1 files changed, 766 insertions, 0 deletions

diff --git a/llvm/lib/Object/XCOFFObjectFile.cpp b/llvm/lib/Object/XCOFFObjectFile.cpp
new file mode 100644
index 000000000000..98782c2701c1
--- /dev/null
+++ b/llvm/lib/Object/XCOFFObjectFile.cpp
@@ -0,0 +1,766 @@
+//===--- 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 <cstddef>
+#include <cstring>
+
+namespace llvm {
+namespace object {
+
+enum { FUNCTION_SYM = 0x20, SYM_TYPE_MASK = 0x07, RELOC_OVERFLOW = 65535 };
+
+// Checks that [Ptr, Ptr + Size) bytes fall inside the memory buffer
+// 'M'. Returns a pointer to the underlying object on success.
+template <typename T>
+static Expected<const T *> getObject(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 errorCodeToError(EC);
+  return reinterpret_cast<const T *>(Addr);
+}
+
+static uintptr_t getWithOffset(uintptr_t Base, ptrdiff_t Offset) {
+  return reinterpret_cast<uintptr_t>(reinterpret_cast<const char *>(Base) +
+                                     Offset);
+}
+
+template <typename T> static const T *viewAs(uintptr_t in) {
+  return reinterpret_cast<const T *>(in);
+}
+
+static StringRef generateXCOFFFixedNameStringRef(const char *Name) {
+  auto NulCharPtr =
+      static_cast<const char *>(memchr(Name, '\0', XCOFF::NameSize));
+  return NulCharPtr ? StringRef(Name, NulCharPtr - Name)
+                    : StringRef(Name, XCOFF::NameSize);
+}
+
+bool XCOFFRelocation32::isRelocationSigned() const {
+  return Info & XR_SIGN_INDICATOR_MASK;
+}
+
+bool XCOFFRelocation32::isFixupIndicated() const {
+  return Info & XR_FIXUP_INDICATOR_MASK;
+}
+
+uint8_t XCOFFRelocation32::getRelocatedLength() const {
+  // The relocation encodes the bit length being relocated minus 1. Add back
+  // the 1 to get the actual length being relocated.
+  return (Info & XR_BIASED_LENGTH_MASK) + 1;
+}
+
+void XCOFFObjectFile::checkSectionAddress(uintptr_t Addr,
+                                          uintptr_t TableAddress) const {
+  if (Addr < TableAddress)
+    report_fatal_error("Section header outside of section header table.");
+
+  uintptr_t Offset = Addr - TableAddress;
+  if (Offset >= getSectionHeaderSize() * getNumberOfSections())
+    report_fatal_error("Section header outside of section header table.");
+
+  if (Offset % getSectionHeaderSize() != 0)
+    report_fatal_error(
+        "Section header pointer does not point to a valid section header.");
+}
+
+const XCOFFSectionHeader32 *
+XCOFFObjectFile::toSection32(DataRefImpl Ref) const {
+  assert(!is64Bit() && "32-bit interface called on 64-bit object file.");
+#ifndef NDEBUG
+  checkSectionAddress(Ref.p, getSectionHeaderTableAddress());
+#endif
+  return viewAs<XCOFFSectionHeader32>(Ref.p);
+}
+
+const XCOFFSectionHeader64 *
+XCOFFObjectFile::toSection64(DataRefImpl Ref) const {
+  assert(is64Bit() && "64-bit interface called on a 32-bit object file.");
+#ifndef NDEBUG
+  checkSectionAddress(Ref.p, getSectionHeaderTableAddress());
+#endif
+  return viewAs<XCOFFSectionHeader64>(Ref.p);
+}
+
+const XCOFFSymbolEntry *XCOFFObjectFile::toSymbolEntry(DataRefImpl Ref) const {
+  assert(!is64Bit() && "Symbol table support not implemented for 64-bit.");
+  assert(Ref.p != 0 && "Symbol table pointer can not be nullptr!");
+#ifndef NDEBUG
+  checkSymbolEntryPointer(Ref.p);
+#endif
+  auto SymEntPtr = viewAs<XCOFFSymbolEntry>(Ref.p);
+  return SymEntPtr;
+}
+
+const XCOFFFileHeader32 *XCOFFObjectFile::fileHeader32() const {
+  assert(!is64Bit() && "32-bit interface called on 64-bit object file.");
+  return static_cast<const XCOFFFileHeader32 *>(FileHeader);
+}
+
+const XCOFFFileHeader64 *XCOFFObjectFile::fileHeader64() const {
+  assert(is64Bit() && "64-bit interface called on a 32-bit object file.");
+  return static_cast<const XCOFFFileHeader64 *>(FileHeader);
+}
+
+const XCOFFSectionHeader32 *
+XCOFFObjectFile::sectionHeaderTable32() const {
+  assert(!is64Bit() && "32-bit interface called on 64-bit object file.");
+  return static_cast<const XCOFFSectionHeader32 *>(SectionHeaderTable);
+}
+
+const XCOFFSectionHeader64 *
+XCOFFObjectFile::sectionHeaderTable64() const {
+  assert(is64Bit() && "64-bit interface called on a 32-bit object file.");
+  return static_cast<const XCOFFSectionHeader64 *>(SectionHeaderTable);
+}
+
+void XCOFFObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
+  const XCOFFSymbolEntry *SymEntPtr = toSymbolEntry(Symb);
+  SymEntPtr += SymEntPtr->NumberOfAuxEntries + 1;
+#ifndef NDEBUG
+  // This function is used by basic_symbol_iterator, which allows to
+  // point to the end-of-symbol-table address.
