o)" or "baz.o". +std::string elf::getFilename(const InputFile *F) { + if (!F) + return "(internal)"; + if (!F->ArchiveName.empty()) + return (F->ArchiveName + "(" + F->getName() + ")").str(); + return F->getName(); +} + +template <class ELFT> +static ELFFile<ELFT> createELFObj(MemoryBufferRef MB) { + std::error_code EC; + ELFFile<ELFT> F(MB.getBuffer(), EC); + if (EC) + error(EC, "failed to read " + MB.getBufferIdentifier()); + return F; +} + +template <class ELFT> static ELFKind getELFKind() { + if (ELFT::TargetEndianness == support::little) + return ELFT::Is64Bits ? ELF64LEKind : ELF32LEKind; + return ELFT::Is64Bits ? ELF64BEKind : ELF32BEKind; +} + +template <class ELFT> +ELFFileBase<ELFT>::ELFFileBase(Kind K, MemoryBufferRef MB) + : InputFile(K, MB), ELFObj(createELFObj<ELFT>(MB)) { + EKind = getELFKind<ELFT>(); + EMachine = ELFObj.getHeader()->e_machine; +} + +template <class ELFT> +typename ELFT::SymRange ELFFileBase<ELFT>::getElfSymbols(bool OnlyGlobals) { + if (!Symtab) + return Elf_Sym_Range(nullptr, nullptr); + Elf_Sym_Range Syms = ELFObj.symbols(Symtab); + uint32_t NumSymbols = std::distance(Syms.begin(), Syms.end()); + uint32_t FirstNonLocal = Symtab->sh_info; + if (FirstNonLocal > NumSymbols) + fatal(getFilename(this) + ": invalid sh_info in symbol table"); + + if (OnlyGlobals) + return makeArrayRef(Syms.begin() + FirstNonLocal, Syms.end()); + return makeArrayRef(Syms.begin(), Syms.end()); +} + +template <class ELFT> +uint32_t ELFFileBase<ELFT>::getSectionIndex(const Elf_Sym &Sym) const { + uint32_t I = Sym.st_shndx; + if (I == ELF::SHN_XINDEX) + return ELFObj.getExtendedSymbolTableIndex(&Sym, Symtab, SymtabSHNDX); + if (I >= ELF::SHN_LORESERVE) + return 0; + return I; +} + +template <class ELFT> void ELFFileBase<ELFT>::initStringTable() { + if (!Symtab) + return; + StringTable = check(ELFObj.getStringTableForSymtab(*Symtab)); +} + +template <class ELFT> +elf::ObjectFile<ELFT>::ObjectFile(MemoryBufferRef M) + : ELFFileBase<ELFT>(Base::ObjectKind, M) {} + +template <class ELFT> +ArrayRef<SymbolBody *> elf::ObjectFile<ELFT>::getNonLocalSymbols() { + if (!this->Symtab) + return this->SymbolBodies; + uint32_t FirstNonLocal = this->Symtab->sh_info; + return makeArrayRef(this->SymbolBodies).slice(FirstNonLocal); +} + +template <class ELFT> +ArrayRef<SymbolBody *> elf::ObjectFile<ELFT>::getLocalSymbols() { + if (!this->Symtab) + return this->SymbolBodies; + uint32_t FirstNonLocal = this->Symtab->sh_info; + return makeArrayRef(this->SymbolBodies).slice(1, FirstNonLocal - 1); +} + +template <class ELFT> +ArrayRef<SymbolBody *> elf::ObjectFile<ELFT>::getSymbols() { + if (!this->Symtab) + return this->SymbolBodies; + return makeArrayRef(this->SymbolBodies).slice(1); +} + +template <class ELFT> uint32_t elf::ObjectFile<ELFT>::getMipsGp0() const { + if (ELFT::Is64Bits && MipsOptions && MipsOptions->Reginfo) + return MipsOptions->Reginfo->ri_gp_value; + if (!ELFT::Is64Bits && MipsReginfo && MipsReginfo->Reginfo) + return MipsReginfo->Reginfo->ri_gp_value; + return 0; +} + +template <class ELFT> +void elf::ObjectFile<ELFT>::parse(DenseSet<StringRef> &ComdatGroups) { + // Read section and symbol