Index: lld/trunk/COFF/Chunks.h
===================================================================
--- lld/trunk/COFF/Chunks.h
+++ lld/trunk/COFF/Chunks.h
@@ -28,7 +28,6 @@
 using llvm::object::SectionRef;
 using llvm::object::coff_relocation;
 using llvm::object::coff_section;
-using llvm::sys::fs::file_magic;
 
 class Baserel;
 class Defined;
Index: lld/trunk/COFF/Chunks.cpp
===================================================================
--- lld/trunk/COFF/Chunks.cpp
+++ lld/trunk/COFF/Chunks.cpp
@@ -150,7 +150,7 @@
   // Apply relocations.
   for (const coff_relocation &Rel : Relocs) {
     uint8_t *Off = Buf + OutputSectionOff + Rel.VirtualAddress;
-    SymbolBody *Body = File->getSymbolBody(Rel.SymbolTableIndex)->repl();
+    SymbolBody *Body = File->getSymbolBody(Rel.SymbolTableIndex);
     Defined *Sym = cast<Defined>(Body);
     uint64_t P = RVA + Rel.VirtualAddress;
     switch (Config->Machine) {
@@ -203,7 +203,7 @@
     uint8_t Ty = getBaserelType(Rel);
     if (Ty == IMAGE_REL_BASED_ABSOLUTE)
       continue;
-    SymbolBody *Body = File->getSymbolBody(Rel.SymbolTableIndex)->repl();
+    SymbolBody *Body = File->getSymbolBody(Rel.SymbolTableIndex);
     if (isa<DefinedAbsolute>(Body))
       continue;
     Res->emplace_back(RVA + Rel.VirtualAddress, Ty);
Index: lld/trunk/COFF/Config.h
===================================================================
--- lld/trunk/COFF/Config.h
+++ lld/trunk/COFF/Config.h
@@ -26,7 +26,8 @@
 class DefinedAbsolute;
 class DefinedRelative;
 class StringChunk;
-class Undefined;
+struct Symbol;
+class SymbolBody;
 
 // Short aliases.
 static const auto AMD64 = llvm::COFF::IMAGE_FILE_MACHINE_AMD64;
@@ -37,7 +38,7 @@
 struct Export {
   StringRef Name;       // N in /export:N or /export:E=N
   StringRef ExtName;    // E in /export:E=N
-  Undefined *Sym = nullptr;
+  SymbolBody *Sym = nullptr;
   uint16_t Ordinal = 0;
   bool Noname = false;
   bool Data = false;
@@ -76,7 +77,7 @@
   llvm::COFF::MachineTypes Machine = IMAGE_FILE_MACHINE_UNKNOWN;
   bool Verbose = false;
   WindowsSubsystem Subsystem = llvm::COFF::IMAGE_SUBSYSTEM_UNKNOWN;
-  Undefined *Entry = nullptr;
+  SymbolBody *Entry = nullptr;
   bool NoEntry = false;
   std::string OutputFile;
   bool DoGC = true;
@@ -89,7 +90,7 @@
   StringRef PDBPath;
 
   // Symbols in this set are considered as live by the garbage collector.
-  std::set<Undefined *> GCRoot;
+  std::set<SymbolBody *> GCRoot;
 
   std::set<StringRef> NoDefaultLibs;
   bool NoDefaultLibAll = false;
@@ -100,11 +101,11 @@
   std::vector<Export> Exports;
   std::set<std::string> DelayLoads;
   std::map<std::string, int> DLLOrder;
-  Undefined *DelayLoadHelper = nullptr;
+  SymbolBody *DelayLoadHelper = nullptr;
 
   // Used for SafeSEH.
-  DefinedRelative *SEHTable = nullptr;
-  DefinedAbsolute *SEHCount = nullptr;
+  Symbol *SEHTable = nullptr;
+  Symbol *SEHCount = nullptr;
 
   // Used for /opt:lldlto=N
   unsigned LTOOptLevel = 2;
Index: lld/trunk/COFF/DLL.cpp
===================================================================
--- lld/trunk/COFF/DLL.cpp
+++ lld/trunk/COFF/DLL.cpp
@@ -324,7 +324,7 @@
       if (E.ForwardChunk) {
         write32le(P, E.ForwardChunk->getRVA());
       } else {
-        write32le(P, cast<Defined>(E.Sym->repl())->getRVA());
+        write32le(P, cast<Defined>(E.Sym)->getRVA());
       }
     }
   }
Index: lld/trunk/COFF/Driver.h
===================================================================
--- lld/trunk/COFF/Driver.h
+++ lld/trunk/COFF/Driver.h
@@ -59,6 +59,7 @@
 
 class LinkerDriver {
 public:
+  LinkerDriver() { coff::Symtab = &Symtab; }
   void link(llvm::ArrayRef<const char *> Args);
 
   // Used by the resolver to parse .drectve section contents.
@@ -86,7 +87,7 @@
   std::vector<StringRef> SearchPaths;
   std::set<std::string> VisitedFiles;
 
-  Undefined *addUndefined(StringRef Sym);
+  SymbolBody *addUndefined(StringRef Sym);
   StringRef mangle(StringRef Sym);
 
   // Windows specific -- "main" is not the only main function in Windows.
Index: lld/trunk/COFF/Driver.cpp
===================================================================
--- lld/trunk/COFF/Driver.cpp
+++ lld/trunk/COFF/Driver.cpp
@@ -207,10 +207,10 @@
   }
 }
 
-Undefined *LinkerDriver::addUndefined(StringRef Name) {
-  Undefined *U = Symtab.addUndefined(Name);
-  Config->GCRoot.insert(U);
-  return U;
+SymbolBody *LinkerDriver::addUndefined(StringRef Name) {
+  SymbolBody *B = Symtab.addUndefined(Name);
+  Config->GCRoot.insert(B);
+  return B;
 }
 
 // Symbol names are mangled by appending "_" prefix on x86.
@@ -232,7 +232,7 @@
   };
   for (auto E : Entries) {
     StringRef Entry = Symtab.findMangle(mangle(E[0]));
-    if (!Entry.empty() && !isa<Undefined>(Symtab.find(Entry)->Body))
+    if (!Entry.empty() && !isa<Undefined>(Symtab.find(Entry)->body()))
       return mangle(E[1]);
   }
   return "";
@@ -715,7 +715,7 @@
       Symbol *Sym = Symtab.find(From);
       if (!Sym)
         continue;
-      if (auto *U = dyn_cast<Undefined>(Sym->Body))
+      if (auto *U = dyn_cast<Undefined>(Sym->body()))
         if (!U->WeakAlias)
           U->WeakAlias = Symtab.addUndefined(To);
     }
@@ -734,7 +734,7 @@
   Symtab.addCombinedLTOObjects();
 
   // Make sure we have resolved all symbols.
-  Symtab.reportRemainingUndefines(/*Resolve=*/true);
+  Symtab.reportRemainingUndefines();
 
   // Windows specific -- if no /subsystem is given, we need to infer
   // that from entry point name.
Index: lld/trunk/COFF/DriverUtils.cpp
===================================================================
--- lld/trunk/COFF/DriverUtils.cpp
+++ lld/trunk/COFF/DriverUtils.cpp
@@ -510,13 +510,13 @@
   }
 
   for (Export &E : Config->Exports) {
+    SymbolBody *Sym = E.Sym;
     if (!E.ForwardTo.empty()) {
       E.SymbolName = E.Name;
-    } else if (Undefined *U = cast_or_null<Undefined>(E.Sym->WeakAlias)) {
-      E.SymbolName = U->getName();
-    } else {
-      E.SymbolName = E.Sym->getName();
-    }
+    } else if (auto *U = dyn_cast<Undefined>(Sym))
+      if (U->WeakAlias)
+        Sym = U->WeakAlias;
+    E.SymbolName = Sym->getName();
   }
 
   for (Export &E : Config->Exports) {
Index: lld/trunk/COFF/ICF.cpp
===================================================================
--- lld/trunk/COFF/ICF.cpp
+++ lld/trunk/COFF/ICF.cpp
@@ -115,8 +115,8 @@
         R1.VirtualAddress != R2.VirtualAddress) {
       return false;
     }
-    SymbolBody *B1 = A->File->getSymbolBody(R1.SymbolTableIndex)->repl();
-    SymbolBody *B2 = B->File->getSymbolBody(R2.SymbolTableIndex)->repl();
+    SymbolBody *B1 = A->File->getSymbolBody(R1.SymbolTableIndex);
+    SymbolBody *B2 = B->File->getSymbolBody(R2.SymbolTableIndex);
     if (B1 == B2)
       return true;
     if (auto *D1 = dyn_cast<DefinedRegular>(B1))
@@ -141,8 +141,8 @@
 bool ICF::equalsVariable(const SectionChunk *A, const SectionChunk *B) {
   // Compare relocations.
   auto Eq = [&](const coff_relocation &R1, const coff_relocation &R2) {
-    SymbolBody *B1 = A->File->getSymbolBody(R1.SymbolTableIndex)->repl();
-    SymbolBody *B2 = B->File->getSymbolBody(R2.SymbolTableIndex)->repl();
+    SymbolBody *B1 = A->File->getSymbolBody(R1.SymbolTableIndex);
+    SymbolBody *B2 = B->File->getSymbolBody(R2.SymbolTableIndex);
     if (B1 == B2)
       return true;
     if (auto *D1 = dyn_cast<DefinedRegular>(B1))
Index: lld/trunk/COFF/InputFiles.h
===================================================================
--- lld/trunk/COFF/InputFiles.h
+++ lld/trunk/COFF/InputFiles.h
@@ -31,6 +31,7 @@
 using llvm::object::Archive;
 using llvm::object::COFFObjectFile;
 using llvm::object::COFFSymbolRef;
+using llvm::object::coff_import_header;
 using llvm::object::coff_section;
 
 class Chunk;
@@ -39,6 +40,7 @@
 class DefinedImportThunk;
 class Lazy;
 class SectionChunk;
+struct Symbol;
 class SymbolBody;
 class Undefined;
 
