From b8eb9d3761e4c9dccdd3a990d7f81ca5e3fb0bfd Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Mon, 11 Nov 2024 19:04:40 +0900
Subject: [PATCH 1/7] [ELFYAML] Introduce `CustomRawContent`

---
 llvm/include/llvm/ObjectYAML/ELFYAML.h | 70 +++++++++++++++++++++++++-
 llvm/include/llvm/Support/YAMLTraits.h | 17 +++++++
 llvm/lib/ObjectYAML/ELFEmitter.cpp     | 16 +++++-
 llvm/lib/ObjectYAML/ELFYAML.cpp        | 24 ++++++++-
 llvm/lib/Support/YAMLTraits.cpp        |  8 +++
 llvm/tools/obj2yaml/elf2yaml.cpp       | 63 +++++++++++++++++++++++
 llvm/tools/yaml2obj/yaml2obj.cpp       | 16 ++++++
 7 files changed, 211 insertions(+), 3 deletions(-)

diff --git a/llvm/include/llvm/ObjectYAML/ELFYAML.h b/llvm/include/llvm/ObjectYAML/ELFYAML.h
index 8f045d6383623..ee8ca11aa2ee6 100644
--- a/llvm/include/llvm/ObjectYAML/ELFYAML.h
+++ b/llvm/include/llvm/ObjectYAML/ELFYAML.h
@@ -211,6 +211,7 @@ struct Chunk {
     Dynamic,
     Group,
     RawContent,
+    CustomRawContent,
     Relocation,
     Relr,
     NoBits,
@@ -388,7 +389,7 @@ struct DynamicSection : Section {
 struct RawContentSection : Section {
   std::optional<llvm::yaml::Hex64> Info;
 
-  RawContentSection() : Section(ChunkKind::RawContent) {}
+  RawContentSection(ChunkKind Kind = ChunkKind::RawContent) : Section(Kind) {}
 
   static bool classof(const Chunk *S) {
     return S->Kind == ChunkKind::RawContent;
@@ -398,6 +399,29 @@ struct RawContentSection : Section {
   std::optional<std::vector<uint8_t>> ContentBuf;
 };
 
+/// Abstract base class for non-blob contents.
+struct CustomRawContentSection : RawContentSection {
+  CustomRawContentSection() : RawContentSection(ChunkKind::CustomRawContent) {
+    // Type assumes PROGBITS.
+    Type = ELF::SHT_PROGBITS;
+    Flags = ELF::SHF_GNU_RETAIN;
+    AddressAlign = 1;
+  }
+
+  /// Apply mappings.
+  virtual void sectionMapping(yaml::IO &IO) = 0;
+
+  /// Decode Content and store to members.
+  virtual Error decode(const ArrayRef<uint8_t> Content, bool isLE) = 0;
+
+  /// Encode members and returns Content.
+  virtual std::string encode() const = 0;
+
+  static bool classof(const Chunk *S) {
+    return S->Kind == ChunkKind::CustomRawContent;
+  }
+};
+
 struct NoBitsSection : Section {
   NoBitsSection() : Section(ChunkKind::NoBits) {}
 
@@ -757,6 +781,50 @@ struct Object {
 bool shouldAllocateFileSpace(ArrayRef<ProgramHeader> Phdrs,
                              const NoBitsSection &S);
 
+/// ELFYAML::Opt -- Abstract base class for ELFYAML to provide
+/// the interface for handling CustomRawConetentSection.
+///
+/// Users in ELFYAML should obtain the pointer with
+/// dyn_cast<ELFYAML::Opt> if IO::Opt is the instance from yaml::Opt.
+///
+///     if (auto *Opt = dyn_cast<ELFYAML::Opt>(IO.Opt))
+///
+/// Derivered classes should not modify OptClassID to ensue that
+/// dyn_cast<ELFYAML::Opt> can find this interface.
+class Opt : public yaml::Opt {
+public:
+  Opt() {
+    OptClassID = &ID;
+    ELFOptClassID = &ID;
+  }
+  ~Opt();
+
+  /// Create an empty new object of CustomRawContentSection.
+  /// Its contents will be filled later.
+  /// This is called:
+  ///   - Before preMapping for elf2yaml.
+  ///   - After preMapping for yaml2elf.
+  virtual std::unique_ptr<CustomRawContentSection>
+  makeCustomRawContentSection(StringRef Name) const = 0;
+
+  /// Called before mapping sections for prettyprinting yaml.
+  virtual void preMapping(const ELFYAML::Object &Object, bool IsOutputting) = 0;
+
+  /// Called after mapping sections to gather members for the file format.
+  virtual void postMapping(const ELFYAML::Object &Object,
+                           bool IsOutputting) = 0;
+
+  /// Tell IO::Opt to be this and derivered classes.
+  static bool classof(const yaml::Opt *Obj) { return (Obj->OptClassID == &ID); }
+
+  /// This will be not needed unless the pointer to ELFYAML::Opt would
+  /// be cast further.
+  static bool classof(const Opt *Obj) { return (Obj->ELFOptClassID == &ID); }
+  const char *ELFOptClassID;
+
+private:
+  static const char ID;
+};
 } // end namespace ELFYAML
 } // end namespace llvm
 
diff --git a/llvm/include/llvm/Support/YAMLTraits.h b/llvm/include/llvm/Support/YAMLTraits.h
index 1d04783753d5c..1f1e06a9e3773 100644
--- a/llvm/include/llvm/Support/YAMLTraits.h
+++ b/llvm/include/llvm/Support/YAMLTraits.h
@@ -39,6 +39,18 @@ class VersionTuple;
 
