[lld] r314496 - [NFC] Removed accidenatally added file
Ben Dunbobbin via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 29 02:15:56 PDT 2017
Author: bd1976llvm
Date: Fri Sep 29 02:15:55 2017
New Revision: 314496
URL: http://llvm.org/viewvc/llvm-project?rev=314496&view=rev
Log:
[NFC] Removed accidenatally added file
Removed:
lld/trunk/ELF/SyntheticSections.cpp~RF2791d30b.TMP
Removed: lld/trunk/ELF/SyntheticSections.cpp~RF2791d30b.TMP
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SyntheticSections.cpp%7ERF2791d30b.TMP?rev=314495&view=auto
==============================================================================
--- lld/trunk/ELF/SyntheticSections.cpp~RF2791d30b.TMP (original)
+++ lld/trunk/ELF/SyntheticSections.cpp~RF2791d30b.TMP (removed)
@@ -1,2451 +0,0 @@
-//===- SyntheticSections.cpp ----------------------------------------------===//
-//
-// The LLVM Linker
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file contains linker-synthesized sections. Currently,
-// synthetic sections are created either output sections or input sections,
-// but we are rewriting code so that all synthetic sections are created as
-// input sections.
-//
-//===----------------------------------------------------------------------===//
-
-#include "SyntheticSections.h"
-#include "Config.h"
-#include "Error.h"
-#include "InputFiles.h"
-#include "LinkerScript.h"
-#include "Memory.h"
-#include "OutputSections.h"
-#include "Strings.h"
-#include "SymbolTable.h"
-#include "Target.h"
-#include "Threads.h"
-#include "Writer.h"
-#include "lld/Config/Version.h"
-#include "llvm/BinaryFormat/Dwarf.h"
-#include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
-#include "llvm/Object/Decompressor.h"
-#include "llvm/Object/ELFObjectFile.h"
-#include "llvm/Support/Endian.h"
-#include "llvm/Support/MD5.h"
-#include "llvm/Support/RandomNumberGenerator.h"
-#include "llvm/Support/SHA1.h"
-#include "llvm/Support/xxhash.h"
-#include <cstdlib>
-
-using namespace llvm;
-using namespace llvm::dwarf;
-using namespace llvm::ELF;
-using namespace llvm::object;
-using namespace llvm::support;
-using namespace llvm::support::endian;
-
-using namespace lld;
-using namespace lld::elf;
-
-uint64_t SyntheticSection::getVA() const {
- if (OutputSection *Sec = getParent())
- return Sec->Addr + OutSecOff;
- return 0;
-}
-
-// Create a .bss section for each common section and replace the common symbol
-// with a DefinedRegular symbol.
-template <class ELFT> void elf::createCommonSections() {
- for (Symbol *S : Symtab->getSymbols()) {
- auto *Sym = dyn_cast<DefinedCommon>(S->body());
-
- if (!Sym)
- continue;
-
- // Create a synthetic section for the common data.
- auto *Section = make<BssSection>("COMMON");
- Section->File = Sym->getFile();
- Section->Live = !Config->GcSections;
- Section->reserveSpace(Sym->Size, Sym->Alignment);
- InputSections.push_back(Section);
-
- // Replace all DefinedCommon symbols with DefinedRegular symbols so that we
- // don't have to care about DefinedCommon symbols beyond this point.
- replaceBody<DefinedRegular>(S, Sym->getFile(), Sym->getName(), Sym->IsLocal,
- Sym->StOther, Sym->Type, 0,
- Sym->getSize<ELFT>(), Section);
- }
-}
-
-// Returns an LLD version string.
-static ArrayRef<uint8_t> getVersion() {
- // Check LLD_VERSION first for ease of testing.
- // You can get consitent output by using the environment variable.
- // This is only for testing.
- StringRef S = getenv("LLD_VERSION");
- if (S.empty())
- S = Saver.save(Twine("Linker: ") + getLLDVersion());
-
- // +1 to include the terminating '\0'.
- return {(const uint8_t *)S.data(), S.size() + 1};
-}
-
-// Creates a .comment section containing LLD version info.
-// With this feature, you can identify LLD-generated binaries easily
-// by "readelf --string-dump .comment <file>".
-// The returned object is a mergeable string section.
-template <class ELFT> MergeInputSection *elf::createCommentSection() {
- typename ELFT::Shdr Hdr = {};
- Hdr.sh_flags = SHF_MERGE | SHF_STRINGS;
- Hdr.sh_type = SHT_PROGBITS;
- Hdr.sh_entsize = 1;
- Hdr.sh_addralign = 1;
-
- auto *Ret =
- make<MergeInputSection>((ObjFile<ELFT> *)nullptr, &Hdr, ".comment");
- Ret->Data = getVersion();
- return Ret;
-}
-
-// .MIPS.abiflags section.
-template <class ELFT>
-MipsAbiFlagsSection<ELFT>::MipsAbiFlagsSection(Elf_Mips_ABIFlags Flags)
- : SyntheticSection(SHF_ALLOC, SHT_MIPS_ABIFLAGS, 8, ".MIPS.abiflags"),
- Flags(Flags) {
- this->Entsize = sizeof(Elf_Mips_ABIFlags);
-}
-
-template <class ELFT> void MipsAbiFlagsSection<ELFT>::writeTo(uint8_t *Buf) {
- memcpy(Buf, &Flags, sizeof(Flags));
-}
-
-template <class ELFT>
-MipsAbiFlagsSection<ELFT> *MipsAbiFlagsSection<ELFT>::create() {
- Elf_Mips_ABIFlags Flags = {};
- bool Create = false;
-
- for (InputSectionBase *Sec : InputSections) {
- if (Sec->Type != SHT_MIPS_ABIFLAGS)
- continue;
- Sec->Live = false;
- Create = true;
-
- std::string Filename = toString(Sec->getFile<ELFT>());
- const size_t Size = Sec->Data.size();
- // Older version of BFD (such as the default FreeBSD linker) concatenate
- // .MIPS.abiflags instead of merging. To allow for this case (or potential
- // zero padding) we ignore everything after the first Elf_Mips_ABIFlags
- if (Size < sizeof(Elf_Mips_ABIFlags)) {
- error(Filename + ": invalid size of .MIPS.abiflags section: got " +
- Twine(Size) + " instead of " + Twine(sizeof(Elf_Mips_ABIFlags)));
- return nullptr;
- }
- auto *S = reinterpret_cast<const Elf_Mips_ABIFlags *>(Sec->Data.data());
- if (S->version != 0) {
- error(Filename + ": unexpected .MIPS.abiflags version " +
- Twine(S->version));
- return nullptr;
- }
-
- // LLD checks ISA compatibility in getMipsEFlags(). Here we just
- // select the highest number of ISA/Rev/Ext.
- Flags.isa_level = std::max(Flags.isa_level, S->isa_level);
- Flags.isa_rev = std::max(Flags.isa_rev, S->isa_rev);
- Flags.isa_ext = std::max(Flags.isa_ext, S->isa_ext);
- Flags.gpr_size = std::max(Flags.gpr_size, S->gpr_size);
- Flags.cpr1_size = std::max(Flags.cpr1_size, S->cpr1_size);
- Flags.cpr2_size = std::max(Flags.cpr2_size, S->cpr2_size);
- Flags.ases |= S->ases;
- Flags.flags1 |= S->flags1;
- Flags.flags2 |= S->flags2;
- Flags.fp_abi = elf::getMipsFpAbiFlag(Flags.fp_abi, S->fp_abi, Filename);
- };
-
- if (Create)
- return make<MipsAbiFlagsSection<ELFT>>(Flags);
- return nullptr;
-}
-
-// .MIPS.options section.
-template <class ELFT>
-MipsOptionsSection<ELFT>::MipsOptionsSection(Elf_Mips_RegInfo Reginfo)
- : SyntheticSection(SHF_ALLOC, SHT_MIPS_OPTIONS, 8, ".MIPS.options"),
- Reginfo(Reginfo) {
- this->Entsize = sizeof(Elf_Mips_Options) + sizeof(Elf_Mips_RegInfo);
-}
-
-template <class ELFT> void MipsOptionsSection<ELFT>::writeTo(uint8_t *Buf) {
- auto *Options = reinterpret_cast<Elf_Mips_Options *>(Buf);
- Options->kind = ODK_REGINFO;
- Options->size = getSize();
-
- if (!Config->Relocatable)
- Reginfo.ri_gp_value = InX::MipsGot->getGp();
- memcpy(Buf + sizeof(Elf_Mips_Options), &Reginfo, sizeof(Reginfo));
-}
-
-template <class ELFT>
-MipsOptionsSection<ELFT> *MipsOptionsSection<ELFT>::create() {
- // N64 ABI only.
- if (!ELFT::Is64Bits)
- return nullptr;
-
- Elf_Mips_RegInfo Reginfo = {};
- bool Create = false;
-
- for (InputSectionBase *Sec : InputSections) {
- if (Sec->Type != SHT_MIPS_OPTIONS)
- continue;
- Sec->Live = false;
- Create = true;
-
- std::string Filename = toString(Sec->getFile<ELFT>());
- ArrayRef<uint8_t> D = Sec->Data;
-
- while (!D.empty()) {
- if (D.size() < sizeof(Elf_Mips_Options)) {
- error(Filename + ": invalid size of .MIPS.options section");
- break;
- }
-
- auto *Opt = reinterpret_cast<const Elf_Mips_Options *>(D.data());
- if (Opt->kind == ODK_REGINFO) {
- if (Config->Relocatable && Opt->getRegInfo().ri_gp_value)
- error(Filename + ": unsupported non-zero ri_gp_value");
- Reginfo.ri_gprmask |= Opt->getRegInfo().ri_gprmask;
- Sec->getFile<ELFT>()->MipsGp0 = Opt->getRegInfo().ri_gp_value;
- break;
- }
-
- if (!Opt->size)
- fatal(Filename + ": zero option descriptor size");
- D = D.slice(Opt->size);
- }
- };
-
- if (Create)
- return make<MipsOptionsSection<ELFT>>(Reginfo);
- return nullptr;
-}
-
-// MIPS .reginfo section.
-template <class ELFT>
-MipsReginfoSection<ELFT>::MipsReginfoSection(Elf_Mips_RegInfo Reginfo)
- : SyntheticSection(SHF_ALLOC, SHT_MIPS_REGINFO, 4, ".reginfo"),
- Reginfo(Reginfo) {
- this->Entsize = sizeof(Elf_Mips_RegInfo);
-}
-
-template <class ELFT> void MipsReginfoSection<ELFT>::writeTo(uint8_t *Buf) {
- if (!Config->Relocatable)
- Reginfo.ri_gp_value = InX::MipsGot->getGp();
- memcpy(Buf, &Reginfo, sizeof(Reginfo));
-}
-
-template <class ELFT>
-MipsReginfoSection<ELFT> *MipsReginfoSection<ELFT>::create() {
- // Section should be alive for O32 and N32 ABIs only.
- if (ELFT::Is64Bits)
- return nullptr;
-
- Elf_Mips_RegInfo Reginfo = {};
- bool Create = false;
-
- for (InputSectionBase *Sec : InputSections) {
- if (Sec->Type != SHT_MIPS_REGINFO)
- continue;
- Sec->Live = false;
- Create = true;
-
- if (Sec->Data.size() != sizeof(Elf_Mips_RegInfo)) {
- error(toString(Sec->getFile<ELFT>()) +
- ": invalid size of .reginfo section");
- return nullptr;
- }
- auto *R = reinterpret_cast<const Elf_Mips_RegInfo *>(Sec->Data.data());
- if (Config->Relocatable && R->ri_gp_value)
- error(toString(Sec->getFile<ELFT>()) +
- ": unsupported non-zero ri_gp_value");
-
- Reginfo.ri_gprmask |= R->ri_gprmask;
- Sec->getFile<ELFT>()->MipsGp0 = R->ri_gp_value;
- };
-
- if (Create)
- return make<MipsReginfoSection<ELFT>>(Reginfo);
- return nullptr;
-}
-
-InputSection *elf::createInterpSection() {
- // StringSaver guarantees that the returned string ends with '\0'.
- StringRef S = Saver.save(Config->DynamicLinker);
- ArrayRef<uint8_t> Contents = {(const uint8_t *)S.data(), S.size() + 1};
-
- auto *Sec =
- make<InputSection>(SHF_ALLOC, SHT_PROGBITS, 1, Contents, ".interp");
- Sec->Live = true;
- return Sec;
-}
-
-SymbolBody *elf::addSyntheticLocal(StringRef Name, uint8_t Type, uint64_t Value,
- uint64_t Size, InputSectionBase *Section) {
- auto *S = make<DefinedRegular>(Name, /*IsLocal*/ true, STV_DEFAULT, Type,
- Value, Size, Section);
- if (InX::SymTab)
- InX::SymTab->addSymbol(S);
- return S;
-}
-
-static size_t getHashSize() {
- switch (Config->BuildId) {
- case BuildIdKind::Fast:
- return 8;
- case BuildIdKind::Md5:
- case BuildIdKind::Uuid:
- return 16;
- case BuildIdKind::Sha1:
- return 20;
- case BuildIdKind::Hexstring:
- return Config->BuildIdVector.size();
- default:
- llvm_unreachable("unknown BuildIdKind");
- }
-}
-
-BuildIdSection::BuildIdSection()
- : SyntheticSection(SHF_ALLOC, SHT_NOTE, 1, ".note.gnu.build-id"),
- HashSize(getHashSize()) {}
-
-void BuildIdSection::writeTo(uint8_t *Buf) {
- endianness E = Config->Endianness;
- write32(Buf, 4, E); // Name size
- write32(Buf + 4, HashSize, E); // Content size
- write32(Buf + 8, NT_GNU_BUILD_ID, E); // Type
- memcpy(Buf + 12, "GNU", 4); // Name string
- HashBuf = Buf + 16;
-}
-
-// Split one uint8 array into small pieces of uint8 arrays.