@@ -52,9 +54,6 @@
   // Returns the filename.
   StringRef getName() { return MB.getBufferIdentifier(); }
 
-  // Returns symbols defined by this file.
-  virtual std::vector<SymbolBody *> &getSymbols() = 0;
-
   // Reads a file (the constructor doesn't do that).
   virtual void parse() = 0;
 
@@ -67,14 +66,8 @@
   // Returns .drectve section contents if exist.
   StringRef getDirectives() { return StringRef(Directives).trim(); }
 
-  // Each file has a unique index. The index number is used to
-  // resolve ties in symbol resolution.
-  int Index;
-  static int NextIndex;
-
 protected:
-  InputFile(Kind K, MemoryBufferRef M)
-      : Index(NextIndex++), MB(M), FileKind(K) {}
+  InputFile(Kind K, MemoryBufferRef M) : MB(M), FileKind(K) {}
 
   MemoryBufferRef MB;
   std::string Directives;
@@ -90,22 +83,14 @@
   static bool classof(const InputFile *F) { return F->kind() == ArchiveKind; }
   void parse() override;
 
-  // Returns a memory buffer for a given symbol. An empty memory buffer
-  // is returned if we have already returned the same memory buffer.
-  // (So that we don't instantiate same members more than once.)
-  MemoryBufferRef getMember(const Archive::Symbol *Sym);
-
-  llvm::MutableArrayRef<Lazy> getLazySymbols();
-
-  // All symbols returned by ArchiveFiles are of Lazy type.
-  std::vector<SymbolBody *> &getSymbols() override {
-    llvm_unreachable("internal fatal");
-  }
+  // Returns an input file for a given symbol. A null pointer is returned if we
+  // have already returned the same input file. (So that we don't instantiate
+  // the same member more than once.)
+  InputFile *getMember(const Archive::Symbol *Sym);
 
 private:
   std::unique_ptr<Archive> File;
   std::string Filename;
-  std::vector<Lazy> LazySymbols;
   std::map<uint64_t, std::atomic_flag> Seen;
 };
 
@@ -118,7 +103,7 @@
   MachineTypes getMachineType() override;
   std::vector<Chunk *> &getChunks() { return Chunks; }
   std::vector<SectionChunk *> &getDebugChunks() { return DebugChunks; }
-  std::vector<SymbolBody *> &getSymbols() override { return SymbolBodies; }
+  std::vector<SymbolBody *> &getSymbols() { return SymbolBodies; }
 
   // Returns a SymbolBody object for the SymbolIndex'th symbol in the
   // underlying object file.
@@ -142,8 +127,8 @@
   void initializeSymbols();
   void initializeSEH();
 
-  Defined *createDefined(COFFSymbolRef Sym, const void *Aux, bool IsFirst);
-  Undefined *createUndefined(COFFSymbolRef Sym);
+  SymbolBody *createDefined(COFFSymbolRef Sym, const void *Aux, bool IsFirst);
+  SymbolBody *createUndefined(COFFSymbolRef Sym);
 
   std::unique_ptr<COFFObjectFile> COFFObj;
   llvm::BumpPtrAllocator Alloc;
@@ -181,7 +166,6 @@
   explicit ImportFile(MemoryBufferRef M)
       : InputFile(ImportKind, M), StringAlloc(StringAllocAux) {}
   static bool classof(const InputFile *F) { return F->kind() == ImportKind; }
-  std::vector<SymbolBody *> &getSymbols() override { return SymbolBodies; }
 
   DefinedImportData *ImpSym = nullptr;
   DefinedImportThunk *ThunkSym = nullptr;
@@ -190,10 +174,14 @@
 private:
   void parse() override;
 
-  std::vector<SymbolBody *> SymbolBodies;
   llvm::BumpPtrAllocator Alloc;
   llvm::BumpPtrAllocator StringAllocAux;
   llvm::StringSaver StringAlloc;
+
+public:
+  StringRef ExternalName;
+  const coff_import_header *Hdr;
+  Chunk *Location = nullptr;
 };
 
 // Used for LTO.
@@ -201,7 +189,7 @@
 public:
   explicit BitcodeFile(MemoryBufferRef M) : InputFile(BitcodeKind, M) {}
   static bool classof(const InputFile *F) { return F->kind() == BitcodeKind; }
-  std::vector<SymbolBody *> &getSymbols() override { return SymbolBodies; }
+  std::vector<SymbolBody *> &getSymbols() { return SymbolBodies; }
   MachineTypes getMachineType() override;
   std::unique_ptr<LTOModule> takeModule() { return std::move(M); }
 
Index: lld/trunk/COFF/InputFiles.cpp
===================================================================
--- lld/trunk/COFF/InputFiles.cpp
+++ lld/trunk/COFF/InputFiles.cpp
@@ -12,7 +12,9 @@
 #include "Driver.h"
 #include "Error.h"
 #include "InputFiles.h"
+#include "SymbolTable.h"
 #include "Symbols.h"
+#include "lld/Support/Memory.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/Twine.h"
@@ -39,13 +41,13 @@
 
 using llvm::Triple;
 using llvm::support::ulittle32_t;
+using llvm::sys::fs::file_magic;
+using llvm::sys::fs::identify_magic;
 
 namespace lld {
 namespace coff {
 
-int InputFile::NextIndex = 0;
 LLVMContext BitcodeFile::Context;
-std::mutex BitcodeFile::Mu;
 
 ArchiveFile::ArchiveFile(MemoryBufferRef M) : InputFile(ArchiveKind, M) {}
 
@@ -53,14 +55,6 @@
   // Parse a MemoryBufferRef as an archive file.
   File = check(Archive::create(MB), toString(this));
 
-  // Allocate a buffer for Lazy objects.
-  size_t NumSyms = File->getNumberOfSymbols();
-  LazySymbols.reserve(NumSyms);
-
-  // Read the symbol table to construct Lazy objects.
-  for (const Archive::Symbol &Sym : File->symbols())
-    LazySymbols.emplace_back(this, Sym);
-
   // Seen is a map from member files to boolean values. Initially
   // all members are mapped to false, which indicates all these files
   // are not read yet.
@@ -69,18 +63,22 @@
     Seen[Child.getChildOffset()].clear();
   if (Err)
     fatal(Err, toString(this));
+
+  // Read the symbol table to construct Lazy objects.
+  for (const Archive::Symbol &Sym : File->symbols())
+    Symtab->addLazy(this, Sym);
 }
 
 // Returns a buffer pointing to a member file containing a given symbol.
 // This function is thread-safe.
-MemoryBufferRef ArchiveFile::getMember(const Archive::Symbol *Sym) {
+InputFile *ArchiveFile::getMember(const Archive::Symbol *Sym) {
   const Archive::Child &C =
       check(Sym->getMember(),
             "could not get the member for symbol " + Sym->getName());
 
   // Return an empty buffer if we have already returned the same buffer.
   if (Seen[C.getChildOffset()].test_and_set())
-    return MemoryBufferRef();
+    return nullptr;
 
   MemoryBufferRef MB =
       check(C.getMemoryBufferRef(),
@@ -90,10 +88,21 @@
     Driver->Cpio->append(relativeToRoot(check(C.getFullName())),
                          MB.getBuffer());
 
-  return MB;
-}
+  file_magic Magic = identify_magic(MB.getBuffer());
+  if (Magic == file_magic::coff_import_library)
+    return make<ImportFile>(MB);
+
+  InputFile *Obj;
+  if (Magic == file_magic::coff_object)
+    Obj = make<ObjectFile>(MB);
+  else if (Magic == file_magic::bitcode)
+    Obj = make<BitcodeFile>(MB);
+  else
+    fatal("unknown file type: " + MB.getBufferIdentifier());
 
-MutableArrayRef<Lazy> ArchiveFile::getLazySymbols() { return LazySymbols; }
+  Obj->ParentName = getName();
+  return Obj;
+}
 
 void ObjectFile::parse() {
   // Parse a memory buffer as a COFF file.
@@ -167,7 +176,7 @@
   uint32_t NumSymbols = COFFObj->getNumberOfSymbols();
   SymbolBodies.reserve(NumSymbols);
   SparseSymbolBodies.resize(NumSymbols);
-  SmallVector<std::pair<Undefined *, uint32_t>, 8> WeakAliases;
+  SmallVector<std::pair<SymbolBody *, uint32_t>, 8> WeakAliases;
   int32_t LastSectionNumber = 0;
   for (uint32_t I = 0; I < NumSymbols; ++I) {
     // Get a COFFSymbolRef object.
@@ -188,7 +197,7 @@
       Body = createUndefined(Sym);
       uint32_t TagIndex =
           static_cast<const coff_aux_weak_external *>(AuxP)->TagIndex;
-      WeakAliases.emplace_back((Undefined *)Body, TagIndex);
+      WeakAliases.emplace_back(Body, TagIndex);
     } else {
       Body = createDefined(Sym, AuxP, IsFirst);
     }
@@ -199,23 +208,30 @@
     I += Sym.getNumberOfAuxSymbols();
     LastSectionNumber = Sym.getSectionNumber();
   }
-  for (auto WeakAlias : WeakAliases)
-    WeakAlias.first->WeakAlias = SparseSymbolBodies[WeakAlias.second];
+  for (auto WeakAlias : WeakAliases) {
+    auto *U = dyn_cast<Undefined>(WeakAlias.first);
+    if (!U)
+      continue;
+    // Report an error if two undefined symbols have different weak aliases.
+    if (U->WeakAlias && U->WeakAlias != SparseSymbolBodies[WeakAlias.second])
+      Symtab->reportDuplicate(U->symbol(), this);
+    U->WeakAlias = SparseSymbolBodies[WeakAlias.second];
+  }
 }
 