 namespace yaml {
 
+/// The base class of options.
+class Opt {
+public:
+  virtual ~Opt();
+
+  static bool classof(const Opt *Obj) { return (Obj->OptClassID == &ID); }
+  const char *OptClassID = &ID;
+
+private:
+  static const char ID;
+};
+
 enum class NodeKind : uint8_t {
   Scalar,
   Map,
@@ -964,6 +976,11 @@ class IO {
 
 private:
   void *Ctxt;
+  Opt DefaultOpt;
+
+public:
+  /// This may be overwritten in derivered classes.
+  Opt *Opt = &DefaultOpt;
 };
 
 namespace detail {
diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index fc234581a45a7..09a540b048517 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -251,6 +251,9 @@ template <class ELFT> class ELFState {
   void writeSectionContent(Elf_Shdr &SHeader,
                            const ELFYAML::NoBitsSection &Section,
                            ContiguousBlobAccumulator &CBA);
+  void writeSectionContent(Elf_Shdr &SHeader,
+                           const ELFYAML::CustomRawContentSection &Section,
+                           ContiguousBlobAccumulator &CBA);
   void writeSectionContent(Elf_Shdr &SHeader,
                            const ELFYAML::RawContentSection &Section,
                            ContiguousBlobAccumulator &CBA);
@@ -859,7 +862,9 @@ void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
     if (!isa<ELFYAML::NoBitsSection>(Sec) && (Sec->Content || Sec->Size))
       SHeader.sh_size = writeContent(CBA, Sec->Content, Sec->Size);
 
-    if (auto S = dyn_cast<ELFYAML::RawContentSection>(Sec)) {
+    if (auto S = dyn_cast<ELFYAML::CustomRawContentSection>(Sec)) {
+      writeSectionContent(SHeader, *S, CBA);
+    } else if (auto S = dyn_cast<ELFYAML::RawContentSection>(Sec)) {
       writeSectionContent(SHeader, *S, CBA);
     } else if (auto S = dyn_cast<ELFYAML::SymtabShndxSection>(Sec)) {
       writeSectionContent(SHeader, *S, CBA);
@@ -1264,6 +1269,15 @@ void ELFState<ELFT>::writeSectionContent(
     SHeader.sh_info = *Section.Info;
 }
 
+template <class ELFT>
+void ELFState<ELFT>::writeSectionContent(
+    Elf_Shdr &SHeader, const ELFYAML::CustomRawContentSection &Section,
+    ContiguousBlobAccumulator &CBA) {
+  std::string Storage = Section.encode();
+  SHeader.sh_size = Storage.size();
+  CBA.write(Storage.data(), Storage.size());
+}
+
 static bool isMips64EL(const ELFYAML::Object &Obj) {
   return Obj.getMachine() == llvm::ELF::EM_MIPS &&
          Obj.Header.Class == ELFYAML::ELF_ELFCLASS(ELF::ELFCLASS64) &&
diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index 89ffc383a4a6e..7d06c2c32e23b 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -29,6 +29,9 @@ namespace llvm {
 
 ELFYAML::Chunk::~Chunk() = default;
 
+ELFYAML::Opt::~Opt() = default;
+const char ELFYAML::Opt::ID = 'E';
+
 namespace ELFYAML {
 ELF_ELFOSABI Object::getOSAbi() const { return Header.OSABI; }
 
@@ -1582,6 +1585,19 @@ static bool isInteger(StringRef Val) {
 
 void MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::mapping(
     IO &IO, std::unique_ptr<ELFYAML::Chunk> &Section) {
+  if (!IO.outputting()) {
+    /// Prepare CustomRawContentSection by Name for ELFEmitter.
+    if (auto *Opt = dyn_cast<ELFYAML::Opt>(IO.Opt)) {
+      StringRef Name;
+      IO.mapOptional("Name", Name);
+      if (auto S = Opt->makeCustomRawContentSection(Name)) {
+        S->sectionMapping(IO);
+        Section = std::move(S);
+        return;
+      }
+    }
+  }
+
   ELFYAML::ELF_SHT Type;
   StringRef TypeStr;
   if (IO.outputting()) {
@@ -1731,7 +1747,9 @@ void MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::mapping(
         Section = std::make_unique<ELFYAML::RawContentSection>();
     }
 
-    if (auto S = dyn_cast<ELFYAML::RawContentSection>(Section.get()))
+    if (auto S = dyn_cast<ELFYAML::CustomRawContentSection>(Section.get()))
+      S->sectionMapping(IO);
+    else if (auto S = dyn_cast<ELFYAML::RawContentSection>(Section.get()))
       sectionMapping(IO, *S);
     else
       sectionMapping(IO, *cast<ELFYAML::StackSizesSection>(Section.get()));
@@ -1981,6 +1999,8 @@ void MappingTraits<ELFYAML::ARMIndexTableEntry>::mapping(
 void MappingTraits<ELFYAML::Object>::mapping(IO &IO, ELFYAML::Object &Object) {
   assert(!IO.getContext() && "The IO context is initialized already");
   IO.setContext(&Object);
+  if (auto *Opt = dyn_cast<ELFYAML::Opt>(IO.Opt))
+    Opt->preMapping(Object, IO.outputting());
   IO.mapTag("!ELF", true);
   IO.mapRequired("FileHeader", Object.Header);
   IO.mapOptional("ProgramHeaders", Object.ProgramHeaders);
@@ -1994,6 +2014,8 @@ void MappingTraits<ELFYAML::Object>::mapping(IO &IO, ELFYAML::Object &Object) {
     Object.DWARF->Is64BitAddrSize =
         Object.Header.Class == ELFYAML::ELF_ELFCLASS(ELF::ELFCLASS64);
   }
+  if (auto *Opt = dyn_cast<ELFYAML::Opt>(IO.Opt))
+    Opt->postMapping(Object, IO.outputting());
   IO.setContext(nullptr);
 }
 