-static std::vector<ArrayRef<uint8_t>> split(ArrayRef<uint8_t> Arr,
- size_t ChunkSize) {
- std::vector<ArrayRef<uint8_t>> Ret;
- while (Arr.size() > ChunkSize) {
- Ret.push_back(Arr.take_front(ChunkSize));
- Arr = Arr.drop_front(ChunkSize);
- }
- if (!Arr.empty())
- Ret.push_back(Arr);
- return Ret;
-}
-
-// Computes a hash value of Data using a given hash function.
-// In order to utilize multiple cores, we first split data into 1MB
-// chunks, compute a hash for each chunk, and then compute a hash value
-// of the hash values.
-void BuildIdSection::computeHash(
- llvm::ArrayRef<uint8_t> Data,
- std::function<void(uint8_t *Dest, ArrayRef<uint8_t> Arr)> HashFn) {
- std::vector<ArrayRef<uint8_t>> Chunks = split(Data, 1024 * 1024);
- std::vector<uint8_t> Hashes(Chunks.size() * HashSize);
-
- // Compute hash values.
- parallelForEachN(0, Chunks.size(), [&](size_t I) {
- HashFn(Hashes.data() + I * HashSize, Chunks[I]);
- });
-
- // Write to the final output buffer.
- HashFn(HashBuf, Hashes);
-}
-
-BssSection::BssSection(StringRef Name)
- : SyntheticSection(SHF_ALLOC | SHF_WRITE, SHT_NOBITS, 0, Name) {}
-
-size_t BssSection::reserveSpace(uint64_t Size, uint32_t Alignment) {
- if (OutputSection *Sec = getParent())
- Sec->updateAlignment(Alignment);
- this->Size = alignTo(this->Size, Alignment) + Size;
- this->Alignment = std::max(this->Alignment, Alignment);
- return this->Size - Size;
-}
-
-void BuildIdSection::writeBuildId(ArrayRef<uint8_t> Buf) {
- switch (Config->BuildId) {
- case BuildIdKind::Fast:
- computeHash(Buf, [](uint8_t *Dest, ArrayRef<uint8_t> Arr) {
- write64le(Dest, xxHash64(toStringRef(Arr)));
- });
- break;
- case BuildIdKind::Md5:
- computeHash(Buf, [](uint8_t *Dest, ArrayRef<uint8_t> Arr) {
- memcpy(Dest, MD5::hash(Arr).data(), 16);
- });
- break;
- case BuildIdKind::Sha1:
- computeHash(Buf, [](uint8_t *Dest, ArrayRef<uint8_t> Arr) {
- memcpy(Dest, SHA1::hash(Arr).data(), 20);
- });
- break;
- case BuildIdKind::Uuid:
- if (getRandomBytes(HashBuf, HashSize))
- error("entropy source failure");
- break;
- case BuildIdKind::Hexstring:
- memcpy(HashBuf, Config->BuildIdVector.data(), Config->BuildIdVector.size());
- break;
- default:
- llvm_unreachable("unknown BuildIdKind");
- }
-}
-
-template <class ELFT>
-EhFrameSection<ELFT>::EhFrameSection()
- : SyntheticSection(SHF_ALLOC, SHT_PROGBITS, 1, ".eh_frame") {}
-
-// Search for an existing CIE record or create a new one.
-// CIE records from input object files are uniquified by their contents
-// and where their relocations point to.
-template <class ELFT>
-template <class RelTy>
-CieRecord *EhFrameSection<ELFT>::addCie(EhSectionPiece &Cie,
- ArrayRef<RelTy> Rels) {
- auto *Sec = cast<EhInputSection>(Cie.Sec);
- const endianness E = ELFT::TargetEndianness;
- if (read32<E>(Cie.data().data() + 4) != 0)
- fatal(toString(Sec) + ": CIE expected at beginning of .eh_frame");
-
- SymbolBody *Personality = nullptr;
- unsigned FirstRelI = Cie.FirstRelocation;
- if (FirstRelI != (unsigned)-1)
- Personality =
- &Sec->template getFile<ELFT>()->getRelocTargetSym(Rels[FirstRelI]);
-
- // Search for an existing CIE by CIE contents/relocation target pair.
- CieRecord *&Rec = CieMap[{Cie.data(), Personality}];
-
- // If not found, create a new one.
- if (!Rec) {
- Rec = make<CieRecord>();
- Rec->Cie = &Cie;
- CieRecords.push_back(Rec);
- }
- return Rec;
-}
-
-// There is one FDE per function. Returns true if a given FDE
-// points to a live function.
-template <class ELFT>
-template <class RelTy>
-bool EhFrameSection<ELFT>::isFdeLive(EhSectionPiece &Fde,
- ArrayRef<RelTy> Rels) {
- auto *Sec = cast<EhInputSection>(Fde.Sec);
- unsigned FirstRelI = Fde.FirstRelocation;
-
- // An FDE should point to some function because FDEs are to describe
- // functions. That's however not always the case due to an issue of
- // ld.gold with -r. ld.gold may discard only functions and leave their
- // corresponding FDEs, which results in creating bad .eh_frame sections.
- // To deal with that, we ignore such FDEs.
- if (FirstRelI == (unsigned)-1)
- return false;
-
- const RelTy &Rel = Rels[FirstRelI];
- SymbolBody &B = Sec->template getFile<ELFT>()->getRelocTargetSym(Rel);
- if (auto *D = dyn_cast<DefinedRegular>(&B))
- if (D->Section)
- return cast<InputSectionBase>(D->Section)->Repl->Live;
- return false;
-}
-
-// .eh_frame is a sequence of CIE or FDE records. In general, there
-// is one CIE record per input object file which is followed by
-// a list of FDEs. This function searches an existing CIE or create a new
-// one and associates FDEs to the CIE.
-template <class ELFT>
-template <class RelTy>
-void EhFrameSection<ELFT>::addSectionAux(EhInputSection *Sec,
- ArrayRef<RelTy> Rels) {
- const endianness E = ELFT::TargetEndianness;
-
- DenseMap<size_t, CieRecord *> OffsetToCie;
- for (EhSectionPiece &Piece : Sec->Pieces) {
- // The empty record is the end marker.
- if (Piece.Size == 4)
- return;
-
- size_t Offset = Piece.InputOff;
- uint32_t ID = read32<E>(Piece.data().data() + 4);
- if (ID == 0) {
- OffsetToCie[Offset] = addCie(Piece, Rels);
- continue;
- }
-
- uint32_t CieOffset = Offset + 4 - ID;
- CieRecord *Rec = OffsetToCie[CieOffset];
- if (!Rec)
- fatal(toString(Sec) + ": invalid CIE reference");
-
- if (!isFdeLive(Piece, Rels))
- continue;
- Rec->Fdes.push_back(&Piece);
- NumFdes++;
- }
-}
-
-template <class ELFT>
-void EhFrameSection<ELFT>::addSection(InputSectionBase *C) {
- auto *Sec = cast<EhInputSection>(C);
- Sec->Parent = this;
- updateAlignment(Sec->Alignment);
- Sections.push_back(Sec);
- for (auto *DS : Sec->DependentSections)
- DependentSections.push_back(DS);
-
- // .eh_frame is a sequence of CIE or FDE records. This function
- // splits it into pieces so that we can call
- // SplitInputSection::getSectionPiece on the section.
- Sec->split<ELFT>();
- if (Sec->Pieces.empty())
- return;
-
- if (Sec->NumRelocations == 0)
- addSectionAux(Sec, makeArrayRef<Elf_Rela>(nullptr, nullptr));
- else if (Sec->AreRelocsRela)
- addSectionAux(Sec, Sec->template relas<ELFT>());
- else
- addSectionAux(Sec, Sec->template rels<ELFT>());
-}
-
-template <class ELFT>
-static void writeCieFde(uint8_t *Buf, ArrayRef<uint8_t> D) {
- memcpy(Buf, D.data(), D.size());
-
- size_t Aligned = alignTo(D.size(), sizeof(typename ELFT::uint));
-
- // Zero-clear trailing padding if it exists.
- memset(Buf + D.size(), 0, Aligned - D.size());
-
- // Fix the size field. -4 since size does not include the size field itself.
- const endianness E = ELFT::TargetEndianness;
- write32<E>(Buf, Aligned - 4);
-}
-
-template <class ELFT> void EhFrameSection<ELFT>::finalizeContents() {
- if (this->Size)
- return; // Already finalized.
-
- size_t Off = 0;
- for (CieRecord *Rec : CieRecords) {
- Rec->Cie->OutputOff = Off;
- Off += alignTo(Rec->Cie->Size, Config->Wordsize);
-
- for (EhSectionPiece *Fde : Rec->Fdes) {
- Fde->OutputOff = Off;
- Off += alignTo(Fde->Size, Config->Wordsize);
- }
- }
-
- // The LSB standard does not allow a .eh_frame section with zero
- // Call Frame Information records. Therefore add a CIE record length
- // 0 as a terminator if this .eh_frame section is empty.
- if (Off == 0)
- Off = 4;
-
- this->Size = Off;
-}
-
-template <class ELFT> static uint64_t readFdeAddr(uint8_t *Buf, int Size) {
- const endianness E = ELFT::TargetEndianness;
- switch (Size) {
- case DW_EH_PE_udata2:
- return read16<E>(Buf);
- case DW_EH_PE_udata4:
- return read32<E>(Buf);
- case DW_EH_PE_udata8:
- return read64<E>(Buf);
- case DW_EH_PE_absptr:
- if (ELFT::Is64Bits)
- return read64<E>(Buf);
- return read32<E>(Buf);
- }
- fatal("unknown FDE size encoding");
-}
-
-// Returns the VA to which a given FDE (on a mmap'ed buffer) is applied to.
-// We need it to create .eh_frame_hdr section.
-template <class ELFT>
-uint64_t EhFrameSection<ELFT>::getFdePc(uint8_t *Buf, size_t FdeOff,
- uint8_t Enc) {
- // The starting address to which this FDE applies is
- // stored at FDE + 8 byte.
- size_t Off = FdeOff + 8;
- uint64_t Addr = readFdeAddr<ELFT>(Buf + Off, Enc & 0x7);
- if ((Enc & 0x70) == DW_EH_PE_absptr)
- return Addr;
- if ((Enc & 0x70) == DW_EH_PE_pcrel)
- return Addr + getParent()->Addr + Off;
- fatal("unknown FDE size relative encoding");
-}
-
-template <class ELFT> void EhFrameSection<ELFT>::writeTo(uint8_t *Buf) {
- const endianness E = ELFT::TargetEndianness;
- for (CieRecord *Rec : CieRecords) {
- size_t CieOffset = Rec->Cie->OutputOff;
- writeCieFde<ELFT>(Buf + CieOffset, Rec->Cie->data());
-
- for (EhSectionPiece *Fde : Rec->Fdes) {
- size_t Off = Fde->OutputOff;
- writeCieFde<ELFT>(Buf + Off, Fde->data());
-
- // FDE's second word should have the offset to an associated CIE.
- // Write it.
- write32<E>(Buf + Off + 4, Off + 4 - CieOffset);
- }
- }
-
- for (EhInputSection *S : Sections)
- S->relocateAlloc(Buf, nullptr);
-
- // Construct .eh_frame_hdr. .eh_frame_hdr is a binary search table
- // to get a FDE from an address to which FDE is applied. So here
- // we obtain two addresses and pass them to EhFrameHdr object.
- if (In<ELFT>::EhFrameHdr) {
- for (CieRecord *Rec : CieRecords) {
- uint8_t Enc = getFdeEncoding<ELFT>(Rec->Cie);
- for (EhSectionPiece *Fde : Rec->Fdes) {
- uint64_t Pc = getFdePc(Buf, Fde->OutputOff, Enc);
- uint64_t FdeVA = getParent()->Addr + Fde->OutputOff;
- In<ELFT>::EhFrameHdr->addFde(Pc, FdeVA);
- }
- }
- }
-}
-
-GotSection::GotSection()
- : SyntheticSection(SHF_ALLOC | SHF_WRITE, SHT_PROGBITS,
- Target->GotEntrySize, ".got") {}
-
-void GotSection::addEntry(SymbolBody &Sym) {
- Sym.GotIndex = NumEntries;
- ++NumEntries;
-}
-
-bool GotSection::addDynTlsEntry(SymbolBody &Sym) {
- if (Sym.GlobalDynIndex != -1U)
- return false;
- Sym.GlobalDynIndex = NumEntries;
- // Global Dynamic TLS entries take two GOT slots.
