[obj2yaml] - Cleanup error reporting (remove Error.cpp/.h files)

[grimar]

Summary

This removes Error.cpp/.h files from obj2yaml.
These files are not needed because we are
using Errors instead of error codes widely and do
not need a logic related to obj2yaml specific
error codes anymore.

I had to adjust just a few lines of tool's code
to remove remaining dependencies.

[Higuoxing]

Great, LGTM!

llvm/tools/obj2yaml/macho2yaml.cpp

648

I think it should be Mach-O?

[grimar]

llvm/tools/obj2yaml/macho2yaml.cpp

648

I am not sure honestly. For example, llvm-readobj options has MachO:

cl::opt<bool>
MachOSegment("macho-segment",
                cl::desc("Display MachO Segment command"));

// --macho-version-min
cl::opt<bool>
MachOVersionMin("macho-version-min",
                cl::desc("Display MachO version min command"));

// --macho-dysymtab
cl::opt<bool>
MachODysymtab("macho-dysymtab",
                cl::desc("Display MachO Dysymtab command"));

[jhenderson]

LGTM, with @Higuoxing's nit.

llvm/tools/obj2yaml/macho2yaml.cpp

648

I agree with @Higuoxing - the first half-dozen search results for "MachO" actually use "Mach-O". I didn't look further. I think "Mach-O" is the canonical file format name.

llvm/tools/obj2yaml/CMakeLists.txt

add_llvm_tool(obj2yaml
   obj2yaml.cpp
   coff2yaml.cpp
   dwarf2yaml.cpp
   elf2yaml.cpp
   macho2yaml.cpp
   minidump2yaml.cpp
   xcoff2yaml.cpp
   wasm2yaml.cpp
-  Error.cpp
   )

llvm/tools/obj2yaml/Error.h

-//===- Error.h - system_error extensions for obj2yaml -----------*- 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
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_TOOLS_OBJ2YAML_ERROR_H
-#define LLVM_TOOLS_OBJ2YAML_ERROR_H
-
-#include "llvm/Support/Error.h"
-
-#include <system_error>
-
-namespace llvm {
-const std::error_category &obj2yaml_category();
-
-enum class obj2yaml_error {
-  success = 0,
-  file_not_found,
-  unrecognized_file_format,
-  unsupported_obj_file_format,
-  not_implemented
-};
-
-inline std::error_code make_error_code(obj2yaml_error e) {
-  return std::error_code(static_cast<int>(e), obj2yaml_category());
-}
-
-class Obj2YamlError : public ErrorInfo<Obj2YamlError> {
-public:
-  static char ID;
-  Obj2YamlError(obj2yaml_error C) : Code(C) {}
-  Obj2YamlError(std::string ErrMsg) : ErrMsg(std::move(ErrMsg)) {}
-  Obj2YamlError(obj2yaml_error C, std::string ErrMsg)
-      : ErrMsg(std::move(ErrMsg)), Code(C) {}
-  void log(raw_ostream &OS) const override;
-  const std::string &getErrorMessage() const { return ErrMsg; }
-  std::error_code convertToErrorCode() const override;
-
-private:
-  std::string ErrMsg;
-  obj2yaml_error Code = obj2yaml_error::success;
-};
-
-} // namespace llvm
-
-namespace std {
-template <> struct is_error_code_enum<llvm::obj2yaml_error> : std::true_type {};
-}
-
-#endif

llvm/tools/obj2yaml/Error.cpp

-//===- Error.cpp - system_error extensions for obj2yaml ---------*- 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 "Error.h"
-#include "llvm/Support/ErrorHandling.h"
-
-using namespace llvm;
-
-namespace {
-// FIXME: This class is only here to support the transition to llvm::Error. It
-// will be removed once this transition is complete. Clients should prefer to
-// deal with the Error value directly, rather than converting to error_code.
-class _obj2yaml_error_category : public std::error_category {
-public:
-  const char *name() const noexcept override;
-  std::string message(int ev) const override;
-};
-} // namespace
-
-const char *_obj2yaml_error_category::name() const noexcept {
-  return "obj2yaml";
-}
-
-std::string _obj2yaml_error_category::message(int ev) const {
-  switch (static_cast<obj2yaml_error>(ev)) {
-  case obj2yaml_error::success:
-    return "Success";
-  case obj2yaml_error::file_not_found:
-    return "No such file.";
-  case obj2yaml_error::unrecognized_file_format:
-    return "Unrecognized file type.";
-  case obj2yaml_error::unsupported_obj_file_format:
-    return "Unsupported object file format.";
-  case obj2yaml_error::not_implemented:
-    return "Feature not yet implemented.";
-  }
-  llvm_unreachable("An enumerator of obj2yaml_error does not have a message "
-                   "defined.");
-}
-
-namespace llvm {
-
-const std::error_category &obj2yaml_category() {
-  static _obj2yaml_error_category o;
-  return o;
-}
-
-char Obj2YamlError::ID = 0;
-
-void Obj2YamlError::log(raw_ostream &OS) const { OS << ErrMsg; }
-
-std::error_code Obj2YamlError::convertToErrorCode() const {
-  return std::error_code(static_cast<int>(Code), obj2yaml_category());
-}
-
-} // namespace llvm

llvm/tools/obj2yaml/dwarf2yaml.cpp

 //===------ dwarf2yaml.cpp - obj2yaml conversion tool -----------*- 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 "Error.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
 #include "llvm/ObjectYAML/DWARFYAML.h"

