1 //===- OutputSections.cpp -------------------------------------------------===//
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "OutputSections.h"
13 #include "LinkerScript.h"
16 #include "SymbolTable.h"
17 #include "SyntheticSections.h"
20 #include "llvm/Support/Dwarf.h"
21 #include "llvm/Support/MD5.h"
22 #include "llvm/Support/MathExtras.h"
23 #include "llvm/Support/SHA1.h"
26 using namespace llvm::dwarf;
27 using namespace llvm::object;
28 using namespace llvm::support::endian;
29 using namespace llvm::ELF;
32 using namespace lld::elf;
34 OutputSectionBase::OutputSectionBase(StringRef Name, uint32_t Type,
42 uint32_t OutputSectionBase::getPhdrFlags() const {
44 if (Flags & SHF_WRITE)
46 if (Flags & SHF_EXECINSTR)
52 void OutputSectionBase::writeHeaderTo(typename ELFT::Shdr *Shdr) {
53 Shdr->sh_entsize = Entsize;
54 Shdr->sh_addralign = Addralign;
56 Shdr->sh_offset = Offset;
57 Shdr->sh_flags = Flags;
62 Shdr->sh_name = ShName;
65 template <class ELFT> static uint64_t getEntsize(uint32_t Type) {
68 return sizeof(typename ELFT::Rela);
70 return sizeof(typename ELFT::Rel);
71 case SHT_MIPS_REGINFO:
72 return sizeof(Elf_Mips_RegInfo<ELFT>);
73 case SHT_MIPS_OPTIONS:
74 return sizeof(Elf_Mips_Options<ELFT>) + sizeof(Elf_Mips_RegInfo<ELFT>);
75 case SHT_MIPS_ABIFLAGS:
76 return sizeof(Elf_Mips_ABIFlags<ELFT>);
83 OutputSection<ELFT>::OutputSection(StringRef Name, uint32_t Type, uintX_t Flags)
84 : OutputSectionBase(Name, Type, Flags) {
85 this->Entsize = getEntsize<ELFT>(Type);
88 template <typename ELFT>
89 static bool compareByFilePosition(InputSection<ELFT> *A,
90 InputSection<ELFT> *B) {
91 // Synthetic doesn't have link order dependecy, stable_sort will keep it last
92 if (A->kind() == InputSectionData::Synthetic ||
93 B->kind() == InputSectionData::Synthetic)
95 auto *LA = cast<InputSection<ELFT>>(A->getLinkOrderDep());
96 auto *LB = cast<InputSection<ELFT>>(B->getLinkOrderDep());
97 OutputSectionBase *AOut = LA->OutSec;
98 OutputSectionBase *BOut = LB->OutSec;
100 return AOut->SectionIndex < BOut->SectionIndex;
101 return LA->OutSecOff < LB->OutSecOff;
104 template <class ELFT> void OutputSection<ELFT>::finalize() {
105 if ((this->Flags & SHF_LINK_ORDER) && !this->Sections.empty()) {
106 std::sort(Sections.begin(), Sections.end(), compareByFilePosition<ELFT>);
110 // We must preserve the link order dependency of sections with the
111 // SHF_LINK_ORDER flag. The dependency is indicated by the sh_link field. We
112 // need to translate the InputSection sh_link to the OutputSection sh_link,
113 // all InputSections in the OutputSection have the same dependency.
114 if (auto *D = this->Sections.front()->getLinkOrderDep())
115 this->Link = D->OutSec->SectionIndex;
118 uint32_t Type = this->Type;
119 if (!Config->Relocatable || (Type != SHT_RELA && Type != SHT_REL))
122 this->Link = In<ELFT>::SymTab->OutSec->SectionIndex;
123 // sh_info for SHT_REL[A] sections should contain the section header index of
124 // the section to which the relocation applies.
