[llvm-readobj] - Remove Error.cpp,.h and drop dependencies in the code.

We have Error.cpp/.h which contains some code for working with error codes.
In fact we use Error/Expected<> almost everywhere already and we can get rid
of these files.

Note: a few places in the code used readobj specific error codes,
e.g. `return readobj_error::unknown_symbol`. But these codes are never really used,
i.e. the code checks the fact of a success/error call only.
So I've changes them to `return inconvertibleErrorCode()` for now.
It seems that these places probably should be converted to use `Error`/`Expected<>`.

Differential revision: https://reviews.llvm.org/D86772

test/tools/llvm-readobj/archive.test

@@ -96,5 +96,5 @@ symbols: []
 # RUN: llvm-readelf --all %t2.a 2>&1 | FileCheck %s -DARFILE="%t2.a" --check-prefix=BROKEN
 
 # BROKEN: File: [[ARFILE]](trivial.obj.elf-x86-64)
-# BROKEN: warning: '[[ARFILE]]': Unrecognized file type.
+# BROKEN: warning: '[[ARFILE]]': broken.a has an unsupported file type
 # BROKEN: File: [[ARFILE]](trivial.obj.elf-x86-64)

tools/llvm-readobj/ARMEHABIPrinter.h

@@ -9,7 +9,6 @@
 #ifndef LLVM_TOOLS_LLVM_READOBJ_ARMEHABIPRINTER_H
 #define LLVM_TOOLS_LLVM_READOBJ_ARMEHABIPRINTER_H
 
-#include "Error.h"
 #include "llvm-readobj.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Object/ELF.h"
@@ -367,7 +366,7 @@ ErrorOr<StringRef>
 PrinterContext<ET>::FunctionAtAddress(unsigned Section,
                                       uint64_t Address) const {
   if (!Symtab)
-    return readobj_error::unknown_symbol;
+    return inconvertibleErrorCode();
   auto StrTableOrErr = ELF->getStringTableForSymtab(*Symtab);
   if (!StrTableOrErr)
     reportError(StrTableOrErr.takeError(), FileName);
@@ -380,11 +379,11 @@ PrinterContext<ET>::FunctionAtAddress(unsigned Section,
       if (!NameOrErr) {
         // TODO: Actually report errors helpfully.
         consumeError(NameOrErr.takeError());
-        return readobj_error::unknown_symbol;
+        return inconvertibleErrorCode();
       }
       return *NameOrErr;
     }
-  return readobj_error::unknown_symbol;
+  return inconvertibleErrorCode();
 }
 
 template <typename ET>

tools/llvm-readobj/ARMWinEHPrinter.cpp

@@ -62,7 +62,6 @@
 // epilogue of the function.
 
 #include "ARMWinEHPrinter.h"
-#include "Error.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/ARMWinEH.h"
@@ -217,7 +216,7 @@ Decoder::getSectionContaining(const COFFObjectFile &COFF, uint64_t VA) {
     if (VA >= Address && (VA - Address) <= Size)
       return Section;
   }
-  return readobj_error::unknown_symbol;
+  return inconvertibleErrorCode();
 }
 
 ErrorOr<object::SymbolRef> Decoder::getSymbol(const COFFObjectFile &COFF,
@@ -235,7 +234,7 @@ ErrorOr<object::SymbolRef> Decoder::getSymbol(const COFFObjectFile &COFF,
     if (*Address == VA)
       return Symbol;
   }
-  return readobj_error::unknown_symbol;
+  return inconvertibleErrorCode();
 }
 