+  if (reinterpret_cast<uintptr_t>(SymEntPtr) != getEndOfSymbolTableAddress())
+    checkSymbolEntryPointer(reinterpret_cast<uintptr_t>(SymEntPtr));
+#endif
+  Symb.p = reinterpret_cast<uintptr_t>(SymEntPtr);
+}
+
+Expected<StringRef>
+XCOFFObjectFile::getStringTableEntry(uint32_t Offset) const {
+  // The byte offset is relative to the start of the string table.
+  // A byte offset value of 0 is a null or zero-length symbol
+  // name. A byte offset in the range 1 to 3 (inclusive) points into the length
+  // field; as a soft-error recovery mechanism, we treat such cases as having an
+  // offset of 0.
+  if (Offset < 4)
+    return StringRef(nullptr, 0);
+
+  if (StringTable.Data != nullptr && StringTable.Size > Offset)
+    return (StringTable.Data + Offset);
+
+  return make_error<GenericBinaryError>("Bad offset for string table entry",
+                                        object_error::parse_failed);
+}
+
+Expected<StringRef>
+XCOFFObjectFile::getCFileName(const XCOFFFileAuxEnt *CFileEntPtr) const {
+  if (CFileEntPtr->NameInStrTbl.Magic !=
+      XCOFFSymbolEntry::NAME_IN_STR_TBL_MAGIC)
+    return generateXCOFFFixedNameStringRef(CFileEntPtr->Name);
+  return getStringTableEntry(CFileEntPtr->NameInStrTbl.Offset);
+}
+
+Expected<StringRef> XCOFFObjectFile::getSymbolName(DataRefImpl Symb) const {
+  const XCOFFSymbolEntry *SymEntPtr = toSymbolEntry(Symb);
+
+  // A storage class value with the high-order bit on indicates that the name is
+  // a symbolic debugger stabstring.
+  if (SymEntPtr->StorageClass & 0x80)
+    return StringRef("Unimplemented Debug Name");
+
+  if (SymEntPtr->NameInStrTbl.Magic != XCOFFSymbolEntry::NAME_IN_STR_TBL_MAGIC)
+    return generateXCOFFFixedNameStringRef(SymEntPtr->SymbolName);
+
+  return getStringTableEntry(SymEntPtr->NameInStrTbl.Offset);
+}
+
+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 {
+  assert(!is64Bit() && "Symbol table support not implemented for 64-bit.");
+  return toSymbolEntry(Symb)->Value;
+}
+
+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 {
+  const XCOFFSymbolEntry *SymEntPtr = toSymbolEntry(Symb);
+  int16_t SectNum = SymEntPtr->SectionNumber;
+
+  if (isReservedSectionNumber(SectNum))
+    return section_end();
+
+  Expected<DataRefImpl> ExpSec = getSectionByNum(SectNum);
+  if (!ExpSec)
+    return ExpSec.takeError();
+
+  return section_iterator(SectionRef(ExpSec.get(), this));
+}
+
+void XCOFFObjectFile::moveSectionNext(DataRefImpl &Sec) const {
+  const char *Ptr = reinterpret_cast<const char *>(Sec.p);
+  Sec.p = reinterpret_cast<uintptr_t>(Ptr + getSectionHeaderSize());
+}
+
+Expected<StringRef> XCOFFObjectFile::getSectionName(DataRefImpl Sec) const {
+  return generateXCOFFFixedNameStringRef(getSectionNameInternal(Sec));
+}
+
+uint64_t XCOFFObjectFile::getSectionAddress(DataRefImpl Sec) const {
+  // Avoid ternary due to failure to convert the ubig32_t value to a unit64_t
+  // with MSVC.