125 InputSectionBase<ELFT> *S = Sections[0]->getRelocatedSection();
126 this->Info = S->OutSec->SectionIndex;
129 template <class ELFT>
130 void OutputSection<ELFT>::addSection(InputSectionData *C) {
132 auto *S = cast<InputSection<ELFT>>(C);
133 Sections.push_back(S);
135 this->updateAlignment(S->Alignment);
136 // Keep sh_entsize value of the input section to be able to perform merging
137 // later during a final linking using the generated relocatable object.
138 if (Config->Relocatable && (S->Flags & SHF_MERGE))
139 this->Entsize = S->Entsize;
142 // This function is called after we sort input sections
143 // and scan relocations to setup sections' offsets.
144 template <class ELFT> void OutputSection<ELFT>::assignOffsets() {
145 uintX_t Off = this->Size;
146 for (InputSection<ELFT> *S : Sections) {
147 Off = alignTo(Off, S->Alignment);
154 template <class ELFT>
155 void OutputSection<ELFT>::sort(
156 std::function<int(InputSection<ELFT> *S)> Order) {
157 typedef std::pair<unsigned, InputSection<ELFT> *> Pair;
158 auto Comp = [](const Pair &A, const Pair &B) { return A.first < B.first; };
161 for (InputSection<ELFT> *S : Sections)
162 V.push_back({Order(S), S});
163 std::stable_sort(V.begin(), V.end(), Comp);
166 Sections.push_back(P.second);
169 // Sorts input sections by section name suffixes, so that .foo.N comes
170 // before .foo.M if N < M. Used to sort .{init,fini}_array.N sections.
171 // We want to keep the original order if the priorities are the same
172 // because the compiler keeps the original initialization order in a
173 // translation unit and we need to respect that.
174 // For more detail, read the section of the GCC's manual about init_priority.
175 template <class ELFT> void OutputSection<ELFT>::sortInitFini() {
176 // Sort sections by priority.
177 sort([](InputSection<ELFT> *S) { return getPriority(S->Name); });
180 // Returns true if S matches /Filename.?\.o$/.
181 static bool isCrtBeginEnd(StringRef S, StringRef Filename) {
182 if (!S.endswith(".o"))
185 if (S.endswith(Filename))
187 return !S.empty() && S.drop_back().endswith(Filename);
190 static bool isCrtbegin(StringRef S) { return isCrtBeginEnd(S, "crtbegin"); }
191 static bool isCrtend(StringRef S) { return isCrtBeginEnd(S, "crtend"); }
193 // .ctors and .dtors are sorted by this priority from highest to lowest.
195 // 1. The section was contained in crtbegin (crtbegin contains
196 // some sentinel value in its .ctors and .dtors so that the runtime
197 // can find the beginning of the sections.)
199 // 2. The section has an optional priority value in the form of ".ctors.N"
200 // or ".dtors.N" where N is a number. Unlike .{init,fini}_array,
201 // they are compared as string rather than number.
203 // 3. The section is just ".ctors" or ".dtors".
205 // 4. The section was contained in crtend, which contains an end marker.
207 // In an ideal world, we don't need this function because .init_array and
208 // .ctors are duplicate features (and .init_array is newer.) However, there
209 // are too many real-world use cases of .ctors, so we had no choice to
210 // support that with this rather ad-hoc semantics.
211 template <class ELFT>
212 static bool compCtors(const InputSection<ELFT> *A,
213 const InputSection<ELFT> *B) {
214 bool BeginA = isCrtbegin(A->getFile()->getName());
215 bool BeginB = isCrtbegin(B->getFile()->getName());
216 if (BeginA != BeginB)
218 bool EndA = isCrtend(A->getFile()->getName());
219 bool EndB = isCrtend(B->getFile()->getName());
222 StringRef X = A->Name;
223 StringRef Y = B->Name;
224 assert(X.startswith(".ctors") || X.startswith(".dtors"));
225 assert(Y.startswith(".ctors") || Y.startswith(".dtors"));
228 if (X.empty() && Y.empty())
233 // Sorts input sections by the special rules for .ctors and .dtors.
