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authorDimitry Andric <dim@FreeBSD.org>2017-01-02 19:19:15 +0000
committerDimitry Andric <dim@FreeBSD.org>2017-01-02 19:19:15 +0000
commitd93e1dfac8711cfed1a9d9cd1876a788b83945cd (patch)
tree5896fa6c02a262a6148b215487e545d937de58b7 /ELF/OutputSections.cpp
parent8d43286d630f9224de07809ea253e83ebb9cdee6 (diff)
downloadsrc-d93e1dfac8711cfed1a9d9cd1876a788b83945cd.tar.gz
src-d93e1dfac8711cfed1a9d9cd1876a788b83945cd.zip
Vendor import of lld trunk r290819:vendor/lld/lld-trunk-r290819
Notes
Notes: svn path=/vendor/lld/dist/; revision=311125 svn path=/vendor/lld/lld-trunk-r290819/; revision=311126; tag=vendor/lld/lld-trunk-r290819
Diffstat (limited to 'ELF/OutputSections.cpp')
-rw-r--r--ELF/OutputSections.cpp1768
1 files changed, 227 insertions, 1541 deletions
diff --git a/ELF/OutputSections.cpp b/ELF/OutputSections.cpp
index 50b94015f229..bf7f9c29a29a 100644
--- a/ELF/OutputSections.cpp
+++ b/ELF/OutputSections.cpp
@@ -11,15 +11,16 @@
#include "Config.h"
#include "EhFrame.h"
#include "LinkerScript.h"
+#include "Memory.h"
#include "Strings.h"
#include "SymbolTable.h"
+#include "SyntheticSections.h"
#include "Target.h"
-#include "lld/Core/Parallel.h"
+#include "Threads.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/MD5.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/SHA1.h"
-#include <map>
using namespace llvm;
using namespace llvm::dwarf;
@@ -30,855 +31,152 @@ using namespace llvm::ELF;
using namespace lld;
using namespace lld::elf;
-template <class ELFT>
-OutputSectionBase<ELFT>::OutputSectionBase(StringRef Name, uint32_t Type,
- uintX_t Flags)
+OutputSectionBase::OutputSectionBase(StringRef Name, uint32_t Type,
+ uint64_t Flags)
: Name(Name) {
- memset(&Header, 0, sizeof(Elf_Shdr));
- Header.sh_type = Type;
- Header.sh_flags = Flags;
- Header.sh_addralign = 1;
+ this->Type = Type;
+ this->Flags = Flags;
+ this->Addralign = 1;
}
-template <class ELFT>
-void OutputSectionBase<ELFT>::writeHeaderTo(Elf_Shdr *Shdr) {
- *Shdr = Header;
+uint32_t OutputSectionBase::getPhdrFlags() const {
+ uint32_t Ret = PF_R;
+ if (Flags & SHF_WRITE)
+ Ret |= PF_W;
+ if (Flags & SHF_EXECINSTR)
+ Ret |= PF_X;
+ return Ret;
}
template <class ELFT>
-GotPltSection<ELFT>::GotPltSection()
- : OutputSectionBase<ELFT>(".got.plt", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE) {
- this->Header.sh_addralign = Target->GotPltEntrySize;
-}
-
-template <class ELFT> void GotPltSection<ELFT>::addEntry(SymbolBody &Sym) {
- Sym.GotPltIndex = Target->GotPltHeaderEntriesNum + Entries.size();
- Entries.push_back(&Sym);
-}
-
-template <class ELFT> bool GotPltSection<ELFT>::empty() const {
- return Entries.empty();
-}
-
-template <class ELFT> void GotPltSection<ELFT>::finalize() {
- this->Header.sh_size = (Target->GotPltHeaderEntriesNum + Entries.size()) *
- Target->GotPltEntrySize;
-}
-
-template <class ELFT> void GotPltSection<ELFT>::writeTo(uint8_t *Buf) {
- Target->writeGotPltHeader(Buf);
- Buf += Target->GotPltHeaderEntriesNum * Target->GotPltEntrySize;
- for (const SymbolBody *B : Entries) {
- Target->writeGotPlt(Buf, *B);
- Buf += sizeof(uintX_t);
+void OutputSectionBase::writeHeaderTo(typename ELFT::Shdr *Shdr) {
+ Shdr->sh_entsize = Entsize;
+ Shdr->sh_addralign = Addralign;
+ Shdr->sh_type = Type;
+ Shdr->sh_offset = Offset;
+ Shdr->sh_flags = Flags;
+ Shdr->sh_info = Info;
+ Shdr->sh_link = Link;
+ Shdr->sh_addr = Addr;
+ Shdr->sh_size = Size;
+ Shdr->sh_name = ShName;
+}
+
+template <class ELFT> static uint64_t getEntsize(uint32_t Type) {
+ switch (Type) {
+ case SHT_RELA:
+ return sizeof(typename ELFT::Rela);
+ case SHT_REL:
+ return sizeof(typename ELFT::Rel);
+ case SHT_MIPS_REGINFO:
+ return sizeof(Elf_Mips_RegInfo<ELFT>);
+ case SHT_MIPS_OPTIONS:
+ return sizeof(Elf_Mips_Options<ELFT>) + sizeof(Elf_Mips_RegInfo<ELFT>);
+ case SHT_MIPS_ABIFLAGS:
+ return sizeof(Elf_Mips_ABIFlags<ELFT>);
+ default:
+ return 0;
}
}
template <class ELFT>
-GotSection<ELFT>::GotSection()
- : OutputSectionBase<ELFT>(".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE) {
- if (Config->EMachine == EM_MIPS)
- this->Header.sh_flags |= SHF_MIPS_GPREL;
- this->Header.sh_addralign = Target->GotEntrySize;
-}
-
-template <class ELFT>
-void GotSection<ELFT>::addEntry(SymbolBody &Sym) {
- Sym.GotIndex = Entries.size();
- Entries.push_back(&Sym);
-}
-
-template <class ELFT>
-void GotSection<ELFT>::addMipsEntry(SymbolBody &Sym, uintX_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.
- auto *OutSec = cast<DefinedRegular<ELFT>>(&Sym)->Section->OutSec;
- MipsOutSections.insert(OutSec);
- 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 = Entries.size();
- Entries.push_back(&Sym);
- return;
- }
- auto AddEntry = [&](SymbolBody &S, uintX_t A, MipsGotEntries &Items) {
- if (S.isInGot() && !A)
- return;
- size_t NewIndex = Items.size();
- if (!MipsGotMap.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, MipsGlobal);
- Sym.IsInGlobalMipsGot = true;
- } else
- AddEntry(Sym, Addend, MipsLocal);
-}
-
-template <class ELFT> bool GotSection<ELFT>::addDynTlsEntry(SymbolBody &Sym) {
- if (Sym.GlobalDynIndex != -1U)
- return false;
- Sym.GlobalDynIndex = Entries.size();
- // Global Dynamic TLS entries take two GOT slots.
- Entries.push_back(nullptr);
- Entries.push_back(&Sym);
- return true;
+OutputSection<ELFT>::OutputSection(StringRef Name, uint32_t Type, uintX_t Flags)
+ : OutputSectionBase(Name, Type, Flags) {
+ this->Entsize = getEntsize<ELFT>(Type);
}
-// Reserves TLS entries for a TLS module ID and a TLS block offset.
-// In total it takes two GOT slots.
-template <class ELFT> bool GotSection<ELFT>::addTlsIndex() {
- if (TlsIndexOff != uint32_t(-1))
+template <typename ELFT>
+static bool compareByFilePosition(InputSection<ELFT> *A,
+ InputSection<ELFT> *B) {
+ // Synthetic doesn't have link order dependecy, stable_sort will keep it last
+ if (A->kind() == InputSectionData::Synthetic ||
+ B->kind() == InputSectionData::Synthetic)
return false;
- TlsIndexOff = Entries.size() * sizeof(uintX_t);
- Entries.push_back(nullptr);
- Entries.push_back(nullptr);
- return true;
-}
-
-template <class ELFT>
-typename GotSection<ELFT>::uintX_t
-GotSection<ELFT>::getMipsLocalPageOffset(uintX_t EntryValue) {
- // Initialize the entry by the %hi(EntryValue) expression
- // but without right-shifting.
- EntryValue = (EntryValue + 0x8000) & ~0xffff;
- // Take into account MIPS GOT header.
- // See comment in the GotSection::writeTo.
- size_t NewIndex = MipsLocalGotPos.size() + 2;
- auto P = MipsLocalGotPos.insert(std::make_pair(EntryValue, NewIndex));
- assert(!P.second || MipsLocalGotPos.size() <= MipsPageEntries);
- return (uintX_t)P.first->second * sizeof(uintX_t) - MipsGPOffset;
-}
-
-template <class ELFT>
-typename GotSection<ELFT>::uintX_t
-GotSection<ELFT>::getMipsGotOffset(const SymbolBody &B, uintX_t Addend) const {
- uintX_t Off = MipsPageEntries;
- if (B.isTls())
- Off += MipsLocal.size() + MipsGlobal.size() + B.GotIndex;
- else if (B.IsInGlobalMipsGot)
- Off += MipsLocal.size() + B.GotIndex;
- else if (B.isInGot())
- Off += B.GotIndex;
- else {
- auto It = MipsGotMap.find({&B, Addend});
- assert(It != MipsGotMap.end());
- Off += It->second;
- }
- return Off * sizeof(uintX_t) - MipsGPOffset;
-}
-
-template <class ELFT>
-typename GotSection<ELFT>::uintX_t GotSection<ELFT>::getMipsTlsOffset() {
- return (MipsPageEntries + MipsLocal.size() + MipsGlobal.size()) *
- sizeof(uintX_t);
-}
-
-template <class ELFT>
-typename GotSection<ELFT>::uintX_t
-GotSection<ELFT>::getGlobalDynAddr(const SymbolBody &B) const {
- return this->getVA() + B.GlobalDynIndex * sizeof(uintX_t);
-}
-
-template <class ELFT>
-typename GotSection<ELFT>::uintX_t
-GotSection<ELFT>::getGlobalDynOffset(const SymbolBody &B) const {
- return B.GlobalDynIndex * sizeof(uintX_t);
-}
-
-template <class ELFT>
-const SymbolBody *GotSection<ELFT>::getMipsFirstGlobalEntry() const {
- return MipsGlobal.empty() ? nullptr : MipsGlobal.front().first;
-}
-
-template <class ELFT>
-unsigned GotSection<ELFT>::getMipsLocalEntriesNum() const {
- return MipsPageEntries + MipsLocal.size();
+ auto *LA = cast<InputSection<ELFT>>(A->getLinkOrderDep());
+ auto *LB = cast<InputSection<ELFT>>(B->getLinkOrderDep());
+ OutputSectionBase *AOut = LA->OutSec;
+ OutputSectionBase *BOut = LB->OutSec;
+ if (AOut != BOut)
+ return AOut->SectionIndex < BOut->SectionIndex;
+ return LA->OutSecOff < LB->OutSecOff;
}
-template <class ELFT> void GotSection<ELFT>::finalize() {
- size_t EntriesNum = Entries.size();
- if (Config->EMachine == EM_MIPS) {
- // Take into account MIPS GOT header.