diff --git a/llvm/lib/Support/YAMLTraits.cpp b/llvm/lib/Support/YAMLTraits.cpp
index 56b557646100b..4c5d8d5a138aa 100644
--- a/llvm/lib/Support/YAMLTraits.cpp
+++ b/llvm/lib/Support/YAMLTraits.cpp
@@ -31,6 +31,14 @@
 using namespace llvm;
 using namespace yaml;
 
+//===----------------------------------------------------------------------===//
+//  Opt
+//===----------------------------------------------------------------------===//
+
+Opt::~Opt() = default;
+
+const char Opt::ID = '@';
+
 //===----------------------------------------------------------------------===//
 //  IO
 //===----------------------------------------------------------------------===//
diff --git a/llvm/tools/obj2yaml/elf2yaml.cpp b/llvm/tools/obj2yaml/elf2yaml.cpp
index 9b4644bde36c0..3b3fc0f9e8b3c 100644
--- a/llvm/tools/obj2yaml/elf2yaml.cpp
+++ b/llvm/tools/obj2yaml/elf2yaml.cpp
@@ -22,6 +22,19 @@
 using namespace llvm;
 
 namespace {
+class DumperOpt : public ELFYAML::Opt {
+public:
+  std::unique_ptr<ELFYAML::CustomRawContentSection>
+  makeCustomRawContentSection(StringRef Name) const override {
+    return nullptr;
+  }
+  void preMapping(const ELFYAML::Object &Object, bool IsOutputting) override {
+    // Do nothing.
+  }
+  void postMapping(const ELFYAML::Object &Object, bool IsOutputting) override {
+    // Do nothing.
+  }
+};
 
 template <class ELFT>
 class ELFDumper {
@@ -80,6 +93,8 @@ class ELFDumper {
   Expected<ELFYAML::RelrSection *> dumpRelrSection(const Elf_Shdr *Shdr);
   Expected<ELFYAML::RawContentSection *>
   dumpContentSection(const Elf_Shdr *Shdr);
+  Expected<ELFYAML::CustomRawContentSection *>
+  dumpCustomRawContentSection(const Elf_Shdr *Shdr);
   Expected<ELFYAML::SymtabShndxSection *>
   dumpSymtabShndxSection(const Elf_Shdr *Shdr);
   Expected<ELFYAML::NoBitsSection *> dumpNoBitsSection(const Elf_Shdr *Shdr);
@@ -104,6 +119,8 @@ class ELFDumper {
                           std::optional<DWARFYAML::Data> DWARF);
 
 public:
+  DumperOpt Opt;
+
   ELFDumper(const object::ELFFile<ELFT> &O, std::unique_ptr<DWARFContext> DCtx);
   Expected<ELFYAML::Object *> dump();
 };
@@ -657,6 +674,18 @@ ELFDumper<ELFT>::dumpSections() {
       if (!NameOrErr)
         return NameOrErr.takeError();
 
+      if (auto ResultOrErr = dumpCustomRawContentSection(&Sec)) {
+        auto *Ptr = *ResultOrErr;
+        if (Ptr) {
+          if (Error E = Add(Ptr))
+            return E;
+          continue;
+        } else {
+          // Do nothing -- nullptr
+        }
+      } else
+        return ResultOrErr.takeError();
+
       if (ELFYAML::StackSizesSection::nameMatches(*NameOrErr)) {
         if (Error E = Add(dumpStackSizesSection(&Sec)))
           return std::move(E);
@@ -1654,6 +1683,39 @@ ELFDumper<ELFT>::dumpMipsABIFlags(const Elf_Shdr *Shdr) {
   return S.release();
 }
 
+template <class ELFT>
+Expected<ELFYAML::CustomRawContentSection *>
+ELFDumper<ELFT>::dumpCustomRawContentSection(const Elf_Shdr *Shdr) {
+  Expected<StringRef> NameOrErr = getUniquedSectionName(*Shdr);
+  if (Error E = NameOrErr.takeError())
+    return nullptr;
+  auto Name = std::move(*NameOrErr);
+
+  auto S = Opt.makeCustomRawContentSection(Name);
+  if (!S)
+    return nullptr;
+
+  if (Error E = dumpCommonSection(Shdr, *S))
+    return std::move(E);
+
+  unsigned SecIndex = Shdr - &Sections[0];
+  if (SecIndex == 0 && Shdr->sh_type == ELF::SHT_NULL)
+    return nullptr;
+
+  auto ContentOrErr = Obj.getSectionContents(*Shdr);
+  if (!ContentOrErr)
+    return ContentOrErr.takeError();
+
+  ArrayRef<uint8_t> Content = *ContentOrErr;
+  if (Content.empty())
+    return nullptr;
+
+  S->Content = yaml::BinaryRef(Content);
+  if (Error E = S->decode(Content, Obj.isLE()))
+    return E;
+  return S.release();
+}
+
 template <class ELFT>
 static Error elf2yaml(raw_ostream &Out, const object::ELFFile<ELFT> &Obj,
                       std::unique_ptr<DWARFContext> DWARFCtx) {
@@ -1664,6 +1726,7 @@ static Error elf2yaml(raw_ostream &Out, const object::ELFFile<ELFT> &Obj,
 