+  if (is64Bit())
+    return toSection64(Sec)->VirtualAddress;
+
+  return toSection32(Sec)->VirtualAddress;
+}
+
+uint64_t XCOFFObjectFile::getSectionIndex(DataRefImpl Sec) const {
+  // Section numbers in XCOFF are numbered beginning at 1. A section number of
+  // zero is used to indicate that a symbol is being imported or is undefined.
+  if (is64Bit())
+    return toSection64(Sec) - sectionHeaderTable64() + 1;
+  else
+    return toSection32(Sec) - sectionHeaderTable32() + 1;
+}
+
+uint64_t XCOFFObjectFile::getSectionSize(DataRefImpl Sec) const {
+  // Avoid ternary due to failure to convert the ubig32_t value to a unit64_t
+  // with MSVC.
+  if (is64Bit())
+    return toSection64(Sec)->SectionSize;
+
+  return toSection32(Sec)->SectionSize;
+}
+
+Expected<ArrayRef<uint8_t>>
+XCOFFObjectFile::getSectionContents(DataRefImpl Sec) const {
+  llvm_unreachable("Not yet implemented!");
+}
+
+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 {
+  return getSectionFlags(Sec) & XCOFF::STYP_TEXT;
+}
+
+bool XCOFFObjectFile::isSectionData(DataRefImpl Sec) const {
+  uint32_t Flags = getSectionFlags(Sec);
+  return Flags & (XCOFF::STYP_DATA | XCOFF::STYP_TDATA);
+}
+
+bool XCOFFObjectFile::isSectionBSS(DataRefImpl Sec) const {
+  uint32_t Flags = getSectionFlags(Sec);
+  return Flags & (XCOFF::STYP_BSS | XCOFF::STYP_TBSS);
+}
+
+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 {
+  assert(!is64Bit() && "64-bit support not implemented yet.");
+  DataRefImpl SymDRI;
+  SymDRI.p = reinterpret_cast<uintptr_t>(SymbolTblPtr);
+  return basic_symbol_iterator(SymbolRef(SymDRI, this));
+}
+
+basic_symbol_iterator XCOFFObjectFile::symbol_end() const {
+  assert(!is64Bit() && "64-bit support not implemented yet.");
+  DataRefImpl SymDRI;
+  SymDRI.p = reinterpret_cast<uintptr_t>(
+      SymbolTblPtr + getLogicalNumberOfSymbolTableEntries32());
+  return basic_symbol_iterator(SymbolRef(SymDRI, this));
+}
+
+section_iterator XCOFFObjectFile::section_begin() const {
+  DataRefImpl DRI;
+  DRI.p = getSectionHeaderTableAddress();
+  return section_iterator(SectionRef(DRI, this));
+}
+
+section_iterator XCOFFObjectFile::section_end() const {
+  DataRefImpl DRI;
+  DRI.p = getWithOffset(getSectionHeaderTableAddress(),
+                        getNumberOfSections() * getSectionHeaderSize());
+  return section_iterator(SectionRef(DRI, this));
+}
+
+uint8_t XCOFFObjectFile::getBytesInAddress() const { return is64Bit() ? 8 : 4; }
+
+StringRef XCOFFObjectFile::getFileFormatName() const {
+  return is64Bit() ? "aix5coff64-rs6000" : "aixcoff-rs6000";
+}
+
+Triple::ArchType XCOFFObjectFile::getArch() const {
+  return is64Bit() ? Triple::ppc64 : Triple::ppc;
+}
+
+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;
+}
+
+Expected<uint64_t> XCOFFObjectFile::getStartAddress() const {
+  // TODO FIXME Should get from auxiliary_header->o_entry when support for the
+  // auxiliary_header is added.