- // See comment in the GotSection::writeTo.
- MipsPageEntries += 2;
- for (const OutputSectionBase<ELFT> *OutSec : MipsOutSections) {
- // Calculate 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.
- // Add 0x8000 to the section's size because the page address stored
- // in the GOT entry is calculated as (value + 0x8000) & ~0xffff.
- MipsPageEntries += (OutSec->getSize() + 0x8000 + 0xfffe) / 0xffff;
- }
- EntriesNum += MipsPageEntries + MipsLocal.size() + MipsGlobal.size();
- }
- this->Header.sh_size = EntriesNum * sizeof(uintX_t);
-}
-
-template <class ELFT> void GotSection<ELFT>::writeMipsGot(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.
- auto *P = reinterpret_cast<typename ELFT::Off *>(Buf);
- P[1] = uintX_t(1) << (ELFT::Is64Bits ? 63 : 31);
- // Write 'page address' entries to the local part of the GOT.
- for (std::pair<uintX_t, size_t> &L : MipsLocalGotPos) {
- uint8_t *Entry = Buf + L.second * sizeof(uintX_t);
- write<uintX_t, ELFT::TargetEndianness, sizeof(uintX_t)>(Entry, L.first);
- }
- Buf += MipsPageEntries * sizeof(uintX_t);
- auto AddEntry = [&](const MipsGotEntry &SA) {
- uint8_t *Entry = Buf;
- Buf += sizeof(uintX_t);
- const SymbolBody* Body = SA.first;
- uintX_t VA = Body->template getVA<ELFT>(SA.second);
- write<uintX_t, ELFT::TargetEndianness, sizeof(uintX_t)>(Entry, VA);
- };
- std::for_each(std::begin(MipsLocal), std::end(MipsLocal), AddEntry);
- std::for_each(std::begin(MipsGlobal), std::end(MipsGlobal), AddEntry);
-}
-
-template <class ELFT> void GotSection<ELFT>::writeTo(uint8_t *Buf) {
- if (Config->EMachine == EM_MIPS)
- writeMipsGot(Buf);
- for (const SymbolBody *B : Entries) {
- uint8_t *Entry = Buf;
- Buf += sizeof(uintX_t);
- if (!B)
- continue;
- if (B->isPreemptible())
- continue; // The dynamic linker will take care of it.
- uintX_t VA = B->getVA<ELFT>();
- write<uintX_t, ELFT::TargetEndianness, sizeof(uintX_t)>(Entry, VA);
- }
-}
-
-template <class ELFT>
-PltSection<ELFT>::PltSection()
- : OutputSectionBase<ELFT>(".plt", SHT_PROGBITS, SHF_ALLOC | SHF_EXECINSTR) {
- this->Header.sh_addralign = 16;
-}
-
-template <class ELFT> void PltSection<ELFT>::writeTo(uint8_t *Buf) {
- // At beginning of PLT, we have code to call the dynamic linker
- // to resolve dynsyms at runtime. Write such code.
- Target->writePltHeader(Buf);
- size_t Off = Target->PltHeaderSize;
-
- for (auto &I : Entries) {
- const SymbolBody *B = I.first;
- unsigned RelOff = I.second;
- uint64_t Got = B->getGotPltVA<ELFT>();
- uint64_t Plt = this->getVA() + Off;
- Target->writePlt(Buf + Off, Got, Plt, B->PltIndex, RelOff);
- Off += Target->PltEntrySize;
- }
-}
-
-template <class ELFT> void PltSection<ELFT>::addEntry(SymbolBody &Sym) {
- Sym.PltIndex = Entries.size();
- unsigned RelOff = Out<ELFT>::RelaPlt->getRelocOffset();
- Entries.push_back(std::make_pair(&Sym, RelOff));
-}
-
-template <class ELFT> void PltSection<ELFT>::finalize() {
- this->Header.sh_size =
- Target->PltHeaderSize + Entries.size() * Target->PltEntrySize;
-}
-
-template <class ELFT>
-RelocationSection<ELFT>::RelocationSection(StringRef Name, bool Sort)
- : OutputSectionBase<ELFT>(Name, Config->Rela ? SHT_RELA : SHT_REL,
- SHF_ALLOC),
- Sort(Sort) {
- this->Header.sh_entsize = Config->Rela ? sizeof(Elf_Rela) : sizeof(Elf_Rel);
- this->Header.sh_addralign = sizeof(uintX_t);
-}
-
-template <class ELFT>
-void RelocationSection<ELFT>::addReloc(const DynamicReloc<ELFT> &Reloc) {
- Relocs.push_back(Reloc);
-}
-
-template <class ELFT, class RelTy>
-static bool compRelocations(const RelTy &A, const RelTy &B) {
- return A.getSymbol(Config->Mips64EL) < B.getSymbol(Config->Mips64EL);
-}
-
-template <class ELFT> void RelocationSection<ELFT>::writeTo(uint8_t *Buf) {
- uint8_t *BufBegin = Buf;
- for (const DynamicReloc<ELFT> &Rel : Relocs) {
- auto *P = reinterpret_cast<Elf_Rela *>(Buf);
- Buf += Config->Rela ? sizeof(Elf_Rela) : sizeof(Elf_Rel);
-
- if (Config->Rela)
- P->r_addend = Rel.getAddend();
- P->r_offset = Rel.getOffset();
- if (Config->EMachine == EM_MIPS && Rel.getOutputSec() == Out<ELFT>::Got)
- // 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 += Out<ELFT>::Got->getMipsTlsOffset();
- P->setSymbolAndType(Rel.getSymIndex(), Rel.Type, Config->Mips64EL);
- }
-
- if (Sort) {
- if (Config->Rela)
- 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->Header.sh_entsize * Relocs.size();
-}
-
-template <class ELFT> void RelocationSection<ELFT>::finalize() {
- this->Header.sh_link = Static ? Out<ELFT>::SymTab->SectionIndex
- : Out<ELFT>::DynSymTab->SectionIndex;
- this->Header.sh_size = Relocs.size() * this->Header.sh_entsize;
-}
-
-template <class ELFT>
-InterpSection<ELFT>::InterpSection()
- : OutputSectionBase<ELFT>(".interp", SHT_PROGBITS, SHF_ALLOC) {
- this->Header.sh_size = Config->DynamicLinker.size() + 1;
-}
-
-template <class ELFT> void InterpSection<ELFT>::writeTo(uint8_t *Buf) {
- StringRef S = Config->DynamicLinker;
- memcpy(Buf, S.data(), S.size());
-}
-
-template <class ELFT>
-HashTableSection<ELFT>::HashTableSection()
- : OutputSectionBase<ELFT>(".hash", SHT_HASH, SHF_ALLOC) {
- this->Header.sh_entsize = sizeof(Elf_Word);
- this->Header.sh_addralign = sizeof(Elf_Word);
-}
-
-static uint32_t hashSysv(StringRef Name) {
- uint32_t H = 0;
- for (char C : Name) {
- H = (H << 4) + C;
- uint32_t G = H & 0xf0000000;
- if (G)
- H ^= G >> 24;
- H &= ~G;
- }
- return H;
-}
-
-template <class ELFT> void HashTableSection<ELFT>::finalize() {
- this->Header.sh_link = Out<ELFT>::DynSymTab->SectionIndex;
-
- unsigned NumEntries = 2; // nbucket and nchain.
- NumEntries += Out<ELFT>::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 += Out<ELFT>::DynSymTab->getNumSymbols();
- this->Header.sh_size = NumEntries * sizeof(Elf_Word);
-}
-
-template <class ELFT> void HashTableSection<ELFT>::writeTo(uint8_t *Buf) {
- unsigned NumSymbols = Out<ELFT>::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 std::pair<SymbolBody *, unsigned> &P :
- Out<ELFT>::DynSymTab->getSymbols()) {
- SymbolBody *Body = P.first;
- StringRef Name = Body->getName();
- unsigned I = Body->DynsymIndex;
- uint32_t Hash = hashSysv(Name) % NumSymbols;
- Chains[I] = Buckets[Hash];
- Buckets[Hash] = I;
- }
-}
-
-static uint32_t hashGnu(StringRef Name) {
- uint32_t H = 5381;
- for (uint8_t C : Name)
- H = (H << 5) + H + C;
- return H;
-}
-
-template <class ELFT>
-GnuHashTableSection<ELFT>::GnuHashTableSection()
- : OutputSectionBase<ELFT>(".gnu.hash", SHT_GNU_HASH, SHF_ALLOC) {
- this->Header.sh_entsize = ELFT::Is64Bits ? 0 : 4;
- this->Header.sh_addralign = sizeof(uintX_t);
-}
-
-template <class ELFT>
-unsigned GnuHashTableSection<ELFT>::calcNBuckets(unsigned NumHashed) {
- if (!NumHashed)
- return 0;
-
- // These values are prime numbers which are not greater than 2^(N-1) + 1.