- NumEntries += 2;
- return true;
-}
-
-// Reserves TLS entries for a TLS module ID and a TLS block offset.
-// In total it takes two GOT slots.
-bool GotSection::addTlsIndex() {
- if (TlsIndexOff != uint32_t(-1))
- return false;
- TlsIndexOff = NumEntries * Config->Wordsize;
- NumEntries += 2;
- return true;
-}
-
-uint64_t GotSection::getGlobalDynAddr(const SymbolBody &B) const {
- return this->getVA() + B.GlobalDynIndex * Config->Wordsize;
-}
-
-uint64_t GotSection::getGlobalDynOffset(const SymbolBody &B) const {
- return B.GlobalDynIndex * Config->Wordsize;
-}
-
-void GotSection::finalizeContents() { Size = NumEntries * Config->Wordsize; }
-
-bool GotSection::empty() const {
- // We need to emit a GOT even if it's empty if there's a relocation that is
- // relative to GOT(such as GOTOFFREL) or there's a symbol that points to a GOT
- // (i.e. _GLOBAL_OFFSET_TABLE_).
- return NumEntries == 0 && !HasGotOffRel && !ElfSym::GlobalOffsetTable;
-}
-
-void GotSection::writeTo(uint8_t *Buf) {
- // Buf points to the start of this section's buffer,
- // whereas InputSectionBase::relocateAlloc() expects its argument
- // to point to the start of the output section.
- relocateAlloc(Buf - OutSecOff, Buf - OutSecOff + Size);
-}
-
-MipsGotSection::MipsGotSection()
- : SyntheticSection(SHF_ALLOC | SHF_WRITE | SHF_MIPS_GPREL, SHT_PROGBITS, 16,
- ".got") {}
-
-void MipsGotSection::addEntry(SymbolBody &Sym, int64_t Addend, RelExpr Expr) {
- // For "true" local symbols which can be referenced from the same module
- // only compiler creates two instructions for address loading:
- //
- // lw $8, 0($gp) # R_MIPS_GOT16
- // addi $8, $8, 0 # R_MIPS_LO16
- //
- // The first instruction loads high 16 bits of the symbol address while
- // the second adds an offset. That allows to reduce number of required
- // GOT entries because only one global offset table entry is necessary
- // for every 64 KBytes of local data. So for local symbols we need to
- // allocate number of GOT entries to hold all required "page" addresses.
- //
- // All global symbols (hidden and regular) considered by compiler uniformly.
- // It always generates a single `lw` instruction and R_MIPS_GOT16 relocation
- // to load address of the symbol. So for each such symbol we need to
- // allocate dedicated GOT entry to store its address.
- //
- // If a symbol is preemptible we need help of dynamic linker to get its
- // final address. The corresponding GOT entries are allocated in the
- // "global" part of GOT. Entries for non preemptible global symbol allocated
- // in the "local" part of GOT.
- //
- // See "Global Offset Table" in Chapter 5:
- // ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
- if (Expr == R_MIPS_GOT_LOCAL_PAGE) {
- // At this point we do not know final symbol value so to reduce number
- // of allocated GOT entries do the following trick. Save all output
- // sections referenced by GOT relocations. Then later in the `finalize`
- // method calculate number of "pages" required to cover all saved output
- // section and allocate appropriate number of GOT entries.
- PageIndexMap.insert({Sym.getOutputSection(), 0});
- return;
- }
- if (Sym.isTls()) {
- // GOT entries created for MIPS TLS relocations behave like
- // almost GOT entries from other ABIs. They go to the end
- // of the global offset table.
- Sym.GotIndex = TlsEntries.size();
- TlsEntries.push_back(&Sym);
- return;
- }
- auto AddEntry = [&](SymbolBody &S, uint64_t A, GotEntries &Items) {
- if (S.isInGot() && !A)
- return;
- size_t NewIndex = Items.size();
- if (!EntryIndexMap.insert({{&S, A}, NewIndex}).second)
- return;
- Items.emplace_back(&S, A);
- if (!A)
- S.GotIndex = NewIndex;
- };
- if (Sym.isPreemptible()) {
- // Ignore addends for preemptible symbols. They got single GOT entry anyway.
- AddEntry(Sym, 0, GlobalEntries);
- Sym.IsInGlobalMipsGot = true;
- } else if (Expr == R_MIPS_GOT_OFF32) {
- AddEntry(Sym, Addend, LocalEntries32);
- Sym.Is32BitMipsGot = true;
- } else {
- // Hold local GOT entries accessed via a 16-bit index separately.
- // That allows to write them in the beginning of the GOT and keep
- // their indexes as less as possible to escape relocation's overflow.
- AddEntry(Sym, Addend, LocalEntries);
- }
-}
-
-bool MipsGotSection::addDynTlsEntry(SymbolBody &Sym) {
- if (Sym.GlobalDynIndex != -1U)
- return false;
- Sym.GlobalDynIndex = TlsEntries.size();
- // Global Dynamic TLS entries take two GOT slots.
- TlsEntries.push_back(nullptr);
- TlsEntries.push_back(&Sym);
- return true;
-}
-
-// Reserves TLS entries for a TLS module ID and a TLS block offset.
-// In total it takes two GOT slots.
-bool MipsGotSection::addTlsIndex() {
- if (TlsIndexOff != uint32_t(-1))
- return false;
- TlsIndexOff = TlsEntries.size() * Config->Wordsize;
- TlsEntries.push_back(nullptr);
- TlsEntries.push_back(nullptr);
- return true;
-}
-
-static uint64_t getMipsPageAddr(uint64_t Addr) {
- return (Addr + 0x8000) & ~0xffff;
-}
-
-static uint64_t getMipsPageCount(uint64_t Size) {
- return (Size + 0xfffe) / 0xffff + 1;
-}
-
-uint64_t MipsGotSection::getPageEntryOffset(const SymbolBody &B,
- int64_t Addend) const {
- const OutputSection *OutSec = B.getOutputSection();
- uint64_t SecAddr = getMipsPageAddr(OutSec->Addr);
- uint64_t SymAddr = getMipsPageAddr(B.getVA(Addend));
- uint64_t Index = PageIndexMap.lookup(OutSec) + (SymAddr - SecAddr) / 0xffff;
- assert(Index < PageEntriesNum);
- return (HeaderEntriesNum + Index) * Config->Wordsize;
-}
-
-uint64_t MipsGotSection::getBodyEntryOffset(const SymbolBody &B,
- int64_t Addend) const {
- // Calculate offset of the GOT entries block: TLS, global, local.
- uint64_t Index = HeaderEntriesNum + PageEntriesNum;
- if (B.isTls())
- Index += LocalEntries.size() + LocalEntries32.size() + GlobalEntries.size();
- else if (B.IsInGlobalMipsGot)
- Index += LocalEntries.size() + LocalEntries32.size();
- else if (B.Is32BitMipsGot)
- Index += LocalEntries.size();
- // Calculate offset of the GOT entry in the block.
- if (B.isInGot())
- Index += B.GotIndex;
- else {
- auto It = EntryIndexMap.find({&B, Addend});
- assert(It != EntryIndexMap.end());
- Index += It->second;
- }
- return Index * Config->Wordsize;
-}
-
-uint64_t MipsGotSection::getTlsOffset() const {
- return (getLocalEntriesNum() + GlobalEntries.size()) * Config->Wordsize;
-}
-
-uint64_t MipsGotSection::getGlobalDynOffset(const SymbolBody &B) const {
- return B.GlobalDynIndex * Config->Wordsize;
-}
-
-const SymbolBody *MipsGotSection::getFirstGlobalEntry() const {
- return GlobalEntries.empty() ? nullptr : GlobalEntries.front().first;
-}
-
-unsigned MipsGotSection::getLocalEntriesNum() const {
- return HeaderEntriesNum + PageEntriesNum + LocalEntries.size() +
- LocalEntries32.size();
-}
-
-void MipsGotSection::finalizeContents() { updateAllocSize(); }
-
-void MipsGotSection::updateAllocSize() {
- PageEntriesNum = 0;
- for (std::pair<const OutputSection *, size_t> &P : PageIndexMap) {
- // For each output section referenced by GOT page relocations calculate
- // and save into PageIndexMap an upper bound of MIPS GOT entries required
- // to store page addresses of local symbols. We assume the worst case -
- // each 64kb page of the output section has at least one GOT relocation
- // against it. And take in account the case when the section intersects
- // page boundaries.
- P.second = PageEntriesNum;
- PageEntriesNum += getMipsPageCount(P.first->Size);
- }
- Size = (getLocalEntriesNum() + GlobalEntries.size() + TlsEntries.size()) *
- Config->Wordsize;
-}
-
-bool MipsGotSection::empty() const {
- // We add the .got section to the result for dynamic MIPS target because
- // its address and properties are mentioned in the .dynamic section.
- return Config->Relocatable;
-}
-
-uint64_t MipsGotSection::getGp() const { return ElfSym::MipsGp->getVA(0); }
-
-static uint64_t readUint(uint8_t *Buf) {
- if (Config->Is64)
- return read64(Buf, Config->Endianness);
- return read32(Buf, Config->Endianness);
-}
-
-static void writeUint(uint8_t *Buf, uint64_t Val) {
- if (Config->Is64)
- write64(Buf, Val, Config->Endianness);
- else
- write32(Buf, Val, Config->Endianness);
-}
-
-void MipsGotSection::writeTo(uint8_t *Buf) {
- // Set the MSB of the second GOT slot. This is not required by any
- // MIPS ABI documentation, though.
- //
- // There is a comment in glibc saying that "The MSB of got[1] of a
- // gnu object is set to identify gnu objects," and in GNU gold it
- // says "the second entry will be used by some runtime loaders".
- // But how this field is being used is unclear.
- //
- // We are not really willing to mimic other linkers behaviors
- // without understanding why they do that, but because all files
- // generated by GNU tools have this special GOT value, and because
- // we've been doing this for years, it is probably a safe bet to
- // keep doing this for now. We really need to revisit this to see
- // if we had to do this.
- writeUint(Buf + Config->Wordsize, (uint64_t)1 << (Config->Wordsize * 8 - 1));
- Buf += HeaderEntriesNum * Config->Wordsize;
- // Write 'page address' entries to the local part of the GOT.
- for (std::pair<const OutputSection *, size_t> &L : PageIndexMap) {
- size_t PageCount = getMipsPageCount(L.first->Size);
- uint64_t FirstPageAddr = getMipsPageAddr(L.first->Addr);
- for (size_t PI = 0; PI < PageCount; ++PI) {
- uint8_t *Entry = Buf + (L.second + PI) * Config->Wordsize;
- writeUint(Entry, FirstPageAddr + PI * 0x10000);
- }
- }
- Buf += PageEntriesNum * Config->Wordsize;
- auto AddEntry = [&](const GotEntry &SA) {
- uint8_t *Entry = Buf;
- Buf += Config->Wordsize;
- const SymbolBody *Body = SA.first;
- uint64_t VA = Body->getVA(SA.second);
- writeUint(Entry, VA);
- };
- std::for_each(std::begin(LocalEntries), std::end(LocalEntries), AddEntry);
- std::for_each(std::begin(LocalEntries32), std::end(LocalEntries32), AddEntry);
- std::for_each(std::begin(GlobalEntries), std::end(GlobalEntries), AddEntry);
- // Initialize TLS-related GOT entries. If the entry has a corresponding
- // dynamic relocations, leave it initialized by zero. Write down adjusted
- // TLS symbol's values otherwise. To calculate the adjustments use offsets
- // for thread-local storage.
- // https://www.linux-mips.org/wiki/NPTL
- if (TlsIndexOff != -1U && !Config->Pic)
- writeUint(Buf + TlsIndexOff, 1);
- for (const SymbolBody *B : TlsEntries) {
- if (!B || B->isPreemptible())
- continue;
- uint64_t VA = B->getVA();
- if (B->GotIndex != -1U) {
- uint8_t *Entry = Buf + B->GotIndex * Config->Wordsize;
- writeUint(Entry, VA - 0x7000);
- }
- if (B->GlobalDynIndex != -1U) {
- uint8_t *Entry = Buf + B->GlobalDynIndex * Config->Wordsize;
- writeUint(Entry, 1);
- Entry += Config->Wordsize;
- writeUint(Entry, VA - 0x8000);
- }
- }
-}
-
-GotPltSection::GotPltSection()
- : SyntheticSection(SHF_ALLOC | SHF_WRITE, SHT_PROGBITS,
- Target->GotPltEntrySize, ".got.plt") {}
-
-void GotPltSection::addEntry(SymbolBody &Sym) {
- Sym.GotPltIndex = Target->GotPltHeaderEntriesNum + Entries.size();
- Entries.push_back(&Sym);
-}
-
-size_t GotPltSection::getSize() const {
- return (Target->GotPltHeaderEntriesNum + Entries.size()) *
- Target->GotPltEntrySize;
-}
-
-void GotPltSection::writeTo(uint8_t *Buf) {
- Target->writeGotPltHeader(Buf);
- Buf += Target->GotPltHeaderEntriesNum * Target->GotPltEntrySize;
- for (const SymbolBody *B : Entries) {
- Target->writeGotPlt(Buf, *B);
- Buf += Config->Wordsize;
- }
-}
-
-// On ARM the IgotPltSection is part of the GotSection, on other Targets it is
-// part of the .got.plt
-IgotPltSection::IgotPltSection()
- : SyntheticSection(SHF_ALLOC | SHF_WRITE, SHT_PROGBITS,
- Target->GotPltEntrySize,
- Config->EMachine == EM_ARM ? ".got" : ".got.plt") {}
-
-void IgotPltSection::addEntry(SymbolBody &Sym) {
- Sym.IsInIgot = true;
- Sym.GotPltIndex = Entries.size();
- Entries.push_back(&Sym);
-}
-
-size_t IgotPltSection::getSize() const {
- return Entries.size() * Target->GotPltEntrySize;
-}
-
-void IgotPltSection::writeTo(uint8_t *Buf) {
- for (const SymbolBody *B : Entries) {
- Target->writeIgotPlt(Buf, *B);
- Buf += Config->Wordsize;
- }
-}
-
-StringTableSection::StringTableSection(StringRef Name, bool Dynamic)
- : SyntheticSection(Dynamic ? (uint64_t)SHF_ALLOC : 0, SHT_STRTAB, 1, Name),
- Dynamic(Dynamic) {
- // ELF string tables start with a NUL byte.