   std::unique_ptr<ELFYAML::Object> YAML(YAMLOrErr.get());
   yaml::Output Yout(Out);
+  Yout.Opt = &Dumper.Opt;
   Yout << *YAML;
 
   return Error::success();
diff --git a/llvm/tools/yaml2obj/yaml2obj.cpp b/llvm/tools/yaml2obj/yaml2obj.cpp
index 4a060e1aad427..3d356dc7a006f 100644
--- a/llvm/tools/yaml2obj/yaml2obj.cpp
+++ b/llvm/tools/yaml2obj/yaml2obj.cpp
@@ -58,6 +58,20 @@ static cl::opt<uint64_t> MaxSize(
 cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"),
                                     cl::value_desc("filename"), cl::init("-"),
                                     cl::Prefix, cl::cat(Cat));
+
+class EmitterOpt : public ELFYAML::Opt {
+public:
+  std::unique_ptr<ELFYAML::CustomRawContentSection>
+  makeCustomRawContentSection(StringRef Name) const override {
+    return nullptr;
+  }
+  void preMapping(const ELFYAML::Object &Object, bool IsOutputting) override {
+    // Do nothing.
+  }
+  void postMapping(const ELFYAML::Object &Object, bool IsOutputting) override {
+    // Do nothing.
+  }
+};
 } // namespace
 
 static std::optional<std::string> preprocess(StringRef Buf,
@@ -142,7 +156,9 @@ int main(int argc, char **argv) {
   if (PreprocessOnly) {
     Out->os() << Buffer;
   } else {
+    EmitterOpt Opt;
     yaml::Input YIn(*Buffer);
+    YIn.Opt = &Opt;
 
     if (!convertYAML(YIn, Out->os(), ErrHandler, DocNum,
                      MaxSize == 0 ? UINT64_MAX : MaxSize))

From 94b13aa2e89ed269e6b996cf906d199d011863be Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Tue, 12 Nov 2024 23:48:52 +0900
Subject: [PATCH 2/7] Make CustomRaw more generic

---
 llvm/include/llvm/ObjectYAML/ELFYAML.h | 7 +------
 llvm/lib/ObjectYAML/ELFYAML.cpp        | 6 ++++--
 llvm/tools/obj2yaml/elf2yaml.cpp       | 1 -
 3 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/llvm/include/llvm/ObjectYAML/ELFYAML.h b/llvm/include/llvm/ObjectYAML/ELFYAML.h
index ee8ca11aa2ee6..0723c23a9beff 100644
--- a/llvm/include/llvm/ObjectYAML/ELFYAML.h
+++ b/llvm/include/llvm/ObjectYAML/ELFYAML.h
@@ -401,12 +401,7 @@ struct RawContentSection : Section {
 
 /// Abstract base class for non-blob contents.
 struct CustomRawContentSection : RawContentSection {
-  CustomRawContentSection() : RawContentSection(ChunkKind::CustomRawContent) {
-    // Type assumes PROGBITS.
-    Type = ELF::SHT_PROGBITS;
-    Flags = ELF::SHF_GNU_RETAIN;
-    AddressAlign = 1;
-  }
+  CustomRawContentSection() : RawContentSection(ChunkKind::CustomRawContent) {}
 
   /// Apply mappings.
   virtual void sectionMapping(yaml::IO &IO) = 0;
diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index 7d06c2c32e23b..aff2d5e18ce89 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -1591,6 +1591,7 @@ void MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::mapping(
       StringRef Name;
       IO.mapOptional("Name", Name);
       if (auto S = Opt->makeCustomRawContentSection(Name)) {
+        commonSectionMapping(IO, *S);
         S->sectionMapping(IO);
         Section = std::move(S);
         return;
@@ -1747,9 +1748,10 @@ void MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::mapping(
         Section = std::make_unique<ELFYAML::RawContentSection>();
     }
 
-    if (auto S = dyn_cast<ELFYAML::CustomRawContentSection>(Section.get()))
+    if (auto S = dyn_cast<ELFYAML::CustomRawContentSection>(Section.get())) {
+      commonSectionMapping(IO, *S);
       S->sectionMapping(IO);
-    else if (auto S = dyn_cast<ELFYAML::RawContentSection>(Section.get()))
+    } else if (auto S = dyn_cast<ELFYAML::RawContentSection>(Section.get()))
       sectionMapping(IO, *S);
     else
       sectionMapping(IO, *cast<ELFYAML::StackSizesSection>(Section.get()));
diff --git a/llvm/tools/obj2yaml/elf2yaml.cpp b/llvm/tools/obj2yaml/elf2yaml.cpp
index 3b3fc0f9e8b3c..7ef5db512b6bc 100644
--- a/llvm/tools/obj2yaml/elf2yaml.cpp
+++ b/llvm/tools/obj2yaml/elf2yaml.cpp
@@ -1710,7 +1710,6 @@ ELFDumper<ELFT>::dumpCustomRawContentSection(const Elf_Shdr *Shdr) {
   if (Content.empty())
     return nullptr;
 
-  S->Content = yaml::BinaryRef(Content);
   if (Error E = S->decode(Content, Obj.isLE()))
     return E;
   return S.release();

