1 files changed, 13 insertions, 0 deletions
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index b3556371c9b8..c931b13f65f3 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1093,6 +1093,7 @@ void ASTWriter::WriteBlockInfoBlock() {
   RECORD(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES);
   RECORD(DELETE_EXPRS_TO_ANALYZE);
   RECORD(CUDA_PRAGMA_FORCE_HOST_DEVICE_DEPTH);
+  RECORD(PP_CONDITIONAL_STACK);
 
   // SourceManager Block.
   BLOCK(SOURCE_MANAGER_BLOCK);
@@ -2302,6 +2303,18 @@ void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
     Stream.EmitRecord(PP_COUNTER_VALUE, Record);
   }
 
+  if (PP.isRecordingPreamble() && PP.hasRecordedPreamble()) {
+    assert(!IsModule);
+    for (const auto &Cond : PP.getPreambleConditionalStack()) {
+      AddSourceLocation(Cond.IfLoc, Record);
+      Record.push_back(Cond.WasSkipping);
+      Record.push_back(Cond.FoundNonSkip);
+      Record.push_back(Cond.FoundElse);
+    }
+    Stream.EmitRecord(PP_CONDITIONAL_STACK, Record);
+    Record.clear();
+  }
+
   // Enter the preprocessor block.
   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);