SourceManager: Migrate to FileEntryRef in getOrCreateContentCache, NFC

Change `SourceManager::getOrCreateContentCache` to take a `FileEntryRef`
and update call sites (mostly internal to SourceManager.cpp). In a
couple of cases this temporarily relies on `FileEntry::getLastRef`, but
those can be cleaned up once other APIs switch over.

The one change outside of SourceManager.cpp is in ASTReader.cpp, which
stops relying on the auto-degrade-to-`FileEntry*` behaviour from
`InputFile::getFile` since it now needs a `FileEntryRef`.

No functionality change here.

Differential Revision: https://reviews.llvm.org/D92983

Author: dexonsmith

clang/include/clang/Basic/SourceManager.h

@@ -1838,7 +1838,7 @@ class SourceManager : public RefCountedBase<SourceManager> {
                           SrcMgr::CharacteristicKind DirCharacter, int LoadedID,
                           unsigned LoadedOffset);
 
-  SrcMgr::ContentCache &getOrCreateContentCache(const FileEntry *SourceFile,
+  SrcMgr::ContentCache &getOrCreateContentCache(FileEntryRef SourceFile,
                                                 bool isSystemFile = false);
 
   /// Create a new ContentCache for the specified  memory buffer.

clang/lib/Basic/SourceManager.cpp

@@ -385,10 +385,8 @@ void SourceManager::initializeForReplay(const SourceManager &Old) {
   }
 }
 
-ContentCache &SourceManager::getOrCreateContentCache(const FileEntry *FileEnt,
+ContentCache &SourceManager::getOrCreateContentCache(FileEntryRef FileEnt,
                                                      bool isSystemFile) {
-  assert(FileEnt && "Didn't specify a file entry to use?");
-
   // Do we already have information about this file?
   ContentCache *&Entry = FileInfos[FileEnt];
   if (Entry)
@@ -414,7 +412,7 @@ ContentCache &SourceManager::getOrCreateContentCache(const FileEntry *FileEnt,
 
   Entry->IsFileVolatile = UserFilesAreVolatile && !isSystemFile;
   Entry->IsTransient = FilesAreTransient;
-  Entry->BufferOverridden |= FileEnt->isNamedPipe();
+  Entry->BufferOverridden |= FileEnt.isNamedPipe();
 
   return *Entry;
 }
@@ -542,7 +540,7 @@ FileID SourceManager::createFileID(FileEntryRef SourceFile,
                                    SourceLocation IncludePos,
                                    SrcMgr::CharacteristicKind FileCharacter,
                                    int LoadedID, unsigned LoadedOffset) {
-  SrcMgr::ContentCache &IR = getOrCreateContentCache(&SourceFile.getFileEntry(),
+  SrcMgr::ContentCache &IR = getOrCreateContentCache(SourceFile,
                                                      isSystem(FileCharacter));
 
   // If this is a named pipe, immediately load the buffer to ensure subsequent
@@ -682,13 +680,13 @@ SourceManager::createExpansionLocImpl(const ExpansionInfo &Info,
 
 llvm::Optional<llvm::MemoryBufferRef>
 SourceManager::getMemoryBufferForFileOrNone(const FileEntry *File) {
-  SrcMgr::ContentCache &IR = getOrCreateContentCache(File);
+  SrcMgr::ContentCache &IR = getOrCreateContentCache(File->getLastRef());
   return IR.getBufferOrNone(Diag, getFileManager(), SourceLocation());
 }
 
 void SourceManager::overrideFileContents(
     const FileEntry *SourceFile, std::unique_ptr<llvm::MemoryBuffer> Buffer) {
-  SrcMgr::ContentCache &IR = getOrCreateContentCache(SourceFile);
+  SrcMgr::ContentCache &IR = getOrCreateContentCache(SourceFile->getLastRef());
 
   IR.setBuffer(std::move(Buffer));
   IR.BufferOverridden = true;
@@ -716,12 +714,12 @@ SourceManager::bypassFileContentsOverride(FileEntryRef File) {
   if (!BypassFile)
     return None;
 
-  (void)getOrCreateContentCache(&BypassFile->getFileEntry());
+  (void)getOrCreateContentCache(*BypassFile);
   return BypassFile;
 }
 
 void SourceManager::setFileIsTransient(const FileEntry *File) {
-  getOrCreateContentCache(File).IsTransient = true;
+  getOrCreateContentCache(File->getLastRef()).IsTransient = true;
 }
 
 Optional<StringRef>

clang/lib/Serialization/ASTReader.cpp

@@ -1499,7 +1499,7 @@ bool ASTReader::ReadSLocEntry(int ID) {
     // we will also try to fail gracefully by setting up the SLocEntry.
     unsigned InputID = Record[4];
     InputFile IF = getInputFile(*F, InputID);
-    const FileEntry *File = IF.getFile();
+    Optional<FileEntryRef> File = IF.getFile();
     bool OverriddenBuffer = IF.isOverridden();
 
     // Note that we only check if a File was returned. If it was out-of-date
@@ -1515,9 +1515,8 @@ bool ASTReader::ReadSLocEntry(int ID) {
     }
     SrcMgr::CharacteristicKind
       FileCharacter = (SrcMgr::CharacteristicKind)Record[2];
-    // FIXME: The FileID should be created from the FileEntryRef.
-    FileID FID = SourceMgr.createFileID(File, IncludeLoc, FileCharacter,
-                                        ID, BaseOffset + Record[0]);
+    FileID FID = SourceMgr.createFileID(*File, IncludeLoc, FileCharacter, ID,
+                                        BaseOffset + Record[0]);
     SrcMgr::FileInfo &FileInfo =
           const_cast<SrcMgr::FileInfo&>(SourceMgr.getSLocEntry(FID).getFile());
     FileInfo.NumCreatedFIDs = Record[5];
@@ -1533,14 +1532,14 @@ bool ASTReader::ReadSLocEntry(int ID) {
     }
 
     const SrcMgr::ContentCache &ContentCache =
-        SourceMgr.getOrCreateContentCache(File, isSystem(FileCharacter));
+        SourceMgr.getOrCreateContentCache(*File, isSystem(FileCharacter));
     if (OverriddenBuffer && !ContentCache.BufferOverridden &&
         ContentCache.ContentsEntry == ContentCache.OrigEntry &&
         !ContentCache.getBufferIfLoaded()) {
       auto Buffer = ReadBuffer(SLocEntryCursor, File->getName());
       if (!Buffer)
         return true;
-      SourceMgr.overrideFileContents(File, std::move(Buffer));
+      SourceMgr.overrideFileContents(*File, std::move(Buffer));
     }
 
     break;