[clang] Make `FileEntryRef::getDir()` return the as-requested `DirectoryEntryRef`

For redirected file entries, `FileEntryRef::getDir()` returns the parent directory entry of the target file entry. This differs from `FileEntry::getDir()` that always returns the parent directory that was last used to look up that file.

After switching from `FileEntry` to `FileEntryRef` for umbrella headers in D142113, this discrepancy became observable and caused Clang to emit incorrect diagnostics.

This patch changes Clang so that it always associates `FileEntryRef` with the parent directory that was used to look it up. This brings its behavior closer to `FileEntry`, but without the hacky mutation.

This also ensures that `llvm::sys::path::parent_path(FileRef->getNameAsRequested()) == FileRef->getDir()->getName()`. Previously, `FileRef->getDir()` would fall underneath the redirecting VFS into the world of on-disk paths.

Reviewed By: benlangmuir, rmaz

Differential Revision: https://reviews.llvm.org/D151398

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
index 7d6fc47..0f544f0 100644
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -319,7 +319,7 @@ FileManager::getFileRef(StringRef Filename, bool openFile, bool CacheFailure) {
 
     // Cache the redirection in the previously-inserted entry, still available
     // in the tentative return value.
-    NamedFileEnt->second = FileEntryRef::MapValue(Redirection);
+    NamedFileEnt->second = FileEntryRef::MapValue(Redirection, DirInfo);
   }
 
   FileEntryRef ReturnedRef(*NamedFileEnt);