- addString("");
-}
-
-// Adds a string to the string table. If HashIt is true we hash and check for
-// duplicates. It is optional because the name of global symbols are already
-// uniqued and hashing them again has a big cost for a small value: uniquing
-// them with some other string that happens to be the same.
-unsigned StringTableSection::addString(StringRef S, bool HashIt) {
- if (HashIt) {
- auto R = StringMap.insert(std::make_pair(S, this->Size));
- if (!R.second)
- return R.first->second;
- }
- unsigned Ret = this->Size;
- this->Size = this->Size + S.size() + 1;
- Strings.push_back(S);
- return Ret;
-}
-
-void StringTableSection::writeTo(uint8_t *Buf) {
- for (StringRef S : Strings) {
- memcpy(Buf, S.data(), S.size());
- Buf[S.size()] = '\0';
- Buf += S.size() + 1;
- }
-}
-
-// Returns the number of version definition entries. Because the first entry
-// is for the version definition itself, it is the number of versioned symbols
-// plus one. Note that we don't support multiple versions yet.
-static unsigned getVerDefNum() { return Config->VersionDefinitions.size() + 1; }
-
-template <class ELFT>
-DynamicSection<ELFT>::DynamicSection()
- : SyntheticSection(SHF_ALLOC | SHF_WRITE, SHT_DYNAMIC, Config->Wordsize,
- ".dynamic") {
- this->Entsize = ELFT::Is64Bits ? 16 : 8;
-
- // .dynamic section is not writable on MIPS and on Fuchsia OS
- // which passes -z rodynamic.
- // See "Special Section" in Chapter 4 in the following document:
- // ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
- if (Config->EMachine == EM_MIPS || Config->ZRodynamic)
- this->Flags = SHF_ALLOC;
-
- addEntries();
-}
-
-// There are some dynamic entries that don't depend on other sections.
-// Such entries can be set early.
-template <class ELFT> void DynamicSection<ELFT>::addEntries() {
- // Add strings to .dynstr early so that .dynstr's size will be
- // fixed early.
- for (StringRef S : Config->FilterList)
- add({DT_FILTER, InX::DynStrTab->addString(S)});
- for (StringRef S : Config->AuxiliaryList)
- add({DT_AUXILIARY, InX::DynStrTab->addString(S)});
- if (!Config->Rpath.empty())
- add({Config->EnableNewDtags ? DT_RUNPATH : DT_RPATH,
- InX::DynStrTab->addString(Config->Rpath)});
- for (InputFile *File : SharedFiles) {
- SharedFile<ELFT> *F = cast<SharedFile<ELFT>>(File);
- if (F->isNeeded())
- add({DT_NEEDED, InX::DynStrTab->addString(F->SoName)});
- }
- if (!Config->SoName.empty())
- add({DT_SONAME, InX::DynStrTab->addString(Config->SoName)});
-
- // Set DT_FLAGS and DT_FLAGS_1.
- uint32_t DtFlags = 0;
- uint32_t DtFlags1 = 0;
- if (Config->Bsymbolic)
- DtFlags |= DF_SYMBOLIC;
- if (Config->ZNodelete)
- DtFlags1 |= DF_1_NODELETE;
- if (Config->ZNodlopen)
- DtFlags1 |= DF_1_NOOPEN;
- if (Config->ZNow) {
- DtFlags |= DF_BIND_NOW;
- DtFlags1 |= DF_1_NOW;
- }
- if (Config->ZOrigin) {
- DtFlags |= DF_ORIGIN;
- DtFlags1 |= DF_1_ORIGIN;
- }
-
- if (DtFlags)
- add({DT_FLAGS, DtFlags});
- if (DtFlags1)
- add({DT_FLAGS_1, DtFlags1});
-
- // DT_DEBUG is a pointer to debug informaion used by debuggers at runtime. We
- // need it for each process, so we don't write it for DSOs. The loader writes
- // the pointer into this entry.
- //
- // DT_DEBUG is the only .dynamic entry that needs to be written to. Some
- // systems (currently only Fuchsia OS) provide other means to give the
- // debugger this information. Such systems may choose make .dynamic read-only.
- // If the target is such a system (used -z rodynamic) don't write DT_DEBUG.
- if (!Config->Shared && !Config->Relocatable && !Config->ZRodynamic)
- add({DT_DEBUG, (uint64_t)0});
-}
-
-// Add remaining entries to complete .dynamic contents.
-template <class ELFT> void DynamicSection<ELFT>::finalizeContents() {
- if (this->Size)
- return; // Already finalized.
-
- this->Link = InX::DynStrTab->getParent()->SectionIndex;
- if (In<ELFT>::RelaDyn->getParent() && !In<ELFT>::RelaDyn->empty()) {
- bool IsRela = Config->IsRela;
- add({IsRela ? DT_RELA : DT_REL, In<ELFT>::RelaDyn});
- add({IsRela ? DT_RELASZ : DT_RELSZ, In<ELFT>::RelaDyn->getParent(),
- Entry::SecSize});
- add({IsRela ? DT_RELAENT : DT_RELENT,
- uint64_t(IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel))});
-
- // MIPS dynamic loader does not support RELCOUNT tag.
- // The problem is in the tight relation between dynamic
- // relocations and GOT. So do not emit this tag on MIPS.
- if (Config->EMachine != EM_MIPS) {
- size_t NumRelativeRels = In<ELFT>::RelaDyn->getRelativeRelocCount();
- if (Config->ZCombreloc && NumRelativeRels)
- add({IsRela ? DT_RELACOUNT : DT_RELCOUNT, NumRelativeRels});
- }
- }
- if (In<ELFT>::RelaPlt->getParent() && !In<ELFT>::RelaPlt->empty()) {
- add({DT_JMPREL, In<ELFT>::RelaPlt});
- add({DT_PLTRELSZ, In<ELFT>::RelaPlt->getParent(), Entry::SecSize});
- switch (Config->EMachine) {
- case EM_MIPS:
- add({DT_MIPS_PLTGOT, In<ELFT>::GotPlt});
- break;
- case EM_SPARCV9:
- add({DT_PLTGOT, In<ELFT>::Plt});
- break;
- default:
- add({DT_PLTGOT, In<ELFT>::GotPlt});
- break;
- }
- add({DT_PLTREL, uint64_t(Config->IsRela ? DT_RELA : DT_REL)});
- }
-
- add({DT_SYMTAB, InX::DynSymTab});
- add({DT_SYMENT, sizeof(Elf_Sym)});
- add({DT_STRTAB, InX::DynStrTab});
- add({DT_STRSZ, InX::DynStrTab->getSize()});
- if (!Config->ZText)
- add({DT_TEXTREL, (uint64_t)0});
- if (InX::GnuHashTab)
- add({DT_GNU_HASH, InX::GnuHashTab});
- if (In<ELFT>::HashTab)
- add({DT_HASH, In<ELFT>::HashTab});
-
- if (Out::PreinitArray) {
- add({DT_PREINIT_ARRAY, Out::PreinitArray});
- add({DT_PREINIT_ARRAYSZ, Out::PreinitArray, Entry::SecSize});
- }
- if (Out::InitArray) {
- add({DT_INIT_ARRAY, Out::InitArray});
- add({DT_INIT_ARRAYSZ, Out::InitArray, Entry::SecSize});
- }
- if (Out::FiniArray) {
- add({DT_FINI_ARRAY, Out::FiniArray});
- add({DT_FINI_ARRAYSZ, Out::FiniArray, Entry::SecSize});
- }
-
- if (SymbolBody *B = Symtab->find(Config->Init))
- if (B->isInCurrentDSO())
- add({DT_INIT, B});
- if (SymbolBody *B = Symtab->find(Config->Fini))
- if (B->isInCurrentDSO())
- add({DT_FINI, B});
-
- bool HasVerNeed = In<ELFT>::VerNeed->getNeedNum() != 0;
- if (HasVerNeed || In<ELFT>::VerDef)
- add({DT_VERSYM, In<ELFT>::VerSym});
- if (In<ELFT>::VerDef) {
- add({DT_VERDEF, In<ELFT>::VerDef});
- add({DT_VERDEFNUM, getVerDefNum()});
- }
- if (HasVerNeed) {
- add({DT_VERNEED, In<ELFT>::VerNeed});
- add({DT_VERNEEDNUM, In<ELFT>::VerNeed->getNeedNum()});
- }
-
- if (Config->EMachine == EM_MIPS) {
- add({DT_MIPS_RLD_VERSION, 1});
- add({DT_MIPS_FLAGS, RHF_NOTPOT});
- add({DT_MIPS_BASE_ADDRESS, Config->ImageBase});
- add({DT_MIPS_SYMTABNO, InX::DynSymTab->getNumSymbols()});
- add({DT_MIPS_LOCAL_GOTNO, InX::MipsGot->getLocalEntriesNum()});
- if (const SymbolBody *B = InX::MipsGot->getFirstGlobalEntry())
- add({DT_MIPS_GOTSYM, B->DynsymIndex});
- else
- add({DT_MIPS_GOTSYM, InX::DynSymTab->getNumSymbols()});
- add({DT_PLTGOT, InX::MipsGot});
- if (InX::MipsRldMap)
- add({DT_MIPS_RLD_MAP, InX::MipsRldMap});
- }
-
- getParent()->Link = this->Link;
-
- // +1 for DT_NULL
- this->Size = (Entries.size() + 1) * this->Entsize;
-}
-
-template <class ELFT> void DynamicSection<ELFT>::writeTo(uint8_t *Buf) {
- auto *P = reinterpret_cast<Elf_Dyn *>(Buf);
-
- for (const Entry &E : Entries) {
- P->d_tag = E.Tag;
- switch (E.Kind) {
- case Entry::SecAddr:
- P->d_un.d_ptr = E.OutSec->Addr;
- break;
- case Entry::InSecAddr:
- P->d_un.d_ptr = E.InSec->getParent()->Addr + E.InSec->OutSecOff;
- break;
- case Entry::SecSize:
- P->d_un.d_val = E.OutSec->Size;
- break;
- case Entry::SymAddr:
- P->d_un.d_ptr = E.Sym->getVA();
- break;
- case Entry::PlainInt:
- P->d_un.d_val = E.Val;
- break;
- }
- ++P;
- }
-}
-
-uint64_t DynamicReloc::getOffset() const {
- return InputSec->getOutputSection()->Addr + InputSec->getOffset(OffsetInSec);
-}
-
-int64_t DynamicReloc::getAddend() const {
- if (UseSymVA)
- return Sym->getVA(Addend);
- return Addend;
-}
-
-uint32_t DynamicReloc::getSymIndex() const {
- if (Sym && !UseSymVA)
- return Sym->DynsymIndex;
- return 0;
-}
-
-template <class ELFT>
-RelocationSection<ELFT>::RelocationSection(StringRef Name, bool Sort)
- : SyntheticSection(SHF_ALLOC, Config->IsRela ? SHT_RELA : SHT_REL,
- Config->Wordsize, Name),
- Sort(Sort) {
- this->Entsize = Config->IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel);
-}
-
-template <class ELFT>
-void RelocationSection<ELFT>::addReloc(const DynamicReloc &Reloc) {
- if (Reloc.Type == Target->RelativeRel)
- ++NumRelativeRelocs;
- Relocs.push_back(Reloc);
-}
-
-template <class ELFT, class RelTy>
-static bool compRelocations(const RelTy &A, const RelTy &B) {
- bool AIsRel = A.getType(Config->IsMips64EL) == Target->RelativeRel;
- bool BIsRel = B.getType(Config->IsMips64EL) == Target->RelativeRel;
- if (AIsRel != BIsRel)
- return AIsRel;
-
- return A.getSymbol(Config->IsMips64EL) < B.getSymbol(Config->IsMips64EL);
-}
-
-template <class ELFT> void RelocationSection<ELFT>::writeTo(uint8_t *Buf) {
- uint8_t *BufBegin = Buf;
- for (const DynamicReloc &Rel : Relocs) {
- auto *P = reinterpret_cast<Elf_Rela *>(Buf);
- Buf += Config->IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel);
-
- if (Config->IsRela)
- P->r_addend = Rel.getAddend();
- P->r_offset = Rel.getOffset();
- if (Config->EMachine == EM_MIPS && Rel.getInputSec() == InX::MipsGot)
- // Dynamic relocation against MIPS GOT section make deal TLS entries
- // allocated in the end of the GOT. We need to adjust the offset to take
- // in account 'local' and 'global' GOT entries.