+  return 0;
+}
+
+size_t XCOFFObjectFile::getFileHeaderSize() const {
+  return is64Bit() ? sizeof(XCOFFFileHeader64) : sizeof(XCOFFFileHeader32);
+}
+
+size_t XCOFFObjectFile::getSectionHeaderSize() const {
+  return is64Bit() ? sizeof(XCOFFSectionHeader64) :
+                     sizeof(XCOFFSectionHeader32);
+}
+
+bool XCOFFObjectFile::is64Bit() const {
+  return Binary::ID_XCOFF64 == getType();
+}
+
+uint16_t XCOFFObjectFile::getMagic() const {
+  return is64Bit() ? fileHeader64()->Magic : fileHeader32()->Magic;
+}
+
+Expected<DataRefImpl> XCOFFObjectFile::getSectionByNum(int16_t Num) const {
+  if (Num <= 0 || Num > getNumberOfSections())
+    return errorCodeToError(object_error::invalid_section_index);
+
+  DataRefImpl DRI;
+  DRI.p = getWithOffset(getSectionHeaderTableAddress(),
+                        getSectionHeaderSize() * (Num - 1));
+  return DRI;
+}
+
+Expected<StringRef>
+XCOFFObjectFile::getSymbolSectionName(const XCOFFSymbolEntry *SymEntPtr) const {
+  assert(!is64Bit() && "Symbol table support not implemented for 64-bit.");
+  int16_t SectionNum = SymEntPtr->SectionNumber;
+
+  switch (SectionNum) {
+  case XCOFF::N_DEBUG:
+    return "N_DEBUG";
+  case XCOFF::N_ABS:
+    return "N_ABS";
+  case XCOFF::N_UNDEF:
+    return "N_UNDEF";
+  default:
+    Expected<DataRefImpl> SecRef = getSectionByNum(SectionNum);
+    if (SecRef)
+      return generateXCOFFFixedNameStringRef(
+          getSectionNameInternal(SecRef.get()));
+    return SecRef.takeError();
+  }
+}
+
+bool XCOFFObjectFile::isReservedSectionNumber(int16_t SectionNumber) {
+  return (SectionNumber <= 0 && SectionNumber >= -2);
+}
+
+uint16_t XCOFFObjectFile::getNumberOfSections() const {
+  return is64Bit() ? fileHeader64()->NumberOfSections
+                   : fileHeader32()->NumberOfSections;
+}
+
+int32_t XCOFFObjectFile::getTimeStamp() const {
+  return is64Bit() ? fileHeader64()->TimeStamp : fileHeader32()->TimeStamp;
+}
+
+uint16_t XCOFFObjectFile::getOptionalHeaderSize() const {
+  return is64Bit() ? fileHeader64()->AuxHeaderSize
+                   : fileHeader32()->AuxHeaderSize;
+}
+
+uint32_t XCOFFObjectFile::getSymbolTableOffset32() const {
+  return fileHeader32()->SymbolTableOffset;
+}
+
+int32_t XCOFFObjectFile::getRawNumberOfSymbolTableEntries32() const {
+  // As far as symbol table size is concerned, if this field is negative it is
+  // to be treated as a 0. However since this field is also used for printing we
+  // don't want to truncate any negative values.
