vendor/llvm-project/llvmorg-10-init-17466-ge26a78e7085

8 files changed, 692 insertions, 157 deletions

diff --git a/llvm/lib/ObjectYAML/COFFEmitter.cpp b/llvm/lib/ObjectYAML/COFFEmitter.cpp
index efcdc51e1670..ec3ec55011f9 100644
--- a/llvm/lib/ObjectYAML/COFFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/COFFEmitter.cpp
@@ -260,9 +260,12 @@ static bool layoutCOFF(COFFParser &CP) {
       CurrentSectionDataOffset += S.Header.SizeOfRawData;
       if (!S.Relocations.empty()) {
         S.Header.PointerToRelocations = CurrentSectionDataOffset;
-        S.Header.NumberOfRelocations = S.Relocations.size();
-        CurrentSectionDataOffset +=
-            S.Header.NumberOfRelocations * COFF::RelocationSize;
+        if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL) {
+          S.Header.NumberOfRelocations = 0xffff;
+          CurrentSectionDataOffset += COFF::RelocationSize;
+        } else
+          S.Header.NumberOfRelocations = S.Relocations.size();
+        CurrentSectionDataOffset += S.Relocations.size() * COFF::RelocationSize;
       }
     } else {
       // Leave SizeOfRawData unaltered. For .bss sections in object files, it
@@ -506,6 +509,10 @@ static bool writeCOFF(COFFParser &CP, raw_ostream &OS) {
     S.SectionData.writeAsBinary(OS);
     assert(S.Header.SizeOfRawData >= S.SectionData.binary_size());
     OS.write_zeros(S.Header.SizeOfRawData - S.SectionData.binary_size());
+    if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL)
+      OS << binary_le<uint32_t>(/*VirtualAddress=*/ S.Relocations.size() + 1)
+         << binary_le<uint32_t>(/*SymbolTableIndex=*/ 0)
+         << binary_le<uint16_t>(/*Type=*/ 0);
     for (const COFFYAML::Relocation &R : S.Relocations) {
       uint32_t SymbolTableIndex;
       if (R.SymbolTableIndex) {
diff --git a/llvm/lib/ObjectYAML/CodeViewYAMLDebugSections.cpp b/llvm/lib/ObjectYAML/CodeViewYAMLDebugSections.cpp
index eeebb694589b..02f053bb0e0f 100644
--- a/llvm/lib/ObjectYAML/CodeViewYAMLDebugSections.cpp
+++ b/llvm/lib/ObjectYAML/CodeViewYAMLDebugSections.cpp
@@ -421,7 +421,7 @@ std::shared_ptr<DebugSubsection> YAMLLinesSubsection::toCodeViewSubsection(
   for (const auto &LC : Lines.Blocks) {
     Result->createBlock(LC.FileName);
     if (Result->hasColumnInfo()) {
-      for (const auto &Item : zip(LC.Lines, LC.Columns)) {
+      for (auto Item : zip(LC.Lines, LC.Columns)) {
         auto &L = std::get<0>(Item);
         auto &C = std::get<1>(Item);
         uint32_t LE = L.LineStart + L.EndDelta;
diff --git a/llvm/lib/ObjectYAML/DWARFEmitter.cpp b/llvm/lib/ObjectYAML/DWARFEmitter.cpp
index 2ae66997cf59..b410fed16f09 100644
--- a/llvm/lib/ObjectYAML/DWARFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/DWARFEmitter.cpp
@@ -314,7 +314,10 @@ public:
   DIEFixupVisitor(DWARFYAML::Data &DI) : DWARFYAML::Visitor(DI){};
 
 private:
-  virtual void onStartCompileUnit(DWARFYAML::Unit &CU) { Length = 7; }
+  virtual void onStartCompileUnit(DWARFYAML::Unit &CU) {
+    // Size of the unit header, excluding the length field itself.
+    Length = CU.Version >= 5 ? 8 : 7;
+  }
 
   virtual void onEndCompileUnit(DWARFYAML::Unit &CU) {
     CU.Length.setLength(Length);
diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index e0faed256f6b..ee7d5f616a73 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/MC/StringTableBuilder.h"
@@ -36,6 +37,16 @@ class ContiguousBlobAccumulator {
   SmallVector<char, 128> Buf;
   raw_svector_ostream OS;
 
+public:
+  ContiguousBlobAccumulator(uint64_t InitialOffset_)
+      : InitialOffset(InitialOffset_), Buf(), OS(Buf) {}
+
+  template <class Integer>
+  raw_ostream &getOSAndAlignedOffset(Integer &Offset, unsigned Align) {
+    Offset = padToAlignment(Align);
+    return OS;
+  }
+
   /// \returns The new offset.
   uint64_t padToAlignment(unsigned Align) {
     if (Align == 0)
@@ -46,14 +57,6 @@ class ContiguousBlobAccumulator {
     return AlignedOffset; // == CurrentOffset;
   }
 
-public:
-  ContiguousBlobAccumulator(uint64_t InitialOffset_)
-      : InitialOffset(InitialOffset_), Buf(), OS(Buf) {}
-  template <class Integer>
-  raw_ostream &getOSAndAlignedOffset(Integer &Offset, unsigned Align) {
-    Offset = padToAlignment(Align);
-    return OS;
-  }
   void writeBlobToStream(raw_ostream &Out) { Out << OS.str(); }
 };
 
@@ -86,6 +89,15 @@ public:
   unsigned size() const { return Map.size(); }
 };
 
+namespace {
+struct Fragment {
+  uint64_t Offset;
+  uint64_t Size;
+  uint32_t Type;
+  uint64_t AddrAlign;
+};
+} // namespace
+
 /// "Single point of truth" for the ELF file construction.
 /// TODO: This class still has a ways to go before it is truly a "single
 /// point of truth".
@@ -98,6 +110,7 @@ template <class ELFT> class ELFState {
   typedef typename ELFT::Rela Elf_Rela;
   typedef typename ELFT::Relr Elf_Relr;
   typedef typename ELFT::Dyn Elf_Dyn;
+  typedef typename ELFT::uint uintX_t;
 
   enum class SymtabType { Static, Dynamic };
 
@@ -140,6 +153,11 @@ template <class ELFT> class ELFState {
                                ELFYAML::Section *YAMLSec);
   void setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders,
                               std::vector<Elf_Shdr> &SHeaders);
+
+  std::vector<Fragment>
+  getPhdrFragments(const ELFYAML::ProgramHeader &Phdr,
+                   ArrayRef<typename ELFT::Shdr> SHeaders);
+
   void finalizeStrings();
   void writeELFHeader(ContiguousBlobAccumulator &CBA, raw_ostream &OS);
   void writeSectionContent(Elf_Shdr &SHeader,
@@ -148,6 +166,9 @@ template <class ELFT> class ELFState {
   void writeSectionContent(Elf_Shdr &SHeader,
                            const ELFYAML::RelocationSection &Section,
                            ContiguousBlobAccumulator &CBA);
+  void writeSectionContent(Elf_Shdr &SHeader,
+                           const ELFYAML::RelrSection &Section,
+                           ContiguousBlobAccumulator &CBA);
   void writeSectionContent(Elf_Shdr &SHeader, const ELFYAML::Group &Group,
                            ContiguousBlobAccumulator &CBA);
   void writeSectionContent(Elf_Shdr &SHeader,
@@ -177,6 +198,20 @@ template <class ELFT> class ELFState {
   void writeSectionContent(Elf_Shdr &SHeader,
                            const ELFYAML::AddrsigSection &Section,
                            ContiguousBlobAccumulator &CBA);
+  void writeSectionContent(Elf_Shdr &SHeader,
+                           const ELFYAML::NoteSection &Section,
+                           ContiguousBlobAccumulator &CBA);
+  void writeSectionContent(Elf_Shdr &SHeader,
+                           const ELFYAML::GnuHashSection &Section,
+                           ContiguousBlobAccumulator &CBA);
+  void writeSectionContent(Elf_Shdr &SHeader,
+                           const ELFYAML::LinkerOptionsSection &Section,
+                           ContiguousBlobAccumulator &CBA);
+  void writeSectionContent(Elf_Shdr &SHeader,
+                           const ELFYAML::DependentLibrariesSection &Section,
+                           ContiguousBlobAccumulator &CBA);
+
+  void writeFill(ELFYAML::Fill &Fill, ContiguousBlobAccumulator &CBA);
 
   ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH);
 
@@ -199,31 +234,25 @@ template <class T> static void zero(T &Obj) { memset(&Obj, 0, sizeof(Obj)); }
 template <class ELFT>
 ELFState<ELFT>::ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH)
     : Doc(D), ErrHandler(EH) {
+  std::vector<ELFYAML::Section *> Sections = Doc.getSections();
   StringSet<> DocSections;
-  for (std::unique_ptr<ELFYAML::Section> &D : Doc.Sections) {
-    if (!D->Name.empty())
-      DocSections.insert(D->Name);
-
-    // Some sections wants to link to .symtab by default.
-    // That means we want to create the symbol table for them.
-    if (D->Type == llvm::ELF::SHT_REL || D->Type == llvm::ELF::SHT_RELA)
-      if (!Doc.Symbols && D->Link.empty())
-        Doc.Symbols.emplace();
-  }
+  for (const ELFYAML::Section *Sec : Sections)
+    if (!Sec->Name.empty())
+      DocSections.insert(Sec->Name);
 
   // Insert SHT_NULL section implicitly when it is not defined in YAML.
-  if (Doc.Sections.empty() || Doc.Sections.front()->Type != ELF::SHT_NULL)
-    Doc.Sections.insert(
-        Doc.Sections.begin(),
+  if (Sections.empty() || Sections.front()->Type != ELF::SHT_NULL)
+    Doc.Chunks.insert(
+        Doc.Chunks.begin(),
         std::make_unique<ELFYAML::Section>(
-            ELFYAML::Section::SectionKind::RawContent, /*IsImplicit=*/true));
+            ELFYAML::Chunk::ChunkKind::RawContent, /*IsImplicit=*/true));
 
   std::vector<StringRef> ImplicitSections;
   if (Doc.Symbols)
     ImplicitSections.push_back(".symtab");
   ImplicitSections.insert(ImplicitSections.end(), {".strtab", ".shstrtab"});
 
-  if (!Doc.DynamicSymbols.empty())
+  if (Doc.DynamicSymbols)
     ImplicitSections.insert(ImplicitSections.end(), {".dynsym", ".dynstr"});
 
   // Insert placeholders for implicit sections that are not
@@ -232,10 +261,10 @@ ELFState<ELFT>::ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH)
     if (DocSections.count(SecName))
       continue;
 
-    std::unique_ptr<ELFYAML::Section> Sec = std::make_unique<ELFYAML::Section>(
-        ELFYAML::Section::SectionKind::RawContent, true /*IsImplicit*/);
+    std::unique_ptr<ELFYAML::Chunk> Sec = std::make_unique<ELFYAML::Section>(
+        ELFYAML::Chunk::ChunkKind::RawContent, true /*IsImplicit*/);
     Sec->Name = SecName;
-    Doc.Sections.push_back(std::move(Sec));
+    Doc.Chunks.push_back(std::move(Sec));
   }
 }
 
@@ -273,7 +302,7 @@ void ELFState<ELFT>::writeELFHeader(ContiguousBlobAccumulator &CBA, raw_ostream
   Header.e_shoff =
       Doc.Header.SHOff ? typename ELFT::uint(*Doc.Header.SHOff) : SHOff;
   Header.e_shnum =
-      Doc.Header.SHNum ? (uint16_t)*Doc.Header.SHNum : Doc.Sections.size();
+      Doc.Header.SHNum ? (uint16_t)*Doc.Header.SHNum : Doc.getSections().size();
   Header.e_shstrndx = Doc.Header.SHStrNdx ? (uint16_t)*Doc.Header.SHStrNdx
                                           : SN2I.get(".shstrtab");
 
@@ -325,6 +354,20 @@ unsigned ELFState<ELFT>::toSymbolIndex(StringRef S, StringRef LocSec,
 }
 
 template <class ELFT>
+static void overrideFields(ELFYAML::Section *From, typename ELFT::Shdr &To) {
+  if (!From)
+    return;
+  if (From->ShFlags)
+    To.sh_flags = *From->ShFlags;
+  if (From->ShName)
+    To.sh_name = *From->ShName;
+  if (From->ShOffset)
+    To.sh_offset = *From->ShOffset;
+  if (From->ShSize)
+    To.sh_size = *From->ShSize;
+}
+
+template <class ELFT>
 bool ELFState<ELFT>::initImplicitHeader(ContiguousBlobAccumulator &CBA,
                                         Elf_Shdr &Header, StringRef SecName,
                                         ELFYAML::Section *YAMLSec) {
@@ -345,16 +388,8 @@ bool ELFState<ELFT>::initImplicitHeader(ContiguousBlobAccumulator &CBA,
   else
     return false;
 
-  // Override the fields if requested.
-  if (YAMLSec) {
-    if (YAMLSec->ShName)
-      Header.sh_name = *YAMLSec->ShName;
-    if (YAMLSec->ShOffset)
-      Header.sh_offset = *YAMLSec->ShOffset;
-    if (YAMLSec->ShSize)
-      Header.sh_size = *YAMLSec->ShSize;
-  }
-
+  // Override section fields if requested.
+  overrideFields<ELFT>(YAMLSec, Header);
   return true;
 }
 
@@ -370,18 +405,25 @@ void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
                                         ContiguousBlobAccumulator &CBA) {
   // Ensure SHN_UNDEF entry is present. An all-zero section header is a
   // valid SHN_UNDEF entry since SHT_NULL == 0.
-  SHeaders.resize(Doc.Sections.size());
+  SHeaders.resize(Doc.getSections().size());
+
+  size_t SecNdx = -1;
+  for (const std::unique_ptr<ELFYAML::Chunk> &D : Doc.Chunks) {
+    if (auto S = dyn_cast<ELFYAML::Fill>(D.get())) {
+      writeFill(*S, CBA);
+      continue;
+    }
 
-  for (size_t I = 0; I < Doc.Sections.size(); ++I) {
-    ELFYAML::Section *Sec = Doc.Sections[I].get();
-    if (I == 0 && Sec->IsImplicit)
+    ++SecNdx;
+    ELFYAML::Section *Sec = cast<ELFYAML::Section>(D.get());
+    if (SecNdx == 0 && Sec->IsImplicit)
       continue;
 
     // We have a few sections like string or symbol tables that are usually
     // added implicitly to the end. However, if they are explicitly specified
     // in the YAML, we need to write them here. This ensures the file offset
     // remains correct.
-    Elf_Shdr &SHeader = SHeaders[I];
+    Elf_Shdr &SHeader = SHeaders[SecNdx];
     if (initImplicitHeader(CBA, SHeader, Sec->Name,
                            Sec->IsImplicit ? nullptr : Sec))
       continue;
@@ -400,7 +442,7 @@ void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
     if (!Sec->Link.empty())
       SHeader.sh_link = toSectionIndex(Sec->Link, Sec->Name);
 
-    if (I == 0) {
+    if (SecNdx == 0) {
       if (auto RawSec = dyn_cast<ELFYAML::RawContentSection>(Sec)) {
         // We do not write any content for special SHN_UNDEF section.
         if (RawSec->Size)
@@ -416,6 +458,8 @@ void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
       writeSectionContent(SHeader, *S, CBA);
     } else if (auto S = dyn_cast<ELFYAML::RelocationSection>(Sec)) {
       writeSectionContent(SHeader, *S, CBA);
+    } else if (auto S = dyn_cast<ELFYAML::RelrSection>(Sec)) {
+      writeSectionContent(SHeader, *S, CBA);
     } else if (auto S = dyn_cast<ELFYAML::Group>(Sec)) {
       writeSectionContent(SHeader, *S, CBA);
     } else if (auto S = dyn_cast<ELFYAML::MipsABIFlags>(Sec)) {
@@ -440,19 +484,20 @@ void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
       writeSectionContent(SHeader, *S, CBA);
     } else if (auto S = dyn_cast<ELFYAML::AddrsigSection>(Sec)) {
       writeSectionContent(SHeader, *S, CBA);
+    } else if (auto S = dyn_cast<ELFYAML::LinkerOptionsSection>(Sec)) {
+      writeSectionContent(SHeader, *S, CBA);
+    } else if (auto S = dyn_cast<ELFYAML::NoteSection>(Sec)) {
+      writeSectionContent(SHeader, *S, CBA);
+    } else if (auto S = dyn_cast<ELFYAML::GnuHashSection>(Sec)) {
+      writeSectionContent(SHeader, *S, CBA);
+    } else if (auto S = dyn_cast<ELFYAML::DependentLibrariesSection>(Sec)) {
+      writeSectionContent(SHeader, *S, CBA);
     } else {
       llvm_unreachable("Unknown section type");
     }
 
