[DWARFLinker][dsymutil][NFC] Move DwarfStreamer into DWARFLinker.

[avl]

Summary

For implementing "remove obsolete debug info in lld", it is neccesary
to have DWARF generation code implementation. dsymutil uses DwarfStreamer
for that purpose. DwarfStreamer uses AsmPrinter. It is considered OK
to use AsmPrinter based code in lld(D74169). This patch moves
DwarfStreamer implementation into DWARFLinker, so that it could be reused
from lld.

Generally, a better place for such a common DWARF generation code would be
not DWARFLinker but an additional separate library. Such a library could
contain a single version of DWARF generation routines and could also
be independent of AsmPrinter. At the current moment, DwarfStreamer
does not pretend to be such a general implementation of DWARF generation.
So I decided to put it into DWARFLinker since it is the only user
of DwarfStreamer.

Testing: it passes "check-all" lit testing. MD5 checksum for clang .dSYM
bundle matches for the dsymutil with/without that patch.

[avl]

added mistakenly missed part of patch.

[fedor.sergeev]

Folks, we have a problem with this fix - when running a build that dynamically links tools with libLLVM.so (LVM_LINK_LLVM_DYLIB) we have massive failures on llvm-readobj
which asserts because it now has a conflict between MC "-W" and readobj "-W" command line options.
Seems like moving DWARFStreamer.cpp into the library w/o first removing its

static mc::RegisterMCTargetOptionsFlags MOF;

was a mistake.

[avl]

@fedor.sergeev Thank you for the info and sorry for the problem. I would make a fix shortly.

[avl]

@fedor.sergeev I integrated the fix for the problem: https://reviews.llvm.org/rG0ed2170dc47718b0c0f4907d14676839a1210a8a , would you mind to check that the problem is cured on your side, please ?

llvm/include/llvm/DWARFLinker/DWARFStreamer.h

-//===- tools/dsymutil/DwarfStreamer.h - Dwarf Streamer ----------*- C++ -*-===//
+//===- DwarfStreamer.h ------------------------------------------*- 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_DSYMUTIL_DWARFSTREAMER_H
-#define LLVM_TOOLS_DSYMUTIL_DWARFSTREAMER_H
+#ifndef LLVM_DWARFLINKER_DWARFSTREAMER_H
+#define LLVM_DWARFLINKER_DWARFSTREAMER_H
 
-#include "DebugMap.h"
-#include "LinkUtils.h"
 #include "llvm/CodeGen/AccelTable.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/NonRelocatableStringpool.h"
 #include "llvm/DWARFLinker/DWARFLinker.h"
 #include "llvm/DWARFLinker/DWARFLinkerCompileUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/MC/MCAsmBackend.h"

 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCTargetOptions.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
 
 namespace llvm {
-namespace dsymutil {
+
+enum class OutputFileType {
+  Object,
+  Assembly,
+};
+
+///   User of DwarfStreamer should call initialization code
+///   for AsmPrinter:
+///
+///   InitializeAllTargetInfos();
+///   InitializeAllTargetMCs();
+///   InitializeAllTargets();
+///   InitializeAllAsmPrinters();
 
 /// The Dwarf streaming logic.
 ///
 /// All interactions with the MC layer that is used to build the debug
 /// information binary representation are handled in this class.
 class DwarfStreamer : public DwarfEmitter {
 public:
-  DwarfStreamer(raw_fd_ostream &OutFile, LinkOptions Options)
-      : OutFile(OutFile), Options(std::move(Options)) {}
+  DwarfStreamer(OutputFileType OutFileType, raw_pwrite_stream &OutFile,
+                std::function<StringRef(StringRef Input)> Translator,
+                bool Minimize, messageHandler Error, messageHandler Warning)
+      : OutFile(OutFile), OutFileType(OutFileType), Translator(Translator),
+        Minimize(Minimize), ErrorHandler(Error), WarningHandler(Warning) {}
 
   bool init(Triple TheTriple);
 