+  return fileHeader32()->NumberOfSymTableEntries;
+}
+
+uint32_t XCOFFObjectFile::getLogicalNumberOfSymbolTableEntries32() const {
+  return (fileHeader32()->NumberOfSymTableEntries >= 0
+              ? fileHeader32()->NumberOfSymTableEntries
+              : 0);
+}
+
+uint64_t XCOFFObjectFile::getSymbolTableOffset64() const {
+  return fileHeader64()->SymbolTableOffset;
+}
+
+uint32_t XCOFFObjectFile::getNumberOfSymbolTableEntries64() const {
+  return fileHeader64()->NumberOfSymTableEntries;
+}
+
+uintptr_t XCOFFObjectFile::getEndOfSymbolTableAddress() const {
+  uint32_t NumberOfSymTableEntries =
+      is64Bit() ? getNumberOfSymbolTableEntries64()
+                : getLogicalNumberOfSymbolTableEntries32();
+  return getWithOffset(reinterpret_cast<uintptr_t>(SymbolTblPtr),
+                       XCOFF::SymbolTableEntrySize * NumberOfSymTableEntries);
+}
+
+void XCOFFObjectFile::checkSymbolEntryPointer(uintptr_t SymbolEntPtr) const {
+  if (SymbolEntPtr < reinterpret_cast<uintptr_t>(SymbolTblPtr))
+    report_fatal_error("Symbol table entry is outside of symbol table.");
+
+  if (SymbolEntPtr >= getEndOfSymbolTableAddress())
+    report_fatal_error("Symbol table entry is outside of symbol table.");
+
+  ptrdiff_t Offset = reinterpret_cast<const char *>(SymbolEntPtr) -
+                     reinterpret_cast<const char *>(SymbolTblPtr);
+
+  if (Offset % XCOFF::SymbolTableEntrySize != 0)
+    report_fatal_error(
+        "Symbol table entry position is not valid inside of symbol table.");
+}
+
+uint32_t XCOFFObjectFile::getSymbolIndex(uintptr_t SymbolEntPtr) const {
+  return (reinterpret_cast<const char *>(SymbolEntPtr) -
+          reinterpret_cast<const char *>(SymbolTblPtr)) /
+         XCOFF::SymbolTableEntrySize;
+}
+
+Expected<StringRef>
+XCOFFObjectFile::getSymbolNameByIndex(uint32_t Index) const {
+  if (is64Bit())
+    report_fatal_error("64-bit symbol table support not implemented yet.");
+
+  if (Index >= getLogicalNumberOfSymbolTableEntries32())
+    return errorCodeToError(object_error::invalid_symbol_index);
+
+  DataRefImpl SymDRI;
+  SymDRI.p = reinterpret_cast<uintptr_t>(getPointerToSymbolTable() + Index);
+  return getSymbolName(SymDRI);
+}
+
+uint16_t XCOFFObjectFile::getFlags() const {
+  return is64Bit() ? fileHeader64()->Flags : fileHeader32()->Flags;
+}
+
+const char *XCOFFObjectFile::getSectionNameInternal(DataRefImpl Sec) const {
+  return is64Bit() ? toSection64(Sec)->Name : toSection32(Sec)->Name;
+}
+
+uintptr_t XCOFFObjectFile::getSectionHeaderTableAddress() const {
+  return reinterpret_cast<uintptr_t>(SectionHeaderTable);
+}
+
+int32_t XCOFFObjectFile::getSectionFlags(DataRefImpl Sec) const {
+  return is64Bit() ? toSection64(Sec)->Flags : toSection32(Sec)->Flags;
+}
+
+XCOFFObjectFile::XCOFFObjectFile(unsigned int Type, MemoryBufferRef Object)
+    : ObjectFile(Type, Object) {
+  assert(Type == Binary::ID_XCOFF32 || Type == Binary::ID_XCOFF64);
+}
+
+ArrayRef<XCOFFSectionHeader64> XCOFFObjectFile::sections64() const {
+  assert(is64Bit() && "64-bit interface called for non 64-bit file.");
+  const XCOFFSectionHeader64 *TablePtr = sectionHeaderTable64();
+  return ArrayRef<XCOFFSectionHeader64>(TablePtr,
+                                        TablePtr + getNumberOfSections());
+}
+
+ArrayRef<XCOFFSectionHeader32> XCOFFObjectFile::sections32() const {
+  assert(!is64Bit() && "32-bit interface called for non 32-bit file.");
+  const XCOFFSectionHeader32 *TablePtr = sectionHeaderTable32();
+  return ArrayRef<XCOFFSectionHeader32>(TablePtr,
+                                        TablePtr + getNumberOfSections());
+}
+
+// In an XCOFF32 file, when the field value is 65535, then an STYP_OVRFLO
+// section header contains the actual count of relocation entries in the s_paddr
+// field. STYP_OVRFLO headers contain the section index of their corresponding
+// sections as their raw "NumberOfRelocations" field value.
