[clang] NFCI: Use FileEntryRef in SrcMgr::ContentCache

Author: jansvoboda11

clang/include/clang/Basic/SourceManager.h

@@ -148,7 +148,7 @@ class alignas(8) ContentCache {
   ///
   /// Can be different from 'Entry' if we overridden the contents of one file
   /// with the contents of another file.
-  const FileEntry *ContentsEntry;
+  OptionalFileEntryRef ContentsEntry;
 
   /// The filename that is used to access OrigEntry.
   ///
@@ -180,13 +180,13 @@ class alignas(8) ContentCache {
   mutable unsigned IsBufferInvalid : 1;
 
   ContentCache()
-      : OrigEntry(std::nullopt), ContentsEntry(nullptr),
+      : OrigEntry(std::nullopt), ContentsEntry(std::nullopt),
         BufferOverridden(false), IsFileVolatile(false), IsTransient(false),
         IsBufferInvalid(false) {}
 
   ContentCache(FileEntryRef Ent) : ContentCache(Ent, Ent) {}
 
-  ContentCache(FileEntryRef Ent, const FileEntry *contentEnt)
+  ContentCache(FileEntryRef Ent, FileEntryRef contentEnt)
       : OrigEntry(Ent), ContentsEntry(contentEnt), BufferOverridden(false),
         IsFileVolatile(false), IsTransient(false), IsBufferInvalid(false) {}
 

clang/lib/Basic/SourceManager.cpp

@@ -114,7 +114,7 @@ ContentCache::getBufferOrNone(DiagnosticsEngine &Diag, FileManager &FM,
   // return paths.
   IsBufferInvalid = true;
 
-  auto BufferOrError = FM.getBufferForFile(ContentsEntry, IsFileVolatile);
+  auto BufferOrError = FM.getBufferForFile(*ContentsEntry, IsFileVolatile);
 
   // If we were unable to open the file, then we are in an inconsistent
   // situation where the content cache referenced a file which no longer