-Undefined *ObjectFile::createUndefined(COFFSymbolRef Sym) {
+SymbolBody *ObjectFile::createUndefined(COFFSymbolRef Sym) {
   StringRef Name;
   COFFObj->getSymbolName(Sym, Name);
-  return new (Alloc) Undefined(Name);
+  return Symtab->addUndefined(Name, this, Sym.isWeakExternal())->body();
 }
 
-Defined *ObjectFile::createDefined(COFFSymbolRef Sym, const void *AuxP,
-                                   bool IsFirst) {
+SymbolBody *ObjectFile::createDefined(COFFSymbolRef Sym, const void *AuxP,
+                                      bool IsFirst) {
   StringRef Name;
   if (Sym.isCommon()) {
     auto *C = new (Alloc) CommonChunk(Sym);
     Chunks.push_back(C);
-    return new (Alloc) DefinedCommon(this, Sym, C);
+    return Symtab->addCommon(this, Sym, C)->body();
   }
   if (Sym.isAbsolute()) {
     COFFObj->getSymbolName(Sym, Name);
@@ -228,7 +244,10 @@
         SEHCompat = true;
       return nullptr;
     }
-    return new (Alloc) DefinedAbsolute(Name, Sym);
+    if (Sym.isExternal())
+      return Symtab->addAbsolute(Name, Sym)->body();
+    else
+      return new (Alloc) DefinedAbsolute(Name, Sym);
   }
   int32_t SectionNumber = Sym.getSectionNumber();
   if (SectionNumber == llvm::COFF::IMAGE_SYM_DEBUG)
@@ -258,7 +277,11 @@
     SC->Checksum = Aux->CheckSum;
   }
 
-  auto *B = new (Alloc) DefinedRegular(this, Sym, SC);
+  DefinedRegular *B;
+  if (Sym.isExternal())
+    B = cast<DefinedRegular>(Symtab->addRegular(this, Sym, SC)->body());
+  else
+    B = new (Alloc) DefinedRegular(this, Sym, SC);
   if (SC->isCOMDAT() && Sym.getValue() == 0 && !AuxP)
     SC->setSymbol(B);
 
@@ -320,22 +343,23 @@
     ExtName = ExtName.substr(0, ExtName.find('@'));
     break;
   }
-  ImpSym = new (Alloc) DefinedImportData(DLLName, ImpName, ExtName, Hdr);
-  SymbolBodies.push_back(ImpSym);
+
+  this->Hdr = Hdr;
+  ExternalName = ExtName;
+
+  ImpSym = cast<DefinedImportData>(
+      Symtab->addImportData(ImpName, this)->body());
 
   // If type is function, we need to create a thunk which jump to an
   // address pointed by the __imp_ symbol. (This allows you to call
   // DLL functions just like regular non-DLL functions.)
   if (Hdr->getType() != llvm::COFF::IMPORT_CODE)
     return;
-  ThunkSym = new (Alloc) DefinedImportThunk(Name, ImpSym, Hdr->Machine);
-  SymbolBodies.push_back(ThunkSym);
+  ThunkSym = cast<DefinedImportThunk>(
+      Symtab->addImportThunk(Name, ImpSym, Hdr->Machine)->body());
 }
 
 void BitcodeFile::parse() {
-  // Usually parse() is thread-safe, but bitcode file is an exception.
-  std::lock_guard<std::mutex> Lock(Mu);
-
   Context.enableDebugTypeODRUniquing();
   ErrorOr<std::unique_ptr<LTOModule>> ModOrErr = LTOModule::createFromBuffer(
       Context, MB.getBufferStart(), MB.getBufferSize(), llvm::TargetOptions());
@@ -350,15 +374,15 @@
     StringRef SymName = Saver.save(M->getSymbolName(I));
     int SymbolDef = Attrs & LTO_SYMBOL_DEFINITION_MASK;
     if (SymbolDef == LTO_SYMBOL_DEFINITION_UNDEFINED) {
-      SymbolBodies.push_back(new (Alloc) Undefined(SymName));
+      SymbolBodies.push_back(Symtab->addUndefined(SymName, this, false)->body());
     } else {
       bool Replaceable =
           (SymbolDef == LTO_SYMBOL_DEFINITION_TENTATIVE || // common
            (Attrs & LTO_SYMBOL_COMDAT) ||                  // comdat
            (SymbolDef == LTO_SYMBOL_DEFINITION_WEAK &&     // weak external
             (Attrs & LTO_SYMBOL_ALIAS)));
-      SymbolBodies.push_back(new (Alloc) DefinedBitcode(this, SymName,
-                                                        Replaceable));
+      SymbolBodies.push_back(
+          Symtab->addBitcode(this, SymName, Replaceable)->body());
     }
   }
 
Index: lld/trunk/COFF/MarkLive.cpp
===================================================================
--- lld/trunk/COFF/MarkLive.cpp
+++ lld/trunk/COFF/MarkLive.cpp
@@ -38,8 +38,8 @@
   };
 
   // Add GC root chunks.
-  for (Undefined *U : Config->GCRoot)
-    if (auto *D = dyn_cast<DefinedRegular>(U->repl()))
+  for (SymbolBody *B : Config->GCRoot)
+    if (auto *D = dyn_cast<DefinedRegular>(B))
       Enqueue(D->getChunk());
 
   while (!Worklist.empty()) {
@@ -48,7 +48,7 @@
 
     // Mark all symbols listed in the relocation table for this section.
     for (SymbolBody *S : SC->symbols())
-      if (auto *D = dyn_cast<DefinedRegular>(S->repl()))
+      if (auto *D = dyn_cast<DefinedRegular>(S))
         Enqueue(D->getChunk());
 
     // Mark associative sections if any.
Index: lld/trunk/COFF/SymbolTable.h
===================================================================
--- lld/trunk/COFF/SymbolTable.h
+++ lld/trunk/COFF/SymbolTable.h
@@ -22,6 +22,7 @@
 #endif
 
 #include <future>
+#include <list>
 
 namespace llvm {
 struct LTOCodeGenerator;
@@ -31,6 +32,7 @@
 namespace coff {
 
 class Chunk;
+class CommonChunk;
 class Defined;
 class DefinedAbsolute;
 class DefinedRelative;
@@ -48,7 +50,9 @@
 // conflicts. For example, obviously, a defined symbol is better than
 // an undefined symbol. Or, if there's a conflict between a lazy and a
 // undefined, it'll read an archive member to read a real definition
-// to replace the lazy symbol. The logic is implemented in resolve().
+// to replace the lazy symbol. The logic is implemented in the
+// add*() functions, which are called by input files as they are parsed.
+// There is one add* function per symbol type.
 class SymbolTable {
 public:
   void addFile(InputFile *File);
@@ -57,9 +61,10 @@
   void run();
   bool queueEmpty();
 
-  // Print an error message on undefined symbols. If Resolve is true, try to
-  // resolve any undefined symbols and update the symbol table accordingly.
-  void reportRemainingUndefines(bool Resolve);
+  // Try to resolve any undefined symbols and update the symbol table
+  // accordingly, then print an error message for any remaining undefined
+  // symbols.
+  void reportRemainingUndefines();
 
   // Returns a list of chunks of selected symbols.
   std::vector<Chunk *> getChunks();
@@ -72,7 +77,7 @@
   // mangled symbol. This function tries to find a mangled name
   // for U from the symbol table, and if found, set the symbol as
   // a weak alias for U.
-  void mangleMaybe(Undefined *U);
+  void mangleMaybe(SymbolBody *B);
   StringRef findMangle(StringRef Name);
 
   // Print a layout map to OS.
@@ -91,36 +96,49 @@
   std::vector<ObjectFile *> ObjectFiles;
 
   // Creates an Undefined symbol for a given name.
-  Undefined *addUndefined(StringRef Name);
-  DefinedRelative *addRelative(StringRef Name, uint64_t VA);
-  DefinedAbsolute *addAbsolute(StringRef Name, uint64_t VA);
+  SymbolBody *addUndefined(StringRef Name);
+
+  Symbol *addRelative(StringRef N, uint64_t VA);
+  Symbol *addAbsolute(StringRef N, uint64_t VA);
+
+  Symbol *addUndefined(StringRef Name, InputFile *F, bool IsWeakAlias);
+  void addLazy(ArchiveFile *F, const Archive::Symbol Sym);
+  Symbol *addAbsolute(StringRef N, COFFSymbolRef S);
+  Symbol *addRegular(ObjectFile *F, COFFSymbolRef S, SectionChunk *C);
+  Symbol *addBitcode(BitcodeFile *F, StringRef N, bool IsReplaceable);
+  Symbol *addCommon(ObjectFile *F, COFFSymbolRef S, CommonChunk *C);
+  Symbol *addImportData(StringRef N, ImportFile *F);
+  Symbol *addImportThunk(StringRef Name, DefinedImportData *S,
+                         uint16_t Machine);
+
+  void reportDuplicate(Symbol *Existing, InputFile *NewFile);
 
   // A list of chunks which to be added to .rdata.
   std::vector<Chunk *> LocalImportChunks;
 
 private:
-  void readArchives();
+  void readArchive();
   void readObjects();
 