 ErrorOr<SymbolRef> Decoder::getRelocatedSymbol(const COFFObjectFile &,
@@ -246,7 +245,7 @@ ErrorOr<SymbolRef> Decoder::getRelocatedSymbol(const COFFObjectFile &,
     if (RelocationOffset == Offset)
       return *Relocation.getSymbol();
   }
-  return readobj_error::unknown_symbol;
+  return inconvertibleErrorCode();
 }
 
 bool Decoder::opcode_0xxxxxxx(const uint8_t *OC, unsigned &Offset,

tools/llvm-readobj/CMakeLists.txt

@@ -15,7 +15,6 @@ add_llvm_tool(llvm-readobj
   COFFDumper.cpp
   COFFImportDumper.cpp
   ELFDumper.cpp
-  Error.cpp
   llvm-readobj.cpp
   MachODumper.cpp
   ObjDumper.cpp

tools/llvm-readobj/COFFDumper.cpp

@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "ARMWinEHPrinter.h"
-#include "Error.h"
 #include "ObjDumper.h"
 #include "StackMapPrinter.h"
 #include "Win64EHDumper.h"
@@ -262,9 +261,9 @@ std::error_code COFFDumper::resolveSymbol(const coff_section *Section,
     }
   }
   if (SymI == Obj->symbol_end())
-    return readobj_error::unknown_symbol;
+    return inconvertibleErrorCode();
   Sym = *SymI;
-  return readobj_error::success;
+  return std::error_code();
 }
 
 // Given a section and an offset into this section the function returns the name
@@ -578,7 +577,7 @@ static std::error_code getSymbolAuxData(const COFFObjectFile *Obj,
   ArrayRef<uint8_t> AuxData = Obj->getSymbolAuxData(Symbol);
   AuxData = AuxData.slice(AuxSymbolIdx * Obj->getSymbolTableEntrySize());
   Aux = reinterpret_cast<const T*>(AuxData.data());
-  return readobj_error::success;
+  return std::error_code();
 }
 
 void COFFDumper::cacheRelocations() {

tools/llvm-readobj/DwarfCFIEHPrinter.h

@@ -9,7 +9,6 @@
 #ifndef LLVM_TOOLS_LLVM_READOBJ_DWARFCFIEHPRINTER_H
 #define LLVM_TOOLS_LLVM_READOBJ_DWARFCFIEHPRINTER_H
 
-#include "Error.h"
 #include "llvm-readobj.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/BinaryFormat/Dwarf.h"

tools/llvm-readobj/ELFDumper.cpp

@@ -13,7 +13,6 @@
 
 #include "ARMEHABIPrinter.h"
 #include "DwarfCFIEHPrinter.h"
-#include "Error.h"
 #include "ObjDumper.h"
 #include "StackMapPrinter.h"
 #include "llvm-readobj.h"

tools/llvm-readobj/Error.cpp

@@ -1,56 +0,0 @@
-//===- Error.cpp - system_error extensions for llvm-readobj -----*- 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 defines a new error_category for the llvm-readobj tool.
-//
-//===----------------------------------------------------------------------===//
-
-#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 _readobj_error_category : public std::error_category {
-public:
-  const char* name() const noexcept override;
-  std::string message(int ev) const override;
-};
-} // namespace
-
-const char *_readobj_error_category::name() const noexcept {
-  return "llvm.readobj";
-}
-
-std::string _readobj_error_category::message(int EV) const {
-  switch (static_cast<readobj_error>(EV)) {
-  case readobj_error::success: return "Success";
-  case readobj_error::file_not_found:
-    return "No such file.";
-  case readobj_error::unsupported_file_format:
-    return "The file was not recognized as a valid object file.";
-  case readobj_error::unrecognized_file_format:
-    return "Unrecognized file type.";
-  case readobj_error::unsupported_obj_file_format:
-    return "Unsupported object file format.";
-  case readobj_error::unknown_symbol:
-    return "Unknown symbol.";
-  }
-  llvm_unreachable("An enumerator of readobj_error does not have a message "
-                   "defined.");
-}
-
-namespace llvm {
-const std::error_category &readobj_category() {
-  static _readobj_error_category o;
-  return o;
-}
-} // namespace llvm