234 // Unfortunately, the rules are different from the one for .{init,fini}_array.
235 // Read the comment above.
236 template <class ELFT> void OutputSection<ELFT>::sortCtorsDtors() {
237 std::stable_sort(Sections.begin(), Sections.end(), compCtors<ELFT>);
240 // Fill [Buf, Buf + Size) with Filler. Filler is written in big
241 // endian order. This is used for linker script "=fillexp" command.
242 void fill(uint8_t *Buf, size_t Size, uint32_t Filler) {
244 write32be(V, Filler);
246 for (; I + 4 < Size; I += 4)
247 memcpy(Buf + I, V, 4);
248 memcpy(Buf + I, V, Size - I);
251 template <class ELFT> void OutputSection<ELFT>::writeTo(uint8_t *Buf) {
253 if (uint32_t Filler = Script<ELFT>::X->getFiller(this->Name))
254 fill(Buf, this->Size, Filler);
256 auto Fn = [=](InputSection<ELFT> *IS) { IS->writeTo(Buf); };
257 forEach(Sections.begin(), Sections.end(), Fn);
259 // Linker scripts may have BYTE()-family commands with which you
260 // can write arbitrary bytes to the output. Process them if any.
261 Script<ELFT>::X->writeDataBytes(this->Name, Buf);
264 template <class ELFT>
265 EhOutputSection<ELFT>::EhOutputSection()
266 : OutputSectionBase(".eh_frame", SHT_PROGBITS, SHF_ALLOC) {}
268 // Search for an existing CIE record or create a new one.
269 // CIE records from input object files are uniquified by their contents
270 // and where their relocations point to.
271 template <class ELFT>
272 template <class RelTy>
273 CieRecord *EhOutputSection<ELFT>::addCie(EhSectionPiece &Piece,
274 ArrayRef<RelTy> Rels) {
275 auto *Sec = cast<EhInputSection<ELFT>>(Piece.ID);
276 const endianness E = ELFT::TargetEndianness;
277 if (read32<E>(Piece.data().data() + 4) != 0)
278 fatal(toString(Sec) + ": CIE expected at beginning of .eh_frame");
280 SymbolBody *Personality = nullptr;
281 unsigned FirstRelI = Piece.FirstRelocation;
282 if (FirstRelI != (unsigned)-1)
283 Personality = &Sec->getFile()->getRelocTargetSym(Rels[FirstRelI]);
285 // Search for an existing CIE by CIE contents/relocation target pair.
286 CieRecord *Cie = &CieMap[{Piece.data(), Personality}];
288 // If not found, create a new one.
289 if (Cie->Piece == nullptr) {
296 // There is one FDE per function. Returns true if a given FDE
297 // points to a live function.
298 template <class ELFT>
299 template <class RelTy>
300 bool EhOutputSection<ELFT>::isFdeLive(EhSectionPiece &Piece,
301 ArrayRef<RelTy> Rels) {
302 auto *Sec = cast<EhInputSection<ELFT>>(Piece.ID);
303 unsigned FirstRelI = Piece.FirstRelocation;
304 if (FirstRelI == (unsigned)-1)
305 fatal(toString(Sec) + ": FDE doesn't reference another section");
306 const RelTy &Rel = Rels[FirstRelI];
307 SymbolBody &B = Sec->getFile()->getRelocTargetSym(Rel);
308 auto *D = dyn_cast<DefinedRegular<ELFT>>(&B);
309 if (!D || !D->Section)
311 InputSectionBase<ELFT> *Target = D->Section->Repl;
312 return Target && Target->Live;
315 // .eh_frame is a sequence of CIE or FDE records. In general, there
316 // is one CIE record per input object file which is followed by
317 // a list of FDEs. This function searches an existing CIE or create a new
318 // one and associates FDEs to the CIE.