-    // Override the fields if requested.
-    if (Sec) {
-      if (Sec->ShName)
-        SHeader.sh_name = *Sec->ShName;
-      if (Sec->ShOffset)
-        SHeader.sh_offset = *Sec->ShOffset;
-      if (Sec->ShSize)
-        SHeader.sh_size = *Sec->ShSize;
-    }
+    // Override section fields if requested.
+    overrideFields<ELFT>(Sec, SHeader);
   }
 }
 
@@ -487,7 +532,7 @@ ELFState<ELFT>::toELFSymbols(ArrayRef<ELFYAML::Symbol> Symbols,
   Ret.resize(Symbols.size() + 1);
 
   size_t I = 0;
-  for (const auto &Sym : Symbols) {
+  for (const ELFYAML::Symbol &Sym : Symbols) {
     Elf_Sym &Symbol = Ret[++I];
 
     // If NameIndex, which contains the name offset, is explicitly specified, we
@@ -522,21 +567,24 @@ void ELFState<ELFT>::initSymtabSectionHeader(Elf_Shdr &SHeader,
   ArrayRef<ELFYAML::Symbol> Symbols;
   if (IsStatic && Doc.Symbols)
     Symbols = *Doc.Symbols;
-  else if (!IsStatic)
-    Symbols = Doc.DynamicSymbols;
+  else if (!IsStatic && Doc.DynamicSymbols)
+    Symbols = *Doc.DynamicSymbols;
 
   ELFYAML::RawContentSection *RawSec =
       dyn_cast_or_null<ELFYAML::RawContentSection>(YAMLSec);
-  if (RawSec && !Symbols.empty() && (RawSec->Content || RawSec->Size)) {
-    if (RawSec->Content)
-      reportError("cannot specify both `Content` and " +
-                  (IsStatic ? Twine("`Symbols`") : Twine("`DynamicSymbols`")) +
-                  " for symbol table section '" + RawSec->Name + "'");
-    if (RawSec->Size)
-      reportError("cannot specify both `Size` and " +
-                  (IsStatic ? Twine("`Symbols`") : Twine("`DynamicSymbols`")) +
-                  " for symbol table section '" + RawSec->Name + "'");
-    return;
+  if (RawSec && (RawSec->Content || RawSec->Size)) {
+    bool HasSymbolsDescription =
+        (IsStatic && Doc.Symbols) || (!IsStatic && Doc.DynamicSymbols);
+    if (HasSymbolsDescription) {
+      StringRef Property = (IsStatic ? "`Symbols`" : "`DynamicSymbols`");
+      if (RawSec->Content)
+        reportError("cannot specify both `Content` and " + Property +
+                    " for symbol table section '" + RawSec->Name + "'");
+      if (RawSec->Size)
+        reportError("cannot specify both `Size` and " + Property +
+                    " for symbol table section '" + RawSec->Name + "'");
+      return;
+    }
   }
 
   zero(SHeader);
@@ -636,22 +684,43 @@ template <class ELFT> void ELFState<ELFT>::reportError(const Twine &Msg) {
 }
 
 template <class ELFT>
+std::vector<Fragment>
+ELFState<ELFT>::getPhdrFragments(const ELFYAML::ProgramHeader &Phdr,
+                                 ArrayRef<typename ELFT::Shdr> SHeaders) {
+  DenseMap<StringRef, ELFYAML::Fill *> NameToFill;
+  for (const std::unique_ptr<ELFYAML::Chunk> &D : Doc.Chunks)
+    if (auto S = dyn_cast<ELFYAML::Fill>(D.get()))
+      NameToFill[S->Name] = S;
+
+  std::vector<Fragment> Ret;
+  for (const ELFYAML::SectionName &SecName : Phdr.Sections) {
+    unsigned Index;
+    if (SN2I.lookup(SecName.Section, Index)) {
+      const typename ELFT::Shdr &H = SHeaders[Index];
+      Ret.push_back({H.sh_offset, H.sh_size, H.sh_type, H.sh_addralign});
+      continue;
+    }
+
+    if (ELFYAML::Fill *Fill = NameToFill.lookup(SecName.Section)) {
+      Ret.push_back({Fill->ShOffset, Fill->Size, llvm::ELF::SHT_PROGBITS,
+                     /*ShAddrAlign=*/1});
+      continue;
+    }
+
+    reportError("unknown section or fill referenced: '" + SecName.Section +
+                "' by program header");
+  }
+
+  return Ret;
+}
+
+template <class ELFT>
 void ELFState<ELFT>::setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders,
                                             std::vector<Elf_Shdr> &SHeaders) {
   uint32_t PhdrIdx = 0;
   for (auto &YamlPhdr : Doc.ProgramHeaders) {
     Elf_Phdr &PHeader = PHeaders[PhdrIdx++];
-
-    std::vector<Elf_Shdr *> Sections;
-    for (const ELFYAML::SectionName &SecName : YamlPhdr.Sections) {
-      unsigned Index;
-      if (!SN2I.lookup(SecName.Section, Index)) {
-        reportError("unknown section referenced: '" + SecName.Section +
-                    "' by program header");
-        continue;
-      }
-      Sections.push_back(&SHeaders[Index]);
-    }
+    std::vector<Fragment> Fragments = getPhdrFragments(YamlPhdr, SHeaders);
 
     if (YamlPhdr.Offset) {
       PHeader.p_offset = *YamlPhdr.Offset;
@@ -662,19 +731,19 @@ void ELFState<ELFT>::setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders,
         PHeader.p_offset = 0;
 
       // Find the minimum offset for the program header.
-      for (Elf_Shdr *SHeader : Sections)
-        PHeader.p_offset = std::min(PHeader.p_offset, SHeader->sh_offset);
+      for (const Fragment &F : Fragments)
+        PHeader.p_offset = std::min((uint64_t)PHeader.p_offset, F.Offset);
     }
 
     // Find the maximum offset of the end of a section in order to set p_filesz
     // and p_memsz. When setting p_filesz, trailing SHT_NOBITS sections are not
     // counted.
     uint64_t FileOffset = PHeader.p_offset, MemOffset = PHeader.p_offset;
-    for (Elf_Shdr *SHeader : Sections) {
-      uint64_t End = SHeader->sh_offset + SHeader->sh_size;
+    for (const Fragment &F : Fragments) {
+      uint64_t End = F.Offset + F.Size;
       MemOffset = std::max(MemOffset, End);
 
-      if (SHeader->sh_type != llvm::ELF::SHT_NOBITS)
+      if (F.Type != llvm::ELF::SHT_NOBITS)
         FileOffset = std::max(FileOffset, End);
     }
 
@@ -691,8 +760,8 @@ void ELFState<ELFT>::setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders,
       // sections so that by default the segment has a valid and sensible
       // alignment.
       PHeader.p_align = 1;
-      for (Elf_Shdr *SHeader : Sections)
-        PHeader.p_align = std::max(PHeader.p_align, SHeader->sh_addralign);
+      for (const Fragment &F : Fragments)
+        PHeader.p_align = std::max((uint64_t)PHeader.p_align, F.AddrAlign);
     }
   }
 }
@@ -707,10 +776,6 @@ void ELFState<ELFT>::writeSectionContent(
 
   if (Section.EntSize)
     SHeader.sh_entsize = *Section.EntSize;
-  else if (Section.Type == llvm::ELF::SHT_RELR)
-    SHeader.sh_entsize = sizeof(Elf_Relr);
-  else
-    SHeader.sh_entsize = 0;
 
   if (Section.Info)
     SHeader.sh_info = *Section.Info;
@@ -735,8 +800,9 @@ void ELFState<ELFT>::writeSectionContent(
   SHeader.sh_size = SHeader.sh_entsize * Section.Relocations.size();
 