tools/llvm-readobj/Error.h

@@ -1,40 +0,0 @@
-//===- Error.h - system_error extensions for llvm-readobj -------*- 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 declares a new error_category for the llvm-readobj tool.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_TOOLS_LLVM_READOBJ_ERROR_H
-#define LLVM_TOOLS_LLVM_READOBJ_ERROR_H
-
-#include <system_error>
-
-namespace llvm {
-const std::error_category &readobj_category();
-
-enum class readobj_error {
-  success = 0,
-  file_not_found,
-  unsupported_file_format,
-  unrecognized_file_format,
-  unsupported_obj_file_format,
-  unknown_symbol
-};
-
-inline std::error_code make_error_code(readobj_error e) {
-  return std::error_code(static_cast<int>(e), readobj_category());
-}
-
-} // namespace llvm
-
-namespace std {
-template <> struct is_error_code_enum<llvm::readobj_error> : std::true_type {};
-}
-
-#endif

tools/llvm-readobj/MachODumper.cpp

@@ -10,7 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "Error.h"
 #include "ObjDumper.h"
 #include "StackMapPrinter.h"
 #include "llvm-readobj.h"

tools/llvm-readobj/ObjDumper.cpp

@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "ObjDumper.h"
-#include "Error.h"
 #include "llvm-readobj.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/Error.h"

tools/llvm-readobj/WasmDumper.cpp

@@ -10,7 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "Error.h"
 #include "ObjDumper.h"
 #include "llvm-readobj.h"
 #include "llvm/Object/Wasm.h"

tools/llvm-readobj/Win64EHDumper.cpp

@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "Win64EHDumper.h"
-#include "Error.h"
 #include "llvm-readobj.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -120,10 +119,10 @@ static std::error_code getSymbol(const COFFObjectFile &COFF, uint64_t VA,
       return errorToErrorCode(Address.takeError());
     if (*Address == VA) {
       Sym = Symbol;
-      return readobj_error::success;
+      return std::error_code();
     }
   }
-  return readobj_error::unknown_symbol;
+  return inconvertibleErrorCode();
 }
 
 static std::string formatSymbol(const Dumper::Context &Ctx,

tools/llvm-readobj/WindowsResourceDumper.cpp

@@ -11,7 +11,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "WindowsResourceDumper.h"
-#include "Error.h"
 #include "llvm/Object/WindowsResource.h"
 #include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/ScopedPrinter.h"

tools/llvm-readobj/XCOFFDumper.cpp

@@ -10,7 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "Error.h"
 #include "ObjDumper.h"
 #include "llvm-readobj.h"
 #include "llvm/Object/XCOFFObjectFile.h"

tools/llvm-readobj/llvm-readobj.cpp

@@ -19,7 +19,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm-readobj.h"
-#include "Error.h"
 #include "ObjDumper.h"
 #include "WindowsResourceDumper.h"
 #include "llvm/DebugInfo/CodeView/GlobalTypeTableBuilder.h"
@@ -579,12 +578,16 @@ static void dumpArchive(const Archive *Arc, ScopedPrinter &Writer) {
         reportError(std::move(E), Arc->getFileName());
       continue;
     }
-    if (ObjectFile *Obj = dyn_cast<ObjectFile>(&*ChildOrErr.get()))
+
+    Binary *Bin = ChildOrErr->get();
+    if (ObjectFile *Obj = dyn_cast<ObjectFile>(Bin))
       dumpObject(*Obj, Writer, Arc);
-    else if (COFFImportFile *Imp = dyn_cast<COFFImportFile>(&*ChildOrErr.get()))
+    else if (COFFImportFile *Imp = dyn_cast<COFFImportFile>(Bin))
       dumpCOFFImportFile(Imp, Writer);
     else
-      reportWarning(errorCodeToError(readobj_error::unrecognized_file_format),
+      reportWarning(createStringError(errc::invalid_argument,
+                                      Bin->getFileName() +
+                                          " has an unsupported file type"),
                     Arc->getFileName());
   }
   if (Err)
@@ -634,8 +637,7 @@ static void dumpInput(StringRef File, ScopedPrinter &Writer) {
   else if (WindowsResource *WinRes = dyn_cast<WindowsResource>(&Binary))
     dumpWindowsResourceFile(WinRes, Writer);
   else
-    reportError(errorCodeToError(readobj_error::unrecognized_file_format),
-                File);
+    llvm_unreachable("unrecognized file type");
 
   CVTypes.Binaries.push_back(std::move(*BinaryOrErr));
 }