1 files changed, 12 insertions, 3 deletions
diff --git a/llvm/lib/Support/VirtualFileSystem.cpp b/llvm/lib/Support/VirtualFileSystem.cpp
index bec4e8d..7b752b5 100644
--- a/llvm/lib/Support/VirtualFileSystem.cpp
+++ b/llvm/lib/Support/VirtualFileSystem.cpp
@@ -1649,10 +1649,19 @@ private:
                                         sys::path::Style::windows_backslash)) {
         path_style = sys::path::Style::windows_backslash;
       } else {
-        assert(NameValueNode && "Name presence should be checked earlier");
-        error(NameValueNode,
+        // Relative VFS root entries are made absolute to the current working
+        // directory, then we can determine the path style from that.
+        auto EC = sys::fs::make_absolute(Name);
+        if (EC) {
+          assert(NameValueNode && "Name presence should be checked earlier");
+          error(
+              NameValueNode,
               "entry with relative path at the root level is not discoverable");
-        return nullptr;
+          return nullptr;
+        }
+        path_style = sys::path::is_absolute(Name, sys::path::Style::posix)
+                         ? sys::path::Style::posix
+                         : sys::path::Style::windows_backslash;
       }
     }