-  void addSymbol(SymbolBody *New);
-  void addLazy(Lazy *New, std::vector<Symbol *> *Accum);
-  Symbol *insert(SymbolBody *New);
+  std::pair<Symbol *, bool> insert(StringRef Name);
   StringRef findByPrefix(StringRef Prefix);
 
-  void addMemberFile(Lazy *Body);
+  void addMemberFile(ArchiveFile *F, const Archive::Symbol Sym);
   void addCombinedLTOObject(ObjectFile *Obj);
   std::vector<ObjectFile *> createLTOObjects(llvm::LTOCodeGenerator *CG);
 
   llvm::DenseMap<StringRef, Symbol *> Symtab;
 
   std::vector<InputFile *> Files;
-  std::vector<std::future<ArchiveFile *>> ArchiveQueue;
-  std::vector<std::future<InputFile *>> ObjectQueue;
+  std::list<ArchiveFile *> ArchiveQueue;
+  std::vector<InputFile *> ObjectQueue;
 
   std::vector<BitcodeFile *> BitcodeFiles;
   std::vector<SmallString<0>> Objs;
 };
 
+extern SymbolTable *Symtab;
+
 } // namespace coff
 } // namespace lld
 
Index: lld/trunk/COFF/SymbolTable.cpp
===================================================================
--- lld/trunk/COFF/SymbolTable.cpp
+++ lld/trunk/COFF/SymbolTable.cpp
@@ -12,7 +12,6 @@
 #include "Driver.h"
 #include "Error.h"
 #include "Symbols.h"
-#include "lld/Core/Parallel.h"
 #include "lld/Support/Memory.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/LTO/legacy/LTOCodeGenerator.h"
@@ -25,21 +24,15 @@
 namespace lld {
 namespace coff {
 
-void SymbolTable::addFile(InputFile *File) {
-#if LLVM_ENABLE_THREADS
-  std::launch Policy = std::launch::async;
-#else
-  std::launch Policy = std::launch::deferred;
-#endif
+SymbolTable *Symtab;
 
+void SymbolTable::addFile(InputFile *File) {
   Files.push_back(File);
   if (auto *F = dyn_cast<ArchiveFile>(File)) {
-    ArchiveQueue.push_back(
-        std::async(Policy, [=]() { F->parse(); return F; }));
+    ArchiveQueue.push_back(F);
     return;
   }
-  ObjectQueue.push_back(
-      std::async(Policy, [=]() { File->parse(); return File; }));
+  ObjectQueue.push_back(File);
   if (auto *F = dyn_cast<ObjectFile>(File)) {
     ObjectFiles.push_back(F);
   } else if (auto *F = dyn_cast<BitcodeFile>(File)) {
@@ -53,7 +46,7 @@
   if (queueEmpty())
     return;
   readObjects();
-  readArchives();
+  readArchive();
 }
 
 void SymbolTable::run() {
@@ -61,26 +54,17 @@
     step();
 }
 
-void SymbolTable::readArchives() {
+void SymbolTable::readArchive() {
   if (ArchiveQueue.empty())
     return;
 
   // Add lazy symbols to the symbol table. Lazy symbols that conflict
   // with existing undefined symbols are accumulated in LazySyms.
-  std::vector<Symbol *> LazySyms;
-  for (std::future<ArchiveFile *> &Future : ArchiveQueue) {
-    ArchiveFile *File = Future.get();
-    if (Config->Verbose)
-      outs() << "Reading " << toString(File) << "\n";
-    for (Lazy &Sym : File->getLazySymbols())
-      addLazy(&Sym, &LazySyms);
-  }
-  ArchiveQueue.clear();
-
-  // Add archive member files to ObjectQueue that should resolve
-  // existing undefined symbols.
-  for (Symbol *Sym : LazySyms)
-    addMemberFile(cast<Lazy>(Sym->Body));
+  ArchiveFile *File = ArchiveQueue.front();
+  ArchiveQueue.pop_front();
+  if (Config->Verbose)
+    outs() << "Reading " << toString(File) << "\n";
+  File->parse();
 }
 
 void SymbolTable::readObjects() {
@@ -90,14 +74,12 @@
   // Add defined and undefined symbols to the symbol table.
   std::vector<StringRef> Directives;
   for (size_t I = 0; I < ObjectQueue.size(); ++I) {
-    InputFile *File = ObjectQueue[I].get();
+    InputFile *File = ObjectQueue[I];
     if (Config->Verbose)
       outs() << "Reading " << toString(File) << "\n";
+    File->parse();
     // Adding symbols may add more files to ObjectQueue
     // (but not to ArchiveQueue).
-    for (SymbolBody *Sym : File->getSymbols())
-      if (Sym->isExternal())
-        addSymbol(Sym);
     StringRef S = File->getDirectives();
     if (!S.empty()) {
       Directives.push_back(S);
@@ -117,127 +99,239 @@
   return ArchiveQueue.empty() && ObjectQueue.empty();
 }
 
-void SymbolTable::reportRemainingUndefines(bool Resolve) {
+void SymbolTable::reportRemainingUndefines() {
   SmallPtrSet<SymbolBody *, 8> Undefs;
   for (auto &I : Symtab) {
     Symbol *Sym = I.second;
-    auto *Undef = dyn_cast<Undefined>(Sym->Body);
+    auto *Undef = dyn_cast<Undefined>(Sym->body());
     if (!Undef)
       continue;
+    if (!Sym->IsUsedInRegularObj)
+      continue;
     StringRef Name = Undef->getName();
     // A weak alias may have been resolved, so check for that.
     if (Defined *D = Undef->getWeakAlias()) {
-      if (Resolve)
-        Sym->Body = D;
+      // We resolve weak aliases by replacing the alias's SymbolBody with the
+      // target's SymbolBody. This causes all SymbolBody pointers referring to
+      // the old symbol to instead refer to the new symbol. However, we can't
+      // just blindly copy sizeof(Symbol::Body) bytes from D to Sym->Body
+      // because D may be an internal symbol, and internal symbols are stored as
+      // "unparented" SymbolBodies. For that reason we need to check which type
+      // of symbol we are dealing with and copy the correct number of bytes.
+      if (isa<DefinedRegular>(D))
+        memcpy(Sym->Body.buffer, D, sizeof(DefinedRegular));
+      else if (isa<DefinedAbsolute>(D))
+        memcpy(Sym->Body.buffer, D, sizeof(DefinedAbsolute));
+      else
+        // No other internal symbols are possible.
+        Sym->Body = D->symbol()->Body;
       continue;
     }
     // If we can resolve a symbol by removing __imp_ prefix, do that.
     // This odd rule is for compatibility with MSVC linker.
     if (Name.startswith("__imp_")) {
       Symbol *Imp = find(Name.substr(strlen("__imp_")));
-      if (Imp && isa<Defined>(Imp->Body)) {
-        if (!Resolve)
-          continue;
-        auto *D = cast<Defined>(Imp->Body);
-        auto *S = make<DefinedLocalImport>(Name, D);
-        LocalImportChunks.push_back(S->getChunk());
-        Sym->Body = S;
+      if (Imp && isa<Defined>(Imp->body())) {
+        auto *D = cast<Defined>(Imp->body());
+        replaceBody<DefinedLocalImport>(Sym, Name, D);
+        LocalImportChunks.push_back(
+            cast<DefinedLocalImport>(Sym->body())->getChunk());
         continue;
       }
     }
     // Remaining undefined symbols are not fatal if /force is specified.
     // They are replaced with dummy defined symbols.
-    if (Config->Force && Resolve)
-      Sym->Body = make<DefinedAbsolute>(Name, 0);
-    Undefs.insert(Sym->Body);
+    if (Config->Force)
+      replaceBody<DefinedAbsolute>(Sym, Name, 0);
+    Undefs.insert(Sym->body());
   }
   if (Undefs.empty())
     return;
-  for (Undefined *U : Config->GCRoot)
-    if (Undefs.count(U->repl()))
-      errs() << "<root>: undefined symbol: " << U->getName() << "\n";
-  for (InputFile *File : Files)
-    if (!isa<ArchiveFile>(File))
-      for (SymbolBody *Sym : File->getSymbols())
-        if (Undefs.count(Sym->repl()))
-          errs() << toString(File) << ": undefined symbol: " << Sym->getName()
-                 << "\n";
+  for (SymbolBody *B : Config->GCRoot)
+    if (Undefs.count(B))
+      errs() << "<root>: undefined symbol: " << B->getName() << "\n";
+  for (ObjectFile *File : ObjectFiles)
+    for (SymbolBody *Sym : File->getSymbols())
+      if (Undefs.count(Sym))
+        errs() << toString(File) << ": undefined symbol: " << Sym->getName()
+               << "\n";
   if (!Config->Force)
     fatal("link failed");
 }
 
