1 files changed, 7 insertions, 2 deletions

diff --git a/contrib/llvm/lib/Object/ModuleSummaryIndexObjectFile.cpp b/contrib/llvm/lib/Object/ModuleSummaryIndexObjectFile.cpp
index 11ace84b9ceb..de1ddab88fd4 100644
--- a/contrib/llvm/lib/Object/ModuleSummaryIndexObjectFile.cpp
+++ b/contrib/llvm/lib/Object/ModuleSummaryIndexObjectFile.cpp
@@ -96,13 +96,18 @@ ModuleSummaryIndexObjectFile::create(MemoryBufferRef Object) {
 // Parse the module summary index out of an IR file and return the summary
 // index object if found, or nullptr if not.
 Expected<std::unique_ptr<ModuleSummaryIndex>>
-llvm::getModuleSummaryIndexForFile(StringRef Path) {
+llvm::getModuleSummaryIndexForFile(StringRef Path, StringRef Identifier) {
   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
       MemoryBuffer::getFileOrSTDIN(Path);
   std::error_code EC = FileOrErr.getError();
   if (EC)
     return errorCodeToError(EC);
-  MemoryBufferRef BufferRef = (FileOrErr.get())->getMemBufferRef();
+  std::unique_ptr<MemoryBuffer> MemBuffer = std::move(FileOrErr.get());
+  // If Identifier is non-empty, use it as the buffer identifier, which
+  // will become the module path in the index.
+  if (Identifier.empty())
+    Identifier = MemBuffer->getBufferIdentifier();
+  MemoryBufferRef BufferRef(MemBuffer->getBuffer(), Identifier);
   if (IgnoreEmptyThinLTOIndexFile && !BufferRef.getBufferSize())
     return nullptr;
   Expected<std::unique_ptr<object::ModuleSummaryIndexObjectFile>> ObjOrErr =