319 template <class ELFT>
320 template <class RelTy>
321 void EhOutputSection<ELFT>::addSectionAux(EhInputSection<ELFT> *Sec,
322 ArrayRef<RelTy> Rels) {
323 const endianness E = ELFT::TargetEndianness;
325 DenseMap<size_t, CieRecord *> OffsetToCie;
326 for (EhSectionPiece &Piece : Sec->Pieces) {
327 // The empty record is the end marker.
328 if (Piece.size() == 4)
331 size_t Offset = Piece.InputOff;
332 uint32_t ID = read32<E>(Piece.data().data() + 4);
334 OffsetToCie[Offset] = addCie(Piece, Rels);
338 uint32_t CieOffset = Offset + 4 - ID;
339 CieRecord *Cie = OffsetToCie[CieOffset];
341 fatal(toString(Sec) + ": invalid CIE reference");
343 if (!isFdeLive(Piece, Rels))
345 Cie->FdePieces.push_back(&Piece);
350 template <class ELFT>
351 void EhOutputSection<ELFT>::addSection(InputSectionData *C) {
352 auto *Sec = cast<EhInputSection<ELFT>>(C);
354 this->updateAlignment(Sec->Alignment);
355 Sections.push_back(Sec);
357 // .eh_frame is a sequence of CIE or FDE records. This function
358 // splits it into pieces so that we can call
359 // SplitInputSection::getSectionPiece on the section.
361 if (Sec->Pieces.empty())
364 if (Sec->NumRelocations) {
365 if (Sec->AreRelocsRela)
366 addSectionAux(Sec, Sec->relas());
368 addSectionAux(Sec, Sec->rels());
371 addSectionAux(Sec, makeArrayRef<Elf_Rela>(nullptr, nullptr));
374 template <class ELFT>
375 static void writeCieFde(uint8_t *Buf, ArrayRef<uint8_t> D) {
376 memcpy(Buf, D.data(), D.size());
378 // Fix the size field. -4 since size does not include the size field itself.
379 const endianness E = ELFT::TargetEndianness;
380 write32<E>(Buf, alignTo(D.size(), sizeof(typename ELFT::uint)) - 4);
383 template <class ELFT> void EhOutputSection<ELFT>::finalize() {
385 return; // Already finalized.
388 for (CieRecord *Cie : Cies) {
389 Cie->Piece->OutputOff = Off;
390 Off += alignTo(Cie->Piece->size(), sizeof(uintX_t));
392 for (EhSectionPiece *Fde : Cie->FdePieces) {
393 Fde->OutputOff = Off;
394 Off += alignTo(Fde->size(), sizeof(uintX_t));
400 template <class ELFT> static uint64_t readFdeAddr(uint8_t *Buf, int Size) {
401 const endianness E = ELFT::TargetEndianness;
403 case DW_EH_PE_udata2:
404 return read16<E>(Buf);
405 case DW_EH_PE_udata4:
406 return read32<E>(Buf);
407 case DW_EH_PE_udata8:
408 return read64<E>(Buf);
409 case DW_EH_PE_absptr:
411 return read64<E>(Buf);
412 return read32<E>(Buf);
414 fatal("unknown FDE size encoding");
417 // Returns the VA to which a given FDE (on a mmap'ed buffer) is applied to.
418 // We need it to create .eh_frame_hdr section.
419 template <class ELFT>
420 typename ELFT::uint EhOutputSection<ELFT>::getFdePc(uint8_t *Buf, size_t FdeOff,
422 // The starting address to which this FDE applies is
423 // stored at FDE + 8 byte.