   // For relocation section set link to .symtab by default.
-  if (Section.Link.empty())
-    SHeader.sh_link = SN2I.get(".symtab");
+  unsigned Link = 0;
+  if (Section.Link.empty() && SN2I.lookup(".symtab", Link))
+    SHeader.sh_link = Link;
 
   if (!Section.RelocatableSec.empty())
     SHeader.sh_info = toSectionIndex(Section.RelocatableSec, Section.Name);
@@ -764,6 +830,33 @@ void ELFState<ELFT>::writeSectionContent(
 }
 
 template <class ELFT>
+void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
+                                         const ELFYAML::RelrSection &Section,
+                                         ContiguousBlobAccumulator &CBA) {
+  raw_ostream &OS =
+      CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+  SHeader.sh_entsize =
+      Section.EntSize ? uint64_t(*Section.EntSize) : sizeof(Elf_Relr);
+
+  if (Section.Content) {
+    SHeader.sh_size = writeContent(OS, Section.Content, None);
+    return;
+  }
+
+  if (!Section.Entries)
+    return;
+
+  for (llvm::yaml::Hex64 E : *Section.Entries) {
+    if (!ELFT::Is64Bits && E > UINT32_MAX)
+      reportError(Section.Name + ": the value is too large for 32-bits: 0x" +
+                  Twine::utohexstr(E));
+    support::endian::write<uintX_t>(OS, E, ELFT::TargetEndianness);
+  }
+
+  SHeader.sh_size = sizeof(uintX_t) * Section.Entries->size();
+}
+
+template <class ELFT>
 void ELFState<ELFT>::writeSectionContent(
     Elf_Shdr &SHeader, const ELFYAML::SymtabShndxSection &Shndx,
     ContiguousBlobAccumulator &CBA) {
@@ -784,10 +877,16 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
   assert(Section.Type == llvm::ELF::SHT_GROUP &&
          "Section type is not SHT_GROUP");
 
+  unsigned Link = 0;
+  if (Section.Link.empty() && SN2I.lookup(".symtab", Link))
+    SHeader.sh_link = Link;
+
   SHeader.sh_entsize = 4;
   SHeader.sh_size = SHeader.sh_entsize * Section.Members.size();
-  SHeader.sh_info =
-      toSymbolIndex(Section.Signature, Section.Name, /*IsDynamic=*/false);
+
+  if (Section.Signature)
+    SHeader.sh_info =
+        toSymbolIndex(*Section.Signature, Section.Name, /*IsDynamic=*/false);
 
   raw_ostream &OS =
       CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
@@ -819,7 +918,6 @@ template <class ELFT>
 void ELFState<ELFT>::writeSectionContent(
     Elf_Shdr &SHeader, const ELFYAML::StackSizesSection &Section,
     ContiguousBlobAccumulator &CBA) {
-  using uintX_t = typename ELFT::uint;
   raw_ostream &OS =
       CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
 
@@ -835,6 +933,52 @@ void ELFState<ELFT>::writeSectionContent(
 }
 
 template <class ELFT>
+void ELFState<ELFT>::writeSectionContent(
+    Elf_Shdr &SHeader, const ELFYAML::LinkerOptionsSection &Section,
+    ContiguousBlobAccumulator &CBA) {
+  raw_ostream &OS =
+      CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+
+  if (Section.Content) {
+    SHeader.sh_size = writeContent(OS, Section.Content, None);
+    return;
+  }
+
+  if (!Section.Options)
+    return;
+
+  for (const ELFYAML::LinkerOption &LO : *Section.Options) {
+    OS.write(LO.Key.data(), LO.Key.size());
+    OS.write('\0');
+    OS.write(LO.Value.data(), LO.Value.size());
+    OS.write('\0');
+    SHeader.sh_size += (LO.Key.size() + LO.Value.size() + 2);
+  }
+}
+
+template <class ELFT>
+void ELFState<ELFT>::writeSectionContent(
+    Elf_Shdr &SHeader, const ELFYAML::DependentLibrariesSection &Section,
+    ContiguousBlobAccumulator &CBA) {
+  raw_ostream &OS =
+      CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+
+  if (Section.Content) {
+    SHeader.sh_size = writeContent(OS, Section.Content, None);
+    return;
+  }
+
+  if (!Section.Libs)
+    return;
+
+  for (StringRef Lib : *Section.Libs) {
+    OS.write(Lib.data(), Lib.size());
+    OS.write('\0');
+    SHeader.sh_size += Lib.size() + 1;
+  }
+}
+
+template <class ELFT>
 void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                          const ELFYAML::HashSection &Section,
                                          ContiguousBlobAccumulator &CBA) {
@@ -871,9 +1015,19 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
   raw_ostream &OS =
       CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
 
+  SHeader.sh_info = Section.Info;
+
+  if (Section.Content) {
+    SHeader.sh_size = writeContent(OS, Section.Content, None);
+    return;
+  }
+
+  if (!Section.Entries)
+    return;
+
   uint64_t AuxCnt = 0;
-  for (size_t I = 0; I < Section.Entries.size(); ++I) {
-    const ELFYAML::VerdefEntry &E = Section.Entries[I];
+  for (size_t I = 0; I < Section.Entries->size(); ++I) {
+    const ELFYAML::VerdefEntry &E = (*Section.Entries)[I];
 
     Elf_Verdef VerDef;
     VerDef.vd_version = E.Version;
@@ -882,7 +1036,7 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
     VerDef.vd_hash = E.Hash;
     VerDef.vd_aux = sizeof(Elf_Verdef);
     VerDef.vd_cnt = E.VerNames.size();
-    if (I == Section.Entries.size() - 1)
+    if (I == Section.Entries->size() - 1)
       VerDef.vd_next = 0;
     else
       VerDef.vd_next =
@@ -900,9 +1054,8 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
     }
   }
 
-  SHeader.sh_size = Section.Entries.size() * sizeof(Elf_Verdef) +
+  SHeader.sh_size = Section.Entries->size() * sizeof(Elf_Verdef) +
                     AuxCnt * sizeof(Elf_Verdaux);
-  SHeader.sh_info = Section.Info;
 }
 
 template <class ELFT>
@@ -913,15 +1066,24 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
   typedef typename ELFT::Vernaux Elf_Vernaux;
 
   auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+  SHeader.sh_info = Section.Info;
+
+  if (Section.Content) {
+    SHeader.sh_size = writeContent(OS, Section.Content, None);
+    return;
+  }
+
+  if (!Section.VerneedV)
+    return;
 
   uint64_t AuxCnt = 0;
-  for (size_t I = 0; I < Section.VerneedV.size(); ++I) {
-    const ELFYAML::VerneedEntry &VE = Section.VerneedV[I];
+  for (size_t I = 0; I < Section.VerneedV->size(); ++I) {
+    const ELFYAML::VerneedEntry &VE = (*Section.VerneedV)[I];
 
     Elf_Verneed VerNeed;
     VerNeed.vn_version = VE.Version;
     VerNeed.vn_file = DotDynstr.getOffset(VE.File);
-    if (I == Section.VerneedV.size() - 1)
+    if (I == Section.VerneedV->size() - 1)
       VerNeed.vn_next = 0;
     else
       VerNeed.vn_next =
@@ -946,9 +1108,8 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
     }
   }
 
-  SHeader.sh_size = Section.VerneedV.size() * sizeof(Elf_Verneed) +
+  SHeader.sh_size = Section.VerneedV->size() * sizeof(Elf_Verneed) +
                     AuxCnt * sizeof(Elf_Vernaux);
-  SHeader.sh_info = Section.Info;
 }
 
 template <class ELFT>
@@ -982,8 +1143,6 @@ template <class ELFT>
 void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                          const ELFYAML::DynamicSection &Section,
                                          ContiguousBlobAccumulator &CBA) {
-  typedef typename ELFT::uint uintX_t;
-
   assert(Section.Type == llvm::ELF::SHT_DYNAMIC &&
          "Section type is not SHT_DYNAMIC");
 
@@ -1035,16 +1194,158 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
   }
 }
 
