[XCOFF] Add functionality for parsing AIX XCOFF object file headers

Summary:
1. Add functionality for parsing AIX XCOFF object files headers.
2. Only support 32-bit AIX XCOFF object files in this patch.
3. Print out the AIX XCOFF object file header in YAML format.

Reviewers: sfertile, hubert.reinterpretcast, jasonliu, mstorsjo, zturner, rnk

Reviewed By: sfertile, hubert.reinterpretcast

Subscribers: jsji, mgorny, hiraditya, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59419

Patch by Digger Lin


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357663 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/BinaryFormat/Magic.h

@@ -45,6 +45,7 @@ struct file_magic {
     coff_import_library, ///< COFF import library
     pecoff_executable,   ///< PECOFF executable file
     windows_resource,    ///< Windows compiled resource file (.res)
+    xcoff_object_32,     ///< 32-bit XCOFF object file
     wasm_object,         ///< WebAssembly Object file
     pdb,                 ///< Windows PDB debug info file
   };

include/llvm/Object/Binary.h

@@ -50,6 +50,7 @@ protected:
     // Object and children.
     ID_StartObjects,
     ID_COFF,
+    ID_XCOFF32, // AIX XCOFF 32-bit
 
     ID_ELF32L, // ELF 32-bit, little endian
     ID_ELF32B, // ELF 32-bit, big endian
@@ -119,6 +120,8 @@ public:
     return TypeID == ID_COFF;
   }
 
+  bool isXCOFF() const { return TypeID == ID_XCOFF32; }
+
   bool isWasm() const { return TypeID == ID_Wasm; }
 
   bool isCOFFImportFile() const {

include/llvm/Object/ObjectFile.h

@@ -363,6 +363,9 @@ public:
   static Expected<std::unique_ptr<COFFObjectFile>>
   createCOFFObjectFile(MemoryBufferRef Object);
 
+  static Expected<std::unique_ptr<ObjectFile>>
+  createXCOFFObjectFile(MemoryBufferRef Object);
+
   static Expected<std::unique_ptr<ObjectFile>>
   createELFObjectFile(MemoryBufferRef Object);
 