424 size_t Off = FdeOff + 8;
425 uint64_t Addr = readFdeAddr<ELFT>(Buf + Off, Enc & 0x7);
426 if ((Enc & 0x70) == DW_EH_PE_absptr)
428 if ((Enc & 0x70) == DW_EH_PE_pcrel)
429 return Addr + this->Addr + Off;
430 fatal("unknown FDE size relative encoding");
433 template <class ELFT> void EhOutputSection<ELFT>::writeTo(uint8_t *Buf) {
434 const endianness E = ELFT::TargetEndianness;
435 for (CieRecord *Cie : Cies) {
436 size_t CieOffset = Cie->Piece->OutputOff;
437 writeCieFde<ELFT>(Buf + CieOffset, Cie->Piece->data());
439 for (EhSectionPiece *Fde : Cie->FdePieces) {
440 size_t Off = Fde->OutputOff;
441 writeCieFde<ELFT>(Buf + Off, Fde->data());
443 // FDE's second word should have the offset to an associated CIE.
445 write32<E>(Buf + Off + 4, Off + 4 - CieOffset);
449 for (EhInputSection<ELFT> *S : Sections)
450 S->relocate(Buf, nullptr);
452 // Construct .eh_frame_hdr. .eh_frame_hdr is a binary search table
453 // to get a FDE from an address to which FDE is applied. So here
454 // we obtain two addresses and pass them to EhFrameHdr object.
455 if (In<ELFT>::EhFrameHdr) {
456 for (CieRecord *Cie : Cies) {
457 uint8_t Enc = getFdeEncoding<ELFT>(Cie->Piece);
458 for (SectionPiece *Fde : Cie->FdePieces) {
459 uintX_t Pc = getFdePc(Buf, Fde->OutputOff, Enc);
460 uintX_t FdeVA = this->Addr + Fde->OutputOff;
461 In<ELFT>::EhFrameHdr->addFde(Pc, FdeVA);
467 template <class ELFT>
468 MergeOutputSection<ELFT>::MergeOutputSection(StringRef Name, uint32_t Type,
469 uintX_t Flags, uintX_t Alignment)
470 : OutputSectionBase(Name, Type, Flags),
471 Builder(StringTableBuilder::RAW, Alignment) {}
473 template <class ELFT> void MergeOutputSection<ELFT>::writeTo(uint8_t *Buf) {
477 template <class ELFT>
478 void MergeOutputSection<ELFT>::addSection(InputSectionData *C) {
479 auto *Sec = cast<MergeInputSection<ELFT>>(C);
481 this->updateAlignment(Sec->Alignment);
482 this->Entsize = Sec->Entsize;
483 Sections.push_back(Sec);
486 template <class ELFT> bool MergeOutputSection<ELFT>::shouldTailMerge() const {
487 return (this->Flags & SHF_STRINGS) && Config->Optimize >= 2;
490 template <class ELFT> void MergeOutputSection<ELFT>::finalizeTailMerge() {
491 // Add all string pieces to the string table builder to create section
493 for (MergeInputSection<ELFT> *Sec : Sections)
494 for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
495 if (Sec->Pieces[I].Live)
496 Builder.add(Sec->getData(I));
498 // Fix the string table content. After this, the contents will never change.
500 this->Size = Builder.getSize();
502 // finalize() fixed tail-optimized strings, so we can now get
503 // offsets of strings. Get an offset for each string and save it
504 // to a corresponding StringPiece for easy access.
505 for (MergeInputSection<ELFT> *Sec : Sections)
506 for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
507 if (Sec->Pieces[I].Live)
508 Sec->Pieces[I].OutputOff = Builder.getOffset(Sec->getData(I));
511 template <class ELFT> void MergeOutputSection<ELFT>::finalizeNoTailMerge() {
512 // Add all string pieces to the string table builder to create section
513 // contents. Because we are not tail-optimizing, offsets of strings are
514 // fixed when they are added to the builder (string table builder contains
515 // a hash table from strings to offsets).