+template <class ELFT>
+void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
+                                         const ELFYAML::NoteSection &Section,
+                                         ContiguousBlobAccumulator &CBA) {
+  raw_ostream &OS =
+      CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+  uint64_t Offset = OS.tell();
+
+  if (Section.Content || Section.Size) {
+    SHeader.sh_size = writeContent(OS, Section.Content, Section.Size);
+    return;
+  }
+
+  for (const ELFYAML::NoteEntry &NE : *Section.Notes) {
+    // Write name size.
+    if (NE.Name.empty())
+      support::endian::write<uint32_t>(OS, 0, ELFT::TargetEndianness);
+    else
+      support::endian::write<uint32_t>(OS, NE.Name.size() + 1,
+                                       ELFT::TargetEndianness);
+
+    // Write description size.
+    if (NE.Desc.binary_size() == 0)
+      support::endian::write<uint32_t>(OS, 0, ELFT::TargetEndianness);
+    else
+      support::endian::write<uint32_t>(OS, NE.Desc.binary_size(),
+                                       ELFT::TargetEndianness);
+
+    // Write type.
+    support::endian::write<uint32_t>(OS, NE.Type, ELFT::TargetEndianness);
+
+    // Write name, null terminator and padding.
+    if (!NE.Name.empty()) {
+      support::endian::write<uint8_t>(OS, arrayRefFromStringRef(NE.Name),
+                                      ELFT::TargetEndianness);
+      support::endian::write<uint8_t>(OS, 0, ELFT::TargetEndianness);
+      CBA.padToAlignment(4);
+    }
+
+    // Write description and padding.
+    if (NE.Desc.binary_size() != 0) {
+      NE.Desc.writeAsBinary(OS);
+      CBA.padToAlignment(4);
+    }
+  }
+
+  SHeader.sh_size = OS.tell() - Offset;
+}
+
+template <class ELFT>
+void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
+                                         const ELFYAML::GnuHashSection &Section,
+                                         ContiguousBlobAccumulator &CBA) {
+  raw_ostream &OS =
+      CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+
+  unsigned Link = 0;
+  if (Section.Link.empty() && SN2I.lookup(".dynsym", Link))
+    SHeader.sh_link = Link;
+
+  if (Section.Content) {
+    SHeader.sh_size = writeContent(OS, Section.Content, None);
+    return;
+  }
+
+  // We write the header first, starting with the hash buckets count. Normally
+  // it is the number of entries in HashBuckets, but the "NBuckets" property can
+  // be used to override this field, which is useful for producing broken
+  // objects.
+  if (Section.Header->NBuckets)
+    support::endian::write<uint32_t>(OS, *Section.Header->NBuckets,
+                                     ELFT::TargetEndianness);
+  else
+    support::endian::write<uint32_t>(OS, Section.HashBuckets->size(),
+                                     ELFT::TargetEndianness);
+
+  // Write the index of the first symbol in the dynamic symbol table accessible
+  // via the hash table.
+  support::endian::write<uint32_t>(OS, Section.Header->SymNdx,
+                                   ELFT::TargetEndianness);
+
+  // Write the number of words in the Bloom filter. As above, the "MaskWords"
+  // property can be used to set this field to any value.
+  if (Section.Header->MaskWords)
+    support::endian::write<uint32_t>(OS, *Section.Header->MaskWords,
+                                     ELFT::TargetEndianness);
+  else
+    support::endian::write<uint32_t>(OS, Section.BloomFilter->size(),
+                                     ELFT::TargetEndianness);
+
+  // Write the shift constant used by the Bloom filter.
+  support::endian::write<uint32_t>(OS, Section.Header->Shift2,
+                                   ELFT::TargetEndianness);
+
+  // We've finished writing the header. Now write the Bloom filter.
+  for (llvm::yaml::Hex64 Val : *Section.BloomFilter)
+    support::endian::write<typename ELFT::uint>(OS, Val,
+                                                ELFT::TargetEndianness);
+
+  // Write an array of hash buckets.
+  for (llvm::yaml::Hex32 Val : *Section.HashBuckets)
+    support::endian::write<uint32_t>(OS, Val, ELFT::TargetEndianness);
+
+  // Write an array of hash values.
+  for (llvm::yaml::Hex32 Val : *Section.HashValues)
+    support::endian::write<uint32_t>(OS, Val, ELFT::TargetEndianness);
+
+  SHeader.sh_size = 16 /*Header size*/ +
+                    Section.BloomFilter->size() * sizeof(typename ELFT::uint) +
+                    Section.HashBuckets->size() * 4 +
+                    Section.HashValues->size() * 4;
+}
+
+template <class ELFT>
+void ELFState<ELFT>::writeFill(ELFYAML::Fill &Fill,
+                               ContiguousBlobAccumulator &CBA) {
+  raw_ostream &OS = CBA.getOSAndAlignedOffset(Fill.ShOffset, /*Align=*/1);
+
+  size_t PatternSize = Fill.Pattern ? Fill.Pattern->binary_size() : 0;
+  if (!PatternSize) {
+    OS.write_zeros(Fill.Size);
+    return;
+  }
+
+  // Fill the content with the specified pattern.
+  uint64_t Written = 0;
+  for (; Written + PatternSize <= Fill.Size; Written += PatternSize)
+    Fill.Pattern->writeAsBinary(OS);
+  Fill.Pattern->writeAsBinary(OS, Fill.Size - Written);
+}
+
 template <class ELFT> void ELFState<ELFT>::buildSectionIndex() {
-  for (unsigned I = 0, E = Doc.Sections.size(); I != E; ++I) {
-    StringRef Name = Doc.Sections[I]->Name;
-    if (Name.empty())
+  size_t SecNdx = -1;
+  StringSet<> Seen;
+  for (size_t I = 0; I < Doc.Chunks.size(); ++I) {
+    const std::unique_ptr<ELFYAML::Chunk> &C = Doc.Chunks[I];
+    bool IsSection = isa<ELFYAML::Section>(C.get());
+    if (IsSection)
+      ++SecNdx;
+
+    if (C->Name.empty())
+      continue;
+
+    if (!Seen.insert(C->Name).second)
+      reportError("repeated section/fill name: '" + C->Name +
+                  "' at YAML section/fill number " + Twine(I));
+    if (!IsSection || HasError)
       continue;
 
-    DotShStrtab.add(ELFYAML::dropUniqueSuffix(Name));
-    if (!SN2I.addName(Name, I))
-      reportError("repeated section name: '" + Name +
-                  "' at YAML section number " + Twine(I));
+    if (!SN2I.addName(C->Name, SecNdx))
+      llvm_unreachable("buildSectionIndex() failed");
+    DotShStrtab.add(ELFYAML::dropUniqueSuffix(C->Name));
   }
 
   DotShStrtab.finalize();
@@ -1061,7 +1362,8 @@ template <class ELFT> void ELFState<ELFT>::buildSymbolIndexes() {
 
   if (Doc.Symbols)
     Build(*Doc.Symbols, SymN2I);
-  Build(Doc.DynamicSymbols, DynSymN2I);
+  if (Doc.DynamicSymbols)
+    Build(*Doc.DynamicSymbols, DynSymN2I);
 }
 
 template <class ELFT> void ELFState<ELFT>::finalizeStrings() {
@@ -1072,22 +1374,26 @@ template <class ELFT> void ELFState<ELFT>::finalizeStrings() {
   DotStrtab.finalize();
 
   // Add the dynamic symbol names to .dynstr section.
-  for (const ELFYAML::Symbol &Sym : Doc.DynamicSymbols)
-    DotDynstr.add(ELFYAML::dropUniqueSuffix(Sym.Name));
+  if (Doc.DynamicSymbols)
+    for (const ELFYAML::Symbol &Sym : *Doc.DynamicSymbols)
+      DotDynstr.add(ELFYAML::dropUniqueSuffix(Sym.Name));
 
   // SHT_GNU_verdef and SHT_GNU_verneed sections might also
   // add strings to .dynstr section.
-  for (const std::unique_ptr<ELFYAML::Section> &Sec : Doc.Sections) {
-    if (auto VerNeed = dyn_cast<ELFYAML::VerneedSection>(Sec.get())) {
-      for (const ELFYAML::VerneedEntry &VE : VerNeed->VerneedV) {
-        DotDynstr.add(VE.File);
-        for (const ELFYAML::VernauxEntry &Aux : VE.AuxV)
-          DotDynstr.add(Aux.Name);
+  for (const ELFYAML::Chunk *Sec : Doc.getSections()) {
+    if (auto VerNeed = dyn_cast<ELFYAML::VerneedSection>(Sec)) {
+      if (VerNeed->VerneedV) {
+        for (const ELFYAML::VerneedEntry &VE : *VerNeed->VerneedV) {
+          DotDynstr.add(VE.File);
+          for (const ELFYAML::VernauxEntry &Aux : VE.AuxV)
+            DotDynstr.add(Aux.Name);
+        }
       }
-    } else if (auto VerDef = dyn_cast<ELFYAML::VerdefSection>(Sec.get())) {
-      for (const ELFYAML::VerdefEntry &E : VerDef->Entries)
-        for (StringRef Name : E.VerNames)
-          DotDynstr.add(Name);
+    } else if (auto VerDef = dyn_cast<ELFYAML::VerdefSection>(Sec)) {
+      if (VerDef->Entries)
+        for (const ELFYAML::VerdefEntry &E : *VerDef->Entries)
+          for (StringRef Name : E.VerNames)
+            DotDynstr.add(Name);
     }
   }
 