   /// Dump the file to the disk.
-  bool finish(const DebugMap &, SymbolMapTranslator &T);
+  void finish();
 
   AsmPrinter &getAsmPrinter() const { return *Asm; }
 
   /// Set the current output section to debug_info and change
   /// the MC Dwarf version to \p DwarfVersion.
   void switchToDebugInfoSection(unsigned DwarfVersion);
 
   /// Emit the compilation unit header for \p Unit in the
public:
 
   uint64_t getFrameSectionSize() const override { return FrameSectionSize; }
 
   uint64_t getDebugInfoSectionSize() const override {
     return DebugInfoSectionSize;
   }
 
 private:
+  inline void error(const Twine &Error, StringRef Context = "") {
+    if (ErrorHandler)
+      ErrorHandler(Error, Context, nullptr);
+  }
+
+  inline void warn(const Twine &Warning, StringRef Context = "") {
+    if (WarningHandler)
+      WarningHandler(Warning, Context, nullptr);
+  }
+
   /// \defgroup MCObjects MC layer objects constructed by the streamer
   /// @{
   std::unique_ptr<MCRegisterInfo> MRI;
   std::unique_ptr<MCAsmInfo> MAI;
   std::unique_ptr<MCObjectFileInfo> MOFI;
   std::unique_ptr<MCContext> MC;
   MCAsmBackend *MAB; // Owned by MCStreamer
   std::unique_ptr<MCInstrInfo> MII;
   std::unique_ptr<MCSubtargetInfo> MSTI;
   MCInstPrinter *MIP; // Owned by AsmPrinter
   MCCodeEmitter *MCE; // Owned by MCStreamer
   MCStreamer *MS;     // Owned by AsmPrinter
   std::unique_ptr<TargetMachine> TM;
   std::unique_ptr<AsmPrinter> Asm;
   /// @}
 
-  /// The file we stream the linked Dwarf to.
-  raw_fd_ostream &OutFile;
-
-  LinkOptions Options;
+  /// The output file we stream the linked Dwarf to.
+  raw_pwrite_stream &OutFile;
+  OutputFileType OutFileType = OutputFileType::Object;
+  std::function<StringRef(StringRef Input)> Translator;
+  bool Minimize = true;
 
   uint64_t RangesSectionSize = 0;
   uint64_t LocSectionSize = 0;
   uint64_t LineSectionSize = 0;
   uint64_t FrameSectionSize = 0;
   uint64_t DebugInfoSectionSize = 0;
 
   /// Keep track of emitted CUs and their Unique ID.
   struct EmittedUnit {
     unsigned ID;
     MCSymbol *LabelBegin;
   };
   std::vector<EmittedUnit> EmittedUnits;
 
   /// Emit the pubnames or pubtypes section contribution for \p
   /// Unit into \p Sec. The data is provided in \p Names.
   void emitPubSectionForUnit(MCSection *Sec, StringRef Name,
                              const CompileUnit &Unit,
                              const std::vector<CompileUnit::AccelInfo> &Names);
+
+  messageHandler ErrorHandler = nullptr;
+  messageHandler WarningHandler = nullptr;
 };
 
-} // end namespace dsymutil
 } // end namespace llvm
 
-#endif // LLVM_TOOLS_DSYMUTIL_DWARFSTREAMER_H
+#endif // LLVM_DWARFLINKER_DWARFSTREAMER_H

llvm/lib/DWARFLinker/CMakeLists.txt

 add_llvm_component_library(LLVMDWARFLinker
   DWARFLinkerCompileUnit.cpp
   DWARFLinkerDeclContext.cpp
   DWARFLinker.cpp
+  DWARFStreamer.cpp
 