516 for (MergeInputSection<ELFT> *Sec : Sections)
517 for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
518 if (Sec->Pieces[I].Live)
519 Sec->Pieces[I].OutputOff = Builder.add(Sec->getData(I));
521 Builder.finalizeInOrder();
522 this->Size = Builder.getSize();
525 template <class ELFT> void MergeOutputSection<ELFT>::finalize() {
526 if (shouldTailMerge())
529 finalizeNoTailMerge();
532 template <class ELFT>
533 static typename ELFT::uint getOutFlags(InputSectionBase<ELFT> *S) {
534 return S->Flags & ~SHF_GROUP & ~SHF_COMPRESSED;
538 template <> struct DenseMapInfo<lld::elf::SectionKey> {
539 static lld::elf::SectionKey getEmptyKey();
540 static lld::elf::SectionKey getTombstoneKey();
541 static unsigned getHashValue(const lld::elf::SectionKey &Val);
542 static bool isEqual(const lld::elf::SectionKey &LHS,
543 const lld::elf::SectionKey &RHS);
547 template <class ELFT>
548 static SectionKey createKey(InputSectionBase<ELFT> *C, StringRef OutsecName) {
549 // The ELF spec just says
550 // ----------------------------------------------------------------
551 // In the first phase, input sections that match in name, type and
552 // attribute flags should be concatenated into single sections.
553 // ----------------------------------------------------------------
555 // However, it is clear that at least some flags have to be ignored for
556 // section merging. At the very least SHF_GROUP and SHF_COMPRESSED have to be
557 // ignored. We should not have two output .text sections just because one was
558 // in a group and another was not for example.
560 // It also seems that that wording was a late addition and didn't get the
561 // necessary scrutiny.
563 // Merging sections with different flags is expected by some users. One
564 // reason is that if one file has
566 // int *const bar __attribute__((section(".foo"))) = (int *)0;
568 // gcc with -fPIC will produce a read only .foo section. But if another
572 // int *const bar __attribute__((section(".foo"))) = (int *)&zed;
574 // gcc with -fPIC will produce a read write section.
576 // Last but not least, when using linker script the merge rules are forced by
577 // the script. Unfortunately, linker scripts are name based. This means that
578 // expressions like *(.foo*) can refer to multiple input sections with
579 // different flags. We cannot put them in different output sections or we
580 // would produce wrong results for
582 // start = .; *(.foo.*) end = .; *(.bar)
584 // and a mapping of .foo1 and .bar1 to one section and .foo2 and .bar2 to
585 // another. The problem is that there is no way to layout those output
586 // sections such that the .foo sections are the only thing between the start
589 // Given the above issues, we instead merge sections by name and error on
590 // incompatible types and flags.
592 // The exception being SHF_MERGE, where we create different output sections
593 // for each alignment. This makes each output section simple. In case of
594 // relocatable object generation we do not try to perform merging and treat
595 // SHF_MERGE sections as regular ones, but also create different output
596 // sections for them to allow merging at final linking stage.
598 // Fortunately, creating symbols in the middle of a merge section is not
599 // supported by bfd or gold, so the SHF_MERGE exception should not cause
600 // problems with most linker scripts.
