Index: include/llvm/LTO/Caching.h
===================================================================
--- include/llvm/LTO/Caching.h
+++ include/llvm/LTO/Caching.h
@@ -24,13 +24,8 @@
 /// This type defines the callback to add a pre-existing native object file
 /// (e.g. in a cache).
 ///
-/// Path is generally expected to be a valid path for the file at the point when
-/// the AddBufferFn function is called, but clients should prefer to access MB
-/// directly in order to avoid a potential race condition.
-///
 /// Buffer callbacks must be thread safe.
-typedef std::function<void(unsigned Task, std::unique_ptr<MemoryBuffer> MB,
-                           StringRef Path)>
+typedef std::function<void(unsigned Task, std::unique_ptr<MemoryBuffer> MB)>
     AddBufferFn;
 
 /// Create a local file system cache which uses the given cache directory and
Index: lib/LTO/Caching.cpp
===================================================================
--- lib/LTO/Caching.cpp
+++ lib/LTO/Caching.cpp
@@ -36,7 +36,7 @@
     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
         MemoryBuffer::getFile(EntryPath);
     if (MBOrErr) {
-      AddBuffer(Task, std::move(*MBOrErr), EntryPath);
+      AddBuffer(Task, std::move(*MBOrErr));
       return AddStreamFn();
     }
 
@@ -103,7 +103,7 @@
                              TempFile.TmpName + " to " + EntryPath + ": " +
                              toString(std::move(E)) + "\n");
 
-        AddBuffer(Task, std::move(*MBOrErr), EntryPath);
+        AddBuffer(Task, std::move(*MBOrErr));
       }
     };
 
Index: tools/gold/gold-plugin.cpp
===================================================================
--- tools/gold/gold-plugin.cpp
+++ tools/gold/gold-plugin.cpp
@@ -901,8 +901,7 @@
         llvm::make_unique<llvm::raw_fd_ostream>(FD, true));
   };
 
-  auto AddBuffer = [&](size_t Task, std::unique_ptr<MemoryBuffer> MB,
-                       StringRef Path) {
+  auto AddBuffer = [&](size_t Task, std::unique_ptr<MemoryBuffer> MB) {
     *AddStream(Task)->OS << MB->getBuffer();
   };
 
Index: tools/llvm-lto2/llvm-lto2.cpp
===================================================================
--- tools/llvm-lto2/llvm-lto2.cpp
+++ tools/llvm-lto2/llvm-lto2.cpp
@@ -296,8 +296,7 @@
     return llvm::make_unique<lto::NativeObjectStream>(std::move(S));
   };
 
-  auto AddBuffer = [&](size_t Task, std::unique_ptr<MemoryBuffer> MB,
-                       StringRef Path) {
+  auto AddBuffer = [&](size_t Task, std::unique_ptr<MemoryBuffer> MB) {
     *AddStream(Task)->OS << MB->getBuffer();
   };