From eedb1bfb63d077a9c1dc333fe3bda32d6ff7359a Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Tue, 12 Nov 2024 23:49:34 +0900
Subject: [PATCH 3/7] Emit Content as the fallback

---
 llvm/lib/ObjectYAML/ELFEmitter.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index 09a540b048517..1c7297bf5f09f 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -1273,6 +1273,13 @@ template <class ELFT>
 void ELFState<ELFT>::writeSectionContent(
     Elf_Shdr &SHeader, const ELFYAML::CustomRawContentSection &Section,
     ContiguousBlobAccumulator &CBA) {
+  if (Section.Info)
+    SHeader.sh_info = *Section.Info;
+
+  // If Section has Content, emit it w/o encoding other fields.
+  if (Section.Content)
+    return;
+
   std::string Storage = Section.encode();
   SHeader.sh_size = Storage.size();
   CBA.write(Storage.data(), Storage.size());

From 4b47bb25feb84116315173293beecd8086220911 Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Tue, 12 Nov 2024 23:50:38 +0900
Subject: [PATCH 4/7] Make CustomRawContentSection sibling and independet from
 RawContentSection

---
 llvm/include/llvm/ObjectYAML/ELFYAML.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/llvm/include/llvm/ObjectYAML/ELFYAML.h b/llvm/include/llvm/ObjectYAML/ELFYAML.h
index 0723c23a9beff..30d83fcf1a158 100644
--- a/llvm/include/llvm/ObjectYAML/ELFYAML.h
+++ b/llvm/include/llvm/ObjectYAML/ELFYAML.h
@@ -389,7 +389,7 @@ struct DynamicSection : Section {
 struct RawContentSection : Section {
   std::optional<llvm::yaml::Hex64> Info;
 
-  RawContentSection(ChunkKind Kind = ChunkKind::RawContent) : Section(Kind) {}
+  RawContentSection() : Section(ChunkKind::RawContent) {}
 
   static bool classof(const Chunk *S) {
     return S->Kind == ChunkKind::RawContent;
@@ -400,8 +400,10 @@ struct RawContentSection : Section {
 };
 
 /// Abstract base class for non-blob contents.
-struct CustomRawContentSection : RawContentSection {
-  CustomRawContentSection() : RawContentSection(ChunkKind::CustomRawContent) {}
+struct CustomRawContentSection : Section {
+  std::optional<llvm::yaml::Hex64> Info;
+
+  CustomRawContentSection() : Section(ChunkKind::CustomRawContent) {}
 
   /// Apply mappings.
   virtual void sectionMapping(yaml::IO &IO) = 0;

From 6f449538308c796295e78931bc0e27cd6b979122 Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Thu, 14 Nov 2024 21:50:01 +0900
Subject: [PATCH 5/7] Move yaml::Opt to yaml::IO::OptBase [-fpermissive]

---
 llvm/include/llvm/ObjectYAML/ELFYAML.h | 14 +++++++-----
 llvm/include/llvm/Support/YAMLTraits.h | 31 ++++++++++++++------------
 llvm/lib/Support/YAMLTraits.cpp        |  6 ++---
 3 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/llvm/include/llvm/ObjectYAML/ELFYAML.h b/llvm/include/llvm/ObjectYAML/ELFYAML.h
index 30d83fcf1a158..983d9fe9c3320 100644
--- a/llvm/include/llvm/ObjectYAML/ELFYAML.h
+++ b/llvm/include/llvm/ObjectYAML/ELFYAML.h
@@ -788,11 +788,11 @@ bool shouldAllocateFileSpace(ArrayRef<ProgramHeader> Phdrs,
 ///
 /// Derivered classes should not modify OptClassID to ensue that
 /// dyn_cast<ELFYAML::Opt> can find this interface.
-class Opt : public yaml::Opt {
+class Opt : public yaml::IO::OptBase {
 public:
   Opt() {
+    OptBaseClassID = &ID;
     OptClassID = &ID;
-    ELFOptClassID = &ID;
   }
   ~Opt();
 
@@ -811,13 +811,15 @@ class Opt : public yaml::Opt {
   virtual void postMapping(const ELFYAML::Object &Object,
                            bool IsOutputting) = 0;
 
-  /// Tell IO::Opt to be this and derivered classes.
-  static bool classof(const yaml::Opt *Obj) { return (Obj->OptClassID == &ID); }
+  /// Tell IO::OptBase to be this and derivered classes.
+  static bool classof(const yaml::IO::OptBase *Obj) {
+    return (Obj->OptBaseClassID == &ID);
+  }
 
   /// This will be not needed unless the pointer to ELFYAML::Opt would
   /// be cast further.
-  static bool classof(const Opt *Obj) { return (Obj->ELFOptClassID == &ID); }
-  const char *ELFOptClassID;
+  static bool classof(const Opt *Obj) { return (Obj->OptClassID == &ID); }
+  const char *OptClassID;
 
 private:
   static const char ID;
diff --git a/llvm/include/llvm/Support/YAMLTraits.h b/llvm/include/llvm/Support/YAMLTraits.h
index 1f1e06a9e3773..2b16dd21c56b6 100644
--- a/llvm/include/llvm/Support/YAMLTraits.h
+++ b/llvm/include/llvm/Support/YAMLTraits.h
@@ -39,18 +39,6 @@ class VersionTuple;
 
 namespace yaml {
 
-/// The base class of options.
-class Opt {
-public:
-  virtual ~Opt();
-
-  static bool classof(const Opt *Obj) { return (Obj->OptClassID == &ID); }
-  const char *OptClassID = &ID;
-
-private:
-  static const char ID;
-};
-
 enum class NodeKind : uint8_t {
   Scalar,
   Map,
@@ -974,13 +962,28 @@ class IO {
     }
   }
 