tables. + initializeSections(ComdatGroups); + initializeSymbols(); +} + +// Sections with SHT_GROUP and comdat bits define comdat section groups. +// They are identified and deduplicated by group name. This function +// returns a group name. +template <class ELFT> +StringRef elf::ObjectFile<ELFT>::getShtGroupSignature(const Elf_Shdr &Sec) { + const ELFFile<ELFT> &Obj = this->ELFObj; + const Elf_Shdr *Symtab = check(Obj.getSection(Sec.sh_link)); + const Elf_Sym *Sym = Obj.getSymbol(Symtab, Sec.sh_info); + StringRef Strtab = check(Obj.getStringTableForSymtab(*Symtab)); + return check(Sym->getName(Strtab)); +} + +template <class ELFT> +ArrayRef<typename elf::ObjectFile<ELFT>::Elf_Word> +elf::ObjectFile<ELFT>::getShtGroupEntries(const Elf_Shdr &Sec) { + const ELFFile<ELFT> &Obj = this->ELFObj; + ArrayRef<Elf_Word> Entries = + check(Obj.template getSectionContentsAsArray<Elf_Word>(&Sec)); + if (Entries.empty() || Entries[0] != GRP_COMDAT) + fatal(getFilename(this) + ": unsupported SHT_GROUP format"); + return Entries.slice(1); +} + +template <class ELFT> +bool elf::ObjectFile<ELFT>::shouldMerge(const Elf_Shdr &Sec) { + // We don't merge sections if -O0 (default is -O1). This makes sometimes + // the linker significantly faster, although the output will be bigger. + if (Config->Optimize == 0) + return false; + + uintX_t Flags = Sec.sh_flags; + if (!(Flags & SHF_MERGE)) + return false; + if (Flags & SHF_WRITE) + fatal(getFilename(this) + ": writable SHF_MERGE section is not supported"); + uintX_t EntSize = Sec.sh_entsize; + if (!EntSize || Sec.sh_size % EntSize) + fatal(getFilename(this) + + ": SHF_MERGE section size must be a multiple of sh_entsize"); + + // Don't try to merge if the alignment is larger than the sh_entsize and this + // is not SHF_STRINGS. + // + // Since this is not a SHF_STRINGS, we would need to pad after every entity. + // It would be equivalent for the producer of the .o to just set a larger + // sh_entsize. + if (Flags & SHF_STRINGS) + return true; + + return Sec.sh_addralign <= EntSize; +} + +template <class ELFT> +void elf::ObjectFile<ELFT>::initializeSections( + DenseSet<StringRef> &ComdatGroups) { + uint64_t Size = this->ELFObj.getNumSections(); + Sections.resize(Size); + unsigned I = -1; + const ELFFile<ELFT> &Obj = this->ELFObj; + for (const Elf_Shdr &Sec : Obj.sections()) { + ++I; + if (Sections[I] == &InputSection<ELFT>::Discarded) + continue; + + switch (Sec.sh_type) { + case SHT_GROUP: + Sections[I] = &InputSection<ELFT>::Discarded; + if (ComdatGroups.insert(getShtGroupSignature(Sec)).second) + continue; + for (uint32_t SecIndex : getShtGroupEntries(Sec)) { + if (SecIndex >= Size) + fatal(getFilename(this) + ": invalid section index in group: " + + Twine(SecIndex)); + Sections[SecIndex] = &InputSection<ELFT>::Discarded; + } + break; + case SHT_SYMTAB: + this->Symtab = &Sec; + break; + case SHT_SYMTAB_SHNDX: + this->SymtabSHNDX = check(Obj.getSHNDXTable(Sec)); + break; + case SHT_STRTAB: + case SHT_NULL: + break; + case SHT_RELA: + case SHT_REL: { + // This section contains relocation information. + // If -r is given, we do not interpret or apply relocation + // but just copy relocation sections to output. + if (Config->Relocatable) { + Sections[I] = new (IAlloc.Allocate()) InputSection<ELFT>(this, &Sec); + break; + } + + // Find the relocation target section and associate this + // section with it. + InputSectionBase<ELFT> *Target = getRelocTarget(Sec); + if (!Target) + break; + if (auto *S = dyn_cast<InputSection<ELFT>>(Target)) { + S->RelocSections.push_back(&Sec); + break; + } + if (auto *S = dyn_cast<EhInputSection<ELFT>>(Target)) { + if (S->RelocSection) + fatal( + getFilename(this) + + ": multiple relocation sections to .eh_frame are not supported"); + S->RelocSection = &Sec; + break; + } + fatal(getFilename(this) + + ": relocations pointing to SHF_MERGE are not supported"); + } + case SHT_ARM_ATTRIBUTES: + // FIXME: ARM meta-data section. At present attributes are ignored, + // they can be used to reason about object compatibility. + Sections[I] = &InputSection<ELFT>::Discarded; + break; + default: + Sections[I] = createInputSection(Sec); + } + } +} + +template <class ELFT> +InputSectionBase<ELFT> * +elf::ObjectFile<ELFT>::getRelocTarget(const Elf_Shdr &Sec) { + uint32_t Idx = Sec.sh_info; + if (Idx >= Sections.size()) + fatal(getFilename(this) + ": invalid relocated section index: " + + Twine(Idx)); + InputSectionBase<ELFT> *Target = Sections[Idx]; + + // Strictly speaking, a relocation section must be included in the + // group of the section it relocates. However, LLVM 3.3 and earlier + // would fail to do so, so we gracefully handle that case. + if (Target == &InputSection<ELFT>::Discarded) + return nullptr; + + if (!Target) + fatal(getFilename(this) + ": unsupported relocation reference"); + return Target; +} + +template <class ELFT> +InputSectionBase<ELFT> * +elf::ObjectFile<ELFT>::createInputSection(const Elf_Shdr &Sec) { + StringRef Name = check(this->ELFObj.getSectionName(&Sec)); + + // .note.GNU-stack is a marker section to control the presence of + // PT_GNU_STACK segment in outputs. Since the presence of the segment + // is controlled only by the command line option (-z execstack) in LLD, + // .note.GNU-stack is ignored. + if (Name == ".note.GNU-stack") + return &InputSection<ELFT>::Discarded; + + if (Name == ".note.GNU-split-stack") { + error("objects using splitstacks are not supported"); + return &InputSection<ELFT>::Discarded; + } + + if (Config->StripDebug && Name.startswith(".debug")) + return &InputSection<ELFT>::Discarded; + + // A MIPS object file has a special sections that contain register + // usage info, which need to be handled by the linker specially. + if (Config->EMachine == EM_MIPS) { + if (Name == ".reginfo") { + MipsReginfo.reset(new MipsReginfoInputSection<ELFT>(this, &Sec)); + return MipsReginfo.get(); + } + if (Name == ".MIPS.options") { + MipsOptions.reset(new MipsOptionsInputSection<ELFT>(this, &Sec)); + return MipsOptions.get(); + } + } + + // The linker merges EH (exception handling) frames and creates a + // .eh_frame_hdr section for runtime. So we handle them with a special + // class. For relocatable outputs, they are just passed through. + if (Name == ".eh_frame" && !Config->Relocatable) + return new (EHAlloc.Allocate()) EhInputSection<ELFT>(this, &Sec); + + if (shouldMerge(Sec)) + return new (MAlloc.Allocate()) MergeInputSection<ELFT>(this, &Sec); + return new (IAlloc.Allocate()) InputSection<ELFT>(this, &Sec); +} + +template <class ELFT> void elf::ObjectFile<ELFT>::initializeSymbols() { + this->initStringTable(); + Elf_Sym_Range Syms = this->getElfSymbols(false); + uint32_t NumSymbols = std::distance(Syms.begin(), Syms.end()); + SymbolBodies.reserve(NumSymbols); + for (const Elf_Sym &Sym : Syms) + SymbolBodies.push_back(createSymbolBody(&Sym)); +} + +template <class ELFT> +InputSectionBase<ELFT> * +elf::ObjectFile<ELFT>::getSection(const Elf_Sym &Sym) const { + uint32_t Index = this->getSectionIndex(Sym); + if (Index == 0) + return nullptr; + if (Index >= Sections.size() || !Sections[Index]) + fatal(getFilename(this) + ": invalid section index: " + Twine(Index)); + InputSectionBase<ELFT> *S = Sections[Index]; + if (S == &InputSectionBase<ELFT>::Discarded) + return S; + return S->Repl; +} + +template <class ELFT> +SymbolBody *elf::ObjectFile<ELFT>::createSymbolBody(const Elf_Sym *Sym) { + int Binding = Sym->getBinding(); + InputSectionBase<ELFT> *Sec = getSection(*Sym); + if (Binding == STB_LOCAL) { + if (Sym->st_shndx == SHN_UNDEF) + return new (this->Alloc) + Undefined(Sym->st_name, Sym->st_other, Sym->getType(), this); + return new (this->Alloc) DefinedRegular<ELFT>(*Sym, Sec); + } + + StringRef Name = check(Sym->getName(this->StringTable)); + + switch (Sym->st_shndx) { + case SHN_UNDEF: + return elf::Symtab<ELFT>::X + ->addUndefined(Name, Binding, Sym->st_other, Sym->getType(), + /*CanOmitFromDynSym*/ false, this) + ->body(); + case SHN_COMMON: + return elf::Symtab<ELFT>::X + ->addCommon(Name, Sym->st_size, Sym->st_value, Binding, Sym->st_other, + Sym->getType(), this) + ->body(); + } + + switch (Binding) { + default: + fatal(getFilename(this) + ": unexpected binding: " + Twine(Binding)); + case STB_GLOBAL: + case STB_WEAK: + case STB_GNU_UNIQUE: + if (Sec == &InputSection<ELFT>::Discarded) + return elf::Symtab<ELFT>::X + ->addUndefined(Name, Binding, Sym->st_other, Sym->getType(), + /*CanOmitFromDynSym*/ false, this) + ->body(); + return elf::Symtab<ELFT>::X->addRegular(Name, *Sym, Sec)->body(); + } +} + +template <class ELFT> void ArchiveFile::parse() { + File = check(Archive::create(MB), "failed to parse archive"); + + // Read the symbol table to construct Lazy objects. + for (const Archive::Symbol &Sym : File->symbols()) + Symtab<ELFT>::X->addLazyArchive(this, Sym); +} + +// Returns a buffer pointing to a member file containing a given symbol. +MemoryBufferRef ArchiveFile::getMember(const Archive::Symbol *Sym) { + Archive::Child C = + check(Sym->getMember(), + "could not get the member for symbol " + Sym->getName()); + + if (!Seen.insert(C.getChildOffset()).second) + return MemoryBufferRef(); + + MemoryBufferRef Ret = + check(C.getMemoryBufferRef(), + "could not get the buffer for the member defining symbol " + + Sym->getName()); + + if (C.getParent()->isThin() && Driver->Cpio) + Driver->Cpio->append(relativeToRoot(check(C.getFullName())), + Ret.getBuffer()); + + return Ret; +} + +template <class ELFT> +SharedFile<ELFT>::SharedFile(MemoryBufferRef M) + : ELFFileBase<ELFT>(Base::SharedKind, M), AsNeeded(Config->AsNeeded) {} + +template <class ELFT> +const typename ELFT::Shdr * +SharedFile<ELFT>::getSection(const Elf_Sym &Sym) const { + uint32_t Index = this->getSectionIndex(Sym); + if (Index == 0) + return nullptr; + return check(this->ELFObj.getSection(Index)); +} + +// Partially parse the shared object file so that we can call +// getSoName on this object. +template <class ELFT> void SharedFile<ELFT>::parseSoName() { + typedef typename ELFT::Dyn Elf_Dyn; + typedef typename ELFT::uint uintX_t; + const Elf_Shdr *DynamicSec = nullptr; + + const ELFFile<ELFT> Obj = this->ELFObj; + for (const Elf_Shdr &Sec : Obj.sections()) { + switch (Sec.sh_type) { + default: + continue; + case SHT_DYNSYM: + this->Symtab = &Sec; + break; + case SHT_DYNAMIC: + DynamicSec = &Sec; + break; + case SHT_SYMTAB_SHNDX: + this->SymtabSHNDX = check(Obj.getSHNDXTable(Sec)); + break; + case SHT_GNU_versym: + this->VersymSec = &Sec; + break; + case SHT_GNU_verdef: + this->VerdefSec = &Sec; + break; + } + } + + this->initStringTable(); + SoName = sys::path::filename(this->getName()); + + if (!DynamicSec) + return; + auto *Begin = + reinterpret_cast<const Elf_Dyn *>(Obj.base() + DynamicSec->sh_offset); + const Elf_Dyn *End = Begin + DynamicSec->sh_size / sizeof(Elf_Dyn); + + for (const Elf_Dyn &Dyn : make_range(Begin, End)) { + if (Dyn.d_tag == DT_SONAME) { + uintX_t Val = Dyn.getVal(); + if (Val >= this->StringTable.size()) + fatal(getFilename(this) + ": invalid DT_SONAME entry"); + SoName = StringRef(this->StringTable.data() + Val); + return; + } + } +} + +// Parse the version definitions in the object file if present. Returns a vector +// whose nth element contains a pointer to the Elf_Verdef for version identifier +// n. Version identifiers that are not definitions map to nullptr. The array +// always has at least length 1. +template <class ELFT> +std::vector<const typename ELFT::Verdef *> +SharedFile<ELFT>::parseVerdefs(const Elf_Versym *&Versym) { + std::vector<const Elf_Verdef *> Verdefs(1); + // We only need to process symbol versions for this DSO if it has both a + // versym and a verdef section, which indicates that the DSO contains symbol + // version definitions. + if (!VersymSec || !VerdefSec) + return Verdefs; + + // The location of the first global versym entry. + Versym = reinterpret_cast<const Elf_Versym *>(this->ELFObj.base() + + VersymSec->sh_offset) + + this->Symtab->sh_info; + + // We cannot determine the largest verdef identifier without inspecting + // every Elf_Verdef, but both bfd and gold assign verdef identifiers + // sequentially starting from 1, so we predict that the largest identifier + // will be VerdefCount. + unsigned VerdefCount = VerdefSec->sh_info; + Verdefs.resize(VerdefCount + 1); + + // Build the Verdefs array by following the chain of Elf_Verdef objects + // from the start of the .gnu.version_d section. + const uint8_t *Verdef = this->ELFObj.base() + VerdefSec->sh_offset; + for (unsigned I = 0; I != VerdefCount; ++I) { + auto *CurVerdef = reinterpret_cast<const Elf_Verdef *>(Verdef); + Verdef += CurVerdef->vd_next; + unsigned VerdefIndex = CurVerdef->vd_ndx; + if (Verdefs.size() <= VerdefIndex) + Verdefs.resize(VerdefIndex + 1); + Verdefs[VerdefIndex] = CurVerdef; + } + + return Verdefs; +} + +// Fully parse the shared object file. This must be called after parseSoName(). +template <class ELFT> void SharedFile<ELFT>::parseRest() { + // Create mapping from version identifiers to Elf_Verdef entries. + const Elf_Versym *Versym = nullptr; + std::vector<const Elf_Verdef *> Verdefs = parseVerdefs(Versym); + + Elf_Sym_Range Syms = this->getElfSymbols(true); + for (const Elf_Sym &Sym : Syms) { + unsigned VersymIndex = 0; + if (Versym) { + VersymIndex = Versym->vs_index; + ++Versym; + } + + StringRef Name = check(Sym.getName(this->StringTable)); + if (Sym.isUndefined()) { + Undefs.push_back(Name); + continue; + } + + if (Versym) { + // Ignore local symbols and non-default versions. + if (VersymIndex == VER_NDX_LOCAL || (VersymIndex & VERSYM_HIDDEN)) + continue; + } + + const Elf_Verdef *V = + VersymIndex == VER_NDX_GLOBAL ? nullptr : Verdefs[VersymIndex]; + elf::Symtab<ELFT>::X->addShared(this, Name, Sym, V); + } +} + +static ELFKind getELFKind(MemoryBufferRef MB) { + std::string TripleStr = getBitcodeTargetTriple(MB, Driver->Context); + Triple TheTriple(TripleStr); + bool Is64Bits = TheTriple.isArch64Bit(); + if (TheTriple.isLittleEndian()) + return Is64Bits ? ELF64LEKind : ELF32LEKind; + return Is64Bits ? ELF64BEKind : ELF32BEKind; +} + +static uint8_t getMachineKind(MemoryBufferRef MB) { + std::string TripleStr = getBitcodeTargetTriple(MB, Driver->Context); + switch (Triple(TripleStr).getArch()) { + case Triple::aarch64: + return EM_AARCH64; + case Triple::arm: + return EM_ARM; + case Triple::mips: + case Triple::mipsel: + case Triple::mips64: + case Triple::mips64el: + return EM_MIPS; + case Triple::ppc: + return EM_PPC; + case Triple::ppc64: + return EM_PPC64; + case Triple::x86: + return EM_386; + case Triple::x86_64: + return EM_X86_64; + default: + fatal(MB.getBufferIdentifier() + + ": could not infer e_machine from bitcode target triple " + + TripleStr); + } +} + +BitcodeFile::BitcodeFile(MemoryBufferRef MB) : InputFile(BitcodeKind, MB) { + EKind = getELFKind(MB); + EMachine = getMachineKind(MB); +} + +static uint8_t getGvVisibility(const GlobalValue *GV) { + switch (GV->getVisibility()) { + case GlobalValue::DefaultVisibility: + return STV_DEFAULT; + case GlobalValue::HiddenVisibility: + return STV_HIDDEN; + case GlobalValue::ProtectedVisibility: + return STV_PROTECTED; + } + llvm_unreachable("unknown visibility"); +} + +template <class ELFT> +Symbol *BitcodeFile::createSymbol(const DenseSet<const Comdat *> &KeptComdats, + const IRObjectFile &Obj, + const BasicSymbolRef &Sym) { + const GlobalValue *GV = Obj.getSymbolGV(Sym.getRawDataRefImpl()); + + SmallString<64> Name; + raw_svector_ostream OS(Name); + Sym.printName(OS); + StringRef NameRef = Saver.save(StringRef(Name)); + + uint32_t Flags = Sym.getFlags(); + bool IsWeak = Flags & BasicSymbolRef::SF_Weak; + uint32_t Binding = IsWeak ? STB_WEAK : STB_GLOBAL; + + uint8_t Type = STT_NOTYPE; + bool CanOmitFromDynSym = false; + // FIXME: Expose a thread-local flag for module asm symbols. + if (GV) { + if (GV->isThreadLocal()) + Type = STT_TLS; + CanOmitFromDynSym = canBeOmittedFromSymbolTable(GV); + } + + uint8_t Visibility; + if (GV) + Visibility = getGvVisibility(GV); + else + // FIXME: Set SF_Hidden flag correctly for module asm symbols, and expose + // protected visibility. + Visibility = STV_DEFAULT; + + if (GV) + if (const Comdat *C = GV->getComdat()) + if (!KeptComdats.count(C)) + return Symtab<ELFT>::X->addUndefined(NameRef, Binding, Visibility, Type, + CanOmitFromDynSym, this); + + const Module &M = Obj.getModule(); + if (Flags & BasicSymbolRef::SF_Undefined) + return Symtab<ELFT>::X->addUndefined(NameRef, Binding, Visibility, Type, + CanOmitFromDynSym, this); + if (Flags & BasicSymbolRef::SF_Common) { + // FIXME: Set SF_Common flag correctly for module asm symbols, and expose + // size and alignment. + assert(GV); + const DataLayout &DL = M.getDataLayout(); + uint64_t Size = DL.getTypeAllocSize(GV->getValueType()); + return Symtab<ELFT>::X->addCommon(NameRef, Size, GV->getAlignment(), + Binding, Visibility, STT_OBJECT, this); + } + return Symtab<ELFT>::X->addBitcode(NameRef, IsWeak, Visibility, Type, + CanOmitFromDynSym, this); +} + +bool BitcodeFile::shouldSkip(uint32_t Flags) { + return !(Flags & BasicSymbolRef::SF_Global) || + (Flags & BasicSymbolRef::SF_FormatSpecific); +} + +template <class ELFT> +void BitcodeFile::parse(DenseSet<StringRef> &ComdatGroups) { + Obj = check(IRObjectFile::create(MB, Driver->Context)); + const Module &M = Obj->getModule(); + + DenseSet<const Comdat *> KeptComdats; + for (const auto &P : M.getComdatSymbolTable()) { + StringRef N = Saver.save(P.first()); + if (ComdatGroups.insert(N).second) + KeptComdats.insert(&P.second); + } + + for (const BasicSymbolRef &Sym : Obj->symbols()) + if (!shouldSkip(Sym.getFlags())) + Symbols.push_back(createSymbol<ELFT>(KeptComdats, *Obj, Sym)); +} + +template <template <class> class T> +static std::unique_ptr<InputFile> createELFFile(MemoryBufferRef MB) { + unsigned char Size; + unsigned char Endian; + std::tie(Size, Endian) = getElfArchType(MB.getBuffer()); + if (Endian != ELFDATA2LSB && Endian != ELFDATA2MSB) + fatal("invalid data encoding: " + MB.getBufferIdentifier()); + + std::unique_ptr<InputFile> Obj; + if (Size == ELFCLASS32 && Endian == ELFDATA2LSB) + Obj.reset(new T<ELF32LE>(MB)); + else if (Size == ELFCLASS32 && Endian == ELFDATA2MSB) + Obj.reset(new T<ELF32BE>(MB)); + else if (Size == ELFCLASS64 && Endian == ELFDATA2LSB) + Obj.reset(new T<ELF64LE>(MB)); + else if (Size == ELFCLASS64 && Endian == ELFDATA2MSB) + Obj.reset(new T<ELF64BE>(MB)); + else + fatal("invalid file class: " + MB.getBufferIdentifier()); + + if (!Config->FirstElf) + Config->FirstElf = Obj.get(); + return Obj; +} + +static bool isBitcode(MemoryBufferRef MB) { + using namespace sys::fs; + return identify_magic(MB.getBuffer()) == file_magic::bitcode; +} + +std::unique_ptr<InputFile> elf::createObjectFile(MemoryBufferRef MB, + StringRef ArchiveName) { + std::unique_ptr<InputFile> F; + if (isBitcode(MB)) + F.reset(new BitcodeFile(MB)); + else + F = createELFFile<ObjectFile>(MB); + F->ArchiveName = ArchiveName; + return F; +} + +std::unique_ptr<InputFile> elf::createSharedFile(MemoryBufferRef MB) { + return createELFFile<SharedFile>(MB); +} + +MemoryBufferRef