-void SymbolTable::addLazy(Lazy *New, std::vector<Symbol *> *Accum) {
-  Symbol *Sym = insert(New);
-  if (Sym->Body == New)
-    return;
-  SymbolBody *Existing = Sym->Body;
-  if (isa<Defined>(Existing))
-    return;
-  if (Lazy *L = dyn_cast<Lazy>(Existing))
-    if (L->getFileIndex() < New->getFileIndex())
-      return;
-  Sym->Body = New;
-  New->setBackref(Sym);
-  if (isa<Undefined>(Existing))
-    Accum->push_back(Sym);
-}
-
-void SymbolTable::addSymbol(SymbolBody *New) {
-  // Find an existing symbol or create and insert a new one.
-  assert(isa<Defined>(New) || isa<Undefined>(New));
-  Symbol *Sym = insert(New);
-  if (Sym->Body == New)
-    return;
-  SymbolBody *Existing = Sym->Body;
-
-  // If we have an undefined symbol and a lazy symbol,
-  // let the lazy symbol to read a member file.
-  if (auto *L = dyn_cast<Lazy>(Existing)) {
-    // Undefined symbols with weak aliases need not to be resolved,
-    // since they would be replaced with weak aliases if they remain
-    // undefined.
-    if (auto *U = dyn_cast<Undefined>(New)) {
-      if (!U->WeakAlias) {
-        addMemberFile(L);
-        return;
-      }
-    }
-    Sym->Body = New;
-    return;
+std::pair<Symbol *, bool> SymbolTable::insert(StringRef Name) {
+  Symbol *&Sym = Symtab[Name];
+  if (Sym)
+    return {Sym, false};
+  Sym = make<Symbol>();
+  Sym->IsUsedInRegularObj = false;
+  return {Sym, true};
+}
+
+Symbol *SymbolTable::addUndefined(StringRef Name, InputFile *F,
+                                  bool IsWeakAlias) {
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(Name);
+  if (!F || !isa<BitcodeFile>(F))
+    S->IsUsedInRegularObj = true;
+  if (WasInserted || (isa<Lazy>(S->body()) && IsWeakAlias)) {
+    replaceBody<Undefined>(S, Name);
+    return S;
   }
-
-  // compare() returns -1, 0, or 1 if the lhs symbol is less preferable,
-  // equivalent (conflicting), or more preferable, respectively.
-  int Comp = Existing->compare(New);
-  if (Comp == 0)
-    fatal("duplicate symbol: " + toString(*Existing) + " in " +
-          toString(Existing->getFile()) + " and in " +
-          toString(New->getFile()));
-  if (Comp < 0)
-    Sym->Body = New;
-}
-
-Symbol *SymbolTable::insert(SymbolBody *New) {
-  Symbol *&Sym = Symtab[New->getName()];
-  if (Sym) {
-    New->setBackref(Sym);
-    return Sym;
-  }
-  Sym = make<Symbol>(New);
-  New->setBackref(Sym);
-  return Sym;
+  if (auto *L = dyn_cast<Lazy>(S->body()))
+    addMemberFile(L->File, L->Sym);
+  return S;
+}
+
+void SymbolTable::addLazy(ArchiveFile *F, const Archive::Symbol Sym) {
+  StringRef Name = Sym.getName();
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(Name);
+  if (WasInserted) {
+    replaceBody<Lazy>(S, F, Sym);
+    return;
+  }
+  auto *U = dyn_cast<Undefined>(S->body());
+  if (!U || U->WeakAlias)
+    return;
+  addMemberFile(F, Sym);
+}
+
+void SymbolTable::reportDuplicate(Symbol *Existing, InputFile *NewFile) {
+  fatal("duplicate symbol: " + toString(*Existing->body()) + " in " +
+        toString(Existing->body()->getFile()) + " and in " +
+        (NewFile ? toString(NewFile) : "(internal)"));
+}
+
+Symbol *SymbolTable::addAbsolute(StringRef N, COFFSymbolRef Sym) {
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(N);
+  S->IsUsedInRegularObj = true;
+  if (WasInserted || isa<Undefined>(S->body()) || isa<Lazy>(S->body()))
+    replaceBody<DefinedAbsolute>(S, N, Sym);
+  else if (!isa<DefinedCOFF>(S->body()))
+    reportDuplicate(S, nullptr);
+  return S;
+}
+
+Symbol *SymbolTable::addAbsolute(StringRef N, uint64_t VA) {
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(N);
+  S->IsUsedInRegularObj = true;
+  if (WasInserted || isa<Undefined>(S->body()) || isa<Lazy>(S->body()))
+    replaceBody<DefinedAbsolute>(S, N, VA);
+  else if (!isa<DefinedCOFF>(S->body()))
+    reportDuplicate(S, nullptr);
+  return S;
+}
+
+Symbol *SymbolTable::addRelative(StringRef N, uint64_t VA) {
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(N);
+  S->IsUsedInRegularObj = true;
+  if (WasInserted || isa<Undefined>(S->body()) || isa<Lazy>(S->body()))
+    replaceBody<DefinedRelative>(S, N, VA);
+  else if (!isa<DefinedCOFF>(S->body()))
+    reportDuplicate(S, nullptr);
+  return S;
+}
+
+Symbol *SymbolTable::addRegular(ObjectFile *F, COFFSymbolRef Sym,
+                                SectionChunk *C) {
+  StringRef Name;
+  F->getCOFFObj()->getSymbolName(Sym, Name);
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(Name);
+  S->IsUsedInRegularObj = true;
+  if (WasInserted || isa<Undefined>(S->body()) || isa<Lazy>(S->body()))
+    replaceBody<DefinedRegular>(S, F, Sym, C);
+  else if (auto *R = dyn_cast<DefinedRegular>(S->body())) {
+    if (!C->isCOMDAT() || !R->isCOMDAT())
+      reportDuplicate(S, F);
+  } else if (auto *B = dyn_cast<DefinedBitcode>(S->body())) {
+    if (B->IsReplaceable)
+      replaceBody<DefinedRegular>(S, F, Sym, C);
+    else if (!C->isCOMDAT())
+      reportDuplicate(S, F);
+  } else
+    replaceBody<DefinedRegular>(S, F, Sym, C);
+  return S;
+}
+
+Symbol *SymbolTable::addBitcode(BitcodeFile *F, StringRef N, bool IsReplaceable) {
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(N);
+  if (WasInserted || isa<Undefined>(S->body()) || isa<Lazy>(S->body())) {
+    replaceBody<DefinedBitcode>(S, F, N, IsReplaceable);
+    return S;
+  }
+  if (isa<DefinedCommon>(S->body()))
+    return S;
+  if (IsReplaceable)
+    if (isa<DefinedRegular>(S->body()) || isa<DefinedBitcode>(S->body()))
+      return S;
+  reportDuplicate(S, F);
+  return S;
+}
+
+Symbol *SymbolTable::addCommon(ObjectFile *F, COFFSymbolRef Sym,
+                               CommonChunk *C) {
+  StringRef Name;
+  F->getCOFFObj()->getSymbolName(Sym, Name);
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(Name);
+  S->IsUsedInRegularObj = true;
+  if (WasInserted || !isa<DefinedCOFF>(S->body()))
+    replaceBody<DefinedCommon>(S, F, Sym, C);
+  else if (auto *DC = dyn_cast<DefinedCommon>(S->body()))
+    if (Sym.getValue() > DC->getSize())
+      replaceBody<DefinedCommon>(S, F, Sym, C);
+  return S;
+}
+
+Symbol *SymbolTable::addImportData(StringRef N, ImportFile *F) {
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(N);
+  S->IsUsedInRegularObj = true;
+  if (WasInserted || isa<Undefined>(S->body()) || isa<Lazy>(S->body()))
+    replaceBody<DefinedImportData>(S, N, F);
+  else if (!isa<DefinedCOFF>(S->body()))
+    reportDuplicate(S, nullptr);
+  return S;
+}
+
+Symbol *SymbolTable::addImportThunk(StringRef Name, DefinedImportData *ID,
+                                    uint16_t Machine) {
+  Symbol *S;
+  bool WasInserted;
+  std::tie(S, WasInserted) = insert(Name);
+  S->IsUsedInRegularObj = true;
+  if (WasInserted || isa<Undefined>(S->body()) || isa<Lazy>(S->body()))
+    replaceBody<DefinedImportThunk>(S, Name, ID, Machine);
+  else if (!isa<DefinedCOFF>(S->body()))
+    reportDuplicate(S, nullptr);
+  return S;
 }
 
 // Reads an archive member file pointed by a given symbol.
-void SymbolTable::addMemberFile(Lazy *Body) {
-  InputFile *File = Body->getMember();
+void SymbolTable::addMemberFile(ArchiveFile *F, const Archive::Symbol Sym) {
+  InputFile *File = F->getMember(&Sym);
 
   // getMember returns an empty buffer if the member was already
   // read from the library.
   if (!File)
     return;
   if (Config->Verbose)
-    outs() << "Loaded " << toString(File) << " for " << Body->getName() << "\n";
+    outs() << "Loaded " << toString(File) << " for " << Sym.getName() << "\n";
   addFile(File);
 }
 
@@ -274,7 +368,7 @@
 
 StringRef SymbolTable::findMangle(StringRef Name) {
   if (Symbol *Sym = find(Name))
-    if (!isa<Undefined>(Sym->Body))
+    if (!isa<Undefined>(Sym->body()))
       return Name;
   if (Config->Machine != I386)
     return findByPrefix(("?" + Name + "@@Y").str());
@@ -288,34 +382,17 @@
   return findByPrefix(("?" + Name.substr(1) + "@@Y").str());
 }
 
-void SymbolTable::mangleMaybe(Undefined *U) {
-  if (U->WeakAlias)
-    return;
-  if (!isa<Undefined>(U->repl()))
+void SymbolTable::mangleMaybe(SymbolBody *B) {
+  auto *U = dyn_cast<Undefined>(B);
+  if (!U || U->WeakAlias)
     return;
   StringRef Alias = findMangle(U->getName());
   if (!Alias.empty())
     U->WeakAlias = addUndefined(Alias);
 }
 