include/llvm/Object/XCOFFObjectFile.h

@@ -0,0 +1,110 @@
+//===- XCOFFObjectFile.h - XCOFF object file implementation -----*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the XCOFFObjectFile class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_OBJECT_XCOFFOBJECTFILE_H
+#define LLVM_OBJECT_XCOFFOBJECTFILE_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/iterator_range.h"
+#include "llvm/BinaryFormat/Magic.h"
+#include "llvm/MC/SubtargetFeature.h"
+#include "llvm/Object/Binary.h"
+#include "llvm/Object/Error.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Object/SymbolicFile.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include <cassert>
+#include <cstdint>
+#include <memory>
+#include <system_error>
+
+namespace llvm {
+namespace object {
+
+struct XCOFFFileHeader {
+  support::ubig16_t Magic;
+  support::ubig16_t NumberOfSections;
+
+  // Unix time value, value of 0 indicates no timestamp.
+  // Negative values are reserved.
+  support::big32_t TimeStamp;
+
+  support::ubig32_t SymbolTableOffset; // File offset to symbol table.
+  support::big32_t NumberOfSymTableEntries;
+  support::ubig16_t AuxHeaderSize;
+  support::ubig16_t Flags;
+};
+
+class XCOFFObjectFile : public ObjectFile {
+private:
+  const XCOFFFileHeader *FileHdrPtr = nullptr;
+
+public:
+  void moveSymbolNext(DataRefImpl &Symb) const override;
+  uint32_t getSymbolFlags(DataRefImpl Symb) const override;
+  basic_symbol_iterator symbol_begin() const override;
+  basic_symbol_iterator symbol_end() const override;
+
+  Expected<StringRef> getSymbolName(DataRefImpl Symb) const override;
+  Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override;
+  uint64_t getSymbolValueImpl(DataRefImpl Symb) const override;
+  uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override;
+  Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override;
+  Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override;
+
+  void moveSectionNext(DataRefImpl &Sec) const override;
+  std::error_code getSectionName(DataRefImpl Sec,
+                                 StringRef &Res) const override;
+  uint64_t getSectionAddress(DataRefImpl Sec) const override;
+  uint64_t getSectionIndex(DataRefImpl Sec) const override;
+  uint64_t getSectionSize(DataRefImpl Sec) const override;
+  std::error_code getSectionContents(DataRefImpl Sec,
+                                     StringRef &Res) const override;
+  uint64_t getSectionAlignment(DataRefImpl Sec) const override;
+  bool isSectionCompressed(DataRefImpl Sec) const override;
+  bool isSectionText(DataRefImpl Sec) const override;
+  bool isSectionData(DataRefImpl Sec) const override;
+  bool isSectionBSS(DataRefImpl Sec) const override;
+
+  bool isSectionVirtual(DataRefImpl Sec) const override;
+  relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
+  relocation_iterator section_rel_end(DataRefImpl Sec) const override;
+
+  void moveRelocationNext(DataRefImpl &Rel) const override;
+  uint64_t getRelocationOffset(DataRefImpl Rel) const override;
+  symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override;
+  uint64_t getRelocationType(DataRefImpl Rel) const override;
+  void getRelocationTypeName(DataRefImpl Rel,
+                             SmallVectorImpl<char> &Result) const override;
+
+  section_iterator section_begin() const override;
+  section_iterator section_end() const override;
+  uint8_t getBytesInAddress() const override;
+  StringRef getFileFormatName() const override;
+  Triple::ArchType getArch() const override;
+  SubtargetFeatures getFeatures() const override;
+  bool isRelocatableObject() const override;
+
+public:
+  XCOFFObjectFile(MemoryBufferRef Object, std::error_code &EC);
+
+  const XCOFFFileHeader *getFileHeader() const { return FileHdrPtr; }
+
+}; // XCOFFObjectFile
+
+} // namespace object
+} // namespace llvm
+
+#endif // LLVM_OBJECT_XCOFFOBJECTFILE_H

include/llvm/ObjectYAML/XCOFFYAML.h

@@ -0,0 +1,50 @@
+//===----- XCOFFYAML.h - XCOFF YAMLIO implementation ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares classes for handling the YAML representation of XCOFF.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_OBJECTYAML_XCOFFYAML_H
+#define LLVM_OBJECTYAML_XCOFFYAML_H
+
+#include "llvm/ObjectYAML/YAML.h"
+#include <cstdint>
+
+namespace llvm {
+namespace XCOFFYAML {
+
+struct FileHeader {
+  llvm::yaml::Hex16 Magic;
+  uint16_t NumberOfSections;
+  int32_t TimeStamp;
+  llvm::yaml::Hex32 SymbolTableOffset; // File offset to symbol table.
+  int32_t NumberOfSymTableEntries;
+  uint16_t AuxHeaderSize;
+  llvm::yaml::Hex16 Flags;
+};
+
+struct Object {
+  FileHeader Header;
+  Object();
+};
+} // namespace XCOFFYAML
+
+namespace yaml {
+
+template <> struct MappingTraits<XCOFFYAML::FileHeader> {
+  static void mapping(IO &IO, XCOFFYAML::FileHeader &H);
+};
+
+template <> struct MappingTraits<XCOFFYAML::Object> {
+  static void mapping(IO &IO, XCOFFYAML::Object &Obj);
+};
+
+} // namespace yaml
+} // namespace llvm
+
+#endif // LLVM_OBJECTYAML_XCOFFYAML_H

lib/BinaryFormat/Magic.cpp

@@ -61,6 +61,13 @@ file_magic llvm::identify_magic(StringRef Magic) {
       return file_magic::wasm_object;
     break;
   }
+
+  case 0x01:
+    // XCOFF format
+    if (startswith(Magic, "\x01\xDF"))
+      return file_magic::xcoff_object_32;
+    break;
+
   case 0xDE: // 0x0B17C0DE = BC wraper
     if (startswith(Magic, "\xDE\xC0\x17\x0B"))
       return file_magic::bitcode;

