Revert "Remove FileManager::invalidateCache as it has no callers an…

…ymore. NFC." This reverts commit 0785f8d.
sbingner · Jan 7, 2020 · 043a234 · 043a234
1 parent 5d60b79
commit 043a234
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diff --git a/clang/include/clang/Basic/FileManager.h b/clang/include/clang/Basic/FileManager.h
@@ -398,6 +398,9 @@ class FileManager : public RefCountedBase<FileManager> {
   std::error_code getNoncachedStatValue(StringRef Path,
                                         llvm::vfs::Status &Result);
 
+  /// Remove the real file \p Entry from the cache.
+  void invalidateCache(const FileEntry *Entry);
+
   /// If path is not absolute and FileSystemOptions set the working
   /// directory, the path is modified to be relative to the given
   /// working directory.

diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
@@ -522,6 +522,20 @@ FileManager::getNoncachedStatValue(StringRef Path,
   return std::error_code();
 }
 
+void FileManager::invalidateCache(const FileEntry *Entry) {
+  assert(Entry && "Cannot invalidate a NULL FileEntry");
+
+  SeenFileEntries.erase(Entry->getName());
+
+  // FileEntry invalidation should not block future optimizations in the file
+  // caches. Possible alternatives are cache truncation (invalidate last N) or
+  // invalidation of the whole cache.
+  //
+  // FIXME: This is broken. We sometimes have the same FileEntry* shared
+  // between multiple SeenFileEntries, so this can leave dangling pointers.
+  UniqueRealFiles.erase(Entry->getUniqueID());
+}
+
 void FileManager::GetUniqueIDMapping(
                    SmallVectorImpl<const FileEntry *> &UIDToFiles) const {
   UIDToFiles.clear();