   DEPENDS
   intrinsics_gen
   )

llvm/lib/DWARFLinker/DWARFStreamer.cpp

-//===- tools/dsymutil/DwarfStreamer.cpp - Dwarf Streamer ------------------===//
+//===- DwarfStreamer.cpp --------------------------------------------------===//
 //
 // 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 "DwarfStreamer.h"
-#include "LinkUtils.h"
-#include "MachOUtils.h"
+#include "llvm/DWARFLinker/DWARFStreamer.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/DWARFLinker/DWARFLinkerCompileUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/MC/MCTargetOptions.h"
 #include "llvm/MC/MCTargetOptionsCommandFlags.h"
 #include "llvm/Support/LEB128.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
 
 namespace llvm {
 
 static mc::RegisterMCTargetOptionsFlags MOF;
 
-namespace dsymutil {
-
 bool DwarfStreamer::init(Triple TheTriple) {
   std::string ErrorStr;
   std::string TripleName;
   StringRef Context = "dwarf streamer init";
 
   // Get the target.
   const Target *TheTarget =
       TargetRegistry::lookupTarget(TripleName, TheTriple, ErrorStr);
   if (!TheTarget)
-    return error(ErrorStr, Context);
+    return error(ErrorStr, Context), false;
   TripleName = TheTriple.getTriple();
 
   // Create all the MC Objects.
   MRI.reset(TheTarget->createMCRegInfo(TripleName));
   if (!MRI)
-    return error(Twine("no register info for target ") + TripleName, Context);
+    return error(Twine("no register info for target ") + TripleName, Context),
+           false;
 
   MCTargetOptions MCOptions = mc::InitMCTargetOptionsFromFlags();
   MAI.reset(TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
   if (!MAI)
-    return error("no asm info for target " + TripleName, Context);
+    return error("no asm info for target " + TripleName, Context), false;
 
   MOFI.reset(new MCObjectFileInfo);
   MC.reset(new MCContext(MAI.get(), MRI.get(), MOFI.get()));
   MOFI->InitMCObjectFileInfo(TheTriple, /*PIC*/ false, *MC);
 
   MSTI.reset(TheTarget->createMCSubtargetInfo(TripleName, "", ""));
   if (!MSTI)
-    return error("no subtarget info for target " + TripleName, Context);
+    return error("no subtarget info for target " + TripleName, Context), false;
 
   MAB = TheTarget->createMCAsmBackend(*MSTI, *MRI, MCOptions);
   if (!MAB)
-    return error("no asm backend for target " + TripleName, Context);
+    return error("no asm backend for target " + TripleName, Context), false;
 
   MII.reset(TheTarget->createMCInstrInfo());
   if (!MII)
-    return error("no instr info info for target " + TripleName, Context);
+    return error("no instr info info for target " + TripleName, Context), false;
 
   MCE = TheTarget->createMCCodeEmitter(*MII, *MRI, *MC);
   if (!MCE)
-    return error("no code emitter for target " + TripleName, Context);
+    return error("no code emitter for target " + TripleName, Context), false;
 
-  switch (Options.FileType) {
+  switch (OutFileType) {
   case OutputFileType::Assembly: {
     MIP = TheTarget->createMCInstPrinter(TheTriple, MAI->getAssemblerDialect(),
                                          *MAI, *MII, *MRI);
     MS = TheTarget->createAsmStreamer(
         *MC, std::make_unique<formatted_raw_ostream>(OutFile), true, true, MIP,
         std::unique_ptr<MCCodeEmitter>(MCE), std::unique_ptr<MCAsmBackend>(MAB),
         true);
     break;
   }
   case OutputFileType::Object: {
     MS = TheTarget->createMCObjectStreamer(
         TheTriple, *MC, std::unique_ptr<MCAsmBackend>(MAB),
         MAB->createObjectWriter(OutFile), std::unique_ptr<MCCodeEmitter>(MCE),
         *MSTI, MCOptions.MCRelaxAll, MCOptions.MCIncrementalLinkerCompatible,
         /*DWARFMustBeAtTheEnd*/ false);
     break;
   }
   }
 
   if (!MS)
-    return error("no object streamer for target " + TripleName, Context);
+    return error("no object streamer for target " + TripleName, Context), false;
 
