Revert "[VFS] RedirectingFileSystem only replace path if not already mapped"

This reverts commit 3fda0edc51fd68192a30e302d45db081bb02d7f9, which
breaks crash reproducers in very specific circumstances. Specifically,
since crash reproducers have `UseExternalNames` set to false, the
`File->getFileEntry().getDir()->getName()` call in `DoFrameworkLookup`
would use the *cached* directory name instead of the directory of the
looked-up file.

The plan is to re-commit this patch but to *add*
`ExposesExternalVFSPath` rather than replace `IsVFSMapped`.

Differential Revision: https://reviews.llvm.org/D123103

1 files changed, 2 insertions, 10 deletions

diff --git a/llvm/lib/Support/VirtualFileSystem.cpp b/llvm/lib/Support/VirtualFileSystem.cpp
index 14e9f02..cb34fa60 100644
--- a/llvm/lib/Support/VirtualFileSystem.cpp
+++ b/llvm/lib/Support/VirtualFileSystem.cpp
@@ -2163,16 +2163,10 @@ RedirectingFileSystem::lookupPathImpl(
 static Status getRedirectedFileStatus(const Twine &OriginalPath,
                                       bool UseExternalNames,
                                       Status ExternalStatus) {
-  // The path has been mapped by some nested VFS, don't override it with the
-  // original path.
-  if (ExternalStatus.ExposesExternalVFSPath)
-    return ExternalStatus;
-
   Status S = ExternalStatus;
   if (!UseExternalNames)
     S = Status::copyWithNewName(S, OriginalPath);
-  else
-    S.ExposesExternalVFSPath = true;
+  S.IsVFSMapped = true;
   return S;
 }
 
@@ -2274,9 +2268,7 @@ public:
 
 ErrorOr<std::unique_ptr<File>>
 File::getWithPath(ErrorOr<std::unique_ptr<File>> Result, const Twine &P) {
-  // See \c getRedirectedFileStatus - don't update path if it's already been
-  // mapped.
-  if (!Result || (*Result)->status()->ExposesExternalVFSPath)
+  if (!Result)
     return Result;
 
   ErrorOr<std::unique_ptr<File>> F = std::move(*Result);