- // In result, for any particular NumHashed we return a prime number
- // which is not greater than NumHashed.
- static const unsigned Primes[] = {
- 1, 1, 3, 3, 7, 13, 31, 61, 127, 251,
- 509, 1021, 2039, 4093, 8191, 16381, 32749, 65521, 131071};
-
- return Primes[std::min<unsigned>(Log2_32_Ceil(NumHashed),
- array_lengthof(Primes) - 1)];
-}
-
-// Bloom filter estimation: at least 8 bits for each hashed symbol.
-// GNU Hash table requirement: it should be a power of 2,
-// the minimum value is 1, even for an empty table.
-// Expected results for a 32-bit target:
-// calcMaskWords(0..4) = 1
-// calcMaskWords(5..8) = 2
-// calcMaskWords(9..16) = 4
-// For a 64-bit target:
-// calcMaskWords(0..8) = 1
-// calcMaskWords(9..16) = 2
-// calcMaskWords(17..32) = 4
-template <class ELFT>
-unsigned GnuHashTableSection<ELFT>::calcMaskWords(unsigned NumHashed) {
- if (!NumHashed)
- return 1;
- return NextPowerOf2((NumHashed - 1) / sizeof(Elf_Off));
-}
-
-template <class ELFT> void GnuHashTableSection<ELFT>::finalize() {
- unsigned NumHashed = Symbols.size();
- NBuckets = calcNBuckets(NumHashed);
- MaskWords = calcMaskWords(NumHashed);
- // Second hash shift estimation: just predefined values.
- Shift2 = ELFT::Is64Bits ? 6 : 5;
-
- this->Header.sh_link = Out<ELFT>::DynSymTab->SectionIndex;
- this->Header.sh_size = sizeof(Elf_Word) * 4 // Header
- + sizeof(Elf_Off) * MaskWords // Bloom Filter
- + sizeof(Elf_Word) * NBuckets // Hash Buckets
- + sizeof(Elf_Word) * NumHashed; // Hash Values
-}
-
-template <class ELFT> void GnuHashTableSection<ELFT>::writeTo(uint8_t *Buf) {
- writeHeader(Buf);
- if (Symbols.empty())
- return;
- writeBloomFilter(Buf);
- writeHashTable(Buf);
-}
-
-template <class ELFT>
-void GnuHashTableSection<ELFT>::writeHeader(uint8_t *&Buf) {
- auto *P = reinterpret_cast<Elf_Word *>(Buf);
- *P++ = NBuckets;
- *P++ = Out<ELFT>::DynSymTab->getNumSymbols() - Symbols.size();
- *P++ = MaskWords;
- *P++ = Shift2;
- Buf = reinterpret_cast<uint8_t *>(P);
-}
-
-template <class ELFT>
-void GnuHashTableSection<ELFT>::writeBloomFilter(uint8_t *&Buf) {
- unsigned C = sizeof(Elf_Off) * 8;
-
- auto *Masks = reinterpret_cast<Elf_Off *>(Buf);
- for (const SymbolData &Sym : Symbols) {
- size_t Pos = (Sym.Hash / C) & (MaskWords - 1);
- uintX_t V = (uintX_t(1) << (Sym.Hash % C)) |
- (uintX_t(1) << ((Sym.Hash >> Shift2) % C));
- Masks[Pos] |= V;
- }
- Buf += sizeof(Elf_Off) * MaskWords;
-}
+template <class ELFT> void OutputSection<ELFT>::finalize() {
+ if ((this->Flags & SHF_LINK_ORDER) && !this->Sections.empty()) {
+ std::sort(Sections.begin(), Sections.end(), compareByFilePosition<ELFT>);
+ Size = 0;
+ assignOffsets();
-template <class ELFT>
-void GnuHashTableSection<ELFT>::writeHashTable(uint8_t *Buf) {
- Elf_Word *Buckets = reinterpret_cast<Elf_Word *>(Buf);
- Elf_Word *Values = Buckets + NBuckets;
-
- int PrevBucket = -1;
- int I = 0;
- for (const SymbolData &Sym : Symbols) {
- int Bucket = Sym.Hash % NBuckets;
- assert(PrevBucket <= Bucket);
- if (Bucket != PrevBucket) {
- Buckets[Bucket] = Sym.Body->DynsymIndex;
- PrevBucket = Bucket;
- if (I > 0)
- Values[I - 1] |= 1;
- }
- Values[I] = Sym.Hash & ~1;
- ++I;
+ // We must preserve the link order dependency of sections with the
+ // SHF_LINK_ORDER flag. The dependency is indicated by the sh_link field. We
+ // need to translate the InputSection sh_link to the OutputSection sh_link,
+ // all InputSections in the OutputSection have the same dependency.
+ if (auto *D = this->Sections.front()->getLinkOrderDep())
+ this->Link = D->OutSec->SectionIndex;
}
- if (I > 0)
- Values[I - 1] |= 1;
-}
-// 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.
-template <class ELFT>
-void GnuHashTableSection<ELFT>::addSymbols(
- std::vector<std::pair<SymbolBody *, size_t>> &V) {
- // Ideally this will just be 'auto' but GCC 6.1 is not able
- // to deduce it correctly.
- std::vector<std::pair<SymbolBody *, size_t>>::iterator Mid =
- std::stable_partition(V.begin(), V.end(),
- [](std::pair<SymbolBody *, size_t> &P) {
- return P.first->isUndefined();
- });
- if (Mid == V.end())
+ uint32_t Type = this->Type;
+ if (!Config->Relocatable || (Type != SHT_RELA && Type != SHT_REL))
return;
- for (auto I = Mid, E = V.end(); I != E; ++I) {
- SymbolBody *B = I->first;
- size_t StrOff = I->second;
- Symbols.push_back({B, StrOff, hashGnu(B->getName())});
- }
-
- unsigned NBuckets = calcNBuckets(Symbols.size());
- std::stable_sort(Symbols.begin(), Symbols.end(),
- [&](const SymbolData &L, const SymbolData &R) {
- return L.Hash % NBuckets < R.Hash % NBuckets;
- });
-
- V.erase(Mid, V.end());
- for (const SymbolData &Sym : Symbols)
- V.push_back({Sym.Body, Sym.STName});
-}
-
-// 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()
- : OutputSectionBase<ELFT>(".dynamic", SHT_DYNAMIC, SHF_ALLOC | SHF_WRITE) {
- Elf_Shdr &Header = this->Header;
- Header.sh_addralign = sizeof(uintX_t);
- Header.sh_entsize = ELFT::Is64Bits ? 16 : 8;
-
- // .dynamic section is not writable on MIPS.
- // 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)
- Header.sh_flags = SHF_ALLOC;
-}
-
-template <class ELFT> void DynamicSection<ELFT>::finalize() {
- if (this->Header.sh_size)
- return; // Already finalized.
-
- Elf_Shdr &Header = this->Header;
- Header.sh_link = Out<ELFT>::DynStrTab->SectionIndex;
-
- auto Add = [=](Entry E) { Entries.push_back(E); };
-
- // Add strings. We know that these are the last strings to be added to
- // DynStrTab and doing this here allows this function to set DT_STRSZ.
