Index: lld/COFF/PDB.cpp
===================================================================
--- lld/COFF/PDB.cpp
+++ lld/COFF/PDB.cpp
@@ -291,7 +291,8 @@
 }
 
 static Expected<std::unique_ptr<pdb::NativeSession>>
-tryToLoadPDB(const GUID &GuidFromObj, StringRef TSPath) {
+tryToLoadPDB(BumpPtrAllocator &Allocator, const GUID &GuidFromObj,
+             StringRef TSPath) {
   ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr = MemoryBuffer::getFile(
       TSPath, /*FileSize=*/-1, /*RequiresNullTerminator=*/false);
   if (!MBOrErr)
@@ -301,7 +302,7 @@
   if (auto EC = pdb::NativeSession::createFromPdb(
           MemoryBuffer::getMemBuffer(Driver->takeBuffer(std::move(*MBOrErr)),
                                      /*RequiresNullTerminator=*/false),
-          ThisSession))
+          Allocator, ThisSession))
     return std::move(EC);
 
   std::unique_ptr<pdb::NativeSession> NS(
@@ -345,7 +346,7 @@
   // Check for a PDB at:
   // 1. The given file path
   // 2. Next to the object file or archive file
-  auto ExpectedSession = tryToLoadPDB(TSId, TSPath);
+  auto ExpectedSession = tryToLoadPDB(Alloc, TSId, TSPath);
   if (!ExpectedSession) {
     consumeError(ExpectedSession.takeError());
     StringRef LocalPath =
@@ -353,7 +354,7 @@
     SmallString<128> Path = sys::path::parent_path(LocalPath);
     sys::path::append(
         Path, sys::path::filename(TSPath, sys::path::Style::windows));
-    ExpectedSession = tryToLoadPDB(TSId, Path);
+    ExpectedSession = tryToLoadPDB(Alloc, TSId, Path);
   }
   if (auto E = ExpectedSession.takeError()) {
     TypeServerIndexMappings.erase(TSId);
Index: llvm/include/llvm/DebugInfo/PDB/Native/NativeSession.h
===================================================================
--- llvm/include/llvm/DebugInfo/PDB/Native/NativeSession.h
+++ llvm/include/llvm/DebugInfo/PDB/Native/NativeSession.h
@@ -29,7 +29,9 @@
 class NativeSession : public IPDBSession {
 public:
   NativeSession(std::unique_ptr<PDBFile> PdbFile,
-                std::unique_ptr<BumpPtrAllocator> Allocator);
+                BumpPtrAllocator &BorrowedAllocator);
+  NativeSession(std::unique_ptr<PDBFile> PdbFile,
+                std::unique_ptr<BumpPtrAllocator> OwnedAllocator);
   ~NativeSession() override;
 
   static Error createFromPdb(std::unique_ptr<MemoryBuffer> MB,
@@ -37,6 +39,12 @@
   static Error createFromExe(StringRef Path,
                              std::unique_ptr<IPDBSession> &Session);
 
+  static Error createFromPdb(std::unique_ptr<MemoryBuffer> MB,
+                             BumpPtrAllocator &Allocator,
+                             std::unique_ptr<IPDBSession> &Session);
+  static Error createFromExe(StringRef Path, BumpPtrAllocator &Allocator,
+                             std::unique_ptr<IPDBSession> &Session);
+
   std::unique_ptr<PDBSymbolCompiland>
   createCompilandSymbol(DbiModuleDescriptor MI);
 
@@ -90,7 +98,8 @@
 
 private:
   std::unique_ptr<PDBFile> Pdb;
-  std::unique_ptr<BumpPtrAllocator> Allocator;
+  std::unique_ptr<BumpPtrAllocator> OwnedAllocator;
+  BumpPtrAllocator &Allocator;
   std::vector<std::unique_ptr<NativeRawSymbol>> SymbolCache;
   DenseMap<codeview::TypeIndex, SymIndexId> TypeIndexToSymbolId;
 };
Index: llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
===================================================================
--- llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
+++ llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
@@ -63,30 +63,61 @@
 } // namespace
 
 NativeSession::NativeSession(std::unique_ptr<PDBFile> PdbFile,
-                             std::unique_ptr<BumpPtrAllocator> Allocator)
-    : Pdb(std::move(PdbFile)), Allocator(std::move(Allocator)) {}
+                             std::unique_ptr<BumpPtrAllocator> OwnedAllocator)
+    : Pdb(std::move(PdbFile)), OwnedAllocator(std::move(OwnedAllocator)),
+      Allocator(*OwnedAllocator) {}
+NativeSession::NativeSession(std::unique_ptr<PDBFile> PdbFile,
+                             BumpPtrAllocator &BorrowedAllocator)
+    : Pdb(std::move(PdbFile)), Allocator(BorrowedAllocator) {}
 
 NativeSession::~NativeSession() = default;
 
-Error NativeSession::createFromPdb(std::unique_ptr<MemoryBuffer> Buffer,
-                                   std::unique_ptr<IPDBSession> &Session) {
+static Expected<std::unique_ptr<PDBFile>>
+createPdbFile(std::unique_ptr<MemoryBuffer> Buffer,
+              BumpPtrAllocator &Allocator) {
   StringRef Path = Buffer->getBufferIdentifier();
   auto Stream = llvm::make_unique<MemoryBufferByteStream>(
       std::move(Buffer), llvm::support::little);
 
-  auto Allocator = llvm::make_unique<BumpPtrAllocator>();
-  auto File = llvm::make_unique<PDBFile>(Path, std::move(Stream), *Allocator);
+  auto File = llvm::make_unique<PDBFile>(Path, std::move(Stream), Allocator);
   if (auto EC = File->parseFileHeaders())
-    return EC;
+    return std::move(EC);
   if (auto EC = File->parseStreamData())
-    return EC;
+    return std::move(EC);
+  return std::move(File);
+}
+
+Error NativeSession::createFromPdb(std::unique_ptr<MemoryBuffer> Buffer,
+                                   BumpPtrAllocator &Allocator,
+                                   std::unique_ptr<IPDBSession> &Session) {
+  auto ExpectedFile = createPdbFile(std::move(Buffer), Allocator);
+  if (!ExpectedFile)
+    return ExpectedFile.takeError();
 
   Session =
-      llvm::make_unique<NativeSession>(std::move(File), std::move(Allocator));
+      llvm::make_unique<NativeSession>(std::move(*ExpectedFile), Allocator);
+
+  return Error::success();
+}
+
+Error NativeSession::createFromPdb(std::unique_ptr<MemoryBuffer> Buffer,
+                                   std::unique_ptr<IPDBSession> &Session) {
+  auto Allocator = llvm::make_unique<BumpPtrAllocator>();
+  auto ExpectedFile = createPdbFile(std::move(Buffer), *Allocator);
+  if (!ExpectedFile)
+    return ExpectedFile.takeError();
+
+  Session = llvm::make_unique<NativeSession>(std::move(*ExpectedFile),
+                                             std::move(Allocator));
 
   return Error::success();
 }
 
+Error NativeSession::createFromExe(StringRef Path, BumpPtrAllocator &Allocator,
+                                   std::unique_ptr<IPDBSession> &Session) {
+  return make_error<RawError>(raw_error_code::feature_unsupported);
+}
+
 Error NativeSession::createFromExe(StringRef Path,
                                    std::unique_ptr<IPDBSession> &Session) {
   return make_error<RawError>(raw_error_code::feature_unsupported);