-Undefined *SymbolTable::addUndefined(StringRef Name) {
-  auto *New = make<Undefined>(Name);
-  addSymbol(New);
-  if (auto *U = dyn_cast<Undefined>(New->repl()))
-    return U;
-  return New;
-}
-
-DefinedRelative *SymbolTable::addRelative(StringRef Name, uint64_t VA) {
-  auto *New = make<DefinedRelative>(Name, VA);
-  addSymbol(New);
-  return New;
-}
-
-DefinedAbsolute *SymbolTable::addAbsolute(StringRef Name, uint64_t VA) {
-  auto *New = make<DefinedAbsolute>(Name, VA);
-  addSymbol(New);
-  return New;
+SymbolBody *SymbolTable::addUndefined(StringRef Name) {
+  return addUndefined(Name, nullptr, false)->body();
 }
 
 void SymbolTable::printMap(llvm::raw_ostream &OS) {
@@ -329,59 +406,19 @@
   }
 }
 
-void SymbolTable::addCombinedLTOObject(ObjectFile *Obj) {
-  for (SymbolBody *Body : Obj->getSymbols()) {
-    if (!Body->isExternal())
-      continue;
-    // We should not see any new undefined symbols at this point, but we'll
-    // diagnose them later in reportRemainingUndefines().
-    StringRef Name = Body->getName();
-    Symbol *Sym = insert(Body);
-    SymbolBody *Existing = Sym->Body;
-
-    if (Existing == Body)
-      continue;
-
-    if (isa<DefinedBitcode>(Existing)) {
-      Sym->Body = Body;
-      continue;
-    }
-    if (isa<Undefined>(Body)) {
-      if (auto *L = dyn_cast<Lazy>(Existing)) {
-        // We may see new references to runtime library symbols such as __chkstk
-        // here. These symbols must be wholly defined in non-bitcode files.
-        addMemberFile(L);
-        continue;
-      }
-    }
-
-    int Comp = Existing->compare(Body);
-    if (Comp == 0)
-      fatal("LTO: unexpected duplicate symbol: " + Name);
-    if (Comp < 0)
-      Sym->Body = Body;
-  }
-}
-
 void SymbolTable::addCombinedLTOObjects() {
   if (BitcodeFiles.empty())
     return;
 
-  // Diagnose any undefined symbols early, but do not resolve weak externals,
-  // as resolution breaks the invariant that each Symbol points to a unique
-  // SymbolBody, which we rely on to replace DefinedBitcode symbols correctly.
-  reportRemainingUndefines(/*Resolve=*/false);
-
   // Create an object file and add it to the symbol table by replacing any
   // DefinedBitcode symbols with the definitions in the object file.
   LTOCodeGenerator CG(BitcodeFile::Context);
   CG.setOptLevel(Config->LTOOptLevel);
   std::vector<ObjectFile *> Objs = createLTOObjects(&CG);
 
-  for (ObjectFile *Obj : Objs)
-    addCombinedLTOObject(Obj);
-
   size_t NumBitcodeFiles = BitcodeFiles.size();
+  for (ObjectFile *Obj : Objs)
+    Obj->parse();
   run();
   if (BitcodeFiles.size() != NumBitcodeFiles)
     fatal("LTO: late loaded symbol created new bitcode reference");
@@ -390,25 +427,17 @@
 // Combine and compile bitcode files and then return the result
 // as a vector of regular COFF object files.
 std::vector<ObjectFile *> SymbolTable::createLTOObjects(LTOCodeGenerator *CG) {
-  // All symbols referenced by non-bitcode objects must be preserved.
-  for (ObjectFile *File : ObjectFiles)
-    for (SymbolBody *Body : File->getSymbols())
-      if (auto *S = dyn_cast<DefinedBitcode>(Body->repl()))
-        CG->addMustPreserveSymbol(S->getName());
-
-  // Likewise for bitcode symbols which we initially resolved to non-bitcode.
+  // All symbols referenced by non-bitcode objects, including GC roots, must be
+  // preserved. We must also replace bitcode symbols with undefined symbols so
+  // that they may be replaced with real definitions without conflicting.
   for (BitcodeFile *File : BitcodeFiles)
-    for (SymbolBody *Body : File->getSymbols())
-      if (isa<DefinedBitcode>(Body) && !isa<DefinedBitcode>(Body->repl()))
+    for (SymbolBody *Body : File->getSymbols()) {
+      if (!isa<DefinedBitcode>(Body))
+        continue;
+      if (Body->symbol()->IsUsedInRegularObj)
         CG->addMustPreserveSymbol(Body->getName());
-
-  // Likewise for other symbols that must be preserved.
-  for (Undefined *U : Config->GCRoot) {
-    if (auto *S = dyn_cast<DefinedBitcode>(U->repl()))
-      CG->addMustPreserveSymbol(S->getName());
-    else if (auto *S = dyn_cast_or_null<DefinedBitcode>(U->getWeakAlias()))
-      CG->addMustPreserveSymbol(S->getName());
-  }
+      replaceBody<Undefined>(Body->symbol(), Body->getName());
+    }
 
   CG->setModule(BitcodeFiles[0]->takeModule());
   for (unsigned I = 1, E = BitcodeFiles.size(); I != E; ++I)
@@ -438,7 +467,6 @@
     auto *ObjFile = new ObjectFile(MemoryBufferRef(Obj, "<LTO object>"));
     Files.emplace_back(ObjFile);
     ObjectFiles.push_back(ObjFile);
-    ObjFile->parse();
     ObjFiles.push_back(ObjFile);
   }
 
Index: lld/trunk/COFF/Symbols.h
===================================================================
--- lld/trunk/COFF/Symbols.h
+++ lld/trunk/COFF/Symbols.h
@@ -32,15 +32,8 @@
 class BitcodeFile;
 class InputFile;
 class ObjectFile;
-class SymbolBody;
-
-// A real symbol object, SymbolBody, is usually accessed indirectly
-// through a Symbol. There's always one Symbol for each symbol name.
-// The resolver updates SymbolBody pointers as it resolves symbols.
-struct Symbol {
-  explicit Symbol(SymbolBody *P) : Body(P) {}
-  SymbolBody *Body;
-};
+struct Symbol;
+class SymbolTable;
 
 // The base class for real symbol classes.
 class SymbolBody {
@@ -78,21 +71,13 @@
   // Returns the file from which this symbol was created.
   InputFile *getFile();
 
-  // A SymbolBody has a backreference to a Symbol. Originally they are
-  // doubly-linked. A backreference will never change. But the pointer
-  // in the Symbol may be mutated by the resolver. If you have a
-  // pointer P to a SymbolBody and are not sure whether the resolver
-  // has chosen the object among other objects having the same name,
-  // you can access P->Backref->Body to get the resolver's result.
-  void setBackref(Symbol *P) { Backref = P; }
-  SymbolBody *repl() { return Backref ? Backref->Body : this; }
-
-  // Decides which symbol should "win" in the symbol table, this or
-  // the Other. Returns 1 if this wins, -1 if the Other wins, or 0 if
-  // they are duplicate (conflicting) symbols.
-  int compare(SymbolBody *Other);
+  Symbol *symbol();
+  const Symbol *symbol() const {
+    return const_cast<SymbolBody *>(this)->symbol();
+  }
 
 protected:
+  friend SymbolTable;
   explicit SymbolBody(Kind K, StringRef N = "")
       : SymbolKind(K), IsExternal(true), IsCOMDAT(false),
         IsReplaceable(false), Name(N) {}
@@ -107,7 +92,6 @@
   unsigned IsReplaceable : 1;
 
   StringRef Name;
-  Symbol *Backref = nullptr;
 };
 
 // The base class for any defined symbols, including absolute symbols,
@@ -149,7 +133,6 @@
   }
 
   ObjectFile *getFile() { return File; }
-  int getFileIndex() { return File->Index; }
 
   COFFSymbolRef getCOFFSymbol();
 
@@ -195,7 +178,7 @@
   uint64_t getRVA() { return Data->getRVA(); }
 
 private:
-  friend SymbolBody;
+  friend SymbolTable;
   uint64_t getSize() { return Sym->Value; }
   CommonChunk *Data;
 };
@@ -254,15 +237,12 @@
 
   static bool classof(const SymbolBody *S) { return S->kind() == LazyKind; }
 
-  // Returns an object file for this symbol, or a nullptr if the file
-  // was already returned.
-  InputFile *getMember();
-
-  int getFileIndex() { return File->Index; }
-
   ArchiveFile *File;
 
 private:
+  friend SymbolTable;
+
+private:
   const Archive::Symbol Sym;
 };
 
@@ -295,26 +275,22 @@
 // table in an output. The former has "__imp_" prefix.
 class DefinedImportData : public Defined {
 public:
-  DefinedImportData(StringRef D, StringRef N, StringRef E,
-                    const coff_import_header *H)
-      : Defined(DefinedImportDataKind, N), DLLName(D), ExternalName(E), Hdr(H) {
+  DefinedImportData(StringRef N, ImportFile *F)
+      : Defined(DefinedImportDataKind, N), File(F) {
   }
 
   static bool classof(const SymbolBody *S) {
     return S->kind() == DefinedImportDataKind;
   }
 
-  uint64_t getRVA() { return Location->getRVA(); }
-  StringRef getDLLName() { return DLLName; }
-  StringRef getExternalName() { return ExternalName; }
-  void setLocation(Chunk *AddressTable) { Location = AddressTable; }
-  uint16_t getOrdinal() { return Hdr->OrdinalHint; }
+  uint64_t getRVA() { return File->Location->getRVA(); }
+  StringRef getDLLName() { return File->DLLName; }
+  StringRef getExternalName() { return File->ExternalName; }
+  void setLocation(Chunk *AddressTable) { File->Location = AddressTable; }
+  uint16_t getOrdinal() { return File->Hdr->OrdinalHint; }
 
 private:
-  StringRef DLLName;
-  StringRef ExternalName;
-  const coff_import_header *Hdr;
-  Chunk *Location = nullptr;
+  ImportFile *File;
 };
 