   // Finally create the AsmPrinter we'll use to emit the DIEs.
   TM.reset(TheTarget->createTargetMachine(TripleName, "", "", TargetOptions(),
                                           None));
   if (!TM)
-    return error("no target machine for target " + TripleName, Context);
+    return error("no target machine for target " + TripleName, Context), false;
 
   Asm.reset(TheTarget->createAsmPrinter(*TM, std::unique_ptr<MCStreamer>(MS)));
   if (!Asm)
-    return error("no asm printer for target " + TripleName, Context);
+    return error("no asm printer for target " + TripleName, Context), false;
 
   RangesSectionSize = 0;
   LocSectionSize = 0;
   LineSectionSize = 0;
   FrameSectionSize = 0;
   DebugInfoSectionSize = 0;
 
   return true;
 }
 
-bool DwarfStreamer::finish(const DebugMap &DM, SymbolMapTranslator &T) {
-  bool Result = true;
-  if (DM.getTriple().isOSDarwin() && !DM.getBinaryPath().empty() &&
-      Options.FileType == OutputFileType::Object)
-    Result = MachOUtils::generateDsymCompanion(DM, T, *MS, OutFile);
-  else
-    MS->Finish();
-  return Result;
-}
+void DwarfStreamer::finish() { MS->Finish(); }
 
 void DwarfStreamer::switchToDebugInfoSection(unsigned DwarfVersion) {
   MS->SwitchSection(MOFI->getDwarfInfoSection());
   MC->setDwarfVersion(DwarfVersion);
 }
 
 /// Emit the compilation unit header for \p Unit in the debug_info section.
 ///
void DwarfStreamer::translateLineTable(DataExtractor Data, uint64_t Offset) {
   Asm->OutStreamer->emitBytes(Contents.slice(AfterHeaderLengthOffset, Offset));
   LineSectionSize += Offset - AfterHeaderLengthOffset;
 
   // Offset points to the first directory.
   while (const char *Dir = Data.getCStr(&Offset)) {
     if (Dir[0] == 0)
       break;
 
-    StringRef Translated = Options.Translator(Dir);
+    StringRef Translated = Translator(Dir);
     Asm->OutStreamer->emitBytes(Translated);
     Asm->emitInt8(0);
     LineSectionSize += Translated.size() + 1;
   }
   Asm->emitInt8(0);
   LineSectionSize += 1;
 
   while (const char *File = Data.getCStr(&Offset)) {
     if (File[0] == 0)
       break;
 
-    StringRef Translated = Options.Translator(File);
+    StringRef Translated = Translator(File);
     Asm->OutStreamer->emitBytes(Translated);
     Asm->emitInt8(0);
     LineSectionSize += Translated.size() + 1;
 
     uint64_t OffsetBeforeLEBs = Offset;
     Asm->emitULEB128(Data.getULEB128(&Offset));
     Asm->emitULEB128(Data.getULEB128(&Offset));
     Asm->emitULEB128(Data.getULEB128(&Offset));
void DwarfStreamer::emitPubSectionForUnit(
   if (!HeaderEmitted)
     return;
   Asm->emitInt32(0); // End marker.
   Asm->OutStreamer->emitLabel(EndLabel);
 }
 
 /// Emit .debug_pubnames for \p Unit.
 void DwarfStreamer::emitPubNamesForUnit(const CompileUnit &Unit) {
-  if (Options.Minimize)
+  if (Minimize)
     return;
   emitPubSectionForUnit(MC->getObjectFileInfo()->getDwarfPubNamesSection(),
                         "names", Unit, Unit.getPubnames());
 }
 
