Re-land "Migrate Binary::checkOffset from error_code to Error, NFC"

This reverts commit 38f3ba5.

Fix the XCOFF error handling. Unlike std::error_code, Error must be
consumed or handled.

llvm/include/llvm/Object/Binary.h

@@ -160,14 +160,14 @@ class Binary {
     return Triple::UnknownObjectFormat;
   }
 
-  static std::error_code checkOffset(MemoryBufferRef M, uintptr_t Addr,
-                                     const uint64_t Size) {
+  static Error checkOffset(MemoryBufferRef M, uintptr_t Addr,
+                           const uint64_t Size) {
     if (Addr + Size < Addr || Addr + Size < Size ||
         Addr + Size > uintptr_t(M.getBufferEnd()) ||
         Addr < uintptr_t(M.getBufferStart())) {
-      return object_error::unexpected_eof;
+      return errorCodeToError(object_error::unexpected_eof);
     }
-    return std::error_code();
+    return Error::success();
   }
 };
 

llvm/include/llvm/Object/ELFObjectFile.h

@@ -744,10 +744,10 @@ ELFObjectFile<ELFT>::getSectionContents(DataRefImpl Sec) const {
   const Elf_Shdr *EShdr = getSection(Sec);
   if (EShdr->sh_type == ELF::SHT_NOBITS)
     return makeArrayRef((const uint8_t *)base(), 0);
-  if (std::error_code EC =
+  if (Error E =
           checkOffset(getMemoryBufferRef(),
                       (uintptr_t)base() + EShdr->sh_offset, EShdr->sh_size))
-    return errorCodeToError(EC);
+    return std::move(E);
   return makeArrayRef((const uint8_t *)base() + EShdr->sh_offset,
                       EShdr->sh_size);
 }

llvm/lib/Object/COFFObjectFile.cpp

@@ -59,8 +59,8 @@ 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;
+  if (Error E = Binary::checkOffset(M, Addr, Size))
+    return errorToErrorCode(std::move(E));
   Obj = reinterpret_cast<const T *>(Addr);
   return std::error_code();
 }
@@ -374,9 +374,11 @@ getFirstReloc(const coff_section *Sec, MemoryBufferRef M, const uint8_t *Base) {
     // relocations.
     begin++;
   }
-  if (Binary::checkOffset(M, uintptr_t(begin),
-                          sizeof(coff_relocation) * NumRelocs))
+  if (auto E = Binary::checkOffset(M, uintptr_t(begin),
+                                   sizeof(coff_relocation) * NumRelocs)) {
+    consumeError(std::move(E));
     return nullptr;
+  }
   return begin;
 }
 
@@ -555,8 +557,8 @@ std::error_code COFFObjectFile::initImportTablePtr() {
   uintptr_t IntPtr = 0;
   if (std::error_code EC = getRvaPtr(ImportTableRva, IntPtr))
     return EC;
-  if (std::error_code EC = checkOffset(Data, IntPtr, DataEntry->Size))
-    return EC;
+  if (Error E = checkOffset(Data, IntPtr, DataEntry->Size))
+    return errorToErrorCode(std::move(E));
   ImportDirectory = reinterpret_cast<
       const coff_import_directory_table_entry *>(IntPtr);
   return std::error_code();
@@ -1093,8 +1095,8 @@ Error COFFObjectFile::getSectionContents(const coff_section *Sec,
   // data, as there's nothing that says that is not allowed.
   uintptr_t ConStart = uintptr_t(base()) + Sec->PointerToRawData;
   uint32_t SectionSize = getSectionSize(Sec);
-  if (checkOffset(Data, ConStart, SectionSize))
-    return make_error<BinaryError>();
+  if (Error E = checkOffset(Data, ConStart, SectionSize))
+    return E;
   Res = makeArrayRef(reinterpret_cast<const uint8_t *>(ConStart), SectionSize);
   return Error::success();
 }

llvm/lib/Object/XCOFFObjectFile.cpp

@@ -29,8 +29,8 @@ 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);
+  if (Error E = Binary::checkOffset(M, Addr, Size))
+    return std::move(E);
   return reinterpret_cast<const T *>(Addr);
 }
 
@@ -668,9 +668,11 @@ 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))
+  if (Error E = Binary::checkOffset(
+          Obj->Data, reinterpret_cast<uintptr_t>(Obj->base() + Offset), 4)) {
+    consumeError(std::move(E));
     return XCOFFStringTable{0, nullptr};
+  }
 
   // Read the size out of the buffer.
   uint32_t Size = support::endian::read32be(Obj->base() + Offset);