Index: clang/include/clang/Lex/PreprocessorExcludedConditionalDirectiveSkipMapping.h
===================================================================
--- clang/include/clang/Lex/PreprocessorExcludedConditionalDirectiveSkipMapping.h
+++ clang/include/clang/Lex/PreprocessorExcludedConditionalDirectiveSkipMapping.h
@@ -23,8 +23,7 @@
 /// The datastructure that holds the mapping between the active memory buffers
 /// and the individual skip mappings.
 using ExcludedPreprocessorDirectiveSkipMapping =
-    llvm::DenseMap<const llvm::MemoryBuffer *,
-                   const PreprocessorSkippedRangeMapping *>;
+    llvm::DenseMap<const char *, const PreprocessorSkippedRangeMapping *>;
 
 } // end namespace clang
 
Index: clang/lib/Lex/PPDirectives.cpp
===================================================================
--- clang/lib/Lex/PPDirectives.cpp
+++ clang/lib/Lex/PPDirectives.cpp
@@ -380,7 +380,10 @@
   std::pair<FileID, unsigned> HashFileOffset =
       SourceMgr.getDecomposedLoc(HashLoc);
   const llvm::MemoryBuffer *Buf = SourceMgr.getBuffer(HashFileOffset.first);
-  auto It = ExcludedConditionalDirectiveSkipMappings->find(Buf);
+  if (!Buf)
+    return None;
+  auto It =
+      ExcludedConditionalDirectiveSkipMappings->find(Buf->getBufferStart());
   if (It == ExcludedConditionalDirectiveSkipMappings->end())
     return None;
 
Index: clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
===================================================================
--- clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
+++ clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
@@ -219,8 +219,6 @@
 
   llvm::ErrorOr<llvm::vfs::Status> status() override { return Stat; }
 
-  const llvm::MemoryBuffer *getBufferPtr() const { return Buffer.get(); }
-
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBuffer(const Twine &Name, int64_t FileSize, bool RequiresNullTerminator,
             bool IsVolatile) override {
@@ -248,7 +246,7 @@
                                        /*RequiresNullTerminator=*/false),
       *Entry->getStatus());
   if (!Entry->getPPSkippedRangeMapping().empty() && PPSkipMappings)
-    (*PPSkipMappings)[Result->getBufferPtr()] =
+    (*PPSkipMappings)[Result->Buffer->getBufferStart()] =
         &Entry->getPPSkippedRangeMapping();
   return llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>(
       std::unique_ptr<llvm::vfs::File>(std::move(Result)));