 // This class represents a symbol for a jump table entry which jumps
@@ -345,17 +321,17 @@
 class DefinedLocalImport : public Defined {
 public:
   DefinedLocalImport(StringRef N, Defined *S)
-      : Defined(DefinedLocalImportKind, N), Data(S) {}
+      : Defined(DefinedLocalImportKind, N), Data(new LocalImportChunk(S)) {}
 
   static bool classof(const SymbolBody *S) {
     return S->kind() == DefinedLocalImportKind;
   }
 
-  uint64_t getRVA() { return Data.getRVA(); }
-  Chunk *getChunk() { return &Data; }
+  uint64_t getRVA() { return Data->getRVA(); }
+  Chunk *getChunk() { return Data.get(); }
 
 private:
-  LocalImportChunk Data;
+  std::unique_ptr<LocalImportChunk> Data;
 };
 
 class DefinedBitcode : public Defined {
@@ -363,6 +339,11 @@
 public:
   DefinedBitcode(BitcodeFile *F, StringRef N, bool IsReplaceable)
       : Defined(DefinedBitcodeKind, N), File(F) {
+    // IsReplaceable tracks whether the bitcode symbol may be replaced with some
+    // other (defined, common or bitcode) symbol. This is the case for common,
+    // comdat and weak external symbols. We try to replace bitcode symbols with
+    // "real" symbols (see SymbolTable::add{Regular,Bitcode}), and resolve the
+    // result against the real symbol from the combined LTO object.
     this->IsReplaceable = IsReplaceable;
   }
 
@@ -398,6 +379,45 @@
   llvm_unreachable("unknown symbol kind");
 }
 
+// A real symbol object, SymbolBody, is usually stored within a Symbol. There's
+// always one Symbol for each symbol name. The resolver updates the SymbolBody
+// stored in the Body field of this object as it resolves symbols. Symbol also
+// holds computed properties of symbol names.
+struct Symbol {
+  // True if this symbol was referenced by a regular (non-bitcode) object.
+  unsigned IsUsedInRegularObj : 1;
+
+  // This field is used to store the Symbol's SymbolBody. This instantiation of
+  // AlignedCharArrayUnion gives us a struct with a char array field that is
+  // large and aligned enough to store any derived class of SymbolBody.
+  llvm::AlignedCharArrayUnion<DefinedRegular, DefinedCommon, DefinedAbsolute,
+                              DefinedRelative, Lazy, Undefined,
+                              DefinedImportData, DefinedImportThunk,
+                              DefinedLocalImport, DefinedBitcode>
+      Body;
+
+  SymbolBody *body() {
+    return reinterpret_cast<SymbolBody *>(Body.buffer);
+  }
+  const SymbolBody *body() const { return const_cast<Symbol *>(this)->body(); }
+};
+
+template <typename T, typename... ArgT>
+void replaceBody(Symbol *S, ArgT &&... Arg) {
+  static_assert(sizeof(T) <= sizeof(S->Body), "Body too small");
+  static_assert(alignof(T) <= alignof(decltype(S->Body)),
+                "Body not aligned enough");
+  assert(static_cast<SymbolBody *>(static_cast<T *>(nullptr)) == nullptr &&
+         "Not a SymbolBody");
+  new (S->Body.buffer) T(std::forward<ArgT>(Arg)...);
+}
+
+inline Symbol *SymbolBody::symbol() {
+  assert(isExternal());
+  return reinterpret_cast<Symbol *>(reinterpret_cast<char *>(this) -
+                                    offsetof(Symbol, Body));
+}
+
 std::string toString(SymbolBody &B);
 
 } // namespace coff
Index: lld/trunk/COFF/Symbols.cpp
===================================================================
--- lld/trunk/COFF/Symbols.cpp
+++ lld/trunk/COFF/Symbols.cpp
@@ -18,8 +18,6 @@
 
 using namespace llvm;
 using namespace llvm::object;
-using llvm::sys::fs::identify_magic;
-using llvm::sys::fs::file_magic;
 
 namespace lld {
 namespace coff {
@@ -49,120 +47,6 @@
   return nullptr;
 }
 
-// Returns 1, 0 or -1 if this symbol should take precedence
-// over the Other, tie or lose, respectively.
-int SymbolBody::compare(SymbolBody *Other) {
-  Kind LK = kind(), RK = Other->kind();
-
-  // Normalize so that the smaller kind is on the left.
-  if (LK > RK)
-    return -Other->compare(this);
-
-  // First handle comparisons between two different kinds.
-  if (LK != RK) {
-    if (RK > LastDefinedKind) {
-      if (LK == LazyKind && cast<Undefined>(Other)->WeakAlias)
-        return -1;
-
-      // The LHS is either defined or lazy and so it wins.
-      assert((LK <= LastDefinedKind || LK == LazyKind) && "Bad kind!");
-      return 1;
-    }
-
-    // Bitcode has special complexities.
-    if (RK == DefinedBitcodeKind) {
-      auto *RHS = cast<DefinedBitcode>(Other);
-
-      switch (LK) {
-      case DefinedCommonKind:
-        return 1;
-
-      case DefinedRegularKind:
-        // As an approximation, regular symbols win over bitcode symbols,
-        // but we definitely have a conflict if the regular symbol is not
-        // replaceable and neither is the bitcode symbol. We do not
-        // replicate the rest of the symbol resolution logic here; symbol
-        // resolution will be done accurately after lowering bitcode symbols
-        // to regular symbols in addCombinedLTOObject().
-        if (cast<DefinedRegular>(this)->isCOMDAT() || RHS->IsReplaceable)
-          return 1;
-
-        // Fallthrough to the default of a tie otherwise.
-      default:
-        return 0;
-      }
-    }
-
-    // Either of the object file kind will trump a higher kind.
-    if (LK <= LastDefinedCOFFKind)
-      return 1;
-
-    // The remaining kind pairs are ties amongst defined symbols.
-    return 0;
-  }
-
-  // Now handle the case where the kinds are the same.
-  switch (LK) {
-  case DefinedRegularKind: {
-    auto *LHS = cast<DefinedRegular>(this);
-    auto *RHS = cast<DefinedRegular>(Other);
-    if (LHS->isCOMDAT() && RHS->isCOMDAT())
-      return LHS->getFileIndex() < RHS->getFileIndex() ? 1 : -1;
-    return 0;
-  }
-
-  case DefinedCommonKind: {
-    auto *LHS = cast<DefinedCommon>(this);
-    auto *RHS = cast<DefinedCommon>(Other);
-    if (LHS->getSize() == RHS->getSize())
-      return LHS->getFileIndex() < RHS->getFileIndex() ? 1 : -1;
-    return LHS->getSize() > RHS->getSize() ? 1 : -1;
-  }
-
-  case DefinedBitcodeKind: {
-    auto *LHS = cast<DefinedBitcode>(this);
-    auto *RHS = cast<DefinedBitcode>(Other);
-    // If both are non-replaceable, we have a tie.
-    if (!LHS->IsReplaceable && !RHS->IsReplaceable)
-      return 0;
-
-    // Non-replaceable symbols win, but even two replaceable symboles don't
-    // tie. If both symbols are replaceable, choice is arbitrary.
-    if (RHS->IsReplaceable && LHS->IsReplaceable)
-      return uintptr_t(LHS) < uintptr_t(RHS) ? 1 : -1;
-    return LHS->IsReplaceable ? -1 : 1;
-  }
-
-  case LazyKind: {
-    // Don't tie, pick the earliest.
-    auto *LHS = cast<Lazy>(this);
-    auto *RHS = cast<Lazy>(Other);
-    return LHS->getFileIndex() < RHS->getFileIndex() ? 1 : -1;
-  }
-
-  case UndefinedKind: {
-    auto *LHS = cast<Undefined>(this);
-    auto *RHS = cast<Undefined>(Other);
-    // Tie if both undefined symbols have different weak aliases.
-    if (LHS->WeakAlias && RHS->WeakAlias) {
-      if (LHS->WeakAlias->getName() != RHS->WeakAlias->getName())
-        return 0;
-      return uintptr_t(LHS) < uintptr_t(RHS) ? 1 : -1;
-    }
-    return LHS->WeakAlias ? 1 : -1;
-  }
-
-  case DefinedLocalImportKind:
-  case DefinedImportThunkKind:
-  case DefinedImportDataKind:
-  case DefinedAbsoluteKind:
-  case DefinedRelativeKind:
-    // These all simply tie.
-    return 0;
-  }
-  llvm_unreachable("unknown symbol kind");
-}
-
 COFFSymbolRef DefinedCOFF::getCOFFSymbol() {
   size_t SymSize = File->getCOFFObj()->getSymbolTableEntrySize();
   if (SymSize == sizeof(coff_symbol16))
@@ -182,34 +66,10 @@
   }
 }
 