+public:
+  /// The base class of options.
+  class OptBase {
+  public:
+    virtual ~OptBase();
+
+    static bool classof(const OptBase *Obj) {
+      return (Obj->OptBaseClassID == &ID);
+    }
+    const char *OptBaseClassID = &ID;
+
+  private:
+    static const char ID;
+  };
+
 private:
   void *Ctxt;
-  Opt DefaultOpt;
+  OptBase DefaultOpt;
 
 public:
   /// This may be overwritten in derivered classes.
-  Opt *Opt = &DefaultOpt;
+  OptBase *Opt = &DefaultOpt;
 };
 
 namespace detail {
diff --git a/llvm/lib/Support/YAMLTraits.cpp b/llvm/lib/Support/YAMLTraits.cpp
index 4c5d8d5a138aa..4b1c4b368d239 100644
--- a/llvm/lib/Support/YAMLTraits.cpp
+++ b/llvm/lib/Support/YAMLTraits.cpp
@@ -32,12 +32,12 @@ using namespace llvm;
 using namespace yaml;
 
 //===----------------------------------------------------------------------===//
-//  Opt
+//  IO::OptBase
 //===----------------------------------------------------------------------===//
 
-Opt::~Opt() = default;
+IO::OptBase::~OptBase() = default;
 
-const char Opt::ID = '@';
+const char IO::OptBase::ID = '@';
 
 //===----------------------------------------------------------------------===//
 //  IO

From 9f7a0c4524bd95f39ddde9c254920ba7dd13510a Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Thu, 14 Nov 2024 22:10:06 +0900
Subject: [PATCH 6/7] Make ELFYAML::Opt non-abstract

---
 llvm/include/llvm/ObjectYAML/ELFYAML.h | 12 ++++++------
 llvm/lib/ObjectYAML/ELFYAML.cpp        | 13 +++++++++++++
 llvm/tools/obj2yaml/elf2yaml.cpp       | 14 +-------------
 llvm/tools/yaml2obj/yaml2obj.cpp       | 14 +-------------
 4 files changed, 21 insertions(+), 32 deletions(-)

diff --git a/llvm/include/llvm/ObjectYAML/ELFYAML.h b/llvm/include/llvm/ObjectYAML/ELFYAML.h
index 983d9fe9c3320..59af9ac8851c0 100644
--- a/llvm/include/llvm/ObjectYAML/ELFYAML.h
+++ b/llvm/include/llvm/ObjectYAML/ELFYAML.h
@@ -778,8 +778,8 @@ struct Object {
 bool shouldAllocateFileSpace(ArrayRef<ProgramHeader> Phdrs,
                              const NoBitsSection &S);
 
-/// ELFYAML::Opt -- Abstract base class for ELFYAML to provide
-/// the interface for handling CustomRawConetentSection.
+/// ELFYAML::Opt -- Null base class for ELFYAML to provide the
+/// interface for handling CustomRawConetentSection.
 ///
 /// Users in ELFYAML should obtain the pointer with
 /// dyn_cast<ELFYAML::Opt> if IO::Opt is the instance from yaml::Opt.
@@ -801,15 +801,15 @@ class Opt : public yaml::IO::OptBase {
   /// This is called:
   ///   - Before preMapping for elf2yaml.
   ///   - After preMapping for yaml2elf.
+  /// Returns nullptr to delegate default actions.
   virtual std::unique_ptr<CustomRawContentSection>
-  makeCustomRawContentSection(StringRef Name) const = 0;
+  makeCustomRawContentSection(StringRef Name) const;
 
   /// Called before mapping sections for prettyprinting yaml.
-  virtual void preMapping(const ELFYAML::Object &Object, bool IsOutputting) = 0;
+  virtual void preMapping(const ELFYAML::Object &Object, bool IsOutputting);
 
   /// Called after mapping sections to gather members for the file format.
-  virtual void postMapping(const ELFYAML::Object &Object,
-                           bool IsOutputting) = 0;
+  virtual void postMapping(const ELFYAML::Object &Object, bool IsOutputting);
 
   /// Tell IO::OptBase to be this and derivered classes.
   static bool classof(const yaml::IO::OptBase *Obj) {
diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index aff2d5e18ce89..83ee88e57d66b 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -32,6 +32,19 @@ ELFYAML::Chunk::~Chunk() = default;
 ELFYAML::Opt::~Opt() = default;
 const char ELFYAML::Opt::ID = 'E';
 
+std::unique_ptr<ELFYAML::CustomRawContentSection>
+ELFYAML::Opt::makeCustomRawContentSection(StringRef Name) const {
+  return nullptr;
+}
+
+/// Called before mapping sections for prettyprinting yaml.
+void ELFYAML::Opt::preMapping(const ELFYAML::Object &Object,
+                              bool IsOutputting) {}
+
+/// Called after mapping sections to gather members for the file format.
+void ELFYAML::Opt::postMapping(const ELFYAML::Object &Object,
+                               bool IsOutputting) {}
+
 namespace ELFYAML {
 ELF_ELFOSABI Object::getOSAbi() const { return Header.OSABI; }
 