- if (!Config->RPath.empty())
- Add({Config->EnableNewDtags ? DT_RUNPATH : DT_RPATH,
- Out<ELFT>::DynStrTab->addString(Config->RPath)});
- for (const std::unique_ptr<SharedFile<ELFT>> &F :
- Symtab<ELFT>::X->getSharedFiles())
- if (F->isNeeded())
- Add({DT_NEEDED, Out<ELFT>::DynStrTab->addString(F->getSoName())});
- if (!Config->SoName.empty())
- Add({DT_SONAME, Out<ELFT>::DynStrTab->addString(Config->SoName)});
-
- Out<ELFT>::DynStrTab->finalize();
-
- if (Out<ELFT>::RelaDyn->hasRelocs()) {
- bool IsRela = Config->Rela;
- Add({IsRela ? DT_RELA : DT_REL, Out<ELFT>::RelaDyn});
- Add({IsRela ? DT_RELASZ : DT_RELSZ, Out<ELFT>::RelaDyn->getSize()});
- Add({IsRela ? DT_RELAENT : DT_RELENT,
- uintX_t(IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel))});
- }
- if (Out<ELFT>::RelaPlt && Out<ELFT>::RelaPlt->hasRelocs()) {
- Add({DT_JMPREL, Out<ELFT>::RelaPlt});
- Add({DT_PLTRELSZ, Out<ELFT>::RelaPlt->getSize()});
- Add({Config->EMachine == EM_MIPS ? DT_MIPS_PLTGOT : DT_PLTGOT,
- Out<ELFT>::GotPlt});
- Add({DT_PLTREL, uint64_t(Config->Rela ? DT_RELA : DT_REL)});
- }
- Add({DT_SYMTAB, Out<ELFT>::DynSymTab});
- Add({DT_SYMENT, sizeof(Elf_Sym)});
- Add({DT_STRTAB, Out<ELFT>::DynStrTab});
- Add({DT_STRSZ, Out<ELFT>::DynStrTab->getSize()});
- if (Out<ELFT>::GnuHashTab)
- Add({DT_GNU_HASH, Out<ELFT>::GnuHashTab});
- if (Out<ELFT>::HashTab)
- Add({DT_HASH, Out<ELFT>::HashTab});
-
- if (PreInitArraySec) {
- Add({DT_PREINIT_ARRAY, PreInitArraySec});
- Add({DT_PREINIT_ARRAYSZ, PreInitArraySec->getSize()});
- }
- if (InitArraySec) {
- Add({DT_INIT_ARRAY, InitArraySec});
- Add({DT_INIT_ARRAYSZ, (uintX_t)InitArraySec->getSize()});
- }
- if (FiniArraySec) {
- Add({DT_FINI_ARRAY, FiniArraySec});
- Add({DT_FINI_ARRAYSZ, (uintX_t)FiniArraySec->getSize()});
- }
-
- if (SymbolBody *B = Symtab<ELFT>::X->find(Config->Init))
- Add({DT_INIT, B});
- if (SymbolBody *B = Symtab<ELFT>::X->find(Config->Fini))
- Add({DT_FINI, B});
-
- uint32_t DtFlags = 0;
- uint32_t DtFlags1 = 0;
- if (Config->Bsymbolic)
- DtFlags |= DF_SYMBOLIC;
- if (Config->ZNodelete)
- DtFlags1 |= DF_1_NODELETE;
- 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});
-
- if (!Config->Entry.empty())
- Add({DT_DEBUG, (uint64_t)0});
-
- bool HasVerNeed = Out<ELFT>::VerNeed->getNeedNum() != 0;
- if (HasVerNeed || Out<ELFT>::VerDef)
- Add({DT_VERSYM, Out<ELFT>::VerSym});
- if (Out<ELFT>::VerDef) {
- Add({DT_VERDEF, Out<ELFT>::VerDef});
- Add({DT_VERDEFNUM, getVerDefNum()});
- }
- if (HasVerNeed) {
- Add({DT_VERNEED, Out<ELFT>::VerNeed});
- Add({DT_VERNEEDNUM, Out<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, Out<ELFT>::DynSymTab->getNumSymbols()});
- Add({DT_MIPS_LOCAL_GOTNO, Out<ELFT>::Got->getMipsLocalEntriesNum()});
- if (const SymbolBody *B = Out<ELFT>::Got->getMipsFirstGlobalEntry())
- Add({DT_MIPS_GOTSYM, B->DynsymIndex});
- else
- Add({DT_MIPS_GOTSYM, Out<ELFT>::DynSymTab->getNumSymbols()});
- Add({DT_PLTGOT, Out<ELFT>::Got});
- if (Out<ELFT>::MipsRldMap)
- Add({DT_MIPS_RLD_MAP, Out<ELFT>::MipsRldMap});
- }
-
- // +1 for DT_NULL
- Header.sh_size = (Entries.size() + 1) * Header.sh_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->getVA();
- break;
- case Entry::SymAddr:
- P->d_un.d_ptr = E.Sym->template getVA<ELFT>();
- break;
- case Entry::PlainInt:
- P->d_un.d_val = E.Val;
- break;
- }
- ++P;
- }
-}
-
-template <class ELFT>
-EhFrameHeader<ELFT>::EhFrameHeader()
- : OutputSectionBase<ELFT>(".eh_frame_hdr", SHT_PROGBITS, SHF_ALLOC) {}
-
-// .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, Out<ELFT>::EhFrame->getVA() - this->getVA() - 4);
- write32<E>(Buf + 8, Fdes.size());
- Buf += 12;
-
- uintX_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> void EhFrameHeader<ELFT>::finalize() {
- // .eh_frame_hdr has a 12 bytes header followed by an array of FDEs.
- this->Header.sh_size = 12 + Out<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>
-OutputSection<ELFT>::OutputSection(StringRef Name, uint32_t Type, uintX_t Flags)
- : OutputSectionBase<ELFT>(Name, Type, Flags) {
- if (Type == SHT_RELA)
- this->Header.sh_entsize = sizeof(Elf_Rela);
- else if (Type == SHT_REL)
- this->Header.sh_entsize = sizeof(Elf_Rel);
-}
-
-template <class ELFT> void OutputSection<ELFT>::finalize() {
- uint32_t Type = this->Header.sh_type;
- if (Type != SHT_RELA && Type != SHT_REL)
- return;
- this->Header.sh_link = Out<ELFT>::SymTab->SectionIndex;
+ this->Link = In<ELFT>::SymTab->OutSec->SectionIndex;
// sh_info for SHT_REL[A] sections should contain the section header index of
// the section to which the relocation applies.
InputSectionBase<ELFT> *S = Sections[0]->getRelocatedSection();
- this->Header.sh_info = S->OutSec->SectionIndex;
+ this->Info = S->OutSec->SectionIndex;
}
template <class ELFT>
-void OutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
+void OutputSection<ELFT>::addSection(InputSectionData *C) {
assert(C->Live);
auto *S = cast<InputSection<ELFT>>(C);
Sections.push_back(S);
S->OutSec = this;
this->updateAlignment(S->Alignment);
-}
-
-// If an input string is in the form of "foo.N" where N is a number,
-// return N. Otherwise, returns 65536, which is one greater than the
-// lowest priority.
-static int getPriority(StringRef S) {
- size_t Pos = S.rfind('.');
- if (Pos == StringRef::npos)
- return 65536;
- int V;
- if (S.substr(Pos + 1).getAsInteger(10, V))
- return 65536;
- return V;
+ // Keep sh_entsize value of the input section to be able to perform merging
+ // later during a final linking using the generated relocatable object.
+ if (Config->Relocatable && (S->Flags & SHF_MERGE))
+ this->Entsize = S->Entsize;
}
// This function is called after we sort input sections
// and scan relocations to setup sections' offsets.
template <class ELFT> void OutputSection<ELFT>::assignOffsets() {
- uintX_t Off = this->Header.sh_size;
+ uintX_t Off = this->Size;
for (InputSection<ELFT> *S : Sections) {
Off = alignTo(Off, S->Alignment);
S->OutSecOff = Off;
Off += S->getSize();
}
- this->Header.sh_size = Off;
+ this->Size = Off;
}
-// Sorts input sections by section name suffixes, so that .foo.N comes
-// before .foo.M if N < M. Used to sort .{init,fini}_array.N sections.
-// We want to keep the original order if the priorities are the same
-// because the compiler keeps the original initialization order in a
-// translation unit and we need to respect that.
-// For more detail, read the section of the GCC's manual about init_priority.
-template <class ELFT> void OutputSection<ELFT>::sortInitFini() {
- // Sort sections by priority.
- typedef std::pair<int, InputSection<ELFT> *> Pair;
+template <class ELFT>
+void OutputSection<ELFT>::sort(
+ std::function<int(InputSection<ELFT> *S)> Order) {
+ typedef std::pair<unsigned, InputSection<ELFT> *> Pair;
auto Comp = [](const Pair &A, const Pair &B) { return A.first < B.first; };
std::vector<Pair> V;
for (InputSection<ELFT> *S : Sections)
- V.push_back({getPriority(S->getSectionName()), S});
+ V.push_back({Order(S), S});
std::stable_sort(V.begin(), V.end(), Comp);
Sections.clear();
for (Pair &P : V)
Sections.push_back(P.second);
}
+// Sorts input sections by section name suffixes, so that .foo.N comes
+// before .foo.M if N < M. Used to sort .{init,fini}_array.N sections.
+// We want to keep the original order if the priorities are the same
+// because the compiler keeps the original initialization order in a
+// translation unit and we need to respect that.
+// For more detail, read the section of the GCC's manual about init_priority.
+template <class ELFT> void OutputSection<ELFT>::sortInitFini() {
+ // Sort sections by priority.
+ sort([](InputSection<ELFT> *S) { return getPriority(S->Name); });
+}
+
// Returns true if S matches /Filename.?\.o$/.
static bool isCrtBeginEnd(StringRef S, StringRef Filename) {
if (!S.endswith(".o"))
@@ -921,8 +219,8 @@ static bool compCtors(const InputSection<ELFT> *A,
bool EndB = isCrtend(B->getFile()->getName());
if (EndA != EndB)
return EndB;
- StringRef X = A->getSectionName();
- StringRef Y = B->getSectionName();
+ StringRef X = A->Name;
+ StringRef Y = B->Name;
assert(X.startswith(".ctors") || X.startswith(".dtors"));
assert(Y.startswith(".ctors") || Y.startswith(".dtors"));
X = X.substr(6);
@@ -939,65 +237,50 @@ template <class ELFT> void OutputSection<ELFT>::sortCtorsDtors() {
std::stable_sort(Sections.begin(), Sections.end(), compCtors<ELFT>);
}
-static void fill(uint8_t *Buf, size_t Size, ArrayRef<uint8_t> A) {
+// Fill [Buf, Buf + Size) with Filler. Filler is written in big
+// endian order. This is used for linker script "=fillexp" command.
+void fill(uint8_t *Buf, size_t Size, uint32_t Filler) {
+ uint8_t V[4];
+ write32be(V, Filler);
size_t I = 0;
- for (; I + A.size() < Size; I += A.size())
- memcpy(Buf + I, A.data(), A.size());
- memcpy(Buf + I, A.data(), Size - I);
+ for (; I + 4 < Size; I += 4)
+ memcpy(Buf + I, V, 4);
+ memcpy(Buf + I, V, Size - I);
}
template <class ELFT> void OutputSection<ELFT>::writeTo(uint8_t *Buf) {
- ArrayRef<uint8_t> Filler = Script<ELFT>::X->getFiller(this->Name);
- if (!Filler.empty())
- fill(Buf, this->getSize(), Filler);
- if (Config->Threads) {
- parallel_for_each(Sections.begin(), Sections.end(),
- [=](InputSection<ELFT> *C) { C->writeTo(Buf); });
- } else {
- for (InputSection<ELFT> *C : Sections)
- C->writeTo(Buf);
- }
+ Loc = Buf;
+ if (uint32_t Filler = Script<ELFT>::X->getFiller(this->Name))
+ fill(Buf, this->Size, Filler);
+
+ auto Fn = [=](InputSection<ELFT> *IS) { IS->writeTo(Buf); };
+ forEach(Sections.begin(), Sections.end(), Fn);
+
+ // Linker scripts may have BYTE()-family commands with which you
+ // can write arbitrary bytes to the output. Process them if any.