lib/Object/Binary.cpp

@@ -69,6 +69,7 @@ Expected<std::unique_ptr<Binary>> object::createBinary(MemoryBufferRef Buffer,
   case file_magic::coff_import_library:
   case file_magic::pecoff_executable:
   case file_magic::bitcode:
+  case file_magic::xcoff_object_32:
   case file_magic::wasm_object:
     return ObjectFile::createSymbolicFile(Buffer, Type, Context);
   case file_magic::macho_universal_binary:

lib/Object/CMakeLists.txt

@@ -23,6 +23,7 @@ add_llvm_library(LLVMObject
   SymbolSize.cpp
   WasmObjectFile.cpp
   WindowsResource.cpp
+  XCOFFObjectFile.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/Object

lib/Object/ObjectFile.cpp

@@ -151,6 +151,8 @@ ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type) {
   case file_magic::coff_import_library:
   case file_magic::pecoff_executable:
     return createCOFFObjectFile(Object);
+  case file_magic::xcoff_object_32:
+    return createXCOFFObjectFile(Object);
   case file_magic::wasm_object:
     return createWasmObjectFile(Object);
   }

lib/Object/SymbolicFile.cpp

@@ -69,6 +69,7 @@ SymbolicFile::createSymbolicFile(MemoryBufferRef Object, file_magic Type,
   case file_magic::macho_dsym_companion:
   case file_magic::macho_kext_bundle:
   case file_magic::pecoff_executable:
+  case file_magic::xcoff_object_32:
   case file_magic::wasm_object:
     return ObjectFile::createObjectFile(Object, Type);
   case file_magic::coff_import_library:

lib/Object/XCOFFObjectFile.cpp

@@ -0,0 +1,270 @@
+//===--- XCOFFObjectFile.cpp - XCOFF object file implementation -----------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the XCOFFObjectFile class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Object/XCOFFObjectFile.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/Support/BinaryStreamReader.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MathExtras.h"
+#include <cstddef>
+#include <cstring>
+
+namespace llvm {
+namespace object {
+
+// Sets Obj unless any bytes in [addr, addr + size) fall outsize of m.
+// Returns unexpected_eof on error.
+template <typename T>
+static std::error_code getObject(const T *&Obj, MemoryBufferRef M,
+                                 const void *Ptr,
+                                 const uint64_t Size = sizeof(T)) {
+  uintptr_t Addr = uintptr_t(Ptr);
+  if (std::error_code EC = Binary::checkOffset(M, Addr, Size))
+    return EC;
+  Obj = reinterpret_cast<const T *>(Addr);
+  return std::error_code();
+}
+
+void XCOFFObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
+  llvm_unreachable("Not yet implemented!");
+  return;
+}
+
+Expected<StringRef> XCOFFObjectFile::getSymbolName(DataRefImpl Symb) const {
+  StringRef Result;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+Expected<uint64_t> XCOFFObjectFile::getSymbolAddress(DataRefImpl Symb) const {
+  uint64_t Result = 0;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+uint64_t XCOFFObjectFile::getSymbolValueImpl(DataRefImpl Symb) const {
+  uint64_t Result = 0;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+uint64_t XCOFFObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const {
+  uint64_t Result = 0;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+Expected<SymbolRef::Type>
+XCOFFObjectFile::getSymbolType(DataRefImpl Symb) const {
+  llvm_unreachable("Not yet implemented!");
+  return SymbolRef::ST_Other;
+}
+
+Expected<section_iterator>
+XCOFFObjectFile::getSymbolSection(DataRefImpl Symb) const {
+  llvm_unreachable("Not yet implemented!");
+  return section_iterator(SectionRef());
+}
+
+void XCOFFObjectFile::moveSectionNext(DataRefImpl &Sec) const {
+  llvm_unreachable("Not yet implemented!");
+  return;
+}
+
+std::error_code XCOFFObjectFile::getSectionName(DataRefImpl Sec,
+                                                StringRef &Res) const {
+  llvm_unreachable("Not yet implemented!");
+  return std::error_code();
+}
+
+uint64_t XCOFFObjectFile::getSectionAddress(DataRefImpl Sec) const {
+  uint64_t Result = 0;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+uint64_t XCOFFObjectFile::getSectionIndex(DataRefImpl Sec) const {
+  uint64_t Result = 0;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+uint64_t XCOFFObjectFile::getSectionSize(DataRefImpl Sec) const {
+  uint64_t Result = 0;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+std::error_code XCOFFObjectFile::getSectionContents(DataRefImpl Sec,
+                                                    StringRef &Res) const {
+  llvm_unreachable("Not yet implemented!");
+  return std::error_code();
+}
+
+uint64_t XCOFFObjectFile::getSectionAlignment(DataRefImpl Sec) const {
+  uint64_t Result = 0;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+bool XCOFFObjectFile::isSectionCompressed(DataRefImpl Sec) const {
+  bool Result = false;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+bool XCOFFObjectFile::isSectionText(DataRefImpl Sec) const {
+  bool Result = false;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+bool XCOFFObjectFile::isSectionData(DataRefImpl Sec) const {
+  bool Result = false;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+bool XCOFFObjectFile::isSectionBSS(DataRefImpl Sec) const {
+  bool Result = false;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+bool XCOFFObjectFile::isSectionVirtual(DataRefImpl Sec) const {
+  bool Result = false;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+relocation_iterator XCOFFObjectFile::section_rel_begin(DataRefImpl Sec) const {
+  llvm_unreachable("Not yet implemented!");
+  return relocation_iterator(RelocationRef());
+}
+
+relocation_iterator XCOFFObjectFile::section_rel_end(DataRefImpl Sec) const {
+  llvm_unreachable("Not yet implemented!");
+  return relocation_iterator(RelocationRef());
+}
+
+void XCOFFObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
+  llvm_unreachable("Not yet implemented!");
+  return;
+}
+
+uint64_t XCOFFObjectFile::getRelocationOffset(DataRefImpl Rel) const {
+  llvm_unreachable("Not yet implemented!");
+  uint64_t Result = 0;
+  return Result;
+}
+
+symbol_iterator XCOFFObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
+  llvm_unreachable("Not yet implemented!");
+  return symbol_iterator(SymbolRef());
+}
+
+uint64_t XCOFFObjectFile::getRelocationType(DataRefImpl Rel) const {
+  llvm_unreachable("Not yet implemented!");
+  uint64_t Result = 0;
+  return Result;
+}
+
+void XCOFFObjectFile::getRelocationTypeName(
+    DataRefImpl Rel, SmallVectorImpl<char> &Result) const {
+  llvm_unreachable("Not yet implemented!");
+  return;
+}
+
+uint32_t XCOFFObjectFile::getSymbolFlags(DataRefImpl Symb) const {
+  uint32_t Result = 0;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+basic_symbol_iterator XCOFFObjectFile::symbol_begin() const {
+  llvm_unreachable("Not yet implemented!");
+  return basic_symbol_iterator(SymbolRef());
+}
+
+basic_symbol_iterator XCOFFObjectFile::symbol_end() const {
+  llvm_unreachable("Not yet implemented!");
+  return basic_symbol_iterator(SymbolRef());
+}
+
+section_iterator XCOFFObjectFile::section_begin() const {
+  llvm_unreachable("Not yet implemented!");
+  return section_iterator(SectionRef());
+}
+
+section_iterator XCOFFObjectFile::section_end() const {
+  llvm_unreachable("Not yet implemented!");
+  return section_iterator(SectionRef());
+}
+
+uint8_t XCOFFObjectFile::getBytesInAddress() const {
+  uint8_t Result = 0;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+StringRef XCOFFObjectFile::getFileFormatName() const {
+  llvm_unreachable("Not yet implemented!");
+  return "";
+}
+
+Triple::ArchType XCOFFObjectFile::getArch() const {
+  llvm_unreachable("Not yet implemented!");
+  return Triple::UnknownArch;
+}
+
+SubtargetFeatures XCOFFObjectFile::getFeatures() const {
+  llvm_unreachable("Not yet implemented!");
+  return SubtargetFeatures();
+}
+
+bool XCOFFObjectFile::isRelocatableObject() const {
+  bool Result = false;
+  llvm_unreachable("Not yet implemented!");
+  return Result;
+}
+
+XCOFFObjectFile::XCOFFObjectFile(MemoryBufferRef Object, std::error_code &EC)
+    : ObjectFile(Binary::ID_XCOFF32, Object) {
+
+  // Current location within the file.
+  uint64_t CurPtr = 0;
+
+  if ((EC = getObject(FileHdrPtr, Data, base() + CurPtr)))
+    return;
+}
+
+Expected<std::unique_ptr<ObjectFile>>
+ObjectFile::createXCOFFObjectFile(MemoryBufferRef Object) {
+  StringRef Data = Object.getBuffer();
+  file_magic Type = identify_magic(Data);
+  std::error_code EC;
+  std::unique_ptr<ObjectFile> Ret;
+
+  if (Type == file_magic::xcoff_object_32) {
+    Ret.reset(new XCOFFObjectFile(Object, EC));
+  } else {
+    llvm_unreachable("Encountered an unexpected binary file type!");
+  }
+
+  if (EC)
+    return errorCodeToError(EC);
+  return std::move(Ret);
+}
+
+} // namespace object
+} // namespace llvm