- P->r_offset += InX::MipsGot->getTlsOffset();
- P->setSymbolAndType(Rel.getSymIndex(), Rel.Type, Config->IsMips64EL);
- }
-
- if (Sort) {
- if (Config->IsRela)
- std::stable_sort((Elf_Rela *)BufBegin,
- (Elf_Rela *)BufBegin + Relocs.size(),
- compRelocations<ELFT, Elf_Rela>);
- else
- std::stable_sort((Elf_Rel *)BufBegin, (Elf_Rel *)BufBegin + Relocs.size(),
- compRelocations<ELFT, Elf_Rel>);
- }
-}
-
-template <class ELFT> unsigned RelocationSection<ELFT>::getRelocOffset() {
- return this->Entsize * Relocs.size();
-}
-
-template <class ELFT> void RelocationSection<ELFT>::finalizeContents() {
- this->Link = InX::DynSymTab ? InX::DynSymTab->getParent()->SectionIndex
- : InX::SymTab->getParent()->SectionIndex;
-
- // Set required output section properties.
- getParent()->Link = this->Link;
-}
-
-SymbolTableBaseSection::SymbolTableBaseSection(StringTableSection &StrTabSec)
- : SyntheticSection(StrTabSec.isDynamic() ? (uint64_t)SHF_ALLOC : 0,
- StrTabSec.isDynamic() ? SHT_DYNSYM : SHT_SYMTAB,
- Config->Wordsize,
- StrTabSec.isDynamic() ? ".dynsym" : ".symtab"),
- StrTabSec(StrTabSec) {}
-
-// Orders symbols according to their positions in the GOT,
-// in compliance with MIPS ABI rules.
-// See "Global Offset Table" in Chapter 5 in the following document
-// for detailed description:
-// ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
-static bool sortMipsSymbols(const SymbolTableEntry &L,
- const SymbolTableEntry &R) {
- // Sort entries related to non-local preemptible symbols by GOT indexes.
- // All other entries go to the first part of GOT in arbitrary order.
- bool LIsInLocalGot = !L.Symbol->IsInGlobalMipsGot;
- bool RIsInLocalGot = !R.Symbol->IsInGlobalMipsGot;
- if (LIsInLocalGot || RIsInLocalGot)
- return !RIsInLocalGot;
- return L.Symbol->GotIndex < R.Symbol->GotIndex;
-}
-
-// Finalize a symbol table. The ELF spec requires that all local
-// symbols precede global symbols, so we sort symbol entries in this
-// function. (For .dynsym, we don't do that because symbols for
-// dynamic linking are inherently all globals.)
-void SymbolTableBaseSection::finalizeContents() {
- getParent()->Link = StrTabSec.getParent()->SectionIndex;
-
- // If it is a .dynsym, there should be no local symbols, but we need
- // to do a few things for the dynamic linker.
- if (this->Type == SHT_DYNSYM) {
- // Section's Info field has the index of the first non-local symbol.
- // Because the first symbol entry is a null entry, 1 is the first.
- getParent()->Info = 1;
-
- if (InX::GnuHashTab) {
- // NB: It also sorts Symbols to meet the GNU hash table requirements.
- InX::GnuHashTab->addSymbols(Symbols);
- } else if (Config->EMachine == EM_MIPS) {
- std::stable_sort(Symbols.begin(), Symbols.end(), sortMipsSymbols);
- }
-
- size_t I = 0;
- for (const SymbolTableEntry &S : Symbols)
- S.Symbol->DynsymIndex = ++I;
- return;
- }
-}
-
-void SymbolTableBaseSection::postThunkContents() {
- if (this->Type == SHT_DYNSYM)
- return;
- // move all local symbols before global symbols.
- auto It = std::stable_partition(
- Symbols.begin(), Symbols.end(), [](const SymbolTableEntry &S) {
- return S.Symbol->isLocal() ||
- S.Symbol->symbol()->computeBinding() == STB_LOCAL;
- });
- size_t NumLocals = It - Symbols.begin();
- getParent()->Info = NumLocals + 1;
-}
-
-void SymbolTableBaseSection::addSymbol(SymbolBody *B) {
- // Adding a local symbol to a .dynsym is a bug.
- assert(this->Type != SHT_DYNSYM || !B->isLocal());
-
- bool HashIt = B->isLocal();
- Symbols.push_back({B, StrTabSec.addString(B->getName(), HashIt)});
-}
-
-size_t SymbolTableBaseSection::getSymbolIndex(SymbolBody *Body) {
- auto I = llvm::find_if(Symbols, [&](const SymbolTableEntry &E) {
- if (E.Symbol == Body)
- return true;
- // This is used for -r, so we have to handle multiple section
- // symbols being combined.
- if (Body->Type == STT_SECTION && E.Symbol->Type == STT_SECTION)
- return Body->getOutputSection() == E.Symbol->getOutputSection();
- return false;
- });
- if (I == Symbols.end())
- return 0;
- return I - Symbols.begin() + 1;
-}
-
-template <class ELFT>
-SymbolTableSection<ELFT>::SymbolTableSection(StringTableSection &StrTabSec)
- : SymbolTableBaseSection(StrTabSec) {
- this->Entsize = sizeof(Elf_Sym);
-}
-
-// Write the internal symbol table contents to the output symbol table.
-template <class ELFT> void SymbolTableSection<ELFT>::writeTo(uint8_t *Buf) {
- // The first entry is a null entry as per the ELF spec.
- Buf += sizeof(Elf_Sym);
-
- auto *ESym = reinterpret_cast<Elf_Sym *>(Buf);
-
- for (SymbolTableEntry &Ent : Symbols) {
- SymbolBody *Body = Ent.Symbol;
-
- // Set st_info and st_other.
- if (Body->isLocal()) {
- ESym->setBindingAndType(STB_LOCAL, Body->Type);
- } else {
- ESym->setBindingAndType(Body->symbol()->computeBinding(), Body->Type);
- ESym->setVisibility(Body->symbol()->Visibility);
- }
-
- ESym->st_name = Ent.StrTabOffset;
-
- // Set a section index.
- if (const OutputSection *OutSec = Body->getOutputSection())
- ESym->st_shndx = OutSec->SectionIndex;
- else if (isa<DefinedRegular>(Body))
- ESym->st_shndx = SHN_ABS;
- else if (isa<DefinedCommon>(Body))
- ESym->st_shndx = SHN_COMMON;
-
- // Copy symbol size if it is a defined symbol. st_size is not significant
- // for undefined symbols, so whether copying it or not is up to us if that's
- // the case. We'll leave it as zero because by not setting a value, we can
- // get the exact same outputs for two sets of input files that differ only
- // in undefined symbol size in DSOs.
- if (ESym->st_shndx != SHN_UNDEF)
- ESym->st_size = Body->getSize<ELFT>();
-
- // st_value is usually an address of a symbol, but that has a
- // special meaining for uninstantiated common symbols (this can
- // occur if -r is given).
- if (!Config->DefineCommon && isa<DefinedCommon>(Body))
- ESym->st_value = cast<DefinedCommon>(Body)->Alignment;
- else
- ESym->st_value = Body->getVA();
-
- ++ESym;
- }
-
- // On MIPS we need to mark symbol which has a PLT entry and requires
- // pointer equality by STO_MIPS_PLT flag. That is necessary to help
- // dynamic linker distinguish such symbols and MIPS lazy-binding stubs.
- // https://sourceware.org/ml/binutils/2008-07/txt00000.txt
- if (Config->EMachine == EM_MIPS) {
- auto *ESym = reinterpret_cast<Elf_Sym *>(Buf);
-
- for (SymbolTableEntry &Ent : Symbols) {
- SymbolBody *Body = Ent.Symbol;
- if (Body->isInPlt() && Body->NeedsPltAddr)
- ESym->st_other |= STO_MIPS_PLT;
-
- if (Config->Relocatable)
- if (auto *D = dyn_cast<DefinedRegular>(Body))
- if (D->isMipsPIC<ELFT>())
- ESym->st_other |= STO_MIPS_PIC;
- ++ESym;
- }
- }
-}
-
-// .hash and .gnu.hash sections contain on-disk hash tables that map
-// symbol names to their dynamic symbol table indices. Their purpose
-// is to help the dynamic linker resolve symbols quickly. If ELF files
-// don't have them, the dynamic linker has to do linear search on all
-// dynamic symbols, which makes programs slower. Therefore, a .hash
-// section is added to a DSO by default. A .gnu.hash is added if you
-// give the -hash-style=gnu or -hash-style=both option.
-//
-// The Unix semantics of resolving dynamic symbols is somewhat expensive.
-// Each ELF file has a list of DSOs that the ELF file depends on and a
-// list of dynamic symbols that need to be resolved from any of the
-// DSOs. That means resolving all dynamic symbols takes O(m)*O(n)
-// where m is the number of DSOs and n is the number of dynamic
-// symbols. For modern large programs, both m and n are large. So
-// making each step faster by using hash tables substiantially
-// improves time to load programs.
-//
-// (Note that this is not the only way to design the shared library.
-// For instance, the Windows DLL takes a different approach. On
-// Windows, each dynamic symbol has a name of DLL from which the symbol
-// has to be resolved. That makes the cost of symbol resolution O(n).
-// This disables some hacky techniques you can use on Unix such as
-// LD_PRELOAD, but this is arguably better semantics than the Unix ones.)
-//
-// Due to historical reasons, we have two different hash tables, .hash
-// and .gnu.hash. They are for the same purpose, and .gnu.hash is a new
-// and better version of .hash. .hash is just an on-disk hash table, but
-// .gnu.hash has a bloom filter in addition to a hash table to skip
-// DSOs very quickly. If you are sure that your dynamic linker knows
-// about .gnu.hash, you want to specify -hash-style=gnu. Otherwise, a
-// safe bet is to specify -hash-style=both for backward compatibilty.
-GnuHashTableSection::GnuHashTableSection()
- : SyntheticSection(SHF_ALLOC, SHT_GNU_HASH, Config->Wordsize, ".gnu.hash") {
-}
-
-void GnuHashTableSection::finalizeContents() {
- getParent()->Link = InX::DynSymTab->getParent()->SectionIndex;
-
- // Computes bloom filter size in word size. We want to allocate 8
- // bits for each symbol. It must be a power of two.
- if (Symbols.empty())
- MaskWords = 1;
- else
- MaskWords = NextPowerOf2((Symbols.size() - 1) / Config->Wordsize);
-
- Size = 16; // Header
- Size += Config->Wordsize * MaskWords; // Bloom filter
- Size += NBuckets * 4; // Hash buckets
- Size += Symbols.size() * 4; // Hash values
-}
-
-void GnuHashTableSection::writeTo(uint8_t *Buf) {
- // Write a header.
- write32(Buf, NBuckets, Config->Endianness);
- write32(Buf + 4, InX::DynSymTab->getNumSymbols() - Symbols.size(),
- Config->Endianness);
- write32(Buf + 8, MaskWords, Config->Endianness);
- write32(Buf + 12, getShift2(), Config->Endianness);
- Buf += 16;
-
- // Write a bloom filter and a hash table.
- writeBloomFilter(Buf);
- Buf += Config->Wordsize * MaskWords;
- writeHashTable(Buf);
-}
-
-// This function writes a 2-bit bloom filter. This bloom filter alone
-// usually filters out 80% or more of all symbol lookups [1].
-// The dynamic linker uses the hash table only when a symbol is not
-// filtered out by a bloom filter.
-//
-// [1] Ulrich Drepper (2011), "How To Write Shared Libraries" (Ver. 4.1.2),
-// p.9, https://www.akkadia.org/drepper/dsohowto.pdf
-void GnuHashTableSection::writeBloomFilter(uint8_t *Buf) {
- const unsigned C = Config->Wordsize * 8;
- for (const Entry &Sym : Symbols) {
- size_t I = (Sym.Hash / C) & (MaskWords - 1);
- uint64_t Val = readUint(Buf + I * Config->Wordsize);
- Val |= uint64_t(1) << (Sym.Hash % C);
- Val |= uint64_t(1) << ((Sym.Hash >> getShift2()) % C);
- writeUint(Buf + I * Config->Wordsize, Val);
- }
-}
-
-void GnuHashTableSection::writeHashTable(uint8_t *Buf) {
- // Group symbols by hash value.
- std::vector<std::vector<Entry>> Syms(NBuckets);
- for (const Entry &Ent : Symbols)
- Syms[Ent.Hash % NBuckets].push_back(Ent);
-
- // Write hash buckets. Hash buckets contain indices in the following
- // hash value table.