+ Script<ELFT>::X->writeDataBytes(this->Name, Buf);
}
template <class ELFT>
EhOutputSection<ELFT>::EhOutputSection()
- : OutputSectionBase<ELFT>(".eh_frame", SHT_PROGBITS, SHF_ALLOC) {}
-
-// Returns the first relocation that points to a region
-// between Begin and Begin+Size.
-template <class IntTy, class RelTy>
-static const RelTy *getReloc(IntTy Begin, IntTy Size, ArrayRef<RelTy> &Rels) {
- for (auto I = Rels.begin(), E = Rels.end(); I != E; ++I) {
- if (I->r_offset < Begin)
- continue;
-
- // Truncate Rels for fast access. That means we expect that the
- // relocations are sorted and we are looking up symbols in
- // sequential order. It is naturally satisfied for .eh_frame.
- Rels = Rels.slice(I - Rels.begin());
- if (I->r_offset < Begin + Size)
- return I;
- return nullptr;
- }
- Rels = ArrayRef<RelTy>();
- return nullptr;
-}
+ : OutputSectionBase(".eh_frame", SHT_PROGBITS, SHF_ALLOC) {}
// 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 *EhOutputSection<ELFT>::addCie(SectionPiece &Piece,
- EhInputSection<ELFT> *Sec,
- ArrayRef<RelTy> &Rels) {
+CieRecord *EhOutputSection<ELFT>::addCie(EhSectionPiece &Piece,
+ ArrayRef<RelTy> Rels) {
+ auto *Sec = cast<EhInputSection<ELFT>>(Piece.ID);
const endianness E = ELFT::TargetEndianness;
if (read32<E>(Piece.data().data() + 4) != 0)
- fatal("CIE expected at beginning of .eh_frame: " + Sec->getSectionName());
+ fatal(toString(Sec) + ": CIE expected at beginning of .eh_frame");
SymbolBody *Personality = nullptr;
- if (const RelTy *Rel = getReloc(Piece.InputOff, Piece.size(), Rels))
- Personality = &Sec->getFile()->getRelocTargetSym(*Rel);
+ unsigned FirstRelI = Piece.FirstRelocation;
+ if (FirstRelI != (unsigned)-1)
+ Personality = &Sec->getFile()->getRelocTargetSym(Rels[FirstRelI]);
// Search for an existing CIE by CIE contents/relocation target pair.
CieRecord *Cie = &CieMap[{Piece.data(), Personality}];
@@ -1014,13 +297,14 @@ CieRecord *EhOutputSection<ELFT>::addCie(SectionPiece &Piece,
// points to a live function.
template <class ELFT>
template <class RelTy>
-bool EhOutputSection<ELFT>::isFdeLive(SectionPiece &Piece,
- EhInputSection<ELFT> *Sec,
- ArrayRef<RelTy> &Rels) {
- const RelTy *Rel = getReloc(Piece.InputOff, Piece.size(), Rels);
- if (!Rel)
- fatal("FDE doesn't reference another section");
- SymbolBody &B = Sec->getFile()->getRelocTargetSym(*Rel);
+bool EhOutputSection<ELFT>::isFdeLive(EhSectionPiece &Piece,
+ ArrayRef<RelTy> Rels) {
+ auto *Sec = cast<EhInputSection<ELFT>>(Piece.ID);
+ unsigned FirstRelI = Piece.FirstRelocation;
+ if (FirstRelI == (unsigned)-1)
+ fatal(toString(Sec) + ": FDE doesn't reference another section");
+ const RelTy &Rel = Rels[FirstRelI];
+ SymbolBody &B = Sec->getFile()->getRelocTargetSym(Rel);
auto *D = dyn_cast<DefinedRegular<ELFT>>(&B);
if (!D || !D->Section)
return false;
@@ -1039,7 +323,7 @@ void EhOutputSection<ELFT>::addSectionAux(EhInputSection<ELFT> *Sec,
const endianness E = ELFT::TargetEndianness;
DenseMap<size_t, CieRecord *> OffsetToCie;
- for (SectionPiece &Piece : Sec->Pieces) {
+ for (EhSectionPiece &Piece : Sec->Pieces) {
// The empty record is the end marker.
if (Piece.size() == 4)
return;
@@ -1047,16 +331,16 @@ void EhOutputSection<ELFT>::addSectionAux(EhInputSection<ELFT> *Sec,
size_t Offset = Piece.InputOff;
uint32_t ID = read32<E>(Piece.data().data() + 4);
if (ID == 0) {
- OffsetToCie[Offset] = addCie(Piece, Sec, Rels);
+ OffsetToCie[Offset] = addCie(Piece, Rels);
continue;
}
uint32_t CieOffset = Offset + 4 - ID;
CieRecord *Cie = OffsetToCie[CieOffset];
if (!Cie)
- fatal("invalid CIE reference");
+ fatal(toString(Sec) + ": invalid CIE reference");
- if (!isFdeLive(Piece, Sec, Rels))
+ if (!isFdeLive(Piece, Rels))
continue;
Cie->FdePieces.push_back(&Piece);
NumFdes++;
@@ -1064,7 +348,7 @@ void EhOutputSection<ELFT>::addSectionAux(EhInputSection<ELFT> *Sec,
}
template <class ELFT>
-void EhOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
+void EhOutputSection<ELFT>::addSection(InputSectionData *C) {
auto *Sec = cast<EhInputSection<ELFT>>(C);
Sec->OutSec = this;
this->updateAlignment(Sec->Alignment);
@@ -1077,12 +361,11 @@ void EhOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
if (Sec->Pieces.empty())
return;
- if (const Elf_Shdr *RelSec = Sec->RelocSection) {
- ELFFile<ELFT> &Obj = Sec->getFile()->getObj();
- if (RelSec->sh_type == SHT_RELA)
- addSectionAux(Sec, Obj.relas(RelSec));
+ if (Sec->NumRelocations) {
+ if (Sec->AreRelocsRela)
+ addSectionAux(Sec, Sec->relas());
else
- addSectionAux(Sec, Obj.rels(RelSec));
+ addSectionAux(Sec, Sec->rels());
return;
}
addSectionAux(Sec, makeArrayRef<Elf_Rela>(nullptr, nullptr));
@@ -1098,7 +381,7 @@ static void writeCieFde(uint8_t *Buf, ArrayRef<uint8_t> D) {
}
template <class ELFT> void EhOutputSection<ELFT>::finalize() {
- if (this->Header.sh_size)
+ if (this->Size)
return; // Already finalized.
size_t Off = 0;
@@ -1106,12 +389,12 @@ template <class ELFT> void EhOutputSection<ELFT>::finalize() {
Cie->Piece->OutputOff = Off;
Off += alignTo(Cie->Piece->size(), sizeof(uintX_t));
- for (SectionPiece *Fde : Cie->FdePieces) {
+ for (EhSectionPiece *Fde : Cie->FdePieces) {
Fde->OutputOff = Off;
Off += alignTo(Fde->size(), sizeof(uintX_t));
}
}
- this->Header.sh_size = Off;
+ this->Size = Off;
}
template <class ELFT> static uint64_t readFdeAddr(uint8_t *Buf, int Size) {
@@ -1143,7 +426,7 @@ typename ELFT::uint EhOutputSection<ELFT>::getFdePc(uint8_t *Buf, size_t FdeOff,
if ((Enc & 0x70) == DW_EH_PE_absptr)
return Addr;
if ((Enc & 0x70) == DW_EH_PE_pcrel)
- return Addr + this->getVA() + Off;
+ return Addr + this->Addr + Off;
fatal("unknown FDE size relative encoding");
}
@@ -1153,7 +436,7 @@ template <class ELFT> void EhOutputSection<ELFT>::writeTo(uint8_t *Buf) {
size_t CieOffset = Cie->Piece->OutputOff;
writeCieFde<ELFT>(Buf + CieOffset, Cie->Piece->data());
- for (SectionPiece *Fde : Cie->FdePieces) {
+ for (EhSectionPiece *Fde : Cie->FdePieces) {
size_t Off = Fde->OutputOff;
writeCieFde<ELFT>(Buf + Off, Fde->data());
@@ -1169,13 +452,13 @@ template <class ELFT> void EhOutputSection<ELFT>::writeTo(uint8_t *Buf) {
// 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 (Out<ELFT>::EhFrameHdr) {
+ if (In<ELFT>::EhFrameHdr) {
for (CieRecord *Cie : Cies) {
- uint8_t Enc = getFdeEncoding<ELFT>(Cie->Piece->data());
+ uint8_t Enc = getFdeEncoding<ELFT>(Cie->Piece);
for (SectionPiece *Fde : Cie->FdePieces) {
uintX_t Pc = getFdePc(Buf, Fde->OutputOff, Enc);
- uintX_t FdeVA = this->getVA() + Fde->OutputOff;
- Out<ELFT>::EhFrameHdr->addFde(Pc, FdeVA);
+ uintX_t FdeVA = this->Addr + Fde->OutputOff;
+ In<ELFT>::EhFrameHdr->addFde(Pc, FdeVA);
}
}
}
@@ -1184,620 +467,127 @@ template <class ELFT> void EhOutputSection<ELFT>::writeTo(uint8_t *Buf) {
template <class ELFT>
MergeOutputSection<ELFT>::MergeOutputSection(StringRef Name, uint32_t Type,
uintX_t Flags, uintX_t Alignment)
- : OutputSectionBase<ELFT>(Name, Type, Flags),
+ : OutputSectionBase(Name, Type, Flags),
Builder(StringTableBuilder::RAW, Alignment) {}
template <class ELFT> void MergeOutputSection<ELFT>::writeTo(uint8_t *Buf) {
- if (shouldTailMerge()) {
- StringRef Data = Builder.data();
- memcpy(Buf, Data.data(), Data.size());
- return;
- }
- for (const std::pair<CachedHash<StringRef>, size_t> &P : Builder.getMap()) {
- StringRef Data = P.first.Val;
- memcpy(Buf + P.second, Data.data(), Data.size());
- }
-}
-
-static StringRef toStringRef(ArrayRef<uint8_t> A) {
- return {(const char *)A.data(), A.size()};
+ Builder.write(Buf);
}
template <class ELFT>
-void MergeOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
+void MergeOutputSection<ELFT>::addSection(InputSectionData *C) {
auto *Sec = cast<MergeInputSection<ELFT>>(C);
Sec->OutSec = this;
this->updateAlignment(Sec->Alignment);
- this->Header.sh_entsize = Sec->getSectionHdr()->sh_entsize;
+ this->Entsize = Sec->Entsize;
Sections.push_back(Sec);
-
- bool IsString = this->Header.sh_flags & SHF_STRINGS;
-
- for (SectionPiece &Piece : Sec->Pieces) {
- if (!Piece.Live)
- continue;
- uintX_t OutputOffset = Builder.add(toStringRef(Piece.data()));
- if (!IsString || !shouldTailMerge())
- Piece.OutputOff = OutputOffset;
- }
-}
-
-template <class ELFT>
-unsigned MergeOutputSection<ELFT>::getOffset(StringRef Val) {
- return Builder.getOffset(Val);
}
template <class ELFT> bool MergeOutputSection<ELFT>::shouldTailMerge() const {
- return Config->Optimize >= 2 && this->Header.sh_flags & SHF_STRINGS;
+ return (this->Flags & SHF_STRINGS) && Config->Optimize >= 2;
}
-template <class ELFT> void MergeOutputSection<ELFT>::finalize() {
- if (shouldTailMerge())
- Builder.finalize();
- this->Header.sh_size = Builder.getSize();
-}
-
-template <class ELFT> void MergeOutputSection<ELFT>::finalizePieces() {
+template <class ELFT> void MergeOutputSection<ELFT>::finalizeTailMerge() {
+ // Add all string pieces to the string table builder to create section
+ // contents.