 /// Emit .debug_pubtypes for \p Unit.
 void DwarfStreamer::emitPubTypesForUnit(const CompileUnit &Unit) {
-  if (Options.Minimize)
+  if (Minimize)
     return;
   emitPubSectionForUnit(MC->getObjectFileInfo()->getDwarfPubTypesSection(),
                         "types", Unit, Unit.getPubtypes());
 }
 
 /// Emit a CIE into the debug_frame section.
 void DwarfStreamer::emitCIE(StringRef CIEBytes) {
   MS->SwitchSection(MC->getObjectFileInfo()->getDwarfFrameSection());
void DwarfStreamer::emitFDE(uint32_t CIEOffset, uint32_t AddrSize,
 
   MS->emitIntValue(FDEBytes.size() + 4 + AddrSize, 4);
   MS->emitIntValue(CIEOffset, 4);
   MS->emitIntValue(Address, AddrSize);
   MS->emitBytes(FDEBytes);
   FrameSectionSize += FDEBytes.size() + 8 + AddrSize;
 }
 
-} // namespace dsymutil
 } // namespace llvm

llvm/lib/DWARFLinker/LLVMBuild.txt

 ;   http://llvm.org/docs/LLVMBuild.html
 ;
 ;===------------------------------------------------------------------------===;
 
 [component_0]
 type = Library
 name = DWARFLinker
 parent = Libraries
-required_libraries = DebugInfoDWARF AsmPrinter CodeGen MC Object Support
+required_libraries = DebugInfoDWARF AsmPrinter CodeGen MC Object Support 

llvm/tools/dsymutil/CMakeLists.txt

set(LLVM_LINK_COMPONENTS
   )
 
 add_llvm_tool(dsymutil
   dsymutil.cpp
   BinaryHolder.cpp
   CFBundle.cpp
   DebugMap.cpp
   DwarfLinkerForBinary.cpp
-  DwarfStreamer.cpp
   MachODebugMapParser.cpp
   MachOUtils.cpp
   SymbolMap.cpp
 
   DEPENDS
   intrinsics_gen
   ${tablegen_deps}
   )
 
 if(APPLE)
   target_link_libraries(dsymutil PRIVATE "-framework CoreFoundation")
 endif(APPLE)
 
 if(HAVE_CXX_ATOMICS_WITH_LIB OR HAVE_CXX_ATOMICS64_WITH_LIB)
   target_link_libraries(dsymutil PRIVATE atomic)
 endif()

llvm/tools/dsymutil/DwarfLinkerForBinary.h

 //===- tools/dsymutil/DwarfLinkerForBinary.h --------------------*- 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_DSYMUTIL_DWARFLINKER_H
 #define LLVM_TOOLS_DSYMUTIL_DWARFLINKER_H
 
 #include "BinaryHolder.h"
 #include "DebugMap.h"
-#include "DwarfStreamer.h"
 #include "LinkUtils.h"
 #include "llvm/DWARFLinker/DWARFLinker.h"
 #include "llvm/DWARFLinker/DWARFLinkerCompileUnit.h"
 #include "llvm/DWARFLinker/DWARFLinkerDeclContext.h"
+#include "llvm/DWARFLinker/DWARFStreamer.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/Remarks/RemarkFormat.h"
 #include "llvm/Remarks/RemarkLinker.h"
 
 namespace llvm {
 namespace dsymutil {
 
 /// The core of the Dsymutil Dwarf linking logic.

llvm/tools/dsymutil/DwarfLinkerForBinary.cpp

 //===- tools/dsymutil/DwarfLinkerForBinary.cpp ----------------------------===//
 //
 // 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 "DwarfLinkerForBinary.h"
 #include "BinaryHolder.h"
 #include "DebugMap.h"
-#include "DwarfStreamer.h"
 #include "MachOUtils.h"
 #include "dsymutil.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/FoldingSet.h"
void DwarfLinkerForBinary::reportWarning(const Twine &Warning,
   DIE->dump(errs(), 6 /* Indent */, DumpOpts);
 }
 
 bool DwarfLinkerForBinary::createStreamer(const Triple &TheTriple,
                                           raw_fd_ostream &OutFile) {
   if (Options.NoOutput)
     return true;
 