@@ -1105,6 +1411,9 @@ bool ELFState<ELFT>::writeELF(raw_ostream &OS, ELFYAML::Object &Doc,
   State.finalizeStrings();
 
   State.buildSectionIndex();
+  if (State.HasError)
+    return false;
+
   State.buildSymbolIndexes();
 
   std::vector<Elf_Phdr> PHeaders;
@@ -1119,7 +1428,7 @@ bool ELFState<ELFT>::writeELF(raw_ostream &OS, ELFYAML::Object &Doc,
   std::vector<Elf_Shdr> SHeaders;
   State.initSectionHeaders(SHeaders, CBA);
 
-  // Now we can decide segment offsets
+  // Now we can decide segment offsets.
   State.setProgramHeaderLayout(PHeaders, SHeaders);
 
   if (State.HasError)
diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index 29585abe6e80..efa7ecb4728b 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -24,7 +24,7 @@
 
 namespace llvm {
 
-ELFYAML::Section::~Section() = default;
+ELFYAML::Chunk::~Chunk() = default;
 
 namespace yaml {
 
@@ -54,6 +54,7 @@ void ScalarEnumerationTraits<ELFYAML::ELF_PT>::enumeration(
   ECase(PT_GNU_EH_FRAME);
   ECase(PT_GNU_STACK);
   ECase(PT_GNU_RELRO);
+  ECase(PT_GNU_PROPERTY);
 #undef ECase
   IO.enumFallback<Hex32>(Value);
 }
@@ -252,6 +253,7 @@ void ScalarEnumerationTraits<ELFYAML::ELF_ELFOSABI>::enumeration(
   ECase(ELFOSABI_HPUX);
   ECase(ELFOSABI_NETBSD);
   ECase(ELFOSABI_GNU);
+  ECase(ELFOSABI_LINUX);
   ECase(ELFOSABI_HURD);
   ECase(ELFOSABI_SOLARIS);
   ECase(ELFOSABI_AIX);
@@ -273,6 +275,7 @@ void ScalarEnumerationTraits<ELFYAML::ELF_ELFOSABI>::enumeration(
   ECase(ELFOSABI_C6000_LINUX);
   ECase(ELFOSABI_STANDALONE);
 #undef ECase
+  IO.enumFallback<Hex8>(Value);
 }
 
 void ScalarBitSetTraits<ELFYAML::ELF_EF>::bitset(IO &IO,
@@ -863,6 +866,24 @@ template <> struct SequenceElementTraits<StOtherPiece> {
   static const bool flow = true;
 };
 
+template <> struct ScalarTraits<ELFYAML::YAMLFlowString> {
+  static void output(const ELFYAML::YAMLFlowString &Val, void *,
+                     raw_ostream &Out) {
+    Out << Val;
+  }
+  static StringRef input(StringRef Scalar, void *,
+                         ELFYAML::YAMLFlowString &Val) {
+    Val = Scalar;
+    return {};
+  }
+  static QuotingType mustQuote(StringRef S) {
+    return ScalarTraits<StringRef>::mustQuote(S);
+  }
+};
+template <> struct SequenceElementTraits<ELFYAML::YAMLFlowString> {
+  static const bool flow = true;
+};
+
 namespace {
 
 struct NormalizedOther {
@@ -998,10 +1019,12 @@ static void commonSectionMapping(IO &IO, ELFYAML::Section &Section) {
   // are producing YAML, because yaml2obj sets appropriate values for them
   // automatically when they are not explicitly defined.
   assert(!IO.outputting() ||
-         (!Section.ShOffset.hasValue() && !Section.ShSize.hasValue()));
+         (!Section.ShOffset.hasValue() && !Section.ShSize.hasValue() &&
+          !Section.ShName.hasValue() && !Section.ShFlags.hasValue()));
   IO.mapOptional("ShName", Section.ShName);
   IO.mapOptional("ShOffset", Section.ShOffset);
   IO.mapOptional("ShSize", Section.ShSize);
+  IO.mapOptional("ShFlags", Section.ShFlags);
 }
 
 static void sectionMapping(IO &IO, ELFYAML::DynamicSection &Section) {
@@ -1032,6 +1055,22 @@ static void sectionMapping(IO &IO, ELFYAML::HashSection &Section) {
   IO.mapOptional("Size", Section.Size);
 }
 
+static void sectionMapping(IO &IO, ELFYAML::NoteSection &Section) {
+  commonSectionMapping(IO, Section);
+  IO.mapOptional("Content", Section.Content);
+  IO.mapOptional("Size", Section.Size);
+  IO.mapOptional("Notes", Section.Notes);
+}
+
+
+static void sectionMapping(IO &IO, ELFYAML::GnuHashSection &Section) {
+  commonSectionMapping(IO, Section);
+  IO.mapOptional("Content", Section.Content);
+  IO.mapOptional("Header", Section.Header);
+  IO.mapOptional("BloomFilter", Section.BloomFilter);
+  IO.mapOptional("HashBuckets", Section.HashBuckets);
+  IO.mapOptional("HashValues", Section.HashValues);
+}
 static void sectionMapping(IO &IO, ELFYAML::NoBitsSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapOptional("Size", Section.Size, Hex64(0));
@@ -1040,7 +1079,8 @@ static void sectionMapping(IO &IO, ELFYAML::NoBitsSection &Section) {
 static void sectionMapping(IO &IO, ELFYAML::VerdefSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapRequired("Info", Section.Info);
-  IO.mapRequired("Entries", Section.Entries);
+  IO.mapOptional("Entries", Section.Entries);
+  IO.mapOptional("Content", Section.Content);
 }
 
 static void sectionMapping(IO &IO, ELFYAML::SymverSection &Section) {
@@ -1051,7 +1091,8 @@ static void sectionMapping(IO &IO, ELFYAML::SymverSection &Section) {
 static void sectionMapping(IO &IO, ELFYAML::VerneedSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapRequired("Info", Section.Info);
-  IO.mapRequired("Dependencies", Section.VerneedV);
+  IO.mapOptional("Dependencies", Section.VerneedV);
+  IO.mapOptional("Content", Section.Content);
 }
 
 static void sectionMapping(IO &IO, ELFYAML::RelocationSection &Section) {
@@ -1060,9 +1101,15 @@ static void sectionMapping(IO &IO, ELFYAML::RelocationSection &Section) {
   IO.mapOptional("Relocations", Section.Relocations);
 }
 
+static void sectionMapping(IO &IO, ELFYAML::RelrSection &Section) {
+  commonSectionMapping(IO, Section);
+  IO.mapOptional("Entries", Section.Entries);
+  IO.mapOptional("Content", Section.Content);
+}
+
 static void groupSectionMapping(IO &IO, ELFYAML::Group &Group) {
   commonSectionMapping(IO, Group);
-  IO.mapOptional("Info", Group.Signature, StringRef());
+  IO.mapOptional("Info", Group.Signature);
   IO.mapRequired("Members", Group.Members);
 }
 
@@ -1078,6 +1125,25 @@ static void sectionMapping(IO &IO, ELFYAML::AddrsigSection &Section) {
   IO.mapOptional("Symbols", Section.Symbols);
 }
 
+static void fillMapping(IO &IO, ELFYAML::Fill &Fill) {
+  IO.mapOptional("Name", Fill.Name, StringRef());
+  IO.mapOptional("Pattern", Fill.Pattern);
+  IO.mapRequired("Size", Fill.Size);
+}
+
+static void sectionMapping(IO &IO, ELFYAML::LinkerOptionsSection &Section) {
+  commonSectionMapping(IO, Section);
+  IO.mapOptional("Options", Section.Options);
+  IO.mapOptional("Content", Section.Content);
+}
+
+static void sectionMapping(IO &IO,
+                           ELFYAML::DependentLibrariesSection &Section) {
+  commonSectionMapping(IO, Section);
+  IO.mapOptional("Libraries", Section.Libs);
+  IO.mapOptional("Content", Section.Content);
+}
+
 void MappingTraits<ELFYAML::SectionOrType>::mapping(
     IO &IO, ELFYAML::SectionOrType &sectionOrType) {
   IO.mapRequired("SectionOrType", sectionOrType.sectionNameOrType);
@@ -1108,15 +1174,27 @@ static void sectionMapping(IO &IO, ELFYAML::MipsABIFlags &Section) {
   IO.mapOptional("Flags2", Section.Flags2, Hex32(0));
 }
 