lib/ObjectYAML/CMakeLists.txt

@@ -12,5 +12,6 @@ add_llvm_library(LLVMObjectYAML
   ObjectYAML.cpp
   MinidumpYAML.cpp
   WasmYAML.cpp
+  XCOFFYAML.cpp
   YAML.cpp
   )

lib/ObjectYAML/XCOFFYAML.cpp

@@ -0,0 +1,42 @@
+//===-- XCOFFYAML.cpp - XCOFF YAMLIO implementation -------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines classes for handling the YAML representation of XCOFF.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ObjectYAML/XCOFFYAML.h"
+#include <string.h>
+
+namespace llvm {
+namespace XCOFFYAML {
+
+Object::Object() { memset(&Header, 0, sizeof(Header)); }
+
+} // namespace XCOFFYAML
+
+namespace yaml {
+
+void MappingTraits<XCOFFYAML::FileHeader>::mapping(
+    IO &IO, XCOFFYAML::FileHeader &FileHdr) {
+  IO.mapRequired("MagicNumber", FileHdr.Magic);
+  IO.mapRequired("NumberOfSections", FileHdr.NumberOfSections);
+  IO.mapRequired("CreationTime", FileHdr.TimeStamp);
+  IO.mapRequired("OffsetToSymbolTable", FileHdr.SymbolTableOffset);
+  IO.mapRequired("EntriesInSymbolTable", FileHdr.NumberOfSymTableEntries);
+  IO.mapRequired("AuxiliaryHeaderSize", FileHdr.AuxHeaderSize);
+  IO.mapRequired("Flags", FileHdr.Flags);
+}
+
+void MappingTraits<XCOFFYAML::Object>::mapping(IO &IO, XCOFFYAML::Object &Obj) {
+  IO.mapTag("!XCOFF", true);
+  IO.mapRequired("FileHeader", Obj.Header);
+}
+
+} // namespace yaml
+} // namespace llvm

test/tools/obj2yaml/aix_xcoff.test

@@ -0,0 +1,11 @@
+# RUN: obj2yaml %S/Inputs/aix_xcoff.o | FileCheck %s
+# Test that we can parse the XCOFF object file correctly.
+# CHECK: --- !XCOFF
+# CHECK-NEXT: FileHeader:
+# CHECK-NEXT: MagicNumber:     0x01DF
+# CHECK-NEXT: NumberOfSections: 2
+# CHECK-NEXT: CreationTime:    1548692020
+# CHECK-NEXT: OffsetToSymbolTable: 0x00000108
+# CHECK-NEXT: EntriesInSymbolTable: 18
+# CHECK-NEXT: AuxiliaryHeaderSize: 0
+# CHECK-NEXT: Flags:           0x0000