-  Streamer = std::make_unique<DwarfStreamer>(OutFile, Options);
+  Streamer = std::make_unique<DwarfStreamer>(
+      Options.FileType, OutFile, Options.Translator, Options.Minimize,
+      [&](const Twine &Error, StringRef Context, const DWARFDie *) {
+        error(Error, Context);
+      },
+      [&](const Twine &Warning, StringRef Context, const DWARFDie *) {
+        warn(Warning, Context);
+      });
   return Streamer->init(TheTriple);
 }
 
 ErrorOr<const object::ObjectFile &>
 DwarfLinkerForBinary::loadObject(const DebugMapObject &Obj,
                                  const Triple &Triple) {
   auto ObjectEntry =
       BinHolder.getObjectEntry(Obj.getObjectFilename(), Obj.getTimestamp());
bool DwarfLinkerForBinary::link(const DebugMap &Map) {
   GeneralLinker.setPrependPath(Options.PrependPath);
   if (Options.Translator)
     GeneralLinker.setStringsTranslator(TranslationLambda);
   GeneralLinker.setWarningHandler(
       [&](const Twine &Warning, StringRef Context, const DWARFDie *DIE) {
         reportWarning(Warning, Context, DIE);
       });
   GeneralLinker.setErrorHandler(
-      [&](const Twine &Error, StringRef Context, const DWARFDie *DIE) {
+      [&](const Twine &Error, StringRef Context, const DWARFDie *) {
         error(Error, Context);
       });
   GeneralLinker.setObjFileLoader(
       [&DebugMap, &RL, this](StringRef ContainerName,
                              StringRef Path) -> ErrorOr<DwarfFile &> {
         auto &Obj = DebugMap.addDebugMapObject(
             Path, sys::TimePoint<std::chrono::seconds>(), MachO::N_OSO);
 
bool DwarfLinkerForBinary::link(const DebugMap &Map) {
 
   if (Options.ResourceDir && !ParseableSwiftInterfaces.empty()) {
     StringRef ArchName = Triple::getArchTypeName(Map.getTriple().getArch());
     if (auto E =
             copySwiftInterfaces(ParseableSwiftInterfaces, ArchName, Options))
       return error(toString(std::move(E)));
   }
 
-  return Streamer->finish(Map, Options.Translator);
+  if (Map.getTriple().isOSDarwin() && !Map.getBinaryPath().empty() &&
+      Options.FileType == OutputFileType::Object)
+    return MachOUtils::generateDsymCompanion(
+        Map, Options.Translator, *Streamer->getAsmPrinter().OutStreamer,
+        OutFile);
+  else
+    return Streamer->finish(), true;
 }
 
 static bool isMachOPairedReloc(uint64_t RelocType, uint64_t Arch) {
   switch (Arch) {
   case Triple::x86:
     return RelocType == MachO::GENERIC_RELOC_SECTDIFF ||
            RelocType == MachO::GENERIC_RELOC_LOCAL_SECTDIFF;
   case Triple::x86_64:

llvm/tools/dsymutil/LinkUtils.h

 
 #include "SymbolMap.h"
 
 #include "llvm/ADT/Twine.h"
 #include "llvm/Remarks/RemarkFormat.h"
 #include "llvm/Support/WithColor.h"
 
 #include "llvm/DWARFLinker/DWARFLinker.h"
+#include "llvm/DWARFLinker/DWARFStreamer.h"
 #include <string>
 
 namespace llvm {
 namespace dsymutil {
 
-enum class OutputFileType {
-  Object,
-  Assembly,
-};
-
 struct LinkOptions {
   /// Verbosity
   bool Verbose = false;
 
   /// Skip emitting output
   bool NoOutput = false;
 
   /// Do not unique types according to ODR