+Expected<uint32_t> XCOFFObjectFile::getLogicalNumberOfRelocationEntries(
+    const XCOFFSectionHeader32 &Sec) const {
+
+  uint16_t SectionIndex = &Sec - sectionHeaderTable32() + 1;
+
+  if (Sec.NumberOfRelocations < RELOC_OVERFLOW)
+    return Sec.NumberOfRelocations;
+  for (const auto &Sec : sections32()) {
+    if (Sec.Flags == XCOFF::STYP_OVRFLO &&
+        Sec.NumberOfRelocations == SectionIndex)
+      return Sec.PhysicalAddress;
+  }
+  return errorCodeToError(object_error::parse_failed);
+}
+
+Expected<ArrayRef<XCOFFRelocation32>>
+XCOFFObjectFile::relocations(const XCOFFSectionHeader32 &Sec) const {
+  uintptr_t RelocAddr = getWithOffset(reinterpret_cast<uintptr_t>(FileHeader),
+                                      Sec.FileOffsetToRelocationInfo);
+  auto NumRelocEntriesOrErr = getLogicalNumberOfRelocationEntries(Sec);
+  if (Error E = NumRelocEntriesOrErr.takeError())
+    return std::move(E);
+
+  uint32_t NumRelocEntries = NumRelocEntriesOrErr.get();
+
+  auto RelocationOrErr =
+      getObject<XCOFFRelocation32>(Data, reinterpret_cast<void *>(RelocAddr),
+                                   NumRelocEntries * sizeof(XCOFFRelocation32));
+  if (Error E = RelocationOrErr.takeError())
+    return std::move(E);
+
+  const XCOFFRelocation32 *StartReloc = RelocationOrErr.get();
+
+  return ArrayRef<XCOFFRelocation32>(StartReloc, StartReloc + NumRelocEntries);
+}
+
+Expected<XCOFFStringTable>
+XCOFFObjectFile::parseStringTable(const XCOFFObjectFile *Obj, uint64_t Offset) {
+  // If there is a string table, then the buffer must contain at least 4 bytes
+  // for the string table's size. Not having a string table is not an error.
+  if (auto EC = Binary::checkOffset(
+          Obj->Data, reinterpret_cast<uintptr_t>(Obj->base() + Offset), 4))
+    return XCOFFStringTable{0, nullptr};
+
+  // Read the size out of the buffer.
+  uint32_t Size = support::endian::read32be(Obj->base() + Offset);
+
+  // If the size is less then 4, then the string table is just a size and no
+  // string data.
+  if (Size <= 4)
+    return XCOFFStringTable{4, nullptr};
+
+  auto StringTableOrErr =
+      getObject<char>(Obj->Data, Obj->base() + Offset, Size);
+  if (Error E = StringTableOrErr.takeError())
+    return std::move(E);
+
+  const char *StringTablePtr = StringTableOrErr.get();
+  if (StringTablePtr[Size - 1] != '\0')
+    return errorCodeToError(object_error::string_table_non_null_end);
+
+  return XCOFFStringTable{Size, StringTablePtr};
+}
+
+Expected<std::unique_ptr<XCOFFObjectFile>>
+XCOFFObjectFile::create(unsigned Type, MemoryBufferRef MBR) {
+  // Can't use std::make_unique because of the private constructor.
+  std::unique_ptr<XCOFFObjectFile> Obj;
+  Obj.reset(new XCOFFObjectFile(Type, MBR));
+
+  uint64_t CurOffset = 0;
+  const auto *Base = Obj->base();
+  MemoryBufferRef Data = Obj->Data;
+
+  // Parse file header.
+  auto FileHeaderOrErr =
+      getObject<void>(Data, Base + CurOffset, Obj->getFileHeaderSize());
+  if (Error E = FileHeaderOrErr.takeError())
+    return std::move(E);
+  Obj->FileHeader = FileHeaderOrErr.get();
+
+  CurOffset += Obj->getFileHeaderSize();
+  // TODO FIXME we don't have support for an optional header yet, so just skip
+  // past it.
+  CurOffset += Obj->getOptionalHeaderSize();
+
+  // Parse the section header table if it is present.
+  if (Obj->getNumberOfSections()) {
+    auto SecHeadersOrErr = getObject<void>(Data, Base + CurOffset,
+                                           Obj->getNumberOfSections() *
+                                               Obj->getSectionHeaderSize());
+    if (Error E = SecHeadersOrErr.takeError())
+      return std::move(E);
+    Obj->SectionHeaderTable = SecHeadersOrErr.get();
+  }
+
+  // 64-bit object supports only file header and section headers for now.
+  if (Obj->is64Bit())
+    return std::move(Obj);
+
+  // If there is no symbol table we are done parsing the memory buffer.
+  if (Obj->getLogicalNumberOfSymbolTableEntries32() == 0)
+    return std::move(Obj);
+
+  // Parse symbol table.