for (MergeInputSection<ELFT> *Sec : Sections)
- Sec->finalizePieces();
-}
-
-template <class ELFT>
-StringTableSection<ELFT>::StringTableSection(StringRef Name, bool Dynamic)
- : OutputSectionBase<ELFT>(Name, SHT_STRTAB,
- Dynamic ? (uintX_t)SHF_ALLOC : 0),
- Dynamic(Dynamic) {}
-
-// 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.
-template <class ELFT>
-unsigned StringTableSection<ELFT>::addString(StringRef S, bool HashIt) {
- if (HashIt) {
- auto R = StringMap.insert(std::make_pair(S, Size));
- if (!R.second)
- return R.first->second;
- }
- unsigned Ret = Size;
- Size += S.size() + 1;
- Strings.push_back(S);
- return Ret;
-}
-
-template <class ELFT> void StringTableSection<ELFT>::writeTo(uint8_t *Buf) {
- // ELF string tables start with NUL byte, so advance the pointer by one.
- ++Buf;
- for (StringRef S : Strings) {
- memcpy(Buf, S.data(), S.size());
- Buf += S.size() + 1;
- }
-}
-
-template <class ELFT>
-typename ELFT::uint DynamicReloc<ELFT>::getOffset() const {
- if (OutputSec)
- return OutputSec->getVA() + OffsetInSec;
- return InputSec->OutSec->getVA() + InputSec->getOffset(OffsetInSec);
-}
-
-template <class ELFT>
-typename ELFT::uint DynamicReloc<ELFT>::getAddend() const {
- if (UseSymVA)
- return Sym->getVA<ELFT>(Addend);
- return Addend;
-}
-
-template <class ELFT> uint32_t DynamicReloc<ELFT>::getSymIndex() const {
- if (Sym && !UseSymVA)
- return Sym->DynsymIndex;
- return 0;
-}
-
-template <class ELFT>
-SymbolTableSection<ELFT>::SymbolTableSection(
- StringTableSection<ELFT> &StrTabSec)
- : OutputSectionBase<ELFT>(StrTabSec.isDynamic() ? ".dynsym" : ".symtab",
- StrTabSec.isDynamic() ? SHT_DYNSYM : SHT_SYMTAB,
- StrTabSec.isDynamic() ? (uintX_t)SHF_ALLOC : 0),
- StrTabSec(StrTabSec) {
- this->Header.sh_entsize = sizeof(Elf_Sym);
- this->Header.sh_addralign = sizeof(uintX_t);
-}
-
-// 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 std::pair<SymbolBody *, unsigned> &L,
- const std::pair<SymbolBody *, unsigned> &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.first->IsInGlobalMipsGot;
- bool RIsInLocalGot = !R.first->IsInGlobalMipsGot;
- if (LIsInLocalGot || RIsInLocalGot)
- return !RIsInLocalGot;
- return L.first->GotIndex < R.first->GotIndex;
-}
-
-static uint8_t getSymbolBinding(SymbolBody *Body) {
- Symbol *S = Body->symbol();
- uint8_t Visibility = S->Visibility;
- if (Visibility != STV_DEFAULT && Visibility != STV_PROTECTED)
- return STB_LOCAL;
- if (Config->NoGnuUnique && S->Binding == STB_GNU_UNIQUE)
- return STB_GLOBAL;
- return S->Binding;
-}
-
-template <class ELFT> void SymbolTableSection<ELFT>::finalize() {
- if (this->Header.sh_size)
- return; // Already finalized.
-
- this->Header.sh_size = getNumSymbols() * sizeof(Elf_Sym);
- this->Header.sh_link = StrTabSec.SectionIndex;
- this->Header.sh_info = NumLocals + 1;
-
- if (Config->Relocatable) {
- size_t I = NumLocals;
- for (const std::pair<SymbolBody *, size_t> &P : Symbols)
- P.first->DynsymIndex = ++I;
- return;
- }
-
- if (!StrTabSec.isDynamic()) {
- std::stable_sort(Symbols.begin(), Symbols.end(),
- [](const std::pair<SymbolBody *, unsigned> &L,
- const std::pair<SymbolBody *, unsigned> &R) {
- return getSymbolBinding(L.first) == STB_LOCAL &&
- getSymbolBinding(R.first) != STB_LOCAL;
- });
- return;
- }
- if (Out<ELFT>::GnuHashTab)
- // NB: It also sorts Symbols to meet the GNU hash table requirements.
- Out<ELFT>::GnuHashTab->addSymbols(Symbols);
- else if (Config->EMachine == EM_MIPS)
- std::stable_sort(Symbols.begin(), Symbols.end(), sortMipsSymbols);
- size_t I = 0;
- for (const std::pair<SymbolBody *, size_t> &P : Symbols)
- P.first->DynsymIndex = ++I;
-}
-
-template <class ELFT>
-void SymbolTableSection<ELFT>::addSymbol(SymbolBody *B) {
- Symbols.push_back({B, StrTabSec.addString(B->getName(), false)});
-}
-
-template <class ELFT> void SymbolTableSection<ELFT>::writeTo(uint8_t *Buf) {
- Buf += sizeof(Elf_Sym);
-
- // All symbols with STB_LOCAL binding precede the weak and global symbols.
- // .dynsym only contains global symbols.
- if (!Config->DiscardAll && !StrTabSec.isDynamic())
- writeLocalSymbols(Buf);
-
- writeGlobalSymbols(Buf);
-}
-
-template <class ELFT>
-void SymbolTableSection<ELFT>::writeLocalSymbols(uint8_t *&Buf) {
- // Iterate over all input object files to copy their local symbols
- // to the output symbol table pointed by Buf.
- for (const std::unique_ptr<ObjectFile<ELFT>> &File :
- Symtab<ELFT>::X->getObjectFiles()) {
- for (const std::pair<const DefinedRegular<ELFT> *, size_t> &P :
- File->KeptLocalSyms) {
- const DefinedRegular<ELFT> &Body = *P.first;
- InputSectionBase<ELFT> *Section = Body.Section;
- auto *ESym = reinterpret_cast<Elf_Sym *>(Buf);
-
- if (!Section) {
- ESym->st_shndx = SHN_ABS;
- ESym->st_value = Body.Value;
- } else {
- const OutputSectionBase<ELFT> *OutSec = Section->OutSec;
- ESym->st_shndx = OutSec->SectionIndex;
- ESym->st_value = OutSec->getVA() + Section->getOffset(Body);
- }
- ESym->st_name = P.second;
- ESym->st_size = Body.template getSize<ELFT>();
- ESym->setBindingAndType(STB_LOCAL, Body.Type);
- Buf += sizeof(*ESym);
- }
- }
-}
-
-template <class ELFT>
-void SymbolTableSection<ELFT>::writeGlobalSymbols(uint8_t *Buf) {
- // Write the internal symbol table contents to the output symbol table
- // pointed by Buf.