- uint32_t *Buckets = reinterpret_cast<uint32_t *>(Buf);
- for (size_t I = 0; I < NBuckets; ++I)
- if (!Syms[I].empty())
- write32(Buckets + I, Syms[I][0].Body->DynsymIndex, Config->Endianness);
-
- // Write a hash value table. It represents a sequence of chains that
- // share the same hash modulo value. The last element of each chain
- // is terminated by LSB 1.
- uint32_t *Values = Buckets + NBuckets;
- size_t I = 0;
- for (std::vector<Entry> &Vec : Syms) {
- if (Vec.empty())
- continue;
- for (const Entry &Ent : makeArrayRef(Vec).drop_back())
- write32(Values + I++, Ent.Hash & ~1, Config->Endianness);
- write32(Values + I++, Vec.back().Hash | 1, Config->Endianness);
- }
-}
-
-static uint32_t hashGnu(StringRef Name) {
- uint32_t H = 5381;
- for (uint8_t C : Name)
- H = (H << 5) + H + C;
- return H;
-}
-
-// Returns a number of hash buckets to accomodate given number of elements.
-// We want to choose a moderate number that is not too small (which
-// causes too many hash collisions) and not too large (which wastes
-// disk space.)
-//
-// We return a prime number because it (is believed to) achieve good
-// hash distribution.
-static size_t getBucketSize(size_t NumSymbols) {
- // List of largest prime numbers that are not greater than 2^n + 1.
- for (size_t N : {131071, 65521, 32749, 16381, 8191, 4093, 2039, 1021, 509,
- 251, 127, 61, 31, 13, 7, 3, 1})
- if (N <= NumSymbols)
- return N;
- return 0;
-}
-
-// Add symbols to this symbol hash table. Note that this function
-// destructively sort a given vector -- which is needed because
-// GNU-style hash table places some sorting requirements.
-void GnuHashTableSection::addSymbols(std::vector<SymbolTableEntry> &V) {
- // We cannot use 'auto' for Mid because GCC 6.1 cannot deduce
- // its type correctly.
- std::vector<SymbolTableEntry>::iterator Mid =
- std::stable_partition(V.begin(), V.end(), [](const SymbolTableEntry &S) {
- return S.Symbol->isUndefined();
- });
- if (Mid == V.end())
- return;
-
- for (SymbolTableEntry &Ent : llvm::make_range(Mid, V.end())) {
- SymbolBody *B = Ent.Symbol;
- Symbols.push_back({B, Ent.StrTabOffset, hashGnu(B->getName())});
- }
-
- NBuckets = getBucketSize(Symbols.size());
- std::stable_sort(Symbols.begin(), Symbols.end(),
- [&](const Entry &L, const Entry &R) {
- return L.Hash % NBuckets < R.Hash % NBuckets;
- });
-
- V.erase(Mid, V.end());
- for (const Entry &Ent : Symbols)
- V.push_back({Ent.Body, Ent.StrTabOffset});
-}
-
-template <class ELFT>
-HashTableSection<ELFT>::HashTableSection()
- : SyntheticSection(SHF_ALLOC, SHT_HASH, 4, ".hash") {
- this->Entsize = 4;
-}
-
-template <class ELFT> void HashTableSection<ELFT>::finalizeContents() {
- getParent()->Link = InX::DynSymTab->getParent()->SectionIndex;
-
- unsigned NumEntries = 2; // nbucket and nchain.
- NumEntries += InX::DynSymTab->getNumSymbols(); // The chain entries.
-
- // Create as many buckets as there are symbols.
- // FIXME: This is simplistic. We can try to optimize it, but implementing
- // support for SHT_GNU_HASH is probably even more profitable.
- NumEntries += InX::DynSymTab->getNumSymbols();
- this->Size = NumEntries * 4;
-}
-
-template <class ELFT> void HashTableSection<ELFT>::writeTo(uint8_t *Buf) {
- // A 32-bit integer type in the target endianness.
- typedef typename ELFT::Word Elf_Word;
-
- unsigned NumSymbols = InX::DynSymTab->getNumSymbols();
-
- auto *P = reinterpret_cast<Elf_Word *>(Buf);
- *P++ = NumSymbols; // nbucket
- *P++ = NumSymbols; // nchain
-
- Elf_Word *Buckets = P;
- Elf_Word *Chains = P + NumSymbols;
-
- for (const SymbolTableEntry &S : InX::DynSymTab->getSymbols()) {
- SymbolBody *Body = S.Symbol;
- StringRef Name = Body->getName();
- unsigned I = Body->DynsymIndex;
- uint32_t Hash = hashSysV(Name) % NumSymbols;
- Chains[I] = Buckets[Hash];
- Buckets[Hash] = I;
- }
-}
-
-PltSection::PltSection(size_t S)
- : SyntheticSection(SHF_ALLOC | SHF_EXECINSTR, SHT_PROGBITS, 16, ".plt"),
- HeaderSize(S) {
- // The PLT needs to be writable on SPARC as the dynamic linker will
- // modify the instructions in the PLT entries.
- if (Config->EMachine == EM_SPARCV9)
- this->Flags |= SHF_WRITE;
-}
-
-void PltSection::writeTo(uint8_t *Buf) {
- // At beginning of PLT but not the IPLT, we have code to call the dynamic
- // linker to resolve dynsyms at runtime. Write such code.
- if (HeaderSize != 0)
- Target->writePltHeader(Buf);
- size_t Off = HeaderSize;
- // The IPlt is immediately after the Plt, account for this in RelOff
- unsigned PltOff = getPltRelocOff();
-
- for (auto &I : Entries) {
- const SymbolBody *B = I.first;
- unsigned RelOff = I.second + PltOff;
- uint64_t Got = B->getGotPltVA();
- uint64_t Plt = this->getVA() + Off;
- Target->writePlt(Buf + Off, Got, Plt, B->PltIndex, RelOff);
- Off += Target->PltEntrySize;
- }
-}
-
-template <class ELFT> void PltSection::addEntry(SymbolBody &Sym) {
- Sym.PltIndex = Entries.size();
- RelocationSection<ELFT> *PltRelocSection = In<ELFT>::RelaPlt;
- if (HeaderSize == 0) {
- PltRelocSection = In<ELFT>::RelaIplt;
- Sym.IsInIplt = true;
- }
- unsigned RelOff = PltRelocSection->getRelocOffset();
- Entries.push_back(std::make_pair(&Sym, RelOff));
-}
-
-size_t PltSection::getSize() const {
- return HeaderSize + Entries.size() * Target->PltEntrySize;
-}
-
-// Some architectures such as additional symbols in the PLT section. For
-// example ARM uses mapping symbols to aid disassembly
-void PltSection::addSymbols() {
- // The PLT may have symbols defined for the Header, the IPLT has no header
- if (HeaderSize != 0)
- Target->addPltHeaderSymbols(this);
- size_t Off = HeaderSize;
- for (size_t I = 0; I < Entries.size(); ++I) {
- Target->addPltSymbols(this, Off);
- Off += Target->PltEntrySize;
- }
-}
-
-unsigned PltSection::getPltRelocOff() const {
- return (HeaderSize == 0) ? InX::Plt->getSize() : 0;
-}
-
-// The string hash function for .gdb_index.
-static uint32_t computeGdbHash(StringRef S) {
- uint32_t H = 0;
- for (uint8_t C : S)
- H = H * 67 + tolower(C) - 113;
- return H;
-}
-
-static std::vector<GdbIndexChunk::CuEntry> readCuList(DWARFContext &Dwarf) {
- std::vector<GdbIndexChunk::CuEntry> Ret;
- for (std::unique_ptr<DWARFCompileUnit> &Cu : Dwarf.compile_units())
- Ret.push_back({Cu->getOffset(), Cu->getLength() + 4});
- return Ret;
-}
-
-static std::vector<GdbIndexChunk::AddressEntry>
-readAddressAreas(DWARFContext &Dwarf, InputSection *Sec) {
- std::vector<GdbIndexChunk::AddressEntry> Ret;
-
- uint32_t CuIdx = 0;
- for (std::unique_ptr<DWARFCompileUnit> &Cu : Dwarf.compile_units()) {
- DWARFAddressRangesVector Ranges;
- Cu->collectAddressRanges(Ranges);
-
- ArrayRef<InputSectionBase *> Sections = Sec->File->getSections();
- for (DWARFAddressRange &R : Ranges) {
- InputSectionBase *S = Sections[R.SectionIndex];
- if (!S || S == &InputSection::Discarded || !S->Live)
- continue;
- // Range list with zero size has no effect.
- if (R.LowPC == R.HighPC)
- continue;
- auto *IS = cast<InputSection>(S);
- uint64_t Offset = IS->getOffsetInFile();
- Ret.push_back({IS, R.LowPC - Offset, R.HighPC - Offset, CuIdx});
- }
- ++CuIdx;
- }
- return Ret;
-}
-
-static std::vector<GdbIndexChunk::NameTypeEntry>
-readPubNamesAndTypes(DWARFContext &Dwarf) {
- StringRef Sec1 = Dwarf.getDWARFObj().getGnuPubNamesSection();
- StringRef Sec2 = Dwarf.getDWARFObj().getGnuPubTypesSection();
-
- std::vector<GdbIndexChunk::NameTypeEntry> Ret;
- for (StringRef Sec : {Sec1, Sec2}) {
- DWARFDebugPubTable Table(Sec, Config->IsLE, true);
- for (const DWARFDebugPubTable::Set &Set : Table.getData()) {
- for (const DWARFDebugPubTable::Entry &Ent : Set.Entries) {
- CachedHashStringRef S(Ent.Name, computeGdbHash(Ent.Name));
- Ret.push_back({S, Ent.Descriptor.toBits()});
- }
- }
- }
- return Ret;
-}
-
-static std::vector<InputSection *> getDebugInfoSections() {
- std::vector<InputSection *> Ret;
- for (InputSectionBase *S : InputSections)
- if (InputSection *IS = dyn_cast<InputSection>(S))
- if (IS->Name == ".debug_info")
- Ret.push_back(IS);
- return Ret;
-}
-
-void GdbIndexSection::fixCuIndex() {
- uint32_t Idx = 0;
- for (GdbIndexChunk &Chunk : Chunks) {
- for (GdbIndexChunk::AddressEntry &Ent : Chunk.AddressAreas)
- Ent.CuIndex += Idx;
- Idx += Chunk.CompilationUnits.size();
- }
-}
-
-std::vector<std::vector<uint32_t>> GdbIndexSection::createCuVectors() {
- std::vector<std::vector<uint32_t>> Ret;
- uint32_t Idx = 0;
- uint32_t Off = 0;
-
- for (GdbIndexChunk &Chunk : Chunks) {
- for (GdbIndexChunk::NameTypeEntry &Ent : Chunk.NamesAndTypes) {
- GdbSymbol *&Sym = Symbols[Ent.Name];
- if (!Sym) {
- Sym = make<GdbSymbol>(GdbSymbol{Ent.Name.hash(), Off, Ret.size()});
- Off += Ent.Name.size() + 1;
- Ret.push_back({});
- }
-
- // gcc 5.4.1 produces a buggy .debug_gnu_pubnames that contains
- // duplicate entries, so we want to dedup them.
- std::vector<uint32_t> &Vec = Ret[Sym->CuVectorIndex];
- uint32_t Val = (Ent.Type << 24) | Idx;
- if (Vec.empty() || Vec.back() != Val)
- Vec.push_back(Val);
- }
- Idx += Chunk.CompilationUnits.size();
- }
-
- StringPoolSize = Off;
- return Ret;
-}
-
-template <class ELFT> GdbIndexSection *elf::createGdbIndex() {
- std::vector<InputSection *> Sections = getDebugInfoSections();
- std::vector<GdbIndexChunk> Chunks(Sections.size());
-
- parallelForEachN(0, Chunks.size(), [&](size_t I) {
- ObjFile<ELFT> *File = Sections[I]->getFile<ELFT>();
- DWARFContext Dwarf(make_unique<LLDDwarfObj<ELFT>>(File));
-
- Chunks[I].DebugInfoSec = Sections[I];
- Chunks[I].CompilationUnits = readCuList(Dwarf);
- Chunks[I].AddressAreas = readAddressAreas(Dwarf, Sections[I]);
- Chunks[I].NamesAndTypes = readPubNamesAndTypes(Dwarf);
- });
-
- return make<GdbIndexSection>(std::move(Chunks));
-}
-
-static size_t getCuSize(ArrayRef<GdbIndexChunk> Arr) {
- size_t Ret = 0;
- for (const GdbIndexChunk &D : Arr)
- Ret += D.CompilationUnits.size();
- return Ret;
-}
-
-static size_t getAddressAreaSize(ArrayRef<GdbIndexChunk> Arr) {
- size_t Ret = 0;
- for (const GdbIndexChunk &D : Arr)
- Ret += D.AddressAreas.size();
- return Ret;
-}
-
-std::vector<GdbSymbol *> GdbIndexSection::createGdbSymtab() {
- uint32_t Size = NextPowerOf2(Symbols.size() * 4 / 3);
- if (Size < 1024)
- Size = 1024;
-
- uint32_t Mask = Size - 1;
- std::vector<GdbSymbol *> Ret(Size);
-
- for (auto &KV : Symbols) {
- GdbSymbol *Sym = KV.second;
- uint32_t I = Sym->NameHash & Mask;
- uint32_t Step = ((Sym->NameHash * 17) & Mask) | 1;
-
- while (Ret[I])
- I = (I + Step) & Mask;
- Ret[I] = Sym;
- }
- return Ret;
-}
-
-GdbIndexSection::GdbIndexSection(std::vector<GdbIndexChunk> &&C)
- : SyntheticSection(0, SHT_PROGBITS, 1, ".gdb_index"), Chunks(std::move(C)) {
- fixCuIndex();
- CuVectors = createCuVectors();
- GdbSymtab = createGdbSymtab();
-
- // Compute offsets early to know the section size.