-void MappingTraits<std::unique_ptr<ELFYAML::Section>>::mapping(
-    IO &IO, std::unique_ptr<ELFYAML::Section> &Section) {
-  ELFYAML::ELF_SHT sectionType;
-  if (IO.outputting())
-    sectionType = Section->Type;
-  else
-    IO.mapRequired("Type", sectionType);
+void MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::mapping(
+    IO &IO, std::unique_ptr<ELFYAML::Chunk> &Section) {
+  ELFYAML::ELF_SHT Type;
+  if (IO.outputting()) {
+    Type = cast<ELFYAML::Section>(Section.get())->Type;
+  } else {
+    // When the Type string does not have a "SHT_" prefix, we know it is not a
+    // description of a regular ELF output section. Currently, we have one
+    // special type named "Fill". See comments for Fill.
+    StringRef StrType;
+    IO.mapRequired("Type", StrType);
+    if (StrType == "Fill") {
+      Section.reset(new ELFYAML::Fill());
+      fillMapping(IO, *cast<ELFYAML::Fill>(Section.get()));
+      return;
+    }
+
+    IO.mapRequired("Type", Type);
+  }
 
-  switch (sectionType) {
+  switch (Type) {
   case ELF::SHT_DYNAMIC:
     if (!IO.outputting())
       Section.reset(new ELFYAML::DynamicSection());
@@ -1128,6 +1206,11 @@ void MappingTraits<std::unique_ptr<ELFYAML::Section>>::mapping(
       Section.reset(new ELFYAML::RelocationSection());
     sectionMapping(IO, *cast<ELFYAML::RelocationSection>(Section.get()));
     break;
+  case ELF::SHT_RELR:
+    if (!IO.outputting())
+      Section.reset(new ELFYAML::RelrSection());
+    sectionMapping(IO, *cast<ELFYAML::RelrSection>(Section.get()));
+    break;
   case ELF::SHT_GROUP:
     if (!IO.outputting())
       Section.reset(new ELFYAML::Group());
@@ -1143,6 +1226,16 @@ void MappingTraits<std::unique_ptr<ELFYAML::Section>>::mapping(
       Section.reset(new ELFYAML::HashSection());
     sectionMapping(IO, *cast<ELFYAML::HashSection>(Section.get()));
     break;
+  case ELF::SHT_NOTE:
+    if (!IO.outputting())
+      Section.reset(new ELFYAML::NoteSection());
+    sectionMapping(IO, *cast<ELFYAML::NoteSection>(Section.get()));
+    break;
+ case ELF::SHT_GNU_HASH:
+    if (!IO.outputting())
+      Section.reset(new ELFYAML::GnuHashSection());
+    sectionMapping(IO, *cast<ELFYAML::GnuHashSection>(Section.get()));
+    break;
   case ELF::SHT_MIPS_ABIFLAGS:
     if (!IO.outputting())
       Section.reset(new ELFYAML::MipsABIFlags());
@@ -1173,6 +1266,17 @@ void MappingTraits<std::unique_ptr<ELFYAML::Section>>::mapping(
       Section.reset(new ELFYAML::AddrsigSection());
     sectionMapping(IO, *cast<ELFYAML::AddrsigSection>(Section.get()));
     break;
+  case ELF::SHT_LLVM_LINKER_OPTIONS:
+    if (!IO.outputting())
+      Section.reset(new ELFYAML::LinkerOptionsSection());
+    sectionMapping(IO, *cast<ELFYAML::LinkerOptionsSection>(Section.get()));
+    break;
+  case ELF::SHT_LLVM_DEPENDENT_LIBRARIES:
+    if (!IO.outputting())
+      Section.reset(new ELFYAML::DependentLibrariesSection());
+    sectionMapping(IO,
+                   *cast<ELFYAML::DependentLibrariesSection>(Section.get()));
+    break;
   default:
     if (!IO.outputting()) {
       StringRef Name;
@@ -1192,17 +1296,18 @@ void MappingTraits<std::unique_ptr<ELFYAML::Section>>::mapping(
   }
 }
 
-StringRef MappingTraits<std::unique_ptr<ELFYAML::Section>>::validate(
-    IO &io, std::unique_ptr<ELFYAML::Section> &Section) {
-  if (const auto *RawSection =
-          dyn_cast<ELFYAML::RawContentSection>(Section.get())) {
+StringRef MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::validate(
+    IO &io, std::unique_ptr<ELFYAML::Chunk> &C) {
+  if (const auto *RawSection = dyn_cast<ELFYAML::RawContentSection>(C.get())) {
     if (RawSection->Size && RawSection->Content &&
         (uint64_t)(*RawSection->Size) < RawSection->Content->binary_size())
       return "Section size must be greater than or equal to the content size";
+    if (RawSection->Flags && RawSection->ShFlags)
+      return "ShFlags and Flags cannot be used together";
     return {};
   }
 
-  if (const auto *SS = dyn_cast<ELFYAML::StackSizesSection>(Section.get())) {
+  if (const auto *SS = dyn_cast<ELFYAML::StackSizesSection>(C.get())) {
     if (!SS->Entries && !SS->Content && !SS->Size)
       return ".stack_sizes: one of Content, Entries and Size must be specified";
 
@@ -1222,7 +1327,7 @@ StringRef MappingTraits<std::unique_ptr<ELFYAML::Section>>::validate(
     return {};
   }
 
-  if (const auto *HS = dyn_cast<ELFYAML::HashSection>(Section.get())) {
+  if (const auto *HS = dyn_cast<ELFYAML::HashSection>(C.get())) {
     if (!HS->Content && !HS->Bucket && !HS->Chain && !HS->Size)
       return "one of \"Content\", \"Size\", \"Bucket\" or \"Chain\" must be "
              "specified";
@@ -1245,7 +1350,7 @@ StringRef MappingTraits<std::unique_ptr<ELFYAML::Section>>::validate(
     return {};
   }
 
-  if (const auto *Sec = dyn_cast<ELFYAML::AddrsigSection>(Section.get())) {
+  if (const auto *Sec = dyn_cast<ELFYAML::AddrsigSection>(C.get())) {
     if (!Sec->Symbols && !Sec->Content && !Sec->Size)
       return "one of \"Content\", \"Size\" or \"Symbols\" must be specified";
 
@@ -1270,6 +1375,89 @@ StringRef MappingTraits<std::unique_ptr<ELFYAML::Section>>::validate(
     return {};
   }
 