llvm/tools/obj2yaml/elf2yaml.cpp

 //===------ utils/elf2yaml.cpp - obj2yaml conversion tool -------*- 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 "Error.h"
 #include "obj2yaml.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/Object/ELFObjectFile.h"
 #include "llvm/ObjectYAML/DWARFYAML.h"
 #include "llvm/ObjectYAML/ELFYAML.h"
for (const Elf_Shdr &Sec : Sections) {
     if (Sec.sh_type == ELF::SHT_SYMTAB) {
       SymTab = &Sec;
     } else if (Sec.sh_type == ELF::SHT_DYNSYM) {
       DynSymTab = &Sec;
     } else if (Sec.sh_type == ELF::SHT_SYMTAB_SHNDX) {
       // ABI allows us to have one SHT_SYMTAB_SHNDX for each symbol table.
       // We only support having the SHT_SYMTAB_SHNDX for SHT_SYMTAB now.
       if (SymTabShndx)
-        return createStringError(obj2yaml_error::not_implemented,
-                                 "multiple SHT_SYMTAB_SHNDX sections are not supported");
+        return createStringError(
+            errc::not_supported,
       SymTabShndx = &Sec;
     }
   }
 
   // We need to locate the SHT_SYMTAB_SHNDX section early, because it might be
   // needed for dumping symbols.
   if (SymTabShndx) {
     if (!SymTab ||
         SymTabShndx->sh_link != (unsigned)(SymTab - Sections.begin()))
       return createStringError(
-          obj2yaml_error::not_implemented,
+          errc::not_supported,
           "only SHT_SYMTAB_SHNDX associated with SHT_SYMTAB are supported");
 
     auto TableOrErr = Obj.getSHNDXTable(*SymTabShndx);
     if (!TableOrErr)
       return TableOrErr.takeError();
     ShndxTable = *TableOrErr;
   }
 

llvm/tools/obj2yaml/macho2yaml.cpp

 //===------ macho2yaml.cpp - obj2yaml conversion tool -----------*- 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 "Error.h"
 #include "obj2yaml.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/Object/MachOUniversal.h"
 #include "llvm/ObjectYAML/DWARFYAML.h"
 #include "llvm/ObjectYAML/ObjectYAML.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/LEB128.h"
Error macho2yaml(raw_ostream &Out, const object::MachOUniversalBinary &Obj) {
   }
 
   yaml::Output Yout(Out);
   Yout << YAML;
   return Error::success();
 }
 
 Error macho2yaml(raw_ostream &Out, const object::Binary &Binary) {
-  if (const auto *MachOObj = dyn_cast<object::MachOUniversalBinary>(&Binary)) {
-    if (auto Err = macho2yaml(Out, *MachOObj)) {
-      return Err;
-    }
-    return Error::success();
-  }
+  if (const auto *MachOObj = dyn_cast<object::MachOUniversalBinary>(&Binary))
+    return macho2yaml(Out, *MachOObj);
 
-  if (const auto *MachOObj = dyn_cast<object::MachOObjectFile>(&Binary)) {
-    if (auto Err = macho2yaml(Out, *MachOObj)) {
-      return Err;
-    }
-    return Error::success();
-  }
+  if (const auto *MachOObj = dyn_cast<object::MachOObjectFile>(&Binary))
+    return macho2yaml(Out, *MachOObj);
 
-  return errorCodeToError(obj2yaml_error::unsupported_obj_file_format);
+  llvm_unreachable("unexpected Mach-O file format");
 }

llvm/tools/obj2yaml/minidump2yaml.cpp

 //===- minidump2yaml.cpp - Minidump to yaml conversion tool -----*- 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 "Error.h"
 #include "obj2yaml.h"
 #include "llvm/Object/Minidump.h"
 #include "llvm/ObjectYAML/MinidumpYAML.h"
 #include "llvm/Support/YAMLTraits.h"
 
 using namespace llvm;
 
 Error minidump2yaml(raw_ostream &Out, const object::MinidumpFile &Obj) {
   auto ExpectedObject = MinidumpYAML::Object::create(Obj);
   if (!ExpectedObject)
     return ExpectedObject.takeError();
   yaml::Output Output(Out);
   Output << *ExpectedObject;
   return llvm::Error::success();
 }

llvm/tools/obj2yaml/obj2yaml.cpp

 //===------ utils/obj2yaml.cpp - obj2yaml conversion tool -------*- 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 "Error.h"
 #include "llvm/Object/Archive.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/Object/Minidump.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Errc.h"
 #include "llvm/Support/InitLLVM.h"
 
 using namespace llvm;
 using namespace llvm::object;
 
 static Error dumpObject(const ObjectFile &Obj) {
   if (Obj.isCOFF())
     return errorCodeToError(coff2yaml(outs(), cast<COFFObjectFile>(Obj)));
 
   if (Obj.isXCOFF())
     return errorCodeToError(xcoff2yaml(outs(), cast<XCOFFObjectFile>(Obj)));
 
   if (Obj.isELF())
     return elf2yaml(outs(), Obj);
 
   if (Obj.isWasm())
     return errorCodeToError(wasm2yaml(outs(), cast<WasmObjectFile>(Obj)));
 
-  return errorCodeToError(obj2yaml_error::unsupported_obj_file_format);
+  llvm_unreachable("unexpected object file format");
 }
 
 static Error dumpInput(StringRef File) {
   Expected<OwningBinary<Binary>> BinaryOrErr = createBinary(File);
   if (!BinaryOrErr)
     return BinaryOrErr.takeError();
 
   Binary &Binary = *BinaryOrErr.get().getBinary();