- // Each chunk size needs to be in sync with what we write in writeTo.
- CuTypesOffset = CuListOffset + getCuSize(Chunks) * 16;
- SymtabOffset = CuTypesOffset + getAddressAreaSize(Chunks) * 20;
- ConstantPoolOffset = SymtabOffset + GdbSymtab.size() * 8;
-
- size_t Off = 0;
- for (ArrayRef<uint32_t> Vec : CuVectors) {
- CuVectorOffsets.push_back(Off);
- Off += (Vec.size() + 1) * 4;
- }
- StringPoolOffset = ConstantPoolOffset + Off;
-}
-
-size_t GdbIndexSection::getSize() const {
- return StringPoolOffset + StringPoolSize;
-}
-
-void GdbIndexSection::writeTo(uint8_t *Buf) {
- // Write the section header.
- write32le(Buf, 7);
- write32le(Buf + 4, CuListOffset);
- write32le(Buf + 8, CuTypesOffset);
- write32le(Buf + 12, CuTypesOffset);
- write32le(Buf + 16, SymtabOffset);
- write32le(Buf + 20, ConstantPoolOffset);
- Buf += 24;
-
- // Write the CU list.
- for (GdbIndexChunk &D : Chunks) {
- for (GdbIndexChunk::CuEntry &Cu : D.CompilationUnits) {
- write64le(Buf, D.DebugInfoSec->OutSecOff + Cu.CuOffset);
- write64le(Buf + 8, Cu.CuLength);
- Buf += 16;
- }
- }
-
- // Write the address area.
- for (GdbIndexChunk &D : Chunks) {
- for (GdbIndexChunk::AddressEntry &E : D.AddressAreas) {
- uint64_t BaseAddr =
- E.Section->getParent()->Addr + E.Section->getOffset(0);
- write64le(Buf, BaseAddr + E.LowAddress);
- write64le(Buf + 8, BaseAddr + E.HighAddress);
- write32le(Buf + 16, E.CuIndex);
- Buf += 20;
- }
- }
-
- // Write the symbol table.
- for (GdbSymbol *Sym : GdbSymtab) {
- if (Sym) {
- write32le(Buf, Sym->NameOffset + StringPoolOffset - ConstantPoolOffset);
- write32le(Buf + 4, CuVectorOffsets[Sym->CuVectorIndex]);
- }
- Buf += 8;
- }
-
- // Write the CU vectors.
- for (ArrayRef<uint32_t> Vec : CuVectors) {
- write32le(Buf, Vec.size());
- Buf += 4;
- for (uint32_t Val : Vec) {
- write32le(Buf, Val);
- Buf += 4;
- }
- }
-
- // Write the string pool.
- for (auto &KV : Symbols) {
- CachedHashStringRef S = KV.first;
- GdbSymbol *Sym = KV.second;
- size_t Off = Sym->NameOffset;
- memcpy(Buf + Off, S.val().data(), S.size());
- Buf[Off + S.size()] = '\0';
- }
-}
-
-bool GdbIndexSection::empty() const { return !Out::DebugInfo; }
-
-template <class ELFT>
-EhFrameHeader<ELFT>::EhFrameHeader()
- : SyntheticSection(SHF_ALLOC, SHT_PROGBITS, 1, ".eh_frame_hdr") {}
-
-// .eh_frame_hdr contains a binary search table of pointers to FDEs.
-// Each entry of the search table consists of two values,
-// the starting PC from where FDEs covers, and the FDE's address.
-// It is sorted by PC.
-template <class ELFT> void EhFrameHeader<ELFT>::writeTo(uint8_t *Buf) {
- const endianness E = ELFT::TargetEndianness;
-
- // Sort the FDE list by their PC and uniqueify. Usually there is only
- // one FDE for a PC (i.e. function), but if ICF merges two functions
- // into one, there can be more than one FDEs pointing to the address.
- auto Less = [](const FdeData &A, const FdeData &B) { return A.Pc < B.Pc; };
- std::stable_sort(Fdes.begin(), Fdes.end(), Less);
- auto Eq = [](const FdeData &A, const FdeData &B) { return A.Pc == B.Pc; };
- Fdes.erase(std::unique(Fdes.begin(), Fdes.end(), Eq), Fdes.end());
-
- Buf[0] = 1;
- Buf[1] = DW_EH_PE_pcrel | DW_EH_PE_sdata4;
- Buf[2] = DW_EH_PE_udata4;
- Buf[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4;
- write32<E>(Buf + 4, In<ELFT>::EhFrame->getParent()->Addr - this->getVA() - 4);
- write32<E>(Buf + 8, Fdes.size());
- Buf += 12;
-
- uint64_t VA = this->getVA();
- for (FdeData &Fde : Fdes) {
- write32<E>(Buf, Fde.Pc - VA);
- write32<E>(Buf + 4, Fde.FdeVA - VA);
- Buf += 8;
- }
-}
-
-template <class ELFT> size_t EhFrameHeader<ELFT>::getSize() const {
- // .eh_frame_hdr has a 12 bytes header followed by an array of FDEs.
- return 12 + In<ELFT>::EhFrame->NumFdes * 8;
-}
-
-template <class ELFT>
-void EhFrameHeader<ELFT>::addFde(uint32_t Pc, uint32_t FdeVA) {
- Fdes.push_back({Pc, FdeVA});
-}
-
-template <class ELFT> bool EhFrameHeader<ELFT>::empty() const {
- return In<ELFT>::EhFrame->empty();
-}
-
-template <class ELFT>
-VersionDefinitionSection<ELFT>::VersionDefinitionSection()
- : SyntheticSection(SHF_ALLOC, SHT_GNU_verdef, sizeof(uint32_t),
- ".gnu.version_d") {}
-
-static StringRef getFileDefName() {
- if (!Config->SoName.empty())
- return Config->SoName;
- return Config->OutputFile;
-}
-
-template <class ELFT> void VersionDefinitionSection<ELFT>::finalizeContents() {
- FileDefNameOff = InX::DynStrTab->addString(getFileDefName());
- for (VersionDefinition &V : Config->VersionDefinitions)
- V.NameOff = InX::DynStrTab->addString(V.Name);
-
- getParent()->Link = InX::DynStrTab->getParent()->SectionIndex;
-
- // sh_info should be set to the number of definitions. This fact is missed in
- // documentation, but confirmed by binutils community:
- // https://sourceware.org/ml/binutils/2014-11/msg00355.html
- getParent()->Info = getVerDefNum();
-}
-
-template <class ELFT>
-void VersionDefinitionSection<ELFT>::writeOne(uint8_t *Buf, uint32_t Index,
- StringRef Name, size_t NameOff) {
- auto *Verdef = reinterpret_cast<Elf_Verdef *>(Buf);
- Verdef->vd_version = 1;
- Verdef->vd_cnt = 1;
- Verdef->vd_aux = sizeof(Elf_Verdef);
- Verdef->vd_next = sizeof(Elf_Verdef) + sizeof(Elf_Verdaux);
- Verdef->vd_flags = (Index == 1 ? VER_FLG_BASE : 0);
- Verdef->vd_ndx = Index;
- Verdef->vd_hash = hashSysV(Name);
-
- auto *Verdaux = reinterpret_cast<Elf_Verdaux *>(Buf + sizeof(Elf_Verdef));
- Verdaux->vda_name = NameOff;
- Verdaux->vda_next = 0;
-}
-
-template <class ELFT>
-void VersionDefinitionSection<ELFT>::writeTo(uint8_t *Buf) {
- writeOne(Buf, 1, getFileDefName(), FileDefNameOff);
-
- for (VersionDefinition &V : Config->VersionDefinitions) {
- Buf += sizeof(Elf_Verdef) + sizeof(Elf_Verdaux);
- writeOne(Buf, V.Id, V.Name, V.NameOff);
- }
-
- // Need to terminate the last version definition.
- Elf_Verdef *Verdef = reinterpret_cast<Elf_Verdef *>(Buf);
- Verdef->vd_next = 0;
-}
-
-template <class ELFT> size_t VersionDefinitionSection<ELFT>::getSize() const {
- return (sizeof(Elf_Verdef) + sizeof(Elf_Verdaux)) * getVerDefNum();
-}
-
-template <class ELFT>
-VersionTableSection<ELFT>::VersionTableSection()
- : SyntheticSection(SHF_ALLOC, SHT_GNU_versym, sizeof(uint16_t),
- ".gnu.version") {
- this->Entsize = sizeof(Elf_Versym);
-}
-
-template <class ELFT> void VersionTableSection<ELFT>::finalizeContents() {
- // At the moment of june 2016 GNU docs does not mention that sh_link field
- // should be set, but Sun docs do. Also readelf relies on this field.
- getParent()->Link = InX::DynSymTab->getParent()->SectionIndex;
-}
-
-template <class ELFT> size_t VersionTableSection<ELFT>::getSize() const {
- return sizeof(Elf_Versym) * (InX::DynSymTab->getSymbols().size() + 1);
-}
-
-template <class ELFT> void VersionTableSection<ELFT>::writeTo(uint8_t *Buf) {
- auto *OutVersym = reinterpret_cast<Elf_Versym *>(Buf) + 1;
- for (const SymbolTableEntry &S : InX::DynSymTab->getSymbols()) {
- OutVersym->vs_index = S.Symbol->symbol()->VersionId;
- ++OutVersym;
- }
-}
-
-template <class ELFT> bool VersionTableSection<ELFT>::empty() const {
- return !In<ELFT>::VerDef && In<ELFT>::VerNeed->empty();
-}
-
-template <class ELFT>
-VersionNeedSection<ELFT>::VersionNeedSection()
- : SyntheticSection(SHF_ALLOC, SHT_GNU_verneed, sizeof(uint32_t),
- ".gnu.version_r") {
- // Identifiers in verneed section start at 2 because 0 and 1 are reserved
- // for VER_NDX_LOCAL and VER_NDX_GLOBAL.
- // First identifiers are reserved by verdef section if it exist.
- NextIndex = getVerDefNum() + 1;
-}
-
-template <class ELFT>
-void VersionNeedSection<ELFT>::addSymbol(SharedSymbol *SS) {
- auto *Ver = reinterpret_cast<const typename ELFT::Verdef *>(SS->Verdef);
- if (!Ver) {
- SS->symbol()->VersionId = VER_NDX_GLOBAL;
- return;
- }
-
- SharedFile<ELFT> *File = SS->getFile<ELFT>();
-
- // If we don't already know that we need an Elf_Verneed for this DSO, prepare
- // to create one by adding it to our needed list and creating a dynstr entry
- // for the soname.
- if (File->VerdefMap.empty())
- Needed.push_back({File, InX::DynStrTab->addString(File->SoName)});
- typename SharedFile<ELFT>::NeededVer &NV = File->VerdefMap[Ver];
- // If we don't already know that we need an Elf_Vernaux for this Elf_Verdef,
- // prepare to create one by allocating a version identifier and creating a
- // dynstr entry for the version name.
- if (NV.Index == 0) {
- NV.StrTab = InX::DynStrTab->addString(File->getStringTable().data() +
- Ver->getAux()->vda_name);
- NV.Index = NextIndex++;
- }
- SS->symbol()->VersionId = NV.Index;
-}
-
-template <class ELFT> void VersionNeedSection<ELFT>::writeTo(uint8_t *Buf) {
- // The Elf_Verneeds need to appear first, followed by the Elf_Vernauxs.
- auto *Verneed = reinterpret_cast<Elf_Verneed *>(Buf);
- auto *Vernaux = reinterpret_cast<Elf_Vernaux *>(Verneed + Needed.size());
-
- for (std::pair<SharedFile<ELFT> *, size_t> &P : Needed) {
- // Create an Elf_Verneed for this DSO.
- Verneed->vn_version = 1;
- Verneed->vn_cnt = P.first->VerdefMap.size();
- Verneed->vn_file = P.second;
- Verneed->vn_aux =
- reinterpret_cast<char *>(Vernaux) - reinterpret_cast<char *>(Verneed);
- Verneed->vn_next = sizeof(Elf_Verneed);
- ++Verneed;
-
- // Create the Elf_Vernauxs for this Elf_Verneed. The loop iterates over
- // VerdefMap, which will only contain references to needed version
- // definitions. Each Elf_Vernaux is based on the information contained in
- // the Elf_Verdef in the source DSO. This loop iterates over a std::map of
- // pointers, but is deterministic because the pointers refer to Elf_Verdef
- // data structures within a single input file.
