diff --git a/include/clang/Basic/FileManager.h b/include/clang/Basic/FileManager.h
--- a/include/clang/Basic/FileManager.h
+++ b/include/clang/Basic/FileManager.h
@@ -299,6 +299,9 @@
   std::error_code getNoncachedStatValue(StringRef Path,
                                         llvm::vfs::Status &Result);
 
+  /// Remove the real file \p Entry from the cache.
+  void invalidateCache(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/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h
--- a/include/clang/Basic/SourceManager.h
+++ b/include/clang/Basic/SourceManager.h
@@ -797,7 +797,7 @@
 
   void clearIDTables();
 
-  void invalidateCache(const FileEntry* Entry);
+  void invalidateCache(FileID FID);
 
   /// Initialize this source manager suitably to replay the compilation
   /// described by \p Old. Requires that \p Old outlive \p *this.
diff --git a/lib/Basic/FileManager.cpp b/lib/Basic/FileManager.cpp
--- a/lib/Basic/FileManager.cpp
+++ b/lib/Basic/FileManager.cpp
@@ -604,7 +604,7 @@
   return std::error_code();
 }
 
-void FileManager::invalidateCache(const FileEntry *Entry) {
+void FileManager::invalidateCache(FileEntry *Entry) {
   assert(Entry && "Cannot invalidate a NULL FileEntry");
   FileEntriesToReread.insert(Entry->getLastRef());
   Entry->IsValid = false;
diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -358,12 +358,23 @@
   return false;
 }
 
-void SourceManager::invalidateCache(const FileEntry* Entry) {
+void SourceManager::invalidateCache(FileID FID) {
+  const FileEntry *Entry = getFileEntryForID(FID);
+  if (!Entry)
+    return;
   if (ContentCache *&E = FileInfos[Entry]) {
-    E->replaceBuffer(0, /*free*/ true);
+    E->setBuffer(nullptr);
     E = 0;
   }
-  getFileManager().invalidateCache(Entry);
+  if (!FID.isInvalid()) {
+    const SrcMgr::SLocEntry &SLocE = getSLocEntry(FID);
+    if (SLocE.isFile()) {
+      SrcMgr::ContentCache &CC =
+          const_cast<SrcMgr::ContentCache &>(SLocE.getFile().getContentCache());
+      CC.setBuffer(nullptr);
+    }
+  }
+  getFileManager().invalidateCache(const_cast<FileEntry *>(Entry));
 }
 
 void SourceManager::initializeForReplay(const SourceManager &Old) {
diff --git a/unittests/Basic/FileManagerTest.cpp b/unittests/Basic/FileManagerTest.cpp
--- a/unittests/Basic/FileManagerTest.cpp
+++ b/unittests/Basic/FileManagerTest.cpp
@@ -6,7 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#define private public
 #include "clang/Basic/FileManager.h"
+#undef private
 #include "clang/Basic/FileSystemOptions.h"
 #include "clang/Basic/FileSystemStatCache.h"
 #include "llvm/ADT/STLExtras.h"
@@ -98,6 +100,22 @@
   FileManager manager;
 };
 
+// If file entry valid, mark the file entry invalid, until reread.
+TEST_F(FileManagerTest, invalidateCacheSuccess) {
+  manager.setStatCache(std::make_unique<FakeStatCache>());
+
+  manager.getVirtualFile("file.cpp", 100, 0);
+  auto file = manager.getFile("file.cpp");
+
+  // Check for file null assertion success
+  manager.InvalidateCache(NULL);
+
+  manager.InvalidateCache(*file);
+  ASSERT_TRUE(manager.FileEntriesToReread);
+
+  ASSERT_FALSE((*file)->isValid());
+}
+
 // When a virtual file is added, its getDir() field is set correctly
 // (not NULL, correct name).
 TEST_F(FileManagerTest, getVirtualFileSetsTheDirFieldCorrectly) {
diff --git a/unittests/Basic/SourceManagerTest.cpp b/unittests/Basic/SourceManagerTest.cpp
--- a/unittests/Basic/SourceManagerTest.cpp
+++ b/unittests/Basic/SourceManagerTest.cpp
@@ -9,7 +9,9 @@
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticOptions.h"
+#define private public
 #include "clang/Basic/FileManager.h"
+#undef private
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/TargetOptions.h"
@@ -51,6 +53,26 @@
   IntrusiveRefCntPtr<TargetInfo> Target;
 };
 
+// Test for invalidate cache success, making the file entry invalid, until
+// reread
+TEST_F(SourceManagerTest, invalidateCacheSuccess) {
+  const char *Source = "int x;";
+
+  std::unique_ptr<llvm::MemoryBuffer> Buf =
+      llvm::MemoryBuffer::getMemBuffer(source);
+  const FileEntry *SourceFile =
+      FileMgr.getVirtualFile("mainFile.cpp", Buf->getBufferSize(), 0);
+
+  FileID mainFileID = SourceMgr.createFileID(std::move(Buf));
+  SourceMgr.overrideFileContents(SourceFile, std::move(Buf));
+  SourceMgr.setMainFileID(mainFileID);
+  SourceMgr::invalidateCache(mainFileID);
+
+  EXPECT_FALSE(SrcMgr::ContentCache);
+  EXPECT_TRUE(SourceFile->FileEntriesToReread);
+  EXPECT_FALSE(SourceFile->isValid());
+}
+
 TEST_F(SourceManagerTest, isBeforeInTranslationUnit) {
   const char *source =
     "#define M(x) [x]\n"