602 typedef typename ELFT::uint uintX_t;
603 uintX_t Flags = C->Flags & (SHF_MERGE | SHF_STRINGS);
605 uintX_t Alignment = 0;
606 if (isa<MergeInputSection<ELFT>>(C) ||
607 (Config->Relocatable && (C->Flags & SHF_MERGE)))
608 Alignment = std::max<uintX_t>(C->Alignment, C->Entsize);
610 return SectionKey{OutsecName, Flags, Alignment};
613 template <class ELFT> OutputSectionFactory<ELFT>::OutputSectionFactory() {}
615 template <class ELFT> OutputSectionFactory<ELFT>::~OutputSectionFactory() {}
617 template <class ELFT>
618 std::pair<OutputSectionBase *, bool>
619 OutputSectionFactory<ELFT>::create(InputSectionBase<ELFT> *C,
620 StringRef OutsecName) {
621 SectionKey Key = createKey(C, OutsecName);
622 return create(Key, C);
625 static uint64_t getIncompatibleFlags(uint64_t Flags) {
626 return Flags & (SHF_ALLOC | SHF_TLS);
629 template <class ELFT>
630 std::pair<OutputSectionBase *, bool>
631 OutputSectionFactory<ELFT>::create(const SectionKey &Key,
632 InputSectionBase<ELFT> *C) {
633 uintX_t Flags = getOutFlags(C);
634 OutputSectionBase *&Sec = Map[Key];
636 if (getIncompatibleFlags(Sec->Flags) != getIncompatibleFlags(C->Flags))
637 error("Section has flags incompatible with others with the same name " +
639 // Convert notbits to progbits if they are mixed. This happens is some
641 if (Sec->Type == SHT_NOBITS && C->Type == SHT_PROGBITS)
642 Sec->Type = SHT_PROGBITS;
643 if (Sec->Type != C->Type &&
644 !(Sec->Type == SHT_PROGBITS && C->Type == SHT_NOBITS))
645 error("Section has different type from others with the same name " +
651 uint32_t Type = C->Type;
653 case InputSectionBase<ELFT>::Regular:
654 case InputSectionBase<ELFT>::Synthetic:
655 Sec = make<OutputSection<ELFT>>(Key.Name, Type, Flags);
657 case InputSectionBase<ELFT>::EHFrame:
658 return {Out<ELFT>::EhFrame, false};
659 case InputSectionBase<ELFT>::Merge:
660 Sec = make<MergeOutputSection<ELFT>>(Key.Name, Type, Flags, Key.Alignment);
666 SectionKey DenseMapInfo<SectionKey>::getEmptyKey() {
667 return SectionKey{DenseMapInfo<StringRef>::getEmptyKey(), 0, 0};
670 SectionKey DenseMapInfo<SectionKey>::getTombstoneKey() {
671 return SectionKey{DenseMapInfo<StringRef>::getTombstoneKey(), 0, 0};
674 unsigned DenseMapInfo<SectionKey>::getHashValue(const SectionKey &Val) {
675 return hash_combine(Val.Name, Val.Flags, Val.Alignment);
678 bool DenseMapInfo<SectionKey>::isEqual(const SectionKey &LHS,
679 const SectionKey &RHS) {
680 return DenseMapInfo<StringRef>::isEqual(LHS.Name, RHS.Name) &&
681 LHS.Flags == RHS.Flags && LHS.Alignment == RHS.Alignment;
687 template void OutputSectionBase::writeHeaderTo<ELF32LE>(ELF32LE::Shdr *Shdr);
688 template void OutputSectionBase::writeHeaderTo<ELF32BE>(ELF32BE::Shdr *Shdr);
689 template void OutputSectionBase::writeHeaderTo<ELF64LE>(ELF64LE::Shdr *Shdr);
690 template void OutputSectionBase::writeHeaderTo<ELF64BE>(ELF64BE::Shdr *Shdr);
692 template class OutputSection<ELF32LE>;
693 template class OutputSection<ELF32BE>;
694 template class OutputSection<ELF64LE>;
695 template class OutputSection<ELF64BE>;
697 template class EhOutputSection<ELF32LE>;
698 template class EhOutputSection<ELF32BE>;
699 template class EhOutputSection<ELF64LE>;
700 template class EhOutputSection<ELF64BE>;
702 template class MergeOutputSection<ELF32LE>;
703 template class MergeOutputSection<ELF32BE>;
704 template class MergeOutputSection<ELF64LE>;
705 template class MergeOutputSection<ELF64BE>;
707 template class OutputSectionFactory<ELF32LE>;
708 template class OutputSectionFactory<ELF32BE>;
709 template class OutputSectionFactory<ELF64LE>;
710 template class OutputSectionFactory<ELF64BE>;