diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
index 14a9033..5cbcdf4 100644
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -534,23 +534,9 @@
 
   StringRef CanonicalName(Dir->getName());
 
-#ifdef LLVM_ON_UNIX
-  char CanonicalNameBuf[PATH_MAX];
-  if (realpath(Dir->getName().str().c_str(), CanonicalNameBuf))
+  SmallString<4096> CanonicalNameBuf;
+  if (!FS->getRealPath(Dir->getName(), CanonicalNameBuf))
     CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage);
-#else
-  SmallString<256> CanonicalNameBuf(CanonicalName);
-  llvm::sys::fs::make_absolute(CanonicalNameBuf);
-  llvm::sys::path::native(CanonicalNameBuf);
-  // We've run into needing to remove '..' here in the wild though, so
-  // remove it.
-  // On Windows, symlinks are significantly less prevalent, so removing
-  // '..' is pretty safe.
-  // Ideally we'd have an equivalent of `realpath` and could implement
-  // sys::fs::canonical across all the platforms.
-  llvm::sys::path::remove_dots(CanonicalNameBuf, /* remove_dot_dot */ true);
-  CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage);
-#endif
 
   CanonicalDirNames.insert(std::make_pair(Dir, CanonicalName));
   return CanonicalName;