+  if (const auto *NS = dyn_cast<ELFYAML::NoteSection>(C.get())) {
+    if (!NS->Content && !NS->Size && !NS->Notes)
+      return "one of \"Content\", \"Size\" or \"Notes\" must be "
+             "specified";
+
+    if (!NS->Content && !NS->Size)
+      return {};
+
+    if (NS->Size && NS->Content &&
+        (uint64_t)*NS->Size < NS->Content->binary_size())
+      return "\"Size\" must be greater than or equal to the content "
+             "size";
+
+    if (NS->Notes)
+      return "\"Notes\" cannot be used with \"Content\" or \"Size\"";
+    return {};
+  }
+
+  if (const auto *Sec = dyn_cast<ELFYAML::GnuHashSection>(C.get())) {
+    if (!Sec->Content && !Sec->Header && !Sec->BloomFilter &&
+        !Sec->HashBuckets && !Sec->HashValues)
+      return "either \"Content\" or \"Header\", \"BloomFilter\", "
+             "\"HashBuckets\" and \"HashBuckets\" must be specified";
+
+    if (Sec->Header || Sec->BloomFilter || Sec->HashBuckets ||
+        Sec->HashValues) {
+      if (!Sec->Header || !Sec->BloomFilter || !Sec->HashBuckets ||
+          !Sec->HashValues)
+        return "\"Header\", \"BloomFilter\", "
+               "\"HashBuckets\" and \"HashValues\" must be used together";
+      if (Sec->Content)
+        return "\"Header\", \"BloomFilter\", "
+               "\"HashBuckets\" and \"HashValues\" can't be used together with "
+               "\"Content\"";
+      return {};
+    }
+
+    // Only Content is specified.
+    return {};
+  }
+
+  if (const auto *Sec = dyn_cast<ELFYAML::LinkerOptionsSection>(C.get())) {
+    if (Sec->Options && Sec->Content)
+      return "\"Options\" and \"Content\" can't be used together";
+    return {};
+  }
+
+  if (const auto *Sec = dyn_cast<ELFYAML::DependentLibrariesSection>(C.get())) {
+    if (Sec->Libs && Sec->Content)
+      return "SHT_LLVM_DEPENDENT_LIBRARIES: \"Libraries\" and \"Content\" "
+             "can't "
+             "be used together";
+    return {};
+  }
+
+  if (const auto *F = dyn_cast<ELFYAML::Fill>(C.get())) {
+    if (!F->Pattern)
+      return {};
+    if (F->Pattern->binary_size() != 0 && !F->Size)
+      return "\"Size\" can't be 0 when \"Pattern\" is not empty";
+    return {};
+  }
+
+  if (const auto *VD = dyn_cast<ELFYAML::VerdefSection>(C.get())) {
+    if (VD->Entries && VD->Content)
+      return "SHT_GNU_verdef: \"Entries\" and \"Content\" can't be used "
+             "together";
+    return {};
+  }
+
+  if (const auto *VD = dyn_cast<ELFYAML::VerneedSection>(C.get())) {
+    if (VD->VerneedV && VD->Content)
+      return "SHT_GNU_verneed: \"Dependencies\" and \"Content\" can't be used "
+             "together";
+    return {};
+  }
+
+  if (const auto *RS = dyn_cast<ELFYAML::RelrSection>(C.get())) {
+    if (RS->Entries && RS->Content)
+      return "\"Entries\" and \"Content\" can't be used together";
+    return {};
+  }
+
   return {};
 }
 
@@ -1305,6 +1493,15 @@ void MappingTraits<ELFYAML::StackSizeEntry>::mapping(
   IO.mapRequired("Size", E.Size);
 }
 
+void MappingTraits<ELFYAML::GnuHashHeader>::mapping(IO &IO,
+                                                    ELFYAML::GnuHashHeader &E) {
+  assert(IO.getContext() && "The IO context is not initialized");
+  IO.mapOptional("NBuckets", E.NBuckets);
+  IO.mapRequired("SymNdx", E.SymNdx);
+  IO.mapOptional("MaskWords", E.MaskWords);
+  IO.mapRequired("Shift2", E.Shift2);
+}
+
 void MappingTraits<ELFYAML::DynamicEntry>::mapping(IO &IO,
                                                    ELFYAML::DynamicEntry &Rel) {
   assert(IO.getContext() && "The IO context is not initialized");
@@ -1313,6 +1510,14 @@ void MappingTraits<ELFYAML::DynamicEntry>::mapping(IO &IO,
   IO.mapRequired("Value", Rel.Val);
 }
 
+void MappingTraits<ELFYAML::NoteEntry>::mapping(IO &IO, ELFYAML::NoteEntry &N) {
+  assert(IO.getContext() && "The IO context is not initialized");
+
+  IO.mapOptional("Name", N.Name);
+  IO.mapOptional("Desc", N.Desc);
+  IO.mapRequired("Type", N.Type);
+}
+
 void MappingTraits<ELFYAML::VerdefEntry>::mapping(IO &IO,
                                                   ELFYAML::VerdefEntry &E) {
   assert(IO.getContext() && "The IO context is not initialized");
@@ -1371,7 +1576,7 @@ void MappingTraits<ELFYAML::Object>::mapping(IO &IO, ELFYAML::Object &Object) {
   IO.mapTag("!ELF", true);
   IO.mapRequired("FileHeader", Object.Header);
   IO.mapOptional("ProgramHeaders", Object.ProgramHeaders);
-  IO.mapOptional("Sections", Object.Sections);
+  IO.mapOptional("Sections", Object.Chunks);
   IO.mapOptional("Symbols", Object.Symbols);
   IO.mapOptional("DynamicSymbols", Object.DynamicSymbols);
   IO.setContext(nullptr);
@@ -1383,6 +1588,13 @@ void MappingTraits<ELFYAML::AddrsigSymbol>::mapping(IO &IO, ELFYAML::AddrsigSymb
   IO.mapOptional("Index", Sym.Index);
 }
 
+void MappingTraits<ELFYAML::LinkerOption>::mapping(IO &IO,
+                                                   ELFYAML::LinkerOption &Opt) {
+  assert(IO.getContext() && "The IO context is not initialized");
+  IO.mapRequired("Name", Opt.Key);
+  IO.mapRequired("Value", Opt.Value);
+}
+
 LLVM_YAML_STRONG_TYPEDEF(uint8_t, MIPS_AFL_REG)
 LLVM_YAML_STRONG_TYPEDEF(uint8_t, MIPS_ABI_FP)
 LLVM_YAML_STRONG_TYPEDEF(uint32_t, MIPS_AFL_EXT)
diff --git a/llvm/lib/ObjectYAML/MachOEmitter.cpp b/llvm/lib/ObjectYAML/MachOEmitter.cpp
index b56f811ce67d..bda4aed885b4 100644
--- a/llvm/lib/ObjectYAML/MachOEmitter.cpp
+++ b/llvm/lib/ObjectYAML/MachOEmitter.cpp
@@ -494,7 +494,8 @@ void UniversalWriter::writeMachO(raw_ostream &OS) {
   writeFatArchs(OS);
 
   auto &FatFile = *ObjectFile.FatMachO;
-  assert(FatFile.FatArchs.size() == FatFile.Slices.size());
+  assert(FatFile.FatArchs.size() >= FatFile.Slices.size() &&
+         "Cannot write Slices if not decribed in FatArches");
   for (size_t i = 0; i < FatFile.Slices.size(); i++) {
     ZeroToOffset(OS, FatFile.FatArchs[i].offset);
     MachOWriter Writer(FatFile.Slices[i]);
diff --git a/llvm/lib/ObjectYAML/MinidumpYAML.cpp b/llvm/lib/ObjectYAML/MinidumpYAML.cpp
index 21b2a4d78629..77ea42c41a4c 100644
--- a/llvm/lib/ObjectYAML/MinidumpYAML.cpp
+++ b/llvm/lib/ObjectYAML/MinidumpYAML.cpp
@@ -337,6 +337,7 @@ static void streamMapping(yaml::IO &IO, SystemInfoStream &Stream) {
     break;
   case ProcessorArchitecture::ARM:
   case ProcessorArchitecture::ARM64:
+  case ProcessorArchitecture::BP_ARM64:
     IO.mapOptional("CPU", Info.CPU.Arm);
     break;
   default:
diff --git a/llvm/lib/ObjectYAML/YAML.cpp b/llvm/lib/ObjectYAML/YAML.cpp
index 6eba16e36c2a..5dcb113d3395 100644
--- a/llvm/lib/ObjectYAML/YAML.cpp
+++ b/llvm/lib/ObjectYAML/YAML.cpp
@@ -37,15 +37,17 @@ StringRef yaml::ScalarTraits<yaml::BinaryRef>::input(StringRef Scalar, void *,
   return {};
 }
 
-void yaml::BinaryRef::writeAsBinary(raw_ostream &OS) const {
+void yaml::BinaryRef::writeAsBinary(raw_ostream &OS, uint64_t N) const {
   if (!DataIsHexString) {
-    OS.write((const char *)Data.data(), Data.size());
+    OS.write((const char *)Data.data(), std::min<uint64_t>(N, Data.size()));
     return;
   }
-  for (unsigned I = 0, N = Data.size(); I != N; I += 2) {
-    uint8_t Byte = llvm::hexDigitValue(Data[I]);
+
+  for (uint64_t I = 0, E = std::min<uint64_t>(N, Data.size() / 2); I != E;
+       ++I) {
+    uint8_t Byte = llvm::hexDigitValue(Data[I * 2]);
     Byte <<= 4;
-    Byte |= llvm::hexDigitValue(Data[I + 1]);
+    Byte |= llvm::hexDigitValue(Data[I * 2 + 1]);
     OS.write(Byte);
   }
 }