diff --git a/llvm/tools/obj2yaml/elf2yaml.cpp b/llvm/tools/obj2yaml/elf2yaml.cpp
index 7ef5db512b6bc..d3fbe9c2d17c1 100644
--- a/llvm/tools/obj2yaml/elf2yaml.cpp
+++ b/llvm/tools/obj2yaml/elf2yaml.cpp
@@ -22,19 +22,7 @@
 using namespace llvm;
 
 namespace {
-class DumperOpt : public ELFYAML::Opt {
-public:
-  std::unique_ptr<ELFYAML::CustomRawContentSection>
-  makeCustomRawContentSection(StringRef Name) const override {
-    return nullptr;
-  }
-  void preMapping(const ELFYAML::Object &Object, bool IsOutputting) override {
-    // Do nothing.
-  }
-  void postMapping(const ELFYAML::Object &Object, bool IsOutputting) override {
-    // Do nothing.
-  }
-};
+struct DumperOpt : public ELFYAML::Opt {};
 
 template <class ELFT>
 class ELFDumper {
diff --git a/llvm/tools/yaml2obj/yaml2obj.cpp b/llvm/tools/yaml2obj/yaml2obj.cpp
index 3d356dc7a006f..b899b8d7cdf2c 100644
--- a/llvm/tools/yaml2obj/yaml2obj.cpp
+++ b/llvm/tools/yaml2obj/yaml2obj.cpp
@@ -59,19 +59,7 @@ cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"),
                                     cl::value_desc("filename"), cl::init("-"),
                                     cl::Prefix, cl::cat(Cat));
 
-class EmitterOpt : public ELFYAML::Opt {
-public:
-  std::unique_ptr<ELFYAML::CustomRawContentSection>
-  makeCustomRawContentSection(StringRef Name) const override {
-    return nullptr;
-  }
-  void preMapping(const ELFYAML::Object &Object, bool IsOutputting) override {
-    // Do nothing.
-  }
-  void postMapping(const ELFYAML::Object &Object, bool IsOutputting) override {
-    // Do nothing.
-  }
-};
+struct EmitterOpt : public ELFYAML::Opt {};
 } // namespace
 
 static std::optional<std::string> preprocess(StringRef Buf,

From 67df0dc3bac0462137d34bc2cdb315634a2dae97 Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Thu, 14 Nov 2024 22:11:07 +0900
Subject: [PATCH 7/7] s/CustomRawContentSection/CustomSection/

---
 llvm/include/llvm/ObjectYAML/ELFYAML.h | 14 +++++++-------
 llvm/lib/ObjectYAML/ELFEmitter.cpp     | 10 +++++-----
 llvm/lib/ObjectYAML/ELFYAML.cpp        | 10 +++++-----
 llvm/tools/obj2yaml/elf2yaml.cpp       | 11 +++++------
 4 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/llvm/include/llvm/ObjectYAML/ELFYAML.h b/llvm/include/llvm/ObjectYAML/ELFYAML.h
index 59af9ac8851c0..38497c813c0fa 100644
--- a/llvm/include/llvm/ObjectYAML/ELFYAML.h
+++ b/llvm/include/llvm/ObjectYAML/ELFYAML.h
@@ -211,7 +211,7 @@ struct Chunk {
     Dynamic,
     Group,
     RawContent,
-    CustomRawContent,
+    CustomContent,
     Relocation,
     Relr,
     NoBits,
@@ -400,10 +400,10 @@ struct RawContentSection : Section {
 };
 
 /// Abstract base class for non-blob contents.
-struct CustomRawContentSection : Section {
+struct CustomSection : Section {
   std::optional<llvm::yaml::Hex64> Info;
 
-  CustomRawContentSection() : Section(ChunkKind::CustomRawContent) {}
+  CustomSection() : Section(ChunkKind::CustomContent) {}
 
   /// Apply mappings.
   virtual void sectionMapping(yaml::IO &IO) = 0;
@@ -415,7 +415,7 @@ struct CustomRawContentSection : Section {
   virtual std::string encode() const = 0;
 
   static bool classof(const Chunk *S) {
-    return S->Kind == ChunkKind::CustomRawContent;
+    return S->Kind == ChunkKind::CustomContent;
   }
 };
 
@@ -796,14 +796,14 @@ class Opt : public yaml::IO::OptBase {
   }
   ~Opt();
 
-  /// Create an empty new object of CustomRawContentSection.
+  /// Create an empty new object of CustomSection.
   /// Its contents will be filled later.
   /// This is called:
   ///   - Before preMapping for elf2yaml.
   ///   - After preMapping for yaml2elf.
   /// Returns nullptr to delegate default actions.
-  virtual std::unique_ptr<CustomRawContentSection>
-  makeCustomRawContentSection(StringRef Name) const;
+  virtual std::unique_ptr<CustomSection>
+  makeCustomSection(StringRef Name) const;
 
   /// Called before mapping sections for prettyprinting yaml.
   virtual void preMapping(const ELFYAML::Object &Object, bool IsOutputting);
diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index 1c7297bf5f09f..f70f9e5601403 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -252,7 +252,7 @@ template <class ELFT> class ELFState {
                            const ELFYAML::NoBitsSection &Section,
                            ContiguousBlobAccumulator &CBA);
   void writeSectionContent(Elf_Shdr &SHeader,
-                           const ELFYAML::CustomRawContentSection &Section,
+                           const ELFYAML::CustomSection &Section,
                            ContiguousBlobAccumulator &CBA);
   void writeSectionContent(Elf_Shdr &SHeader,
                            const ELFYAML::RawContentSection &Section,
@@ -862,7 +862,7 @@ void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
     if (!isa<ELFYAML::NoBitsSection>(Sec) && (Sec->Content || Sec->Size))
       SHeader.sh_size = writeContent(CBA, Sec->Content, Sec->Size);
 
