[obj2yaml] Recognize input file format automatically

[atanasyan]

Summary

Recognize input file format automatically using llvm::object::ObjectFileinterface methods isCOFF(). The '-coff' command line option has been removed. It was not used in any test cases. As a part of this patch I reimplement error diagnostics in a more standard way.

[Bigcheese]

lgtm

[atanasyan]

Thanks for review.

Closed by commit rL208157 (authored by @atanasyan)

tools/obj2yaml/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   Object
   Support
   )
 
 add_llvm_utility(obj2yaml
-  obj2yaml.cpp coff2yaml.cpp
+  obj2yaml.cpp coff2yaml.cpp Error.cpp
   )

tools/obj2yaml/Error.h

+//===- Error.h - system_error extensions for obj2yaml -----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_ERROR_H
+#define LLVM_TOOLS_ERROR_H
+
+#include "llvm/Support/system_error.h"
+
+namespace llvm {
+
+const error_category &obj2yaml_category();
+
+struct obj2yaml_error {
+  enum _ {
+    success = 0,
+    file_not_found,
+    unrecognized_file_format,
+    unsupported_obj_file_format
+  };
+  _ v_;
+
+  obj2yaml_error(_ v) : v_(v) {}
+  explicit obj2yaml_error(int v) : v_(_(v)) {}
+  operator int() const {return v_;}
+};
+
+inline error_code make_error_code(obj2yaml_error e) {
+  return error_code(static_cast<int>(e), obj2yaml_category());
+}
+
+template <> struct is_error_code_enum<obj2yaml_error> : std::true_type { };
+template <> struct is_error_code_enum<obj2yaml_error::_> : std::true_type { };
+
+} // namespace llvm
+
+#endif

tools/obj2yaml/Error.cpp

+//===- Error.cpp - system_error extensions for obj2yaml ---------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Error.h"
+#include "llvm/Support/ErrorHandling.h"
+
+using namespace llvm;
+
+namespace {
+class _obj2yaml_error_category : public error_category {
+public:
+  const char *name() const override;
+  std::string message(int ev) const override;
+  error_condition default_error_condition(int ev) const override;
+};
+} // namespace
+
+const char *_obj2yaml_error_category::name() const { return "obj2yaml"; }
+
+std::string _obj2yaml_error_category::message(int ev) const {
+  switch (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.";
+  default:
+    llvm_unreachable("An enumerator of obj2yaml_error does not have a message "
+                     "defined.");
+  }
+}
+
+error_condition
+_obj2yaml_error_category::default_error_condition(int ev) const {
+  if (ev == obj2yaml_error::success)
+    return errc::success;
+  return errc::invalid_argument;
+}
+
+namespace llvm {
+const error_category &obj2yaml_category() {
+  static _obj2yaml_error_category o;
+  return o;
+}
+} // namespace llvm

tools/obj2yaml/coff2yaml.cpp

for (const auto &S : Obj.symbols()) {
     Symbols.push_back(Sym);
   }
 }
 
 COFFYAML::Object &COFFDumper::getYAMLObj() {
   return YAMLObj;
 }
 
-error_code coff2yaml(raw_ostream &Out, MemoryBuffer *Buff) {
-  error_code ec;
-  object::COFFObjectFile Obj(Buff, ec);
-  check(ec);
+error_code coff2yaml(raw_ostream &Out, const object::COFFObjectFile &Obj) {
   COFFDumper Dumper(Obj);
 
   yaml::Output Yout(Out);
   Yout << Dumper.getYAMLObj();
 
   return object::object_error::success;
 }

tools/obj2yaml/obj2yaml.h

 //===------ utils/obj2yaml.hpp - obj2yaml conversion tool -------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 // This file declares some helper routines, and also the format-specific
 // writers. To add a new format, add the declaration here, and, in a separate
 // source file, implement it.
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_TOOLS_OBJ2YAML_H
 #define LLVM_TOOLS_OBJ2YAML_H
 
-#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Object/COFF.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/system_error.h"
 
-llvm::error_code coff2yaml(llvm::raw_ostream &Out, llvm::MemoryBuffer *TheObj);
+llvm::error_code coff2yaml(llvm::raw_ostream &Out,
+                           const llvm::object::COFFObjectFile &Obj);
 
 #endif

tools/obj2yaml/obj2yaml.cpp

 //===------ utils/obj2yaml.cpp - obj2yaml conversion tool -------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
+#include "Error.h"
 #include "obj2yaml.h"
 #include "llvm/Object/Archive.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/Signals.h"
 
 using namespace llvm;
+using namespace llvm::object;
 
-namespace {
-enum ObjectFileType {
-  coff
-};
+static error_code dumpObject(const ObjectFile &Obj) {
+  if (Obj.isCOFF())
+    return coff2yaml(outs(), cast<COFFObjectFile>(Obj));
+
+  return obj2yaml_error::unsupported_obj_file_format;
 }
 
-cl::opt<ObjectFileType> InputFormat(
-    cl::desc("Choose input format"),
-    cl::values(clEnumVal(coff, "process COFF object files"), clEnumValEnd));
+static error_code dumpInput(StringRef File) {
+  if (File != "-" && !sys::fs::exists(File))
+    return obj2yaml_error::file_not_found;
+
+  ErrorOr<Binary *> BinaryOrErr = createBinary(File);
+  if (error_code EC = BinaryOrErr.getError())
+    return EC;
+
+  std::unique_ptr<Binary> Binary(BinaryOrErr.get());
+  // TODO: If this is an archive, then burst it and dump each entry
+  if (ObjectFile *Obj = dyn_cast<ObjectFile>(Binary.get()))
+    return dumpObject(*Obj);
+
+  return obj2yaml_error::unrecognized_file_format;
+}
 
 cl::opt<std::string> InputFilename(cl::Positional, cl::desc("<input file>"),
                                    cl::init("-"));
 
 int main(int argc, char *argv[]) {
   cl::ParseCommandLineOptions(argc, argv);
   sys::PrintStackTraceOnErrorSignal();
   PrettyStackTraceProgram X(argc, argv);
   llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
 
-  // Process the input file
-  std::unique_ptr<MemoryBuffer> buf;
-
-  // TODO: If this is an archive, then burst it and dump each entry
-  if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFilename, buf)) {
-    errs() << "Error: '" << ec.message() << "' opening file '" << InputFilename
-           << "'\n";
-  } else {
-    ec = coff2yaml(outs(), buf.release());
-    if (ec)
-      errs() << "Error: " << ec.message() << " dumping COFF file\n";
+  if (error_code EC = dumpInput(InputFilename)) {
+    errs() << "Error: '" << EC.message() << "'\n";
+    return 1;
   }
 
   return 0;
 }