diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1040,7 +1040,7 @@
   // Emit the total number of basic blocks in this function.
   OutStreamer->emitULEB128IntValue(MF.size());
   // Emit BB Information for each basic block in the funciton.
-  for (auto &MBB : MF) {
+  for (const auto &MBB : MF) {
     const MCSymbol *MBBSymbol =
         MBB.pred_empty() ? FunctionSymbol : MBB.getSymbol();
     // Emit the basic block offset.