-    if (auto S = dyn_cast<ELFYAML::CustomRawContentSection>(Sec)) {
+    if (auto S = dyn_cast<ELFYAML::CustomSection>(Sec)) {
       writeSectionContent(SHeader, *S, CBA);
     } else if (auto S = dyn_cast<ELFYAML::RawContentSection>(Sec)) {
       writeSectionContent(SHeader, *S, CBA);
@@ -1270,9 +1270,9 @@ void ELFState<ELFT>::writeSectionContent(
 }
 
 template <class ELFT>
-void ELFState<ELFT>::writeSectionContent(
-    Elf_Shdr &SHeader, const ELFYAML::CustomRawContentSection &Section,
-    ContiguousBlobAccumulator &CBA) {
+void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
+                                         const ELFYAML::CustomSection &Section,
+                                         ContiguousBlobAccumulator &CBA) {
   if (Section.Info)
     SHeader.sh_info = *Section.Info;
 
diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index 83ee88e57d66b..3f73637929cad 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -32,8 +32,8 @@ ELFYAML::Chunk::~Chunk() = default;
 ELFYAML::Opt::~Opt() = default;
 const char ELFYAML::Opt::ID = 'E';
 
-std::unique_ptr<ELFYAML::CustomRawContentSection>
-ELFYAML::Opt::makeCustomRawContentSection(StringRef Name) const {
+std::unique_ptr<ELFYAML::CustomSection>
+ELFYAML::Opt::makeCustomSection(StringRef Name) const {
   return nullptr;
 }
 
@@ -1599,11 +1599,11 @@ static bool isInteger(StringRef Val) {
 void MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::mapping(
     IO &IO, std::unique_ptr<ELFYAML::Chunk> &Section) {
   if (!IO.outputting()) {
-    /// Prepare CustomRawContentSection by Name for ELFEmitter.
+    /// Prepare CustomSection by Name for ELFEmitter.
     if (auto *Opt = dyn_cast<ELFYAML::Opt>(IO.Opt)) {
       StringRef Name;
       IO.mapOptional("Name", Name);
-      if (auto S = Opt->makeCustomRawContentSection(Name)) {
+      if (auto S = Opt->makeCustomSection(Name)) {
         commonSectionMapping(IO, *S);
         S->sectionMapping(IO);
         Section = std::move(S);
@@ -1761,7 +1761,7 @@ void MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::mapping(
         Section = std::make_unique<ELFYAML::RawContentSection>();
     }
 
-    if (auto S = dyn_cast<ELFYAML::CustomRawContentSection>(Section.get())) {
+    if (auto S = dyn_cast<ELFYAML::CustomSection>(Section.get())) {
       commonSectionMapping(IO, *S);
       S->sectionMapping(IO);
     } else if (auto S = dyn_cast<ELFYAML::RawContentSection>(Section.get()))
diff --git a/llvm/tools/obj2yaml/elf2yaml.cpp b/llvm/tools/obj2yaml/elf2yaml.cpp
index d3fbe9c2d17c1..8567de489a0bf 100644
--- a/llvm/tools/obj2yaml/elf2yaml.cpp
+++ b/llvm/tools/obj2yaml/elf2yaml.cpp
@@ -81,8 +81,7 @@ class ELFDumper {
   Expected<ELFYAML::RelrSection *> dumpRelrSection(const Elf_Shdr *Shdr);
   Expected<ELFYAML::RawContentSection *>
   dumpContentSection(const Elf_Shdr *Shdr);
-  Expected<ELFYAML::CustomRawContentSection *>
-  dumpCustomRawContentSection(const Elf_Shdr *Shdr);
+  Expected<ELFYAML::CustomSection *> dumpCustomSection(const Elf_Shdr *Shdr);
   Expected<ELFYAML::SymtabShndxSection *>
   dumpSymtabShndxSection(const Elf_Shdr *Shdr);
   Expected<ELFYAML::NoBitsSection *> dumpNoBitsSection(const Elf_Shdr *Shdr);
@@ -662,7 +661,7 @@ ELFDumper<ELFT>::dumpSections() {
       if (!NameOrErr)
         return NameOrErr.takeError();
 
-      if (auto ResultOrErr = dumpCustomRawContentSection(&Sec)) {
+      if (auto ResultOrErr = dumpCustomSection(&Sec)) {
         auto *Ptr = *ResultOrErr;
         if (Ptr) {
           if (Error E = Add(Ptr))
@@ -1672,14 +1671,14 @@ ELFDumper<ELFT>::dumpMipsABIFlags(const Elf_Shdr *Shdr) {
 }
 
 template <class ELFT>
-Expected<ELFYAML::CustomRawContentSection *>
-ELFDumper<ELFT>::dumpCustomRawContentSection(const Elf_Shdr *Shdr) {
+Expected<ELFYAML::CustomSection *>
+ELFDumper<ELFT>::dumpCustomSection(const Elf_Shdr *Shdr) {
   Expected<StringRef> NameOrErr = getUniquedSectionName(*Shdr);
   if (Error E = NameOrErr.takeError())
     return nullptr;
   auto Name = std::move(*NameOrErr);
 
-  auto S = Opt.makeCustomRawContentSection(Name);
+  auto S = Opt.makeCustomSection(Name);
   if (!S)
     return nullptr;