- for (auto &NV : P.first->VerdefMap) {
- Vernaux->vna_hash = NV.first->vd_hash;
- Vernaux->vna_flags = 0;
- Vernaux->vna_other = NV.second.Index;
- Vernaux->vna_name = NV.second.StrTab;
- Vernaux->vna_next = sizeof(Elf_Vernaux);
- ++Vernaux;
- }
-
- Vernaux[-1].vna_next = 0;
- }
- Verneed[-1].vn_next = 0;
-}
-
-template <class ELFT> void VersionNeedSection<ELFT>::finalizeContents() {
- getParent()->Link = InX::DynStrTab->getParent()->SectionIndex;
- getParent()->Info = Needed.size();
-}
-
-template <class ELFT> size_t VersionNeedSection<ELFT>::getSize() const {
- unsigned Size = Needed.size() * sizeof(Elf_Verneed);
- for (const std::pair<SharedFile<ELFT> *, size_t> &P : Needed)
- Size += P.first->VerdefMap.size() * sizeof(Elf_Vernaux);
- return Size;
-}
-
-template <class ELFT> bool VersionNeedSection<ELFT>::empty() const {
- return getNeedNum() == 0;
-}
-
-MergeSyntheticSection::MergeSyntheticSection(StringRef Name, uint32_t Type,
- uint64_t Flags, uint32_t Alignment)
- : SyntheticSection(Flags, Type, Alignment, Name),
- Builder(StringTableBuilder::RAW, Alignment) {}
-
-void MergeSyntheticSection::addSection(MergeInputSection *MS) {
- MS->Parent = this;
- Sections.push_back(MS);
-}
-
-void MergeSyntheticSection::writeTo(uint8_t *Buf) { Builder.write(Buf); }
-
-bool MergeSyntheticSection::shouldTailMerge() const {
- return (this->Flags & SHF_STRINGS) && Config->Optimize >= 2;
-}
-
-void MergeSyntheticSection::finalizeTailMerge() {
- // Add all string pieces to the string table builder to create section
- // contents.
- for (MergeInputSection *Sec : Sections)
- for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
- if (Sec->Pieces[I].Live)
- Builder.add(Sec->getData(I));
-
- // Fix the string table content. After this, the contents will never change.
- Builder.finalize();
-
- // finalize() fixed tail-optimized strings, so we can now get
- // offsets of strings. Get an offset for each string and save it
- // to a corresponding StringPiece for easy access.
- for (MergeInputSection *Sec : Sections)
- for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
- if (Sec->Pieces[I].Live)
- Sec->Pieces[I].OutputOff = Builder.getOffset(Sec->getData(I));
-}
-
-void MergeSyntheticSection::finalizeNoTailMerge() {
- // Add all string pieces to the string table builder to create section
- // contents. Because we are not tail-optimizing, offsets of strings are
- // fixed when they are added to the builder (string table builder contains
- // a hash table from strings to offsets).
- for (MergeInputSection *Sec : Sections)
- for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
- if (Sec->Pieces[I].Live)
- Sec->Pieces[I].OutputOff = Builder.add(Sec->getData(I));
-
- Builder.finalizeInOrder();
-}
-
-void MergeSyntheticSection::finalizeContents() {
- if (shouldTailMerge())
- finalizeTailMerge();
- else
- finalizeNoTailMerge();
-}
-
-size_t MergeSyntheticSection::getSize() const { return Builder.getSize(); }
-
-// This function decompresses compressed sections and scans over the input
-// sections to create mergeable synthetic sections. It removes
-// MergeInputSections from the input section array and adds new synthetic
-// sections at the location of the first input section that it replaces. It then
-// finalizes each synthetic section in order to compute an output offset for
-// each piece of each input section.
-void elf::decompressAndMergeSections() {
- // splitIntoPieces needs to be called on each MergeInputSection before calling
- // finalizeContents(). Do that first.
- parallelForEach(InputSections, [](InputSectionBase *S) {
- if (!S->Live)
- return;
- if (Decompressor::isCompressedELFSection(S->Flags, S->Name))
- S->uncompress();
- if (auto *MS = dyn_cast<MergeInputSection>(S))
- MS->splitIntoPieces();
- });
-
- std::vector<MergeSyntheticSection *> MergeSections;
- for (InputSectionBase *&S : InputSections) {
- MergeInputSection *MS = dyn_cast<MergeInputSection>(S);
- if (!MS)
- continue;
-
- // We do not want to handle sections that are not alive, so just remove
- // them instead of trying to merge.
- if (!MS->Live)
- continue;
-
- StringRef OutsecName = getOutputSectionName(MS->Name);
- uint32_t Alignment = std::max<uint32_t>(MS->Alignment, MS->Entsize);
-
- auto I = llvm::find_if(MergeSections, [=](MergeSyntheticSection *Sec) {
- return Sec->Name == OutsecName && Sec->Flags == MS->Flags &&
- Sec->Alignment == Alignment;
- });
- if (I == MergeSections.end()) {
- MergeSyntheticSection *Syn = make<MergeSyntheticSection>(
- OutsecName, MS->Type, MS->Flags, Alignment);
- MergeSections.push_back(Syn);
- I = std::prev(MergeSections.end());
- S = Syn;
- } else {
- S = nullptr;
- }
- (*I)->addSection(MS);
- }
- for (auto *MS : MergeSections)
- MS->finalizeContents();
-
- std::vector<InputSectionBase *> &V = InputSections;
- V.erase(std::remove(V.begin(), V.end(), nullptr), V.end());
-}
-
-MipsRldMapSection::MipsRldMapSection()
- : SyntheticSection(SHF_ALLOC | SHF_WRITE, SHT_PROGBITS, Config->Wordsize,
- ".rld_map") {}
-
-ARMExidxSentinelSection::ARMExidxSentinelSection()
- : SyntheticSection(SHF_ALLOC | SHF_LINK_ORDER, SHT_ARM_EXIDX,
- Config->Wordsize, ".ARM.exidx") {}
-
-// Write a terminating sentinel entry to the end of the .ARM.exidx table.
-// This section will have been sorted last in the .ARM.exidx table.
-// This table entry will have the form:
-// | PREL31 upper bound of code that has exception tables | EXIDX_CANTUNWIND |
-// The sentinel must have the PREL31 value of an address higher than any
-// address described by any other table entry.
-void ARMExidxSentinelSection::writeTo(uint8_t *Buf) {
- // The Sections are sorted in order of ascending PREL31 address with the
- // sentinel last. We need to find the InputSection that precedes the
- // sentinel. By construction the Sentinel is in the last
- // InputSectionDescription as the InputSection that precedes it.
- OutputSection *C = getParent();
- auto ISD = std::find_if(C->Commands.rbegin(), C->Commands.rend(),
- [](const BaseCommand *Base) {
- return isa<InputSectionDescription>(Base);
- });
- auto L = cast<InputSectionDescription>(*ISD);
- InputSection *Highest = L->Sections[L->Sections.size() - 2];
- InputSection *LS = Highest->getLinkOrderDep();
- uint64_t S = LS->getParent()->Addr + LS->getOffset(LS->getSize());
- uint64_t P = getVA();
- Target->relocateOne(Buf, R_ARM_PREL31, S - P);
- write32le(Buf + 4, 0x1);
-}
-
-ThunkSection::ThunkSection(OutputSection *OS, uint64_t Off)
- : SyntheticSection(SHF_ALLOC | SHF_EXECINSTR, SHT_PROGBITS,
- Config->Wordsize, ".text.thunk") {
- this->Parent = OS;
- this->OutSecOff = Off;
-}
-
-void ThunkSection::addThunk(Thunk *T) {
- uint64_t Off = alignTo(Size, T->Alignment);
- T->Offset = Off;
- Thunks.push_back(T);
- T->addSymbols(*this);
- Size = Off + T->size();
-}
-
-void ThunkSection::writeTo(uint8_t *Buf) {
- for (const Thunk *T : Thunks)
- T->writeTo(Buf + T->Offset, *this);
-}
-
-InputSection *ThunkSection::getTargetInputSection() const {
- const Thunk *T = Thunks.front();
- return T->getTargetInputSection();
-}
-
-InputSection *InX::ARMAttributes;
-BssSection *InX::Bss;
-BssSection *InX::BssRelRo;
-BuildIdSection *InX::BuildId;
-SyntheticSection *InX::Dynamic;
-StringTableSection *InX::DynStrTab;
-SymbolTableBaseSection *InX::DynSymTab;
-InputSection *InX::Interp;
-GdbIndexSection *InX::GdbIndex;
-GotSection *InX::Got;
-GotPltSection *InX::GotPlt;
-GnuHashTableSection *InX::GnuHashTab;
-IgotPltSection *InX::IgotPlt;
-MipsGotSection *InX::MipsGot;
-MipsRldMapSection *InX::MipsRldMap;
-PltSection *InX::Plt;
-PltSection *InX::Iplt;
-StringTableSection *InX::ShStrTab;
-StringTableSection *InX::StrTab;
-SymbolTableBaseSection *InX::SymTab;
-
-template GdbIndexSection *elf::createGdbIndex<ELF32LE>();
-template GdbIndexSection *elf::createGdbIndex<ELF32BE>();
-template GdbIndexSection *elf::createGdbIndex<ELF64LE>();
-template GdbIndexSection *elf::createGdbIndex<ELF64BE>();
-
-template void PltSection::addEntry<ELF32LE>(SymbolBody &Sym);
-template void PltSection::addEntry<ELF32BE>(SymbolBody &Sym);
-template void PltSection::addEntry<ELF64LE>(SymbolBody &Sym);
-template void PltSection::addEntry<ELF64BE>(SymbolBody &Sym);
-
-template void elf::createCommonSections<ELF32LE>();
-template void elf::createCommonSections<ELF32BE>();
-template void elf::createCommonSections<ELF64LE>();
-template void elf::createCommonSections<ELF64BE>();
-
-template MergeInputSection *elf::createCommentSection<ELF32LE>();
-template MergeInputSection *elf::createCommentSection<ELF32BE>();
-template MergeInputSection *elf::createCommentSection<ELF64LE>();
-template MergeInputSection *elf::createCommentSection<ELF64BE>();
-
-template class elf::MipsAbiFlagsSection<ELF32LE>;
-template class elf::MipsAbiFlagsSection<ELF32BE>;
-template class elf::MipsAbiFlagsSection<ELF64LE>;
-template class elf::MipsAbiFlagsSection<ELF64BE>;
-
-template class elf::MipsOptionsSection<ELF32LE>;
-template class elf::MipsOptionsSection<ELF32BE>;
-template class elf::MipsOptionsSection<ELF64LE>;
-template class elf::MipsOptionsSection<ELF64BE>;
-
-template class elf::MipsReginfoSection<ELF32LE>;
-template class elf::MipsReginfoSection<ELF32BE>;
-template class elf::MipsReginfoSection<ELF64LE>;
-template class elf::MipsReginfoSection<ELF64BE>;
-
-template class elf::DynamicSection<ELF32LE>;
-template class elf::DynamicSection<ELF32BE>;
-template class elf::DynamicSection<ELF64LE>;
-template class elf::DynamicSection<ELF64BE>;
-
-template class elf::RelocationSection<ELF32LE>;
-template class elf::RelocationSection<ELF32BE>;
-template class elf::RelocationSection<ELF64LE>;
-template class elf::RelocationSection<ELF64BE>;
-
-template class elf::SymbolTableSection<ELF32LE>;
-template class elf::SymbolTableSection<ELF32BE>;
-template class elf::SymbolTableSection<ELF64LE>;
-template class elf::SymbolTableSection<ELF64BE>;
-
-template class elf::HashTableSection<ELF32LE>;
-template class elf::HashTableSection<ELF32BE>;
-template class elf::HashTableSection<ELF64LE>;
-template class elf::HashTableSection<ELF64BE>;
-
-template class elf::EhFrameHeader<ELF32LE>;
-template class elf::EhFrameHeader<ELF32BE>;
-template class elf::EhFrameHeader<ELF64LE>;
-template class elf::EhFrameHeader<ELF64BE>;
-
-template class elf::VersionTableSection<ELF32LE>;
-template class elf::VersionTableSection<ELF32BE>;
-template class elf::VersionTableSection<ELF64LE>;
-template class elf::VersionTableSection<ELF64BE>;
-
-template class elf::VersionNeedSection<ELF32LE>;
-template class elf::VersionNeedSection<ELF32BE>;
-template class elf::VersionNeedSection<ELF64LE>;
-template class elf::VersionNeedSection<ELF64BE>;
-
-template class elf::VersionDefinitionSection<ELF32LE>;
-template class elf::VersionDefinitionSection<ELF32BE>;
-template class elf::VersionDefinitionSection<ELF64LE>;
-template class elf::VersionDefinitionSection<ELF64BE>;
-
-template class elf::EhFrameSection<ELF32LE>;
-template class elf::EhFrameSection<ELF32BE>;
-template class elf::EhFrameSection<ELF64LE>;
-template class elf::EhFrameSection<ELF64BE>;
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