- auto *ESym = reinterpret_cast<Elf_Sym *>(Buf);
- for (const std::pair<SymbolBody *, size_t> &P : Symbols) {
- SymbolBody *Body = P.first;
- size_t StrOff = P.second;
-
- uint8_t Type = Body->Type;
- uintX_t Size = Body->getSize<ELFT>();
-
- ESym->setBindingAndType(getSymbolBinding(Body), Type);
- ESym->st_size = Size;
- ESym->st_name = StrOff;
- ESym->setVisibility(Body->symbol()->Visibility);
- ESym->st_value = Body->getVA<ELFT>();
-
- if (const OutputSectionBase<ELFT> *OutSec = getOutputSection(Body))
- ESym->st_shndx = OutSec->SectionIndex;
- else if (isa<DefinedRegular<ELFT>>(Body))
- ESym->st_shndx = SHN_ABS;
-
- // 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 && Body->isInPlt() &&
- Body->NeedsCopyOrPltAddr)
- ESym->st_other |= STO_MIPS_PLT;
- ++ESym;
- }
-}
-
-template <class ELFT>
-const OutputSectionBase<ELFT> *
-SymbolTableSection<ELFT>::getOutputSection(SymbolBody *Sym) {
- switch (Sym->kind()) {
- case SymbolBody::DefinedSyntheticKind:
- return cast<DefinedSynthetic<ELFT>>(Sym)->Section;
- case SymbolBody::DefinedRegularKind: {
- auto &D = cast<DefinedRegular<ELFT>>(*Sym);
- if (D.Section)
- return D.Section->OutSec;
- break;
- }
- case SymbolBody::DefinedCommonKind:
- return Out<ELFT>::Bss;
- case SymbolBody::SharedKind:
- if (cast<SharedSymbol<ELFT>>(Sym)->needsCopy())
- return Out<ELFT>::Bss;
- break;
- case SymbolBody::UndefinedKind:
- case SymbolBody::LazyArchiveKind:
- case SymbolBody::LazyObjectKind:
- break;
- case SymbolBody::DefinedBitcodeKind:
- llvm_unreachable("should have been replaced");
- }
- return nullptr;
-}
-
-template <class ELFT>
-VersionDefinitionSection<ELFT>::VersionDefinitionSection()
- : OutputSectionBase<ELFT>(".gnu.version_d", SHT_GNU_verdef, SHF_ALLOC) {
- this->Header.sh_addralign = sizeof(uint32_t);
-}
-
-static StringRef getFileDefName() {
- if (!Config->SoName.empty())
- return Config->SoName;
- return Config->OutputFile;
-}
-
-template <class ELFT> void VersionDefinitionSection<ELFT>::finalize() {
- FileDefNameOff = Out<ELFT>::DynStrTab->addString(getFileDefName());
- for (VersionDefinition &V : Config->VersionDefinitions)
- V.NameOff = Out<ELFT>::DynStrTab->addString(V.Name);
-
- this->Header.sh_size =
- (sizeof(Elf_Verdef) + sizeof(Elf_Verdaux)) * getVerDefNum();
- this->Header.sh_link = Out<ELFT>::DynStrTab->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
- this->Header.sh_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>
-VersionTableSection<ELFT>::VersionTableSection()
- : OutputSectionBase<ELFT>(".gnu.version", SHT_GNU_versym, SHF_ALLOC) {
- this->Header.sh_addralign = sizeof(uint16_t);
-}
-
-template <class ELFT> void VersionTableSection<ELFT>::finalize() {
- this->Header.sh_size =
- sizeof(Elf_Versym) * (Out<ELFT>::DynSymTab->getSymbols().size() + 1);
- this->Header.sh_entsize = sizeof(Elf_Versym);
- // 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.
- this->Header.sh_link = Out<ELFT>::DynSymTab->SectionIndex;
-}
-
-template <class ELFT> void VersionTableSection<ELFT>::writeTo(uint8_t *Buf) {
- auto *OutVersym = reinterpret_cast<Elf_Versym *>(Buf) + 1;
- for (const std::pair<SymbolBody *, size_t> &P :
- Out<ELFT>::DynSymTab->getSymbols()) {
- OutVersym->vs_index = P.first->symbol()->VersionId;
- ++OutVersym;
- }
-}
-
-template <class ELFT>
-VersionNeedSection<ELFT>::VersionNeedSection()
- : OutputSectionBase<ELFT>(".gnu.version_r", SHT_GNU_verneed, SHF_ALLOC) {
- this->Header.sh_addralign = sizeof(uint32_t);
-
- // 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<ELFT> *SS) {
- if (!SS->Verdef) {
- SS->symbol()->VersionId = VER_NDX_GLOBAL;
- return;
- }
- SharedFile<ELFT> *F = SS->file();
- // 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 (F->VerdefMap.empty())
- Needed.push_back({F, Out<ELFT>::DynStrTab->addString(F->getSoName())});
- typename SharedFile<ELFT>::NeededVer &NV = F->VerdefMap[SS->Verdef];
- // 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 = Out<ELFT>::DynStrTab->addString(
- SS->file()->getStringTable().data() + SS->Verdef->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>::finalize() {
- this->Header.sh_link = Out<ELFT>::DynStrTab->SectionIndex;
- this->Header.sh_info = Needed.size();
- unsigned Size = Needed.size() * sizeof(Elf_Verneed);
- for (std::pair<SharedFile<ELFT> *, size_t> &P : Needed)
- Size += P.first->VerdefMap.size() * sizeof(Elf_Vernaux);
- this->Header.sh_size = Size;
-}
-
-template <class ELFT>
-BuildIdSection<ELFT>::BuildIdSection(size_t HashSize)
- : OutputSectionBase<ELFT>(".note.gnu.build-id", SHT_NOTE, SHF_ALLOC),
- HashSize(HashSize) {
- // 16 bytes for the note section header.
- this->Header.sh_size = 16 + HashSize;
-}
-
-template <class ELFT> void BuildIdSection<ELFT>::writeTo(uint8_t *Buf) {
- const endianness E = ELFT::TargetEndianness;
- write32<E>(Buf, 4); // Name size
- write32<E>(Buf + 4, HashSize); // Content size
- write32<E>(Buf + 8, NT_GNU_BUILD_ID); // Type
- memcpy(Buf + 12, "GNU", 4); // Name string
- HashBuf = Buf + 16;
-}
-
-template <class ELFT>
-void BuildIdFnv1<ELFT>::writeBuildId(ArrayRef<ArrayRef<uint8_t>> Bufs) {
- const endianness E = ELFT::TargetEndianness;
+ for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
+ if (Sec->Pieces[I].Live)
+ Builder.add(Sec->getData(I));
- // 64-bit FNV-1 hash
- uint64_t Hash = 0xcbf29ce484222325;
- for (ArrayRef<uint8_t> Buf : Bufs) {
- for (uint8_t B : Buf) {
- Hash *= 0x100000001b3;
- Hash ^= B;
- }
- }
- write64<E>(this->HashBuf, Hash);
-}
+ // Fix the string table content. After this, the contents will never change.
+ Builder.finalize();
+ this->Size = Builder.getSize();
-template <class ELFT>
-void BuildIdMd5<ELFT>::writeBuildId(ArrayRef<ArrayRef<uint8_t>> Bufs) {
- MD5 Hash;
- for (ArrayRef<uint8_t> Buf : Bufs)
- Hash.update(Buf);
- MD5::MD5Result Res;
- Hash.final(Res);
- memcpy(this->HashBuf, Res, 16);
-}
-
-template <class ELFT>
-void BuildIdSha1<ELFT>::writeBuildId(ArrayRef<ArrayRef<uint8_t>> Bufs) {
- SHA1 Hash;
- for (ArrayRef<uint8_t> Buf : Bufs)
- Hash.update(Buf);
- memcpy(this->HashBuf, Hash.final().data(), 20);
+ // 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<ELFT> *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));
}
-template <class ELFT>
-BuildIdHexstring<ELFT>::BuildIdHexstring()
- : BuildIdSection<ELFT>(Config->BuildIdVector.size()) {}
+template <class ELFT> void MergeOutputSection<ELFT>::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<ELFT> *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));
-template <class ELFT>
-void BuildIdHexstring<ELFT>::writeBuildId(ArrayRef<ArrayRef<uint8_t>> Bufs) {
- memcpy(this->HashBuf, Config->BuildIdVector.data(),
- Config->BuildIdVector.size());
+ Builder.finalizeInOrder();
+ this->Size = Builder.getSize();
}
-template <class ELFT>
-MipsReginfoOutputSection<ELFT>::MipsReginfoOutputSection()
- : OutputSectionBase<ELFT>(".reginfo", SHT_MIPS_REGINFO, SHF_ALLOC) {
- this->Header.sh_addralign = 4;
- this->Header.sh_entsize = sizeof(Elf_Mips_RegInfo);
- this->Header.sh_size = sizeof(Elf_Mips_RegInfo);
+template <class ELFT> void MergeOutputSection<ELFT>::finalize() {
+ if (shouldTailMerge())
+ finalizeTailMerge();
+ else
+ finalizeNoTailMerge();
}
template <class ELFT>
-void MipsReginfoOutputSection<ELFT>::writeTo(uint8_t *Buf) {
- auto *R = reinterpret_cast<Elf_Mips_RegInfo *>(Buf);
- R->ri_gp_value = Out<ELFT>::Got->getVA() + MipsGPOffset;
- R->ri_gprmask = GprMask;
+static typename ELFT::uint getOutFlags(InputSectionBase<ELFT> *S) {
+ return S->Flags & ~SHF_GROUP & ~SHF_COMPRESSED;
}
template <class ELFT>
-void MipsReginfoOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
- // Copy input object file's .reginfo gprmask to output.
- auto *S = cast<MipsReginfoInputSection<ELFT>>(C);
- GprMask |= S->Reginfo->ri_gprmask;
- S->OutSec = this;
-}
+static SectionKey<ELFT::Is64Bits> createKey(InputSectionBase<ELFT> *C,
+ StringRef OutsecName) {
+ typedef typename ELFT::uint uintX_t;
+ uintX_t Flags = getOutFlags(C);
-template <class ELFT>
-MipsOptionsOutputSection<ELFT>::MipsOptionsOutputSection()
- : OutputSectionBase<ELFT>(".MIPS.options", SHT_MIPS_OPTIONS,
- SHF_ALLOC | SHF_MIPS_NOSTRIP) {
- this->Header.sh_addralign = 8;
- this->Header.sh_entsize = 1;
- this->Header.sh_size = sizeof(Elf_Mips_Options) + sizeof(Elf_Mips_RegInfo);
-}
+ // For SHF_MERGE we create different output sections for each alignment.
+ // This makes each output section simple and keeps a single level mapping from
+ // input to output.
+ // In case of relocatable object generation we do not try to perform merging
+ // and treat SHF_MERGE sections as regular ones, but also create different
+ // output sections for them to allow merging at final linking stage.