test/tools/obj2yaml/aix_xcoff_truncated_file_header.test

@@ -0,0 +1,2 @@
+# RUN: not obj2yaml %S/Inputs/aix_xcoff_truncated_file_header.o 2>&1 | FileCheck %s
+# CHECK: The end of the file was unexpectedly encountered

tools/obj2yaml/CMakeLists.txt

@@ -14,6 +14,7 @@ add_llvm_tool(obj2yaml
   elf2yaml.cpp
   macho2yaml.cpp
   minidump2yaml.cpp
+  xcoff2yaml.cpp
   wasm2yaml.cpp
   Error.cpp
   )

tools/obj2yaml/obj2yaml.cpp

@@ -20,6 +20,10 @@ using namespace llvm::object;
 static std::error_code dumpObject(const ObjectFile &Obj) {
   if (Obj.isCOFF())
     return coff2yaml(outs(), cast<COFFObjectFile>(Obj));
+
+  if (Obj.isXCOFF())
+    return xcoff2yaml(outs(), cast<XCOFFObjectFile>(Obj));
+
   if (Obj.isELF())
     return elf2yaml(outs(), Obj);
   if (Obj.isWasm())

tools/obj2yaml/obj2yaml.h

@@ -15,6 +15,7 @@
 #include "llvm/Object/COFF.h"
 #include "llvm/Object/Minidump.h"
 #include "llvm/Object/Wasm.h"
+#include "llvm/Object/XCOFFObjectFile.h"
 #include "llvm/Support/raw_ostream.h"
 #include <system_error>
 
@@ -26,6 +27,8 @@ std::error_code macho2yaml(llvm::raw_ostream &Out,
                            const llvm::object::Binary &Obj);
 llvm::Error minidump2yaml(llvm::raw_ostream &Out,
                           const llvm::object::MinidumpFile &Obj);
+std::error_code xcoff2yaml(llvm::raw_ostream &Out,
+                           const llvm::object::XCOFFObjectFile &Obj);
 std::error_code wasm2yaml(llvm::raw_ostream &Out,
                           const llvm::object::WasmObjectFile &Obj);
 

tools/obj2yaml/xcoff2yaml.cpp

@@ -0,0 +1,52 @@
+//===------ xcoff2yaml.cpp - XCOFF YAMLIO implementation --------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "obj2yaml.h"
+#include "llvm/Object/XCOFFObjectFile.h"
+#include "llvm/ObjectYAML/XCOFFYAML.h"
+#include "llvm/Support/YAMLTraits.h"
+
+using namespace llvm;
+using namespace llvm::object;
+namespace {
+
+class XCOFFDumper {
+  const object::XCOFFObjectFile &Obj;
+  XCOFFYAML::Object YAMLObj;
+  void dumpHeader();
+
+public:
+  XCOFFDumper(const object::XCOFFObjectFile &obj);
+  XCOFFYAML::Object &getYAMLObj() { return YAMLObj; }
+};
+} // namespace
+
+XCOFFDumper::XCOFFDumper(const object::XCOFFObjectFile &obj) : Obj(obj) {
+  dumpHeader();
+}
+
+void XCOFFDumper::dumpHeader() {
+  const XCOFFFileHeader *FileHdrPtr = Obj.getFileHeader();
+
+  YAMLObj.Header.Magic = FileHdrPtr->Magic;
+  YAMLObj.Header.NumberOfSections = FileHdrPtr->NumberOfSections;
+  YAMLObj.Header.TimeStamp = FileHdrPtr->TimeStamp;
+  YAMLObj.Header.SymbolTableOffset = FileHdrPtr->SymbolTableOffset;
+  YAMLObj.Header.NumberOfSymTableEntries = FileHdrPtr->NumberOfSymTableEntries;
+  YAMLObj.Header.AuxHeaderSize = FileHdrPtr->AuxHeaderSize;
+  YAMLObj.Header.Flags = FileHdrPtr->Flags;
+}
+
+std::error_code xcoff2yaml(raw_ostream &Out,
+                           const object::XCOFFObjectFile &Obj) {
+  XCOFFDumper Dumper(Obj);
+  yaml::Output Yout(Out);
+  Yout << Dumper.getYAMLObj();
+
+  return std::error_code();
+}