LazyObjectFile::getBuffer() { + if (Seen) + return MemoryBufferRef(); + Seen = true; + return MB; +} + +template <class ELFT> +void LazyObjectFile::parse() { + for (StringRef Sym : getSymbols()) + Symtab<ELFT>::X->addLazyObject(Sym, *this); +} + +template <class ELFT> std::vector<StringRef> LazyObjectFile::getElfSymbols() { + typedef typename ELFT::Shdr Elf_Shdr; + typedef typename ELFT::Sym Elf_Sym; + typedef typename ELFT::SymRange Elf_Sym_Range; + + const ELFFile<ELFT> Obj = createELFObj<ELFT>(this->MB); + for (const Elf_Shdr &Sec : Obj.sections()) { + if (Sec.sh_type != SHT_SYMTAB) + continue; + Elf_Sym_Range Syms = Obj.symbols(&Sec); + uint32_t FirstNonLocal = Sec.sh_info; + StringRef StringTable = check(Obj.getStringTableForSymtab(Sec)); + std::vector<StringRef> V; + for (const Elf_Sym &Sym : Syms.slice(FirstNonLocal)) + if (Sym.st_shndx != SHN_UNDEF) + V.push_back(check(Sym.getName(StringTable))); + return V; + } + return {}; +} + +std::vector<StringRef> LazyObjectFile::getBitcodeSymbols() { + LLVMContext Context; + std::unique_ptr<IRObjectFile> Obj = + check(IRObjectFile::create(this->MB, Context)); + std::vector<StringRef> V; + for (const BasicSymbolRef &Sym : Obj->symbols()) { + uint32_t Flags = Sym.getFlags(); + if (BitcodeFile::shouldSkip(Flags)) + continue; + if (Flags & BasicSymbolRef::SF_Undefined) + continue; + SmallString<64> Name; + raw_svector_ostream OS(Name); + Sym.printName(OS); + V.push_back(Saver.save(StringRef(Name))); + } + return V; +} + +// Returns a vector of globally-visible defined symbol names. +std::vector<StringRef> LazyObjectFile::getSymbols() { + if (isBitcode(this->MB)) + return getBitcodeSymbols(); + + unsigned char Size; + unsigned char Endian; + std::tie(Size, Endian) = getElfArchType(this->MB.getBuffer()); + if (Size == ELFCLASS32) { + if (Endian == ELFDATA2LSB) + return getElfSymbols<ELF32LE>(); + return getElfSymbols<ELF32BE>(); + } + if (Endian == ELFDATA2LSB) + return getElfSymbols<ELF64LE>(); + return getElfSymbols<ELF64BE>(); +} + +template void ArchiveFile::parse<ELF32LE>(); +template void ArchiveFile::parse<ELF32BE>(); +template void ArchiveFile::parse<ELF64LE>(); +template void ArchiveFile::parse<ELF64BE>(); + +template void BitcodeFile::parse<ELF32LE>(DenseSet<StringRef> &); +template void BitcodeFile::parse<ELF32BE>(DenseSet<StringRef> &); +template void BitcodeFile::parse<ELF64LE>(DenseSet<StringRef> &); +template void BitcodeFile::parse<ELF64BE>(DenseSet<StringRef> &); + +template void LazyObjectFile::parse<ELF32LE>(); +template void LazyObjectFile::parse<ELF32BE>(); +template void LazyObjectFile::parse<ELF64LE>(); +template void LazyObjectFile::parse<ELF64BE>(); + +template class elf::ELFFileBase<ELF32LE>; +template class elf::ELFFileBase<ELF32BE>; +template class elf::ELFFileBase<ELF64LE>; +template class elf::ELFFileBase<ELF64BE>; + +template class elf::ObjectFile<ELF32LE>; +template class elf::ObjectFile<ELF32BE>; +template class elf::ObjectFile<ELF64LE>; +template class elf::ObjectFile<ELF64BE>; + +template class elf::SharedFile<ELF32LE>; +template class elf::SharedFile<ELF32BE>; +template class elf::SharedFile<ELF64LE>; +template class elf::SharedFile<ELF64BE>; |