+ uintX_t Alignment = 0;
+ if (isa<MergeInputSection<ELFT>>(C) ||
+ (Config->Relocatable && (C->Flags & SHF_MERGE)))
+ Alignment = std::max<uintX_t>(C->Alignment, C->Entsize);
-template <class ELFT>
-void MipsOptionsOutputSection<ELFT>::writeTo(uint8_t *Buf) {
- auto *Opt = reinterpret_cast<Elf_Mips_Options *>(Buf);
- Opt->kind = ODK_REGINFO;
- Opt->size = this->Header.sh_size;
- Opt->section = 0;
- Opt->info = 0;
- auto *Reg = reinterpret_cast<Elf_Mips_RegInfo *>(Buf + sizeof(*Opt));
- Reg->ri_gp_value = Out<ELFT>::Got->getVA() + MipsGPOffset;
- Reg->ri_gprmask = GprMask;
+ return SectionKey<ELFT::Is64Bits>{OutsecName, C->Type, Flags, Alignment};
}
template <class ELFT>
-void MipsOptionsOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
- auto *S = cast<MipsOptionsInputSection<ELFT>>(C);
- if (S->Reginfo)
- GprMask |= S->Reginfo->ri_gprmask;
- S->OutSec = this;
-}
-
-template <class ELFT>
-std::pair<OutputSectionBase<ELFT> *, bool>
+std::pair<OutputSectionBase *, bool>
OutputSectionFactory<ELFT>::create(InputSectionBase<ELFT> *C,
StringRef OutsecName) {
SectionKey<ELFT::Is64Bits> Key = createKey(C, OutsecName);
- OutputSectionBase<ELFT> *&Sec = Map[Key];
- if (Sec)
+ return create(Key, C);
+}
+
+template <class ELFT>
+std::pair<OutputSectionBase *, bool>
+OutputSectionFactory<ELFT>::create(const SectionKey<ELFT::Is64Bits> &Key,
+ InputSectionBase<ELFT> *C) {
+ uintX_t Flags = getOutFlags(C);
+ OutputSectionBase *&Sec = Map[Key];
+ if (Sec) {
+ Sec->Flags |= Flags;
return {Sec, false};
+ }
- switch (C->SectionKind) {
+ uint32_t Type = C->Type;
+ switch (C->kind()) {
case InputSectionBase<ELFT>::Regular:
- Sec = new OutputSection<ELFT>(Key.Name, Key.Type, Key.Flags);
+ case InputSectionBase<ELFT>::Synthetic:
+ Sec = make<OutputSection<ELFT>>(Key.Name, Type, Flags);
break;
case InputSectionBase<ELFT>::EHFrame:
return {Out<ELFT>::EhFrame, false};
case InputSectionBase<ELFT>::Merge:
- Sec = new MergeOutputSection<ELFT>(Key.Name, Key.Type, Key.Flags,
- Key.Alignment);
- break;
- case InputSectionBase<ELFT>::MipsReginfo:
- Sec = new MipsReginfoOutputSection<ELFT>();
- break;
- case InputSectionBase<ELFT>::MipsOptions:
- Sec = new MipsOptionsOutputSection<ELFT>();
+ Sec = make<MergeOutputSection<ELFT>>(Key.Name, Type, Flags, Key.Alignment);
break;
}
return {Sec, true};
}
-template <class ELFT>
-OutputSectionBase<ELFT> *OutputSectionFactory<ELFT>::lookup(StringRef Name,
- uint32_t Type,
- uintX_t Flags) {
- return Map.lookup({Name, Type, Flags, 0});
-}
-
-template <class ELFT>
-SectionKey<ELFT::Is64Bits>
-OutputSectionFactory<ELFT>::createKey(InputSectionBase<ELFT> *C,
- StringRef OutsecName) {
- const Elf_Shdr *H = C->getSectionHdr();
- uintX_t Flags = H->sh_flags & ~SHF_GROUP & ~SHF_COMPRESSED;
-
- // For SHF_MERGE we create different output sections for each alignment.
- // This makes each output section simple and keeps a single level mapping from
- // input to output.
- uintX_t Alignment = 0;
- if (isa<MergeInputSection<ELFT>>(C))
- Alignment = std::max(H->sh_addralign, H->sh_entsize);
-
- uint32_t Type = H->sh_type;
- return SectionKey<ELFT::Is64Bits>{OutsecName, Type, Flags, Alignment};
-}
-
template <bool Is64Bits>
typename lld::elf::SectionKey<Is64Bits>
DenseMapInfo<lld::elf::SectionKey<Is64Bits>>::getEmptyKey() {
@@ -1832,55 +622,11 @@ template struct DenseMapInfo<SectionKey<false>>;
namespace lld {
namespace elf {
-template class OutputSectionBase<ELF32LE>;
-template class OutputSectionBase<ELF32BE>;
-template class OutputSectionBase<ELF64LE>;
-template class OutputSectionBase<ELF64BE>;
-
-template class EhFrameHeader<ELF32LE>;
-template class EhFrameHeader<ELF32BE>;
-template class EhFrameHeader<ELF64LE>;
-template class EhFrameHeader<ELF64BE>;
-
-template class GotPltSection<ELF32LE>;
-template class GotPltSection<ELF32BE>;
-template class GotPltSection<ELF64LE>;
-template class GotPltSection<ELF64BE>;
-
-template class GotSection<ELF32LE>;
-template class GotSection<ELF32BE>;
-template class GotSection<ELF64LE>;
-template class GotSection<ELF64BE>;
-
-template class PltSection<ELF32LE>;
-template class PltSection<ELF32BE>;
-template class PltSection<ELF64LE>;
-template class PltSection<ELF64BE>;
-
-template class RelocationSection<ELF32LE>;
-template class RelocationSection<ELF32BE>;
-template class RelocationSection<ELF64LE>;
-template class RelocationSection<ELF64BE>;
-
-template class InterpSection<ELF32LE>;
-template class InterpSection<ELF32BE>;
-template class InterpSection<ELF64LE>;
-template class InterpSection<ELF64BE>;
-
-template class GnuHashTableSection<ELF32LE>;
-template class GnuHashTableSection<ELF32BE>;
-template class GnuHashTableSection<ELF64LE>;
-template class GnuHashTableSection<ELF64BE>;
-
-template class HashTableSection<ELF32LE>;
-template class HashTableSection<ELF32BE>;
-template class HashTableSection<ELF64LE>;
-template class HashTableSection<ELF64BE>;
-
-template class DynamicSection<ELF32LE>;
-template class DynamicSection<ELF32BE>;
-template class DynamicSection<ELF64LE>;
-template class DynamicSection<ELF64BE>;
+
+template void OutputSectionBase::writeHeaderTo<ELF32LE>(ELF32LE::Shdr *Shdr);
+template void OutputSectionBase::writeHeaderTo<ELF32BE>(ELF32BE::Shdr *Shdr);
+template void OutputSectionBase::writeHeaderTo<ELF64LE>(ELF64LE::Shdr *Shdr);
+template void OutputSectionBase::writeHeaderTo<ELF64BE>(ELF64BE::Shdr *Shdr);
template class OutputSection<ELF32LE>;
template class OutputSection<ELF32BE>;
@@ -1892,71 +638,11 @@ template class EhOutputSection<ELF32BE>;
template class EhOutputSection<ELF64LE>;
template class EhOutputSection<ELF64BE>;
-template class MipsReginfoOutputSection<ELF32LE>;
-template class MipsReginfoOutputSection<ELF32BE>;
-template class MipsReginfoOutputSection<ELF64LE>;
-template class MipsReginfoOutputSection<ELF64BE>;
-
-template class MipsOptionsOutputSection<ELF32LE>;
-template class MipsOptionsOutputSection<ELF32BE>;
-template class MipsOptionsOutputSection<ELF64LE>;
-template class MipsOptionsOutputSection<ELF64BE>;
-
template class MergeOutputSection<ELF32LE>;
template class MergeOutputSection<ELF32BE>;
template class MergeOutputSection<ELF64LE>;
template class MergeOutputSection<ELF64BE>;
-template class StringTableSection<ELF32LE>;
-template class StringTableSection<ELF32BE>;
-template class StringTableSection<ELF64LE>;
-template class StringTableSection<ELF64BE>;
-
-template class SymbolTableSection<ELF32LE>;
-template class SymbolTableSection<ELF32BE>;
-template class SymbolTableSection<ELF64LE>;
-template class SymbolTableSection<ELF64BE>;
-
-template class VersionTableSection<ELF32LE>;
-template class VersionTableSection<ELF32BE>;
-template class VersionTableSection<ELF64LE>;
-template class VersionTableSection<ELF64BE>;
-
-template class VersionNeedSection<ELF32LE>;
-template class VersionNeedSection<ELF32BE>;
-template class VersionNeedSection<ELF64LE>;
-template class VersionNeedSection<ELF64BE>;
-
-template class VersionDefinitionSection<ELF32LE>;
-template class VersionDefinitionSection<ELF32BE>;
-template class VersionDefinitionSection<ELF64LE>;
-template class VersionDefinitionSection<ELF64BE>;
-
-template class BuildIdSection<ELF32LE>;
-template class BuildIdSection<ELF32BE>;
-template class BuildIdSection<ELF64LE>;
-template class BuildIdSection<ELF64BE>;
-
-template class BuildIdFnv1<ELF32LE>;
-template class BuildIdFnv1<ELF32BE>;
-template class BuildIdFnv1<ELF64LE>;
-template class BuildIdFnv1<ELF64BE>;
-
-template class BuildIdMd5<ELF32LE>;
-template class BuildIdMd5<ELF32BE>;
-template class BuildIdMd5<ELF64LE>;
-template class BuildIdMd5<ELF64BE>;
-
-template class BuildIdSha1<ELF32LE>;
-template class BuildIdSha1<ELF32BE>;
-template class BuildIdSha1<ELF64LE>;
-template class BuildIdSha1<ELF64BE>;
-
-template class BuildIdHexstring<ELF32LE>;
-template class BuildIdHexstring<ELF32BE>;
-template class BuildIdHexstring<ELF64LE>;
-template class BuildIdHexstring<ELF64BE>;
-
template class OutputSectionFactory<ELF32LE>;
template class OutputSectionFactory<ELF32BE>;
template class OutputSectionFactory<ELF64LE>;