-InputFile *Lazy::getMember() {
-  MemoryBufferRef MBRef = File->getMember(&Sym);
-
-  // getMember returns an empty buffer if the member was already
-  // read from the library.
-  if (MBRef.getBuffer().empty())
-    return nullptr;
-
-  file_magic Magic = identify_magic(MBRef.getBuffer());
-  if (Magic == file_magic::coff_import_library)
-    return make<ImportFile>(MBRef);
-
-  InputFile *Obj;
-  if (Magic == file_magic::coff_object)
-    Obj = make<ObjectFile>(MBRef);
-  else if (Magic == file_magic::bitcode)
-    Obj = make<BitcodeFile>(MBRef);
-  else
-    fatal("unknown file type: " + File->getName());
-
-  Obj->ParentName = File->getName();
-  return Obj;
-}
-
 Defined *Undefined::getWeakAlias() {
   // A weak alias may be a weak alias to another symbol, so check recursively.
   for (SymbolBody *A = WeakAlias; A; A = cast<Undefined>(A)->WeakAlias)
-    if (auto *D = dyn_cast<Defined>(A->repl()))
+    if (auto *D = dyn_cast<Defined>(A))
       return D;
   return nullptr;
 }
Index: lld/trunk/COFF/Writer.cpp
===================================================================
--- lld/trunk/COFF/Writer.cpp
+++ lld/trunk/COFF/Writer.cpp
@@ -388,7 +388,7 @@
     if (!File->SEHCompat)
       return;
     for (SymbolBody *B : File->SEHandlers)
-      Handlers.insert(cast<Defined>(B->repl()));
+      Handlers.insert(cast<Defined>(B));
   }
 
   SEHTable.reset(new SEHTableChunk(Handlers));
@@ -428,7 +428,7 @@
       Sec->addChunk(C);
   }
   if (!DelayIdata.empty()) {
-    Defined *Helper = cast<Defined>(Config->DelayLoadHelper->repl());
+    Defined *Helper = cast<Defined>(Config->DelayLoadHelper);
     DelayIdata.create(Helper);
     OutputSection *Sec = createSection(".didat");
     for (Chunk *C : DelayIdata.getChunks())
@@ -471,6 +471,10 @@
 }
 
 Optional<coff_symbol16> Writer::createSymbol(Defined *Def) {
+  // Relative symbols are unrepresentable in a COFF symbol table.
+  if (isa<DefinedRelative>(Def))
+    return None;
+
   if (auto *D = dyn_cast<DefinedRegular>(Def))
     if (!D->getChunk()->isLive())
       return None;
@@ -497,7 +501,6 @@
 
   switch (Def->kind()) {
   case SymbolBody::DefinedAbsoluteKind:
-  case SymbolBody::DefinedRelativeKind:
     Sym.Value = Def->getRVA();
     Sym.SectionNumber = IMAGE_SYM_ABSOLUTE;
     break;
@@ -530,16 +533,13 @@
     Sec->setStringTableOff(addEntryToStringTable(Name));
   }
 
+  std::set<SymbolBody *> SeenSymbols;
   for (lld::coff::ObjectFile *File : Symtab->ObjectFiles)
     for (SymbolBody *B : File->getSymbols())
       if (auto *D = dyn_cast<Defined>(B))
-        if (Optional<coff_symbol16> Sym = createSymbol(D))
-          OutputSymtab.push_back(*Sym);
-
-  for (ImportFile *File : Symtab->ImportFiles)
-    for (SymbolBody *B : File->getSymbols())
-      if (Optional<coff_symbol16> Sym = createSymbol(cast<Defined>(B)))
-        OutputSymtab.push_back(*Sym);
+        if (SeenSymbols.insert(D).second)
+          if (Optional<coff_symbol16> Sym = createSymbol(D))
+            OutputSymtab.push_back(*Sym);
 
   OutputSection *LastSection = OutputSections.back();
   // We position the symbol table to be adjacent to the end of the last section.
@@ -630,7 +630,7 @@
   PE->SizeOfImage = SizeOfImage;
   PE->SizeOfHeaders = SizeOfHeaders;
   if (!Config->NoEntry) {
-    Defined *Entry = cast<Defined>(Config->Entry->repl());
+    Defined *Entry = cast<Defined>(Config->Entry);
     PE->AddressOfEntryPoint = Entry->getRVA();
     // Pointer to thumb code must have the LSB set, so adjust it.
     if (Config->Machine == ARMNT)
@@ -685,7 +685,7 @@
     Dir[BASE_RELOCATION_TABLE].Size = Sec->getVirtualSize();
   }
   if (Symbol *Sym = Symtab->findUnderscore("_tls_used")) {
-    if (Defined *B = dyn_cast<Defined>(Sym->Body)) {
+    if (Defined *B = dyn_cast<Defined>(Sym->body())) {
       Dir[TLS_TABLE].RelativeVirtualAddress = B->getRVA();
       Dir[TLS_TABLE].Size = Config->is64()
                                 ? sizeof(object::coff_tls_directory64)
@@ -697,7 +697,7 @@
     Dir[DEBUG_DIRECTORY].Size = DebugDirectory->getSize();
   }
   if (Symbol *Sym = Symtab->findUnderscore("_load_config_used")) {
-    if (auto *B = dyn_cast<DefinedRegular>(Sym->Body)) {
+    if (auto *B = dyn_cast<DefinedRegular>(Sym->body())) {
       SectionChunk *SC = B->getChunk();
       assert(B->getRVA() >= SC->getRVA());
       uint64_t OffsetInChunk = B->getRVA() - SC->getRVA();
@@ -754,8 +754,10 @@
 void Writer::fixSafeSEHSymbols() {
   if (!SEHTable)
     return;
-  Config->SEHTable->setRVA(SEHTable->getRVA());
-  Config->SEHCount->setVA(SEHTable->getSize() / 4);
+  if (auto *T = dyn_cast<DefinedRelative>(Config->SEHTable->body()))
+    T->setRVA(SEHTable->getRVA());
+  if (auto *C = dyn_cast<DefinedAbsolute>(Config->SEHCount->body()))
+    C->setVA(SEHTable->getSize() / 4);
 }
 
 // Handles /section options to allow users to overwrite
Index: lld/trunk/test/COFF/include2.test
===================================================================
--- lld/trunk/test/COFF/include2.test
+++ lld/trunk/test/COFF/include2.test
@@ -9,6 +9,6 @@
 
 CHECK: include2.test.tmp1.obj
 CHECK: include2.test.tmp2.lib
-CHECK: include2.test.tmp3.lib
 CHECK: include2.test.tmp2.lib(include2.test.tmp2.obj) for foo
+CHECK: include2.test.tmp3.lib
 CHECK: include2.test.tmp3.lib(include2.test.tmp3.obj) for bar
Index: lld/trunk/test/COFF/order.test
===================================================================
--- lld/trunk/test/COFF/order.test
+++ lld/trunk/test/COFF/order.test
@@ -11,5 +11,5 @@
 CHECK: order.test.tmp1.obj
 CHECK: order.test.tmp3.obj
 CHECK: order.test.tmp2.lib
-CHECK: order.test.tmp3.lib
 CHECK: order.test.tmp2.lib(order.test.tmp2.obj) for foo
+CHECK: order.test.tmp3.lib
Index: lld/trunk/test/COFF/symtab.test
===================================================================
--- lld/trunk/test/COFF/symtab.test
+++ lld/trunk/test/COFF/symtab.test
@@ -36,17 +36,17 @@
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: message
-# CHECK-NEXT:     Value: 6
-# CHECK-NEXT:     Section: .text2 (3)
+# CHECK-NEXT:     Name: MessageBoxA
+# CHECK-NEXT:     Value: 80
+# CHECK-NEXT:     Section: .text (2)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
-# CHECK-NEXT:     StorageClass: Static (0x3)
+# CHECK-NEXT:     StorageClass: External (0x2)
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: main
-# CHECK-NEXT:     Value: 0
+# CHECK-NEXT:     Name: ExitProcess
+# CHECK-NEXT:     Value: 64
 # CHECK-NEXT:     Section: .text (2)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
@@ -54,8 +54,8 @@
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: caption
-# CHECK-NEXT:     Value: 0
+# CHECK-NEXT:     Name: message
+# CHECK-NEXT:     Value: 6
 # CHECK-NEXT:     Section: .text2 (3)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
@@ -63,26 +63,8 @@
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: abs_symbol
-# CHECK-NEXT:     Value: 2662186735
-# CHECK-NEXT:     Section: IMAGE_SYM_ABSOLUTE (-1)
-# CHECK-NEXT:     BaseType: Null (0x0)
-# CHECK-NEXT:     ComplexType: Null (0x0)
-# CHECK-NEXT:     StorageClass: External (0x2)
-# CHECK-NEXT:     AuxSymbolCount: 0
-# CHECK-NEXT:   }
-# CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: __imp_ExitProcess
-# CHECK-NEXT:     Value: 64
-# CHECK-NEXT:     Section: .idata (5)
-# CHECK-NEXT:     BaseType: Null (0x0)
-# CHECK-NEXT:     ComplexType: Null (0x0)
-# CHECK-NEXT:     StorageClass: External (0x2)
-# CHECK-NEXT:     AuxSymbolCount: 0
-# CHECK-NEXT:   }
-# CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: ExitProcess
-# CHECK-NEXT:     Value: 64
+# CHECK-NEXT:     Name: main
+# CHECK-NEXT:     Value: 0
 # CHECK-NEXT:     Section: .text (2)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
@@ -90,18 +72,18 @@
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: __imp_MessageBoxA
-# CHECK-NEXT:     Value: 72
-# CHECK-NEXT:     Section: .idata (5)
+# CHECK-NEXT:     Name: caption
+# CHECK-NEXT:     Value: 0
+# CHECK-NEXT:     Section: .text2 (3)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
-# CHECK-NEXT:     StorageClass: External (0x2)
+# CHECK-NEXT:     StorageClass: Static (0x3)
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: MessageBoxA
-# CHECK-NEXT:     Value: 80
-# CHECK-NEXT:     Section: .text (2)
+# CHECK-NEXT:     Name: abs_symbol
+# CHECK-NEXT:     Value: 2662186735
+# CHECK-NEXT:     Section: IMAGE_SYM_ABSOLUTE (-1)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
 # CHECK-NEXT:     StorageClass: External (0x2)