+  CurOffset = Obj->fileHeader32()->SymbolTableOffset;
+  uint64_t SymbolTableSize = (uint64_t)(sizeof(XCOFFSymbolEntry)) *
+                             Obj->getLogicalNumberOfSymbolTableEntries32();
+  auto SymTableOrErr =
+      getObject<XCOFFSymbolEntry>(Data, Base + CurOffset, SymbolTableSize);
+  if (Error E = SymTableOrErr.takeError())
+    return std::move(E);
+  Obj->SymbolTblPtr = SymTableOrErr.get();
+  CurOffset += SymbolTableSize;
+
+  // Parse String table.
+  Expected<XCOFFStringTable> StringTableOrErr =
+      parseStringTable(Obj.get(), CurOffset);
+  if (Error E = StringTableOrErr.takeError())
+    return std::move(E);
+  Obj->StringTable = StringTableOrErr.get();
+
+  return std::move(Obj);
+}
+
+Expected<std::unique_ptr<ObjectFile>>
+ObjectFile::createXCOFFObjectFile(MemoryBufferRef MemBufRef,
+                                  unsigned FileType) {
+  return XCOFFObjectFile::create(FileType, MemBufRef);
+}
+
+StringRef XCOFFSectionHeader32::getName() const {
+  return generateXCOFFFixedNameStringRef(Name);
+}
+
+StringRef XCOFFSectionHeader64::getName() const {
+  return generateXCOFFFixedNameStringRef(Name);
+}
+
+XCOFF::StorageClass XCOFFSymbolRef::getStorageClass() const {
+  return OwningObjectPtr->toSymbolEntry(SymEntDataRef)->StorageClass;
+}
+
+uint8_t XCOFFSymbolRef::getNumberOfAuxEntries() const {
+  return OwningObjectPtr->toSymbolEntry(SymEntDataRef)->NumberOfAuxEntries;
+}
+
+const XCOFFCsectAuxEnt32 *XCOFFSymbolRef::getXCOFFCsectAuxEnt32() const {
+  assert(!OwningObjectPtr->is64Bit() &&
+         "32-bit interface called on 64-bit object file.");
+  assert(hasCsectAuxEnt() && "No Csect Auxiliary Entry is found.");
+
+  // In XCOFF32, the csect auxilliary entry is always the last auxiliary
+  // entry for the symbol.
+  uintptr_t AuxAddr = getWithOffset(
+      SymEntDataRef.p, XCOFF::SymbolTableEntrySize * getNumberOfAuxEntries());
+
+#ifndef NDEBUG
+  OwningObjectPtr->checkSymbolEntryPointer(AuxAddr);
+#endif
+
+  return reinterpret_cast<const XCOFFCsectAuxEnt32 *>(AuxAddr);
+}
+
+uint16_t XCOFFSymbolRef::getType() const {
+  return OwningObjectPtr->toSymbolEntry(SymEntDataRef)->SymbolType;
+}
+
+int16_t XCOFFSymbolRef::getSectionNumber() const {
+  return OwningObjectPtr->toSymbolEntry(SymEntDataRef)->SectionNumber;
+}
+
+bool XCOFFSymbolRef::hasCsectAuxEnt() const {
+  XCOFF::StorageClass SC = getStorageClass();
+  return (SC == XCOFF::C_EXT || SC == XCOFF::C_WEAKEXT ||
+          SC == XCOFF::C_HIDEXT);
+}
+
+bool XCOFFSymbolRef::isFunction() const {
+  if (OwningObjectPtr->is64Bit())
+    report_fatal_error("64-bit support is unimplemented yet.");
+
+  if (getType() & FUNCTION_SYM)
+    return true;
+
+  if (!hasCsectAuxEnt())
+    return false;
+
+  const XCOFFCsectAuxEnt32 *CsectAuxEnt = getXCOFFCsectAuxEnt32();
+
+  // A function definition should be a label definition.
+  if ((CsectAuxEnt->SymbolAlignmentAndType & SYM_TYPE_MASK) != XCOFF::XTY_LD)
+    return false;
+
+  if (CsectAuxEnt->StorageMappingClass != XCOFF::XMC_PR)
+    return false;
+
+  int16_t SectNum = getSectionNumber();
+  Expected<DataRefImpl> SI = OwningObjectPtr->getSectionByNum(SectNum);
+  if (!SI)
+    return false;
+
+  return (OwningObjectPtr->getSectionFlags(SI.get()) & XCOFF::STYP_TEXT);
+}
+
+} // namespace object
+} // namespace llvm